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Non-motor symptoms (NMS) of Parkinson's disease (PD), such as constipation, sleep disorders, and olfactory deficits, may emerge up to 20 years earlier than motor symptoms. A series of evidence indicates that the pathology of PD may occur from the gastrointestinal tract to the brain. Numerous studies support that the gut microbiota communicates with the brain through the immune system, special amino acid metabolism, and the nervous system in PD. Recently, there is growing recognition that the gut microbiota plays a vital role in the modulation of multiple neurochemical pathways via the "gut microbiota-brain axis" (GMBA). Many gut microbiota metabolites, such as fatty acids, amino acids, and bile acids, convey signaling functions as they mediate the crosstalk between gut microbiota and host physiology. Amino acids' abundance and species alteration, including glutamate and tryptophan, may disturb the signaling transmission between nerve cells and disrupt the normal basal ganglia function in PD. Specific amino acids and their receptors are considered new potential targets for ameliorating PD. The present study aimed to systematically summarize all available evidence on the gut microbiota-derived amino acid metabolism alterations associated with PD. [ABSTRACT FROM AUTHOR]

Osteoporosis is a systemic bone metabolism disorder, which increases the risk of fractures, and in severe cases it may cause disability or even death. An important factor contributing to osteoporosis is the imbalance between bone formation and resorption. Naringin was reported to promote osteoblast differentiation, thus enhancing bone formation and alleviating osteoporosis development. However, the signalling pathways related to the regulatory mechanism of naringin in osteoporosis development are not clear. Proliferation of bone mesenchymal stem cells (BMSCs) treated with naringin in vitro was detected by CCK‐8. An osteogenesis differentiation medium supplemented with naringin was applied to explore the effects of naringin on BMSC osteogenic differentiation, as detected by Alizarin red staining. Ovariectomy (OVX)‐induced postmenopausal osteoporosis (PMOP) rats were orally administered with naringin. Dual‐energy X‐ray absorptiometry (DEXA) and micro‐CT were applied to measure bone mineral density (BMD), bone volume/total volume (BV/TV), trabecula thickness (Tb.Th), trabecula number (Tb.N), trabecular separation (Tb.Sp) and bone surface/bone volume (BS/BV). H&E staining was performed to show pathological changes of the femur in PMOP rats after naringin treatment. Bone metabolism indicators were assessed by ELISA. We found that naringin suppressed the activation of the JAK2/STAT3 pathway. Naringin promoted BMSC proliferation and osteogenic differentiation. Furthermore, naringin alleviates bone loss and improves abnormal bone metabolism of PMOP rats. Collectively, naringin promotes BMSC osteogenic differentiation to ameliorate osteoporosis development by targeting JAK2/STAT3 signalling. [ABSTRACT FROM AUTHOR]

Mitochondrion is an organelle critically responsible for energy production and intracellular signaling in eukaryotic cells and its dysfunction often accompanies and contributes to human disease. Superoxide is the primary reactive oxygen species (ROS) produced in mitochondria. In vivo detection of superoxide has been a challenge in biomedical research. Here we describe the methods used to characterize a circularly permuted yellow fluorescent protein (cpYFP) as a biosensor for mitochondrial superoxide and pH dynamics. In vitro characterization reveals the high selectivity of cpYFP to superoxide over other ROS species and its dual sensitivity to pH. Confocal and two-photon imaging in conjunction with transgenic expression of the biosensor cpYFP targeted to the mitochondrial matrix detects mitochondrial flash events in living cells, perfused intact hearts, and live animals. The mitochondrial flashes are discrete and stochastic single mitochondrial events triggered by transient mitochondrial permeability transition (tMPT) and composed of a bursting superoxide signal and a transient alkalization signal. The real-time monitoring of single mitochondrial flashes provides a unique tool to study the integrated dynamism of mitochondrial respiration, ROS production, pH regulation and tMPT kinetics under diverse physiological and pathophysiological conditions. [ABSTRACT FROM AUTHOR]

