The beneficial effects of relaxin peptide treatment have been demonstrated in animal models of liver fibrosis. However, the low stability of peptide in vivo prevents using it in chronic treatments. We have identified a series of small molecule allosteric agonists of the human relaxin receptor, RXFP1. The therapeutic effects of lead compound ML290 was tested in various models of liver fibrosis. To analyze the anti-fibrotic effects of ML290 on gene expression, we used primary human hepatic stellate cells followed by RNAseq analysis of ML290 treatment in an established human stellate cell line, LX-2. We then tested the effects of ML290 in fibrotic human liver organoids and in a carbon tetrachloride model of mouse liver fibrosis. We demonstrated that RXFP1 expression is increased in fibrotic mouse liver, specifically in activated hepatic stellate cells. The lead compound, ML290, was selected based on its effects on the gene expression profile associated with fibrosis in primary human stellate cells. RNA-Seq analysis of TGFβ1-activated LX-2 cells showed that about 500 genes were misregulated by ML290. Gene Ontology analysis demonstrated that ML290 treatment primarily affects extracellular matrix remodeling and cytokine signaling. ML290 treatment in human liver organoids with lipopolysaccharide-induced fibrotic phenotype resulted in dramatic reduction of type I collagen. The pharmacokinetics of ML290 in mice after multiple daily injections demonstrated its high stability in vivo, as evidenced by the sustained concentration of compound in the liver. In mice expressing human RXFP1 gene treated with carbon tetrachloride, ML290 significantly reduced collagen content, alpha-smooth muscle actin expression, and cell proliferation around portal ducts. In summary, ML290, the small molecule agonist of relaxin receptor, has anti-fibrotic effects in liver fibrosis.
18 - 21 May 2019
European Society of Endocrinology