Triphenyl phosphate induces cardiotoxicity through myocardial fibrosis mediated by apoptosis and mitophagy of cardiomyocyte in mice.

Triphenyl phosphate (TPHP) is an organophosphorus flame retardant, but its cardiac toxicity has not been adequately investigated. Therefore, in the current study, the effect of TPHP on the heart and the underlying mechanism involved was evaluated. C57BL/6 J mice were administered TPHP (0, 5, and 50 mg/kg/day) for 30 days. In addition, H9c2 cells were treated with three various concentrations (0, 50, and 150 µM) of TPHP, with and without the reactive oxygen species (ROS) scavenger N-acetyl-L-cysteine or the mitochondrial fusion promoter M1. TPHP caused cardiac fibrosis and increased the levels of CK-MB and LDH in the serum. TPHP increased the levels of ROS, malondialdehyde (MDA), and decreased the level of superoxide dismutase (SOD) and Glutathione peroxidase (GSH-Px). Furthermore, TPHP caused mitochondrial damage, and induced fusion and fission disorders that contributed to mitophagy in both the heart of C57BL/6 J mice and H9c2 cells. Transcriptome analysis showed that TPHP induced up- or down-regulated expression of various genes in myocardial tissue and revealed enriched apoptosis pathways. It was also found that TPHP could remarkably increase the expression levels of Bax, cleaved Caspase-9, cleaved Caspase-3, and decreased Bcl-2, thereby causing apoptosis in H9c2 cells. Taken together, the results suggested that TPHP promoted mitophagy through mitochondria fusion dysfunction resulting from oxidative stress, leading to fibrosis by inducing myocardial apoptosis.

Ferritinophagy-mediated ferroptosis of spermatogonia is involved in busulfan-induced oligospermia in the mice.

Busulfan, a bifunctional alkylated chemotherapeutic agent, has male reproductive toxicity and induce oligospermia, which is associated with ferroptosis. However, the specific target cells of busulfan-induced oligospermia triggered by ferroptosis are largely elusive, and the detailed mechanisms also require further exploration. In the present study, busulfan (0.6, and 1.2 mM, 48 h) causes ferroptosis in GC-1 spg cells through inducing Fe2+, ROS and MDA accumulation and functional inhibition of Xc-GSH-GPX4 antioxidant system. After inhibition of ferroptosis by Fer-1 (1 µM, pretreatment for 2 h) or DFO (10 µM, pretreatment for 2 h) reverses busulfan-induced destructive effects in GC-1 spg cells. Furthermore, using RNA-seq and Western blotting, we found that busulfan promotes autophagy-dependent ferritin degradation, as reflected by enriching in autophagy, increased LC3 II, Beclin1 and NCOA4, as well as decreased P62 and ferritin heavy chain 1 (FTH1). Ultimately, GC-1 spg cells and Balb/c mice were treated with busulfan and/or 3-MA, the inhibitor of autophagy. The results displayed that inhibition of autophagy relieves busulfan-induced FTH1 degradation and then blocks the occurrence of ferroptosis in GC-1 spg cells and testicular spermatogonia, which subsequently alleviates busulfan-caused testicular damage and spermatogenesis disorders. In summary, these data collectively indicated that ferroptosis of spermatogonia is involved in busulfan-induced oligospermia and mediated by autophagy-dependent FTH1 degradation, identifying a new target for the therapy of busulfan-induced male infertility.

Chronic exposure to polystyrene nanoplastics induces intestinal mechanical and immune barrier dysfunction in mice.

