A bivalent anti-CTGF aptamer modulates multiple signaling pathways to attenuate liver fibrosis

Liver fibrosis is a pressing clinical problem without effective drugs. Connective tissue growth factor (CTGF), as a pivotal driver of fibrosis, is targeted with a dimer-inducing strategy to inhibit its pro-fibrotic activity. Here, a series of high-affinity aptamers targeting CTGF are screened through micro-SELEX, among which CApt10 shows high efficiency in inhibiting the interaction between CTGF and TGF-β1. By linking two CApt10-3 molecules, we generated a bivalent aptamer, termed PDM, which may not only induce CTGF dimerization but also disrupt its interaction with TGF-β1 more potently than the monomeric CApt10-3. In vitro, PDM significantly reduced the expression of α-SMA in LX-2 cells and murine primary hepatic stellate cells (HSCs). In a CCl₄-induced mouse liver fibrosis model, PDM treatment markedly decreased the expression of fibrotic markers, including Sirius Red, Masson, and α-SMA compared to vehicle-treated controls. Mechanistically, PDM may exert its anti-liver fibrosis effects by dimerizing CTGF protein, which modulates multiple downstream signaling pathways and suppresses pro-fibrotic genes expression. These findings establish CTGF dimerization as a potential therapeutic strategy and highlight PDM as a promising lead for the treatment of liver fibrosis.