Fattori implicati nel rimodellamento tissutale epatico

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1 tissutale epatico Dr. Simone Carotti Unità di Ricerca di Anatomia Microscopica e Ultrastrutturale Facoltà Dipartimentale di Medicina e Chirurgia

2 Background Duncan AW, Dorrell C, Grompe M. Gastroenterology The liver displays an extraordinary regenerative capacity upon parenchymal tissue loss as a result of partial resection or hepatocellular injury Mohammed FF, Khokha R. Trends Cell Biol Burt AD, Portmann B, Ferrell LD & MacSween RNM (2012)

3 Background This regenerative response is tightly regulated, involving an array of cytokines, growth factors and metabolites, whose fluctuations contribute to initiate the proliferation of liver cells as well as the arrest of cell replication once the optimal hepatic functional mass is restored Mohammed FF, Khokha R. Trends Cell Biol Taub R. Nat Rev Mol Cell Biol An essential additional component of the regenerative response of the liver is remodelling of the extracellular matrix (ECM), which also entails the release of matrixbound growthregulatory molecules

4 Background This reaction is part of a wound healing process aimed at the restoration of liver architecture, in which a provisional matrix composed of various macromolecules, such as fibrin (ogen) and fibronectin is transiently formed to stabilize wound areas and provide support to the regenerating liver cells. Forbes SJ, Rosenthal N. Nat Med Dollè L et al. Am J Physiol Gastrointest Liver Physiol. 2015

5 Background This controlled ECM remodeling process is mediated by two major classes of proteases, serine proteases and matrix metalloproteinases (MMPs), acting in a complex and interlinked fashion. Wilkins-Port CE et al. Biochem Res Int Weis SM, Cheresh DA. Nat Med MMP10 is able to process a wide range of ECM components, it can activate other MMPs such as prommp-1, -7, -8 and -9, has profibrinolytic effects in vivo by enhancing tissue plasminogen activator fibrinolytic activity.

6 Background Signals and pathways activated during liver injury and regeneration Involvement in the liver carcinogenic process, when the reparative reaction goes awry in the setting of chronic liver injury. Berasain C, Avila MA. Eur J Med Res. 2014

7 Aim To evaluate the expression and function of MMP10 in liver wound healing and regeneration

8 Methods The hepatic expression of MMP10 was examined in two murine models: liver regeneration after two thirds partial hepatectomy (PH) and bile duct ligation (BDL). MMP10 was detected in liver tissues by immunohistochemistry, qpcr and western blotting. The effect of growth factors and toll-like receptor 4 (TLR4) agonists on MMP10 expression was studied in cultured parenchymal and biliary epithelial cells and macrophages respectively. The role of MMP10 was evaluated by comparing the response of Mmp10 +/+ and Mmp10 -/- mice to PH and BDL. The intrahepatic turnover of the extracellular matrix proteins fibrin(ogen) and fibronectin was examined.

9 Results Expression of MMP10 during mouse liver regeneration after two-thirds partial hepatectomy 100 µm Sham 24 hr 48 hr 72 hr 96 hr

10 Results Expression of MMP10 in mouse liver after bile duct ligation 100 µm Sham 3 days 7 days 14 days 21 days

11 Results Expression of EGFR ligands in mouse liver upon bile duct ligation Expression of MMP10 in mouse and human liver cells in response to growth factors Expression of MMP10 in mouse Kupffer cells and RAW macrophage treated with toll-like receptor 4 (TLR4) agonists

12 Results Liver regeneration in Mmp10+/+ and Mmp10-/- mice after two-third partial hepatectomy

13 Results Liver necrosis in Mmp10+/+ and Mmp10-/- mice after bile duct ligation Liver fibrosis after bile duct ligation in Mmp10+/+ and Mmp10-/- mice

14 Results Macrphages and expression of α-smooth muscle actin and monocyte chemoattractant protein 1 in Mmp10 +/+ and Mmp10 -/- mice after bile duct ligation 3 days 7 days 14 days Mmp10 +/+ Mmp10 -/-

15 Results Fibrinogen levels and fibronectin fragments in liver extract from Mmp10+/+ and Mmp10-/- mice after partial hepatectomy and bile duct ligation

16 Conclusions In the two experimental models of hepatic damage and repair tested, a transient pattern of MMP10 expression was observed, which onset overlapped with the early inflammatory response The EGFR ligands AR, HB-EGF and Ereg were markedly up-regulated in mouse liver upon BDL. Additive effects of TGFb1 and EGFR ligands on MMP10 expression in parenchymal and biliary cells was observed LPS an EDA domain of fibronectin can induce MMP10 expression in liver macrophages. Mmp10 gene transcription also responds to molecular changes in the ECM composition of the liver Upon experimental liver resection and BDL, lack of MMP10 resulted in - persistent parenchymal injury, which, in the case of PH, was associated with significant mortality and in cholestatic damage was accompanied by increased fibrosis. - dysregulated dynamics of fibrinogen and fibronectin turnover, with enhanced intrahepatic accumulation of insoluble aggregates of these proteins

17 Perspectives

18 Prof. Sergio Morini Dott. Simone Carotti Dott.ssa Maria Zingariello Prof.ssa Francesca Zalfa Prof. Matias Avila Prof. Jesus Prieto Dott. Antonio Picardi Dott. Umberto Vespasiani Gentilucci Dott. Giovanni Galati Dott.ssa Oihane Garcia-Irigoyen Dott. Iker Uriarte Dott.ssa Maria Latasa Prof. Andrea Onetti Muda Dott.ssa Raquel Urtasun Prof. Giuseppe Perrone Dott.ssa Maria Elizalde Dott.ssa Carmen Berasain