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1.
Science ; 368(6498): 1495-1499, 2020 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-32587022

RESUMO

Although sled dogs are one of the most specialized groups of dogs, their origin and evolution has received much less attention than many other dog groups. We applied a genomic approach to investigate their spatiotemporal emergence by sequencing the genomes of 10 modern Greenland sled dogs, an ~9500-year-old Siberian dog associated with archaeological evidence for sled technology, and an ~33,000-year-old Siberian wolf. We found noteworthy genetic similarity between the ancient dog and modern sled dogs. We detected gene flow from Pleistocene Siberian wolves, but not modern American wolves, to present-day sled dogs. The results indicate that the major ancestry of modern sled dogs traces back to Siberia, where sled dog-specific haplotypes of genes that potentially relate to Arctic adaptation were established by 9500 years ago.


Assuntos
Adaptação Fisiológica/genética , Cães/genética , Animais , Apolipoproteínas/genética , Regiões Árticas , Ácidos Graxos/metabolismo , Genoma , Groenlândia , Haplótipos , Proteínas de Transporte da Membrana Mitocondrial/genética , Seleção Artificial , Análise de Sequência de DNA , Sibéria , Triglicerídeos/metabolismo , Lobos/genética
2.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(2): 377-384, 2020 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-32319366

RESUMO

OBJECTIVE: To investigate the clinical and prognostic value of SLC25A12 in patients with acute myeloid leukemia (AML). METHODS: The expression levels of SLC25A12 in bone marrow or peripheral blood cells of AML patients and healthy people in two independent cohorts (n=46, n=290, respectively) were compared. Then it was assessed that the prognostic value of SLC25A12 expression in two independent AML study cohorts (n=163, n=329, respectively) by mean of integrated analysis of genomic, transcriptome, clinical and prognosis information. RESULTS: The expression of SLC25A12 in AML patients significantly increased as compared with that of healthy people (P=0.0001, P=0.0238, respectively). Univariate and multivariate analyze showed that high SLC25A12 expression was significantly associated with shorter event-free survival (EFS)(HR=1.605, P=0.018) and overall survival (OS)(HR=1.818, P=0.002) of patients. In favorable-risk and intermediate-risk subgroups, patients with high SLC25A12 expression showed shorter EFS and OS than patients with low SLC25A12 expression. CONCLUSION: High SLC25A12 expression significantly associated with poor prognosis of AML patients, which suggests that SLC25A12 aberrant expression can be used as a potential molecular marker for prognosis evaluation of AML patients.


Assuntos
Leucemia Mieloide Aguda , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Medula Óssea , Intervalo Livre de Doença , Humanos , Prognóstico , Transcriptoma
3.
Nature ; 580(7804): 542-547, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32322059

RESUMO

Prolonged mitosis often results in apoptosis1. Shortened mitosis causes tumorigenic aneuploidy, but it is unclear whether it also activates the apoptotic machinery2. Separase, a cysteine protease and trigger of all eukaryotic anaphases, has a caspase-like catalytic domain but has not previously been associated with cell death3,4. Here we show that human cells that enter mitosis with already active separase rapidly undergo death in mitosis owing to direct cleavage of anti-apoptotic MCL1 and BCL-XL by separase. Cleavage not only prevents MCL1 and BCL-XL from sequestering pro-apoptotic BAK, but also converts them into active promoters of death in mitosis. Our data strongly suggest that the deadliest cleavage fragment, the C-terminal half of MCL1, forms BAK/BAX-like pores in the mitochondrial outer membrane. MCL1 and BCL-XL are turned into separase substrates only upon phosphorylation by NEK2A. Early mitotic degradation of this kinase is therefore crucial for preventing apoptosis upon scheduled activation of separase in metaphase. Speeding up mitosis by abrogation of the spindle assembly checkpoint results in a temporal overlap of the enzymatic activities of NEK2A and separase and consequently in cell death. We propose that NEK2A and separase jointly check on spindle assembly checkpoint integrity and eliminate cells that are prone to chromosome missegregation owing to accelerated progression through early mitosis.


