Expression of basic fibroblast growth factor in rat liver fibrosis and hepatic stellate cells

Astaxanthin Prevents Diet-Induced NASH Progression by Shaping Intrahepatic Immunity

Dietary change leads to a precipitous increase in non-alcoholic fatty liver disease (NAFLD) from simple steatosis to the advanced form of non-alcoholic steatohepatitis (NASH), affecting approximately 25% of the global population. Although significant efforts greatly advance progress in clarifying the pathogenesis of NAFLD and identifying therapeutic targets, no therapeutic agent has been approved. Astaxanthin (ASTN), a natural antioxidant product, exerts an anti-inflammation and anti-fibrotic effect in mice induced with carbon tetrachloride (CCl₄) and bile duct ligation (BDL); thus, we proposed to further investigate the potential effect of ASTN on a diet-induced mouse NASH and liver fibrosis, as well as the underlying cellular and molecular mechanisms. By treating pre-development of NASH in mice induced with a choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD), we have demonstrated that oral administration ASTN preventively ameliorated NASH development and liver fibrosis by modulating the hepatic immune response, liver inflammation, and oxidative stress. Specifically, ASTN treatment led to the reduction in liver infiltration of monocyte-derived macrophages, hepatic stellate cell (HSC) activation, oxidative stress response, and hepatocyte death, accompanied by the decreased hepatic gene expression of proinflammatory cytokines such as TNF-α, TGF-β1, and IL-1β. In vitro studies also demonstrated that ASTN significantly inhibited the expression of proinflammatory cytokines and chemokine CCL2 in macrophages in response to lipopolysaccharide (LPS) stimulation. Overall, in vivo and in vitro studies suggest that ASTN functions as a promising therapeutic agent to suppress NASH and liver fibrosis via modulating intrahepatic immunity.

Panax notoginseng saponins ameliorates experimental hepatic fibrosis and hepatic stellate cell proliferation by inhibiting the Jak2/ Stat3 pathways

OBJECTIVE

To investigate the inhibitory effect of Panax notoginseng saponins (PNS) on liver fibrosis and explore the underlying mechanisms.

METHODS

Carbon tetrachloride (CCl4)-treated rats and hepatic stellate cells (HSCs) were used. The effect of PNS on CCl4-induced liver fibrosis was studied with histochemical and biochemical analysis. Transforming growth factor (TGF)-β1, α-smooth muscle actin (α-SMA), and collagen I mRNA expression were determined by reverse transcripwhile, the protein expression levels of α-SMA, collagen I, phosphorylation-Janus activated kinase signal transducer (p-Jak2)/Jak2, and phosphorylation-activator of transcription (p-Stat)3/Stat3 were determined by immunohistochemistry and/or immunoblotting.

RESULTS

PNS treatment significantly improved the liver function of rats as indicated by decreased serum enzymatic activities of alanine aminotransferase and aspartate aminotransferase. Histopathological results indicated that PNS alleviated liver damage and reduced the formation of fibrous septa. Moreover, PNS significantly decreased liver hydroxyproline and significantly attenuated expressions of collagen I, α-SMA, TGF-β1, p-Jak2 / Jak2, and p-Stat3/Stat3 in the rat liver fibrosis model and HSCs.

CONCLUSION

PNS can relieve liver fibrosis by modulating Jak2/Stat3 signaling transduction pathway, which may be one of its mechanisms to suppress hepatic fibrosis.

Review of experimental models for inducing hepatic cirrhosis by bile duct ligation and carbon tetrachloride injection

PURPOSE

To present a review about a comparative study of bile duct ligation versus carbon tetrachloride Injection for inducing experimental liver cirrhosis.

METHODS

This research was made through Medline/PubMed and SciELO web sites looking for papers on the content "induction of liver cirrhosis in rats". We have found 107 articles but only 30 were selected from 2004 to 2011.

