Resveratrol up regulates the expression of SIRT1 and mediates protective effect on radiation-induced myocardial injury / 中华放射肿瘤学杂志

Objective:To evaluate the effect of resveratrol on radiation-induced myocardial injury in mice.Methods:A total of 80 C57BL/6 mice were randomly divided into the control group, resveratrol (Res) group, radiation (RT) group and radiation+resveratrol (RT+Res) group. In the RT group, mice were given with heart radiation and mice in the Res group were given with resveratrol by gavage for 3 months. Cardiac ultrasound was used to evaluate cardiac function at 3 months after cardiac radiation. The hearts of mice were collected for HE staining, immunofluorescence, TUNEL staining, Masson staining and Western blot to evaluate the expression of silent information regulator 1 (SIRT1), the level of oxidative stress, inflammatory response, apoptosis and the degree of fibrosis in myocardial tissues. Experimental data were expressed as Mean ± SD. Continous data were statistically analyzed by t-test. Results:After 3 months of irradiation, compared with the control group, the ejection fraction (EF) and fractional shortening (FS) of cardiac function were decreased, and myocardial degeneration and disorder, reactive oxygen species (ROS) and inflammatory levels (interleukin-1β, interleukin-6, tumor necrosis factor-α), myocardial apoptosis (TUNEL positive cell rate) and fibrosis were increased in the RT group. In the RT+Res group, the cardiac function was improved, the expression of SIRT1 was increased, and the levels of oxidative stress, inflammation, myocardial apoptosis and fibrosis were decreased.Conclusions:Resveratrol can reduce oxidative stress, inflammatory infiltration, apoptosis and fibrosis of myocardium in mice with radiation-induced myocardial injury, thereby improving cardiac structural abnormalities and cardiac dysfunction. This protective effect can be mediated by upregulation of SIRT1 expression.

Effect of Gegen Qinliantang on SIRT1/FoxO1 Autophagy Pathway in db/db Diabetic Mice / 中国实验方剂学杂志

ObjectiveTo validate the alleviating effect of Gegen Qinliantang （GGQLT） on insulin resistance in db/db diabetic mice by regulating the silent information regulator 1 （SIRT1）/forkhead transcription factor O1 （FoxO1） autophagy pathway. MethodSeventy-five SPF-grade spontaneous type 2 diabetic db/db mice and 15 control db/m mice were selected and maintained on regular feed for one week before measuring blood glucose. They were randomly divided into six groups， with 15 mice in each group. The groups included a normal group （physiological saline， 0.2 g·kg-1）， a metformin group （0.2 g·kg-1）， high-， medium-， and low-dose GGQLT groups （31.9， 19.1， 6.9 g·kg-1）， and a model group （physiological saline， 0.2 g·kg-1）. They were orally treated with corresponding drugs for eight weeks， once daily. Fasting blood glucose （FBG） was measured using a Roche glucometer. Serum levels of high-density lipoprotein cholesterol （HDL-C）， low-density lipoprotein cholesterol （LDL-C）， triglyceride （TG）， and total cholesterol （TC） were measured using an automated biochemical analyzer. Fasting serum insulin （INS） levels were determined using enzyme-linked immunosorbent assay （ELISA）， and the homeostasis model assessment of insulin resistance （HOMA-IR） was calculated. Western blot was used to detect the expression of Beclin-1， microtubule-associated protein 1 light chain 3 （LC3）， and SIRT1/FoxO1 autophagy pathway-related proteins in liver tissues. Immunohistochemistry was performed to assess the expression of SIRT1， FoxO1， Beclin-1， and LC3B proteins in liver tissues. Transmission electron microscopy was used to observe the formation of autophagosomes in the liver. ResultCompared with the normal group， the model group showed significant increases in FBG， FINS， HOMA-IR， TC， TG， LDL-C， and HDL-C levels （P<0.01）， and significant increases in the expression of SIRT1， Beclin-1， LC3， and FoxO1 proteins in liver tissues （P<0.01）. Transmission electron microscopy revealed the highest number of autophagosomes in the model group. Compared with the model group， the metformin group and the low-， medium-， and high-dose GGQLT groups showed significant decreases in serum FBG， FINS， HOMA-IR， TC， TG， LDL-C， and HDL-C levels （P<0.05， P<0.01）， significant decreases in the expression of SIRT1， Beclin-1， LC3 （P<0.05， P<0.01）， and up-regulated FoxO1 protein （P<0.01）. Transmission electron microscopy showed a reduction in the degree of autophagy in the treatment groups. Compared with the metformin group， the medium- and high-dose GGQLT groups showed significant decreases in FBG， FINS， and TG levels （P<0.01）， significant decreases in the expression of SIRT1， Beclin-1， and LC3 in liver tissues （P<0.05， P<0.01）， and reduced FoxO1 protein （P<0.01）. The high-dose GGQLT group showed reduced HOMA-IR， TC， LDL-C， and HDL-C levels （P<0.05， P<0.01）. Transmission electron microscopy revealed a significant reduction in autophagosomes in the medium- and high-dose GGQLT groups. ConclusionGGQLT can significantly improve glucose and lipid metabolism disorders， alleviate insulin resistance in db/db mice， and prevent and treat type 2 diabetes by activating the SIRT1/FoxO1 autophagy pathway.

Regulatory Mechanism of Berberine in Inhibiting Apoptosis and Autophagy in Ovarian Granulosa Cells Based on SIRT1/FoxO1 Pathway / 中国实验方剂学杂志