Micro(nano)plastics are prevalent in the environment, and prolonged exposure to them represents a threat to human health. The goal of this study is to assess the health risk of long-term exposure to nanoplastics (NPs) at environmental concentrations on the intestinal mechanical and immune barrier in mice. In this study, mice were provided drinking water containing polystyrene NPs (PS-NPs; 0.1, 1, and 10 mg·L-1) for 32 consecutive weeks. The levels of endocytosis proteins caveolin and clathrin and of tight junctional proteins claudin-1, occludin, and ZO-1, and morphological changes, proportion of lymphocytes B in MLNs and lymphocytes T in IELs and LPLs were determined by immunohistochemistry, hematoxylin-eosin, and flow cytometry assays in the intestinal tissues of mice at 28 weeks. The activities or concentrations of ROS, SOD, MDA, and GSH-Px and inflammatory factors (IL-1ß, IL-6, and TNF-α) in the intestinal tissues of mice were measured by ELISA at 12, 16, 20, 24, and 32 weeks. Compared with the control group, oral ingested PS-NPs entered the intestinal tissues of mice and upregulated expression levels of the clathrin and caveolin. The intestinal tissue structure of mice in the PS-NPs (1 and 10 mg·L-1) exposure groups showed significant abnormalities, such as villus erosion, decreased of crypts numbers and large infiltration of inflammatory cells. Exposure to 0.1 mg·L-1 PS-NPs decreased occludin protein levels, but not claudin-1 and ZO-1 levels. The levels of these three tight junction proteins decreased significantly in the 1 and 10 mg·L-1 PS-NPs exposed groups. Exposure to PS-NPs led to a significant time- and dose-dependent increase in ROS and MDA levels, and concurrently decreased GSH-Px and SOD contents. Exposure to PS-NPs increased the proportion of B cells in MLNs, and decreased the proportion of CD8+ T cells in IELs and LPLs. The levels of pro-inflammatory cytokines IL-6, TNF-α and IL-1ß were markedly elevated after PS-NPs exposure. Long-term PS-NPs exposure impaired intestinal mechanical and immune barrier, and indicate a potentially significant threat to human health.

Effects of exposure to PM2.5 during pregnancy on the multigenerational reproductive outcomes of male mouse offspring and the role of Sertoli cells.

There is a paucity of studies on the multigenerational reproductive toxicity of fine particle matter (PM2.5) exposure during pregnancy on male offspring and the underlying mechanisms. This study explored the effects of PM2.5 exposure during pregnancy on the spermatogenesis of three consecutive generations of male mouse offspring. We randomized pregnant C57BL/6 mice into the control group, the Quartz Fiber Membrane control group, and two experimental groups exposed to different concentrations of PM2.5 (4.8 and 43.2 mg/kg B.Wt.). Pregnant mice from experimental groups received intratracheal instillation of PM2.5 of different doses on a three-day basis until birth. F1 mature male offspring from PM2.5-exposed pregnant mice were mated with normal female C57BL/6 mice. Likewise, their F2 mature male followed the same to produce the F3 generation. The results showed that PM2.5 exposure during pregnancy led to decreased body and tail length, body weight, and survival rates, decreased sperm concentration and sperm motility, and increased sperm abnormality rates significantly in F1 male offspring. We barely observed significant impacts of PM2.5 on the birth number, survival rates, and index of testes in the F2 and F3 offspring. Further exploration showed that PM2.5 exposure during pregnancy caused the morphological abnormality of Sertoli cells, downregulated androgen receptor (AR) and connexin43, upregulated anti-Müllerian hormone (AMH), cytokeratin-18 (CK-18), caspase-3, and cleaved caspase-3, decreased thyroid-stimulating hormone (TSH) and testosterone (T), and increased triiodothyronine (T3) in F1 male mouse offspring. Overall, we hypothesize that PM2.5 exposure during pregnancy mainly negatively impacts spermatogenesis in the F1 offspring. The possible mechanism could be that PM2.5 exposure during pregnancy disrupts endocrine hormone release in the F1 generation, thereby influencing the maturation and proliferation of their Sertoli cells and hindering spermatogenesis. This study for the first time investigates the role of Sertoli cells in the reproductive toxicity of PM2.5 on offspring.

Triphenyl phosphate induced apoptosis of mice testicular Leydig cells and TM3 cells through ROS-mediated mitochondrial fusion inhibition.

