Expression of sirtuin 2 and 7 in placenta accreta spectrum

SUMMARY OBJECTIVE: This study aimed to investigate the expression levels of sirtuin 2 and sirtuin 7 in the placenta accreta spectrum to reveal their role in its pathogenesis. METHODS: A total of 30 placenta accreta spectrum, 20 placenta previa, and 30 controls were experienced. The sirtuin 2 and sirtuin 7 expression levels in the placentas of these groups were determined by Western blot. sirtuin 2 and sirtuin 7 serum levels in the maternal and fetal cord blood were examined by enzyme-linked immunosorbent assay. RESULTS: It was found that sirtuin 7 in placenta accreta spectrum was significantly lower in the placenta compared to the control and placenta previa groups (p<0.05). However, a significant difference was not observed between the sirtuin 2 and sirtuin 7 levels in the maternal and fetal cord serum samples of those three groups (p>0.05). CONCLUSION: Sirtuin 7 may play an important role in the formation of placenta accreta spectrum. The effect of decreased expression of sirtuin 7 might be tissue-dependent in the placenta accreta spectrum and needs to be investigated further.

Evaluación y caracterización de la sirtuina 2.3 de Giardia duodenalis (CdSir2.3)

La giardiasis es la enfermedad gastrointestinal de mayor incidencia mundial, causada por el protozoario Giardia duodenalis, para la cual no se cuenta con una vacuna o tratamiento eficiente. En aras de buscar nuevos blancos farmacológicos contra este parásito, se han estudiado las enzimas del metabolismo energético, como las sirtuinas, deacetilasas dependientes del dinucleótido de adenina y nicotinamida (NAD). Previamente se identificó a GdSir2.1 y GdSir2.2 como deacetilasas dependientes de NAD, con localizaciones subcelulares diferentes. En este trabajo se estudió otro candidato a sirtuina (GdSir2.3) mediante herramientas bioinformáticas para la identificación de características típicas de la familia sirtuina en la secuencia del candidato, y experimentales como la obtención de la proteína recombinante 6xHis-GdSir2.3 que demostró actividad deacetilasa dependiente de NAD y que sirvió como antígeno en la producción de los IgY - α -6xHis-GdSir2.3 para la localización subcelular de la proteína endógena en G. duodenalis. Lo anterior concuerda con otros estudios donde se señala a GdSir2.3 como un importante regulador de la enquistación, debido a su aumento de expresión durante esta etapa del ciclo de vida, constituyéndola como un blanco farmacológico promisorio para el control de esta parasitemia.

Giardiasis is the gastrointestinal disease with the highest incidence worldwide, caused by the protozoan Giardia duodenalis, for which there is no vaccine or efficient treatment. In order to find new pharmacological targets against this parasite, energy metabolism enzymes such as sirtuins, deacetylases dependent on the nicotinamide adenine dinucleotide (NAD), have been studied. GdSir2.1 and GdSir2.2 were previously identified as NAD-dependent deacetylases, with different subcellular locations. In this work, another candidate for sirtuin (GdSir2.3) was studied using bioinformatic tools for the identification of typical characteristics of the sirtuin family in the sequence of the candidate; and experimental ones such as obtaining the recombinant protein 6xHis-GdSir2.3 that demonstrated NAD-dependent deacetylase activity; and that it served as an antigen in the production of IgY - α - 6xHis-GdSir2.3 for the subcellular localization of the endogenous protein in G. duodenalis. The foregoing is consistent with other studies where GdSir2.3 is indicated as an important regulator of encyst due to its increased expression during this stage of the life cycle, constituting it as a promising drug target for the control of this parasitaemia.

A giardíase é a doença gastrointestinal de maior incidência no mundo, causada pelo protozoário Giardia duodenalis, para a qual não existe vacina ou tratamento eficaz. Com o objetivo de encontrar novos alvos farmacológicos contra esse parasita, têm sido estudadas enzimas do metabolismo energético, como as sirtuínas, desacetilases dependentes do dinucleotídeo adenina nicotinamida (NAD). GdSir2.1 e GdSir2.2 foram previamente identificados como desacetilases dependentes de NAD, com diferentes localizações subcelulares. Neste trabalho, outro candidato a sirtuin (GdSir2.3) foi estudado usando ferramentas de bioinformática para a identificação de características típicas da família sirtuin na sequência do candidato; e experimentais, como a obtenção da proteína recombinante 6xHis-GdSir2.3 que demonstrou atividade desacetilase dependente de NAD; e que serviu como antígeno na produção de IgY - α - 6xHis-GdSir2.3 para a localização subcelular da proteína endógena em G. duodenalis. O exposto é consistente com outros estudos em que o GdSir2.3 é apontado como um importante regulador de encisto devido à sua expressão aumentada durante esta fase do ciclo de vida, constituindo-se como um alvo promissor para o controle dessa parasitemia.

