Antisense oligonucleotides modulate high glucose-induced laminin overexpression and cell proliferation: a potential for therapeutic application in diabetic microangiopathy.

Vascular basement membrane (BM) thickening is a prominent and characteristic lesion of diabetic microangiopathy. Studies suggest that increased synthesis of laminin, a BM component, is associated with the development of thickened BM in diabetic vessels. In this study, we evaluated whether an interventive strategy using laminin antisense phosphorothioate oligonucleotides (Lam AS-oligos) could specifically inhibit high-glucose-induced laminin gene overexpression in vascular endothelial cells and normalize cell proliferation. Rat endothelial cells grown in high-glucose (30 mM) medium for 7 days showed increased laminin mRNA and protein level (195% +/- 28% of control, p < 0.05; 143% +/- 26% of control, p < 0.05, respectively) and reduced cell number (79% +/- 6% of control, p < 0.05) compared with cells grown in normal (5 mM) glucose medium. When cells grown in high-glucose medium were transfected with 0.4 microM Lam AS-oligos for 48 hours in the presence of 8 microM lipofectin, the laminin mRNA and protein level decreased (121% +/- 19% and 99% +/- 15% of control, respectively), and the cell number was restored to near normal level (93% +/- 7% of control). The results indicate that the antisense strategy is effective in selectively reducing laminin overexpression and improving endothelial cell proliferation under high-glucose conditions. Thus, the As-oligos may be potentially useful for preventing the development of thickened vascular BM in diabetic microangiopathy.