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1.
Immunity ; 43(3): 451-62, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-26341399

RESUMO

Endoplasmic reticulum (ER) stress is observed in many human diseases, often associated with inflammation. ER stress can trigger inflammation through nucleotide-binding domain and leucine-rich repeat containing (NLRP3) inflammasome, which might stimulate inflammasome formation by association with damaged mitochondria. How ER stress triggers mitochondrial dysfunction and inflammasome activation is ill defined. Here we have used an infection model to show that the IRE1α ER stress sensor regulates regulated mitochondrial dysfunction through an NLRP3-mediated feed-forward loop, independently of ASC. IRE1α activation increased mitochondrial reactive oxygen species, promoting NLRP3 association with mitochondria. NLRP3 was required for ER stress-induced cleavage of caspase-2 and the pro-apoptotic factor, Bid, leading to subsequent release of mitochondrial contents. Caspase-2 and Bid were necessary for activation of the canonical inflammasome by infection-associated or general ER stress. These data identify an NLRP3-caspase-2-dependent mechanism that relays ER stress to the mitochondria to promote inflammation, integrating cellular stress and innate immunity.


Assuntos
Proteínas de Transporte/imunologia , Caspase 2/imunologia , Estresse do Retículo Endoplasmático/imunologia , Inflamassomos/imunologia , Mitocôndrias/imunologia , Animais , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/genética , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/imunologia , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/metabolismo , Western Blotting , Brucella abortus/imunologia , Brucella abortus/fisiologia , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Caspase 2/genética , Caspase 2/metabolismo , Células Cultivadas , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/imunologia , Proteínas de Ligação a DNA/metabolismo , Estresse do Retículo Endoplasmático/genética , Endorribonucleases/imunologia , Endorribonucleases/metabolismo , Células HEK293 , Interações Hospedeiro-Patógeno/imunologia , Humanos , Inflamassomos/metabolismo , Interleucina-1beta/imunologia , Interleucina-1beta/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR , Proteínas Serina-Treonina Quinases/imunologia , Proteínas Serina-Treonina Quinases/metabolismo , Interferência de RNA/imunologia , Espécies Reativas de Oxigênio/imunologia , Espécies Reativas de Oxigênio/metabolismo , Fatores de Transcrição de Fator Regulador X , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/genética , Fatores de Transcrição/imunologia , Fatores de Transcrição/metabolismo
2.
Am J Pathol ; 192(10): 1358-1367, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35752228

RESUMO

Extracellular vesicles (EVs) are generated by cells in the form of exosomes, microvesicles, and apoptotic bodies. They can be taken up by neighboring cells, and their contents can have functional impact on the cells that engulf them. As the mediators of intercellular communication, EVs can play important roles in both physiological and pathologic contexts. In addition, early detection of EVs in different body fluids may offer a sensitive diagnostic tool for certain diseases, such as cancer. Furthermore, targeting specific EVs may also become a promising therapeutic approach. This review summarizes the latest findings of EVs in the field of liver research, with a focus on the different contents of the EVs and their impact on liver function and on the development of inflammation, fibrosis, and tumor in the liver. The goal of this review is to provide a succinct account of the various molecules that can mediate the function of EVs so the readers may apply this knowledge to their own research.


Assuntos
Micropartículas Derivadas de Células , Exossomos , Vesículas Extracelulares , Neoplasias , Comunicação Celular , Micropartículas Derivadas de Células/patologia , Vesículas Extracelulares/patologia , Humanos , Fígado/patologia , Neoplasias/patologia
3.
Emerg Infect Dis ; 28(3): 510-517, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35138244

RESUMO

Severe coronavirus disease in neonates is rare. We analyzed clinical, laboratory, and autopsy findings from a neonate in the United States who was delivered at 25 weeks of gestation and died 4 days after birth; the mother had asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and preeclampsia. We observed severe diffuse alveolar damage and localized SARS-CoV-2 by immunohistochemistry, in situ hybridization, and electron microscopy of the lungs of the neonate. We localized SARS-CoV-2 RNA in neonatal heart and liver vascular endothelium by using in situ hybridization and detected SARS-CoV-2 RNA in neonatal and placental tissues by using reverse transcription PCR. Subgenomic reverse transcription PCR suggested viral replication in lung/airway, heart, and liver. These findings indicate that in utero SARS-CoV-2 transmission contributed to this neonatal death.


