Expression Of Endoplasmic Reticulum Stress Genes Research Articles

Increased expression of ER stress, inflammasome activation, and mitochondrial biogenesis-related genes in peripheral blood mononuclear cells in major depressive disorder.

A subset of major depressive disorder (MDD) is characterized by immune system dysfunction, but the intracellular origin of these immune changes remains unclear. Here we tested the hypothesis that abnormalities in endoplasmic reticulum (ER) stress, inflammasome activity and mitochondrial biogenesis contribute to the development of systemic inflammation in MDD. RT-qPCR was used to measure mRNA expression of key organellar genes from peripheral blood mononuclear cells (PBMCs) isolated from 186 MDD and 67 healthy control (HC) subjects. The comparative CT (2-ΔΔCT) method was applied to quantify mRNA expression using GAPDH as the reference gene. After controlling for age, sex, BMI, and medication status using linear regression models, expression of the inflammasome (NLRC4 and NLRP3) and the ER stress (XBP1u, XBP1s, and ATF4) genes was found to be significantly increased in the MDD versus the HC group. Sensitivity analyses excluding covariates yielded similar results. After excluding outliers, expression of the inflammasome genes was no longer statistically significant but expression of the ER stress genes (XBP1u, XBP1s, and ATF4) remained significant and the mitochondrial biogenesis gene, MFN2, was significantly increased in the MDD group. NLRC4 and MFN2 were positively correlated with serum C-reactive protein concentrations, while ASC trended significant. The altered expression of inflammasome activation, ER stress, and mitochondrial biogenesis pathway components suggest that dysfunction of these organelles may play a role in the pathogenesis of MDD.

Dietary resveratrol supplementation alleviates cold exposure-induced pyroptosis and inflammation in broiler heart by modulating oxidative stress and endoplasmic reticulum stress

To explore the potential protective effect of resveratrol (RES) on cold-exposed broilers, 360 21-day-old broilers were equally divided into 5 groups with 6 replicates. A control (CON) group was reared at the normal feeding temperature and received a basal diet, and 4 cold exposure (8 ± 1°C for 10 h/d from d 29 to 42) groups were fed the basal diet with 0 (CE), 250 (CE + RES250), 500 (CE + RES500), and 750 (CE + RES750) mg/kg RES from d 22 to 42. Broilers were slaughtered on d 42 and heart tissues were collected to measure the relevant indexes. The results showed that heart tissues of all CE-broilers had inflammatory cell infiltrations, and dietary RES supplementation reduced this phenomenon. Compared to CON group, the concentrations of MDA and H2O2 were increased and activities of SOD and CAT were decreased in all CE-broilers (P < 0.05). mRNA expression of genes related to endoplasmic reticulum (ER) stress (GRP78, IRE1, PERK, EIF-2α, ATF4, ATF6, and CHOP), pyroptosis (NLRP3, ASC, Caspase1, GSDME, IL-18, and IL-1β), and proinflammation (TNF-α, IFN-γ, IL-2, and IL-6) was upregulated and that of ant-inflammatory cytokines (IL-4 and IL-10) was downregulated in CE and all CE + RES groups compared to CON group (P < 0.05). Compared to CE group, the activities of SOD and CAT and mRNA expression of anti-inflammatory genes were increased (P < 0.05), and concentrations of MDA and H2O2 and mRNA expression of ER stress, pyroptosis and proinflammatory genes were reduced (P < 0.05) in 3 CE + RES groups. Additionally, protein levels of PERK, ATF4, CHOP, NLRP3, Caspase1, GSDMD, IL-18, IL-1β, TNF-α, and IL-10 were similar in their mRNA expression. Overall, cold exposure caused oxidative stress and ER stress, and induced pyroptosis and inflammatory response, resulting in heart injury in broilers, and dietary RES addition reduced heart damage by enhancing antioxidant defense function. This study indicates that RES can be a feed additive to alleviate cold exposure-induced heart injury in broilers, and a 500 mg RES/kg diet is the optimal supplemental level.

