Project description:Background and aims: There are considerable evidences demonstrating that angiogenesis and chronic inflammation are mutually dependent. However, although cirrhosis progression is characterized with a chronic hepatic inflammatory process, this connection is not sufficiently explored as a therapeutic strategy. Therefore, this study was aimed to assess the potential benefits of targeting angiogenesis in cirrhotic livers to modulate inflammation and fibrosis. For this purpose, we evaluate the therapeutic utility of angiogenesis inhibitors. Methods: The in vivo effects of angiogenesis inhibitors were monitored in liver of cirrhotic rats by measuring angiogenesis, inflammatory infiltrate, fibrosis, a-smooth muscle actin (a-SMA) accumulation, differential gene expression (by microarrays), and portal pressure. Results: Cirrhosis progression was associated with a significant enhancement of vascular density and expression of vascular endothelial growth factor-A (VEGF-A), angiopoietin-1, angiopoietin-2 and placental growth factor (PlGF) in cirrhotic livers. The newly formed hepatic vasculature expressed vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). Interestingly, the expression of these adhesion molecules correlated well with local inflammatory infiltrate. Livers of cirrhotic rats treated with angiogenesis inhibitors presented a significant decrease in hepatic vascular density, inflammatory infiltrate, a-SMA abundance, collagen expression and portal pressure. Conclusion: Angiogenesis inhibitors may offer a potential novel therapy for cirrhosis due to its multiple mechanisms of action against angiogenesis, inflammation and fibrosis in cirrhotic livers. Experiment Overall Design: RNA from liver of 4 non-treated cirrhotic rats or 4 rats treated with angiogenesis inhibitors was hybridized to 8 high-density oligonucleotide microarray (Rat2302, Affymetrix, Santa Clara, CA)
Project description:Background and aims: There are considerable evidences demonstrating that angiogenesis and chronic inflammation are mutually dependent. However, although cirrhosis progression is characterized with a chronic hepatic inflammatory process, this connection is not sufficiently explored as a therapeutic strategy. Therefore, this study was aimed to assess the potential benefits of targeting angiogenesis in cirrhotic livers to modulate inflammation and fibrosis. For this purpose, we evaluate the therapeutic utility of angiogenesis inhibitors. Methods: The in vivo effects of angiogenesis inhibitors were monitored in liver of cirrhotic rats by measuring angiogenesis, inflammatory infiltrate, fibrosis, a-smooth muscle actin (a-SMA) accumulation, differential gene expression (by microarrays), and portal pressure. Results: Cirrhosis progression was associated with a significant enhancement of vascular density and expression of vascular endothelial growth factor-A (VEGF-A), angiopoietin-1, angiopoietin-2 and placental growth factor (PlGF) in cirrhotic livers. The newly formed hepatic vasculature expressed vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). Interestingly, the expression of these adhesion molecules correlated well with local inflammatory infiltrate. Livers of cirrhotic rats treated with angiogenesis inhibitors presented a significant decrease in hepatic vascular density, inflammatory infiltrate, a-SMA abundance, collagen expression and portal pressure. Conclusion: Angiogenesis inhibitors may offer a potential novel therapy for cirrhosis due to its multiple mechanisms of action against angiogenesis, inflammation and fibrosis in cirrhotic livers. Keywords: angiogenesis, cirrhosis, liver, Affymetrix, fibrosis
Project description:Background and aims. Portal hypertension is the main consequence of cirrhosis, responsible for the complications defining clinical decompensation. The only cure for decompensated cirrhosis is liver transplantation, but it is a limited resource and opens the possibility of regenerative therapy. We investigated the potential of human amniotic membrane-derived mesenchymal stromal (hAMSCs) and epithelial (hAECs) stem cells for the treatment of portal hypertension and chronic liver disease. Methods. In vivo: hAMSCs and hAECs were isolated from human amniotic membranes. Cirrhotic rats with ascites (chronic CCl4 inhalation) received 4x10e6 hAMSCs, 4x10e6 hAECs, or vehicle (NaCl 0.9%) (intraperitoneal; n=10 per group). After 2-week we analyzed: a) portal pressure (PP) and liver microcirculatory function; b) liver sinusoidal endothelial (LSECs) and hepatic stellate (HSCs) cells phenotype; c) hepatic fibrosis, inflammation and hepatic function. In vitro: HSCs isolated from CCl4-cirrhotic rats were co-cultured with hAMSCs, hAECs or vehicle for 24h. RNA profile was analyzed by RNAseq. Results. Cirrhotic rats receiving hAMSCs or hAECs had significantly lower PP than vehicle-treated animals, together with improved liver microcirculatory function. This hemodynamic amelioration was associated with improvement in LSECs capillarization and HSCs de-activation, although hepatic collagen/fibrosis was not significantly reduced. Rats that received placenta derived stem cells had markedly reduced hepatic inflammation and oxidative stress. Finally, liver function tests significantly improved in rats receiving hAMSCs. In vitro experiments confirmed HSCs de-activation when co-cultured with stem cells. Conclusion. This pre-clinical study shows that infusion of human amniotic stem cells effectively decreases PP by ameliorating liver microcirculation, suggesting that it may represent a new treatment option for advanced cirrhosis with portal hypertension.