ObjectiveTo investigate the protective effect and regulatory mechanism of berberine （BBR） against the senescence of ovarian granulosa cells. MethodA cell senescence model in the human ovarian granulosa-like tumor （KGN） cell line was induced by H2O2. A control group， a model group， and high-dose （1 μmol·L-1） and low-dose （0.5 μmol·L-1） BBR groups were set up. The cells in the model group and the BBR groups were incubated with 10 μmol·L-1 H2O2 for 40 min. The effect of BBR on KGN cell proliferation was detected by cell counting kit-8 （CCK-8） assay. The effect of BBR on the senescence of KGN cells was detected by β-galactosidase staining. The effects of BBR on the apoptosis and ROS content of KGN cells were detected by flow cytometry. The effects of BBR on the mRNA expression of B-cell lymphoma-2 （Bcl-2）/Bcl-2-associated X protein （Bax）， cysteinyl aspartate-specific protease-3 （Caspase-3）， forkhead transcription factor O1 （FoxO1）， and catalase （CAT） was detected by Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. Western blot was used to detect the effects of BBR on protein expression of silent information regulator1 （SIRT1）， superoxide dismutase 2 （SOD2）， c-Jun N-terminal kinase （JNK）， FoxO1， autophagy-associated protein microtubule-associated protein light chain 3Ⅱ （LC3BⅡ）， mammalian ortholog of yeast Atg6 （Beclin-1）， and ubiquitin-binding protein p62. ResultAfter H2O2 induction for 40 min， the cell proliferation rate of the model group decreased compared with that of the control group （P<0.01）， and the cell proliferation rates of the BBR groups increased compared with that of the model group （P<0.05）. The results of β-galactosidase staining showed that the cells of the model group showed significant senescence compared with those of the control group （P<0.01）， and the cellular senescence in the BBR groups was reduced compared with that of the model group （P<0.01）. As revealed by flow cytometry， compared with the control group， the model group showed increased apoptosis rate （P<0.01）， and compared with the model group， BBR groups showed decreased apoptosis rates （P<0.05）. Meanwhile， the ROS content in the model group increased compared with that in the control group （P<0.01）， and compared with the model group， the BBR groups showed reduced cellular ROS content （P<0.01）. The Real-time PCR results showed that compared with the control group， the model group showed decreased mRNA expression of CAT and Bcl-2/Bax in KGN cells and increased mRNA expression of Caspase-3 and FoxO1 （P<0.05）， and compared with the model group， the BBR groups showed increased mRNA expression of CAT and Bcl-2/Bax （P<0.05） and reduced mRNA expression of Caspase-3 and FoxO1 in KGN cells （P<0.05）. As revealed by Western blot results， SIRT1， SOD2， and p62 protein levels decreased in the model group compared with those in the control group （P<0.01）， and JNK FoxO1， LC3BⅡ， and Beclin-1 protein levels increased （P<0.05）. After BBR intervention， SIRT1， SOD2， and p62 protein levels increased （P<0.01）， and JNK， FoxO1， LC3BⅡ， and Beclin-1 protein levels decreased compared with those in the model group （P<0.05）. ConclusionBBR has an inhibitory effect on ovarian granulosa cell senescence， and the mechanism is related to the inhibition of apoptosis and autophagy mediated by the SIRT1/FoxO1 pathway.

Mechanism of Salvianolate in Inducing Autophagy in Podocytes of Rats with Membranous Nephropathy via AMPK/SIRT1/PGC-1α Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo observe the effect of salvianolate on the protein expressions of adenosine monophosphate （AMP）-activated protein kinase （AMPK）， silent information regulator 1 （SIRT1） and peroxisome proliferator-activated receptor-γ coactivator-1α （PGC-1α）， autophagy and apoptosis in kidney tissue of rats with membranous nephropathy （MN）， and to explore its possible molecular mechanism against MN. MethodEighty male SD rats were randomly divided into normal group， model group， benazepril hydrochloride group （10 mg·kg-1）， and salvianolate low-， medium-， and high-dose groups （16.7， 33.3 and 66.7 mg·kg-1）. The rats were modeled by injection of cationized bovine serum albumin （C-BSA） into the tail vein. After successful modeling， rats in the administration groups were given corresponding doses of drugs for 4 consecutive weeks， and then 24-hour urine， serum and kidney tissue were collected for the detection of 24-hour urinary protein （UTP）， blood urea nitrogen （BUN）， serum creatinine （SCr）， interleukin-6 （IL-6）， tumor necrosis factor-α （TNF-α）， C reactive protein （CRP）， glutathione peroxidase （GSH-Px）， superoxide dismutase （SOD）， and malondialdehyde （MDA）. The pathological changes of kidneys were observed by light microscope， electron microscope and immunofluorescence. Western blot was used to detect the protein expressions of phospho-AMPK （p-AMPK）， AMPK， phospho-SIRT1 （p-SIRT1）， SIRT1 and PGC-1α in rat kidney tissue. The protein expressions of autophagy-specific gene （Beclin-1）， microtubule-associated protein 1 light chain 3 （LC3） Ⅱ， ubiquitin-binding protein （p62）， B cell lymphoma （Bcl-2）， Bcl-2-associated X （Bax）， and cysteine aspartic protease-7 （Caspase-7） in rat kidney tissue were determined by immunohistochemistry （IHC）. ResultCompared with the conditions in the normal group， the levels of UTP， IL-6， TNF-α， CRP and MDA in the model group were increased （P<0.05） while the levels of SOD and GSH-Px were decreased （P<0.05）， and there was no difference in BUN and SCr. Compared with the model group， the administration groups had lowered UTP， IL-6， TNF-α， CRP and MDA （P<0.05） while elevated SOD and GSH-Px （P<0.05）. It could be seen from hematoxylin and eosin （HE） staining， Masson staining， immunofluorescence and electron microscopy that the pathological damage of rat kidney tissue in the model group was significant， but after treatment with benazepril hydrochloride and salvianolate， the pathological damage of kidney cells was gradually improved. The expressions of p-AMPK/AMPK， p-SIRT1/SIRT1， PGC-1α， Bcl-2， Beclin-1 and LC3Ⅱ in rat kidney in the model group were lower than those in the normal group （P<0.05） while the expressions of Bax， Caspase-7 and p62 were higher （P<0.05）. Compared with the model group， benazepril hydrochloride group and salvianolate groups had an up-regulation in the expressions of p-AMPK/AMPK， p-SIRT1/SIRT1， PGC-1α， Bcl-2， Beclin-1 and LC3Ⅱ in the kidney （P<0.05） while a down-regulation in the expressions of Bax， Caspase-7 and p62 （P<0.05）. ConclusionThe protective effect of salvianolate on the kidneys of MN rats may be related to the activation of AMPK/SIRT1/PGC-1α signaling pathway， the up-regulation of autophagy and the reduction of apoptosis.

Correlation of macrophage-related cytokines and silent information regulator 1 and forkhead box protein O3 levels in peripheral blood mononuclear cells in patients with active pulmonary tuberculosis / 中国热带医学

