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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.
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BACKGROUND: The 78-kDa glucose-regulated protein (GRP78) expressed on the cell surface (csGRP78) has been reported to regulate tissue factor procoagulant activity (TF PCA) in lesion-resident endothelial cells (ECs), which is further enhanced by circulating anti-GRP78 autoantibodies that bind to the Leu98-Leu115 epitope in GRP78. OBJECTIVES: Determine the effects of the engagement of the anti-GRP78 autoantibody to cell surface GRP78 on endothelial cells and the underlying mechanisms that impact TF PCA. METHODS: Immunofluorescent staining was used to determine the presence of csGRP78 in TNFα-treated endothelial cells. An established TF PCA assay was used to evaluate human ECs following treatment with anti-GRP78 autoantibodies. The Fura 2-AM assay was used to quantify changes in intracellular Ca2+ levels. Small molecules predicted to bind csGRP78 were identified using artificial intelligence. ELISAs were used to assess the ability of these GRP78 binders to mitigate TF activity and interfere with the autoantibody/csGRP78 complex. RESULTS: In TNFα-treated ECs, anti-GRP78 autoantibodies increased TF PCA. This observation was further enhanced by ER-stress-induced elevation of csGRP78 levels. Anti-GRP78 autoantibody treatment increased intracellular Ca2+ levels. Sequestering the anti-GRP78 autoantibody with a conformational peptide or blocking with heparin molecules attenuated anti-GRP78 autoantibody-induced TF PCA. We identified B07*, a GRP78 binder that diminished anti-GRP78 autoantibody-induced TF PCA on ECs. CONCLUSIONS: These findings show how anti-GRP78 autoantibodies enhance TF PCA that contributes to thrombosis and identify novel GRP78 binders that represent a potential novel therapeutic strategy for treating and managing atherothrombotic disease.
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ETHNOPHARMACOLOGICAL RELEVANCE: Osteosarcoma (OS) is characterized by rapid growth and frequent pulmonary metastasis. Eurycoma longifolia Jack, a flowering plant primarily found in Southeast Asian countries, is commonly used in traditional herbal medicine. Its root extract is mainly used for against cancer, malaria, parasites and other conditions. The active compound in its root extract, eurycomanone (EUR), has been proven to inhibit lung and liver cancer proliferation. AIM OF THE STUDY: Our research aimed to investigate the inhibitory effect and underlying molecular mechanism of EUR on OS growth and metastasis. MATERIALS AND METHODS: In vitro experiments: western blotting (WB) screened 41 compounds that inhibited GRP78 expression and evaluated the protein levels of GRP78, PARP, cleaved-PARP, MMP2, and MMP9. Cell proliferation was evaluated using CCK-8, EdU, colony formation assay, and cell apoptosis was assessed by flow cytometry. Transwell, wound healing, and tube formation assays were performed to determine the effect of EUR on tumor invasion, migration, and angiogenesis, respectively. Quantitative real-time polymerase chain (qRT-PCR) and dual-luciferase activity assays detected GRP78 mRNA stability and transcription levels post-EUR and thapsigargin treatment. RNA-Seq identified signaling pathways inhibited by EUR. In vivo experiments: effects of EUR in mice were evaluated by H&E staining to detect lung metastasis and potential toxic effects in tissues. Immunohistochemical (IHC) staining detected the expression of Ki-67, CD31, and cleaved caspase-3 in tumors. RESULTS: GRP78 is highly expressed in OS and correlated with poor prognosis. In vitro, eurycomanone (EUR) significantly downregulated GRP78 expression, inhibited cell proliferation, migration, invasion, tube formation, and induced apoptosis. Moreover, it enhanced trichostatin A (TSA) sensitivity and exhibited inhibitory effects on other cancer types. Mechanistically, EUR decreased GRP78 mRNA stability and transcription. In vivo, EUR inhibited proliferation and invasion in tibial and PDX models. CONCLUSIONS: Our study demonstrated that EUR inhibits the growth and metastasis of OS by reducing GRP78 mRNA stability and inhibiting its transcription, which offers a novel approach for clinical treatment of OS.
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OBJECTIVE: The purpose of the present study was to potential effects of forsythiaside A (FA) on Sjogren's syndrome (SS). METHODS: Enzyme linked immunosorbent assay for detecting cytokines and Western blotting was used for detecting related protein expression. RESULTS: FA effectively reduced the secretion of inflammatory cytokines, the expression of Caspase-1 and NLRP3 proteins and the expression of p65 in SS. FA also effectively inhibited the high expression of Grp78 in SS. When Grp78 expression was silenced, it effectively reduced the secretion of inflammatory cytokines, the expression of Caspase-1 and NLRP3 proteins and the expression of p65 in the nucleus in SS. FA effectively inhibit the secretion of inflammatory cytokines induced by overexpression of Grp78, the expression of Caspase-1 and NLRP3 proteins and the expression of p65 in the nucleus in SS. CONCLUSION: FA induces the degradation of Grp78 protein, regulates the NF-κB signaling pathway in SS and inhibited NLRP3 inflammasome activation and reduced the release of inflammatory cytokines to alleviate SS.
