Epilepsies are a group of chronic neurological disorders characterized by spontaneous recurrent seizures caused by abnormal synchronous firing of neurons and transient brain dysfunction. The underlying mechanisms are complex and not yet fully understood. Endoplasmic reticulum (ER) stress, as a condition of excessive accumulation of unfolded and/or misfolded proteins in the ER lumen, has been considered as a pathophysiological mechanism of epilepsy in recent years. ER stress can enhance the protein processing capacity of the ER to restore protein homeostasis through unfolded protein response, which may inhibit protein translation and promote misfolded protein degradation through the ubiquitin-proteasome system. However, persistent ER stress can also cause neuronal apoptosis and loss, which may aggravate the brain damage and epilepsy. This review has summarized the role of ER stress in the pathogenesis of genetic epilepsy.
Humans ; Endoplasmic Reticulum Stress/genetics* ; Unfolded Protein Response ; Endoplasmic Reticulum/pathology* ; Apoptosis ; Epilepsy/genetics*

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*

Endoplasmic reticulum (ER) stress, as an emerging hallmark feature of cancer, has a considerable impact on cell proliferation, metastasis, invasion, and chemotherapy resistance. Ovarian cancer (OvCa) is one of the leading causes of cancer-related mortality across the world due to the late stage of disease at diagnosis. Studies have explored the influence of ER stress on OvCa in recent years, while the predictive role of ER stress-related genes in OvCa prognosis remains unexplored. Here, we enrolled 552 cases of ER stress-related genes involved in OvCa from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) cohorts for the screening of prognosis-related genes. The least absolute shrinkage and selection operator (LASSO) regression was applied to establish an ER stress-related risk signature based on the TCGA cohort. A seven-gene signature revealed a favorable predictive efficacy for the TCGA, International Cancer Genome Consortium (ICGC), and another GEO cohort (P<0.001, P<0.001, and P=0.04, respectively). Moreover, functional annotation indicated that this signature was enriched in cellular response and senescence, cytokines interaction, as well as multiple immune-associated terms. The immune infiltration profiles further delineated an immunologic unresponsive status in the high-risk group. In conclusion, ER stress-related genes are vital factors predicting the prognosis of OvCa, and possess great application potential in the clinic.
Humans ; Female ; Ovarian Neoplasms/genetics* ; Cell Proliferation ; Cytokines ; Endoplasmic Reticulum Stress/genetics*

This study investigated the mechanism of Gegen Qinlian Decoction(GQD) in improving glucose metabolism in vitro and in vivo by alleviating endoplasmic reticulum stress(ERS). Molecular docking was used to predict the binding affinity between the main effective plasma components of GQD and ERS-related targets. Liver tissue samples were obtained from normal rats, high-fat-induced diabetic rats, rats treated with metformin, and rats treated with GQD. RNA and protein were extracted. qPCR was used to measure the mRNA expression of ERS marker glucose-regulated protein 78(GRP78), and unfolded protein response(UPR) genes inositol requiring enzyme 1(Ire1), activating transcription factor 6(Atf6), Atf4, C/EBP-homologous protein(Chop), and caspase-12. Western blot was used to detect the protein expression of GRP78, IRE1, protein kinase R-like ER kinase(PERK), ATF6, X-box binding protein 1(XBP1), ATF4, CHOP, caspase-12, caspase-9, and caspase-3. The calcium ion content in liver tissues was determined by the colorimetric assay. The ERS-HepG2 cell model was established in vitro by inducing with tunicamycin for 6 hours, and 2.5%, 5%, and 10% GQD-containing serum were administered for 9 hours. The glucose oxidase method was used to measure extracellular glucose levels, flow cytometry to detect cell apoptosis, glycogen staining to measure cellular glycogen content, and immunofluorescence to detect the expression of GRP78. The intracellular calcium ion content was measured by the colorimetric assay. Whereas Western blot was used to detect GRP78 and ERS-induced IRE1, PERK, ATF6, and eukaryotic translation initiation factor 2α(eIF2α) phosphorylation. Additionally, the phosphorylation levels of insulin receptor substrate 1(IRS1), phosphatidylinositol 3-kinase regulatory subunit p85(PI3Kp85), and protein kinase B(Akt), which were involved in the insulin signaling pathway, were also measured. In addition, the phosphorylation levels of c-Jun N-terminal kinases(JNKs), which were involved in both the ERS and insulin signaling pathways, were measured by Western blot. Molecular docking results showed that GRP78, IRE1, PERK, ATF4, and various compounds such as baicalein, berberine, daidzein, jateorhizine, liquiritin, palmatine, puerarin and wogonoside had strong binding affinities, indicating that GQD might interfere with ERS-induced UPR. In vivo results showed that GQD down-regulated the mRNA transcription of Ire1, Atf6, Atf4, Grp78, caspase-12, and Chop in diabetic rats, and down-regulated GRP78, IRE1, PERK, as well as ERS-induced apoptotic factors ATF4 and CHOP, caspase-12, caspase-9, and caspase-3, while up-regulating XBP1 to enhance adaptive UPR. In addition, GQD increased the calcium ion content in liver tissues, which facilitated correct protein folding. In vitro results showed that GQD increased glucose consumption in ERS-induced HepG2 cells without significantly affecting cell viability, increased liver glycogen synthesis, down-regulated ATF6 and p-eIF2α(Ser51), and down-regulated IRE1, PERK, and GRP78, as well as p-IRS1(Ser312) and p-JNKs(Thr183/Tyr185), while up-regulating p-PI3Kp85(Tyr607) and p-Akt(Ser473). These findings suggested that GQD alleviates excessive ERS in the liver, reduces insulin resistance, and improves hepatic glucose metabolism in vivo and in vitro.
Rats ; Animals ; Proto-Oncogene Proteins c-akt ; Endoplasmic Reticulum Chaperone BiP ; Caspase 3 ; Caspase 9 ; Diabetes Mellitus, Experimental ; Caspase 12 ; Calcium/pharmacology* ; Molecular Docking Simulation ; Endoplasmic Reticulum Stress ; Protein Serine-Threonine Kinases/genetics* ; Liver ; Apoptosis ; Insulin ; Glucose ; Glycogen/pharmacology* ; RNA, Messenger

