As the most homologic homologue of silent information regulator 2 of yeast, Sirt1 gene is extensively expressed in mature tissues, and is rich in early embryo and reproductive cells. It is involved in the regulation of gene transcription, energy metabolism and cell aging. It promotes fat mobilization in adipocytes and glucose production in liver and regulates insulin secretion in islet beta cell. Furthermore, Sirt1 gene is an essential endogenous apoptosis inhibitor. In future, it may be used as new drug targets or applied in other disease management modalities.
Animals ; Humans ; Sirtuin 1 ; genetics ; metabolism ; physiology

The sirtuin proteins constitute class III histone deacetylases (HDACs). These evolutionarily conserved NAD(+)-dependent enzymes form an important component in a variety of cellular and biological processes with highly divergent as well as convergent roles in maintaining metabolic homeostasis, safeguarding genomic integrity, regulating cancer metabolism and also inflammatory responses. Amongst the seven known mammalian sirtuin proteins, SIRT1 has gained much attention due to its widely acknowledged roles in promoting longevity and ameliorating age-associated pathologies. The contributions of other sirtuins in the field of aging are also gradually emerging. Here, we summarize some of the recent discoveries in sirtuins biology which clearly implicate the functions of sirtuin proteins in the regulation of premature cellular senescence and accelerated aging. The roles of sirtuins in various cellular processes have been extrapolated to draw inter-linkage with anti-aging mechanisms. Also, the latest findings on sirtuins which might have potential effects in the process of aging have been reviewed.
Aging, Premature ; enzymology ; genetics ; Animals ; Humans ; Longevity ; genetics ; Sirtuin 1 ; genetics ; metabolism

OBJECTIVE: To construct cytarabine-resistant acute myeloid leukemia (AML) cell lines, and explore the correlation between Sirt1, PGC-1α expression levels and drug resistance. METHODS: Human acute promyelocytic leukemia Kasumi-1 cells were induced by the method of gradually increasing the concentration of Ara-C drug. The IC₅₀ value of Kasumi-1 cells before and after drug addition was detected by CCK-8 method, so as to construct Ara-C resistant cell lines. The expression levels of Sirt1 and PGC-1α mRNA in Kasumi-1 drug-resistant cell lines and their parental cell lines were detected by real-time fluorescence quantitative PCR, and the expression levels of Sirt1 and PGC-1α protein in kasumi-1 drug-resistant cell lines and their parental cell lines were detected by Western blot. RESULTS: The constructed Kasumi-1 cell line had common morphological characteristics of drug-resistant cell lines under microscope, and the drug resistance index was greater than 5, indicating that Kasumi-1 drug-resistant cells had good drug resistance after the construction. The RT-qPCR and Western blot assays showed that the expression levels of Sirt1 and PGC-1α mRNA and protein in the drug-resistant cell lines were higher than those of the parental cell lines (P<0.001). CONCLUSION AML cell lines resistant to Ara-C can be successfully induced by the method of gradually increasing the concentration, and the co-high expression of Sirt1 and PGC-1α may mediate the drug resistance of AML cells.
Cell Line ; Cytarabine/pharmacology* ; Drug Resistance ; Humans ; Leukemia, Myeloid, Acute/genetics* ; RNA, Messenger/genetics* ; Sirtuin 1

China ; Depressive Disorder, Major ; genetics ; Humans ; Polymorphism, Single Nucleotide ; Sirtuin 1 ; genetics

Animals ; Cell Cycle Proteins/metabolism* ; Insulin Resistance/genetics* ; Liver/physiopathology* ; Mice ; Sirtuin 1/metabolism*