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Chaperón BiP del Retículo Endoplásmico , Proteínas de Choque Térmico , Inflamasomas , Proteína con Dominio Pirina 3 de la Familia NLR , Síndrome de Sjögren , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Humanos , Chaperón BiP del Retículo Endoplásmico/metabolismo , Inflamasomas/metabolismo , Síndrome de Sjögren/inmunología , Síndrome de Sjögren/metabolismo , Proteínas de Choque Térmico/metabolismo , Proteínas de Choque Térmico/genética , Femenino , Transducción de Señal , Citocinas/metabolismo , Caspasa 1/metabolismo , Persona de Mediana Edad , Masculino , Factor de Transcripción ReIA/metabolismo , FN-kappa B/metabolismoRESUMEN
The HSPA5 protein (BiP/Grp78) serves as a pivotal chaperone in maintaining cellular protein quality control. As a member of the human HSP70 family, HSPA5 comprises two distinct domains: a nucleotide-binding domain (NBD) and a peptide-binding domain (PBD). In this study, we investigated the interdomain interactions of HSPA5, aiming to elucidate how these domains regulate its function as a chaperone. Our findings revealed that HSPA5-FL, HSPA5-T, and HSPA5-N exhibit varying affinities for ATP and ADP, with a noticeable dependency on Mg2+ for optimal interactions. Interestingly, in ADP assays, the presence of the metal ion seems to enhance NBD binding only for HSPA5-FL and HSPA5-T. Moreover, while the truncation of the C-terminus does not significantly impact the thermal stability of HSPA5, experiments involving MgATP underscore its essential role in mediating interactions and nucleotide hydrolysis. Thermal stability assays further suggested that the NBD-PBD interface enhances the stability of the NBD, more pronounced for HSPA5 than for the orthologous HSPA1A, and prevents self-aggregation through interdomain coupling. Enzymatic analyses indicated that the presence of PBD enhances NBD ATPase activity and augments its nucleotide affinity. Notably, the intrinsic chaperone activity of the PBD is dependent on the presence of the NBD, potentially due to the propensity of the PBD for self-oligomerization. Collectively, our data highlight the pivotal role of allosteric mechanisms in modulating thermal stability, nucleotide interaction, and ATPase activity of HSPA5, underscoring its significance in protein quality control within cellular environments.
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Adenosina Trifosfato , Chaperón BiP del Retículo Endoplásmico , Proteínas de Choque Térmico , Estabilidad Proteica , Proteínas de Choque Térmico/química , Proteínas de Choque Térmico/metabolismo , Humanos , Adenosina Trifosfato/metabolismo , Adenosina Trifosfato/química , Adenosina Difosfato/metabolismo , Adenosina Difosfato/química , Unión Proteica , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas HSP70 de Choque Térmico/química , Dominios Proteicos , Magnesio/metabolismo , Magnesio/químicaRESUMEN
Background: Aggressive mature T-cell lymphoma (TCL) is a disease that carries a poor prognosis. Methods: We analyzed the expression of 22 tumor cell functional proteins in 16 randomly selected patients with TCL. Immunohistochemistry was performed in paraffin-embedded tumor tissue sections to determine the protein expression statuses in tumor cells. Results: Glucose-regulated protein 94 (GRP94), a protein that serves as a pro-survival component under endoplasmic reticulum (ER) stress in the tumor microenvironment, was significantly associated with a shortened survival. Furthermore, significant differences were observed when GRP94 was combined with six other factors. The six factors were (1) programmed cell death-ligand 1 (PD-L1); (2) programmed cell death 1 (PD-1); (3) aldo-keto reductase family 1 member C3 (AKR1C3); (4) P53, a tumor suppressor; (5) glucose-regulated protein 78 (GRP78), an ER stress protein; and (6) thymidine phosphorylase (TP). Based on the combination of GRP94 and the six other factors expressed in the tumors, we propose a new prognostic classification system for TCL (TCL Urayasu classification). Group 1 (relatively good prognosis): GRP94-negative (n = 6; median OS, 88 months; p < 0.01); Group 2 (poor prognosis): GRP94-positive, plus expression of two of the six factors mentioned above (n = 5; median OS, 25 months; p > 0.05); and Group 3 (very poor prognosis): GRP94-positive, plus expression of at least three of the six factors mentioned above (n = 5; median OS, 10 months; p < 0.01). Conclusions: Thus, the TCL Urayasu prognostic classification may be a simple, useful, and innovative classification that also explains the mechanism of resistance to treatment for each functional protein. If validated in a larger number of patients, the TCL Urayasu classification will enable a targeted treatment using selected inhibitors acting on the abnormal protein found in each patient.
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The purpose of this study was to evaluate the spatiotemporal immunoexpression pattern of microtubule-associated protein 1 light chain 3 beta (LC3B), glucose-regulated protein 78 (GRP78), heat shock protein 70 (HSP70), and lysosomal-associated membrane protein 2A (LAMP2A) in normal human fetal kidney development (CTRL) and kidneys affected with congenital anomalies of the kidney and urinary tract (CAKUT). Human fetal kidneys (control, horseshoe, dysplastic, duplex, and hypoplastic) from the 18th to the 38th developmental week underwent epifluorescence microscopy analysis after being stained with antibodies. Immunoreactivity was quantified in various kidney structures, and expression dynamics were examined using linear and nonlinear regression modeling. The punctate expression of LC3B was observed mainly in tubules and glomerular cells, with dysplastic kidneys displaying distinct staining patterns. In the control group's glomeruli, LAMP2A showed a sporadic, punctate signal; in contrast to other phenotypes, duplex kidneys showed significantly stronger expression in convoluted tubules. GRP78 had a weaker expression in CAKUT kidneys, especially hypoplastic ones, while normal kidneys exhibited punctate staining of convoluted tubules and glomeruli. HSP70 staining varied among phenotypes, with dysplastic and hypoplastic kidneys exhibiting stronger staining compared to controls. Expression dynamics varied among observed autophagy markers and phenotypes, indicating their potential roles in normal and dysfunctional kidney development.
