The aim of this study was to investigate the role of selenoprotein M (SelM) in endoplasmic reticulum stress and apoptosis in nickel-exposed mouse hearts and to explore the detoxifying effects of melatonin. At 21 d after intraperitoneal injection of nickel chloride (NiCl₂) and/or melatonin into male wild-type (WT) and SelM knockout (KO) C57BL/6J mice, NiCl₂ was found to induce changes in the microstructure and ultrastructure of the hearts of both WT and SelM KO mice, which were caused by oxidative stress, endoplasmic reticulum stress, and apoptosis, as evidenced by decreases in malondialdehyde (MDA) content and total antioxidant capacity (T-AOC) activity. Changes in the messenger RNA (mRNA) and protein expression of genes related to endoplasmic reticulum stress (activating transcription factor 4 (ATF4), inositol-requiring protein 1 (IRE1), c-Jun N-terminal kinase (JNK), and C/EBP homologous protein (CHOP)) and apoptosis (B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), Caspase-3, Caspase-9, and Caspase-12) were also observed. Notably, the observed damage was worse in SelM KO mice. Furthermore, melatonin alleviated the heart injury caused by NiCl₂ in WT mice but could not exert a good protective effect in the heart of SelM KO mice. Overall, the findings suggested that the antioxidant capacity of SelM, as well as its modulation of endoplasmic reticulum stress and apoptosis, plays important roles in nickel-induced heart injury.
Animals ; Male ; Mice ; Antioxidants/pharmacology* ; Apoptosis ; Endoplasmic Reticulum Stress ; Melatonin/pharmacology* ; Mice, Inbred C57BL ; Nickel/adverse effects* ; Selenoproteins/genetics* ; Heart/drug effects*

BACKGROUND: Pilea umbrosa (Urticaceae) is used by local communities (district Abbotabad) for liver disorders, as anticancer, in rheumatism and in skin disorders. METHODS: Methanol extract of P. umbrosa (PUM) was investigated for the presence of polyphenolic constituents by HPLC-DAD analysis. PUM (150 mg/kg and 300 mg/kg) was administered on alternate days for eight weeks in rats exposed with carbon tetrachloride (CCl). Serum analysis was performed for liver function tests while in liver tissues level of antioxidant enzymes and biochemical markers were also studied. In addition, semi quantitative estimation of antioxidant genes, endoplasmic reticulum (ER) induced stress markers, pro-inflammatory cytokines and fibrosis related genes were carried out on liver tissues by RT-PCR analysis. Liver tissues were also studied for histopathological injuries. RESULTS: Level of antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD), peroxidase (POD) and glutathione (GSH) decreased (p < 0.05) whereas level of thiobarbituric acid reactive substance (TBARS), HO and nitrite increased in liver tissues of CCl treated rat. Likewise increase in the level of serum markers; alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP) and total bilirubin was observed. Moreover, CCl caused many fold increase in expression of ER stress markers; glucose regulated protein (GRP-78), x-box binding protein1-total (XBP-1 t), x-box binding protein1-unspliced (XBP-1 u) and x-box binding protein1-spliced (XBP-1 s). The level of inflammatory mediators such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) was aggregated whereas suppressed the level of antioxidant enzymes; γ-glutamylcysteine ligase (GCLC), protein disulfide isomerase (PDI) and nuclear erythroid 2 p45-related factor 2 (Nrf-2). Additionally, level of fibrosis markers; transforming growth factor-β (TGF-β), Smad-3 and collagen type 1 (Col1-α) increased with CCl induced liver toxicity. Histopathological scrutiny depicted damaged liver cells, neutrophils infiltration and dilated sinusoids in CCl intoxicated rats. PUM was enriched with rutin, catechin, caffeic acid and apigenin as evidenced by HPLC analysis. Simultaneous administration of PUM and CCl in rats retrieved the normal expression of these markers and prevented hepatic injuries. CONCLUSION Collectively these results suggest that PUM constituted of strong antioxidant chemicals and could be a potential therapeutic agent for stress related liver disorders.
Animals ; Carbon Tetrachloride ; adverse effects ; Chemical and Drug Induced Liver Injury ; drug therapy ; etiology ; pathology ; Endoplasmic Reticulum Stress ; drug effects ; Fibrosis ; drug therapy ; genetics ; Inflammation ; drug therapy ; genetics ; Liver ; drug effects ; enzymology ; metabolism ; Male ; Protective Agents ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Urticaceae ; chemistry