Assuntos
Apoptose , Mitose , Separase/metabolismo , Animais , Linhagem Celular , Sobrevivência Celular , Segregação de Cromossomos , Humanos , Pontos de Checagem da Fase M do Ciclo Celular , Camundongos , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Proteína de Sequência 1 de Leucemia de Células Mieloides/química , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Quinases Relacionadas a NIMA/metabolismo , Fosforilação , Especificidade por Substrato , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteína bcl-X/metabolismo
4.
BMC Med Genet ; 21(1): 77, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32293312

RESUMO

BACKGROUND: Myopathy with extrapyramidal signs (MPXPS) is an autosomal recessive mitochondrial disorder which is caused by mutation in mitochondrial calcium uptake 1 (MICU1) gene located on chromosome 10q22.1. Next Generation Sequencing (NGS) technology is the most effective method for identification of pathogenic variants with the ability to overcome some limitations which Sanger sequencing may encountered. There are few reports on this rare disease around the world and here in this study we first revealed genetic identification of two affected individuals in an Iranian family with a novel mutation. CASE PRESENTATION: The proband was a 5-year-old girl from consanguenous parents. She was first clinically suspicious of affected with limb-girdle muscular dystrophy (LGMD). Muscle biopsy studies and autozygosity mapping, using four short tandem repeat (STR) markers linked to 6 genes of the most prevalent forms of LGMD, ruled out calpainopathy, dysferlinopathy, and sarcoglycanopathis. DNA sample of the proband was sent for NGS. Whole exome sequencing (WES) revealed a novel mutation c.1295delA in exon 13 of MICU1 gene. This homozygous deletion creates a frameshift and a premature stop codon downstream of canonical EF4 calcium binding motif of MICU1. According to the American College of Medical Genetics and Genomics (ACMG) guidline for sequence interpretation, this variant was a pathogenic one. Sanger sequencing in all family members confirmed the results of the WES. CONCLUSIONS: This study was the first report of MPXPS in Iranian population which also revealed a novel mutation in the MICU1 gene.


Assuntos
Proteínas de Ligação ao Cálcio/genética , Proteínas de Transporte de Cátions/genética , Repetições de Microssatélites/genética , Proteínas de Transporte da Membrana Mitocondrial/genética , Doenças Musculares/genética , Distrofia Muscular do Cíngulo dos Membros/genética , Pré-Escolar , Exoma/genética , Éxons/genética , Tratos Extrapiramidais/metabolismo , Tratos Extrapiramidais/patologia , Feminino , Mutação da Fase de Leitura/genética , Sequenciamento de Nucleotídeos em Larga Escala , Homozigoto , Humanos , Irã (Geográfico)/epidemiologia , Doenças Musculares/patologia , Distrofia Muscular do Cíngulo dos Membros/patologia , Linhagem , Deleção de Sequência/genética , Sequenciamento Completo do Exoma
5.
Med Sci Monit ; 26: e918216, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32129321

RESUMO

BACKGROUND Chemoresistance is a primary hindrance for current cancer treatments. The influence of abnormal mitochondria in chemotherapy resistance is not well known. To explore the correlation between mitochondria and acquired chemoresistance, this work studied alterations in mitochondrial dynamics, biogenesis, and functions for paclitaxel-resistant cancer cell line A549/Taxol and its parental line A549. MATERIAL AND METHODS Mitochondrial morphology was observed by transmission electron microscopy and confocal microscopy. We measured the mitochondrial mass and mitochondrial membrane potential using fluorescent dyes. The glucose metabolic profile and ATP (adenosine triphosphate) content were determined by bioluminescent cell assays. Seahorse bio-energy analyzer XF24 was used to detect the mitochondrial respiratory function. The expressions of mitochondrial dynamics and biogenesis related genes were quantified using real-time polymerase chain reaction. RESULTS We observed fusion morphology of the mitochondrial network in A549/Taxol cells, with upregulation of fusion genes (Mfn1 and Mfn2) and downregulation of fission gene Fis1. In A549/Taxol cells, mitochondrial mass showed a significant decrease, while the mitochondrial biogenesis pathway was strongly activated. Despite the decreased mitochondrial membrane potential, the capability for mitochondrial respiration was not impaired in A549/Taxol cells. CONCLUSIONS Our study revealed a series changes of mitochondrial characteristics in paclitaxel-resistant cells. Mfn1 and Mfn2 and PGC-1alpha increased, while Fis1 expression and mitochondrial oxidative phosphorylation decreased in A549/Taxol cell lines. These changes to mitochondrial fusion, fission, and biological function contributed to the occurrence of paclitaxel resistance in tumor cells which induced paclitaxel resistance.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Dinâmica Mitocondrial , Biogênese de Organelas , Paclitaxel/farmacologia , Células A549 , GTP Fosfo-Hidrolases/metabolismo , Humanos , Potencial da Membrana Mitocondrial , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Mitocôndrias/ultraestrutura , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Proteínas Mitocondriais/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo
6.
Cell Physiol Biochem ; 54(2): 211-229, 2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-32100973

