Modulation Of Endoplasmic Reticulum Stress Research Articles

Lipid-Modulated, Graduated Inhibition of N-Glycosylation Pathway Priming Suggests Wide Tolerance of ER Proteostasis to Stress.

Protein N-glycosylation is a cotranslational modification that takes place in the endoplasmic reticulum (ER). Disruption of this process can result in accumulation of misfolded proteins, known as ER stress. In response, the unfolded protein response (UPR) restores proteostasis or responds by controlling cellular fate, including increased expression of activating transcription factor 4 (ATF4) that can lead to apoptosis. The ability to control and manipulate such a stress pathway could find use in relevant therapeutic areas, such as in treating cancerous states in which the native ER stress response is often already perturbed. The first committed step in the N-glycosylation pathway is therefore a target for potential ER stress modulation. Here, using structure-based design, the scaffold of the natural product tunicamycin allows construction of a panel capable of graduated inhibition of DPAGT1 through lipid-substituent-modulated interaction. The development of a quantitative, high-content, cellular immunofluorescence assay allowed precise determination of downstream mechanistic consequences (through the nuclear localization of key proxy transcription factor ATF4 as a readout of resulting ER stress). Only the most potent inhibition of DPAGT1 generates an ER stress response. This suggests that even low-level "background" biosynthetic flux toward protein glycosylation is sufficient to prevent response to ER stress. "Tuned" inhibitors of DPAGT1 also now seemingly successfully decouple protein glycosylation from apoptotic response to ER stress, thereby potentially allowing access to cellular states that operate at the extremes of normal ER stress.

Osthole ameliorates wear particle-induced osteogenic impairment by mitigating endoplasmic reticulum stress via PERK signaling cascade

BackgroundPeriprosthetic osteolysis and subsequent aseptic loosening are the leading causes of failure following total joint arthroplasty. Osteogenic impairment induced by wear particles is regarded as a crucial contributing factor in the development of osteolysis, with endoplasmic reticulum (ER) stress identified as a key underlying mechanism. Therefore, identifying potential therapeutic targets and agents that can regulate ER stress adaption in osteoblasts is necessary for arresting aseptic loosening. Osthole (OST), a natural coumarin derivative, has demonstrated promising osteogenic properties and the ability to modulate ER stress adaption in various diseases. However, the impact of OST on ER stress-mediated osteogenic impairment caused by wear particles remains unclear.MethodsTiAl6V4 particles (TiPs) were sourced from the prosthesis of patients who underwent revision hip arthroplasty due to aseptic loosening. A mouse calvarial osteolysis model was utilized to explore the effects of OST on TiPs-induced osteogenic impairment in vivo. Primary mouse osteoblasts were employed to investigate the impact of OST on ER stress-mediated osteoblast apoptosis and osteogenic inhibition induced by TiPs in vitro. The mechanisms underlying OST-modulated alleviation of ER stress induced by TiPs were elucidated through Molecular docking, immunochemistry, PCR, and Western blot analysis.ResultsIn this study, we found that OST treatment effectively mitigated TiAl6V4 particles (TiPs)-induced osteolysis by enhancing osteogenesis in a mouse calvarial model. Furthermore, we observed that OST could attenuate ER stress-mediated apoptosis and osteogenic reduction in osteoblasts exposed to TiPs in vitro and in vivo. Mechanistically, we demonstrated that OST exerts bone-sparing effects on stressed osteoblasts upon TiPs exposure by specifically suppressing the ER stress-dependent PERK signaling cascade.ConclusionOsthole ameliorates wear particle-induced osteogenic impairment by mitigating endoplasmic reticulum stress via PERK signaling cascade. These findings suggest that OST may serve as a potential therapeutic agent for combating wear particle-induced osteogenic impairment, offering a novel alternative strategy for managing aseptic prosthesis loosening.

Nitazoxanide mitigates methotrexate hepatotoxicity in rats: role in inhibiting apoptosis and regulating endoplasmic reticulum stress.

