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1.
J Environ Pathol Toxicol Oncol ; 39(3): 261-279, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32865917

RESUMO

Among the neurodegenerative diseases, Alzheimer's disease (AD) is a predominant public health issue, affecting 16 million people around the world. It is clinically manifested by the presence of amyloid plaques (Aß) and neurofibrillary tangles (NFT) within the brain. Due to intraneuronal processing, Aß interacts with cellular targets such as mitochondria, ER, and Golgi apparatus and hampers their normal functions. Alteration in the mitochondrial function, closely related to the production of reactive oxygen species (ROS), Ca+2 overload, and apoptosis in the brain, is one of the key pathological events studied in AD pathogenesis. It is also an important pivot for the intracellular interaction with ER and Golgi through signal transduction and membrane contact to regulate cell survival and death mechanism. Alteration in mitochondrial function is intimately connected with abnormal ER or Golgi function. Stimuli that enhance perturbation in the normal ER or Golgi organelles function can involve mitochondria mediated apoptotic cell death. In this review, we address the importance of the mitochondria and their cross talk with ER and Golgi in AD pathogenesis and animal models with a therapeutic strategy to improve the mitochondrial functions.


Assuntos
Doença de Alzheimer/metabolismo , Encéfalo/metabolismo , Retículo Endoplasmático/metabolismo , Complexo de Golgi/metabolismo , Mitocôndrias/metabolismo , Doença de Alzheimer/patologia , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Apoptose , Encéfalo/patologia , Retículo Endoplasmático/patologia , Complexo de Golgi/patologia , Humanos , Mitocôndrias/patologia , Transdução de Sinais
2.
PLoS One ; 15(9): e0235960, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32986718

RESUMO

OBJECTIVE: To investigate the effects of AMPK activation on mitochondrial inhibition by uremic serum through the AMPK-activated rat peritoneal macrophages stimulated by uremic serum, thereby providing a reference for the clinical treatment of chronic kidney disease. METHODS: Twenty-two male Sprague-Dawley (SD) rats were included as experimental subjects. Fifteen rats were constructed into chronic kidney disease models (the model group). The remaining seven rats only received renal capsule stripping instead of nephrectomy (the sham-operated group). Ten weeks after model construction, the bodyweight, blood biochemical indicators, and metabolic parameters of rats in groups were measured. Meanwhile, the expression of the M1 phenotype marker protein in peritoneal macrophages was determined. RESULTS: Ten weeks after model construction, the bodyweight of rats in the model group was significantly lower than that in the sham-operated group. The values of urea nitrogen and serum creatinine were significantly higher than those in the sham-operated group (P<0.01). The levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and the monocyte chemoattractant protein 1 (MCP-1) of rats in the model group were significantly higher than those in the sham-operated group (P <0.01). After the lipopolysaccharide (LPS) stimulation, the expressions of M1 phenotype marker mRNA in the model group was significantly increased. The expression of mitochondrial structural protein mRNA in the peritoneal macrophages of rats in the model group was significantly lower than that in the sham-operated group. The expression of M1 phenotype marker mRNA was significantly decreased in the uremic serum group after AMPK agonist (P<0.01). CONCLUSION: In rats with chronic renal insufficiency, mitochondrial regeneration was dysfunctional in macrophages. By activating AMPK, the inhibitory effect of uremia serum on mitochondrial regeneration of macrophages was improved. Therefore, AMPK was a critical factor that could regulate mitochondrial regeneration of macrophages.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Ativação Enzimática , Macrófagos Peritoneais/metabolismo , Mitocôndrias/metabolismo , Uremia/metabolismo , Animais , Macrófagos Peritoneais/patologia , Masculino , Mitocôndrias/patologia , Dinâmica Mitocondrial , RNA Mensageiro/metabolismo , RNA Mitocondrial/metabolismo , Ratos , Ratos Sprague-Dawley , Uremia/sangue , Uremia/patologia
3.
Adv Exp Med Biol ; 1274: 71-99, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32894508

