SIRT3 is a downstream target of PPAR-alpha implicated in high glucose-induced cardiomyocyte injury in AC16 cells
EXPERIMENTAL AND THERAPEUTIC MEDICINE
Authors: Zong, Xiaojuan; Cheng, Kuan; Yin, Guizhi; Wu, Zhaodi; Su, Qian; Yu, Dong; Liao, Pengfei; Hu, Wei; Chen, Yueguang
Abstract
Diabetic cardiomyopathy (DCM) is a worldwide public health concern that continues to display rapid growth trends. This study investigated the function of sirtuin 3 (SIRT3), a primary mitochondrial deacetylase with important roles in antioxidant defense and oxidative metabolism, during high glucose-induced cardiomyocyte (AC16 cell) injury. Peroxisome proliferator-activated receptor-alpha (PPAR-alpha) is directly related to the occurrence of DCM. Hence, we further examined the relationship between SIRT3 and PPAR-alpha. AC16 cells were treated with various concentrations of glucose. Relative mRNA expression and protein levels were detected by RT-qPCR and western blot analysis, respectively. Cell proliferation and apoptosis were assessed using CCK8 and Annexin V-FITC apoptosis detection kits, respectively. DCFH-DA assay was used to measure reactive oxygen species (ROS) accumulation. The results indicated that high glucose treatment reduced the expression of mRNA and protein of SIRT3 and PPAR-alpha in AC16 cells. Moreover, high glucose inhibited cell proliferation, as well as induced apoptosis, intracellular hydrogen peroxide production, and JNK1/2 phosphorylation. These effects were antagonized by SIRT3 overexpression or treatment with the PPAR-alpha agonist, Wy14643. Conversely, inhibition of SIRT3 via 3-TYP led to similar phenomena as those induced by high glucose treatment in AC16 cells, which were blocked by Wy14643. Lastly, chromatin immunoprecipitation (ChIP) and luciferase assays demonstrated SIRT3 as a direct target of PPAR-alpha. Taken together, the results provide evidence for an important role of SIRT3 in high glucose-induced cardiomyocyte injury and regulation of JNK1/2 signaling. Further, SIRT3 is a direct downstream target of PPAR-alpha.
Ovarian expression, polymorphism identification and association of SIRT3 gene with reproduction traits in goats
ANIMAL BIOTECHNOLOGY
Authors: Silpa, M., V; Naicy, T.; Aravindakshan, T., V; Radhika, G.; Joan, J.; Jinty, S.
Abstract
The NAD(+)-dependent protein deacetylase, Sirtuin3 (SIRT3), plays a role in fertility by preventing the activation of reactive oxygen species (ROS). A novel study was conducted on caprine SIRT3, to study its ovarian expression, explore the sequence variability in exon 7 and analyze its association with prolificacy in two native goat breeds of Kerala, Malabari and Attappady Black. The mRNA isolated from ovaries of six Malabari and Attappady Black goats were subjected to quantitative PCR (qPCR) using GAPDH and beta-actin as reference genes. Genomic DNA was isolated from 185 goats (99 Malabari and 86 Attappady Black) and subjected to PCR-SSCP to identify polymorphism in exon 7 of SIRT3 and association with litter size was analyzed. The ovarian expression of caprine SIRT3 was significantly higher (p <= 0.01) in Malabari than low prolific Attappady Black. PCR-SSCP analysis revealed, exon 7 of SIRT3 was polymorphic with three genotypes namely, AA, AB and BB with a novel SNP, g.154C > T in the 3 ' UTR. A significant association (p <= 0.05) was noticed between the genotypes of SIRT3 and litter size. The results obtained from this study highlight the role of SIRT3 in reproduction and hence SIRT3 may be considered as a potential candidate gene for genetic improvement in goats.