Development of an Endoplasmic Reticulum Stress-Related Diagnostic Signature in Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS) is a prevalent endocrine and metabolic disorder in premenopausal women. This investigation was to elucidate the underlying mechanism of endoplasmic reticulum stress (ERS) activation in granulosa cells, which has been implicated in the etiology of PCOS. Differentially expressed genes (DEGs) between PCOS and control groups were integrated with ERS gene lists from databases to identify DE-ERS genes, and functional analyses were performed. Univariate regression analysis and the LASSO method were used to select diagnostic factors, followed by establishing a DE-ERS gene-based diagnostic model. A nomogram model was further generated to predict the risk of PCOS. The correlation between ERS gene expression and immune cell proportion was assessed. A total of 14 DE-ERS genes associated with "protein processing in endoplasmic reticulum", "ferroptosis", and "glycerophospholipid metabolism" were selected as PCOS-related factors. An eight-DE-ERS genes-based diagnostic model was developed and displayed satisfactory performance in the training (Area under curve (AUC) = 0.983) and validation datasets (AUC = 0.802). High risk of PCOS can be accurately predicted, which might contribute to clinical decision-making. Moreover, EDEM1 expression was significantly positively correlated with naive B cell infiltration, while PDIA6 was negatively correlated with neutrophil proportion (P < 0.001). We identified eight novel molecules and developed an ERS gene-based diagnostic model in PCOS, which might provide novel insight for finding biomarkers and treatment methods.

Pharmacological SERCA activation limits diet-induced steatohepatitis and restores liver metabolic function in mice

Metabolic dysfunction-associated steatotic liver disease is the most common form of liver disease and poses significant health risks to patients who progress to metabolic dysfunction-associated steatohepatitis. Fatty acid overload alters endoplasmic reticulum (ER) calcium stores and induces mitochondrial oxidative stress in hepatocytes, leading to hepatocellular inflammation and apoptosis. Obese mice have impaired liver sarco/ER Ca2+-ATPase (SERCA) function, which normally maintains intracellular calcium homeostasis by transporting Ca2+ ions from the cytoplasm to the ER. We hypothesized that restoration of SERCA activity would improve diet-induced steatohepatitis in mice by limiting ER stress and mitochondrial dysfunction. WT and melanocortin-4 receptor KO (Mc4r−/−) mice were placed on either chow or Western diet (WD) for 8 weeks. Half of the WD-fed mice were administered CDN1163 to activate SERCA, which reduced liver fibrosis and inflammation. SERCA activation also restored glucose tolerance and insulin sensitivity, improved histological markers of metabolic dysfunction-associated steatohepatitis, increased expression of antioxidant enzymes, and decreased expression of oxidative stress and ER stress genes. CDN1163 decreased hepatic citric acid cycle flux and liver pyruvate cycling, enhanced expression of mitochondrial respiratory genes, and shifted hepatocellular [NADH]/[NAD+] and [NADPH]/[NADP+] ratios to a less oxidized state, which was associated with elevated PUFA content of liver lipids. In sum, the data demonstrate that pharmacological SERCA activation limits metabolic dysfunction-associated steatotic liver disease progression and prevents metabolic dysfunction induced by WD feeding in mice.

Integrated analysis of TCGA data identifies endoplasmic reticulum stress-related lncRNA signature in stomach adenocarcinoma

Abstract Objectives To investigaed the role of endoplasmic reticulum stress (ERS)-related long non-coding RNAs (lncRNAs) in stomach adenocarcinoma (STAD) using TCGA data. Methods This study integrated clinical, transcriptomic, and tumor data from the Cancer Genome Atlas (TCGA). The expression of ERS genes was evaluated, alongside their association with identified lncRNAs. Gene set enrichment analysis and immune cell infiltration analysis were performed to elucidate the biological pathways influenced by these lncRNAs. Results The study identified five lncRNAs – AC012055.1, LINC01235, LINC00571, LINC02073, and CFAP61-AS1 – strongly correlated with ERS pathways and cancer prognosis. A prognostic model based on these lncRNAs was developed and validated across low- and high-risk groups. Potential biological pathways associated with these lncRNAs were uncovered through immune cell infiltration and GSEA. Additionally, screening identified drugs potentially effective against STAD, highlighting co-expressed genes as probable therapeutic targets. Conclusions This research offers detailed insights into the molecular mechanisms of STAD, enhancing understanding of potential therapeutic targets and showing promise for clinical applications.

