Hepatic Epithelial Cells Research Articles

The Role of TWEAK/Fn14 Signaling in Liver Regeneration after Mouse Partial Hepatectomy

Introduction: Liver regeneration is important after liver resection and transplantation, though the mechanisms surrounding this process are complex and incompletely understood. Tumor necrosis factor-like weak inducer of apoptosis (TWEAK), acts via its specific receptor fibroblast growth factor-inducible 14 (Fn14), and Fn14 receptors have been shown to be highly expressed in chronically damaged livers, such as in hepatitis C, and in regenerating livers after partial hepatectomy (PH), suggesting a strong role for the TWEAK/Fn14 pathway in the proliferation of hepatic epithelial cells and/or their transformation. This is the first attempt to study the effect of stimulating the TWEAK/Fn14 pathway via administration of an agonistic anti-Fn14 monoclonal antibody (mAb), on liver regeneration after mouse PH. Methods: Mice were divided into 4 groups: sham (control), PH alone, PH + anti-Fn14 mAb, and sham + anti-Fn14 mAb, and sacrificed at 24, 48, 72 hrs (n=5 per group at each time point), or 7 days (n=2 per group). Anti-Fn14 mAb (ITEM-4: 200 μg/mouse) was administered at the time of initial surgery via intraperitoneal injection. Liver regeneration at point of sacrifice was estimated by remnant liver weight to body weight ratio (LBWr). Serum was taken for liver function assessment, and mice livers were resected for western blot assessment of the Fn14 receptor. Fn14 to actin ratios were calculated to standardize the results. Results: Resected LBWr, a marker for consistency of resection, was similar in both PH and PH + anti-Fn14 mAb groups (0.027 vs. 0.028, p=0.2). Remnant LBWr, a marker of regeneration, was significantly higher at 24 and 48 hrs after PH + anti-Fn14 mAb vs. PH alone, although it became similar at 72 hrs after PH. Western blot data indicates a trend toward higher expression of Fn14 at 24 hrs in the PH + anti-Fn14 mAb than in the sham group (Fn14:actin: 1.21 vs. 0.49, p=0.1) or PH alone group (Fn14:actin: 1.21 vs. 0.75, p=0.3). Values of LFTs (ALP, ALT, AST and total Bili) were similar between PH alone and PH + anti-Fn14 mAb groups at 24 and 48 hrs after PH, but all values were significantly higher in the PH + anti-Fn14 mAb group at 72 hrs compared with PH alone. At 7 days, all LFTs in both PH and PH + anti-Fn14 mAb groups returned to baseline. Conclusion: The TWEAK/Fn14 signaling pathway contributes to the early phase of liver regeneration by stimulating it after PH with upregulation of Fn14 in the liver. Agonistic anti-Fn14 mAb might be useful to stimulate liver regeneration after liver resection or liver transplantation with cautious monitoring of LFTs.

Liver Progenitor Cells Yield Functional Hepatocytes in Response to Chronic Liver Injury in Mice

Self-renewal of mature hepatocytes promotes homeostasis and regeneration of adult liver. However, recent studies have indicated that liver progenitor cells (LPC) could give rise to hepatic epithelial cells during normal turnover of the liver and after acute injury. We investigated the capacity of LPC to differentiate into hepatocytes in vivo and contribute to liver regeneration. We performed lineage tracing experiments, using mice that express tamoxifen-inducible Cre recombinase under control of osteopontin regulatory region crossed with yelow fluorescent protein reporter mice, to follow the fate of LPC and biliary cells. Adult mice received partial (two-thirds) hepatectomy, acute or chronic administration of carbon tetrachloride (CCl(4)), choline-deficient diet supplemented with ethionine, or 3,5-diethoxycarbonyl-1,4-dihydrocollidine diet. LPC and/or biliary cells generated 0.78% and 2.45% of hepatocytes during and upon recovery of mice from liver injury, respectively. Repopulation efficiency by LPC and/or biliary cells increased when extracellular matrix and laminin deposition were reduced. The newly formed hepatocytes integrated into hepatic cords, formed biliary canaliculi, expressed hepato-specific enzymes, accumulated glycogen, and proliferated in response to partial hepatectomy, as neighboring native hepatocytes. By contrast, LPC did not contribute to hepatocyte regeneration during normal liver homeostasis, in response to surgical or toxic loss of liver mass, during chronic liver injury (CCl(4)-induced), or during ductular reactions. LPC or biliary cells terminally differentiate into functional hepatocytes in mice with liver injury.

