1. Figure 1 Overview of canonical TGF-β/Smad signalling in tissue fibrosis
Figure 1 | Overview of canonical TGF-β/Smad signalling in tissue fibrosis. Once released from the latency associated peptide (LAP)–latent TGF-β binding protein (LTBP) complex, the active homodimer form of TGF-β1 binds to TGF-β receptor 2 (TGFR2), which then recruits and activates TGFR1. The active TGFR1 then phosphorylates Smad2 and Smad3, which complex with Smad4 and translocate to the nucleus. The Smad3 component of the complex binds directly to gene promoters to induce transcription of profibrotic molecules, including α-smooth muscle actin (α-SMA), collagen I and tissue inhibitor of matrix metalloproteinases (TIMP), which induce myofibroblast activation and matrix deposition. In addition, Smad3 can induce transcription of profibrotic microRNA (miRNA) and long noncoding RNA (lncRNA), while acting indirectly to inhibit transcription of antifibrotic miRNAs. Finally, Smad3 can increase transcription of profibrotic molecules by influencing epigenetic modifications of DNA and histone proteins. Smad7 is a negative regulator of Smad2/3 and inhibits fibrosis.
Meng, X.-m. et al. (2016) TGF-β: the master regulator of fibrosis
Nat. Rev. Nephrol. doi: /nrneph