Search Results (1,508)

The retina is highly sensitive to oxygen and blood supply, and hypoxia plays a key role in retinal diseases such as diabetic retinopathy (DR) and age-related macular degeneration (AMD). Müller glial cells, which are essential for retinal homeostasis, respond to injury and hypoxia with reactive gliosis, characterized by the upregulation of the glial fibrillary acidic protein (GFAP) and vimentin, cellular hypertrophy, and extracellular matrix changes, which can impair retinal function and repair. The retinal pigment epithelium (RPE) supports photoreceptors, forms part of the blood–retinal barrier, and protects against oxidative stress; its dysfunction contributes to retinal degenerative diseases such as AMD, retinitis pigmentosa (RP), and Stargardt disease (SD). Extracellular vesicles (EVs) play a crucial role in intercellular communication, protein homeostasis, and immune modulation, and have emerged as promising diagnostic and therapeutic tools. Understanding the role of extracellular vesicles’ (EVs’) signaling machinery of glial cells and the retinal pigment epithelium (RPE) is critical for developing effective treatments for retinal degeneration. In this study, we investigated the bidirectional EV-mediated crosstalk between RPE and Müller cells under hypoxic conditions and its impact on cellular metabolism and retinal cell integrity. Our findings demonstrate that RPE-derived extracellular vesicles (RPE EVs) induce time-dependent metabolic reprogramming in Müller cells. Short-term exposure (24 h) promotes pathways supporting neurotransmitter cycling, calcium and mineral absorption, and glutamate metabolism, while prolonged exposure (72 h) shifts Müller cell metabolism toward enhanced mitochondrial function and ATP production. Conversely, Müller cell-derived EVs under hypoxia influenced RPE metabolic pathways, enhancing fatty acid metabolism, intracellular vesicular trafficking, and the biosynthesis of mitochondrial co-factors such as ubiquinone. Proteomic analysis revealed significant modulation of key regulatory proteins. In Müller cells, hypoxic RPE-EV exposure led to reduced expression of Dyskerin Pseudouridine Synthase 1 (DKc1), Eukaryotic Translation Termination Factor 1 (ETF1), and Protein Ser/Thr phosphatases (PPP2R1B), suggesting alterations in RNA processing, translational fidelity, and signaling. RPE cells exposed to hypoxic Müller cell EVs exhibited elevated Ribosome-binding protein 1 (RRBP1), RAC1/2, and Guanine Nucleotide-Binding Protein G(i) Subunit Alpha-1 (GNAI1), supporting enhanced endoplasmic reticulum (ER) function and cytoskeletal remodeling. Functional assays also revealed the compromised barrier integrity of the outer blood–retinal barrier (oBRB) under hypoxic co-culture conditions. These results underscore the adaptive but time-sensitive nature of retinal cell communication via EVs in response to hypoxia. Targeting this crosstalk may offer novel therapeutic strategies to preserve retinal structure and function in ischemic retinopathies. Full article

Cardiopulmonary bypass (CPB) is associated with significant neurological complications, yet the mechanisms underlying brain injury remain unclear. This study investigated the role of interleukin-17A (IL-17A) in exacerbating CPB-induced neuronal apoptosis and identified vulnerable brain regions. Utilizing a rat CPB model and an oxygen–glucose deprivation/reoxygenation (OGD/R) cellular model, we demonstrated that IL-17A levels were markedly elevated in the hippocampus post-CPB, correlating with endoplasmic reticulum stress (ERS)-mediated apoptosis. Transcriptomic analysis revealed the enrichment of IL-17 signaling and apoptosis-related pathways. IL-17A-Neutralizing monoclonal antibody (mAb) and the ERS inhibitor 4-phenylbutyric acid (4-PBA) significantly attenuated neurological deficits and hippocampal neuronal damage. Mechanistically, IL-17A activated the Act1-IRE1-JNK1 axis, wherein heat shock protein 90 (Hsp90) competitively regulated Act1-IRE1 interactions. Co-immunoprecipitation confirmed the enhanced Hsp90-Act1 binding post-CPB, promoting IRE1 phosphorylation and downstream caspase-12 activation. In vitro, IL-17A exacerbated OGD/R-induced apoptosis via IRE1-JNK1 signaling, reversible by IRE1 inhibition. These findings identify the hippocampus as a key vulnerable region and delineate a novel IL-17A/Act1-IRE1-JNK1 pathway driving ERS-dependent apoptosis. Targeting IL-17A or Hsp90-mediated chaperone switching represents a promising therapeutic strategy for CPB-associated neuroprotection. This study provides critical insights into the molecular crosstalk between systemic inflammation and neuronal stress responses during cardiac surgery. Full article

