Weight Loss Is Associated With Increased NAD(+)/SIRT1 Expression But Reduced PARP Activity in White Adipose Tissue

: Rappou E, Jukarainen S, Rinnankoski-Tuikka R, Kaye S, Heinonen S, Hakkarainen A, Lundbom J, Lundbom N, Saunavaara V, Rissanen A, Virtanen KA, Pirinen E, Pietilainen KH

Publisher: ENDOCRINE SOC

: 2016

: Journal of Clinical Endocrinology and Metabolism

: JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM

: J CLIN ENDOCR METAB

: 101

: 3

: 1263

: 1273

: 11

: 0021-972X

: 1945-7197

DOI: https://doi.org/10.1210/jc.2015-3054

Context: Sirtuins (SIRTs) and poly(ADP-ribose) polymerases (PARPs) are 2 important nicotinamide adenine dinucleotide (NAD)(+)-dependent enzyme families with opposing metabolic effects. Energy shortage increases NAD(+) biosynthesis and SIRT activity but reduces PARP activity in animals. Effects of energy balance on these pathways in humans are unknown.Objective: We compared NAD(+)/SIRT pathway expressions and PARP activities in sc adipose tissue (SAT) between lean and obese subjects and investigated their change in the obese subjects during a 12-month weight loss.Design, Setting and Participants: SAT biopsies were obtained from 19 clinically healthy obese subjects (mean +/- SE body mass index, 34.6 +/- 2.7 kg/m(2)) during a weight-loss intervention (0, 5, and 12 mo) and from 19 lean reference subjects (body mass index, 22.7 +/- 1.1 kg/m(2)) at baseline.Main Outcome Measures: SAT mRNA expressions of SIRTs 1-7 and the rate-limiting gene in NAD(+) biosynthesis, nicotinamide phosphoribosyltransferase (NAMPT) were measured by Affymetrix, and total PARP activity by ELISA kit.Results: SIRT1, SIRT3, SIRT7, and NAMPT expressions were significantly lower, whereas total PARP activity was increased in obese compared with lean subjects. SIRT1 and NAMPT expressions increased in obese subjects between 0 and 5 months, after a mean weight loss of 11.7%. In subjects who continued to lose weight between 5 and 12 months, SIRT1 expression increased progressively, whereas in subjects with weight regain, SIRT1 reverted to baseline levels. PARP activity significantly decreased in all subjects upon weight loss.Conclusions: Calorie restriction is an attractive strategy to improve the NAD(+)/SIRT pathway and decrease PARPs in SAT in human obesity.