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1.
Nat Commun ; 11(1): 5661, 2020 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-33168829

RESUMO

Sarcopenia is characterized by decreased skeletal muscle mass and function with age. Aged muscles have altered lipid compositions; however, the role and regulation of lipids are unknown. Here we report that FABP3 is upregulated in aged skeletal muscles, disrupting homeostasis via lipid remodeling. Lipidomic analyses reveal that FABP3 overexpression in young muscles alters the membrane lipid composition to that of aged muscle by decreasing polyunsaturated phospholipid acyl chains, while increasing sphingomyelin and lysophosphatidylcholine. FABP3-dependent membrane lipid remodeling causes ER stress via the PERK-eIF2α pathway and inhibits protein synthesis, limiting muscle recovery after immobilization. FABP3 knockdown induces a young-like lipid composition in aged muscles, reduces ER stress, and improves protein synthesis and muscle recovery. Further, FABP3 reduces membrane fluidity and knockdown increases fluidity in vitro, potentially causing ER stress. Therefore, FABP3 drives membrane lipid composition-mediated ER stress to regulate muscle homeostasis during aging and is a valuable target for sarcopenia.


Assuntos
Envelhecimento/fisiologia , Estresse do Retículo Endoplasmático/fisiologia , Proteína 3 Ligante de Ácido Graxo/metabolismo , Lipídeos de Membrana/metabolismo , Músculo Esquelético/metabolismo , Animais , Linhagem Celular , Fator de Iniciação 2 em Eucariotos/metabolismo , Proteína 3 Ligante de Ácido Graxo/genética , Feminino , Técnicas de Silenciamento de Genes , Lipidômica , Fluidez de Membrana , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Esquelético/patologia , Mioblastos/patologia , Mioblastos/fisiologia , Fosfolipídeos/metabolismo , Proteínas Serina-Treonina Quinases , Sarcopenia , Regulação para Cima
2.
Am J Physiol Lung Cell Mol Physiol ; 319(4): L728-L741, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32877223

RESUMO

Airway epithelial homeostasis is under constant threat due to continuous exposure to the external environment, and abnormally robust sensitivity to external stimuli is critical to the development of airway diseases, including asthma. Ku is a key nonhomologous end-joining DNA repair protein with diverse cellular functions such as VDJ recombination and telomere length maintenance. Here, we show a novel function of Ku in alleviating features of allergic airway inflammation via the regulation of mitochondrial and endoplasmic reticulum (ER) stress. We first determined that airway epithelial cells derived from both asthmatic lungs and murine asthma models demonstrate increased expression of 8-hydroxy-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage. Ku protein expression was dramatically reduced in the bronchial epithelium of patients with asthma as well as in human bronchial epithelial cells exposed to oxidative stress. Knockdown of Ku70 or Ku80 in naïve mice elicited mitochondrial collapse or ER stress, leading to bronchial epithelial cell apoptosis and spontaneous development of asthma-like features, including airway hyperresponsiveness, airway inflammation, and subepithelial fibrosis. These findings demonstrate an essential noncanonical role for Ku proteins in asthma pathogenesis, likely via maintenance of organelle homeostasis. This novel function of Ku proteins may also be important in other disease processes associated with organelle stress.


Assuntos
Células Epiteliais/metabolismo , Homeostase/fisiologia , Inflamação/prevenção & controle , Autoantígeno Ku/metabolismo , Animais , Asma/patologia , Asma/prevenção & controle , Estresse do Retículo Endoplasmático/fisiologia , Células Epiteliais/patologia , Humanos , Inflamação/metabolismo , Pulmão/metabolismo , Pulmão/patologia , Camundongos , Estresse Oxidativo/fisiologia , Hipersensibilidade Respiratória/patologia
3.
Am J Chin Med ; 48(6): 1435-1454, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32907363

RESUMO

Endoplasmic reticulum stress (ER stress) plays a main role in pancreatic [Formula: see text]-cell dysfunction and death because of intracellular Ca[Formula: see text] turbulence and inflammation activation. Although several drugs are targeting pancreatic [Formula: see text]-cell to improve [Formula: see text]-cell function, there still lacks agents to alleviate [Formula: see text]-cell ER stress conditions. Therefore we used thapsigargin (THAP) or high glucose (HG) to induce ER stress in [Formula: see text]-cell and aimed to screen natural molecules against ER stress-induced [Formula: see text]-cell dysfunction. Through screening the Traditional Chinese drug library ([Formula: see text] molecules), luteolin was finally discovered to improve [Formula: see text]-cell function. Cellular viability results indicated luteolin reduced the THAP or HG-induced [Formula: see text]-cell death and apoptosis through MTT and flow cytometry assay. Moreover, luteolin improved [Formula: see text]-cell insulin secretion ability under ER stress conditions. Also ER stress-induced intracellular Ca[Formula: see text] turbulence and inflammation activation were inhibited by luteolin treatment. Mechanically, luteolin inhibited HNF4[Formula: see text] signaling, which was induced by ER stress. Moreover, luteolin reduced the transcriptional level of HNF4[Formula: see text] downstream gene, such as Asnk4b and HNF1[Formula: see text]. Conversely HNF4[Formula: see text] knockdown abolished the effect of luteolin on [Formula: see text]-cell using siRNA. These results suggested the protective effect of luteolin on [Formula: see text]-cell was through HNF4[Formula: see text]/Asnk4b pathway. In conclusion, our study discovered that luteolin improved [Formula: see text]-cell function and disclosed the underlying mechanism of luteolin on [Formula: see text]-cell, suggesting luteolin is a promising agent against pancreatic dysfunction.