RESULTS

The most common methods used for inducing liver cirrhosis in the rat were administration of carbon tetrachloride (CCl4) and bile duct ligation (BDL). CCl4 has induced cirrhosis from 36 hours to 18 weeks after injection and BDL from seven days to four weeks after surgery.

CONCLUSION

For a safer inducing cirrhosis method BDL is better than CCl4 because of the absence of toxicity for researches and shorter time for achieving it.

Hypertrophy of the ligamentum flavum in lumbar spinal canal stenosis is associated with increased bFGF expression

PURPOSE

A prospective study was undertaken to investigate basic fibroblast growth factor (bFGF) expression in hypertrophic ligamentum flavum (LF) from patients with lumbar spinal canal stenosis (LSCS) and to determine whether there was a correlation of bFGF expression with LF thickness.

METHODS

Twenty patients with lumbar spinal canal stenosis were enrolled in this study. bFGF mRNA and protein expressions in LF were analyzed using quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA), respectively. The thickness of LF was measured by axial T1-weighted magnetic resonance imaging.

RESULTS

Expression of bFGF was substantially higher in the hypertrophic LF group than in the control group (P < 0.001) as quantified by quantitative real-time PCR. In immunohistochemical study, bFGF was positively stained on the fibroblasts within hypertrophic LF compared to nonpathologic LF of controls. Subsequent ELISA analysis revealed that bFGF concentration in the hypertrophic LF group was remarkably higher than that in the control group (P = 0.003). The thickness of LF in the hypertrophic LF was significantly greater than that in the control group (P < 0.001). LSCS patients with greater severity of LF hypertrophy had significantly higher bFGF levels in the LF tissues (P < 0.001). Furthermore, the bFGF concentration exhibited a positive correlation with the LF thickness (r = 0.974, P < 0.001).

CONCLUSIONS

These findings suggest that the increased expression of bFGF is associated with the hypertrophy of ligamentum flavum in patients with LSCS.

Gremlin in the pathogenesis of hepatocellular carcinoma complicating chronic hepatitis C: an immunohistochemical and PCR study of human liver biopsies

Background

The possible role of secretory products of fibrous tissue in the development of hepatocellular carcinoma (HCC) complicating chronic hepatitis C was investigated. Our hypothesis was that gremlin, secreted by fibroblasts, inhibited bone morphogenic protein (BMP), which mediates stem cell maturation into adult functioning hepatocytes, and thus, arrest stem cell maturation and promoted their proliferation in an immature state possibly culminating into development of HCCs.

Results

Protein expression of cytokeratin 19 (CK19) and fibroblast growth factor 2 (FGF-2), and mRNA expression of gremlin and BMP-7 were studied in 35 cases of chronic hepatitis, cirrhosis and HCC complicating chronic hepatitis C. CK19 expression was higher in cases of cirrhosis (0.004), which correlated with the grade (r = 0.64, p = 0.009) and stage (r = 0.71, p = 0.001). All HCCs were negative for CK19. Stem cell niche activation (as indicated as a ductular reaction) was highest in cases of cirrhosis (p = 0.001) and correlated with CK19 expression (r = 0.42, p = 0.012), the grade(r = 0.56, p = 0.024) and stage (0.66, p = 0.006). FGF-2 expression was highest in HCCs and correlated with the grade (r = 0.6, p = 0.013), stage (0.72, p = 0.002), CK19 expression (r = 0.71, p = 002) and ductular reaction (0.68, p = 0.004) in hepatitis cases. Higher numbers of cirrhosis cases and HCCs (p = 0.009) showed gremlin expression, which correlated with the stage (r = 0.7, p = 0.002). Gremlin expression correlated with that of CK19 (r = 0.699, p = 0.003) and FGF2 (r = 0.75, p = 0.001) in hepatitis cases.

Conclusions

Fibrosis promotes carcinogenesis by fibroblast-secreted gremlin that blocks BMP function and promotes stem cell activation and proliferation as well as possibly HCC development.