RESUMO

Bioactive lipid mediators resulting from the metabolism of polyunsaturated fatty acids (PUFA) are controlled by many pathways that regulate the levels of these mediators and maintain homeostasis to prevent disease. PUFA metabolism is driven primarily through three pathways. Two pathways, the cyclooxygenase (COX) and lipoxygenase (LO) enzymatic pathways, form metabolites that are mostly inflammatory, while the third route of metabolism results from the oxidation by the cytochrome P450 enzymes to form hydroxylated PUFA and epoxide metabolites. These epoxygenated fatty acids (EpFA) demonstrate largely anti-inflammatory and beneficial properties, in contrast to the other metabolites formed from the degradation of PUFA. Dysregulation of these systems often leads to chronic disease. Pharmaceutical targets of disease focus on preventing the formation of inflammatory metabolites from the COX and LO pathways, while maintaining the EpFA and increasing their concentration in the body is seen as beneficial to treating and preventing disease. The soluble epoxide hydrolase (sEH) is the major route of metabolism of EpFA. Inhibiting its activity increases concentrations of beneficial EpFA, and often disease states correlate to mutations in the sEH enzyme that increase its activity and decrease the concentrations of EpFA in the body. Recent approaches to increasing EpFA include synthetic mimics that replicate biological activity of EpFA while preventing their metabolism, while other approaches focus on developing small molecule inhibitors to the sEH. Increasing EpFA concentrations in the body has demonstrated multiple beneficial effects in treating many diseases, including inflammatory and painful conditions, cardiovascular disease, neurological and disease of the central nervous system. Demonstration of efficacy in so many disease states can be explained by the fundamental mechanism that EpFA have of maintaining healthy microvasculature and preventing mitochondrial and endoplasmic reticulum stress. While there are no FDA approved methods that target the sEH or other enzymes responsible for metabolizing EpFA, current clinical efforts to test for efficacy by increasing EpFA that include inhibiting the sEH or administration of EpFA mimics that block metabolism are in progress.


Assuntos
Doenças Cardiovasculares/tratamento farmacológico , Estresse do Retículo Endoplasmático , Ácidos Graxos/metabolismo , Inflamação/tratamento farmacológico , Mitocôndrias/patologia , Terapia de Alvo Molecular , Manejo da Dor , Doenças Cardiovasculares/metabolismo , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Humanos , Inflamação/patologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Dor
5.
Free Radic Res ; 54(7): 477-496, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32842814

RESUMO

Smokeless tobacco (SLT) or chewing tobacco has been a highly addictive practice in India across ages, posing major threat to the systemic health and possibly neurodegeneration. Earlier studies showed components of SLT could be harmful to neuronal health. However, mechanism of SLT in neurodegeneration remained unexplored. This study investigated the detrimental role of SLT on differentiated neuronal cell lines, PC12 and SH-SY5Y by using graded doses of water soluble lyophilised SLT. Reduced cell viability, compromised mitochondrial structure and functions were observed when neuronal cell lines were treated with SLT (6 mg/mL) for 24 h. There was reduction of oxidative phosphorylation and aerobic glycolysis as determined by diminution of ATP production (2.5X) and basal respiration (1.9X). Mitochondrial membrane potential was dropped by 3.5 times. Bid, a pro-apoptotic Bcl-2 family protein, has imperative role in regulating mitochondrial outer membrane permeabilization and subsequent cytochrome c release leading to apoptosis. This article for the first time indicated the involvement of Bid in SLT mediated neurotoxicity and possibly neurodegeneration. SLT treatment enhanced expression of cleaved-Bid in time dependent manner. The involvement of Bid was further confirmed by using Bid specific shRNA which reversed the effects of SLT and conferred significant protection from apoptosis up to 72 h. Thus, our results clearly indicated that SLT induced neuronal cell death occurred via production of ROS, alteration of mitochondrial morphology, membrane potential and oxidative phosphorylation, inactivation of survival pathway and activation of apoptotic markers mediated by Bid. Therefore, Bid could be a potential future therapeutic target for SLT induced neurodegeneration.


Assuntos
Neurônios/patologia , Tabaco sem Fumaça/toxicidade , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Linhagem Celular Tumoral , Citocromos c/metabolismo , Dano ao DNA , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fosforilação Oxidativa , Células PC12 , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Proteína Supressora de Tumor p53/metabolismo
6.
Inflamm Res ; 69(11): 1077-1085, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32767095

