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Previous studies have reported a strong association between gut microbiome and hypertension; yet, the exact bacterial species associated with the disease development and progression have not yet been detected. This study aimed to investigate whether opportunistic pathogenThe enrichment ofThese results provide evidence that the enrichment of

Hyperglycemia associated with diabetes mellitus (DM) causes oxidative stress, which is involved in the onset and development of diabetic neuropathy. Taurine, a powerful antioxidant, is an effective inhibitor of oxidative stress. The present experiment was conducted to explore the effect of taurine treatment on alterations in body weight, blood glucose, oxidative stress, and Keap1-Nrf2 signaling in the spinal cords of DM rats. The DM rat model was established by STZ injection, and taurine was administered in the drinking water. Body weight and blood glucose were recorded during the experiment. The expression of Gap-43 and MBP proteins was examined by Western blot. Superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were examined as indicators of oxidative stress. The expression of Keap1, Nrf2, and HO-1 gene was examined by real-time PCR. The results showed that compared with the control group, the body weight was decreased, blood glucose was increased, and both Gap-43 and MBP expression were decreased in DM rats, which were all remarkably reversed by taurine treatment. Oxidative stress, as reflected by lower SOD activity and higher MDA concentration, was inhibited in taurine-treated DM rats. Supplemental taurine also downregulated the mRNA level of Keap1, while upregulating Nrf2 and HO-1 mRNA levels. These results showed that taurine inhibits oxidative stress in the spinal cords of DM rats, an effect that might involve the regulation of Keap1-Nrf2 signaling.

Diabetic nephropathy is one of the major diabetic complications which has become the major cause of end-stage renal disease. It has been demonstrated that apoptosis induced by hyperglycemia is a critical factor in the pathophysiology of diabetic nephropathy. Taurine is a semi-essential amino acid in mammals and has been shown to be a potent endogenous antioxidant. The protective effect of taurine against apoptosis in diabetic kidney deserves to be explored. In the present study, mRNA expression of cysteinyl aspartate-specific proteinase-3 (caspase-3) and caspase-9 was examined, and the activity of caspase-3 was also detected as the marker of apoptosis. The expression of Bax and Bcl-2 was detected by Western blot. In addition, the level of total Akt and phosphorylated Akt (p-Akt) was measured. We found that caspase-3 and caspase-9 mRNA expression was decreased in diabetic kidney, which was recovered by taurine treatment. The activity of caspase-3 was increased in diabetic kidney, while the increased activity was significantly attenuated after taurine treatment. We also found that the expressions of Bax and Bcl-2 were disturbed in diabetic kidney, which were reversed by taurine treatment. The decrease of the p-Akt level was also prevented by taurine treatment. These results indicated that taurine-ameliorated apoptosis in diabetic kidney may be through activating of the Akt signaling pathway.

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes and axonopathy is its main pathological feature. Previous studies suggested an advantage of taurine against diabetes. However, there are few reports which study the effect of taurine against axonopathy. In this study, we confirmed that taurine significantly decreased blood glucose level, mitigated insulin resistance and improved dysfunctional nerve conduction in diabetic rats. Taurine corrected damaged axonal morphology of sciatic nerve in diabetic rats and induced axon outgrowth of Dorsal root ganglion (DRG) neurons exposed to high glucose. Taurine up-regulated phosphorylation levels of PI3K, Akt, and mTOR in sciatic nerve of diabetic rats and DRG neurons exposed to high glucose. However, Akt and mTOR inhibitors (MK-2206 and Rapamycin) blocked the effect of taurine on improving axonal damage. These results indicate that taurine ameliorates axonal damage in sciatic nerve of diabetic rats by activating PI3K/Akt/mTOR signal pathway. Our findings provide taurine as a potential candidate for axonopathy and a new evidence for elucidating protective mechanism of taurine on DPN.

Although some co-risk factors and hemodynamic alterations are involved in hypertension progression, their direct biomechanical effects are unclear. Here, we constructed a high-hydrostatic-pressure cell-culture system to imitate constant hypertension and identified novel molecular classifications of human aortic smooth muscle cells (HASMCs) by single-cell transcriptome analysis. Under 100-mmHg (analogous to healthy human blood pressure) or 200-mmHg (analogous to hypertension) hydrostatic pressure for 48 h, HASMCs showed six distinct vascular SMC (VSMC) clusters according to differential gene expression and gene ontology enrichment analysis. Especially, two novel HASMC subsets were identified, named the inflammatory subset, with CXCL2, CXCL3 and CCL2 as markers, and the endothelial-function inhibitory subset, with AKR1C2, AKR1C3, SERPINF1 as markers. The inflammatory subset promoted CXCL2&3 and CCL2 chemokine expression and secretion, triggering monocyte migration; the endothelial-function inhibitory subset secreted SERPINF1 and accelerated prostaglandin F2α generation to inhibit angiogenesis. The expression of the two VSMC subsets was greatly increased in arterial media from patients with hypertension and experimental animal models of hypertension. Collectively, we identified high hydrostatic pressure directly driving VSMCs into two new subsets, promoting or exacerbating endothelial dysfunction, thereby contributing to the pathogenesis of cardiovascular diseases.

Type 2 Diabetes causes learning and memory deficits that might be mediated by hippocampus neuron apoptosis. Studies found that taurine might improve cognitive deficits under diabetic condition because of its ability to prevent hippocampus neuron apoptosis. However, the effect and mechanism is not clear. In this study, we explore the effect and mechanism of taurine on inhibiting hippocampus neuron apoptosis. Sixty male Sprague-Dawley rats were randomly divided into control, T2D, taurine treatment (giving 0.5%, 1%, and 2% taurine in drinking water) groups. Streptozotocin was used to establish the diabetes model. HT-22 cell (hippocampus neurons line) was used for in vitro experiments. Morris Water Maze test was used to check the learning and memory ability, TUNEL assay was used to measure apoptosis and nerve growth factor (NGF); Akt/Bad pathway relevant protein was detected by western blot. Taurine improved learning and memory ability and significantly decreased apoptosis of the hippocampus neurons in T2D rats. Moreover, taurine supplement also inhibited high glucose-induced apoptosis in HT-22 cell in vitro. Mechanistically, taurine increased the expression of NGF, phosphorylation of Trka, Akt, and Bad, as well as reduced cytochrome c release from mitochondria to cytosol. However, beneficial effects of taurine were blocked in the presence of anti-NGF antibody or Akt inhibitor. Taurine could inhibit hippocampus neuron apoptosis via NGF-Akt/Bad pathway. These results provide some clues that taurine might be efficient and feasible candidate for improvement of learning and memory ability in T2D rats.