Background/Objectives: The aim of this research is to analyze the effect of paclitaxel on endoplasmic reticulum (ER) stress in spermatogenic cells. Methods: In the study, spermatogonium (GC1) and spermatocyte (GC2) cell lines were used. The IC50 dose of paclitaxel was calculated using an MTT assay. Each cell line was separated into two different groups: control (GC1-C, GC2-C) and paclitaxel-treated (GC1-P, GC2-P). The control cells were incubated under standard culture conditions. The paclitaxel group cells were incubated in culture medium containing the paclitaxel IC50 dose for 24 h. After the experiments, all groups were stained with GRP78, p-PERK, and p-eIF2α antibodies using semi-quantitative immunocytochemistry. Results: Paclitaxel showed cytotoxicity. In the experimental model of the paclitaxel-treated cells, all the markers showed elevated levels of immunoreactivity, indicating ER stress. Conclusions: Paclitaxel administration triggered ER stress in spermatogenic cells. Studies of ER-related stress mechanisms in spermatogenic cells with further advanced molecular analyses will be important for therapeutic strategies. Full article

Bisphenol A (BPA), a prevalent endocrine-disrupting chemical, is widely found in various consumer products and poses significant health risks, particularly through hormone receptor interactions, oxidative stress, and mitochondrial dysfunction. BPA exposure is associated with reproductive, metabolic, and neurodevelopmental disorders. Melatonin, a neurohormone with strong antioxidant and anti-inflammatory properties, has emerged as a potential therapeutic agent to counteract the toxic effects of BPA. This review consolidates recent findings from in vitro and animal/preclinical studies, highlighting melatonin’s protective mechanisms against BPA-induced toxicity. These include its capacity to reduce oxidative stress, restore mitochondrial function, modulate inflammatory responses, and protect against DNA damage. In animal models, melatonin also mitigates reproductive toxicity, enhances fertility parameters, and reduces histopathological damage. Melatonin’s ability to regulate endoplasmic reticulum (ER) stress and cell death pathways underscores its multifaceted protective role. Despite promising preclinical results, human clinical trials are needed to validate these findings and establish optimal dosages, treatment durations, and safety profiles. This review discusses the wide range of potential uses of melatonin for treating BPA toxicity and suggests directions for future research. Full article

Alzheimer’s disease (AD) is increasingly recognized as a multifactorial disorder driven by a combination of disruptions in proteostasis and organelle communication. The 2020 Lancet commission reported that approximately 10 million people worldwide were affected by AD in the mid-20th century. AD is the most prevalent cause of dementia. By early 2030, the global cost of dementia is projected to rise by USD 2 trillion per year, with up to 85% of that cost attributed to daily patient care. Several factors have been implicated in the progression of neurodegeneration, including increased oxidative stress, the accumulation of misfolded proteins, the formation of amyloid plaques and aggregates, the unfolded protein response (UPR), and mitochondrial–endoplasmic reticulum (ER) calcium homeostasis. However, the exact triggers that initiate these pathological processes remain unclear, in part because clinical symptoms often emerge gradually and subtly, complicating early diagnosis. Among the early hallmarks of neurodegeneration, elevated levels of reactive oxygen species (ROS) and the buildup of misfolded proteins are believed to play pivotal roles in disrupting proteostasis, leading to cognitive deficits and neuronal cell death. The accumulation of amyloid-β (Aβ) plaques and tau neurofibrillary tangles is a characteristic feature of AD. These features contribute to chronic neuroinflammation, which is marked by the release of pro-inflammatory cytokines and chemokines that exacerbate oxidative stress. Given these interconnected mechanisms, targeting stress-related signaling pathways, such as oxidative stress (ROS) generated in the mitochondria and ER, ER stress, UPR, and cytosolic chaperones, represents a promising strategy for therapeutic intervention. This review focuses on the relationship between stress chaperone responses and organelle function, particularly the interaction between mitochondria and the ER, in the development of new therapies for AD and related neurodegenerative disorders. Full article

