Altered Sirtuin1 and Sirtuin6 Expression in Aging: A Systematic Review and Meta-Analysis - Abstract
Abstract The sirtuin family, comprising nicotinamide adenine dinucleotide-dependent deacetylases, is involved in diverse physiological functions in mammals. Sirtuin 1 (SIRT1) and 6 (SIRT6) are involved in age-related biological processes, primarily in deacetylating metabolic stability and DNA repair-related factors. The expression patterns of SIRT1 and SIRT6 in aging remain controversial. Therefore, we performed a meta-analysis to evaluate the expression patterns of SIRT1 and SIRT6 in aged humans and rodents. Twenty-five studies (n = 1,417) were included to analyze SIRT1
expression, and three studies (n = 312) were included to analyze SIRT6 expression in aging. Meta-analysis showed that SIRT1 expression decreased (n = 1,208) (standard mean difference [SMD]=-0.46; 95 % confidence interval [CI]: -1.89 to 0.97; P < 0.00001) in humans, while increased in rodents (n = 209) (SMD=2.38; 95 % CI: -0.22 to 4.97; P < 0.00001). SIRT6 expression showed consistently decreased tendency (SMD=-11.04; 95 % CI: -17.73 to -4.36; P < 0.00001) in the aging group compared with to the young group. Especially, subgroup analysis for the brain area also showed a decrease in SIRT6 expression in all included studies. This systematic review and metaanalysis proposes a various and comprehensive understanding of SIRT1 and SIRT6 expression during normal aging.