Send to

Choose Destination
Diabetes Res Clin Pract. 2009 Feb;83(2):190-9. doi: 10.1016/j.diabres.2008.11.018. Epub 2008 Dec 24.

Upregulated IL-18 expression in type 2 diabetic subjects with nephropathy: TGF-beta1 enhanced IL-18 expression in human renal proximal tubular epithelial cells.

Author information

Division of Metabolism and Biosystemic Science, Department of Medicine, Asahikawa Medical College, Asahikawa, Japan.



In order to clarify the importance of Interleukin (IL)-18 in the development of diabetic nephropathy (DN), we evaluated the expressions of IL-18 in diabetic kidney.


We performed immmunohistochemical analysis of IL-18 and IL-18 receptor (IL-18 R) in human kidney tissue derived from 12 subjects with type 2 diabetes and overt nephropathy, and compared with those in 7 subjects with minimal change nephrotic syndrome (MCNS). In addition, we examined the regulation of IL-18 expression using human renal proximal tubular epithelial cells (HRPTECs) in culture.


IL-18 expression in tubular cells was observed in higher rate (83%) in patients with diabetes, whereas one positive specimen (14.3%) for IL-18 in patients with MCNS. In contrast, IL-18 R was expressed in glomerular mesangial cells and endothelial cells as well as tubular cells, similarly in almost of both groups. Exposure to transforming growth factor beta (TGF-beta(1)) led to two-fold increase in IL-18 gene expression in HRPTECs, and mitogen-activated protein kinases (MAPK) inhibitors abolished TGF-beta(1)-induced IL-18 mRNA expression. Western blot analysis showed the IL-18 protein in HRPTECs.


The present data indicate that IL-18 is overexpressed in human tubular epithelial cells in diabetic nephropathy, probably through the activation of MAPK pathways induced by TGF-beta(1).

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center