Triphenyl phosphate (TPHP) is a widely used organophosphate flame retardant and has biological toxicity. Previous studies showed TPHP can restrain testosterone biosynthesis in Leydig cells, while the underlying mechanisms remain unclear. In this study, C57BL/6J male mice were exposed to 0, 5, 50, and 200 mg/kg B.W. of TPHP for 30 d by oral, as well as TM3 cells were treated with 0, 50, 100, and 200 µM of TPHP for 24 h. Results showed that TPHP induced testes damage, including spermatogenesis disorders and testosterone synthesis inhibition. Meanwhile, TPHP can cause apoptosis in testicular Leydig cells and TM3 cells, as evidenced by the increased apoptosis rate and decreased Bcl-2/Bax ratio. Moreover, TPHP disrupted mitochondrial ultrastructure of testicular Leydig cells and TM3 cells, reduced healthy mitochondria content and depressed mitochondrial membrane potential of TM3 cells, as well as inhibited mitochondrial fusion proteins mitofusin 1 (Mfn1), mitofusin 2 (Mfn2), and optic atrophy 1 (Opa1) expression, without effect on mitochondrial fission proteins dynamin-related protein 1 (Drp1) and fission 1 (Fis1) in testicular tissue and/or TM3 cells. Then, the mitochondrial fusion promoter M1 was used to pre-treat TPHP-exposed TM3 cells to determine the roles of mitochondrial fusion inhibition in TPHP-induced Leydig cells apoptosis. The results showed M1 pretreatment alleviated the above changes and further mitigated TM3 cells apoptosis and testosterone levels decreased, indicating TPHP induced TM3 cells apoptosis by inhibited mitochondrial fusion. Intriguingly, the intervention experiment of N-acetylcysteine (NAC) showed that TPHP-induced mitochondrial fusion inhibition is ROS dependent, because inhibition of ROS overproduction alleviated mitochondrial fusion inhibition, and subsequently relieved TPHP-induced apoptosis in TM3 cells. In summary, above data revealed that apoptosis is a specific mechanism for TPHP-induced male reproductive toxicity, and that ROS-mediated mitochondrial fusion inhibition is responsible for Leydig cells apoptosis caused by TPHP.

Maternal exposure to PM2.5 induces the testicular cell apoptosis in offspring triggered by the UPR-mediated JNK pathway.

Contemporary exposure to PM2.5 has been reported to disrupt spermatogenesis. However, the subsequent toxicological responses and the mechanisms of male reproductive damage in offspring induced by maternal exposure to PM2.5 remain largely unknown. For the first time, this study aimed to explore the apoptotic response in spermatogenesis of male offspring following maternal exposure to PM2.5 and its mechanisms. The C57BL/6 mice with vaginal plugs were randomly divided into four groups. Mice in the PM2.5 groups were intratracheally exposed to PM2.5 (4.8 mg/kg body weight, 43.2 mg/kg body weight) during pregnancy (every 3 days, six times in total). The mice in the membrane control group were treated similarly to the PM2.5 groups, applying only PM2.5 sampling membrane, while mice in the control group were kept untreated. The results showed that maternal exposure to PM2.5 during pregnancy resulted in structural lesions of the testis, reduced numbers of primary spermatocytes and spermatids, decreased sperm count and quality, shortened diameter of seminiferous tubules, and reduced testosterone and ABP in the offspring testes. Furthermore, cell apoptosis was increased and protein expression of IRE-1/P-JNK/cleaved caspase-12/cleaved caspase-3 was activated. These findings suggested that maternal exposure to PM2.5 may affect spermatogenesis by increasing apoptosis through activation of UPR-mediated JNK apoptotic pathway in offspring testicles and by reducing testosterone secretion.

Polystyrene microplastics induce blood-testis barrier disruption regulated by the MAPK-Nrf2 signaling pathway in rats.

As a persistent pollutant, microplastics (MPs) have been reported to induce sperm quantity decrease in mice. However, the related mechanism remains obscure. Therefore, this study is intended to explore the effects of polystyrene microplastics (PS-MPs) on male reproduction and its related mechanism of blood-testis barrier (BTB) impairment. Thirty-two adult male Wistar rats were divided randomly into four groups fed with PS-MPs for 90 days at doses of 0 mg/day (control group), 0.015 mg/day, 0.15 mg/day, and 1.5 mg/day, respectively. The present results have shown that PS-MP exposure led to the damage of seminiferous tubule, resulted in apoptosis of spermatogenic cells, and decreased the motility and concentration of sperm, while the abnormality of sperm was elevated. Meanwhile, PS-MPs could induce oxidative stress and activate the p38 MAPK pathway and thus deplete the nuclear factor erythroid-2 related factor 2 (Nrf2). Noteworthily, PS-MPs led to the BTB-related protein expression decrease. All these results demonstrated that PS-MP exposure may lead to the destruction of BTB integrity and the apoptosis of spermatogenic cells through the activation of the MAPK-Nrf2 pathway. The current study provided novelty evidence for elucidating the effects of PS-MPs on male reproductive toxicity and its potential mechanism.

Polystyrene microplastics lead to pyroptosis and apoptosis of ovarian granulosa cells via NLRP3/Caspase-1 signaling pathway in rats.