Project description:Persistent liver injury triggers a fibrogenic program that causes pathologic remodelling of the hepatic microenvironment (i.e., liver fibrosis) and portal hypertension. The dynamics of gene regulation during liver disease progression and regression remain understudied. Here, we generated hepatic transcriptome profiles in two well-established liver disease models at peak fibrosis and during spontaneous regression after the removal of the inducing agents. We linked the dynamics of key liver disease readouts, such as portal pressure, collagen proportionate area, and transaminase serum levels, to most differentially expressed genes, enabling the identification of transcriptomic signatures of progressive vs. regressive liver fibrosis and portal hypertension. These candidate biomarkers (e.g., Scube1, Tcf4, Src, Hmga1, Trem2, Mafk, Mmp7) were also validated in RNA-seq datasets of patients with cirrhosis and portal hypertension. Finally, deconvolution analysis identified major cell types and suggested an association of macrophage and portal hepatocyte signatures with portal hypertension and fibrosis area in both models.
Project description:Nevirapine alone produces only mild hepatic hypertrophy in the rat. Single ip dose galactosamine produces transient hepatocellular apoptotic and oncotic cell death mimicking viral hepatitis with portal inflammatory infiltrate and biliary hypertrophy and hyperplasia. Damage is typically resolved within 7-10 days. However if rats are pretreated with nevirapine at specific doses for 7 days prior to the single galactosamine dose, bridging fibrosis is observed, 8 days after the single galactosamine dose is given. We used microarrays to detail the global programme of gene expression underlying the sequential responses of nevirapine alone, galactosamine alone, and the identified distinct classes of up-regulated genes during this process.
Project description:In variceal bleeding liver function deterioration is a major cause of death. The effects of bleeding on intrahepatic microvascular dysfunction, which contributes to liver injury in cirrhosis, are largely unknown. The aims of this study were to evaluate the impact of hemorrhage/resuscitation (H/R) on cirrhotic microcirculation, and whether simvastatin, a drug that improves liver microcirculation, has hepatoprotective effects. The study was performed in three groups of rats: controls, rats with biliary cirrhosis (CBDL) and CBDL rats pre-treated with 3 doses (5 mg*Kg-1*day-1) of simvastatin. Rats were submitted to H/R or sham procedure. Subsequently, livers were isolated and perfused for functional assessment of liver microcirculation. Liver transcriptome was assessed with microarrays. H/R significantly impaired endothelial-dependent vasorelaxation in cirrhotic (p=0.035) but not control livers. H/R induced a similar increase in ALT in control and cirrhotic rats, whereas the increase in AST was 10 times higher in cirrhotic than in control rats (p=0.007). Simvastatin prevented the impairment in endothelial-dependent vasorelaxation induced by H/R, and reduced by half the increase in ALT and AST (p<0.05). Transcriptomics showed a marked upregulation of genes related to inflammatory response after H/R in cirrhotic livers, but not in controls, and this was blunted by simvastatin. In conclusion, H/R aggravates liver microvascular dysfunction in cirrhosis, and upregulates liver inflammatory pathways. This does not occur in control livers. Simvastatin prevented H/R-induced liver endothelial dysfunction, and attenuated liver injury and liver inflammatory response, suggesting that it might have potential for protecting the cirrhotic liver during bleeding complications.
Project description:The interplay between the inflammatory infiltrate and tissue resident cell populations (e.g. epithelial cells, fibroblasts and macrophages) invokes fibrogenesis. However, the temporal and mechanistic contributions of these cell populations to fibrosis remain poorly defined. To address this issue, liver inflammation, ductular reaction (DR) and fibrosis were induced in C57BL/6 mice by thioacetamide (TAA) administration for up to 12 weeks. TAA treatment induced two phases of liver fibrosis. A rapid peri-central inflammatory infiltrate enriched in F4/80+ monocytes co-localized with SMA+ myofibroblasts resulted in early collagen deposition, marking the start of an initial fibrotic phase (1-6 weeks). An expansion of bone marrow derived macrophages proceeded a second phase, characterized by accelerated progression of fibrosis (> 6 weeks) followed the migration of the DR from the portal tracts to the centrilobular site of injury, in association an increase in DR/macrophage interactions. Although CCL2 mRNA was rapidly induced in response to TAA, CCL2 deficiency only partially abrogated fibrosis. In contrast, CSF-1R blockade diminished CCR2neg (Ly6Clo) monocytes, attenuated the DR and significantly reduced fibrosis, illustrating the critical role of CSF-1 dependent monocyte/macrophage differentiation and linking the two phases of injury. We demonstrate that in response to liver injury, CSF-1 drives early monocyte mediated myofibroblast activation and collagen deposition, subsequent macrophage differentiation and their association with the advancing DR, the formation of fibrotic septa and the progression of liver fibrosis to cirrhosis.