Hepatotoxicity is a severe outcome of methotrexate (MTX) therapy, limiting its clinical use and contributing to its related morbidity and mortality. This study investigated the hepatoprotective effects of nitazoxanide (NTZ), an antiprotozoal drug, against MTX-induced hepatotoxicity and whether endoplasmic reticulum (ER) stress-modulation underlies the expected beneficial effects of NTZ. Thirty-six rats were allocated to six groups, one control group and five MTX groups, where induction of hepatotoxicity was achieved via injecting MTX (20mg/kg). Groups were assigned as MTX-vehicle, NTZ-100, and NTZ-200 groups (at 100 and 200mg/kg/day, gavage, respectively), N-acetyl cysteine (NAC) group (500mg/kg), and 4-phenyl butyric acid (4-PBA) group (150mg/kg, i.p). Liver function enzymes in serum, hepatic oxidative stress, proinflammatory cytokines, apoptosis, and ER-stress biomarkers were assessed. A histopathological examination was performed. Treatment with NTZ lessened the serum liver enzymes, reduced malondialdehyde (lipid peroxidation product), enhanced antioxidant capacity, attenuated proinflammatory cytokines, and suppressed apoptosis. The protective effect of NTZ was dose-dependent, and the findings observed with the high-dose NTZ were similar to those obtained with the ER-stress inhibitor (4-PBA). NTZ exerted a hepatoprotective effect in MTX-challenged rats that is mediated via modulation of ER stress and inhibiting apoptosis.

Endoplasmic Reticulum Stress Induces ROS Production and Activates NLRP3 Inflammasome Via the PERK-CHOP Signaling Pathway in Dry Eye Disease.

The purpose of this study was to investigate the potential roles of endoplasmic reticulum (ER) stress in the development of dry eye disease (DED). Single-cell RNA sequencing (scRNA-seq) data from the Gene Expression Omnibus (GEO) database, derived from corneal tissues of a dry eye mouse model, was processed using the Seurat R program. The results were validated using a scopolamine-induced dry eye mouse model and a hyperosmotic-induced cell model involving primary human corneal epithelial cells (HCECs) and immortalized human corneal epithelial (HCE-2) cells. The HCE-2 cells were treated with 4-phenylbutyric acid (4-PBA) or tunicamycin (TM) to modulate ER stress. TXNIP and PERK knockdown were performed by siRNA transfection. Immunofluorescence, Western blotting, and real-time PCR were used to assess oxidative stress, ER stress, unfolded protein response (UPR) marker proteins, and TXNIP/NLRP3 axis activation. The analysis of scRNAseq data shows an increase in the ER stress marker GRP78, and the activation of the PERK-CHOP of UPR in DED mouse. These findings were confirmed both in vivo and in vitro. Additionally, HCE-2 cells treated with 4-PBA or TM showed significant effects on the production of reactive oxygen species (ROS) and the activation of the TXNIP/NLRP3-IL1β signaling pathway. Furthermore, siRNA knockdown of PERK or TXNIP, which alleviated the TXNIP/NLRP3-IL1β signaling axis, showed protective effects on HCECs. This study explores the role of ER stress-induced oxidative stress and NLRP3-IL-1β mediated inflammation in DED, and highlights the therapeutic potential of PERK-CHOP axis and TXNIP in the treatment of DED.

Modulating Endoplasmic Reticulum Stress in Gastrointestinal Cancers: Insights from Traditional Chinese Medicine.

Endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) play critical roles in tumorigenesis, cancer progression, and drug resistance. Persistent activation of the ER stress system enhances the survival capacities of malignant tumor cells, including increased proliferation, invasion, and resistance to treatment. Dysregulation of ER function and the resultant stress is a common cellular response to cancer therapies and may lead to cancer cell death. Currently, growing evidence suggests that Traditional Chinese medicine (TCM), either as a monotherapy or in combination with other treatments, offers significant advantages in preventing cancer, inhibiting tumor growth, reducing surgical complications, improving drug sensitivity, and mitigating drug-induced damage. Some of these natural products have even entered clinical trials as primary or complementary anticancer agents. In this review, we summarize the anticancer effects of TCM monomers/natural products on the gastrointestinal (GI) tumors and explore their mechanisms through ER stress modulation. We believe that ongoing laboratory research and the clinical development of TCM-based cancer therapies hold considerable potential for advancing future cancer treatments.

SIRT1-Dependent Neuroprotection by Resveratrol in TOCP-Induced Spinal Cord Injury: Modulation of ER Stress and Autophagic Flux.

This study explores the neuroprotective effects of resveratrol (Resv) against tri-o-cresyl phosphate (TOCP)-induced neurotoxicity in the spinal cord of adult hens. It is well documented that TOCP exposure causes significant neurodegeneration via mechanisms that involve endoplasmic reticulum (ER) stress and impaired autophagy. In this experiment, adult hens were assigned to one of four groups: Control, Resv, TOCP, and TOCP + Resv. The spinal cord tissues were examined through transmission electron microscopy, hematoxylin and eosin (HE) staining, Nissl staining, and Western blotting to evaluate key proteins associated with ER stress and autophagy. Additionally, RT-qPCR and immunofluorescence were employed to measure sirtuin1 (SIRT1) expression. The findings revealed that TOCP induced severe ultrastructural damage, including disrupted myelin sheaths, dilated ER, and extensive neurodegeneration, as confirmed by histological evaluations. The expression levels of GRP78, p-PERK, p-eIF2α, ATF4, CHOP, Beclin-1, P62, and LC3-II were also significantly elevated by TOCP. However, Resv treatment markedly attenuated these pathological changes by reducing ER stress, restoring autophagic flux, and upregulating SIRT1 expression, preserving spinal cord integrity. These results indicate that Resv can effectively counteract TOCP-induced neurotoxicity by modulating ER stress and autophagy, underscoring its potential as a therapeutic agent for neuroprotection.

Sigma-1 receptor modulation by fluvoxamine ameliorates valproic acid-induced autistic behavior in rats: Involvement of chronic ER stress modulation, enhanced autophagy and M1/M2 microglia polarization

Autism spectrum disorder (ASD) is a neurodevelopmental disorder. While, fluvoxamine (FVX) is an antidepressant and widely prescribed to ASD patients, clinical results are inconclusive and the mechanism of FVX in the management of ASD is unclear. This study determined the potential therapeutic impact of FVX, a sigma-1 receptor (S1R) agonist, against the valproic acid (VPA)-induced model of autism. On gestational day 12.5, Wistar pregnant rats were given a single intraperitoneal (i.p.) injection of either VPA (600 mg/kg) or normal saline (10 mL/kg, vehicle-control). Starting on postnatal day (PND) 21 to PND 50, FVX (30 mg/kg, P·O. daily) and NE-100, (S1R) antagonist, (1 mg/kg, i.p. daily) were given to male pups. Behavior tests and histopathological changes were identified at the end of the experiment. In addition, the cerebellum biomarkers of endoplasmic reticulum (ER) stress and autophagy were assessed. Microglial cell polarization to M1 and M2 phenotypes was also assessed. FVX effectively mitigated the histopathological alterations in the cerebellum caused by VPA. FVX enhanced sociability and stereotypic behaviors in addition to its noteworthy impact on autophagy enhancement, ER stress deterioration, and controlling microglial cell polarization. The current investigation confirmed that the S1R agonist, FVX, can lessen behavioral and neurochemical alterations in the VPA-induced rat model of autism.

