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Endoplasmic reticulum stress triggers the unfolded protein response (UPR) to promote cell survival or apoptosis. Transient endoplasmic reticulum stress activation has been reported to trigger megakaryocyte production, and UPR activation has been reported as a feature of megakaryocytic cancers. However, the role of UPR signaling in megakaryocyte biology is not fully understood. We studied the involvement of UPR in human megakaryocytic differentiation using PMA (phorbol 12-myristate 13-acetate)-induced maturation of megakaryoblastic cell lines and thrombopoietin-induced differentiation of human peripheral blood-derived progenitors. Our results demonstrate that an adaptive UPR is a feature of megakaryocytic differentiation and that this response is not associated with ER stress-induced apoptosis. Differentiation did not alter the response to the canonical endoplasmic reticulum stressors DTT or thapsigargin. However, thapsigargin, but not DTT, inhibited differentiation, consistent with the involvement of Ca2+ signaling in megakaryocyte differentiation.
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Parkinson disease represents a significant and growing burden on global healthcare systems, necessitating a deeper understanding of their underlying molecular mechanisms for the development of effective treatments. The AKT and ERK pathways play crucial roles in the disease, influencing multiple cellular pathways that support neuronal survival. Researchers have made notable progress in uncovering how these pathways are controlled by upstream kinases and how their downstream effects contribute to cell signalling. However, as we delve deeper into their intricacies, we encounter increasing complexity, compounded by the convergence of multiple signalling pathways. Many of their targets overlap with those of other kinases, and they not only affect specific substrates but also influence entire signalling networks. This review explores the intricate interplay of the AKT/ERK pathways with several other signalling cascades, including oxidative stress, endoplasmic reticulum stress, calcium homeostasis, inflammation, and autophagy, in the context of Parkinson disease. We discuss how dysregulation of these pathways contributes to disease progression and neuronal dysfunction, highlighting potential therapeutic targets for intervention. By elucidating the complex network of interactions between the AKT/ERK pathways and other signalling cascades, this review aims to provide insights into the pathogenesis of Parkinson disease and describe the development of novel therapeutic strategies.
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There is an urgent need for new antifungal drugs to treat invasive fungal diseases. Unfortunately, the echinocandin drugs that are fungicidal against other important fungal pathogens are ineffective against Cryptococcus neoformans, the causative agent of life-threatening meningoencephalitis in immunocompromised people. Contributing mechanisms for echinocandin tolerance are emerging with connections to calcineurin signaling, the cell wall, and membrane composition. In this context, we discovered that a defect in phosphate uptake impairs the tolerance of C. neoformans to the echinocandin caspofungin. Our previous analysis of mutants lacking three high affinity phosphate transporters revealed reduced elaboration of the polysaccharide capsule and attenuated virulence in mice. We investigated the underlying mechanisms and found that loss of the transporters and altered phosphate availability influences the cell wall and membrane composition. These changes contribute to the shedding of capsule polysaccharide thus explaining the reduced size of capsules on mutants lacking the phosphate transporters. We also found an influence of the calcineurin pathway including calcium sensitivity and an involvement of the endoplasmic reticulum in the response to phosphate limitation. Furthermore, we identified membrane and lipid composition changes consistent with the role of phosphate in phospholipid biosynthesis and with previous studies implicating membrane integrity in caspofungin tolerance. Finally, we discovered a contribution of phosphate to titan cell formation, a cell type that displays modified cell wall and capsule composition. Overall, our analysis reinforces the importance of phosphate as a regulator of cell wall and membrane composition with implications for capsule attachment and antifungal drug susceptibility.
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Endoplasmic reticulum (ER) stress exerts significant effects on cell growth, proliferation, migration, invasion, chemoresistance, and angiogenesis in various cancers. However, the impact of ER stress on the outcomes of osteosarcoma patients remains unclear. In this study, we established an ER stress risk model based on The Cancer Genome Atlas (TARGET) osteosarcoma dataset to reflect immune features and predict the prognosis of osteosarcoma patients. Survival analysis revealed significant differences in overall survival among osteosarcoma patients with different ER stress-related risk scores. Furthermore, ER stress-related risk features were significantly associated with the clinical pathological characteristics of osteosarcoma patients and could serve as independent prognostic indicators. Functional enrichment analysis indicated associations of the risk model with cell chemotaxis, leukocyte migration, and regulation of leukocyte migration. Additionally, the ER stress-related risk model suggested the presence of an immunosuppressive microenvironment and immune checkpoint responses. We validated the significance of 7 ER stress-related genes obtained from LASSO regression analysis through RT-qPCR testing on osteosarcoma samples from a local hospital, and inferred the importance of STC2 based on the literature. Subsequently, IHC experiments using samples from 70 osteosarcoma cases and 21 adjacent tissue samples confirmed differential expression of STC2 between cancer and normal tissues, and explored the gene's expression in pan-cancer and its association with clinical pathological parameters of osteosarcoma. In conclusion, we have proposed an ER stress risk model as an independent prognostic factor and identified STC2 as a novel risk indicator for disease progression, providing a promising direction for further research and treatment of osteosarcoma.