The majority of risk loci identified by genome-wide association studies (GWAS) are in non-coding regions, hampering their functional interpretation. Instead, transcriptome-wide association studies (TWAS) identify gene-trait associations, which can be used to prioritize candidate genes in disease-relevant tissue(s). Here, we aimed to systematically identify susceptibility genes for coronary artery disease (CAD) by TWAS. We trained prediction models of nine CAD-relevant tissues using EpiXcan based on two genetics-of-gene-expression panels, the Stockholm-Tartu Atherosclerosis Reverse Network Engineering Task (STARNET) and the Genotype-Tissue Expression (GTEx). Based on these prediction models, we imputed gene expression of respective tissues from individual-level genotype data on 37,997 CAD cases and 42,854 controls for the subsequent gene-trait association analysis. Transcriptome-wide significant association (i.e. P RGS19 and KPTN, in a human hepatocyte cell line resulted in reduced secretion of APOB100 and lipids in the cell culture medium. Our CAD TWAS work (i) prioritized candidate causal genes at known GWAS loci, (ii) identified 18 novel genes to be associated with CAD, and iii) suggested potential tissues and pathways of action for these TWAS CAD genes.

Background N-hexane, with its metabolite 2,5-hexanedine (HD), is an industrial hazardous material. Chronic hexane exposure causes segmental demyelination in the peripheral nerves, and high-dose intoxication may also affect central nervous system. Demyelinating conditions are difficult to treat and stem cell therapy using bone marrow mesenchymal stem cells (BMSCs) is a promising novel strategy. Our previous study found that BMSCs promoted motor function recovery in rats modeling hexane neurotoxicity. This work aimed to explore the underlying mechanisms and focused on the changes in spinal cord. Methods Sprague Dawley rats were intoxicated with HD (400 mg/kg/day, i.p, for 5 weeks). A bolus of BMSCs (5 × 107 cells/kg) was injected via tail vein. Demyelination and remyelination of the spinal cord before and after BMSC treatment were examined microscopically. Cultured oligodendrocyte progenitor cells (OPCs) were incubated with HD ± BMSC-derived conditional medium (BMSC-CM). OPC differentiation was studied by immunostaining and morphometric analysis. The expressional changes of Hes1, a transcription factor negatively regulating OPC-differentiation, were studied. The upstream Notch1 and TNFα/RelB pathways were studied, and some key signaling molecules were measured. The correlation between neurotrophin NGF and TNFα was also investigated. Statistical significance was evaluated using one-way ANOVA and performed using SPSS 13.0. Results The demyelinating damage by HD and remyelination by BMSCs were evidenced by electron microscopy, LFB staining and NG2/MBP immunohistochemistry. In vitro cultured OPCs showed more differentiation after incubation with BMSC-CM. Hes1 expression was found to be significantly increased by HD and decreased by BMSC or BMSC-CM. The change of Hes1 was found, however, independent of Notch1 activation, but dependent on TNFα/RelB signaling. HD was found to increase TNFα, RelB and Hes1 expression, and BMSCs were found to have the opposite effect. Addition of recombinant TNFα to OPCs or RelB overexpression similarly caused upregulation of Hes1 expression. The secretion of NGF by BMSC and activation of NGF receptor was found important for suppression of TNFα production in OPCs. Conclusions Our findings demonstrated that BMSCs promote remyelination in the spinal cord of HD-exposed rats via TNFα/RelB-Hes1 pathway, providing novel insights for evaluating and further exploring the therapeutical effect of BMSCs on demyelinating neurodegenerative disease.

Vascular smooth muscle cell (VSMC) phenotypic switch plays an essential role in the pathogenesis of hypertension. Mitochondrial dynamics, such as mitochondrial fission, can also contribute to VSMC phenotypic switch. Whether mitochondrial fission act as a novel target for anti-hypertensive drug development remains unknown. In the present study, we confirmed that angiotensin II (AngII) rapidly and continuously induced mitochondrial fission in VSMCs. We also detected the phosphorylation status of dynamin-related protein-1 (Drp1), a key protein involved in mitochondrial fission, at Ser616 site; and observed Drp1 mitochondrial translocation in VSMCs or arteries of AngII-induced hypertensive mice. The Drp1 inhibitor mitochondrial division inhibitor-1 (Mdivi-1) dramatically reversed AngII-induced Drp1 phosphorylation, mitochondrial fission, and reactive oxidative species generation. Treatment with Mdivi-1 (20 mg/kg/every other day) significantly attenuated AngII-induced hypertension (22 mmHg), arterial remodeling, and cardiac hypertrophy, in part by preventing VSMC phenotypic switch. In addition, Mdivi-1 treatment was not associated with liver or renal functional injury. Collectively, these results indicate that Mdivi-1 inhibited mitochondrial fission, recovered mitochondrial activity, and prevented AngII-induced VSMC phenotypic switch, resulting in reduced hypertension.