Assuntos
COVID-19 , Complicações Infecciosas na Gravidez , Autopsia , Feminino , Humanos , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas , Pulmão , Placenta , Gravidez , RNA Viral/genética , SARS-CoV-2
4.
Anal Chem ; 94(11): 4866-4873, 2022 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-35274930

RESUMO

Sugar phosphates are important metabolic intermediates in organisms and play a vital role in energy and central carbon metabolism. Profiling of sugar phosphates is of great significance but full of challenges due to their high structural similarity and low sensitivities in liquid chromatography (LC)-mass spectrometry (MS). In this study, we developed a novel stable isotope chemical labeling combined with the reversed-phase (RP)LC-MS method for ultrasensitive determination of sugar phosphates at the single-cell level. By chemical derivatization with 2-(diazo-methyl)-N-methyl-N-phenyl-benzamide (2-DMBA) and d5-2-DMBA, sugar phosphate isomers can obtain better separation and identification, and the detection sensitivities of sugar phosphates increased by 3.5-147 folds. The obtained limits of detection of sugar phosphates ranged from 5 to 16 pg/mL. Using this method, we achieved ultrasensitive and accurate quantification of 12 sugar phosphates in different trace biological samples. Benefiting from the improved separation and detection sensitivity, we successfully quantified five sugar phosphates (d-glucose 1-phosphate, d-mannose 6-phosphate, d-fructose 6-phosphate, d-glucose 6-phosphate, and seduheptulose 7-phosphate) in a single protoplast of Arabidopsis thaliana.


Assuntos
Fosfatos Açúcares , Cromatografia Líquida , Glucose , Marcação por Isótopo , Isótopos , Fosfatos , Fosfatos Açúcares/análise
5.
Nutr Cancer ; 74(10): 3623-3633, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35838018

RESUMO

This study aimed to quantitatively identify the prognostic and clinicopathological value of the geriatric nutritional risk index (GNRI) in non-small cell lung cancer (NSCLC) through a meta-analysis. The electronic databases PubMed, Web of Science, Embase, and Cochrane Library were thoroughly searched from inception to December 14, 2021. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated to evaluate the prognostic value of GNRI. Odds ratios (ORs) and 95%CIs were combined to estimate the clinicopathological significance of the GNRI in NSCLC. Seven studies with 2,023 patients were included in the meta-analysis. A low GNRI score was significantly associated with poor overall survival (OS) (HR = 2.01, 95%CI = 1.65-2.44, p < 0.001) and worse progression-free survival (PFS), recurrence-free survival (RFS), and cancer-specific survival (CSS) (HR = 1.81, 95%CI = 1.48-2.22, p < 0.001) in NSCLC. Furthermore, a low GNRI score was significantly associated with the histological type of non-adenocarcinoma (OR= 1.55, 95%CI = 1.19-2.03, p = 0.001) and Eastern Cooperative Oncology Group performance status (ECOG PS) ≥2 (OR= 2.81, 95%CI= 1.49-5.32, p = 0.001). A low GNRI score is a significant and effective prognostic marker for poor survival outcomes in patients with NSCLC. In addition, low GNRI score was correlated with higher ECOG PS scores.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Idoso , Carcinoma Pulmonar de Células não Pequenas/patologia , Humanos , Neoplasias Pulmonares/patologia , Prognóstico
6.
Anal Chem ; 93(5): 3002-3009, 2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33497194

RESUMO

cis-Diol-containing metabolites are widely distributed in living organisms, and they participate in the regulation of various important biological activities. The profiling of cis-diol-containing metabolites could help us in fully understanding their functions. In this work, based on the characteristic isotope pattern of boron, we employed a boronic acid reagent as the isotope tag to establish a sensitive and selective liquid chromatography-high-resolution mass spectrometry method for the screening and annotation of cis-diol-containing metabolites in biological samples. Boronic acid reagent 2-methyl-4-phenylaminomethylphenylboronic acid was used to label the cis-diol-containing metabolites in biological samples to improve the selectivity and MS sensitivity of cis-diol-containing metabolites. Based on the characteristic 0.996 Da mass difference of precursor ions and the peak intensity ratio of 1:4 originating from 10B and 11B natural isotopes, the potential cis-diol-containing metabolites were rapidly screened from biological samples. Potential cis-diol-containing metabolites were annotated by database searching and analysis of fragmentation patterns obtained by multistage MS (MSn) via collision-induced dissociation. Importantly, the cis-diol position could be readily resolved by the MS3 spectrum. With this method, a total of 45 cis-diol-containing metabolites were discovered in rice, including monoglycerides, polyhydroxy fatty acids, fatty alcohols, and so forth. Furthermore, the established method showed superiority in avoiding false-positive results in profiling cis-diol-containing metabolites.