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The regulation of the circadian clock plays an important role in influencing physiological conditions. While it is reported that the timing and quantity of energy intake impact circadian regulation, the underlying mechanisms remain unclear. This study investigated the impact of dietary protein intake on peripheral clocks. Firstly, transcriptomic analysis was conducted to investigate molecular targets of low-protein intake. Secondly, mPer2::Luc knock-in mice, fed with either a low-protein, normal, or high-protein diet for 6 weeks, were analyzed for the oscillation of PER2 expression in peripheral tissues and for the expression profiles of circadian and metabolic genes. Lastly, the candidate pathway identified by the in vivo analysis was validated using AML12 cells. As a result, using transcriptomic analysis, we found that the low-protein diet hardly altered the circadian rhythm in the central clock. In animal experiments, expression levels and period lengths of PER2 were different in peripheral tissues depending on dietary protein intake; moreover, mRNA levels of clock-controlled genes and endoplasmic reticulum (ER) stress genes were affected by dietary protein intake. Induction of ER stress in AML12 cells caused an increased amplitude of Clock and Bmal1 and an advanced peak phase of Per2. This result shows that the intake of different dietary protein ratios causes an alteration of the circadian rhythm, especially in the peripheral clock of mice. Dietary protein intake modifies the oscillation of ER stress genes, which may play key roles in the regulation of the circadian clock.
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Ritmo Circadiano , Proteínas Alimentares , Proteínas Circadianas Period , Animais , Camundongos , Ritmo Circadiano/genética , Proteínas Circadianas Period/genética , Proteínas Circadianas Period/metabolismo , Proteínas Alimentares/administração & dosagem , Estresse do Retículo Endoplasmático , Relógios Circadianos/genética , Masculino , Camundongos Endogâmicos C57BL , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas CLOCK/genética , Proteínas CLOCK/metabolismo , Fatores de Transcrição ARNTL/genética , Fatores de Transcrição ARNTL/metabolismo , Perfilação da Expressão Gênica , Linhagem Celular , TranscriptomaRESUMO
Pathogenic variants in GFPT1, encoding a key enzyme to synthesize UDP-N-acetylglucosamine (UDP-GlcNAc), cause congenital myasthenic syndrome (CMS). We made a knock-in (KI) mouse model carrying a frameshift variant in Gfpt1 exon 9, simulating that found in a patient with CMS. As Gfpt1 exon 9 is exclusively expressed in striated muscles, Gfpt1-KI mice were deficient for Gfpt1 only in skeletal muscles. In Gfpt1-KI mice, (1) UDP-HexNAc, CMP-NeuAc and protein O-GlcNAcylation were reduced in skeletal muscles; (2) aged Gfpt1-KI mice showed poor exercise performance and abnormal neuromuscular junction structures; and (3) markers of the unfolded protein response (UPR) were elevated in skeletal muscles. Denervation-mediated enhancement of endoplasmic reticulum (ER) stress in Gfpt1-KI mice facilitated protein folding, ubiquitin-proteasome degradation and apoptosis, whereas autophagy was not induced and protein aggregates were markedly increased. Lack of autophagy was accounted for by enhanced degradation of FoxO1 by increased Xbp1-s/u proteins. Similarly, in Gfpt1-silenced C2C12 myotubes, ER stress exacerbated protein aggregates and activated apoptosis, but autophagy was attenuated. In both skeletal muscles in Gfpt1-KI mice and Gfpt1-silenced C2C12 myotubes, maladaptive UPR failed to eliminate protein aggregates and provoked apoptosis.
