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1.
Mol Cell ; 75(4): 823-834.e5, 2019 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-31302001

RESUMO

Sirt3, as a major mitochondrial nicotinamide adenine dinucleotide (NAD)-dependent deacetylase, is required for mitochondrial metabolic adaption to various stresses. However, how to regulate Sirt3 activity responding to metabolic stress remains largely unknown. Here, we report Sirt3 as a SUMOylated protein in mitochondria. SUMOylation suppresses Sirt3 catalytic activity. SUMOylation-deficient Sirt3 shows elevated deacetylation on mitochondrial proteins and increased fatty acid oxidation. During fasting, SUMO-specific protease SENP1 is accumulated in mitochondria and quickly de-SUMOylates and activates Sirt3. SENP1 deficiency results in hyper-SUMOylation of Sirt3 and hyper-acetylation of mitochondrial proteins, which reduces mitochondrial metabolic adaption responding to fasting. Furthermore, we find that fasting induces SENP1 translocation into mitochondria to activate Sirt3. The studies on mice show that Sirt3 SUMOylation mutation reduces fat mass and antagonizes high-fat diet (HFD)-induced obesity via increasing oxidative phosphorylation and energy expenditure. Our results reveal that SENP1-Sirt3 signaling modulates Sirt3 activation and mitochondrial metabolism during metabolic stress.


Assuntos
Cisteína Endopeptidases/metabolismo , Mitocôndrias/metabolismo , Mutação , Obesidade/metabolismo , Transdução de Sinais , Sirtuína 3/metabolismo , Sumoilação , Acetilação , Animais , Cisteína Endopeptidases/genética , Gorduras na Dieta/efeitos adversos , Gorduras na Dieta/farmacologia , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Mutantes , Mitocôndrias/genética , Mitocôndrias/patologia , Obesidade/induzido quimicamente , Obesidade/genética , Obesidade/patologia , Sirtuína 3/genética
2.
Diabetes Res Clin Pract ; 155: 107801, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31356832

RESUMO

AIM: A growing body of evidence supports the impact of intermittent fasting on normalizing body metabolism and lowering oxidative stress and inflammation. Mounting evidence confirms that oxidative stress and chronic inflammation trigger the way for the development of metabolic diseases, such as diabetes. This research was conducted to evaluate the impact of Ramadan intermittent fasting (RIF) on the expression of cellular metabolism (SIRT1 and SIRT3) and antioxidant genes (TFAM, SOD2, and Nrf2). METHODS: Fifty-six (34 males and 22 females) overweight and obese subjects and six healthy body weight controls were recruited and monitored before and after Ramadan. RESULTS: Results showed that the relative gene expressions in obese subjects in comparison to counterpart expressions of controls for the antioxidant genes (TFAM, SOD2, and Nrf2) were significantly increased at the end of Ramadan, with percent increments of 90.5%, 54.1% and 411.5% for the three genes, respectively. However, the metabolism-controlling gene (SIRT3) showed a highly significant (P < 0.001) downregulation accompanied with a trend for reduction in SIRT1 gene at the end of Ramadan month, with percent decrements of 61.8% and 10.4%, respectively. Binary regression analysis revealed significant positive correlation (P < 0.05) between high energy intake (>2000 Kcal/day vs. <2000 Kcal/day) and expressions of SOD2 and TFAM (r = 0.84 and r = 0.9, respectively). CONCLUSION: Results suggest that RIF ameliorates the genetic expression of antioxidant and anti-inflammatory, and metabolic regulatory genes. Thus, RIF presumably may entail a protective impact against oxidative stress and its adverse metabolic-related derangements in non-diabetic obese patients.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Jejum/fisiologia , Proteínas Mitocondriais/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Obesidade/fisiopatologia , Sobrepeso/fisiopatologia , Sirtuína 1/metabolismo , Sirtuína 3/metabolismo , Superóxido Dismutase/metabolismo , Fatores de Transcrição/metabolismo , Adulto , Estudos de Casos e Controles , Proteínas de Ligação a DNA/genética , Feminino , Regulação da Expressão Gênica , Humanos , Islamismo , Masculino , Proteínas Mitocondriais/genética , Fator 2 Relacionado a NF-E2/genética , Estresse Oxidativo , Estudos Prospectivos , Sirtuína 1/genética , Sirtuína 3/genética , Superóxido Dismutase/genética , Fatores de Transcrição/genética
3.
Mol Carcinog ; 58(10): 1876-1885, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31292999

RESUMO

Sirtuin-1 and -3 (SIRT1 and SIRT3) are important nicotinamide adenine dinucleotide (NAD+ )-dependent deacetylases known to regulate a variety of cellular functions. Studies have shown that SIRT1 and SIRT3 were overexpressed in human melanoma cells and tissues and their inhibition resulted in a significant antiproliferative response in human melanoma cells and antitumor response in a mouse xenograft model of melanoma. In this study, we determined the antiproliferative efficacy of a newly identified dual small molecule inhibitor of SIRT1 and SIRT3, 4'-bromo-resveratrol (4'-BR), in human melanoma cell lines (G361, SK-MEL-28, and SK-MEL-2). Our data demonstrate that 4'-BR treatment of melanoma cells resulted in (a) decrease in proliferation and clonogenic survival; (b) induction of apoptosis accompanied by a decrease in procaspase-3, procaspase-8, and increase in the cleavage of caspase-3 and poly (ADP-ribose) polymerase (PARP); (c) marked downregulation of proliferating cell nuclear antigen (PCNA); and (d) inhibition of melanoma cell migration. Further, 4'-BR caused a G0/G1 phase arrest of melanoma cells that was accompanied by an increase in WAF-1/P21 and decrease in Cyclin D1/Cyclin-dependent kinase 6 protein levels. Furthermore, we found that 4'-BR causes a decrease in lactate production, glucose uptake, and NAD+ /NADH ratio. These responses were accompanied by downregulation in lactate dehydrogenase A and glucose transporter 1 in melanoma cells. Collectively, our data suggest that dual inhibition of SIRT1 and SIRT3 using 4'-BR imparted antiproliferative effects in melanoma cells through a metabolic reprogramming and affecting the cell cycle and apoptosis signaling. Therefore, concomitant pharmacological inhibition of SIRT1 and SIRT3 needs further investigation for melanoma management.