Assuntos
Boro , Espectrometria de Massas em Tandem , Álcoois , Cromatografia Líquida , Marcação por Isótopo , Isótopos
7.
Anal Chem ; 93(17): 6848-6856, 2021 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-33882236

RESUMO

Polar phosphorylated metabolites are involved in a variety of biological processes and play vital roles in energetic metabolism, cofactor regeneration, and nucleic acid synthesis. However, it is often challenging to interrogate polar phosphorylated metabolites and compounds from biological samples. Liquid chromatography-mass spectrometry (LC/MS) now plays a central role in metabolomic studies. However, LC/MS-based approaches have been hampered by the issues of the low ionization efficiencies, low in vivo concentrations, and less chemical stability of polar phosphorylated metabolites. In this work, we synthesized paired reagents of light and heavy isotopomers, 2-(diazomethyl)phenyl)(9-methyl-1,3,4,9-tetrahydro-2H-pyrido[3,4-b]indol-2-yl)methanone (DMPI) and d3-(2-(diazomethyl)phenyl)(9-methyl-1,3,4,9-tetrahydro-2H-pyrido[3,4-b]indol-2-yl)methanone (d3-DMPI). The paired reagents of DMPI and d3-DMPI carry diazo groups that can efficiently and selectively react with the phosphate group on polar phosphorylated metabolites under mild conditions. As a proof of concept, we found that the transfer of the indole heterocycle group from DMPI/d3-DMPI to ribonucleotides led to the significant increase of ionization efficiencies of ribonucleotides during LC/MS analysis. The detection sensitivities of these ribonucleotides increased by 25-1137-fold upon DMPI tagging with the limits of detection (LODs) being between 7 and 150 amol. With the developed method, we achieved the determination of all the 12 ribonucleotides from a single mammalian cell and from a single stamen of Arabidopsis thaliana. The method provides a valuable tool to investigate the dynamic changes of polar phosphorylated metabolites in a single cell under particular conditions.


Assuntos
Metabolômica , Cromatografia Líquida , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Espectrometria de Massas
8.
Eur Spine J ; 30(12): 3607-3613, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34601625

RESUMO

BACKGROUND: The presence vertebral artery (VA) abnormalities in the upper cervical may be a potential cause of catastrophic complication in the posterior approach of the upper cervical spine surgery. The aim of this study was to demonstrate the real incidence of the V3 segment anomaly in patients who need upper cervical surgery, and tried to find out the risk factors of V3 segment anomaly to evaluate the necessary of computed tomographic angiography (CTA) for upper cervical surgery. METHOD: This systematic review was conducted following the preferred reporting items for systematic reviews and meta-Analyses (PRISMA). Retrospective studies and reports of case series involving human subjects with data on anomalies of vertebral artery in upper cervical spine were included. Data on the prevalence of persistent first intersegmental artery (PIA), fenestration of the VA (FA), posterior inferior cerebellar artery (PICA) were extracted. RESULTS: A total of 16 articles involving 5927 subjects met the inclusion criteria. The total incidence of V3 segment anomaly in the patients with bony abnormalities was 25.9% (74/286): PIA was 17.5%, FA was 6.6% and PICA was 1.8%. The total incidence of V3 segment anomaly in the patients without bony abnormalities was 2.7% (152/5671): PIA was 1.76%, FA was 0.4% and PICA was 0.5%. The total incidence of V3 segment anomaly in Asian population without bony abnormalities was 5.8%, while in European and American population was 0.8 and 0.6%, respectively. CONCLUSION: Patients with bone abnormalities are high risk factor for VA abnormalities, CTA is of paramount importance to evaluate the variant VA anatomy. However, regarding to the low incidence of V3 variation in normal population, we do not recommend preoperative CT angiography as mandatory part of preoperative.