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Autofagia , Estresse do Retículo Endoplasmático , Músculo Esquelético , Dobramento de Proteína , Resposta a Proteínas não Dobradas , Animais , Camundongos , Apoptose , Proteína Forkhead Box O1/metabolismo , Técnicas de Introdução de Genes , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patologia , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Junção Neuromuscular/metabolismo , Junção Neuromuscular/patologia , Especificidade de Órgãos , Complexo de Endopeptidases do Proteassoma/metabolismo , Agregados Proteicos , Proteína 1 de Ligação a X-Box/metabolismoRESUMO
INTRODUCTION: Chemoimmunotherapy, which benefits from the combination of chemotherapy and immunotherapy, has emerged as a promising strategy in cancer treatment. However, effectively inducing a robust immune response remains challenging due to the limited responsiveness across patients. Endoplasmic reticulum (ER) stress is essential for activating intracellular signaling pathways associated with immunogenic cell death (ICD), targeting drugs to ER might enhance ER stress and improve ICD-related immunotherapy. OBJECTIVES: To improve the immune response of Chemoimmunotherapy. METHODS: ER targeting nanoparticles TSE-CEL/NP were constructed to enhance immunogenic cancer cell death. Flow cytometry, confocal microscope, TEM and immunofluorescence were used to evaluate the ER targeting effect and immunogenic tumor cell death in vitro on B16F10 tumor cells. Unilateral and bilateral tumor models were constructed to investigate the efficacy of anti-tumor and immunotherapy in vivo. Lung metastasis B16F10 melanoma tumor-bearing mice were used to assess the anti-metastasis efficacy. RESULTS: TSE-CEL/NP could specially accumulate in ER, thereby induce ER stress. High ER stress trigger the exposure of CRT, the extracellular release of HMGB1 and ATP. These danger signals subsequently promote the recruitment and maturation of dendritic cells (DCs), which in turn increase the proliferation of cytotoxic T lymphocytes (CD8+ T cells), ultimately resulted in an improved immunotherapy efficacy against melanoma. Invivo experiments showed that TSE-CEL/NP exhibits excellent antitumor efficacy and triggers a strong immune response. CONCLUSION: Our findings demonstrated that celastrol ER targeting delivery could amplify immunogenic cell death in melanoma, which provide experimental basis for melanoma immunotherapy.
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Stearoyl-CoA desaturase 1 (SCD1) is an attractive target for cancer therapy. However, the clinical efficacy of SCD1 inhibitor monotherapy is limited. There is thus a need to elucidate the mechanisms of resistance to SCD1 inhibition and develop new therapeutic strategies for combination therapy. In this study, we investigated the molecular mechanisms by which cancer cells acquire resistance to endoplasmic reticulum (ER) stress-dependent cancer cell death induced by SCD1 inhibition. SCD1 inhibitor-sensitive and -resistant cancer cells were treated with SCD1 inhibitors in vitro, and SCD1 inhibitor-sensitive cancer cells accumulated palmitic acid and underwent ER stress response-induced cell death. Conversely, SCD1-resistant cancer cells did not undergo ER stress response-induced cell death because fatty acid desaturase 2 (FADS2) eliminated the accumulation of palmitic acid. Furthermore, genetic depletion using siRNA showed that FADS2 is a key determinant of sensitivity/resistance of cancer cells to SCD1 inhibitor. A549 cells, an SCD1 inhibitor-resistant cancer cell line, underwent ER stress-dependent cancer cell death upon dual inhibition of SCD1 and FADS2. Thus, combination therapy with SCD1 inhibition and FADS2 inhibition is potentially a new cancer therapeutic strategy targeting fatty acid metabolism.