1539-P: Effects of Free Fatty Acids (FFA) on Central Regulation of Glucose Metabolism

Activation of hypothalamic KATP channels reduces endogenous glucose production (EGP) in nondiabetic rodents and humans, but this response is lost in T2D. Lowering FFA with nicotinic acid (NA) restored central regulation of EGP in T2D subjects (Diabetes 2019; 1799P). High FFA levels, typical of T2D, may increase endoplasmic reticulum (ER) stress and thereby impair hypothalamic control of EGP. To explore how increased FFA might impact central regulation of EGP, we harvested hypothalamic wedges from n=10 Zucker Diabetic Fatty (ZDF) rats (glucose ~ 370 mg/dL) following infusion of NA or saline (Alzet minipump) for 18 h. Nondiabetic rats (n=5) were studied as controls. Gene expression of KATP channel subunit Kir6.2 was decreased in ZDF rats. Upon lowering FFA with NA, hypothalamic expression of this major subunit was restored (Fig 1a). Conversely, increased expression of genes regulating ER stress was reversed by NA (Fig 1b). Directly treating ZDF rat brain slices with NA did not alter the expression of these genes, suggesting that NA's effects were mediated by lowering FFA (Fig 1c). In conclusion, hypothalamic effects of elevated FFA include reduced KATPchannel expression and increased expression of ER stress genes, both of which may contribute reversibly to the loss of central regulation of EGP in T2D. These findings are consistent with our observations in humans noted above, suggesting that FFA could be a therapeutic target in T2D. Disclosure M. Nogueira Cordeiro: None. V.H. Routh: None. A. Manavalan: None. P.M. Mathias: None. C.E. Boyle: None. A.C. Rios Chen: None. N. Jiang: None. N. Friedman: None. Y. Demirhan: None. M. Hawkins: None. K. Zhang: None. Funding American Diabetes Association (7-08-CR-28 to M.H.); National Institutes of Health (R01DK069861); Diabetes Action Research and Education Foundation

GLI1, a novel target of the ER stress regulator p97/VCP, promotes ATF6f-mediated activation of XBP1

Upon accumulation of improperly folded proteins in the Endoplasmic Reticulum (ER), the Unfolded Protein Response (UPR) is triggered to restore ER homeostasis. The induction of stress genes is a sine qua non condition for effective adaptive UPR. Although this requirement has been extensively described, the mechanisms underlying this process remain in part uncharacterized. Here, we show that p97/VCP, an AAA+ ATPase known to contribute to ER stress-induced gene expression, regulates the transcription factor GLI1, a primary effector of Hedgehog (Hh) signaling. Under basal (non-ER stress) conditions, GLI1 is repressed by a p97/VCP-HDAC1 complex while upon ER stress GLI1 is induced through a mechanism requiring both USF2 binding and increase histone acetylation at its promoter. Interestingly, the induction of GLI1 was independent of ligand-regulated Hh signaling. Further analysis showed that GLI1 cooperates with ATF6f to induce promoter activity and expression of XBP1, a key transcription factor driving UPR. Overall, our work demonstrates a novel role for GLI1 in the regulation of ER stress gene expression and defines the interplay between p97/VCP, HDAC1 and USF2 as essential players in this process.

Reduction in Insulin Mediated ERK Phosphorylation by Palmitate in Liver Cells Is Independent of Fatty Acid Induced ER Stress.

