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1.
Life Sci ; 240: 117107, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31785241

RESUMO

BACKGROUND: Toll-like receptor 4 (Tlr4) is recognized due to its role in the immune response. Also, this protein can participate in the signaling pathway of events triggered by physical exercise such as apoptosis, inflammation, and endoplasmic reticulum (ER) stress. The main objective of this study was to evaluate the role of Tlr4 in the markers of these events in the myocardium of mice submitted to acute physical exercise (APE) protocols at different intensities. METHODS: Echocardiogram, RT-qPCR, and immunoblotting technique were used to evaluate the left ventricle of wild-type (WT) and Tlr4 knockout (Tlr4 KO) submitted to APE protocols at 45, 60, and 75% of their maximal velocity. Also, we performed the bioinformatics analysis to establish the connection of heart mRNA levels of Tlr4 with heart genes of inflammation and ER stress of several isogenic strains of BXD mice. RESULTS: Under basal conditions, the Tlr4 deletion diminished the performance, and expression of inflammation and ER stress genes in the left ventricle, but increased the serum levels of CK, Il-17, and Tnf-alpha. Under the same exercise conditions, the Tlr4 deletion reduced the glycemia, serum levels of CK, Il-17, and Tnf-alpha, as well as genes and/or proteins related to apoptosis, inflammation and ER stress in the left ventricle, but increased the levels of CK-mb and LDH, as well as other genes related to apoptosis, inflammation, and ER stress in the left ventricle. CONCLUSION: Altogether, the current findings highlighted the effects of different acute exercise intensities were attenuated in the heart of Tlr4 KO mice.


Assuntos
Apoptose/fisiologia , Estresse do Retículo Endoplasmático/fisiologia , Coração/fisiologia , Inflamação , Esforço Físico/fisiologia , Receptor 4 Toll-Like/fisiologia , Animais , Apoptose/genética , Biologia Computacional , Creatina Quinase/sangue , Ecocardiografia , Estresse do Retículo Endoplasmático/genética , Coração/diagnóstico por imagem , Interleucina-17/sangue , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Esforço Físico/genética , Transdução de Sinais/fisiologia , Receptor 4 Toll-Like/genética , Fator de Necrose Tumoral alfa/sangue
2.
Sci Total Environ ; 702: 134775, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31710847

RESUMO

Butylated hydroxyanisole (BHA), a synthetic phenolic antioxidant (SPA), has been used as a food additive. However, BHA acts as an environmental hormone, i.e., endocrine disruptor. Here, we investigated BHA-induced male reproductive dysfunction in mouse Leydig and Sertoli cells. We found that BHA suppressed proliferation and induced cell cycle arrest in TM3 and TM4 cells. Furthermore, we investigated mitochondrial permeabilization, expression profiles of pro-apoptotic and anti-apoptotic proteins, calcium influx, and endoplasmic reticulum (ER) stress in testicular cells after BHA treatment. The results indicated that BHA-mediated calcium dysregulation and ER stress downregulated steroidogenesis- and spermatogenesis-related genes in mouse testis cell lines. Additionally, proliferation of both TM3 and TM4 cells in response to BHA treatment was regulated via the Mapk and Akt signaling pathways. Therefore, constant BHA exposure may lead to testicular toxicity via mitochondrial dysfunction, ER stress, and abnormal calcium levels in the testis.


Assuntos
Hidroxianisol Butilado/toxicidade , Estresse do Retículo Endoplasmático/fisiologia , Espermatogênese/efeitos dos fármacos , Testículo/efeitos dos fármacos , Animais , Cálcio/metabolismo , Homeostase/efeitos dos fármacos , Masculino , Camundongos
3.
Chemosphere ; 240: 124905, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31563103

RESUMO

Microcystin-LR (MCLR) was commonly regarded as a potent hepatotoxin and has been reported to cause neurotoxicity. This study was aimed to investigate how maternal MCLR exposure during pregnancy alters behavioral responses in offspring mice and the possible molecular mechanism involved in this procedure. Three doses of MCLR solutions (0, 3 or 15 µg/kg body weight) were administered subcutaneously to pregnant C57bl/6 from gestation day (GD) 6-19. Our results showed that MCLR prenatal exposure led to the impairment of learning and memory function in offspring on postnatal days (PND) 35, accompanied by endoplasmic reticulum (ER) stress and neuronal apoptosis in hippocampal CA1 regions of mice. Sixteen miRNAs in hippocampus of pups on PND 35 were significantly affected by MCLR exposure with the markedly decreased transcription of miR-181a-5p. We then found that miR-181a-5p was down-regulated, accompanied by activation of ER stress after prenatal exposure to MCLR using qPCR analysis. Furthermore, glucose-regulated protein, 78kDa/binding immunoglobulin protein (Grp78/BIP), a major ER chaperone and signaling regulator, was identified as a target of miR-181a-5p. Our study showed that miR-181a could lead to a decrease in the mRNA expression and protein levels of Grp78 by directly binding to its 3'-untranslated region (3'-UTR) in primary hippocampal neurons. Our findings indicate that the up-regulation of Grp78 mediated by inhibition of miR-181a-5p is a possible mechanism resulting in ER stress and cognitive impairment in pups following prenatal MCLR exposure.


