Urinary biomarkers of diabetic nephropathy

Abstract

Abstract:The fervent search for an early biomarker for diabetic nephropathy is continuing because this entity has become the leading cause of end-stage renal disease in many countries. Novel biomarkers are being described in a high-speed manner. Using urine as a biological source is especially appealing given its ease of collection and its ability to serve as a direct conduit to the site of injury. We begin by briefly discussing the merits and pitfalls of our gold standard of microalbuminuria, and shift quickly to several promising nontraditional protein and messenger (m)RNA biomarkers. The quality of the evidence for using urinary podocyte as a marker will be described. Exploring entire sets of protein in humans in terms of proteomics has been a favorite approach in the last decade because the technology of protein separation and mass spectrometry allows for the unbiased search for new biomarkers. Isolating urinary microRNA may become yet another preferred method because these small, noncoding mRNA that regulate gene expression are particularly stable and apt for biomarker studies. Finally, the latest development is perhaps the study of exosomes, which are nanometer particles derived from the fusion of internal vesicles to the plasma membrane. These particles harbor protein, mRNA, and microRNA that may be isolated for further study. With the advent of newer technologic approaches, we hope that these newly discovered biomarkers will be rigorously tested in large, prospective, clinical trials so they can be implemented in clinical practice.