Assuntos
Sobrevivência Celular/efeitos dos fármacos , Medicamentos de Ervas Chinesas/química , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Estresse do Retículo Endoplasmático/genética , Fator 4 Nuclear de Hepatócito/genética , Fator 4 Nuclear de Hepatócito/metabolismo , Células Secretoras de Insulina/patologia , Células Secretoras de Insulina/fisiologia , Luteolina/farmacologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Tapsigargina/efeitos adversos , Apoptose/efeitos dos fármacos , Cálcio/metabolismo , Morte Celular/efeitos dos fármacos , Células Cultivadas , Avaliação Pré-Clínica de Medicamentos , Estresse do Retículo Endoplasmático/fisiologia , Glucose/efeitos adversos , Células Secretoras de Insulina/metabolismo , Luteolina/isolamento & purificação
4.
J Toxicol Sci ; 45(9): 589-598, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32879258

RESUMO

Acute mercury chloride (HgCl2) poisoning may lead to kidney injury, but the underlying mechanism remains largely unknown. Endoplasmic reticulum (ER) stress plays a role in some heavy metal poisoning. Whether it mediates kidney injury in acute HgCl2 poisoning remains unknown. In this study, we examined the kidney injury and the corresponding ER stress in the mouse model of different doses of acute HgCl2 poisoning. To further confirm the role of ER stress, we tested the effects of its chemical chaperone [4-phenylbutyric acid (4-PBA)]. The results revealed that acute HgCl2 poisoning caused more severe kidney injury with dose on and activated ER stress, as indicated by increased expression of GRP78 and CHOP. Inhibition of ER stress restored the functional and morphological changes of kidneys, and partly attenuated renal tubular epithelial cell apoptosis. In summary, ER stress contributes to the acute kidney injury following HgCl2 poisoning, and inhibition of ER stress may alleviate the kidney injury via reducing apoptosis.


Assuntos
Lesão Renal Aguda/etiologia , Estresse do Retículo Endoplasmático/fisiologia , Cloreto de Mercúrio/envenenamento , Animais , Butilaminas , Modelos Animais de Doenças , Estresse do Retículo Endoplasmático/genética , Expressão Gênica , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Humanos , Masculino , Camundongos Endogâmicos C57BL , Fator de Transcrição CHOP/genética , Fator de Transcrição CHOP/metabolismo
5.
Life Sci ; 259: 118276, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32798560

RESUMO

AIMS: The mechanisms underlying the fetal origin of renal disease remains unknown. This study aimed to investigate the profiles of ion channel and transporter proteins in the fetal kidney in fetal growth restriction (FGR)rats, and to explore their association with the fetal origin of renal disease. MAIN METHODS: An FGR rat model was developed by administration of a low-protein diet. Then 367 differentially expressed proteins (DEPs) from quantitative proteome analysis were subjected to Ingenuity Pathway Analysis. 22 DEPs associated with ion channels/transporters were evaluated in the fetal kidney. Na+/H+ exchanger1(NHE1) and its downstream unfolded protein response (UPR) pathway were investigated. Furthermore, overexpression of NHE1 were achieved via plasmid transfection to evaluate the potential influence on the UPR pathway and cell apoptosis in human proximal tubular epithelial cell line HK2 cells. KEY FINDINGS: Findings were as follows: 1) In the FGR fetal kidney, aquaporin 2/4, solute carrier (SLC) 8a1, 33a1, etc. were downregulated, whereas other transporters including SLC 2a1, 4a1, 9a1, 29a3, etc. were upregulated. 2) NHE1 mRNA levels were markedly elevated in the FGR fetus. Further investigation revealed an increase in the UPR pathway regulators. 3) In vitro study showed that NHE1 overexpression in HK2 cells significantly induced expression of the endoplasmic reticulum stress (ERS) regulators and led to a decrease in the anti-apoptotic potential. SIGNIFICANCE: We speculate that maternal protein malnutrition causes dysregulation of ion channels/transporters in the fetal kidney. Upregulated NHE1 may activate the UPR pathway and induce cell apoptosis thus leading to impairment of kidney function.


