DNA microarray analysis of the gene expression profile of kidney tissue in a type 2 diabetic rat model

The aim of this study was to determine differences in the gene expression profile of kidney tissue from type 2 diabetes mellitus (T2D) and control rats using DNA microarray analysis. Total RNA was extracted from the kidney tissue of the T2D and control rats using the original single step method. cDNA retro-transcribed from an equal quantity of mRNA was labeled with Cy5 and Cy3 fluorescence and served as the probes. The mixed probes were hybridized to a DNA microarray. Fluorescence signals were scanned by an ScanArray 4000 laser scanner and further analyzed by QuantArray software. Apoptotic cells were detected in situ using the Roche TUNEL assay. Serum glucose, ApoAI, ApoB, ApoA1/ApoB, cholesterol and triglyceride levels were significantly higher in the T2D rats than in the controls, but there were no significant differences in serum insulin. When the kidney tissue was screened using the DNA microarray, differential expression was found for 41 genes. Five genes in the T2D rats were upregulated by 2-fold compared to the control rats, while 36 genes were down-regulated by 0.5-fold. Moreover, in the renal tubular epithelial cells, there was a significantly greater number of TUNEL-positive cells in the T2D group than in the control group. A total of 41 genes are associated with the occurrence and development of T2D and diabetic nephropathy. The present study suggests that examining differences in gene expression profiles is of benefit to the diagnosis, treatment and prevention of T2D, diabetic nephropathy and other T2D complications.