Metabolic choreography of gene expression: nutrient transactions with the epigenome

Eukaryotic complexity and thus their ability to respond to diverse cues are largely driven by varyingexpression of gene products, qualitatively and quantitatively. Protein adducts in the form of post-translationalmodifications, most of which are derived from metabolic intermediates, allow fine tuning of gene expressionat multiple levels. With the advent of high-throughput and high-resolution mapping technologies there hasbeen an explosion in terms of the kind of modifications on chromatin and other factors that govern geneexpression. Moreover, even the classical notion of acetylation and methylation dependent regulation oftranscription is now known to be intrinsically coupled to biochemical pathways, which were otherwiseregarded as ‘mundane’. Here we have not only reviewed some of the recent literature but also havehighlighted the dependence of gene regulatory mechanisms on metabolic inputs, both direct and indirect. Wehave also tried to bring forth some of the open questions, and how our understanding of gene expression haschanged dramatically over the last few years, which has largely become metabolism centric. Finally,metabolic regulation of epigenome and gene expression has gained much traction due to the increasedincidence of lifestyle and age-related diseases.

The role of Sirtuins in the study of eye diseases / 国际眼科杂志(Guoji Yanke Zazhi)

@#In a variety of eye diseases, such as glaucoma, macular degeneration and other diseases, the occurrence of oxidative stress is very common, oxidative stress can cause cell damage and apoptosis. The Sirtuins family(histone class III deacetylases), as regulators of a variety of cells, is widely expressed in various organs of the human body. Homologous genes of sirtuins(SIRT1)are also widely expressed in the eyes, and their expression and activation can play an anti-oxidative stress role, prevent cell senescence and damage, and thus prevent the progression of disease. This paper discusses the mechanism and expression of Sirtuins family in glaucoma, senile macular degeneration, optic neuritis and senile cataract.

Serum Sirtuin 1, 3 and 6 Levels in Acute Myocardial Infarction Patients / Níveis de Sirtuína 1, 3 e 6 em Pacientes com Infarto Agudo do Miocárdio

Abstract Background: Sirtuins may act in many cellular processes like apoptosis, DNA repair and lipid/glucose metabolism. Experimental studies suggested some sirtuin types may have protective effects against endothelial dysfunction, atherosclerosis, cardiac hypertrophy and reperfusion injury. Data about sirtuins in acute myocardial infarction (AMI) patients are scarce. Objectives: To investigate temporal changes of serum sirtuin 1,3 and 6 levels in AMI patients; to compare the serum sirtuin 1,3 and 6 levels between AMI patients and control subjects; and to investigate the association of serum sirtuin 1,3 and 6 levels with prognostic markers of AMI. Methods: Forty patients with AMI and 40 patients with normal coronary arteries were included. Left ventricular ejection fraction (LVEF), serum proBNP, CRP, sirtuin1, sirtuin 3 and sirtuin 6 levels were processed. Peak troponin T levels, GRACE score, first day / second day sirtuin levels were recorded of AMI patients. A p value < 0.05 was considered statistically significant. Results: Serum sirtuin 1,3 and 6 levels in AMI patients were similar to those in normal coronary patients. No temporal change in serum sirtuin 1,3 and 6 levels were found in AMI course. No correlation was evident between the sirtuin levels and the following parameters: proBNP, CRP, peak troponin and LVEF. Baseline sirtuin 1 and 6 levels were positively correlated with reperfusion duration. Baseline sirtuin 3 levels were negatively correlated with GRACE score. Conclusion: Serum sirtuin 1,3 and 6 levels in AMI patients were similar to those in normal coronary patients. This study does not represent evidence of the possible protective effects of sirtuin1, 3 and 6 in AMI patients.