Chinese hamster ovary (CHO) cells are the most common protein production platform for glycosylated biopharmaceuticals due to their relatively efficient secretion systems, post-translational modification (PTM) machinery, and quality control mechanisms. However, high productivity and titer demands can overburden these processes. In particular, the endoplasmic reticulum (ER) can become overwhelmed with misfolded proteins, triggering the unfolded protein response (UPR) as evidence of ER stress. The UPR increases the expression of multiple genes/proteins, which are beneficial to protein folding and secretion. However, if the stressed ER cannot return to a state of homeostasis, a prolonged UPR results in apoptosis. Because ER stress poses a substantial bottleneck for secreting protein therapeutics, CHO cells are both selected for and engineered to improve high-quality protein production through optimized UPR and ER stress management. This is vital for optimizing industrial CHO cell fermentation. This review begins with an overview of common ER-stress related markers. Next, the optimal UPR profile of high-producing CHO cells is discussed followed by the context-dependency of a UPR profile for any given recombinant CHO cell line. Recent efforts to control and engineer ER stress-related responses in CHO cell lines through the use of various bioprocess operations and activation/inhibition strategies are elucidated. Finally, this review concludes with a discussion on future directions for engineering the CHO cell UPR. Full article

It is well recognized that patients with type 2 diabetes mellitus (T2DM) exhibit significant impairment of immune function resulting in a higher frequency of infections. We hypothesize in this study that a likely contributor to immune dysfunction in T2DM is alteration of T lymphocyte signaling functions induced by chronic hyperglycemia. In this study we have utilized the established UC Davis Type 2 Diabetes Mellitus (UCD-T2DM) rat model of human T2DM to investigate whether progressive hyperglycemia diminishes T cell receptor (TCR)-releasable endoplasmic reticulum (ER) Ca²⁺ stores, an essential early antigen-stimulated signal driving T cell activation. Furthermore, results from this study demonstrate that chronic hyperglycemia markedly alters the expression profile of the sarco/endoplasmic reticulum Ca²⁺-ATPase (SERCA) Ca²⁺ ion pumps, which are the major enzymatic ion transporters maintaining replenished TCR-sensitive Ca²⁺ pools. We conducted companion experiments using Jurkat T lymphocytes exposed to high glucose which allowed finer resolution of early disruptions to ER Ca²⁺ store integrity and greater clarity on SERCA isoform-specific roles in diabetes-induced Ca²⁺ signal dysregulation. In summary, these experiments suggest that hyperglycemia in T2DM drives an ER stress state manifesting in reduced expression of the SERCA pumps, erosion of ER Ca²⁺ stores and culminating in T cell and immune dysfunction. Full article

Bronchopulmonary dysplasia (BPD) remains a significant complication of premature birth and neonatal intensive care. While much is known about the drivers of lung injury, few studies have addressed the interrelationships between oxidative stress, inflammation, and downstream events, such as endoplasmic reticulum (ER) stress. In this review, we explore the concept of a “destructive cycle” in which these drivers self-amplify to push the lung into a state of maladaptive repair. Animal models, primarily the hyperoxic rat pup model, support a sequential progression from the generation of reactive oxygen species (ROS) and inflammation to endoplasmic reticulum (ER) stress and mitochondrial injury. We highlight how these intersecting pathways offer not just therapeutic targets but also opportunities for interventions that reprogram system-wide responses. Accordingly, we explore the potential of systems pharmacology therapeutics (SPTs) to address the multifactorial nature of BPD. As a prototype SPT, we describe the development of N-acetyl-L-lysyl-L-tyrosyl-L-cysteine amide (KYC), a systems chemico-pharmacology drug (SCPD), which is selectively activated in inflamed tissues and modulates key nodal targets such as high-mobility group box-1 (HMGB1) and Kelch-like ECH-associated protein-1 (Keap1). Collectively, the data suggest that future therapies may require a coordinated, network-level approach to break the destructive cycle and enable proper regeneration rather than partial repair. Full article