RESUMO

BACKGROUND/AIMS: Mitochondrial ATP synthase, in addition to being involved in ATP synthesis, is involved in permeability transition pore (PTP) formation, which precedes apoptosis in mammalian cells and programmed cell death in yeast. Mutations in genes encoding ATP synthase subunits cause neuromuscular disorders and have been identified in cancer samples. PTP is also involved in pathology. We previously found that in Saccharomyces cerevisiae, two mutations in ATP synthase subunit a (atp6-P163S and atp6-K90E, equivalent to those detected in prostate and thyroid cancer samples, respectively) in the OM45-GFP background affected ROS and calcium homeostasis and delayed yeast PTP (yPTP) induction upon calcium treatment by modulating the dynamics of ATP synthase dimer/oligomer formation. The Om45 protein is a component of the porin complex, which is equivalent to mammalian VDAC. We aimed to investigate yPTP function in atp6-P163S and atp6-K90E mutants lacking the e and g dimerization subunits of ATP synthase. METHODS: Triple mutants with the atp6-P163S or atp6-K90E mutation, the OM45-GFP gene and deletion of the TIM11 gene encoding subunit e were constructed by crossing and tetrad dissection. In spores capable of growing, the original atp6 mutations reverted to wild type, and two compensatory mutations, namely, atp6-C33S-T215C, were selected. The effects of these mutations on cellular physiology, mitochondrial morphology, bioenergetics and permeability transition (PT) were analyzed by fluorescence and electron microscopy, mitochondrial respiration, ATP synthase activity, calcium retention capacity and swelling assays. RESULTS: The atp6-C33S-T215C mutations in the OM45-GFP background led to delayed growth at elevated temperature on both fermentative and respiratory media and increased sensitivity to high calcium ions concentration or hydrogen peroxide in the medium. The ATP synthase activity was reduced by approximately 50% and mitochondrial network was hyperfused in these cells grown at elevated temperature. The atp6-C33S-T215C stabilized ATP synthase dimers and restored the yPTP properties in Tim11∆ cells. In OM45-GFP cells, in which Tim11 is present, these mutations increased the fraction of swollen mitochondria by up to 85% vs 60% in the wild type, although the time required for calcium release doubled. CONCLUSION: ATP synthase subunit e is essential in the S. cerevisiae atp6-P163S and atp6-K90E mutants. In addition to subunits e and g, subunit a is critical for yPTP induction and conduction. The increased yPTP conduction decrease the S. cerevisiae cell fitness.


Assuntos
Proteínas de Transporte da Membrana Mitocondrial/metabolismo , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Cálcio/metabolismo , Cobre/farmacologia , DNA Mitocondrial/metabolismo , Dimerização , Peróxido de Hidrogênio/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/efeitos dos fármacos , ATPases Mitocondriais Próton-Translocadoras/química , ATPases Mitocondriais Próton-Translocadoras/genética , Mutagênese , Estrutura Quaternária de Proteína , Subunidades Proteicas/química , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/crescimento & desenvolvimento , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Temperatura
7.
Clin Sci (Lond) ; 134(2): 239-259, 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-31943002

RESUMO

Mitochondrial stress has been widely observed in diabetic kidney disease (DKD). Cyclophilin D (CypD) is a functional component of the mitochondrial permeability transition pore (mPTP) which allows the exchange of ions and solutes between the mitochondrial matrix to induce mitochondrial swelling and activation of cell death pathways. CypD has been successfully targeted in other disease contexts to improve mitochondrial function and reduced pathology. Two approaches were used to elucidate the role of CypD and the mPTP in DKD. Firstly, mice with a deletion of the gene encoding CypD (Ppif-/-) were rendered diabetic with streptozotocin (STZ) and followed for 24 weeks. Secondly, Alisporivir, a CypD inhibitor was administered to the db/db mouse model (5 mg/kg/day oral gavage for 16 weeks). Ppif-/- mice were not protected against diabetes-induced albuminuria and had greater glomerulosclerosis than their WT diabetic littermates. Renal hyperfiltration was lower in diabetic Ppif-/- as compared with WT mice. Similarly, Alisporivir did not improve renal function nor pathology in db/db mice as assessed by no change in albuminuria, KIM-1 excretion and glomerulosclerosis. Db/db mice exhibited changes in mitochondrial function, including elevated respiratory control ratio (RCR), reduced mitochondrial H2O2 generation and increased proximal tubular mitochondrial volume, but these were unaffected by Alisporivir treatment. Taken together, these studies indicate that CypD has a complex role in DKD and direct targeting of this component of the mPTP will likely not improve renal outcomes.