Background and purpose Hydrogen sulfide donors can block the cardiovascular injury of hyperhomocysteinemia. H2 S also lowers serum homocysteine in rats with mild hyperhomocysteinemia, but the pharmacological mechanism is unknown. The present study investigated the mechanism(s) involved. Experimental approach ApoE-knockout mice were fed a Paigen diet and L-methionine in drinking water for 16 weeks to create a mouse model of atherosclerosis with hyperhomocysteinemia. H2 S donors (NaHS and GYY4137) were administered by intraperitoneal injection. We also assayed the H2 S produced (by methylene blue assay and mito-HS [H2 S fluorescence probe]), cystathionine γ lyase (CSE) mRNA and protein expression, and CSE sulfhydration and nitrosylation and its activity. Key results H2 S donor treatment significantly lowered atherosclerotic plaque area, macrophage infiltration, and serum homocysteine level in the mouse model of atherosclerosis with co-existing hyperhomocysteinemia. mRNA and protein levels of CSE, a key enzyme catalyzing homocysteine trans-sulfuration, were down-regulated with hyperhomocysteinemia, and CSE catalytic activity was inhibited. All these effects were reversed with H2 S donor treatment. Hyperhomocysteinemia induced CSE nitrosylation, whereas H2 S sulfhydrated CSE at the same cysteine residues. Nitrosylated CSE decreased and sulfhydrated CSE increased its catalytic and binding activities towards L-homocysteine. Mutation of C252, C255, C307, and C310 residues in CSE abolished CSE nitrosylation or sulfhydration and prevented its binding to L-homocysteine. Conclusions and implications Sulfhydration or nitrosylation of CSE represents a yin/yang regulation of catalysis or binding to L-homocysteine. H2 S donor treatment enhanced CSE sulfhydration, thus lowering serum L-homocysteine, which contributed in part to the anti-atherosclerosis effects in ApoE-knockout mice with hyperhomocysteinemia.

Protein S-nitrosylation plays an important role in the progression of cardiovascular diseases. eNOS can be S-nitrosylated in endothelial cells, and this modification reversibly attenuates enzyme activity. Under physiological conditions, eNOS directly interacts with β‑catenin. However, whether and how eNOS S-nitrosylation regulates the β‑catenin signal pathway and participates in endothelial dysfunction remains unknown. Here, we show that OxLDL induces the S-nitrosylation of eNOS, which enhances the interaction between eNOS and β‑catenin, transcriptional activity of β‑catenin, cell migration and adhesion molecule expression in endothelial cells. In addition, these effects are partially abolished after eNOS is mutated at Cys94 and Cys99, but not Cys441, in endothelial cells. Furthermore, OxLDL increases iNOS expression. The specific iNOS inhibitor 1400 W decreases eNOS S-nitrosylation and the association of eNOS and β‑catenin, thereby blocking the β‑catenin signal pathway to alleviate OxLDL-induced endothelial dysfunction. Taken together, OxLDL induces eNOS S-nitrosylation at Cys94 and Cys99 via an iNOS-dependent manner, which may increase β‑catenin activation and trigger endothelial injury. This study describes a novel mechanism of endothelial dysfunction.

Perfluorooctane sulfonate (PFOS) is one of the perfluorinated compounds (PFCs), and has been used in industrial and consumer products. It has already been shown that PFOS could be detected in the environmental media and biological species including humans, due to its resistance to environmental degradation. PFOS is known to induce a series of adverse impacts on human health, e.g., as a potential neurotoxic substance. Recent studies suggest that astrocytes act as the mediator in PFOS-induced neurotoxicity; however, the underlying molecular mechanism needs further investigation. Under the physiological condition, astrocytes play an important role in maintaining brain functions through releasing and up-taking of neurotransmitters between astrocytes and neurons. In the present study, astrocytes-derived d -serine was shown to be involved in PFOS-induced apoptosis and death in the rat primary hippocampal neurons. Significant alterations in d -serine were found in astrocytes, mediated by the molecules in d -serine synthesis (serine racemase), metabolism ( d -amino acid oxidase) and delivery (calcium, vacuolar type H+-ATPase, alanine–serine–cysteine transporter and connexin 43 hemichannels). Meanwhile, the N-methyl- d -aspartate receptor (NMDAR) subunits (NR1, NR2 A and NR2B) gene and protein expressions were significantly increased in the hippocampal neurons exposed to the PFOS-activated astrocytes-conditional medium (ACM). Further, the adverse effects of PFOS could be attenuated by the fluorocitrate (an inhibitor for d -serine up-taken by the glial cells) application. Our data indicated that astrocytes-derived d -serine was involved in PFOS-induced neurotoxicity through the NMDARs in the rat primary hippocampal neurons.

Increasing evidence suggests that n-hexane induces nerve injury via neuronal apoptosis induced by its active metabolite 2,5-hexanedione (HD). However, the underlying mechanism remains unknown. Studies have confirmed that pro-nerve growth factor (proNGF), a precursor of mature nerve growth factor (mNGF), might activate apoptotic signaling by binding to p75 neurotrophin receptor (p75NTR) in neurons. Therefore, we studied the mechanism of the proNGF/p75NTR pathway in HD-induced neuronal apoptosis. Sprague–Dawley (SD) rats were injected with 400 mg/kg HD once a day for 5 weeks, and VSC4.1 cells were treated with 10, 20, and 40 mM HD in vitro. Results showed that HD effectively induced neuronal apoptosis. Moreover, it up-regulated proNGF and p75NTR levels, activated c-Jun N-terminal kinase (JNK) and c-Jun, and disrupted the balance between B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax). Our findings revealed that the proNGF/p75NTR signaling pathway was involved in HD-induced neuronal apoptosis; it can serve as a theoretical basis for further exploration of the neurotoxic mechanisms of HD.