RESUMO

BACKGROUND: Decline in mitochondrial function occurs with aging and may increase mortality. We discuss mitochondrial contribution to Covid-19 sepsis, specifically the complex interaction of innate immune function, viral replication, hyper-inflammatory state, and HIF-α/Sirtuin pathways. METHODS: Articles from PubMed/Medline searches were reviewed using the combination of terms "SARS-CoV-2, Covid-19, sepsis, mitochondria, aging, and immunometabolism". RESULTS: Evidence indicates that mitochondria in senescent cells may be dysfunctional and unable to keep up with hypermetabolic demands associated with Covid-19 sepsis. Mitochondrial proteins may serve as damage-associated molecular pattern (DAMP) activating innate immunity. Disruption in normal oxidative phosphorylation pathways contributes to elevated ROS which activates sepsis cascade through HIF-α/Sirtuin pathway. Viral-mitochondrial interaction may be necessary for replication and increased viral load. Hypoxia and hyper-inflammatory state contribute to increased mortality associated with Covid-19 sepsis. CONCLUSIONS: Aging is associated with worse outcomes in sepsis. Modulating Sirtuin activity is emerging as therapeutic agent in sepsis. HIF-α, levels of mitochondrial DNA, and other mitochondrial DAMP molecules may also serve as useful biomarker and need to be investigated. These mechanisms should be explored specifically for Covid-19-related sepsis. Understanding newly discovered regulatory mechanisms may lead to the development of novel diagnostic and therapeutic targets.


Assuntos
Infecções por Coronavirus/complicações , Infecções por Coronavirus/patologia , Inflamação/etiologia , Inflamação/patologia , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Doenças Mitocondriais/etiologia , Doenças Mitocondriais/patologia , Pneumonia Viral/complicações , Pneumonia Viral/patologia , Sepse/etiologia , Sepse/patologia , Envelhecimento , Infecções por Coronavirus/mortalidade , Humanos , Inflamação/mortalidade , Doenças Mitocondriais/mortalidade , Pandemias , Pneumonia Viral/mortalidade , Sepse/mortalidade
7.
Tumour Biol ; 42(8): 1010428320951057, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32829673

RESUMO

The exchange of metabolites between mitochondria and cytosol occurs through pores formed by voltage-dependent anion channel proteins. Voltage-dependent anion channels appear to be master regulators of mitochondrial bioenergetics and the intracellular flow of energy. Deregulation of voltage-dependent anion channels expression is thought to be related to mitochondrial dysfunction in cancer. The aim of this study was to investigate the mRNA and protein expression levels of VDAC1, VDAC2, and VDAC3 in relation to clinicopathological characteristics of endometrial cancer as well as the prognostic significance of voltage-dependent anion channels expression for overall survival. VDAC1 and VDAC3 expressions were significantly higher in cancer compared to normal tissues. Kaplan-Meier analysis indicated that high expression of all VDAC genes or high VDAC2 protein level predicted poor overall survival. Multivariate analysis identified the VDAC1 and VDAC2 mRNA levels as well as VDAC2 protein level as independent prognostic factors. Our results suggest that increased expression of voltage-dependent anion channels correlates with tumor progression and may serve as a potential prognostic biomarker in endometrial cancer.


Assuntos
Neoplasias do Endométrio/patologia , Mitocôndrias/patologia , Proteínas de Transporte da Membrana Mitocondrial/genética , Canal de Ânion 1 Dependente de Voltagem/genética , Canal de Ânion 2 Dependente de Voltagem/genética , Canais de Ânion Dependentes de Voltagem/genética , Sequência de Aminoácidos , Biomarcadores Tumorais/genética , Citoplasma/metabolismo , Neoplasias do Endométrio/mortalidade , Feminino , Humanos , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/biossíntese , Prognóstico , RNA Mensageiro/genética , Canal de Ânion 1 Dependente de Voltagem/biossíntese , Canal de Ânion 2 Dependente de Voltagem/biossíntese , Canais de Ânion Dependentes de Voltagem/biossíntese
8.
PLoS Biol ; 18(8): e3000808, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32817651

RESUMO

Although dysregulation of mitochondrial dynamics has been linked to cellular senescence, which contributes to advanced age-related disorders, it is unclear how Krüppel-like factor 5 (Klf5), an essential transcriptional factor of cardiovascular remodeling, mediates the link between mitochondrial dynamics and vascular smooth muscle cell (VSMC) senescence. Here, we show that Klf5 down-regulation in VSMCs is correlated with rupture of abdominal aortic aneurysm (AAA), an age-related vascular disease. Mice lacking Klf5 in VSMCs exacerbate vascular senescence and progression of angiotensin II (Ang II)-induced AAA by facilitating reactive oxygen species (ROS) formation. Klf5 knockdown enhances, while Klf5 overexpression suppresses mitochondrial fission. Mechanistically, Klf5 activates eukaryotic translation initiation factor 5a (eIF5a) transcription through binding to the promoter of eIF5a, which in turn preserves mitochondrial integrity by interacting with mitofusin 1 (Mfn1). Accordingly, decreased expression of eIF5a elicited by Klf5 down-regulation leads to mitochondrial fission and excessive ROS production. Inhibition of mitochondrial fission decreases ROS production and VSMC senescence. Our studies provide a potential therapeutic target for age-related vascular disorders.