Saturated free fatty acids (FFAs) such as palmitate in the circulation are known to cause endoplasmic reticulum (ER) stress and insulin resistance in peripheral tissues. In addition to protein kinase B (AKT) signaling, extracellular signal-regulated kinase (ERK) has been implicated in the development of insulin resistance. However, there are conflicting data regarding role of ERK signaling in ER stress-induced insulin resistance. In this study, we investigated the effects of ER stress on insulin resistance and ERK phosphorylation in Huh-7 cells and evaluated how oleate prevents palmitate-mediated ER stress. Treatment with insulin resulted in an increase of 38–45% in the uptake of glucose in control cells compared to non-insulin-treated control cells, along with an increase in the phosphorylation of AKT and ERK. We found that treatment with palmitate increased the expression of ER stress genes, including the splicing of X box binding protein 1 (XBP1) mRNA. At the same time, we observed a decrease in insulin-mediated uptake of glucose and ERK phosphorylation in Huh-7 cells, without any change in AKT phosphorylation. Supplementation of oleate along with palmitate mitigated the palmitate-induced ER stress but did not affect insulin-mediated glucose uptake or ERK phosphorylation. The findings of this study suggest that palmitate reduces insulin-mediated ERK phosphorylation in liver cells and this effect is independent of fatty-acid-induced ER stress.

Targeting IRE1 endoribonuclease activity alleviates cardiovascular lesions in a murine model of Kawasaki disease vasculitis.

Kawasaki disease (KD) is the leading cause of noncongenital heart disease in children. Studies in mice and humans propound the NLRP3/IL-1β pathway as the principal driver of KD pathophysiology. Endoplasmic reticulum (ER) stress can activate the NLRP3 inflammasome, but the potential implication of ER stress in KD pathophysiology has not been investigated to our knowledge. We used human patient data and the Lactobacillus casei cell wall extract (LCWE) murine model of KD vasculitis to characterize the impact of ER stress on the development of cardiovascular lesions. KD patient transcriptomics and single-cell RNA sequencing of the abdominal aorta from LCWE-injected mice revealed changes in the expression of ER stress genes. Alleviating ER stress genetically, by conditional deletion of inositol-requiring enzyme 1 (IRE1) in myeloid cells, or pharmacologically, by inhibition of IRE1 endoribonuclease (RNase) activity, led to significant reduction of LCWE-induced cardiovascular lesion formation as well as reduced caspase-1 activity and IL-1β secretion. These results demonstrate the causal relationship of ER stress to KD pathogenesis and highlight IRE1 RNase activity as a potential new therapeutic target.

Hexadecanoic acid-enriched extract of Halymenia durvillei induces apoptotic and autophagic death of human triple-negative breast cancer cells by upregulating ER stress

Objective: To investigate the effect of the hexane solvent fraction of Halymenia durvillei (HDHE) on triple-negative breast cancer. Methods: The phytochemical profile of HDHE was investigated by GC-MS. The cytotoxicity of HDHE against MDA-MB-231 cells was determined. The apoptotic and autophagic effects of HDHE were analyzed. The expression of molecular markers controlling apoptosis, autophagy, DNA damage, and endoplasmic reticulum (ER) stress was determined. Results: HDHE contains a mixture of fatty acids, mainly hexadecanoic acid. HDHE at a cytotoxic concentration induced apoptotic death of MDA-MB-231 cells through mitochondrial membrane dysfunction, and induction of apoptosis markers, and increased the expression of proteins related to DNA damage response. HDHE also induced the expression of LC-3, a marker of autophagic cell death at a cytotoxic concentration. Moreover, HDHE modulated the expression of ER stress genes. Conclusions: The hexadecanoic acid-enriched extract of Halymenia durvillei promotes apoptosis and autophagy of human triple-negative breast cancer cells. This extract may be further explored as an anticancer agent for triple-negative breast cancer.

Neutrophils Contribute to ER Stress in Lung Epithelial Cells in the Pristane-Induced Diffuse Alveolar Hemorrhage Mouse Model.