Resumo Fundamento: As sirtuínas podem atuar em muitos processos celulares, como a apoptose, reparo de DNA e metabolismo de lipídios e de glicose. Estudos experimentais sugeriram que alguns tipos de sirtuínas possam ter efeitos protetores contra disfunção endotelial, aterosclerose, hipertrofia cardíaca e lesão decorrente de reperfusão. Dados sobre as sirtuínas em pacientes com infarto agudo do miocárdio (IAM) são escassos. Objetivos: Avaliar as mudanças temporais dos níveis de sirtuína 1, 3 e 6 entre pacientes com IAM e indivíduos controles; investigar a associação entre os níveis de sirtuína 1, 3 e 6 e marcadores prognósticos de IAM. Métodos: Quarenta pacientes com IAM e 40 pacientes com artérias coronárias normais foram incluídos. Foram avaliados fração de ejeção do ventrículo esquerdo (FEVE), concentrações séricas de pró-BNP, proteína C-reativa, sirtuína 1, sirtuína 3 e de sirtuína 6. Pico de troponina T, escore GRACE, concentrações de sirtuínas no primeiro e no segundo dia foram registrados dos pacientes com IAM. Um valor de p<0,05 foi considerado estatisticamente significativo. Resultados: Os níveis de sirtuína 1, 3 e 6 em pacientes com IAM foram similares aos de pacientes com coronária normal. Não foram observadas mudanças temporais nos níveis de sirtuína 1, 3 e 6 no curso do IAM. Nenhuma correlação evidente foi observada dos níveis de sirtuína com os seguintes parâmetros: pró-BNP, proteína C-reativa, pico de troponina e FEVE. Níveis basais de sirtuína 1 e 6 apresentaram correlação positiva com a duração da reperfusão. Os níveis basais de sirtuína 3 correlacionaram-se negativamente com o escore GRACE. Conclusão: Os níveis de sirtuína 1, 3 e 6 em pacientes com IAM foram similares aos de pacientes com artérias coronárias normais. Este estudo não apresenta evidência de possíveis efeitos protetores da sirtuína 1, 3 e 6 em pacientes com IAM.

Effects of Mitochondrial Dysfunction via AMPK/PGC-1 α Signal Pathway on Pathogenic Mechanism of Diabetic Peripheral Neuropathy and the Protective Effects of Chinese Medicine / 中国结合医学杂志

Diabetic peripheral neuropathy (DPN) is a progressive neurodegenerative disease of peripheral nervous system with high energy requirement. The adenosine monophosphate-activated protein kinase (AMPK)/peroxisome proliferator-activated receptor- γ coactivator 1 α (PGC-1 α) axis plays a key role in regulating mitochondrial energy metabolism. Increasing preclinical evidences have shown that inhibition of AMPK/PGC-1 α pathway leading to mitochondrial dysfunction in neurons or Schwann cells contributes to neuron apoptosis, distal axonopathy and nerve demyelination in DPN. Some Chinese medicine formulae or extracts from herbs may have potential neuroprotective effects on DPN via activating AMPK/PGC-1 α pathway and improving mitochondrial function.

Emodin exerts protective effect against palmitic acid-induced endoplasmic reticulum stress in HepG2 cells / 한국영양학회지

PURPOSE: Protein overloading in the endoplasmic reticulum (ER) leads to endoplasmic reticulum stress, which exacerbates various disease conditions. Emodin, an anthraquinone compound, is known to have several health benefits. The effect of emodin against palmitic acid (PA) - induced ER stress in HepG2 cells was investigated. METHODS: HepG2 cells were treated with varying concentrations of palmitic acid to determine the working concentration that induced ER stress. ER stress associated genes such as ATF4, XBP1s, CHOP and GRP78 were checked using RT- PCR. In addition, the expression levels of unfolded protein response (UPR) associated proteins such as IRE1α, eIF2α and CHOP were checked using immunoblotting to confirm the induction of ER stress. The effect of emodin on ER stress was analyzed by treating HepG2 cells with 750 µM palmitic acid and varying concentrations of emodin, then analyzing the expression of UPR associated genes. RESULTS: It was evident from the mRNA and protein expression results that palmitic acid significantly increased the expression of UPR associated genes and thereby induced ER stress. Subsequent treatment with emodin reduced the mRNA expression of ATF4, GRP78, and XBP1s. Furthermore, the protein levels of p-IRE1α, p-elF2α and CHOP were also reduced by the treatment of emodin. Analysis of sirtuin mRNA expression showed that emodin increased the levels of SIRT4 and SIRT7, indicating a possible role in decreasing the expression of UPR-related genes. CONCLUSION: Altogether, the results suggest that emodin could exert a protective effect against fatty acid-induced ER stress and could be an agent for the management of various ER stress related diseases.

