The implications of CsA treatment on renal fibrosis: an examination of in vivo and in vitro miR and mRNA changes affecting the TGFβ pathway

Tubulointerstitial fibrosis is by far one of the most common pathological hallmarks associated with cyclosporine (CsA) induced nephrotoxicity. Here we map the effects of altered microRNA (miR) expression levels on the TGFβ pathway in response to CsA treatment. Based on literature reviewed and the microarray data gathered by Gooch et al (publication in progress), we hypothesize that CsA alters the expression of renal miRs, and that the altered expression of the miRs has implications in renal fibrosis that can be mapped out through the use of both in vivo and in vitro models. We predict that HEK 293 cells can be used as an in vitro model for comparison to the microarray data obtained by Gooch et al. We hope to show through parallel experiments in mice renal tissue and HEK 293 cells the usefulness of HEK 293 cells as an in vitro tool for the study of CsA-induced renal fibrosis. Through the use of q-rtPCR we first validate the results obtained in a microarray study, which demonstrated that certain miRs exhibit altered expression in response to CsA treatment in kidney tissues isolated from mice. Next, we look at the use of HEK 293 cells as a proposed model for in vitro study of CsA regulated miRs in renal fibrosis. Finally we map changes in mRNA levels for some projected targets of the miRs shown to control various aspects of the TGFβ pathway. This complete work provides new insights into the involvement of miRs as regulators of the TGFβ pathway as well as demonstrates the usefulness of HEK 293 cells as an in vitro model that can be used for further study of CsA induced renal fibrosis.