Assuntos
Melanoma/tratamento farmacológico , Resorcinóis/farmacologia , Sirtuína 1/genética , Sirtuína 3/genética , Estilbenos/farmacologia , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Reprogramação Celular/efeitos dos fármacos , Reprogramação Celular/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Ácido Láctico/metabolismo , Melanoma/genética , Melanoma/patologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Sirtuína 1/antagonistas & inibidores , Sirtuína 3/antagonistas & inibidores
4.
J Ovarian Res ; 12(1): 47, 2019 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-31113446

RESUMO

OBJECTIVE: Our aim is to analyzed the expression pattern of sirtuin(SIRT) superfamily and evaluated their prognostic values in serous ovarian cancer patients. METHODS: We first analyzed the differential expression of SIRT members among fallopian tube epithelium (FTE), primary serous ovarian cancers/tubal cancers (PSOCs/PSTCs), and omental metastases using GSE10971 and GSE30587 datasets. The prognostic values of SIRT members were evaluated using TCGA and GSE9891 dataset. RESULTS: SIRT3 and SIRT5 expression were significantly decreased and increased in PSOCs/PSTCs compared with that in normal counterparts, respectively. SIRT6 and SIRT7 were overexpressed in ometal metastases compared with corresponding primary counterparts. With respect to recurrence free survival, however, SIRT7 overexpression was correlated with better prognosis. A similar trend was observed by multivariable analysis. Regarding overall survival (OS), increased expression of SIRT3, SIRT5, and SIRT7 were associated with better survival by univariable analysis. Subsequent multivariable analysis showed that SIRT3 remained an independent favorable prognostic factor for OS. The SIRT3-related nomogram illustrated age at initial diagnosis as sharing the largest contribution to OS, followed by SIRT3 expression and FIGO stage. The C-index for OS prediction was 0.65 (95%CI, 0.61-0.69) in training cohort (TCGA dataset) and 0.65 (95%CI, 0.59-0.71) in validation cohort (GSE9891 dataset), respectively. The calibration plots showed optimal agreement between the prediction by SIRT3-related nomogram and actual observation for 1-, 3-, and 5-year OS probability. CONCLUSION: In conclusion, SIRT3 was an independent favorable prognostic factor for OS in serous ovarian cancer, and added prognostic value to the traditional clinicopathological factors used to evaluate patients' prognosis.


Assuntos
Cistadenocarcinoma Seroso/genética , Cistadenocarcinoma Seroso/mortalidade , Neoplasias das Tubas Uterinas/mortalidade , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/mortalidade , Sirtuína 3/genética , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Cistadenocarcinoma Seroso/patologia , Intervalo Livre de Doença , Neoplasias das Tubas Uterinas/genética , Neoplasias das Tubas Uterinas/patologia , Feminino , Expressão Gênica , Humanos , Pessoa de Meia-Idade , Metástase Neoplásica/genética , Estadiamento de Neoplasias , Nomogramas , Neoplasias Ovarianas/patologia , Prognóstico , Sirtuínas/genética , Taxa de Sobrevida
5.
Neoplasia ; 21(7): 665-675, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31108370

RESUMO

SIRT3 is a major mitochondrial deacetylase, which regulates various metabolic pathways by deacetylation; however, the effect of SIRT3 on proline metabolism is not reported. Pyrroline-5-carboxylate reductase 1 (PYCR1) participates in proline synthesis process by catalyzing the reduction of P5C to proline with concomitant generation of NAD+ and NADP+. PYCR1 is highly expressed in various cancers, and it can promote the growth of tumor cells. Here, through immunoprecipitation and mass spectrometry, we found that PYCR1 is in SIRT3's interacting network. PYCR1 directly binds to SIRT3 both in vivo and in vitro. CBP is the acetyltransferase for PYCR1, whereas SIRT3 deacetylates PYCR1. We further identified that K228 is the major acetylation site for PYCR1. Acetylation of PYCR1 at K228 reduced its enzymatic activity by impairing the formation of the decamer of PYCR1. As a result, acetylation of PYCR1 at K228 inhibits cell proliferation, while deacetylation of PYCR1 mediated by SIRT3 increases PYCR1's activity. Our findings on the regulation of PYCR1 linked proline metabolism with SIRT3, CBP and cell growth, thus providing a potential approach for cancer therapy.


