Sirtuin 1

Fatty Liver ; drug therapy ; Humans ; Sirtuin 1

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

Fatty Liver, Alcoholic ; etiology ; metabolism ; Humans ; Sirtuin 1 ; metabolism

BACKGROUND: Silent mating type information regulation 2 homolog 1 (SIRT1), an NAD+-dependent deacetylase, might act as a tumor promoter by inhibiting p53, but may also as a tumor suppressor by inhibiting several oncogenes such as beta-catenin and survivin. Deleted in breast cancer 1 (DBC1) is known as a negative regulator of SIRT1. METHODS: Immunohistochemical expressions of SIRT1, DBC1, beta-catenin, surviving, and p53 were evaluated using 2 mm tumor cores from 349 colorectal cancer patients for tissue microarray. RESULTS: Overexpression of SIRT1, DBC1, survivin, and p53 was seen in 235 (67%), 183 (52%), 193 (55%), and 190 (54%) patients, respectively. Altered expression of beta-catenin was identified in 246 (70%) patients. On univariate analysis, overexpression of SIRT1 (p=0.029) and altered expression of beta-catenin (p=0.008) were significantly associated with longer overall survival. Expression of SIRT1 was significantly related to DBC1 (p=0.001), beta-catenin (p=0.001), and survivin (p=0.002), but not with p53. On multivariate analysis, age, tumor stage, differentiation, and expression of SIRT1 were independent prognostic factors significantly associated with overall survival. CONCLUSIONS: SIRT1 overexpression is a good prognostic factor for colorectal cancer, and SIRT1 may interact with beta-catenin and survivin rather than p53.
Adenocarcinoma ; beta Catenin ; Breast Neoplasms ; Colon ; Colorectal Neoplasms ; Humans ; Multivariate Analysis ; Oncogenes ; Prognosis ; Sirtuin 1

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*

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

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

To investigate the effects of geniposidic acid( GPA) on hepato-enteric circulation in cholestasis rats,and to explore the mechanism based on the sirtuin 1( Sirt1)-farnesol X receptor( FXR) pathway,sixty SD rats were randomly divided into 6 groups:blank control group,ANIT model group,ursodeoxycholic acid group( 100 mg·kg~(-1)·d-1 UDCA),and GPA high,medium and low( 100,50 and 25 mg·kg~(-1)·d-1) dosage groups,10 rats in each group. Corresponding drugs were intragastrically( ig) administered for10 days. After administration on day 8,all rats except blank rats were administered with 65 mg·kg~(-1)α-naphthalene isothiocyanate( ANIT) once. After the last administration,the serum levels of alanine aminotransferase( ALT),glutamine oxalacetate aminotransferase( AST),gamma-glutamyltransferase( γ-GGT),alkaline phosphatase( ALP),total bilirubin( TB) and total bile acid( TBA)were measured,and the mRNA transcription levels of Sirt1,FXR,multidrug resistant associated protein 2( MRP2),bile salt export pump( BSEP),sodium taurocholate contractible polypeptide( NTCP) in liver and apical sodium bile acid transporter( ASBT),ileum bile acid binding protein( IBABP) in ileum were detected by reverse transcription-polymerase chain reaction( RT-PCR). The protein expression levels of Sirt1,FXR and NTCP were detected by Western blot; the expression of MRP2,BSEP in liver and ASBT,IBABP in ileum were determined by immunofluorescence three staining. Primary rat hepatocytes were cultured in vitro to investigate the inhibitory effect of GPA on a potent and selective Sirt1 inhibitor( EX 527),and the mRNA and protein expression levels of Sirt1 and FXR were detected by RT-PCR and Western blot. GPA significantly decreased the levels of ALT,AST,γ-GGT,ALP,TB,TBA in serum( P<0.01) and improved the pathological damage of liver tissues in ANIT-induced cholestasis rats; significantly increased the mRNA and protein expression levels of Sirt1,FXR,MRP2,BSEP,NTCP in liver and ASBT,IBABP in ileum( P< 0.01). In vitro primary hepatocytes experiment indicated that the gene and protein expression levels of FXR and Sirt1 were noticeably improved by GPA in primary hepatocytes inhibited by EX-527( P<0.01). It was found that the improvement of GPA was in a dose-dependent manner. GPA could improve bile acid hepatointestinal circulation and play a liver protection and cholagogu role in cholestasis rats induced by ANIT.The mechanism may be that GPA activated FXR by regulating Sirt1,a key regulator of oxidative stress injury,and then the activated FXR could regulate protein of bile acid hepato-enteric circulation.
Animals ; Cholestasis ; Iridoid Glucosides ; Liver ; Rats ; Rats, Sprague-Dawley ; Receptors, Cytoplasmic and Nuclear ; Signal Transduction ; Sirtuin 1

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