RESUMEN

BACKGROUND: Inositol-requiring enzyme 1 (IRE1) is an endoplasmic reticulum (ER)-resident transmembrane protein that senses ER stress and mediates an essential arm of the unfolded protein response (UPR). IRE1 reduces ER stress by upregulating the expression of multiple ER chaperones through activation of X-box-binding protein 1 (XBP1). Emerging lines of evidence have revealed that IRE1-XBP1 axis serves as a multipurpose signal transducer during oncogenic transformation and cancer development. In this study, we explore how IRE1-XBP1 signaling promotes chemoresistance in lung cancer. METHODS: The expression patterns of UPR components and MRP1 were examined by Western blot. qRT-PCR was employed to determine RNA expression. The promoter activity was determined by luciferase reporter assay. Chemoresistant cancer cells were analyzed by viability, apoptosis. CUT & Tag (Cleavage under targets and tagmentation)-qPCR analysis was used for analysis of DNA-protein interaction. RESULTS: Here we show that activation of IRE1α-XBP1 pathway leads to an increase in MDR-related protein 1 (MRP1) expression, which facilitates drug extrusion and confers resistance to cytotoxic chemotherapy. At the molecular level, XBP1-induced c-Myc is necessary for SREBP1 expression, and SREBP1 binds to the MRP1 promoter to directly regulate its transcription. CONCLUSIONS: We conclude that IRE1α-XBP1 had important role in chemoresistance and appears to be a novel prognostic marker for lung cancer.

RESUMEN

BACKGROUND: Currently, there is a lack of validated pharmacological interventions for non-alcoholic fatty liver disease (NAFLD), which is characterized by the accumulation of hepatic triglyceride. Zhimu-Huangbai (ZH) herb-pair is a traditional Chinese medicine that regulates glucose and lipid metabolism disorders. However, the precise mechanisms underlying the preventive effects of hepatic triglyceride induced by high-fat diet (HFD) remain elusive. PURPOSE: The study aimed to examine the impact of ZH herb-pair on NAFLD in mice and explore the underlying mechanisms, particularly its effects on endoplasmic reticulum (ER) stress and lipid metabolism. METHODS: NAFLD was induced in mice using HFD, and the treated mice were orally administered ZH, metformin (Glucophage) or lovastatin. The lipid metabolism factors, ER stress markers, and the unfolded protein response (UPR) branch factors were measured using immunohistochemistry, western blotting or qRT-PCR. Co-Immunoprecipitation (CoIP) was performed to reveal the connection between SCAP and SREBP-1c. Tunicamycin (TM) and plasmid delivery were used to induce acute ER stress or crease XBP1 gain function models. The main compounds in ZH binding to IRE1α protein were studied by molecular docking and cellular thermal shift assay (CETSA). RESULTS: Treatment with ZH significantly ameliorated hepatic steatosis and reduced lipid synthesis process mainly inhibiting the expression of mature active form of SREBP-1c through relieving ER stress. The expression of IRE1α and XBP1s was inhibited after treatment with ZH. In addition, ZH improved the fatty liver phenotype caused by XBP1 overexpression via decreasing srebp1c transcription. In vitro experimental results suggested that the main compounds in ZH decreased cellular TG contents. Mechanistically, ZH targeted IRE1α and inhibited XBP1s mRNA expression to relieve ER stress and inhibit SREBP-1c production. CONCLUSIONS: ZH herb-pair can protect against NAFLD by reducing the expression of SREBP-1c, in part, via regulating IRE1α/XBP1s pathway.

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Microcystin-LR (MC-LR), a cyanobacterial toxin, is a potent carcinogen implicated in colorectal cancer (CRC) progression. However, its impact on the tumor microenvironment (TME) during CRC development remains poorly understood. This study investigates the interaction between tumor cells and macrophages mediated by MC-LR within the TME and its influence on CRC progression. CRC mice exposed to MC-LR demonstrated a significant transformation from adenoma to adenocarcinoma. The infiltration of macrophages increased, and the IRE1α/XBP1 pathway was activated in CRC cells after MC-LR exposure, influencing macrophage M2 polarization under co-culture conditions. Additionally, hexokinase 2 (HK2), a downstream target of the IRE1α/XBP1 pathway, was identified, regulating glycolysis and lactate production. The MC-LR-induced IRE1α/XBP1/HK2 axis enhanced lactate production in CRC cells, promoting M2 macrophage polarization. Furthermore, co-culturing MC-LR-exposed CRC cells with macrophages, along with the IRE1α/XBP1 pathway inhibitor 4µ8C and the hexokinase inhibitor 2-DG, suppressed M2 macrophage-induced CRC cell migration, clonogenicity, and M2 macrophage polarization. This study elucidates the mechanism by which MC-LR-mediated interactions through the IRE1α/XBP1 pathway promote CRC progression, highlighting potential therapeutic targets.