Assuntos
Aneurisma da Aorta Abdominal/genética , Células Endoteliais/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Mitocôndrias/metabolismo , Fatores de Iniciação de Peptídeos/genética , Proteínas de Ligação a RNA/genética , Idoso , Angiotensina II/genética , Angiotensina II/metabolismo , Angiotensina II/farmacologia , Animais , Aorta/diagnóstico por imagem , Aorta/metabolismo , Aorta/patologia , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/metabolismo , Aneurisma da Aorta Abdominal/patologia , Senescência Celular/efeitos dos fármacos , Ecocardiografia , Células Endoteliais/patologia , Feminino , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Humanos , Fatores de Transcrição Kruppel-Like/deficiência , Masculino , Camundongos , Camundongos Knockout , Mitocôndrias/patologia , Dinâmica Mitocondrial/efeitos dos fármacos , Fatores de Iniciação de Peptídeos/deficiência , Cultura Primária de Células , Regiões Promotoras Genéticas , Ligação Proteica , Espécies Reativas de Oxigênio/metabolismo
9.
Nat Commun ; 11(1): 4269, 2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32859890

RESUMO

Mitochondria generate most cellular energy via oxidative phosphorylation. Twenty-two species of mitochondrial (mt-)tRNAs encoded in mtDNA translate essential subunits of the respiratory chain complexes. mt-tRNAs contain post-transcriptional modifications introduced by nuclear-encoded tRNA-modifying enzymes. They are required for deciphering genetic code accurately, as well as stabilizing tRNA. Loss of tRNA modifications frequently results in severe pathological consequences. Here, we perform a comprehensive analysis of post-transcriptional modifications of all human mt-tRNAs, including 14 previously-uncharacterized species. In total, we find 18 kinds of RNA modifications at 137 positions (8.7% in 1575 nucleobases) in 22 species of human mt-tRNAs. An up-to-date list of 34 genes responsible for mt-tRNA modifications are provided. We identify two genes required for queuosine (Q) formation in mt-tRNAs. Our results provide insight into the molecular mechanisms underlying the decoding system and could help to elucidate the molecular pathogenesis of human mitochondrial diseases caused by aberrant tRNA modifications.


Assuntos
Processamento Pós-Transcricional do RNA , RNA Mitocondrial/química , RNA de Transferência/química , Feminino , Código Genético , Células HEK293 , Células HeLa , Humanos , Espectrometria de Massas , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Doenças Mitocondriais/genética , Doenças Mitocondriais/patologia , Estrutura Molecular , Nucleosídeo Q/biossíntese , Nucleosídeo Q/química , Fosforilação Oxidativa , Placenta , Gravidez , RNA Mitocondrial/isolamento & purificação , RNA Mitocondrial/metabolismo , RNA de Transferência/isolamento & purificação , RNA de Transferência/metabolismo , RNA-Seq
10.
J Toxicol Sci ; 45(8): 423-434, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32741895

RESUMO

Paraquat (PQ) as a non-selective heterocyclic herbicide, has been applied worldwide for over a few decades. But PQ is very harmful to humans and rodents. The lung is the main target organ of PQ poisoning. It is an important event that lung epithelial cells are injured during PQ-induced acute lung injury and pulmonary fibrosis. As a regulator of mRNA expression, microRNA (miRNA) may play an important role in the progress. Our study was to investigate the mechanisms of PQ-induced injury of pulmonary epithelial cells through analyzing the profiling of miRNAs and their target genes. As a result, 11 differentially expressed miRNAs were screened, including 1 upregulated miRNA and 10 downregulated miRNAs in PQ-treated murine lung alveolar epithelial cells (MLE-12 cells). The bioinformatic analyses suggested that the target genes of these miRNAs were involved in mitochondrial apoptosis pathway and DNA methylation, and participated in the regulation of PI3K-Akt, mTOR, RAS, TNF, MAPK and other signal pathways which related to oxidative stress and apoptosis. This indicated that miRNAs were an important regulator of oxidative stress and apoptosis during PQ-induced injury of murine lung alveolar epithelial cells. The findings would deepen our understanding of the mechanisms of PQ-induced pulmonary injury and might provide new treatment targets for this disease.


