TCF7L2 Gene Polymorphism and AGEs in Diabetic Nephropathy

Diabetic nephropathy is one of microvascular complications of diabetes mellitus. DN is a multifactorial disorder that occurs in one third of patients with long standing DM. DN is one of the most serious complications that being a major contributing factor to end-stage renal disease and death in diabetic patients. The earliest clinical indication of DN is the appearance of microalbuminuria. Detection of diabetic nephropathy as early as possible, is the best chance of delaying progression to ESRD. Thus, screening for microalbuminuria is recommended annually immediately after a diagnosis of diabetes. Transcription factor 7-like 2 is a highly variable transcription factor, which is a key component of the Wnt-signaling pathway and plays a role in the regulation of insulin secretion by pancreatic beta cells and the maintenance of glucose homeostasis. TCF7L2 rs7903146 polymorphism is more associated with T2DM which mediated by decreased insulin secretion associated with defects in insulin processing, reduced effects of glucagon-like peptide-1, increased hepatic glucose production and insulin resistance. The mutant TT genotype and the T allele frequency was associated with diabetic patients who developed nephropathy. Advanced glycation end products are generated by the non-enzymatic reaction of amino groups in DNA and proteins with reducing sugars. AGEs accumulate in glomerular basement membrane. The AGEs-RAGE interaction is a causative factor for DN through activating a series of intracellular signal-cascade pathways which induce the generation of further signalling factors, such as vascular endothelial growth factor, transforming growth factor B, nuclear factor-κβ. Those signalling factors cause mesangial expansion and glomerulosclerosis.