Assuntos
Estresse do Retículo Endoplasmático/fisiologia , MicroRNAs/metabolismo , Microcistinas/toxicidade , Animais , Apoptose , Regulação para Baixo , Feminino , Hipocampo/metabolismo , Masculino , Memória , Camundongos , MicroRNAs/genética , Gravidez , Regulação para Cima
4.
J Dairy Sci ; 102(11): 10543-10553, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31495631

RESUMO

Zearalenone (ZEA) is a common mycotoxin produced by fungi within the genus Fusarium. However, few studies have examined the direct effects of the toxin on the mammary glands. In the present study, the effects of ZEA treatment on bovine mammary epithelial cells (MAC-T) from dairy cows were investigated. The cells were treated with different concentrations of ZEA to evaluate the effect of the toxin on cell viability, intracellular reactive oxygen species (ROS) concentrations, mitochondrial membrane potential, endoplasmic reticulum (ER) stress, and the expression of apoptosis-related genes. The results indicated that different concentrations (5, 10, 15, 20, 25, 30, 50, 60, or 100 µM) of ZEA were able to inhibit growth of MAC-T cells. After exposing the MAC-T cells to 30 µM ZEA, compared with the control group, ROS levels increased, mitochondrial membrane potential decreased, and mRNA expression of the ER-specific stress-related genes GRP78, HSP70, ATF6, EIF2A, ASK1, and CHOP was upregulated in the ZEA-treated group. Further, we analyzed the increase in apoptotic rate by flow cytometry. At the mRNA level, compared with the control group, the expression of the apoptosis-promoting gene BAX was increased in the ZEA-treated group, the expression of the inhibitory gene BCL2 decreased, and the expression of the gene CASP3 increased. We observed a significant increase in caspase-3 activity in ZEA-treated MAC-T cells. Furthermore, the apoptotic rate of the cells in the ZEA group treated with 4-phenylbutyric acid (ER stress inhibitor) decreased and the mRNA expression levels of ER stress markers GRP78 and CHOP decreased. Compared with the ZEA treatment group, the mRNA expression level of the apoptosis-related gene BAX was decreased and the expression level of BCL2 was increased in the ZEA + 4-phenylbutyric acid cotreatment group. These findings indicate that ZEA-induced ER stress increases apoptosis in MAC-T cells. The treatment of MAC-T cells with ZEA reduced cell viability, increased ROS content, decreased mitochondrial membrane potential, increased ER stress marker expression, and induced apoptosis.


Assuntos
Apoptose/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Glândulas Mamárias Animais/efeitos dos fármacos , Zearalenona/farmacologia , Animais , Apoptose/genética , Caspase 3/metabolismo , Bovinos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Estresse do Retículo Endoplasmático/genética , Estresse do Retículo Endoplasmático/fisiologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Feminino , Citometria de Fluxo , Expressão Gênica/efeitos dos fármacos , Glândulas Mamárias Animais/citologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Fenilbutiratos/farmacologia , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase em Tempo Real
5.
Shanghai Kou Qiang Yi Xue ; 28(3): 259-263, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31489412

RESUMO

PURPOSE: This study was aimed to figure out the way that cyclic-stretch influenced the apoptosis of myoblasts and evaluate the importance of PERK and its possible mechanism involved. METHODS: L6 rat myoblasts were cultured in vitro and mechanical stimulation model was constructed successfully. The myoblasts were imposed tension for 0, 2, 6, 12 and 24 hours respectively by multi-channel cell stress loading system. The force value was 15% cell deformation and the frequency was 10 cycles/min. Each cycle was consisted of stretch for 3 seconds and relaxation for 3 seconds, and the group without tension was used as the control group. The apoptotic myoblasts were dyed by DAPI and observed through fluorescence microscopy to detect the apoptosis rate; the mRNA levels of PERK and CHOP in different groups were detected by real-time PCR and protein levels of PERK and p-PERK in different groups were detected by Western blot. PERK inhibitor was used to clear the role of PERK in apoptosis induced by cyclic-stretch and clarify the relationship between the endoplasmic reticulum stress and apoptosis induced by cyclic-stretch. SPSS 17.0 software package was used to analyze the data statistically. RESULTS: DAPI nuclear stain showed that cyclical tensile stress can induce apoptosis in vitro cultured myoblast. Apoptosis rate showed a trend of rising gradually over time, peaked at 24 h. After dealt with the inhibitor of PERK, the apoptosis rate of the 24 h group under the cyclic stretch showed no difference compared with the control. The results of real- time PCR showed that the mRNA of CHOP was increased with the extension loading time, while the mRNA of PERK showed no difference compared with the control. Western blot results showed that the protein level of p-PERK was increased with the extension of loading time, while the expression of PERK showed no difference compared with the control group. When PERK inhibitor added, the mRNA level of CHOP along with the protein expression level of p-PERK showed no significant difference compared to the control. CONCLUSIONS: PERK signaling pathway is involved in the apoptosis of myoblasts induced by cyclic stretch, and the possible mechanism may be closely related to the phosphorylation of PERK.