Hypoxia-induced pulmonary hypertension (HPH) is a clinical syndrome associated with high morbidity and mortality. However, the underlying mechanisms remain unclear. Both the mammalian target of rapamycin (mTOR) and the Notch3 signaling pathways have been reported to be involved in HPH; however, it is unknown whether there is a connection between these two signaling pathways in HPH. This study was designed to investigate the relationship between mTOR and Notch3 in HPH. After treatment with 10% O2 for 4 weeks, male C57BL/6 mice developed HPH with gradually increased right ventricular systolic pressure (RVSP), right ventricular hypertrophy index (RVHI), and pulmonary arteriolar remodeling accompanied by the activation of mTOR complex 1 (mTORC1) and Notch3 in the lung tissue and pulmonary arterioles. Pretreatment with the mTORC1 inhibitor rapamycin not only alleviated pulmonary arterial pressure and pulmonary arteriolar remodeling but also suppressed hypoxia-induced mTORC1 and Notch3 activation. Prophylactic N-[ N-(3,5-difluorophenacetyl)- L-alanyl]- S-phenylglycine t-butyl ester (DAPT) administration, a Notch signaling inhibitor, protected against the effects of hypoxia. These in vivo data were confirmed by in vitro experiments on human pulmonary arterial smooth muscle cell (PASMC) exposed to 3% O2. Furthermore, overexpression of Notch3 intracellular domain partially abrogated the inhibitory effects of rapamycin on human PASMC proliferation. These data indicate that both mTORC1 and Notch3 signaling are involved in HPH and the downstream effects of mTORC1 activation in HPH are partially dependent on the activation of Notch3 signaling. J. Cell. Physiol. 229: 2117-2125, 2014. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Abstract: In this study, a combined proteomic and transcriptomic analysis was performed to understand the mechanisms underlying the immunomodulation induced by recombinant galectins of Haemonchus contortus (rHco-gal-m/f) on goat peripheral blood mononuclear cells (PBMC). We demonstrated that rHco-gal-m/f could be distinguished by antisera from goats experimentally infected with H. contortus and bound to the surface of goat PBMC. Following rHco-gal-m/f exposure, 16 differentially expressed proteins were identified, which function in biological processes such as stimulus response, biological regulation and localization. According to Gene Ontology Annotation, 15 proteins (93.8%) had binding activity and 9 proteins (56.3%) had catalytic activity. A series of transcriptomic analyses were performed subsequently to assess the expression change of certain pathway members. The integrated results of proteomic and transcriptomic analysis suggested that the activation of VEGF pathway, free radical producing pathway, NFκB pathway and ubiquitin–proteasome pathway was inhibited following exposure to rHco-gal-m/f, while the TLR pathway and CASPASE pathway were activated. Cytokine production and T cell differentiation were also influenced. Cell migration assays and ELISA were performed and the results were in accordance with the change of the proteins and genes. The protein and gene profiles determined here identified several mechanisms underlying the rHco-gal-m/f-induced immunomodulation of goat PBMC. Biological significance: This research provided insight into the interactive relationship between parasitic nematode galectins and host PBMC. It also shed new lights on the understanding of molecular mechanisms of helminthic immune evasion. [Copyright &y& Elsevier]

[Display omitted] • Three series of lathyrane diterpenoid derivatives with introduction of nitrogen-containing heterocyclic moieties were synthesized. • Among all derivatives, 23d showed the strongest anti-inflammatory activity on RAW264.7 cells. • 23d could inhibit Nrf2/HO-1 signaling pathway. As our ongoing work on lathyrane diterpenoid derivatization, three series of lathyrane diterpenoid derivatives were designed and synthesized based combination principles, including pyrazole, thiazole and furoxan moieties. Biological evaluation indicated that compound 23d exhibited excellently inhibitory activity on LPS-induced NO production in RAW264.7 cells (IC 50 = 0.38 ± 0.18 μM). The preliminary structure–activity relationships (SARs) suggested that phenylsulfonyl substituted furoxan moiety had the strongest ability to improve anti-inflammatory activity of lathyrane diterpenoids. Furthermore, compound 23d significantly reduced the level of ROS. Its molecular mechanism was related to inhibiting the transcriptional activation of Nrf2/HO-1 pathway. Based on these considerations, 23d might be a promising anti-inflammatory agent, which is noteworthy for further exploration. [ABSTRACT FROM AUTHOR]

The traditional Chinese medicine bufalin, extracted from toad's skin, has been demonstrated to exert anticancer activities in various kinds of human cancers. The mechanisms of action lie in its capacity to induce apoptosis, or termed type I programmed cell death (PCD). However, type II PCD, or autophagy, participates in cancer proliferation, progression, and relapse, as well. Recent studies on autophagy seem to be controversial because of the dual roles of autophagy in cancer survival and death. In good agreement with previous studies, we found that 100 nM bufalin induced extensive HepG2 cell apoptosis. However, we also noticed bufalin triggered autophagy and enhanced Beclin-1 expression, LC3-I to LC3-II conversion, as well as decreased p62 expression and mTOR signaling activation in HepG2 cells. Blockage of autophagy by selective inhibitor 3-MA decreased apoptotic ratio in bufalin-treated HepG2 cells, suggesting a proapoptotic role of bufalin-induced autophagy. Furthermore, we investigated the underlying mechanisms of bufalin-induced autophagy. Bufalin treatment dose-dependently promoted AMPK phosphorylation while AMPK inhibition by compound C significantly attenuated bufalin-induced autophagy. Taken together, we report for the first time that bufalin induces HepG2 cells PCD, especially for autophagy, and the mechanism of action is, at least in part, AMPK-mTOR dependent. [ABSTRACT FROM AUTHOR]