Lipotoxicity of palmitic acid is associated with DGAT1 downregulation and abolished by PPARα activation in liver cells

Lipotoxicity refers to the harmful effects of excess fatty acids on metabolic health, and it can vary depending on the type of fatty acids involved. Saturated and unsaturated fatty acids exhibit distinct effects, though the precise mechanisms behind these differences remain unclear. Here, we investigated the lipotoxicity of palmitic acid (PA), a saturated fatty acid, compared with oleic acid (OA), a monounsaturated fatty acid, in the hepatic cell line HuH7. Our results demonstrated that PA, unlike OA, induces lipotoxicity, endoplasmic reticulum (ER) stress, and autophagy inhibition. Compared with OA, PA treatment leads to less lipid droplet (LD) accumulation and a significant reduction in the mRNA and protein level of diacylglycerol acyltransferase 1 (DGAT1), a key enzyme of triacylglycerol synthesis. Using modulators of ER stress and autophagy, we established that DGAT1 downregulation by PA is closely linked to these cellular pathways. Notably, the ER stress inhibitor 4-phenylbutyrate can suppress PA-induced DGAT1 downregulation. Furthermore, knockdown of DGAT1 by siRNA or with A922500, a specific DGAT1 inhibitor, resulted in cell death, even with OA. Both PA and OA increased the oxygen consumption rate; however, the increase associated with PA was only partially coupled to ATP synthesis. Importantly, treatment with GW7647 a specific PPARα agonist mitigated the lipotoxic effects of PA, restoring PA-induced ER stress, autophagy block, and DGAT1 suppression. In conclusion, our study highlights the crucial role of DGAT1 in PA-induced lipotoxicity, broadening the knowledge of the mechanisms underlying hepatic lipotoxicity and providing the basis for potential therapeutic interventions.

Exploring Endocannabinoid System: Unveiling New Roles in Modulating ER Stress.

The endoplasmic reticulum (ER) is the organelle mainly involved in maintaining cellular homeostasis and driving correct protein folding. ER-dependent defects or dysfunctions are associated with the genesis/progression of several pathological conditions, including cancer, inflammation, and neurodegenerative disorders, that are directly or indirectly correlated to a wide set of events collectively named under the term "ER stress". Despite the recent increase in interest concerning ER activity, further research studies are needed to highlight all the mechanisms responsible for ER failure. In this field, recent discoveries paved the way for the comprehension of the strong interaction between ER stress development and the endocannabinoid system. The activity of the endocannabinoid system is mediated by the activation of cannabinoid receptors (CB), G protein-coupled receptors that induce a decrease in cAMP levels, with downstream anti-inflammatory effects. CB activation drives, in most cases, the recovery of ER homeostasis through the regulation of ER stress hallmarks PERK, ATF6, and IRE1. In this review, we focus on the CB role in modulating ER stress, with particular attention to the cellular processes leading to UPR activation and oxidative stress response extinguishment, and to the mechanisms underlying natural cannabinoids' modulation of this complex cellular machine.

The Tumor Suppressor TPD52-Governed Endoplasmic Reticulum Stress is Modulated by APCCdc20.

Aberrant regulation of unfolded protein response (UPR)/endoplasmic reticulum (ER) stress pathway is associated with cancer development, metastasis, and relapse, and the UPR signal transducer ATF6 has been proposed as a diagnostic and prognostic marker for many cancers. However, a causal molecular link between ATF6 activation and carcinogenesis is not established. Here, it is found that tumor protein D52 (TPD52) integrates ER stress and UPR signaling with the chaperone machinery by promoting S2P-mediated cleavage of ATF6. Although TPD52 has been generally considered as an oncogene, TPD52 is identified as a novel tumor suppressor in bladder cancer. Significantly, attenuation of the ER stress via depletion of TPD52 facilitated tumorigenesis in a subset of human carcinomas. Furthermore, the APCCdc20 E3 ligase is validated as the upstream regulator marking TPD52 for polyubiquitination-mediated proteolysis. In addition, inactivation of Cdc20 sensitized cancer cells to treatment with the ER stress inducer in a TPD52-dependent manner. Thus, the study suggests that TPD52 is a novel Cdc20 substrate that may modulate ER stress to prevent tumorigenesis.

