Search Results (227)

Chilo sacchariphagus is a destructive sugarcane borer worldwide, and frequent extreme high temperatures disrupt its field populations. Clarifying larval thermal response mechanisms provides theoretical support for pest risk prediction under climate warming. Previous work has illustrated moderate heat induces canonical HSP activation, but the molecular responses of this pest to 41 °C extreme heat remain unclear. As such, we conducted non-reference transcriptome sequencing and 11 physio-biochemical assays on fifth-instar larvae exposed to 41 °C for 12 h (26 °C as control) to characterize its thermal regulatory network. De novo assembly yielded a comprehensive transcriptome resource, and analysis of differentially expressed genes revealed enrichment in energy metabolism, ER protein processing, MAPK signaling and autophagy pathways. Core HSP70/40 transcripts were significantly down-regulated while HSP80 showed stable transcription, suggesting that 41 °C may exceed the heat-shock protective threshold and potentially trigger heat damage. qRT-PCR validation of seven core stress genes confirmed the RNA-seq trends. Catalase (CAT) activity increased significantly; however, none of the annotated catalase genes showed transcriptional changes, whereas elevated CarE and AchE activities also lacked corresponding transcriptional shifts, implying post-translational or alternative regulatory mechanisms. Our data showed coordinated transcriptional and physiological changes under extreme heat. These findings provide a basis for further investigation into how C. sacchariphagus may respond to extreme heat under climate warming scenarios. Full article

Uremic conditions are common in end-stage kidney disease (ESKD) patients. Accelerated vascular diseases in uremic patients lead to heart failure, stroke, and hypertension. To investigate the effects of uremia on porcine arterial smooth muscle cells (aSMCs), bulk RNA sequencing was used to identify uremia-induced alterations in signaling pathways of aSMCs that might explain the aggressive cardiovascular diseases seen in patients with chronic kidney disease (CKD) and ESKD. Bulk RNA sequencing was performed on porcine aSMCs cultured with serum from normal or uremic pigs. Differentially expressed gene (DEG) analysis revealed that 295 genes were upregulated and 138 genes were downregulated after uremic serum exposure. Gene Ontology molecular function analysis demonstrated that ATP-dependent activity, translation factor activity, and ATP-dependent protein folding chaperones were predicted to be negatively enriched after uremic serum exposure, while proton transmembrane transporter activity, antioxidant activity, and glutathione peroxidase activity were predicted to be positively enriched. Gene set enrichment analysis indicated that the cell cycle was predicted to be negatively enriched after uremic serum exposure in aSMCs. Overrepresentation analysis found that focal adhesion, protein processing in the endoplasmic reticulum (ER) and cell senescence were predicted to be negatively enriched, while lysosome, phagosome, apoptosis, and autophagy were predicted to be positively enriched after uremic serum exposure. This study suggests that the signaling pathways that regulate cellular redox homeostasis, the cellular waste disposal system, ER stress and autophagy are major signaling pathways involved in aSMCs’ responses to uremic serum exposure. These pathways may contribute to the severe arterial-specific clinical symptoms observed in CKD/ESKD patients, such as arterial stiffness, vascular calcification and cardiovascular disease. Full article