Aims Angiotensin-converting enzyme 2 (ACE2) is an important negative regulator of the renin-angiotensin system. Loss of ACE2 enhances the susceptibility to heart disease but the mechanism remains elusive. We hypothesized that ACE2 deficiency activates the NADPH oxidase system in pressure overload-induced heart failure. Methods and results Using the aortic constriction model, we subjected wild-type (Ace2+/y), ACE2 knockout (ACE2KO, Ace2−/y), p47phox knockout (p47phoxKO, p47phox−/−), and ACE2/p47phox double KO mice to pressure overload. We examined changes in peptide levels, NADPH oxidase activity, gene expression, matrix metalloproteinases (MMP) activity, pathological signalling, and heart function. Loss of ACE2 resulted in enhanced susceptibility to biomechanical stress leading to eccentric remodelling, increased pathological hypertrophy, and worsening of systolic performance. Myocardial angiotensin II (Ang II) levels were increased, whereas Ang 1–7 levels were lowered. Activation of Ang II-stimulated signalling pathways in the ACE2-deficient myocardium was associated with increased expression and phosphorylation of p47phox, NADPH oxidase activity, and superoxide generation, leading to enhanced MMP-mediated degradation of the extracellular matrix. Additional loss of p47phox in the ACE2KO mice normalized the increased NADPH oxidase activity, superoxide production, and systolic dysfunction following pressure overload. Ang 1–7 supplementation suppressed the increased NADPH oxidase and rescued the early dilated cardiomyopathy in pressure-overloaded ACE2KO mice. Conclusion In the absence of ACE2, biomechanical stress triggers activation of the myocardial NAPDH oxidase system with a critical role of the p47phox subunit. Increased production of superoxide, activation of MMP, and pathological signalling leads to severe adverse myocardial remodelling and dysfunction in ACE2KO mice. [ABSTRACT FROM PUBLISHER]

The heart is an excitable organ that undergoes spontaneous force generation and relaxation cycles driven by excitation–contraction (EC) coupling. A fraction of the oscillating cytosolic Ca 2 + during each heartbeat is taken up by mitochondria to stimulate mitochondrial metabolism, the major source of energy in the heart. Whether the mitochondrial metabolism is regulated individually during EC coupling and whether this heterogeneous regulation bears any physiological or pathological relevance have not been studied. Here, we developed a novel approach to determine the regulation of individual mitochondrial metabolism during cardiac EC coupling. Through monitoring superoxide flashes, which are stochastic and bursting superoxide production events arising from increased metabolism in individual mitochondria, we found that EC coupling stimulated the metabolism in individual mitochondria as indicated by significantly increased superoxide flash activity during electrical stimulation of the cultured intact myocytes or perfused heart. Mechanistically, cytosolic calcium transients promoted individual mitochondria to take up calcium via mitochondrial calcium uniporter, which subsequently triggered transient opening of the permeability transition pore and stimulated metabolism and bursting superoxide flash in that mitochondrion. The bursting superoxide, in turn, promoted local calcium release. In the early stage of heart failure, EC coupling regulation of superoxide flashes was compromised. This study highlights the heterogeneity in the regulation of cardiac mitochondrial metabolism, which may contribute to local redox signaling. [ABSTRACT FROM AUTHOR]