Combatiendo el metabolismo de las células cancerosas mediante la activación de SIRT3 y el ejercicio físico / Combating tumor cells through SIRT3 activation and exercise

One of the main features of cancer is the high rate of cell proliferation and growth. To do this, cancer cells need to redirect their metabolism mainly towards anaerobic glycolysis and an increased mitochondrial glutamine energy metabolism. Sirtuins are cellular proteins with regulatory functions on metabolic pathways, genomic stability, apoptosis, longevity, inflammation, energy metabolism and oxidative stress. Sirtuins have emerged recently as a potential therapeutic option to treat several chronic diseases including cancer. This review summarizes the tumor suppressor function of Sirtuin 3 (SIRT3), highlighting its repressor effect on glycolytic metabolism, promoting mitochondrial metabolism and oxidative stress reduction. SIRT3 activation by exercise is particularly described since it may represent a potent tool for several types of cancer treatment.

Sirtuins in malignant progression of tumor / 药学学报

As a post-translational modification, protein acetylation plays an important role in the regulation of apoptosis, mitochondriopoiesis, lipid metabolism and cellular stress response. The imbalance of acetylation and deacetylation has been blamed for the tumorigenesis and malignant progression, which is gradually considered as a promising therapeutic target. Mammalian sirtuins, a NAD+ dependent class Ⅲ HDACs, are closely related to the development of aging, tumor, diabetes, obesity and neurodegenerative diseases. To provide a theoretical basis for the development of new anti-tumor drugs and the treatment of malignant tumors, this paper is prepared to focus on the irreplaceable role of sirtuins in tumor evolution:maintaining genomic stability, regulating energy metabolism, and facilitating tumor cells stemness. The modulator and pathways of sirtuins family and the research progress of agonists and inhibitors are also reviewed. The functions of SIRT2 in resistance, proliferation and metastasis have been highlighted.

Role of short-term starvation in alleviating hepatic ischemia-reperfusion injury in mice and possible mechanism of action / 中华肝脏病杂志

Objective@#To investigate the role of short-term starvation (STS) in alleviating hepatic ischemia-reperfusion injury in mice and possible mechanism of action.@*Methods@#Wild-type male C57BL/6 mice aged 8 weeks were randomly divided into 75% hepatic ischemia-reperfusion injury group (IR group), STS+75% hepatic ischemia-reperfusion injury group (STS group), and sirtinol+STS+75% hepatic ischemia-reperfusion injury group (SIR group), using a random number table, and sham-operation groups (IR-Sham group, STS-Sham group, and SIR-Sham group) were also established. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured, and the histomorphological changes of the liver were observed, as well as the expression of Sirt1, LC3B, and P62 proteins in liver tissue and the results of LC3B fluorescence staining. An analysis of variance was used for comparison of data between multiple groups, and the t-test was used for comparison of data between two groups.@*Results@#Compared with the IR group, the STS group had significant reductions in the serum levels of ALT (3 152.7 ± 735.6 U/L vs 8 414.2 ± 1 052.2 U/L, P < 0.01) and AST (3 577.0 ± 714.0 U/L vs 10 845.8 ± 1 145.7 U/L, P < 0.01) and significant alleviation of liver pathological injury (Suzuki score: 1.50±0.55 vs 3.50±0.55, P < 0.01). Compared with the STS group, the SIR group had significant increases in the serum levels of ALT (7 002.7 ± 1 485.2 U/L vs 3 152.7 ± 735.6 U/L, P < 0.01) and AST (8 980.7 ± 1 739.1 U/L vs 3 577.0 ± 714.0 U/L, P < 0.01) and significant exacerbation of liver pathological injury (Suzuki score: 3.33 ± 0.52 vs 1.50 ± 0.55, P < 0.01). Compared with the IR group and the IR-Sham group, the STS group and the STS-Sham group had significant increases in the mRNA and protein expression of Sirt1 and the protein expression of LC3B and a significant reduction in the protein expression of P62, as well as a significant increase in the percentage of LC3B-positive cells in liver tissue (22.83% ± 5.19% / 22.17% ± 4.83% vs 10.16% ± 3.06% / 10.83% ± 1.94%, both P < 0.01). Compared with the STS group and the STS-Sham group, the SIR group and the SIR-Sham group had significant reductions in the expression of Sirt1 and LC3B proteins and a significant increase in the expression of P62 protein, as well as a significant reduction in the percentage of LC3B-positive cells in liver tissue (11.83% ± 9.24% / 14.67% ± 4.68% vs 22.83% ± 5.19% / 22.17% ± 4.83%, both P < 0.01).@*Conclusion@#STS can effectively alleviate hepatic ischemia-reperfusion injury, and its protective effect may be associated with increasing the expression of Sirt1, inducing and promoting hepatocyte autophagy, and reducing hepatocyte death.