Keratin 8/18 Regulation of Cell Stiffness-Extracellular Matrix Interplay through Modulation of Rho-Mediated Actin Cytoskeleton Dynamics

Cell mechanical activity generated from the interplay between the extracellular matrix (ECM) and the actin cytoskeleton is essential for the regulation of cell adhesion, spreading and migration during normal and cancer development. Keratins are the intermediate filament (IF) proteins of epithelial cells, expressed as pairs in a lineage/differentiation manner. Hepatic epithelial cell IFs are made solely of keratins 8/18 (K8/K18), hallmarks of all simple epithelia. Notably, our recent work on these epithelial cells has revealed a key regulatory function for K8/K18 IFs in adhesion/migration, through modulation of integrin interactions with ECM, actin adaptors and signaling molecules at focal adhesions. Here, using K8-knockdown rat H4 hepatoma cells and their K8/K18-containing counterparts seeded on fibronectin-coated substrata of different rigidities, we show that the K8/K18 IF-lacking cells lose their ability to spread and exhibit an altered actin fiber organization, upon seeding on a low-rigidity substratum. We also demonstrate a concomitant reduction in local cell stiffness at focal adhesions generated by fibronectin-coated microbeads attached to the dorsal cell surface. In addition, we find that this K8/K18 IF modulation of cell stiffness and actin fiber organization occurs through RhoA-ROCK signaling. Together, the results uncover a K8/K18 IF contribution to the cell stiffness-ECM rigidity interplay through a modulation of Rho-dependent actin organization and dynamics in simple epithelial cells.

Identification of the couple GSK3α/c-Myc as a new regulator of hexokinase II in benzo[a]pyrene-induced apoptosis

The early apoptotic events induced by environmental pollutants with carcinogenic properties are poorly understood. Here, we focus on the early cytotoxic effects of benzo[a]pyrene (B[a]P). In F258 rat hepatic epithelial cells, B[a]P induces intrinsic apoptosis via a mitochondrial dysfunction characterized by the release of hexokinase II (HKII) from the mitochondria. Cancer cells often have an anomalous cell energy metabolism; since HKII dysfunction regulates B[a]P-induced apoptosis in F258 cells, but may also alter cell energy metabolism, HKII release from the mitochondria may represent an important B[a]P-related carcinogenic issue. Thus in the present study, we aimed at deciphering the mechanisms underlying HKII dysfunction upon B[a]P exposure.We show that while glycogen synthase kinase 3 beta (GSK3β) regulated the expression of HKII at the transcriptional level, glycogen synthase kinase 3 alpha (GSK3α) was involved in B[a]P-induced apoptosis via a decrease in c-Myc expression. The reduced level of c-Myc caused the relocation of HKII from the mitochondria to the cytosol, thereby being involved in the formation of reactive oxygen species and apoptosis.In conclusion, we show that the couple GSK3α/c-Myc plays a key role in B[a]P-induced early apoptotic cell signaling via HKII dysfunction.

Down-regulation of formin-like 2 predicts poor prognosis in hepatocellular carcinoma