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Autofagia , Chaperón BiP del Retículo Endoplásmico , Proteínas HSP70 de Choque Térmico , Riñón , Proteína 2 de la Membrana Asociada a los Lisosomas , Proteínas Asociadas a Microtúbulos , Humanos , Proteína 2 de la Membrana Asociada a los Lisosomas/metabolismo , Proteína 2 de la Membrana Asociada a los Lisosomas/genética , Riñón/metabolismo , Riñón/anomalías , Riñón/patología , Proteínas Asociadas a Microtúbulos/metabolismo , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas de Choque Térmico/metabolismo , Anomalías Urogenitales/metabolismo , Anomalías Urogenitales/patología , Sistema Urinario/metabolismo , Sistema Urinario/anomalías , Reflujo Vesicoureteral/metabolismo , Reflujo Vesicoureteral/patologíaRESUMEN
The 78-kDa glucose regulated protein (GRP78) commonly upregulated in a wide variety of tumors is an important prognostic marker and a promising target for suppressing tumorigenesis and treatment resistance. While GRP78 is well established as a major endoplasmic reticulum (ER) chaperone with anti-apoptotic properties and a master regulator of the unfolded protein response, its new role as a regulator of oncoprotein expression is just emerging. MYC is dysregulated in about 70 % of human cancers and is the most commonly activated oncoprotein. However, despite recent advances, therapeutic targeting of MYC remains challenging. Here we identify GRP78 as a new target for suppression of MYC expression. Using multiple MYC-dependent cancer models including head and neck squamous cell carcinoma and their cisplatin-resistant clones, breast and pancreatic adenocarcinoma, our studies revealed that GRP78 knockdown by siRNA or inhibition of its activity by small molecule inhibitors (YUM70 or HA15) reduced c-MYC expression, leading to onset of apoptosis and loss of cell viability. This was observed in 2D cell culture, 3D spheroid and in xenograft models. Mechanistically, we determined that the suppression of c-MYC is at the post-transcriptional level and that YUM70 and HA15 treatment potently upregulated the eukaryotic translation inhibitor 4E-BP1, which targets eIF4E critical for c-MYC translation initiation. Furthermore, knock-down of 4E-BP1 via siRNA rescued YUM70-mediated c-MYC suppression. As YUM70 is also capable of suppressing N-MYC expression, this study offers a new approach to suppress MYC protein expression through knockdown or inhibition of GRP78.
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Proteínas Adaptadoras Transductoras de Señales , Proteínas de Ciclo Celular , Chaperón BiP del Retículo Endoplásmico , Regulación Neoplásica de la Expresión Génica , Proteínas de Choque Térmico , Proteínas Proto-Oncogénicas c-myc , Humanos , Chaperón BiP del Retículo Endoplásmico/metabolismo , Proteínas Proto-Oncogénicas c-myc/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Animales , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Proteínas de Choque Térmico/antagonistas & inhibidores , Ratones , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Adaptadoras Transductoras de Señales/antagonistas & inhibidores , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/antagonistas & inhibidores , Fosfoproteínas/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/antagonistas & inhibidores , Apoptosis/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto , Neoplasias/genética , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Neoplasias/patología , Regulación hacia Arriba/efectos de los fármacosRESUMEN
BACKGROUND: Various factors, including blood, inflammatory, infectious, and immune factors, can cause ischemic stroke. However, the primary cause is often the instability of cervical arteriosclerosis plaque. It is estimated that 18-25% of ischemic strokes are caused by the rupture of carotid plaque.1 Plaque stability is crucial in determining patient prognosis. Developing a highly accurate, non-invasive, or minimally invasive technique to assess carotid plaque stability is crucial for diagnosing and treating stroke.Previous research by our group has demonstrated that the expression levels of CHOP (C/EBP homologous protein) and GRP78 (glucose-regulated protein 78) are correlated with the stability of atherosclerotic plaques.2 OBJECT: This research assesses changes in GRP78 and CHOP expressions in human umbilical vein endothelial cells(HUVEC) following experiments within the hemodynamic influencing factors test system. Additionally, it includes conducting an empirical study on the impact of blood flow shear force on the stability of human carotid atherosclerotic plaques. The objective is to explore the implications of blood flow shear force on the stability of carotid atherosclerotic plaques. METHOD: The hemodynamic influencing factors test bench system was configured with low (Group A, 4 dyns/cm²), medium (Group B, 8 dyns/cm²), and high shear force groups (Group C, 12 dyns/cm²). Relative expression levels of GRP78 and CHOP proteins in human umbilical vein endothelial cells were measured using Western blot analysis, and quantitative analysis of GRP78 and CHOP mRNA was conducted using RT-qPCR. Meanwhile, plaques from 60 carotid artery patients, retrieved via Carotid Endarterectomy (CEA), were classified into stable (S) and unstable (U) groups based on pathological criteria. Shear force at the carotid bifurcation was measured preoperatively using ultrasound. Western blot and RT-qPCR were used to analyze the relative expression levels of GRP78 and CHOP proteins and mRNA, respectively, in the plaque specimens from both groups. RESULT: Expression levels of GRP78, CHOP proteins, and their mRNAs were assessed in groups A, B, and C via Western blot and RT-qPCR. Results showed that in the low-shear group, all markers were elevated in group A compared to groups B and C. Statistical analysis revealed significantly lower shear forces at the carotid bifurcation in group U compared to group S. In group U plaques, GRP78 and CHOP expressions were significantly higher in group U than in group S. CONCLUSION: Blood flow shear forces variably affect the expression of GRP78 and CHOP proteins, as well as their mRNA levels, in vascular endothelial cells. The lower the shear force and fluid flow rate, the higher the expression of GRP78 and CHOP, potentially leading to endoplasmic reticulum stress(ERS), which may destabilize the plaque.
