ly-2157299 and Liver-Cirrhosis

Topics: Animals; Carbon Tetrachloride; Diethylnitrosamine; Hepatectomy; Hepatic Stellate Cells; Hepatocytes; Ligation; Liver; Liver Cirrhosis; Liver Regeneration; Portal Vein; Primary Cell Culture; Pyrazoles; Quinolines; Rats; Signal Transduction; Transforming Growth Factor beta1

Fibrosis is the hallmark of pathologic tissue remodelling in most chronic diseases. Despite advances in our understanding of the mechanisms of fibrosis, it remains uncured. Fibrogenic processes share conserved core cellular and molecular pathways across organs. In this study, we aimed to elucidate shared and organ-specific features of fibrosis using murine precision-cut tissue slices (PCTS) prepared from small intestine, liver and kidneys. PCTS displayed substantial differences in their baseline gene expression profiles: 70% of the extracellular matrix (ECM)-related genes were differentially expressed across the organs. Culture for 48 h induced significant changes in ECM regulation and triggered the onset of fibrogenesis in all PCTS in organ-specific manner. TGFβ signalling was activated during 48 h culture in all PCTS. However, the degree of its involvement varied: both canonical and non-canonical TGFβ pathways were activated in liver and kidney slices, while only canonical, Smad-dependent, cascade was involved in intestinal slices. The treatment with galunisertib blocked the TGFβRI/SMAD2 signalling in all PCTS, but attenuated culture-induced dysregulation of ECM homeostasis and mitigated the onset of fibrogenesis with organ-specificity. In conclusion, regardless the many common features in pathophysiology of organ fibrosis, PCTS displayed diversity in culture-induced responses and in response to the treatment with TGFβRI kinase inhibitor galunisertib, even though it targets a core fibrosis pathway. A clear understanding of the common and organ-specific features of fibrosis is the basis for developing novel antifibrotic therapies.

Topics: Animals; Fibrosis; Kidney; Liver; Liver Cirrhosis; Mice; Mice, Inbred C57BL; Protein Kinase Inhibitors; Pyrazoles; Quinolines; Signal Transduction; Smad2 Protein; Transforming Growth Factor beta

Transforming growth factor (TGF)-β stimulates extracellular matrix (ECM) deposition during development of liver fibrosis and cirrhosis, the most important risk factor for the onset of hepatocellular carcinoma. In liver cancer, TGF-β is responsible for a more aggressive and invasive phenotype, orchestrating remodeling of the tumor microenvironment and triggering epithelial-mesenchymal transition of cancer cells. This is the scientific rationale for targeting the TGF-β pathway via a small molecule, galunisertib (intracellular inhibitor of ALK5) in clinical trials to treat liver cancer patients at an advanced disease stage. In this study, the hypothesis that galunisertib modifies the tissue microenvironment via inhibition of the TGF-β pathway is tested in an experimental preclinical model. At the age of 6 months, Abcb4ko mice-a well-established model for chronic liver disease development and progression-are treated twice daily with galunisertib (150 mg/kg) via oral gavage for 14 consecutive days. Two days after the last treatment, blood plasma and livers are harvested for further assessment, including fibrosis scoring and ECM components. The reduction of Smad2 phosphorylation in both parenchymal and non-parenchymal liver cells following galunisertib administration confirms the treatment effectiveness. Damage-related galunisertib does not change cell proliferation, macrophage numbers and leucocyte recruitment. Furthermore, no clear impact on the amount of fibrosis is evident, as documented by PicroSirius red and Gomori-trichome scoring. On the other hand, several fibrogenic genes, e.g., collagens (Col1α1 and Col1α2), Tgf-β1 and Timp1, mRNA levels are significantly downregulated by galunisertib administration when compared to controls. Most interestingly, ECM/stromal components, fibronectin and laminin-332, as well as the carcinogenic β-catenin pathway, are remarkably reduced by galunisertib-treated Abcb5ko mice. In conclusion, TGF-β inhibition by galunisertib interferes, to some extent, with chronic liver progression, not by reducing the stage of liver fibrosis as measured by different scoring systems, but rather by modulating the biochemical composition of the deposited ECM, likely affecting the fate of non-parenchymal cells.

Topics: Animals; ATP Binding Cassette Transporter, Subfamily B; ATP-Binding Cassette Sub-Family B Member 4; Disease Models, Animal; Extracellular Matrix; Liver; Liver Cirrhosis; Mice, Inbred BALB C; Mice, Knockout; Pyrazoles; Quinolines; Smad2 Protein; Transforming Growth Factor beta

Liver fibrosis is a major cause of liver-related mortality and, so far, no effective antifibrotic drug is available. Galunisertib, a TGF-β receptor type I kinase inhibitor, is a potential candidate for the treatment of liver fibrosis. Here, we evaluated the potency of galunisertib in a human ex vivo model of liver fibrosis.. Antifibrotic potency and associated mechanisms were studied ex vivo, using both healthy and cirrhotic human precision-cut liver slices. Fibrosis-related parameters, both transcriptional and translational level, were assessed after treatment with galunisertib.. Galunisertib showed a prominent antifibrotic potency. Phosphorylation of SMAD2 was inhibited, while that of SMAD1 remained unchanged. In healthy and cirrhotic human livers, spontaneous transcription of numerous genes encoding collagens, including collagen type I, α 1, collagen maturation, non-collageneous extracellular matrix (ECM) components, ECM remodelling and selected ECM receptors was significantly decreased. The reduction of fibrosis-related transcription was paralleled by a significant inhibition of procollagen I C-peptide released by both healthy and cirrhotic human liver slices. Moreover, galunisertib showed similar antifibrotic potency in human and rat lives.. Galunisertib is a drug that deserves to be further investigated for the treatment of liver fibrosis. Inhibition of SMAD2 phosphorylation is probably a central mechanism of action. In addition, blocking the production and maturation of collagens and promoting their degradation are related to the antifibrotic action of galunisertib.

Topics: Animals; Dose-Response Relationship, Drug; Humans; Liver Cirrhosis; Male; Phosphorylation; Pyrazoles; Quinolines; Rats; Rats, Wistar; Smad2 Protein; Structure-Activity Relationship