The growth of tumor cells is accompanied by an increased rate of endoplasmic reticulum stress (ERS), the accumulation of misfolded proteins, and the activation of a network of adaptive signaling pathways known as the unfolded protein response (UPR). Although the UPR is an adaptive reaction aiming to restore ER proteostasis, prolonged and severe ERS leads to cell death. Taking into account that the components of the ERS/UPR machinery in cancers of different types can be overexpressed or downregulated, both the induction of excessive ERS and suppression of UPR have been proposed as therapeutic strategies to sensitize cells to conventional chemotherapy. This narrative review presents a several examples of using natural and synthetic compounds that can either induce persistent ERS by selectively blocking ER Ca²⁺ pumps (SERCA) to disrupt ER Ca²⁺ homeostasis, or altering the activity of UPR chaperones and sensors (GRP78, PERK, IRE1α, and ATF6) to impair protein degradation signaling. The molecular alterations induced by miscellaneous inhibitors of ERS/UPR effectors are described as well. These agents showed promising therapeutic effects as a part of combination therapy in preclinical experimental settings; however, the number of clinical trials is still limited, while their results are inconsistent. Multiple side effects, high toxicity to normal cells, or poor bioavailability also hampers their clinical application. Since the pharmacological modulation of ERS/UPR is a valuable approach to sensitize cancer cells to standard chemotherapy, the search for more selective agents with better stability and low toxicity, as well as the development of more efficient delivery systems that can increase their therapeutic specificity, are highly required goals for future studies. Full article

Background: Chronic postsurgical pain (CPSP) poses a major clinical challenge due to unresolved links between neurotrophic pathways and endoplasmic reticulum (ER) stress. While Neurotrophic Tyrosine Kinase Receptor Type 1 (NTRK1) modulates ER stress in neuropathic pain, its interaction with Insulin-Like Growth Factor II (IGF2) in CPSP remains uncharacterized, impeding targeted therapy. This study defined the spinal NTRK1-IGF2-ER stress axis in CPSP. Methods: Using a skin/muscle incision–retraction (SMIR) rat model, we integrated molecular analyses and intrathecal targeting of NTRK1 (GW441756) or IGF2 (siRNA). Results: SMIR surgery upregulated spinal NTRK1, IGF2, and ER stress mediators. NTRK1 inhibition reduced both NTRK1/IGF2 expression and ER stress, reversing mechanical allodynia. IGF2 silencing attenuated ER stress and pain but did not affect NTRK1, revealing a unidirectional signaling cascade where NTRK1 drives IGF2-dependent ER stress amplification. These findings expand understanding of stress-response networks in chronic pain. Conclusions: We show that spinal NTRK1 drives IGF2-mediated ER stress to sustain CPSP. The NTRK1-IGF2-ER stress axis represents a novel therapeutic target; NTRK1 inhibitors and IGF2 biologics offer non-opioid strategies for precision analgesia. This work advances CPSP management and demonstrates how decoding unidirectional signaling hierarchies can transform neurological disorder interventions. Full article

Trachinotus ovatus is a euryhaline, warm-water pelagic fish species with strong adaptability, rapid growth, and a high survival rate, making it one of the most important marine aquaculture species in China. In recent years, extensive experience has been accumulated in the cage farming of T. ovatus, but whether it can adapt to deep-sea environments and grow normally remains a current research focus. This study used RNA-Seq sequencing technology to analyze the gene expression changes in the liver of T. ovatus under three conditions: rest (0 cm/s), medium flow velocity (54 cm/s), and high flow velocity (90 cm/s). Through differential expression analysis, Short Time-series Expression Miner (STEM) analysis and protein–protein interaction (PPI) network analysis, a total of 5107 differentially expressed genes (DEGs), three significantly expressed gene profiles (profile6, profile1, and profile5), and 15 hub genes were identified. The results showed that changes in flow speed significantly impacted key biological processes such as energy metabolism, protein homeostasis, and endoplasmic reticulum (ER) stress response. Under moderate and high flow conditions, glycolysis-related genes were upregulated to meet the energy demands of swimming, while the downregulation of the PPARγ-RXRG complex and its downstream genes in the lipid metabolism pathway suggested a limitation in its fatty acid β-oxidation capacity. At the same time, protein synthesis was enhanced, and the unfolded protein response (UPR) was activated to help cope with ER stress. Furthermore, when the flow speed reached 90 cm/s, the expression of UPR- related genes and the anti-apoptotic factor JNK significantly decreased, suggesting that the stress response was nearing its limit and could potentially trigger cell apoptosis. These findings provide new insights into the molecular adaptation mechanisms of T. ovatus to flow speed stress and offer theoretical support for its rational farming in deep-sea cages, suggesting that the water flow speed in farming should not exceed 90 cm/s. Full article

