Expression pattern of genes in peripheral blood mononuclear cells in diabetic nephropathy

Only one-third of Type 1 diabetes patients develop diabetic nephropathy, and a genetic predisposition is postulated. To obtain more insight into processes that lead to diabetic nephropathy, messenger RNA expression profiles of peripheral blood mononuclear cells from patients with and without diabetic nephropathy were compared.

We studied seven male patients with Type 1 diabetes and proteinuria and 12 male patients with Type 1 diabetes and normoalbuminuria after at least 20 years of diabetes duration. The expression of genes was examined using the microarray method with Human Genome U133A Arrays (Affymetrix, Santa Clara, CA, USA). We analysed the expression of all candidate genes suggested to be involved in the pathogenesis of diabetic nephropathy in previously published articles. Altogether, expression of 198 genes was analysed.

We found that thrombospondin 1 (THBS1) and cyclooxygenase 1(COX1) genes were over-expressed in patients with diabetic nephropathy, and matrix metalloproteinase 9 (MMP9) and cyclooxygenase 2 (COX2) genes had lower expression in diabetic nephropathy. For other genes, we did not observe different expression between patients with and without diabetic nephropathy,or the expression was too low for analysis.

The different gene expression pattern in peripheral blood mononuclear cells in patients with diabetic nephropathy might indicate an important pathway in the pathogenesis of this complication.