Glutamine-Fructose-6-Phosphate Transaminase 1 (GFPT1), the rate-limiting enzyme of the hexosamine biosynthetic pathway (HBP), provides the UDP-N-acetylglucosamine (UDP-GlcNAc) required for protein glycosylation. Biallelic mutations in GFPT1 cause congenital myasthenic syndromes (GFPT1-CMS), yet the molecular mechanisms linking impaired glycosylation to skeletal muscle dysfunction remain incompletely understood. Here, we combine cellular models of inducible Gfpt1 knockdown and a skeletal muscle-specific Gfpt1 knockout mouse (Gfpt1^Tm1d/Tm1d) with whole-cell proteomics, immunoblot studies and secretomics to define glycosylation-dependent defects in intracellular trafficking, ER stress signaling and autophagy. Global proteomic profiling of Gfpt1-deficient myoblasts revealed marked downregulation of protein trafficking pathways and impaired secretion of key muscle cargo proteins, including serglycin (Srgn). Loss of GFPT1 reduced both high-molecular-weight glycosylated serglycin and its core protein, accompanied by intracellular retention and decreased secretion. These trafficking defects coincide with robust activation of the unfolded protein response (UPR), evidenced by increased Xbp1 expression and accumulation of spliced Xbp1s across pharmacologic, cellular, and mouse models of GFPT1 deficiency. Converging evidence from proteomics, immunoblotting, and immunofluorescence demonstrated impaired autophagy, including increased LC3-II accumulation, elevated p62/Sqstm1 levels, and enhanced p62-positive puncta in both Gfpt1-deficient C2C12 myoblasts and skeletal muscle. Soluble/insoluble fractionation further confirmed p62 accumulation, indicating defective autophagic flux and buildup of aggregated cargo. Together, these findings identify a glycosylation-dependent failure in protein trafficking that triggers ER stress, UPR activation, and autophagy impairment in Gfpt1-deficient skeletal muscle. This mechanistic cascade provides a unifying explanation for muscle pathology in GFPT1-CMS and suggests that restoring glycosylation or improving proteostasis may represent viable therapeutic approaches. Full article

Background: Gentamicin-induced nephrotoxicity limits clinical pharmacotherapy and involves multiple converging stress-response pathways. Ellagic acid (EA) has renoprotective potential, yet its role in coordinating endoplasmic reticulum (ER) stress-mediated apoptosis, autophagy, and inflammation remains unclear. We hypothesized that EA co-treatment would protect the kidney by modulating ER stress-dependent pathways and associated inflammatory and adaptive signaling. Methods: For an integrated mechanistic analysis in a rat model of gentamicin nephrotoxicity, 40 male Sprague-Dawley rats were assigned to control, gentamicin (100 mg/kg), EA (100 mg/kg), and gentamicin + EA groups for 14 days. Renal function, oxidative stress, inflammatory mediators, ER stress markers, apoptosis, autophagy, tubular injury markers, and histopathological changes were assessed. Results: Gentamicin induced renal dysfunction, tubular injury, and ER stress across all unfolded protein response (UPR) branches (IRE1α, PERK, ATF6), C/EBP homologous protein (CHOP)-associated apoptosis, dysregulated autophagy, and upregulated kidney injury molecule-1 (KIM-1). A selective inflammatory signature was observed, with increased cyclooxygenase-2 (COX-2) and interleukin-6 (IL-6), whereas tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) remained unchanged. Co-administration of ellagic acid with gentamicin significantly improved renal function markers compared to the gentamicin group. In contrast, ellagic acid alone did not show significant differences compared to the control group. Notably, gentamicin induced compensatory upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) expression, while ellagic acid co-treatment attenuated this compensatory upregulation, likely secondary to reduced oxidative stress burden. Conclusions: This study provides integrated evidence that ER stress is closely associated with gentamicin nephrotoxicity. The key novel findings include selective suppression of IL-6, modulation of the apoptosis-autophagy balance, and attenuation of Nrf2/HO-1 signaling without direct reactive oxygen species (ROS) scavenging, demonstrating a multi-target framework for EA’s renoprotective effects. These findings suggest that ellagic acid mitigates renal injury in a context-dependent manner rather than confirming a direct causal mechanism. Full article