Assuntos
Neoplasias/genética , Fragmentos de Peptídeos/genética , Pirrolina Carboxilato Redutases/genética , Sialoglicoproteínas/genética , Sirtuína 3/genética , Acetilação , Proliferação de Células/genética , Humanos , Células MCF-7 , Mitocôndrias/genética , Mitocôndrias/metabolismo , Neoplasias/patologia , Prolina/biossíntese , Prolina/metabolismo
6.
Food Funct ; 10(5): 2752-2765, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31041965

RESUMO

Mitochondrial dysfunction contributed greatly to myocardial ischemia-reperfusion (MI/R)-induced cardiomyocyte apoptosis. Naringenin is a flavonoid exhibiting potential protective effects on myocardial mitochondria under stress conditions. However, the detailed down-stream signaling pathway involved remains uncovered. This study was designed to elucidate naringenin's mitochondrial protective actions during MI/R with a focus on AMPK-SIRT3 signaling. Sprague-Dawley rats were administered with naringenin (50 mg kg-1 d-1) and subjected to MI/R surgery in the presence or absence of compound C (0.25 mg kg-1, Com.C, an AMPK inhibitor) co-treatment. An in vitro study was performed on H9c2 cardiomyoblasts subjected to simulated ischemia-reperfusion treatment. Before the treatment, the cells were administered with naringenin (80 µmol L-1) with or without SIRT3 siRNA/AMPK1α siRNA transfection. Naringenin improved post-reperfusion left ventricular systolic pressure and the instantaneous first derivative of left ventricular pressure, and reduced the infarction size and myocardial apoptosis index by suppressing mitochondrial oxidative stress damage (as evidenced by decreased mitochondrial cytochrome c release and oxidative markers) and enhancing mitochondrial biogenesis [as evidenced by increased NRF1, TFAM and oxidative phosphorylation subunit complexes (II, III and IV)]. These protective actions were abolished by Com.C (in vivo) or SIRT3 siRNA (in vitro) administration. Further investigation revealed that Com.C (in vivo) or AMPK1α siRNA (in vitro) markedly suppressed PGC-1α and SIRT3 levels while SIRT3 siRNA (in vitro) inhibited SIRT3 expression without significantly changing AMPK phosphorylation and PGC-1α levels. Taken together, we found that naringenin directly inhibits mitochondrial oxidative stress damage and preserves mitochondrial biogenesis, thus attenuating MI/R injury. Importantly, AMPK-SIRT3 signaling played a key role in this process.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Flavanonas/administração & dosagem , Mitocôndrias/efeitos dos fármacos , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Sirtuína 3/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Animais , Apoptose/efeitos dos fármacos , Citocromos c/metabolismo , Coração/efeitos dos fármacos , Humanos , Masculino , Mitocôndrias/metabolismo , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/metabolismo , Miocárdio/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Sirtuína 3/genética
7.
Oxid Med Cell Longev ; 2019: 4824035, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31093315

RESUMO

Background: The sedative anesthetic, propofol, is a cardioprotective agent for hyperglycemia-induced myocardial hypertrophy and dysfunction in rats. However, the specific protective mechanism has not been clarified. Methods and Results: In this experiment, we used H9c2 cells subjected to 22 mM glucose lasting for 72 hours as an in vitro model of cardiomyocyte injury by hyperglycemia and investigated the potential mechanism of propofol against hyperglycemic stress in cells. Propofol (5, 10, or 20 µM) was added to the cell cultures before and during the high glucose culture phases. Cell viability and levels of ROS were measured. The levels of proinflammatory cytokines were tested by ELISA. The levels of SIRT3, SOD2, PHD2, HIF-1α, Bcl-2, P53, and cleaved caspase-3 proteins were detected by western blotting. Our data showed that propofol attenuated high glucose-induced cell apoptosis accompanied by a decrease in the level of reactive oxygen species (ROS) and proinflammatory cytokines. Meanwhile, propofol decreased the apoptosis of H9c2 cells via increasing the expression of Bcl-2, SIRT3, SOD2, and PHD2 proteins and decreasing the expression of cleaved caspase-3, P53, and HIF-1α. Real-time PCR analysis showed that propofol did not significantly change the HIF-1α but increase PHD2 at mRNA level. HIF-1α silence significantly decreased apoptosis and inflammation in H9c2 cell during high glucose stress. Pretreatment of IOX2 (the inhibitor of PHD2) inhibited cell viability until the concentration reached 200 µM during high glucose stress. However, 50 µM TYP (the inhibitor of SIRT3) significantly inhibited cell viability during high glucose stress. Delayed IOX2 treatment for 6 hours significantly inhibited cell viability during high glucose stress. Conclusions: Propofol might alleviate cell apoptosis via SIRT3-HIF-1α axis during high glucose stress.


Assuntos
Apoptose/efeitos dos fármacos , Glucose/toxicidade , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Propofol/farmacologia , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Inflamação/patologia , Mediadores da Inflamação/metabolismo , Modelos Biológicos , Pró-Colágeno-Prolina Dioxigenase/genética , Pró-Colágeno-Prolina Dioxigenase/metabolismo , Substâncias Protetoras/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismo , Sirtuína 3/genética , Sirtuína 3/metabolismo , Estresse Fisiológico/efeitos dos fármacos
8.
Nat Commun ; 10(1): 1886, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-31015456

RESUMO

Intermittent food deprivation (fasting, IF) improves mood and cognition and protects neurons against excitotoxic degeneration in animal models of epilepsy and Alzheimer's disease (AD). The mechanisms by which neuronal networks adapt to IF and how such adaptations impact neuropathological processes are unknown. We show that hippocampal neuronal networks adapt to IF by enhancing GABAergic tone, which is associated with reduced anxiety-like behaviors and improved hippocampus-dependent memory. These neuronal network and behavioral adaptations require the mitochondrial protein deacetylase SIRT3 as they are abolished in SIRT3-deficient mice and wild type mice in which SIRT3 is selectively depleted from hippocampal neurons. In the AppNL-G-F mouse model of AD, IF reduces neuronal network hyperexcitability and ameliorates deficits in hippocampal synaptic plasticity in a SIRT3-dependent manner. These findings demonstrate a role for a mitochondrial protein deacetylase in hippocampal neurons in behavioral and GABAergic synaptic adaptations to IF.