Rationale: Dysregulated purinergic signaling transduction plays important roles in the pathogenesis of cardiovascular diseases. However, the role and mechanism of vascular smooth muscle cell (VSMC)-released ATP in the regulation of blood pressure, and the pathogenesis of hypertension remain unknown. FAM3A (family with sequence similarity 3 member A) is a new mitochondrial protein that enhances ATP production and release. High expression of FAM3A in VSMC suggests it may play a role in regulating vascular constriction and blood pressure. Objective: To determine the role and mechanism of FAM3A-ATP signaling pathway in VSMCs in the regulation of blood pressure and the pathogenesis of hypertension. Methods and Results: In the media layer of hypertensive rat and mouse arteries, and the internal mammary artery of hypertensive patients, FAM3A expression was increased. VSMC-specific deletion of FAM3A reduced vessel contractility and blood pressure levels in mice. Moreover, deletion of FAM3A in VSMC attenuated Ang II (angiotensin II)-induced vascular constriction and remodeling, hypertension, and cardiac hypertrophy in mice. In cultured VSMCs, Ang II activated HSF1 (heat shock factor 1) to stimulate FAM3A expression, activating ATP-P2 receptor pathway to promote the change of VSMCs from contractile phenotype to proliferative phenotype. In the VSMC layer of spontaneously hypertensive rat arteries, Ang II-induced hypertensive mouse arteries and the internal mammary artery of hypertensive patients, HSF1 expression was increased. Treatment with HSF1 inhibitor reduced artery contractility and ameliorated hypertension of spontaneously hypertensive rats. Conclusions: FAM3A is an important regulator of vascular constriction and blood pressure. Overactivation of HSF1-FAM3A-ATP signaling cascade in VSMCs plays important roles in Ang II-induced hypertension and cardiovascular diseases. Inhibitors of HSF1 could be potentially used to treat hypertension.

Nerve damage often leads to nervous system dysfunction and neuropathic pain. The serine-threonine kinases receptor-interacting protein 1 (RIP1) and 3 (RIP3) are associated with inflammation and cell necrosis. This study aimed to explore the role of RIP1 and RIP3 in sciatic nerve chronic constriction injury (CCI) in mice. On a total of thirty mice, sciatic nerve CCI was performed. The paw withdrawal threshold was measured using Von Frey filaments. The mRNA expression and protein levels of inflammatory factors RIP1 and RIP3 in the dorsal root ganglion (DRG), spinal cord (SC) and hippocampus (HIP) were also determined. We found that paw withdrawal threshold was significantly reduced from the second day after the operation, and the levels of tumour necrosis factor-α and interferon-γ in DRG, SC and HIP were significantly increased on the eighth and 14th days in CCI mice. Furthermore, the downstream signalling molecules of RIP1 and RIP3, GTPase dynamin-related protein-1, NLR family pyrin domain containing-3 (NLRP3) and nuclear factor κB-p65 were upregulated. Increased protein levels of programmed cell death protein 1, which indicate cell death of peripheral and central nervous tissue, were induced by CCI of the sciatic nerve. Overall, this study showed that RIP1 and RIP3 were highly expressed in DRG, SC and HIP of the sciatic nerve in CCI mice and may be involved in chronic neuroinflammation and neuronecrosis.

We aimed to investigate the effects of bone marrow mesenchymal stem cell conditioned medium (BMSC-CM) in preventing 2,5-hexanedione (HD)-induced damage to motoneurons, and examined the molecular mechanisms that mediate these effects. VSC4.1 cells were exposed to 25 mM HD for 24 h followed by incubation with DMEM for 24 h. HD-treated cells were incubated with BMSC-CM at varied concentrations. Incubation with BMSC-CM ameliorated the decreased cell viability and reduced LDH release from cells exposed to HD. BMSC-CM suppressed the elevated number of autophagic vacuoles, cells with LC3 puncta, increased LC3-II/LC3-I ratio, and decreased p62 caused by HD exposure. BMSC-CM elevated NGF and p-TrkA expressions in HD-treated cells. Administration of NGF inhibited autophagy, an effect that was similar to that observed after BMSC-CM treatment; this effect was abolished by the addition of NGF-neutralizing antibodies. BMSC-CM or NGF elevated p-protein kinase B (Akt) and p-mammalian target of rapamycin (mTOR) in HD-exposed cells, which was interrupted by TrkA inhibitor, K252a and mTOR inhibitor, rapamycin. BMSC-CM prevented HD-induced autophagic cell damage in VSC4.1 cells. The neuroprotective effect of BMSC-CM appeared to be at least partly associated with its ability to trigger the NGF-phosphatidylinositol-3-kinase (PI3K)/Akt/mTOR signaling pathway.

2,5-Hexanedione (HD) is an important bioactive metabolite of n-hexane and mediates the neurotoxicity of parent compound. Studies show that HD induces apoptotic death of neural progenitor cells. However, its underlying mechanism remains unknown. Mesenchymal stem cells (MSCs) are multipotential stem cells with the ability to differentiate into various cell types and have been used as cell model for studying the toxic effects of chemicals on stem cells. In this study, we exposed rat bone marrow MSCs to 0, 10, 20, and 40 mM HD in vitro. Apoptosis and disruption of mitochondrial transmembrane potential were estimated by immunochemistry staining. The expression of Akt, Bad, phosphorylated Akt (p-Akt), and Bad (p-Bad) as well as cytochrome c in mitochondria and cytosol were examined by Western blot. Moreover, caspase 3 activity, viability, and death of cells were measured by spectrophotometry. Our results showed that HD induced cell apoptosis and increased caspase 3 activity. HD down-regulated the expression levels of p-Akt, p-Bad and induced MMP depolarization, followed by cytochrome c release. Moreover, HD led to a concentration-dependent increase in the MSCs death, which was relative to MSCs apoptosis. However, these toxic effects of HD on the MSCs were significantly mitigated in the presence of IGF, which could activate PI3 K/Akt pathway. These results indicated that HD induced mitochondria-mediated apoptosis in the MSCs via inhibiting Akt/Bad signaling pathway and apoptotic death of MSCs via the signaling pathway. These results might provide some clues for studying further the mechanisms of HD-induced stem cell apoptosis and adverse effect on neurogenesis.

