Circulating exosomal miRNAs both reflect and potentially influence these processes—miR-122 and miR-34a, which are elevated in obese PCOS, facilitate hepatic lipid accumulation by targeting SIRT1 and PPARα, whereas altered levels of vascular-regulatory miRNAs (e.g., miR-320a, miR-126) diminish endothelial nitric oxide synthase activity, thereby reducing nitric oxide bioavailability [31]. Here, NOS3 is linked to polycystic ovary syndrome.