Screening for genes up-regulated in 5/6 nephrectomized mouse kidney

Background. In diabetic and nondiabetic renal diseases, glomerular hyperfil tration is believed to play a central role in the subsequent progression of glomerulosclerosis and interstitial renal scarring. To identify genes invo lved in the process of hyperfiltration and hypertrophy, a polymerase chain reaction (PCR)-based subtraction method, that is, representational differen ce analysis of cDNA (cDNA-RDA), was employed. Methods. Ten-week-old ICR mice were 5/6 nephrectomized and sham operated. A fter two weeks, mRNAs were isolated from control and remnant kidneys and we re subjected to the cDNA-RDA procedure. Results. We identified 10 known and 9 novel genes. Among 19 clones, 12 clon es (8 known and 4 novel) showed 1.5- to 6-fold up-regulation by Northern bl ot analyses. The remaining seven clones were rarely expressed genes and wer e barely detected by Northern blot analyses, and their up-regulated express ion was confirmed by Southern blot analysis using the PCR-amplified represe ntative amplicons. The known genes included kidney androgen-regulated prote in, major urinary protein, lysozyme M, metalloproteinase-3 tissue inhibitor , chaperonin 10, cytochrome oxidase I, epsilon-sarcoglycan, ribosomal prote in S3a, G-protein gamma(10) subunit, and splicing factor 9G8. All of the is olated known genes have not been reported to be up-regulated in the nephrec tomized mouse kidney and suggest the possible role of androgen action: mito chondrial functions, matrix metabolism, cell-matrix interactions, and intra cellular signaling events in the initiation of the progressive renal injury of the remnant kidney. Furthermore, cDNA-RDA facilitates the discovery of novel genes, including two kidney-specific genes. Conclusions. The isolated known and novel genes may be involved in the path obiological process of initial hyperfiltration and hypertrophy of remnant k idney.