Hyperglycemic RhoB−/− kidneys showed fewer signs of early nephropathy compared with those of the wild-type control group. A: Hematoxylin-eosin staining of the glomeruli. Both diabetic groups (bottom) had an enlarged glomerular surface area and accumulation of mesangial matrix compared with the nondiabetic groups (top) at 6 months of diabetes duration. B: Glomerular size increases with hyperglycemia in both RhoB+/+ (white bars) and RhoB−/− (black bars) groups. Values are the mean ± SE. The SE is shown as the error bar. RhoB+/+, n = 79; RhoB−/−, n = 60; STZ-RhoB+/+, n = 80; and STZ-RhoB−/−, n = 60. *P < 0.01 versus non-STZ. C: The STZ-treated RhoB−/− mice (black bar, right) showed less severe mesangial matrix accumulation compared with diabetic RhoB+/+ (white bar, right). Values are the mean ± SE. The SE is shown as the error bar. #P < 0.01 versus STZ RhoB+/+, and *P < 0.01 versus non-STZ. RhoB+/+, n = 79; RhoB−/−, n = 60; STZ-RhoB+/+, n = 80; and STZ-RhoB−/−, n = 60.