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Chaperón BiP del Retículo Endoplásmico , Proteínas de Choque Térmico , Células Endoteliales de la Vena Umbilical Humana , Placa Aterosclerótica , Factor de Transcripción CHOP , Humanos , Factor de Transcripción CHOP/metabolismo , Factor de Transcripción CHOP/genética , Proteínas de Choque Térmico/metabolismo , Proteínas de Choque Térmico/genética , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Masculino , Anciano , Estrés Mecánico , Femenino , Persona de Mediana Edad , Células Cultivadas , Enfermedades de las Arterias Carótidas/metabolismo , Enfermedades de las Arterias Carótidas/cirugía , Enfermedades de las Arterias Carótidas/fisiopatología , Enfermedades de las Arterias Carótidas/genética , Enfermedades de las Arterias Carótidas/patología , Estenosis Carotídea/fisiopatología , Estenosis Carotídea/metabolismo , ARN Mensajero/metabolismoRESUMEN
The present study aimed to investigate the role of antidiabetic drug metformin on the cytoplasmic organization of oocytes. Germinal vesicle (GV) stage oocytes were collected from adult female Swiss albino mice and subjected to in vitro maturation (IVM) in various experimental groups- control, vehicle control (0.3% ethanol), metformin (50 µg/mL), high glucose and high lipid (HGHL, 10 mM glucose; 150 µM palmitic acid; 75 µM stearic acid and 200 µM oleic acid in ethanol), and HGHL supplemented with metformin. The metaphase II (MII) oocytes were analyzed for lipid accumulation, mitochondrial and endoplasmic reticulum (ER) distribution pattern, oxidative and ER stress, actin filament organization, cortical granule distribution pattern, spindle organization and chromosome alignment. An early polar body extrusion was observed in the HGHL group. However, the maturation rate at 24 h did not differ significantly among the experimental groups compared to the control. The HGHL conditions exhibited significantly higher levels of oxidative stress, ER stress, poor actin filament organization, increased lipid accumulation, altered mitochondrial distribution, spindle abnormalities, and chromosome misalignment compared to the control. Except for spindle organization, supplementation of metformin to the HGHL conditions improved all the parameters (non-significant for ER and actin distribution pattern). These results show that metformin exposure in the culture media helped to improve the hyperglycemia and hyperlipidemia-induced cytoplasmic anomalies except for spindle organization. Given the crucial role of spindle organization in proper chromosome segregation during oocyte maturation and meiotic resumption, the implications of metformin's limitations in this aspect warrant careful evaluation and further investigation.
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Hiperglucemia , Hiperlipidemias , Metformina , Oocitos , Estrés Oxidativo , Huso Acromático , Animales , Metformina/farmacología , Femenino , Oocitos/efectos de los fármacos , Oocitos/metabolismo , Ratones , Huso Acromático/efectos de los fármacos , Hiperglucemia/metabolismo , Estrés Oxidativo/efectos de los fármacos , Hiperlipidemias/tratamiento farmacológico , Hipoglucemiantes/farmacología , Citoplasma/metabolismo , Citoplasma/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Estrés del Retículo Endoplásmico/efectos de los fármacos , Células Cultivadas , Ácido Palmítico/toxicidad , Ácido Palmítico/farmacología , Técnicas de Maduración In Vitro de los Oocitos/métodosRESUMEN
Long-term radiofrequency radiation (RFR) exposure, which adversely affects organisms, deteriorates testicular functions. Misfolding or unfolding protein accumulation in the endoplasmic reticulum (ER) initiates an intracellular reaction known as ER stress (ERS), which activates the unfolded protein response (UPR) for proteostasis. Since both RFR exposure and ERS can cause male infertility, we hypothesized that RFR exposure causes ERS to adversely affect testicular functions in rats. To investigate role of ERS in mediating RFR effects on rat testis, we established five experimental groups in male rats: control, short-term 2100-megahertz (MHz) RFR (1-week), short-term sham (sham/1-week), long-term 2100-MHz RFR (10-week), and long-term sham (sham/10-week). ERS markers Grp78 and phosphorylated PERK (p-Perk) levels and ERS-related apoptosis markers Chop and caspase 12 were investigated by immunohistochemistry, immunoblotting, and quantitative real-time polymerase chain reaction (qPCR). Long-term RFR exposure increased Grp78, p-Perk, and Chop levels, while short-term RFR exposure elevated Chop and caspase 12 levels. Chop expression was not observed in spermatogonia and primary spermatocytes, which may protect spermatogonia and primary spermatocytes against RFR-induced ERS-mediated apoptosis, thereby allowing transmission of genetic material to next generations. While short and long-term RFR exposures trigger ERS and ERS-related apoptotic pathways, further functional analyses are needed to elucidate whether this RFR-induced apoptosis has long-term male infertility effects.