Microplastics (MPs) considered as a new persistent environmental pollutant could enter into the circulatory system and result in decrease of sperm quantity and quality in mice. However, the effects of Polystyrene MPs (PS MPs) on the ovary and its mechanism in rats remained unclear. In this present study, thirty-two healthy female Wistar rats were exposed to different concentrations of 0.5 µm PS MPs dispersed in deionized water for 90 days. Using hematoxylin-eosin (HE) staining, the number of growing follicles was decreased compared to the control group. In addition, the activity of glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD) were decreased while the expression level of malondialdehyde (MDA) was increased in ovary tissue. Confirmed by immunohistochemistry, the integrated optical density of NLRP3 and Cleaved-Caspase-1 had been elevated by 13.9 and 14 in granulosa cells in the 1.5 mg/kg/d group. Furthermore, compared to the control group, the level of AMH had been decreased by 23.3 pg/ml while IL-1ß and IL-18 had been increased by 32 and 18.5 pg/ml in the 1.5 mg/kg/d group using the enzyme-linked immune sorbent assay (ELISA). Besides, the apoptosis of granulosa cells was elevated measured by terminal deoxyribonucleotide transferase-mediated nick end labeling (TUNEL) staining and flow cytometry. Moreover, western blot assays showed that the expressions of NLRP3/Caspase-1 signaling pathway related factors and Cleaved-Caspase-3 were increased. These results demonstrated that PS MPs could induce pyroptosis and apoptosis of ovarian granulosa cells via the NLRP3/Caspase-1 signaling pathway maybe triggered by oxidative stress. The present study suggested that exposure to microplastics had adverse effects on ovary and could be a potential risk factor for female infertility, which provided new insights into the toxicity of MPs on female reproduction.

The impact of polystyrene microplastics on cardiomyocytes pyroptosis through NLRP3/Caspase-1 signaling pathway and oxidative stress in Wistar rats.

The extensive existing of microplastics (MPs) in the ecosystem have increased considerable attention concerning their potential adverse effects, the toxicities and the underlying mechanism of MPs are still scarce. To explore the effect of MPs on cardiac tissue in Wistar rats and unravel the mechanism of pyroptosis and oxidative stress in the process of cardiomyocytes injury, 32 male Wister rats were divided into control group and three model groups, which were exposed to 0.5 mm PS MPs at 0.5, 5 and 50 mg/L for 90 days. Results revealed that MPs could damage cardiac structure and function with impaired mitochondria integrity, as well as increased levels of creatine kinase-MB and cardiac troponinI (cTnI). Moreover, MPs administration triggered oxidative stress as indicated by increased levels of malondialdehyde and decreased activity of superoxide dismutase, glutathione peroxidase and catalase. Treatment with MPs resulted in apoptosis and pyroptosis as evidenced by increasing expressions of interleukin (IL)-1ß, IL-18. Additionally, MPs were shown to induce the NOD-like receptor protein 3 inflammasomes activation in cardiac tissue, enabling activation of Caspase-1-dependent signaling pathway induced by inflammatory stimuli resulting from oxidative stress. In summary, these results illustrated that pyroptosis played a vital role in polystyrene MPs-induced cardiotoxicity, which might be helpful to understand the mechanism of cardiac dysfunction and induced by MPs.

Tetramethylpyrazine Protects Blood-Spinal Cord Barrier Integrity by Modulating Microglia Polarization Through Activation of STAT3/SOCS3 and Inhibition of NF-кB Signaling Pathways in Experimental Autoimmune Encephalomyelitis Mice.

We previously reported that tetramethylpyrazine (TMP) alleviates experimental autoimmune encephalomyelitis (EAE) by decreasing glia activation. Activated microglia has been shown to mediate blood-spinal cord barrier (BSCB) disruption, which is a primary and continuous pathological characteristic of multiple sclerosis (MS). Therefore, in this study, we further investigated whether TMP protects the BSCB integrity by inhibition of glia activation to alleviate EAE. Extravasation of evans blue was used to detect the BSCB disruption. Tumor necrosis factor-α (TNF-α)/interlukine-1ß (IL-1ß) and interlukine-4 (IL-4)/interlukine-10 (IL-10) were determined by enzyme-linked immunosorbent assay. BV2 glial cells stimulated by interferon-γ (IFN-γ) were co-cultured with human brain microvascular endothelial cells to investigate the effect of TMP on the BSCB disruption. Flow cytometry was used to analyze the microglia phenotype. Western blot was performed to reveal the signaling pathways involved in the microglia activation. In this study, most importantly, we found that TMP protects the BSCB integrity by modulating microglia polarization from M1 phenotype to M2 phenotype through activation of STAT3/SOCS3 and inhibition of NF-кB signaling pathways. Moreover, TMP significantly preserves the tight junction proteins, reduces the secretion of pro-inflammatory cytokines (TNF-α, IL-1ß) and increases the secretion of anti-inflammatory cytokines (IL-4, IL-10) from IFN-γ-stimulated BV2 microglia cells. Consequently, protection of the BSCB integrity leads to alleviation of clinical symptoms and demyelination in EAE mice. Therefore, TMP might be an effective therapeutic agent for cerebral disorders with BBB or BSCB disruption, such as ischemic stroke, MS, and traumatic brain injury.

