206 results on '"Andersen JK"'
Search Results
2. Plasma vitamin D levels and inflammation in the aortic wall of patients with coronary artery disease with and without inflammatory rheumatic disease.
- Author
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Oma, I, Andersen, JK, Lyberg, T, Molberg, Ø, Whist, JE, Fagerland, MW, Almdahl, SM, and Hollan, I
- Subjects
- *
THERAPEUTIC use of vitamin D , *CORONARY heart disease treatment , *HEART diseases , *MYOCARDIAL infarction , *CORONARY artery stenosis , *CORONARY heart disease complications , *AORTA , *CONNECTIVE tissues , *CORONARY disease , *MULTIVARIATE analysis , *RADIOIMMUNOASSAY , *REGRESSION analysis , *RHEUMATISM , *VITAMIN D , *CASE-control method , *CALCITRIOL , *MONONUCLEAR leukocytes , *DISEASE complications - Abstract
Objectives: Vitamin D modulates inflammation, and this may explain the observed associations between vitamin D status and disorders driven by systemic inflammation, such as coronary artery disease (CAD) and inflammatory rheumatic diseases (IRDs). The aims of this study were to assess vitamin D status in patients with CAD alone and in patients with CAD and IRD, and to explore potential associations between vitamin D status and the presence of mononuclear cell infiltrates (MCIs) in the aortic adventitia of these patients.Method: Plasma levels of 25-hydroxyvitamin D3 [(25(OH)D3] were determined by radioimmunoassay and 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] by enzyme immunoassay in the 121 patients from the Feiring Heart Biopsy Study (FHBS) who had available histology data on adventitial MCIs; 53 of these had CAD alone and 68 had CAD and IRD.Results: In the crude analysis, vitamin D levels were similar in CAD patients with and without IRD. After adjustment for potential confounders, IRD was associated with an increase of 8.8 nmol/L [95% confidence interval (CI) 1.0-16.6; p = 0.027] in 25(OH)D3 and an increase of 18.8 pmol/L (95% CI 4.3-33.3; p = 0.012) in 1,25(OH)2D3, while MCIs in the aortic adventitia were associated with lower levels of 1,25(OH)2D3 (β = -18.8, 95% CI -33.6 to -4.0; p = 0.014).Conclusions: IRD was associated with higher levels of both 25(OH)D3 and 1,25(OH)2D3. These findings argue against the hypothesis that patients with high systemic inflammatory burden (CAD+IRD) should have lower vitamin D levels than those with less inflammation (CAD only). Of note, when controlled for potential confounders, low 1,25(OH)2D3 levels were associated with adventitial aortic inflammation. [ABSTRACT FROM AUTHOR]- Published
- 2017
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3. Diabetic nephropathy in type 1 (insulin-dependent) diabetes: An epidemiological study
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Andersen Ar, Torsten Deckert, J. Sandahl Christiansen, S. Kreiner, and Andersen Jk
- Subjects
medicine.medical_specialty ,Proteinuria ,business.industry ,Endocrinology, Diabetes and Metabolism ,Incidence (epidemiology) ,medicine.disease ,Surgery ,Nephropathy ,Diabetic nephropathy ,Diabetes mellitus ,Internal medicine ,Internal Medicine ,medicine ,Cumulative incidence ,medicine.symptom ,business ,Complication ,Cause of death - Abstract
A follow-up of 1475 Type 1 (insulin-dependent) diabetic patients diagnosed before 1953 (815 males, 660 females) and before the age of 31 years was conducted. All patients were seen at the Steno Memorial Hospital and were referred from all parts of Denmark; 91 (6%) could not be traced. The rest (94%) were followed until death or for at least 25 years; 249 (17%) were followed for >40 years. Clinical diabetic nephropathy developed in 531 (41%) of the 1303 patients in whom sufficient information was available regarding proteinuria. Other causes of proteinuria were found in 3%, and 57% did not develop persistent proteinuria. The prevalence of diabetic nephropathy was 21% after 20–25 years of diabetes duration followed by a decline to 10% after 40 years. Two incidence peaks of the onset of proteinuria were seen, one after 16 and another after 32 years duration of diabetes. Incidence increased steeply 10 years after onset of diabetes and was low after 35 years duration. The cumulative incidence was 45% after 40 years of diabetes. A male preponderance was seen among patients with nephropathy. A significant difference in the pattern of annual incidence rates of diabetic nephropathy was seen, when groups with onset of diabetes before 1933, between 1933–1942, and 1943–1952, respectively, were compared. An association between daily insulin requirement and nephropathy incidence was found. Patients with nephropathy had a much poorer survival than those without proteinuria; 40 years after onset of diabetes, only 10% of patients who developed nephropathy were alive, whereas >70% of patients who did not develop nephropathy survived. Uraemia was the cause of death in 66% of the patients with nephropathy; 7 years after the onset of persistent proteinuria, 49% of the patients had died. It is concluded that diabetic nephropathy is the major life threatening complication in Type I diabetes of juvenile onset.
- Published
- 1983
4. Aβ-targeting synNotch Receptor for Alzheimer's Disease: Expanding Applications to Extracellular Protein Aggregates.
- Author
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Bergo NJ, Lee S, Siebrand CJ, Andersen JK, and Walton CC
- Abstract
The synthetic Notch receptor (synNotch) system is a versatile platform that induces gene transcription in response to extracellular signals. However, its application has been largely confined to membrane-bound targets due to specific activation requirements. Whether synNotch can also target extracellular protein aggregates, such as amyloid beta (Aβ) in Alzheimer's disease (AD), is unclear. To address this, we engineered an Aβ-targeting synNotch receptor controlling the production of chimeric human-mouse versions of Lecanemab (Leqembi®) or Aducanumab (Aduhelm®), both FDA-approved antibodies for AD. We demonstrate that NIH 3T3 cells expressing this synNotch system detect and respond to extracellular Aβ aggregates by synthesizing and secreting Aducanumab or Lecanemab. These findings broaden the potential applications of synNotch, extending its targets beyond membrane-bound proteins to extracellular protein aggregates, providing obvious benefits to research in this scientific arena.
- Published
- 2024
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5. Amyloid β accelerates age-related proteome-wide protein insolubility.
- Author
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Anderton E, Chamoli M, Bhaumik D, King CD, Xie X, Foulger A, Andersen JK, Schilling B, and Lithgow GJ
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- Animals, Humans, Proteomics, Proteostasis, Solubility, Disease Models, Animal, Amyloid beta-Peptides metabolism, Proteome metabolism, Aging metabolism, Aging genetics, Caenorhabditis elegans metabolism, Alzheimer Disease metabolism, Alzheimer Disease genetics
- Abstract
Loss of proteostasis is a highly conserved feature of aging across model organisms and results in the accumulation of insoluble protein aggregates. Protein insolubility is also a unifying feature of major age-related neurodegenerative diseases, including Alzheimer's Disease (AD), in which hundreds of insoluble proteins associate with aggregated amyloid beta (Aβ) in senile plaques. Despite the connection between aging and AD risk, therapeutic approaches to date have overlooked aging-driven generalized protein insolubility as a contributing factor. However, proteins that become insoluble during aging in model organisms are capable of accelerating Aβ aggregation in vitro and lifespan in vivo. Here, using an unbiased proteomics approach, we questioned the relationship between Aβ and age-related protein insolubility. Specifically, we uncovered that Aβ expression drives proteome-wide protein insolubility in C. elegans, even in young animals, and this insoluble proteome is highly similar to the insoluble proteome driven by normal aging, this vulnerable sub-proteome we term the core insoluble proteome (CIP). We show that the CIP is enriched with proteins that modify Aβ toxicity in vivo, suggesting the possibility of a vicious feedforward cycle in the context of AD. Importantly, using human genome-wide association studies (GWAS), we show that the CIP is replete with biological processes implicated not only in neurodegenerative diseases but also across a broad array of chronic, age-related diseases (CARDs). This provides suggestive evidence that age-related loss of proteostasis could play a role in general CARD risk. Finally, we show that the geroprotective, gut-derived metabolite, Urolithin A, relieves Aβ toxicity, supporting its use in clinical trials for dementia and age-related diseases., (© 2024. The Author(s).)
- Published
- 2024
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6. Neuronal expression of human amyloid-β and Tau drives global phenotypic and multi-omic changes in C. elegans .
- Author
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Holcom A, Fuentealba M, Sivapatham R, King CD, Osman H, Foulger A, Bhaumik D, Schilling B, Furman D, Andersen JK, and Lithgow GJ
- Abstract
Alzheimer's disease (AD) and Alzheimer's related diseases (ADRD) are prevalent age-related neurodegenerative disorders characterized by the accumulation of amyloid-β (Aβ) plaques and Tau neurofibrillary tangles. The nematode Caenorhabditis elegan s ( C. elegans ) serves as an invaluable model organism in diseases of old age-due to its rapid aging. Here we performed an unbiased systems analysis of a C. elegans strain expressing both Aβ and Tau proteins within neurons. We set out to determine if there was a phenotypic interaction between Aβ and Tau. In addition, we were interested in determining the temporal order of the phenotypic and multi-omic (geromic) outcomes. At an early stage of adulthood, we observed reproductive impairments and mitochondrial dysfunction consistent with disruptions in mRNA transcript abundance, protein solubility, and metabolite levels. Notably, the expression of these neurotoxic proteins exhibited a synergistic effect, leading to accelerated aging. Our findings shed light on the close relationship between normal aging and ADRD. Specifically, we demonstrate alterations to metabolic functions preceding age-related neurotoxicity, offering a resource for the development of new therapeutic strategies.
- Published
- 2024
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7. Early aerial expedition photos reveal 85 years of glacier growth and stability in East Antarctica.
- Author
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Dømgaard M, Schomacker A, Isaksson E, Millan R, Huiban F, Dehecq A, Fleischer A, Moholdt G, Andersen JK, and Bjørk AA
- Abstract
During the last few decades, several sectors in Antarctica have transitioned from glacial mass balance equilibrium to mass loss. In order to determine if recent trends exceed the scale of natural variability, long-term observations are vital. Here we explore the earliest, large-scale, aerial image archive of Antarctica to provide a unique record of 21 outlet glaciers along the coastline of East Antarctica since the 1930s. In Lützow-Holm Bay, our results reveal constant ice surface elevations since the 1930s, and indications of a weakening of local land-fast sea-ice conditions. Along the coastline of Kemp and Mac Robertson, and Ingrid Christensen Coast, we observe a long-term moderate thickening of the glaciers since 1937 and 1960 with periodic thinning and decadal variability. In all regions, the long-term changes in ice thickness correspond with the trends in snowfall since 1940. Our results demonstrate that the stability and growth in ice elevations observed in terrestrial basins over the past few decades are part of a trend spanning at least a century, and highlight the importance of understanding long-term changes when interpreting current dynamics., (© 2024. The Author(s).)
- Published
- 2024
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8. Single-cell transcriptomics reveals colonic immune perturbations during amyloid-β driven Alzheimer's disease in mice.
