109 results on '"Larsen SD"'
Search Results
2. Differential gene expression during larval development of silver sea bream
- Author
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Deane, EE, primary, Kelly, SP, additional, Larsen, SD, additional, Collins, PM, additional, and Woo, NYS, additional
- Published
- 1999
- Full Text
- View/download PDF
3. Patient satisfaction in military medicine: model refinement and assessment of Department of Defense effects.
- Author
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Mangelsdorff AD, Finstuen K, Larsen SD, Weinberg EJ, Mangelsdorff, A David, Finstuen, Kenn, Larsen, Stephen D, and Weinberg, Edward J
- Abstract
A sample of 154,893 patient responses from the Customer Satisfaction Survey database was drawn for 1999 to 2000. Average patient satisfaction levels consistently appeared to be high (between 6, very satisfied, and 7, completely satisfied, on the 7-point rating scale). Hierarchical regression results essentially replicated all three major constructs of an earlier theoretical attitude model. Refinements included adjustment and addition of categorical age and military beneficiary status for individual patient variables, addition of two beliefs about the care itself, substitution of waiting time variables, and addition of reason for visit situation variables. Hypothesis test results indicated that patient satisfaction constructs were homogeneous across the uniformed services for patients from all service branches, both enrolled and not enrolled within TRICARE regions, and among branch of service medical center, hospital, and clinic facilities. The final attitude model coefficient of multiple determinations obtained was R2 = 0.701 [F(25,154,867) = 14,539.33, p < 0.0001]. [ABSTRACT FROM AUTHOR]
- Published
- 2005
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4. Staffing model for dental wellness and readiness.
- Author
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Chaffin J, Rothfuss LG, Johnson SA, Larsen SD, Finstuen K, Rothfuss, Larry G, Johnson, Scott A, Larsen, Stephen D, Chaffin, Jeffrey, and Finstuen, Kenn
- Abstract
Oral health is an integral part of general health. Previous research has shown that untreated oral conditions can result in increased rates of disease and nonbattle injury for deployed soldiers. The purpose of this study was to develop models for U.S. Army dental wellness and readiness using a multivariate regression analysis approach. Staffing levels and dental wellness and readiness rates were examined for the first three quarters of fiscal year 2002 at 40 Army installations. Full regression model equations were developed for percent dental wellness and readiness using location, time, dental provider types, and basic training installation as predictor variables. Both models were shown to be statistically significant, with wellness R2 = 0.37, F12,107 = 5.18, p < 0.001 and readiness R2 = 0.23, F12,107 = 2.65, p < 0.01. Further tests of specific predictor effects revealed that wellness was significantly associated with the specialties of general dentistry, hygienists, and oral surgery, and that readiness was significantly associated with region and the oral surgery specialty. Results may be useful for the U.S. Army to identify the best practices in an effort to optimize dental wellness and readiness. [ABSTRACT FROM AUTHOR]
- Published
- 2004
5. Identification of the MRTFA/SRF pathway as a critical regulator of quiescence in cancer.
- Author
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Panesso-Gómez S, Cole AJ, Wield A, Anyaeche VI, Shah J, Jiang Q, Ebai T, Sharrow AC, Tseng G, Yoon E, Brown DD, Clark AM, Larsen SD, Eder I, Gau D, Roy P, Dahl KN, Tran L, Jiang H, McAuliffe PF, Lee AV, and Buckanovich RJ
- Abstract
Chemoresistance is a major driver of cancer deaths. One understudied mechanism of chemoresistance is quiescence. We used single cell culture to identify, retrieve, and RNA-Seq profile primary quiescent ovarian cancer cells (qOvCa). We found that many qOvCa differentially expressed genes are transcriptional targets of the Myocardin Related Transcription Factor/Serum Response Factor (MRTF/SRF) pathway. We also found that genetic disruption of MRTF-SRF interaction, or an MRTF/SRF inhibitor (CCG257081) impact qOvCa gene expression and induce a quiescent state in cancer cells. Suggesting a broad role for this pathway in quiescence, CCG257081 treatment induced quiescence in breast, lung, colon, pancreatic and ovarian cancer cells. Furthermore, CCG081 (i) maintained a quiescent state in patient derived breast cancer organoids and, (ii) induced tumor growth arrest in ovarian cancer xenografts. Together, these data suggest that MRTF/SRF pathway is a critical regulator of quiescence in cancer and a possible therapeutic target., Significance: Quiescence is a critical driver of chemoresistance. The MRFT-SRF pathway regulates cancer cell quiescence and inhibiting the MRTF-SRF pathway can prevent the outgrowth of quiescent cancer cells and improve cancer outcomes.
- Published
- 2024
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6. Protocol for quantifying pyramidal neuron hyperexcitability in a mouse model of neurodevelopmental encephalopathy.
- Author
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Dos Santos AB, Larsen SD, Gomez CD, Sørensen JB, and Perrier JF
- Subjects
- Animals, Mice, Neurodevelopmental Disorders physiopathology, Pyramidal Cells, Disease Models, Animal
- Abstract
Here, we present a protocol for quantifying pyramidal neuron hyperexcitability in a mouse model of STXBP1 neurodevelopmental encephalopathy (Stxbp1
hap ). We describe steps for preparing brain slices, positioning electrodes, and performing an excitability test to investigate microcircuit failures. This protocol is based on recording layer 2/3 cortical pyramidal neurons in response to stimulation of two independent sets of excitatory axons that recruit feedforward inhibition microcircuits. For complete details on the use and execution of this protocol, please refer to Dos Santos et al.1 ., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2024
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7. Development of substituted benzimidazoles as inhibitors of human aldehyde dehydrogenase 1A isoenzymes.
- Author
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Takahashi C, Chtcherbinine M, Huddle BC, Wilson MW, Emmel T, Hohlman RM, McGonigal S, Buckanovich RJ, Larsen SD, and Hurley TD
- Subjects
- Humans, Aldehyde Dehydrogenase metabolism, Retinal Dehydrogenase metabolism, Aldehyde Oxidoreductases metabolism, Isoenzymes, Neoplasms
- Abstract
Aldehyde dehydrogenase 1A (ALDH1A) isoforms may be a useful target for overcoming chemotherapy resistance in high-grade serous ovarian cancer (HGSOC) and other solid tumor cancers. However, as different cancers express different ALDH1A isoforms, isoform selective inhibitors may have a limited therapeutic scope. Furthermore, resistance to an ALDH1A isoform selective inhibitor could arise via induction of expression of other ALDH1A isoforms. As such, we have focused on the development of pan-ALDH1A inhibitors, rather than on ALDH1A isoform selective compounds. Herein, we report the development of a new group of pan-ALDH1A inhibitors to assess whether broad spectrum ALDH1A inhibition is an effective adjunct to chemotherapy in HGSOC. Optimization of the CM10 scaffold, aided by ALDH1A1 crystal structures, led to improved biochemical potencies, improved cellular efficacy as demonstrated by reduction in ALDEFLUOR signal in HGSOC cells, and substantial improvements in liver microsomal stability. Based on this work we identified two compounds 17 and 25 suitable for future in vivo proof of concept experiments., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Thomas D. Hurley reports a relationship with Maze Therapeutics Inc that includes: consulting or advisory and equity or stocks. Thomas D. Hurley reports a relationship with SAJE Pharma that includes: equity or stocks. Ronald J Buckanovich reports a relationship with Tradewind Bioscience that includes: equity or stocks. Ronald J Buckanovich reports a relationship with Galapagos that includes: consulting or advisory. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2024
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8. Microcircuit failure in STXBP1 encephalopathy leads to hyperexcitability.
- Author
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Dos Santos AB, Larsen SD, Guo L, Barbagallo P, Montalant A, Verhage M, Sørensen JB, and Perrier JF
- Subjects
- Animals, Humans, Mice, Munc18 Proteins genetics, Munc18 Proteins metabolism, Mutation, Neurons metabolism, Synapses metabolism, Synaptic Transmission genetics, Brain Diseases genetics, Brain Diseases metabolism
- Abstract
De novo mutations in STXBP1 are among the most prevalent causes of neurodevelopmental disorders and lead to haploinsufficiency, cortical hyperexcitability, epilepsy, and other symptoms in people with mutations. Given that Munc18-1, the protein encoded by STXBP1, is essential for excitatory and inhibitory synaptic transmission, it is currently not understood why mutations cause hyperexcitability. We find that overall inhibition in canonical feedforward microcircuits is defective in a P15-22 mouse model for Stxbp1 haploinsufficiency. Unexpectedly, we find that inhibitory synapses formed by parvalbumin-positive interneurons were largely unaffected. Instead, excitatory synapses fail to recruit inhibitory interneurons. Modeling confirms that defects in the recruitment of inhibitory neurons cause hyperexcitation. CX516, an ampakine that enhances excitatory synapses, restores interneuron recruitment and prevents hyperexcitability. These findings establish deficits in excitatory synapses in microcircuits as a key underlying mechanism for cortical hyperexcitability in a mouse model of Stxbp1 disorder and identify compounds enhancing excitation as a direction for therapy., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
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9. Prevention of bleomycin-induced lung fibrosis via inhibition of the MRTF/SRF transcription pathway.
- Author
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Pawelec KM, Varnum M, Harkema JR, Auerbach B, Larsen SD, and Neubig RR
- Subjects
- Humans, Animals, Mice, Inflammation, Fibroblasts, Prednisolone, Bleomycin toxicity, Pulmonary Fibrosis chemically induced, Pulmonary Fibrosis drug therapy, Pulmonary Fibrosis prevention & control
- Abstract
Bleomycin-induced lung fibrosis is a debilitating disease, linked to high morbidity and mortality in chemotherapy patients. The MRTF/SRF transcription pathway has been proposed as a potential therapeutic target, as it is critical for myofibroblast differentiation, a hallmark of fibrosis. In human lung fibroblasts, the MRTF/SRF pathway inhibitor, CCG-257081, effectively decreased mRNA levels of downstream genes: smooth muscle actin and connective tissue growth factor, with IC
50 s of 4 and 15 μM, respectively. The ability of CCG-257081 to prevent inflammation and fibrosis, measured via pulmonary collagen content and histopathology, was tested in a murine model of bleomycin-induced lung fibrosis. Animals were given intraperitoneal bleomycin for 4 weeks and concurrently dosed with CCG-257081 (0, 10, 30, and 100 mg/kg PO), a clinical anti-fibrotic (nintedanib) or the clinical standard of care (prednisolone). Mice treated with 100 mg/kg CCG-257081 gained weight vs. vehicle-treated control mice, while those receiving nintedanib and prednisolone lost significant weight. Hydroxyproline content and histological findings in tissue of animals on 100 mg/kg CCG-257081 were not significantly different from naive tissue, indicating successful prevention. Measures of tissue fibrosis were comparable between CCG-257081 and nintedanib, but only the MRTF/SRF inhibitor decreased plasminogen activator inhibitor-1 (PAI-1), a marker linked to fibrosis, in bronchoalveolar lavage fluid. In contrast, prednisolone led to marked increases in lung fibrosis by all metrics. This study demonstrates the potential use of MRTF/SRF inhibitors to prevent bleomycin-induced lung fibrosis in a clinically relevant model of the disease., (© 2022 The Authors. Pharmacology Research & Perspectives published by British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics and John Wiley & Sons Ltd.)- Published
- 2022
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10. Synthesis and biological activity of conformationally restricted indole-based inhibitors of neurotropic alphavirus replication: Generation of a three-dimensional pharmacophore.