As a kind of mental illness, depression produces great difficulties in clinical diagnosis and treatment, and has a high disability rate. It is urgent to clarify the mechanism of depression to find potential therapeutic targets and effective clinical treatment methods. As a deacetylase, silent mating type information regulator 2 homolog 1 (SIRT1) is involved in many biological processes such as cell aging, cancer, and cardiovascular disease. In recent years, more and more studies have found that SIRT1 gene plays an important role in the pathogenesis of depression, but the mechanism is still unclear. Therefore, this review mainly summarizes the relevant research progress on the role and mechanism of SIRT1 gene in the hippocampus, prefrontal cortex, amygdala, hypothalamic suprachiasmatic nucleus, and nucleus accumbens in depression, in order to provide new ideas for exploring the mechanism and prevention of depression.
Cellular Senescence ; Depression/genetics* ; Hippocampus/metabolism* ; Humans ; Nucleus Accumbens ; Sirtuin 1/metabolism*

The silent information regulator protein 2 (Sir2) and its homologues play an important role in the regulation of cellular physiological processes such as survival, apoptosis, and aging. SIRT1, the mammalian Sir 2 homologue, has been shown to deacetylate a wide range of non-histone substrates and histone substrates. It has been constantly reported that SIRT1 may be associated with the occurrence of metabolic syndrome, genomic homeostasis, tumors, and neurodegenerative diseases. Calorie restriction may mitigate many major diseases in rodent models by SIRT1-mediated deacetylase activity and prolong the life expectancies in these animals. Therefore, SIRT1 may be emphasized as a new therapy target for many different diseases.
Animals ; Caloric Restriction ; Humans ; Longevity ; Sirtuin 1 ; genetics ; physiology ; Substrate Specificity

This study was aimed to construct Sirt1 shRNA interfering vector and to analyze the effects of Sirtl on cell proliferation and apoptosis in HepG2, A549 and 293T cell lines. To design and synthisize Sirtl shRNA sequence then recombinate it to pGenesil-1.0 plasmid, the positive pGenesil-1.0-Sirtl vector clone was screened by effective detections and sequencing. The vectors were transfected into HepG2, A549, 293T cell lines, and Sirtl expression levels in these clones were detected by RT-PCR and Western-blot. These clone cell proliferation activities were detected by MTT, and these cells apoptosis incidences were detected by MTT experiment after treated with DOX. The results showed that Sirt1 shRNA interfering vectors were successfully screened. The levels of Sirtl expression in HepG2-sh, A549-sh and 293T-sh cells were significantly reduced compared with their control cells. It was indicated that the proliferation activities of these cells were impaired and anti-apoptosis capabilities of HepG2-sh, A549-sh and 293T-sh were also impaired notably. Sirt1 took an important role in maintaining cell proliferation and resisting cell apoptosis caused by DNA damage, and this result also provided theoretical information for the further research.
Apoptosis ; genetics ; Cell Line, Tumor ; Cell Proliferation ; Genetic Vectors ; Humans ; RNA Interference ; RNA, Small Interfering ; genetics ; Sirtuin 1 ; genetics ; Transfection