Asunto(s)

Neoplasias Colorrectales , Progresión de la Enfermedad , Endorribonucleasas , Macrófagos , Microcistinas , Proteínas Serina-Treonina Quinasas , Transducción de Señal , Proteína 1 de Unión a la X-Box , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/metabolismo , Proteína 1 de Unión a la X-Box/metabolismo , Transducción de Señal/efectos de los fármacos , Microcistinas/farmacología , Ratones , Humanos , Macrófagos/metabolismo , Macrófagos/efectos de los fármacos , Endorribonucleasas/metabolismo , Línea Celular Tumoral , Toxinas Marinas , Hexoquinasa/metabolismo , Microambiente Tumoral/efectos de los fármacos

RESUMEN

Conserved signaling cascades monitor protein-folding homeostasis to ensure proper cellular function. One of the evolutionary conserved key players is IRE1, which maintains endoplasmic reticulum (ER) homeostasis through the unfolded protein response (UPR). Upon accumulation of misfolded proteins in the ER, IRE1 forms clusters on the ER membrane to initiate UPR signaling. What regulates IRE1 cluster formation is not fully understood. Here, we show that the ER lumenal domain (LD) of human IRE1α forms biomolecular condensates in vitro. IRE1α LD condensates were stabilized both by binding to unfolded polypeptides as well as by tethering to model membranes, suggesting their role in assembling IRE1α into signaling-competent stable clusters. Molecular dynamics simulations indicated that weak multivalent interactions drive IRE1α LD clustering. Mutagenesis experiments identified disordered regions in IRE1α LD to control its clustering in vitro and in cells. Importantly, dysregulated clustering of IRE1α mutants led to defects in IRE1α signaling. Our results revealed that disordered regions in IRE1α LD control its clustering and suggest their role as a common strategy in regulating protein assembly on membranes.

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Exosomes regulate lipid metabolism by carrying miRNAs, nucleic acids, and proteins, thereby influencing the function of receptor cells. Glucose-regulated protein 78 (GRP78) is also involved in the regulation of lipid metabolism. However, it remains unclear whether exosomes derived from fatty hepatocytes (OA-Exo) regulate lipid metabolism through the enrichment of GRP78. In this study, we observed the expression of GRP78 was significantly increased in fatty hepatocytes (incubating hepatocytes with oleic acid (OA) for 24 h) and OA-Exo (P < 0.05). In addition, OA-Exo (50 µg/mL) and GRP78 protein (1 µg/mL) significant increased the content of triacylglycerol (TG) and total cholesterol (TC), as well as up-regulated the expression of GRP78 and inositol-requiring enzyme-1alpha (IRE1α) protein (P < 0.05). We further used YUM70 (an inhibitor of GRP78) to inhibit endogenous GRP78, and compared with the YUM70 group, OA-Exo reversed the effect of YUM70 and increased the content of TG, TC, and the expression of GRP78 protein in hepatocytes (P < 0.05). Furthermore, the inhibition of the IRE1α pathway with 4µ8C resulted in a significant decrease in TG content compared to the control group (P < 0.05). However, when compared with the 4µ8C group, OA-Exo and GRP78 reversed the effect of 4µ8C and significantly increased TG content (P < 0.05). Taken together, these results indicated that OA-Exo activated IRE1α to promote lipid accumulation in hepatocytes through the enrichment of GRP78. This study provided a new perspective for further exploration of exosomal lipid metabolism in fish.