Assuntos
Apoptose , Estresse do Retículo Endoplasmático , Mioblastos , eIF-2 Quinase , Animais , Estresse do Retículo Endoplasmático/fisiologia , Ratos , Transdução de Sinais , eIF-2 Quinase/metabolismo
6.
Int J Mol Sci ; 20(16)2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31443163

RESUMO

Retinal neurodegeneration, an early characteristic of several blinding diseases, triggers glial activation, resulting in inflammation, secondary damage and visual impairment. Treatments that aim only at neuroprotection have failed clinically. Here, we examine the impact of modulating thioredoxin interacting protein (TXNIP) to the inflammatory secondary damage and visual impairment in a model of ischemia/reperfusion (IR). Wild type (WT) and TXNIP knockout (TKO) mice underwent IR injury by increasing intraocular pressure for 40 min, followed by reperfusion. An additional group of WT mice received intravitreal TXNIP-antisense oligomers (ASO, 100 µg/2 µL) 2 days post IR injury. Activation of Müller glial cells, apoptosis and expression of inflammasome markers and visual function were assessed. IR injury triggered early TXNIP mRNA expression that persisted for 14 days and was localized within activated Müller cells in WT-IR, compared to sham controls. Exposure of Müller cells to hypoxia-reoxygenation injury triggered endoplasmic reticulum (ER) stress markers and inflammasome activation in WT cells, but not from TKO cells. Secondary damage was evident by the significant increase in the number of occluded acellular capillaries and visual impairment in IR-WT mice but not in IR-TKO. Intervention with TXNIP-ASO prevented ischemia-induced glial activation and neuro-vascular degeneration, and improved visual function compared to untreated WT. Targeting TXNIP expression may offer an effective approach in the prevention of secondary damage associated with retinal neurodegenerative diseases.


Assuntos
Proteínas de Transporte/metabolismo , Traumatismo por Reperfusão/metabolismo , Tiorredoxinas/metabolismo , Animais , Proteínas de Transporte/genética , Modelos Animais de Doenças , Estresse do Retículo Endoplasmático/genética , Estresse do Retículo Endoplasmático/fisiologia , Gliose/metabolismo , Hipóxia/metabolismo , Inflamassomos/metabolismo , Camundongos , Camundongos Knockout , RNA Mensageiro/metabolismo , Traumatismo por Reperfusão/genética , Tiorredoxinas/genética
7.
Biomed Pharmacother ; 117: 109155, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31387178

RESUMO

Stroke is a leading cause of mortality and disability globally. Cerebral ischaemia-reperfusion (I/R) injury is characterized by significant inflammation and extensive cell death. Multiple signaling pathways play essential roles in the process, and identifying the unclear crucial regulators of these pathways may provide promising targets for treatment. CASP8 and FADD-like apoptosis regulator (CFLAR) is expressed in multiple organs to regulate inflammation. Here, we reported that CFLAR expression was markedly reduced in brain samples of mice with middle cerebral artery occlusion (MCAO) stroke. Furthermore, CFLAR knockdown markedly elevated the neurological deficit, brain water content and the infarct volume. In addition, significantly promoted inflammation and endoplasmic reticulum (ER) stress was detected in brain tissues of mice after MCAO, as evidenced by the promoted expression of p-IκBα, p-nuclear factor (NF)-κB (p65), glucose-regulated protein 78 (GRP78), PKR-like ER kinase (PERK), activating transcription factor-6 (ATF-6) and cleaved Caspase-12. Notably, MCAO-induced cerebral I/R injury was markedly alleviated in mice over-expressing CFLAR through suppressing inflammation and ER stress. Furthermore, our in vitro results indicated that oxygen-glucose deprivation (OGD)-induced cell death was evidently ameliorated by CFLAR over-expression. In contrast, the cell death triggered by OGD was accelerated by CFLAR knockdown in vitro through enhancing Caspase-3 cleavage, and this effect was obviously ameliorated by the blockage of ER stress using 4-phenyl butyric acid (4-PBA). Collectively, these results demonstrated that CFLAR could be considered as a novel candidate to develop effective therapeutic treatment against cerebral I/R injury.


Assuntos
Isquemia Encefálica/metabolismo , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Estresse do Retículo Endoplasmático/fisiologia , Retículo Endoplasmático/metabolismo , Inflamação/metabolismo , Traumatismo por Reperfusão/metabolismo , Animais , Apoptose/fisiologia , Encéfalo/metabolismo , Linhagem Celular , Células HEK293 , Humanos , Infarto da Artéria Cerebral Média/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Inibidor de NF-kappaB alfa/metabolismo , NF-kappa B/metabolismo , Transdução de Sinais/fisiologia , Acidente Vascular Cerebral/metabolismo
8.
Chem Commun (Camb) ; 55(65): 9629-9632, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31353368

RESUMO

Excessive accumulation of reducing agents in the ER leads to a constitutively high UPR. And the co-function of GSH, Cys and HOCl in biological processes is not well understood. To address this, a TP probe, NPCC, was developed for monitoring reductive stress in the ER. It can also distinguish cancer cells from normal cells.