@#Abstract: Objective　To explore the correlation between the levels of silent information regulator 1 (SIRT1) and forkhead box protein O3 (FOXO3) in peripheral blood mononuclear cells of patients with active pulmonary tuberculosis (APTB) and macrophage-related cytokines-inducible nitric oxide synthase (iNOS) and arginase-1 (Arg-1). Methods　A total of 64 APTB patients who were treated in Yubei Hospital, the First Affiliated Hospital of Chongqing Medical University from January 2020 to December 2021 were gathered as the APTB group, 59 people with latent tuberculosis infection (LTBI) were gathered as the LTBI group, and 62 healthy people were gathered as the control group. Quantitative real-time PCR (qPCR) method was performed to measure the levels of SIRT1 mRNA and FOXO3 mRNA in peripheral blood mononuclear cells. The enzyme-linked immunosorbent assay (ELISA) was performed to measure serum iNOS and Arg-1 levels; ROC curve was used to analyze the value of SIRT1 mRNA and FOXO3 mRNA levels in the differential diagnosis of LTBI and APTB; Pearson correlation was performed to analyze the correlation of SIRT1 mRNA and FOXO3 mRNA in peripheral blood mononuclear cells of APTB patients with serum iNOS and Arg-1 levels. Results　The levels of SIRT1 mRNA, FOXO3 mRNA and serum iNOS in peripheral blood mononuclear cells decreased in control group, LTBI group and APTB group, and the level of serum Arg-1 increased in turn (P<0.05). The AUCs of SIRT1 mRNA and FOXO3 mRNA in differential diagnosis of LTBI and APTB were 0.876 and 0.887, respectively, the sensitivity was 71.2% and 76.3%, and the specificity was 96.9% and 90.6% respectively. The levels of SIRT1 mRNA and FOXO3 mRNA in peripheral blood mononuclear cells of APTB patients were positively correlated (r=0.500, P<0.05), and they were positively correlated with serum iNOS and negatively correlated with serum Arg-1 (P<0.05). The SIRT1 mRNA, FOXO3 mRNA and serum iNOS in peripheral blood mononuclear cells of APTB patients after 6 months of treatment were higher than those before treatment, and serum Arg-1 was lower than before treatment (P<0.05). Conclusions　The levels of SIRT1 mRNA and FOXO3 mRNA in peripheral blood mononuclear cells of APTB patients are low, and they are positively correlated with macrophage-related cytokine iNOS and negatively correlated with Arg-1.

Promoting effect of miR-15a on high glucose-induced oxidative stress in human lens epithelial cells and its mechanism / 中华实验眼科杂志

Objective:To investigate the effect of microRNA-15a (miR-15a) on the anti-oxidative stress ability of human lens epithelial cells (LECs) induced by high glucose and its possible mechanism.Methods:The anterior lens capsule specimens from patients with diabetic cataract (DC) and healthy donors were collected.The expressions of miR-15a and silent information regulator 1 (SIRT1) in the specimens were detected by real-time quantitative PCR (RT-qPCR) and Western blot, respectively.The human lens epithelial cell line HLEB-3 cells were cultured with 0, 10, 20, or 50 mmol/L glucose for 24 hours.The expression of miR-15a in the cells was detected by RT-qPCR.The expressions of SIRT1, forkhead transcription factor 3a (FOXO3a), and p53 proteins in the cells were determined by Western blot.The cell apoptosis was assayed by flow cytometry.The endogenous reactive oxygen species (ROS) content in the cells was measured by 2, 7-dichlorodihydrofluorescein diacetate (DCFH-DA). The total antioxidant capacity (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activity, and malondialdehyde (MDA) activities in the cells were identified.HLEB-3 cells were transfected with miR-15a control or miR-15a inhibitor, then incubated with 50 mmol/L glucose for 24 hours.Cell apoptosis of the transfected cells was detected by flow cytometry.The endogenous ROS expression in the transfected cells was determined by DCFH-DA.The T-AOC, SOD, and GSH-Px activities as well as MDA concentration were measured.The relationship between miR-15a and SIRT1 was verified by dual-luciferase reporter assay.The SIRT1, FOXO3a, and p53 protein expressions in the transfected cells were detected by Western blot.This study was approved by an Ethics Committee of the Second Affiliated Hospital of Zhengzhou University (No.ZDEFY201803160023). Written informed consent was obtained from each subject.Results:The relative expression of miR-15a in normal lens anterior capsule tissue was 0.21±0.02, which was lower than 0.96±0.10 in lens anterior capsule tissue of DC patients, and the difference was statistically significant ( t=12.231, P<0.001). The relative expression of SIRT1 in the anterior lens capsule tissue was 0.89±0.09, which was higher than 0.31±0.05 in the anterior lens capsule tissue of DC patients, showing a statistically significant difference ( t=8.964, P<0.001). With the increase of glucose concentration, the relative expression of miR-15a, FOXO3a, and p53 in cells increased, and the relative expression of SIRT1 decreased; the apoptosis rate of cells increased; the ROS content and MDA concentration increased; the activities of T-AOC, SOD and GSH-Px decreased, and the differences were statistically significant (all at P<0.05). The apoptosis rate, ROS content, and MDA concentrations were higher in miR-15a control group than miR-15a inhibitor group, and the activities of T-AOC, SOD, and GSH-Px were lower in miR-15a control group than miR-15a inhibitor group, with statistically significant differences (all at P<0.05). The luciferase activity of the SIRT1-3'-untranslated region (UTR)-wild type (WT) reporter gene in miR-15a control group was significantly lower than that in miR-15a inhibitor group, and the difference was statistically significant ( t=5.978, P=0.004). No significant difference was found in the luciferase activity of the SIRT1-3'-UTR-mutant type (MUT) reporter gene ( t=0.432, P=0.688). The relative expressions of FOXO3a and p53 proteins were significantly higher in miR-15a control group than miR-15a inhibitor group, and the relative expression of SIRT1 protein was significantly lower in miR-15a control group than miR-15a inhibitor group, showing statistically significant differences (all at P<0.05). Conclusions:miR-15a can inhibit the anti-oxidative stress damage ability of LECs induced by high glucose, which may be achieved by inhibiting the expression of SIRT1 to up-regulate the activities of FOXO3a and p53, and aggravating apoptosis.

Perfluorooctanoic acid-induced lipid metabolism disorder in SD rat liver and its effect on the expression of fatty acid metabolism-related proteins / 中南大学学报(医学版)