- Author
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Makhijani P, Emani R, Aguirre CG, Mu WC, Rane A, Ng JHY, Valentino TR, Manwaring-Mueller M, Tan CR, Du H, Wu F, Khan S, Wilson KA, Winer S, Wang C, Mortha A, Furman D, Ellerby LM, Rojas OL, Andersen JK, and Winer DA
- Abstract
The "gut-brain axis" is emerging as an important target in Alzheimer's disease (AD). However, immunological mechanisms underlying this axis remain poorly understood. Using single-cell RNA sequencing of the colon immune compartment in the 5XFAD amyloid-β (Aβ) mouse model, we uncovered AD-associated changes in ribosomal activity, oxidative stress, and BCR/plasma cell activity. Strikingly, levels of colon CXCR4
+ antibody secreting cells (ASCs) were significantly reduced. This corresponded with accumulating CXCR4+ B cells and gut-specific IgA+ cells in the brain and dura mater, respectively. Consistently, a chemokine ligand for CXCR4, CXCL12, was expressed at higher levels in 5XFAD glial cells and in in silico analyzed human brain studies, supporting altered neuroimmune trafficking. An inulin prebiotic fiber diet attenuated AD markers including Aβ plaques and overall frailty. These changes corresponded to an expansion of gut IgA+ cells and rescued peripheral Tregs levels. Our study points to a key glia-gut axis and potential targets against AD., Study Highlights: AD is associated with altered immune parameters in the gut of 5XFAD mice. 5 XFAD colon has reduced ASCs, including CXCR4+ cells with a migratory gene signature. 5XFAD brain gliosis includes increased CXCL12 expression. CXCR4+ B cells and gut-specific IgA+ ASCs accumulate in the 5XFAD brain and/or dura mater. Inulin diet attenuates AD disease parameters while boosting IgA+ cell and Treg levels.- Published
- 2024
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9. Amyloid β accelerates age-related proteome-wide protein insolubility.
- Author
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Anderton E, Chamoli M, Bhaumik D, King CD, Xie X, Foulger A, Andersen JK, Schilling B, and Lithgow GJ
- Abstract
Loss of proteostasis is a highly conserved feature of aging across model organisms and typically results in the accumulation of insoluble protein aggregates. Protein insolubility is a central feature of major age-related neurodegenerative diseases, including Alzheimer's Disease (AD), where hundreds of insoluble proteins associate with aggregated amyloid beta (Aβ) in senile plaques. Moreover, proteins that become insoluble during aging in model organisms are capable of accelerating Aβ aggregation in vitro. Despite the connection between aging and AD risk, therapeutic approaches to date have overlooked aging-driven protein insolubility as a contributory factor. Here, using an unbiased proteomics approach, we questioned the relationship between Aβ and age-related protein insolubility. We demonstrate that Aβ expression drives proteome-wide protein insolubility in C. elegans and this insoluble proteome closely resembles the insoluble proteome driven by normal aging, suggesting the possibility of a vicious feedforward cycle of aggregation in the context of AD. Importantly, using human genome-wide association studies (GWAS), we show that the CIP is replete with biological processes implicated not only in neurodegenerative diseases but also across a broad array of chronic, age-related diseases (CARDs). This provides suggestive evidence that age-related loss of proteostasis could play a role in general CARD risk. Finally, we show that the CIP is enriched with proteins that modulate the toxic effects of Aβ and that the gut-derived metabolite, Urolithin A, relieves Aβ toxicity, supporting its use in clinical trials for dementia and other age-related diseases., Competing Interests: Competing Interest Statement: The authors declare no competing interests. COI Statement The authors declare no conflict of interest.
- Published
- 2023
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10. A drug-like molecule engages nuclear hormone receptor DAF-12/FXR to regulate mitophagy and extend lifespan.
- Author
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Chamoli M, Rane A, Foulger A, Chinta SJ, Shahmirzadi AA, Kumsta C, Nambiar DK, Hall D, Holcom A, Angeli S, Schmidt M, Pitteri S, Hansen M, Lithgow GJ, and Andersen JK
- Subjects
- Animals, Longevity genetics, Caenorhabditis elegans genetics, Autophagy, Receptors, Cytoplasmic and Nuclear genetics, Mammals metabolism, Basic Helix-Loop-Helix Transcription Factors metabolism, Mitophagy, Caenorhabditis elegans Proteins genetics
- Abstract
Autophagy-lysosomal function is crucial for maintaining healthy lifespan and preventing age-related diseases. The transcription factor TFEB plays a key role in regulating this pathway. Decreased TFEB expression is associated with various age-related disorders, making it a promising therapeutic target. In this study, we screened a natural product library and discovered mitophagy-inducing coumarin (MIC), a benzocoumarin compound that enhances TFEB expression and lysosomal function. MIC robustly increases the lifespan of Caenorhabditis elegans in an HLH-30/TFEB-dependent and mitophagy-dependent manner involving DCT-1/BNIP3 while also preventing mitochondrial dysfunction in mammalian cells. Mechanistically, MIC acts by inhibiting ligand-induced activation of the nuclear hormone receptor DAF-12/FXR, which, in turn, induces mitophagy and extends lifespan. In conclusion, our study uncovers MIC as a promising drug-like molecule that enhances mitochondrial function and extends lifespan by targeting DAF-12/FXR. Furthermore, we discovered DAF-12/FXR as a previously unknown upstream regulator of HLH-30/TFEB and mitophagy., (© 2023. The Author(s), under exclusive licence to Springer Nature America, Inc.)
- Published
- 2023
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11. The intestinal immune system and gut barrier function in obesity and ageing.
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Shemtov SJ, Emani R, Bielska O, Covarrubias AJ, Verdin E, Andersen JK, and Winer DA
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- Humans, Obesity metabolism, Inflammation, Aging, Liver metabolism, Diabetes Mellitus, Type 2
- Abstract
Obesity and ageing predispose to numerous, yet overlapping chronic diseases. For example, metabolic abnormalities, including insulin resistance (IR) and type 2 diabetes (T2D) are important causes of morbidity and mortality. Low-grade chronic inflammation of tissues, such as the liver, visceral adipose tissue and neurological tissues, is considered a significant contributor to these chronic diseases. Thus, it is becoming increasingly important to understand what drives this inflammation in affected tissues. Recent evidence, especially in the context of obesity, suggests that the intestine plays an important role as the gatekeeper of inflammatory stimuli that ultimately fuels low-grade chronic tissue inflammation. In addition to metabolic diseases, abnormalities in the intestinal mucosal barrier have been linked to a range of other chronic inflammatory conditions, such as neurodegeneration and ageing. The flow of inflammatory stimuli from the gut is in part controlled by local immunological inputs impacting the intestinal barrier. Here, we will review the impact of obesity and ageing on the intestinal immune system and its downstream consequences on gut barrier function, which is strongly implicated in the pathogenesis of obesity and age-related diseases. In particular, we will discuss the effects of age-related intestinal dysfunction on neurodegenerative diseases., (© 2022 Federation of European Biochemical Societies.)
- Published
- 2023
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12. A retrospective study on veterinary antimicrobial use in Nigeria, 2014 to 2017.
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Kwange D, Ndahi MD, Alabi O, Usman BA, Umanah P, Andersen JK, and Kwaghe AV
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- Humans, Retrospective Studies, Nigeria, Anti-Infective Agents
- Abstract
Competing Interests: The authors declare no competing interest.
- Published
- 2023
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13. Taurine deficiency as a driver of aging.
- Author
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Singh P, Gollapalli K, Mangiola S, Schranner D, Yusuf MA, Chamoli M, Shi SL, Lopes Bastos B, Nair T, Riermeier A, Vayndorf EM, Wu JZ, Nilakhe A, Nguyen CQ, Muir M, Kiflezghi MG, Foulger A, Junker A, Devine J, Sharan K, Chinta SJ, Rajput S, Rane A, Baumert P, Schönfelder M, Iavarone F, di Lorenzo G, Kumari S, Gupta A, Sarkar R, Khyriem C, Chawla AS, Sharma A, Sarper N, Chattopadhyay N, Biswal BK, Settembre C, Nagarajan P, Targoff KL, Picard M, Gupta S, Velagapudi V, Papenfuss AT, Kaya A, Ferreira MG, Kennedy BK, Andersen JK, Lithgow GJ, Ali AM, Mukhopadhyay A, Palotie A, Kastenmüller G, Kaeberlein M, Wackerhage H, Pal B, and Yadav VK
- Subjects
- Animals, Humans, Mice, Cellular Senescence, Haplorhini, Longevity drug effects, Longevity physiology, Dietary Supplements, DNA Damage drug effects, Telomerase metabolism, Aging blood, Aging drug effects, Aging metabolism, Taurine blood, Taurine deficiency, Taurine pharmacology
- Abstract
Aging is associated with changes in circulating levels of various molecules, some of which remain undefined. We find that concentrations of circulating taurine decline with aging in mice, monkeys, and humans. A reversal of this decline through taurine supplementation increased the health span (the period of healthy living) and life span in mice and health span in monkeys. Mechanistically, taurine reduced cellular senescence, protected against telomerase deficiency, suppressed mitochondrial dysfunction, decreased DNA damage, and attenuated inflammaging. In humans, lower taurine concentrations correlated with several age-related diseases and taurine concentrations increased after acute endurance exercise. Thus, taurine deficiency may be a driver of aging because its reversal increases health span in worms, rodents, and primates and life span in worms and rodents. Clinical trials in humans seem warranted to test whether taurine deficiency might drive aging in humans.
- Published
- 2023
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14. Determination of antimicrobial use in commercial poultry farms in Plateau and Oyo States, Nigeria.
- Author
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Ndahi MD, Hendriksen R, Helwigh B, Card RM, Fagbamila IO, Abiodun-Adewusi OO, Ekeng E, Adetunji V, Adebiyi I, and Andersen JK
- Subjects
- Animals, Farms, Nigeria epidemiology, Anti-Bacterial Agents therapeutic use, Penicillins, Aminoglycosides, Fluoroquinolones, Health Knowledge, Attitudes, Practice, Poultry, Anti-Infective Agents therapeutic use
- Abstract
Background: Indiscriminate use of antimicrobials for the prevention and treatment of bacterial infection in animals is a common practice in Nigeria as in other developing countries. These antimicrobials are purchased over the counter without restrictions and often administered in form of medicated feedstuffs. In Nigeria, like most developing countries, antimicrobial prescription data are not routinely collected or reported at the farm level, instead import data are used in reporting antimicrobial consumption. Farmers can be useful sources of data on the use of antimicrobial agents by class, animal species, production type and age. The objective of the study was to determine the knowledge, attitude and practices of poultry farmers on antimicrobial resistance and to generate data on antimicrobial use (AMU) in poultry farms in Plateau and Oyo states in accordance with the guidelines of the World Organization for Animal Health (WOAH)., Methods: A questionnaire used by the Food and Agriculture Organization (FAO) of the United Nations in Ghana was adopted and modified to collect data on the knowledge, attitude and practices of farmers on AMR and AMU and to collect AMU data from selected poultry farms. A focus group discussion (FGD) was conducted in Plateau state with poultry farmers and representatives from the state veterinary services, using a checklist. The aim of the FGD was to have an idea on antimicrobial use among poultry farmers and to generate additional questions that might be added to the questionnaire. Stratified random sampling technique was used to select 50 farms from Plateau and Oyo states, using the list of registered poultry farms in the two states as sampling frame., Results: Ninety eight percent (98%) of farmers gave antibiotics as prophylactic treatment to day old chicks. There were 47 different products used in the two states within the study period. We observed that five classes of antibiotics (Tetracyclines, Penicillins, Aminoglycosides, Polypeptides and Fluoroquinolone) were used in the two states. A total of 351 kg of active ingredients from seven different classes, namely: tetracyclines, penicillins, aminoglycosides, polypeptide, fluoroquinolones, amphenicol and macrolides were recorded from the two states. Some products contained cocktail of antibiotics, having up to six different classes with very high concentration of active ingredients which are not in the list of registered antimicrobials reported to WOAH., Conclusion: The concept used for this survey proved that the approach can be applied for AMU surveillance in the animal health sector. It also provided insight on farmers' knowledge and practices with regards to the use of antimicrobials which is missing in the national import data. The need for "stronger" antibiotics was identified as one of the drivers of antibiotic resistance., (© 2023. The Author(s).)