Perfluorooctane sulfonate (PFOS) is a potential neurotoxicant reported by epidemiological investigations and experimental studies, while the underlying mechanisms are still unclear. Astrocytes not only support for the construction of neurons, but also conduct neuronal functions through glutamate-glutamine cycle in astrocyte-neuron crosstalk. In the present study, the effect of PFOS exposure on rat primary hippocampal neurons or cortex astrocytes was evaluated. Then the role of the astrocytes in PFOS-induced toxic effect on neurons was explored with astrocyte-neuron co-culture system. Exposure of rat primary hippocampal neurons to PFOS has led to oxidation-antioxidation imbalance, increased apoptosis and abnormal autophagy. The adverse effect of PFOS on rat primary cortex astrocytes manifested in the form of altered extracellular glutamate and glutamine concentrations, decreased glutamine synthase activity, as well as decreased gene expression of glutamine synthase, glutamate transporters and glutamine transporters in the glutamate-glutamine cycle. Especially, the alleviation of PFOS-inhibited neurite outgrowth in neurons could be observed in astrocyte-neuron co-culture system, though the ability of astrocytes in fostering neurite outgrowth was affected by PFOS. These results indicated that both astrocytes and neurons might be the targets of PFOS-induced neurotoxicity, and astrocytes could protect against PFOS-inhibited neurite outgrowth in primary cultured neurons. Our research might render some information in explaining the mechanisms of PFOS-induced neurotoxicity.

2,5-hexanedione (HD) is the ultimate neurotoxic metabolite of hexane, causing the progression of nerve diseases in human. It was reported that HD induced apoptosis and oxidative stress. Taurine has been shown to be a potent antioxidant. In the present study, we investigated the protection of taurine against HD-induced apoptosis in PC12 cells and the underlying mechanism. Our results showed the decreased viability and increased apoptosis in HD-exposed PC12 cells. HD also induced the disturbance of Bax and Bcl-2 expression, the loss of MMP, the release of mitochondrial cytochrome c and caspase-3 activation in PC12 cells. Moreover, HD resulted in an increase in reactive oxygen species (ROS) level and a decline in the activities of superoxidedismutase and catalase in PC12 cells. However, taurine pretreatment ameliorated the increased apoptosis and the alterations in key regulators of mitochondria-dependent pathway in PC12 exposed to HD. The increased ROS level and the decreased activities of the antioxidant enzymes in HD group were attenuated by taurine. These results indicate that pretreatment of taurine may, at least partly, prevent HD-induced apoptosis via inhibiting mitochondria-dependent pathway. It is also suggested that the potential of taurine against HD-induced apoptosis may benefit from its anti-oxidative property.

2,5-Hexanedione (HD) is an important bioactive metabolite of n-hexane, which mediates the neurotoxicity of the parent compound. Increasing evidence suggests that over-activated autophagy can lead to autophagic neuronal death; however, whether the excessive autophagy is involved in HD-induced neurotoxicity remains unknown. To investigate the effect of HD on autophagy and to find its underlying mechanism, we respectively treated VSC4.1 cells with 5, 15 and 25 mM HD for 24 h. Our results show that HD induced excessive autophagy of VSC4.1 cells in a dose-dependent manner, also, the over-activated autophagy was significantly mitigated in the presence of PI3K activator or Akt activator or mTOR activator. These results indicate that HD induces excessive autophagy of VSC4.1 cells by repressing the PI3K/Akt/mTOR signaling pathway. LDH assay showed that HD contributed to a concentration dependent increase in VSC4.1 cell death, which was significantly reduced by the administration of PIK-III, an autophagy inhibitor. These results also indicate that HD induces autophagic death of VSC4.1 cells via the signaling pathway.

It was reported that apoptosis of Schwann cells could increase in the diabetic rats. The studies showed that taurine inhibited apoptosis in a variety of cells. However, there were few reports on studying the protection of taurine against apoptosis of Schwann cells induced by high glucose (HG) and the underlying mechanism. In our study, the cells were divided into five groups: Control: the normal medium; HG group: 50 mM high glucose; T1: 50 mM high glucose+Taurine (10 mM) group; T2: 50 mM high glucose+Taurine (20 mM) group; T3: 50 mM high glucose+Taurine (40 mM) group. We used MTT and Tunel assays to measure the cell viability and apoptosis, respectively. Then, we also used western blotting to detect the protein levels of apoptosis-related protein. The results demonstrate that taurine promoted cell viability and decreased apoptosis in RSC96 cells exposed to HG. Furthermore, taurine markedly improved imbalance of Bax and Bcl-2, inhibited the translocation of Cytochrome C (Cyt C) from mitochondria to cytosol and reduced caspase-3 activity in HG-induced RSC96 cells. Our results indicate that taurine protect against apoptosis of Schwann cells induced by HG via inhibiting mitochondria-dependent caspase-3 pathway.

Our group previously reported that taurine has a protective capacity on the hippocampus and cerebellum of arsenic (As)-exposed mouse. In the present study, we explore whether taurine demonstrates protection against As toxicity in primary cortical neurons. Primary cortical neurons were exposed to various concentrations of arsenite and cell viability was assessed to confirm the toxicity of As on cortical neurons. The protection of taurine was examined after primary cortical neurons were treating with arsenite and taurine for 24 h. The cell viability was examined by MTT and caspase-3 activity assay. The expression of Bax and Bcl-2 was determined by western blot. The results showed that As exposure reduced cell viability and enhanced the activity of caspase-3, which were markedly inhibited by taurine treatment. The expression of Bax and Bcl-2 were disturbed by As exposure, which were reversed by taurine. These results indicated that taurine expose protective effect on As-exposed primary cortical neurons and its mechanism maybe involved the regulation of Bax/Bcl-2.

Chronic exposure to n-hexane, a widely used organic solvent in industry, induces central-peripheral neuropathy, which is mediated by its active metabolite, 2,5-hexanedione (HD). We recently reported that transplantation of bone marrow-mesenchymal stem cells (BMSC) significantly ameliorated HD-induced neuronal damage and motor deficits in rats. However, the mechanisms remain unclear. Here, we reported that inhibition of HD-induced autophagy contributed to BMSC-afforded protection. BMSC transplantation significantly reduced the levels of microtubule-associated protein 1 light chain 3-II (LC3-II) and the degradation of sequestosome-1 (p62) in the spinal cord and sciatic nerve of HD-intoxicated rats. Downregulation of autophagy by BMSC was also confirmed in VSC4.1 cells exposed to HD. Moreover, inhibition of autophagy by PIK III mitigated the neurotoxic effects of HD and, meanwhile, abolished BMSC-afforded neuroprotection. Furthermore, we found that BMSC failed to interfere with Beclin 1, but promoted activation of mammalian target of rapamycin (mTOR). Unc-like kinse 1 (ULK1) was further recognized as the downstream target of mTOR responsible for BMSC-mediated inhibition of autophagy. Altogether, BMSC transplantation potently ameliorated HD-induced autophagy through beclin 1-independent activation of mTOR pathway, providing a novel insight for the therapeutic effects of BMSC against n-hexane and other environmental toxicants-induced neurotoxicity.

