Fibrosis is a hallmark histologic event of chronic liver diseases and is characterized by the excessive accumulation and reorganization of the extracellular matrix (ECM). The gold standard for assessment of fibrosis is liver biopsy. As this procedure has various limitations, including risk of patient injury and sampling error, a non-invasive serum marker for liver fibrosis is desirable. The increasing understanding of the pathogenesis of hepatic fibrosis has suggested several markers which could be useful indicators of hepatic fibrogenesis and fibrosis. These markers include serum markers of liver function, ECM synthesis, fibrolytic processes, ECM degradation and fibrogenesis related cytokines. Recently, neo-epitopes, which are post-translational modifications of proteins, have been successfully used in bone and cartilage diseases which are characterized by extensive ECM remodeling. Increasing numbers of studies are being undertaken to identify neo-epitopes generated during liver fibrosis, and which ultimately might be useful for diagnosing and monitoring fibrogenesis. To date, the metalloproteinases generated fragment of collagen I, III, IV and VI have been proven to be elevated in two rat models of fibrosis. This review summarizes the recent efforts that have been made to identify potentially reliable non-invasive serum markers. We used the recently proposed BIPED (Burden of disease, Investigative, Prognostic, Efficacy and Diagnostic) system to characterize potential serum markers and neo-epitope markers that have been identified to date.

Activation of TGFB (transforming growth factor β) promotes liver fibrosis by activating hepatic stellate cells (HSCs), but the mechanisms of TGFB activation are not clear. We investigated the role of ECM1 (extracellular matrix protein 1), which interacts with extracellular and structural proteins, in TGFB activation in mouse livers. We performed studies with C57BL/6J mice (controls), ECM1-knockout (ECM1-KO) mice, and mice with hepatocyte-specific knockout of EMC1 (ECM1Δhep). ECM1 or soluble TGFBR2 (TGFB receptor 2) were expressed in livers of mice after injection of an adeno-associated virus vector. Liver fibrosis was induced by carbon tetrachloride (CCl4) administration. Livers were collected from mice and analyzed by histology, immunohistochemistry, in situ hybridization, and immunofluorescence analyses. Hepatocytes and HSCs were isolated from livers of mice and incubated with ECM1; production of cytokines and activation of reporter genes were quantified. Liver tissues from patients with viral or alcohol-induced hepatitis (with different stages of fibrosis) and individuals with healthy livers were analyzed by immunohistochemistry and in situ hybridization. ECM1-KO mice spontaneously developed liver fibrosis and died by 2 months of age without significant hepatocyte damage or inflammation. In liver tissues of mice, we found that ECM1 stabilized extracellular matrix-deposited TGFB in its inactive form by interacting with αv integrins to prevent activation of HSCs. In liver tissues from patients and in mice with CCl4-induced liver fibrosis, we found an inverse correlation between level of ECM1 and severity of fibrosis. CCl4-induced liver fibrosis was accelerated in ECM1Δhep mice compared with control mice. Hepatocytes produced the highest levels of ECM1 in livers of mice. Ectopic expression of ECM1 or soluble TGFBR2 in liver prevented fibrogenesis in ECM1-KO mice and prolonged their survival. Ectopic expression of ECM1 in liver also reduced the severity of CCl4-induced fibrosis in mice. ECM1, produced by hepatocytes, inhibits activation of TGFB and its activation of HSCs to prevent fibrogenesis in mouse liver. Strategies to increase levels of ECM1 in liver might be developed for treatment of fibrosis.

Serum Golgi protein 73 is not a suitable diagnostic marker for hepatocellular carcinoma Serum Golgi protein 73 is not a suitable diagnostic marker for hepatocellular carcinoma

Double-negative (DN) T cells could delay the onset and the progression of autoimmune diabetes, yet they were less efficient on reversing autoimmune diabetes. The aim of this study was to investigate whether the combination of DN T cells and anti-thymocyte serum (ATS) could reverse new-onset diabetes in NOD mice. The regulation of different subsets of T cells in vitro and in vivo by ATS and DN T cells were examined using flow cytometry. At the day of diabetes onset, ATS was administered on the same day and 2 days later, and DN T cells were transferred at day 7. The reversion of diabetes was assessed by monitoring blood glucose levels. The efficacy of inhibition of DN T cells on CD8+ T cells was lower than that on CD4+ T cells both in vitro and in vivo. ATS resulted in a significant depletion of CD8+ T cells, while DN T cells were less sensitive to ATS depletion. 80 % diabetic NOD mice achieved long term (6 months) reversion of diabetes by combined ATS and DN T cells treatment, compared to 16 % in ATS single treatment and none in DN T cell single treatment. DN T cells preferentially resided in spleen and pancreatic draining lymph nodes in ATS plus DN T cells treated NOD mice. DN T cells plus ATS therapy show promising reversion effects on diabetic NOD mice due to a shift of balance from a destructive T cell response to one that favors DN T cell regulation.

Matrix metalloproteinase-1 (MMP-1) plays an important role in fibrolysis by degrading excessively deposited collagen I and III. We previously demonstrated that diethyldithiocarbamate (DDC) up-regulates MMP-1 in hepatic stellate cells via the ERK1/2 and Akt signalling pathways. In the current study, we attempted to further explore the molecular mechanisms involved in the regulation of MMP-1. We treated a co-cultured system that included hepatocytes (C3A) and hepatic stellate cells (LX-2) with DDC. The data revealed that the transcriptional factor ETS-1, which is an important regulator of MMP-1, was up-regulated in LX-2 cells following DDC treatment. Furthermore, the up-regulation of MMP-1 by DDC has been abrogated through employing si-ETS-1 to block expression of ETS-1. We found that DDC significantly inhibited the expression of miR-222 in LX-2 cells. We transfected miR-222 mimic into LX-2 cells and then co-cultured the cells with C3A. The up-regulation of ETS-1 and MMP-1 in LX-2 cells treated with DDC were inhibited after miR-222 mimic transfection. These data indicate that DDC up-regulated MMP-1 in LX-2 cells through the miR-222/ETS-1 pathway. Finally, we treated the co-cultured system with an Akt inhibitor (T3830) and an ERK1/2 inhibitor (U0126). Both T3830 and U0126 blocked the suppression of miR-222 by DDC in LX-2. Collectively, these data indicate that DDC up-regulated MMP-1 in LX-2 cells through the Akt and ERK/miR-222/ETS-1 pathways. Our study provides experimental data that will aid the control of the process of fibrolysis in liver fibrosis prevention and treatment.