- Published
- 2023
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15. Potassium-chelating drug sodium polystyrene sulfonate enhances lysosomal function and suppresses proteotoxicity.
- Author
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Arputhasamy C, Foulger AC, Lucanic M, Rane A, Schmidt M, Garrett T, Broussalian M, Battistoni E, Brem RB, Lithgow GJ, Chamoli M, and Andersen JK
- Subjects
- Animals, Humans, Prospective Studies, Lysosomes metabolism, Potassium metabolism, Caenorhabditis elegans
- Abstract
Lysosomes are crucial for degradation and recycling of damaged proteins and cellular components. Therapeutic strategies enhancing lysosomal function are a promising approach for aging and age-related neurodegenerative diseases. Here, we show that an FDA approved drug sodium polystyrene sulfonate (SPS), used to reduce high blood potassium in humans, enhances lysosomal function both in C. elegans and in human neuronal cells. Enhanced lysosomal function following SPS treatment is accompanied by the suppression of proteotoxicity caused by expression of the neurotoxic peptides Aβ and TAU. Additionally, treatment with SPS imparts health benefits as it significantly increases lifespan in C. elegans. Overall our work supports the potential use of SPS as a prospective geroprotective intervention., (© 2022. The Author(s), under exclusive licence to American Aging Association.)
- Published
- 2023
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16. Urolithin A reduces amyloid-beta load and improves cognitive deficits uncorrelated with plaque burden in a mouse model of Alzheimer's disease.
- Author
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Ballesteros-Álvarez J, Nguyen W, Sivapatham R, Rane A, and Andersen JK
- Subjects
- Mice, Animals, Mice, Transgenic, Maze Learning, Amyloid beta-Peptides metabolism, Cognition, Alzheimer Disease drug therapy, Alzheimer Disease metabolism, Cognitive Dysfunction drug therapy
- Abstract
In the present study, we investigated the effects of urolithin A (UA), a metabolite generated from ellagic acid via its metabolism by gut bacteria, as an autophagy activator with potential neuroprotective activity. WT and 3xTg-AD mice were administered long-term intermittent dietary supplementation with UA. UA was found to prevent deficits in spatial memory, cued fear response, and exploratory behavior in this model. It also decreased the Aβ plaque burden in areas of the hippocampus where these protein deposits are prominent in the model. Interestingly, correlation analyses demonstrate that Aβ plaque burden positively correlates with enhanced spatial memory in 3xTg-AD mice on a control diet but not in those supplemented with UA. In contrast, Aβ42 abundance in cortical and hippocampal homogenates negatively correlate with spatial memory in UA-fed mice. Our data suggest that plaque formation may be a protective mechanism against neurodegeneration and cognitive decline and that targeting the generation of proteotoxic Aβ species might be a more successful approach in halting disease progression. UA was also found to extend lifespan in normal aging mice. Mechanistically, we demonstrate that UA is able to induce autophagy and to increase Aβ clearance in neuronal cell lines. In summary, our studies reveal UA, likely via its actions as a autophagy inducer, is capable of removing Aβ from neurons and its dietary administration prevents the onset of cognitive deficits associated with pathological Aβ deposition in the 3xTg-AD mouse model as well as extending lifespan in normal aging mice., (© 2022. The Author(s).)
- Published
- 2023
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17. Aging, Parkinson's Disease, and Models: What Are the Challenges?
- Author
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Rocha E, Chamoli M, Chinta SJ, Andersen JK, Wallis R, Bezard E, Goldberg M, Greenamyre T, Hirst W, Kuan WL, Kirik D, Niedernhofer L, Rappley I, Padmanabhan S, Trudeau LE, Spillantini M, Scott S, Studer L, Bellantuono I, and Mortiboys H
- Abstract
Parkinson's disease (PD) is a chronic, neurodegenerative condition characterized by motor symptoms such as bradykinesia, rigidity, and tremor, alongside multiple nonmotor symptoms. The appearance of motor symptoms is linked to progressive dopaminergic neuron loss within the substantia nigra. PD incidence increases sharply with age, suggesting a strong association between mechanisms driving biological aging and the development and progression of PD. However, the role of aging in the pathogenesis of PD remains understudied. Numerous models of PD, including cell models, toxin-induced models, and genetic models in rodents and nonhuman primates (NHPs), reproduce different aspects of PD, but preclinical studies of PD rarely incorporate age as a factor. Studies using patient neurons derived from stem cells via reprogramming methods retain some aging features, but their characterization, particularly of aging markers and reproducibility of neuron type, is suboptimal. Investigation of age-related changes in PD using animal models indicates an association, but this is likely in conjunction with other disease drivers. The biggest barrier to drawing firm conclusions is that each model lacks full characterization and appropriate time-course assessments. There is a need to systematically investigate whether aging increases the susceptibility of mouse, rat, and NHP models to develop PD and understand the role of cell models. We propose that a significant investment in time and resources, together with the coordination and sharing of resources, knowledge, and data, is required to accelerate progress in understanding the role of biological aging in PD development and improve the reliability of models to test interventions., Competing Interests: Conflict of Interest statement All authors declare that they have no competing interests.
- Published
- 2023
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18. An aco-2::gfp knock-in enables the monitoring of mitochondrial morphology throughout C. elegans lifespan.
- Author
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Begelman DV, Woods G, Bhaumik D, Angeli S, Foulger AC, Lucanic M, Lan J, Andersen JK, and Lithgow GJ
- Abstract
We used CRISPR/Cas9 gene editing in C. elegans in order to fluorescently tag endogenous aconitase-2 (ACO-2). ACO-2 is a mitochondrially localized protein, and the aco-2::gfp strain enabled the examination of native mitochondrial morphology in live animals. Here we validate that the aco-2::gfp strain displays the prototypic changes in mitochondrial morphology known to occur during aging and upon paraquat (PQ) induced mitochondrial stress. We also provide evidence that the ACO-2::GFP reporter can serve as a superior means for tracking mitochondrial morphology than conventional MitoTracker dyes-especially in aged-worms., (Copyright: © 2022 by the authors.)
- Published
- 2022
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19. Tumor-Associated Macrophages in Gliomas-Basic Insights and Treatment Opportunities.
- Author
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Andersen JK, Miletic H, and Hossain JA
- Abstract
Glioma refers to a group of primary brain tumors which includes glioblastoma (GBM), astrocytoma and oligodendroglioma as major entities. Among these, GBM is the most frequent and most malignant one. The highly infiltrative nature of gliomas, and their intrinsic intra- and intertumoral heterogeneity, pose challenges towards developing effective treatments. The glioma microenvironment, in addition, is also thought to play a critical role during tumor development and treatment course. Unlike most other solid tumors, the glioma microenvironment is dominated by macrophages and microglia-collectively known as tumor-associated macrophages (TAMs). TAMs, like their homeostatic counterparts, are plastic in nature and can polarize to either pro-inflammatory or immunosuppressive states. Many lines of evidence suggest that immunosuppressive TAMs dominate the glioma microenvironment, which fosters tumor development, contributes to tumor aggressiveness and recurrence and, very importantly, impedes the therapeutic effect of various treatment regimens. However, through the development of new therapeutic strategies, TAMs can potentially be shifted towards a proinflammatory state which is of great therapeutic interest. In this review, we will discuss various aspects of TAMs in the context of glioma. The focus will be on the basic biology of TAMs in the central nervous system (CNS), potential biomarkers, critical evaluation of model systems for studying TAMs and finally, special attention will be given to the potential targeted therapeutic options that involve the TAM compartment in gliomas.
- Published
- 2022
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20. Going beyond conventional wastewater treatment plants within circular bioeconomy concept - a sustainability assessment study.
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Marami H, Tsapekos P, Khoshnevisan B, Madsen JA, Andersen JK, Rafiee S, and Angelidaki I
- Subjects
- Biofuels analysis, Sewage, Solid Waste analysis, Ecosystem, Water Purification
- Abstract
Wastewater treatment plants (WWTP) have extensive energy processes that undermine their economic and environmental performance. In this context, the integration of wastewater treatment with other biochemical processes such as co-digestion of sludge with organic wastes, and production of value-added products at their downstream processes will shift conventional WWTPs into biorefinery platforms with better sustainability performance. The sustainability of such a biorefinery platform has been investigated herein using an economic and life cycle assessment approach. This WWTP-based biorefinery treats wastewater from Copenhagen municipality, co-digests the source-sorted organic fraction of municipal solid waste and sludge, and upgrades biogas into biomethane using a hydrogen-assisted upgrading method. Apart from bioenergy, this biorefinery also produces microbial protein (MP) using recovered nutrients from WWTP's reject water. The net environmental savings achieved in two damage categories, i.e., -1.07 × 10
-2 species.yr/FU in ecosystem quality and -1.68 × 106 USD/FU in resource scarcity damage categories along with high potential windows for the further environmental profile improvements make this biorefinery platform so encouraging. Despite being promising in terms of environmental performance, the high capital expenditure and low gross profit have undermined the economic performance of the proposed biorefinery. Technological improvements, process optimization, and encouraging incentives/subsidies are still needed to make this platform economically feasible.- Published
- 2022
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21. Integrating Environment and Aging Research: Opportunities for Synergy and Acceleration.
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Malecki KMC, Andersen JK, Geller AM, Harry GJ, Jackson CL, James KA, Miller GW, and Ottinger MA
- Abstract
Despite significant overlaps in mission, the fields of environmental health sciences and aging biology are just beginning to intersect. It is increasingly clear that genetics alone does not predict an individual's neurological aging and sensitivity to disease. Accordingly, aging neuroscience is a growing area of mutual interest within environmental health sciences. The impetus for this review came from a workshop hosted by the National Academies of Sciences, Engineering, and Medicine in June of 2020, which focused on integrating the science of aging and environmental health research. It is critical to bridge disciplines with multidisciplinary collaborations across toxicology, comparative biology, epidemiology to understand the impacts of environmental toxicant exposures and age-related outcomes. This scoping review aims to highlight overlaps and gaps in existing knowledge and identify essential research initiatives. It begins with an overview of aging biology and biomarkers, followed by examples of synergy with environmental health sciences. New areas for synergistic research and policy development are also discussed. Technological advances including next-generation sequencing and other-omics tools now offer new opportunities, including exposomic research, to integrate aging biomarkers into environmental health assessments and bridge disciplinary gaps. This is necessary to advance a more complete mechanistic understanding of how life-time exposures to toxicants and other physical and social stressors alter biological aging. New cumulative risk frameworks in environmental health sciences acknowledge that exposures and other external stressors can accumulate across the life course and the advancement of new biomarkers of exposure and response grounded in aging biology can support increased understanding of population vulnerability. Identifying the role of environmental stressors, broadly defined, on aging biology and neuroscience can similarly advance opportunities for intervention and translational research. Several areas of growing research interest include expanding exposomics and use of multi-omics, the microbiome as a mediator of environmental stressors, toxicant mixtures and neurobiology, and the role of structural and historical marginalization and racism in shaping persistent disparities in population aging and outcomes. Integrated foundational and translational aging biology research in environmental health sciences is needed to improve policy, reduce disparities, and enhance the quality of life for older individuals., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Malecki, Andersen, Geller, Harry, Jackson, James, Miller and Ottinger.)
- Published
- 2022
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22. A guide to senolytic intervention in neurodegenerative disease.