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Estrés del Retículo Endoplásmico , Ratas Sprague-Dawley , Testículo , Animales , Masculino , Estrés del Retículo Endoplásmico/efectos de la radiación , Testículo/efectos de la radiación , Testículo/metabolismo , Ratas , Ondas de Radio/efectos adversos , Apoptosis/efectos de la radiaciónRESUMEN
Objective: To analyze the effect of allicin on the immunoreactivity of osteosarcoma (OS) cells and further explore whether its mechanism is related to the long non-coding Ribonucleic Acid (lncRNA) CBR3-AS1/miR-145-5p/GRP78 axis, so as to provide clinical evidence. Methods: The human OS cell line Saos-2 was treated with allicin at 25, 50, and 100 µmol/L, respectively, to observe changes in cell biological behaviors. Subsequently, CBR3-AS1 abnormal expression vectors were constructed and transfected into Saos-2 to discuss their influence on OS. Furthermore, the regulatory relationship between allicin and the CBR3-AS1/miR-145-5p/GRP78 axis was validated by rescue experiments. Finally, a nude mice tumorigenesis experiment was carried out to analyze the effects of allicin and CBR3-AS1/miR-145-5p/GRP78 axis on the growth of living tumors. Alterations in T-lymphocyte subsets were also detected to assess the effect of allicin on OS immunoreactivity. Results: With the increase of allicin concentration, Saos-2 activity decreased and apoptosis increased (P < 0.05). In addition, the expression of CBR3-AS1 and GRP78 decreased after allicin intervention, while miR-145-5p increased (P < 0.05). Silencing CBR3-AS1 led to reduced Saos-2 activity, enhanced apoptosis, and activated mitophagy and endoplasmic reticulum stress (P < 0.05). In the rescue experiment, the effect of CBR3-AS1 on OS cells was reversed by silencing miR-145-5p, while the impact of miR-145-5p was reversed by GRP78. Finally, the tumorigenesis experiment in nude mice confirmed the regulatory effects of allicin and CBR3-AS1/miR-145-5p/GRP78 on tumor growth in vivo. Meanwhile, it was seen that allicin activated CD4+CD8+ in OS mice, confirming that allicin has the effect of activating OS immunoreactivity. Conclusions: Allicin activates OS immunoreactivity and induces apoptosis through the CBR3-AS1/miR-145-5p/GRP78 molecular axis.
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Successful treatment of glioblastoma multiforme (GBM), an aggressive form of primary brain neoplasm, mandates the need to develop new therapeutic strategies. In this study, we investigated the potential of PBI-05204 in targeting GBM stem cells (GSCs) and the underlying mechanisms. Treatment with PBI-05204 significantly reduced both the number and size of tumor spheres derived from patient-derived GSCs (GBM9, GSC28 and TS543), and suppressed the tumorigenesis of GBM9 xenografts. Moreover, PBI-05204 treatment led to a significant decrease in the expression of CD44 and NANOG, crucial markers of progenitor stem cells, in GBM9 and GSC28 GSCs. This treatment also down-regulated GRP78 expression in both GSC types. Knocking down GRP78 expression through GRP78 siRNA transfection in GBM9 and GSC28 GSCs also resulted in reduced spheroid size and CD44 expression. Combining PBI-05204 with GRP78 siRNA further decreased spheroid numbers compared to GRP78 siRNA treatment alone. PBI-05204 treatment led to increased expression of pRIP1K and pRIP3K, along with enhanced binding of RIPK1/RIPK3 in GBM9 and GSC28 cells, resembling the effects observed in GRP78-silenced GSCs, suggesting that PBI-05204 induced necroptosis in these cells. Furthermore, oleandrin, a principle active cardiac glycoside component of PBI-05204, showed the ability to inhibit the self-renewal capacity in GSCs. These findings highlight the potential of PBI-05204 as a promising candidate for the development of novel therapies that target GBM stem cells.
