title: Overexpression of SIRT6 in porcine fetal fibroblasts attenuates cytotoxicity and premature senescence caused by D-galactose and tert-butylhydroperoxide.
abstract: SIRT6, a member of the yeast silent information regulator 2 (SIR2) family, possesses both robust ADP-ribosyltransferase activity and protein deacetylase activity depending on NAD(+). It has been shown to maintain genomic stability and telomere integrity, and to prevent age-related disorders and premature ageing. However, the mechanism by which SIRT6 overexpression affects cellular ageing is not well understood. In this study, we investigated the effect of SIRT6 overexpression on cytotoxicity and ageing syndromes. A full-length cDNA of porcine SIRT6 was inserted into pcDNA3.1(-) and subsequently transfected into porcine fetal fibroblasts (PFFs). Overexpression of SIRT6 was identified by quantitative real-time polymerase chain reaction and western blot assay. The cells were incubated with D-galactose and tert-butylhydroperoxide at their cytotoxic concentrations. The damage caused by the stresses was detected with fluorescence microscopy using 4',6-diamidino-2-phenylindole (DAPI) staining, DNA ladder analysis, and observation under transmission electron microscopy. The results showed that SIRT6 overexpression in cells decreased damage to the nuclei. It also protected against the generation of DNA fragmentation and damage in the ultramicrostructure of the cells, especially damage to mitochondria. Our observations suggested that one function of SIRT6 in PFFs was to dampen cytotoxicity, and, therefore, to decrease the damage that causes premature senescence.
authors.affiliation: Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, People's Republic of China.
authors.forename: Xiaoxian
authors.initials: X
authors.lastname: Xie
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Gao
authors.forename: Liangliang
authors.initials: L
authors.lastname: Wang
authors.forename: Ailing
authors.initials: A
authors.lastname: Zhang
authors.forename: Shuihua
authors.initials: S
authors.lastname: Xie
authors.forename: Jiaqi
authors.initials: J
authors.lastname: Li
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000187:drug effects* / Q000502:physiology*; D053938:DNA Fragmentation / Q000187:drug effects*; D005333:Fetus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005690:Galactose / Q000494:pharmacology*; D009243:NAD / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D037761:Sirtuins / Q000235:genetics / Q000378:metabolism*; D013552:Swine; D020122:tert-Butylhydroperoxide / Q000494:pharmacology*
chemical_list: D012333:RNA, Messenger; D009243:NAD; D020122:tert-Butylhydroperoxide; D037761:Sirtuins; D005690:Galactose