The m6A reader IGF2BP1 contributes to the activation of hepatic stellate cells through facilitating TUBB4B mRNA...

The m6A reader insulin-like growth factor-2 mRNA-binding protein 1 (IGF2BP1) is involved in multiple pathophysiological processes through enhanced expression of the proteins encoded by their target mRNAs. However, the functional role of IGF2BP1-mediated m6A in liver fibrosis remains elusive. Here, we report that IGF2BP1 is highly expressed in activated hepatic stellate cells (HSCs), the major driver of fibrogenesis, and TUBB4B is identified as a potential target of IGF2BP1 by re-analysis of the RNA-seq, RIP-seq, and m6A-seq data. The relevant findings were subsequently demonstrated by a series of molecular and cellular evidences. The knockdown of IGF2BP1 or TUBB4B and pharmacological inhibition of TUBB4B by mebendazole treatments significantly suppress the proliferation, migration, and activation of HSCs. Mechanistically, IGF2BP1 upregulates TUBB4B expression through stabilizing TUBB4B in an m6A-dependent manner, and TUBB4B induces liver fibrosis by activating the FAK signaling pathway. Collectively, our results indicate that targeting IGF2BP1/TUBB4B/FAK axis in HSCs could be a promising therapeutic approach for liver fibrosis.