Assuntos
Ciclofilina D/metabolismo , Diabetes Mellitus Experimental/metabolismo , Nefropatias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Albuminúria/genética , Albuminúria/metabolismo , Animais , Ciclofilina D/antagonistas & inibidores , Ciclofilina D/genética , Ciclosporina/farmacologia , Diabetes Mellitus Experimental/genética , Nefropatias Diabéticas/genética , Nefropatias Diabéticas/metabolismo , Peróxido de Hidrogênio/metabolismo , Rim/efeitos dos fármacos , Rim/metabolismo , Rim/patologia , Nefropatias/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/genética , ATPases Translocadoras de Prótons/metabolismo
8.
Arch Biochem Biophys ; 681: 108258, 2020 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-31917961

RESUMO

Phenylglyoxal (PGO), known to cause post-translational modifications of Arg residues, was used to highlight the role of arginine residues of the F1FO-ATPase, which may be crucial to yield the mitochondrial permeability transition pore (mPTP). In swine heart mitochondria PGO inhibits ATP hydrolysis by the F1FO-ATPase either sustained by the natural cofactor Mg2+ or by Ca2+ by a similar uncompetitive inhibition mechanism, namely the tertiary complex (ESI) only forms when the ATP substrate is already bound to the enzyme, and with similar strength, as shown by the similar K'i values (0.82 ± 0.07 mM in presence of Mg2+ and 0.64 ± 0.05 mM in the presence of Ca2+). Multiple inhibitor analysis indicates that features of the F1 catalytic sites and/or the FO proton binding sites are apparently unaffected by PGO. However, PGO and F1 or FO inhibitors can bind the enzyme combine simultaneously. However they mutually hinder to bind the Mg2+-activated F1FO-ATPase, whereas they do not mutually exclude to bind the Ca2+-activated F1FO-ATPase. The putative formation of PGO-arginine adducts, and the consequent spatial rearrangement in the enzyme structure, inhibits the F1FO-ATPase activity but, as shown by the calcium retention capacity evaluation in intact mitochondria, apparently favours the mPTP formation.


Assuntos
Glioxilatos/metabolismo , Ácidos Mandélicos/metabolismo , Mitocôndrias Cardíacas/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , ATPases Translocadoras de Prótons/metabolismo , Animais , Cálcio/metabolismo , Magnésio/metabolismo , Suínos
9.
Nat Commun ; 11(1): 433, 2020 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-31974380

RESUMO

Ferroptosis is a newly defined form of regulated cell death characterized by the iron-dependent accumulation of lipid hydroperoxides. Erastin, the ferroptosis activator, binds to voltage-dependent anion channels VDAC2 and VDCA3, but treatment with erastin can result in the degradation of the channels. Here, the authors show that Nedd4 is induced following erastin treatment, which leads to the ubiquitination and subsequent degradation of the channels. Depletion of Nedd4 limits the protein degradation of VDAC2/3, which increases the sensitivity of cancer cells to erastin. By understanding the molecular mechanism of erastin-induced cellular resistance, we can discover how cells adapt to new molecules to maintain homeostasis. Furthermore, erastin-induced resistance mediated by FOXM1-Nedd4-VDAC2/3 negative feedback loop provides an initial framework for creating avenues to overcome the drug resistance of ferroptosis activators.


Assuntos
Antineoplásicos/farmacologia , Melanoma/tratamento farmacológico , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Ubiquitina-Proteína Ligases Nedd4/metabolismo , Piperazinas/farmacologia , Canal de Ânion 2 Dependente de Voltagem/metabolismo , Canais de Ânion Dependentes de Voltagem/metabolismo , Animais , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/fisiologia , Feminino , Ferroptose/efeitos dos fármacos , Ferroptose/fisiologia , Proteína Forkhead Box M1/metabolismo , Humanos , Melanoma/metabolismo , Melanoma/patologia , Camundongos Nus , Proteínas de Transporte da Membrana Mitocondrial/genética , Ubiquitina-Proteína Ligases Nedd4/genética , Ubiquitinação/efeitos dos fármacos , Canal de Ânion 2 Dependente de Voltagem/genética , Canais de Ânion Dependentes de Voltagem/genética , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Circ Res ; 126(2): 280-293, 2020 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-31944918

RESUMO

Adult cardiomyocytes are postmitotic cells that undergo very limited cell division. Thus, cardiomyocyte death as occurs during myocardial infarction has very detrimental consequences for the heart. Mitochondria have emerged as an important regulator of cardiovascular health and disease. Mitochondria are well established as bioenergetic hubs for generating ATP but have also been shown to regulate cell death pathways. Indeed many of the same signals used to regulate metabolism and ATP production, such as calcium and reactive oxygen species, are also key regulators of mitochondrial cell death pathways. It is widely hypothesized that an increase in calcium and reactive oxygen species activate a large conductance channel in the inner mitochondrial membrane known as the PTP (permeability transition pore) and that opening of this pore leads to necroptosis, a regulated form of necrotic cell death. Strategies to reduce PTP opening either by inhibition of PTP or inhibiting the rise in mitochondrial calcium or reactive oxygen species that activate PTP have been proposed. A major limitation of inhibiting the PTP is the lack of knowledge about the identity of the protein(s) that form the PTP and how they are activated by calcium and reactive oxygen species. This review will critically evaluate the candidates for the pore-forming unit of the PTP and discuss recent data suggesting that assumption that the PTP is formed by a single molecular identity may need to be reconsidered.