RESUMEN

Objective: The fungal unfolded protein response consists of a two-component relay in which the ER-bound sensor, IreA, splices and activates the mRNA of the transcription factor, HacA. Previously, we demonstrated that hacA is essential for Aspergillus fumigatus virulence in a murine model of fungal keratitis (FK), suggesting the pathway could serve as a therapeutic target. Here we investigate the antifungal properties of known inhibitors of the mammalian Ire1 protein both in vitro and in a treatment model of FK. Methods: The antifungal activity of Ire1 inhibitors was tested against conidia of several A. fumigatus isolates by a microbroth dilution assay and against fungal biofilm by XTT reduction. The influence of 4µ8C on hacA mRNA splicing in A. fumigatus was assessed through gel electrophoresis and qRT-PCR of UPR regulatory genes. The toxicity and antifungal profile of 4µ8C in the cornea was assessed by applying drops to uninfected or A. fumigatus-infected corneas 3 times daily starting 4 hours post-inoculation. Corneas were evaluated daily through slit-lamp imaging and optical coherence tomography, or at endpoint through histology or fungal burden quantification via colony forming units. Results: Among six Ire1 inhibitors screened, the endonuclease inhibitor 4µ8C displayed the strongest antifungal profile with an apparent fungicidal action. The compound both blocked conidial germination and hyphal metabolism of A. fumigatus Af293 in the same concentration range that blocked hacA splicing and UPR gene induction (60-120 µM). Topical treatment of sham-inoculated corneas with 0.5 and 2.5 mM 4µ8C did not impact corneal clarity, but did transiently inhibit epithelialization of corneal ulcers. Relative to vehicle-treated Af293-infected corneas, treatment with 0.5 and 2.5 mM drug resulted in a 50% and >90% reduction in fungal load, respectively, the latter of which corresponded to an absence of clinical signs of infection or corneal pathology. Conclusion: The in vitro data suggest that 4µ8C displays antifungal activity against A. fumigatus through the specific inhibition of IreA. Topical application of the compound to the murine cornea can furthermore block the establishment of infection, suggesting this class of drugs can be developed as novel antifungals that improve visual outcomes in FK patients.

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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.

RESUMEN

OBJECTIVE: To explore the related research of PD-L1 in IRE1α/XBP-1 signaling pathway on non-small cell lung cancer. METHODS: The tumor model of mice was established and divided into four groups; after successful modeling, the tumor tissue of mice was removed for subsequent experiments; the bought THP-1 cells were grouped into four different groups, a control group, nivolumab intervention group, IRE1α inhibition group, and nivolumab intervention + IRE1α inhibition group; after co-culture of the four groups of THP-1 cells with A549, THP-1 cell protein levels in the four groups were analyzed using Western blot; A549 cell migration, invasion and proliferation were assessed using the scratch assay, Transwell method, monoclonal experiment and CCK-8 method. RESULTS: In vivo studies indicated that the stimulation of nivolumab could strongly check the progress of NSCLC (non-small cell lung); two groups treated with 4 µ8c showed obvious effects on check point of NSCLC; In vitro experiments including Western-blot experiment, Scratch experiment, Transwell method, Monoclonal experiment and CCK-8 experiment suggest that nivolumab could inhibit migration, invasion and proliferation of NSCLC tumor cells and it. CONCLUSION: PD-L1 is capable of controlling metastatic and proliferative potential of NSCLC by the way of the modification of IRE1α/XBP-1 signaling in tumor-associated macrophages.

Asunto(s)

Antígeno B7-H1 , Carcinoma de Pulmón de Células no Pequeñas , Proliferación Celular , Endorribonucleasas , Neoplasias Pulmonares , Proteínas Serina-Treonina Quinasas , Transducción de Señal , Macrófagos Asociados a Tumores , Proteína 1 de Unión a la X-Box , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Animales , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/secundario , Antígeno B7-H1/metabolismo , Antígeno B7-H1/genética , Proteína 1 de Unión a la X-Box/metabolismo , Proteína 1 de Unión a la X-Box/genética , Humanos , Endorribonucleasas/metabolismo , Endorribonucleasas/genética , Proliferación Celular/efectos de los fármacos , Ratones , Macrófagos Asociados a Tumores/metabolismo , Movimiento Celular/efectos de los fármacos , Células A549 , Células THP-1

RESUMEN

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.