Assuntos
Doenças da Coluna Vertebral , Artéria Vertebral , Vértebras Cervicais/diagnóstico por imagem , Vértebras Cervicais/cirurgia , Humanos , Prevalência , Estudos Retrospectivos , Artéria Vertebral/diagnóstico por imagem
9.
Am J Pathol ; 189(9): 1744-1762, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31199920

RESUMO

Alcoholic fatty liver disease is often complicated by other pathologic insults, such as viral infection or high-fat diet. Autophagy plays a homeostatic role in the liver but can be compromised by alcohol, high-fat diet, or viral infection, which in turn affects the disease process caused by these etiologies. To understand the full impact of autophagy modulation on alcohol-induced liver injury, several genetic models of autophagy deficiency, which have different levels of functional alterations, were examined after acute binge or chronic-plus-binge treatment. Mice given alcohol with either mode and induced with deficiency in liver-specific Atg7 shortly after the induction of Atg7 deletion had elevated liver injury, indicating the protective role of autophagy. Constitutive hepatic Atg7-deficient mice, in which Atg7 was deleted in embryos, were more susceptible with chronic-plus-binge but not with acute alcohol treatment. Constitutive hepatic Atg5-deficient mice, in which Atg5 was deleted in embryos, were more susceptible with acute alcohol treatment, but liver injury was unexpectedly improved with the chronic-plus-binge regimen. A prolonged autophagy deficiency may complicate the hepatic response to alcohol treatment, likely in part due to endogenous liver injury. The complexity of the relationship between autophagy deficiency and alcohol-induced liver injury can thus be affected by the timing of autophagy dysfunction, the exact autophagy gene being affected, and the alcohol treatment regimen.


Assuntos
Proteína 7 Relacionada à Autofagia/fisiologia , Autofagia , Depressores do Sistema Nervoso Central/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Etanol/toxicidade , Fígado Gorduroso Alcoólico/etiologia , Animais , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Fígado Gorduroso Alcoólico/metabolismo , Fígado Gorduroso Alcoólico/patologia , Feminino , Masculino , Camundongos , Camundongos Knockout
10.
Hepatology ; 69(5): 2196-2213, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30520052

RESUMO

Autophagy is important for hepatic homeostasis, nutrient regeneration, and organelle quality control. We investigated the mechanisms by which liver injury occurred in the absence of autophagy function. We found that mice deficient in autophagy because of the lack of autophagy-related gene 7 or autophagy-related gene 5, key autophagy-related genes, manifested intracellular cholestasis with increased levels of serum bile acids, a higher ratio of tauromuricholic acid/taurocholic acid in the bile, increased hepatic bile acid load, abnormal bile canaliculi, and altered expression of hepatic transporters. In determining the underlying mechanism, we found that autophagy sustained and promoted the basal and up-regulated expression of farnesoid X receptor (Fxr) in the fed and starved conditions, respectively. Consequently, expression of Fxr and its downstream genes, particularly bile salt export pump, and the binding of FXR to the promoter regions of these genes, were suppressed in autophagy-deficient livers. In addition, codeletion of nuclear factor erythroid 2-related factor 2 (Nrf2) in autophagy deficiency status reversed the FXR suppression. Furthermore, the cholestatic injury of autophagy-deficient livers was reversed by enhancement of FXR activity or expression, or by Nrf2 deletion. Conclusion: Together with earlier reports that FXR can suppress autophagy, our findings indicate that autophagy and FXR form a regulatory loop and deficiency of autophagy causes abnormal FXR functionality, leading to the development of intracellular cholestasis and liver injury.


Assuntos
Autofagia , Colestase Intra-Hepática/etiologia , Fator 2 Relacionado a NF-E2/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Animais , Ácidos e Sais Biliares/sangue , Colestase Intra-Hepática/metabolismo , Feminino , Privação de Alimentos , Fígado/ultraestrutura , Masculino , Camundongos Transgênicos
11.
Neurochem Res ; 45(4): 760-771, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31953741