- Author
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Lee S, Wang EY, Steinberg AB, Walton CC, Chinta SJ, and Andersen JK
- Subjects
- Animals, Humans, Mice, Senescence-Associated Secretory Phenotype drug effects, Aging drug effects, Aging physiology, Cellular Senescence drug effects, Cellular Senescence physiology, Neurodegenerative Diseases drug therapy, Neurodegenerative Diseases metabolism, Senotherapeutics pharmacology
- Abstract
Cellular senescence is a potential tumor-suppressive mechanism that generally results in an irreversible cell cycle arrest. Senescent cells accumulate with age and actively secrete soluble factors, collectively termed the 'senescence-associated secretory phenotype' (SASP), which has both beneficial and detrimental effects. Although the contribution of senescent cells to age-related pathologies has been well-established outside the brain, emerging evidence indicates that brain cells also undergo cellular senescence and contribute to neuronal loss in the context of age-related neurodegenerative diseases. Contribution of senescent cells in the pathogenesis of neurological disorders has led to the possibility of eliminating senescence cells via pharmacological compounds called senolytics. Recently several senolytics have been demonstrated to elicit improved cognitive performance and healthspan in mouse models of neurodegeneration. However, their translation for use in the clinic still holds several potential challenges. This review summarizes available senolytics, their purported mode of action, and possible off-target effects. We also discuss possible alternative strategies that may help minimize potential side-effects associated with the senolytics approach., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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23. From wastewater treatment to water resource recovery: Environmental and economic impacts of full-scale implementation.
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Faragò M, Damgaard A, Madsen JA, Andersen JK, Thornberg D, Andersen MH, and Rygaard M
- Subjects
- Biofuels, Wastewater, Water Resources, Waste Disposal, Fluid, Water Purification
- Abstract
To reduce greenhouse gas emissions and promote resource recovery, many wastewater treatment operators are retrofitting existing plants to implement new technologies for energy, nutrient and carbon recovery. In literature, there is a lack of studies that can unfold the potential environmental and economic impacts of the transition that wastewater utilities are undertaking to transform their treatment plants to water resource recovery facilities (WRRFs). When existing, literature studies are mostly based on simulations rather than real plant data and pilot-scale results. This study combines life cycle assessment and economic evaluations to quantify the environmental and economic impacts of retrofitting an existing wastewater treatment plant (WWTP), which already implements energy recovery, into a full-scale WRRF with a series of novel technologies, the majority of which are already implemented full-scale or tested through pilot-scales. We evaluate five technology alternatives against the current performance of the WWTP: real-time N
2 O control, biological biogas upgrading coupled with power-to-hydrogen, phosphorus recovery, pre-filtration carbon harvest and enhanced nitrogen removal. Our results show that real-time N2 O control, biological biogas upgrading and pre-filtration lead to a decrease in climate change and fossil resource depletion impacts. The implementation of the real-time measurement and control of N2 O achieved the highest reduction in direct CO2-eq emissions (-35%), with no significant impacts in other environmental categories. Biological biogas upgrading contributed to counterbalancing direct and indirect climate change impacts by substituting natural gas consumption and production. Pre-filtration increased climate change reduction by 13%, while it increased impacts in other categories. Enhanced sidestream nitrogen removal increased climate change impacts by 12%, but decreased marine eutrophication impacts by 14%. The reserve base resource depletion impacts, however, were the highest in the plant configurations implementing biological biogas upgrading coupled with power-to-hydrogen. Environmental improvements generated economic costs for all alternatives except for real-time N2 O control. The results expose possible environmental and economic trade-offs and hotspots of the journey that large wastewater treatment plants will undertake in transitioning into resource recovery facilities in the coming years., (Copyright © 2021. Published by Elsevier Ltd.)- Published
- 2021
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24. mTORC2: The other mTOR in autophagy regulation.
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Ballesteros-Álvarez J and Andersen JK
- Subjects
- Humans, Autophagy immunology, Mechanistic Target of Rapamycin Complex 2 metabolism
- Abstract
The mechanistic target of rapamycin (mTOR) has gathered significant attention as a ubiquitously expressed multimeric kinase with key implications for cell growth, proliferation, and survival. This kinase forms the central core of two distinct complexes, mTORC1 and mTORC2, which share the ability of integrating environmental, nutritional, and hormonal cues but which regulate separate molecular pathways that result in different cellular responses. Particularly, mTORC1 has been described as a major negative regulator of endosomal biogenesis and autophagy, a catabolic process that degrades intracellular components and organelles within the lysosomes and is thought to play a key role in human health and disease. In contrast, the role of mTORC2 in the regulation of autophagy has been considerably less studied despite mounting evidence this complex may regulate autophagy in a different and perhaps complementary manner to that of mTORC1. Genetic ablation of unique subunits is currently being utilized to study the differential effects of the two mTOR complexes. RICTOR is the best-described subunit specific to mTORC2 and as such has become a useful tool for investigating the specific actions of this complex. The development of complex-specific inhibitors for mTORC2 is also an area of intense interest. Studies to date have demonstrated that mTORC1/2 complexes each signal to a variety of exclusive downstream molecules with distinct biological roles. Pinpointing the particular effects of these downstream effectors is crucial toward the development of novel therapies aimed at accurately modulating autophagy in the context of human aging and disease., (© 2021 The Authors. Aging Cell published by Anatomical Society and John Wiley & Sons Ltd.)
- Published
- 2021
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25. Alpha-Synuclein Preformed Fibrils Induce Cellular Senescence in Parkinson's Disease Models.
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Verma DK, Seo BA, Ghosh A, Ma SX, Hernandez-Quijada K, Andersen JK, Ko HS, and Kim YH
- Subjects
- 1-Methyl-4-phenylpyridinium, Animals, Astrocytes metabolism, Astrocytes pathology, Biomarkers metabolism, Brain metabolism, Brain pathology, Cell Line, Cyclin-Dependent Kinase Inhibitor p16 metabolism, Cyclin-Dependent Kinase Inhibitor p21 metabolism, Disease Models, Animal, Dopaminergic Neurons metabolism, Female, Glial Fibrillary Acidic Protein metabolism, HMGB1 Protein metabolism, Homeodomain Proteins metabolism, Humans, Lamin Type B metabolism, Male, Mice, Inbred C57BL, Microglia metabolism, Microglia pathology, Postmortem Changes, Rats, Mice, Cellular Senescence, Parkinson Disease pathology, alpha-Synuclein metabolism
- Abstract
Emerging evidence indicates that cellular senescence could be a critical inducing factor for aging-associated neurodegenerative disorders. However, the involvement of cellular senescence remains unclear in Parkinson's disease (PD). To determine this, we assessed the effects of α-synuclein preformed fibrils (α-syn PFF) or 1-methyl-4-phenylpyridinium (MPP
+ ) on changes in cellular senescence markers, employing α-syn PFF treated-dopaminergic N27 cells, primary cortical neurons, astrocytes and microglia and α-syn PFF-injected mouse brain tissues, as well as human PD patient brains. Our results demonstrate that α-syn PFF-induced toxicity reduces the levels of Lamin B1 and HMGB1, both established markers of cellular senescence, in correlation with an increase in the levels of p21, a cell cycle-arrester and senescence marker, in both reactive astrocytes and microglia in mouse brains. Using Western blot and immunohistochemistry, we found these cellular senescence markers in reactive astrocytes as indicated by enlarged cell bodies within GFAP-positive cells and Iba1-positive activated microglia in α-syn PFF injected mouse brains. These results indicate that PFF-induced pathology could lead to astrocyte and/or microglia senescence in PD brains, which may contribute to neuropathology in this model. Targeting senescent cells using senolytics could therefore constitute a viable therapeutic option for the treatment of PD.- Published
- 2021
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26. Swimming exercise reduces native ⍺-synuclein protein species in a transgenic C. elegans model of Parkinson's disease.
- Author
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Schmidt MY, Chamoli M, Lithgow GJ, and Andersen JK
- Abstract
Exercise has been historically recommended to prevent many disease conditions. Intense exercise in particular, has been shown to be beneficial for Parkinson's disease (PD) - stopping and even reversing symptoms in some patients. Recent research in mammalian animal models of Parkinson's have shown that exercise affects ⍺-synuclein aggregate species, considered to be a hallmark of PD. However, the exact changes in native ⍺-synuclein protein species after exercise and the downstream effects of exercise upon the health of the animals remains unclear. Recently, it was shown that swimming constitutes a form of exercise in C. elegans worms that confers a protective effect in several worm models of tau and Huntington protein neurodegeneration. Here we show that a period of swimming exercise (Ex) - 15-20 mins - dramatically reduces several native human ⍺-synuclein protein species in the NL5901 C. elegans worm model of Parkinson's. Exercise on Day 1 of adulthood was found to improve motor function measured by the thrashing rate of worms on Day 2 and Day 4 when compared to both control (untreated) and food restricted (FR) worms. Moreover, exercised worms show smaller ⍺-synuclein::YFP puncta than food restricted worms. Here we show that exercise reduces native human ⍺-synuclein levels independent of food restriction in C. elegans ., (Copyright: © 2021 by the authors.)
- Published
- 2021
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27. Longitudinal Functional Study of Murine Aging: A Resource for Future Study Designs.
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Evans DS, O'Leary MN, Murphy R, Schmidt M, Koenig K, Presley M, Garrett B, Kim HN, Han L, Academia EC, Laye MJ, Edgar D, Zambataro CA, Barhydt T, Dewey CM, Mayfield J, Wilson J, Alavez S, Lucanic M, Kennedy BK, Almeida M, Andersen JK, Kapahi P, Lithgow GJ, and Melov S
- Abstract
Aging is characterized by systemic declines in tissue and organ functions. Interventions that slow these declines represent promising therapeutics to protect against age-related disease and improve the quality of life. In this study, several interventions associated with lifespan extension in invertebrates or improvement of age-related disease were tested in mouse models to determine if they were effective in slowing tissue aging in a broad spectrum of functional assays. Benzoxazole, which extends the lifespan of Caenorhabditis elegans , slowed age-related femoral bone loss in mice. Rates of change were established for clinically significant parameters in untreated mice, including kyphosis, blood glucose, body composition, activity, metabolic measures, and detailed parameters of skeletal aging in bone. These findings have implications for the study of preclinical physiological aging and therapies targeting aging. Finally, an online application was created that includes the calculated rates of change and that enables power and variance to be calculated for many clinically important metrics of aging with an emphasis on bone. This resource will help in future study designs employing novel interventions in aging mice. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research., (© 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.)
- Published
- 2021
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28. Quantification of Insoluble Protein Aggregation in Caenorhabditis elegans during Aging with a Novel Data-Independent Acquisition Workflow.
- Author
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Xie X, Chamoli M, Bhaumik D, Sivapatham R, Angeli S, Andersen JK, Lithgow GJ, and Schilling B
- Subjects
- Aging, Animals, Caenorhabditis elegans embryology, Longevity, Workflow, Caenorhabditis elegans metabolism, Caenorhabditis elegans Proteins metabolism, Protein Aggregates, Proteome analysis, Proteomics methods
- Abstract
We and others have shown that the aging process results in a proteome-wide accumulation of insoluble proteins. Knocking down genes encoding the insoluble proteins over 40% of the time results in an extension of the lifespan in C. elegans, suggesting that many of these proteins are key determinants of the aging process. Isolation and quantitative identification of these insoluble proteins are crucial to understand key biological processes that occur during aging. Here, we present a modified and improved protocol that details how to extract and isolate the SDS-insoluble proteins (insolublome) from C. elegans more efficiently to streamline mass spectrometric workflows via a novel label-free quantitative proteomics analysis. This improved protocol utilizes a highly efficient sonicator for worm lysis that greatly increases efficiency for protein extraction and allows us to use significantly less starting material (approximately 3,000 worms) than in previous protocols (typically using at least 40,000 worms). Subsequent quantitative proteomic analysis of the insolublome was performed using data-dependent acquisition (DDA) for protein discovery and identification and data-independent acquisition (DIA) for comprehensive and more accurate protein quantification. Bioinformatic analysis of quantified proteins provides potential candidates that can be easily followed up with other molecular methods in C. elegans. With this workflow, we routinely identify more than 1000 proteins and quantify more than 500 proteins. This new protocol enables efficient compound screening with C. elegans. Here, we validated and applied this improved protocol to wild-type C. elegans N2-Bristol strain and confirmed that aged day-10 N2 worms showed greater accumulation of the insolublome than day-2 young worms.