- Author
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Barraza SJ, Sindac JA, Dobry CJ, Delekta PC, Lee PH, Miller DJ, and Larsen SD
- Subjects
- Antiviral Agents chemical synthesis, Antiviral Agents chemistry, Dose-Response Relationship, Drug, Drug Design, Indoles chemical synthesis, Indoles chemistry, Microbial Sensitivity Tests, Molecular Conformation, Structure-Activity Relationship, Virus Replication drug effects, Alphavirus drug effects, Antiviral Agents pharmacology, Indoles pharmacology
- Abstract
We have previously reported the development of indole-based CNS-active antivirals for the treatment of neurotropic alphavirus infection, but further optimization is impeded by a lack of knowledge of the molecular target and binding site. Herein we describe the design, synthesis and evaluation of a series of conformationally restricted analogues with the dual objectives of improving potency/selectivity and identifying the most bioactive conformation. Although this campaign was only modestly successful at improving potency, the sharply defined SAR of the rigid analogs enabled the definition of a three-dimensional pharmacophore, which we believe will be of value in further analog design and virtual screening for alternative antiviral leads., (Copyright © 2021 Elsevier Ltd. All rights reserved.)
- Published
- 2021
- Full Text
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11. AC2P20 selectively kills Mycobacterium tuberculosis at acidic pH by depleting free thiols.
- Author
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Dechow SJ, Coulson GB, Wilson MW, Larsen SD, and Abramovitch RB
- Abstract
Mycobacterium tuberculosis (Mtb) senses and adapts to host immune cues as part of its pathogenesis. One environmental cue sensed by Mtb is the acidic pH of its host niche in the macrophage phagosome. Disrupting the ability of Mtb to sense and adapt to acidic pH has the potential to reduce survival of Mtb in macrophages. Previously, a high throughput screen of a ∼220 000 compound small molecule library was conducted to discover chemical probes that inhibit Mtb growth at acidic pH. The screen discovered chemical probes that kill Mtb at pH 5.7 but are inactive at pH 7.0. In this study, AC2P20 was prioritized for continued study to test the hypothesis that it was targeting Mtb pathways associated with pH-driven adaptation. RNAseq transcriptional profiling studies showed AC2P20 modulates expression of genes associated with redox homeostasis. Gene enrichment analysis revealed that the AC2P20 transcriptional profile had significant overlap with a previously characterized pH-selective inhibitor, AC2P36. Like AC2P36, we show that AC2P20 kills Mtb by selectively depleting free thiols at acidic pH. Mass spectrometry studies show the formation of a disulfide bond between AC2P20 and reduced glutathione, supporting a mechanism where AC2P20 is able to deplete intracellular thiols and dysregulate redox homeostasis. The observation of two independent molecules targeting free thiols to kill Mtb at acidic pH further supports that Mtb has restricted redox homeostasis and sensitivity to thiol-oxidative stress at acidic pH., Competing Interests: R. B. A. is the founder and owner of Tarn Biosciences, Inc., a company that is working to develop new TB drugs., (This journal is © The Royal Society of Chemistry.)
- Published
- 2021
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12. Quality of the Diagnostic Process, Treatment Decision, and Predictors for Antibiotic Use in General Practice for Nursing Home Residents with Suspected Urinary Tract Infection.
- Author
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Sommer-Larsen SD, Arnold SH, Holm A, Aamand Olesen J, and Cordoba G
- Abstract
Urinary tract infections (UTIs) are common in nursing home (NH) residents and Denmark is one of the countries with the highest antibiotic use in NHs. The aim of this study was to assess the quality of the diagnostic process and treatment decision on the day of the first contact from NHs to general practice and assess predictors for prescription of antibiotics in NH residents without an indwelling urinary catheter. The study was a prospective observational study in general practice in the Capital Region of Denmark; 490 patients were included; 158 out of 394 (40.1%, 95% CI 35; 45) patients with suspected UTI had urinary tract symptoms; 270 out of 296 (91.2%, 95% CI 87; 94) patients without urinary tract symptoms had a urine culture performed. Performing urine culture in the general practice was inversely associated to prescription of antibiotics on day one (OR 0.27, 95% CI 0.13; 0.56). It is imperative to support the implementation of interventions aimed at improving the quality of the diagnostic process on day one, as less than half of the patients given the diagnosis "suspected UTI" had urinary tract symptoms, and most patients without urinary tract symptoms had a urine culture performed.
- Published
- 2021
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13. Physicochemical properties and formulation development of a novel compound inhibiting Staphylococcus aureus biofilm formation.
- Author
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Wang N, Qi F, Yu H, Yestrepsky BD, Larsen SD, Shi H, Ji J, Anderson DW, Li H, and Sun H
- Subjects
- Virulence Factors metabolism, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents pharmacology, Biofilms drug effects, Biofilms growth & development, Staphylococcus aureus drug effects
- Abstract
The emergence of antibiotic resistance over the past several decades has given urgency to new antibacterial strategies that apply less selective pressure. A new class of anti-virulence compounds were developed that are active against methicillin-resistant Staphylococcus aureus (MRSA), by inhibiting bacterial virulence without hindering their growth to reduce the selective pressure for resistance development. One of the compounds CCG-211790 has demonstrated potent anti-biofilm activity against MRSA. This new class of anti-virulence compounds inhibited the gene expression of virulence factors involved in biofilm formation and disrupted the biofilm structures. In this study, the physicochemical properties of CCG-211790, including morphology, solubility in pure water or in water containing sodium dodecyl sulfate, solubility in organic solvents, and stability with respect to pH were investigated for the first time. Furthermore, a topical formulation was developed to enhance the therapeutic potential of the compound. The formulation demonstrated acceptable properties for drug release, viscosity, pH, cosmetic elegance and stability of over nine months., Competing Interests: The authors have read the journal’s policy and have the following competing interests: HY, DWA and HL are currently employed by Ivogen Inc., which is a subsidiary of Nanova, Inc. HSu is a consultant of Nanova Inc., Ivogen Inc., and own stocks in Nanova, Inc. FQ is currently employed by BeiGene Ltd. and BDY is currently employed by Abbvie Inc. The authors would like to declare the following patents associated with this research for methods and compositions for treating bacterial infection: HSu, SDL and BDY are co-inventors on patents US 8501722, US 9504688, Japan 6293736, and European 2844258; HSu and DWA are co-inventors on patent US 9814719; HSu, DWA, FQ are co-inventors on patent US 10441588. Ivogen Inc. are developing products related to these patents. This does not alter the authors’ adherence to all the PLOS ONE policies on sharing data and materials.
- Published
- 2021
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14. Development of 2,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one inhibitors of aldehyde dehydrogenase 1A (ALDH1A) as potential adjuncts to ovarian cancer chemotherapy.
- Author
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Huddle BC, Grimley E, Chtcherbinine M, Buchman CD, Takahashi C, Debnath B, McGonigal SC, Mao S, Li S, Felton J, Pan S, Wen B, Sun D, Neamati N, Buckanovich RJ, Hurley TD, and Larsen SD
- Subjects
- Aldehyde Dehydrogenase pharmacology, Female, Humans, Molecular Structure, Structure-Activity Relationship, Aldehyde Dehydrogenase antagonists & inhibitors, Aldehyde Dehydrogenase therapeutic use, Ovarian Neoplasms drug therapy
- Abstract
There is strong evidence that inhibition of one or more Aldehyde Dehydrogenase 1A (ALDH1A) isoforms may be beneficial in chemotherapy-resistant ovarian cancer and other tumor types. While many previous efforts have focused on development of ALDH1A1 selective inhibitors, the most deadly ovarian cancer subtype, high-grade serous (HGSOC), exhibits elevated expression of ALDH1A3. Herein, we report continued development of pan-ALDH1A inhibitors to assess whether broad spectrum ALDH1A inhibition is an effective adjunct to chemotherapy in this critical tumor subtype. Optimization of the CM39 scaffold, aided by metabolite ID and several new ALDH1A1 crystal structures, led to improved biochemical potencies, improved cellular ALDH inhibition in HGSOC cell lines, and substantial improvements in microsomal stability culminating in orally bioavailable compounds. We demonstrate that two compounds 68 and 69 are able to synergize with chemotherapy in a resistant cell line and patient-derived HGSOC tumor spheroids, indicating their suitability for future in vivo proof of concept experiments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)
- Published
- 2021
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15. Optimization of Eliglustat-Based Glucosylceramide Synthase Inhibitors as Substrate Reduction Therapy for Gaucher Disease Type 3.
- Author
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Wilson MW, Shu L, Hinkovska-Galcheva V, Jin Y, Rajeswaran W, Abe A, Zhao T, Luo R, Wang L, Wen B, Liou B, Fannin V, Sun D, Sun Y, Shayman JA, and Larsen SD
- Subjects
- Animals, Enzyme Inhibitors pharmacology, Glucosyltransferases, Mice, Pyrrolidines pharmacology, Gaucher Disease drug therapy
- Abstract
There remain no approved therapies for rare but devastating neuronopathic glyocosphingolipid storage diseases, such as Sandhoff, Tay-Sachs, and Gaucher disease type 3. We previously reported initial optimization of the scaffold of eliglustat, an approved therapy for the peripheral symptoms of Gaucher disease type 1, to afford 2 , which effected modest reductions in brain glucosylceramide (GlcCer) in normal mice at 60 mg/kg. The relatively poor pharmacokinetic properties and high Pgp-mediated efflux of 2 prompted further optimization of the scaffold. With a general objective of reducing topological polar surface area, and guided by multiple metabolite identification studies, we were successful at identifying 17 (CCG-222628), which achieves remarkably greater brain exposure in mice than 2 . After demonstrating an over 60-fold improvement in potency over 2 at reducing brain GlcCer in normal mice, we compared 17 with Sanofi clinical candidate venglustat (Genz-682452) in the CBE mouse model of Gaucher disease type 3. At doses of 10 mg/kg, 17 and venglustat effected comparable reductions in both brain GlcCer and glucosylsphingosine. Importantly, 17 achieved these equivalent pharmacodynamic effects at significantly lower brain exposure than venglustat.
- Published
- 2020
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16. Discovery and Optimization of Triazine Nitrile Inhibitors of Toxoplasma gondii Cathepsin L for the Potential Treatment of Chronic Toxoplasmosis in the CNS.
- Author
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Zwicker JD, Smith D, Guerra AJ, Hitchens JR, Haug N, Vander Roest S, Lee P, Wen B, Sun D, Wang L, Keep RF, Xiang J, Carruthers VB, and Larsen SD
- Subjects
- Animals, Cathepsin L, Central Nervous System, Humans, Mice, Nitriles pharmacology, Protozoan Proteins, Triazines pharmacology, Toxoplasma, Toxoplasmosis drug therapy
- Abstract
With roughly 2 billion people infected, the neurotropic protozoan Toxoplasma gondii remains one of the most pervasive and infectious parasites. Toxoplasma infection is the second leading cause of death due to foodborne illness in the United States, causes severe disease in immunocompromised patients, and is correlated with several cognitive and neurological disorders. Currently, no therapies exist that are capable of eliminating the persistent infection in the central nervous system (CNS). In this study we report the identification of triazine nitrile inhibitors of Toxoplasma cathepsin L ( Tg CPL) from a high throughput screen and their subsequent optimization. Through rational design, we improved inhibitor potency to as low as 5 nM, identified pharmacophore features that can be exploited for isoform selectivity (up to 7-fold for Tg CPL versus human isoform), and improved metabolic stability ( t
1/2 > 60 min in mouse liver microsomes) guided by a metabolite ID study. We demonstrated that this class of compounds is capable of crossing the blood-brain barrier in mice (1:1 brain/plasma at 2 h). Importantly, we also show for the first time that treatment of T. gondii bradyzoite cysts in vitro with triazine nitrile inhibitors reduces parasite viability with efficacy equivalent to a Tg CPL genetic knockout.- Published
- 2020
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17. The Rate of Infectious Complications After Intrathecal Drug Delivery System Implant for Cancer-Related Pain Is Low Despite Frequent Concurrent Anticancer Treatment or Leukopenia.