Assuntos
Doença de Alzheimer/dietoterapia , Jejum/fisiologia , Neurônios GABAérgicos/metabolismo , Hipocampo/fisiologia , Sirtuína 3/metabolismo , Doença de Alzheimer/genética , Precursor de Proteína beta-Amiloide/genética , Animais , Comportamento Animal/fisiologia , Cognição/fisiologia , Excitabilidade Cortical/fisiologia , Modelos Animais de Doenças , Hipocampo/citologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mitocôndrias/metabolismo , Rede Nervosa/fisiologia , Plasticidade Neuronal/fisiologia , Estresse Oxidativo/fisiologia , Sirtuína 3/genética , Superóxido Dismutase/genética
9.
Int Immunopharmacol ; 71: 361-371, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30952100

RESUMO

Trans sodium crocetinate (TSC) has been reported to exert a protective effect against cerebral ischemia/reperfusion (I/R) injury. However, whether TSC protects against myocardial ischemia/reperfusion (MI/R) injury remains unknown. Herein, we found that TSC treatment reduced myocardial infract size and elevated serum LDH and CK activities of MI/R rats. TSC administration attenuated oxidative stress in MI/R rats and H9C2 cells exposed to oxygen glucose deprivation/reperfusion (OGD/R). TSC administration relieved I/R-induced myocardial apoptosis in vivo and in vitro, as evidenced by reduced number of TUNEL positive cells, accompanying with marked decreases in caspase-3 activity and Bax protein level and an increase in Bcl-2 protein level. TSC treatment markedly increased SIRT3 activity and SIRT3 and SOD2 protein levels, and could also diminished the phosphorylation of FOXO3a protein. Additionally, TSC treatment attenuated the acetylation of FOXO3a and SOD2 protein. But, these effects were obviously blocked by SIRT3 knockdown. Besides, SIRT3 knockdown blocked the cardioprotective effect of TSC on OGD/R-induced oxidative stress, apoptosis and mitochondrial dysfunction in vitro. In summary, TSC alleviates I/R-induced myocardial oxidative stress and apoptosis via the SIRT3/FOXO3a/SOD2 signaling pathway. Our study suggests that TSC may become a novel drug for the treatment of MI/R injury.


Assuntos
Antioxidantes/uso terapêutico , Carotenoides/uso terapêutico , Infarto do Miocárdio/tratamento farmacológico , Miocárdio/metabolismo , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Oclusão Coronária , Modelos Animais de Doenças , Proteína Forkhead Box O3/metabolismo , Humanos , Masculino , Estresse Oxidativo/efeitos dos fármacos , RNA Interferente Pequeno/genética , Ratos , Ratos Wistar , Transdução de Sinais , Sirtuína 3/genética , Sirtuína 3/metabolismo
10.
Mol Med Rep ; 19(4): 2849-2860, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30816450

RESUMO

Diabetic nephropathy results from hyperglycemia­mediated renal glomerular cell death via mitochondrial apoptosis. There is an emerging requirement for novel approaches with mitochondrial protective effects that alleviate the hyperglycemia­induced loss of functional cells during diabetic renal damage. Liraglutide, a type of glucagon­like peptide­1 agonist, has been suggested to inhibit the progression of obesity and hyperglycemia. However, the contributions and mechanism of action of liraglutide on hyperglycemia­mediated cell mitochondrial apoptosis in diabetic kidneys have not been illustrated. The present study demonstrated that liraglutide may protect human renal mesangial cells (HRMCs) against hyperglycemia­induced cell death by inhibiting mitochondrial apoptosis. Liraglutide administration also maintained HRMC viability and promoted HRMC proliferation within a high glucose stress environment. Functional studies demonstrated that hyperglycemia triggered mitochondrial dysfunction, including mitochondrial potential reduction, mitochondrial permeability transition pore opening, reactive oxygen species overproduction and the activation of the mitochondrial apoptotic pathway. However, liraglutide treatment preserved mitochondrial function and prevented activation of mitochondrial apoptosis by upregulating sirtuin 3 (Sirt3) expression. Deletion of Sirt3 abrogated the protective effects of liraglutide on mitochondrial homeostasis following high glucose challenge. In addition, molecular analysis confirmed that liraglutide upregulated Sirt3 via activating the extracellular signal­regulated kinase­Yes­associated protein (ERK­Yap) signaling pathway. Inhibition of the ERK­Yap axis negated the action of liraglutide on Sirt3 activation, leading to mitochondrial injury and HRMC apoptosis. Taken together, the present study illustrated that liraglutide protected renal mesangial cells from hyperglycemia­mediated mitochondrial apoptosis by upregulating Sirt3 expression and activation of the ERK­Yap signaling pathway.