Diffuse alveolar hemorrhage (DAH), although rare, is a life-threatening complication of systemic lupus erythematosus (SLE). Little is known about the pathophysiology of DAH in humans, although increasingly neutrophils, NETosis and inflammatory monocytes have been shown to play an important role in the pristane-induced model of SLE which develops lung hemorrhage and recapitulates many of the pathologic features of human DAH. Using this experimental model, we asked whether endoplasmic reticulum (ER) stress played a role in driving the pathology of pulmonary hemorrhage and what role infiltrating neutrophils had in this process. Analysis of lung tissue from pristane-treated mice showed genes associated with ER stress and NETosis were increased in a time-dependent manner and reflected the timing of CD11b+Ly6G+ neutrophil accumulation in the lung. Using precision cut lung slices from untreated mice we observed that neutrophils isolated from the peritoneal cavity of pristane-treated mice could directly induce the expression of genes associated with ER stress, namely Chop and Bip. Mice which had myeloid-specific deletion of PAD4 were generated and treated with pristane to assess the involvement of PAD4 and PAD4-dependent NET formation in pristane-induced lung inflammation. Specific deletion of PAD4 in myeloid cells resulted in decreased expression of ER stress genes in the pristane model, with accompanying reduction in IFN-driven genes and pathology. Lastly, coculture experiments of human neutrophils and human lung epithelial cell line (BEAS-2b) showed neutrophils from SLE patients induced significantly more ER stress and interferon-stimulated genes in epithelial cells compared to healthy control neutrophils. These results support a pathogenic role of neutrophils and NETs in lung injury during pristane-induced DAH through the induction of ER stress response and suggest that overactivation of neutrophils in SLE and NETosis may underlie development of DAH.

Influences of Unmodified and Carboxylated Carbon Nanotubes on Lipid Profiles in THP-1 Macrophages: A Lipidomics Study.

Since the possible roles of surface modifications in determining multi-walled carbon nanotube (MWCNT)-promoted endoplasmic reticulum (ER) stress-mediated lipid-laden macrophage foam cell formation are still in debate, we compared unmodified and carboxylated MWCNT-induced cytotoxicity, lipid profile changes, and expression of ER stress genes in THP-1 macrophages. Particularly, we focused on lipid profile changes by using lipidomics approaches. We found that unmodified and carboxylated MWCNTs significantly decreased cellular viability and appeared to damage the cellular membrane to a similar extent. Likewise, the results from Oil Red O staining showed that both types of MWCNTs slightly but significantly induced lipid accumulation. In keeping with Oil Red O staining results, lipidomics data showed that both types of MWCNTs up-regulated most of the lipid classes. Interestingly, almost all lipid classes were relatively higher in carboxylated MWCNT-exposed THP-1 macrophages compared with unmodified MWCNT-exposed cells, indicating that carboxylated MWCNTs more effectively changed lipid profiles. But in contrast to our expectation, none of the MWCNTs significantly induced the expression of ER stress genes. Even, compared with carboxylated MWCNTs, unmodified MWCNTs induced higher expression of lipid genes, including macrophage scavenger receptor 1 and fatty acid synthase. Combined, our results suggested that even though carboxylation did not significantly affect MWCNT-induced lipid accumulation, carboxylated MWCNTs were more potent to alter lipid profiles in THP-1 macrophages, indicating the need to use omics techniques to understand the exact nanotoxicological effects of MWCNTs. However, the differential effects of unmodified and carboxylated MWCNTs on lipid profiles might not be related with the induction of ER stress.

Mir-221, mir-190b, mir-363-3p, mir-200c are involved in rat liver ischaemia-reperfusion injury through oxidative stress, apoptosis and endoplasmic reticulum stress.

In this study, it was aimed to investigate the relationship between expression levels of micro-RNAs, endoplasmic reticulum (ER) stress, apoptosis and oxidative stress markers in hepatic ischaemia-reperfusion (IR) injury. Sixteen rats were randomised into two groups: Sham and IR groups. In the IR group, portal vein and hepatic artery were totally clamped with an atraumatic microvascular clamp and 60minutes later unclamped and finally IR model was accomplished (60minutes ischaemia and 60minutes reperfusion). After sacrification, serum insulin-like growth factor-1 (IGF-1), tumour necrosis factor-α (TNF-α), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured. Liver tissue samples were evaluated histopathologically. The expression levels of IR1-alpha, Perk, Catalase, Gpx-1, Caspase-3, Bcl-2 genes and miR-33a, miR-221, miR-190b, miR-363-3p, miR-200c, miR-223, miR-133b were measured by quantitative real-time polymerase chain reaction method. Biochemical parameters of the IR group showed significantly higher changes compared with the Sham group (P<.01). Histological tissue damage was significantly prominent in the IR group. ER stress, oxidative stress and apoptosis gene expression levels were significantly higher in the IR group (P<.01). Expression levels of miR-221, miR-190b, miR-363-3p and miR-200c were increased in the IR group compared with the Sham group. No significant difference was found between the two groups in terms of miR-33a, miR-133b and miR-223 expression levels (P>.05). There is a strong need to enlighten the physiopathological and molecular mechanisms of liver IR injury and to find more specific biomarkers for IR damage, and miR-221, miR-190b, miR-363-3p and miR-200c maybe used as potential biomarkers of hepatic IR injury.