Kai Xin San (KXS), first proposed by Sun Simiao during the Tang Dynasty, has been utilized to treat dementia by tonifying qi and dispersing phlegm. This study aimed to elucidate the mechanism by which KXS exerts its therapeutic effects on Alzheimer's disease (AD) by targeting ferroptosis, using a combination of network pharmacology, bioinformatics, and experimental validation strategies. The active target sites and the further potential mechanisms of KXS in protecting against AD were investigated through molecular docking, molecular dynamics simulation, and network pharmacology, and combined with the validation of animal experiments. Computational and experimental findings provide the first indication that KXS significantly improves learning and memory defects and inhibits neuronal ferroptosis by repairing mitochondria damage and upregulating the protein expression of ferroptosis suppressor protein 1 (FSP1) in vivo APP/PS1 mice AD model. According to bioinformatics analysis, the mechanism by which KXS inhibits ferroptosis may involve SIRT1. KXS notably upregulated the mRNA and protein expression of SIRT1 in both vivo APP/PS1 mice and in vitro APP -overexpressed HT22 cells. Additionally, KXS inhibited ferroptosis induced by APP- overexpression in HT22 cells through activating the SIRT1-FSP1 signal pathway. Collectively, our findings suggest that KXS may inhibit neuronal ferroptosis through activating the SIRT1/FSP1 signaling pathway. This study reveals the scientific basis and underlying modern theory of replenishing qi and eliminating phlegm, which involves the inhibition of ferroptosis. Moreover, it highlights the potential application of SIRT1 or FSP1 activators in the treatment of AD and other ferroptosis-related diseases. Schematic representation of proposed mechanism of KXS on the protective effect of AD. [Display omitted] • Kai-Xin-San inhibits the neuronal ferroptosis in APP/PS1 transgenic AD mice and APP -overexpressed HT22 cells. • SIRT1 is the core of Kai-Xin-San's protein-protein interaction networks regulating ferroptosis. • Kai-Xin-San inhibits the neuronal ferroptosis through activating SIRT1-FSP1 signal pathway. [ABSTRACT FROM AUTHOR]

Abstract: Classical ischemia–reperfusion (IR) preconditioning relies on phosphatidylinositol 3-kinase (PI3K) for protective signaling. Surprisingly, inhibition of PI3Kα activity using a dominant negative (DN) strategy protected the murine heart from IR injury. It has been proposed that increased signaling through PI3Kγ may contribute to the improved recovery of PI3KαDN hearts following IR. To investigate the mechanism by which PI3KαDN hearts are protected from IR injury, we created a double mutant (PI3KDM) model by crossing p110γ−/– (PI3KγKO) with cardiac-specific PI3KαDN mice. The PI3KDM model has morphological and hemodynamic features that are characteristic of both PI3Kγ–/– and PI3KαDN mice. Interestingly, when subjected to IR using ex vivo Langendorff perfusion, PI3KDM hearts showed significantly enhanced functional recovery when compared to wildtype (WT) hearts. However, signaling downstream of PI3K through Akt and GSK3β, which has been associated with IR protection, was reduced in PI3KDM hearts. Using ex vivo working heart perfusion, we found no difference in functional recovery after IR between PI3KDM and PI3KαDN; also, glucose oxidation rates were significantly increased in PI3KαDN hearts when compared to WT, and this metabolic shift has been associated with enhanced IR recovery. However, we found that PI3KαDN hearts still had enhanced recovery when perfused exclusively with fatty acids (FA). We then investigated parallel signaling pathways, and found that mitogen-activated protein kinase signaling was increased in PI3KαDN hearts, possibly through the inhibition of negative feedback loops downstream of PI3Kα. [Copyright &y& Elsevier]

Ilex rotunda Thunb. (IR) is widely used for gastrointestinal diseases by Yao physician, and it has a better clinical curative effect on ulcerative colitis (UC). However, the main active components and mechanism of IR in the treatment of UC remain to be clarified. To investigate the main active components and mechanism of IR in the treatment of UC. Ten biological active components of IR were quantified by UPLC-MS/MS. In vitro , Caco2 cell monolayers were stimulated by lipopolysaccharide, and were treated with 10 biologically active components individually to investigate the protective role of the components of IR in mucosal barrier damage. In vivo , a mouse model of UC was induced by dextran sulfate sodium and administered with the candidate active components of IR. On day 8, the serum and colon tissue were collected for histological and molecular analysis to investigate the main active components and mechanism of IR. Ziyuglycoside I, ziyuglycoside II, syringin, and pedunculoside in IR reduced phenol red transmission of the monolayer, and inhibited the protein expression of oncostatin M and oncostatin M receptor in Caco2 cells. Notably, ziyuglycoside II and syringin decreased the transepithelial electrical resistance of the monolayer, and promoted the protein expression of Occludin, Claudin-1 and zonula occludens-1 (ZO-1) in Caco2 cells. In vivo , ziyuglycoside II and syringin improved the symptoms of UC mice, including body weight, disease activity score, shortening of colon length, damaging of acidic mucus layer, histopathological changes, and protein expression of Occludin, Claudin-1, and ZO-1. Pedunculoside reduced the neutrophils and inflammatory response in the UC mice. Moreover, when the combination of ziyuglycoside II, syringin and pedunculoside was used for the treatment of UC, syringin and pedunculoside enhanced the therapeutic effect of ziyuglycoside II. Finally, RNA sequencing and RT-qPCR analysis revealed that ziyuglycoside II + syringin + pedunculoside and IR coregulated up to 42.7% of genes, and mainly reduced the overexpression of C-X-C motif ligand 1(CXCL1), oncostatin M receptor (OSMR), interleukin 1 receptor type I (IL1R1), tumor necrosis factor receptor superfamily member 9 (TNFRSF9), C-X-C motif chemokine 13 (CXCL13), oncostatin M (OSM), and interleukin 6 (IL-6) in the cytokine-cytokine interaction pathways. The combination of ziyuglycoside II, syringin, and pedunculoside protects against UC by modulating the intestinal mucosal barrier and inhibiting the cytokine-cytokine interaction pathways, and the effect is relatively equivalent to that of the water extract of Ilex rotunda Thunb. [Display omitted] • Ilex rotunda Thunb. (IR) has been demonstrated that has an obvious effect on the treatment of ulcerative colitis (UC) mice. • Ziyuglycoside I (ZiyuI), Ziyuglycoside II (ZiyuII), syringin (SYR), and pedunculoside (PE) are the candidate active components of IR according to the research in vitro. • ZiyuII, SYR, and PE are the main active components of IR in the treatment of UC mice, and the ZiyuII, SYR, and PE used in combination is relatively equivalent to the IR in the treatment of UC mice. • IR and the compositions of ZiyuII + SYR + PE protect against UC by restoring the intestinal mucosal barrier and modulating the cytokine-cytokine interaction pathways. [ABSTRACT FROM AUTHOR]