Jiangu Recipe Suppresses ER Stress-Induced Apoptosis and Inhibits Extracellular Matrix Degradation in Chondrocytes through Upregulating SIRT1 Expression.

This study aimed to explore the effects of Jiangu Recipe (JGR) on chondrocyte responses under tert-Butyl hydroperoxide (TBHP)-induced oxidative stress, specifically focusing on apoptosis and extracellular matrix (ECM) degradation. Chondrocytes were treated with varying JGR concentrations, and cell viability was assessed. The impact of JGR on TBHP-induced apoptosis and protein expression levels of apoptosis- related molecules (Bcl-2, Bax, and cleaved caspase-3) and ECM components (Collagen II, Aggrecan, MMP-13) was evaluated. JGR exhibited protective effects against oxidative stress in chondrocytes. Moreover, it maintained cell viability under tert-butyl hydroperoxide (TBHP) induction, suppressing apoptosis (Bax, cleaved caspase-3) and enhancing anti-apoptotic Bcl-2. JGR also attenuated extracellular matrix (ECM) degradation, promoting Collagen II and Aggrecan while reducing MMP-13 expression. Investigating endoplasmic reticulum (ER) stress, it was found that JGR downregulated TBHP-induced GRP78, CHOP, ATF4, p-PERK, and p-eIF2α, thus indicating ER stress modulation. SIRT1 played a key role, as JGR upregulated SIRT1, mitigating TBHP-induced downregulation. SIRT1 knockdown reversed JGR's protective effects, highlighting its crucial role in JGR-mediated responses. Our findings suggest that JGR mitigated TBHP-induced chondrocyte apoptosis and ECM degradation, highlighting its potential therapeutic application in osteoarthritis. Mechanistically, our study highlights that SIRT1 plays a crucial role in mediating the protective effects of JGR against ER stress-induced chondrocyte apoptosis and ECM degradation, providing a foundation for further clinical exploration in managing osteoarthritic conditions.

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.

Protein folding dependence on selenoprotein M contributes to steady cartilage extracellular matrix repressing ferroptosis via PERK/ATF4/CHAC1 axis

ObjectiveInitiation of endoplasmic reticulum (ER) stress is pivotal to the advancement of osteoarthritis (OA). We aimed to explore the function of ER-resident selenoprotein M (SELM) in cartilage-forming chondrocytes, investigating how SELM participates in cartilage extracellular matrix (ECM) metabolism and ER stress modulation. MethodsArticular cartilage samples with knee OA undergoing total knee arthroplasty were categorized into OA-smooth and OA-damaged groups, with primary chondrocytes extracted from smooth areas. Destabilization of the medial meniscus was induced in male C57BL6/J mice, with sham operations on the left knee as controls. After 8 weeks, knee joint tissues were collected for analysis. Histology and immunohistochemistry examined cartilage damage. Molecular biology techniques investigated how SELM affects ECM metabolism and ER stress regulation. RNA sequencing revealed the pathway changes after SELM intervention. AlphaFold demonstrated how SELM interacts with other molecules. Cultured cartilage explants helped determine the effects of SELM supplementation. ResultsSELM expression was reduced in the damaged cartilage. Increasing SELM levels positively impacted ECM equilibrium. Decreasing SELM expression activated genes linked to degenerative ailments and impaired the cellular response to misfolded proteins, initiating the PERK/P-EIF2A/ATF4 pathway and exacerbating GSH/GSSG imbalance via the ATF4/CHAC1 axis. SELM likely participated in protein folding and modification by leveraging its thioredoxin domains. In vitro SELM supplementation mitigated IL-1β effects on damaged cartilage explants and suppressed beneficial chondrocyte phenotypes. ConclusionsOur results confirm the involvement of SELM in ER stress-induced cartilage damage as well as protein folding, pointing to new directions in molecular therapy for degenerative diseases.