Assuntos
Estresse do Retículo Endoplasmático/fisiologia , Retardo do Crescimento Fetal/metabolismo , Canais Iônicos/metabolismo , Nefropatias/metabolismo , Rim/embriologia , Proteínas de Membrana Transportadoras/metabolismo , Animais , Apoptose/fisiologia , Linhagem Celular , Humanos , Rim/metabolismo , Masculino , Ratos , Trocador 1 de Sódio-Hidrogênio/metabolismo , Resposta a Proteínas não Dobradas
6.
Phytomedicine ; 78: 153288, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32782218

RESUMO

BACKGROUND: Timosaponin BⅡ (TBⅡ), one of the primary bioactive compounds from Anemarrhena asphodeloides Bunge, possesses potential cardioprotective effects. However, the mechanism underlying TBⅡ-mediated cardioprotection, especially the involvement of endoplasmic reticulum stress, remains largely unknown. PURPOSE: This study was designed to evaluate the role of TBⅡ in myocardial injury protection and explore its possible mechanisms. METHODS: In vivo models of isoproterenol-induced myocardial injury and H2O2-induced cytotoxicty were established to investigate the effect of anti-myocardial injury of TBⅡ. The potential mechanisms were investigated in vitro and in vivo using multiple detection methods like electrocardiography, histo-pathological examination, JC-1 staining, TUNEL staining, ELISA technology, and western blot analysis. RESULTS: In vivo study revealed that TBⅡ improved electrocardiography and heart vacuolation, reduced myocyte apoptosis, and improved the antioxidant potential. In vitro investigation demonstrated that TBⅡ pretreatment inhibited ER stress-mediated apoptosis pathways. Further investigation of the underlying mechanisms revealed that TBⅡ prevented H2O2-induced H9c2 cardiomyocytes injury by the PI3K/Akt pathways, whereas the addition of LY294002, the pharmacologic antagonist of PI3K, attenuated TBⅡ-induced expression of apoptotic protein and cytoprotective effects. CONCLUSION: These results suggested that TBⅡ protects against myocardial injury in vitro and enhances cellular defense capacity by inhibiting ER stress-mediated apoptosis pathways in vivo by activating the PI3K/Akt pathways.


Assuntos
Apoptose/efeitos dos fármacos , Cardiotônicos/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Saponinas/farmacologia , Esteroides/farmacologia , Animais , Apoptose/fisiologia , Células Cultivadas , Cromonas/farmacologia , Eletrocardiografia , Estresse do Retículo Endoplasmático/fisiologia , Peróxido de Hidrogênio/toxicidade , Isoproterenol/toxicidade , Masculino , Morfolinas/farmacologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos Sprague-Dawley
7.
Med Hypotheses ; 143: 110148, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32759016

RESUMO

Estrogen hormone acts as a potential key player in providing immunity against certain viral infection. It is found to be associated in providing immunity against acute lungs inflammation and influenza virus by modulating cytokines storm and mediating adaptive immune alterations respectively. Women are less affected by SARS-CoV-2 infection because of the possible influence of estrogen hormone as compared to men. We hypothesized that SARS-CoV-2 causes stress in endoplasmic reticulum (ER) which in turn aggravates the infection, estrogen hormone might play key role in decreasing ER stress by activating estrogen mediated signaling pathways, results in unfolded protein response (UPR). Estrogen governs degradation of phosphotidylinositol 4,5-bisphosphate (PIP2) into diacylglycerol (DAG) and inositol triphosphate (IP3) with the help of phospholipase C. IP3 start in-fluxing Ca+2 ions that helps in UPR activation. To support our hypothesis, we analyzed the data of 162,392 COVID-19 patients to determine the relation of this disease with gender. We observed that 26% of women and 74% of men were affected by SARS-CoV-2. It indicated that women are less affected because of the possible influence of estrogen hormone in women.


Assuntos
Betacoronavirus , Infecções por Coronavirus/fisiopatologia , Estresse do Retículo Endoplasmático/fisiologia , Estrogênios/fisiologia , Modelos Biológicos , Pandemias , Pneumonia Viral/fisiopatologia , Adulto , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/metabolismo , Conjuntos de Dados como Assunto/estatística & dados numéricos , Diglicerídeos/metabolismo , Resistência à Doença , Feminino , Humanos , Inositol 1,4,5-Trifosfato/metabolismo , Masculino , Pessoa de Meia-Idade , Paquistão/epidemiologia , Fosfatidilinositol 4,5-Difosfato/metabolismo , Pneumonia Viral/epidemiologia , Pneumonia Viral/metabolismo , Caracteres Sexuais , Distribuição por Sexo , Transdução de Sinais , Fosfolipases Tipo C/metabolismo , Resposta a Proteínas não Dobradas , Proteínas Virais/biossíntese , Proteínas Virais/genética
8.
Life Sci ; 257: 118004, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32621918