2,5-hexanedione (HD) induces apoptosis of nerve cells. However,the mechanism of HD-induced apoptosis remains unknown. Mesenchymal stem cells (MSCs) are multipotential stem cells with the ability to differentiate into various cell types. This study is designed to investigate the apoptosis induced by HD in rat bone marrow MSCs (BMSCs) and the related underlying mechanisms. The fifth generation of MSCs was treated with 0, 10, 20 and 40 mM HD respectively. The viability of BMSCs was observed by MTT. Apoptosis were estimated by Hoechst 33342 staining and TUNEL assay. The disruption of mitochondrial transmembrane potential (MMP) was examined by JC-1 staining. Moreover, the expression of Bax and Bcl-2, cytochrome c release, and caspase-3 activity were determined by real-time RT-PCR, Western blot and Spectrophotometry. Our results showed that HD induced apoptosis in MSCs in a dose dependent manner. Moreover, HD downregulated the Bcl-2 expression,upregulated the Bax expression and the Bax/Bcl-2 ratio, promoted the disruption of MMP, induced the release of cytochrome c from mitochondria to cytosol, and increased the activity of caspase-3 in MSCs. These results indicate that HD induces apoptosis in MSCs and the activated mitochondria-dependent caspase-3 pathway may be involved in the HD-induced apoptosis.

The purpose of this study was to explore the protective capacity of taurine on arsenic (As)-induced neurotoxicity. Thirty mice were used and ten rats in each group. We treated the As exposure group with 4 ppm As

We previously reported that the impairment of cerebrum may relate with neurotoxicity induced by arsenic (As) exposure. In the present study, we investigated whether autophagy of the cerebrum neurons were responsible for As-induced neurotoxicity and the protective role of taurine (Tau). Forty mice were randomly divided into control group, Tau control group, As exposure group and Tau protection group. The results showed that LC3 II expression was elevated and P62 expression was lower after As exposure, whereas the effects were obviously attenuated by Tau treatment. More important, As induced increase of MDA level and decrease of Nrf2 expression were significantly inversed in protective group. In sum, autophagy inhibition might play a strong role in the neuroprotection of Tau in As-induced toxicity via Nrf2 pathway.

Hexabromocyclododecane (HBCD) is a widely used brominated flame retardant (BFR). Because of their presence in human issues, including brain tissue, concern has been raised on their possible neurotoxicity. Presently, we explored the neuroprotection of taurine against HBCD-induced apoptotic damages in PC12 cells. Cells were pre-treated with taurine before HBCD exposure and the viability was assayed via the methyl-thiazolyl-tetrazolium (MTT) method. Apoptotic features were observed with Hoechst 33342 staining. Apoptotic ratio was measured using flow cytometry with Annexin V-FITC coupled propidium iodide (PI) double staining. The changes in the levels of Bcl-2 and Bax proteins were quantitated by the western blot. The activity of caspase-3 was tested and the results revealed that presence of HBCD decreased cell survival and led to apoptosis in the tested cells. Further, exposure of HBCD reduced protein expression of Bcl-2, increased expression in Bax protein and activity of caspase-3. Taurine attenuated HBCD-induced cell viability loss and cell apoptosis. Moreover, taurine significantly prevented from reducing Bcl-2 protein expression and elevating Bax protein expression and caspase-3 activity induced by HBCD. These results demonstrated that taurine can alleviate HBCD-induced apoptosis by altering Bcl-2 expression and Bax protein and Caspase-3 activity in PC12.

Polybrominated diphenyl ethers (PBDEs) are globally dispersed throughout the environment, and the levels of some PBDEs in the environment may still be increasing. Previous studies showed that BDE 209 exerted neurodevelopmental and neurobehavioral effects in humans and animals. Oxidative stress is a common mechanism reported in PBDEs-induced neurotoxicity. Taurine, as an antioxidant, whether it is effective in alleviating BDE 209-induced neurotoxicity is still unknown. PC12 cells were exposed to various concentrations of BDE 209 (6.25, 12.5, 25, 50, and 100 μM). 3-(4,5-Dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay was used to assess the cell viability. 2',7'-Dichlorofluorescin diacetate (DCFH-DA) detector was used to explore the production of ROS. Acridine orange was used to reflect the permeation of lysosomal membrane. Rhodamine 123 was used to reflect the permeation of mitochondrial membrane. Lactate dehydrogenase and catalase in PC12 cells exposed to BDE 209 were examined by kits. The results showed that taurine could significantly reverse the decreased viability, the serious oxidative stress and abnormal autophagy in PC12 cells exposed to BDE 209. Collectively, our results indicated that taurine could protect PC12 cells from BDE 209-induced neurotoxicity by alleviating oxidative stress.

To evaluate protection of taurine against arsenic (As)-induced impairment of learning and memory as well as explore its protective mechanism, mice were divided into control, As and taurine protection groups. Mice of As exposure group exposed to drinking water containing 4 ppm As

Our group previously reported that arsenic (As) exposure induced apoptosis in hippocampus neurons. The aim of the present study was to clarify the protective capacity of taurine (Tau) on As-induced neuronal apoptosis and the related mechanism in mouse hippocampus. Mice were divided into: control group, Tau control group, As exposure group and Tau protective group, randomly. The apoptotic rate of mouse hippocampus was determined by TUNEL staining. The levels of Bcl-2 and Bax gene and protein were analyzed by real time RT-PCR and WB, respectively. Furthermore, cytochrome c (Cyt C) release, and the activity of caspase-8 and caspase-3 were also determined. The results showed that Tau treatment induced the decrease of TUNEL-positive cells, prohibited the disturbance of Bcl-2 and Bax expression, and inhibited Cyt C release and caspase-8 and caspase-3 activation significantly. The results indicated that Tau supplement markedly ameliorates As-induced apoptosis by mitochondria-related pathway in mouse hippocampus.