Heparan sulfate proteoglycans in beta cells provide a critical link between endoplasmic reticulum stress, oxidative stress and type 2 diabetes.

Heparan sulfate proteoglycans (HSPGs) consist of a core protein with side chains of the glycosaminoglycan heparan sulfate (HS). We have previously identified (i) the HSPGs syndecan-1 (SDC1), and collagen type XVIII (COL18) inside mouse and human islet beta cells, and (ii) a critical role for HS in beta cell survival and protection from reactive oxygen species (ROS). The objective of this study was to investigate whether endoplasmic reticulum (ER) stress contributes to oxidative stress and type 2 diabetes (T2D) by depleting beta cell HSPGs/HS. A rapid loss of intra-islet/beta cell HSPGs, HS and heparanase (HPSE, an HS-degrading enzyme) accompanied upregulation of islet ER stress gene expression in both young T2D-prone db/db and Akita Ins2WT/C96Y mice. In MIN6 beta cells, HSPGs, HS and HPSE were reduced following treatment with pharmacological inducers of ER stress (thapsigargin or tunicamycin). Treatment of young db/db mice with Tauroursodeoxycholic acid (TUDCA), a chemical protein folding chaperone that relieves ER stress, improved glycemic control and increased intra-islet HSPG/HS. In vitro, HS replacement with heparin (a highly sulfated HS analogue) significantly increased the survival of wild-type and db/db beta cells and restored their resistance to hydrogen peroxide-induced death. We conclude that ER stress inhibits the synthesis/maturation of HSPG core proteins which are essential for HS assembly, thereby exacerbating oxidative stress and promoting beta cell failure. Diminished intracellular HSPGs/HS represent a previously unrecognized critical link bridging ER stress, oxidative stress and beta cell failure in T2D.

Different Expression of Mitochondrial and Endoplasmic Reticulum Stress Genes in Epicardial Adipose Tissue Depends on Coronary Atherosclerosis.

The aim of our study was to analyze mitochondrial and endoplasmic reticulum (ER) gene expression profiles in subcutaneous (SAT) and epicardial (EAT) adipose tissue, skeletal muscle, and myocardium in patients with and without CAD undergoing elective cardiac surgery. Thirty-eight patients, 27 with (CAD group) and 11 without CAD (noCAD group), undergoing coronary artery bypass grafting and/or valvular surgery were included in the study. EAT, SAT, intercostal skeletal muscle, and right atrium tissue and blood samples were collected at the start and end of surgery; mRNA expression of selected mitochondrial and ER stress genes was assessed using qRT-PCR. The presence of CAD was associated with decreased mRNA expression of most of the investigated mitochondrial respiratory chain genes in EAT, while no such changes were seen in SAT or other tissues. In contrast, the expression of ER stress genes did not differ between the CAD and noCAD groups in almost any tissue. Cardiac surgery further augmented mitochondrial dysfunction in EAT. In our study, CAD was associated with decreased expression of mitochondrial, but not endoplasmic reticulum stress genes in EAT. These changes may contribute to the acceleration of coronary atherosclerosis.

MicroRNA-210 Regulates Endoplasmic Reticulum Stress and Apoptosis in Porcine Embryos.