- Author
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Sindt JE, Larsen SD, Dalley AP, Collier WH, and Brogan SE
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Antineoplastic Agents adverse effects, Cancer Pain complications, Cancer Pain diagnosis, Drug Delivery Systems trends, Female, Humans, Infusions, Spinal trends, Leukopenia diagnosis, Male, Middle Aged, Pain Management adverse effects, Surgical Wound Infection diagnosis, Young Adult, Cancer Pain drug therapy, Drug Delivery Systems adverse effects, Drug Implants adverse effects, Infusions, Spinal adverse effects, Leukopenia etiology, Surgical Wound Infection etiology
- Abstract
Background: The efficacy of intrathecal drug delivery (IDD) for cancer-related pain is well established. Cancer therapies are often associated with immunosuppression and increased risk of infection, and the rate of infection after intrathecal drug delivery system (IDDS) implant in cancer patients has been reported as 2.4%-6.3%. Our objective is to report on the rate of surgical site infections (SSI) in patients implanted with IDDS for cancer-related pain and to provide a data-driven discussion on the relationship between antineoplastic treatment, leukopenia, and other clinical or demographic characteristics and SSI., Methods: Following local institutional review board approval, we conducted a retrospective chart review of IDDS implants from May 2014 through December 2018. Data collected included demographic data, health status, prophylactic antibiotic administration, surgery duration, presence of leukopenia (white blood cell [WBC] count of <4.0 K/µL) or moderate neutropenia (absolute neutrophil count [ANC] of <1000/μL) within the 30 days before IDDS implant, and details of antineoplastic treatment or systemic corticosteroid use in the perioperative period. This information was assessed in relation to SSI incidence up to 6 months following implant., Results: Two hundred seventeen IDDS implants were identified. A majority of patients (79.3%) received ≥1 form of antineoplastic therapy within 30 days before or after implant, and 42.4% received multiple forms of antineoplastic therapy. Therapies included chemotherapy in 46.5%, immunotherapy in 28.6%, systemic steroids in 32.3%, and radiation therapy in 28.1%. One-quarter of patients (25.8%) were leukopenic within 30 days before implant, with 3.2% having moderate neutropenia. There were 2 infectious complications representing an infection rate of 0.9% (95% CI, 0.1%-3.3%), with limited shared characteristics between those experiencing SSI., Conclusions: SSI risk after IDDS placement for cancer pain is low, despite frequent concurrent antineoplastic therapy and leukopenia in the perioperative period. Concomitant cancer therapies should not be a barrier to the implementation of IDD for cancer pain.
- Published
- 2020
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18. A New Paroxetine-Based GRK2 Inhibitor Reduces Internalization of the μ -Opioid Receptor.
- Author
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Bouley RA, Weinberg ZY, Waldschmidt HV, Yen YC, Larsen SD, Puthenveedu MA, and Tesmer JJG
- Subjects
- Animals, Blotting, Western, Cell Membrane Permeability, Crystallography, X-Ray, Female, HEK293 Cells, Humans, Indazoles pharmacology, Mice, Microsomes, Liver drug effects, Microsomes, Liver metabolism, Molecular Structure, Pyrimidines pharmacology, Indazoles chemistry, Paroxetine chemistry, Pyrimidines chemistry, Receptors, Opioid, mu antagonists & inhibitors, Receptors, Opioid, mu metabolism
- Abstract
G protein-coupled receptor (GPCR) kinases (GRKs) play a key role in terminating signals initiated by agonist-bound GPCRs. However, chronic stimulation of GPCRs, such as that which occurs during heart failure, leads to the overexpression of GRKs and maladaptive downregulation of GPCRs on the cell surface. We previously reported the discovery of potent and selective families of GRK inhibitors based on either the paroxetine or GSK180736A scaffold. A new inhibitor, CCG258747 , which is based on paroxetine, demonstrates increased potency against the GRK2 subfamily and favorable pharmacokinetic parameters in mice. CCG258747 and the closely related compound CCG258208 also showed high selectivity for the GRK2 subfamily in a kinome panel of 104 kinases. We developed a cell-based assay to screen the ability of CCG258747 and 10 other inhibitors with different GRK subfamily selectivities and with either the paroxetine or GSK180736A scaffold to block internalization of the μ -opioid receptor (MOR). CCG258747 showed the best efficacy in blocking MOR internalization among the compounds tested. Furthermore, we show that compounds based on paroxetine had much better cell permeability than those based on GSK180736A , which explains why GSK180736A -based inhibitors, although being potent in vitro, do not always show efficacy in cell-based assays. This study validates the paroxetine scaffold as the most effective for GRK inhibition in living cells, confirming that GRK2 predominantly drives internalization of MOR in the cell lines we tested and underscores the utility of high-resolution cell-based assays for assessment of compound efficacy. SIGNIFICANCE STATEMENT: G protein-coupled receptor kinases (GRKs) are attractive targets for developing therapeutics for heart failure. We have synthesized a new GRK2 subfamily-selective inhibitor, CCG258747 , which has nanomolar potency against GRK2 and excellent selectivity over other kinases. A live-cell receptor internalization assay was used to test the ability of GRK2 inhibitors to impart efficacy on a GRK-dependent process in cells. Our data indicate that CCG258747 blocked the internalization of the μ -opioid receptor most efficaciously because it has the ability to cross cell membranes., (Copyright © 2020 by The American Society for Pharmacology and Experimental Therapeutics.)
- Published
- 2020
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19. Pregnancy or cord 25-hydroxyvitamin D is not associated with measures of body fat or adiposity in children from three months to three years of age. An Odense Child Cohort study.
- Author
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Larsen SD, Christensen ME, Dalgård C, Lykkedegn S, Andersen LB, Andersen MS, Glintborg D, and Christesen HT
- Subjects
- Adult, Age Factors, Biomarkers blood, Child, Preschool, Denmark, Female, Humans, Infant, Pediatric Obesity diagnosis, Pediatric Obesity physiopathology, Pregnancy, Prenatal Exposure Delayed Effects, Prospective Studies, Risk Assessment, Risk Factors, Vitamin D blood, Adiposity, Child Development, Fetal Blood metabolism, Pediatric Obesity etiology, Vitamin D analogs & derivatives
- Abstract
Background & Aims: The susceptibility to overweight in adults born during winter season may suggest foetal programming of prenatal vitamin D levels on adiposity. We investigated whether cord or pregnancy serum 25-hydroxyvitamin D (s-25OHD) was associated with infant and child body fat measures in a Danish population-based prospective cohort., Methods: In the Odense Child Cohort, 1905 singletons had cord s-25OHD and data on waist circumference (WC), weight, body mass index (BMI), and sum of skin folds (SSF) at median 3.7 months, 18.9 months and three years' age. Early and late pregnancy samples of s-25OHD (mean gestational age 12 and 29 weeks) were chosen as secondary exposures. Multiple linear and logistic regression as well as linear mixed models was applied testing the relation between cord and pregnancy s-25OHD and body fat outcomes and their Z-scores by use of updated national reference populations. Models were adjusted for maternal educational level, maternal ethnicity, pre-gestational BMI and season of birth, a priori stratified by sex., Results: The median [IQR] cord s-25OHD was 45.5 [31.1; 60.9] nmol/L. Cord s-25OHD <50 nmol/L was found in 57.5%; values < 25 nmol/L in 16.3%. The mean Z-scores of body fat measures at all ages were in the range of -0.32 to +0.42. No consistent associations were found between s-25OHD in cord, early pregnancy or late pregnancy and WC, weight, BMI, SSF, or their Z-scores at ages 3.7 months, 18.9 months, or 3 years. Neither did a computed composite outcome (WC, SSF, BMI, or weight >90th vs. ≤90 percentile) associate with cord or pregnancy s-25OHD., Conclusion: Cord or pregnancy s-25OHD was not associated with measures of body fat or adiposity in children up to three years of age. Our data suggested no programming effect of maternal s-25OHD on offspring obesity in a relatively lean and healthy population of mothers., (Copyright © 2019 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)
- Published
- 2020
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20. Rho-mediated signaling promotes BRAF inhibitor resistance in de-differentiated melanoma cells.
- Author
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Misek SA, Appleton KM, Dexheimer TS, Lisabeth EM, Lo RS, Larsen SD, Gallo KA, and Neubig RR
- Subjects
- Adaptor Proteins, Signal Transducing metabolism, Cell Line, Tumor, Enzyme Activation drug effects, Humans, Melanocytes drug effects, Melanocytes pathology, Transcription Factors metabolism, Transcription, Genetic drug effects, YAP-Signaling Proteins, Cell Dedifferentiation drug effects, Melanoma pathology, Protein Kinase Inhibitors pharmacology, Proto-Oncogene Proteins B-raf antagonists & inhibitors, Signal Transduction drug effects, rho-Associated Kinases metabolism
- Abstract
Over half of cutaneous melanoma tumors have BRAF
V600E/K mutations. Acquired resistance to BRAF inhibitors (BRAFi) remains a major hurdle in attaining durable therapeutic responses. In this study we demonstrate that ~50-60% of melanoma cell lines with vemurafenib resistance acquired in vitro show activation of RhoA family GTPases. In BRAFi-resistant melanoma cell lines and tumors, activation of RhoA is correlated with decreased expression of melanocyte lineage genes. Using a machine learning approach, we built gene expression-based models to predict drug sensitivity for 265 common anticancer compounds. We then projected these signatures onto the collection of TCGA cutaneous melanoma and found that poorly differentiated tumors were predicted to have increased sensitivity to multiple Rho kinase (ROCK) inhibitors. Two transcriptional effectors downstream of Rho, MRTF and YAP1, are activated in the RhoHigh BRAFi-resistant cell lines, and resistant cells are more sensitive to inhibition of these transcriptional mechanisms. Taken together, these results support the concept of targeting Rho-regulated gene transcription pathways as a promising therapeutic approach to restore sensitivity to BRAFi-resistant tumors or as a combination therapy to prevent the onset of drug resistance.- Published
- 2020
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21. Pre- and Post-Race Intestinal Microbiota in Long-Distance Sled Dogs and Associations with Performance.
- Author
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Tysnes KR, Angell IL, Fjellanger I, Larsen SD, Søfteland SR, Robertson LJ, Skancke E, and Rudi K
- Abstract
Although our understanding of the role of the gut microbiota in different diseases is improving, our knowledge regarding how the gut microbiota affects functioning in healthy individuals is still limited. Here, we hypothesize that the gut microbiota could be associated with sled dog endurance-race performance. We investigated the gut microbiota in 166 fecal samples from 96 Alaskan Huskies, representing 16 teams participating in the 2016 Femund Race (400 km) in Norway, relating the microbiota composition to performance and metadata derived from questionnaires. For 16S rRNA gene sequencing-derived compositional data, we found a strong negative association between Enterobacteriaceae (dysbiosis-associated) and Clostridium hiranonis (normobiosis-associated) . The teams with the best performances showed both the lowest levels of dysbiosis-associated bacteria prior to the race and the lowest change (decrease) in these bacteria after the race. Taken together, our results support the hypothesis that normobiosis-associated bacteria are involved in resilience mechanisms, potentially preventing growth of Enterobacteriaceae during the race., Competing Interests: The authors declare that they have no competing interests.
- Published
- 2020
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22. Structure-Based Design of Selective, Covalent G Protein-Coupled Receptor Kinase 5 Inhibitors.