Research progress of the relationship between Sirtuins and diabetic retinopathy / 中华实验眼科杂志

As one of the serious complications of diabetes melitus,diabetic retinopathy (DR) is one of the major causes of blindness.It is urgent to figure out the mechanism of DR and identify an effective therapeutic target to prevent it.Sirtuins is a major catabolic pathway involved in degrading and recycling damaged organelles and macromolecules to maintain intracellular homeostasis.The study of Sirtuins in mammalian systems has been advancing rapidly and revealed that Sirtuins is involved in the pathogenesis of various metabolic and age-related diseases.The study of Sirtuins in such diseases as tumors,diabetic nephropathy,has been currently under intense investigation.Moreover,there is also a close relationship between Sirtuins and DR related factors including hypoxia,oxidative stress,inflammation,and so on.In this paper,recent research progress in Sirtuins and its application in DR are reviewed,so as to provide a new perspective on pathogenesis and therapy of DR.

Silent information regulator protein 6 and autophagy in age-related macular degeneration / 中华眼底病杂志

Age-related macular degeneration is one of the major causes of blindness in the elderly.As an important pathway of cell metabolism,autophagy maintains intracellular homeostasis through the degradation and recycle of damaged organelles and macromolecules.Understanding its mechanism may promote discoveries to delay aging process,reduce the incidence of age-related diseases.In mammals,silent information regulator protein 6 (SIRT6) plays its deacetylase and ribonucleotransferase activity in multiple signaling pathways,including inhibition of cellular senescence,tumorigenesis,metabolic diseases,regulating cellular lifespan.It has a significant impact on the structure and function of tissues and organs.SIRT6 regulates intracellular autophagy mainly through the insulin-like growth factor-protein kinase B-mammalian target of rapamycin,reducing the accumulation of toxic metabolites and cellular senescence.The function of SIRT6 in age-related macular degeneration need to be combined with the genetic background,pathogenesis,clinical manifestations and other aspects of the disease,and it is expected to be further studied in subsequent studies.

Role of SIRT3∕FOXO3α signaling pathway in dexmedetomidine-induced reduction of hepatic ische-mia-reperfusion injury in mice / 中华麻醉学杂志