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Resistencia a Medicamentos Antineoplásicos , Estresse do Retículo Endoplasmático , Ácidos Graxos Dessaturases , Estearoil-CoA Dessaturase , Estearoil-CoA Dessaturase/metabolismo , Estearoil-CoA Dessaturase/genética , Estearoil-CoA Dessaturase/antagonistas & inibidores , Humanos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Dessaturases/metabolismo , Linhagem Celular Tumoral , Células A549 , Ácido Palmítico/farmacologia , Morte Celular/efeitos dos fármacos , Neoplasias/metabolismo , Neoplasias/genética , Neoplasias/patologia , Neoplasias/tratamento farmacológicoRESUMO
Pancreatic ß-cell mass is a critical determinant of insulin secretion. Severe endoplasmic reticulum (ER) stress causes ß-cell apoptosis; however, the mechanisms of progression and suppression are not yet fully understood. Here, we report that the autocrine/paracrine function of insulin reduces ER stress-induced ß-cell apoptosis. Insulin reduced the ER-stress inducer tunicamycin- and thapsigargin-induced cell viability loss due to apoptosis in INS-1 ß-cells. Moreover, the effect of insulin was greater than that of insulin-like growth factor-1 at physiologically relevant concentrations. Insulin did not attenuate the ER stress-induced increase in unfolded protein response genes. ER stress did not induce cytochrome c release from mitochondria. Mitochondrial hyperpolarization was induced by ER stress and prevented by insulin. The protonophore/mitochondrial oxidative phosphorylation uncoupler, but not the antioxidants N-acetylcysteine and α-tocopherol, exhibited potential cytoprotection during ER stress. Both procaspase-12 and cleaved caspase-12 levels increased under ER stress. The caspase-12 inhibitor Z-ATAD-FMK decreased ER stress-induced apoptosis. Caspase-12 overexpression reduced cell viability, which was diminished in the presence of insulin. Insulin decreased caspase-12 levels at the post-translational stages. These results demonstrate that insulin protects against ER stress-induced ß-cell apoptosis in this cell line. Furthermore, mitochondrial hyperpolarization and increased caspase-12 levels are involved in ER stress-induced and insulin-suppressed ß-cell apoptosis.
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Apoptose , Caspase 12 , Estresse do Retículo Endoplasmático , Células Secretoras de Insulina , Insulina , Mitocôndrias , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Animais , Insulina/farmacologia , Insulina/metabolismo , Caspase 12/metabolismo , Caspase 12/genética , Ratos , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacosRESUMO
OBJECTIVE: Osteoarthritis (OA) is a degenerative disease characterized by the gradual degeneration of chondrocytes, involving endoplasmic reticulum (ER) stress. Esculin is a natural compound with antioxidant, anti-inflammatory and anti-tumor properties. However, its impact on ER stress in OA therapy has not been thoroughly investigated. We aim to determine the efficiency of Esculin in OA treatment and its underlying mechanism. METHODS: We utilized the tert-butyl hydroperoxide (TBHP) to establish OA model in chondrocytes. The expression of SIRT1, PERK/eIF2α pathway-related proteins, apoptosis-associated proteins and ER stress-related proteins were detected by Western blot and Real-time PCR. The apoptosis was evaluated by flow cytometry and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. X-ray imaging, Hematoxylin & Eosin staining, Safranin O staining and immunohistochemistry were used to assess the pharmacological effects of Esculin in the anterior cruciate ligament transection (ACLT) rat OA model. RESULTS: Esculin downregulated the expression of PERK/eIF2α pathway-related proteins, apoptosis-associated proteins and ER stress-related proteins, while upregulated the expression of SIRT1 and Bcl2 in the TBHP-induced OA model in vitro. It was coincident with the results of TUNEL staining and flow cytometry. We further confirmed the protective effect of Esculin in the rat ACLT-related model. CONCLUSION: Our results suggest the potential therapeutic value of Esculin on osteoarthritis. It probably inhibits the PERK-eIF2α-ATF4-CHOP pathway by upregulating SIRT1, thereby mitigating endoplasmic reticulum stress and protecting chondrocytes from apoptosis.
