Modulation of sirtuin expression by a high-sugar diet and regular swimming trained precedes the loss of kidney function.

Abstract

Sirtuins (SIRTs) are key regulators of cellular metabolism, involved in a wide range of physiological and pathological processes. However, there is scarce knowledge about the effect of sugar consumption and physical activity on SIRTs in kidney disorders. Here, we evaluated the impact of prolonged consumption of an isocaloric high-sugar diet (HSD) and physical training on the modulation of renal Sirts and the link between these alterations and possible obesity-associated kidney damage. Newly weaned male Wistar rats were fed a standard chow diet (STD) or HSD ad libitum and then subjected or not to regular workload swimming training for 18 weeks. Morphometric and biochemical parameters were analyzed, and the kidneys were removed for lipid quantification, histological analysis, and for Sirts1-7 expression. HSD led to the development of obesity, increased serum triglyceride levels, and glucose intolerance, regardless of higher caloric consumption. However, training was able to partially inhibit the HSD-induced obesogenic effect. No changes were identified in kidney mass, lipid content, histology, and creatinine clearance among the groups; these results were associated with a decrease in the renal expression of Sirt2-3 and Sirt7; however, training was able to reverse this modulation. The interaction between HSD and training led to an increase in Sirt4-7. However, Sirt1 remained constant among experimental groups. In conclusion, our results indicated that the transcriptional modulation of Sirts precedes HSD-induced damage and loss of kidney function, as well as a possible protective adaptive response of physical exercise on long-term Sirts expression.