Assuntos
Cumarínicos/química , Estresse do Retículo Endoplasmático/fisiologia , Retículo Endoplasmático/metabolismo , Corantes Fluorescentes/química , Pirazóis/química , Animais , Cumarínicos/síntese química , Cisteína/química , Cisteína/metabolismo , Corantes Fluorescentes/síntese química , Glutationa/química , Glutationa/metabolismo , Cabras , Células HeLa , Humanos , Ácido Hipocloroso/química , Ácido Hipocloroso/metabolismo , Camundongos , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Oxirredução , Pirazóis/síntese química , Peixe-Zebra
9.
Nat Commun ; 10(1): 3185, 2019 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-31320625

RESUMO

Unfolded protein response (UPR) is an adaptive mechanism that aims at restoring ER homeostasis under severe environmental stress. Malignant cells are resistant to environmental stress, which is largely due to an activated UPR. However, the molecular mechanisms by which different UPR branches are selectively controlled in tumor cells are not clearly understood. Here, we provide evidence that PRKCSH, previously known as glucosidase II beta subunit, functions as a regulator for selective activation of the IRE1α branch of UPR. PRKCSH boosts ER stress-mediated autophosphorylation and oligomerization of IRE1α through mutual interaction. PRKCSH contributes to the induction of tumor-promoting factors and to tumor resistance to ER stress. Increased levels of PRKCSH in various tumor tissues are positively correlated with the expression of XBP1-target genes. Taken together, our data provide a molecular rationale for selective activation of the IRE1α branch in tumors and adaptation of tumor cells to severe environmental stress.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Transformação Celular Neoplásica/patologia , Estresse do Retículo Endoplasmático/fisiologia , Endorribonucleases/metabolismo , Glucosidases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Resposta a Proteínas não Dobradas/fisiologia , Animais , Proteínas de Ligação ao Cálcio/genética , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Endorribonucleases/genética , Glucosidases/genética , Células Hep G2 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias/patologia , Proteínas Serina-Treonina Quinases/genética , Interferência de RNA , RNA Interferente Pequeno/genética , Transdução de Sinais/genética
10.
Nat Chem Biol ; 15(8): 764-775, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31320759

RESUMO

Accumulation of unfolded proteins at the endoplasmic reticulum (ER) is a salient attribute of many human diseases including obesity, liver disorders, cancer, diabetes and neurodegeneration. To restore ER proteostasis, cells activate the unfolded protein response (UPR), a signaling pathway that imposes adaptive programs or triggers apoptosis of damaged cells. The UPR is critical to sustain the normal function of specialized secretory cells (i.e., pancreatic ß cells and B lymphocytes) and to control the production of lipids and cholesterol in the liver. In the context of disease, adaptive UPR responses have been linked to the growth of solid tumors, whereas chronic ER stress contributes to cell dysfunction in brain diseases, metabolic syndromes, among other conditions. Here we discuss recent developments in the design and optimization of novel compounds to manipulate UPR signaling and their efficacy in various disease models.


Assuntos
Sistemas de Liberação de Medicamentos , Transdução de Sinais , Resposta a Proteínas não Dobradas , Animais , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Estresse do Retículo Endoplasmático/fisiologia , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo
11.
Life Sci ; 232: 116612, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31260687

RESUMO

AIMS: Accumulating evidence suggest that endoplasmic reticulum (ER) stress is an important mechanism underlying the development of diabetes. We have reported that sustained treatment with N-methyl-d-aspartate (NMDA) results in apoptotic ß-cell death and impairs insulin secretion. However, the molecular mechanism responsible for NMDA-induced ß-cell dysfunction remains largely obscure. Thus, this study aimed to determine whether sustained activation of NMDA receptors (NMDARs) causes ß-cell dysfunction through ER stress. MAIN METHODS: Primary mouse islets and MIN6 mouse pancreatic ß-cells were treated with NMDA for 24 h or high-glucose for 72 h. After the treatment, glucose-stimulated insulin secretion (GSIS) and the expression of ER stress markers were measured, respectively. In vivo, the expression of ER stress markers was measured in the pancreas of diabetic mice treated with or without NMDARs inhibitor Memantine. KEY FINDINGS: NMDA treatment caused an increase in the expression of ER stress markers (ATF4, CHOP, GRP78, and Xbp1s) in primary islets. While, tauroursodeoxycholic acid (TUDCA), an inhibitor of ER stress, significantly attenuated NMDA-induced ß-cell dysfunction, including the loss of glucose-stimulated insulin secretion and reduction of pancreas duodenum homeobox factor-1 (Pdx-1) mRNA expression, a transcription factor regulating insulin synthesis. Besides, NMDA-induced ER stress strongly promoted pro-inflammatory cytokines synthesis (IL-1ß and TNF-α) in ß cells. Interestingly, knockdown of CHOP attenuated ß-cell dysfunction evoked by NMDA. Furthermore, we demonstrated that blockade of NMDARs ameliorated high-glucose-induced ER stress in vitro and in vivo. SIGNIFICANCE: This study confirms that ER stress is actively involved in the activation of NMDARs-related ß-cell dysfunction.