J147 treatment protects against traumatic brain injury by inhibiting neuronal endoplasmic reticulum stress potentially via the AMPK/SREBP-1 pathway

Endoplasmic reticulum (ER) stress is recognized as a crucial contributor to the progression of traumatic brain injury (TBI) and represents a potential target for therapeutic intervention. This study aimed to assess the potential of J147, a novel neurotrophic compound, in alleviating ER stress by modulating related signaling pathways, thereby promoting functional recovery in TBI. To this end, adult mice underwent controlled cortical impact (CCI) injury to induce TBI, followed by oral administration of J147 one-hour post-injury, with daily dosing for 3 to 7 days. Multiple behavioral assessments were conducted over 35 days, revealing a significant, dose-dependent improvement in neurofunctional recovery with J147 treatment. The neuropathological analysis demonstrated reduced acute neurodegeneration (observed at three days through FJC staining), enhanced long-term neuron survival (H&E and Nissl staining), and improved neuroplasticity (Golgi staining) at 35 days post-TBI. At the molecular level, TBIinduced AMP-activated protein kinase (AMPK) dephosphorylation, sterol regulatory element binding protein-1 (SREBP-1) activation, and upregulation of ER stress marker proteins, including phosphorylated eukaryotic initiation factor-2α (p-eIF2a), activating transcription factor 4 (ATF4), and C/EBP homologous protein (CHOP) in perilesional cortex neurons at three days post-injury. Notably, the J147 treatment significantly attenuated AMPK dephosphorylation, SERBP-1 activation, and expression of the ER stress markers. In summary, this study reveals the therapeutic promise of J147 in mitigating secondary brain damage associated with TBI and improving long-term functional recovery by modulating ER stress pathways.

Corilagin alleviated intestinal ischemia-reperfusion injury by modulating endoplasmic reticulum stress via bonding with Bip

BackgroundIntestinal ischemia-reperfusion (II/R) injury is a common clinical emergency with high morbidity and mortality. Given the absence of efficacious prophylactic and therapeutic interventions and specific drugs, sustained efforts are essential to develop new targeted drugs. Corilagin, a naturally polyphenolic tannic acid widespread in longan, rambutan and many other edible economic crops with medicinal properties in China, is of interest due to its multiple bioactivities, including the potential to mitigate II/R injuries. Nevertheless, a clear understanding of its molecular targets and the intricate mechanisms against II/R injury remains obscure and requires further elucidation. ObjectiveThis study aimed to investigate corilagin's pharmacological impact and molecular mechanism for II/R injury. MethodsAn animal II/R model was established by clamping superior mesenteric artery (SMA), and the therapeutic efficacy of corilagin against II/R was evaluated by biochemical and pathological analysis. Next, integrated transcriptomic and proteomic analyses was performed to identify key targets. Moreover, endoplasmic reticulum stress (ERS) damage was respectively observed by transmission electron microscope (TEM), immunohistochemistry, TUNEL, flow cytometry and western blotting (WB). Finally, molecular docking, molecular dynamics (MD) simulation, cellular thermal shift assay (CETSA) and drug affinity responsive target stability (DARTS) assays were utilized to assess the interaction between corilagin and binding immunoglobulin protein (Bip, Grp78 or Hspa5), and co-IP assay was conducted to investigate the interaction between Bip and its substrate proteins. ResultsCorilagin exhibited robust protection against II/R injuries, effectively alleviating intestinal tissue damage and oxidative stress induced by II/R. The modulation of ERS as a potential regulatory mechanism was investigated through an integrated transcriptomic and proteomic analysis, identifying Bip as a key target contributing to corilagin's protective effects. Further experimental evidence using molecular docking, MD simulation, CETSA, and DARTS assays confirmed the potentially direct interaction of corilagin with Bip. This interaction promoted the ubiquitin-dependent degradation of the Bip-substrate complex, thereby suppressing ERS-related signalling pathways, including the IRE1 branch, PERK branch, and ATF6 branch, to alleviate tissue damage. ConclusionThis study confirmed that corilagin could selectively bind to Bip, facilitating its ubiquitin-dependent recognition and degradation, thereby inhibiting severe endoplasmic reticulum stress signalling and alleviating II/R injury. A detailed mechanistic insight into the action mode of corilagin had been proposed, supporting its potential usage as an ERS inhibitor.