Assuntos
Cálcio/metabolismo , Morte Celular , Mitocôndrias Cardíacas/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Animais , Humanos , Espécies Reativas de Oxigênio/metabolismo
12.
Proc Natl Acad Sci U S A ; 117(5): 2519-2525, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-31964807

RESUMO

The highly conserved COP9 signalosome (CSN), composed of 8 subunits (Cops1 to Cops8), has been implicated in pluripotency maintenance of human embryonic stem cells (ESCs). Yet, the mechanism for the CSN to regulate pluripotency remains elusive. We previously showed that Cops2, independent of the CSN, is essential for the pluripotency maintenance of mouse ESCs. In this study, we set out to investigate how Cops5 and Cops8 regulate ESC differentiation and tried to establish Cops5 and Cops8 knockout (KO) ESC lines by CRISPR/Cas9. To our surprise, no Cops5 KO ESC clones were identified out of 127 clones, while three Cops8 KO ESC lines were established out of 70 clones. We then constructed an inducible Cops5 KO ESC line. Cops5 KO leads to decreased expression of the pluripotency marker Nanog, proliferation defect, G2/M cell-cycle arrest, and apoptosis of ESCs. Further analysis revealed dual roles of Cops5 in maintaining genomic stability of ESCs. On one hand, Cops5 suppresses the autophagic degradation of Mtch2 to direct cellular metabolism toward glycolysis and minimize reactive oxygen species (ROS) production, thereby reducing endogenous DNA damage. On the other hand, Cops5 is required for high DNA damage repair (DDR) activities in ESCs. Without Cops5, elevated ROS and reduced DDR activities lead to DNA damage accumulation in ESCs. Subsequently, p53 is activated to trigger G2/M arrest and apoptosis. Altogether, our studies reveal an essential role of Cops5 in maintaining genome integrity and self-renewal of ESCs by regulating cellular metabolism and DDR pathways.


Assuntos
Complexo do Signalossomo COP9/metabolismo , Reparo do DNA , Células-Tronco Embrionárias/enzimologia , Instabilidade Genômica , Peptídeo Hidrolases/metabolismo , Animais , Apoptose , Complexo do Signalossomo COP9/genética , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Diferenciação Celular , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Pontos de Checagem da Fase G2 do Ciclo Celular , Técnicas de Inativação de Genes , Camundongos , Proteínas de Transporte da Membrana Mitocondrial/genética , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Fosforilação Oxidativa , Peptídeo Hidrolases/genética , Espécies Reativas de Oxigênio/metabolismo
13.
Life Sci ; 247: 116942, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-31715185

RESUMO

AIMS: The cardioprotective effects of preconditioning against ischemia-reperfusion (I/R) injury depend on the structural integrity of membrane caveolae and signaling through G protein-coupled receptors (GPCRs). However, the mechanisms underlying opioid preconditioning are not fully understood. Here, we examined whether caveolins transmitted opioid-GPCR signals to the mitochondria to mediate cardioprotection. MAIN METHODS: Mice were treated with pertussis toxin (PTX) or saline. Thirty-six hours later, mice from each group were randomly assigned to receive the δ-opioid receptor agonist SNC-121 or saline intraperitoneally 15 min before in vivo I/R. Infarct sizes in each group were compared, and immunoblot analysis was used to detect caveolin expression. The structures of caveolae and mitochondria were determined by electron microscopy (EM). The opening degree of the mitochondrial permeability transition pore (mPTP) was assessed by colorimetry, and mitochondrial respiratory function was assessed by Oxygraph-2k. KEY FINDINGS: Treatment with an opioid receptor agonist reduced the myocardial infarct size after I/R injury, increased caveolin expression, decreased mitochondrial mPTP opening, and improved mitochondrial respiratory function. EM analysis revealed that opioids induced caveolae formation in myocytes and tended to promote translocation to mitochondria. However, these protective effects were blocked by PTX. SIGNIFICANCE: Opioid-induced preconditioning depended on Gi signaling, which promoted caveolin translocation to mitochondria, supported their functional integrity, and enhanced cardiac stress adaption. Verification of this pathway will establish new targets for opioid agents in the field of cardiac protection.