OBJECTIVE: To investigate the regulatory effect of iridoid glycoside of radix scrophulariae (IGRS) on endoplasmic reticulum stress induced by oxygen-glucose deprivation and reperfusion METHODS: Rat pheochromocytoma PC12 cells were pretreated with IGRS (50, 100, 200 μg/mL) for 24h, and the RESULTS: The damage caused by OGD/R to PC12 cells was significantly reduced by IGRS, with significant effect on increasing survival rate and reducing LDH release (all CONCLUSIONS IGRS has neuroprotective effect, which may alleviate cerebral ischemia-reperfusion injury by regulating SERCA2, maintaining calcium balance, and inhibiting endoplasmic reticulum stress-mediated apoptosis.
Animals ; Cell Survival/drug effects* ; Down-Regulation/drug effects* ; Endoplasmic Reticulum Stress/drug effects* ; Glucose ; In Vitro Techniques ; Iridoid Glycosides/pharmacology* ; Oxygen ; PC12 Cells ; Rats ; Reperfusion ; Reperfusion Injury/prevention & control* ; Snails/chemistry*

This study is aimed to investigate the intervention effect and possible mechanism of ophiopogonin D( OPD) in protecting cardiomyocytes against ophiopogonin D'( OPD')-induced injury,and provide reference for further research on toxicity difference of saponins from ophiopogonins. CCK-8 assay was used to evaluate the effect of OPD and OPD' on cell viability. The effect of OPD on OPD'-induced cell apoptosis was measured by flow cytometry. Morphologies of endoplasmic reticulum were observed by endoplasmic reticulum fluorescent probe. PERK,ATF-4,Bip and CHOP mRNA levels were detected by Real-time quantitative polymerase chain reaction( PCR) analysis. ATF-4,phosphorylated PERK and e IF2α protein levels were detected by Western blot assay. RESULTS:: showed that treatment with OPD'( 6 μmol·L-1) significantly increased the rate of apoptosis; expressions of endoplasmic reticulum stress related genes were increased. The morphology of the endoplasmic reticulum was changed. In addition,different concentrations of OPD could partially reverse the myocardial cell injury caused by OPD'. The experimental results showed that OPD'-induced myocardial toxicity may be associated with the endoplasmic reticulum stress,and OPD may modulate the expression of CYP2 J3 to relieve the endoplasmic reticulum stress caused by OPD'.
Apoptosis ; Cardiotonic Agents ; pharmacology ; Cells, Cultured ; Endoplasmic Reticulum Stress ; drug effects ; Humans ; Myocytes, Cardiac ; drug effects ; Saponins ; pharmacology ; Spirostans ; pharmacology

OBJECTIVE: This study was conducted to investigate the regulation of endoplasmic reticulum stress on Nrf2 signaling pathway in the kidneys of rats. METHODS: Rats were divided into twelve groups of six animals each. Some groups were pre-administered with bacitracin or tauroursodeoxycholic acid (TUDCA), and all of them were treated with 5-20 μmol/kg cadmium (Cd) for 48 h. The oxidative stress levels were analyzed using kits. The mRNA and protein expression levels of endoplasmic reticulum stress-related factors and Nrf2 signaling pathway-related factors were determined using RT-PCR and western blot. RESULTS: Cd exposure resulted in oxidative stress in the kidneys of rats and upregulated the expression of endoplasmic reticulum stress (ERS)-related factors and Nrf2 signaling pathway-related factors, especially at doses of 10 and 20 μmol/kg Cd, and the expression changes were particularly obvious. Moreover, after pretreatment with bacitracin, Cd upregulated the expression of ERS-related factors to a certain extent and, at higher doses, increased the mRNA expression of Nrf2. After pretreatment with TUDCA, Cd reduced the level of ERS to a certain extent; however, at these doses, there were no significant changes in the expression of Nrf2. CONCLUSION Cadmium can result in ERS and oxidative stress in the kidneys of rats, activate Nrf2, and upregulate the transcriptional expression of phase II detoxification enzymes under these experimental conditions. ERS has a positive regulation effect on Nrf2 signaling pathway but has little effect on the negative regulation of Nrf2 signaling pathway in cadmium toxicity.
Animals ; Cadmium ; toxicity ; Endoplasmic Reticulum Stress ; drug effects ; Environmental Pollutants ; toxicity ; Female ; Kidney ; drug effects ; metabolism ; Male ; NF-E2-Related Factor 2 ; genetics ; metabolism ; Oxidative Stress ; drug effects ; Rats, Sprague-Dawley ; Signal Transduction ; drug effects ; Taurochenodeoxycholic Acid ; pharmacology

