SIRT3, SIRT4 and SIRT5 are located in mitochondria and also known as mitochondrial sirtuins. They play important roles in regulating many cellular functions including cell survival, cell cycle or apoptosis, DNA repair and metabolism. Mitochondrial sirtuins are involved in the protection of mitochondrial integrity and energy metabolism under stress regulating the expression of neurotransmitter receptors, neurotrophins, extracellular matrix proteins and various transcription factors, thus involved in epileptogenesis triggered by both genetic or acquired factors. Here we review research progress on the actions of mitochondrial sirtuin in epilepsy; and discuss the challenges and perspectives of mitochondrial sirtuin as a potential therapeutic target for epilepsy.
Apoptosis ; Epilepsy/genetics* ; Humans ; Mitochondria/genetics* ; Sirtuin 3 ; Sirtuins

Apoptosis ; Autophagy ; Electric Stimulation ; Oxidative Stress ; Reactive Oxygen Species ; Signal Transduction ; Sirtuin 3/metabolism*

We demonstrated the effect of resveratrol on porcine primary preadipocytes apoptosis, to study the intracellular molecular mechanism. Porcine primary preadipocyte was treated with different concentration of resveratrol (0 micromol/L, 50 micromol/L, 100 micromol/L, 200 micromol/L, 400 micromol/L). We used optical microscope and fluorescence microscope to observe morphological changes during apoptosis after Hoechst 33258 Fluorescent dyes staining; and RT-PCR and Western blotting to measure the expression of apoptosis-associated gene sirt1, caspase-3, bcl-2, bax, p53, NF-kappaB. Primary preadipocyte apoptosis was apparent, accompanied by reduced cell volume, chromatin condensation, and nuclear shrinkage. Compared to the control and low concentration group, high dose group (200 micromol/L) significantly increased the ratio of primary preadipocyte apoptosis. The expression of sirt1, caspase-3, and bax was up-regulated markedly in response to resveratrol; in contrast, apoptotic inhibitor bcl-2, p53, NF-kappaB down-regulated. We further proved fact that resveratrol can specifically promote the activity of sirt1; moreover, activated sirt1 modulates the activity of caspase-3 and bcl-2 family, involving in transcriptional regulation of p53 and NF-kappaB through antagonizing factor-induced acetylation. Taken together, our data established resveratrol as new regulator in porcine primary preadipocyte apoptosis via activating the expression of sirt1, modulating activity of apoptotic-associated factor.
Adipocytes ; cytology ; Adipogenesis ; Animals ; Antioxidants ; pharmacology ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cells, Cultured ; Sirtuin 1 ; metabolism ; Stilbenes ; pharmacology ; Swine

This study was aimed to determine the effect of acute cerebral ischemia on the protein expression level of silent mating type information regulator 2 homolog 3 (Sirt3) in the neurons and clarify the pathological role of Sirt3 in acute cerebral ischemia. The mice with middle cerebral artery occlusion (MCAO) and primary cultured rat hippocampal neurons with oxygen glucose deprivation (OGD) were used as acute cerebral ischemia models in vivo and in vitro, respectively. Sirt3 overexpression was induced in rat hippocampal neurons by lentivirus transfection. Western blot was utilized to measure the changes in Sirt3 protein expression level. CCK8 assay was used to detect cell viability. Immunofluorescent staining was used to detect mitochondrial function. Transmission electron microscope was used to detect mitochondrial autophagy. The results showed that, compared with the normoxia group, hippocampal neurons from OGD1 h/reoxygenation 2 h (R2 h) and OGD1 h/R12 h groups exhibited down-regulated Sirt3 protein expression levels. Compared with contralateral normal brain tissue, the ipsilateral penumbra region from MCAO1 h/reperfusion 24 h (R24 h) and MCAO1 h/R72 h groups exhibited down-regulated Sirt3 protein expression levels, while there was no significant difference between the Sirt3 protein levels on both sides of sham group. OGD1 h/R12 h treatment damaged mitochondrial function, activated mitochondrial autophagy and reduced cell viability in hippocampal neurons, whereas Sirt3 over-expression attenuated the above damage effects of OGD1 h/R12 h treatment. These results suggest that acute cerebral ischemia results in a decrease in Sirt3 protein level. Sirt3 overexpression can alleviate acute cerebral ischemia-induced neural injuries by improving the mitochondrial function. The current study sheds light on a novel strategy against neural injuries caused by acute cerebral ischemia.
Animals ; Brain Ischemia ; Down-Regulation ; Infarction, Middle Cerebral Artery ; Mice ; Mitochondria ; Neurons/metabolism* ; Rats ; Reperfusion Injury ; Sirtuin 3/metabolism* ; Sirtuins

