Figure 1.

Myo9A is downregulated in advanced diabetic kidney disease. (A) Kidney PAS stain from uninduced diabetic mouse (DM-iVEGF₁₆₄, - dox) showing mild mesangial proliferation; (B) kidney PAS stain from induced diabetic mouse (DM-iVEGF₁₆₄, + dox) showing nodular glomerulosclerosis and large protein casts; (C) Urine ACR (albumin:creatinine ratio, mg/mg) shows mild albuminuria in uninduced diabetic mice (DM-iVEGF₁₆₄, - dox, n = 7) and nephrotic range proteinuria in induced diabetic mice (DM-iVEGF₁₆₄, + dox, n = 8), unpaired t-test with Welch's correction, P = 0.033; (D) representative immunoblot shows decreased kidney Myo9A expression in mice with advanced DKD (DM-iVEGF₁₆₄, + dox); quantitation of Myo9A expression normalized to actin confirms significant Myo9A downregulation in n = 4 immunoblots (kidney lysates pooled from 4 to 6 mice/experimental group), mean ± SD, P < 0.05; (E) Fluorescence IHC shows S-nitrosylated proteins (red) and Myo9A (green) partially co-localized (merge) in glomeruli from uninduced diabetic kidneys (DM-iVEGF₁₆₄, - dox), both Myo9A and nitroso-Cys IF signals are reduced in glomeruli from kidneys with advanced DKD (DM-iVEGF₁₆₄, + dox); (F) quantitation of Myo9A and nitroso-Cys IF signals confirm a dramatic decrease in glomerular Myo9A expression and S-nitrosylated proteins in kidneys with advanced DKD (DM-iVEGF₁₆₄, + dox), mean ± SD, n = 19 glomeruli/experimental group (each from 3 to 5 mice), unpaired t-test with Welch's correction, p < 0.0001; (G) quantitation of the IF signals' ratio Nitroso-Cys/Myo9A shows significant decrease in kidneys with advanced DKD, mean ± SD, n = 19 glomeruli/experimental group, unpaired t-test with Welch's correction, p = 0.0002. Scale bars = 50μm. *p < 0.05, ***p < 0.005, ****p < 0.0001.