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Apoptose , Condrócitos , Modelos Animais de Doenças , Fator de Iniciação 2 em Eucariotos , Osteoartrite , Estresse Oxidativo , Ratos Sprague-Dawley , Transdução de Sinais , Sirtuína 1 , Fator de Transcrição CHOP , eIF-2 Quinase , Animais , Condrócitos/efeitos dos fármacos , Condrócitos/metabolismo , Condrócitos/patologia , Sirtuína 1/metabolismo , Sirtuína 1/genética , eIF-2 Quinase/metabolismo , eIF-2 Quinase/genética , Osteoartrite/tratamento farmacológico , Osteoartrite/metabolismo , Osteoartrite/patologia , Fator de Iniciação 2 em Eucariotos/metabolismo , Fator de Transcrição CHOP/metabolismo , Fator de Transcrição CHOP/genética , Ratos , Estresse Oxidativo/efeitos dos fármacos , Masculino , Transdução de Sinais/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Células CultivadasRESUMO
Acute kidney injury (AKI) is a common and serious global health problem with high risks of mortality and the development of chronic kidney diseases. Leonurine is a unique bioactive component from Leonurus japonicus Houtt. and exerts antioxidant, antiapoptotic or anti-inflammatory properties. This study aimed to explore the benefits of leonurine on AKI and the possible mechanisms involved, with a particular foc on the regulation of ferroptosis and endoplasmic reticulum (ER) stress. Our results showed that leonurine exhibited prominent protective effects against AKI, as evidenced by the amelioration of histopathological alterations and reduction of renal dysfunction. In addition, leonurine significantly suppressed ferroptosis in AKI both in vivo and in vitro by effectively restoring ultrastructural abnormalities in mitochondria, decreasing ASCL4 and 4-HNE levels, scavenging reactive oxygen species (ROS), as well as increasing GPX4 and GSH levels. In parallel, leonurine also markedly mitigated ER stress via down-regulating PERK, eIF-2α, ATF4, CHOP and CHAC1. Further studies suggested that ER stress was closely involved in erastin-induced ferroptosis, and leonurine protected tubular epithelial cells in vitro by inhibiting ER stress-associated ferroptosis via regulating ATF4/CHOP/ASCL4 signalling pathway. Mechanistically, ATF4 silencing in vitro regulated CHOP and ACSL4 expressions, ultimately weakening both ER stress and ferroptosis. Notably, analyses of single-cell RNA sequencing data revealed that ATF4, CHOP and ASCL4 in renal tubular cells were all abnormally upregulated in patients with AKI compared to healthy controls, suggesting their contributions to the pathogenesis of AKI. Altogether, these findings suggest that leonurine alleviates AKI by inhibiting ER stress-associated ferroptosis via regulating ATF4/CHOP/ASCL4 signalling pathway, thus providing novel mechanisms for AKI treatment.
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Fator 4 Ativador da Transcrição , Injúria Renal Aguda , Estresse do Retículo Endoplasmático , Ferroptose , Ácido Gálico , Transdução de Sinais , Fator de Transcrição CHOP , Ferroptose/efeitos dos fármacos , Injúria Renal Aguda/tratamento farmacológico , Injúria Renal Aguda/metabolismo , Injúria Renal Aguda/patologia , Fator 4 Ativador da Transcrição/metabolismo , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Animais , Fator de Transcrição CHOP/metabolismo , Ácido Gálico/análogos & derivados , Ácido Gálico/farmacologia , Ácido Gálico/uso terapêutico , Camundongos , Transdução de Sinais/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Humanos , Espécies Reativas de Oxigênio/metabolismo , Substâncias Protetoras/farmacologiaRESUMO
Dihydroartemisinin (DHA) exerts an anti-tumor effect in multiple cancers, however, the molecular mechanism of DHA and whether DHA facilitates the anti-tumor efficacy of cisplatin in non-small cell lung cancer (NSCLC) are unclear. Here, we found that DHA potentiated the anti-tumor effects of cisplatin in NSCLC cells by stimulating reactive oxygen species (ROS)-mediated endoplasmic reticulum (ER) stress, C-Jun-amino-terminal kinase (JNK) and p38 MAPK signaling pathways both in vitro and in vivo. Of note, we demonstrated for the first time that DHA inhibits prostaglandin G/H synthase 1 (PTGS1) expression, resulting in enhanced ROS production. Importantly, silencing PTGS1 sensitized DHA-induced cell death by increasing ROS production and activating ER-stress, JNK and p38 MAPK signaling pathways. In summary, our findings provided new experimental basis and therapeutic prospect for the combined therapy with DHA and cisplatin in some NSCLC patients.
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Artemisininas , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Espécies Reativas de Oxigênio , Humanos , Apoptose , Artemisininas/farmacologia , Artemisininas/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Morte Celular , Linhagem Celular Tumoral , Cisplatino/farmacologia , Ciclo-Oxigenase 1/metabolismo , Neoplasias Pulmonares/patologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Inibidores de Ciclo-Oxigenase/farmacologiaRESUMO
The Unfolded Protein Response (UPR) serves as a critical cellular mechanism dedicated to maintaining protein homeostasis, primarily within the endoplasmic reticulum (ER). This pathway diligently responds to a variety of intracellular indicators of ER stress with the objective of reinstating balance by diminishing the accumulation of unfolded proteins, amplifying the ER's folding capacity, and eliminating slow-folding proteins. Prolonged ER stress and UPR irregularities have been linked to a range of neuropsychiatric disorders, including major depressive disorder, bipolar disorder, and schizophrenia. This review offers a comprehensive overview of the UPR pathway, delineating its activation mechanisms and its role in the pathophysiology of neuropsychiatric disorders. It highlights the intricate interplay within the UPR and its profound influence on brain function, synaptic perturbations, and neural developmental processes. Additionally, it explores evolving therapeutic strategies targeting the UPR within the context of these disorders, underscoring the necessity for precision and further research to effective treatments. The research findings presented in this work underscore the promising potential of UPR-focused therapeutic approaches to address the complex landscape of neuropsychiatric disorders, giving rise to optimism for improving outcomes for individuals facing these complex conditions.
