SIRT1 and diabetic kidney disease: Figure 5 reveals that Dab1 downregulation inhibited phosphorylation of p38, whereas phosphorylation of ERK was not affected, indicating that Dab1 was involved in Ang II-induced podocyte apoptosis via p38 pathway. Our previous study has confirmed that Ang II induces podocyte apoptosis through p38 MAPK pathway [31]. Recently, Gu et al. [32] have found that olmesartan decreases albuminuria in diabetic nephropathy through inhibiting Ang II/p38/SIRT1-caused podocyte apoptosis.