The formin-like 2 protein is a member of the diaphanous-related formin family that controls actin-dependent processes such as cell motility and invasion. This study aimed at clarifying formin-like 2 expression in hepatocellular carcinoma and its correlation with clinicopathologic features and also exploring the effects of formin-like 2 transfection on cell motility and invasion in vitro. Real-time polymerase chain reaction and Western blotting showed that expression of formin-like 2 was lower in 4 hepatocellular carcinoma cell lines than those in normal hepatic epithelial cells (P < .05). Surgical hepatocellular carcinoma samples were taken from patients who had been followed for 5 years. Immunohistochemical analysis revealed down-expression of formin-like 2 in 86 (71.7%) of 120 cases. The expression of formin-like 2 was significantly lower in hepatocellular carcinoma tissues than in adjacent cirrhotic or normal livers (P < .01). Statistical analysis showed that formin-like 2 expression correlated positively with tumor differentiation (P = .046) and vascular invasion (P = .008). Patients whose tumors had lower formin-like 2 expression had shorter overall survival times (P = .040). Multivariate analysis suggested that formin-like 2 expression was a significant and independent prognostic indicator (P = .041). Transient transfection of formin-like 2 suppressed motility and invasion of hepatocellular carcinoma cells in vitro. Our results suggest that formin-like 2 is a valuable marker for the progression of hepatocellular carcinoma. Down-regulation is associated with poor overall survival.

In vitro generation of myofibroblasts-like cells from liver epithelial progenitor cells of rhesus monkey (Macaca mulatta)

The origin of the myofibroblast, the primary effector cell of liver fibrosis, is still elusive. Here, we report that fluorescence-activated cell sorting purified E-cad + rhesus monkey liver epithelial progenitor cells (mLEPCs) may serve as a potential source for liver myofibroblasts. Adult mLEPCs colonies were cultured in medium containing 2ng/ml transforming growth factor β (TGF-β) and 10% fetal bovine serum (FBS) to induce differentiation. Phenotypic changes of cells were analyzed by morphological observation, immunostaining, and reverse transcription-polymerase chain reaction (RT-PCR). After cultured with TGF-β and FBS, some cells in adult mLEPCs colonies converted to fibroblasts-like cells. Immunostaining showed that fibroblasts-like cells had acquired the expression of mesenchymal cell marker vimentin but lost the expression of epithelial cell marker CK8. Fibroblasts-like cells were maintained in culture for up to 40 passages. RT-PCR analysis revealed that fibroblasts-like cells had acquired the expression of mesenchymal genes (snail, PAI-1, and collagen I) and lost the expression of epithelial specific genes (E-cad, ZO-1, CK18, and occludin). In addition, more than 60% of fibroblasts-like cells expressed myofibroblastic-related proteins such as αSMA, vimentin, and N-cad, which were not presented in mLEPCs. Furthermore, increased cell motility was also detected in these fibroblasts-like cells by time-lapse video observation. Our results demonstrate that hepatic epithelial progenitor cells, mLEPCs, transform to myofibroblast-like cells via epithelial-mesenchymal transition. This finding will facilitate understanding of the origin of myofibroblasts in liver fibrosis.

Enhanced expression of fibroblast growth factor 2 in bone marrow cells and its potential role in the differentiation of hepatic epithelial stem-like cells into the hepatocyte lineage

The transplantation of bone marrow cells (BMCs) has been applied in liver regenerative cell therapy. However, details of the interaction between the transplanted BMCs and hepatic stem cells have not been elucidated. The aim of the present study was to investigate the interaction of BMCs with hepatic stem-like cells (HSLCs) and to determine the BMC factor that steers HSLC differentiation into the hepatocyte lineage. Both BMCs and HSLCs were obtained from an adult Sprague-Dawley rat, and a co-culture system was established. Cell proliferation was analyzed by a proliferation assay, and the differentiation of HSLCs into the hepatocyte lineage was evaluated by the detection of cellular mRNA for liver-specific proteins. DNA microarray analysis was applied to BMCs co-cultured with HSLCs to determine the genes upregulated by their interaction. The proliferation of HSLCs co-cultured with BMCs was significantly higher than that of HSLCs cultured alone, and the expression of mRNAs for both albumin and tryptophan-2,3-dioxygenase was detectable in the co-cultured HSLCs. DNA microarray analysis showed the upregulated expression of fibroblast growth factor 2 (FGF2) mRNA in BMCs co-cultured with HSLCs, and the expression of mRNAs for both albumin and tyrosine aminotransferase became detectable in HSLCs cultured with FGF2. Thus, BMCs stimulate both the proliferation of HSLCs and their differentiation into the hepatocyte lineage. FGF2 is one of the factors that is produced by the interacting BMCs and that stimulates this differentiation.