Cellular replicative senescence is a major contributing factor to aging and to the development and progression of aging-associated diseases. In this study, we sought to determine viral replication efficiency of influenza virus (IFV) and Varicella Zoster Virus (VZV) infection in senescent cells. Primary human bronchial epithelial cells (HBE) or human dermal fibroblasts (HDF) were allowed to undergo numbers of passages to induce replicative senescence. Induction of replicative senescence in cells was validated by positive senescence-associated β-galactosidase staining. Increased susceptibility to both IFV and VZV infection was observed in senescent HBE and HDF cells, respectively, resulting in higher numbers of plaque formation, along with the upregulation of major viral antigen expression than that in the non-senescent cells. Interestingly, mRNA fold induction level of virus-induced type I interferon (IFN) was attenuated by senescence, whereas IFN-mediated antiviral effect remained robust and potent in virus-infected senescent cells. Additionally, we show that a longevity-promoting gene, sirtuin 1 (SIRT1), has antiviral role against influenza virus infection. In conclusion, our data indicate that enhanced viral replication by cellular senescence could be due to senescence-mediated reduction of virus-induced type I IFN expression.
Aging ; Cell Aging* ; Epithelial Cells ; Fibroblasts ; Herpesvirus 3, Human ; Humans ; Influenza, Human ; Interferon Type I ; Orthomyxoviridae ; RNA, Messenger ; Sirtuin 1 ; Up-Regulation

OBJECTIVETo observe the changes of mitochondria stress in locus coeruleus and the tyrosine hydroxylasic projection after long-term sleep deprivation.

METHODSSleep deprivation mice model was set up by employing "novel environments" method. The expression of NAD -dependent deacetylase Sirtuin type 3 (SIRT3), which regulates mitochondrial energy production and oxidative stress, and heat shock protein 60 (HSP60), a major biomarker of mitochondrial stress, and the tyrosine hydroxylasic projection from locus coeruleus were analyzed after a 5-day sleep deprivation.

RESULTSCompared to the control group, the expression of SIRT3 in locus coeruleus was significantly decreased in respouse to long-term sleep deprivation, while the expression of HSP60 was significantly increased. In addition, relative to control group, pereentage area of the tyrosine hydroxylasic projection to anterior cingulate cortex was substantial decreased in long-term sleep deprivation group.

CONCLUSIONLong-term sleep deprivation induced the decreased level of SIRT3 expression and the elevation of mitochondrial stress in locus coenileus, which may further lead to the loss of tyrosine hydroxylasic projection in mice.

Animals ; Chaperonin 60 ; metabolism ; Locus Coeruleus ; metabolism ; physiology ; Mice ; Mitochondria ; metabolism ; Mitochondrial Proteins ; metabolism ; Oxidative Stress ; physiology ; Sirtuin 3 ; metabolism ; Sleep Deprivation ; Tyrosine ; metabolism

BACKGROUNDSIRT3 is an important regulator in cell metabolism, and recent studies have shown that it may be involved in the pharmacological effects of metformin. However, the molecular mechanisms underlying this process are unclear.

METHODSThe effects of SIRT3 on the regulation of oxidative stress and insulin resistance in skeletal muscle were evaluated in vitro. Differentiated L6 skeletal muscle cells were treated with 750 µmol/L palmitic acid to induce insulin resistance. SIRT3 was knocked down and overexpressed in L6 cells. SIRT3, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65, c-Jun N-terminal kinase 1 (JNK1), and superoxide dismutase 2 (SOD2) were evaluated by Western blotting.