This study identified 13 endoplasmic reticulum stress (ERS)-related biomarkers associated with multiple sclerosis (MS) through integrated bioinformatics analysis (including weighted gene co-expression network analysis and machine learning algorithms) and single-cell sequencing, combined with validation in an experimental autoimmune encephalomyelitis (EAE) mouse model. Among them, GPX1, RCN1, and UBE2D3 exhibited high diagnostic value (AUC > 0.7, p < 0.05), and the diagnostic potential of GPX1 and RCN1 was confirmed in the animal model. The study found that memory B cells, plasma cells, neutrophils, and M1 macrophages were significantly increased in MS patients, while naive B cells and activated NK cells decreased. Consensus clustering based on key ERS-related genes divided MS patients into two subtypes. Single-cell sequencing showed that microglia and pericytes were the cell types with the highest expression of key ERS-related genes, and the APP-CD74 pathway was enhanced in the brain tissue of MS patients. Mendelian randomization analysis suggested that GPX1 plays a protective role in MS. These findings reveal the mechanisms of ERS-related biomarkers in MS and provide potential targets for diagnosis and treatment. Full article

Lysosomal dysfunction and endoplasmic reticulum (ER) stress play essential roles in cancer cell survival, growth, and stress adaptation. Among the various stressors in the tumor microenvironment, oxidative stress (OS) is a central driver that exacerbates both lysosomal and ER dysfunction. In healthy cells, the ER manages protein folding and redox balance, while lysosomes regulate autophagy and degradation. Cancer cells, however, are frequently exposed to elevated levels of reactive oxygen species (ROS), which disrupt protein folding in the ER and damage lysosomal membranes and enzymes, promoting dysfunction. Persistent OS activates the unfolded protein response (UPR) and contributes to lysosomal membrane permeabilization (LMP), leading to pro-survival autophagy or cell death depending on the context and on the modulation of pathways like PERK, IRE1, and ATF6. Cancer cells exploit these pathways by enhancing their tolerance to OS and shifting UPR signaling toward survival. Moreover, lysosomal impairment due to ROS accumulation compromises autophagy, resulting in the buildup of damaged organelles and further amplifying oxidative damage. This vicious cycle of ROS-induced ER stress and lysosomal dysfunction contributes to tumor progression, therapy resistance, and metabolic adaptation. Thus, targeting lysosomal and ER stress responses offers potential as cancer therapy, particularly in increasing oxidative stress and promoting apoptosis. This review explores the interconnected roles of lysosomal dysfunction, ER stress, and OS in cancer, focusing on the mechanisms driving their crosstalk and its implications for tumor progression and therapeutic resistance. Full article