Organ Siderosis In a Murine Graft-Versus-Host-Model After Allogeneic Stem Cell Transplantations Unrelated to Red Cell Transfusion

AbstractAbstract 2048▪ Introduction:Organ siderosis (OS) occurs frequently after allogeneic stem cell transplantations and is associated with worse survival. Although commonly attributed to transfusions of erythrocyte sediments, we present the occurrence of OS in mice suffering from Graft-versus-Host-disease (GvHD) independent of transfusions. Methods:Prior to transplantation (day 0), C57BL/10-wildtype (wt) mice received treosulfan 2000mg/kg on day -3 to -1 and cyclophosphamide 200 mg/kg on day-1. Mice were transplanted with 5×106 bone marrow cells and 3×106 splenocytes of Balb/c (allogeneic) or C57BL/10 (syngeneic) origin. Mice were sacrificed on day+9. Liver iron content was determined by atomabsorption spectroscopy in graphit tubes. In addition, a semi-quantitative analysis of liver, kidney and spleen sections was performed in kinetic studies. Macroscopic and histological GvHD-Scores were assessed according to standard scores. Results:Treatment of mice without additional transplantation or transplantation of syngeneic cells did not increase the iron content of the liver compared to untreated mice (naïve: 6.7 +/− 1.3 μmol/g; chemotherapy only: 7.2 +/− 1.9; syngeneic: 7.2 +/− 2.1). In contrast, allogeneic transplantated mice suffering from GvHD developed a siderosis of the liver of 13.6 +/− 3.1 (p=0.01, Kruskal-Wallis test). Furthermore, the iron deposition was correlated with the macroscopic and histologic GvHD score. Conclusion:These results show the occurrence of OS in wildtype animals after allogeneic stem cell transplantation. Since the detection of iron deposition occurs early after transplantation, OS is unlikely due to increased intestinal iron absorption, but appears to be a consequence of blocked iron export out of hepatic epithelial cells and macrophages and potentially by redistribution of iron as a consequence of liver cell destruction. Further studies are needed to elucidate the role of regulatory proteins such as hepcidin and ferroportin for OS in the context of GvHD following stem cell transplantation. In view of GvHD-associated OS in transplanted patients occuring frequently independent of transfusions, the effect appears clinically relevant with treatment options remaining to be defined. Disclosures:No relevant conflicts of interest to declare.

MiR-194 is a marker of hepatic epithelial cells and suppresses metastasis of liver cancer cells in mice

MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression by interacting with the 3' untranslated region (3'-UTR) of multiple mRNAs. Recent studies have linked miRNAs to the development of cancer metastasis. In this study, we show that miR-194 is specifically expressed in the human gastrointestinal tract and kidney. Moreover, miR-194 is highly expressed in hepatic epithelial cells, but not in Kupffer cells or hepatic stellate cells, two types of mesenchymal cells in the liver. miR-194 expression was decreased in hepatocytes cultured in vitro, which had undergone a dedifferentiation process. Furthermore, expression of miR-194 was low in liver mesenchymal-like cancer cell lines. The overexpression of miR-194 in liver mesenchymal-like cancer cells reduced the expression of the mesenchymal cell marker N-cadherin and suppressed invasion and migration of the mesenchymal-like cancer cells both in vitro and in vivo. We further demonstrated that miR-194 targeted the 3'-UTRs of several genes that were involved in epithelial-mesenchymal transition and cancer metastasis. These results support a role of miR-194, which is specifically expressed in liver parenchymal cells, in preventing liver cancer cell metastasis.

Construct Double Reporter Vector Enhanced by CK19 Promoter and Its Application in Differentiation of Hepatic Progenitor Cells*

Liver progenitor cells are co-precursor cells of hepatic cells and bile duct epithelial cells, a reporter gene was used to research the differentiation of liver progenitor cells. First of all, the cytokeratin 19 promoter segment was cloned from hepatocellular carcinoma cell line HepG2 and then following the promoter a renilla luciferase and a red fluorescence protein's fusion gene were inserted to finish the double report lentiviral vector. Second, the liver progenitor cells were transducted with lentivirus, and then GFP positive cells were enriched by flow cytometry sorting. Third, the GFP positive liver progenitor cells were co-cultured with PT67 cells which could express the molecule-epimorphin for 5 days. Then, it was found that the stable transducted liver progenitor cells' shape were not only transformed and arranged as cord like structure, but also renilla luciferase and red fluorescence protein which enhanced by CK19 promoter were detected. So, these results proved that the liver progenitor cells had been induced to bile duct epithelial cells. The vector enhanced by CK19 promoter can monitor the differentiation of liver progenitor cells in different environment. In a word, this lentivirus vector can help us study the differentiation mechanism of liver progenitor cells, and scan the molecules which can do a help in differentiation.