Background: Acetaminophen (APAP) overdose remains a major cause of acute liver injury. Although N-acetylcysteine (NAC) is the clinically established antidote for APAP toxicity, its efficacy is greatest when administered early, and additional therapeutic strategies are still needed for patients with delayed presentation or progressive injury. Because APAP hepatotoxicity involves coupled disturbances in redox control, mitochondrial performance, and cellular metabolism, metabolic enzymes that sustain NADPH availability may critically influence disease severity. Malic enzyme 1 (ME1), a cytosolic NADPH-generating enzyme, has not been functionally defined in this context. Methods: To determine the contribution of ME1 to APAP-induced liver injury (AILI), we used hepatocyte-specific ME1 knockout mice, hepatic overexpression and reconstitution approaches, primary mouse hepatocytes, and an enzymatically inactive ME1 mutant. Liver injury and associated changes in oxidative stress, mitochondrial function, energy metabolism, autophagic flux, and endoplasmic reticulum (ER) stress were evaluated using biochemical, histological, molecular, and ultrastructural analyses, together with pharmacological interventions. Results: Genetic loss of ME1 did not substantially alter early APAP metabolic activation-related indices, including APAP-protein adduct formation, but markedly increased hepatocellular metabolic vulnerability after APAP challenge. This phenotype was characterized by enhanced lipid peroxidation, impaired mitochondrial polarization, reduced ATP availability, defective autophagic flux, and amplified ER stress, leading to more severe liver damage. In contrast, ME1 overexpression or reconstitution promoted a more adaptive metabolic response and limited tissue injury. These effects depended largely on ME1 catalytic activity, as protection was markedly weakened with the mutant enzyme. Pharmacological analyses further supported the involvement of AMPK/mTOR-associated autophagy regulation and ER stress adaptation in the downstream actions of ME1. Malic acid also partially attenuated APAP-induced hepatotoxicity in vivo and in vitro. Conclusions: ME1 functions as an endogenous metabolic factor that influences the outcome of APAP-induced liver injury. Its catalytic activity supports hepatocyte survival primarily by preserving reductive capacity, bioenergetic balance, and adaptive stress responses, rather than by altering APAP metabolic activation. Full article

Mastitis limits yak dairy production and is associated with lipopolysaccharide (LPS)-mediated inflammation in yak mammary epithelial cells (YMECs). This study aimed to investigate the protective effect of caffeic acid (CA) against LPS-induced cellular injury and to elucidate the underlying mechanisms, with a particular focus on autophagy regulation via the NF-κB signaling pathway. LPS exposure strikingly reduced cellular viability and increased intracellular reactive oxygen species (ROS) levels, accompanied by activation of the NF-κB pathway. Furthermore, it increased the expression of pro-inflammatory cytokines (TNF-α, IL-8, and IL-1β). In addition, LPS enhanced endoplasmic reticulum (ER) stress and Ca²⁺ dysregulation, increased LC3-II/LC3-I ratio, and reduced synthesis of α-casein and β-casein. Pretreatment with CA resulted in the effective alleviation of these alterations by restoring cellular viability, suppressing inflammatory responses, and normalizing autophagy-related markers. Additionally, inhibition of Nrf2 reversed the partial reversal of the protective effects of CA, resulting in increased ROS accumulation and autophagy activation, but did not impact NF-κB suppression. These findings indicate that CA attenuates LPS-induced inflammatory injury in YMECs involved in both Nrf2-dependent and independent pathways. These findings provide a mechanistic analysis of yak mastitis pathogenesis and CA potential as a natural therapeutic for improving mammary health and milk quality in yak dairy systems. Full article

Pyrrolizidine alkaloids (PAs), a category of naturally occurring secondary metabolites, are commonly found in various botanical sources. Accumulating evidence indicates that PAs and their biologically active metabolites can interact with cellular components and trigger a variety of toxic effects in animals and humans. Notably, PAs exhibit significant hepatotoxic potential via nutritional supplements, environmental dissemination, food chain contamination, and broader ecological pollution. In this review, we summarize PA-induced hepatotoxicity in humans and animals and the underlying molecular mechanisms. It involves oxidative stress, mitochondrial dysfunction, apoptosis, ER stress, inflammation, autophagy, and ferroptosis. Several key signaling pathways, such as nuclear factor-erythroid 2 related factor 2 (Nrf2), mitogen-activated protein kinase (MAPK), protein kinase RNA-like endoplasmic reticulum kinase (PERK), toll like receptor 4 (TLR4), nuclear factor kappa-B (NF-κB), transforming growth factor beta (TGF-β), p53, farnesoid X receptor (FXR), and pregnane X receptor (PXR), are also implicated. Furthermore, this review discusses diagnostic approaches, metabolic activation pathways, and detoxification strategies targeting PA-induced liver injury. Collectively, this review provides a comprehensive understanding of the molecular basis of PA hepatotoxicity and underscores the urgent need for improved risk assessment, early diagnosis, and effective detoxification interventions to mitigate PA-related liver diseases in humans and animals. Full article

