Endoplasmic Reticulum Stress Markers Research Articles

Isoliquiritigenin induced hepatotoxicity and endoplasmic reticulum stress in zebrafish embryos.

Isoliquiritigenin (ISL), a naturally occurring flavonoid derived from licorice root, exhibits antioxidant, anticancer, anti-inflammatory, and anti-allergic properties, and is frequently detected in both environmental and human samples. Previous studies from our lab have demonstrated that ISL exposure can lead to developmental deformities and aberrant immune responses. However, the molecular mechanisms underlying ISL toxicity in zebrafish embryos remain incompletely elucidated. Therefore, this study aimed to elucidate the effects of ISL exposure on endoplasmic reticulum (ER) stress in zebrafish embryos by assessing the expression levels of ER stress markers HSPA5 and CHOP, along with associated apoptosis factors, under various ISL concentrations, with tunicamycin (TM) serving as a positive control. Furthermore, targeted analyses of ER stress-related pathways were conducted using RNA transcriptome sequencing, and the up-regulated gene was verified by western blot. The results revealed that ISL exposure significantly elevated the expression levels of HSPA5 and CHOP, concomitantly activating ER stress pathways, including pPERK-eIF2α-ATF4 and ATF6 pathways in zebrafish embryos. These findings suggest that the activation of endoplasmic reticulum stress signaling pathways may contribute to the developmental deformities observed in zebrafish embryos following ISL exposure, thereby highlighting the potential ecological risks associated with ISL usage.

ER stress-induced YAP upregulation leads to chondrocyte phenotype loss in age-related osteoarthritis

BackgroundOsteoarthritis (OA) is a common degenerative joint disease, leading to pain and restricted mobility. Age-related endoplasmic reticulum (ER) stress has been implicated in the pathogenesis of OA, but the underlying mechanisms remain unclear. This study aims to explore the relationship between age-related ER stress, YAP overexpression, and chondrocyte phenotype loss in the development of OA.MethodsCartilage samples were collected from patients undergoing amputation, and age-related ER stress markers and YAP expression were assessed using immunohistochemical staining and qPCR. Transgenic mice with cartilage-specific YAP overexpression (YAPOE) were created, and Pamrevlumab was administered to evaluate its therapeutic effects.ResultsHigher expression of ER stress markers and YAP were showed in aged tissues compared to younger tissues. YAP overexpression led to decreased levels of cartilage phenotype markers and increased osteogenesis-related proteins. In vivo, YAPOE mice exhibited OA-like cartilage degeneration, which was mitigated by Pamrevlumab treatment.ConclusionAge-related ER stress induces YAP overexpression, contributing to OA pathogenesis. Pamrevlumab effectively prevents this phenotype loss in YAPOE mice, suggesting its potential as a therapeutic agent for OA. These findings provide new insights into the molecular mechanisms of OA and highlight the importance of targeting the ER stress-YAP-CTGF signaling pathway in OA treatment and prevention.

4-Phenylbutyric acid mitigates ER stress-induced neurodegeneration in the spinal cords of a GM2 gangliosidosis mouse model.

Sandhoff disease (SD), a fatal and rare lysosomal storage disorder (LSD), is caused by a deficiency of the enzyme β-hexosaminidase B and leads to severe accumulation of GM2 gangliosides in lysosomes, primarily within the central nervous system (CNS). This accumulation results in severe neurological impairment, lower motor neuron disease, and death. Currently, there are no effective therapies available for SD. Here, we explored the role of endoplasmic reticulum (ER) stress in the spinal cord during disease progression in an established mouse model of SD and revealed the beneficial outcome of off-label treatment with the FDA-approved drug, 4-phenylbutyric acid (4-PBA). We analyzed the expression and localization of ER stress and cellular apoptosis markers, which revealed significant upregulation of these factors within motor neurons. Additionally, we observed a > 50% reduction in neuronal numbers throughout all spinal cord regions. Our studies also tested the impact of the chemical chaperone 4-PBA on ER stress in mice, and following administration, we observed significant improvements in motor neuromuscular function and life span throughout disease progression. 4-PBA treatment significantly reduced apoptosis in spinal cord neurons and increased the number of choline acetyltransferase (ChAT)-positive neurons, with little effect on astrogliosis or sensory interneurons. Overall, this study provides strong evidence for the role of chronic ER stress in the pathophysiology of SD and highlights 4-PBA as a promising therapeutic treatment for SD and potentially other related LSDs.