Assuntos
Apoptose/efeitos dos fármacos , Hiperglicemia/metabolismo , Liraglutida/farmacologia , Células Mesangiais/efeitos dos fármacos , Células Mesangiais/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteínas de Ciclo Celular , Células Cultivadas , Relação Dose-Resposta a Droga , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Hiperglicemia/genética , Ativação do Canal Iônico , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Proteínas Nucleares/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sirtuína 3/genética , Fatores de Transcrição/metabolismo
11.
Exp Eye Res ; 182: 1-9, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30849386

RESUMO

Acetylation of lysine residues occurs in lens proteins. Previous studies have shown an improvement in the chaperone activity of αA-crystallin upon acetylation. Sirtuins are NAD+-dependent enzymes that can deacylate proteins. The roles of sirtuins in regulating the acetylation of lens proteins and their impacts on the function of α-crystallin are not known. Here, we detected sirtuin activity in mouse lenses, and SIRT3 and SIRT5 were present primarily in the mitochondria of cultured primary mouse lens epithelial cells. Western blotting showed higher levels of protein acetylation in the lenses of SIRT3 KO and SIRT5 KO mice than in lenses of WT mice. Mass spectrometry analyses revealed a greater number of acetylated lysine residues in α-crystallin isolated from the SIRT3 and SIRT5 KO lenses than from WT lenses. α-Crystallin isolated from SIRT3 and SIRT5 KO lenses displayed a higher surface hydrophobicity and higher chaperone activity than the protein isolated from WT lenses. Thus, SIRTs regulate the acetylation levels of crystallins in mouse lenses, and acetylation in lenses enhances the chaperone activity of α-crystallin.


Assuntos
Catarata/genética , Regulação da Expressão Gênica , Cristalino/metabolismo , Chaperonas Moleculares/metabolismo , Sirtuína 3/genética , Sirtuínas/genética , alfa-Cristalinas/genética , Acetilação , Animais , Western Blotting , Catarata/metabolismo , Modelos Animais de Doenças , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , RNA/genética , Sirtuína 3/biossíntese , Sirtuínas/biossíntese , alfa-Cristalinas/metabolismo
12.
Exp Eye Res ; 181: 223-231, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30794763

RESUMO

We aim to investigate how Sirt3 (silent mating type information regulation 2 homolog 3) promoting diabetic corneal epithelial wound healing by regulating mitophagy. The effect of HG(High Glucose, 25 mM D-glucose) on Sirt3 and LC3B(light chain 3 beta)which representing of mitophagy were investigated in TKE2 cells (a murine limbal/corneal epithelium-derived progenitor cell line) and corneal epithelium from C57BL/6J-Ins2Akita (Ins2Akita/+) mice using RT-PCR and Western blotting. How overexpression of Sirt3 promoting diabetic corneal epithelial wound healing was investigated with cell migration assay、immunofluorescence、 immunofluorescence colocalization and corneal injury model. We found that HG reduced the expression of Sirt3 as well the mitophagy both in TKE2 cells and corneas from Ins2Akita/+ mice. And overexpression of Sirt3 prominently promoted wound healing speed under HG condition via upregulating the level of mitophagy. Mitophagy level was increased dramatically when the Foxo3a (Forkhead box O3)/PINK1(PTEN Induced putative kinase protein 1)-Parkin pathway was activated by Sirt3 overexpression which suggested that the mitophagy was involved in cell injury under HG condition. This study demonstrated the mechanism of Sirt3 regulating mitophagy to promote diabetic corneal epithelial wound healing in vivo and in vitro, which suggested that Sirt3 may positively impact diabetic keratopathy(DK).


Assuntos
Lesões da Córnea/genética , Diabetes Mellitus Experimental , Epitélio Anterior/metabolismo , Sirtuína 3/genética , Regulação para Cima/genética , Cicatrização , Animais , Western Blotting , Células Cultivadas , Lesões da Córnea/metabolismo , Lesões da Córnea/patologia , Epitélio Anterior/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Sirtuína 3/biossíntese
13.
Biochim Biophys Acta Mol Basis Dis ; 1865(6): 1389-1401, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30771486

RESUMO

Methylglyoxal (MG), a highly reactive dicarbonyl derived from metabolic processes, is the most powerful precursor of advanced glycation end products (AGEs). Glycative stress has been recently associated with ovarian dysfunctions in aging and PCOS syndrome. We have investigated the role of the NAD+-dependent Class III deacetylase SIRT1 in the adaptive response to MG in mouse oocytes and ovary. In mouse oocytes, MG induced up-expression of glyoxalase 1 (Glo1) and glyoxalase 2 (Glo2) genes, components of the main MG detoxification system, whereas inhibition of SIRT1 by Ex527 or sirtinol reduced this response. In addition, the inhibition of SIRT1 worsened the effects of MG on oocyte maturation rates, while SIRT1 activation by resveratrol counteracted MG insult. Ovaries from female mice receiving 100 mg/kg MG by gastric administration for 28 days (MG mice) exhibited increased levels of SIRT1 along with over-expression of catalase, superoxide dismutase 2, SIRT3, PGC1α and mtTFA. Similar levels of MG-derived AGEs were observed in the ovaries from MG and control groups, along with enhanced protein expression of glyoxalase 1 in MG mice. Oocytes ovulated by MG mice exhibited atypical meiotic spindles, a condition predisposing to embryo aneuploidy. Our results from mouse oocytes revealed for the first time that SIRT1 could modulate MG scavenging by promoting expression of glyoxalases. The finding that up-regulation of glyoxalase 1 is associated with that of components of a SIRT1 functional network in the ovaries of MG mice provides strong evidence that SIRT1 participates in the response to methylglyoxal-dependent glycative stress in the female gonad.