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Chaperón BiP del Retículo Endoplásmico , Glioblastoma , Proteínas de Choque Térmico , Células Madre Neoplásicas , Ensayos Antitumor por Modelo de Xenoinjerto , Humanos , Glioblastoma/patología , Glioblastoma/tratamiento farmacológico , Glioblastoma/metabolismo , Glioblastoma/genética , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Animales , Ratones , Proteínas de Choque Térmico/metabolismo , Proteínas de Choque Térmico/genética , Línea Celular Tumoral , Extractos Vegetales/farmacología , Necroptosis/efectos de los fármacos , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/genética , Proliferación Celular/efectos de los fármacos , Apoptosis/efectos de los fármacos , Modelos Animales de Enfermedad , Receptores de Hialuranos/metabolismo , Receptores de Hialuranos/genéticaRESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Jiedu Tongluo Tiaogan Formula (JTTF), a traditional Chinese herbal decoction, exhibits the potential to treat type 2 diabetes mellitus (T2DM) by inhibiting endoplasmic reticulum stress (ERS) and excessive autophagy, which are the risk factors for the abnormal development and progression of ß cells. AIM OF THE STUDY: We aimed to assess the effect of JTTF on pancreatic glucotoxicity by inhibiting ERS and excessive autophagy, for which db/db mice and INS-1 insulinoma cells were used. MATERIALS AND METHODS: The chemical composition of the JTTF was analyzed by UPLC-Q/TOF-MS. Diabetic (db/db) mice were treated with distilled water or JTTF (2.4 and 7.2 g/kg/day) for 8 weeks. Furthermore, INS-1 cells induced by high glucose (HG) levels were treated with or without JTTF (50, 100, and 200 µg/mL) for 48 h to elucidate the protective mechanism of JTTF on glucose toxicity. The experimental methods included an oral glucose tolerance test, hematoxylin-eosin staining, immunohistochemistry, western blotting, RT-qPCR, and acridine orange staining. RESULT: 28 chemical components of JTTF were identified. Additionally, treatment with JTTF significantly decreased the severity of glycemic symptoms in the db/db mice. Moreover, the treatment partially restored glucose homeostasis in the db/db mice and protected the pancreatic ß-cell function. JTTF protected INS-1 cells from HG injury by upregulating GSIS and PDX1, MafA mRNA expression. Further, treatment with JTTF downregulated GRP78 and ATF6 expression, whereas it inhibited Beclin-1 and LC3 activation. The treatment protected the cells from HG-induced ERS and excessive autophagy by downregulating the CaMKKß/AMPK pathway. CONCLUSIONS: The present study findings show that JTTF may protects ß-cells by inhibiting the CaMKKß/AMPK pathway, which deepens our understanding of the effectiveness of JTTF as a treatment strategy against T2DM.
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Proteínas Quinasas Activadas por AMP , Autofagia , Quinasa de la Proteína Quinasa Dependiente de Calcio-Calmodulina , Medicamentos Herbarios Chinos , Estrés del Retículo Endoplásmico , Células Secretoras de Insulina , Transducción de Señal , Animales , Células Secretoras de Insulina/efectos de los fármacos , Células Secretoras de Insulina/metabolismo , Estrés del Retículo Endoplásmico/efectos de los fármacos , Medicamentos Herbarios Chinos/farmacología , Autofagia/efectos de los fármacos , Ratones , Masculino , Quinasa de la Proteína Quinasa Dependiente de Calcio-Calmodulina/metabolismo , Transducción de Señal/efectos de los fármacos , Proteínas Quinasas Activadas por AMP/metabolismo , Ratas , Chaperón BiP del Retículo Endoplásmico , Ratones Endogámicos C57BL , Línea Celular Tumoral , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Experimental/tratamiento farmacológicoRESUMEN
Colorectal cancer (CRC) is the second most deadly cancer worldwide. Although various treatments for CRC have made progress, they have limitations. Therefore, the search for new effective molecular targets is important for the treatment of CRC. p20BAP31 induces apoptosis through diverse pathways and exhibits greater sensitivity in CRC. Therefore, a comprehensive exploration of the molecular functions of p20BAP31 is important for its application in anti-tumor therapy. In this study, we showed that exogenous p20BAP31 was still located in the ER and significantly activated the unfolded protein response (UPR) through the PERK pathway. The activation of the PERK pathway is prominent in p20BAP31-induced reactive oxygen species (ROS) accumulation and apoptosis. We found, for the first time, that p20BAP31 leads to ER stress and markedly attenuates tumor cell growth in vivo. Importantly, mechanistic investigations indicated that p20BAP31 competitively binds to GRP78 from PERK and causes hyperactivation of the UPR. Furthermore, p20BAP31 upregulates the expression of GRP78 by promoting HSF1 nuclear translocation and enhancing its binding to the GRP78 promoter. These findings reveal p20BAP31 as a regulator of ER stress and a potential target for tumor therapy, and elucidate the underlying mechanism by which p20BAP31 mediates signal transduction between ER and mitochondria.
