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: 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

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

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

OBJECTIVE: To investigate the effects of total flavonids of astragalus(TFA) on arrhythmia, endoplasmic reticulum stress and connexcin in mice with viral myocarditis and to clarify the mechanisms of TFA against viral myocarditis complicated with arrhythmia. METHODS: Thirty-six male Balb/c mice were randomly divided into control group, viral myocarditis group and total flavonoids group (=12). The mice of viral myocarditis were intraperitonealy injected with 0.1 ml/day 10-950 TCID CVB3 for 3 days. The mice of TFA group were intraperitoneal injected with 0.1 ml/day 10-950 TCID CVB3 for 3 days and treated with 0.1ml, 20 mg/L TFA by tail vein injection. At the end of the experiment, arrhythmia was detected by electrocardiogram, the heart of mice were stained by HE, the expressions of glucose-regulated protein 78(GRP78), endoplasmic reticulum stress signaling pathway factor activating transcription factor 4(ATF4) and connexcin 43(Cx43) were detected by Western blot. RESULTS: The expressions of GRP78 and ATF4 were increased and the expression of Cx43 was decreased in viral myocarditis, while TFA inhibited these effect of viral myocarditis in heart of mice. CONCLUSIONS The antiarrhythmic effect of TFA may be related to the alleviation of endoplasmic reticulum stress and the increase of Cx43 expression.
Activating Transcription Factor 4 ; metabolism ; Animals ; Arrhythmias, Cardiac ; drug therapy ; Astragalus Plant ; chemistry ; Connexin 43 ; metabolism ; Coxsackievirus Infections ; drug therapy ; Drugs, Chinese Herbal ; pharmacology ; Endoplasmic Reticulum Stress ; drug effects ; Flavonoids ; pharmacology ; Heat-Shock Proteins ; metabolism ; Male ; Mice ; Mice, Inbred BALB C ; Myocarditis ; drug therapy ; virology ; Myocardium

BackgroundOxidized low-density lipoprotein (ox-LDL)-induced oxidative stress and endothelial apoptosis are essential for atherosclerosis. Our previous study has shown that ox-LDL-induced apoptosis is mediated by the protein kinase RNA-like endoplasmic reticulum kinase (PERK)/eukaryotic translation initiation factor 2α-subunit (eIF2α)/CCAAT/enhancer-binding protein homologous protein (CHOP) endoplasmic reticulum (ER) stress pathway in endothelial cells. Statins are cholesterol-lowering drugs that exert pleiotropic effects including suppression of oxidative stress. This study aimed to explore the roles of simvastatin on ox-LDL-induced ER stress and apoptosis in endothelial cells.

MethodsHuman umbilical vein endothelial cells (HUVECs) were treated with simvastatin (0.1, 0.5, or 2.5 μmol/L) or DEVD-CHO (selective inhibitor of caspase-3, 100 μmol/L) for 1 h before the addition of ox-LDL (100 μg/ml) and then incubated for 24 h, and untreated cells were used as a control group. Apoptosis, expression of PERK, phosphorylation of eIF2α, CHOP mRNA level, and caspase-3 activity were measured. Comparisons among multiple groups were performed with one-way analysis of variance (ANOVA) followed by post hoc pairwise comparisons using Tukey's tests. A value of P < 0.05 was considered statistically significant.

ResultsExposure of HUVECs to ox-LDL resulted in a significant increase in apoptosis (31.9% vs. 4.9%, P < 0.05). Simvastatin (0.1, 0.5, and 2.5 μmol/L) led to a suppression of ox-LDL-induced apoptosis (28.0%, 24.7%, and 13.8%, F = 15.039, all P < 0.05, compared with control group). Ox-LDL significantly increased the expression of PERK (499.5%, P < 0.05) and phosphorylation of eIF2α (451.6%, P < 0.05), if both of which in the control groups were considered as 100%. Simvastatin treatment (0.1, 0.5, and 2.5 μmol/L) blunted ox-LDL-induced expression of PERK (407.8%, 339.1%, and 187.5%, F = 10.121, all P < 0.05, compared with control group) and phosphorylation of eIF2α (407.8%, 339.1%, 187.5%, F = 11.430, all P < 0.05, compared with control group). In contrast, DEVD-CHO treatment had no significant effect on ox-LDL-induced expression of PERK (486.4%) and phosphorylation of eIF2α (418.8%). Exposure of HUVECs to ox-LDL also markedly induced caspase-3 activity together with increased CHOP mRNA level; these effects were inhibited by simvastatin treatment.

ConclusionsThis study suggested that simvastatin could inhibit ox-LDL-induced ER stress and apoptosis in vascular endothelial cells.

Apoptosis ; drug effects ; Cells, Cultured ; Endoplasmic Reticulum Stress ; drug effects ; Human Umbilical Vein Endothelial Cells ; drug effects ; metabolism ; Humans ; Lipoproteins, LDL ; pharmacology ; Oligopeptides ; pharmacology ; Simvastatin ; pharmacology

OBJECTIVETo investigate the effect of arctiin on advanced oxidation protein product (AOPP)-induced epithelial-to-mesenchymal transition (EMT) in tubular cells and explore the mechanisms underlying this effect.