DEPTOR attenuates asthma progression by suppressing endoplasmic reticulum stress through SOD1.

Endoplasmic reticulum (ER) stress has been shown to play a pivotal role in the pathogenesis of asthma. DEPTOR (DEP Domain Containing MTOR Interacting Protein) is an endogenous mTOR inhibitor that participates in various physiological processes such as cell growth, apoptosis, autophagy, and ER homeostasis. However, the role of DEPTOR in the pathogenesis of asthma is still unknown. In this study, an ovalbumin (OVA)-induced mice model and IL-13 induced 16HBE cells were used to evaluate the effect of DEPTOR on asthma. A decreased DEPTOR expression was shown in the lung tissues of OVA-mice and IL-13 induced 16HBE cells. Upregulation of DEPTOR attenuated airway goblet cell hyperplasia, inhibited mucus hypersecretion, decreased the expression of mucin MUC5AC, and suppressed the level of inflammatory factors IL-4 and IL-5, which were all induced by OVA treatment. The increased protein expression of ER stress markers GRP78, CHOP, unfolded protein response (UPR) related proteins, and apoptosis markers in OVA mice were also inhibited by DEPTOR overexpression. In IL-13 induced 16HBE cells, overexpression of DEPTOR decreased IL-4, IL-5, and MUC5AC levels, preventing ER stress response and UPR process. Furthermore, from the proteomics results, we identified that SOD1 (Cu/Zn Superoxide Dismutase 1) may be the downstream factor of DEPTOR. Similar to DEPTOR, upregulation of SOD1 alleviated asthma progression. Rescue experiments showed that SOD1 inhibition abrogates the remission effect of DEPTOR on ER stress in vitro. In conclusion, these data suggested that DEPTOR attenuates asthma progression by suppressing endoplasmic reticulum stress through SOD1.

EXTH-04. COMBINATION OF BEVACIZUMAB ENHANCES THE ANTI-TUMOR EFFICACY OF AD-SGE-REIC FOR GLIOMA

Abstract Reduced expression in immortalized cells/Dickkopf-3 (REIC/Dkk-3) is a tumor suppressor gene and its overexpression has been shown to exert anti-tumor effects as a therapeutic target gene in many human cancers. Recently, we revealed the anti-glioma effects of an adenoviral vector carrying REIC/Dkk-3 with the super gene expression system (Ad-SGE-REIC) and conducted the phase Ⅰ/Ⅱ a clinical trial for recurrent malignant glioma (jRCT2063190013). Anti-vascular endothelial growth factor treatments such as bevacizumab have demonstrated convincing therapeutic efficacy in patients with glioma. In this study, we examined the effects of Ad-SGE-REIC on glioma treated with bevacizumab in vitro and in vivo. Ad-SGE-REIC treatment resulted in a significant reduction in the number of invasion cells treated with bevacizumab. Western blot analyses revealed the increased expression of several endoplasmic reticulum stress markers in cells treated with both bevacizumab and Ad-SGE-REIC, as well as decreased β-catenin protein levels. In glioma-bearing mouse models, survival was extended in the combination therapy group. These results suggest that the combination therapy of Ad-SGE-REIC and bevacizumab showed anti-glioma effects by suppressing the angiogenesis and invasion of tumor cells. Combined Ad-SGE-REIC and bevacizumab might be a promising strategy for the treatment of malignant glioma.

Polystyrene microplastics cause reproductive toxicity in male mice

Microplastics are a common environmental pollutant that disrupts the reproductive system of living organisms. We investigated the reproductive toxicity of 2μm polystyrene microplastics (PS-MPs) in mice and treated them with PS-MPs for 6 weeks. We demonstrated that PS-MPs decreased the gonadosomatic index and the serum concentration of pituitary-testicular axis hormones (Follicle-stimulating hormone, Luteinizing hormone, and testosterone). The PS-MPs treatment also reduced viable epididymal sperm number and sperm motility. Our results also demonstrated a marked decrease in tubular differentiation index, spermatogenesis index, repopulation index, and steroidogenic foci. The PS-MPs treated mice demonstrated marketed tissue damage in the testis. We also found that reproductive abnormality in PS-MPs treated mice accompanied by reduced antioxidant capacity elevated oxidative stress, and, elevated apoptotic signaling. It was observed that Endoplasmic reticulum (ER) stress markers, including GRP78 and Chop, were upregulated. Based on these findings, oxidative stress and endoplasmic reticulum stress may contribute to the decline in the steroidogenic function of Leydig cells with PS-MPs treated.