Assuntos
Benzamidas/farmacologia , Cardiotônicos/farmacologia , Caveolinas/metabolismo , Mitocôndrias Cardíacas/metabolismo , Piperazinas/farmacologia , Receptores Opioides delta/agonistas , Receptores Opioides delta/metabolismo , Animais , Cavéolas/metabolismo , Cavéolas/ultraestrutura , Masculino , Camundongos , Mitocôndrias Cardíacas/ultraestrutura , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/ultraestrutura , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/ultraestrutura , Receptores Acoplados a Proteínas-G/metabolismo
14.
BMB Rep ; 53(1): 47-55, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31818365

RESUMO

Alzheimer's disease (AD) is a multifactorial neurodegenerative disease and has become a major socioeconomic issue in many developed countries. Currently available therapeutic agents for AD provide only symptomatic treatments, mainly because the complete mechanism of the AD pathogenesis is still unclear. Although several different hypotheses have been proposed, mitochondrial dysfunction has gathered interest because of its profound effect on brain bioenergetics and neuronal survival in the pathophysiology of AD. Various therapeutic agents targeting the mitochondrial pathways associated with AD have been developed over the past decade. Although most of these agents are still early in the clinical development process, they are used to restore mitochondrial function, which provides an alternative therapeutic strategy that is likely to slow the progression of the disease. In this mini review, we will survey the AD-related mitochondrial pathways and their small-molecule modulators that have therapeutic potential. We will focus on recently reported examples, and also overview the current challenges and future perspectives of ongoing research. [BMB Reports 2020; 53(1): 47-55].


Assuntos
Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Encéfalo/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , 17-Hidroxiesteroide Desidrogenases/antagonistas & inibidores , 17-Hidroxiesteroide Desidrogenases/metabolismo , 3-Hidroxiacil-CoA Desidrogenases/antagonistas & inibidores , 3-Hidroxiacil-CoA Desidrogenases/metabolismo , Animais , Progressão da Doença , Dinaminas/metabolismo , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/enzimologia , Proteínas de Transporte da Membrana Mitocondrial/antagonistas & inibidores , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Neuroesteroides/química , Neuroesteroides/metabolismo , Neuroesteroides/farmacologia , Estresse Oxidativo/genética , Estresse Oxidativo/fisiologia , Proteínas Quinases/química , Proteínas Quinases/metabolismo , Receptores de GABA/metabolismo
15.
Mol Cell Biochem ; 463(1-2): 189-201, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31612353

RESUMO

Human triple negative breast cancer cells, MDA-MB-231, show typical epithelial to mesenchymal transition associated with cancer progression. Mitochondria play a major role in cancer progression, including metastasis. Changes in mitochondrial architecture affect cellular migration, autophagy and apoptosis. Silibinin is reported to have anti-breast cancer effect. We here report that silibinin at lower concentrations (30-90 µM) inhibits epithelial to mesenchymal transition (EMT) of MDA-MB-231, by increasing the expression of epithelial marker, E-cadherin, and decreasing the expression of mesenchymal markers, N-cadherin and vimentin. Besides, silibinin inhibition of cell migration is associated with reduction in the protein expression of matrix metalloproteinases 2 and 9 (MMP2 and MMP9) and paxillin. In addition, silibinin treatment increases mitochondrial fusion through down-regulating the expression of mitochondrial fission-associated protein dynamin-related protein 1 (DRP1) and up-regulating the expression of mitochondrial fusion-associated proteins, optic atrophy 1, mitofusin 1 and mitofusin 2. Silibinin perturbed mitochondrial biogenesis via down-regulating the levels of mitochondrial biogenesis regulators including mitochondrial transcription factor A (TFAM), peroxisome proliferator-activated receptor gamma coactivator (PGC1) and nuclear respiratory factor (NRF2). Moreover, DRP1 knockdown or silibinin inhibited cell migration, and MFN1&2 knockdown restored it. Mitochondrial fusion contributes to silibinin's negative effect on cell migration. Silibinin decreased reactive oxygen species (ROS) generation, leading to inhibition of the NLRP3 inflammasome activation. In addition, knockdown of mitofusin 1&2 (MFN 1&2) relieved silibinin-induced inhibition of NLRP3 inflammasome activation. Repression of ROS contributes to the inhibition of the expression of NLRP3, caspase-1 and IL-ß proteins as well as of cell migration. Taken together, our study provides evidence that silibinin impairs mitochondrial dynamics and biogenesis, resulting in reduced migration and invasion of the MDA-MB-231 breast cancer cells.