RESUMO

BACKGROUND: Patients undergoing cardiopulmonary bypass (CPB) often develop acute kidney injury (AKI) caused by myocardial ischemia reperfusion (MI/R), and this renal injury can be resolved notably by dexmedetomidine. Endoplasmic reticulum (ER) stress was reported to get involved in organ injury including AKI. OBJECTIVES: The current study aimed to address the correlation between MI/R induced AKI with ER stress and to assess the effects of dexmedetomidine pretreatment on AKI protection. METHOD: Patients selected for heart valve replacement surgery were randomly assigned to NS group (pre-anesthesia with 0.9% NaCl) and DEX group (pre-anesthesia with dexmedetomidine). Rat MI/R model was induced by occluding coronary artery for 30 min followed by 48-hour reperfusion. Rats were randomized into Sham (0.9% NaCl), I/R (MI/R + 0.9% NaCl) and I/R + DEX (MI/R + dexmedetomidine). Organ function and ER stress condition were evaluated by blood chemistry, pathology, and molecular test. RESULTS: Clinical data indicated dexmedetomidine pretreatment attenuated AKI and oxidative stress as well as postischemic myocardial injury in patients. Accordingly animal results suggested dexmedetomidine reduced cellular injury and improved postischemic myocardial and renal function. Dexmedetomidine also reduced myocardial and renal cells apoptosis and down-regulated ER stress. CONCLUSIONS: These results suggested that dexmedetomidine pretreatment attenuates MI/R injury-induced AKI by relieving the ER stress.


Assuntos
Dexmedetomidina/farmacologia , Isquemia Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Lesão Renal Aguda/metabolismo , Lesão Renal Aguda/prevenção & controle , Idoso , Animais , Apoptose/efeitos dos fármacos , China , Dexmedetomidina/metabolismo , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Estresse do Retículo Endoplasmático/fisiologia , Feminino , Humanos , Isquemia/metabolismo , Rim/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/metabolismo , Reperfusão Miocárdica/métodos , Traumatismo por Reperfusão Miocárdica/patologia , Miocárdio/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estudos Prospectivos , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/metabolismo , Transdução de Sinais/efeitos dos fármacos
9.
Nat Commun ; 11(1): 3642, 2020 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-32686688

RESUMO

Carpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment syndrome, affecting a large proportion of the general population. Genetic susceptibility has been implicated in CTS, but the causative genes remain elusive. Here, we report the identification of two mutations in cartilage oligomeric matrix protein (COMP) that segregate with CTS in two large families with or without multiple epiphyseal dysplasia (MED). Both mutations impair the secretion of COMP by tenocytes, but the mutation associated with MED also perturbs its secretion in chondrocytes. Further functional characterization of the CTS-specific mutation reveals similar histological and molecular changes of tendons/ligaments in patients' biopsies and the mouse models. The mutant COMP fails to oligomerize properly and is trapped in the ER, resulting in ER stress-induced unfolded protein response and cell death, leading to inflammation, progressive fibrosis and cell composition change in tendons/ligaments. The extracellular matrix (ECM) organization is also altered. Our studies uncover a previously unrecognized mechanism in CTS pathogenesis.


Assuntos
Síndrome do Túnel Carpal , Proteína de Matriz Oligomérica de Cartilagem , Animais , Síndrome do Túnel Carpal/etiologia , Síndrome do Túnel Carpal/genética , Síndrome do Túnel Carpal/metabolismo , Síndrome do Túnel Carpal/patologia , Proteína de Matriz Oligomérica de Cartilagem/genética , Proteína de Matriz Oligomérica de Cartilagem/metabolismo , Condrócitos/patologia , Estresse do Retículo Endoplasmático/fisiologia , Matriz Extracelular/patologia , Humanos , Inflamação , Ligamentos/citologia , Ligamentos/patologia , Mutação , Osteocondrodisplasias/genética , Osteocondrodisplasias/patologia , Tendões/citologia , Tendões/patologia , Tenócitos/patologia
10.
Am J Respir Cell Mol Biol ; 63(4): 478-489, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32551949

RESUMO

Although endoplasmic reticulum (ER) unfolded protein response (UPRER) is well known, mitochondrial unfolded protein response (UPRmt) has not been recognized in alveolar epithelial cells. Furthermore, ER stress and mitochondrial dysfunction are frequently encountered in alveolar epithelial cells from an array of lung disorders. However, these two scenarios have been often regarded as separate mechanisms contributing to the pathogeneses. It is unclear whether there is interplay between these two phenomena or an integrator that couples these two signaling cascades in the stressed alveolar epithelial cells from those pathologies. In this study, we defined UPRmt in alveolar epithelial cells and identified ATF4 (activating transcription factor 4), but not ATF5, as the key regulator of UPRmt. We found that UPRER led to UPRmt and mitochondrial dysfunction in an ATF4-dependent manner. In contrast, mitochondrial stresses did not activate UPRER. We found that alveolar epithelial ATF4 and UPRmt were induced in aged mice with experimental pulmonary fibrosis as well as in patients with idiopathic pulmonary fibrosis. Finally, we found that the inducible expression of ATF4 in mouse alveolar epithelial cells aggravated pulmonary UPRmt, lung inflammation, body weight loss, and death upon bleomycin-induced lung injury. In conclusion, ER stress induces ATF4-dependent UPRmt and mitochondrial dysfunction, indicating a novel mechanism by which ER stress contributes to the pathogeneses of a variety of pulmonary disorders.