Oxidative and endoplasmic reticulum stress in diabetes-related hearing loss: Protective effects of thioredoxin

Diabetes mellitus (DM) induces complex physiological changes in the inner ear environment. This study investigates the roles of oxidative stress (OS) and endoplasmic reticulum stress (ERS) in diabetic hearing loss and explores the potential of thioredoxin (Trx) in regulating OS, ERS, and apoptosis-related factors to mitigate the progression of hearing impairment. We conducted auditory and serological assessments in 63 patients with type 2 diabetes and 30 healthy controls. Type 2 diabetes models were induced in wild-type and Trx transgenic (Tg) mice, with auditory brainstem response (ABR) used to evaluate hearing changes. Cochlear tissues were isolated to analyse markers of apoptosis, OS, and ERS. Both patients with diabetes and mouse models exhibited hearing loss, alongside increased serum levels of Trx1, TXNIP, and AOPP, indicating oxidative damage. H&E and succinate dehydrogenase (SDH) staining revealed varying degrees of hair cell loss from the base to the apex of the cochlea in diabetic mice, with decreased expression of the hair cell protein prestin gene. Notably, Tg mice showed significant delay in hearing loss progression. In vitro, advanced glycation end-products (AGEs) induced OS and ERS in cochlear-like HEI-OC1 cells, while Trx overexpression enhanced Nrf2 activity, alleviating AGE-induced cellular stress. In conclusion, Trx exhibits protective effects against diabetes-related hearing loss, potentially by enhancing Nrf2/HO-1/SOD2 function to reduce OS and ERS.

Pathogenic mechanism and therapeutic intervention of impaired N7-methylguanosine (m7G) tRNA modification

Mutations modification enzymes including the tRNA N7-methylguanosine (m7G) methyltransferase complex component WDR4 were frequently found in patients with neural disorders, while the pathogenic mechanism and therapeutic intervention strategies are poorly explored. In this study, we revealed that patient-derived WDR4 mutation leads to temporal and cell-type-specific neural degeneration, and directly causes neural developmental disorders in mice. Mechanistically, WDR4 point mutation disrupts the interaction between WDR4 and METTL1 and accelerates METTL1 protein degradation. We further uncovered that impaired tRNA m7G modification caused by Wdr4 mutation decreases the mRNA translation of genes involved in mTOR pathway, leading to elevated endoplasmic reticulum stress markers, and increases neural cell apoptosis. Importantly, treatment with stress-attenuating drug Tauroursodeoxycholate (TUDCA) significantly decreases neural cell death and improves neural functions of the Wdr4 mutated mice. Moreover, adeno-associated virus mediated transduction of wild-type WDR4 restores METTL1 protein level and tRNA m7G modification in the mouse brain, and achieves long-lasting therapeutic effect in Wdr4 mutated mice. Most importantly, we further demonstrated that both TUDCA treatment and WDR4 restoration significantly improve the survival and functions of human iPSCs-derived neuron stem cells that harbor the patient's WDR4 mutation. Overall, our study uncovers molecular insights underlying WDR4 mutation in the pathogenesis of neural diseases and develops two promising therapeutic strategies for treatment of neural diseases caused by impaired tRNA modifications.

Secreted GRP78 attenuates endothelial inflammation and predicts outcome in coronary artery disease