Simple SummaryThe purpose of this study was to explore the effect of miR-210 on in vitro embryo development, mRNA expression related endoplasmic reticulum (ER) stress. Treatment with a miR-210-inhibitor significantly improved in vitro embryo development and total blastocyst cell number (TCN). Furthermore, miR-210-inhibitor treatment downregulated ER stress and apoptosis-related gene expression, while simultaneously improving embryo capacity. In contrast, a miR-210-mimic decreased in vitro embryo development, TCN, upregulated ER stress and apoptosis genes, and concomitantly impaired embryo quality. Therefore, we suggest that miR-210 plays an important role in porcine in vitro embryo development.Endoplasmic reticulum (ER) stress can be triggered during in vitro embryo production and is a major obstacle to embryo survival. MicroRNA (miR)-210 is associated with cellular adaptation to cellular stress and inflammation. An experiment was conducted to understand the effects of miR-210 on in vitro embryo development, ER stress, and apoptosis; to achieve this, miR-210 was microinjected into parthenogenetically activated embryos. Our results revealed that miR-210 inhibition significantly enhanced the cleavage rate, blastocyst formation rate, and total cell number (TCN) of blastocysts, and reduced expression levels of XBP1 (p < 0.05). miR-210 inhibition greatly reduced the expression of ER stress-related genes (uXBP1, sXBP1, ATF4, and PTPN1) and Caspase 3 and increased the levels of NANOG and SOX2 (p < 0.05). A miR-210-mimic significantly decreased the cleavage, blastocyst rate, TCN, and expression levels of XBP1 compared with other groups (p < 0.05). The miR-210-mimic impaired the expression levels of uXBP1, sXBP1, ATF4, PTPN1, and Caspase 3 and decreased the expression of NANOG and SOX2 (p < 0.05). In conclusion, miR-210 plays an essential role in porcine in vitro embryo development. Therefore, we suggest that miR-210 inhibition could alleviate ER stress and reduce apoptosis to support the enhancement of in vitro embryo production.

MKP-1 Overexpression Reduces Postischemic Myocardial Damage through Attenuation of ER Stress and Mitochondrial Damage.

Mitochondrial dysfunction and endoplasmic reticulum (ER) stress contribute to postischemic myocardial damage, but the upstream regulatory mechanisms have not been identified. In this study, we analyzed the role of mitogen-activated protein kinase (MAPK) phosphatase 1 (MKP-1) in the regulation of mitochondrial function and ER stress in hypoxic cardiomyocytes. Our results show that MKP-1 overexpression sustains viability and reduces hypoxia-induced apoptosis among H9C2 cardiomyocytes. MKP-1 overexpression attenuates ER stress and expression of ER stress genes and improves mitochondrial function in hypoxia-treated H9C2 cells. MKP-1 overexpression also increases ATP production and mitochondrial respiration and attenuates mitochondrial oxidative damage in hypoxic cardiomyocytes. Moreover, our results demonstrate that ERK and JNK are the downstream signaling targets of MKP-1 and that MKP-1 overexpression activates ERK, while it inhibits JNK. Inhibition of ERK reduces the ability of MKP-1 to preserve mitochondrial function and ER homeostasis in hypoxic cardiomyocytes. These results show that MKP-1 plays an essential role in the regulation of mitochondrial function and ER stress in hypoxic H9C2 cardiomyocytes through normalization of the ERK pathway and suggest that MKP-1 may serve as a novel target for the treatment of postischemic myocardial injury.

Comparison of cytotoxicity of Ag/ZnO and Ag@ZnO nanocomplexes to human umbilical vein endothelial cells in vitro.

Novel metal and metal oxide-based nanocomplexes are being developed due to their superior properties compared with nanoparticles (NPs) based on single composition. In this study, we synthesized Ag-coated ZnO (Ag/ZnO) and Ag-doped ZnO (Ag@ZnO) NPs. The cytotoxicity and mechanisms associated with the synthesized NPs were investigated to understand the influence of Ag positions on biocompatibility of the NPs. After exposure to human umbilical vein endothelial cells (HUVECs), Ag/ZnO, Ag@ZnO, and ZnO NPs all significantly induced cytotoxicity, but the cytotoxic effects of Ag/ZnO and Ag@ZnO NPs were more modest in comparison with ZnO NPs. At cytotoxic concentrations, all NPs significantly induced intracellular Zn ions, which suggested a role of excessive Zn ions on cytotoxicity of NPs. All types of NPs significantly induced the expression of endoplasmic reticulum (ER) stress genes including DNA damage-inducible transcript 3 (DDIT3), X-box binding protein 1 (XBP-1), and ER to nucleus signaling 1 (ERN1), but Ag/ZnO and Ag@ZnO NPs were less effective to induce DDIT3 and XBP-1 expression compared with ZnO NPs. Not surprisingly, only ZnO NPs significantly induced the expression of caspase 3. Combined, the results from this study showed that Ag/ZnO and Ag@ZnO NPs were less cytotoxic and less potent to induce ER stress gene expression compared with ZnO NPs, but there were no significant differences between Ag/ZnO and Ag@ZnO NPs. Our results may provide novel understanding about the biocompatibility of Ag-ZnO nanocomplexes.