Assuntos
Fator 4 Ativador da Transcrição/metabolismo , Células Epiteliais Alveolares/metabolismo , Mitocôndrias/metabolismo , Resposta a Proteínas não Dobradas/fisiologia , Células Epiteliais Alveolares/fisiologia , Animais , Apoptose/fisiologia , Linhagem Celular , Estresse do Retículo Endoplasmático/fisiologia , Humanos , Fibrose Pulmonar Idiopática/metabolismo , Fibrose Pulmonar Idiopática/fisiopatologia , Pulmão/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/fisiologia , Transdução de Sinais/fisiologia
11.
Sci Rep ; 10(1): 10188, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32576923

RESUMO

Proteostasis imbalance is emerging as a major hallmark of cancer, driving tumor growth and aggressiveness. Endoplasmic Reticulum (ER) stress has been documented in most major cancers, and the ability to tolerate persistent ER stress through an effective unfolded protein response enhances cancer cell survival, angiogenesis, metastasis, drug resistance and immunosuppression. The ER stress sensor IRE1α contributes to tumor progression through XBP1 mRNA splicing and regulated IRE1α-dependent decay of mRNA and miRNA. The aim of this study was to perform a molecular characterization of series of tumor samples to explore the impact of intratumoral IRE1 signaling in non-small cell lung cancer characteristics. To monitor IRE1 splicing activity, we adopted a fragment length analysis to detect changes in the length of the XBP1 mRNA before and after splicing as a method for measuring sXBP1 mRNA levels in tumors because sXBP1 mRNA is not probed by standard transcriptomic analyses. We demonstrate for the first time that XBP1 splicing is a valuable marker of lung cancer aggressiveness, and our results support a model in which IRE1 downstream signaling could act as a regulator of Epithelial to Mesenchymal Transition (EMT). Our findings study highlights the role of IRE1α downstream signaling in non-small cell lung cancer and opens a conceptual framework to determine how IRE1α endoribonuclease activity shapes the EMT program.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/metabolismo , Transição Epitelial-Mesenquimal/fisiologia , Neoplasias Pulmonares/metabolismo , Proteína 1 de Ligação a X-Box/metabolismo , Idoso , Carcinoma Pulmonar de Células não Pequenas/patologia , Sobrevivência Celular/fisiologia , Retículo Endoplasmático/metabolismo , Estresse do Retículo Endoplasmático/fisiologia , Endorribonucleases/metabolismo , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino , Processamento de RNA/fisiologia , RNA Mensageiro/metabolismo , Transdução de Sinais/fisiologia , Resposta a Proteínas não Dobradas/fisiologia
12.
J Toxicol Sci ; 45(6): 305-317, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32493873

RESUMO

The aim of the present study was to evaluate the underlying mechanism of multi-walled carbon nanotubes (MWCNT) induced cellular response and their potential cross-talk, specifically, between endoplasmic reticulum (ER) stress, MAPK activation and apoptosis and how these nano-bio interactions depend on the physico-chemical properties of MWCNT. For this purpose, human bronchial epithelial (Beas2B) and human hepatoma (HepG2) cell lines, were exposed to five kinds of MWCNTs which differ in functionalization and aspect ratios. Tissue-specific sensitivity was evident for calcium homeostasis, ER-stress response, MAPK activation and apoptosis, which further depended on surface functionalization as well as aspect ratios of MWCNT. By applying specific pharmaceutical inhibitors, relevant biomarkers gene and proteins expressions, we found that possibly MWCNT induce activation of IRE1α-XPB1 pathway-mediated ER-stress response, which in turn trigger apoptosis through JNK activation in both type of cells but with variable intensity. The information presented here would have relevance in better understanding of MWCNT toxicity and their safer applications.


Assuntos
Apoptose/fisiologia , Estresse do Retículo Endoplasmático/fisiologia , Proteínas Quinases JNK Ativadas por Mitógeno , Proteínas Quinases Ativadas por Mitógeno , Nanotubos de Carbono/efeitos adversos , Células Cultivadas , Humanos
13.
Life Sci ; 255: 117842, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: covidwho-403331

RESUMO

The outbreak of COVID-19 caused by 2019-nCov/SARS-CoV-2 has become a pandemic with an urgent need for understanding the mechanisms and identifying a treatment. Viral infections including SARS-CoV are associated with increased levels of reactive oxygen species, disturbances of Ca++ caused by unfolded protein response (UPR) mediated by endoplasmic reticulum (ER) stress and is due to the exploitation of virus's own protein i.e., viroporins into the host cells. Several clinical trials are on-going including testing Remdesivir (anti-viral), Chloroquine and Hydroxychloroquine derivatives (anti-malarial drugs) etc. Unfortunately, each drug has specific limitations. Herein, we review the viral protein involvement to activate ER stress transducers (IRE-1, PERK, ATF-6) and their downstream signals; and evaluate combination therapies for COVID-19 mediated ER stress alterations. Melatonin is an immunoregulator, anti-pyretic, antioxidant, anti-inflammatory and ER stress modulator during viral infections. It enhances protective mechanisms for respiratory tract disorders. Andrographolide, isolated from Andrographis paniculata, has versatile biological activities including immunomodulation and determining SARS-CoV-2 binding site. Considering the properties of both compounds in terms of anti-inflammatory, antioxidant, anti-pyrogenic, anti-viral and ER stress modulation and computational approaches revealing andrographolide docks with the SARS-CoV2 binding site, we predict that this combination therapy may have potential utility against COVID-19.