Patients with sepsis often receive mechanical ventilation (MV). Continued use of MV may increase overdistention in the lungs, inflammatory mediator production, and inflammatory cell recruitment, eventually causing ventilator-induced lung injury (VILI). Endoplasmic reticulum (ER) stress caused by MV, oxidative stress, and sepsis results in dissociation of GRP78 from transmembrane proteins (PERK, IRE1α, and ATF6) and generates abundant incorrect protein structures. Phosphoinositide 3-kinase-γ (PI3K-γ) has been demonstrated to modulate ER stress associated with sepsis and acute lung injury (ALI). However, the regulatory mechanisms by which ER stress is involved in VILI remain unclear. In this study, MV was hypothesized to augment lung injury and induce ER stress through the PI3K-γ pathway, regardless of endotoxemia. Wild-type or PI3K-γ-deficient C57BL/6 mice were exposed to 30 mL/kg tidal volume of MV with or without endotoxemia for 5 h. The control group comprised nonventilated mice. MV with endotoxemia increased microvascular permeability, lung edema, interleukin-6 and metalloproteinase-9 production, oxidative loads, ER stress biomarkers (GRP78, IRE-1α, PERK), morphological rearrangement, PI3K-γ expression, and bronchial epithelial apoptosis in rodent lungs. The increase in lung injury was substantially reduced in PI3K-γ-deficient mice and in mice administered 4-phenylbutyric acid. In conclusion, MV-augmented ALI after endotoxemia partially depends on the PI3K-γ pathway. Full article

Synbiotics can be used to reduce intestinal inflammation and mitigate dysbiosis in dogs with chronic inflammatory enteropathy (CIE). Prior research has not assessed the colonic mucosal ultrastructure of dogs with active CIE treated with synbiotics, nor has it determined a possible association between morphologic injury and signaling pathways. Twenty client-owned dogs diagnosed with CIE were randomized to receive either a hydrolyzed diet (placebo; PL) or a hydrolyzed diet supplemented with synbiotic-IgY (SYN) for 6 weeks. Endoscopic biopsies of the colon were obtained for histopathologic, ultrastructural, and molecular analyses and were compared before and after treatment. Using transmission electron microscopy (TEM), an analysis of the ultrastructural alterations in microvilli length (MVL), mitochondria (MITO), and rough endoplasmic reticulum (ER) was compared between treatment groups. To explore potential signaling pathways that might modulate MITO and ER stress, a transcriptomic analysis was also performed. The degree of mucosal ultrastructural pathology differed among individual dogs before and after treatment. Morphologic alterations in enterocytes, MVL, MITO, and ER were detected without significant differences between PL and SYN dogs prior to treatment. Notable changes in ultrastructural alterations were identified post-treatment, with SYN-treated dogs exhibiting significant improvement in MVL, MITO, and ER injury scores compared to PL-treated dogs. Transcriptomic profiling showed many pathways and key genes to be associated with MITO and ER injury. Multiple signaling pathways and their associated genes with protective effects, including fibroblast growth factor 2 (FGF2), fibroblast growth factor 7 (FGF7), fibroblast growth factor 10 (FGF10), synaptic Ras GTPase activating protein 1 (SynGAP1), RAS guanyl releasing protein 2 (RASGRP2), RAS guanyl releasing protein 3 (RASGRP3), thrombospondin 1 (THBS1), colony stimulating factor 1 (CSF1), colony stimulating factor 3 (CSF3), interleukin 21 receptor (IL21R), collagen type VI alpha 6 chain (COL6A6), ectodysplasin A receptor (EDAR), forkhead box P3 (FoxP3), follistatin (FST), gremlin 1 (GREM1), myocyte enhancer factor 2B (MEF2B), neuregulin 1 (NRG1), collagen type I alpha 1 chain (COL1A1), hepatocyte growth factor (HGF), 5-hydroxytryptamine receptor 7 (HTR7), and platelet derived growth factor receptor beta (PDGFR-β), were upregulated with SYN treatment. Differential gene expression was associated with improved MITO and ER ultrastructural integrity and a reduction in oxidative stress. Conversely, other genes, such as protein kinase cAMP-activated catalytic subunit beta (PRKACB), phospholipase A2 group XIIB (PLA2G12B), calmodulin 1 (CALM1), calmodulin 2 (CALM2), and interleukin-18 (IL18), which have harmful effects, were downregulated following SYN treatment. In dogs treated with PL, genes including PRKACB and CALM2 were upregulated, while other genes, such as FGF2, FGF10, SynGAP1, RASGRP2, RASGRP3, and IL21R, were downregulated. Dogs with CIE have colonic ultrastructural pathology at diagnosis, which improves following synbiotic treatment. Ultrastructural improvement is associated with an upregulation of protective genes and a downregulation of harmful genes that mediate their effects through multiple signaling pathways. Full article