OBJECTIVES@#Perfluorooctanoic acid (PFOA) can cause lipid metabolism disorders in animal body and affect the lipolysis and synthesis of fatty acids. Peroxisome proliferators-activated receptor (PPAR) plays an extremely important role in this process. This study aims to explore the effects of PFOA on liver lipid metabolism disorders in Sprague Dewley (SD) rats and the expression of PPAR.@*METHODS@#A total of 40 male SD rats were randomly divided into 4 groups (n=10 in each group): a control group (ddH2O), a low-dose PFOA group [PFOA 1.25 mg/(kg·d)], a middle-dose PFOA group [PFOA 5.00 mg/(kg·d)], and a high-dose PFOA group [PFOA 20.00 mg/(kg·d)]. The rats were fed with normal diet, and PFOA exposure were performed by oral gavage for 14 days, and the rats were observed, weighted and recorded every day during the exposure. After the exposure, the blood was collected, and the livers were quickly stripped after the rats were killed. Part of the liver tissues were fixed in 4% paraformaldehyde for periodic acid-schiff (PAS) staining; the contents of HDLC, LDLC, TG, TC in serum and liver tissues, as well as the activities of their related enzymes were assayed; The expression levels of cyclic adenosine monophosphate-response element binding protein (Cbp), general control of amino acid synthesis 5-like 2 (Gcn5L2), peroxidation peroxisome proliferation factor activated receptor γ (PPAR), silent information regulator 1 (Sirt1) and human retinoid X receptor alpha 2 (Rxrα2) ) were detected by Western blotting.@*RESULTS@#After 14 days of PFOA exposure, the PAS staining positive particles in the cytoplasm and nucleus of SD rats in the medium and high dose groups were significantly reduced compared with the control group. The serum levels of LDLC and TC in the low-dose and middle-dose groups were significantly reduced compared with the control group (all P<0.05), while the high-dose group showed an increasing tendency, without siginificant difference (P>0.05), there was no significant difference in HDLC and TG (both P>0.05). The activities of alkaline phosphatase (AKP) and alanine aminotransferase (ALT) were increased significantly (both P<0.05) compared with control group; the ratio of ALT/aspartate aminotransferase (AST) in the high-dose group was increased significantly (P<0.05), there was no significant difference in LDH and TG (both P>0.05); the HDLC content in the liver tissues in the high-dose group was significantly reduced, compared with the control group (P<0.05); the TC contents in the liver tissues in the low, medium and high-dose groups were significantly increased (all P<0.05), there was no significant difference in LDLC and TG (both P>0.05); the AKP activity in the livers in the medium and high-dose groups was significantly increased (both P<0.05), there was no siginificant difference in LDH, ALT, and the ratio of ALT/AST (all P>0.05); the protein expression levels of Ppar γ, Cbp and Rxrα2 in the liver in the high dose groups were significantly down-regulated compared with the control group (all P<0.05), while the protein expression levels of Sirt1 were significantly up-regulated (all P<0.05).@*CONCLUSIONS@#PFOA exposure can cause lipid metabolism disorder and glycogen reduction in SD rat livers, which may be related to the activation of Sirt1 and inhibition of Ppar γ expression, leading to affecting the normal metabolism of fatty acids and promoting glycolysis.

Effects of hyperbaric oxygen on the blood-brain barrier via the SIRT1/FoxO1 signaling pathway after cerebral ischemia and reperfusion / 中华物理医学与康复杂志

Objective:To explore the effect of hyperbaric oxygen (HBO) on the blood-brain barrier via the silent information regulator 1 (SIRT1)/Forkhead box O1(FoxO1) signaling pathway after cerebral ischemia and reperfusion using a rat model.Methods:Forty Wistar rats were randomly assigned into sham, cerebral ischemia-reperfusion (CIR), CIR+ HBO and CIR+ HBO+ EX527 groups, each of 10. The cerebral ischemia-reperfusion model was established in all groups except the sham group by right middle cerebral artery occlusion using the modified thread-occlusion method. The sham group was not ligated. Both the CIR+ HBO and CIR+ HBO+ EX527 groups were given HBO 1, 9, 21, 45 and 69 hours after the reperfusion. The CIR+ HBO+ EX527 group was additionally injected with 5mg/kg of EX527(a SIRT1inhibitor) peritoneally 4, 12, 24, 48 and 72 hours after the reperfusion. Then 2% Evens blue (EB) was injected into the tail vein an hour before the rats were sacrificed. The content of EB and the expression of SIRT1, FoxO1, ZO-1, Occludin, Claudin-5 mRNA and their proteins were determined using spectrophotometry, reverse transcription-polymerase chain reactions and Western blotting.Results:The average EB content of the hippocampal brain tissue from the CIR, CIR+ HBO and CIR+ HBO+ EX527 rats was significantly greater than the Sham group′s average 72h after reperfusion. The average expression of SIRT1, FoxO1, ZO-1, Occludin and Claudin-5 mRNA and their proteins was significantly lower, with the CIR + HBO + EX 527 group′s average significantly lower than that of the CIR+ HBO group.Conclusions:HBO can increase the expression of tight junction protein via the SIRT1/FoxO1 pathway. It helps to protect the blood-brain barrier in CIR injury situations.

Effects of resveratrol-mediated inhibition of NOD-like receptor protein 3 inflammasomevia activating silent information regulator 1 on the injury of intestinal mucosal barrier function after sepsis / 中华危重病急救医学

Objective:To explore whether resveratrol (RSV) could activate silent information regulator 1 (SIRT1) to regulate the activation of NOD-like receptor protein 3 (NLRP3) inflammasome in sepsis induced intestinal injury model, and then reduce intestinal inflammation and cell apoptosis, so as to play a protective role in intestinal barrier function.Methods:① In vitro experiment: human Colorectal adenocarcinoma cells (Caco-2) were cultured, which were divided into normal group (normal culture on complete medium for 48 hours), lipopolysaccharide (LPS) group (normal culture on complete medium for 24 hours, then LPS containing 2 mg/L complete medium intervention for 6 hours), RSV low, medium and high concentration groups and SIRT1 inhibitor (EX-527) group (complete medium normal culture for 24 hours, LPS containing 2 mg/L complete medium intervention for 6 hours, followed by RSV 10, 20, 40 μmol/L or EX-527 10 μmol/L intervention for 6 hours, respectively). The levels of tumor necrosis factor-α (TNF-α) and interleukins (IL-6, IL-18, IL-1β) in the cell supernatant were determined by enzyme linked immunosorbent assay (ELISA). The apoptosis level of the cells was detected by flow cytometry. Western blotting was used to detect the protein levels of NLRP3, SIRT1, caspase-1 and apoptosis-associated speck-like protein containing a CARD (ASC). ② In vivo experiment: according to random number table method, 24 male Wistar rats were divided into sham operation group (Sham group), cecal ligation and perforation (CLP) 6 hours group (CLP 6 h group), CLP 24 h group and RSV intervention group [RSV (20 mg/kg) was intraperitoneally injected 6 hours and 12 hours after CLP], with 6 rats in each group. The levels of NLRP3, caspase-1 and ASC in the intestine of rats were detected by immunohistochemistry. Results:① Compared with the normal group, the levels of inflammatory factors in the cell supernatant of the LPS group were increased and the expression of SIRT1 protein was decreased, while the protein expressions of NLRP3, caspase-1 and ASC were increased. Compared with LPS group, different concentrations of RSV reduced the level of inflammatory factors, increased the activity of SIRT1, inhibited the expression of NLRP3 inflammasome and its downstream products caspase-1 and ASC, and the effect of high concentration of RSV (40 μmol/L) was the most significant [TNF-α (ng/L): 8.77±0.43 vs. 12.66±0.81, IL-6 (ng/L): 1.35±0.20 vs. 1.93±0.09, IL-1β (ng/L): 1.05±0.04 vs. 1.31±0.07, IL-18 (ng/L): 519.50±11.16 vs. 622.70±30.69, SIRT1/β-actin: 0.80±0.05 vs. 0.58±0.02, caspase-1/β-actin: 0.55±0.06 vs. 0.78±0.06, ASC/β-actin: 0.78±0.08 vs. 1.04±0.15, all P < 0.05], while SIRT1 inhibitor EX-527 had the opposite effects. There was no significant difference in the apoptosis rate among normal group, LPS group, and low, medium and high concentration RSV groups, as well as EX-527 group [(7.03±0.57)%, (9.67±0.55)%, (9.57±0.70)%, (9.30±2.15)%, (9.87±0.97)%, (9.07±0.93)%, F = 2.590, P = 0.082]. ② Immunohistochemical results showed that compared with the Sham group, the expressions of NLRP3 inflammasomes and downstream products caspase-1 and ASC in the intestinal epithelial cells in CLP 6 h group, CLP 24 h group and RSV intervention group were significantly increased. The percentage of ASC-positive area in intestinal epithelium of RSV intervention group was significantly lower than that of CLP 6 h group [(15.22±2.73)% vs. (19.88±2.67)%, P < 0.05], and the expressions of NLRP3 and caspase-1 were significantly lower than those of CLP 24 h group [(9.31±1.37)% vs. (13.19±1.92)%, (19.57±3.92)% vs. (27.28±6.33)%, both P < 0.05]. Conclusion:After sepsis, high concentration of RSV could inhibit the activation of NLRP3 inflammasome by activating SIRT1, thereby reduce the expression of caspase-1 and ASC, and inhibit the secretion of inflammatory factors to reduce the inflammatory response.