Angiogenesis and clinicopathologic characteristics in different hepatocellular carcinoma subtypes defined by EpCAM and α-fetoprotein expression status

Recently, two hepatic lineage markers epithelial cell adhesion molecule (EpCAM) and α-fetoprotein (AFP) were used to classify hepatocellular carcinoma (HCC) into four subtypes with prognostic implication. In the present study, we further evaluated the clinicopathologic and angiogenic characteristics among these HCC subtypes. EpCAM expression was investigated by immunohistochemistry in 115 HCC primary tumors. Based on EpCAM immunostaining and serum AFP levels, 115 HCC cases were classified into four subtypes: EpCAM+AFP+ (26.1%), EpCAM-AFP+ (20.0%), EpCAM+AFP- (20.8%), and EpCAM-AFP- (33.1%). EpCAM+AFP+ and EpCAM-AFP+ HCC were associated with late TNM stages and high frequencies of venous invasion, whereas EpCAM+AFP- and EpCAM-AFP- subtypes were associated with early TNM stages and low frequencies of venous invasion. Furthermore, EpCAM+AFP+ HCC had a significantly higher microvessel density (MVD) and higher level of VEGF (Vascular epithelial growth factor) expression than the other three subtypes. In conclusion, our study indicated that subtype classification of HCC based on EpCAM and AFP status had clinicopathologic and biologic implications in aggressive phenotype and angiogenesis. We also suggest that the EpCAM+AFP+ HCC patients might be potential therapeutic candidates for anti-angiogenesis therapy.

An Implantable Vascularized Protein Gel Construct That Supports Human Fetal Hepatoblast Survival and Infection by Hepatitis C Virus in Mice

BackgroundWidely accessible small animal models suitable for the study of hepatitis C virus (HCV) in vivo are lacking, primarily because rodent hepatocytes cannot be productively infected and because human hepatocytes are not easily engrafted in immunodeficient mice.Methodology/Principal FindingsWe report here on a novel approach for human hepatocyte engraftment that involves subcutaneous implantation of primary human fetal hepatoblasts (HFH) within a vascularized rat collagen type I/human fibronectin (rCI/hFN) gel containing Bcl-2-transduced human umbilical vein endothelial cells (Bcl-2-HUVEC) in severe combined immunodeficient X beige (SCID/bg) mice. Maturing hepatic epithelial cells in HFH/Bcl-2-HUVEC co-implants displayed endocytotic activity at the basolateral surface, canalicular microvilli and apical tight junctions between adjacent cells assessed by transmission electron microscopy. Some primary HFH, but not Huh-7.5 hepatoma cells, appeared to differentiate towards a cholangiocyte lineage within the gels, based on histological appearance and cytokeratin 7 (CK7) mRNA and protein expression. Levels of human albumin and hepatic nuclear factor 4α (HNF4α) mRNA expression in gel implants and plasma human albumin levels in mice engrafted with HFH and Bcl-2-HUVEC were somewhat enhanced by including murine liver-like basement membrane (mLBM) components and/or hepatocyte growth factor (HGF)-HUVEC within the gel matrix. Following ex vivo viral adsorption, both HFH/Bcl-2-HUVEC and Huh-7.5/Bcl-2-HUVEC co-implants sustained HCV Jc1 infection for at least 2 weeks in vivo, based on qRT-PCR and immunoelectron microscopic (IEM) analyses of gel tissue.Conclusion/SignificanceThe system described here thus provides the basis for a simple and robust small animal model of HFH engraftment that is applicable to the study of HCV infections in vivo.