OBJECTIVE: To observe the effect of moxibustion at oppositely-located points "Mingmen" (GV 4) and "Shenque" (CV 8) on the motor function of the hind limbs and bladder function in rats with neurogenic bladder after suprasacral spinal cord injury (SCI), so as to explore the effect of this therapy on bladder tissue apoptosis mediated by endoplasmic reticulum stress pathway. METHODS: Twenty-eight female Wistar rats were randomly divided into a sham-operation group (8 rats) and a model establishment group (20 rats). Using the modified Allen's method, the spinal cord of T₁₀ segment was injured to establish a neurogenic bladder model in the model establishment group. Sixteen rats were modeled successfully and then divided into a model group (8 rats) and a moxibustion group (8 rats). In the moxibustion group, 2 h after consciousness regaining from modeling anesthesia, moxibustion was exerted at "Shenque" (CV 8) and "Mingmen" (GV 4), 2 cones at each acupoint in one intervention. The intervention was administered once every two days and 5-time intervention was required totally. After intervention, Basso, Beattie and Bresnahan locomotor rating scale (BBB) score for the motor function of the hind limbs, and the urodynamics indexes (maximum bladder capacity, urine leakage pressure and bladder compliance) were compared among groups. HE staining method was adopted to observe the morphological changes of bladder tissue. With Western blot method and real-time PCR assay, the protein and mRNA expressions of the endoplasmic reticulum stress-related genes (glucose- regulated protein 78 [GRP78], activating transcription factor 4 [ATF4] and cysteinyl aspartate specific proteinase-12 [Caspase-12]) were determined. RESULTS: The transitional epithelial cells were arranged irregularly, the bladder wall was getting thinner, and the cellular vacuolar degeneration and neutrophil infiltration were found in the model group. Whereas, compared with the model group, in the moxibustion group, the arrangement of transitional epithelial cells was clear and continuous in layers, the cellular vacuolar degeneration was mild and the infiltration presented in a small amount of neutrophil granulocytes. Compared with the sham-operation group, in the model group, the BBB score was reduced (P<0.01), the maximum bladder capacity and bladder compliance were increased (P<0.01), and the protein expression levels of GRP78, ATF4 and Caspase-12, as well as mRNA expressions were all increased (P<0.01). In comparison with the model group, in the moxibustion group, BBB score was increased (P<0.01), the maximum bladder capacity and bladder compliance were decreased (P<0.01), and the protein and mRNA expression levels of GRP78, ATF4 and Caspase-12 were all decreased (P<0.01). CONCLUSION Moxibustion at the "oppositely-located points" improves the urination function, alleviate urine retention in neurogenic bladder rats after spinal cord injury. The underlying mechanism may be related to the down-regulation of the expressions of GRP78, ATF4 and Caspase-12 in the endoplasmic reticulum stress pathway of the bladder tissues, and thus to alleviate the apoptosis of bladder tissue.
Animals ; Caspase 12/genetics* ; Electroacupuncture ; Endoplasmic Reticulum Stress ; Female ; Moxibustion ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley ; Rats, Wistar ; Spinal Cord ; Spinal Cord Injuries/therapy* ; Urinary Bladder, Neurogenic/therapy*