Esveratrol inhibits NLRP3 inflammasome activation in rabbits with spinal cord injury / 中国临床药理学与治疗学

AIM: To study the mechanism of resveratrol inhibiting NLRP3 inflammasome activation in rabbits with spinal cord injury. METHODS: Fifty male Japanese big ear rabbits were randomly divided into 5 groups: blank control group (CON group), spinal cord injury model group (SCI group), low-dose resveratrol group (RSV(L) group), and resveratrol high-dose group (RSV(H) group), methylprednisolone group (MP group), 10 rabbits in each group. Spinal cord injury models were prepared in all four groups except the CON group. All groups received iv administration daily, and the same amount of normal saline was given to the CON group and the SCI group for 14 consecutive days. The Tarlov method was used to evaluate the neurobehavioral score in rabbits. The chromogenic substrate method was used to determine the MDA content and the activity of SOD and GSH-Px in spinal cord tissues. Western blot was used to determine the proteins expression of NLRP3, Caspase1 p20, IL-1β, Sirt1, NF-κB p65 in spinal cord neural tissues, HE staining to observe the pathological changes of spinal cord tissue. RESULTS: Resveratrol increased the behavioral score of spinal cord injury rabbits, promoted the repair of injured tissues, reduced the MDA content, increased the activity of SOD and GSH-Px in spinal cord tissues, down-regulated the expression of NF-κB p65, up-regulated the expression of Sirt1 in spinal cord tissues, and inhibited expression of NLRP3 in inflammasome (reduction in expression of NLRP3, Caspase1 p20, and IL-1β in spinal cord tissues). CONCLUSION: Resveratrol can promote the recovery of spinal cord injury rabbits, and its mechanism may play a role by activating Sirt1, regulating NF-κB pathway and antioxidant level in vivo, and further inhibiting the activation of NLRP3 inflammasome.

Xuefu Zhuyu Oral Liquid () Prevents Apoptosis of Ischemic Myocardium Cells in Rats by Regulating SIRT1 and Its Pathway-Related Genes / 中国结合医学杂志

OBJECTIVE@#To observe the changes of ischemic myocardial cells apoptosis in rats following intervention with Xuefu Zhuyu Oral Liquid (, XFZY), as well as changes of protein expression of silent information regulator 1 (SIRT1) and SIRT1 pathway-related genes.@*METHODS@#H9c2 rat myocardial cells were divided into 6 groups: control group, oxygen glucose deprivation (OGD) group, SIRT1 siRNA group, OGD+SIRT1 siRNA group, OGD+XFZY group, and OGD+SIRT1 siRNA+XFZY group. Quantitative fluorescent polymerase chain reaction (PCR) and Western blot were used to detect the concentration variations of SIRT1 and its pathway-related genes and corresponding protein expression after XFZY intervention and SIRT1 transfection.@*RESULTS@#Compared with the control group, the mRNA and protein expressions of SIRT1 were decreased obviously, while the mRNA and protein levels of P53, FoxO1, FoxO3, FoxO4 and nuclear factor kappa B (NF-ΚB) were increased in the OGD group, SIRT1 siRNA group, and OGD+SIRT1 siRNA group (P<0.01). Compared with the OGD group and OGD+SIRT1 siRNA group, the treatment of XFZY inhibited the decline in SIRT1 mRNA and protein expressions (P<0.01), and down-regulated the mRNA and protein levels of P53, FoxO1, FoxO3, FoxO4 and NF-ΚB, respectively (P<0.05 or P<0.01).@*CONCLUSION@#XFZY could prevent myocardial cells apoptosis probably by increasing the mRNA and protein expressions of SIRT1 and inhibiting the mRNA and protein expressions of P53, NF- K B, FoxO1, FoxO3 and FoxO4.

Effect of electroacupuncture on silent information regulator 1, fork head transcription factor O1 and proopiomelanocortin in the hypothalamus of rats with obesity induced by high-fat diet / 针刺研究