- Published
- 2020
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29. Dysregulated iron metabolism in C. elegans catp-6/ATP13A2 mutant impairs mitochondrial function.
- Author
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Anand N, Holcom A, Broussalian M, Schmidt M, Chinta SJ, Lithgow GJ, Andersen JK, and Chamoli M
- Subjects
- Animals, Autophagy, Caenorhabditis elegans, Dopaminergic Neurons metabolism, Humans, Lysosomes metabolism, Mutation, Parkinson Disease metabolism, Parkinsonian Disorders metabolism, Adenosine Triphosphatases metabolism, Caenorhabditis elegans Proteins metabolism, Iron metabolism, Mitochondria metabolism, Proton-Translocating ATPases metabolism
- Abstract
Mutations in the human ATP13A2 gene are associated with an early-onset form of Parkinson's disease (PD) known as Kufor Rakeb Syndrome (KRS). Patients with KRS show increased iron deposition in the basal ganglia, suggesting iron toxicity-induced neurodegeneration as a potential pathogenesis associated with the ATP13A2 mutation. Previously we demonstrated that functional losses of ATP13A2 disrupt the lysosomes ability to store excess iron, leading to reduce survival of dopaminergic neuronal cells. To understand the possible mechanisms involved, we studied a Caenorhabditis elegans mutant defective in catp-6 function, an ortholog of human ATP13A2 gene. Here we show that catp-6 mutant worms have defective autophagy and lysosomal function, demonstrate characteristic PD phenotypes including reduced motor function and dysregulated iron metabolism. Additionally, these mutants have defective mitochondrial health, which is rescuable via iron chelation or mitophagy induction., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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30. Kavain suppresses human Aβ-induced paralysis in C. elegans .
- Author
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Chamoli M, Chinta SJ, Andersen JK, and Lithgow GJ
- Published
- 2020
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31. Senescence as an Amyloid Cascade: The Amyloid Senescence Hypothesis.
- Author
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Walton CC, Begelman D, Nguyen W, and Andersen JK
- Abstract
Due to their postmitotic status, the potential for neurons to undergo senescence has historically received little attention. This lack of attention has extended to some non-postmitotic cells as well. Recently, the study of senescence within the central nervous system (CNS) has begun to emerge as a new etiological framework for neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). The presence of senescent cells is known to be deleterious to non-senescent neighboring cells via development of a senescence-associated secretory phenotype (SASP) which includes the release of inflammatory, oxidative, mitogenic, and matrix-degrading factors. Senescence and the SASP have recently been hailed as an alternative to the amyloid cascade hypothesis and the selective killing of senescence cells by senolytic drugs as a substitute for amyloid beta (Aß) targeting antibodies. Here we call for caution in rejecting the amyloid cascade hypothesis and to the dismissal of Aß antibody intervention at least in early disease stages, as Aß oligomers (AßO), and cellular senescence may be inextricably linked. We will review literature that portrays AßO as a stressor capable of inducing senescence. We will discuss research on the potential role of secondary senescence, a process by which senescent cells induce senescence in neighboring cells, in disease progression. Once this seed of senescent cells is present, the elimination of senescence-inducing stressors like Aß would likely be ineffective in abrogating the spread of senescence. This has potential implications for when and why AßO clearance may or may not be effective as a therapeutic for AD. The selective killing of senescent cells by the immune system via immune surveillance naturally curtails the SASP and secondary senescence outside the CNS. Immune privilege restricts the access of peripheral immune cells to the brain parenchyma, making the brain a safe harbor for the spread of senescence and the SASP. However, an increasingly leaky blood brain barrier (BBB) compromises immune privilege in aging AD patients, potentially enabling immune infiltration that could have detrimental consequences in later AD stages. Rather than an alternative etiology, senescence itself may constitute an essential component of the cascade in the amyloid cascade hypothesis., (Copyright © 2020 Walton, Begelman, Nguyen and Andersen.)
- Published
- 2020
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32. The effects of preoperative point-of-care focused cardiac ultrasound in high-risk patients: study protocol for a prospective randomised controlled trial.
- Author
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Pallesen J, Bhavsar R, Fjølner J, Krog J, Malachauskiené L, Bakke SA, Andersen MAS, Vang ML, Andersen JK, Bøndergaard MH, Jessing TD, Thee C, Mortensen L, Nielsen MB, and Juhl-Olsen P
- Subjects
- Aged, Aged, 80 and over, Female, Humans, Male, Abdomen surgery, Heart diagnostic imaging, Orthopedic Procedures adverse effects, Prospective Studies, Randomized Controlled Trials as Topic, Risk Factors, Multicenter Studies as Topic, Cardiovascular Diseases complications, Cardiovascular Diseases diagnostic imaging, Point-of-Care Systems, Postoperative Complications etiology, Postoperative Complications prevention & control, Preoperative Care methods, Ultrasonography methods
- Abstract
Introduction: Perioperative mortality and morbidity remain substantial in acute surgery. Risk factors include known cardiovascular disease, but preoperative screening is insensitive to occult cardiopulmonary conditions. Focused cardiac ultrasound (FOCUS) can disclose both structural and functional cardiac disease and provides insight into the patient's haemodynamic status. This study aims to clarify whether preoperative FOCUS changes clinical outcomes in high-risk patients., Methods: This is a multi-centre, randomised, controlled, prospective study including patients ≥ 65 years of age scheduled for acute/emergency abdominal- or orthopaedic surgery. A total of 800 patients will be randomised to ± application of preoperative FOCUS. The primary endpoint is the proportion of patients admitted to hospital > 10 days or death within 30 days of surgery. The secondary endpoints include changes in the anaesthesia approach facilitated by FOCUS, biomarkers of organ function and perioperative complications., Conclusions: The knowledge generated from this study may facilitate changes in the anaesthesia evaluation and decision process and, consequently, in the entire perioperative anaesthesia clinical practice. The study has the potential to reduce the risk of perioperative cardiopulmonary complications which directly implies improved patient outcome and reduced hospital costs., Funding: The Research Fund of the Department of Anaesthesiology, Randers Regional Hospital, The Central Denmark Region's Medical Research Fund and the Hospital of Southern Jutland., Trial Registration: NCT03501927., (Articles published in the DMJ are “open access”. This means that the articles are distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits any non-commercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.)
- Published
- 2020
33. Gedunin Inhibits Oligomeric Aβ 1-42 -Induced Microglia Activation Via Modulation of Nrf2-NF-κB Signaling.
- Author
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Tom S, Rane A, Katewa AS, Chamoli M, Matsumoto RR, Andersen JK, and Chinta SJ
- Subjects
- Animals, Cell Line, Cell Nucleus drug effects, Cell Nucleus metabolism, Humans, Interleukin-1beta metabolism, Mice, Microglia drug effects, Microglia metabolism, Neurotoxins toxicity, Nitric Oxide metabolism, Nitric Oxide Synthase Type II metabolism, Phosphorylation drug effects, Protein Transport drug effects, tau Proteins metabolism, Amyloid beta-Peptides toxicity, Limonins pharmacology, Microglia pathology, NF-E2-Related Factor 2 metabolism, NF-kappa B metabolism, Peptide Fragments toxicity, Signal Transduction drug effects
- Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder and the leading cause of dementia in aged populations worldwide. The deposition of toxic protein aggregates such as amyloid beta (Aβ) is a hallmark of AD, and there is growing awareness that a key driver of AD pathogenesis is the neuroinflammatory cascade triggered and sustained by these proteins. Consequently, interventions that suppress prolonged neuroinflammation represent viable therapeutic approaches for AD. In this context, we tested the natural product gedunin which is an anti-inflammatory molecule, found in the seeds of the neem tree (Azadirachta indica), whose mechanism of action remains to be fully elucidated. Using a mouse microglia cell line (IMG), we show that gedunin suppresses neuroinflammation arising from Aβ
1-42 oligomer exposure. Our results demonstrate that gedunin suppresses Aβ1-42 -induced NF-κB activation and its targets, including nitric oxide (NO) and IL-1β, known proinflammatory molecules. Further, we show that gedunin inhibits neuroinflammation by activating nuclear factor 2 erythroid-related factor 2 (Nrf2) and its downstream targets γ-glutamylcysteine synthetase, heme oxygenase 1, and NADPH quinone dehydrogenase 1, which are involved in quenching reactive oxygen and nitrogen species (NO) generated by NF-κB activation. Nrf2 activation appears essential for the anti-inflammatory effect because when silenced, the proinflammatory effects of Aβ1-42 are enhanced and the protective effect of gedunin against NO production is reduced. Additionally, using human neuronal cells (SH-SY5Y), we show that gedunin prevents neurotoxicity secondary to Aβ-induced microglial activation. In conclusion, our findings highlight a potential therapeutic role of gedunin in neurodegenerative diseases.- Published
- 2019
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34. Targeting kinases in Parkinson's disease: A mechanism shared by LRRK2, neurotrophins, exenatide, urate, nilotinib and lithium.
- Author
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Guttuso T Jr, Andrzejewski KL, Lichter DG, and Andersen JK
- Subjects
- Humans, Parkinson Disease drug therapy, Antiparkinson Agents therapeutic use, Cyclin-Dependent Kinase 5 metabolism, Glycogen Synthase Kinases metabolism, Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 metabolism, Parkinson Disease metabolism, Proto-Oncogene Proteins c-abl metabolism, Proto-Oncogene Proteins c-akt metabolism
- Abstract
Several kinases have been implicated in the pathogenesis of Parkinson's disease (PD), most notably leucine-rich repeat kinase 2 (LRRK2), as LRRK2 mutations are the most common genetic cause of a late-onset parkinsonism that is clinically indistinguishable from sporadic PD. More recently, several other kinases have emerged as promising disease-modifying targets in PD based on both preclinical studies and clinical reports on exenatide, the urate precursor inosine, nilotinib and lithium use in PD patients. These kinases include protein kinase B (Akt), glycogen synthase kinases-3β and -3α (GSK-3β and GSK-3α), c-Abelson kinase (c-Abl) and cyclin-dependent kinase 5 (cdk5). Activities of each of these kinases are involved either directly or indirectly in phosphorylating tau or increasing α-synuclein levels, intracellular proteins whose toxic oligomeric forms are strongly implicated in the pathogenesis of PD. GSK-3β, GSK-3α and cdk5 are the principle kinases involved in phosphorylating tau at sites critical for the formation of tau oligomers. Exenatide analogues, urate, nilotinib and lithium have been shown to affect one or more of the above kinases, actions that can decrease the formation and increase the clearance of intraneuronal phosphorylated tau and α-synuclein. Here we review the current preclinical and clinical evidence supporting kinase-targeting agents as potential disease-modifying therapies for PD patients enriched with these therapeutic targets and incorporate LRRK2 physiology into this novel model., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2019
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35. Unknown fates of (brain) oxidation or UFO: Close encounters with neuronal senescence.