Asunto(s)
Apoptosis , Neoplasias Colorrectales , Chaperón BiP del Retículo Endoplásmico , Estrés del Retículo Endoplásmico , Proteínas de Choque Térmico , Especies Reactivas de Oxígeno , Transducción de Señal , Respuesta de Proteína Desplegada , eIF-2 Quinasa , Humanos , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/genética , Apoptosis/efectos de los fármacos , eIF-2 Quinasa/metabolismo , eIF-2 Quinasa/genética , Proteínas de Choque Térmico/metabolismo , Proteínas de Choque Térmico/genética , Animales , Línea Celular Tumoral , Especies Reactivas de Oxígeno/metabolismo , Ratones , Proliferación Celular , Unión Proteica , Regulación Neoplásica de la Expresión GénicaRESUMEN
Lethal neurodegenerative prion diseases result from the continuous accumulation of infectious and variably protease-resistant prion protein aggregates (PrPD) which are misfolded forms of the normally detergent soluble and protease-sensitive cellular prion protein. Molecular chaperones like Grp78 have been found to reduce the accumulation of PrPD, but how different cellular environments and other chaperones influence the ability of Grp78 to modify PrPD is poorly understood. In this work, we investigated how pH and protease-mediated structural changes in PrPD from two mouse-adapted scrapie prion strains, 22L and 87V, influenced processing by Grp78 in the presence or absence of chaperones Hsp90, DnaJC1, and Stip1. We developed a cell-free in vitro system to monitor chaperone-mediated structural changes to, and disaggregation of, PrPD. For both strains, Grp78 was most effective at structurally altering PrPD at low pH, especially when additional chaperones were present. While Grp78, DnaJC1, Stip1, and Hsp90 were unable to disaggregate the majority of PrPD from either strain, pretreatment of PrPD with proteases increased disaggregation of 22L PrPD compared to 87V, indicating strain-specific differences in aggregate structure were impacting chaperone activity. Hsp90 also induced structural changes in 87V PrPD as indicated by an increase in the susceptibility of its n-terminus to proteases. Our data suggest that, while chaperones like Grp78, DnaJC1, Stip1, and Hsp90 disaggregate only a small fraction of PrPD, they may still facilitate its clearance by altering aggregate structure and sensitizing PrPD to proteases in a strain and pH-dependent manner.
Asunto(s)
Chaperón BiP del Retículo Endoplásmico , Proteínas de Choque Térmico , Chaperonas Moleculares , Chaperón BiP del Retículo Endoplásmico/metabolismo , Chaperón BiP del Retículo Endoplásmico/genética , Animales , Concentración de Iones de Hidrógeno , Proteínas de Choque Térmico/metabolismo , Proteínas de Choque Térmico/genética , Ratones , Chaperonas Moleculares/metabolismo , Chaperonas Moleculares/genética , Chaperonas Moleculares/química , Proteínas del Choque Térmico HSP40/metabolismo , Proteínas del Choque Térmico HSP40/genética , Proteínas HSP90 de Choque Térmico/metabolismo , Proteínas HSP90 de Choque Térmico/genética , Proteínas HSP90 de Choque Térmico/química , Agregado de ProteínasRESUMEN
Here we report the results of a single-center phase 2 clinical trial combining sorafenib tosylate, valproic acid, and sildenafil for the treatment of patients with recurrent high-grade glioma (NCT01817751). Clinical toxicities were grade 1 and grade 2, with one grade 3 toxicity for maculopapular rash (6.4%). For all evaluable patients, the median progression-free survival was 3.65 months and overall survival (OS) 10.0 months. There was promising evidence showing clinical activity and benefit. In the 33 evaluable patients, low protein levels of the chaperone GRP78 (HSPA5) was significantly associated with a better OS (p < 0.0026). A correlation between the expression of PDGFRα and OS approached significance (p < 0.0728). Five patients presently have a mean OS of 73.6 months and remain alive. This is the first therapeutic intervention glioblastoma trial to significantly associate GRP78 expression to OS. Our data suggest that the combination of sorafenib tosylate, valproic acid, and sildenafil requires additional clinical development in the recurrent glioma population.
RESUMEN
Enteroviruses are the causative agents associated with several human and animal diseases, posing a significant threat to human and animal health. As one of the host immune defense strategies, innate immunity plays a crucial role in defending against invading pathogens, where the host utilizes a variety of mechanisms to inhibit or eliminate the pathogen. Here, we report a new strategy for the host to repress enterovirus replication by the 78 kDa glucose-regulated protein (GRP78), also known as heat shock protein family A member 5 (HSPA5). The GRP78 recognizes the EV-encoded RNA-dependent RNA polymerases (RdRPs) 3D protein and interacts with the nuclear factor kappa B kinase complex (CHUK) and subunit beta gene (IKBKB) to facilitate the phosphorylation and nuclear translocation of NF-κB, which induces the production of inflammatory factors and leads to a broad inhibition of enterovirus replication. These findings demonstrate a new role of GRP78 in regulating host innate immunity in response to viral infection and provide new insights into the mechanism underlying enterovirus replication and NF-κB activation.IMPORTANCEGRP78 is known as a molecular chaperone for protein folding and plays a critical role in maintaining protein folding and participating in cell proliferation, cell survival, apoptosis, and metabolism. However, the functions of GRP78 to participate in enterovirus genome replication and innate immune responses are rarely documented. In this study, we explored the functions of the EV-3D-interacting protein GRP78 and found that GRP78 inhibits enterovirus replication by activating NF-κB through binding to EV-F 3D and interacting with the NF-κB signaling molecules CHUK/IKBKB. This is the first report that GRP78 interacts with CHUK/IKBKB to activate the NF-κB signaling pathway, which leads to the expression of the proinflammatory cytokines and inhibition of enterovirus replication. These results demonstrate a unique mechanism of virus replication regulation by GRP78 and provide insights into the prevention and treatment of viral infections.