Assuntos
Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/genética , Apoptose/genética , Células Epiteliais/efeitos dos fármacos , Perfilação da Expressão Gênica , Expressão Gênica , Herbicidas/toxicidade , MicroRNAs/genética , MicroRNAs/metabolismo , Estresse Oxidativo/genética , Paraquat/toxicidade , Alvéolos Pulmonares/citologia , Lesão Pulmonar Aguda/patologia , Animais , Células Cultivadas , Metilação de DNA/genética , Camundongos , MicroRNAs/fisiologia , Mitocôndrias/patologia
11.
Cancer Invest ; 38(7): 375-393, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32673136

RESUMO

mtDNA is the closed circular, ds-DNA present in mitochondria of eukaryotic cells and are inherited maternally. Besides being the power house of the cell, mitochondria are also responsible for the regulation of redox homeostasis, signaling, metabolism, immunity, survival and apoptosis. Lack of a 'Systematic Review' on mtDNA variations and cancers encouraged us to perform the present study. Pubmed', 'Embase' and 'Cochrane Library' databases were searched using keywords 'Mitochondrial DNA' OR 'mtDNA' OR 'mDNA' AND 'polymorphism' AND 'cancer' AND 'risk' to retrieve literature. Polymorphisms occupy first rank among mtDNA variations followed by CNV, MSI, mutations and hold a great potential to emerge as key predictors for human cancers.


Assuntos
DNA Mitocondrial/genética , Neoplasias/genética , Polimorfismo Genético , Feminino , Humanos , Masculino , Mitocôndrias/genética , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Mutação
12.
Life Sci ; 256: 118031, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32615186

RESUMO

AIMS: We had previously reported that addition of putrescine to the culture medium was reported to reduce methylmercury toxicity in C17.2 neural stem cells. Here, we have examined the inhibition of methylmercury-induced cytotoxicity by putrescine using ODC1-overexpressing C17.2 cells. MATERIALS AND METHODS: We established stable ODC1-overexpressing C17.2 cells and evaluated methylmercury-induced apoptosis by examining the TUNEL assay and cleaved caspase-3 levels. Mitochondria-mediated apoptosis was also evaluated by reduction of mitochondrial membrane potential and recruitment of Bax and Bak to the mitochondria. KEY FINDINGS: ODC is encoded by ODC1 gene, and putrescine levels in ODC1-overexpressing cells were significantly higher than in control cells. Overexpression of ODC1 and addition of putrescine to the culture medium suppressed DNA fragmentation and caspase-3 activation, which are observed when apoptosis is induced by methylmercury. Moreover, mitochondrial dysfunction and reactive oxygen species (ROS) generation, caused by methylmercury, were also inhibited by the overexpression of ODC1 and putrescine; pretreatment with ODC inhibitor, however, promoted both ROS generation and apoptosis by methylmercury. Finally, we found that Bax and Bak, the apoptosis-promoting factors, to be increased in mitochondria, following methylmercury treatment, and the same was inhibited by overexpression of ODC1. These results suggest that overexpression of ODC1 may prevent mitochondria-mediated apoptosis by methylmercury via increase of putrescine levels. SIGNIFICANCE: Our findings provide important clues to clarify mechanisms involved in the defense against methylmercury toxicity and suggest novel biological functions of putrescine.


Assuntos
Compostos de Metilmercúrio/toxicidade , Mitocôndrias/efeitos dos fármacos , Células-Tronco Neurais/efeitos dos fármacos , Ornitina Descarboxilase/genética , Putrescina/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Marcação In Situ das Extremidades Cortadas , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Mitocôndrias/patologia , Células-Tronco Neurais/patologia
13.
Adv Exp Med Biol ; 1207: 111-134, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32671742

RESUMO

Ischemic stroke refers to brain tissue ischemia, hypoxic necrosis, and brain softening caused by the interruption of the blood supply to the brain without adequate collateral circulation, thus resulting in neurological symptoms. Autophagy is activated in various cell types in the brain, such as neurons, glial cells, and microvascular cells, upon ischemic stroke. Autophagy efflux injury plays an important role in this pathologic process. This chapter outlines the induction of basal autophagy, autophagy in neurons, and the crosstalk between autophagy, necrosis, and apoptosis that contributes to ischemic stroke. We will highlight the interactions between autophagy, oxidative stress, endoplasmic reticulum stress, and mitochondrial dysfunction, and the role of autophagy in ischemic stroke. We will also review the recent advances in the understanding of the involvement of autophagy in the pathological process of cerebral ischemic preconditioning, periconditioning, and postconditioning.