Polystyrene microplastics cause granulosa cells apoptosis and fibrosis in ovary through oxidative stress in rats.

Microplastics (MPs) are receiving increased attention as a harmful environmental pollutant. Studies have investigated that MPs have reproductive toxicity, but the mechanism is little known. Here, we aimed to investigate the effects of polystyrene microplastics (PS-MPs) on ovary in rats and the underlying molecular mechanisms. in vivo, thirty-two female Wistar rats were exposed to 0.5 µm PS-MPs at different concentrations (0, 0.015, 0.15 and 1.5 mg/d) for 90 days. And then, all animals were sacrificed, ovaries and blood were collected for testing. in vitro, granulosa cells (GCs) were separated from rat ovary and treated with 0、1、5、25 µg/mL PS-MPs and reactive oxygen species (ROS) inhibitor N-Acetyl-l-cysteine (NAC) respectively. Our results showed that PS-MPs could enter into GCs and result in the reducing of growing follicles number. And the Enzyme-linked immunosorbent assay (ELISA) manifested that PS-MPs could obviously decrease the level of anti-Müllerian hormone (AMH). In addition, PS-MPs induced oxidative stress, apoptosis of GCs and ovary fibrosis evidenced by assay kits, flow cytometry, immunohistochemistry, Masson's trichrome and Sirius red staining. Moreover, the western blot assay manifested that PS-MPs exposure significantly increased the expression levels of Wnt/ß-Catenin signaling pathways-related proteins (Wnt, ß-catenin, p-ß-catenin) and the main fibrosis markers (transforming growth factor-ß (TGF-ß), fibronectin, α-smooth muscle actin (α-SMA). Additionally, the expression levels of Wnt and p-ß-catenin, apoptosis of GCs decreased after NAC treatment. In summary, polystyrene microplastics cause fibrosis via Wnt/ß-Catenin signaling pathway activation and granulosa cells apoptosis of ovary through oxidative stress in rats, both of which ultimately resulted in decrease of ovarian reserve capacity.

Polystyrene microplastics cause cardiac fibrosis by activating Wnt/ß-catenin signaling pathway and promoting cardiomyocyte apoptosis in rats.

Microplastics (MPs) are new persistent organic pollutants derived from the degradation of plastics. They can accumulate along the food chain and enter the human body through oral administration, inhalation and dermal exposure. To identify the impact of Polystyrene (PS) MPs on the cardiovascular system and the underlying toxicological mechanism, 32 male Wister rats were divided into control group and three model groups, which were exposed to 0.5 µm PS MPs at 0.5, 5 and 50 mg/L for 90 days. Our results suggested that PS MPs exposure increased Troponin I and creatine kinase-MB (CK-MB) levels in serum, resulted in structure damage and apoptosis of myocardium, and led to collagen proliferation of heart. Moreover, PS MPs could induce oxidative stress and thus activate fibrosis-related Wnt/ß-catenin signaling pathway. These results suggested that PS MPs could lead to cardiovascular toxicity by inducing cardiac fibrosis via activating Wnt/ß-catenin pathway and myocardium apoptosis triggered by oxidative stress. The present study provided some novelty evidence to elucidate the potential mechanism of cardiovascular toxicity induced by PS MPs.

hUMSC transplantation restores ovarian function in POI rats by inhibiting autophagy of theca-interstitial cells via the AMPK/mTOR signaling pathway.