Assuntos
Produtos Finais de Glicação Avançada/genética , Oócitos/efeitos dos fármacos , Ovário/efeitos dos fármacos , Aldeído Pirúvico/farmacologia , Sirtuína 1/genética , Animais , Benzamidas/farmacologia , Carbazóis/farmacologia , Catalase/genética , Catalase/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Inibidores Enzimáticos/farmacologia , Feminino , Regulação da Expressão Gênica , Produtos Finais de Glicação Avançada/metabolismo , Lactoilglutationa Liase/antagonistas & inibidores , Lactoilglutationa Liase/genética , Lactoilglutationa Liase/metabolismo , Camundongos , Camundongos Endogâmicos , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Naftóis/farmacologia , Oócitos/citologia , Oócitos/metabolismo , Ovário/citologia , Ovário/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Cultura Primária de Células , Aldeído Pirúvico/antagonistas & inibidores , Resveratrol/farmacologia , Transdução de Sinais , Sirtuína 1/metabolismo , Sirtuína 3/genética , Sirtuína 3/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Tioléster Hidrolases/antagonistas & inibidores , Tioléster Hidrolases/genética , Tioléster Hidrolases/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
14.
Cell Stress Chaperones ; 24(2): 369-383, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30656603

RESUMO

Sirtuin 3 (Sirt3)-modified mitochondrial fission participates in the progression of several types of cancers. However, its role in tongue cancer requires investigation. The aim of our study is to determine whether Sirt3 knockdown regulates the viability of tongue cancer cells via modulating mitochondrial fission. Two types of tongue cancer cells were used in the present study, and siRNA was transfected into the cells to suppress Sirt3 expression. Mitochondrial function and cell apoptosis were determined via immunofluorescence, Western blotting, ELISA, and qPCR assays. A pathway blocker was applied to verify the role of the JNK-Fis1 signaling pathway in regulation of mitochondrial fission. The present study showed that loss of Sirt3 promoted tongue cancer cell death in a manner dependent on mitochondrial apoptosis. Mitochondrial oxidative stress, energy metabolism disorder, mitochondrial cyt-c liberation, and mitochondrial apoptosis activation were observed after Sirt3 silencing. Furthermore, we demonstrated that Sirt3 knockdown activated mitochondrial stress via triggering Fis1-related mitochondrial fission and that inhibition of Fis1-related mitochondrial fission abrogated the pro-apoptotic effect of Sirt3 knockdown on tongue cancer cells. To this end, we found that Sirt3 modulated Fis1 expression via the c-Jun N-terminal kinases (JNK) signaling pathway and that blockade of the JNK pathway attenuated mitochondrial stress and repressed apoptosis in Sirt3 knockdown cells. Altogether, our results identified a tumor-suppressive role for Sirt3 deficiency in tongue cancer via activation of the JNK-Fis1 axis and subsequent initiation of fatal mitochondrial fission. Given these findings, strategies to repress Sirt3 activity and enhance the JNK-Fis1-mitochondrial fission cascade have clinical benefits for patients with tongue cancer.


Assuntos
Carcinoma de Células Escamosas/patologia , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Proteínas de Membrana/metabolismo , Dinâmica Mitocondrial , Proteínas Mitocondriais/metabolismo , Sirtuína 3/metabolismo , Estresse Fisiológico , Neoplasias da Língua/patologia , Apoptose , Linhagem Celular Tumoral , Técnicas de Silenciamento de Genes , Humanos , Sistema de Sinalização das MAP Quinases , Mitocôndrias/metabolismo , Sirtuína 3/antagonistas & inibidores , Sirtuína 3/genética
15.
Diabetes Metab Syndr ; 13(1): 582-589, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30641770

RESUMO

INTRODUCTION: Sirtuins regulate energy metabolism and insulin sensitivity through their ability to act as energy sensors and regulators in several metabolic tissues. AIM: To evaluate the expression levels of sirtuin genes SIRT1, SIRT2, SIRT3 and SIRT6 and their target genes (PPAR-α, PGC1-α, NRF1, DGAT1, PPAR-γ and FOXO3a) in subcutaneous adipose tissue collected from individuals with normoweight, overweight and obesity. METHODS: Adipose tissue samples, obtained by lipoaspiration during liposuction surgery, were processed to obtain RNA, which was reverse-transcribed to cDNA. Then, we measured the expression levels of each gene by qPCR. RESULTS: We found differences in the mRNA expression of SIRT1, SIRT2, SIRT3 and SIRT6 and their target genes (PPAR-α, PGC1-α, NRF1, DGAT1, PPAR-γ and FOXO3a) in adipose tissue from overweight or obese subjects when compared to normoweight subjects. All genes analyzed, except SIRT2, showed correlation with BMI. CONCLUSIONS: Our findings in human subcutaneous adipose tissue show that increased body mass index modifies the expression of genes encoding sirtuins and their target genes, which are metabolic regulators of adipose tissue. Therefore, these could be used as biomarkers to predict the ability of adipose tissue to gain mass of adipose tissue.