- Author
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Rowlands RA, Cato MC, Waldschmidt HV, Bouley RA, Chen Q, Avramova L, Larsen SD, Tesmer JJG, and White AD
- Abstract
The ability of G protein-coupled receptor (GPCR) kinases (GRKs) to regulate desensitization of GPCRs has made GRK2 and GRK5 attractive targets for treating heart failure and other diseases such as cancer. Although advances have been made toward developing inhibitors that are selective for GRK2, there have been far fewer reports of GRK5 selective compounds. Herein, we describe the development of GRK5 subfamily selective inhibitors, 5 and 16d that covalently interact with a nonconserved cysteine (Cys474) unique to this subfamily. Compounds 5 and 16d feature a highly amenable pyrrolopyrimidine scaffold that affords high nanomolar to low micromolar activity that can be easily modified with Michael acceptors with various reactivities and geometries. Our work thereby establishes a new pathway toward further development of subfamily selective GRK inhibitors and establishes Cys474 as a new and useful covalent handle in GRK5 drug discovery., Competing Interests: The authors declare no competing financial interest., (Copyright © 2019 American Chemical Society.)
- Published
- 2019
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23. Correction to "Structure-Based Design of Highly Selective and Potent G Protein-Coupled Receptor Kinase 2 Inhibitors Based on Paroxetine".
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Waldschmidt HV, Homan KT, Cato MC, Cruz-Rodríguez O, Cannavo A, Wilson MW, Song J, Cheung JY, Koch WJ, Tesmer JJG, and Larsen SD
- Published
- 2019
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- View/download PDF
24. Synthesis of deuterium-labelled amlexanox and its metabolic stability against mouse, rat, and human microsomes.
- Author
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Gan X, Wilson MW, Beyett TS, Wen B, Sun D, Larsen SD, Tesmer JJG, Saltiel AR, and Showalter HD
- Subjects
- Aminopyridines chemistry, Aminopyridines pharmacology, Animals, Chemistry Techniques, Synthetic, Drug Stability, Humans, Isotope Labeling, Kinetics, Mice, Protein Serine-Threonine Kinases antagonists & inhibitors, Rats, Aminopyridines chemical synthesis, Aminopyridines metabolism, Deuterium chemistry, Microsomes metabolism
- Abstract
As part of a program toward making analogues of amlexanox (1), currently under clinical investigation for the treatment of type 2 diabetes and obesity, we have synthesized derivative 5 in which deuterium has been introduced into two sites of metabolism on the C-7 isopropyl function of amlexanox. The synthesis of 5 was completed in an efficient three-step process utilizing reduction of key olefin 7b to 8 by Wilkinson's catalyst to provide specific incorporation of di-deuterium across the double bond. Compound 5 displayed nearly equivalent potency to amlexanox (IC
50 , 1.1μM vs 0.6μM, respectively) against recombinant human TBK1. When incubated with human, rat, and mouse liver microsomes, amlexanox (1) and d2 -amlexanox (5) were stable (t1/2 > 60 minutes) with 1 showing marginally greater stability relative to 5 except for rat liver microsomes. These data show that incorporating deuterium into two sites of metabolism does not majorly suppress Cyp-mediated metabolism relative to amlexanox., (© 2019 John Wiley & Sons, Ltd.)- Published
- 2019
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25. 5-Aryl-1,3,4-oxadiazol-2-ylthioalkanoic Acids: A Highly Potent New Class of Inhibitors of Rho/Myocardin-Related Transcription Factor (MRTF)/Serum Response Factor (SRF)-Mediated Gene Transcription as Potential Antifibrotic Agents for Scleroderma.
- Author
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Kahl DJ, Hutchings KM, Lisabeth EM, Haak AJ, Leipprandt JR, Dexheimer T, Khanna D, Tsou PS, Campbell PL, Fox DA, Wen B, Sun D, Bailie M, Neubig RR, and Larsen SD
- Subjects
- Animals, Carboxylic Acids chemical synthesis, Carboxylic Acids pharmacokinetics, Connective Tissue Growth Factor metabolism, Enzyme Inhibitors chemical synthesis, Enzyme Inhibitors pharmacokinetics, Female, Fibrosis pathology, Mice, Inbred C57BL, Microsomes, Liver drug effects, Molecular Structure, Oxadiazoles chemical synthesis, Oxadiazoles pharmacokinetics, Scleroderma, Systemic drug therapy, Scleroderma, Systemic pathology, Signal Transduction drug effects, Skin pathology, Structure-Activity Relationship, Transcription, Genetic drug effects, rho GTP-Binding Proteins antagonists & inhibitors, Carboxylic Acids therapeutic use, Enzyme Inhibitors therapeutic use, Fibrosis drug therapy, Oxadiazoles therapeutic use, Serum Response Factor antagonists & inhibitors, Trans-Activators antagonists & inhibitors
- Abstract
Through a phenotypic high-throughput screen using a serum response element luciferase promoter, we identified a novel 5-aryl-1,3,4-oxadiazol-2-ylthiopropionic acid lead inhibitor of Rho/myocardin-related transcription factor (MRTF)/serum response factor (SRF)-mediated gene transcription with good potency (IC
50 = 180 nM). We were able to rapidly improve the cellular potency by 5 orders of magnitude guided by sharply defined and synergistic SAR. The remarkable potency and depth of the SAR, as well as the relatively low molecular weight of the series, suggests, but does not prove, that binding to the unknown molecular target may be occurring through a covalent mechanism. The series nevertheless has no observable cytotoxicity up to 100 μM. Ensuing pharmacokinetic optimization resulted in the development of two potent and orally bioavailable anti-fibrotic agents that were capable of dose-dependently reducing connective tissue growth factor gene expression in vitro as well as significantly reducing the development of bleomycin-induced dermal fibrosis in mice in vivo.- Published
- 2019
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26. Identification of Pirin as a Molecular Target of the CCG-1423/CCG-203971 Series of Antifibrotic and Antimetastatic Compounds.
- Author
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Lisabeth EM, Kahl D, Gopallawa I, Haynes SE, Misek SA, Campbell PL, Dexheimer TS, Khanna D, Fox DA, Jin X, Martin BR, Larsen SD, and Neubig RR
- Abstract
A series of compounds (including CCG-1423 and CCG-203971) discovered through an MRTF/SRF-dependent luciferase screen has shown remarkable efficacy in a variety of in vitro and in vivo models, including significant reduction of melanoma metastasis and bleomycin- induced fibrosis. Although these compounds are efficacious in these disease models, the molecular target is unknown. Here, we describe affinity isolation-based target identification efforts which yielded pirin, an iron-dependent cotranscription factor, as a target of this series of compounds. Using biophysical techniques including isothermal titration calorimetry and X-ray crystallography, we verify that pirin binds these compounds in vitro. We also show with genetic approaches that pirin modulates MRTF- dependent luciferase reporter activity. Finally, using both siRNA and a previously validated pirin inhibitor, we show a role for pirin in TGF- β - induced gene expression in primary dermal fibroblasts. A recently developed analog, CCG-257081, which co crystallizes with pirin, is also effective in the prevention of bleomycin-induced dermal fibrosis.
- Published
- 2019
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27. A Pan-ALDH1A Inhibitor Induces Necroptosis in Ovarian Cancer Stem-like Cells.
- Author
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Chefetz I, Grimley E, Yang K, Hong L, Vinogradova EV, Suciu R, Kovalenko I, Karnak D, Morgan CA, Chtcherbinine M, Buchman C, Huddle B, Barraza S, Morgan M, Bernstein KA, Yoon E, Lombard DB, Bild A, Mehta G, Romero I, Chiang CY, Landen C, Cravatt B, Hurley TD, Larsen SD, and Buckanovich RJ
- Subjects
- AC133 Antigen genetics, AC133 Antigen metabolism, Aldehyde Dehydrogenase 1 Family metabolism, Animals, Cell Line, Tumor, Drug Resistance, Neoplasm, Female, Humans, Mice, Neoplastic Stem Cells drug effects, Oxidative Phosphorylation, Retinal Dehydrogenase metabolism, Aldehyde Dehydrogenase 1 Family antagonists & inhibitors, Antineoplastic Agents pharmacology, Enzyme Inhibitors pharmacology, Necroptosis, Neoplastic Stem Cells metabolism, Ovarian Neoplasms metabolism, Retinal Dehydrogenase antagonists & inhibitors
- Abstract
Ovarian cancer is typified by the development of chemotherapy resistance. Chemotherapy resistance is associated with high aldehyde dehydrogenase (ALDH) enzymatic activity, increased cancer "stemness," and expression of the stem cell marker CD133. As such, ALDH activity has been proposed as a therapeutic target. Although it remains controversial which of the 19 ALDH family members drive chemotherapy resistance, ALDH1A family members have been primarily linked with chemotherapy resistant and stemness. We identified two ALDH1A family selective inhibitors (ALDH1Ai). ALDH1Ai preferentially kills CD133
+ ovarian cancer stem-like cells (CSCs). ALDH1Ai induce necroptotic CSC death, mediated, in part, by the induction of mitochondrial uncoupling proteins and reduction in oxidative phosphorylation. ALDH1Ai is highly synergistic with chemotherapy, reducing tumor initiation capacity and increasing tumor eradication in vivo. These studies link ALDH1A with necroptosis and confirm the family as a critical therapeutic target to overcome chemotherapy resistance and improve patient outcomes., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)- Published
- 2019
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28. Dual inhibition of Kif15 by oxindole and quinazolinedione chemical probes.
- Author
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Dumas ME, Chen GY, Kendrick ND, Xu G, Larsen SD, Jana S, Waterson AG, Bauer JA, Hancock W, Sulikowski GA, and Ohi R
- Subjects
- Dose-Response Relationship, Drug, Enzyme Inhibitors chemical synthesis, Enzyme Inhibitors chemistry, Humans, Kinesins metabolism, Molecular Probes chemical synthesis, Molecular Probes chemistry, Molecular Structure, Oxindoles chemical synthesis, Oxindoles chemistry, Quinazolinones chemical synthesis, Quinazolinones chemistry, Structure-Activity Relationship, Enzyme Inhibitors pharmacology, Kinesins antagonists & inhibitors, Molecular Probes pharmacology, Oxindoles pharmacology, Quinazolinones pharmacology
- Abstract
The mitotic spindle is a microtubule-based machine that segregates a replicated set of chromosomes during cell division. Many cancer drugs alter or disrupt the microtubules that form the mitotic spindle. Microtubule-dependent molecular motors that function during mitosis are logical alternative mitotic targets for drug development. Eg5 (Kinesin-5) and Kif15 (Kinesin-12), in particular, are an attractive pair of motor proteins, as they work in concert to drive centrosome separation and promote spindle bipolarity. Furthermore, we hypothesize that the clinical failure of Eg5 inhibitors may be (in part) due to compensation by Kif15. In order to test this idea, we screened a small library of kinase inhibitors and identified GW108X, an oxindole that inhibits Kif15 in vitro. We show that GW108X has a distinct mechanism of action compared with a commercially available Kif15 inhibitor, Kif15-IN-1 and may serve as a lead with which to further develop Kif15 inhibitors as clinically relevant agents., (Copyright © 2018. Published by Elsevier Ltd.)
- Published
- 2019
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29. Blood pressure in 3-year-old girls associates inversely with umbilical cord serum 25-hydroxyvitamin D: an Odense Child Cohort study.