RESUMEN

OBJECTIVE: To investigate the effect of PD-1 monoclonal antibodies in tumor-associated macrophages on angiogenesis in cervical cancer and its mechanism of action. METHODS: The effect of PD-1 monoclonal antibodies on the progression of cervical cancer was assessed using the nude mouse xenograft model and HE staining; the impact of PD-1 monoclonal antibodies on cervical cancer cell migration was evaluated using wound healing assay and Transwell assay; the effect on vascular formation in cervical cancer cells was examined using an angiogenesis assay; the impact on the expression of related proteins was tested using Western blotting. RESULTS: PD-1 monoclonal antibodies in tumor-associated macrophages can regulate and thus inhibit the progression of cervical cancer while promoting the expression of SHP2. Additionally, Sindilizumab inhibited the expression of tissue-type fibrinogen activator K and HIF1α through the PD-1/IRE1α/SHP2 signaling pathway, which inhibited the migration and neovascularization of cervical cancer cells. CONCLUSIONS: This study discovered that PD-1 monoclonal antibodies in tumor-associated macrophages inhibit vascular generation inside cervical cancer by affecting the PD-1/IRE1α/SHP2/HIF1α signaling pathway, providing a new therapeutic target for the treatment of cervical cancer.

RESUMEN

Epilepsy is a neurological disorder characterized by recurrent spontaneous seizures alongside other neurological comorbidities. Cognitive impairment is the most frequent comorbidity secondary to progressive neurologic changes in epilepsy. Sigma 1 receptors (σ1 receptors) are involved in the neuroprotection and pathophysiology of both conditions and targeting these receptors may have the potential to modulate both seizures and comorbidities. The current research demonstrated the effect of clemastine (10 mg/kg, P.O.), a non-selective σ1 receptor agonist, on pentylenetetrazol (PTZ) (35 mg/kg, i.p., every 48 h for 14 doses)-kindling rats by acting on σ1 receptors through its anti-inflammatory/antioxidant capacity. Clemastine and phenytoin (30 mg/kg, P.O.) or their combination were given once daily. Clemastine treatment showed a significant effect on neurochemical, behavioural, and histopathological analyses through modulation of σ1 receptors. It protected the kindling animals from seizures and attenuated their cognitive impairment in the Morris water maze test by reversing the PTZ hippocampal neuroinflammation/oxidative stress state through a significant increase in inositol-requiring enzyme 1 (IRE1), x-box binding protein 1 (XBP1), along with a reduction of total reactive oxygen species (TROS) and amyloid beta protein (Aß). The involvement of σ1 receptors in the protective effects of clemastine was confirmed by their abrogation when utilizing NE-100, a selective σ1 receptor antagonist. In light of our findings, modulating σ1 receptors emerges as a compelling therapeutic strategy for epilepsy and its associated cognitive impairments. The significant neuroprotective effects observed with clemastine underscore the potential of σ1 receptor-targeted treatments to address both the primary symptoms and comorbidities of neurological disorders.

Asunto(s)

Disfunción Cognitiva , Excitación Neurológica , Fármacos Neuroprotectores , Pentilenotetrazol , Receptores sigma , Convulsiones , Receptor Sigma-1 , Animales , Receptores sigma/metabolismo , Receptores sigma/agonistas , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Convulsiones/tratamiento farmacológico , Convulsiones/metabolismo , Masculino , Ratas , Disfunción Cognitiva/tratamiento farmacológico , Disfunción Cognitiva/metabolismo , Disfunción Cognitiva/prevención & control , Excitación Neurológica/efectos de los fármacos , Reposicionamiento de Medicamentos , Ratas Wistar , Estrés Oxidativo/efectos de los fármacos , Modelos Animales de Enfermedad , Antioxidantes/farmacología , Antioxidantes/uso terapéutico , Anticonvulsivantes/farmacología , Anticonvulsivantes/uso terapéutico

RESUMEN

The pathogenesis of non-alcoholic fatty liver disease (NAFLD) is influenced by a number of variables, including endoplasmic reticulum stress (ER). Thioredoxin domain-containing 5 (TXNDC5) is a member of the protein disulfide isomerase family and acts as an endoplasmic reticulum (ER) chaperone. Nevertheless, the function of TXNDC5 in hepatocytes under ER stress remains largely uncharacterized. In order to identify the role of TXNDC5 in hepatic wild-type (WT) and TXNDC5-deficient (KO) AML12 cell lines, tunicamycin, palmitic acid, and thapsigargin were employed as stressors. Cell viability, mRNA, protein levels, and mRNA splicing were then assayed. The protein expression results of prominent ER stress markers indicated that the ERN1 and EIF2AK3 proteins were downregulated, while the HSPA5 protein was upregulated. Furthermore, the ATF6 protein demonstrated no significant alterations in the absence of TXNDC5 at the protein level. The knockout of TXNDC5 has been demonstrated to increase cellular ROS production and its activity is required to maintain normal mitochondrial function during tunicamycin-induced ER stress. Tunicamycin has been observed to disrupt the protein levels of HSPA5, ERN1, and EIF2AK3 in TXNDC5-deficient cells. However, palmitic acid has been observed to disrupt the protein levels of ATF6, HSPA5, and EIF2AK3. In conclusion, TXNDC5 can selectively activate distinct ER stress pathways via HSPA5, contingent on the origin of ER stress. Conversely, the absence of TXNDC5 can disrupt the EIF2AK3 cascade.