METHODSHuman proximal tubular cells (HK-2 cells) were treated with bovine serum albumin (BSA) or AOPPs in the presence or absence of arctiin. The expressions of E-cadherin, vimentin, and GRP78 at the protein and mRNA levels in the cells were examined using Western blotting and quantitative real-time PCR. The level of reactive oxygen species (ROS) was measured by flow cytometry with DCFH-DA as the fluorescent probe.

RESULTSCompared with BSA-treated cells, the cells treated with AOPPs showed decreased expression of epithelial cell marker E-cadherin and overexpression of mesenchymal marker vimentin and endoplasmic reticulum stress marker GRP78 with an increased ROS level. These changes induced by AOPPs were partly inhibited by arctiin.

CONCLUSIONArctiin can ameliorate AOPP-induced EMT in tubular cells by inhibiting endoplasmic reticulum stress, and oxidative stress response may participate in this process.

Advanced Oxidation Protein Products ; adverse effects ; Cadherins ; metabolism ; Cell Line ; Endoplasmic Reticulum Stress ; Epithelial Cells ; cytology ; drug effects ; Epithelial-Mesenchymal Transition ; Furans ; pharmacology ; Glucosides ; pharmacology ; Heat-Shock Proteins ; metabolism ; Humans ; Kidney Tubules ; cytology ; drug effects ; Oxidative Stress ; Reactive Oxygen Species ; metabolism ; Vimentin ; metabolism

OBJECTIVETo investigate the effect of total flavonoids of astragalus on the expression of endoplasmic reticulum chaperone, calumenin and connecxin 43 (CX43) in suckling mouse myocardium with myocarditis caused by coxsackievirus B3 (CVB3).

METHODSThe primary culture of suckling mouse myocardium cells were randomly divided into control group, CVB3 infected group and total flavonoids of astragalus group. Firstly, to confirm the identity of the suckling mouse myocardium, α-SMA was monitored by immunohistochemistry method. Then the protein expression changes of endoplasmic reticulum chaperone-glucose regulatory protein 78 ( GRP78), calumenin and CX43 were detected by Western blot.

RESULTS(1) Compared with that of the control group, the GRP78 expression level in CVB3 infected group was improved, the expression levels of calumenin and CX43 were all reduced. (2) Compared with that of CVB3 infected group, GRP78 expression level was decreased, and the expression levels of calumenin and CX43 were increased in total flavonoids of astragalus group.

CONCLUSIONCVB3 infection may cause endoplasmic reticulum stress of rat myocardium cells by increasing the expression of GRP78 and decreasing the expression of calumenin and CX43. On the other hand, total flavonoids of astragalus can reduce the expression of GRP78 and increase the expression of calumenin and CX43.The results of this experiment may be closely related to the effects of anti-arrhythmia with viral myocarditis caused by CVB3.

Animals ; Astragalus Plant ; chemistry ; Blotting, Western ; Calcium-Binding Proteins ; metabolism ; Cells, Cultured ; Connexin 43 ; metabolism ; Coxsackievirus Infections ; drug therapy ; Endoplasmic Reticulum ; metabolism ; Endoplasmic Reticulum Stress ; drug effects ; Flavonoids ; pharmacology ; Heat-Shock Proteins ; metabolism ; Mice ; Myocarditis ; drug therapy ; virology ; Myocardium ; cytology ; Myocytes, Cardiac ; drug effects ; virology ; Rats

Effective expression of pIFN-α in recombinant Pichia pastoris was conducted in a 5 L fermentor. Ethanol accumulation during the late glycerol feeding period inhibited heterologous protein expression. Comparative transcriptome analysis was thus performed to compare the gene transcription profiles of Pichia pastoris KM71H in high and low ethanol concentration environments. The results showed that during the glycerol cultivation stage, 545 genes (265 up-regulated and 280 down-regulated) were differentially expressed with ethanol stress. These genes were mainly involved in protein synthesis, energy metabolism, cell cycle and peroxisome metabolism. During the methanol induction stage, 294 genes (171 up-regulated and 123 down-regulated) were differentially expressed, which were mainly related to methanol metabolism, amino acid metabolism and protein synthesis. Ethanol stress increased protein misfolding and reduced structural integrity of ribosome and mitochondria during cultivation stage, and led to the failure of endoplasmic reticulum stress removal and damaged amino acid metabolism during induction stage in Pichia pastoris.
Amino Acids ; metabolism ; Bioreactors ; Endoplasmic Reticulum Stress ; Energy Metabolism ; Ethanol ; chemistry ; Gene Expression Profiling ; Gene Expression Regulation, Fungal ; Glycerol ; Methanol ; Pichia ; metabolism ; Protein Biosynthesis ; drug effects ; Protein Folding ; Recombinant Proteins ; biosynthesis ; Transcriptome