DNAzyme for TGF-β suppressed extracellular matrix accumulation in experimental glomerulonephritis

Abstract

Background. We developed an electroporation-mediated gene transfer method targeting glomerular mesangial cells. Injecting DNA solution via renal artery followed by electric pulses using tweezers-type electrodes could result in efficient transfection in mesangial cells. Therefore, this gene transfer system opened a feasible strategy to manipulate the function of several cytokines and growth factors in mesangial cells. Recently, a new generation of catalytic nucleic acid composed of DNA, named DNA enzyme (DNAzyme), has been developed. Method. We generated a DNAzyme (TGFDE) targeting transforming growth factor-β1 (TGF-β1), and examined the therapeutic effect of TGFDE in vitro and in vivo. Results. In cultured rat mesangial cells, treatment with TGFDE blocked TGF-β1 mRNA expression, and thereby suppressed type I collagen mRNA expression. Next, we introduced TGFDE or scrambled DNAzyme (TGFSCR) into anti-Thy-1 model of nephritic rats by electroporation 3 days after disease induction. Northern blot analysis and immunohistochemical staining demonstrated that glomerular message and protein ex-pression of TGF-β1, α-smooth muscle actin (α-SMA), and type I collagen were suppressed in TGFDE-transfected nephritic rats compared with untreated nephritic rats and TGFSCR-transfected rats on day 7. Consequently, we observed significant reduction in glomerular matrix score in TGFDE-transfected nephritic rats. Conclusion. Inhibition of TGF-β1 expression by electroporation-mediated DNAzyme transfer might be useful for the therapy of glomerulonephritis.