Abstract Background Endoplasmic-reticulum-stress (ER-Stress) chaperones like the main ER-Stress moderator GRP78 (glucose-regulated-protein, 78kDa) are involved in the pathogenesis of coronary artery disease (CAD). In addition to their established intracellular localization, chaperones are also secreted into the extracellular space. However, the significance of extracellular ER chaperones in CAD remains unclear. Here, we investigated the role of extracellular GRP78 in patients with suspected CAD and its impact on endothelial cell inflammation. Methods Serum concentration of GRP78 was measured by ELISA in 622 patients undergoing coronary angiography (70.0 ± 12.2 years, 33.6% female and 28.4% with acute coronary syndrome: ACS). The primary endpoint was defined as one-year mortality. Human coronary artery endothelial cells (HCAEC) were treated with ER-Stressors and the effects of ER-Stress conditioned medium (CM) on recipient cell viability, apoptosis, reactive oxygen species (ROS) formation and gene expression were examined. Results GRP78 levels were higher in blood samples of patients with CAD than in patients without CAD (2584 ng/ml vs. 2061 ng/ml, p = 0.047). In patients presenting with ACS, GRP78 levels were lower than in patients presenting with chronic coronary syndrome. Elevated GRP78 levels were independently associated with lower one-year mortality, even after adjustment for cardiovascular risk factors and demographic parameters (4.5% vs. 9.0%, log-rank p = 0.022; Fig.1A). Increased levels of GRP78 (> median of 1710 ng/ml) were associated with a higher BMI (29.0 kg/m2 ± 7.3 vs. 27.0 kg/m2 ± 6.2, p < 0.0001) while there was no difference regarding age, sex, or cardiovascular risk factors. Mass spectrometry analyses of the HCAEC secretome and ELISA revealed increased extracellular GRP78 secretion after ER-Stress activation. Co-incubation with Brefeldin A, an inhibitor of ER-Golgi-trafficking, confirmed active regulation of GRP78 secretion. GRP78-containing CM improved viability while reducing apoptosis, formation of ROS, ER-Stress-signaling, and inflammation in recipient HCAEC compared to CM lacking GRP78 due to BFA treatment or GRP78-knockdown. Likewise, recombinant GRP78 improved HCAEC viability while reducing expression of markers of inflammation and ER stress (Fig.1B). CRIPTO is a membrane-bound co-receptor for growth factors and was previously linked to GRP78-signalling. siRNA-Knockdown of CRIPTO reduces viability and leads to cell apoptosis, irrespective of GRP78-treatment (relative viability: Scr-siRNA+1µg/ml GRP78 vs. Criptodown+1µg/ml GRP78 1.22 ± 0.23 vs. 1.02 ± 0.13, p<0.01, Fig.1C). Thus, GRP78-mediated effects may be mediated by CRIPTO. Conclusion GRP78 is significantly increased in patients with CAD. Intriguingly, elevated levels are associated with reduced one-year mortality. ER-Stress-induced GRP78 secretion represents a feedback mechanism to ameliorate ER-Stress and inflammation in recipient endothelial cells (Fig.2).

A novel VCP modulator, KUS121, attenuates atherosclerosis progression by maintaining intracellular ATP and mitigating ER stress in endothelial cells

Abstract Back ground: Endoplasmic reticulum (ER) stress signaling pathways have pivotal roles in atherosclerosis progression. Recently, we have developed Kyoto University Substance (KUS) 121, which selectively inhibits ATPase activities of valosin-containing protein (VCP) and consequently saves intracellular ATP consumption and mitigates ER stress. KUS121 are known to have protective effects on several disease models including ischemic heart disease and heart failure. However, the efficacy of KUS121 against atherosclerosis was still unclear. Purpose To elucidate the effect of KUS121 on atherosclerosis and its mechanisms. Methods and Results The daily treatment of KUS121 reduced atherosclerosis progression by approximately 40% and macrophage burden in the plaques were also significantly decreased in ApoE knockout mice on high fat diet. Interestingly, we found that C/EBP homologous protein (CHOP), an established ER stress marker, was mainly expressed in plaque endothelium. Therefore, we assessed the action of KUS 121 in endothelial cells using the EA.hy926 cell line. Consequently, it was demonstrated that KUS121 attenuated ER stress-induced apoptosis and downregulated the IRE1α-associated inflammatory pathways. Consistent with these in vitro findings, KUS121 treatment also significantly reduced endothelial apoptosis assessed by TUNEL staining and inflammation examined by immunostaining of NF-κB and ICAM1 in atherosclerotic plaques. Moreover, KUS121 treatment attenuated the recruitment of inflammatory Ly6C high monocytes assessed by bead-labeling technique, which could be due to the reduction of endothelial ICAM1 expression. Furthermore, we also demonstrated that maintenance of intracellular ATP levels mitigates ER stress and prevents pathological states in endothelial cells. Conclusion KUS121 can be a new therapeutic option for atherosclerotic diseases by maintaining intracellular ATP levels and attenuating ER stress-induced apoptosis and inflammation in plaque endothelium.

MicroRNA-5572 Is Associated with Endoplasmic Reticulum Stress Responses in Low Zinc Treated and SOD1 G85R-Transfected HEK293 Cells.