Asunto(s)
Chaperón BiP del Retículo Endoplásmico , Quinasa I-kappa B , FN-kappa B , Proteínas Virales , Replicación Viral , Animales , Humanos , Chlorocebus aethiops , Chaperón BiP del Retículo Endoplásmico/metabolismo , Enterovirus/crecimiento & desarrollo , Enterovirus/inmunología , Enterovirus/metabolismo , Enterovirus/fisiología , Infecciones por Enterovirus/virología , Infecciones por Enterovirus/metabolismo , Infecciones por Enterovirus/inmunología , Proteínas de Choque Térmico/metabolismo , Células HEK293 , Interacciones Huésped-Patógeno/inmunología , Quinasa I-kappa B/metabolismo , Inmunidad Innata , Mediadores de Inflamación/inmunología , Mediadores de Inflamación/metabolismo , FN-kappa B/metabolismo , Fosforilación , Unión Proteica , ARN Polimerasa Dependiente del ARN/metabolismo , Transducción de Señal , Células Vero , Proteínas Virales/metabolismoRESUMEN
Pediatric neuroblastomas (NBs) are heterogeneous, aggressive, therapy-resistant embryonal tumors that originate from cells of neural crest origin committed to the sympathoadrenal progenitor cell lineage. Stress- and drug-resistance mechanisms drive post-therapeutic relapse and metastatic progression, the characterization and inhibition of which are major goals in improving therapeutic responses. Stress- and drug-resistance mechanisms in NBs include alternative TrkAIII splicing of the neurotrophin receptor tropomyosin-related kinase A (NTRK1/TrkA), which correlates with post-therapeutic relapse and advanced-stage metastatic disease. The TrkAIII receptor variant exerts oncogenic activity in NB models by mechanisms that include stress-induced mitochondrial importation and activation. In this study, we characterize novel targetable and non-targetable participants in this pro-survival mechanism in TrkAIII-expressing SH-SY5Y NB cells, using dithiothreitol (DTT) as an activator and a variety of inhibitors by regular and immunoprecipitation Western blotting of purified mitochondria and IncuCyte cytotoxicity assays. We report that stress-induced TrkAIII misfolding initiates this mechanism, resulting in Grp78, Ca2+-calmodulin, adenosine ribosylating factor (Arf) and Hsp90-regulated mitochondrial importation. TrkAIII imported into inner mitochondrial membranes is cleaved by Omi/high temperature requirement protein A2 (HtrA2) then activated by a mechanism dependent upon calmodulin kinase II (CaMKII), alpha serine/threonine kinase (Akt), mitochondrial Ca2+ uniporter and reactive oxygen species (ROS), involving inhibitory mitochondrial protein tyrosine phosphatase (PTPase) oxidation, resulting in phosphoinositide 3 kinase (PI3K) activation of mitochondrial Akt, which enhances stress resistance. This novel pro-survival function for misfolded TrkAIII mitigates the cytotoxicity of mitochondrial Ca2+ homeostasis disrupted during integrated stress responses, and is prevented by clinically approved Trk and Akt inhibitors and also by inhibitors of 78kDa glucose regulated protein (Grp78), heat shock protein 90 (Hsp90), Ca2+-calmodulin and PI3K. This identifies Grp78, Ca2+-calmodulin, Hsp90, PI3K and Akt as novel targetable participants in this mechanism, in addition to TrkAIII, the inhibition of which has the potential to enhance the stress-induced elimination of TrkAIII-expressing NB cells, with the potential to improve therapeutic outcomes in NBs that exhibit TrkAIII expression and activation.
Asunto(s)
Chaperón BiP del Retículo Endoplásmico , Mitocondrias , Neuroblastoma , Receptor trkA , Humanos , Chaperón BiP del Retículo Endoplásmico/metabolismo , Receptor trkA/metabolismo , Neuroblastoma/metabolismo , Neuroblastoma/patología , Mitocondrias/metabolismo , Mitocondrias/efectos de los fármacos , Línea Celular Tumoral , Pliegue de Proteína , Transducción de Señal/efectos de los fármacos , Estrés Fisiológico/efectos de los fármacosRESUMEN
AIMS: While significant upregulation of GRP78 has been documented in lung cancer patients, its association with resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) remains underexamined. Our study aimed to elucidate the functional importance of GRP78 in acquired resistance to EGFR-TKIs in non-small cell lung cancer (NSCLC) and to evaluate its potential as a therapeutic target. MAIN METHODS: Immunoblot analysis or flow cytometry was employed to assess several markers for endoplasmic reticulum (ER) stress and apoptosis. Ru(II) complex I and HA15, two known GRP78 inhibitors, were used to evaluate the functional role of GRP78. A Xenograft assay was performed to evaluate the in vivo anti-cancer effects of the GRP78 inhibitors. KEY FINDINGS: We validated a significant increase in GRP78 protein levels in HCC827-GR, H1993-GR, and H1993-ER cells. The EGFR-TKI-resistant cells overexpressing GRP78 exhibited significantly higher cell proliferation rates than did their parental counterparts. Notably, GRP78 inhibition resulted in a more profound anti-proliferative and apoptotic response via heightened ER stress and subsequent reactive oxygen species (ROS) production in EGFR-TKI-resistant cell lines compared with their parental cells. In xenograft models implanted with HCC827-GR, both Ru(II) complex I and HA15 significantly suppressed tumor growth and reduced tumor weight. Additionally, we confirmed that GRP78 plays a critical role in the proliferation of H1975, an EGFR-TKI-resistant T790M-mutant cell line, relative to other NSCLC cell lines. SIGNIFICANCE: Our findings strongly support targeting of GRP78 as a promising therapeutic strategy for NSCLC patients with acquired resistance to EGFR-TKIs.