RESUMO

Spinal cord injury (SCI) is a devastating event which caused high mortality and morbidity. Recently, nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasome has been showed to act a critical t role in the secondly injury phase of SCI. In current study, we aimed to investigate the effect and underlying molecular mechanisms of extracellular vesicles derived from epidural fat (EF)- mesenchymal stem cells (MSCs) for the treatment of SCI. Ninety-six Sprague-Dawley rats were used for current study and randomly divided into four groups: sham group, SCI group, SCI + Saline group, SCI + Extracellular vesicles group. Basso-Beattie-Bresnahan (BBB) scores was applied to evaluate the neurological functional recovery. Cresyl violet-stained was conducted evaluate the protective effect of EF-MSCs-Extracellular vesicles on lesion volume after SCI. ELISA, immunohistochemistry assay, TUNEL assay and western blotting were conducted to investigate the underlying molecular mechanisms. Our results demonstrated that the administration of EF-MSCs-Extracellular vesicles via tail vein injection improved neurological functional recovery and reduced the lesion volume after SCI. And systemic administration of EF-MSCs-Extracellular vesicles significantly inhibited NLRP3 inflammasome activation and reduced the expression of inflammatory cytokines. Additionally, the expression levels of proapoptotic protein Bax was decreased and antiapoptotic Bcl-2 was upregulated with the treatment of EF-MSCs-Extracellular vesicles after SCI. In summary, in current study, we demonstrated for the first time that the EF-MSCs-Extracellular vesicles can improve neurological functional recovery after SCI, and the underlying molecular mechanisms may partly through the inhibition of NLRP3 inflammasome activation.


Assuntos
Vesículas Extracelulares , Inflamassomos/metabolismo , Células-Tronco Mesenquimais/citologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Traumatismos da Medula Espinal/terapia , Tecido Adiposo/citologia , Animais , Apoptose/efeitos dos fármacos , Citocinas/metabolismo , Espaço Epidural/citologia , Humanos , Masculino , Ratos Sprague-Dawley , Recuperação de Função Fisiológica , Medula Espinal/metabolismo , Medula Espinal/patologia , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/patologia
12.
J Am Soc Nephrol ; 30(7): 1174-1191, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31126972

RESUMO

BACKGROUND: Mitochondria are dynamic organelles that undergo fission and fusion. During cell stress, mitochondrial dynamics shift to fission, leading to mitochondrial fragmentation, membrane leakage, and apoptosis. Mitochondrial fragmentation requires the cleavage of both outer and inner membranes, but the mechanism of inner membrane cleavage is unclear. Bif-1 and prohibitin-2 may regulate mitochondrial dynamics. METHODS: We used azide-induced ATP depletion to incite cell stress in mouse embryonic fibroblasts and renal proximal tubular cells, and renal ischemia-reperfusion to induce stress in mice. We also used knockout cells and mice to determine the role of Bif-1, and used multiple techniques to analyze the molecular interaction between Bif-1 and prohibitin-2. RESULTS: Upon cell stress, Bif-1 translocated to mitochondria to bind prohibitin-2, resulting in the disruption of prohibitin complex and proteolytic inactivation of the inner membrane fusion protein OPA1. Bif-1-deficiency inhibited prohibitin complex disruption, OPA1 proteolysis, mitochondrial fragmentation, and apoptosis. Domain deletion analysis indicated that Bif-1 interacted with prohibitin-2 via its C-terminus. Notably, mutation of Bif-1 at its C-terminal tryptophan-344 not only prevented Bif-1/prohibitin-2 interaction but also reduced prohibitin complex disruption, OPA1 proteolysis, mitochondrial fragmentation, and apoptosis, supporting a pathogenic role of Bif-1/prohibitin-2 interaction. In mice, Bif-1 bound prohibitin-2 during renal ischemia/reperfusion injury, and Bif-1-deficiency protected against OPA1 proteolysis, mitochondrial fragmentation, apoptosis and kidney injury. CONCLUSIONS: These findings suggest that during cell stress, Bif-1 regulates mitochondrial inner membrane by interacting with prohibitin-2 to disrupt prohibitin complexes and induce OPA1 proteolysis and inactivation.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Apoptose , Membranas Mitocondriais/fisiologia , Proteínas Repressoras/fisiologia , Animais , Citocromos c/fisiologia , GTP Fosfo-Hidrolases/metabolismo , Células HEK293 , Células HeLa , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proibitinas , Proteólise
13.
Int J Mol Sci ; 20(21)2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31731454

RESUMO

High-mobility group box 1 (HMGB1) is a highly abundant DNA-binding protein that can relocate to the cytosol or undergo extracellular release during cellular stress or death. HMGB1 has a functional versatility depending on its cellular location. While intracellular HMGB1 is important for DNA structure maintenance, gene expression, and autophagy induction, extracellular HMGB1 acts as a damage-associated molecular pattern (DAMP) molecule to alert the host of damage by triggering immune responses. The biological function of HMGB1 is mediated by multiple receptors, including the receptor for advanced glycation end products (RAGE) and Toll-like receptors (TLRs), which are expressed in different hepatic cells. Activation of HMGB1 and downstream signaling pathways are contributing factors in the pathogenesis of non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), and drug-induced liver injury (DILI), each of which involves sterile inflammation, liver fibrosis, ductular reaction, and hepatic tumorigenesis. In this review, we will discuss the critical role of HMGB1 in these pathogenic contexts and propose HMGB1 as a bona fide and targetable DAMP in the setting of common liver diseases.