Assuntos
Betacoronavirus/metabolismo , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/virologia , Diterpenos/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Melatonina/farmacologia , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/virologia , Fator 6 Ativador da Transcrição/metabolismo , Antivirais/farmacologia , Sinergismo Farmacológico , Estresse do Retículo Endoplasmático/fisiologia , Endorribonucleases/metabolismo , Humanos , Terapia de Alvo Molecular , Pandemias , Proteínas Serina-Treonina Quinases/metabolismo , Resposta a Proteínas não Dobradas/efeitos dos fármacos , eIF-2 Quinase/metabolismo
14.
Nat Rev Mol Cell Biol ; 21(8): 421-438, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32457508

RESUMO

Cellular stress induced by the abnormal accumulation of unfolded or misfolded proteins at the endoplasmic reticulum (ER) is emerging as a possible driver of human diseases, including cancer, diabetes, obesity and neurodegeneration. ER proteostasis surveillance is mediated by the unfolded protein response (UPR), a signal transduction pathway that senses the fidelity of protein folding in the ER lumen. The UPR transmits information about protein folding status to the nucleus and cytosol to adjust the protein folding capacity of the cell or, in the event of chronic damage, induce apoptotic cell death. Recent advances in the understanding of the regulation of UPR signalling and its implications in the pathophysiology of disease might open new therapeutic avenues.


Assuntos
Estresse do Retículo Endoplasmático/fisiologia , Resposta a Proteínas não Dobradas/genética , Resposta a Proteínas não Dobradas/fisiologia , Animais , Apoptose/fisiologia , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/fisiologia , Humanos , Neoplasias/metabolismo , Dobramento de Proteína , Proteínas/metabolismo , Transdução de Sinais
15.
Arch Biochem Biophys ; 688: 108402, 2020 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-32418909

RESUMO

A/J mouse is a model of age-related hearing loss (AHL). Mutation in the citrate synthase (Cs) gene of the mouse plays an important role in the hearing loss and degeneration of cochlear cells. To investigate the pathogenesis of cochlear cell damage in A/J mice resulted from Cs mutation, we downregulated the expression level of CS in HEI-OC1, a cell line of mouse cochlea, by shRNA. The results showed that low CS expression led to low ability of cell proliferation. Further study revealed an increase level of reactive oxygen species (ROS), activation of ATF6 mediated endoplasmic reticulum stress (ERS) and high expression levels of caspase12 and Bax in the cells. Moreover, the AEBSF, an ATF6 inhibitor, could reduce the expression levels of caspase-12 and Bax by inhibiting the hydrolysis of ATF6 in the cells. Finally, antioxidant alpha-lipoic acid (ALA) reduced the ROS levels and the apoptotic signals in the cell model with low CS expression. We therefore conclude that the ERS mediated apoptosis, which is triggered by ROS, may be involved in the cell degeneration in the cochleae of A/J mice.


Assuntos
Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Citrato (si)-Sintase/metabolismo , Estresse do Retículo Endoplasmático/fisiologia , Estresse Oxidativo/efeitos dos fármacos , Ácido Tióctico/farmacologia , Fator 6 Ativador da Transcrição/antagonistas & inibidores , Animais , Apoptose/fisiologia , Caspase 12/metabolismo , Linhagem Celular , Proliferação de Células/fisiologia , Regulação para Baixo , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Camundongos , Mitocôndrias/metabolismo , Modelos Biológicos , Estresse Oxidativo/fisiologia , Presbiacusia/fisiopatologia , Espécies Reativas de Oxigênio/metabolismo , Sulfonas/farmacologia , Proteína X Associada a bcl-2/metabolismo
16.
Artigo em Inglês | MEDLINE | ID: mdl-32383993

RESUMO

Cerebrovascular dysfunction is a critical risk factor for the pathogenesis of Alzheimer's disease (AD). The purinergic P2Y2 receptor and endoplasmic reticulum (ER) stress are tightly associated with vascular dysfunction and the pathogenesis of AD. However, the protective effects of exercise training on P2Y2 receptor- and ER stress-associated cerebrovascular dysfunction in AD are mostly unknown. Control (C57BL/6, CON) and AD (APP/PS1dE9, AD) mice underwent treadmill exercise training (EX). 2-MeS-ATP-induced dose-dependent vasoreactivity was determined by using a pressurized posterior cerebral artery (PCA) from 10-12-mo-old mice. Human brain microvascular endothelial cells (HBMECs) were exposed to laminar shear stress (LSS) at 20 dyn/cm2 for 30 min, 2 h, and 24 h. The expression of P2Y2 receptors, endothelial nitric oxide synthase (eNOS), and ER stress signaling were quantified by Western blot analysis. Notably, exercise converted ATP-induced vasoconstriction in the PCA from AD mice to vasodilation in AD+EX mice to a degree commensurate to the vascular reactivity observed in CON mice. Exercise reduced the expression of amyloid peptide precursor (APP) and increased the P2Y2 receptor and Akt/eNOS expression in AD mice brain. Mechanistically, LSS increased the expression of both P2Y2 receptor and eNOS protein in HBMECs, but these increases were blunted by a P2Y2 receptor antagonist in HBMECs. Exercise also reduced the expression of aberrant ER stress markers p-IRE1, p/t-eIF2α, and CHOP, as well as Bax/Bcl-2, in AD mice brain. Collectively, our results demonstrate for the first time that exercise mitigates cerebrovascular dysfunction in AD through modulating P2Y2 receptor- and ER stress-dependent endothelial dysfunction.NEW & NOTEWORTHY A limited study has investigated whether exercise training can improve cerebrovascular function in Alzheimer's disease. The novel findings of the study are that exercise training improves cerebrovascular dysfunction through enhancing P2Y2 receptor-mediated eNOS signaling and reducing ER stress-associated pathways in AD. These data suggest that exercise training, which regulates P2Y2 receptor and ER stress in AD brain, is a potential therapeutic strategy for Alzheimer's disease.