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The Unfolded protein response (UPR) is an adaptive signalling pathway which is triggered by accumulation of unfolded/misfolded protein in ER lumen. The UPR consist of three transmembrane proteins-IRE1α, PERK and ATF6 that sense ER stress which leads to activation and downstream signaling from ER lumen to cytosol to restore homeostasis. IRE1α is an evolutionary conserved arm of UPR and acts as an interaction platform for many potential proteins that become activated under ER stress conditions. We investigated potential partners of IRE1 α through MS studies and found EXOSC3 as one of the binding partner of IRE1α. Exosomal complex proteins have 3'5' exonuclease properties (EXOSC3) that play an important role in mRNA surveillance. This property of exosomal proteins coincides with IRE1α ribonuclease activities and its mechanism of action is similar to that of IRE1α-RIDD pathway which degrades any unstable mRNA that disrupts cellular homeostasis. At the same time, studies have shown that knockdown of EXOSC3 causes ER stress in human cells, so we speculated that there might be a functional crosstalk between IRE1α and EXOSC3 under ER stress conditions. Therefore, we employed computational tools to predict and explore the stability and dynamics of the IRE1α-EXOSC3 complex. The analysis indicates that IRE1α and EXOSC3 exhibit potential interaction with the involvement of ScanNet, predicting binding pockets between the two proteins. Further, the interaction was validated via co-immunoprecipitation and yeast two-hybrid assays, thus suggesting EXOSC3 as a component of the UPRosome complex. Hence, this functional crosstalk might influence the dynamic functional output of IRE1α.Communicated by Ramaswamy H. Sarma.
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African swine fever virus (ASFV) has caused enormous economic losses since its first reported detection, and there is still no effective vaccines or drug treatment. During infection, viruses may employ various strategies, such as regulating the host endoplasmic reticulum stress/unfolded protein response or the formation of stress granules (SGs), to form an optimal environment for virus replication. However, how ASFV infection regulates host endoplasmic reticulum stress, eIF2α-regulated protein synthesis, and the formation of SGs remains unclear. Here, we evaluated the activation of ER stress and its three downstream axes during ASFV infection and identified a powerful dephosphorylation of eIF2α by ASFV ex vivo. This strong dephosphorylation property could maintain the efficiency of eIF2α-mediated de novo global protein synthesis, thus ensuring efficient viral protein synthesis at early stage. In addition, the powerful dephosphorylation of eIF2α by ASFV upon infection could also inhibit the formation of SGs induced by sodium arsenite. In addition, a specific eIF2α dephosphorylation inhibitor, salubrinal, could partially counteract ASFV-mediated eIF2α dephosphorylation and inhibit viral replication. Our results provide new insights into the areas of ASFV`s escape from host immunity and hijacking of the host protein translation system.
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Vírus da Febre Suína Africana , Febre Suína Africana , Doenças dos Suínos , Animais , Suínos , Vírus da Febre Suína Africana/genética , Grânulos de Estresse , Replicação Viral , Biossíntese de ProteínasRESUMO
It has been shown that exposure to nanoplastics (MNPs) through inhalation can induce pulmonary toxicity, but the toxicological mechanism of MNPs on the respiratory system remains unclear. Therefore, we explored the toxicological mechanism of exposure to polystyrene nanoplastics (PS-NPs) (0.05, 0.15, 0.2 mg/mL) on BEAS-2B cells. Results revealed that PS-NPs induce oxidative stress, increased apoptosis rate measured by flow cytometry, the key ferroptosis protein (GPX4 and FTH1) reduction, increased iron content, mitochondrial alterations, and increased malondialdehyde (MDA) level. Besides, consistent results were observed in mice exposed to PS-NPs (5 mg/kg/2d, 10 mg/kg/2d). Thus, we proved that PS-NPs induced cell death and lung damage through apoptosis and ferroptosis. In terms of mechanism, the elevation of the endoplasmic reticulum (ER) stress protein expression (IRE1α, PERK, XBP1S, and CHOP) revealed that PS-NPs induce lung damage by activating the two main ER stress pathways. Furthermore, the toxicological effects of PS-NPs observed in this study are attenuated by the ROS inhibitor N-acetylcysteine (NAC). Collectively, NPs-induced apoptosis and ferroptosis are attenuated by NAC via inhibiting the ROS-dependent ER stress in vitro and in vivo. This improves our understanding of the mechanism by which PS-NPs exposure leads to pulmonary injury and the potential protective effects of NAC.