Amyotrophic lateral sclerosis (ALS) is a fetal neurodegenerative disease. The mechanism of sporadic ALS onset remains unclarified in detail. Disruption of zinc homeostasis could be related to sporadic ALS. Previously, we first reported miR-5572 as a microRNA (miRNA) among those identified in the spinal cords of patients with sporadic ALS. However, since its function in ALS remained unknown, this study further examined the role of miR-5572 in low-zinc status and ALS model cells which transfected with causative gene, Cu/Zn superoxide dismutase 1 (SOD1) G85R mutant vector. The miR-5572 level was increased by low-zinc condition accompanied by increase of endoplasmic reticulum (ER) stress. In addition, increase of miR-5572 enhanced the cellular toxicity induced by low-zinc treatment. The expression of miR-5572 was also increased, which was accompanied by an increase of ER stress markers associated with SOD1 aggregation formation. Cell death and ER stress makers levels induced by tunicamycin treatment were further increased in miR-5572 mimic-transfected cells. This study showed that miR-5572 exacerbated ER stress toxicity associated with low-zinc status and mutant SOD1 aggregates in ALS.

Transcriptome-wide analysis reveal dynamic expression changes during endoplasmic reticulum stress in tomato

Endoplasmic reticulum (ER) stress is a cellular condition induced by environmental stressors. Transcriptomic approaches reveal the response of plants to ER stress and provide a broadened view. Tomato plants were treated with tunicamycin, and total RNA isolated from the tomato leaves was sequenced on an RNA-sequencing platform to be analyzed for differential expressions. A total of 856 differentially expressed genes (DEGs) were discovered in tunicamycin-treated tomato leaves. Upregulation of ER stress marker gene expressions was detected after 2h, while a prolonged ER stress downregulated most of the protein-coding genes. Pathways such as: response to stress, jasmonic acid mediated signaling, signal transduction regulation, plant hormone signal transduction, and protein processing in ER were enriched. Prolonged stress mostly resulted in reduced transcript levels, possibly related to a mechanism functioning to lower the load of nascent transcripts in the ER. Our findings emphasize the key role of JA-regulated signaling in tomato ER stress responses due to the differential expressions of the pathway components, along with other plant hormones and signaling-related or regulatory genes. ER stress being a common response to many stressors in plants, transcriptome data obtained here will provide for further studies of understanding plant stress tolerance or generating stress-resistant tomato plants.

L-arginine, aminoguanidine and mesenchymal stem cells reduce the level of endoplasmic reticulum stress markers and D-dimer in the lungs of mice with antiphospholipid syndrome

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by damage to the intima of the microcirculatory blood vessels as a result of the formation of autoimmune antibodies to phospholipids of cell membranes. Recent data indicate a possible link between the occurrence of autoimmune diseases and endoplasmic reticulum stress, impaired nitric oxide availability, high plasma D-dimer level. The aim of the study was to estimate the effect of nitric oxide synthesis modulators L-arginine and aminoguanidine, and mesenchymal stem cells on the level of inositol-requiring enzyme-1a (IRE-1a), glucose-regulated protein 78 (GRP-78) as ER stress markers, and the level of D-dimer in the lung tissue of female BALB/c line mice with experimental APS induced with cardiolipin administration. 30 experimental animals were divided into five groups: 1 – control animals; 2 – mice with APS; 3 – mice with APS, injected intraperitoneally with L-arginine hydrochloride (25 mg/kg) and aminoguanidine (10 mg/kg); 4 – mice with APS, injected intraperitoneally with stem cells (5×106/kg); 5 – mice with APS, injected with L-arginine hydrochloride, aminoguanidine and stem cells in combination. After 10 days post APS formation animals were removed from the experiment, proteins were extracted from the lung tissue and their level was determined with Western blotting. It was established that in group with APS the levels of IRE-1, GRP-78 and D-dimer were substantially increased as compared to the control group. After separate administration of both arginine with aminoguanidine and MSC, as well as with their combined use, the level of IRE-1, GRP-78 and D-dimer decreased compared to the indices in animals with induced APS. The obtained data indicated that this effect is probably due to the reduction of ER stress through iNOS inhibition and the anti-inflammatory action of MSCs. Keywords: aminoguanidine, antiphospholipid syndrome, D-dimer, endoplasmic reticulume stress, GRP-78, IRE-1, L-arginine, lung, mesenchymal stem cells

Potential ameliorative effect of Dapagliflozin on systemic inflammation-induced cardiovascular injury via endoplasmic reticulum stress and autophagy pathway.