OBJECTIVE: To investigate the effect of electroacupuncture (EA) on silent information regulator 1 (SIRT1), forkhead transcription factor O1 (FoxO1), and proopiomelanocortin (POMC) in the hypothalamus of rats with high-fat diet-induced obesity (DIO), as well as the mechanism of EA in regulating central appetite peptides to help lose weight. METHODS: Male Wistar rats were randomly divided into normal group, model group, EA group, EA＋inhibitor group, inhibitor group, and sham-operation group, with 10 rats in each group. High-fat diet was used to establish a rat model of DIO. The rats in the EA group and EA＋inhibitor group were given EA at "Fenglong" (ST40), "Zhongwan "(CV12)，"Guanyuan "(CV4), and"Zusanli" (ST36) with continuous wave at a frequency of 2 Hz and an intensity of 1 mA, for 10 minutes each time. The rats in the EA＋inhibitor group and inhibitor group were given tube placement in the third ventricle and injection of the specific SIRT1 antagonist EX-527. The rats in the sham-operation group were given tube placement in the third ventricle and injection of artificial cerebrospinal fluid. The above treatment was given 3 times a week for 8 weeks in total. Body weight, food intake, and Lee's index were observed before and after treatment. An automatic biochemical analyzer was used to measure the serum levels of total cholesterol (TC), triglyceride (TG), and free fatty acid (FFA), and Western blot was used to measure the protein expression of SIRT1, FoxO1, acetylated FoxO1(AC-FoxO1), and POMC in the hypothalamus. RESULTS: Before treatment, the model group, the EA group, the EA＋inhibitor group, the inhibitor group, and the sham-operation group had significantly higher body weight and food intake than the normal group (P<0.01), and the model group and the sham-operation group had a significantly higher Lee's index than the normal group (P<0.05). Compared with the model group after treatment, the EA group and the EA＋inhibitor group had significant reductions in body weight, food intake, TC, and the protein expression of AC-FoxO1 (P<0.01, P<0.05) and significant increases in the protein expression of SIRT1, FoxO1 and POMC (P<0.01, P<0.05); the EA group had significant reductions in Lee's index and the levels of TG, FFA(P<0.05，P<0.01)；the inhibitor group had significant increases in food intake, the serum levels of TC, TG, FFA(P<0.01) and significant reductions in the protein expression of SIRT1, FoxO1 and POMC (P<0.01，P<0.05). Compared with the EA group, the EA＋inhibitor group and the inhibitor group had significant increases in body weight, food intake, Lee's index, the levels of TG, FFA and the protein expression of AC-FoxO1 (P<0.01, P<0.05) and significant reductions in the protein expression of SIRT1, FoxO1 and POMC (P<0.01); the inhibitor group had significant increases in the serum levels of TC (P<0.01). Compared with the EA＋inhibitor group, the inhibitor group had significant increases in body weight, food intake, the serum levels of TC, TG, FFA, and the protein expression of AC-FoxO1 (P<0.01), as well as significant reductions in the protein expression of SIRT1, FoxO1 and POMC (P<0.01). CONCLUSION: In rats with DIO, EA can effectively up-regulate the expression of SIRT1 in the hypothalamus, exert a deacetylation effect on FoxO1, and promote the expression of the downstream appetite-inhibiting peptide POMC, which may be one of the mechanisms of EA to help lose weight by regulating central appetite peptides in the obesity model.

Effect of miR-181a on acute lung injury induced by sepsis in mice by targeting SIRT1 and its mechanism / 西安交通大学学报(医学版)

Objective To explore the effect and mechanism of miR-181a on sepsis-induced acute lung injury in mice by targeting silent information regulator 1 (SIRT1). Methods Lipopolysaccharide was used to induce the A549 cell model of acute lung injury. miR-181 inhibitor and inhibitor negative control (inhibitor NC) were transfected in the cells. Cecal ligation and puncture (CLP) was used to establish the mouse model of sepsis-induced acute lung injury. The mice were intravenously infused with miR-181a antagomir and antagomir NC. Then survival rate and wet-to-dry ratio of the lungs were examined, the targeting relationship between miR-181a and SIRT1 was tested by luciferase reporter assay, RT-PCR was used to detect the gene expression of miR-181a and SIRT1 in vitro and vivo. Western blotting was used to detect the protein level of SIRT1 in vitro and vivo, as well as the levels of apoptosis-related protein B-cell lymphoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), and cleave caspase-3 (cl-CASP3). Cell apoptosis was quantified by flow cytometry, cell viability was measured by CCK-8, CASP3 activity was detected by kit. HE staining was used to observe the histopathological changes in the lungs; TUNNEL staining was used to detected the cell apoptosis in the lungs. The concentrations of inflammatory cytokines were measured by ELISA. Results In cellular experiments, compared with those in control group, the expression of miR-181a was increased and the expression of SIRT1 was decreased in LPS group (P<0.01). Meanwhile the cell apoptosis rate was increased, CASP3 activity was increased, and cell viability was decreased. Treatment by miR-181a inhibitor could reverse the changes of the above indicators (P<0.01). In animal experiments, compared with those in sham group, in CLP group the mice's survival rate was decreased, wet-to-dry ratio of the lungs was increased, significant pathological changes and cell apoptosis in the lungs could be observed. Meanwhile, the concentrations of inflammatory cytokines were increased, the protein levels of miR-181a, Bax and cl-CASP3 were increased, and the protein levels of SIRT1 and Bcl-2 were decreased (P<0.01). Treatment by miR-181a antagomir could reverse the changes of the above indicators (P<0.05, P<0.01). Conclusion miR-181a can be targeted to SIRT1, and inhibition of miR-181a expression can increase SIRT1 expression, there by protecting against acute lung injury induced by sepsis in mice.

Effect of triptolide on cognitive dysfunction in vascular dementia rats through SIRT1/NF-κB signaling pathway / 中国中药杂志

To investigate the effect of triptolide on cognitive dysfunction in vascular dementia rats and its effect on SIRT1/NF-κB pathway,fifty healthy male Sprague-Dawley rats were randomly divided into 5 groups: Sham operation group( Sham group),vascular dementia model group( 2 VO group),triptolide intraperitoneal injection group( TR group),triptolide intraperitoneal injection + EX527 intracerebroventricular administration group( T+E group),EX527 intracerebroventricular administration group( EX527 group). After 4 weeks of modeling,Morris water maze test and object recognition test were used to evaluate the learning and memory ability of rats. The morphological changes of hippocampus in each group were observed in brain tissue. The chemical colorimetry was used to detect the activities of SOD and MDA in hippocampus. IL-6 and TNF-α levels were detected by ELISA. Western blot was used to detect the expression of SIRT1,NF-κB,IκBα and caspase 3 in hippocampus. The results showed that compared with the Sham group,the learning and memory ability of the vascular dementia model rats was reduced,the SOD activity in the hippocampus was decreased,the MDA activity and IL-6 level were increased,the neuronal degeneration changed significantly,the expression of SIRT1 and IκBα was decreased and the expression of caspase 3 and NF-κB was significantly increased. After intervention by triptolide,the level of oxidative stress and the degenerative changes in hippocampus were significantly slowed down. The expression of SIRT1 and IκBα protein was increased and the expression of caspase 3 and NF-κB was significantly decreased. While,after intervention by triptolide and EX527,the expression of SIRT1 was decreased,the levels of oxidative stress and neuronal degeneration in the hippocampus were aggravated,and the learning and memory ability was reduced. The results showed that triptolide could improve cognitive impairment in vascular dementia rats and its mechanism may be related to SIRT1/NF-κB signaling pathway.