Project description:Background and Aims: Transforming growth factor (TGF-β) induced activation of quiescent hepatic stellate cells (HSC) and their transformation to myofibroblasts is a key event in liver fibrosis and portal hypertension. GIPC (also referred to as synectin) is a downstream signal activation molecule of TGF-β and other receptors. In this study, we sought to identify novel genes targeted by TGF-β and GIPC and elucidate if and how they may contribute to liver fibrosis. Methods and Results: We performed sequential mRNA sequencing analysis on TGF-β stimulated HSC and then on TGF-β-stimulated HSC in presence and absence of GIPC knockdown. IGFBP-3, an insulin growth factor transport protein, emerged as a top activation target of both TGF-β and GIPC, which was confirmed by qPCR, ELISA and Western blot (WB) analysis. Targeted chromatin immunoprecipitation (ChIP) revealed that GIPC increases the histone 3 lysine 27 (H3K27) acetylation activating mark and concurrently decreases the H3K27 inhibitory trimethylation (H3K27m3) mark providing an epigenetic correlate to the gene regulation changes. In vivo, global knockout of IGFBP-3 mice resulted in attenuation of HSC activation markers and attenuation of portal pressure in response to chronic liver injury models. Analysis of serum levels from cirrhotic patients also showed IGFBP-3 increase of more than 2-fold compared to healthy controls. Finally, in vitro mechanism studies revealed that IGFBP-3 promotes HSC migration through integrin dependent phosphorylation of AKT. Conclusion: TGF-β upregulates IGFBP-3 through GIPC leading to increased HSC migration in vitro and promotes portal hypertension in vivo. These studies support the role of IGFBP-3 as a potential pathophysiologic target or biomarker in chronic liver disease.
Project description:Background and Aims: Transforming growth factor (TGF-β) induced activation of quiescent hepatic stellate cells (HSC) and their transformation to myofibroblasts is a key event in liver fibrosis and portal hypertension. GIPC (also referred to as synectin) is a downstream signal activation molecule of TGF-β and other receptors. In this study, we sought to identify novel genes targeted by TGF-β and GIPC and elucidate if and how they may contribute to liver fibrosis. Methods and Results: We performed sequential mRNA sequencing analysis on TGF-β stimulated HSC and then on TGF-β-stimulated HSC in presence and absence of GIPC knockdown. IGFBP-3, an insulin growth factor transport protein, emerged as a top activation target of both TGF-β and GIPC, which was confirmed by qPCR, ELISA and Western blot (WB) analysis. Targeted chromatin immunoprecipitation (ChIP) revealed that GIPC increases the histone 3 lysine 27 (H3K27) acetylation activating mark and concurrently decreases the H3K27 inhibitory trimethylation (H3K27m3) mark providing an epigenetic correlate to the gene regulation changes. In vivo, global knockout of IGFBP-3 mice resulted in attenuation of HSC activation markers and attenuation of portal pressure in response to chronic liver injury models. Analysis of serum levels from cirrhotic patients also showed IGFBP-3 increase of more than 2-fold compared to healthy controls. Finally, in vitro mechanism studies revealed that IGFBP-3 promotes HSC migration through integrin dependent phosphorylation of AKT. Conclusion: TGF-β upregulates IGFBP-3 through GIPC leading to increased HSC migration in vitro and promotes portal hypertension in vivo. These studies support the role of IGFBP-3 as a potential pathophysiologic target or biomarker in chronic liver disease.
Project description:Elevated levels of an endogenous Na/K‐ATPase inhibitor marinobufagenin accompany salt‐sensitive hypertension and are implicated in cardiac fibrosis. Immunoneutralization of marinobufagenin reduces blood pressure in Dahl salt‐sensitive (Dahl‐S) rats. The effect of the anti‐marinobufagenin monoclonal antibody on blood pressure, left ventricular (LV) and renal remodeling, and LV gene expression were investigated in hypertensive Dahl‐S rats.