α7KO mice fed an AD showed significant upregulation of the Col1a1 gene encoding alpha-1 type I collagen, which is involved in liver fibrosis, and the Ccl2 gene encoding C-C motif chemokine ligand 2, a pro-inflammatory chemokine; α7KO mice fed an MCD had significant upregulation of the Col1a1 gene and the Tnf gene, an inflammatory cytokine.
Here, the relationship between SM α-actin and type 1 collagen expression (COL1A1), a major extracellular matrix protein important in liver fibrosis, is investigated with the results demonstrating that knockout of SM α-actin leads to reduced liver fibrosis and COL1 expression.
COL1A1 can precisely control sTβRII expression to inhibit excessive bioactive TGF-β level and thus inhibit hepatic fibrosis but without inducing autoimmune responses.
It also effectively inhibited the expression of two representative collagen proteins (COL1A1 and α-SMA) on both the mRNA and protein levels and showed a high safety profile in vivo, indicating its great promise as an anti-liver fibrosis agent.
The mRNA expression levels of markers of liver fibrosis [alpha-smooth muscle actin (α-SMA) and collagen 1A1 (Col1A1)] were analyzed by quantitative reverse transcription-polymerase chain reaction (RT-PCR).
Compared with CCl<sub>4</sub> injection alone, CCl<sub>4</sub> plus LPS injection exaggerated liver fibrosis in mice, as demonstrated by increased Col1a1 (collagen, type I, α 1), Acta2, Tgfb and Timp1 mRNA expression, ACTA2/α-SMA and COL1A1 protein expression, and Sirius Red staining area, which could be attenuated by injection of an autophagy inhibitor.
In vitro analysis using LX2 HSC cells indicated that AT‑II can augment TGF‑β1 and collagen type I α1 mRNA expression via periostin expression, suggesting that the interaction between AT‑II and periostin may serve a role in liver fibrosis development.
Infusion of Ang-(1-7) alleviated BDL-induced liver fibrosis and inhibited the expression of Col1A1 and the activation of NLRP3 inflammasome in hepatocytes.