Dapagliflozin (DPG) is a sodium-glucose cotransporter-2 inhibitor and is used in the treatment of diabetes. In this study, we aimed to investigate the effect of DPG on cardiotoxicity caused by systemic inflammation via endoplasmic reticulum (ER) stress and autophagy. Four groups of thirty-two Wistar Albino rats were created: Control (1ml oral physiological saline for five days and intraperitoneal saline on the 5th day), LPS (1ml oral physiological saline for five days and intraperitoneal 5mg/kg of LPS on the 5th day), LPS + DPG (10mg/kg of DPG orally for five days and 5mg/kg of LPS intraperitoneally on the 5th day), and DPG (10mg/kg of DPG orally for five days and 5mg/kg of SF intraperitoneally on the 5th day). Histopathological and immunohistochemical analyses were performed on heart and aorta tissues. ER stress and autophagy gene markers in heart tissues were evaluated by RT-qPCR. Oxidative stress in heart tissues and serum cardiac enzymes were analyzed by spectrophotometric method. The heart and aortic tissues of the LPS group showed increased expressions of Tumor Necrosis Factor-α (TNF-α) and Caspase-3 (Cas-3), along with mild hyperemia, slight inflammatory cell infiltrations, and myocardial cell damage. The heart tissues also showed genetically increased expressions of include binding immunoglobulin protein (BiP/ GRP78), protein kinase RNA-like ER Kinase (PERK), inositol-requiring enzyme 1 (IRE-1), activating transcription factors 4 (ATF-4), activating transcription factors 4 (ATF6), C/EBP homologous protein (CHOP), and BECLIN 1. Furthermore, Creatine kinase-MB (CK-MB) and Lactate dehydrogenase (LDH) levels in blood tissue significantly increased, according to biochemical analysis. With DPG therapy, all of these findings were reversed. In conclusion, DPG protects against the cardiotoxic effect of systemic inflammation with its antioxidant and anti-inflammatory properties by regulating ER stress and autophagy pathways.

Inhibitory Effect of Luteolin on Spike S1 Glycoprotein-Induced Inflammation in THP-1 Cells via the ER Stress-Inducing Calcium/CHOP/MAPK Pathway.

The global SARS-CoV-2 outbreak has escalated into a critical public health emergency, with the spike glycoprotein S1 subunit of SARS-CoV-2 (spike-S1) linked to inflammation in lung tissue and immune cells. Luteolin, a flavone with anti-inflammatory properties, shows promise, but research on its effectiveness against long-COVID-related inflammation and spike protein-induced responses remains limited. This study aims to elucidate the underlying mechanisms of inflammation in THP-1 cells induced by the spike-S1. Additionally, it seeks to assess the potential of luteolin in mitigating inflammatory responses induced by the spike-S1 in a THP-1 macrophage model. The gene expression profiles of spike-S1 in THP-1 cells were analyzed by transcriptome sequencing. The inhibitory effect of luteolin on ER stress and inflammation in spike-S1-induced THP-1 cells was investigated using Western blotting, RT-PCR, and ELISA. The candidate genes (CAMK2A, SIGLEC7, PPARGC1B, SEC22B, USP28, IER2, and TIRAP) were upregulated in the spike-S1-induced THP-1 group compared to the control group. Among these, calcium/calmodulin-dependent protein kinase II alpha (CAMK2A) was identified as the most promising molecule in spike-S1-induced THP-1 cells. Our results indicate that the spike S1 significantly increased the expression of ER-stress markers at both gene and protein levels. Luteolin significantly reduced ER stress by decreasing the expression of ER-stress marker genes and ER-stress marker proteins (p < 0.01). Additionally, luteolin exhibited anti-inflammatory properties upon spike S1-induction in THP-1 cells by significantly suppressing IL-6, IL-8, and IL-1β cytokine secretion in a dose-dependent manner (p < 0.05). Furthermore, our results revealed that luteolin exhibited the downregulation of the MAPK pathway, as evidenced by modulating the phosphorylation of p-ERK1/2, p-JNK and p-p38 proteins (p < 0.05). The results from this study elucidate the mechanisms by which the spike S1 induces inflammation in THP-1 cells and supports the use of naturally occurring bioactive compounds, like luteolin, against inflammation-related SARS-CoV-2 infection.