Assuntos
Proteína HMGB1/metabolismo , Hepatopatias/metabolismo , Fígado/metabolismo , Transdução de Sinais , Animais , Humanos , Fígado/patologia , Hepatopatias/patologia , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Receptores Toll-Like/metabolismo
14.
Int J Mol Sci ; 20(20)2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31614437

RESUMO

Alcohol-related liver disease (ALD) is caused by over-consumption of alcohol. ALD can develop a spectrum of pathological changes in the liver, including steatosis, inflammation, cirrhosis, and complications. Autophagy is critical to maintain liver homeostasis, but dysfunction of autophagy has been observed in ALD. Generally, autophagy is considered to protect the liver from alcohol-induced injury and steatosis. In this review, we will summarize novel modulators of autophagy in hepatic metabolism and ALD, including autophagy-mediating non-coding RNAs (ncRNAs), and crosstalk of autophagy machinery and nuclear factors. We will also discuss novel functions of autophagy in hepatocytes and non-parenchymal hepatic cells during the pathogenesis of ALD and other liver diseases.


Assuntos
Hepatopatias Alcoólicas/metabolismo , Fígado/metabolismo , Animais , Autofagia , Regulação da Expressão Gênica , Humanos , Fígado/patologia , Hepatopatias Alcoólicas/genética , Hepatopatias Alcoólicas/patologia , RNA não Traduzido/genética , Receptores Citoplasmáticos e Nucleares/metabolismo
15.
Semin Liver Dis ; 38(4): 308-319, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30357768

RESUMO

Autophagy actively participates in the physiological process of the liver. While the direct effect of autophagy may be limited to the sequestration and degradation of a selective cargo, its overall impact can be broad, affecting many more physiological processes regulated by the particular cargo. This review will discuss two aspects of the importance of autophagy in the liver: metabolic regulation in response to feeding and starvation, and pathological consequences in the absence of autophagy. These two aspects illustrate the homeostatic functions of autophagy in the liver, one in a more direct fashion, regulating the cellular nutrient supply, and the other in a more indirect fashion, controlling the pathological signaling triggered by the abnormal accumulation of cargos. Remarkably, the hepatic pathology in autophagy-deficient livers does not seem different from that presented in other chronic liver diseases. Autophagy deficiency can be a model for the study of the relevant molecular mechanisms.


Assuntos
Autofagia , Hepatócitos/fisiologia , Homeostase/fisiologia , Hepatopatias/patologia , Alarminas/metabolismo , Animais , Doença Crônica , Humanos , Hepatopatias/metabolismo , Camundongos
16.
J Am Soc Nephrol ; 28(4): 1131-1144, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27799485

RESUMO

Nephrotoxicity is a major adverse effect in cisplatin chemotherapy, and renoprotective approaches are unavailable. Recent work unveiled a critical role of protein kinase Cδ (PKCδ) in cisplatin nephrotoxicity and further demonstrated that inhibition of PKCδ not only protects kidneys but enhances the chemotherapeutic effect of cisplatin in tumors; however, the underlying mechanisms remain elusive. Here, we show that cisplatin induced rapid activation of autophagy in cultured kidney tubular cells and in the kidneys of injected mice. Cisplatin also induced the phosphorylation of mammalian target of rapamycin (mTOR), p70S6 kinase downstream of mTOR, and serine/threonine-protein kinase ULK1, a component of the autophagy initiating complex. In vitro, pharmacologic inhibition of mTOR, directly or through inhibition of AKT, enhanced autophagy after cisplatin treatment. Notably, in both cells and kidneys, blockade of PKCδ suppressed the cisplatin-induced phosphorylation of AKT, mTOR, p70S6 kinase, and ULK1 resulting in upregulation of autophagy. Furthermore, constitutively active and inactive forms of PKCδ respectively enhanced and suppressed cisplatin-induced apoptosis in cultured cells. In mechanistic studies, we showed coimmunoprecipitation of PKCδ and AKT from lysates of cisplatin-treated cells and direct phosphorylation of AKT at serine-473 by PKCδin vitro Finally, administration of the PKCδ inhibitor rottlerin with cisplatin protected against cisplatin nephrotoxicity in wild-type mice, but not in renal autophagy-deficient mice. Together, these results reveal a pathway consisting of PKCδ, AKT, mTOR, and ULK1 that inhibits autophagy in cisplatin nephrotoxicity. PKCδ mediates cisplatin nephrotoxicity at least in part by suppressing autophagy, and accordingly, PKCδ inhibition protects kidneys by upregulating autophagy.