RESULTSOver expression of SIRT3 increased glucose uptake and decreased ROS production in L6-IR cells as well as in L6 cells. Knock-down of SIRT3 induced increased production of ROS while decreased glucose uptake in both L6 and L6-IR cells, and these effects were reversed by N-acetyl-L-cysteine (NAC). Metformin increased the expression of SIRT3 (1.5-fold) and SOD2 (2-fold) while down regulating NF-κB p65 (1.5-fold) and JNK1 (1.5-fold). Knockdown of SIRT3 (P < 0.05) reversed the metformin-induced decreases in NF-κB p65 and JNK1 and the metformin-induced increase in SOD2 (P < 0.05).

CONCLUSIONSUpregulated SIRT3 is involved in the pharmacological mechanism by which metformin promotes glucose uptake. Additionally, SIRT3 may function as an important regulator of oxidative stress and a new alternative approach for targeting insulin resistance-related diseases.

Animals ; Cell Line ; Insulin Resistance ; physiology ; Metformin ; pharmacology ; Muscle Fibers, Skeletal ; drug effects ; metabolism ; Oxidative Stress ; drug effects ; Rats ; Sirtuin 3 ; metabolism ; Transcription Factor RelA ; metabolism

This study aims to explore the anti-depression mechanism of Zuojin Pills based on the plasma constituents, network pharmacology, and experimental verification. UHPLC-TOF-MS was used for qualitative analysis of Zuojin Pills-containing serum. Targets of the plasma constituents and the disease were retrieved from PharmMapper and GeneCards. Then the protein-protein interaction(PPI) network was constructed and core targets were screened for GO term enrichment and KEGG pathway enrichment. Cytoscape 3.7.2 was employed construct the "compound-target-pathway" network and the targets and signaling pathways of Zuojin Pills against depression were predicted. CUMS-induced depression mouse model was established to verify the key targets. The results showed that a total of 21 constituents migrating to blood of Zuojin Pills were identified, which were mainly alkaloids. A total of 155 common targets of the constituents and the disease and 67 core targets were screened out. KEGG enrichment and PPI network analysis showed that Zuojin Pills may play a role in the treatment of depression through AMPK/SIRT1, NLRP3, insulin and other targets and pathways. Furthermore, the results of animal experiments showed that Zuojin Pills could significantly improve the depression behaviors of depression, reduce the levels of IL-1β, IL-6 and TNF-α in hippocampus and serum, activate AMPK/SIRT1 signaling, and reduce the protein expression of NLRP3. In conclusion, Zuojin Pills may play a role in the treatment of depression by activating AMPK/SIRT1 signaling pathway, and inhibiting NLRP3 activation and neuroinflammation in the hippocampus of mice.
Animals ; Mice ; Network Pharmacology ; AMP-Activated Protein Kinases ; Chromatography, High Pressure Liquid ; NLR Family, Pyrin Domain-Containing 3 Protein ; Sirtuin 1 ; Drugs, Chinese Herbal/pharmacology* ; Molecular Docking Simulation