BACKGROUND: Previous studies of primary ovarian insufficiency (POI) have focused on granulosa cells (GCs) and ignored the role of theca-interstitial cells (TICs). This study aims to explore the mechanism of the protective effects of human umbilical cord-derived mesenchymal stem cells (hUMSCs) on ovarian function in POI rats by regulating autophagy of TICs. METHODS: The POI model was established in rats treated with cisplatin (CDDP). The hUMSCs were transplanted into POI rats by tail vein. Enzyme-linked immunosorbent assay (ELISA) analysis, hematoxylin and eosin (HE) staining, and immunohistochemistry were used to measure the protective effects of hUMSCs. The molecular mechanisms of injury and repairment of TICs were assessed by immunofluorescence, transmission electron microscope (TEM), flow cytometry (FCM), western blot, and quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: In vivo, hUMSC transplantation restored the ovarian function and alleviated the apoptosis of TICs in POI rats. In vitro, hUMSCs reduced the autophagy levels of TICs by reducing oxidative stress and regulating AMPK/mTOR signaling pathway, thereby alleviating the apoptosis of TICs. CONCLUSION: This study indicates that hUMSCs protected ovarian function in POI by regulating autophagy signaling pathway AMPK/mTOR.

Hydrogen-rich saline ameliorates hippocampal neuron apoptosis through up-regulating the expression of cystathionine ß-synthase (CBS) after cerebral ischemia- reperfusion in rats.

OBJECTIVES: This study aimed to evaluate the potential role of hydrogen in rats after cerebral ischemic/reperfusion (I/R) injury. MATERIALS AND METHODS: The experimental samples were composed of sham group, model group of rats that received middle cerebral artery occlusion (MCAO) for 2 hr followed by reperfusion for 24 hr, and the hydrogen saline group treated by hydro¬gen-rich saline (1 ml/kg) after MCAO. Hydrogen sulfide (H2S), S100-ßprotein (S100-ß), and neuron-specific enolase (NSE) levels were measured; the levels of malondialdehyde (MDA), reactive oxygen species (ROS), and superoxide dismutase (SOD) were detected; the histologic structure and apoptotic cells of hippocampus were observed; the expressions of cystathionine ß-synthase (CBS), nuclear factor erythroid 2-related factor 2 (Nrf2), and hemeoxygenase-1 (HO-1) were measured. Statistical analyses were performed using one-way analysis of variance (ANOVA) followed by Fisher's least significant difference (LSD) test. RESULTS: Our results showed that hydrogen up-regulated H2S levels via promoting the expression of CBS in the hippocampus, and its treatment alleviated oxidative stress via activating the expression of Nrf2 and HO-1, and then cell apoptosis reduced, furthermore, brain function improved by down-regulating the levels of S100-ßand NSE. CONCLUSION: This study showed that hydrogen-rich saline ameliorates cell injury through up-regulating the expression of CBS in the hippocampus after cerebral ischemia reperfusion (I/R) in rats, this provides new experimental evidence for the treatment of stroke with hydrogen saline.

Endosulfan induces endothelial inflammation and dysfunction via IRE1α/NF-κB signaling pathway.

Cardiovascular diseases are related to vascular endothelial cell injury; our previous studies showed that endosulfan could cause hypercoagulation of blood by inducing endothelial cell injury. To clarify the mechanism of it, we treated human umbilical vein endothelial cells (HUVECs) with 0, 1, 5, and 10 µg/mL endosulfan, while in the inhibition groups, reactive oxygen species (ROS) inhibitor N-acetylcysteine (NAC, 3 mmol) and endoplasmic reticulum (ER) stress inhibitor (STF-083010, 10 µmol) were incubated prior to endosulfan. The results showed that endosulfan could induce inflammatory response and dysfunction by increasing the release of inflammatory cytokines such as interleukin-1ß (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and adhesion molecules such as vascular cell adhesion molecule 1 (VCAM-1) and endothelin-1 (ET-1), and inducing ROS production in HUVECs. We also found that endosulfan could cause ER damage, remarkably increase the expressions of inositol-requiring enzyme 1α (IRE1α), phosphorylated IRE1α (p-IRE1α), GRP78, XBP1, nuclear factor-kappa B (NF-κB), and phosphorylated NF-κB (p-NF-κB) in HUVECs. The presence of NAC antagonized the ROS production, expressions of IRE1α and p-IRE1α; however, STF-083010 could decrease the expression levels of GRP78, XBP1, NF-κB, and p-NF-κB and attenuate IL-1ß, IL-6, TNF-α, VCAM-1, and ET-1 release induced by endosulfan. These results demonstrated that endosulfan-induced endothelial inflammation and dysfunction through the IRE1α/NF-κB signaling pathway may be triggered by oxidative stress. The study provided experimental basis for the correlation between environmental pollutants (endosulfan) and cardiovascular diseases.

