Enhanced glomerular Toll-like receptor 4 expression and signaling in patients with type 2 diabetic nephropathy and microalbuminuria

Toll-like receptor 4 (TLR4), a component of the innate immune system, is recognized to promote tubulointerstitial inflammation in overt diabetic nephropathy (DN). However, there is no information on immune activation in resident renal cells at an early stage of human DN. In order to investigate this, we studied TLR4 gene and protein expression and TLR4 downward signaling in kidney biopsies of 12 patients with type 2 diabetes and microalbuminuria, and compared them with 11 patients with overt DN, 10 with minimal change disease (MCD), and control kidneys from 13 patients undergoing surgery for a small renal mass. Both in microalbuminuria and in overt DN, TLR4 mRNA and protein were overexpress…