Therapy with antisense TGF-β1 oligodeoxynucleotides reduces kidney weight and matrix mRNAs in diabetic mice

Abstract

Inhibition of gene expression by antisense oligodeoxynucleotides (ODNs) relies on their ability to bind complementary mRNA sequences and prevent translation. The proximal tubule is a suitable target for ODN therapy in vivo because circulating ODNs accumulate in the proximal tubule in high concentrations. Because increased proximal tubular transforming growth factor- β1 (TGF-β1) expression may mediate diabetic renal hypertrophy, we investigated the effects of antisense TGF-β1 ODN on the high-glucose-induced proximal tubular epithelial cell hypertrophy in tissue culture and on diabetic renal hypertrophy in vivo. Mouse proximal tubular cells grown in 25 mM d-glucose and exposed to sense ODN as control (1 μM) exhibited increased3[H]leucine incorporation by 120% and total TGF-β1 protein by 50% vs. culture in 5.5 mM d-glucose. Antisense ODN significantly decreased the high-glucose-stimulated TGF-β1 secretion and leucine incorporation. Continuous infusion for 10 days of ODN (100 μg/day) was achieved via osmotic minipumps in diabetic and nondiabetic mice. Sense ODN-treated streptozotocin-diabetic mice had 15.3% increase in kidney weight, 70% increase in α1(IV) collagen and 46% increase in fibronectin mRNA levels compared with nondiabetic mice. Treatment of diabetic mice with antisense ODN partially but significantly decreased kidney TGF-β1 protein levels and attenuated the increase in kidney weight and the α1(IV) collagen and fibronectin mRNAs. In conclusion, therapy with antisense TGF-β1 ODN decreases TGF-β1 production and attenuates high-glucose-induced proximal tubular cell hypertrophy in vitro and partially prevents the increase in kidney weight and extracellular matrix expression in diabetic mice.