Phosphatidylinositide 3-kinase (PI3K) signaling plays a critical role in maintaining normal cardiac structure and function. PI3Kα and PI3Kγ are the dominant cardiac isoforms and have both adaptive and maladaptive roles in heart disease. Broad spectrum PI3K inhibitors are emerging as potential new chemotherapeutic agents which may have deleterious long-term effects on the heart. We created a double mutant (PI3KDM) model by crossing p110γ −/− (PI3KγKO) with cardiac-specific PI3KαDN mice and studied cardiac structure and function at 1-year of age. Pressure–volume loop analysis and echocardiographic assessment showed PI3KDM mice developed marked impairment in systolic function while the wildtype, PI3KαDN, and PI3KγKO mice maintained normal systolic and diastolic function at 1-year of age. The PI3KDM hearts displayed increased expression of disease markers, increased myocardial fibrosis and matrix metalloproteinase (MMP) activity, depolymerization of intracellular F-actin, loss of phospho(threonine-308)-Akt, and normalization of phospho-Erk1/2 signaling. Dual loss of PI3Kα and PI3Kγ isoforms results in an age-dependent cardiomyopathy implying that long-term exposure to pan-PI3K inhibitors may lead to severe cardiotoxicity. [ABSTRACT FROM AUTHOR]

Aims: Mitochondrial Ca2+ homeostasis is crucial for balancing cell survival and death. The recent discovery of the molecular identity of the mitochondrial Ca2+ uniporter pore (MCU) opens new possibilities for applying genetic approaches to study mitochondrial Ca2+ regulation in various cell types, including cardiac myocytes. Basal tyrosine phosphorylation of MCU was reported from mass spectroscopy of human and mouse tissues, but the signaling pathways that regulate mitochondrial Ca2+ entry through posttranslational modifications of MCU are completely unknown. Therefore, we investigated α1-adrenergic-mediated signal transduction of MCU posttranslational modification and function in cardiac cells. Results: α1-adrenoceptor (α1-AR) signaling translocated activated proline-rich tyrosine kinase 2 (Pyk2) from the cytosol to mitochondrial matrix and accelerates mitochondrial Ca2+ uptake via Pyk2-dependent MCU phosphorylation and tetrametric MCU channel pore formation. Moreover, we found that α1-AR stimulation increases reactive oxygen species production at mitochondria, mitochondrial permeability transition pore activity, and initiates apoptotic signaling via Pyk2-dependent MCU activation and mitochondrial Ca2+ overload. Innovation: Our data indicate that inhibition of α1-AR-Pyk2-MCU signaling represents a potential novel therapeutic target to limit or prevent mitochondrial Ca2+ overload, oxidative stress, mitochondrial injury, and myocardial death during pathophysiological conditions, where chronic adrenergic stimulation is present. Conclusion: The α1-AR-Pyk2-dependent tyrosine phosphorylation of the MCU regulates mitochondrial Ca2+ entry and apoptosis in cardiac cells. Antioxid. Redox Signal. 21, 863-879. [ABSTRACT FROM AUTHOR]