As the chemotherapeutic resistance of extranodal NK/T-cell lymphoma (ENKTL) rises year by year, searching for novel chemoprevention compounds has become imminent. Gambogic acid (GA) has recently been shown to have anti-tumor effects, but its role and underling mechanism in ENKTL are rather elusive. In the present study, we showed that GA inhibited the cell growth and potently induced the apoptosis of ENKTL cells in vitro in a time- and concentration-dependent manner. Furthermore, GA induced cell death through endoplasmic reticulum stress (ERS) mediated suppression of Akt signaling pathways and finally the release of the caspase-3 proteases. Overall, our data provided evidences supporting GA as a potential therapeutic agent for ENKTL, which may facilitate further preclinical development of anti-tumor drugs.
Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Endoplasmic Reticulum Stress ; drug effects ; Humans ; Lymphoma, Extranodal NK-T-Cell ; drug therapy ; genetics ; metabolism ; physiopathology ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; Signal Transduction ; drug effects ; Xanthones ; pharmacology

OBJECTIVE: To investigate the effects of sera from rats fed with tablets (HGT) on endoplasmic reticulum (ER) stress in a steatotic hepatocyte model of free fatty acids (FFAs)-induced nonalcoholic fatty liver disease (NAFLD) and explore the possible mechanism. METHODS: FFAs prepared by mixing oleic acid and palmitic acid at the ratio of 2:1. HepG2 cells were treated with the sera from rats fed with low-, moderate-or high-dose HGT (HGT sera) or sera of rats fed with fenofibrate (fenofibrate sera), followed by treatment with 1 mmol/L FFAs for 24 h to induce hepatic steatosis. Oil red O staining was used to observe the distribution of lipid droplets in the cells. The biochemical parameters including triglyceride (TG), lactated hydrogenase (LDH), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured using a commercial kit. The morphological changes of the ER in the cells were observed using transmission electron microscopy. The protein/mRNA expressions of ER stress-related signal molecules including GRP78, PERK, p-PERK, ATF6, ATF4, CASPASE-12, CHOP, XBP-1, PKC, and p-PKC-δ were detected using Western blotting and/or quantitative real-time PCR (qRT-PCR). The changes in the protein expressions of GRP78, p-PERK, CASPASE-12 and CHOP were also detected in cells with transient transfection of PKC-δ siRNA for PKC-δ knockdown. RESULTS: Compared with the control cells, the cells treated with FFAs showed significantly increased levels of TG, AST, and ALT ( < 0.05). Compared with FFAs-treated cells, the cells pretreated with HGT sera or fenofibrate sera all showed significantly decreased TG, AST and ALT levels ( < 0.05), reduced accumulation of the lipid droplets ( < 0.05), and lowered protein or mRNA expression levels of GRP78, p-PERK, ATF6, ATF4, CHOP, CASPASE-12, XBP-1 and p-PKC-δ ( < 0.05). PKC-δ knockdown caused significantly reduced protein expressions of GRP78, p-PERK, CASPASE-12 and CHOP in the cells with FFA-induced hepatic steatosis ( < 0.001); treatment with high-dose HGT serum more significantly reduced the expressions of GRP78 ( < 0.001) and P-PERK ( < 0.01) in FFAs-induced cells with PKC-δ knockdown. CONCLUSIONS HGT serum can effectively prevent FFAs-induced steatosis in HepG2 cells by alleviating ER stress, in which PKC-δ may act as an important target.
Alanine Transaminase ; blood ; Animals ; Aspartate Aminotransferases ; blood ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; Endoplasmic Reticulum ; ultrastructure ; Endoplasmic Reticulum Stress ; drug effects ; Fatty Acids, Nonesterified ; Fenofibrate ; administration & dosage ; Hep G2 Cells ; Humans ; Hypolipidemic Agents ; administration & dosage ; Microscopy, Electron, Transmission ; Non-alcoholic Fatty Liver Disease ; blood ; etiology ; prevention & control ; RNA, Messenger ; blood ; Rats ; Serum ; Tablets ; Triglycerides ; blood