BACKGROUND/OBJECTIVES: Resveratrol, a natural polyphenol, has multiple functions in cellular responses including apoptosis, survival, and differentiation. It also participates in the regulation of inflammatory response and oxidative stress. MicroRNA-Let-7A (miR-Let7A), known as a tumor suppressor miRNA, was recently reported to play a crucial role in both inflammation and apoptosis. Therefore, we examined involvement of miR-Let7A in the modulation of inflammation and cell survival/apoptosis regulated by resveratrol. MATERIALS/METHODS: mRNA expression of pro-/anti-inflammatory cytokines and sirtuin 1 (SIRT1), and protein expression of apoptosis signal-regulating kinase 1 (ASK1), p-ASK1, and caspase-3 and cleaved caspase-3 were measured, and cell viability and Hoechst/PI staining for apoptosis were observed in Lipopolysaccharide (LPS)-stimulated human THP-1 macrophages with the treatment of resveratrol and/or miR-Let7A overexpression. RESULTS: Pre-treatment with resveratrol (25-200 µM) resulted in significant recovery of the reduced cell viabilities under LPS-induced inflammatory condition and in markedly increased expression of miR-Let7A in non-stimulated or LPS-stimulated cells. Increased mRNA levels of tumor necrosis factor-α and interleukin (IL)-6 induced by LPS were significantly attenuated, and decreased levels of IL-10 and brain-derived neurotrophic factor were significantly restored by resveratrol and miR-Let7A overexpression, respectively, or in combination. Decreased expression of IL-4 mRNA by LPS stimulation was also significantly increased by miR-Let7A overexpression co-treated with resveratrol. In addition, decreased SIRT1 mRNA levels, and increased p-ASK1 levels and PI-positive cells by LPS stimulation were significantly restored by resveratrol and miR-Let7A overexpression, respectively, or in combination. CONCLUSIONS: miR-Let7A may be involved in the inflammatory response and cell survival/apoptosis modulated by resveratrol in human THP-1 macrophages.
Apoptosis ; Brain-Derived Neurotrophic Factor ; Caspase 3 ; Cell Survival ; Cytokines ; Humans ; Inflammation ; Interleukin-10 ; Interleukin-4 ; Interleukins ; Macrophages* ; MAP Kinase Kinase Kinase 5 ; MicroRNAs ; Necrosis ; Oxidative Stress ; RNA, Messenger ; Sirtuin 1

Enhanced oxidative stress is a hallmark of cisplatin nephrotoxicity, and inhibition of poly(ADP-ribose) polymerase 1 (PARP1) attenuates oxidative stress during cisplatin nephrotoxicity; however, the precise mechanisms behind its action remain elusive. Here, using an in vitro model of cisplatin-induced injury to human kidney proximal tubular cells, we demonstrated that the protective effect of PARP1 inhibition on oxidative stress is associated with sirtuin 3 (SIRT3) activation. Exposure to 400 µM cisplatin for 8 hours in cells decreased activity and expression of manganese superoxide dismutase (MnSOD), catalase, glutathione peroxidase (GPX), and SIRT3, while it increased their lysine acetylation. However, treatment with 1 µM PJ34 hydrochloride, a potent PARP1 inhibitor, restored activity and/or expression in those antioxidant enzymes, decreased lysine acetylation of those enzymes, and improved SIRT3 expression and activity in the cisplatin-injured cells. Using transfection with SIRT3 double nickase plasmids, SIRT3-deficient cells given cisplatin did not show the ameliorable effect of PARP1 inhibition on lysine acetylation and activity of antioxidant enzymes, including MnSOD, catalase and GPX. Furthermore, SIRT3 deficiency in cisplatin-injured cells prevented PARP1 inhibition-induced increase in forkhead box O3a transcriptional activity, and upregulation of MnSOD and catalase. Finally, loss of SIRT3 in cisplatin-exposed cells removed the protective effect of PARP1 inhibition against oxidative stress, represented by the concentration of lipid hydroperoxide and 8-hydroxy-2'-deoxyguanosine; and necrotic cell death represented by a percentage of propidium iodide–positively stained cells. Taken together, these results indicate that PARP1 inhibition protects kidney proximal tubular cells against oxidative stress through SIRT3 activation during cisplatin nephrotoxicity.
Acetylation ; Catalase ; Cell Death ; Cisplatin* ; Deoxyribonuclease I ; Down-Regulation* ; Glutathione Peroxidase ; Humans ; In Vitro Techniques ; Kidney ; Lipid Peroxides ; Lysine ; Oxidative Stress* ; Plasmids ; Poly Adenosine Diphosphate Ribose* ; Poly(ADP-ribose) Polymerases* ; Propidium ; Sirtuin 3* ; Superoxide Dismutase ; Transfection ; Up-Regulation