- Author
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Walton CC and Andersen JK
- Subjects
- Animals, Humans, Oxidation-Reduction, Phenotype, Brain physiology, Cellular Senescence, Neurodegenerative Diseases physiopathology, Oxidative Stress
- Abstract
Oxidative stress has long been considered a key component contributing to pathologies associated with brain aging and age-related neurodegenerative diseases. The proposed mechanisms involved are varied, but recently have been suggested to include induction of cellular senescence, a cellular growth arrest state characterized by the secretion of pre-inflammatory senescence-associated secretory phenotype (SASP) factors. The post-mitotic status of neurons has been traditionally considered to prohibit cellular senescence, however recent studies have provided compelling evidence that neurons may be capable of undergoing senescence in response to oxidative stress and other factors. Development of senolytics, small molecules that selectively induce senescent cell death, could represent a paradigm change for the treatment of neurodegenerative diseases including Alzheimer's and Parkinson's disease (AD, PD). However, their use depends on unequivocal validation that neurons can senesce and that they do not have detrimental off-target effects in other cell types in the brain and elsewhere., (Copyright © 2019. Published by Elsevier Inc.)
- Published
- 2019
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36. Screening Method for Identifying Toxicants Capable of Inducing Astrocyte Senescence.
- Author
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Woods G and Andersen JK
- Subjects
- Animals, Astrocytes enzymology, Biomarkers analysis, Biomarkers metabolism, Humans, Mice, Primary Cell Culture, beta-Galactosidase biosynthesis, Astrocytes drug effects, Cellular Senescence drug effects, Histocytochemistry methods, Small Molecule Libraries toxicity, beta-Galactosidase analysis
- Abstract
Cellular senescence is a tumor-suppressive mechanism which leads to near irreversible proliferative arrest. However, senescent cells can cause tissue dysfunction, in large part because they express a senescence-associated secretory phenotype (SASP) involving secretion of, amongst other factors, proinflammatory cytokines known to compromise neuronal health. Therefore, established neurotoxicants may cause neurotoxicity in vivo, in part by triggering mitotic cells in the brain to undergo senescence and adopt an inflammatory SASP which in turn could cause deleterious effects to surrounding neurons. To begin to address this hypothesis, we examined whether we could screen known neurotoxicants for their ability to cause astrocytes (a mitotic cell type especially important for maintaining neuronal health) to undergo senescence. For this purpose, we utilized inducible pluripotent stem cell-derived human astrocytes and screened an 80 compound neurotoxicant library provided by the Biomolecular Screening Branch of the NIEHS National Toxicology Program. Here we present a screening method based on induction of the senescent marker, senescent-associated beta-galactosidase (SA-β-gal). We describe in detail an automated method for the unbiased quantitation of percentage of SA-β-gal + astrocytes. Although our results suggest that conducting an SA-β-gal senescence screen using human inducible pluripotent stem cell-derived astrocytes may be feasible, they also highlight challenges that likely preclude its adaptation to high-throughput. We also explore the possibility of using primary mouse astrocytes for this purpose and explain why this platform is problematic and very unlikely to yield meaningful results, even in small screens with compound replicates.
- Published
- 2018
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37. An inducible MAO-B mouse model of Parkinson's disease: a tool towards better understanding basic disease mechanisms and developing novel therapeutics.
- Author
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Chamoli M, Chinta SJ, and Andersen JK
- Subjects
- Animals, Disease Models, Animal, Mice, Mice, Transgenic, Monoamine Oxidase metabolism, Oxidative Stress genetics, Parkinson Disease metabolism, Astrocytes metabolism, Monoamine Oxidase genetics, Parkinson Disease genetics
- Abstract
Several studies have suggested that increases in astrocytic monoamine oxidase B (MAO-B) levels in conjunction with Parkinson's disease (PD) may contribute to subsequent neuropathology associated with the disorder. MAO-B inhibitors are currently widely used as symptomatic therapeutics for PD and, although somewhat controversial, these drugs may also exhibit disease-modifying properties. To obtain a better understanding of the potential role of MAO-B in disease neuropathology, we created an inducible astrocyte-specific transgenic MAO-B mouse model. Here, we summarize findings associated with this model, including neuropathological PD features associated with it.
- Published
- 2018
- Full Text
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38. Differential expression of vitamin D associated genes in the aorta of coronary artery disease patients with and without rheumatoid arthritis.
- Author
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Oma I, Olstad OK, Andersen JK, Lyberg T, Molberg Ø, Fostad I, Wang Fagerland M, Almdahl SM, Rynning SE, Yndestad A, Aukrust P, Whist JE, and Hollan I
- Subjects
- Aged, Arthritis, Rheumatoid complications, Coronary Artery Disease complications, Cross-Sectional Studies, Female, Gene Expression, Humans, Male, Microarray Analysis, RNA, Messenger metabolism, Aorta metabolism, Arthritis, Rheumatoid metabolism, Aryldialkylphosphatase metabolism, Cell Cycle Proteins metabolism, Coronary Artery Disease metabolism, Nuclear Proteins metabolism, Nuclear Receptor Co-Repressor 1 metabolism
- Abstract
Background: Vitamin D has an important role in the immune system, and has been linked to rheumatoid arthritis (RA) and coronary artery disease (CAD). The exact mechanisms by which vitamin D is involved in these processes are still unclear. Therefore, we wanted to search for differences in expression of genes involved in the vitamin D receptor (VDR) activation pathway and genes that are known to alter upon vitamin D stimulation, in the aortic adventitia of CAD patients with and without RA., Methods: Affymetrix microarray was used to determine gene expression profile in surgical specimens from the adventitia of the ascending aorta of CAD patients with RA (n = 8) and without RA (n = 8) from the Feiring Heart Biopsy Study., Results: We identified three vitamin D associated genes that were differentially expressed between RA and non-RA patients: Growth arrest and DNA-damage-inducible protein 45 alpha (GADD45A) (FC = 1.47; p = 0.006), Nuclear Receptor Co-repressor 1 (NCOR1) (FC = 1,21; p = 0.005) and paraoxonases 2 (PON2) (FC = -1.37; p = 0.01). High expression of GADD45A in RA tissues was confirmed by real-time qRT-PCR. GADD45A expression correlated with plasma levels of 1,25(OH)2D3 (rs = 0.69; p = 0.003)., Conclusions: Microarray analyses revealed higher expression of GADD45A and NCOR1; and lower expression of PON2 in the aortic adventitia of RA than non-RA patients. Further studies are needed to elucidate if and how GADD45A, NCOR1 and PON2 are involved in the development of accelerated atherosclerosis in RA. In theory, some of these factors might have proatherogenic effects whereas others might reflect an underlying vascular pathology promoting atherogenesis (such as vascular stress)., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2018
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39. Hsp90 Co-chaperone p23 contributes to dopaminergic mitochondrial stress via stabilization of PHD2: Implications for Parkinson's disease.
- Author
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Rane A, Rajagopalan S, Ahuja M, Thomas B, Chinta SJ, and Andersen JK
- Subjects
- 1-Methyl-4-phenylpyridinium antagonists & inhibitors, Animals, Cells, Cultured, Dopaminergic Neurons drug effects, Gene Knockdown Techniques, Hypoxia-Inducible Factor-Proline Dioxygenases, Limonins pharmacology, Mitochondria drug effects, Molecular Chaperones antagonists & inhibitors, Molecular Chaperones genetics, Neuroprotective Agents pharmacology, Rats, Dopaminergic Neurons pathology, HSP90 Heat-Shock Proteins metabolism, Mitochondria pathology, Molecular Chaperones metabolism, Parkinson Disease metabolism, Procollagen-Proline Dioxygenase metabolism
- Abstract
The heat shock factor 90 (hsp90) complex has long been associated with neuropathological phenotypes linked to Parkinson's disease (PD) and its inhibition is neuroprotective in disease models. Hsp90 is conventionally believed to act by suppressing induction of hsp70. Here, we report a novel hsp70-independent mechanism by which Hsp90 may also contribute to PD-associated neuropathology. We previously reported that inhibition of the enzyme prolyl hydroxylase domain 2 (PHD2) in conjunction with increases in hypoxia-inducible factor 1 alpha (HIF1α) results in protection of vulnerable dopaminergic substantia nigra pars compacta (DAergic SNpc) neurons in in vitro and in vivo models of PD. We discovered an increased interaction between PHD2 and the p23:Hsp90 chaperone complex in response to mitochondrial stress elicited by the mitochondrial neurotoxin 1-methyl-4-phenylpyridine (MPP
+ ) within cultured DAergic cells. Genetic p23 knockdown was found to result in decreases in steady-state PHD2 protein and activity and reduced susceptibility to MPP+ neurotoxicity. Administration of the p23 inhibitor gedunin was also neuroprotective in these cells as well as in human induced pluripotent stem cell (iPSC)-derived neurons. Our data suggests that mitochondrial stress-mediated elevations in PHD2 interaction with the p23-hsp90 complex have detrimental effects on the survival of DAergic neurons, while p23 inhibition is neuroprotective. We propose that neurotoxic effects are tied to enhanced PHD2 stabilization by the hsp90-p23 chaperone complex that is abrogated by p23 inhibition. This demonstrates a novel connection between two independent pathways previously linked to PD, hsp90 and PHD2-HIF1α, which could have important implications for here-to-fore unexplored mechanisms underlying PD neuropathology., (Published by Elsevier B.V.)- Published
- 2018
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40. Cellular Senescence Is Induced by the Environmental Neurotoxin Paraquat and Contributes to Neuropathology Linked to Parkinson's Disease.
- Author
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Chinta SJ, Woods G, Demaria M, Rane A, Zou Y, McQuade A, Rajagopalan S, Limbad C, Madden DT, Campisi J, and Andersen JK
- Subjects
- Animals, Humans, Mice, Parkinson Disease pathology, Risk Factors, Cellular Senescence physiology, Neuropathology methods, Paraquat adverse effects, Parkinson Disease etiology
- Abstract
Exposure to the herbicide paraquat (PQ) is associated with an increased risk of idiopathic Parkinson's disease (PD). Therapies based on PQ's presumed mechanisms of action have not, however, yielded effective disease therapies. Cellular senescence is an anticancer mechanism that arrests proliferation of replication-competent cells and results in a pro-inflammatory senescence-associated secretory phenotype (SASP) capable of damaging neighboring tissues. Here, we demonstrate that senescent cell markers are preferentially present within astrocytes in PD brain tissues. Additionally, PQ was found to induce astrocytic senescence and an SASP in vitro and in vivo, and senescent cell depletion in the latter protects against PQ-induced neuropathology. Our data suggest that exposure to certain environmental toxins promotes accumulation of senescent cells in the aging brain, which can contribute to dopaminergic neurodegeneration. Therapies that target senescent cells may constitute a strategy for treatment of sporadic PD, for which environmental exposure is a major risk factor., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
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41. mTORC1 Activation during Repeated Regeneration Impairs Somatic Stem Cell Maintenance.
- Author
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Haller S, Kapuria S, Riley RR, O'Leary MN, Schreiber KH, Andersen JK, Melov S, Que J, Rando TA, Rock J, Kennedy BK, Rodgers JT, and Jasper H
- Subjects
- Adult Stem Cells drug effects, Animals, Drosophila, Mechanistic Target of Rapamycin Complex 1 antagonists & inhibitors, Mice, Mice, Knockout, Regeneration drug effects, Signal Transduction drug effects, Sirolimus pharmacology, Adult Stem Cells metabolism, Mechanistic Target of Rapamycin Complex 1 metabolism
- Abstract
The balance between self-renewal and differentiation ensures long-term maintenance of stem cell (SC) pools in regenerating epithelial tissues. This balance is challenged during periods of high regenerative pressure and is often compromised in aged animals. Here, we show that target of rapamycin (TOR) signaling is a key regulator of SC loss during repeated regenerative episodes. In response to regenerative stimuli, SCs in the intestinal epithelium of the fly and in the tracheal epithelium of mice exhibit transient activation of TOR signaling. Although this activation is required for SCs to rapidly proliferate in response to damage, repeated rounds of damage lead to SC loss. Consistently, age-related SC loss in the mouse trachea and in muscle can be prevented by pharmacologic or genetic inhibition, respectively, of mammalian target of rapamycin complex 1 (mTORC1) signaling. These findings highlight an evolutionarily conserved role of TOR signaling in SC function and identify repeated rounds of mTORC1 activation as a driver of age-related SC decline., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2017
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42. Guidance on the requirements for the development of microbiological criteria.