Asunto(s)

Chaperón BiP del Retículo Endoplásmico , Estrés del Retículo Endoplásmico , Retículo Endoplásmico , Hepatocitos , Proteína Disulfuro Isomerasas , Transducción de Señal , Tunicamicina , Chaperón BiP del Retículo Endoplásmico/metabolismo , Proteína Disulfuro Isomerasas/metabolismo , Proteína Disulfuro Isomerasas/genética , Hepatocitos/metabolismo , Animales , Tunicamicina/farmacología , Retículo Endoplásmico/metabolismo , Ratones , Especies Reactivas de Oxígeno/metabolismo , Factor de Transcripción Activador 6/metabolismo , Factor de Transcripción Activador 6/genética , Línea Celular , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Proteínas de Choque Térmico/metabolismo , Proteínas de Choque Térmico/genética , Endorribonucleasas/metabolismo , Endorribonucleasas/genética , Ácido Palmítico/farmacología , Ácido Palmítico/metabolismo , Tapsigargina/farmacología , Humanos , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/patología , Tiorredoxinas/metabolismo , Tiorredoxinas/genética , Supervivencia Celular/efectos de los fármacos

RESUMEN

Skeletal muscle regeneration involves a signaling network that regulates the proliferation, differentiation, and fusion of muscle precursor cells to injured myofibers. IRE1α, one of the arms of the unfolded protein response, regulates cellular proteostasis in response to ER stress. Here, we demonstrate that inducible deletion of IRE1α in satellite cells of mice impairs skeletal muscle regeneration through inhibiting myoblast fusion. Knockdown of IRE1α or its downstream target, X-box protein 1 (XBP1), also inhibits myoblast fusion during myogenesis. Transcriptome analysis revealed that knockdown of IRE1α or XBP1 dysregulates the gene expression of molecules involved in myoblast fusion. The IRE1α-XBP1 axis mediates the gene expression of multiple profusion molecules, including myomaker (Mymk). Spliced XBP1 (sXBP1) transcription factor binds to the promoter of Mymk gene during myogenesis. Overexpression of myomaker in IRE1α-knockdown cultures rescues fusion defects. Inducible deletion of IRE1α in satellite cells also inhibits myoblast fusion and myofiber hypertrophy in response to functional overload. Collectively, our study demonstrates that IRE1α promotes myoblast fusion through sXBP1-mediated up-regulation of the gene expression of multiple profusion molecules, including myomaker.

Asunto(s)

Fusión Celular , Endorribonucleasas , Desarrollo de Músculos , Músculo Esquelético , Mioblastos , Proteínas Serina-Treonina Quinasas , Transducción de Señal , Proteína 1 de Unión a la X-Box , Animales , Proteína 1 de Unión a la X-Box/metabolismo , Proteína 1 de Unión a la X-Box/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Ratones , Mioblastos/metabolismo , Mioblastos/citología , Músculo Esquelético/metabolismo , Músculo Esquelético/citología , Desarrollo de Músculos/genética , Endorribonucleasas/metabolismo , Endorribonucleasas/genética , Células Satélite del Músculo Esquelético/metabolismo , Regeneración/genética , Diferenciación Celular/genética , Regulación de la Expresión Génica , Proteínas de la Membrana , Proteínas Musculares

RESUMEN

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.