Delta-like 1 serves as a new target and contributor to liver fibrosis down-regulated by mesenchymal stem cell transplantation

Chronic liver injury always progresses to fibrosis and eventually to cirrhosis, a massive health care burden worldwide. Delta-like 1 (Dlk1) is well known as an inhibitor of adipocyte differentiation. However, whether it is involved in liver fibrosis remains unclear. Here, we provide the first evidence that Dlk1 is a critical contributor to liver fibrosis through promoting activation of hepatic stellate cells (HSCs) during chronic liver injury. We found that upon liver injury, Dlk1 was dramatically induced and initially expressed in hepatocytes and then into the HSCs by a paracrine manner. It leads to the activation of HSCs, which is considered to be a pivotal event in liver fibrogenesis. Two forms (∼50 and ∼25 kDa) of the Dlk1 protein were detected by Western blot analysis. In vitro administration of Dlk1 significantly promoted HSC activation, whereas in vivo knockdown of Dlk1 dramatically inhibited HSC activation and the subsequent fibrosis. The large soluble form (∼50 kDa) of Dlk1 was shown to contribute to HSC activation. We were encouraged to find the Dlk1-promoted HSC activation and liver fibrosis can be depressed by transplantation of bone marrow-mesenchymal stem cells (BM-MSCs). Furthermore, we demonstrated that FGF2 was up-regulated in BM-MSCs under injury stimulation, and it probably participated in the inhibition of Dlk1 by BM-MSCs. Our findings provide a novel role of Dlk1 in liver fibrosis leading to a better understanding of the molecular basis in fibrosis and cirrhosis and also give insights into the cellular and molecular mechanisms of MSC biology in liver repair.

A review of mast cells and liver disease: What have we learned?

BACKGROUND

Mast cells are recognized as diverse and highly complicated cells. Aside from their notorious role in allergic inflammatory reactions, mast cells are being implicated in numerous disease processes from heart disease to cancer. Mast cells have been implicated in liver pathogenesis including hepatitis and host allograft rejection after liver transplantation.

AIMS

The aim of this review is to discuss the traditional function of mast cells, their location and anatomy with regards to hepatic vasculature and the role of mast cells in hepatic diseases including liver regeneration and rejection. Finally, we will touch on the role of mast cells in liver cancer. In conclusion, we hope that the reader comes away with a better understanding of the diverse and potential role(s) that mast cells may play in liver pathologies.

Accelerated orthotopic hepatocellular carcinomas growth is linked to increased expression of pro-angiogenic and prometastatic factors in murine liver fibrosis

BACKGROUND

Most experimental therapy studies are performed in mice that bear subcutaneous or orthotopic hepatoma but are otherwise healthy. We questioned whether a pre-existing fibrosis affects tumour development of implanted syngenic hepatoma cells. To further investigate a selected panel of factors involved in tumour growth, tumour organ samples were characterized for gene expression of vascular endothelial growth factor (VEGF)-A/-C, VEGF receptors Flt1, Flk-1, Flt-4 and for VEGF-A protein levels.

RESULTS

The presented data show that tumour sizes were 3.7-fold increased and fibrotic livers had numerous satellites. Increased tumour sizes were associated with elevated intratumoral VEGF-A protein amounts and intratumoral increased VEGF receptor gene expression levels in tumour tissue from fibrotic livers as compared with non-fibrotic livers. Additionally, intratumoral gene expression levels of matrix metalloproteinase-2 (MMP-2) and MMP-9 were elevated in fibrotic mice.

CONCLUSION

Our results indicate that liver fibrosis stimulates tumour development of implanted syngenic hepatoma cells. Accelerated tumour growth was going along with elevated intratumoral VEGF-A and VEGF-A receptor status, which most probably mediated pro-angiogenic and prometastatic effects in this model. Furthermore, advanced tumour spread was associated with increased MMP-2/-9 expression. These data suggest that the intratumoral VEGF-A proteins levels and VEGF receptor status contribute to accelerated hepatocellular carcinoma development in fibrotic mice and that elevated MMP-2, MMP-9 and VEGF-C levels could promote tumour metastasis in this model.