MicroRNA-21 attenuates doxorubicin-induced cardiotoxicity by activating silent information regulator 1 signaling pathway / 第二军医大学学报

Objective To explore whether microR-21 (miR-21) can alleviate doxorubicin (DOX)-induced cardiotoxicity and whether silent information regulator 1 (SIRT1) signaling pathway mediates the roles. Methods Neonatal rat cardiac myocytes were treated with DOX (1 µmol/L) to induce DOX myocardial toxicity model. The cardiomyocytes were randomized into 8 groups: control group, miR-21 group, miR-21 inhibitor group, DOX group, miR-21+DOX group, miR-21 inhibitor+DOX group, Sirtinol+miR-21+DOX group and Sirtinol+DOX group. The miR-21 mimics, miR-21 inhibitors and Sirtinol (SIRT1 inhibitor) were given at 24 h before DOX treatment. After treatment with DOX for 24 h, the cell viability, apoptosis rate, and the expression levels of apoptosis-related proteins and SIRT1 signaling pathway were detected. Results Compared with the control group, the cell viability, and the expression levels of Bcl-2 and SIRT1 were significantly decreased in the cardiomyocytes after treatment with DOX for 24 h, while the expression levels of Bax and cleaved Caspase-3, and apoptotic rate were significantly increased (P<0.05). Compared with the DOX group, miR-21 significantly increased cell viability and the expression levels of Bcl-2 and SIRT1, and significantly decreased the expression levels of Bax and cleaved Caspase-3 and apoptotic rate (P<0.05). Inhibiting SIRT1 signaling pathway could significantly weaken the protective effect of miR-21 on cardiomyocytes (P<0.05). Conclusion miR-21 can inhibit cardiomyocyte apoptosis, increase cell viability and alleviate DOX-induced cardiotoxicity by activating SIRT1 signaling pathway.

Research advances in the mechanisms of silent information regulator 1 in the treatment of myocardial ischemia / 中华老年医学杂志

Silent information regulator 1(SIRT1)belongs to nicotinamide adenine dinucleotide(a classic coenzyme) dependent class Ⅲ histone deacetylases.SIRT1 regulates gene expression through altering the acetylation level of nuclear histone and participates in the regulation of a range of important life activities,such as cardiomyocyte autophagy,nucleocytoplasmic shuttling,cell aging,inflammatory responses,etc.It has been showed that SIRT1 plays an important role in myocardial ischemia by mitigating cardiomyocyte apoptosis and enhancing cellular resistance to oxidative stress under ischemic conditions.This article gives an overview of the mechanisms and research progress of SIRT1 in myocardial ischemia,aiming to serve as a reference for myocardial ischemia therapy.

Resveratrol alleviates cerebral ischemia/reperfusion injury in mice by promoting mitophagy / 中国药理学通报

Aim: To investigate the effects of resveratrol (Res) pretreatment on focal cerebral ischemia/reperfusion (I/R) injury and the possible mechanism. Methods: Transient focal cerebral ischemia was introduced into mice by right middle cerebral artery occlusion (MCAO) technique. For Res treatment, C57BL/6J mice were given an intraperitoneal injection with ' Res per day for 5 days. After 24 h of reperfusion, infarct volume, neurological function were assessed. Western blot was used to analyse the expression of silent information regulator 1(SIRT1), mitophagy-relat-ed proteins, and the distribution of cytochrome C (CytC). Flow cytometry assay was introduced to test mitochondrial membrane potential (MMP). A micro-plate reader was used to detect the cellular adenosine triphosphate (ATP) levels. Transmission electron microscopy (TEM) was conducted to observe mitochondrial morphology. Results: Res pretreatment reduced infarct volume and neurological deficit, improved the expression of SIRT1 and mitophagy. Meanwhile, Res attenuated CytC release, recovered MMP, and improved ATP levels. TEM results showed Res could protect the mitochondria from I/R injury-induced destruction. However, as 3-MA was used to inhibit the activation of mitophagy, the protective effects of Res on neurological and mitochondrial function were reversed. Conclusions: Res pretreatment could relieve cerebral I/R injury. The mechanism might be associated with the regulation of mitophagy to maintain mitochondrial structural and functional integrity.

Mechanism and effect of H₂S on oxidative stress in diabetic cataract rats / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To explore the effect of hydrogen sulfide(H₂S)on oxidative stress in diabetic cataract rats and its mechanism. <p>METHODS:SD rats were randomly divided into control group, diabetic group, low-dosage NaHS-treated group, high-dosage NaHS-treated group, and NaHS treated alone group. NaHS was used as a donor of H₂S. The diabetic model was established by a single intraperitoneally administrating streptozotocin(STZ, 65mg/kg). BQ900 slit lamp was used to recorded the changes of lenses. At the end of experiment, the level of superoxide dismutase(SOD)was measured by xanthine oxidase test, the activity of malondialdehyde(MDA)was detected by thiobarbituric acid test, and glutathione(GSH-Px)were detected by corresponding assay kits. Western blotting was applied to detect the expression of SIRT1. <p>RESULTS:The lenses of diabetic group showed different levels of turbidity, which demonstrated that diabetic cataract model was successfully established. Low-dosage NaHS and high-dosage NaHS treatment dramatically alleviated turbidity levels of lenses in diabetic rats, respectively. Compared to diabetic group, low-dosage NaHS and high-dosage NaHS treatment obviously decreased the levels of MDA and increased the levels of SOD and GSH-Px. Furthermore, the SIRT1 expression in lens of diabetic rats was downregulated, and low-dosage NaHS as well as high-dosage NaHS treatment significantly reversed this change. <p>CONCLUSION:H₂S protects against oxidative stress in STZ-induced diabetic rats involving upregulation of SIRT1.

Effect of NMN on renal fibrosis of diabetic nephropathy rats and its mechanism / 吉林大学学报(医学版)