Assuntos
Estresse do Retículo Endoplasmático/fisiologia , Células Secretoras de Insulina/metabolismo , Fator de Transcrição CHOP/metabolismo , Fator 4 Ativador da Transcrição/metabolismo , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Diabetes Mellitus Experimental/metabolismo , Modelos Animais de Doenças , Retículo Endoplasmático/metabolismo , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Glucose/metabolismo , Proteínas de Choque Térmico/metabolismo , Insulina/metabolismo , Secreção de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , N-Metilaspartato/farmacologia , Receptores de N-Metil-D-Aspartato/metabolismo , Transdução de Sinais , Proteína 1 de Ligação a X-Box/metabolismo
12.
Chin Med J (Engl) ; 132(15): 1823-1832, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31306228

RESUMO

BACKGROUND: Collagen type IV (COL4)-related nephropathy includes a variety of kidney diseases that occur with or without extra-renal manifestations caused by COL4A3-5 mutations. Previous studies revealed several novel mutations, including three COL4A3 missense mutations (G619R, G801R, and C1616Y) and the COL4A3 chr:228172489delA c.4317delA p.Thr1440ProfsX87 frameshift mutation that resulted in a truncated NC1 domain (hereafter named COL4A3 c.4317delA); however, the mutation mechanisms that lead to podocyte injury remain unclear. This study aimed to further explore the mutation mechanisms that lead to podocyte injury. METHODS: Wild-type (WT) and four mutant COL4A3 segments were constructed into a lentiviral plasmid, then stably transfected into human podocytes. Real-time polymerase chain reaction and Western blotting were applied to detect endoplasmic reticulum stress (ERS)- and apoptosis-related mRNA and protein levels. Then, human podocytes were treated with MG132 (a proteasome inhibitor) and brefeldin A (a transport protein inhibitor). The human podocyte findings were verified by the establishment of a mus-Col4a3 knockout mouse monoclonal podocyte using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) technology. RESULTS: Our data showed that COL4A3 mRNA was significantly overexpressed in the lentivirus stably transfected podocytes. Moreover, the COL4A3 protein level was significantly increased in all groups except the COL4A3 c.4317delA group. Compared to the other test groups, the COL4A3 c.4317delA group showed excessive ERS and apoptosis. Podocytes treated with MG132 showed remarkably increased intra-cellular expression of the COL4A3 c.4317delA mutation. MG132 intervention improved higher ERS and apoptosis levels in the COL4A3 c.4317delA group. Mouse monoclonal podocytes with COL4A3 chr:82717932insA c.4852insA p.Arg1618ThrfsX4 were successfully acquired; this NC1-truncated mutation suggested a higher level of ERS and relatively remarkable level of apoptosis compared to that of the WT group. CONCLUSIONS: We demonstrated that excessive ERS and ERS-induced apoptosis were involved in the podocyte injury caused by the NC1-truncated COL4A3 mutation. Furthermore, proteasome pathway intervention might become a potential treatment for collagen type IV-related nephropathy caused by a severely truncated COL4A3 mutation.


Assuntos
Autoantígenos/genética , Colágeno Tipo IV/genética , Estresse do Retículo Endoplasmático/fisiologia , Mutação/genética , Podócitos/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Animais , Brefeldina A/farmacologia , Estresse do Retículo Endoplasmático/genética , Mutação da Fase de Leitura/genética , Humanos , Lentivirus/genética , Leupeptinas/farmacologia , Camundongos , Camundongos Knockout , Mutação de Sentido Incorreto/genética , Podócitos/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/genética
13.
Cancer Sci ; 110(8): 2471-2484, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31187548

RESUMO

Endoplasmic reticulum stress (ERS) plays a key role in the pathogenesis and development of tumors and protects tumor cells from radiation damage and drug-induced stress. We previously demonstrated that EGFR confers radioresistance in human papillomavirus (HPV)-negative human oropharyngeal carcinoma by activating ERS signaling through PERK and IRE1α. In addition, PERK confers radioresistance by activating the inflammatory cytokine NF-κB. However, the effect of IRE1 on radiosensitivity has not yet been fully elucidated. Here, we clarified that IRE1 overexpression was associated with poor outcome in HPV-negative patients treated with radiotherapy (P = 0.0001). In addition, a significantly higher percentage of radioresistant HPV-negative patients than radiosensitive HPV-negative patients exhibited high IRE expression (66.7% vs 27.8%, respectively; P = 0.001). Silencing IRE1 and XBP1 increased DNA double-strand break (DSB) and radiation-induced apoptosis, thereby increasing the radiosensitivity of HPV-negative oropharyngeal carcinoma cells. IRE1-XBP1 silencing also inhibited radiation-induced IL-6 expression at both the RNA and protein levels. The regulatory effect of IRE1-XBP1 silencing on DNA DSB-induced and radiation-induced apoptosis was inhibited by pretreatment with IL-6. These data indicate that IRE1 regulates radioresistance in HPV-negative oropharyngeal carcinoma through IL-6 activation, enhancing X-ray-induced DNA DSB and cell apoptosis.