- Author
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Larsen SD, Dalgård C, Christensen ME, Lykkedegn S, Andersen LB, Andersen M, Glintborg D, and Christesen HT
- Abstract
Background Low foetal vitamin D status may be associated with higher blood pressure (BP) in later life. Objective To examine whether serum 25-hydroxyvitamin D2+3 (s-25OHD) in cord and pregnancy associates with systolic and diastolic BP (SBP; DBP) in children up to 3 years of age. Design Prospective, population-based cohort study. Methods We included 1594 singletons from the Odense Child Cohort with available cord s-25OHD and BP data at median age 3.7 months (48% girls), 18.9 months (44% girls) or 3 years (48% girls). Maternal s-25OHD was also assessed at gestational ages 12 and 29 weeks. Multiple regression models were stratified by sex a priori and adjusted for maternal educational level, season of birth and child height, weight and age. Results In 3-year-old girls, SBP decreased with -0.7 mmHg (95% CI -1.1; -0.3, P = 0.001) and DBP with -0.4 mmHg (95% CI -0.7; -0.1, P = 0.016) for every 10 nmol/L increase in cord s-25OHD in adjusted analyses. Moreover, the adjusted odds of having SBP >90th percentile were reduced by 30% for every 10 nmol/L increase in cord s-25OHD (P = 0.004) and by 64% for cord s-25OHD above the median 45.1 nmol/L (P = 0.02). Similar findings were observed between pregnancy s-25OHD and 3-year SBP, cord s-25OHD and SBP at 18.9 months, and cord s-25OHD and DBP at 3 years. No consistent associations were observed between s-25OHD and BP in boys. Conclusion Cord s-25OHD was inversely associated with SBP and DBP in young girls, but not in boys. Higher vitamin D status in foetal life may modulate BP in young girls. The sex difference remains unexplained.
- Published
- 2018
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30. PPARγ-sparing thiazolidinediones as insulin sensitizers. Design, synthesis and selection of compounds for clinical development.
- Author
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Tanis SP, Colca JR, Parker TT, Artman GD 3rd, Larsen SD, McDonald WG, Gadwood RC, Kletzien RF, Zeller JB, Lee PH, and Adams WJ
- Subjects
- Dose-Response Relationship, Drug, Humans, Molecular Structure, PPAR gamma metabolism, Structure-Activity Relationship, Thiazolidinediones chemical synthesis, Thiazolidinediones chemistry, Drug Design, Insulin Resistance, PPAR gamma agonists, Thiazolidinediones pharmacology
- Published
- 2018
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- View/download PDF
31. In vitro and in vivo delivery of a sustained release nanocarrier-based formulation of an MRTF/SRF inhibitor in conjunctival fibrosis.
- Author
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Tagalakis AD, Madaan S, Larsen SD, Neubig RR, Khaw PT, Rodrigues I, Goyal S, Lim KS, and Yu-Wai-Man C
- Subjects
- Animals, Conjunctival Diseases drug therapy, Female, Fibroblasts drug effects, Fibrosis drug therapy, Humans, Liposomes chemistry, Nuclear Proteins antagonists & inhibitors, Nuclear Proteins chemistry, Rabbits, Tissue Distribution, Trans-Activators antagonists & inhibitors, Trans-Activators chemistry, Delayed-Action Preparations chemistry, Drug Delivery Systems, Serum Response Factor antagonists & inhibitors, Transcription Factors antagonists & inhibitors
- Abstract
Background: Sustained drug delivery is a large unmet clinical need in glaucoma. Here, we incorporated a Myocardin-Related Transcription Factor/Serum Response Factor inhibitor, CCG-222740, into slow release large unilamellar vesicles derived from the liposomes DOTMA (1,2-di-O-octadecenyl-3-trimethylammonium propane) and DOPC (1,2-dioleoyl-sn-glycero-3-phosphocholine), and tested their effects in vitro and in vivo., Results: The vesicles were spherical particles of around 130 nm and were strongly cationic. A large amount of inhibitor could be incorporated into the vesicles. We showed that the nanocarrier CCG-222740 formulation gradually released the inhibitor over 14 days using high performance liquid chromatography. Nanocarrier CCG-222740 significantly decreased ACTA2 gene expression and was not cytotoxic in human conjunctival fibroblasts. In vivo, nanocarrier CCG-222740 doubled the bleb survival from 11.0 ± 0.6 days to 22.0 ± 1.3 days (p = 0.001), decreased conjunctival scarring and did not have any local or systemic adverse effects in a rabbit model of glaucoma filtration surgery., Conclusions: Our study demonstrates proof-of-concept that a nanocarrier-based formulation efficiently achieves a sustained release of a Myocardin-Related Transcription Factor/Serum Response Factor inhibitor and prevents conjunctival fibrosis in an established rabbit model of glaucoma filtration surgery.
- Published
- 2018
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32. Structure-Based Optimization of a Novel Class of Aldehyde Dehydrogenase 1A (ALDH1A) Subfamily-Selective Inhibitors as Potential Adjuncts to Ovarian Cancer Chemotherapy.
- Author
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Huddle BC, Grimley E, Buchman CD, Chtcherbinine M, Debnath B, Mehta P, Yang K, Morgan CA, Li S, Felton J, Sun D, Mehta G, Neamati N, Buckanovich RJ, Hurley TD, and Larsen SD
- Subjects
- Aldehyde Dehydrogenase 1 Family, Animals, Cell Proliferation, Drug Discovery, Drug Screening Assays, Antitumor, Enzyme Inhibitors classification, Female, Humans, Mice, Neoplastic Stem Cells enzymology, Neoplastic Stem Cells pathology, Ovarian Neoplasms enzymology, Ovarian Neoplasms pathology, Retinal Dehydrogenase, Structure-Activity Relationship, Tumor Cells, Cultured, Xenograft Model Antitumor Assays, Aldehyde Dehydrogenase antagonists & inhibitors, Antineoplastic Agents pharmacology, Drug Resistance, Neoplasm drug effects, Drug Synergism, Enzyme Inhibitors chemistry, Enzyme Inhibitors pharmacology, Neoplastic Stem Cells drug effects, Ovarian Neoplasms drug therapy
- Abstract
Aldehyde dehydrogenase (ALDH) activity is commonly used as a marker to identify cancer stem-like cells. The three ALDH1A isoforms have all been individually implicated in cancer stem-like cells and in chemoresistance; however, which isoform is preferentially expressed varies between cell lines. We sought to explore the structural determinants of ALDH1A isoform selectivity in a series of small-molecule inhibitors in support of research into the role of ALDH1A in cancer stem cells. An SAR campaign guided by a cocrystal structure of the HTS hit CM39 (7) with ALDH1A1 afforded first-in-class inhibitors of the ALDH1A subfamily with excellent selectivity over the homologous ALDH2 isoform. We also discovered the first reported modestly selective single isoform 1A2 and 1A3 inhibitors. Two compounds, 13g and 13h, depleted the CD133
+ putative cancer stem cell pool, synergized with cisplatin, and achieved efficacious concentrations in vivo following IP administration. Compound 13h additionally synergized with cisplatin in a patient-derived ovarian cancer spheroid model.- Published
- 2018
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33. A novel inverse association between cord 25-hydroxyvitamin D and leg length in boys up to three years. An Odense Child Cohort study.
- Author
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Christensen ME, Beck-Nielsen SS, Dalgård C, Larsen SD, Lykkedegn S, Kyhl HB, Husby S, and Christesen HT
- Subjects
- Adult, Body Height, Body Mass Index, Child, Preschool, Cholecalciferol administration & dosage, Cohort Studies, Dietary Supplements, Female, Gestational Age, Humans, Infant, Linear Models, Male, Smoking, Vitamin D blood, Young Adult, Leg physiology, Vitamin D analogs & derivatives
- Abstract
Background and Aim: Long standing vitamin D deficiency in children causes rickets with growth impairment. We investigated whether sub-ischial leg length (SLL) is shorter, and cephalo-caudal length:length (CCL:L) ratio and sitting height:height (SH:H) ratio larger, with lower cord s-25-hydroxyvitamin D (25OHD) in the population-based prospective Odense Child Cohort, Denmark., Methods: We included healthy singletons born to term with available measures of cord 25OHD and anthropometrics up to three years' age. Linear regression was stratified by sex a priori and adjusted for maternal ethnicity, pre-pregnancy body mass index and smoking during pregnancy, season of blood sampling and child age., Results: Median (IQR) cord 25OHD was 48.0 (34.0-62.4) nmol/L. At mean age 19.1 months, n = 504, mean (SD) SLL was 31.7 (1.7) cm; CCL:L-ratio 0.62 (0.01). At 36.3 months, n = 956, mean SLL was 42.9 (2.0) cm; SH:H-ratio 0.56 (0.01). No participants had rickets. In adjusted analyses, 19-months-old boys had 0.1 cm shorter SLL (p = 0.009) and 0.1% higher CCL:L-ratio (p = 0.04) with every 10 nmol/L increase in cord 25OHD. Similar findings were seen for late pregnancy 25OHD. In the highest cord 25OHD quartile (>60.7 nmol/L), SLL was 0.8 cm shorter (95% C.I.: 1.36;-0.29, linear trend, p = 0.004), and CCL:L-ratio 0.8% higher (95% C.I. 8.0x10-05;0.01, linear trend, p = 0.01), compared to lowest quartile (<30.7 nmol/L). Similar associations with cord 25OHD were observed in 3-year-old boys. No consistent associations between 25OHD and anthropometrics were seen in girls at either age., Conclusion: No leg shortening was found with decreasing cord s-25OHD in a healthy population of infants. A small, yet significant inverse association between cord 25OHD and SLL in boys 1½-3 years warrants further investigations., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2018
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34. Optimization of dipeptidic inhibitors of cathepsin L for improved Toxoplasma gondii selectivity and CNS permeability.
- Author
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Zwicker JD, Diaz NA, Guerra AJ, Kirchhoff PD, Wen B, Sun D, Carruthers VB, and Larsen SD
- Subjects
- Animals, Antiprotozoal Agents metabolism, Antiprotozoal Agents pharmacology, Binding Sites, Blood-Brain Barrier drug effects, Blood-Brain Barrier metabolism, Catalytic Domain, Cathepsin L metabolism, Dipeptides metabolism, Dipeptides pharmacology, Half-Life, Humans, Inhibitory Concentration 50, Mice, Microsomes, Liver metabolism, Molecular Dynamics Simulation, Permeability drug effects, Protease Inhibitors metabolism, Protease Inhibitors pharmacology, Protozoan Proteins metabolism, Structure-Activity Relationship, Toxoplasma drug effects, Toxoplasma enzymology, Antiprotozoal Agents chemistry, Cathepsin L antagonists & inhibitors, Central Nervous System metabolism, Dipeptides chemistry, Protease Inhibitors chemistry, Protozoan Proteins antagonists & inhibitors
- Abstract
The neurotropic protozoan Toxoplasma gondii is the second leading cause of death due to foodborne illness in the US, and has been designated as one of five neglected parasitic infections by the Center for Disease Control and Prevention. Currently, no treatment options exist for the chronic dormant-phase Toxoplasma infection in the central nervous system (CNS). T. gondii cathepsin L (TgCPL) has recently been implicated as a novel viable target for the treatment of chronic toxoplasmosis. In this study, we report the first body of SAR work aimed at developing potent inhibitors of TgCPL with selectivity vs the human cathepsin L. Starting from a known inhibitor of human cathepsin L, and guided by structure-based design, we were able to modulate the selectivity for Toxoplasma vs human CPL by nearly 50-fold while modifying physiochemical properties to be more favorable for metabolic stability and CNS penetrance. The overall potency of our inhibitors towards TgCPL was improved from 2 μM to as low as 110 nM and we successfully demonstrated that an optimized analog 18b is capable of crossing the BBB (0.5 brain/plasma). This work is an important first step toward development of a CNS-penetrant probe to validate TgCPL as a feasible target for the treatment of chronic toxoplasmosis., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2018
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35. Utilizing a structure-based docking approach to develop potent G protein-coupled receptor kinase (GRK) 2 and 5 inhibitors.