Objective: To investigate the effect of niacinamide mononucleotide (NMN) on the fibrosis of renal cells in the rats with diabetic nephropathy (DN), and to elucidate the mechanism of NMN in regulating the fibrosis of renal parenchymal cells through silent information regulator 1 (Sirtl) and AKT pathways. Methods: The rat models of type 2 diabetes mellitus were induced by streptozotocin (STZ) and the model rats were randomly divided into experiment group (n= 30) and control group (n=10). The rats in experiment group were divided into diabetes + NMN group (n=15) and diabetes + PBS group (n=15). The rats in diabetes+ NMN group were given subcutaneous injection of NMN for 20 d and the rats in diabetes + PBS group were given 200 μL sterile PBS in the same way. Then the rats were decapitated and the kidney tissues were taken for section and protein extraction. The expression levels of Sirtl, AKT, p-Fox03a and Cav-1 proteins in kidney tissue of the rats in various groups were detected by Western blotting method and immuno-confocal focusing. The glomerular mesangial HBZY-1 cells were treated with high concentration of glucose (200 mmol · L-1) for 3-6 d, and then the cells were further randomly divided into 4 groups (treated with 0, 50, 100, and 200 mmol · L-1 NMN) and the cells only treated with 5. 6 mmol · L-1 glucose were regareded as control group. After 24 h culture, the cells were collected and the expression levels of Sirtl, AKT, and p-Fox03a proteins in the HBZY-1 cells in various groups were detected by Western blotting method. Results: Compared with diabetes +PBS group, the expression levels of Sirtl and AKT proteins in the renal parenchyma cells of the rats in diabetes+ NMN group were significantly increased (P<0. 01) and the expression levels of p-Fox03a and Cav-1 proteins in the renal parenchyma cells of the rats in diabetes + NMN group were also increased (P<0. 01). Compared with control group, the expression levels of Sirtl and AKT proteins in the HBZY-1 cells of the rats in 50 mmol · L-1 NMN group were significantly increased (P<0. 01), and the expression levels of Sirtl, AKT, and p-Fox03a proteins in the HBZY-1 cells in 100 and 200 mmol · L-1 NMN groups were increased significantly (P<0. 05 or P<0. 01). Conclusion: NMN can increase the expression levels of endogenous p-Fox03a and Cav-1 proteins in the glomerular cells of the DN rats by regulating the expression levels of Sirtl and AKT proteins, indicating that NMN and its analogues may play an important role in the prevention and treatment of the renal fibrosis of the DN rats.

Effects of microRNA-34a on regulating silent information regulator 1 and influence of the factor on myocardial damage of rats with severe burns at early stage / 中华烧伤杂志

Objective@#To explore the effects of microRNA-34a on regulating silent information regulator 1 (SIRT1) and influence of SIRT1 on myocardial damage of rats with severe burns at early stage.@*Methods@#(1) Twenty-four Sprague-Dawley (SD) rats were divided into sham injury (SI) group, simple burns (SB) group and SIRT1 agonist (SA) group according to the random number table (the same grouping method below), with 8 rats in each group. Rats in groups SB and SA were inflicted with 30% total body surface area full-thickness scald (hereinafter referred to as burns) on the back, and rats in group SI were sham injuried on the back. Immediately after injury, rats in groups SI and SB were intraperitoneally injected with normal saline of 50 mL/kg, and rats in group SA were intraperitoneally injected with normal saline of 50 mL/kg and 1 mg/mL resveratrol of 50 mg/kg. At 6 h post injury, abdominal aortic blood was collected to make serum and myocardial tissue of rats was collected. (2) Myocardial cells of twelve neonatal SD rats were collected and divided into microRNA-34a mimic control (MMC) group, microRNA-34a mimic (MM) group, microRNA-34a inhibitor control (MIC) group, and microRNA-34a inhibitor (MI) group, which were respectively transfected with gene sequences of mimic control, mimic, inhibitor control, and inhibitor of microRNA-34a. The microRNA-34a expression level and protein expression level of SIRT1 in myocardial cells were respectively detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blotting. Another batch of myocardial cells were divided into microRNA-34a inhibitor control+ burn serum (MCB) group, microRNA-34a inhibitor+ burn serum (MB) group, and microRNA-34a inhibitor+ burn serum + EX527 (MBE) group. Myocardial cells in group MCB were transfected with gene sequence of inhibitor control, and myocardial cells in the later groups were transfected with gene sequence of inhibitor of microRNA-34a. After transfection of 48 h, myocardial cells in group MBE were cultured in Dulbecco′s modified Eagle′s medium (DMEM) solution for 6 hours, with serum in group SB of volume fraction of 10% and final amount-of-substance concentration of 1 mol/L, and myocardial cells in the other 2 groups were cultured in DMEM solution with serum from rats of group SB of volume fraction of 10%. The protein expression levels of myocardial cells of SIRT1, cleaved-caspase-3, and Bax were detected by Western blotting. (3) Myocardial tissue from (1) was collected to detect expression levels of microRNA-34a and mRNA of SIRT1 in groups SI and SB by real-time fluorescence quantitative RT-PCR. Morphology of myocardial tissue of rats in groups SI, SB, and SA was observed with biological image navigator. The mRNA expression levels of interleukin 1β (IL-1β) and tumor necrosis factor (TNF-α) of rats in groups SI, SB, and SA were detected by real-time fluorescence quantitative RT-PCR. The expression levels of cleaved-caspase-3, and Bax of myocardial tissue of rats in groups SI, SB, and SA were detected by Western blotting. Data were processed with one-way analysis of variance and least-significant difference test.@*Results@#(1) After transfection of 48 h, the expression level of microRNA-34a of myocardial cells in group MM was 4.67±0.92, significantly higher than 1.03±0.04 in group MMC (P<0.01); the protein expression level of SIRT1 of myocardial cells in group MM was 0.35±0.06, significantly lower than 1.12±0.11 in group MMC (P<0.01). After transfection of 48 h, the expression level of microRNA-34a of myocardial cells in group MI was 0.26±0.07, significantly lower than 1.33±0.07 in group MIC (P<0.01); the protein expression level of SIRT1 of myocardial cells in group MIC was 1.12±0.16, significantly lower than 1.74±0.34 in group MI (P<0.01). At 6 h after culture, compared with those in group MCB, the SIRT1 protein expression level of myocardial cells in group MB was significantly increased (P<0.05), while cleaved-caspase-3 and Bax protein expression levels of myocardial cells in group MB were significantly decreased (P<0.05). Compared with those in group MB, the SIRT1 protein expression level of myocardial cells in group MBE was with no significantly statistical difference (P>0.05), and cleaved-caspase-3 and Bax protein expression levels were significantly increased (P<0.05). (2) At 6 h post injury, compared with that in group SI, the microRNA-34a expression level of myocardial tissue in group SB was significantly increased (P<0.01), and the mRNA expression level of SIRT1 of myocardial tissue in group SB was significantly decreased (P<0.01). At 6 h post injury, myocardial cells in group SI arranged neatly with normal nucleus and no inflammatory cells infiltration; myocardial cells in group SB arranged disorderly, with no abnormal nucleus, and obvious inflammatory cells infiltration; myocardial cells in group SA arranged neatly, with normal nucleus and little inflammatory cells infiltration. At 6 h post injury, compared with those in group SB, the mRNA expression levels of IL-1β and TNF-α, and the protein expression levels of cleaved-caspase-3 and Bax of myocardial tissue in groups SI and SA were significantly decreased (P<0.01).@*Conclusions@#The microRNA-34a expression level of myocardial tissue of rats with severe burns at early stage increases, which decreases the expression level of SIRT1, and increases the expression levels of IL-1β, TNF-α, cleaved-caspase-3 and Bax, leading to obvious myocardial damage. Activation of SIRT1 can alleviate myocardial damage of rats with severe burns at early stage through decreasing expression levels of IL-1β, TNF-α, cleaved-caspase-3, and Bax.