To explore the protective effect of naringin(Nar) on the injury of myocardium tissues induced by streptozotocin(STZ) in diabetic rats and the relationship with oxidative stress and endoplasmic reticulum stress(ERS)， the male SD rats were intraperitoneally injected with streptozotocin(STZ， 60 mg·kg⁻¹) to establish the diabetic rat model and then randomly divided into the type 1 diabetic rat group(T1DR)， the low-dose Nar group(Nar25)， the middle-dose Nar group(Nar50) and the high-dose Nar group(Nar100). The normal rats were designed as control group(Con). Nar25， Nar50， Nar100 groups were orally administered with Nar at the doses of 25.0， 50.0， 100.0 mg·kg⁻¹ per day， respectively， while the normal group and the T1DR group were orally administered with saline. At the 8th week after treatment， fasting plasma glucose and heart mass index were measured. The pathological changes in myocardial tissues were observed by microscope. The cardiac malondialdehyde(MDA) level and superoxide dismutase(SOD) activities were measured. The gene and protein expressions of glucose-regulated protein 78(GRP78)， C/EBP homologous protein(CHOP)， cysteinyl aspartate-specific proteinase 12(caspase 12) were detected by qRT-PCR and Western blot. According to the results， compared with control group， the myocardial structure was damaged， the content of MDA was increased， while the activities of SOD were decreased(<0.05) in T1DR group. GRP78， CHOP and caspase 12 mRNA and protein expressions were increased significantly in T1DR group(<0.05， <0.01). Compared with T1DR group， myocardial structure damage was alleviated in Nar treatment group. The content of MDA was decreased， while the activities of SOD were increased significantly. The mRNA and protein expressions of GRP78， CHOP and caspase 12 were increased， especially in middle and high-dose groups(<0.05， <0.01). After treatment with Nar for 8 weeks， myocardial structure damage was obviously alleviated in Nar treatment groups. The content of MDA was decreased， while the activities of SOD were increased significantly in myocardial tissues. The mRNA and protein expressions of GRP78， CHOP and caspase 12 were increased， especially in middle and high-dose groups(<0.05， <0.01). The findings suggest that Nar may protect myocardium in diabetic rats by reducing mitochondrial oxidative stress injuries and inhibiting the ERS-mediated cell apoptosis pathway.
Animals ; Apoptosis ; Cardiotonic Agents ; pharmacology ; Caspase 12 ; metabolism ; Diabetes Mellitus, Experimental ; Diabetic Cardiomyopathies ; drug therapy ; Endoplasmic Reticulum Stress ; drug effects ; Flavanones ; pharmacology ; Heat-Shock Proteins ; metabolism ; Male ; Malondialdehyde ; metabolism ; Oxidative Stress ; drug effects ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism ; Transcription Factor CHOP ; metabolism