- Author
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Waldschmidt HV, Bouley R, Kirchhoff PD, Lee P, Tesmer JJG, and Larsen SD
- Subjects
- Amides chemical synthesis, Amides chemistry, Dose-Response Relationship, Drug, G-Protein-Coupled Receptor Kinase 2 metabolism, G-Protein-Coupled Receptor Kinase 5 metabolism, Humans, Molecular Structure, Protein Kinase Inhibitors chemical synthesis, Protein Kinase Inhibitors chemistry, Structure-Activity Relationship, Amides pharmacology, G-Protein-Coupled Receptor Kinase 2 antagonists & inhibitors, G-Protein-Coupled Receptor Kinase 5 antagonists & inhibitors, Molecular Docking Simulation, Protein Kinase Inhibitors pharmacology
- Abstract
G protein-coupled receptor (GPCR) kinases (GRKs) regulate the desensitization and internalization of GPCRs. Two of these, GRK2 and GRK5, are upregulated in heart failure and are promising targets for heart failure treatment. Although there have been several reports of potent and selective inhibitors of GRK2 there are few for GRK5. Herein, we describe a ligand docking approach utilizing the crystal structures of the GRK2-Gβγ·GSK180736A and GRK5·CCG215022 complexes to search for amide substituents predicted to confer GRK2 and/or GRK5 potency and selectivity. From this campaign, we successfully generated two new potent GRK5 inhibitors, although neither exhibited selectivity over GRK2., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2018
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36. Gedunin- and Khivorin-Derivatives Are Small-Molecule Partial Agonists for Adhesion G Protein-Coupled Receptors GPR56/ADGRG1 and GPR114/ADGRG5.
- Author
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Stoveken HM, Larsen SD, Smrcka AV, and Tall GG
- Subjects
- Cell Adhesion, HEK293 Cells, High-Throughput Screening Assays, Humans, Limonins chemistry, Protein Binding, Receptors, G-Protein-Coupled metabolism, Signal Transduction, Structure-Activity Relationship, Receptors, G-Protein-Coupled agonists, Small Molecule Libraries
- Abstract
Adhesion G protein-coupled receptors (aGPCRs) have emerged as potential therapeutic targets in multiple cancers and in neurologic diseases. However, there are few modulatory compounds that act on these receptors. The majority of aGPCRs are orphans and a general activation mechanism has only recently been defined: aGPCRs are activated by a tethered agonist. aGPCRs constitutively cleave themselves during biosynthesis to generated two-part receptors comprising an extracellular domain (ECD) and a 7-transmembrane spanning domain (7TM). ECD dissociation reveals the tethered agonist initiating G protein signaling. Synthetic peptides that mimic the tethered agonist region can activate aGPCRs. We hypothesized that small molecules could act in the same way as peptide agonists. High throughput screening of the 2000-compound Spectrum Collection library using the serum response element luciferase gene reporter assay revealed two related classes of small molecules that could activate the aGPCR GPR56/ADGRG1. The most potent compound identified was 3- α -acetoxydihydrodeoxygedunin, or 3- α -DOG. 3- α -DOG activated engineered, low-activity GPR56 7TM in independent biochemical and cell-based assays with an EC
50 of ∼5 μ M. The compound also activated a subset of aGPCRs but not two class A GPCRs tested. The mode of 3- α -DOG-mediated receptor activation is that of partial agonist. 3- α -DOG activated GPR56 less efficaciously than peptide agonist and could antagonize both the peptide agonist and the endogenous tethered agonist, which are pharmacological hallmarks of partial agonists. Taken together, we have uncovered a novel group of aGPCR partial agonists that will serve as invaluable resources for understanding this unique class receptors., (Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.)- Published
- 2018
- Full Text
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37. Structural Determinants Influencing the Potency and Selectivity of Indazole-Paroxetine Hybrid G Protein-Coupled Receptor Kinase 2 Inhibitors.
- Author
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Bouley R, Waldschmidt HV, Cato MC, Cannavo A, Song J, Cheung JY, Yao XQ, Koch WJ, Larsen SD, and Tesmer JJG
- Subjects
- Animals, G-Protein-Coupled Receptor Kinase 2 pharmacology, Humans, Mice, Mice, Inbred C57BL, Models, Molecular, Selective Serotonin Reuptake Inhibitors, rho-Associated Kinases metabolism, G-Protein-Coupled Receptor Kinase 2 antagonists & inhibitors, G-Protein-Coupled Receptor Kinase 5 pharmacology, Indazoles pharmacology, Paroxetine pharmacology, Protein Kinase Inhibitors pharmacology
- Abstract
G protein-coupled receptor kinases (GRKs) phosphorylate activated receptors to promote arrestin binding, decoupling from heterotrimeric G proteins, and internalization. GRK2 and GRK5 are overexpressed in the failing heart and thus have become therapeutic targets. Previously, we discovered two classes of GRK2-selective inhibitors, one stemming from GSK180736A, a Rho-associated coiled-coil containing kinase 1 (ROCK1) inhibitor, the other from paroxetine, a selective serotonin-reuptake inhibitor. These two classes of compounds bind to the GRK2 active site in a similar configuration but contain different hinge-binding "warheads": indazole and benzodioxole, respectively. We surmised from our prior studies that an indazole would be the stronger hinge binder and would impart increased potency when substituted for benzodioxole in paroxetine derivatives. To test this hypothesis, we synthesized a series of hybrid compounds that allowed us to compare the effects of inhibitors that differ only in the identity of the warhead. The indazole-paroxetine analogs were indeed more potent than their respective benzodioxole derivatives but lost selectivity. To investigate how these two warheads dictate selectivity, we determined the crystal structures of three of the indazole hybrid compounds (CCG224061, CCG257284, and CCG258748) in complex with GRK2-G βγ Comparison of these structures with those of analogous benzodioxole-containing complexes confirmed that the indazole-paroxetine hybrids form stronger interactions with the hinge of the kinase but also stabilize a distinct conformation of the kinase domain of GRK2 compared with previous complexes with paroxetine analogs. This conformation is analogous to one that can be assumed by GRK5, at least partially explaining the loss in selectivity., (Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.)
- Published
- 2017
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38. Minor Structural Variations of Small Molecules Tune Regulatory Activities toward Pathological Factors in Alzheimer's Disease.
- Author
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Beck MW, Derrick JS, Suh JM, Kim M, Korshavn KJ, Kerr RA, Cho WJ, Larsen SD, Ruotolo BT, Ramamoorthy A, and Lim MH
- Subjects
- Alzheimer Disease metabolism, Alzheimer Disease pathology, Amyloid beta-Peptides antagonists & inhibitors, Amyloid beta-Peptides metabolism, Antioxidants chemical synthesis, Antioxidants chemistry, Cell Line, Tumor, Cell Survival drug effects, Humans, Molecular Structure, Oxidative Stress drug effects, Protein Aggregates drug effects, Small Molecule Libraries chemical synthesis, Small Molecule Libraries chemistry, Alzheimer Disease drug therapy, Antioxidants pharmacology, Small Molecule Libraries pharmacology
- Abstract
Chemical tools have been valuable for establishing a better understanding of the relationships between metal ion dyshomeostasis, the abnormal aggregation and accumulation of amyloid-β (Aβ), and oxidative stress in Alzheimer's disease (AD). Still, very little information is available to correlate the structures of chemical tools with specific reactivities used to uncover such relationships. Recently, slight structural variations to the framework of a chemical tool were found to drastically determine the tool's reactivities toward multiple pathological facets to various extents. Herein, we report our rational design and characterization of a structural series to illustrate the extent to which the reactivities of small molecules vary toward different targets as a result of minor structural modifications. These compounds were rationally and systematically modified based on consideration of properties, including ionization potentials and metal binding, to afford their desired reactivities with metal-free or metal-bound Aβ, reactive oxygen species (ROS), and free organic radicals. Our results show that although small molecules are structurally similar, they can interact with multiple factors associated with AD pathogenesis and alleviate their reactivities to different degrees. Together, our studies demonstrate the rational structure-directed design that can be used to develop chemical tools capable of regulating individual or interrelated pathological features in AD., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2017
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39. Optimisation of Intestinal Fibrosis and Survival in the Mouse S. Typhimurium Model for Anti-fibrotic Drug Discovery and Preclinical Applications.
- Author
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Johnson LA, Rodansky ES, Moons DS, Larsen SD, Neubig RR, and Higgins PDR
- Subjects
- Animals, Drug Discovery, Female, Fibrosis drug therapy, Fibrosis pathology, Mice, Mice, Inbred C57BL, Mice, Inbred CBA, Mice, Inbred DBA, Nipecotic Acids therapeutic use, Salmonella Infections, Animal complications, Survival Rate, Disease Models, Animal, Drug Evaluation, Preclinical, Fibrosis microbiology, Intestines pathology, Salmonella Infections, Animal microbiology, Salmonella typhimurium
- Abstract
Background and Aims: Intestinal fibrosis is a frequent complication in Crohn's disease [CD]. The mouse Salmonella typhimurium model, due to its simplicity, reproducibility, manipulability, and penetrance, is an established fibrosis model for drug discovery and preclinical trials. However, the severity of fibrosis and mortality are host- and bacterial strain-dependent, thus limiting the original model. We re-evaluated the S. typhimurium model to optimise fibrosis and survival, using commercially available mouse strains., Methods: Fibrotic and inflammatory markers were evaluated across S. typhimurium ΔaroA:C57bl/6 studies performed in our laboratory. A model optimisation study was performed using three commercially available mouse strains [CBA/J, DBA/J, and 129S1/SvImJ] infected with either SL1344 or ΔaroA S. typhimurium. Fibrotic penetrance was determined by histopathology, gene expression, and αSMA protein expression. Fibrosis severity, penetrance, and survival were analysed across subsequent CBA studies., Results: Fibrosis severity and survival are both host- and bacterial strain-dependent. Marked tissue fibrosis and 100% survival occurred in the CBA/J strain infected with SL1344. Subsequent experiments demonstrated that CBA/J mice develop extensive intestinal fibrosis, characterised by transmural tissue fibrosis, a Th1/Th17 cytokine response, and induction of pro-fibrotic genes and extracellular matrix proteins. A meta-analysis of subsequent SL1344:CBA/J studies demonstrated that intestinal fibrosis is consistent and highly penetrant across histological, protein, and gene expression markers. As proof-of-concept, we tested the utility of the SL1344:CBA/J fibrosis model to evaluate efficacy of CCG-203971, a novel anti-fibrotic drug., Conclusion: The S. typhimurium SL1344:CBA/J model is an optimised model for the study of intestinal fibrosis., (Published by Oxford University Press on behalf of European Crohn’s and Colitis Organisation (ECCO) 2016. This work is written by US Government employee and is in the public domain in the US.)
- Published
- 2017
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40. Histological and clinical evaluation of the hard palate mucous membrane graft for treatment of lower eyelid retraction.