Assuntos
Apoptose , Autofagia/fisiologia , Nefropatias/patologia , Rim/citologia , Proteína Quinase C-delta/fisiologia , Animais , Células Cultivadas , Cisplatino/toxicidade , Nefropatias/induzido quimicamente , Masculino , Camundongos
17.
Amino Acids ; 49(12): 1965-1979, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28478585

RESUMO

Autophagy is an evolutionarily conserved lysosome-mediated cellular degradation program. Accumulating evidence shows that autophagy is important to the maintenance of liver homeostasis. Autophagy involves recycling of cellular nutrients recycling as well as quality control of subcellular organelles. Autophagy deficiency in the liver causes various liver pathologies. Fatty liver disease (FLD) is characterized by the accumulation of lipids in hepatocytes and the dysfunction in energy metabolism. Autophagy is negatively affected by the pathogenesis of FLD and the activation of autophagy could ameliorate steatosis, which suggests a potential therapeutic approach to FLD. In this review, we will discuss autophagy and its relevance to liver diseases, especially FLD. In addition, we will discuss recent findings on potential therapeutic applications of autophagy modulators for FLD.


Assuntos
Autofagossomos/metabolismo , Autofagia/fisiologia , Fígado Gorduroso/fisiopatologia , Fígado Gorduroso/terapia , Lisossomos/metabolismo , Animais , Biomarcadores/análise , Fígado Gorduroso/metabolismo , Humanos , Metabolismo dos Lipídeos/fisiologia , Fígado/citologia , Fígado/metabolismo , Fígado/fisiopatologia , Terapia de Alvo Molecular , Transdução de Sinais
18.
Proc Natl Acad Sci U S A ; 111(46): 16520-5, 2014 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-25368155

RESUMO

Colorectal tumorigenesis is driven by genetic alterations in the adenomatous polyposis coli (APC) tumor suppressor pathway and effectively inhibited by nonsteroidal antiinflammatory drugs (NSAIDs). However, how NSAIDs prevent colorectal tumorigenesis has remained obscure. We found that the extrinsic apoptotic pathway and the BH3 interacting-domain death agonist (BID) are activated in adenomas from NSAID-treated patients. Loss of BID abolishes NSAID-mediated tumor suppression, survival benefit, and apoptosis in tumor-initiating stem cells in APC(Min/+) mice. BID-mediated cross-talk between the extrinsic and intrinsic apoptotic pathways is responsible for selective killing of neoplastic cells by NSAIDs. We further demonstrate that NSAIDs induce death receptor signaling in both cancer and normal cells, but only activate BID in cells with APC deficiency and ensuing c-Myc activation. Our results suggest that NSAIDs suppress intestinal tumorigenesis through BID-mediated synthetic lethality triggered by death receptor signaling and gatekeeper mutations, and provide a rationale for developing more effective cancer prevention strategies and agents.


Assuntos
Polipose Adenomatosa do Colo/prevenção & controle , Anti-Inflamatórios não Esteroides/farmacologia , Apoptose , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/fisiologia , Genes APC , Polipose Adenomatosa do Colo/patologia , Animais , Proteínas Reguladoras de Apoptose/fisiologia , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/antagonistas & inibidores , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/deficiência , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/genética , Caspases/fisiologia , Linhagem Celular Tumoral , Colo/patologia , Regulação Neoplásica da Expressão Gênica , Genes myc , Humanos , Indometacina/farmacologia , Intestino Delgado/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Mitocôndrias/metabolismo , Especificidade de Órgãos , Pirazóis/farmacologia , RNA Interferente Pequeno/farmacologia , Receptores de Morte Celular/fisiologia , Células-Tronco/metabolismo , Células-Tronco/patologia , Sulfonamidas/farmacologia , Sulindaco/farmacologia
19.
J Biol Chem ; 289(16): 11162-11174, 2014 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-24619419