Assuntos
Doença de Alzheimer/metabolismo , Circulação Cerebrovascular/fisiologia , Estresse do Retículo Endoplasmático/fisiologia , Condicionamento Físico Animal/fisiologia , Receptores Purinérgicos P2Y2/metabolismo , Doença de Alzheimer/fisiopatologia , Animais , Encéfalo/metabolismo , Encéfalo/fisiopatologia , Modelos Animais de Doenças , Células Endoteliais/metabolismo , Endotélio Vascular/metabolismo , Endotélio Vascular/fisiopatologia , Camundongos , Óxido Nítrico Sintase Tipo III/metabolismo , Artéria Cerebral Posterior/metabolismo , Artéria Cerebral Posterior/fisiopatologia , Proteínas Proto-Oncogênicas c-akt/metabolismo
17.
Life Sci ; 255: 117842, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32454157

RESUMO

The outbreak of COVID-19 caused by 2019-nCov/SARS-CoV-2 has become a pandemic with an urgent need for understanding the mechanisms and identifying a treatment. Viral infections including SARS-CoV are associated with increased levels of reactive oxygen species, disturbances of Ca++ caused by unfolded protein response (UPR) mediated by endoplasmic reticulum (ER) stress and is due to the exploitation of virus's own protein i.e., viroporins into the host cells. Several clinical trials are on-going including testing Remdesivir (anti-viral), Chloroquine and Hydroxychloroquine derivatives (anti-malarial drugs) etc. Unfortunately, each drug has specific limitations. Herein, we review the viral protein involvement to activate ER stress transducers (IRE-1, PERK, ATF-6) and their downstream signals; and evaluate combination therapies for COVID-19 mediated ER stress alterations. Melatonin is an immunoregulator, anti-pyretic, antioxidant, anti-inflammatory and ER stress modulator during viral infections. It enhances protective mechanisms for respiratory tract disorders. Andrographolide, isolated from Andrographis paniculata, has versatile biological activities including immunomodulation and determining SARS-CoV-2 binding site. Considering the properties of both compounds in terms of anti-inflammatory, antioxidant, anti-pyrogenic, anti-viral and ER stress modulation and computational approaches revealing andrographolide docks with the SARS-CoV2 binding site, we predict that this combination therapy may have potential utility against COVID-19.


Assuntos
Betacoronavirus/metabolismo , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/virologia , Diterpenos/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Melatonina/farmacologia , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/virologia , Fator 6 Ativador da Transcrição/metabolismo , Antivirais/farmacologia , Sinergismo Farmacológico , Estresse do Retículo Endoplasmático/fisiologia , Endorribonucleases/metabolismo , Humanos , Terapia de Alvo Molecular , Pandemias , Proteínas Serina-Treonina Quinases/metabolismo , Resposta a Proteínas não Dobradas/efeitos dos fármacos , eIF-2 Quinase/metabolismo
18.
Life Sci ; 253: 117678, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32376267

RESUMO

AIMS: The endoplasmic reticulum (ER) stress response plays a crucial role in the development of nonalcoholic steatohepatitis (NASH). Heme oxygenase-1 (HO-1) exerts beneficial effects against oxidative injury in NASH. This study is aimed to clarify whether HO-1 is an effective therapeutic strategy for NASH via regulation of ER stress. METHODS: The C57BL/6J mice were fed with methionine-choline deficient (MCD) for 4 weeks and high fat-high carbohydrate-high cholesterol (HFD) diet for 16 weeks, with hemin or zinc protoporphyrin IX (ZnPP-IX), respectively. The LO-2 cells were cultured in palmitic medium, with transfected pEX-HO-1 or sh-HO-1 plasmid for 24 h. Meanwhile, thirty NASH patients and 15 health controls were enrolled. The ER ultrastructure was observed by transmission electron microscopy (TEM) and confocal microscopy. The expressions of mRNAs and proteins of HO-1, ER stress related genes were detected by real time PCR, western blot and immunohistochemical staining, respectively. RESULTS: The swelled and broken rough endoplasmic reticulums were observed in MCD and HFD fed mice. The reactive hepatic expression of HO-1 was related with the increased ROS production and ER stress, companied with upregulation of GRP78, p-IRE1, PERK, ATF6. Through hemin administration, hepatocyte apoptosis was suppressed companied down-regulation of CHOP, caspase12 and up-regulation of BCL2. Conserved results were exhibited in ZnPP-IX administrated mice and HO-1 silent cells. Consistent results were observed in the NASH Patients. CONCLUSIONS: HO-1 could serve as a protective factor in the progression of nutritional steatohepatitis by suppresses hepatocyte excessive ER stress and might be a potential target for therapy of nonalcoholic steatohepatitis.