Asunto(s)

Estrés del Retículo Endoplásmico , ARN Largo no Codificante , Respuesta de Proteína Desplegada , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Estrés del Retículo Endoplásmico/genética , Humanos , Animales , Regulación de la Expresión Génica , Transducción de Señal

RESUMEN

Parkinson's disease (PD) is a neurodegenerative disorder which affects dopaminergic neurons of the midbrain. Accumulation of α-synuclein or exposure to neurotoxins like 6-hydroxydopamine (6-OHDA) induces endoplasmic reticulum (ER) stress along with the unfolded protein response (UPR), which executes apoptosis via activation of PERK/CHOP or IRE1/JNK signaling. The present study aimed to determine which of these pathways is a major contributor to neurodegeneration in an 6-OHDA-induced in vitro model of PD. For this purpose, we have applied pharmacological PERK and JNK inhibitors (AMG44 and JNK V) in differentiated SH-SY5Y cells exposed to 6-OHDA. Inhibition of PERK and JNK significantly decreased genotoxicity and improved mitochondrial respiration, but only JNK inhibition significantly increased cell viability. Gene expression analysis revealed that the effect of JNK inhibition was dependent on a decrease in MAPK10 and XBP1 mRNA levels, whereas inhibition of either PERK or JNK significantly reduced the expression of DDIT3 mRNA. Western blot has shown that JNK inhibition strongly induced the XBP1s protein, and inhibition of each pathway attenuated the phosphorylation of eIF2α and JNK, as well as the expression of CHOP. Collectively, our data suggests that targeting the IRE1/JNK pathway of the UPR is a more effective option for PD treatment as it simultaneously affects more than one pro-apoptotic pathway.

Asunto(s)

Estrés del Retículo Endoplásmico , Endorribonucleasas , Oxidopamina , Proteínas Serina-Treonina Quinasas , Factor de Transcripción CHOP , Respuesta de Proteína Desplegada , eIF-2 Quinasa , Humanos , Apoptosis/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , eIF-2 Quinasa/metabolismo , Estrés del Retículo Endoplásmico/efectos de los fármacos , Endorribonucleasas/metabolismo , Endorribonucleasas/genética , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Proteína Quinasa 10 Activada por Mitógenos/metabolismo , Proteína Quinasa 10 Activada por Mitógenos/genética , Oxidopamina/farmacología , Enfermedad de Parkinson/metabolismo , Enfermedad de Parkinson/patología , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Transducción de Señal/efectos de los fármacos , Factor de Transcripción CHOP/metabolismo , Factor de Transcripción CHOP/genética , Respuesta de Proteína Desplegada/efectos de los fármacos , Proteína 1 de Unión a la X-Box/metabolismo , Proteína 1 de Unión a la X-Box/genética

RESUMEN

The neuroprotective function of ginsenoside Rb1 (GRb1) in cerebral ischemia-reperfusion (I/R) was lately emphasized. However, whether GRb1 plays a regulatory role on endoplasmic reticulum (ER) stress-associated pathway in cerebral I/R damage is still unclear. The aim of this study is to explore the function of GRb1 in cerebral ischemia-induced ER stress and the underlying mechanism related to IRE1/TRAF2/JNK pathway. Longa method, cerebral infarct volume, and HE staining were used to evaluate the efficacy of GRb1 in mice with a mouse model of middle cerebral artery occlusion reperfusion (MCAO/R). We also investigated the effect and mechanism of GRb1 against ischemic stroke using in vitro oxygen-glucose deprivation reperfusion (OGD/R) model. We found that GRb1 could improve neurological scores, infarct volume, and histological injury in ischemic mice. Ischemic attack also activated neuronal apoptosis and ER stress, and this effect was attenuated by GRb1. In addition, GRb1 significantly reduced I/R-induced IRE1-TRAF2 interaction, IRE1, and JNK phosphorylation. The present study also confirmed that GRb1 significantly improved OGD/R-induced PC12 cells injury. GRb1 could decrease ER stress in OGD/R-injured PC12 cells, which was reflected by the decreased expression of GRP78 and CHOP. The ER stress inducer tunicamycin partially prevented the effects of GRb1 on cell viability, ER stress, and apoptosis after OGD/R, whereas the ER stress inhibitor 4-PBA exerted the opposite effect. Moreover, GRb1 markedly decreased IRE1-TRAF2 interaction, IRE1, and JNK phosphorylation in the presence of OGD/R insult. Furthermore, JNK inhibitor SP600125 and IRE1 inhibitor DBSA pretreatment further promoted the inhibition of GRb1 on ER stress induction and cell damage induced by OGD/R. Molecular docking further elucidated that the mechanism by which GRb1 improves cerebral ischemia maybe related to its direct binding to the kinase domain of IRE1, which in turn inhibited the phosphorylation of IRE1. Collectively, these results demonstrated that GRb1 reduced ischemic stroke-induced apoptosis through the ER stress-associated IRE1/TRAF2/JNK pathway and GRb1 has the potential as a protective drug for the treatment of cerebral ischemia.