Vero cells in high-density vaccine cultures often face nutrient starvation, especially in suspension-adapted Vero cells. Previous studies showed that serum starvation dramatically enhances autophagy and mitophagy in suspension-adapted Vero cells. Transcriptomic profiling also revealed significant upregulation of DDIT3, a marker of endoplasmic reticulum stress (ERS), in suspension-adapted Vero cells compared to adherent cells. To investigate the functional role of DDIT3, an Earle’s Balanced Salt Solution (EBSS)-induced starvation model was established in adherent Vero cells, recapitulating key autophagy and ER stress responses observed under suspension conditions. The genetic silencing of DDIT3 by shRNA attenuated autophagy, as evidenced by a reduced LC3-II/LC3-I ratio and impaired autophagosome–lysosome activity. Notably, DDIT3 knockdown enhanced cell proliferation and increased the yield of H1N1 influenza virus under nutrient-deprived conditions. Collectively, these results suggest that DDIT3 may serve as a critical regulator linking ER stress to autophagy in Vero cells, and that the suppression of DDIT3 may represent a promising strategy for developing autophagy-resistant Vero cell lines suitable for high-density suspension culture in vaccine production. Full article

Oleanolic acid (OA) is a hydrophobic pentacyclic triterpene widely distributed in the plant kingdom and characterized by broad biological activity, including antioxidant, anti-inflammatory, neuroprotective, renoprotective, and anticancer effects. Increasing evidence suggests, however, that many of these actions are better explained not by single molecular targets, but by OA-dependent modulation of an integrated organelle stress network involving mitochondria, the endoplasmic reticulum (ER), autophagy, mitophagy, and apoptosis. This review critically analyzes the available evidence on the effects of OA on the mitochondria–ER–autophagy–apoptosis axis, with particular emphasis on mechanisms governing the transition between cellular adaptation and cell death. The available literature indicates that, in non-cancer models, OA most commonly lowers reactive oxygen species (ROS), stabilizes mitochondrial function, attenuates the ER stress signature, and promotes adaptive autophagy and mitophagy. In contrast, in many cancer models, OA may enhance mitochondrial dysfunction, lower the threshold for mitochondrial apoptosis, and induce autophagy that can be either protective or cytotoxic depending on the biological context. Overall, the current evidence supports a model in which OA acts as a context-dependent modulator of the organelle stress threshold, shifting the balance of an integrated mitochondria–ER–autophagy–apoptosis network rather than functioning as a uniformly cytoprotective or uniformly proapoptotic compound. At the same time, the literature remains heterogeneous with respect to models, doses, exposure times, and markers used, while poor aqueous solubility and limited bioavailability continue to constrain translation. Future studies should therefore integrate analyses of mitochondria, ER, mitochondria–ER contact sites (MERCS), autophagy, apoptosis, pharmacokinetics, formulation, and safety in order to define the true potential of OA as a modulator of biological stress. Full article

Acute heat stress frequently causes mass mortality in farmed red swamp crayfish (Procambarus clarkii), yet the mechanisms underlying immune collapse remain poorly understood. We established an acute heat stress model (37 °C, 6 h) and performed an integrative analysis combining hemocyte profiling, redox and immune assays, RNA-seq, and qRT-PCR. Heat stress significantly increased mortality and disrupted the hemocyte system, with a ~25% reduction in total hemocyte count and a selective decline in granular cells. This was associated with severe redox imbalance, evidenced by ROS/H₂O₂ accumulation, suppressed SOD and CAT activities, and lipid peroxidation damage. Transcriptomic analysis revealed 1446 differentially expressed genes, indicating concurrent activation of ER stress and autophagy alongside suppression of energy metabolism. Key gene validation confirmed upregulation of pro-apoptotic factors (CASP3, P53) and ER stress markers (GRP78, XBP1), consistent with hemocyte depletion. These findings provide multi-level evidence that acute heat stress triggers a redox crisis (“oxidative burst–defense suppression”), which in turn activates ER stress and apoptosis, leading to selective loss of granular cells and systemic immune compromise. This study establishes a mechanistic framework for understanding heat-induced mortality in crustaceans and offers a theoretical basis for developing targeted interventions to enhance thermal resilience in crayfish aquaculture. Full article