- Author
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Larsen SD, Heegaard S, and Toft PB
- Subjects
- Adult, Aged, Biopsy, Eyelid Diseases pathology, Eyelids pathology, Female, Follow-Up Studies, Humans, Male, Middle Aged, Mouth Mucosa cytology, Retrospective Studies, Time Factors, Young Adult, Blepharoplasty methods, Eyelid Diseases surgery, Eyelids surgery, Mouth Mucosa transplantation, Palate, Hard cytology
- Abstract
Purpose: To evaluate the histological appearances of the epithelial cells and the clinical effect of the hard palate mucous membrane (HPM) graft for the treatment of lower eyelid retraction (LER)., Methods: This was a follow-up study involving 15 patients, with a total of 16 eyes operated. Five patients had LER as a result of Graves' ophthalmopathy and/or inferior rectus recession, six patients because of wearing an eye prosthesis, two patients because of previous tumour excision, one patient because of proptosis due to sphenoid wing meningioma and one patient because of previous lower eyelid blepharoplasty. Three imprint biopsies were taken from each patient, one from the tarsal conjunctiva in the healthy eye, one from the graft in the operated eye and one from unoperated hard palate. The inferior scleral show was measured on pre- and postoperative photographs and related to the horizontal corneal diameter., Results: Median follow-up time was 21.2 [range 4.5-87.9] months. Imprints from the graft and the hard palate showed equally large epithelial cells; imprints from conjunctiva showed small epithelial cells. The mean (±SD) scleral show was 0.12 ± 0.09 cornea diameter before surgery and 0.0003 ± 0.08 cornea diameter at invited follow-up (p < 0.001, paired t-test). Corrected for direction of gaze, the mean improvement in scleral show was 0.12 ± 0.08 cornea diameter. Thirteen of 14 patients were satisfied with the final result., Conclusion: A HPM graft for LER maintains its native epithelial morphology and gives a lasting improvement in most patients., (© 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)
- Published
- 2017
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41. Pharmacokinetic optimitzation of CCG-203971: Novel inhibitors of the Rho/MRTF/SRF transcriptional pathway as potential antifibrotic therapeutics for systemic scleroderma.
- Author
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Hutchings KM, Lisabeth EM, Rajeswaran W, Wilson MW, Sorenson RJ, Campbell PL, Ruth JH, Amin A, Tsou PS, Leipprandt JR, Olson SR, Wen B, Zhao T, Sun D, Khanna D, Fox DA, Neubig RR, and Larsen SD
- Subjects
- Administration, Oral, Animals, Disease Models, Animal, Fibrosis, HEK293 Cells, Humans, Mice, Nipecotic Acids administration & dosage, Nipecotic Acids chemistry, Rho Factor metabolism, Scleroderma, Systemic genetics, Scleroderma, Systemic metabolism, Scleroderma, Systemic pathology, Serum Response Element drug effects, Skin metabolism, Skin pathology, Trans-Activators antagonists & inhibitors, Trans-Activators metabolism, Nipecotic Acids pharmacokinetics, Nipecotic Acids therapeutic use, Rho Factor antagonists & inhibitors, Scleroderma, Systemic drug therapy, Skin drug effects, Transcriptional Activation drug effects
- Abstract
We recently reported the development of a novel inhibitor of Rho-mediated gene transcription (1, CCG-203971) that is efficacious in multiple animal models of acute fibrosis, including scleroderma, when given intraperitoneally. The modest in vivo potency and poor pharmacokinetics (PK) of this lead, however, make it unsuitable for long term efficacy studies. We therefore undertook a systematic medicinal chemistry effort to improve both the metabolic stability and the solubility of 1, resulting in the identification of two analogs achieving over 10-fold increases in plasma exposures in mice. We subsequently showed that one of these analogs (8f, CCG-232601) could inhibit the development of bleomycin-induced dermal fibrosis in mice when administered orally at 50mg/kg, an effect that was comparable to what we had observed earlier with 1 at a 4-fold higher IP dose., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
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42. Structure-Based Design of Highly Selective and Potent G Protein-Coupled Receptor Kinase 2 Inhibitors Based on Paroxetine.
- Author
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Waldschmidt HV, Homan KT, Cato MC, Cruz-Rodríguez O, Cannavo A, Wilson MW, Song J, Cheung JY, Koch WJ, Tesmer JJ, and Larsen SD
- Subjects
- Animals, Crystallography, X-Ray, G-Protein-Coupled Receptor Kinase 2 chemistry, G-Protein-Coupled Receptor Kinase 2 metabolism, Humans, Mice, Microsomes, Liver metabolism, Molecular Docking Simulation, Paroxetine blood, Paroxetine metabolism, Protein Kinase Inhibitors blood, Protein Kinase Inhibitors metabolism, Drug Design, G-Protein-Coupled Receptor Kinase 2 antagonists & inhibitors, Paroxetine analogs & derivatives, Paroxetine pharmacology, Protein Kinase Inhibitors chemistry, Protein Kinase Inhibitors pharmacology
- Abstract
In heart failure, the β-adrenergic receptors (βARs) become desensitized and uncoupled from heterotrimeric G proteins. This process is initiated by G protein-coupled receptor kinases (GRKs), some of which are upregulated in the failing heart, making them desirable therapeutic targets. The selective serotonin reuptake inhibitor, paroxetine, was previously identified as a GRK2 inhibitor. Utilizing a structure-based drug design approach, we modified paroxetine to generate a small compound library. Included in this series is a highly potent and selective GRK2 inhibitor, 14as, with an IC
50 of 30 nM against GRK2 and greater than 230-fold selectivity over other GRKs and kinases. Furthermore, 14as showed a 100-fold improvement in cardiomyocyte contractility assays over paroxetine and a plasma concentration higher than its IC50 for over 7 h. Three of these inhibitors, including 14as, were additionally crystallized in complex with GRK2 to give insights into the structural determinants of potency and selectivity of these inhibitors.- Published
- 2017
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43. Local delivery of novel MRTF/SRF inhibitors prevents scar tissue formation in a preclinical model of fibrosis.
- Author
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Yu-Wai-Man C, Spencer-Dene B, Lee RMH, Hutchings K, Lisabeth EM, Treisman R, Bailly M, Larsen SD, Neubig RR, and Khaw PT
- Subjects
- Animals, Cells, Cultured, Cicatrix prevention & control, Collagen metabolism, Disease Models, Animal, Drug Evaluation, Preclinical, Extracellular Matrix, Female, Fibroblasts drug effects, Fibroblasts metabolism, Fibrosis, Humans, Rabbits, Signal Transduction drug effects, Cicatrix metabolism, Cicatrix pathology, Serum Response Factor antagonists & inhibitors, Serum Response Factor metabolism, Trans-Activators antagonists & inhibitors, Trans-Activators metabolism
- Abstract
The myocardin-related transcription factor/serum response factor (MRTF/SRF) pathway represents a promising therapeutic target to prevent fibrosis. We have tested the effects of new pharmacological inhibitors of MRTF/SRF signalling in a preclinical model of fibrosis. CCG-222740, a novel MRTF/SRF inhibitor, markedly decreased SRF reporter gene activity and showed a greater inhibitory effect on MRTF/SRF target genes than the previously described MRTF-A inhibitor CCG-203971. CCG-222740 was also five times more potent, with an IC
50 of 5 μM, in a fibroblast-mediated collagen contraction assay, was less cytotoxic, and a more potent inhibitor of alpha-smooth muscle actin protein expression than CCG-203971. Local delivery of CCG-222740 and CCG-203971 in a validated and clinically relevant rabbit model of scar tissue formation after glaucoma filtration surgery increased the long-term success of the surgery by 67% (P < 0.0005) and 33% (P < 0.01), respectively, and significantly decreased fibrosis and scarring histologically. Unlike mitomycin-C, neither CCG-222740 nor CCG-203971 caused any detectable epithelial toxicity or systemic side effects with very low drug levels measured in the aqueous, vitreous, and serum. We conclude that inhibitors of MRTF/SRF-regulated gene transcription such as CCG-222740, potentially represent a new therapeutic strategy to prevent scar tissue formation in the eye and other tissues.- Published
- 2017
- Full Text
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44. Inhibitors of Mycobacterium tuberculosis DosRST signaling and persistence.
- Author
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Zheng H, Colvin CJ, Johnson BK, Kirchhoff PD, Wilson M, Jorgensen-Muga K, Larsen SD, and Abramovitch RB
- Subjects
- Artemisinins chemistry, Dose-Response Relationship, Drug, Drug Discovery, Histidine Kinase metabolism, Molecular Structure, Protein Kinase Inhibitors chemistry, Structure-Activity Relationship, Artemisinins pharmacology, Histidine Kinase antagonists & inhibitors, Mycobacterium tuberculosis enzymology, Protein Kinase Inhibitors pharmacology, Signal Transduction drug effects
- Abstract
The Mycobacterium tuberculosis (Mtb) DosRST two-component regulatory system promotes the survival of Mtb during non-replicating persistence (NRP). NRP bacteria help drive the long course of tuberculosis therapy; therefore, chemical inhibition of DosRST may inhibit the ability of Mtb to establish persistence and thus shorten treatment. Using a DosRST-dependent fluorescent Mtb reporter strain, a whole-cell phenotypic high-throughput screen of a ∼540,000 compound small-molecule library was conducted. The screen discovered novel inhibitors of the DosRST regulon, including three compounds that were subject to follow-up studies: artemisinin, HC102A and HC103A. Under hypoxia, all three compounds inhibit Mtb-persistence-associated physiological processes, including triacylglycerol synthesis, survival and antibiotic tolerance. Artemisinin functions by disabling the heme-based DosS and DosT sensor kinases by oxidizing ferrous heme and generating heme-artemisinin adducts. In contrast, HC103A inhibits DosS and DosT autophosphorylation activity without targeting the sensor kinase heme.
- Published
- 2017
- Full Text
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45. Pharmacological Inhibition of Myocardin-related Transcription Factor Pathway Blocks Lung Metastases of RhoC-Overexpressing Melanoma.
- Author
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Haak AJ, Appleton KM, Lisabeth EM, Misek SA, Ji Y, Wade SM, Bell JL, Rockwell CE, Airik M, Krook MA, Larsen SD, Verhaegen M, Lawlor ER, and Neubig RR
- Subjects
- Actins metabolism, Animals, Cell Cycle drug effects, Cell Line, Tumor, Cell Movement drug effects, Cell Proliferation drug effects, Disease Models, Animal, Disease Progression, Female, Gene Expression, Humans, Melanoma pathology, Mice, Neoplasm Metastasis, Nipecotic Acids pharmacology, Transcription, Genetic, Xenograft Model Antitumor Assays, rhoC GTP-Binding Protein, Antineoplastic Agents pharmacology, Lung Neoplasms secondary, Melanoma genetics, Melanoma metabolism, Signal Transduction drug effects, Trans-Activators antagonists & inhibitors, Trans-Activators metabolism, rho GTP-Binding Proteins genetics
- Abstract
Melanoma is the most dangerous form of skin cancer with the majority of deaths arising from metastatic disease. Evidence implicates Rho-activated gene transcription in melanoma metastasis mediated by the nuclear localization of the transcriptional coactivator, myocardin-related transcription factor (MRTF). Here, we highlight a role for Rho and MRTF signaling and its reversal by pharmacologic inhibition using in vitro and in vivo models of human melanoma growth and metastasis. Using two cellular models of melanoma, we clearly show that one cell type, SK-Mel-147, is highly metastatic, has high RhoC expression, and MRTF nuclear localization and activity. Conversely, SK-Mel-19 melanoma cells have low RhoC expression, and decreased levels of MRTF-regulated genes. To probe the dependence of melanoma aggressiveness to MRTF transcription, we use a previously developed small-molecule inhibitor, CCG-203971, which at low micromolar concentrations blocks nuclear localization and activity of MRTF-A. In SK-Mel-147 cells, CCG-203971 inhibits cellular migration and invasion, and decreases MRTF target gene expression. In addition, CCG-203971-mediated inhibition of the Rho/MRTF pathway significantly reduces cell growth and clonogenicity and causes G
1 cell-cycle arrest. In an experimental model of melanoma lung metastasis, the RhoC-overexpressing melanoma cells (SK-Mel-147) exhibited pronounced lung colonization compared with the low RhoC-expressing SK-Mel-19. Furthermore, pharmacologic inhibition of the MRTF pathway reduced both the number and size of lung metastasis resulting in a marked reduction of total lung tumor burden. These data link Rho and MRTF-mediated signaling with aggressive phenotypes and support targeting the MRTF transcriptional pathway as a novel approach to melanoma therapeutics. Mol Cancer Ther; 16(1); 193-204. ©2016 AACR., (©2016 American Association for Cancer Research.)- Published
- 2017
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46. Blockade of the renin-angiotensin system prevents acute and immunologically relevant colitis in murine models.