Assuntos
Estresse do Retículo Endoplasmático/fisiologia , Heme Oxigenase-1/genética , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Espécies Reativas de Oxigênio/metabolismo , Animais , Apoptose/fisiologia , Células Cultivadas , Progressão da Doença , Hemina/administração & dosagem , Hepatócitos/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Hepatopatia Gordurosa não Alcoólica/genética , Protoporfirinas/administração & dosagem
19.
Free Radic Res ; 54(4): 244-253, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32292073

RESUMO

Crystal modulators play a significant role in the formation of calcium oxalate stone disease. When renal cells are subjected to oxalate stress, the loss in cell integrity leads to exposure of multiple proteins that assist and/or inhibit crystal attachment and retention. Contact between oxalate and calcium oxalate with urothelium proves fatal to cells as a result of reactive oxygen species generation and onset of oxidative stress. Hence, as a therapeutic strategy it was hypothesised that supplementation of antioxidants would suffice. On the contrary to popular belief, the detection of oxalate induced endoplasmic reticulum mediated apoptosis proved the ineffectiveness of antioxidant therapy alone. Thus, the inadequacy of antioxidant supplementation in oxalate stress invoked the presence of an alternative pathway for the induction of kidney fibrosis in hyperoxaluric rats. In addition to settling this query, the link between oxidative stress and ER stress is not well understood, especially in urolithiasis.


Assuntos
Oxalato de Cálcio/metabolismo , Estresse do Retículo Endoplasmático/fisiologia , Estresse Oxidativo/fisiologia , Urolitíase/metabolismo , Animais , Humanos , Masculino , Ratos , Urolitíase/patologia
20.
Cancer Res ; 80(11): 2368-2379, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32265225

RESUMO

Cancer cells exploit the unfolded protein response (UPR) to mitigate endoplasmic reticulum (ER) stress caused by cellular oncogene activation and a hostile tumor microenvironment (TME). The key UPR sensor IRE1α resides in the ER and deploys a cytoplasmic kinase-endoribonuclease module to activate the transcription factor XBP1s, which facilitates ER-mediated protein folding. Studies of triple-negative breast cancer (TNBC)-a highly aggressive malignancy with a dismal posttreatment prognosis-implicate XBP1s in promoting tumor vascularization and progression. However, it remains unknown whether IRE1α adapts the ER in TNBC cells and modulates their TME, and whether IRE1α inhibition can enhance antiangiogenic therapy-previously found to be ineffective in patients with TNBC. To gauge IRE1α function, we defined an XBP1s-dependent gene signature, which revealed significant IRE1α pathway activation in multiple solid cancers, including TNBC. IRE1α knockout in TNBC cells markedly reversed substantial ultrastructural expansion of their ER upon growth in vivo. IRE1α disruption also led to significant remodeling of the cellular TME, increasing pericyte numbers while decreasing cancer-associated fibroblasts and myeloid-derived suppressor cells. Pharmacologic IRE1α kinase inhibition strongly attenuated growth of cell line-based and patient-derived TNBC xenografts in mice and synergized with anti-VEGFA treatment to cause tumor stasis or regression. Thus, TNBC cells critically rely on IRE1α to adapt their ER to in vivo stress and to adjust the TME to facilitate malignant growth. TNBC reliance on IRE1α is an important vulnerability that can be uniquely exploited in combination with antiangiogenic therapy as a promising new biologic approach to combat this lethal disease. SIGNIFICANCE: Pharmacologic IRE1α kinase inhibition reverses ultrastructural distension of the ER, normalizes the tumor vasculature, and remodels the cellular TME, attenuating TNBC growth in mice.


Assuntos
Inibidores da Angiogênese/farmacologia , Antineoplásicos Imunológicos/farmacologia , Estresse do Retículo Endoplasmático/fisiologia , Endorribonucleases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Neoplasias de Mama Triplo Negativas/terapia , Animais , Antineoplásicos Imunológicos/imunologia , Linhagem Celular Tumoral , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Endorribonucleases/genética , Feminino , Técnicas de Inativação de Genes , Humanos , Camundongos , Camundongos SCID , Neovascularização Patológica/terapia , Proteínas Serina-Treonina Quinases/genética , RNA Mensageiro/genética , Neoplasias de Mama Triplo Negativas/irrigação sanguínea , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologia , Microambiente Tumoral , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/imunologia , Proteína 1 de Ligação a X-Box/antagonistas & inibidores , Proteína 1 de Ligação a X-Box/genética , Ensaios Antitumorais Modelo de Xenoenxerto
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