Alpha-1 antitrypsin deficiency (AATD) is an inherited disorder characterized by intracellular retention of mutant Z (Pi*Z) alpha-1 antitrypsin (AAT) within hepatocytes, resulting in progressive liver disease. Currently, no approved pharmacological therapies exist for AATD-associated hepatic injury. Emerging preclinical evidence indicates that inhibition of mammalian target of rapamycin (mTOR) ameliorates liver pathology in AATD; however, the status of mTOR activity and its regulatory mechanisms under Pi*Z AAT-induced cellular stress remains incompletely understood. In this study, we investigated alterations in mTOR signaling and its upstream regulatory pathways using a gene-edited human hepatocyte model harboring the Pi*Z mutation (Huh7.5Z cells) and a Pi*Z AAT transgenic mouse model. Attenuation of mTORC1 activity was observed in both cellular and murine Pi*Z models. In vitro analyses demonstrated activation of AMP-activated protein kinase (AMPKα), a key inhibitory regulator of mTORC1, accompanied by paradoxical activation of Akt and the unfolded protein response (UPR) branch ATF6α. Pharmacological inhibition of mTOR significantly reduced intracellular Pi*Z AAT accumulation, alleviated ER stress, and suppressed apoptotic signaling through enhancement of autophagy. These findings reveal that hepatocytes adapt to Pi*Z AAT-induced stress through coordinated regulation of mTOR by AMPK, Akt, and ATF6α pathways. This study provides mechanistic insight into metabolic and stress-response signaling in AATD and identifies mTOR modulation as a promising therapeutic strategy for AATD-associated liver disease. Full article

Diabetic nephropathy (DN) is a serious complication in diabetic patients, leading to kidney dysfunction and ultimately end-stage renal disease. Although several pharmacological agents have been developed, treating DN remains challenging due to its complex and multifaceted pathogenesis. Endoplasmic reticulum (ER) stress plays a crucial role in DN pathology; however, the molecular mechanisms underlying reduced ER stress remain poorly understood. This study investigated the protective effects of 4-phenylbutyrate (4-PBA), an ER stress inhibitor, on DN and the related regulatory molecules through gene expression network analysis. A C57BL/6 mouse model of DN was used in combination with a high-fat diet and streptozotocin after unilateral nephrectomy and treated with 4-PBA by intraperitoneal injection for 6 weeks. The 4-PBA treatment effectively improves DN-induced renal structural and functional abnormalities by reducing albuminuria, podocyte loss, glomerular and tubular injury, and renal inflammation and cell death. These changes induced by 4-PBA were associated with decreased expression of ER stress markers and increased autophagy activities in diabetic kidneys. Importantly, 4-PBA reduced components of the complement C1q pathway, the NADPH oxidase complex, and chemokines, thereby attenuating chronic renal dysfunction. Conclusively, inhibition of ER stress is a promising pharmacological target for treating patients with DN. Full article