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Ferroptose , Microplásticos , Camundongos , Animais , Espécies Reativas de Oxigênio/metabolismo , Poliestirenos/toxicidade , Chaperona BiP do Retículo Endoplasmático , Endorribonucleases/farmacologia , Proteínas Serina-Treonina Quinases , Pulmão/metabolismo , Acetilcisteína/farmacologia , Apoptose , Estresse do Retículo EndoplasmáticoRESUMO
Tumor-derived extracellular vesicles (TDEs) have potential for therapeutic cancer vaccine applications since they innately possess tumor-associated antigens, mediate antigen presentation, and can incorporate immune adjuvants for enhanced vaccine efficacy. However, the original TDEs also contain immune-suppressive proteins. To address this, we proposed a simple yet powerful preconditioning method to improve the overall immunogenicity of the TDEs. This approach involved inducing endoplasmic reticulum (ER) stress on parental tumor cells via N-glycosylation inhibition with tunicamycin. The generated immunogenic TDEs (iTDEs) contained down-regulated immunosuppressive proteins and up-regulated immune adjuvants, effectively activating dendritic cells (DCs) in vitro. Furthermore, in vivo evidence from a tumor-bearing mouse model showed that iTDEs activated DCs, enabling cytotoxic T lymphocytes (CTLs) to target tumors, and eventually established a systemic antitumor immune response. Additionally, iTDEs significantly delayed tumor recurrence in a postsurgery model compared with control groups. These findings highlight the immense potential of our strategy for utilizing TDEs to develop effective cancer vaccines.
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Vacinas Anticâncer , Vesículas Extracelulares , Neoplasias , Camundongos , Animais , Vacinas Anticâncer/uso terapêutico , Neoplasias/terapia , Linfócitos T Citotóxicos , Adjuvantes Imunológicos , Retículo Endoplasmático , Células DendríticasRESUMO
Sterol regulatory element-binding proteins (SREBPs) are master transcription factors that play a crucial role in regulating genes involved in the biogenesis of cholesterol, fatty acids, and triglycerides. As such, they are implicated in several serious liver diseases, including non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), fibrosis, and hepatocellular carcinoma (HCC). SREBPs are subject to regulation by multiple cofactors and critical signaling pathways, making them an important target for therapeutic interventions. In this review, we first introduce the structure and activation of SREBPs, before focusing on their function in liver disease. We examine the mechanisms by which SREBPs regulate lipogenesis, explore how alterations in these processes are associated with liver disease, and evaluate potential therapeutic strategies using small molecules, natural products, or herb extracts that target these pathways. Through this analysis, we provide new insights into the versatility and multitargets of SREBPs as factors in the modulation of different physiological stages of liver disease, highlighting their potential targets for therapeutic treatment.
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Plants consistently encounter environmental stresses that negatively affect their growth and development. To mitigate these challenges, plants have developed a range of adaptive strategies, including the unfolded protein response (UPR), which enables them to manage endoplasmic reticulum (ER) stress resulting from various adverse conditions. The CRISPR-Cas system has emerged as a powerful tool for plant biotechnology, with the potential to improve plant tolerance and resistance to biotic and abiotic stresses, as well as enhance crop productivity and quality by targeting specific genes, including those related to the UPR. This review highlights recent advancements in UPR signaling pathways and CRISPR-Cas technology, with a particular focus on the use of CRISPR-Cas in studying plant UPR. We also explore prospective applications of CRISPR-Cas in engineering UPR-related genes for crop improvement. The integration of CRISPR-Cas technology into plant biotechnology holds the promise to revolutionize agriculture by producing crops with enhanced resistance to environmental stresses, increased productivity, and improved quality traits.