To evaluate the benefits of taurine on the homeostasis of trace elements induced by toxic metals, we investigated the concentration of Selenium (Se), Copper (Cu), Iron (Fe) and Manganese (Mn) in mouse liver and kidney after arsenic exposure for 2 months. The experimental animals were divided into control group, arsenic exposure group (1, 2, 4 ppm) and taurine protective group randomly. Concentrations of serum, liver and kidney trace elements such as Se, Cu, Fe, Mn were measured by Inductively Coupled Plasma-Mass Spectrometry. Our results showed that the concentration of Cu was higher, however, the concentration of Se and Fe was lower in mice liver and kidney exposed to arsenic. The levels of Se, Cu, Fe were alleviated by co-administered with taurine. Furthermore, there was no difference in the concentration of Mn between the three groups. Our finding suggests that taurine may relieve the disturbed levels of Se, Cu and Fe in liver and kidney induced by arsenic.

As a new member of persistent organic pollutants, the potent neurotoxicity of perfluorooctane sulfonates (PFOS) found in epidemiological studies and laboratory research has drawn increasing attention around the world. Previous studies showed that apoptosis driven by oxidative stress and autophagy were both observed in PFOS-induced toxicity. Taurine has been demonstrated to exert potent protections against oxidative stress as an efficient antioxidant. Whether taurine could protect against the PFOS neurotoxicity is not known. In the present study, PC12 cells were treated with several concentrations of PFOS (31.25, 250 μM) for 24 h. 3-(4,5-Dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay was applied to assess the cell viability. DCFH-DA detector was used to explore the production of ROS. Caspase 3 activity was used to reflect the possible apoptosis pathway. The lyso-tracker red dying was invited to evaluate the autophagy. Our data showed that taurine could significantly reverse the decreased viability and the increased ROS production in PC12 cells treated with PFOS. Moreover, the increased autophagy and apoptosis elicited by PFOS in PC12 cells could also be attenuated by taurine. Collectively, our results indicate that taurine may be an effective antioxidant in fighting against PFOS cytotoxicity and therefore could potentially serve as a preventative and therapeutic agent for environmental pollution-related toxicities.

Testis and sperm are particularly susceptible to inflammation and oxidative stress. Although hydrogen sulfide (HWe found that both subfertile and infertile patients, especially asthenospermic patients, exhibited decreased concentration of HThese results provide the first indication that HH

Recent studies reported some long noncoding RNAs (lncRNAs)–mediated vascular smooth muscle cells (VSMCs) phenotypic switch, which was a common pathophysiological process of vascular diseases. However, whether human-specific expressed lncRNAs would modulate VSMCs phenotype and participate into the pathogenesis of essential hypertension remains unclear. By comparing the circulating lncRNAs expression profiles between hypertensive patients and healthy controls, we identified a lncRNA-AK098656, strongly upregulated in the plasma of hypertensive patients, and predominantly expressed in VSMCs. AK098656 promoted VSMCs synthetic phenotype evidenced by increasing VSMC proliferation and migration, elevating extracellular matrix proteins, whereas lowering contractile proteins. Furthermore, AK098656 was demonstrated to directly bind with the VSMCs-specific contractile protein, myosin heavy chain-11, and an essential component of extracellular matrix, fibronectin-1, and finally lowered these protein levels through protein degradation. AK098656 was also shown to bind with 26S proteasome non-ATPase regulatory subunit 11 and facilitated myosin heavy chain-11 to interact with this protein. In vivo, AK098656 transgenic rats showed spontaneous development of hypertension, with elevated VSMCs synthetic phenotype and narrowed resistant arteries. Transgenic rats also showed slight cardiac hypertrophy without other complications, which was similar with early pathophysiological changes of hypertension. All these data indicated AK098656 as a new human VSMC-dominant lncRNA, which could promote hypertension through accelerating contractile protein degradation, increasing VSMC synthetic phenotype, and finally narrowed resistance arteries.

2,5-hexanedione (2,5-HD) is the main active metabolite of n-hexane and induces apoptosis in nerve tissue, however, the mechanism of which remains unclear. In the present study, neuropathic animal models were successfully constructed in rats by injecting 100, 200 and 400 mg/kg 2,5-HD intraperitoneally for 5 weeks. Rats exposed to 2,5-HD exhibited progressive gait abnormalities and slower motor neural response in a dose-dependent manner. TUNEL analysis and immunofluorescence dual labeling revealed that the spinal cord of the 2,5-HD treated rats underwent significantly more apoptosis in the cells of spinal cord than that of the control group. The neuron apoptosis index in spinal cord was 4.1%, 6.7%, 9.8% respectively in rats exposed to 100, 200 and 400 mg/kg 2,5-HD, compared with 1.1% in the control group (p < 0.05). Biochemical analysis showed that 2,5-HD exposure downregulated NGF expression in the spinal cord of the intoxicated rats; inhibited the phosphorylation of Akt and Bad, two key players in PI3K/Akt pathway downstream of NGF; increased the dimerization of Bad with Bcl-xL in the mitochondrial fraction, followed by the release of cytochrome c and activation of caspase-3 in the spinal cord of rats. In vitro study showed that the NGF expression decreased significantly in VSC4.1 cells dosed with 5.0, 10.0 mM 2,5-HD in comparison with the control group. It was also found that NGF supplement repressed the induced apoptosis, and increased p-Akt and p-Bad level in 2,5-HD treated VSC4.1 cells, which could be antagonized by PI3K kinase (the upstream member of Akt) inhibitor LY294002. Taken together, our experimental results indicate that 2,5-HD may induce apoptosis in the spinal cord of rats via downregulating NGF expression and subsequently repressing PI3K/Akt signaling pathway.