Assuntos
Transição Epitelial-Mesenquimal/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Dinâmica Mitocondrial/efeitos dos fármacos , Proteínas de Transporte da Membrana Mitocondrial/biossíntese , Proteínas de Neoplasias/biossíntese , Silibina/farmacologia , Neoplasias de Mama Triplo Negativas/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Transição Epitelial-Mesenquimal/genética , Feminino , Humanos , Dinâmica Mitocondrial/genética , Proteínas de Transporte da Membrana Mitocondrial/genética , Proteínas de Neoplasias/genética , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologia
16.
DNA Cell Biol ; 39(1): 105-117, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31794266

RESUMO

Septic cardiomyopathy (SC) is a rare and harmful cardiovascular disease with decreased left ventricular (LV) output and multiple organ failure, which poses a serious threat to human life. Despite the advances in SC, its diagnostic basis and treatment methods are limited, and the specific diagnostic biomarkers and its candidate regulatory targets have not yet been fully established. In this study, the GSE79962 gene expression profile was retrieved, with 20 patients with SC and 11 healthy donors as control. Weighted gene coexpression network analysis (WGCNA) was employed to investigate gene modules that were strongly correlated with clinical phenotypes. Blue module was found to be most significantly related to SC. Moreover, Gene Ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed on the coexpression genes in blue module and showed that it was associated with metabolic pathways, oxidative phosphorylation, and cardiac muscle contraction. Furthermore, a total of 10 hub genes NDUFB5, TIMMDC1, VDAC3, COQ10A, MRPL16 (mitochondrial ribosomal protein L16), C3orf43, TMEM182, DLAT, NDUFA8, and PDHB (pyruvate dehydrogenase E1 beta subunit) in the blue module were identified at transcriptional level and further validated at translational level in myocardium of an lipopolysaccharide-induced septic cardiac dysfunction mouse model. Overall, the results of quantitative real-time polymerase chain reaction were consistent with most of the microarray analysis results. Intriguingly, we observed that the highest change was NDUFB5, TIMMDC1, and VDAC3. These identified and validated genes provided references that would advance the understanding of molecular mechanisms of SC. Taken together, using WGCNA, the hub genes NDUFB5, TIMMDC1, and VDAC3 might serve as potential biomarkers for diagnosis and/or therapeutic targets for precise treatment of SC in the future.


Assuntos
Cardiomiopatias/genética , Complexo I de Transporte de Elétrons/genética , Perfilação da Expressão Gênica/métodos , Proteínas de Transporte da Membrana Mitocondrial/genética , Sepse/genética , Canais de Ânion Dependentes de Voltagem/genética , Idoso , Animais , Cardiomiopatias/metabolismo , Cardiomiopatias/patologia , Biologia Computacional/métodos , Progressão da Doença , Complexo I de Transporte de Elétrons/metabolismo , Feminino , Ontologia Genética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Sepse/metabolismo , Sepse/patologia , Canais de Ânion Dependentes de Voltagem/metabolismo
17.
Oncogene ; 39(1): 164-175, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31462712

RESUMO

Citrin, encoded by SLC25A13 gene, is an inner mitochondrial transporter that is part of the malate-aspartate shuttle, which regulates the NAD+/NADH ratio between the cytosol and mitochondria. Citrullinemia type II (CTLN-II) is an inherited disorder caused by germline mutations in SLC25A13, manifesting clinically in growth failure that can be alleviated by dietary restriction of carbohydrates. The association of citrin with glycolysis and NAD+/NADH ratio led us to hypothesize that it may play a role in carcinogenesis. Indeed, we find that citrin is upregulated in multiple cancer types and is essential for supplementing NAD+ for glycolysis and NADH for oxidative phosphorylation. Consequently, citrin deficiency associates with autophagy, whereas its overexpression in cancer cells increases energy production and cancer invasion. Furthermore, based on the human deleterious mutations in citrin, we found a potential inhibitor of citrin that restricts cancerous phenotypes in cells. Collectively, our findings suggest that targeting citrin may be of benefit for cancer therapy.