RESUMEN

BACKGROUND: Glucose and fatty acid overload-induced glucolipid toxicity of pancreatic ß-cells is associated with the development of diabetes. Endoplasmic reticulum stress (ERS) plays an essential role in this process. Ghrelin, a peptide secreted by the pancreas, negatively correlates with oxidative stress. The study aimed to investigate ghrelin's role in glycolipid-induced ß-cell dysfunction and its possible mechanism. METHODS: Mouse insulinoma ß-cell, NIT-1 cells, were stimulated with high fat and high glucose to induce glucolipid toxicity. High fat and high glucose-induced NIT-1 cells were treated with acylated ghrelin (AG) or [d-Lys3]-growth hormone releasing peptide (GHRP)-6. Flow cytometry and Cell Counting Kit-8 (CCK-8) assay were performed to assess apoptosis and cell viability. The protein expression related to apoptosis, inositol-requiring kinase 1 (IRE1)/c-Jun N-terminal kinase (JNK) signaling, and ERS were investigated using western blot. Enzyme-linked immunosorbent assay (ELISA) was adopted to examine insulin's synthesis and secretion levels. RESULTS: Ghrelin treatment improved cell viability while inhibiting cell glucolipotoxicity-induced NIT-1 cell apoptosis. Ghrelin can promote the synthesis and secretion of insulin in NIT-1 cells. Mechanistically, ghrelin attenuates ERS and inhibits the IRE1/JNK signaling pathway in NIT-1 cells induced by glucolipotoxicity. CONCLUSION: Ghrelin improves ß-cellular dysfunction induced by glucolipotoxicity by inhibiting the IRE1/JNK pathway induced by ERS. It could be an effective treatment for ß-cellular dysfunction.

Asunto(s)

Apoptosis , Estrés del Retículo Endoplásmico , Endorribonucleasas , Ghrelina , Células Secretoras de Insulina , Proteínas Serina-Treonina Quinasas , Animales , Ratones , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Estrés del Retículo Endoplásmico/efectos de los fármacos , Endorribonucleasas/metabolismo , Ghrelina/farmacología , Ghrelina/metabolismo , Glucosa , Células Secretoras de Insulina/efectos de los fármacos , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Transducción de Señal/efectos de los fármacos

RESUMEN

OBJECTIVES: To investigate the mechanism of the effect of acupuncture and moxibustion on improving liver injury in cisplatin (DDP) induced liver injury model mice by observing the changes of inositol-requiring enzyme (IRE) -1 signaling pathway. METHODS: Forty KM mice were randomly divided into control, model, acupuncture and moxibustion groups, with 10 mice in each group. The liver injury model was replicated by intraperitoneal injection of DDP (10 mg/kg). In the acupuncture group and the moxibustion group, acupuncture and moxibustion were performed at "Dazhui"(GV14), and bilateral "Ganshu"(BL18), "Shenshu" (BL23), and "Zusanli"(ST36), respectively for 6 min, once per day for 7 d. The apoptosis of hepatocytes was detected by TUNEL staining. The expression of phosphorylation(p)-IRE-1α, glucose-regulated protein (Grp) 78 and cysteine aspartic protease (Caspase) -12 in liver tissue were detected by immunohistochemistry and Western blot, respectively. The expression levels of Grp78 and Caspase-12 mRNA in liver tissue were detected by quantitative real-time PCR. RESULTS: Compared with the control group, the apoptosis rate of hepatocytes was increased (P<0.05), the positive expression and protein expression of p-IRE-1α, Grp78, and Caspase-12 were increased (P<0.05), the expression levels of Grp78 and Caspase-12 mRNA were increased (P<0.05) in the model group. Compared with the model group, all these indicators showed opposite trends (P<0.05) in the acupuncture and moxibustion groups. CONCLUSIONS: Acupuncture and moxibustion can reduce liver injury due to DDP chemotherapy by modulating IRE-1 signaling pathway, inhibiting the excessive activation of endoplasmic reticulum stress, and reducing liver cell apoptosis.