Tetramethylpyrazine enhanced the therapeutic effects of human umbilical cord mesenchymal stem cells in experimental autoimmune encephalomyelitis mice through Nrf2/HO-1 signaling pathway.

INTRODUCTION: The therapeutic effects of mesenchymal stem cells (MSCs) have been limited by their apoptosis induced by oxidative stress after delivery into the injured sites. Therefore, strategies designed to improve the MSC therapeutic efficacy need to be explored. Tetramethylpyrazine (TMP) can promote the proliferation and differentiation of neural stem cells. In this study, we first evaluated the effects and mechanism of TMP on H2O2-stimulated human umbilical cord MSCs (hUCMSCs) and then further investigated the therapeutic effects of TMP-stimulated hUCMSCs on experimental autoimmune encephalomyelitis (EAE) mice. METHODS: The toxicity of hUCMSCs against of TMP was determined by cell count kit-8 (CCK-8) assay. The effects of TMP on the hUCMSC cell cycle, the reactive oxygen species (ROS) production, and the apoptosis of H2O2-stimulated hUCMSCs were determined by flow cytometry. The expression of malondialdehyde (MDA) and superoxide dismutase (SOD) were also measured by colorimetry. The signaling pathway of TMP induced on H2O2-stimulated hUCMSCs was investigated by western blot. EAE was induced using immunization with MOG35-55 in C57BL/6 mice. The inflammatory cell infiltration and demyelination were detected by immunofluorescence staining. The blood-brain barrier (BBB) disruption was detected by Evans blue (EB) stain and the expression of tight junction protein (ZO-1) by western blot. RESULTS: TMP significantly increased cell viability and changed the cell cycle of hUCMSCs. In addition, TMP (100 µM) significantly reduced intracellular ROS production, expression of MDA, and apoptosis, but increased expression of SOD through nuclear factor-erythroid 2-related factor-2 (Nrf2)/heme oxygenase 1 (HO-1) signaling pathway in H2O2-stimulated hUCMSCs. Most importantly, compared with wild hUCMSCs, TMP-stimulated hUCMSCs significantly ameliorated EAE, by attenuation of inflammation, demyelination, and BBB disruption. CONCLUSION: The TMP-stimulated hUCMSCs provide a potential therapeutical protocol to enhance the therapeutic effects of hUCMSCs in multiple sclerosis.

Endosulfan induces cardiotoxicity through apoptosis via unbalance of pro-survival and mitochondrial-mediated apoptotic pathways.

Although the associations between endosulfan and adverse cardiovascular health have been reported, the toxic effects and underlying mechanism of endosulfan on the heart are not well understood. In this study, we examined the cardiotoxicity induced by endosulfan using Wistar rats and human cardiomyocytes (AC16) cells. Wistar rats were divided into control group (received corn oil alone) and three concentrations of endosulfan groups (1, 5 and 10 mg/kg·bw) by gavage. The AC16 cells were treated with three various concentrations (0, 1.25, 5, and 20 µg/mL) of endosulfan. The results showed that endosulfan induced cytotoxicity through damaging myocardial structure, decreasing the viability of cardiomyocytes, and elevating the serum levels of cardiac troponin I, heart fatty acid binding protein, aspartate aminotransferase, and reactive oxygen species (p < 0.05). Moreover, measurement of mitochondrial function showed that endosulfan could significantly decrease adenosine triphosphate levels and cytochrome c oxidase IV expression in AC16 cells (p < 0.05). In addition, endosulfan obviously inhibited Bcl-2 expression, activated the expressions of cytochrome c/Caspase-9/Caspase-3 signaling pathway, and induced the apoptosis of AC16 cells (p < 0.05). Furthermore, endosulfan significantly increased the expression of Bim, and inhibited the expressions of PI3K/Akt/FoxO3a signaling pathways in cardiomyocytes (p < 0.05). These results suggest that endosulfan may induce cardiotoxicity by inducing myocardial apoptosis resulting from activation of mitochondria-mediated apoptosis pathway and inhibition of pro-survival signaling pathways, which might be helpful in elucidating the mechanism of cardiac dysfunction induced by endosulfan.