Proteomic identification of human urinary biomarkers in diabetes mellitus type 2.

Background: During the proteomic era, one of the most rapidly growing areas in biomedical research is biomarker discovery, particularly using proteomic technologies. The urinary proteome is known to be a valuable field of study and has become one of the most attractive subdisciplines in clinical proteomics for human diseases. We have described the levels of protein biomarkers specific to diabetes mellitus type 2 in the Pakistani population using proteomic technology.

Methods: One hundred type 2 diabetes patients with 50 age- and sex-matched normal healthy controls were recruited from Sheikh Zayed Hospital, Lahore, Pakistan. Urinary proteins were analyzed by two-dimensional liquid chromatography, using chromatofocusing in the first dimension and reverse-phase chromatography in the second, followed by mass spectrometric analysis. Levels of the proteins, which were found to vary in the diabetes type 2 patients compared to the controls, were then determined by enzyme-linked immunosorbent assay in all the samples.

Results: Levels of transthyretin, α-1-microglobulin/bikunin precursor, and haptoglobin precursor decreased by 30.8%, 55.2%, and 81.45%, whereas levels of albumin, zinc α2 glycoprotein, retinol binding protein 4, and E-cadherin increased by 486.5%, 29.23%, 100%, and 693%, respectively, in the diabetes patients compared to the controls.

Conclusions: Variation in the levels of these identified protein biomarkers have been reported in other pathological states. Assessment of the levels of these biomarkers will be helpful not only in early diagnosis but also in prognosis of diabetes mellitus type 2.