Assuntos
Endorribonucleases/metabolismo , Interleucina-6/metabolismo , Neoplasias Orofaríngeas/metabolismo , Neoplasias Orofaríngeas/patologia , Proteínas Serina-Treonina Quinases/metabolismo , Tolerância a Radiação/fisiologia , Proteína 1 de Ligação a X-Box/metabolismo , Apoptose/fisiologia , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Quebras de DNA de Cadeia Dupla , Proteínas de Ligação a DNA/metabolismo , Estresse do Retículo Endoplasmático/fisiologia , Humanos , NF-kappa B/metabolismo , Papillomaviridae/patogenicidade , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/patologia , Transdução de Sinais/fisiologia , Fatores de Transcrição/metabolismo
14.
J Dairy Sci ; 102(8): 7359-7370, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31155263

RESUMO

Disruption of endoplasmic reticulum (ER) homeostasis, often termed ER stress, is intrinsically linked with perturbation of lipid metabolism in humans and mice. Whether ER homeostasis is affected in cows experiencing fatty liver is unknown. The aim of this study was to investigate the potential role of ER stress in hepatic lipid accumulation in calf hepatocytes and ER stress status in dairy cows with severe fatty liver. In vitro experiments were conducted in which hepatocytes were isolated from calves and treated with different concentrations of fatty acids, tauroursodeoxycholic acid (TUDCA; a canonical inhibitor of ER stress), or both. The increase in phosphorylation level of protein kinase RNA-like ER kinase (PERK) and inositol requiring protein-1α (IRE1α) proteins, and the cleavage of activating transcription factor-6 (ATF6) protein in response to increasing doses of fatty acids (which were reversed by TUDCA treatment) in primary hepatocytes underscored a mechanistic link between fatty acids and ER stress. In addition, fatty acid treatment increased the abundance of sterol regulatory element-binding protein 1c, acetyl-CoA carboxylase-α, fatty acid synthase, and diacylglycerol acyltransferase 1, and lipid accumulation in calf primary hepatocytes, whereas inhibition of ER stress by incubating with TUDCA significantly weakened these effects. Overall, results in vitro indicate that inhibition of ER stress in calf hepatocytes alleviates fatty acid-induced lipid accumulation by downregulating the expression of lipogenic genes. In vivo experiments, liver and blood samples were collected from cows diagnosed as healthy (n = 15) or with severe fatty liver (n = 15). The phosphorylation level of PERK and IRE1α, the cleavage of ATF6 protein, and the abundance of several unfolded protein response genes (78 kDa glucose-regulated protein, AMP-dependent transcription factor 4, and spliced X-box binding protein 1) were greater in liver of cows with severe fatty liver. The present in vivo study confirms the occurrence of ER stress in dairy cows with severe fatty liver. Considering the causative role of fatty acid-induced ER stress in hepatic lipid accumulation in calf hepatocytes, the existence of ER stress in the liver of severe fatty liver cows may presage its participation in fatty liver progression in dairy cows. However, the mechanistic relationship between ER stress and fatty liver in dairy cows remain to be determined.


Assuntos
Doenças dos Bovinos/fisiopatologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Ácidos Graxos/administração & dosagem , Fígado Gorduroso/veterinária , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Fator 6 Ativador da Transcrição/metabolismo , Animais , Bovinos , Células Cultivadas , Estresse do Retículo Endoplasmático/fisiologia , Endorribonucleases/metabolismo , Feminino , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Lipogênese/genética , Fígado/efeitos dos fármacos , Camundongos , Fosforilação , Ácido Tauroquenodesoxicólico/administração & dosagem , Resposta a Proteínas não Dobradas/genética , eIF-2 Quinase/metabolismo
15.
Life Sci ; 231: 116551, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31185236

RESUMO

Octreotide (OCT) shows clinical efficacies in the treatment of liver cirrhosis complicated with gastrointestinal hemorrhage. Experiments were designed to investigate its function mechanism associated with endoplasmic reticulum stress (ERS)-induced autophagy and microRNA (miR). Protein associated with ERS and autophagy was detected by western blot. miR-101 was examined by qRT-PCR. Besides, miR-101 or G protein-coupled receptor 78 (GPR78)-silenced Caco-2 cells were established by transfection. Furthermore, western blot was used to determine TGF-beta activated kinase 1 (TAK1), AMPK, mTOR, p70S6K as well as their phosphorylated forms. Lipopolysaccharide (LPS) enforced the expression of GPR78. Besides, LPS triggered the production of Beclin-1 and LC3-II while mitigated the accumulation of p62. Then all these above results were reversed by OCT pretreatment. Moreover, miR-101 expression was downregulated by LPS while upregulated by OCT. Further, miR-101 knockdown strengthened ERS and promoted autophagy. GPR78 silence retarded autophagy process. In the end, OCT mitigated phosphorylation of TAK1, AMPK while enhanced the phosphorylated expression of mTOR and p70S6K in LPS-treated Caco-2 cells. The anti-autophagy property of OCT was mediated by miR-101-induced suppression of GPR78 in LPS-treated Caco-2 cells.


