Fig. 7: Role of SIRT3 in regulating islet function and metabolism.

Rat islets (a) and mouse islets (b) transfected with control vector or SIRT3-overexpressing adenovirus were pretreated with 0.25 mM palmitate for 24 h and then stimulated with 3.3 mM glucose for insulin secretion assay. c Western blot analysis of SIRT3, SIRT4, and SIRT5 protein levels in islets isolated from wild type or SIRT3 knockout mice. d Islets isolated from wild type or SIRT3 knockout mice were stimulated with or without 0.25 mM palmitate at 3.3 mM glucose for 1 h and insulin secretion was assayed (n = 8). e Palmitate oxidation rate was measured in islets isolated from wild type or SIRT3 knockout mice (n = 5). f Islets from wild type or SIRT3 knockout mice were transfected with control vector and SIRT3 or ECHA-overexpressing adenovirus, and then stimulated with 0.25 mM palmitate for 1 h for insulin secretion assay. g Islets isolated from wild type or SIRT3 knockout mice were stimulated with 3.3 or 16.7 mM glucose for 1 h, and insulin secretion was assayed (n = 8). h OCR in islets isolated from wild type or SIRT3 knockout mice was measured at baseline or following glucose addition (n = 5). SIRT3 mRNA (i) and protein (j) expressions were detected after rat islets were treated with 3.3 or 16.7 mM glucose for 24 h. k Western blot analysis of SIRT3 protein levels in islets isolated from rats fed or fasted for 24 h. Data are expressed as mean ± SEM of three independent experiments. *p < 0.05, **p < 0.01, ***p < 0.001 vs. control (CON), WT, or 3.3 G. #p < 0.05, ##p < 0.01 vs. vector