Abstract
Deregulated autophagy in diabetes has been a field of many experimental studies recently. Impaired autophagy in diabetic kidneys orchestrates every step of diabetic nephropathy (DN) pathogenesis. This study aimed to evaluate three autophagy regulators; RUBCN, mTOR, and SESN2 as clinically applicable indicators of DN progression and as early predictors of DN.
This retrospective study included 120 participants in 4 groups; G1: diabetic patients without albuminuria, G2: diabetic patients with microalbuminuria, G3: diabetic patients with macroalbuminuria and G4: healthy controls. RUBCN and SESN2 genes expression were tested by RT-qPCR. RUBCN, mTOR, and SESN2 serum proteins were quantitated by ELISA.
RUBCN mRNA was over-expressed in diabetic patients relative to controls with the highest level found in G3 followed by G2 then G1; (9.04 ± 0.64, 5.18 ± 0.73, 1.94 ± 0.41 respectively. P < 0.001). SESN2 mRNA expression was at its lowest level in G3 followed by G2 then G1 (0.1 ± 0.06, 0.48 ± 0.11, 0.78 ± 0.13 respectively. P < 0.001). Similar parallel reduction in serum SENS2 was observed. Serum RUBCN and mTOR were significantly elevated in diabetic patients compared to controls, with the increase parallel to albuminuria degree. RUBCN expression, serum RUBCN and mTOR strongly correlated with albuminuria (r = 0.912, 0.925 and 0.867 respectively). SESN2 expression and serum level negatively correlated with albuminuria (r = - 0.897 and -0.828 respectively); (All p < 0.001). Regression analysis showed that serum RUBCN, mTOR, RUBCN and SESN2 mRNAs could successfully predict DN.
The study proves the overexpression of RUBCN and mTOR in DN and the down-expression of SESN2. The three markers can be clinically used to predict DN and to monitor disease progression.