Assuntos
Tecido Adiposo/fisiologia , Obesidade/genética , Sirtuína 1/genética , Sirtuína 2/genética , Sirtuína 3/genética , Sirtuínas/genética , Adulto , Índice de Massa Corporal , Feminino , Humanos , Pessoa de Meia-Idade , Obesidade/diagnóstico , Obesidade/metabolismo , Sirtuína 1/biossíntese , Sirtuína 2/biossíntese , Sirtuína 3/biossíntese , Sirtuínas/biossíntese , Adulto Jovem
16.
J Cell Physiol ; 234(3): 2252-2265, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30132870

RESUMO

Sirtuin 3 (SIRT3) a mitochondrial enzyme that plays an important role in energy homeostasis, cardiac remodeling, and heart failure (HF). The expression of SIRT3 declines with advanced age, cardiovascular, and metabolic diseases. Accumulating evidence suggests that SIRT3 plays a critical role in protecting the heart from cardiac hypertrophy, cardiac dysfunction associated with HF, and in the protection of cardiac cells from stress-mediated cell death. Clinical studies have demonstrated that HF with preserved ejection fraction (HFpEF) in patients present with abnormalities in coronary microcirculation related to endothelial dysfunction and coronary microvascular rarefaction. Although SIRT3-mediated regulation of mitochondrial homeostasis and heart function has been intensively investigated, the effect of SIRT3 on endothelial cell (EC) glycolytic metabolism and microvascular function has not been well studied. ECs utilize glycolysis for generating ATP rather than oxidative phosphorylation to maintain their normal functions and promote angiogenesis and EC-cardiomyocyte interactions. Emerging evidence indicates that SIRT3 is involved in the regulation of endothelial metabolism and angiogenesis and thus affects the development of cardiovascular diseases associated with aging. This review will discuss the current knowledge of SIRT3 and its functional role on endothelial metabolism, cardiac function, and cardiovascular diseases.


Assuntos
Doenças Cardiovasculares/genética , Insuficiência Cardíaca/genética , Neovascularização Patológica/genética , Sirtuína 3/genética , Doenças Cardiovasculares/patologia , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Glicólise/genética , Insuficiência Cardíaca/patologia , Humanos , Miócitos Cardíacos/metabolismo , Neovascularização Patológica/patologia , Volume Sistólico/genética
17.
Transl Stroke Res ; 10(1): 57-66, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29302794

RESUMO

Sirtuins (Sirt) are a family of NAD+ dependent histone deacetylase (HDAC) proteins implicated in aging, cell cycle regulation, and metabolism. These proteins are involved in the epigenetic modification of neuromodulatory proteins after strokevia acetylation/deacetylation. The specific role of Sirt3, a mitochondrial sirtuin, in post-stroke injury has been relatively unexplored. Using male Sirt3 knockout (KO) mice and wild-type littermates (WT), we show that Sirt3 KO mice show significant neuroprotection at 3 days after ischemia/reperfusion (I/R) or stroke injury. The deacetylation activity of Sirt3, measured as the amount of reduced acetylated lysine, was increased after stroke. Stroke-induced increases in liver kinase 1 (LKB1) activity were also reduced in KO mice at 3 days after stroke. On further investigation, we found that the levels of Sirt1, another important member of the Sirtuin family, were increased in the brains of Sirt3 KO mice after stroke. To determine the translational relevance of these findings, we then tested the effects of pharmacological inhibition of Sirt3. We found no benefit of Sirt3 inhibition despite clear evidence of deacetylation. Overall, these data suggest that Sirt3 KO mice show neuroprotection by a compensatory rise in Sirt1 rather than the loss of Sirt3 after stroke. Further analysis reveals that the beneficial effects of Sirt1 might be mediated by a decrease in LKB1 activity after stroke. Finally, our data clearly demonstrate the importance of using both pharmacological and genetic methods in pre-clinical stroke studies.


Assuntos
Regulação da Expressão Gênica/genética , Infarto da Artéria Cerebral Média/tratamento farmacológico , Infarto da Artéria Cerebral Média/metabolismo , Fármacos Neuroprotetores/uso terapêutico , Sirtuína 3/metabolismo , Animais , Infarto Encefálico/tratamento farmacológico , Infarto Encefálico/etiologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Comportamento Exploratório/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Glutationa/metabolismo , Infarto da Artéria Cerebral Média/genética , Infarto da Artéria Cerebral Média/patologia , Masculino , Camundongos , Camundongos Knockout , Atividade Motora/efeitos dos fármacos , Exame Neurológico , Proteínas Serina-Treonina Quinases/metabolismo , Sirtuína 1/metabolismo , Sirtuína 3/antagonistas & inibidores , Sirtuína 3/genética , Fatores de Tempo
18.
Toxicol Appl Pharmacol ; 363: 142-153, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30502394

RESUMO

The activation of hepatic stellate cells (HSCs) plays a critical role in liver fibrosis. In the current study, γ-mangostin (γ-man), one of the major xanthones from mangosteen (Garcinia mangostana), was found to alleviate fibrogenesis in human immortalized HSCs (LX-2 cells) and in liver from chronic carbon tetrachloride (CCl4) injured mice. γ-Man suppressed the expression levels of collagen I and α-smooth muscle actin (α-SMA) in LX-2 cells in both dose and time dependent manners. Furthermore, γ-man inhibited NAD(P)H oxidase activity through induction of sirtuin 3 (SIRT3), resulting in reduced intracellular oxidative stress in LX-2 cells. Moreover, γ-man stimulated the expression of histone deacetylase 1, which in turn decreased the acetylation and cytoplasmic shuttling of high mobility group box 1 (HMGB1), to impair autocrine HMGB1-induced HSC activation. In CCl4-injured mice, γ-man enhanced the expression of SIRT3 and decreased the expression of HMGB1, resulting in decreased accumulation of collagen I and α-SMA in liver. Consequently, γ-man might be a potent candidate to treat oxidative stress induced liver fibrosis.