OBJECTIVES: To investigate the effect of Astragalus injection on cardiomyocyte apoptosis, endoplasmic reticulum stress and connexin protein in cardiomyopathy rats induced by adriamycin. METHODS: Thirty-six male Wister rats were randomly divided into control group (=12), adriamycin(ADR) group (=12) and Astragalus group (=12). The normal saline (10 ml/kg body weight) was injected intraperitoneally in control group rats, ADR (2 mg/kg body weight) was injected intraperitoneally in ADR group rats, ADR (10 ml/kg body weight) and Astragalus injection (10 ml/kg body weight) were injected intraperitoneally in rats of astragalus group, one time a week, totle 3 times. By the end of the 7 week, the left ventricular end-diastolic diameter(LVEDD), left ventricular end-systolic diameter (LVESD) and left ventricular ejection fraction (LVEF) were measured by echocardiography. Then the rats in the three groups were sacrificed and the left ventricle section was stained by HE, Masson, uranyl acetate/lead citrate respectively, the cardiomyopathy and ultrastructural changes were observed under light microscope and transmission electron microscope. The apoptosis of rat cardiomyocyte were analyzed by TUNEL. The expression of connexin Cx43 and p-Cx43 was detected by immunohistochemistry. The expression of glucose-regulated protein 78 (Grp78),activating transcription factor 4 (ATF-4) and C/EBP homologous protein (CHOP) were detected by real time PCR. RESULTS: Compared with control group, LVEDD, LVESD increased and LVEF decreased, myocardial fibers were disordered and edematous, infiltrated by lymphocytes, the mitochondria were destroyed and vacuolized, and the number of cardiomyocyte apoptosis was increased(<0.01) in ADR group. The expression of Grp78, ATF-4, CHOP and p-Cx43 were increased, and the expression of Cx43 was decreased in ADR group. However, compared with ADR group, LVEDD, LVESD decreased and LVEF increased, the cardiomyopathy and ultrastructural changes were significantly improved, the number of cardiomyocyte apoptosis was significantly decreased (<0. 01); the expression of Grp78, ATF-4, CHOP and p-Cx43 decreased (<0.01); the expression of Cx43 increased in Astragalus group (<0.01). CONCLUSIONS Astragalus injection may effectively improve the myocardial damage induced by adriamycin, its mechanism may be related to the inhibition of endoplasmic reticulum stress (ERS) and the decrease of phosphorylation of CX43 in cardiomyopathy rats induced by adriamycin.
Animals ; Apoptosis ; Astragalus Plant ; chemistry ; Cardiomyopathies ; chemically induced ; drug therapy ; Doxorubicin ; adverse effects ; Drugs, Chinese Herbal ; pharmacology ; Endoplasmic Reticulum Stress ; drug effects ; Male ; Myocytes, Cardiac ; cytology ; drug effects ; Random Allocation ; Rats ; Rats, Wistar

OBJECTIVE: To investigate the effect of rosuvastatin on homocysteine (Hcy) induced mousevascular smooth muscle cells(VSMCs) dedifferentiation and endoplasmic reticulum stress(ERS). METHODS: VSMCs were co-cultured with Hcy and different concentration of rosuvastatin (0.1, 1.0 and 10 μmol/L). Cytoskeleton remodeling, VSMCs phenotype markers (smooth muscle actin-α, calponin and osteopontin) and ERS marker mRNAs (Herpud1, XBP1s and GRP78) were detected at predicted time. Tunicamycin was used to induce, respectively 4-phenylbutyrate(4-PBA) inhibition, ERS in VSMCs and cellular migration, proliferation and expression of phenotype proteins were analyzed. Mammalian target of rapamycin(mTOR)-P70S6 kinase (P70S6K) signaling agonist phosphatidic acid and inhibitor rapamycin were used in Rsv treated VSMCs. And then mTOR signaling and ERS associated mRNAs were detected. RESULTS: Compared with Hcy group, Hcy+ Rsv group (1.0 and 10 μmol/L) showed enhanced α-SMA and calponin expression (<0.01), suppressed ERS mRNA levels (<0.01) and promoted polarity of cytoskeleton. Compared with Hcy group, Hcy+Rsv group and Hcy+4-PBA group showed suppressed proliferation, migration and enhanced contractile protein expression (<0.01); while tunicamycin could reverse the effect of Rsv on Hcy treated cells. Furthermore, alleviated mTOR-P70S6K phosphorylation and ERS (<0.01)were observed in Hcy+Rsv group and Hcy+rapamycin group, compared with Hcy group; while phosphatidic acid inhibited the effect of Rsv on mTOR signaling activation and ERS mRNA levels (<0.01). CONCLUSIONS Rosuvastatin could inhibit Hcy induced VSMCs dedifferentiation suppressing ERS, which might be regulated by mTOR-P70S6K signaling.
Actins ; metabolism ; Animals ; Calcium-Binding Proteins ; metabolism ; Cell Dedifferentiation ; drug effects ; Cells, Cultured ; Endoplasmic Reticulum Stress ; drug effects ; Heat-Shock Proteins ; metabolism ; Homocysteine ; Membrane Proteins ; metabolism ; Mice ; Microfilament Proteins ; metabolism ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; cytology ; drug effects ; Ribosomal Protein S6 Kinases, 70-kDa ; metabolism ; Rosuvastatin Calcium ; pharmacology ; TOR Serine-Threonine Kinases ; metabolism ; X-Box Binding Protein 1 ; metabolism