- Author
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Okawada M, Wilson MW, Larsen SD, Lipka E, Hillfinger J, and Teitelbaum DH
- Subjects
- Acute Disease, Angiotensin II Type 1 Receptor Blockers immunology, Angiotensin II Type 1 Receptor Blockers pharmacology, Angiotensin-Converting Enzyme Inhibitors immunology, Angiotensin-Converting Enzyme Inhibitors pharmacology, Animals, Colitis pathology, Cyclooxygenase Inhibitors immunology, Cyclooxygenase Inhibitors pharmacology, Disease Models, Animal, Enalaprilat immunology, Enalaprilat pharmacology, Losartan immunology, Mice, Mice, Inbred C57BL, Piroxicam immunology, Piroxicam pharmacology, Renin-Angiotensin System immunology, Colitis immunology, Colitis prevention & control, Losartan analogs & derivatives, Losartan pharmacology, Renin-Angiotensin System drug effects
- Abstract
Background: Blockade of the renin-angiotensin system (RAS) has been shown to alleviate inflammatory processes in the gastrointestinal tract. The aim of this study was to determine if blockade of the RAS would be effective in an immunologically relevant colitis model, and to compare outcome with an acute colitis model., Methods: A losartan analog, CCG-203025 (C
23 H26 ClN3 O5 S) containing a highly polar sulfonic acid moiety that we expected would allow localized mucosal antagonism with minimal systemic absorption was selected as an angiotensin II type 1a receptor antagonist (AT1aR-A). Two colitis models were studied: (1) Acute colitis was induced in 8- to 10-week-old C57BL/6J mice by 2.5 % dextran sodium sulfate (DSS, in drinking water) for 7 days. (2) IL10-/-colitis Piroxicam (200 ppm) was administered orally in feed to 5-week-old IL-10-/-mice (C57BL/6J background) for 14 days followed by enalaprilat (ACE-I), CCG-203025 or PBS administered transanally for 14 days., Results: In the DSS model, weight loss and histologic score for CCG-203025 were better than with placebo. In the IL10-/-model, ACE-I suppressed histologic damage better than CCG-203025. Both ACE-I and CCG-203025 reduced pro-inflammatory cytokines and chemokines., Conclusions: This study demonstrated the therapeutic efficacy of both ACE-I and AT1aR-A for preventing the development of both acute and immunologically relevant colitis.- Published
- 2016
- Full Text
- View/download PDF
47. CARP-1 functional mimetics are novel inhibitors of drug-resistant triple negative breast cancers.
- Author
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Cheriyan VT, Muthu M, Patel K, Sekhar S, Rajeswaran W, Larsen SD, Polin L, Levi E, Singh M, and Rishi AK
- Subjects
- Animals, Apoptosis drug effects, Apoptosis Regulatory Proteins genetics, Cell Cycle Proteins genetics, Cell Line, Tumor, Cell Movement drug effects, Cell Proliferation drug effects, Disease Models, Animal, Doxorubicin pharmacology, Female, Gene Expression Regulation, Neoplastic drug effects, Humans, MAP Kinase Signaling System drug effects, Mice, Protein Kinase Inhibitors chemistry, Protein Kinase Inhibitors pharmacology, Rats, Spiro Compounds chemistry, Spiro Compounds pharmacology, Thiadiazoles chemistry, Thiadiazoles pharmacology, Triple Negative Breast Neoplasms genetics, Xenograft Model Antitumor Assays, Apoptosis Regulatory Proteins metabolism, Biological Mimicry, Cell Cycle Proteins metabolism, Drug Resistance, Neoplasm drug effects, Triple Negative Breast Neoplasms metabolism
- Abstract
Doxorubicin and Cisplatin are the frontline therapeutics for treatment of the triple negative breast cancers (TNBCs). Emergence of drug-resistance often contributes to failure of drugs and poor prognosis, and thus necessitates development of new and improved modalities to treat TNBCs. We generated and characterized chemotherapy-resistant TNBC cells following their culture in chronic presence of Doxorubicin or Cisplatin, and tested whether their viabilities were inhibited by a novel class of CARP- 1 functional mimetic (CFM) compounds. Analogs of parent compound CFM-4 were obtained through structure-activity based medicinal chemistry studies. CFM-4.16, a novel analog of CFM-4, caused superior inhibition of viability of TNBC cells when used in combination with doxorubicin. Doxorubicin and cisplatin inhibited viabilities of parental cells with GI50 dose of 0.02-0.1 μM and 1.65 μM, respectively. The GI50 dose of doxorubicin for doxorubicin-resistant TNBC cells was ≥ 10.0 μM. For Cisplatin-resistant cells, the GI50 dose of Cisplatin was ≥ 6-15.0 μM for MDA-MB-468 sublines and ≥ 150.0 μM for MDA-MB-231 sublines. CFM-4.16 inhibited viability of chemotherapy-resistant TNBC cells, in part by inhibiting oncogenic cMet activation and expression, stimulating CARP-1 expression, caspase-8 cleavage and apoptosis. CFM-4.16 pretreatment enhanced anti-TNBC efficacies of inhibitors of cMET (Tevatinib) or cSrc (Dasatinib). CFM-4.16 suppressed growth of resistant TNBC cells in soft agar as well as in three-dimensional suspension cultures derived from enriched, stem-like cells. Finally, a nanolipid formulation of CFM-4.16 in combination with doxorubicin had superior efficacy in inhibiting TNBC xenograft growth. Our findings collectively demonstrate therapeutic potential of CFM-4.16 for parental and drug-resistant TNBCs.
- Published
- 2016
- Full Text
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48. Structure-mechanism-based engineering of chemical regulators targeting distinct pathological factors in Alzheimer's disease.
- Author
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Beck MW, Derrick JS, Kerr RA, Oh SB, Cho WJ, Lee SJ, Ji Y, Han J, Tehrani ZA, Suh N, Kim S, Larsen SD, Kim KS, Lee JY, Ruotolo BT, and Lim MH
- Subjects
- Alzheimer Disease genetics, Alzheimer Disease metabolism, Amyloid metabolism, Amyloid beta-Peptides metabolism, Animals, Drug Design, Free Radicals antagonists & inhibitors, Free Radicals metabolism, Humans, Metals antagonists & inhibitors, Metals metabolism, Mice, Inbred C57BL, Mice, Transgenic, Molecular Structure, Protein Aggregates drug effects, Reactive Oxygen Species antagonists & inhibitors, Reactive Oxygen Species metabolism, Small Molecule Libraries chemistry, Alzheimer Disease drug therapy, Amyloid antagonists & inhibitors, Amyloid beta-Peptides antagonists & inhibitors, Small Molecule Libraries pharmacology
- Abstract
The absence of effective therapeutics against Alzheimer's disease (AD) is a result of the limited understanding of its multifaceted aetiology. Because of the lack of chemical tools to identify pathological factors, investigations into AD pathogenesis have also been insubstantial. Here we report chemical regulators that demonstrate distinct specificity towards targets linked to AD pathology, including metals, amyloid-β (Aβ), metal-Aβ, reactive oxygen species, and free organic radicals. We obtained these chemical regulators through a rational structure-mechanism-based design strategy. We performed structural variations of small molecules for fine-tuning their electronic properties, such as ionization potentials and mechanistic pathways for reactivity towards different targets. We established in vitro and/or in vivo efficacies of the regulators for modulating their targets' reactivities, ameliorating toxicity, reducing amyloid pathology, and improving cognitive deficits. Our chemical tools show promise for deciphering AD pathogenesis and discovering effective drugs.
- Published
- 2016
- Full Text
- View/download PDF
49. Occludin S471 Phosphorylation Contributes to Epithelial Monolayer Maturation.
- Author
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Bolinger MT, Ramshekar A, Waldschmidt HV, Larsen SD, Bewley MC, Flanagan JM, and Antonetti DA
- Subjects
- Animals, Cell Proliferation, Dogs, Epithelial Cells metabolism, Humans, Madin Darby Canine Kidney Cells, Occludin chemistry, Occludin genetics, Phosphorylation, Protein Domains, Epithelial Cells cytology, G-Protein-Coupled Receptor Kinases metabolism, Occludin metabolism, Serine metabolism, Tight Junctions metabolism
- Abstract
Multiple organ systems require epithelial barriers for normal function, and barrier loss is a hallmark of diseases ranging from inflammation to epithelial cancers. However, the molecular processes regulating epithelial barrier maturation are not fully elucidated. After contact, epithelial cells undergo size-reductive proliferation and differentiate, creating a dense, highly ordered monolayer with high resistance barriers. We provide evidence that the tight junction protein occludin contributes to the regulation of epithelial cell maturation upon phosphorylation of S471 in its coiled-coil domain. Overexpression of a phosphoinhibitory occludin S471A mutant prevents size-reductive proliferation and subsequent tight junction maturation in a dominant manner. Inhibition of cell proliferation in cell-contacted but immature monolayers recapitulated this phenotype. A kinase screen identified G-protein-coupled receptor kinases (GRKs) targeting S471, and GRK inhibitors delayed epithelial packing and junction maturation. We conclude that occludin contributes to the regulation of size-reductive proliferation and epithelial cell maturation in a phosphorylation-dependent manner., (Copyright © 2016, American Society for Microbiology. All Rights Reserved.)
- Published
- 2016
- Full Text
- View/download PDF
50. Structure-Based Design, Synthesis, and Biological Evaluation of Highly Selective and Potent G Protein-Coupled Receptor Kinase 2 Inhibitors.
- Author
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Waldschmidt HV, Homan KT, Cruz-Rodríguez O, Cato MC, Waninger-Saroni J, Larimore KM, Cannavo A, Song J, Cheung JY, Kirchhoff PD, Koch WJ, Tesmer JJ, and Larsen SD
- Subjects
- Animals, Cattle, Cells, Cultured, Crystallography, X-Ray, Drug Design, Humans, Mice, Mice, Inbred C57BL, Protein Conformation, Protein Kinase Inhibitors chemical synthesis, Protein Kinase Inhibitors chemistry, Structure-Activity Relationship, rho-Associated Kinases antagonists & inhibitors, Protein Kinase Inhibitors pharmacology, Receptors, G-Protein-Coupled antagonists & inhibitors
- Abstract
G protein-coupled receptors (GPCRs) are central to many physiological processes. Regulation of this superfamily of receptors is controlled by GPCR kinases (GRKs), some of which have been implicated in heart failure. GSK180736A, developed as a Rho-associated coiled-coil kinase 1 (ROCK1) inhibitor, was identified as an inhibitor of GRK2 and co-crystallized in the active site. Guided by its binding pose overlaid with the binding pose of a known potent GRK2 inhibitor, Takeda103A, a library of hybrid inhibitors was developed. This campaign produced several compounds possessing high potency and selectivity for GRK2 over other GRK subfamilies, PKA, and ROCK1. The most selective compound, 12n (CCG-224406), had an IC50 for GRK2 of 130 nM, >700-fold selectivity over other GRK subfamilies, and no detectable inhibition of ROCK1. Four of the new inhibitors were crystallized with GRK2 to give molecular insights into the binding and kinase selectivity of this class of inhibitors.
- Published
- 2016
- Full Text
- View/download PDF
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