- Author
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Ricci A, Allende A, Bolton D, Chemaly M, Davies R, Fernández Escámez PS, Girones R, Herman L, Koutsoumanis K, Lindqvist R, Robertson L, Ru G, Sanaa M, Simmons M, Skandamis P, Snary E, Speybroeck N, Ter Kuile B, Threlfall J, Wahlström H, Andersen JK, Uyttendaele M, Valero A, Da Silva Felício MT, Messens W, and Nørrung B
- Abstract
The European Food Safety Authority asked the Panel on Biological Hazards (BIOHAZ) to deliver a scientific opinion providing: (i) a review of the approaches used by the BIOHAZ Panel to address requests from risk managers to suggest the establishment of microbiological criteria; (ii) guidance on the required scientific evidence, data and methods/tools necessary for considering the development of microbiological criteria for pathogenic microorganisms and indicator microorganisms; (iii) recommendations on methods/tools to design microbiological criteria and (iv) guidelines for the requirements and tasks of risk assessors, compared to risk managers, in relation to microbiological criteria. This document provides guidance on approaches when: (i) a quantitative microbial risk assessment (QMRA) is available, (ii) prevalence and concentration data are available, but not a QMRA model, and (iii) neither a QMRA nor prevalence and/or concentration data are available. The role of risk assessors should be focused on assessing the impact of different microbiological criteria on public health and on product compliance. It is the task of the risk managers to: (1) formulate unambiguous questions, preferably in consultation with risk assessors, (2) decide on the establishment of a microbiological criterion, or target in primary production sectors, and to formulate the specific intended purpose for using such criteria, (3) consider the uncertainties in impact assessments on public health and on product compliance and (4) decide the point in the food chain where the microbiological criteria are intended to be applied and decide on the actions which should be taken in case of non-compliance. It is the task of the risk assessors to support risk managers to ensure that questions are formulated in a way that a precise answer can be given, if sufficient information is available, and to ensure clear and unambiguous answers, including the assessment of uncertainties, based on available scientific evidence., (© 2017 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.)
- Published
- 2017
- Full Text
- View/download PDF
43. Sembragiline: A Novel, Selective Monoamine Oxidase Type B Inhibitor for the Treatment of Alzheimer's Disease.
- Author
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Borroni E, Bohrmann B, Grueninger F, Prinssen E, Nave S, Loetscher H, Chinta SJ, Rajagopalan S, Rane A, Siddiqui A, Ellenbroek B, Messer J, Pähler A, Andersen JK, Wyler R, and Cesura AM
- Subjects
- 5-Hydroxytryptophan pharmacology, Acetamides pharmacokinetics, Animals, Astrocytes drug effects, Astrocytes metabolism, Gliosis drug therapy, Gliosis pathology, Humans, Hypertension chemically induced, Hypertension prevention & control, Male, Monoamine Oxidase genetics, Monoamine Oxidase metabolism, Monoamine Oxidase Inhibitors pharmacokinetics, Motor Activity drug effects, Neurotransmitter Agents metabolism, Pyrrolidinones pharmacokinetics, Rats, Rats, Transgenic, Reactive Oxygen Species metabolism, Substrate Specificity, Tissue Distribution, Acetamides therapeutic use, Alzheimer Disease drug therapy, Monoamine Oxidase drug effects, Monoamine Oxidase Inhibitors therapeutic use, Pyrrolidinones therapeutic use
- Abstract
Monoamine oxidase B (MAO-B) has been implicated in the pathogenesis of Alzheimer's disease (AD) and other neurodegenerative disorders. Increased MAO-B expression in astroglia has been observed adjacent to amyloid plaques in AD patient brains. This phenomenon is hypothesized to lead to increased production of hydrogen peroxide and reactive oxygen species (ROS), thereby contributing to AD pathology. Therefore, reduction of ROS-induced oxidative stress via inhibition of MAO-B activity may delay the progression of the disease. In the present study we report the pharmacological properties of sembragiline, a novel selective MAO-B inhibitor specifically developed for the treatment of AD, and on its effect on ROS-mediated neuronal injury and astrogliosis in MAO-B transgenic animals. Sembragiline showed potent and long-lasting MAO-B-selective inhibition and did not inhibit MAO-A at doses where full inhibition of MAO-B was observed. Such selectivity should translate into a favorable clinical safety profile. Indeed, sembragiline neither induced the serotonin syndrome when administered together with the serotonin precursor l-5-hydroxytryptophan in combination with antidepressants such as fluoxetine, nor potentiated the pressor effect of tyramine. Additionally, in experiments using a transgenic animal model conditionally overexpressing MAO-B in astroglia, sembragiline protected against neuronal loss and reduced both ROS formation and reactive astrogliosis. Taken together, these findings warrant further investigation of the potential therapeutic benefit of MAO-B inhibitors in patients with AD and other neurologic disorders., (Copyright © 2017 by The Author(s).)
- Published
- 2017
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44. A novel iron (II) preferring dopamine agonist chelator D-607 significantly suppresses α-syn- and MPTP-induced toxicities in vivo.
- Author
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Das B, Rajagopalan S, Joshi GS, Xu L, Luo D, Andersen JK, Todi SV, and Dutta AK
- Subjects
- 2,2'-Dipyridyl pharmacology, Animals, Cell Survival drug effects, Cell Survival physiology, Corpus Striatum drug effects, Corpus Striatum metabolism, Corpus Striatum pathology, Dopamine metabolism, Dopaminergic Neurons drug effects, Dopaminergic Neurons metabolism, Dopaminergic Neurons pathology, Dose-Response Relationship, Drug, Drosophila melanogaster, MPTP Poisoning metabolism, MPTP Poisoning pathology, Male, Membrane Potential, Mitochondrial drug effects, Membrane Potential, Mitochondrial physiology, Mice, Inbred C57BL, Mitochondria drug effects, Mitochondria metabolism, Oxidopamine toxicity, PC12 Cells, Pars Compacta drug effects, Pars Compacta metabolism, Pars Compacta pathology, Prolyl Hydroxylases metabolism, Prolyl-Hydroxylase Inhibitors pharmacology, Rats, alpha-Synuclein genetics, alpha-Synuclein metabolism, 2,2'-Dipyridyl analogs & derivatives, MPTP Poisoning drug therapy, Neuroprotective Agents pharmacology, Piperazines pharmacology, alpha-Synuclein toxicity
- Abstract
Here, we report the characterization of a novel hybrid D
2 /D3 agonist and iron (II) specific chelator, D-607, as a multi-target-directed ligand against Parkinson's disease (PD). In our previously published report, we showed that D-607 is a potent agonist of dopamine (DA) D2 /D3 receptors, exhibits efficacy in a reserpinized PD animal model and preferentially chelates to iron (II). As further evidence of its potential as a neuroprotective agent in PD, the present study reveals D-607 to be protective in neuronal PC12 cells against 6-OHDA toxicity. In an in vivo Drosophila melanogaster model expressing a disease-causing variant of α-synuclein (α-Syn) protein in fly eyes, the compound was found to significantly suppress toxicity compared to controls, concomitant with reduced levels of aggregated α-Syn. Furthermore, D-607 was able to rescue DAergic neurons from MPTP toxicity in mice, a well-known PD neurotoxicity model, following both sub-chronic and chronic MPTP administration. Mechanistic studies indicated that possible protection of mitochondria, up-regulation of hypoxia-inducible factor, reduction in formation of α-Syn aggregates and antioxidant activity may underlie the observed neuroprotection effects. These observations strongly suggest that D-607 has potential as a promising multifunctional lead molecule for viable symptomatic and disease-modifying therapy for PD., (Copyright © 2017 Elsevier Ltd. All rights reserved.)- Published
- 2017
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45. Anti-Inflammatory and Neuroprotective Role of Natural Product Securinine in Activated Glial Cells: Implications for Parkinson's Disease.
- Author
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Leonoudakis D, Rane A, Angeli S, Lithgow GJ, Andersen JK, and Chinta SJ
- Subjects
- Animals, Anti-Inflammatory Agents therapeutic use, Astrocytes drug effects, Blotting, Western, Cell Survival drug effects, Interferon-Stimulated Gene Factor 3 metabolism, Lipopolysaccharides pharmacology, Mice, Microglia drug effects, Mitogen-Activated Protein Kinases metabolism, NF-kappa B metabolism, Neuroprotective Agents therapeutic use, Nitric Oxide Synthase Type II metabolism, Nitrites metabolism, Parkinson Disease immunology, Phosphorylation drug effects, Polymerase Chain Reaction, Azepines therapeutic use, Heterocyclic Compounds, Bridged-Ring therapeutic use, Lactones therapeutic use, Parkinson Disease drug therapy, Parkinson Disease metabolism, Piperidines therapeutic use
- Abstract
Glial activation and subsequent release of neurotoxic proinflammatory factors are believed to play an important role in the pathogenesis of several neurological disorders including Parkinson's disease (PD). Inhibition of glial activation and inflammatory processes may represent a therapeutic target to alleviate neurodegeneration. Securinine, a major natural alkaloid product from the root of the plant Securinega suffruticosa , has been reported to have potent biological activity and is used in the treatment of neurological conditions such as amyotrophic lateral sclerosis, poliomyelitis, and multiple sclerosis. In this study, we explored the underlying mechanisms of neuroprotection elicited by securinine, particularly its anti-inflammatory effects in glial cells. Our results demonstrate that securinine significantly and dose-dependently suppressed the nitric oxide production in microglia and astrocytic cultures. In addition, securinine inhibited the activation of the inflammatory mediator NF- κ B, as well as mitogen-activated protein kinases in lipopolysaccharide- (LPS-) stimulated BV2 cells. Additionally, securinine also inhibited interferon- γ - (IFN- γ -) induced nitric oxide levels and iNOS mRNA expression. Furthermore, conditioned media (CM) from securinine pretreated BV2 cells significantly reduced mesencephalic dopaminergic neurotoxicity compared with CM from LPS stimulated microglia. These findings suggest that securinine may be a potential candidate for the treatment of neurodegenerative diseases related to neuroinflammation.
- Published
- 2017
- Full Text
- View/download PDF
46. Inflammatory cell infiltrates in the heart of patients with coronary artery disease with and without inflammatory rheumatic disease: a biopsy study.