Objective To evaluate the role of sirtuin 3 ( SIRT3)∕forkhead box O3α ( FOXO3α) signaling pathway in dexmedetomidine-induced reduction of hepatic ischemia-reperfusion ( I∕R) injury in mice. Methods Forty clean-grade C57BL∕6 mice of both sexes, aged 2 weeks, weighing 6-8 g, were di-vided into 4 groups (n＝10 each) using a random number table method: sham operation group (group S), hepatic I∕R group ( group I∕R), dexmedetomidine group ( group D) and SIRT3 inhibitor 3-TYP plus dexmedetomidine group (group T+D). Portal vein and hepatic artery supplying left and middle lobes of the liver and biliary tract were clamped resulting in ischemia of 70% of the liver in anesthetized rats. Normal sa-line 0. 25 ml was intraperitoneally injected at 1 h before establishing model, and 30 min later dexmedetomi-dine 50 μg∕kg (diluted to 0. 25 ml in normal saline) was intraperitoneally injected in group D. In group T+D, 3-TYP 5 mg∕kg (diluted to 0. 25 ml in normal saline) was intraperitoneally injected at 1 h before estab-lishing model, and 30 min later dexmedetomidine 50 μg∕kg (diluted to 0. 25 ml in normal saline) was in-traperitoneally injected. Mice were selected at 6 h after reperfusion, blood samples were obtained through eyeball, and the mice were then sacrificed and kidneys were removed for determination of the serum concen-trations of creatinine (Cr) and blood urea nitrogen (BUN), cell apoptosis (by TUNEL), malondialdehyde (MDA) content (using thiobarbituric acid method), superoxide dismutase (SOD) activity (by xanthine oxidase method), and acetylation of FOXO3α in renal tissues (by using immunoprecipitation) and for ex-amination of the pathologic changes. The damage to renal tubules was scored. Apoptosis index ( AI) was calculated. Results Compared with group S, the renal tubular damage score and AI were significantly in-creased, serum concentrations of Cr and BUN were increased, the content of MDA was increased, the ac-tivity of SOD was decreased, and the acetylation of FOXO3α was decreased in I∕R, D and T+D groups ( P＜0. 05). Compared with group I∕R, the renal tubular damage score and AI were significantly decreased, serum concentrations of Cr and BUN were decreased, the content of MDA was decreased, the activity of SOD was increased, and the acetylation of FOXO3α was decreased in group D (P＜0. 05), and no signifi-cant change was found in the parameters mentioned above in group T+D (P＞0. 05). Compared with group D, the renal tubular damage score and AI were significantly increased, serum concentrations of Cr and BUN were increased, the content of MDA was increased, the activity of SOD was decreased, and the acetylation of FOXO3α was decreased in group T+D ( P＜0. 05). Conclusion Activation of SIRT3∕FOXO3α signaling pathway is involved in dexmedetomidine-induced reduction of hepatic I∕R injury in mice.

Relationship between SIRT1-ERK1∕2 pathway and chikusetsu saponin IVa-induced reduction of isoflurane-elicited neurotoxicity in fetal rats: an in vitro experiment / 中华麻醉学杂志

Objective To evaluate the relationship between silent information regulator 1 ( SIRT1)-extracellular-regulated kinase1∕2 ( ERK1∕2) pathway and chikusetsu saponin IVa-induced reduc-tion of isoflurane-elicited neurotoxicity in fetal rats in an in vitro experiment. Methods The hippocampal neurons isolated from rats at 16-18 days of gestation were primarily cultured for 7 days and divided into 3 groups ( n = 6 each) using a random number table method: control group ( Con group) , isoflurane group (Iso group) and chikusetsu saponin IVa plus isoflurane group (ChIV+Iso group). Hippocampal neurons were cultured routinely for 6 h in Con group. Hippocampal neurons were exposed to 1. 8％ isoflurane for 6 h in an incubator in Iso group. Chikusetsu saponin IVa 25μg∕ml was added to the culture medium, and hipp-ocampal neurons were incubated for 6 h and then exposed to 1. 8％ isoflurane for 6 h in an incubator in ChIV+Iso group. The supernatant was collected for determination of the amount of lactic dehydrogenase ( LDH) released, neuronal viability ( by CCK-8) and expression of SIRT1, ERK1∕2 and phosphorylated ERK1∕2 ( p-ERK1∕2) ( by Western blot) . Results Compared with Con group, the neuronal viability was significantly decreased, the amount of LDH released was increased, and the expression of SIRT1 and p-ERK1∕2 was down-regulated in Iso group ( P<0. 05) . Compared with Iso group, the neuronal viability was significantly increased, the amount of LDH released was decreased, and the expression of SIRT1 and p-ERK1∕2 was up-regulated in ChIV+Iso group ( P<0. 05) . Conclusion The mechanism by which chikuset-su saponin IVa reduces isoflurane-elicited neurotoxicity is related to activating SIRT1-ERK1∕2 pathway in fe-tal rats in an in vitro experiment.

Synthesis of benzimidazole and benzothiazole derivatives as a sirtuins 2 inhibitor / 药学学报

A series of novel benzimidazole and benzothiazole derivatives were designed and synthesized as inhibitors of SIRT1-SIRT3. The target compounds were synthesized from potassium O-ethyldithiocarbonate through a three-step route. The structures of the obtained compounds were elucidated by 1H NMR and HR-MS. Of all compounds, six showed potent SIRT2-inhibitory activities with IC50 values ranging from 2.8 to 21.2 μmol·L-1. Among them, compound 10c displayed the most potent SIRT2-inhibitory activities (IC50 = 2.8 μmol·L-1), with more than 35-fold selectivity over SIRT1 and SIRT3 (IC50>100 μmol·L-1).