Assuntos
Cirrose Hepática Experimental/tratamento farmacológico , Fígado/patologia , Transdução de Sinais/efeitos dos fármacos , Xantonas/farmacologia , Animais , Tetracloreto de Carbono/toxicidade , Linhagem Celular , Avaliação Pré-Clínica de Medicamentos , Garcinia mangostana/química , Técnicas de Silenciamento de Genes , Proteína HMGB1/metabolismo , Humanos , Fígado/efeitos dos fármacos , Cirrose Hepática Experimental/induzido quimicamente , Cirrose Hepática Experimental/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estresse Oxidativo/efeitos dos fármacos , RNA Interferente Pequeno/metabolismo , Sirtuína 3/genética , Sirtuína 3/metabolismo , Superóxidos/metabolismo , Resultado do Tratamento , Xantonas/uso terapêutico
19.
Chemosphere ; 218: 577-588, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30502696

RESUMO

Exposure to ambient fine particulate matter (PM2.5) is associated with neurodegenerative diseases. Mitochondrion is key to brain degeneration. However, the underlying mechanism of PM2.5-induced brain injury, especially mitochondrial damage, is still unclear. In this study, changes in mitochondrial dynamics, mitochondrial permeability transition pore (mPTP), mitochondrial DNA (mtDNA) and oxidative stress in human SH-SY5Y cells exposed to PM2.5 at different concentrations (0, 25, 100, and 250 µg mL-1) were investigated. The results showed that PM2.5 caused more mitochondrial swell, accompanied by the opening of mPTP and the decrease of ATP levels, mitochondrial membrane potential and mtDNA copy number in SH-SY5Y cells. PM2.5 significantly enhanced the expression of mitochondrial fission/fusion genes (Drp1 and OPA1) and affected the gene expression of CypD, SIRT3, and COX Ⅳ in SH-SY5Y cells. Besides, PM2.5 triggered the increase of cellular ROS, Ca2+ and Aß-42 levels, inhibition of manganese-superoxide dismutase (SOD2) activities, reduction of GSH levels GSH/GSSG ratio, and elevation of mitochondrial malondialdehyde contents. It suggests that mitochondrial dysfunction and oxidative stress are the potential mechanisms underlying PM2.5-induced brain nerve cell injury, which may be related to neurological diseases. Additionally, our study elucidated that PM2.5 components trigger different cytotoxicity.


Assuntos
Mitocôndrias/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Material Particulado/toxicidade , Peptídeos beta-Amiloides/genética , Linhagem Celular , China , DNA Mitocondrial/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Malondialdeído/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Dinâmica Mitocondrial , Proteínas de Transporte da Membrana Mitocondrial/efeitos dos fármacos , Neurônios/metabolismo , Fragmentos de Peptídeos/genética , Espécies Reativas de Oxigênio/metabolismo , Sirtuína 3/genética , Sirtuína 3/metabolismo , Superóxido Dismutase/genética
20.
Blood ; 133(2): 156-167, 2019 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-30455381

RESUMO

Proteasome inhibitors (PI) are extensively used for the therapy of multiple myeloma (MM) and mantle cell lymphoma. However, patients continuously relapse or are intrinsically resistant to this class of drugs. Here, to identify targets that synergize with PI, we carried out a functional screening in MM cell lines using a short hairpin RNA library against cancer driver genes. Isocitrate dehydrogenase 2 (IDH2) was identified as a top candidate, showing a synthetic lethal activity with the PI carfilzomib (CFZ). Combinations of US Food and Drug Administration-approved PI with a pharmacological IDH2 inhibitor (AGI-6780) triggered synergistic cytotoxicity in MM, mantle cell lymphoma, and Burkitt lymphoma cell lines. CFZ/AGI-6780 treatment increased death of primary CD138+ cells from MM patients and exhibited a favorable cytotoxicity profile toward peripheral blood mononuclear cells and bone marrow-derived stromal cells. Mechanistically, the CFZ/AGI-6780 combination significantly decreased tricarboxylic acid cycle activity and adenosine triphosphate levels as a consequence of enhanced IDH2 enzymatic inhibition. Specifically, CFZ treatment reduced the expression of nicotinamide phosphoribosyltransferase (NAMPT), thus limiting IDH2 activation through the NAD+-dependent deacetylase SIRT3. Consistently, combination of CFZ with either NAMPT or SIRT3 inhibitors impaired IDH2 activity and increased MM cell death. Finally, inducible IDH2 knockdown enhanced the therapeutic efficacy of CFZ in a subcutaneous xenograft model of MM, resulting in inhibition of tumor progression and extended survival. Taken together, these findings indicate that NAMPT/SIRT3/IDH2 pathway inhibition enhances the therapeutic efficacy of PI, thus providing compelling evidence for treatments with lower and less toxic doses and broadening the application of PI to other malignancies.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Neoplasias Hematológicas/tratamento farmacológico , Isocitrato Desidrogenase/antagonistas & inibidores , Oligopeptídeos/farmacologia , Inibidores de Proteassoma/farmacologia , Animais , Apoptose , Proliferação de Células , Citocinas/antagonistas & inibidores , Citocinas/genética , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/patologia , Humanos , Isocitrato Desidrogenase/genética , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Nicotinamida Fosforribosiltransferase/antagonistas & inibidores , Nicotinamida Fosforribosiltransferase/genética , RNA Interferente Pequeno/genética , Sirtuína 3/antagonistas & inibidores , Sirtuína 3/genética , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
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