- Author
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Andersen JK, Oma I, Prayson RA, Kvelstad IL, Almdahl SM, Fagerland MW, and Hollan I
- Subjects
- Aged, Biopsy, Female, Humans, Inflammation pathology, Male, Middle Aged, Coronary Artery Disease complications, Myocardium pathology, Pericardium pathology, Rheumatic Diseases complications
- Abstract
Background: The cause of premature cardiovascular disease (CVD) in inflammatory rheumatic diseases (IRDs) has not been fully elucidated. As inflammation may play a role, we wanted to compare the occurrence and extent of inflammatory cell infiltrates (ICIs), small vessel vasculitis, and the amount of adipose tissue and collagen in cardiac biopsies taken from patients with coronary artery disease with and without IRDs., Methods: From among the Feiring Heart Biopsy Study subjects, we selected patients undergoing coronary artery bypass grafting from whom paraffin-embedded, formalin-fixed specimens from the right atrium were available. The sample comprised 48 patients with IRD and 40 non-IRD patients. Hematoxylin and eosin staining was used to examine the presence and location of ICIs and vasculitis, and Lendrum (Martius yellow, scarlet, and blue) staining was carried out for collagen and adipose tissue., Results: Epicardial ICIs were found in 27 (56 %) patients with IRD and 24 (60 %) non-IRD patients. There were no significant differences between patients with IRD and non-IRD patients in the amount of cardiac ICIs and adipose tissue, but patients with IRD had more collagen in the myocardium than non-IRD patients. Small vessel vasculitis was not observed in any cardiac specimen. Patients with epicardial ICIs were, on average, 7 years younger than those without., Conclusions: Our results do not support the notion that inflammation in cardiac peri-, epi-, and myocardium plays a more important role in CVD of patients with IRD than non-IRD patients. The increased amount of collagen in the myocardium of patients with IRD suggests differences in extracellular matrix composition and/or mass, which might play a role in cardiac remodeling, and represent targets for novel therapies against heart failure.
- Published
- 2016
- Full Text
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47. Detrimental effects of oxidative losses in parkin activity in a model of sporadic Parkinson's disease are attenuated by restoration of PGC1alpha.
- Author
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Siddiqui A, Rane A, Rajagopalan S, Chinta SJ, and Andersen JK
- Subjects
- Animals, Humans, Mice, Transgenic, Mitochondria metabolism, Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha genetics, Proteasome Endopeptidase Complex metabolism, Signal Transduction drug effects, Substantia Nigra metabolism, Dopaminergic Neurons metabolism, Oxidative Stress physiology, Parkinson Disease metabolism, Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha metabolism, Ubiquitin-Protein Ligases metabolism
- Abstract
Loss of parkin E3 ligase activity as a result of parkin gene mutation in rare familial forms of Parkinson's disease (PD) has been shown to be detrimental to mitochondrial function and to contribute to ensuing neurodegeneration. This has been shown by ourselves and others to be in part due to reductions in parkin-mediated ubiquitination of the transcriptional repressor PARIS, limiting the protein's subsequent degradation by the proteasome. Subsequent elevations in PARIS protein levels result in reduced expression of the master mitochondrial regulator PGC-1α, impacting in turn on mitochondrial function. Here, we report that oxidatively-mediated reductions in parkin solubility and function in a mouse model of age-related sporadic PD coincides with increased PARIS levels and reduced PGC-1α signaling. Furthermore, restoration of PGC-1α expression was found to abrogate losses in mitochondrial function and degeneration of dopaminergic (DAergic) neurons within the substantia nigra pars compacta (SNpc) associated with this particular model. These findings suggest that the PGC-1α signaling pathway constitutes a viable therapeutic target for the treatment of not only familial PD, but also more common sporadic forms of the disorder., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2016
- Full Text
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48. Whole-genome Sequencing Used to Investigate a Nationwide Outbreak of Listeriosis Caused by Ready-to-eat Delicatessen Meat, Denmark, 2014.
- Author
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Kvistholm Jensen A, Nielsen EM, Björkman JT, Jensen T, Müller L, Persson S, Bjerager G, Perge A, Krause TG, Kiil K, Sørensen G, Andersen JK, Mølbak K, and Ethelberg S
- Subjects
- Adult, Aged, Aged, 80 and over, Cohort Studies, Denmark epidemiology, Female, High-Throughput Nucleotide Sequencing, Humans, Male, Middle Aged, Polymorphism, Single Nucleotide genetics, Disease Outbreaks statistics & numerical data, Foodborne Diseases epidemiology, Foodborne Diseases microbiology, Genome, Bacterial genetics, Listeria monocytogenes genetics, Listeriosis epidemiology, Listeriosis microbiology, Meat microbiology
- Abstract
Background: Listeriosis is a serious foodborne infection. Outbreaks of listeriosis occur rarely, but have often proved difficult to solve. In June 2014, we detected and investigated a listeriosis outbreak in Denmark using patient interviews and whole-genome sequencing (WGS)., Methods: We performed WGS on Listeria monocytogenes isolates from patients and available isolates from ready-to-eat foods and compared them using single-nucleotide polymorphism (SNP) analysis. Case patients had L. monocytogenes with ≤3 SNPs (the outbreak strain) isolated in September 2013-December 2014. Through interviews, we established case patients' food and clinical histories. Food production facilities were inspected and sampled, and we performed trace-back/trace-forward of food delivery chains., Results: In total, 41 cases were identified; 17 deaths occurred (41%). An isolate from a delicatessen meat (spiced meat roll) from company A was identical to the outbreak strain. Half of the patients were infected while hospitalized/institutionalized; institutions were supplied food by company A. The outbreak strain was repeatedly isolated from further samples taken within this company and within companies in its distribution chain. Products from company A were traced and recalled from >6000 food establishments, after which the outbreak ended., Conclusions: Ready-to-eat spiced meat roll from a single production facility caused this outbreak. The product, served sliced and cold, is popular among the elderly; serving it at hospitals probably contributed to the high case-fatality rate. WGS used for patient isolates and isolates from food control inspections, coupled with routine epidemiological follow-up, was instrumental in swiftly locating the source of infections, preventing further illnesses and deaths., (© The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.)
- Published
- 2016
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49. Regulation of ATP13A2 via PHD2-HIF1α Signaling Is Critical for Cellular Iron Homeostasis: Implications for Parkinson's Disease.
- Author
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Rajagopalan S, Rane A, Chinta SJ, and Andersen JK
- Subjects
- Adenosine Triphosphatases genetics, Animals, Disease Models, Animal, Fluoresceins metabolism, Gene Expression Regulation genetics, Homeostasis genetics, Humans, Hypoxia-Inducible Factor 1, alpha Subunit genetics, Hypoxia-Inducible Factor-Proline Dioxygenases genetics, Lysosomes metabolism, Membrane Proteins genetics, Mice, Mice, Transgenic, Neuroblastoma pathology, Parkinsonian Disorders chemically induced, Pluripotent Stem Cells drug effects, Pluripotent Stem Cells physiology, Proton-Translocating ATPases, RNA, Messenger metabolism, RNA, Small Interfering genetics, RNA, Small Interfering metabolism, Signal Transduction drug effects, Signal Transduction genetics, Tyrosine 3-Monooxygenase metabolism, Adenosine Triphosphatases metabolism, Homeostasis physiology, Hypoxia-Inducible Factor 1, alpha Subunit metabolism, Hypoxia-Inducible Factor-Proline Dioxygenases metabolism, Iron metabolism, Membrane Proteins metabolism, Parkinsonian Disorders metabolism, Signal Transduction physiology
- Abstract
We previously reported that pharmacological inhibition of a class of enzymes known as prolyl hydroxylase domain proteins (PHDs) has neuroprotective effects in various in vitro and in vivo models of Parkinson's disease (PD). We hypothesized that this was due to inhibition of the PHD2 isoform, preventing it from hydroxylating the transcription factor hypoxia inducible factor 1 α (HIF1α), targeting it for eventual proteasomal degradation. HIF1α itself induces the transcription of various cellular stress genes, including several involved in iron metabolism. Although all three isoforms of PHD are expressed within vulnerable dopaminergic (DAergic) substantia nigra pars compacta neurons, only select downregulation of the PHD2 isoform was found to protect against in vivo neurodegenerative effects associated with the mitochondrial neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. These findings were corroborated in induced pluripotent stem cell-derived neurons, providing validation in a pertinent human cell model. PHD2 inhibition was found to result in increased expression of ATP13A2, mutation of which is responsible for a rare juvenile form of PD known as Kufor-Rakeb syndrome. Knockdown of ATP13A2 expression within human DAergic cells was found to abrogate restoration of cellular iron homeostasis and neuronal cell viability elicited by inhibition of PHD2 under conditions of mitochondrial stress, likely via effects on lysosomal iron storage. These data suggest that regulation of ATP13A2 by the PHD2-HIF1α signaling pathway affects cellular iron homeostasis and DAergic neuronal survival. This constitutes a heretofore unrecognized process associated with loss of ATP13A2 function that could have wide-ranging implications for it as a therapeutic target for PD and other related conditions., Significance Statement: Reductions in PHD2 activity within dopaminergic neurons in vivo and in cultured human induced pluripotent stem cell-derived neurons protects against mitochondrial stress-induced neurotoxicity. Protective effects are dependent on downstream HIF-1α expression. Knockdown of ATP13A2, a gene linked to a rare juvenile form of Parkinson's disease and recently identified as a novel HIF1α target, was found to abrogate maintenance of cellular iron homeostasis and neuronal viability elicited by PHD2 inhibition in vivo and in cultured dopaminergic cells under conditions of mitochondrial stress. Mechanistically, this was due to ATP13A2's role in maintaining lysosomal iron stores. This constitutes a novel mechanism by which alterations in ATP13A2 activity may be driving PD-related neuropathology., (Copyright © 2016 the authors 0270-6474/16/361086-10$15.00/0.)
- Published
- 2016
- Full Text
- View/download PDF
50. The combination of lithium and l-Dopa/Carbidopa reduces MPTP-induced abnormal involuntary movements (AIMs) via calpain-1 inhibition in a mouse model: Relevance for Parkinson׳s disease therapy.
- Author
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Lazzara CA, Riley RR, Rane A, Andersen JK, and Kim YH
- Subjects
- Animals, Brain Stem drug effects, Brain Stem pathology, Brain Stem physiopathology, Calpain antagonists & inhibitors, Calpain metabolism, Cell Death drug effects, Cell Death physiology, Cell Line, Corpus Striatum drug effects, Corpus Striatum pathology, Corpus Striatum physiopathology, Dopaminergic Neurons drug effects, Dopaminergic Neurons pathology, Dopaminergic Neurons physiology, Drug Therapy, Combination, Histone Acetyltransferases metabolism, MPTP Poisoning pathology, MPTP Poisoning physiopathology, Male, Mice, Inbred C57BL, Motor Activity physiology, Rats, Tyrosine 3-Monooxygenase metabolism, Antiparkinson Agents pharmacology, Carbidopa pharmacology, Levodopa pharmacology, Lithium Chloride pharmacology, MPTP Poisoning drug therapy, Motor Activity drug effects
- Abstract
Lithium has recently been suggested to have neuroprotective effects in several models of neurodegenerative disease including Parkinson׳s disease (PD). Levodopa (l-Dopa) replacement therapy remains the most common and effective treatment for PD, although it induces the complication of l-Dopa induced dyskinesia after years of use. Here we examined the potential use of lithium in combination with l-Dopa/Carbidopa for both reducing MPTP-induced abnormal involuntary movements (AIMs) as well as protecting against cell death in MPTP-lesioned mice. Chronic lithium administration (0.127% LiCl in the feed) in the presence of daily l-Dopa/Carbidopa injection for a period of 2 months was sufficient to effectively reduce MPTP-induced AIMs in mice. Mechanistically, lithium was found to suppress MPTP-induced calpain activities in vivo coinciding with down-regulation of calpain-1 but not calpain-2 expression in both the striatum (ST) and the brain stem (BS). Calpain inhibition has previously been associated with increased levels of the rate-limiting enzyme in dopamine synthesis, tyrosine hydroxylase (TH), which is probably mediated by the up-regulation of the transcription factors MEF-2A and 2D. Lithium was found to induce up-regulation of TH expression in the ST and the BS, as well as in N27 rat dopaminergic cells. Further, histone acetyltransferase (HAT) expression was substantially up-regulated by lithium treatment in vitro. These results suggest the potential use of lithium in combination with l-Dopa/Carbidopa not only as a neuroprotectant, but also for reducing AIMs and possibly alleviating potential side-effects associated with the current treatment for PD., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
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