Trans-chalcone ameliorates CCl4-induced acute liver injury by suppressing endoplasmic reticulum stress, oxidative stress and inflammation

BackgroundAcute liver injury serves as a crucial marker for detecting liver damage due to toxic, viral, metabolic, and autoimmune exposures. Due to the response to adverse external stimuli and various cellular homeostasis, Endoplasmic reticulum stress (ERS), Oxidative stress, and Inflammation have great potential for treating liver injury. Trans-chalcones (TC) is a polyphenolic compound derived from a natural plant with anti-oxidative and anti-inflammatory abilities. Here, TC was aimed to attenuate liver injury by triggering ER stress, oxidative stress, inflammation, and apoptosis. A single dose of carbon tetrachloride (CCl4) 1 mL/kg was administered intraperitoneally into C57BL6 mice to construct an in vivo NAFLD model, whereas AML12 cells were treated with lipopolysaccharides (LPS) to construct an in vitro NAFLD model. The mice used in the experiment were randomly assigned to two groups: a 12-hour set and a 24-hour set. Forty-nine mice were randomly divided into seven groups, the control group (Group I), TC group (Group II) 10 mg/kg TC, negative control group (Group III) CCl4, TC + CCl4 groups (Groups IV−VI), mice were subcutaneously treated with (5, 10, and 20) mg/kg of TC for three consecutive days before the CCl4 injection and the positive control group (Group VII) received 10 mg/kg Silymarin. After the experiment, serum transaminase, liver histological pathology, hepatic expression levels ERS, oxidative stress, and inflammation-related markers were assessed. TC pre-treatment significantly alleviates the expression of ER stress, oxidative stress, inflammatory cytokines, and apoptosis in both in vivo and in vitro models of liver injury. TC treatment significantly reduced serum transaminase levels (ALT and AST), and improved liver histopathological scores. TC administration also led to a reduction in MDA levels and the suppression of ROS generated by CCl4 in hepatic tissue, which contributed to an increase in GSH levels. The protective effect of TC on the liver injury mouse model was achieved by inhibiting hepatocyte apoptosis. Moreover, TC pre-treatment dramatically decreased the protein levels of ER stress indicators such as CHOP, Bip, Ero-Lα, IRE1α, PERK, Calnexin, and PDI when compared to the CCl4-only treated group. TC exerts hepatoprotective effects against CCl4-induced acute liver injuries in mice by modulating ERS, oxidative stress, and inflammation. These results suggest that TC pre-treatment at a dose of (20 mg/kg BW) was as effective as silymarin (10 mg/kg) in preventing CCl4-induced acute liver injury. Further investigations are necessary to elucidate the precise molecular mechanisms underlying the hepatoprotective effects of TC and to explore its therapeutic potential in clinical trials.

Fagopyrum dibotrys extract improves nonalcoholic fatty liver disease via inhibition of lipogenesis and endoplasmic reticulum stress in high-fat diet-fed mice

ObjectiveThe prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing, presenting a treatment challenge due to limited options. Endoplasmic reticulum (ER) stress and associated lipid metabolism disorders are main causes of NAFLD, making it important to inhibit ER stress for effective treatment. Fagopyrum dibotrys has hypolipidemic, anti-inflammatory and hepatoprotective properties, showing promise in treating NAFLD. However, its effects on ER stress in NAFLD remain unclear. This study used a high-fat diet (HFD) to establish NAFLD mouse models and supplemented with Fagopyrum dibotrys extract (FDE) to evaluate its therapeutic effect and underlying mechanisms.ResultsWe showed that FDE supplementation reduced the severity of hepatic steatosis and lowered triglycerides (TG) and total cholesterol (TC) levels in NAFLD mice. At the molecular level, FDE supplementation reduced hepatic lipid deposition by downregulating lipogenic markers (SREBP-1c, SCD1) and upregulating fatty acid oxidase CPT1α expression. Additionally, FDE treatment inhibited the overexpression of ER stress markers (GRP78, CHOP, and P-EIF2α) in NAFLD mice livers, and blocked the activation of the PERK-EIF2α-CHOP pathway, demonstrating its role in maintaining ER homeostasis. Considering that activation of the PERK pathway could exacerbate lipid deposition, our findings suggest that FDE has a protective effect against hepatic steatosis in NAFLD mice by attenuating ER stress, and the potential mechanism is through inhibiting the PERK pathway.

Unstressing the Reticulum: Nutritional Strategies for Modulating Endoplasmic Reticulum Stress in Obesity.