Growing evidence suggests that the increased neuronal apoptosis is involved in n-hexane-induced neuropathy. We have recently reported that bone marrow-mesenchymal stem cells-derived conditioned medium (BMSC-CM) attenuated 2,5-hexanedione (HD, the active metabolite of n-hexane)-induced apoptosis in PC12 cells. Here, we explored the anti-apoptotic efficacy of BMSC in vivo. HD-treated rats received BMSC by tail vein injection 5 weeks after HD intoxication. We found that in grafted rats, BMSC significantly attenuated HD-induced neuronal apoptosis in the spinal cord, which was associated with elevation of nerve growth factor (NGF). Neutralization of NGF in BMSC-CM blocked the protection against HD-induced apoptosis in VSC4.1 cells, suggesting that NGF is essential for BMSC-afforded anti-apoptosis. Mechanistically, we found that the decreased activation of Akt induced by HD was significantly recovered in the spinal cord by BMSC and in VSC4.1 cells by BMSC-CM in a TrkA-dependent manner, leading to dissociation of Bad/Bcl-xL complex in mitochondria and release of anti-apoptotic Bcl-xL. The importance of Akt was further corroborated by showing the reduced anti-apoptotic potency of BMSC in HD-intoxicated VSC4.1 cells in the presence of Akt inhibitor, MK-2206. Thus, our findings show that BMSC attenuated HD-induced neuronal apoptosis in vivo through a NGF/Akt-dependent manner, providing a novel solution against n-hexane-induced neurotoxicity.

Umbilical cord blood (UCB) cells are an attractive choice in cytotherapy and represent an alternative to hepatocytes. The aim of this study was to investigate the feasibility of using the technique of micro-encapsulation to study the differentiation and function of UCB cells in an injured liver model and the potential of encapsulated UCB cells for use in the reversal of hepatic injury.UCB cells were isolated from fresh human UCB, encapsulated using the alginate-poly-lysine-alginate method and transplanted intraperitoneally into liver-injured mice induced by CCl4. Encapsulated UCB cell growth, viability and differentiation in vivo were detected. For evaluating the recovery of injured liver tissues, serum aminotransferases and liver histology were assessed.Encapsulated UCB cells showed better growth behavior after being implanted. Under conditions favoring differentiation in vivo, the expression of alpha-fetoprotein (AFP) and albumin (ALB) and urea synthesis were detected in a time-dependent manner. Serum amino-transferases were decreased after transplantation of encapsulated UCB cells into injured mice, and damage to the histologic structure of the liver was reduced.The cell microencapsulation system provides a novel approach for learning more about the differentiation and function of UCB cells in vivo. Transplantation of encapsulated UCB cells can enhance recovery of CCl4-injured mouse liver. These observations suggest potential as an alternative to hepatocyte transplantation for cellular therapy of liver failure.

Studies suggested that the conditioned medium of mesenchymal stem cells (MSC-CM) inhibited the increased apoptosis in various cells. However, there are no reports underlying the protection of MSC-CM against 2,5-hexanedione (HD)-induced apoptosis in neural cells. In the present study, the viability was observed in PC12 cells that received HD alone or with MSC-CM by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis was estimated by Hoechst 33342 staining and flow cytometry. Mitochondrial transmembrane potential was examined by rhodamine 123. Moreover, we investigated the expression of Bax and Bcl-2, cytochrome c translocation, and caspase 3 activity by real-time polymerase chain reaction, Western blot, and immunochemistry. Nerve growth factor (NGF) was examined in MSCs and MSC-CM. Our results showed that MSC-CM promoted cell survival and reduced apoptosis in HD-exposed PC12 cells. Moreover, MSC-CM significantly reversed disturbance of Bax and Bcl-2, ameliorated disruption of mitochondrial transmembrane potential, and reduced release of cytochrome c and activity of caspase 3 in HD-exposed PC12 cells. In the meantime, NGF was detected in MSCs and MSC-CM. These findings demonstrate that MSC-CM protects against HD-induced apoptosis in PC12 cells via inhibiting mitochondrial pathway. Our results indicate that NGF in MSC-CM may be involved in the protection of MSC-CM against HD-induced apoptosis. Our study clarifies the protection of MSC-CM on HD neurotoxicity and its underlying mechanism.

Some organophosphorus compounds can cause organophosphate-induced delayed neuropathy (OPIDN). Incidents have been documented for decades, however, little is known about which proteins contribute to the initiation, progression and development of OPIDN. In this study, 51 hens were divided into three groups. The tri-ortho-cresyl-phosphate (TOCP) group was treated with 1000 mg kg(-1) TOCP whereas the control group was treated with an equivalent volume of vehicle. The PMSF + TOCP group was treated subcutaneously with 40 mg kg(-1) phenylmethylsulfonyl fluoride (PMSF), followed by 1000 mg kg(-1) TOCP 24 h later. Proteins in the brains of hens were separated by two-dimensional polyacrylamide gel electrophoresis on day 5 after TOCP administration. Mass spectrometry identified eight differentially expressed proteins. Among these proteins, downregulated expression of glutamine synthetase (GS) in the brains of hens after TOCP treatment was further confirmed by real time RT-PCR and ELISA. Moreover, the brains of hens exposed to TOCP exhibited increased levels of glutamate (Glu) and cytosolic calcium concentration ([Ca(2+)](i)), and a decreased level of glutamine (Gln). However, there were no significant differences in GS expression or levels of Glu, Gln, and [Ca(2+)](i) in the brains of hens among the groups on day 21 after TOCP administration. These results indicate that TOCP exposure downregulates GS expression in the brains of hens, and that downregulation of GS is accompanied by increased levels of Glu and [Ca(2+)](i) in the early stage after TOCP administration. It is also suggested that the downregulated expression of GS might be associated with OPIDN through the disruption of homeostasis of the Glu-Gln cycle and [Ca(2+) ](i).