Hepatoprotective Constituents from the Roots and Stems of Erycibe hainanesis

Eleven new diglycosides, erycibosides A-K (1-11), four new chlorogenic acid derivatives (14-17), and a new bis-coumarin (18), together with 21 known compounds, have been isolated from an EtOH extract of the roots and stems of Erycibe hainanesis. Their structures were elucidated by means of spectroscopic methods and chemical evidence. Inhibitory activities of some of the compounds on d-galactosamine-induced cytotoxicity in WB-F344 rat hepatic epithelial stem-like cells were screened, and compounds 2, 6, 10, 18, and 32 showed potent hepatoprotective activities at concentrations of 1 x 10(-5) to 1 x 10(-4) M.

β-Catenin Regulates Mesenchymal Progenitor Cell Differentiation During Hepatogenesis

Understanding the pathways regulating mesenchymal progenitor cell fate during hepatogenesis may provide insight into postnatal liver injury or liver bioengineering. While β-Catenin has been implicated in the proliferation of fetal hepatic epithelial progenitor cells, its role in mesenchymal precursors during hepatogenesis has not been established. We used a murine model of conditional deletion of β-Catenin in mesenchyme using the Dermo1 locus (β-Catenin(Dermo1)) to characterize the role of β-Catenin in liver mesenchyme during hepatogenesis. Lineage tracing using a LacZ reporter indicates that both hepatic stellate cells and pericytes derive from mesenchymal Dermo1 expressing precursor cells. Compared to control littermate livers, β-Catenin(Dermo1) embryonic livers are smaller and filled with dilated sinusoids. While the fraction of mesenchymally-derived cells in β-Catenin(Dermo1) embryos is unchanged compared to littermate controls, there is an increase in the expression of the mesenchymal markers, DESMIN, α-SMA, and extracellular deposition of COLLAGEN type I, particularly concentrated around dilated sinusoids. Analysis of the endothelial cell compartment in β-Catenin(Dermo1)/Flk1(lacZ) embryos revealed a marked reorganization of the intrahepatic vasculature. Analysis of various markers for the endodermally-derived hepatoblast population revealed marked alterations in the spatial expression pattern of pan-cytokeratin but not E-cadherin, or albumin. β-Catenin(Dermo1) phenocopies mesenchymal deletion of Pitx2, a known regulator of hepatic mesenchymal differentiation both during both organogenesis and postnatal injury. Our data implicate mesenchymal β-Catenin signaling pathway in the differentiation of liver mesenchymal progenitor cells during organogenesis, possibly via Pitx2. Hepatic mesenchymal β-Catenin signaling, in turn, modulates the development of both endothelium and endodermally-derived hepatoblasts, presumably via other downstream paracrine pathways.

The Epithelial–Mesenchymal Transition Promotes Transdifferentiation of Subcutaneously Implanted Hepatic Oval Cells Into Mesenchymal Tumor Tissue

Hepatic oval cells are thought to represent facultative hepatic epithelial stem cells in liver in which damage inhibits hepatocyte proliferation and liver regeneration. The LE/6 hepatic stem cell line was derived from the liver of male Sprague-Dawley rats fed a choline-deficient diet containing 0.1% ethionine. They are histochemically characterized by their expression of hepatocytic (hepPar1), cholangiocytic cytokeratin (CK19), hepatic progenitor cell (OV-6), and hematopoietic stem cell (c-kit) markers. In this study, we transplanted LE/6 cells by subcutaneous injection into adult female nude mice, and examined their engraftment and differentiation potential in the subcutaneous microenvironment in vivo. Our results demonstrated that following subcutaneous transplantation, differentiation of LE/6 cells into mesenchymal tumor tissue (MTT) was associated with reduced E-cadherin expression, upregulation of E-cadherin repressor molecules (Snail proteins), and increased expression of vimentin and N-cadherin, all of these events are characteristic of the epithelial-mesenchymal transition (EMT).