Asunto(s)

Terapia por Acupuntura , Apoptosis , Cisplatino , Chaperón BiP del Retículo Endoplásmico , Hígado , Moxibustión , Proteínas Serina-Treonina Quinasas , Transducción de Señal , Animales , Ratones , Masculino , Humanos , Hígado/metabolismo , Hígado/lesiones , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Endorribonucleasas/metabolismo , Endorribonucleasas/genética , Enfermedad Hepática Inducida por Sustancias y Drogas/terapia , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/genética , Puntos de Acupuntura , Proteínas de Choque Térmico/metabolismo , Proteínas de Choque Térmico/genética , Caspasa 12/metabolismo , Caspasa 12/genética , Hepatocitos/metabolismo

RESUMEN

Endoplasmic reticulum stress occurs due to large amounts of misfolded proteins, hypoxia, nutrient deprivation, and more. The unfolded protein is a complex intracellular signaling network designed to operate under this stress. Composed of three individual arms, inositol-requiring enzyme 1, protein kinase RNA-like ER kinase, and activating transcription factor-6, the unfolded protein response looks to resolve stress and return to proteostasis. The CD8+ T cell is a critical cell type for the adaptive immune system. The unfolded protein response has been shown to have a wide-ranging spectrum of effects on CD8+ T cells. CD8+ T cells undergo cellular stress during activation and due to environmental insults. However, the magnitude of the effects this response has on CD8+ T cells is still understudied. Thus, studying these pathways is important to unraveling the inner machinations of these powerful cells. In this review, we will highlight the recent literature in this field, summarize the three pathways of the unfolded protein response, and discuss their roles in CD8+ T cell biology and functionality.

Asunto(s)

Linfocitos T CD8-positivos , Estrés del Retículo Endoplásmico , Transducción de Señal , Respuesta de Proteína Desplegada , Respuesta de Proteína Desplegada/inmunología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Humanos , Animales , Estrés del Retículo Endoplásmico/inmunología , Proteínas Serina-Treonina Quinasas/metabolismo , Factor de Transcripción Activador 6/metabolismo , Endorribonucleasas/metabolismo , Endorribonucleasas/inmunología , Activación de Linfocitos/inmunología

RESUMEN

Background: Premature birth (PTB) is a major cause of neonatal mortality and has enduring consequences. LIM Homeobox 1 (LHX1) is vital in embryonic organogenesis, while Inositol-Requiring Enzyme 1 (IRE-1) regulates endoplasmic reticulum stress (ERS). This study explores whether IRE-1 impacts PTB via LHX1 modulation. Methods: We analyzed LHX1 expression in placental samples from PTB patients and examined its impact on the viability, migration, invasion, and apoptosis of the human placental trophoblast cell line HTR8/Svneo, particularly when treated with the ERS inducer tunicamycin (TM). We also assessed the levels of ERS-related genes and autophagy activation in response to LHX1 deficiency. To gain mechanistic insights, we evaluated the ERS-mediated activation of the IRE-1/XBP1/CHOP signaling pathway in LHX1-silenced HTR8/Svneo cells. Additionally, we examined the transcriptional activation of IRE-1 and the binding of LHX1 to the IRE-1 promoter in HTR8/Svneo cells. We overexpressed IRE-1 in LHX1-silenced HTR8/Svneo cells to assess its effects on cell viability, migration, invasion, apoptosis, and autophagy. Finally, we induced LHX1 knockdown in mice through intraperitoneal injections of tunicamycin (TM) and Sh-LHX1 over a 24-h period to evaluate PTB symptoms. Results: We observed LHX1 overexpression in placental tissue from PTB cases and TM-induced HTR8/Svneo cells. LHX1 depletion enhanced cell viability, migration, and invasion while reducing autophagy and apoptosis. This reduction in LHX1 led to decreased levels of IRE-1, XBP1, CHOP, and other ERS-related genes, indicating LHX1's role in ERS induction and the activation of the IRE-1/XBP1/CHOP pathway. Mechanistically, LHX1 was found to bind to the IRE-1 promoter, inducing its transcriptional activation. Notably, overexpressing IRE-1 counteracted the impact of LHX1 depletion on trophoblast cell behavior, suggesting that LHX1 modulates IRE-1. In line with our in vitro studies, LHX1 knockdown ameliorated PTB symptoms in TM-treated mice. Conclusion: LHX1 contributes to the progression of PTB by regulating the IRE-1-XBP1-CHOP pathway.