Assuntos
Carcinogênese/genética , Mitocôndrias/genética , Proteínas de Transporte da Membrana Mitocondrial/genética , Neoplasias/genética , Carboidratos/genética , Citrulinemia/genética , Citrulinemia/metabolismo , Citosol/metabolismo , Citosol/patologia , Regulação Neoplásica da Expressão Gênica/genética , Mutação em Linhagem Germinativa/genética , Ácido Glutâmico/análogos & derivados , Ácido Glutâmico/farmacologia , Glicólise/genética , Humanos , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Proteínas de Transporte da Membrana Mitocondrial/antagonistas & inibidores , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Fosforilação Oxidativa/efeitos dos fármacos
18.
Toxicol Lett ; 323: 25-34, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31874198

RESUMO

Mitochondrial permeability transition (MPT), which is mainly regulated by cyclophilin D (CypD) encoded by ppif gene, is an early event that occurs during mitochondrial stimuli exposure. Lead (Pb) induces MPT and subsequently causes mitochondrial abnormality, followed by events, including oxidative stress and cell death. Here, we generated a ppif-/- SH-SY5Y cell line to determine the role of CypD in Pb-induced mitochondrial abnormality. CypD deficiency significantly blocked mitochondrial permeability transition pore (MPTP) opening and inhibited mitochondrial membrane potential (MMP) collapse, as well as mitochondrial structure damage and fragmentation caused by Pb. Mitochondria fragmentation and MMP collapse, accompanying with Pb-induced downregulation of Glut1 and Glut3 and inactivation of AMPK signaling pathway, could impair the energy supply in wildtype cells. Meanwhile, ppif knockout can alleviate these impairments and maintain the energy supply. In addition, reactive oxygen species accumulation and cell death caused by Pb can also be attenuated by ppif knockout, thereby promoting cell survival. Our study tends to identify CypD as an important contributor to Pb-induced mitochondrial abnormality and provides a potential strategy to inhibit Pb neurotoxicity.


Assuntos
Ciclofilina D/fisiologia , Chumbo/toxicidade , Mitocôndrias/efeitos dos fármacos , Neuroproteção , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Ciclofilina D/deficiência , Metabolismo Energético/efeitos dos fármacos , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos
19.
Sci Total Environ ; 702: 134994, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31715400

RESUMO

In recent years, nanomaterials have been widely applied in electronics, food, biomedicine and other fields, resulting in increased human exposure and consequent research focus on their biological and toxic effects. Mitochondria, the main target organelle for nanomaterials (NM), play a critical role in their toxic activities. Several studies to date have shown that nanomaterials cause alterations in mitochondrial morphology, mitochondrial membrane potential, opening of the mitochondrial permeability transition pore (MPTP) and mitochondrial respiratory function, and promote cytochrome C release. An earlier mitochondrial toxicity study of NMs additionally reported induction of mitochondrial dynamic changes. Here, we have reviewed the mitochondrial toxicity of NMs and provided a scientific basis for the contribution of mitochondria to the toxicological effects of different NMs along with approaches to reduce mitochondrial and, consequently, overall toxicity of NMs.


Assuntos
Exposição Ambiental/estatística & dados numéricos , Nanoestruturas , Humanos , Mitocôndrias , Proteínas de Transporte da Membrana Mitocondrial
20.
Biochim Biophys Acta Gen Subj ; 1864(2): 129417, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31445064

RESUMO

BACKGROUND: Tim21, a subunit of a highly dynamic translocase of the inner mitochondrial membrane (TIM23) complex, translocates proteins by interacting with subunits in the translocase of the outer membrane (TOM) complex and Tim23 channel in the TIM23 complex. A loop segment in Tim21, which is in close proximity of the binding site of Tim23, has different conformations in X-ray, NMR and new crystal contact-free space (CCFS) structures. MD simulations can provide information on the structure and dynamics of the loop in solution. METHODS: The conformational ensemble of the loop was characterized using loop modeling and molecular dynamics (MD) simulations. RESULTS: MD simulations confirmed mobility of the loop. Multidimensional scaling and clustering were used to characterize the dynamic conformational ensemble of the loop. Free energy landscape showed that the CCFS crystal structure occupied a low energy region as compared to the conventional X-ray crystal structure. Analysis of crystal packing indicates that the CCFS provides larger conformational space for the motions of the loop. CONCLUSIONS: Our work reported the conformational ensemble of the loop in solution, which is in agreement with the structure obtained from CCFS approach. The combination of the experimental techniques and computational methods is beneficial for studying highly flexible regions of proteins. GENERAL SIGNIFICANCE: Computational methods, such as loop modeling and MD simulations, have proved to be useful for studying conformational flexibility of proteins. These methods in integration with experimental techniques such as CCFS has the potential to transform the studies on flexible regions of proteins.


Assuntos
Proteínas de Transporte da Membrana Mitocondrial/química , Proteínas de Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/química , Sítios de Ligação , Proteínas de Transporte/química , Análise por Conglomerados , Espectroscopia de Ressonância Magnética , Mitocôndrias/química , Simulação de Dinâmica Molecular , Estrutura Secundária de Proteína , Transporte Proteico , Raios X
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