OBJECTIVE: To explore the possible effects and mechanism of Zhizhu Decoction (ZZD) on the pathophysiology of slow transit constipation (STC). METHODS: A total of 54 C57BL/6 mice was randomly divided into the following 6 groups by a random number table, including control, STC model (model), positive control, and low-, medium- and high-doses ZZD treatment groups (5, 10, 20 g/kg, namely L, M-, and H-ZZD, respectively), 9 mice in each group. Following 2-week treatment, intestinal transport rate (ITR) and fecal water content were determined, and blood and colon tissue samples were collected. Hematoxylin-eosin and periodic acid-Schiff staining were performed to evaluate the morphology of colon tissues and calculate the number of goblet cells. To determine intestinal permeability, serum levels of lipopolysaccharide (LPS), low-density lipoprotein (LDL) and mannose were measured using enzyme-linked immunosorbent assay (ELISA). Western blot analysis was carried out to detect the expression levels of intestinal tight junction proteins zona-occludens-1 (ZO-1), claudin-1, occludin and recombinant mucin 2 (MUC2). The mRNA expression levels of inflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-4, IL-10 and IL-22 were determined using reverse transcription-quantitative reverse transcription reaction. Colon indexes of oxidative stress were measured by ELISA, and protein expression levels of colon silent information regulator 1/forkhead box O transcription factor 1 (SIRT1/FoxO1) antioxidant signaling pathway were detected by Western blot. RESULTS: Compared with the model group, ITR and fecal moisture were significantly enhanced in STC mice in the M-ZZD and H-ZZD groups (P<0.01). Additionally, ZZD treatment notably increased the thickness of mucosal and muscular tissue, elevated the number of goblet cells in the colon of STC mice, reduced the secretion levels of LPS, LDL and mannose, and upregulated ZO-1, claudin-1, occludin and MUC2 expressions in the colon in a dose-dependent manner, compared with the model group (P<0.05 or P<0.01). In addition, ZZD significantly attenuated intestinal inflammation and oxidative stress and activated the SIRT1/FoxO1 signaling pathway (P<0.05 or P<0.01). CONCLUSION ZZD exhibited beneficial effects on the intestinal system of STC mice and alleviated intestinal inflammation and oxidative stress via activating SIRT1/FoxO1 antioxidant signaling pathway in the colon.
Mice ; Animals ; Sirtuin 1/genetics* ; Antioxidants ; Occludin ; Lipopolysaccharides ; Claudin-1 ; Mannose ; Mice, Inbred C57BL ; Constipation/drug therapy* ; Inflammation ; Signal Transduction

OBJECTIVE: To explore the mechanism of electroacupuncture (EA) for the regulation of lipid production and improvement in obesity by mediating Wnt/β-catenin pathway through activating silent information regulator 1 (SIRT1). METHODS: Of 75 Wistar male rats, 10 rats were selected randomly as the normal group and fed with standard diet. The rest rats were fed with high-fat diet for 8 weeks to establish the obesity model. Forty rats of successful modeling were randomized into a model group, an EA group, an EA plus inhibitor group (EA+I group) and an agonist group, 10 rats in each one. In the EA group, EA was applied at "Guanyuan" (CV 4), "Zhongwan" (CV 12), "Zusanli" (ST 36) and "Fenglong" (ST 40), with continuous wave, 2 Hz in frequency and around 1 mA in intensity. The needles were retained for 20 min. In the EA+I group, sirtinol solution was injected from caudal vein and EA was exerted simultaneously. In the agonist group, resveratrol solution was given by intragastric administration. The intervention of the above three groups was given once every two days, 3 times a week, consecutively for 8 weeks. Before and after intervention, body mass and Lee's index were recorded in the rats of each group. After intervention, the levels of serum total cholesterol (TC), triglyceride (TG) and free fatty acid (FFA) were detected in the rats of each group. After intervention, the mass of white adipose tissue (WAT) and the area of adipocytes were compared in the rats among the 5 groups. Using Western blot method, the protein expressions of SIRT1, glycogen synthase kinase-3β (GSK3β), β-catenin, cyclin D1 and peroxisome proliferators-activated receptor γ (PPARγ) were detected in WAT in the rats of each group. RESULTS: After intervention, compared with the model group, the body mass and Lee's index were reduced in the rats of the EA group and the agonist group ( CONCLUSION Electroacupuncture remarkably improves the body mass, Lee's index and blood lipid metabolism and reduces WAT mass and adipocyte size in obesity model rats, which is probably related to up-regulating the protein expression of SIRT1 in WAT, activating Wnt/β-catenin pathway and inhibiting the expression of PPARγ of downstream lipogenic gene so as to affect lipid production.
Acupuncture Points ; Animals ; Electroacupuncture ; Male ; Obesity/therapy* ; Rats ; Rats, Wistar ; Sirtuin 1/genetics* ; Triglycerides ; beta Catenin/genetics*