RESUMO

Calcium phosphate precipitates (CPPs) form complexes with DNA, which enter cells via endocytosis. Under this condition CPPs induce autophagy via the canonic autophagy machinery. Here we showed that CPP-induced autophagy was also dependent on endocytosis as the process was significantly inhibited by methyl-ß-cyclodextrin and dynasore, which suppress clathrin-dependent endocytosis. Consistently, CPP treatment triggered the formation of filipin-positive intracellular vesicles whose membranes are rich in cholesterol. Unexpectedly, these vesicles were also positive for galectin 3, suggesting that they were damaged and the membrane glycans became accessible to galectins to bind. Endosome damage was caused by endocytosis of CPPs and was reversed by calcium chelators or by endocytosis inhibitors. Notably, CPP-induced LC3-positive autophagosomes were colocalized with galectin 3, ubiquitin, and p62/SQSTM1. Inhibition of galectin 3 reduced p62 puncta and autophagosome formation. Knockdown of p62 additionally inhibited the colocalization of autophagosomes with galectins. Furthermore, most of the galectin 3-positive vesicles were colocalized with Rab7 or LAMP1. Agents that affect endosome/lysosome maturation and function, such as bafilomycin A1, also significantly affected CPP-induced tubulovesicular autophagosome formation. These findings thus indicate that endocytosed CPPs caused endosome damage and recruitment of galectins, particularly at the later endosome stage, which led to the interaction of the autophagosomal membranes with the damaged endosome in the presence of p62.


Assuntos
Autofagia/efeitos dos fármacos , Fosfatos de Cálcio/farmacologia , Endocitose/efeitos dos fármacos , Endossomos/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Autofagia/genética , Proteínas Sanguíneas , Endocitose/genética , Endossomos/genética , Endossomos/patologia , Galectina 3/genética , Galectina 3/metabolismo , Galectinas , Células HEK293 , Humanos , Proteínas de Membrana Lisossomal/genética , Proteínas de Membrana Lisossomal/metabolismo , Proteína Sequestossoma-1 , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/metabolismo , proteínas de unión al GTP Rab7
20.
Eur J Orthop Surg Traumatol ; 25(3): 425-33, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25476243

RESUMO

OBJECTIVE: To assess the safety and efficacy that compare bipolar hemiarthroplasty with unipolar hemiarthroplasty for the treatment of femoral neck fracture in the patient aged more than 65 years. METHODS: We searched databases including PubMed Central, MEDLINE (from 1966), EMBASE (from 1980) and the Cochrane Central Register of Controlled Trials database. Only prospective randomized controlled trials (RCTs) that compare bipolar hemiarthroplasty with unipolar hemiarthroplasty for the treatment of femoral neck fracture in the elder patient were included. RevMan 5.2 from the Cochrane Collaboration was applied to perform the meta-analysis. RESULTS: Six relevant RCTs with a total of 982 patients were retrieved. From this meta-analysis, mortality rates showed no statistical difference between two treatments, 14.7% for bipolar versus 13.8% for unipolar. The acetabular erosion rates were significantly different between two groups (P=0.01), 1.2% in bipolar versus 5.5% in unipolar group. Overall complication rates, dislocation rates, infection rates and reoperation rates between two groups showed no statistical difference (P>0.05). Neither of two treatments appeared to be superior regarding the clinical function assessed by Harris hip scores or return to pre-injury state rates (P>0.05). CONCLUSIONS: Both bipolar and unipolar hemiarthroplasty for the treatment of elderly patient suffering displaced femoral neck fracture achieve similar and satisfy clinical outcome in short-term follow-up. Unipolar hemiarthroplasty seems to be a more cost-effectiveness option for elderly patient.


Assuntos
Fraturas do Colo Femoral/cirurgia , Hemiartroplastia/métodos , Articulação do Quadril/cirurgia , Idoso , Hemiartroplastia/efeitos adversos , Hemiartroplastia/mortalidade , Humanos , Infecções/etiologia , Luxações Articulares/etiologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Recuperação de Função Fisiológica , Reoperação
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