Assuntos
Autofagia , Isquemia Encefálica , Acidente Vascular Cerebral , Estresse do Retículo Endoplasmático , Humanos , Precondicionamento Isquêmico , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Estresse Oxidativo
14.
Adv Exp Med Biol ; 1207: 401-403, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32671762

RESUMO

As a result of its multifunction both in innate and adaptive immune systems, autophagy has been demonstrated to take part in the pathogenesis of several immune-related diseases. The study on the pathological mechanism of autophagy in these diseases may provide an experimental and theoretical basis for targeted intervention of autophagy in the prevention and treatment of immune diseases. To date, it has been reported that autophagy can eliminate impaired mitochondrial to inhibit the activation of NLRP3 inflammasome which promotes the progression of atherosclerosis. Moreover, enhanced autophagy can effectively prevent the occurrence of GVHD. It also plays a key role in the development of viral hepatitis. Therefore, autophagy might be a promising regulatory target for the treatment of immune-related diseases.


Assuntos
Autofagia , Doenças do Sistema Imunitário , Humanos , Doenças do Sistema Imunitário/imunologia , Doenças do Sistema Imunitário/patologia , Inflamassomos , Mitocôndrias/patologia , Proteína 3 que Contém Domínio de Pirina da Família NLR
15.
Life Sci ; 257: 118084, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32663572

RESUMO

Since an outbreak of vaping-related deaths in the US has been reported as a public health crisis, the cardiovascular safety of nicotine nowadays receives increasing attention due to use of tobacco cigarette alternatives, such as electronic cigarettes. However, whether and how nicotine contributes to cardiac detrimental effects are in great controversy, especially less understood in young adult population. We report that chronic nicotine exposure, a major component of Electronic cigarettes, resulted in directly inhibited cardiomyocytes viability, increased cardiac fibrosis, and markedly suppressed cardiac function compared with sham. Gene array combined with bioinformatics analysis identified cardiac apoptosis and mitophagy were the key signals responsible for nicotine induced cardiac detrimental effect. Mechanistically, nicotine exposure markedly increased cleaved Caspase 3 and cleaved Caspase 9 indicating the involvement of intrinsic apoptotic pathway (mitochondrial cell death pathway). Meanwhile, nicotine-induced ROS outbreak promoted lysomal alkalization, furthermore blocked mitophagic degradation, thereby disrupted mitophagic flux promoted mitochondrial cell death cascade. Taken together, these findings indicate that nicotine confers cardiotoxicity via ROS-induced mitophagic flux blockage and provide the first demonstration of a causative link between nicotine and cardiac toxicity in young adult rat which may suggest nicotine induces cardiomyocytes impairment leading to cardiotoxicity in young adult population.


Assuntos
Apoptose/efeitos dos fármacos , Cardiotoxicidade/etiologia , Mitofagia/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Nicotina/toxicidade , Animais , Cardiotoxicidade/fisiopatologia , Sistemas Eletrônicos de Liberação de Nicotina , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Miócitos Cardíacos/patologia , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Vaping/efeitos adversos
16.
Mol Cell ; 79(1): 68-83.e7, 2020 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-32533918

RESUMO

BAX is a pro-apoptotic protein that transforms from a cytosolic monomer into a toxic oligomer that permeabilizes the mitochondrial outer membrane. How BAX monomers assemble into a higher-order conformation, and the structural determinants essential to membrane permeabilization, remain a mechanistic mystery. A key hurdle has been the inability to generate a homogeneous BAX oligomer (BAXO) for analysis. Here, we report the production and characterization of a full-length BAXO that recapitulates physiologic BAX activation. Multidisciplinary studies revealed striking conformational consequences of oligomerization and insight into the macromolecular structure of oligomeric BAX. Importantly, BAXO enabled the assignment of specific roles to particular residues and α helices that mediate individual steps of the BAX activation pathway, including unexpected functionalities of BAX α6 and α9 in driving membrane disruption. Our results provide the first glimpse of a full-length and functional BAXO, revealing structural requirements for the elusive execution phase of mitochondrial apoptosis.


