A novel aptamer targeting TGF-β receptor II inhibits transdifferentiation of human tenon's fibroblasts into myofibroblast

摘要

PURPOSE. To isolate aptamers that were bound to the extracellular segment of TGF-b receptor II (TbRII) and evaluate their effect on the TGF-b-induced transdifferentiation of fibroblasts. METHODS. TbRII-binding aptamers were screened by Systematic Evolution of Ligands by Exponential Enrichment (SELEX) from a single stranded DNA (ssDNA) library. Human Tenon's fibroblasts (HTFs) were cultured and treated with TGF-β2, TGF-β2 and aptamer S58/68, or aptamer S58/68 alone. Western blot analysis was performed to determine levels of a-smooth muscle actin (α-SMA) and the signaling protein phosphorylated Smad2 (p-Smad2). α-SMA and p-Smad2 subcellular distribution and fibrous actin (F-actin) with rhodamine-phalloidin staining were evaluated by confocal immunofluorescence microscopy. Cell contractility was assessed in collagen gel contraction assays. RESULTS. Twenty-one sequences were obtained after eight rounds of selection. Two preferential sequences, aptamer S58 and S68, were isolated and used in the following experiments. Aptamer S58 significantly inhibited a-SMA expression and incorporation into actin stress fibers, as induced by TGF-β2. Aptamer S58 also suppressed TGF-β2-induced cell contraction. Furthermore, aptamer S58 inhibited the TGF-β2-induced phosphorylation and nuclear translocation of Smad2. However, we did not find any effect of aptamer S68 on TGF-β2 activity in vitro. CONCLUSIONS. Our study revealed that a novel aptamer binding TbRII inhibited TGF-β2-induced myofibroblast transdifferentiation in HTFs.