Saffron (Crocus sativus) and its constituents in ovalbumin-induced asthma model: a preclinical systematic review and meta-analysis.

Animal and human studies have demonstrated that the saffron and the active components of saffron, including crocin, crocetin, and safranal, possess anti-inflammatory, antioxidant, and immunomodulatory properties. In this meta-analysis, the preclinical evidence and potential mechanism of saffron were explored in an animal model of ovalbumin-induced asthma. Studies related to saffron and its constituents in an animal model of ovalbumin-induced asthma from the beginning to March 2024 were searched from Scopus, PubMed, and Web of Science databases. The methodological quality of the studies was evaluated using the 15-item CAMARADES checklist. Data analysis was performed using STATA software version 17. Thirteen studies with 536 animals (268 animals in the intervention group and 268 animals in the ovalbumin-induced group) were analyzed. The meta-analysis findings demonstrated that saffron and its constituents played a significant role in reducing total WBC, eosinophil, lymphocyte, and monocyte counts. Moreover, saffron showed a significant decrease in the levels of IL-4, IL-5, IL-13, IgE, histamine, endothelin, nitric oxide, and nitrite. Moreover, saffron was found to elevate EC50 thresholds and lower maximum response rates in experimental animals. The analysis revealed a significant identification of modulation in endoplasmic reticulum (ER) stress markers and miRNAs pathways. Saffron and its components may impact ovalbumin-induced asthma model in animals through anti-inflammatory, antioxidant, and immunomodulatory pathways, as well as improving pulmonary function and modulating ER stress markers and miRNAs pathways. As a result, saffron should be considered for further clinical trials in individuals suffering from asthma.

TUDCA inhibits EV71 replication by regulating ER stress signaling pathway and suppressing autophagy

Tauroursodeoxycholic acid (TUDCA) is a naturally occurring hydrophilic bile acid that alleviates endoplasmic reticulum (ER) stress and inhibits apoptosis, thereby protecting cells. Previous studies have shown that enterovirus 71 (EV71) infection modulates ER stress and induces autophagy to assist viral replication. This study observed the effects of TUDCA pretreatment on HeLa and Vero cells infected with EV71, finding that TUDCA inhibits EV71 replication in TUDCA pretreated HeLa and Vero cells in a dose-dependent manner. We found that TUDCA pretreatment inhibited EV71 replication by regulating three branches of UPR, that is up-regulated ATF6, down-regulated both PERK and IRE1. The results also indicated that autophagy which is downstream of UPR, was inhibited either. The results indicate that TUDCA inhibits EV71 replication by regulating UPR sensor proteins and autophagy following ER stress.

Eucalyptol Ameliorates Retinal Microvascular Defects through Modulating ER Stress and Angiopoietin-Tie Signaling in Diabetic Eyes.