Assuntos
Apoptose , Mitocôndrias/patologia , Membranas Mitocondriais/metabolismo , Multimerização Proteica , Proteína X Associada a bcl-2/química , Proteína X Associada a bcl-2/metabolismo , Animais , Transporte Biológico , Permeabilidade da Membrana Celular , Citosol/metabolismo , Humanos , Camundongos , Mitocôndrias/metabolismo , Modelos Moleculares , Conformação Proteica , Proteínas Proto-Oncogênicas c-fos
17.
Arterioscler Thromb Vasc Biol ; 40(7): e214-e226, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32493171

RESUMO

OBJECTIVE: Mitochondria consistently change their morphology in a process regulated by proteins, including Drp1 (dynamin-related protein 1), a protein promoting mitochondrial fission. Drp1 is involved in the mechanisms underlying various cardiovascular diseases, such as myocardial ischemia/reperfusion injury, heart failure, and pulmonary arterial hypertension. However, its role in macrophages, which promote various vascular diseases, is poorly understood. We therefore tested our hypothesis that macrophage Drp1 promotes vascular remodeling after injury. METHOD AND RESULTS: To explore the selective role of macrophage Drp1, we created macrophage-selective Drp1-deficient mice and performed femoral arterial wire injury. In these mice, intimal thickening and negative remodeling were attenuated at 4 weeks after injury when compared with control mice. Deletion of macrophage Drp1 also attenuated the macrophage accumulation and cell proliferation in the injured arteries. Gain- and loss-of-function experiments using cultured macrophages indicated that Drp1 induces the expression of molecules associated with inflammatory macrophages. Morphologically, mitochondrial fission was induced in inflammatory macrophages, whereas mitochondrial fusion was induced in less inflammatory/reparative macrophages. Pharmacological inhibition or knockdown of Drp1 decreased the mitochondrial reactive oxygen species and chemotactic activity in cultured macrophages. Co-culture experiments of macrophages with vascular smooth muscle cells indicated that deletion of macrophage Drp1 suppresses growth and migration of vascular smooth muscle cells induced by macrophage-derived soluble factors. CONCLUSIONS: Macrophage Drp1 accelerates intimal thickening after vascular injury by promoting macrophage-mediated inflammation. Macrophage Drp1 may be a potential therapeutic target of vascular diseases.


Assuntos
Dinaminas/metabolismo , Artéria Femoral/metabolismo , Macrófagos Peritoneais/metabolismo , Mitocôndrias/metabolismo , Neointima , Remodelação Vascular , Lesões do Sistema Vascular/metabolismo , Animais , Proliferação de Células , Quimiotaxia , Técnicas de Cocultura , Modelos Animais de Doenças , Dinaminas/deficiência , Dinaminas/genética , Artéria Femoral/lesões , Artéria Femoral/patologia , Artéria Femoral/fisiopatologia , Ativação de Macrófagos , Macrófagos Peritoneais/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/patologia , Dinâmica Mitocondrial , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Músculo Liso Vascular/fisiopatologia , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/patologia , Células RAW 264.7 , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Fatores de Tempo , Lesões do Sistema Vascular/genética , Lesões do Sistema Vascular/patologia , Lesões do Sistema Vascular/fisiopatologia
18.
Clin Sci (Lond) ; 134(12): 1319-1331, 2020 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-32542395

RESUMO

Aldosterone, as a major product of renin-angiotensin-aldosterone system (RAAS), determines multiple pathophysiological processes in cardiovascular diseases. The excess inflammatory response is one of the key profiles in aldosterone-mediated cardiac remodeling. However, the potential mechanisms of aldosterone/inflammatory signaling were still not fully disclosed. The present study aimed to investigate whether TIR-domain-containing adapter-inducing interferon-ß (Trif) participated in the aldosterone-induced cardiac remodeling, and to explore potential molecular mechanisms. Trif knockout mice and their littermates were osmotically administrated with aldosterone (50 µg/kg per day) for 21 and 42 days. The cardiac structural analysis, functional parameters, and mitochondrial function were measured. Aldosterone dose- or time-dependently increased the levels of TRIF in primary mouse cardiomyocytes or mouse heart tissues. Trif deficiency protected against aldosterone-induced cardiac hypertrophy, fibrosis and dysfunction. Moreover, Trif deficiency also suppressed aldosterone-induced cardiac inflammatory response and mitochondrial injuries. Mechanistically, overexpression of cardiac microRNAs (miR)-34a reversed the cardiac benefits of Trif deficiency in aldosterone-treated mice. Taken together, Trif/miR-34a axis could provide a novel molecular mechanism for explaining aldosterone-induced cardiac hypertrophy, fibrosis and functional disorders.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Coração/fisiopatologia , Inflamação/induzido quimicamente , Inflamação/patologia , MicroRNAs/metabolismo , Remodelação Ventricular , Aldosterona , Animais , Animais Recém-Nascidos , Cardiomegalia/fisiopatologia , Fibrose , Coração/diagnóstico por imagem , Masculino , Camundongos Knockout , Mitocôndrias/patologia
19.
PLoS Pathog ; 16(6): e1008611, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32511263

