V-ATPase subunit C 1 and IKBIP as tandem prospective biomarkers for diabetic nephropathy

The appearance of low-molecular-weight (LMW) protein in the urine indicates any disruption in the structural integrity of the glomerular capillary wall; therefore, the presence of LMW protein may be a potential predictive marker for DN.

The urine proteomic profiling of T2DM patients (n = 94) and control group (n = 32) was compared by liquid chromatography-tandem mass spectrometry, and the untargeted LMW protein was identified by Progenesis Q1 For Proteomics v4.2.

A total of 73 LMW proteins were identified and quantified, of which, 32 proteins were found to be altered significantly (p < 0.05). Further analysis with heat maps identified two potential proteins with the highest folding alterations in urine. V-ATPase subunit C 1 abundance was significantly inversely correlated with microalbumin and significantly decreased in urine, whereas increased IKBIP was positively correlated with microalbumin. The level of those proteins was significantly different among the control, T2DM, and DN groups, implying an association with the progression of DN.

The present findings of our study indicate that the decreasing V-ATPase subunit C 1 together with increasing IKBIP in urine, were found to be closely associated with DN complications and signifying their value as biomarkers for predicting the risk of DN at initial diagnosis.