Intravaginal poly-(D, L-lactic-co-glycolic acid)-(polyethylene glycol) drug-delivery nanoparticles induce pro-inflammatory responses with Candida albicans infection in a mouse model.

In a recent study, using an in vitro model to study intravaginal nanoparticle exposure during yeast infections, we demonstrated that C. albicans exposure suppressed apoptotic gene expression and induced oxidative stress and pyroptosis in vaginal epithelial cells. The mucous-penetrating drug delivery nanoparticles made from poly-(D, L-lactic-co-glycolic acid)-(polyethylene glycol) induced cytotoxicity by activating apoptosis, endoplasmic reticulum (ER) stress, oxidative stress, and DNA damage repair responses alone and, in some cases with C. albicans. In the current study we evaluated the effects of fluorescently-labelled nanoparticles in CBA/J mice challenged intravaginally for two hours followed by intravaginal challenge with C. albicans for 18 hours. Nanoparticle treatment increased systemic translocation of C. albicans threefold in the heart. C. albicans also increased systemic distribution of the nanoparticles fivefold in the heart. Flow cytometric assays showed co-localization of the nanoparticles with epithelial cells, macrophages and dendritic cells. Nanoparticle-treated, C. albicans-infected mice exhibited induction of autophagy, ER stress, apoptosis, and inflammatory serum cytokines. C. albicans infection was associated with pyroptosis and suppressed expression of ER stress and apoptosis-related genes. Induction of apoptosis during nanoparticle treatment and in nanoparticle-treated-C. albicans infected mice was observed as DNA damage responses, mitochondrial depolarization and (Poly [ADP-Ribose] Polymerase) cleavage. C. albicans infection was associated with increased mRNA expression of anti-apoptotic genes. Both C. albicans infection and nanoparticle treatment showed enhanced chemoattraction of dendritic cells and polymorphonuclear cells to factors in vaginal washings in a chemotaxis assay. This study shows that both intravaginal treatment of mice with the nanoparticles and infection with C. albicans induce cytotoxic and inflammatory responses. C. albicans also suppressed cell apoptosis. These results clarify our understanding of how nanoparticles modulate host cellular responses during C. albicans infection and will be applicable for future research and development of intravaginal nanomedicines.

Melatonin alleviates LPS-induced endoplasmic reticulum stress and inflammation in spermatogonial stem cells.

Orchitis is one of the leading causes of male animal infertility and is associated with inflammatory reactions caused by the bacterium. It has been reported that there is a mutual coupling effect between endoplasmic reticulum stress (ERS) and inflammatory response. Our studies showed that lipopolysaccharide (LPS) could cause testicular damages, apoptosis, ERS, and inflammatory responses in spermatogonial stem cells (SSCs); ERS-related apoptosis proteins were activated and the expression of ERS genes was significantly upregulated;meanwhile, the expression of Toll-like receptor 4and inflammation factors was apparently increased with LPS treatment. Moreover, melatonin (MEL) could rescue testicular damage, and significantly inhibited the expression of ERS-related apoptosis genes, ERS markers, and inflammatory factors in SSCs and MEL played repairing and anti-infection roles in LPS-induced testicular damage. Therefore, MEL may be used as a drug to prevent and control bacterial infections in male reproductive systems. However, the specific molecular mechanism of MEL to resist ERS and inflammatory response remains to be further studied.