RESUMO

Human infection with avian influenza A (H5N1) and (H7N9) viruses causes severe respiratory diseases. PB1-F2 protein is a critical virulence factor that suppresses early type I interferon response, but the mechanism of its action in relation to high pathogenicity is not well understood. Here we show that PB1-F2 protein of H7N9 virus is a particularly potent suppressor of antiviral signaling through formation of protein aggregates on mitochondria and inhibition of TRIM31-MAVS interaction, leading to prevention of K63-polyubiquitination and aggregation of MAVS. Unaggregated MAVS accumulated on fragmented mitochondria is prone to degradation by both proteasomal and lysosomal pathways. These properties are proprietary to PB1-F2 of H7N9 virus but not shared by its counterpart in WSN virus. A recombinant virus deficient of PB1-F2 of H7N9 induces more interferon ß in infected cells. Our findings reveal a subtype-specific mechanism for destabilization of MAVS and suppression of interferon response by PB1-F2 of H7N9 virus.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Subtipo H7N9 do Vírus da Influenza A/metabolismo , Influenza Humana/metabolismo , Agregação Patológica de Proteínas/metabolismo , Transdução de Sinais , Proteínas Virais/metabolismo , Células A549 , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Cães , Células HEK293 , Humanos , Subtipo H7N9 do Vírus da Influenza A/genética , Influenza Humana/genética , Influenza Humana/patologia , Interferon beta/genética , Interferon beta/metabolismo , Células Madin Darby de Rim Canino , Mitocôndrias/genética , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Agregação Patológica de Proteínas/genética , Células THP-1 , Proteínas com Motivo Tripartido/genética , Proteínas com Motivo Tripartido/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Virais/genética
20.
DNA Cell Biol ; 39(8): 1458-1466, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32513025

RESUMO

Polycystic ovary syndrome (PCOS) is a multifactorial disorder characterized by irregular menstrual problems, hyperandrogenism, and presence of polycystic ovaries. Till date, molecular mechanism underlying PCOS remains elusive. Recently mitochondrial displacement loop (D-loop) variants have been identified to be novel players in the pathogenesis of PCOS. At present, rare variants, besides common variants, are also the focus of research as it is believed to make essential contribution to the risk of complex diseases. However, rare and low hetroplasmic variants in mitochondrial D-loop are still not investigated in PCOS women. Furthermore, variants in light-strand origin of DNA replication (OriL) of mitochondrial DNA (mtDNA) have not been explored in PCOS. Hence, in this study, we investigated rare to common mitochondrial D-loop and OriL region variants obtained using mtDNA next-generation sequencing in women with PCOS. Furthermore, we also assessed mtDNA copy number, a biomarker of mitochondrial dysfunction (MD) in women with PCOS, as the variants in mtDNA are known to be associated with low mtDNA copy number in PCOS women. A total of 67 D-loop variants including 6 novel variants were identified in 30 PCOS women. Among 67 variants, 29 variants were reported in PCOS women. A single variant, 5746A was found in OriL region in two PCOS women. Both transition and transversion variants were found but transition variants occur at very high frequency compared with transversions (82.35% vs. 17.64%, respectively). As transition variants in mtDNA are known to arise because of polymerase γ errors, occurrence of high transition rates indicates that most mutation arises because of defect in replication errors that causes mtDNA damage leading to MD. Furthermore, mtDNA copy number was found to be low in women with PCOS compared with healthy control women suggesting that MD may be the contributing factor in the pathogenesis of PCOS.


Assuntos
Variações do Número de Cópias de DNA/genética , DNA Mitocondrial/genética , Mitocôndrias/genética , Síndrome do Ovário Policístico/genética , Adolescente , Adulto , Replicação do DNA/genética , DNA Mitocondrial/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Humanos , Hormônio Luteinizante/sangue , Mitocôndrias/patologia , Síndrome do Ovário Policístico/sangue , Síndrome do Ovário Policístico/patologia , Testosterona/sangue , Tireotropina/sangue , Adulto Jovem
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