Effects of Sirt1 gene knockout on chronic kidney disease induced by 5/6 nephrectomy in mice and VEGF/Flk-1 signaling pathway / 中华肾脏病杂志

Objective To investigate the effect of Sirt1 gene knockout on chronic kidney disease induced by 5/6 nephrectomy in mice and vascular endothelial growth factor (VEGF)/fetal liver kinase-1 (Flk-1) signaling pathway.Methods Twenty four male Sirt1 +/+ and Sirt1 +/-mice wererandomly divided into four groups:Sirt1+/+ mice with sham-operation (WT-Sham,n=6),Sirt1+/-mice with sham-operation (KO-Sham,n=6),Sirt1 +/+ mice with 5/6 nephrectomy (WT-Nx,n=6) and Sirt1 +/-mice with 5/6 nephrectomy (KO-Nx,n=6).Proteinuria was determined by urine collection from 8:00 to 8:00 the next day at 20 weeks.Serum creatinine (Scr),urea nitrogen (BUN) and the renal pathological changes were measured after 20 weeks.Expressions of Sirt1,collagen Ⅰ and transforming growth factor β(TGF-β) were used to analyze the changes of renal fibrosis by immunohistochemistry staining.Real-time PCR and Western blotting were used to measure the mRNA and protein expressions of Sirt1,fibronectin,collagen Ⅰ,VEGF and Flk-1 in kidney.Results Sirt1 expressed in glomernlar endothelial cells,podocytes,mesangial cells and renal tubular epithelial cells in Sirt1 +/+ mice,while Sirt1 expression intensity was significantly reduced in Sirt1 +/-mice.Compared with the WT-Sham group,WT-Nx group had increased proteinuria,BUN,Scr,glomernlar sclerosis index and tubulointerstitial fibrosis index at 12 weeks after operation (all P ＜ 0.01),and KO-Nx group had exacerbated the above up-regulations (all P ＜ 0.01).Compared with those in WT-Sham group,the expressions of fibronectin,collagen Ⅰ and TGF-β were up-regulated in WT-Nx group (all P ＜ 0.01),and were significantly augmented in KO-Nx group (all P ＜ 0.01).Compared with those in WT-Sham group,renal mRNA and protein expressions of VEGF and Flk-1 were decreased in WT-Nx group,and KO-Nx group aggravated their down-regulation (all P ＜ 0.01).Conclusions Sirt1 gene knockout can increase proteinuria and Scr,and aggravate renal pathology and renal fibrosis in 5/6 nephrectomized mice,which is associated with the inhibition of VEGF/Flk-1 signaling pathway.It is suggested that Sirt1 may be a potential therapeutic target of chronic kidney disease.

Role of SIRT1/FoxO3α signaling pathway in berberine pretreatment-induced reduction of hypoxia/ reoxygenation-caused injury to hepatic parenchymal cells / 中华麻醉学杂志