Assuntos
Estresse do Retículo Endoplasmático/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , MicroRNAs/metabolismo , Octreotida/farmacologia , Proteínas Quinases Ativadas por AMP/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Autofagia/fisiologia , Proteína Beclina-1/genética , Células CACO-2 , Sobrevivência Celular/efeitos dos fármacos , Estresse do Retículo Endoplasmático/fisiologia , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Lipopolissacarídeos/farmacologia , MicroRNAs/genética , Octreotida/metabolismo , Fosforilação , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Ativação Transcricional/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
16.
Nat Commun ; 10(1): 2679, 2019 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-31213603

RESUMO

The islet in type 2 diabetes (T2D) is characterized by amyloid deposits derived from islet amyloid polypeptide (IAPP), a protein co-expressed with insulin by ß-cells. In common with amyloidogenic proteins implicated in neurodegeneration, human IAPP (hIAPP) forms membrane permeant toxic oligomers implicated in misfolded protein stress. Here, we establish that hIAPP misfolded protein stress activates HIF1α/PFKFB3 signaling, this increases glycolysis disengaged from oxidative phosphorylation with mitochondrial fragmentation and perinuclear clustering, considered a protective posture against increased cytosolic Ca2+ characteristic of toxic oligomer stress. In contrast to tissues with the capacity to regenerate, ß-cells in adult humans are minimally replicative, and therefore fail to execute the second pro-regenerative phase of the HIF1α/PFKFB3 injury pathway. Instead, ß-cells in T2D remain trapped in the pro-survival first phase of the HIF1α injury repair response with metabolism and the mitochondrial network adapted to slow the rate of cell attrition at the expense of ß-cell function.


Assuntos
Diabetes Mellitus Tipo 2/patologia , Estresse do Retículo Endoplasmático/fisiologia , Células Secretoras de Insulina/patologia , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , Resposta a Proteínas não Dobradas/fisiologia , Adulto , Animais , Animais Geneticamente Modificados , Apoptose , Linhagem Celular Tumoral , Diabetes Mellitus Tipo 2/metabolismo , Modelos Animais de Doenças , Glicólise/fisiologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Polipeptídeo Amiloide das Ilhotas Pancreáticas/genética , Masculino , Pessoa de Meia-Idade , Fosforilação Oxidativa , Fosfofrutoquinase-2/metabolismo , Agregados Proteicos/fisiologia , Ratos
17.
Life Sci ; 231: 116587, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31220526

RESUMO

The endoplasmic reticulum (ER) and mitochondria are two important organelles in cells. Mitochondria-associated membranes (MAMs) are lipid raft-like domains formed in the ER membranes that are in close apposition to mitochondria. They play an important role in signal transmission between these two essential organelles. When cells are exposed to internal or external stressful stimuli, the ER will activate an adaptive response called the ER stress response, which has a significant effect on mitochondrial function. Mitochondrial quality control is an important mechanism to ensure the functional integrity of mitochondria and the effect of ER stress on mitochondrial quality control through MAMs is of great significance. Therefore, in this review, we introduce ER stress and mitochondrial quality control, and discuss how ER stress signals are transmitted to mitochondria through MAMs. We then review the important roles of MAMs in mitochondrial quality control under ER stress.


Assuntos
Estresse do Retículo Endoplasmático/fisiologia , Mitocôndrias/metabolismo , Membranas Mitocondriais/metabolismo , Animais , Cálcio/metabolismo , Canais de Cálcio/metabolismo , Sinalização do Cálcio , Retículo Endoplasmático/metabolismo , Humanos , Microdomínios da Membrana , Membranas Mitocondriais/efeitos dos fármacos , Membranas Mitocondriais/fisiologia
18.
Neurotox Res ; 36(2): 347-356, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31069753

RESUMO

Methamphetamine (Meth) is a widely abused stimulant. High-dose Meth induces degeneration of dopaminergic neurons through p53-mediated apoptosis. A recent study indicated that treatment with the p53 inhibitor, pifithrin-alpha (PFT-α), antagonized Meth-mediated behavioral deficits in mice. The mechanisms underpinning the protective action of PFT-α against Meth have not been identified, and hence, their investigation is the focus of this study. Primary dopaminergic neuronal cultures were prepared from rat embryonic ventral mesencephalic tissue. High-dose Meth challenge reduced tyrosine hydroxylase immunoreactivity and increased terminal deoxynucleotidyl transferase-mediated dNTP nick-end labeling (TUNEL) labeling. PFT-α significantly antagonized these responses. PFT-α also reduced Meth-activated translocation of p53 to the nucleus, an initial step before transcription. Previous studies have indicated that p53 can also activate cell death through transcription-independent pathways. We found that PFT-α attenuated endoplasmic reticulum (ER) stressor thapsigargin (Tg)-mediated loss of dopaminergic neurons. ER stress was further monitored through the release of Gaussia luciferase (GLuc) from SH-SY5Y cells overexpressing GLuc-based Secreted ER Calcium-Modulated Protein (GLuc-SERCaMP). Meth or Tg significantly increased GLuc release in to the media, with PFT-α significantly reducing GLuc release. Additionally, PFT-α significantly attenuated Meth-induced CHOP expression. In conclusion, our data indicate that PFT-α is neuroprotective against Meth-mediated neurodegeneration via transcription-dependent nuclear and -independent cytosolic ER stress pathways.