To explore the protective effect and mechanism of ethyl acetate extract from Bidens bipinnata on hepatocyte damage induced by endoplasmic reticulum stress. Tunicamycin was used to establish the damage model in L02 cells. Methyl thiazolyl tetrazolium(MTT) colorimetric assay was used to investigate the survival rate of ethyl acetate extract from B. bipinnata in L02 cells injury induced by endoplasmic reticulum stress; the protein expressions of endoplasmic reticulum stress-related molecule glucose regulated protein 78(GRP78), PKR-like ER kinase(PERK), eukaryotic initiation factor-2(eIF2α), activating transcription factor 4(ATF4), C/EBP homologous protein(CHOP), B-cell CLL/lymphoma 2(Bcl-2), Bal-2 associated X apoptosis regulator(Bax) were examined by Wes-tern blot. The expressions of the above proteins were also detected after endoplasmic reticulum stress inhibitor(4-phenyl butyric acid) and CHOP shRNA-mediated knockdowns were added. The expressions of GRP78, PERK, CHOP in L02 cells were observed by immunofluorescence method. The results showed that ethyl acetate extract from B. bipinnata could significantly increase the survival rate of L02 cell injury caused by endoplasmic reticulum stress in a dose and time-dependent manner(P<0.05 or P<0.01). The expression levels of GRP78, PERK, eIF2α, ATF4, CHOP and Bax in the drug treatment groups were significantly down-regulated(P<0.05 or P<0.01), while Bcl-2 was significantly up-regulated(P<0.01). After endoplasmic reticulum stress inhibitor and CHOP shRNA-mediated knockdowns were added, the expression levels of GRP78, PERK, eIF2α, ATF4, CHOP, Bax in the drug treatment groups were significantly down-regulated(P<0.01), whereas Bcl-2 was significantly up-regulated(P<0.01). Immunofluorescence results showed that the expressions of GRP78, PERK, CHOP were consistent with the Western blot method. In conclusion, ethyl acetate extract from B. bipinnata has a significant protective effect on the damage of L02 cells caused by endoplasmic reticulum stress. The mechanism may be related to the inhibition of endoplasmic reticulum stress and the down-regulation of apoptosis in cells through the PERK/eIF2α/ATF4/CHOP signaling pathway.
Acetates ; Apoptosis ; Bidens ; Endoplasmic Reticulum Stress ; Hepatocytes ; Transcription Factor CHOP/genetics* ; eIF-2 Kinase/genetics*

There have been recent extensive studies and rapid advancement on the pathogenesis underlying idiopathic pulmonary fibrosis (IPF), and intricate pathogenesis of IPF has been suggested. The purpose of this study was to clarify the logical relationship between these mechanisms. An extensive search was undertaken of the PubMed using the following keywords: "etiology," "pathogenesis," "alveolar epithelial cell (AEC)," "fibroblast," "lymphocyte," "macrophage," "epigenomics," "histone," acetylation," "methylation," "endoplasmic reticulum stress," "mitochondrial dysfunction," "telomerase," "proteases," "plasminogen," "epithelial-mesenchymal transition," "oxidative stress," "inflammation," "apoptosis," and "idiopathic pulmonary fibrosis." This search covered relevant research articles published up to April 30, 2020. Original articles, reviews, and other articles were searched and reviewed for content; 240 highly relevant studies were obtained after screening. IPF is likely the result of complex interactions between environmental, genetic, and epigenetic factors: environmental exposures affect epigenetic marks; epigenetic processes translate environmental exposures into the regulation of chromatin; epigenetic processes shape gene expression profiles; in turn, an individual's genetic background determines epigenetic marks; finally, these genetic and epigenetic factors act in concert to dysregulate gene expression in IPF lung tissue. The pathogenesis of IPF involves various imbalances including endoplasmic reticulum, telomere length homeostasis, mitochondrial dysfunction, oxidant/antioxidant imbalance, Th1/Th2 imbalance, M1-M2 polarization of macrophages, protease/antiprotease imbalance, and plasminogen activation/inhibition imbalance. These affect each other, promote each other, and ultimately promote AEC/fibroblast apoptosis imbalance directly or indirectly. Excessive AEC apoptosis and impaired apoptosis of fibroblasts contribute to fibrosis. IPF is likely the result of complex interactions between environmental, genetic, and epigenetic factors. The pathogenesis of IPF involves various imbalances centered on AEC/fibroblast apoptosis imbalance.
Alveolar Epithelial Cells ; Apoptosis ; Endoplasmic Reticulum Stress ; Fibroblasts ; Humans ; Idiopathic Pulmonary Fibrosis/genetics*

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