Autophagy and paraptosis are two distinct physiological mechanisms involved in regulating cell fate in cancer. Recent studies have demonstrated that autophagy is a crucial process for maintaining cellular homeostasis by facilitating the removal of misfolded proteins and damaged organelles. However, autophagy is found to play a dual role in cancer. Severe ER and mitochondrial dysfunction can trigger different forms of programmed cell death, including autophagic cell death. In cancer cells that evade apoptosis, paraptosis, a caspase-independent alternate death pathway, is triggered by ER and mitochondrial swelling, leading to extensive cytoplasmic vacuolation. It can be induced by natural compounds, metallic complexes, nanoparticles, or chemotherapeutic agents, primarily through excessive ROS production and disruption of protein, thiol, and calcium/ion homeostasis. Autophagy and paraptosis have been found to be connected through crosstalk. While MAPK activation drives paraptosis, ER stress and the unfolded protein response (UPR) can initiate both paraptosis and autophagy. UPR-mediated PERK activation promotes survival autophagy in ER-stressed melanoma, whereas PERK elimination triggers paraptosis via sec61β with unresolved ER stress. Similarly, CHOP and DDIT4 can enhance ER stress and proteotoxicity, thereby favouring paraptosis. This review is unique in exploring the dynamic interplay between autophagy and paraptosis in cancer cells, highlighting promising therapeutic targets for chemotherapy-resistant cancers. Full article

Sympathetic nervous system (SNS) imbalance is a common pathological basis for cardiovascular diseases, non-alcoholic fatty liver disease, and diabetes. This review focuses on these diseases, analyzing two core mechanisms: excessive sympathetic excitation induced by endoplasmic reticulum stress (ERS) or autophagy dysfunction in key central nuclei (e.g., hypothalamus, rostral ventrolateral medulla); and ERS/autophagy abnormalities in peripheral target organs caused by chronic SNS overactivation. Existing studies confirm that chronic SNS overactivation promotes peripheral metabolic overload via sustained catecholamine release, inducing persistent ERS and disrupting the protective unfolded protein response (UPR)–autophagy network, ultimately leading to cell apoptosis, inflammation, and fibrosis. Notably, central ERS or autophagy dysfunction further perturbs autonomic homeostasis, exacerbating sympathetic overexcitation. This review systematically elaborates on SNS overactivation as a critical bridge mediating UPR–autophagy network dysregulation in central and peripheral tissues, and explores therapeutic prospects of targeting key nodes (e.g., chemical chaperones, specific UPR modulators, nanomedicine), providing a theoretical basis for basic research and clinical translation. Full article

The progression of neoplastic diseases is driven by a complex interplay of biological processes, including uncontrolled proliferation, enhanced invasion, metastasis, and profound metabolic reprogramming. Among the hallmarks of cancer, as revised by Hanahan and Weinberg, the reprogramming of energy metabolism has emerged as a critical feature that enables cancer cells to meet their heightened bioenergetic and biosynthetic demands. One significant aspect of this metabolic adaptation is the accumulation of lipid droplets (LDs) dynamic, cytoplasmic organelles primarily involved in lipid storage and metabolic regulation. LDs serve as reservoirs of neutral lipids and play a multifaceted role in cancer cell physiology. Their accumulation is increasingly recognized as a marker of tumor aggressiveness and poor prognosis. By storing lipids, LDs provide a readily accessible source of energy and essential building blocks for membrane synthesis, supporting rapid cell division and growth. Moreover, LDs contribute to cellular homeostasis by modulating oxidative stress, maintaining redox balance, and regulating autophagy, particularly under nutrient-deprived or hypoxic conditions commonly found in the tumor microenvironment. Importantly, LDs have been implicated in the development of resistance to cancer therapies. They protect cancer cells from the cytotoxic effects of chemotherapeutic agents by buffering endoplasmic reticulum (ER) stress, inhibiting apoptosis, and facilitating survival pathways. The presence of LDs has been shown to correlate with increased resistance to a variety of chemotherapeutic drugs, although the precise molecular mechanisms underlying this phenomenon remain incompletely understood. Emerging evidence suggests that chemotherapy itself can induce changes in LD accumulation, further complicating treatment outcomes. Given their central role in cancer metabolism and therapy resistance, LDs represent a promising target for therapeutic intervention. Strategies aimed at disrupting lipid metabolism or inhibiting LD biogenesis have shown potential in sensitizing cancer cells to chemotherapy and overcoming drug resistance. In this review, we comprehensively examine the current understanding of LD biology in cancer, highlight studies that elucidate the link between LDs and drug resistance, and discuss emerging approaches to target lipid metabolic pathways to enhance therapeutic efficacy across diverse cancer types. Full article