Objective To evaluate the role of silent information regulator fac tor 2-related enzyme 1 (SIRT1)/Forkhead Box O3 (FoxO3a) signaling pathway in berberine pretreatment-induced reduction of hypoxia/reoxygenation (H/R)-caused injury to hepatic parenchymnal cells.Methods Hepatic parenchymal cells obtained from AML12 mice were cultured and seeded in 6-well plates (2 ml/well) and in 96-well plates (200 μl/well) at the density of l×l06 cells/ml.The cells were divided into 4 groups (n=36 each)using a randomn number table:control group (group C),group H/R,berberine pretreatment group (group BP) and SIRT1-siRNA group (group SS).The cells were cultured in normal culture atmosphere (5％ CO2-21％ O2-74％ N2) in group C.In H/R,BP and SS groups,the cells were exposed to hypoxic air (5％ CO2-1％ O2-94％ N2) for 12 h,followed by 6 h reoxygenation in normal culture atmosphere (5％ CO2-21％ O2-74％ N2).In group SS,small interference RNA targeting SIRT1 (SIRT1-siRNA) was added to the culture medium at 24 h prior to hypoxia.Berberine (final concentration 5 μmol/L) was added at 2 h prior to hypoxia in BP and SS groups.At the end of reoxygenation,the cell viability was measured by methyl thiazolyl tetrazolium assay,the malondialdehyde (MDA) content and superoxide dismutase (SOD) activity were determined using enzyme-linked immunosorbent assay,cell apoptosis was detected by flow cytometry,the expression of SIRT1 and FoxO3α was detected by Western blot,and the acetylation of FoxO3α was measnred by using immunoprecipitation.Apoptotic rate was calculated.Results Compared with group C,the cell viability was significantly decreased,the MDA content was increased,the SOD activity was decreased,apoptotic rate was increased,the expression of SIRT1 and ratio of FoxO3α expression in nucleus/in cytoplasma were increased,and the acetylation of FoxO3α in the nucleus was increased in H/ R,BP and SS groups (P＜ 0.05).Compared with group H/R,the cell viability was significantly increased,the MDA content was decreased,the SOD activity was increased,apoptotic rate was decreased,the expression of SIRT1 and ratio of FoxO3α expression in nucleus/in cytoplasma were increased,and the acetylation of FoxO3α in the nucleus was increased in group BP (P＜0.05).Compared with group BP,the cell viability was significantly decreased,the MDA content was increased,the SOD activity was decreased,apoptotic rate was increased,the expression of SIRT1 and ratio of FoxO3α expression in nucleus/in cytoplasma were decreased,and the acetylation of FoxO3α in the nucleus was decreased in group SS (P＜O.05).Conclusion The mechanism by which berberine pretreatment attenuates H/R-caused injury to hepatic parenchymal cells is related to promotion of SIRT1 expression in cells and inhibition of FoxO3α acetylation in the nucleus.

Advances in protective effects of thyroid hormone on myocardial mitochondria by sirtuins / 天津医药

Many studies have confirmed that thyroid hormone (TH) and mitochondria have protective effects on myocardium. The partial subtype of sirtuins (SIRTs) can also be able to protect myocardium by mitochondria, which includes improving ischemia reperfusion injury, improving the pathological cardiac hypertrophy and improvement of heart failure. SIRTs can achieve the protective effect for myocardium mainly through inhibiting mitochondrial permeability transition pore and mitochondrial membrane permeabilization, maintaining balance of regulation of mitochondrial morphology, promoting mitochondrial biogenesis, maintaining the function of autophagy of impaired mitochondria. At the same time, there is an interaction between TH and SIRTs. At present, the role of mitochondria has become more and more concerned in apoptosis and necrosis and its protective effect on cells. This review summarized the protective effect of SIRTs on myocardium through mitochondrial and the influence of the interaction between SIRTs and TH on myocardial protection of mitochondrial.

Effects of CD38 gene knockout on inflammatory cytokine production in murine spleen B-cells / 第二军医大学学报

Objective To analyze the number of spleen B-cells and the expression of inflammatory factors and sirtuin 1 (SIRT1) in spleen B-cells of CD38-/- mice, so as to explore the effects of CD38 gene knockout on inflammatory factors in B-cells and its potential mechanism. Methods The DNA levels of CD38 and Neo gene in mouse tail tissues were detected by polymerase chain reaction (PCR). Spleen B-cells from wide-type (WT) C57BL/6 and CD38-/-mice were sorted by magnetic activated cell sorting (MACS), and the purity of sorting B-cells were identified by flow cytometry. The mRNA levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and CD38 gene were detected by real-time PCR, the protein expressions of CD38 and SIRT1 were detected by Western blotting analysis. Results We confirmed the successful establishment of CD38-/-mice and sorted spleen B-cells from WT and CD38-/-mice (purity>95%). Compared with WT mice, the development of spleen was hampered in the CD38-/-mice, the number of spleen cells and spleen B-cells were significantly reduced (P<0. 01), the mRNA levels of TNF-α and IL-1β were significantly decreased (P<0. 01), and the expression level of SIRT1 was significantly increased in CD38-/-mice (P<0. 05). Conclusion CD38 gene knockout can reduce the number of B-cells in the spleen; and it can inhibit the expression of inflammatory factors (TNF-α and IL-1β) in spleen B-cells by activating SIRT1 pathway.