Epithelial‐to‐mesenchymal transitions in the liver†

The outcome of liver injury is dictated by the effectiveness of repair. Successful repair (i.e., regeneration) results in replacement of dead epithelial cells with healthy epithelial cells, and reconstructs normal hepatic structure and function. Liver regeneration is known to involve replication of surviving mature hepatocytes and bile duct cells. This review discusses recent evidence for other mechanisms that might also replace dead hepatic epithelial cells and repair liver damage, particularly during chronic injury. According to this theory, certain epithelial cells in developing livers and/or injured adult livers undergo epithelial-to-mesenchymal transition (EMT) and move into the hepatic mesenchyme where they exhibit fibroblastic features. Some of these epithelia-derived mesenchymal cells, however, may be capable of undergoing subsequent mesenchymal-to-epithelial transition (MET), reverting to epithelial cells that ultimately become hepatocytes or cholangiocytes. Although these concepts remain to be proven, the theory predicts that the balance between EMT and MET modulates the outcome of chronic liver injury. When EMT activity outstrips MET, repair is mainly fibrogenic, causing liver fibrosis. Conversely, predominance of MET favors more normal liver regeneration. In this review, we summarize evidence that certain resident liver cells are capable of EMTs in vitro and during chronic liver injury.

Growth factor-free cultured rat bone marrow derived mesenchymal stem cells towards hepatic progenitor cell differentiation

Induction of mesenchymal stem cells (MSCs) differentiation by growth factors is not likely to be acceptable for clinical application. In this study, MSCs and hepatocytes isolated from male Sprague-Dawley rats were indirectly co-cultured by sharing media, without any growth factor, for 14 days. Differentiation was investigated by detection of hepatic markers, albumin, α-fetoprotein (AFP), cytokeratin-18 (CK18), and bile ductal epithelial cell marker cytokeratin-19 (CK19) on reverse transcription polymerase chain reaction (RT-PCR), immunofluorescence staining, and Western blot. Periodic acid-schiff (PAS) staining, low density lipoproteins (LDL) uptake analysis, and urea assay were performed to detect metabolic activities of differentiated cells. MSCs in co-culture group showed positive expression for albumin, AFP, and CK19, but little for CK18. Data indicates that co-cultured MSCs were differentiated into oval cell stage, the hepatic progenitor, but not directly toward complete hepatocytes. Our finding suggests that indirect co-culture system has potential to generate regenerative hepatocytes by hepatic progenitor cells differentiated from MSCs.

Role of hedgehog signalling in bile ductular cells

Acute and chronic liver pathologies represent an important source of morbidity and mortality. Understanding the mechanisms of cell survival, repair and proliferation are critical to the development of future therapies...

Establishment and characterization of atypical fibroblasts from human adult liver contributing to hepatocyte cord‐like arrangement

We report the phenotypic and functional characterization of fibroblasts established in culture from the non-parenchymal epithelial cell populations of adult human livers. Human liver fibroblasts (hLF) expressed mesenchymal antigens vimentin, alpha-smooth muscle actin, collagen, fibronectin, CD73, CD90, CD105, and CD166 together with non-mesenchymal antigens cytokeratins 8 and 18, glial fibrillary acidic protein, and nestin. Mixed cell lineage-specific protein expression was not associated with stem-like cell properties. Coculturing hepatocytes onto confluent hLF showed that they survived and maintained metabolic activity such as albumin, glycogen, and urea production. Moreover, hepatocytes formed cord-like arrangements resembling those established in vivo. Hepatocyte arrangement depended on cell-to-cell contact and the tissue origin of fibroblasts. Time-lapse video imaging of cocultured cells showed that hepatocyte arrangement was coordinated by the stretching and shortening of underneath hLF. Our data suggest that hLF may represent resident fibroblasts of the adult human liver, which could assume guiding functions for hepatic epithelial cells.

Benzophenone C-glucosides from Polygala glomerata Lour

Four new benzophenone C-glucosides, glomeratides A (1), B (2), C (3), and D (4), along with a known compound arrilanin G (5), have been isolated from the whole plant of Polygala glomerata Lour. Their structures were determined by extensive analyses of their spectral data. Compounds 1–5 showed hepatoprotective activities against d-galactosamine-induced toxicity in WB-F344 rat hepatic epithelial stem-like cells.