Assuntos
Benzotiazóis/farmacologia , Estimulantes do Sistema Nervoso Central/toxicidade , Neurônios Dopaminérgicos/efeitos dos fármacos , Metanfetamina/toxicidade , Tolueno/análogos & derivados , Animais , Linhagem Celular Tumoral , Células Cultivadas , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/patologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Estresse do Retículo Endoplasmático/fisiologia , Feminino , Humanos , Gravidez , Ratos , Tolueno/farmacologia
19.
Nat Rev Gastroenterol Hepatol ; 16(8): 479-496, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31138897

RESUMO

The incidence of acute pancreatitis continues to increase worldwide, and it is one of the most common gastrointestinal causes for hospital admission in the USA. In the past decade, substantial advancements have been made in our understanding of the pathophysiological mechanisms of acute pancreatitis. Studies have elucidated mechanisms of calcium-mediated acinar cell injury and death and the importance of store-operated calcium entry channels and mitochondrial permeability transition pores. The cytoprotective role of the unfolded protein response and autophagy in preventing sustained endoplasmic reticulum stress, apoptosis and necrosis has also been characterized, as has the central role of unsaturated fatty acids in causing pancreatic organ failure. Characterization of these pathways has led to the identification of potential molecular targets for future therapeutic trials. At the patient level, two classification systems have been developed to classify the severity of acute pancreatitis into prognostically meaningful groups, and several landmark clinical trials have informed management strategies in areas of nutritional support and interventions for infected pancreatic necrosis that have resulted in important changes to acute pancreatitis management paradigms. In this Review, we provide a summary of recent advances in acute pancreatitis with a special emphasis on pathophysiological mechanisms and clinical management of the disorder.


Assuntos
Pancreatite/diagnóstico , Pancreatite/terapia , Doença Aguda , Animais , Sinalização do Cálcio/fisiologia , Gerenciamento Clínico , Modelos Animais de Doenças , Estresse do Retículo Endoplasmático/fisiologia , Humanos , Mutação , Apoio Nutricional/métodos , Pancreatite/etiologia , Pancreatite/fisiopatologia , Índice de Gravidade de Doença , Terminologia como Assunto , Tripsinogênio/metabolismo
20.
J Biomed Sci ; 26(1): 41, 2019 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-31133013

RESUMO

BACKGROUND: Endoplasmic reticulum stress has a profound effect on cancer cell proliferation and survival, and also has the capacity to activate cells of the adaptive immune system. Multimodal treatment methods that utilize and combine conventional cancer therapies with antigen-specific immunotherapies have emerged as promising approaches for the treatment and control of cancer. However, it is not well known whether endoplasmic reticulum stress-inducing agents can influence the efficacy of tumor antigen-targeting vaccines. METHODS: In the past, we developed a therapeutic human papillomavirus (HPV) DNA vaccine that encodes for calreticulin (CRT) linked to the HPV16 E7 antigen (CRT/E7). In this study, we utilize the CRT/E7 and further encode for an endoplasmic reticulum (ER) stress-inducing agent, 3-bromopyruvate (3-BrPA), in a preclinical model, by harnessing its potential to enhance HPV16 E7-specific CD8+ T cell immune responses as well as antitumor effects against E7-expressing tumors (TC-1 cells). E7-specific CD8+ T cells were added to evaluate the cytotoxicity of luciferase-expressing TC-1 tumor cells treated with 3-BrPA in vitro, as measured with an IVIS Luminescence Imaging System. We also determined the levels of ER stress markers in 3-BrPA-treated TC-1 cells. TC-1 tumor-bearing mice were treated with either 3-BrPA (10 mg/kg, intraperitoneal injection) and/or CRT/E7 DNA vaccine (30 µg/mouse). RESULTS: Treatment of E7-expressing TC-1 tumor cells with 3-BrPA induced significantly higher in vitro cytotoxicity and resulted in upregulation of endoplasmic reticulum stress markers (CHOP and GRP78). More importantly, combination treatment of 3-BrPA and the CRT/E7 DNA vaccine led to improved antigen-specific CD8+ T cell immune responses as well as therapeutic antitumor effects in TC-1 tumor-bearing mice. CONCLUSIONS: Our data indicate that 3-BrPA can enhance therapeutic HPV vaccine potency in generating improved antigen-specific immune responses and antitumor effects. These findings have important implications for future clinical translation and provide novel strategies for the treatment of HPV-associated diseases.


Assuntos
Calreticulina/imunologia , Estresse do Retículo Endoplasmático/fisiologia , Proteínas E7 de Papillomavirus/imunologia , Infecções por Papillomavirus/tratamento farmacológico , Vacinas contra Papillomavirus/imunologia , Linfócitos T/imunologia , Animais , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Piruvatos/farmacologia
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