The progression of obesity involves several molecular mechanisms that are closely associated with the pathophysiological response of the disease. Endoplasmic reticulum (ER) stress is one such factor. Lipotoxicity disrupts endoplasmic reticulum homeostasis in the context of obesity. Furthermore, it induces ER stress by activating several signaling pathways via inflammatory responses and oxidative stress. ER performs crucial functions in protein synthesis and lipid metabolism; thus, triggers such as lipotoxicity can promote the accumulation of misfolded proteins in the organelle. The accumulation of these proteins can lead to metabolic disorders and chronic inflammation, resulting in cell death. Thus, alternatives, such as flavonoids, amino acids, and polyphenols that are associated with antioxidant and anti-inflammatory responses have been proposed to attenuate this response by modulating ER stress via the administration of nutrients and bioactive compounds. Decreasing inflammation and oxidative stress can reduce the expression of several ER stress markers and improve clinical outcomes through the management of obesity, including the control of body weight, visceral fat, and lipid accumulation. This review explores the metabolic changes resulting from ER stress and discusses the role of nutritional interventions in modulating the ER stress pathway in obesity.

Angiotensin 1 peptide-conjugated CdSe/ZnS quantum dots for cardiac-specific hydrogen sulfide targeted therapy in myocardial ischemia-reperfusion injury.

Myocardial ischemia/reperfusion (I/R) injury remains a major obstacle in cardiovascular therapies. Hydrogen sulfide (H2S) shows promise for mitigating I/R injury, but conventional delivery methods, such as NaHS injections or adenovirus-mediated CSE gene therapy, face low efficiency and systemic side effects. This study explores the use of angiotensin 1 (AT1) peptide-conjugated CdSe/ZnS quantum dots (QDs) for targeted delivery of cystathionine-γ-lyase (CSE) plasmids to the myocardium, aiming to boost local H2S production and minimize I/R injury. CdSe/ZnS QDs were conjugated with AT1 peptides to create a nanocarrier system capable of delivering the CSE plasmid specifically to the myocardium. In vivo fluorescence imaging confirmed heart-specific accumulation. Myocardial infarct size, cardiac function, cell death, and oxidative stress were evaluated. Endoplasmic reticulum stress and mitophagy markers, including CHOP/GRP78/eIF2α, were analyzed, and the CHOP gene's role was further assessed using an adenovirus vector. The AT1-conjugated nanocarriers significantly increased CSE expression in the myocardium, as confirmed by fluorescence imaging, without affecting other organs. This localized delivery reduced myocardial infarct size, improved cardiac function, and decreased oxidative stress and cell death. Importantly, a reduction in endoplasmic reticulum stress and mitophagy markers was observed, suggesting that cardioprotection was mediated via the CHOP/GRP78/eIF2α signaling pathway. Reintroduction of CHOP using an adenovirus vector reversed these protective effects, confirming the pathway's involvement. This study demonstrates that AT1 peptide-conjugated QDs can effectively deliver CSE plasmids to the heart, providing significant protection against I/R injury through enhanced localized H2S production. This approach offers a promising, targeted, and side-effect-free therapy for myocardial I/R injury, with potential for clinical translation.

Cisplatin induces kidney damage through the down-regulation of Prx I by autophagic degradation

In this study, we investigated the potential role of PrxI in cis-diamminedichloroplatinum (cisplatin)-induced renal damage in mice. The anticancer drug cisplatin is a chemotherapeutic agent that is widely used to treat solid tumors. Cisplatin-induced nephrotoxicity is a serious dose-limiting side effect, primarily caused by oxidative stress. The oxidative stress further damages DNA, membranes, and mitochondria, and increases endoplasmic reticulum (ER) stress. Cisplatin produces reactive oxygen species (ROS) through Cytochrome P450 2E1 (CYP2E1) and localizes to the surface of the ER, where CYP2E1 is located.Among the six Prx isoforms, Prx I was selectively degraded in cisplatin-treated kidneys during severe renal function damage. Prx I degradation is blocked in mouse proximal tubular cells treated with 3-methyladenine, an autophagy inhibitor, and in MEF lacking ATG7. Moreover, increased ROS levels on the ER surface due to CYP2E1 overexpression further accelerated Prx I degradation. These results suggest that Prx I degradation is largely mediated through autophagy, which is promoted by cisplatin-induced ER stress. Ablation of Prx I exacerbated cisplatin-induced nephrotoxicity and significantly increased the abundance of oxidative stress, ER stress, and inflammatory markers in the kidney, indicating that Prx I plays a protective role against cisplatin-induced nephrotoxicity.