Loss of the inner blood-retinal barrier (BRB) integrity is a main feature of ocular diseases such as diabetic macular edema. However, there is a lack of clarity on how inner BRB function is modulated within the diabetic retina. The current study examined whether eucalyptol inhibited inner BRB destruction and aberrant retinal angiogenesis in 33 mM glucose-exposed human retinal microvascular endothelial (RVE) cells and db/db mice. This study further examined the molecular mechanisms underlying endothelial dysfunction including retinal endoplasmic reticulum (ER) stress and angiopoietin (Ang)/Tie axis in conjunction with vascular endothelial growth factor (VEGF). Eucalyptol is a naturally occurring monoterpenoid and an achiral aromatic component of many plants including eucalyptus leaves. Nontoxic eucalyptol reduced the production of amyloid-β (Aβ) protein in glucose-loaded RVE cells and in diabetic mice. This natural compound blocked apoptosis of Aβ-exposed RVE cells in diabetic mouse eyes by targeting ER stress via the inhibition of PERK-eIF2α-ATF4-CHOP signaling. Eucalyptol promoted activation of the Ang-1/Tie-2 pathway and dual inhibition of Ang-2/VEGF in Aβ-exposed RVE cells and in diabetic eyes. Supply of eucalyptol reversed the induction of junction proteins in glucose/Aβ-exposed RVE cells within the retina and reduced permeability. In addition, oral administration of eucalyptol reduced vascular leaks in diabetic retinal vessels. Taken together, these findings clearly show that eucalyptol inhibits glucose-induced Aβ-mediated ER stress and manipulates Ang signaling in diabetic retinal vessels, which ultimately blocks abnormal angiogenesis and loss of inner BRB integrity. Therefore, eucalyptol provides new treatment strategies for diabetes-associated RVE defects through modulating diverse therapeutic targets including ER stress, Ang-1/Tie-2 signaling, and Ang-2/VEGF.

Long non-coding RNA-mediated modulation of endoplasmic reticulum stress under pathological conditions.

Endoplasmic reticulum (ER) stress, which ensues from an overwhelming protein folding capacity, activates the unfolded protein response (UPR) in an effort to restore cellular homeostasis. As ER stress is associated with numerous diseases, it is highly important to delineate the molecular mechanisms governing the ER stress to gain insight into the disease pathology. Long non-coding RNAs, transcripts with a length of over 200 nucleotides that do not code for proteins, interact with proteins and nucleic acids, fine-tuning the UPR to restore ER homeostasis via various modes of actions. Dysregulation of specific lncRNAs is implicated in the progression of ER stress-related diseases, presenting these molecules as promising therapeutic targets. The comprehensive analysis underscores the importance of understanding the nuanced interplay between lncRNAs and ER stress for insights into disease mechanisms. Overall, this review consolidates current knowledge, identifies research gaps and offers a roadmap for future investigations into the multifaceted roles of lncRNAs in ER stress and associated diseases to shed light on their pivotal roles in the pathogenesis of related diseases.

Exploring the therapeutic effects of sulforaphane: an in-depth review on endoplasmic reticulum stress modulation across different disease contexts.

The endoplasmic reticulum (ER) is an intracellular organelle that contributes to the folding of proteins and calcium homeostasis. Numerous elements can disrupt its function, leading to the accumulation of proteins that are unfolded or misfolded in the lumen of the ER, a condition that is known as ER stress. This phenomenon can trigger cell death through the activation of apoptosis and inflammation. Glucoraphanin (GRA) is the predominant glucosinolate found in cruciferous vegetables. Various mechanical and biochemical processes activate the enzyme myrosinase, leading to the hydrolysis of glucoraphanin into the bioactive compound sulforaphane. Sulforaphane is an organosulfur compound that belongs to the isothiocyanate group. It possesses a wide range of activities and has shown remarkable potential as an anti-inflammatory, antioxidant, antitumor, and anti-angiogenic substance. Additionally, sulforaphane is resistant to oxidation, has been demonstrated to have low toxicity, and is considered well-tolerable in individuals. These properties make it a valuable natural dietary supplement for research purposes. Sulforaphane has been demonstrated as a potential candidate drug molecule for managing a range of diseases, primarily because of its potent antioxidant, anti-inflammatory, and anti-apoptotic properties, which can be mediated by modulation of ER stress pathways. This review seeks to cover a wealth of data supporting the broad range of protective functions of sulforaphane, improving various diseases, such as cardiovascular, central nervous system, liver, eye, and reproductive diseases, as well as diabetes, cancer, gastroenteritis, and osteoarthritis, through the amelioration of ER stress in both in vivo and in vitro studies.