Hepatocyte growth factor enhances the ability of dental pulp stem cells to ameliorate atherosclerosis in apolipoprotein E-knockout mice

BACKGROUND Atherosclerosis(AS),a chronic inflammatory disease of blood vessels,is a major contributor to cardiovascular disease.Dental pulp stem cells(DPSCs)are capable of exerting immunomodulatory and anti-inflammatory effects by secreting cytokines and exosomes and are widely used to treat autoimmune and inflam-mation-related diseases.Hepatocyte growth factor(HGF)is a pleiotropic cytokine that plays a key role in many inflammatory and autoimmune diseases.AIM To modify DPSCs with HGF(DPSC-HGF)and evaluate the therapeutic effect of DPSC-HGF on AS using an apolipoprotein E-knockout(ApoE-/-)mouse model and an in vitro cellular model.METHODS ApoE-/-mice were fed with a high-fat diet(HFD)for 12 wk and injected with DPSC-HGF or Ad-Null modified DPSCs(DPSC-Null)through tail vein at weeks 4,7,and 11,respectively,and the therapeutic efficacy and mechanisms were analyzed by histopathology,flow cytometry,lipid and glucose measurements,real-time reverse transcription polymerase chain reaction(RT-PCR),and enzyme-linked immunosorbent assay at the different time points of the experiment.An in vitro inflammatory cell model was established by using RAW264.7 cells and human aortic endothelial cells(HAOECs),and indirect co-cultured with supernatant of DPSC-Null(DPSC-Null-CM)or DPSC-HGF-CM,and the effect and mechanisms were analyzed by flow cytometry,RT-PCR and western blot.Nuclear factor-κB(NF-κB)activators and inhibitors were also used to validate the related signaling pathways.RESULTS DPSC-Null and DPSC-HGF treatments decreased the area of atherosclerotic plaques and reduced the expression of inflammatory factors,and the percentage of macrophages in the aorta,and DPSC-HGF treatment had more pronounced effects.DPSCs treatment had no effect on serum lipoprotein levels.The FACS results showed that DPSCs treatment reduced the percentages of monocytes,neutrophils,and M1 macrophages in the peripheral blood and spleen.DPSC-Null-CM and DPSC-HGF-CM reduced adhesion molecule expression in tumor necrosis factor-αstimulated HAOECs and regulated M1 polarization and inflammatory factor expression in lipopolysaccharide-induced RAW264.7 cells by inhibiting the NF-κB signaling pathway.CONCLUSION This study suggested that DPSC-HGF could more effectively ameliorate AS in ApoE-/-mice on a HFD,and could be of greater value in stem cell-based treatments for AS.

Microvesicles derived from mesenchymal stem cells inhibit acute respiratory distress syndrome-related pulmonary fibrosis in mouse partly through hepatocyte growth factor

BACKGROUND Pulmonary fibrosis is one of the main reasons for the high mortality rate among acute respiratory distress syndrome(ARDS)patients.Mesenchymal stromal cell-derived microvesicles(MSC-MVs)have been shown to exert antifibrotic effects in lung diseases.AIM To investigate the effects and mechanisms of MSC-MVs on pulmonary fibrosis in ARDS mouse models.METHODS MSC-MVs with low hepatocyte growth factor(HGF)expression(siHGF-MSC-MVs)were obtained via lentivirus transfection and used to establish the ARDS pulmonary fibrosis mouse model.Following intubation,respiratory mechanics-related indicators were measured via an experimental small animal lung function tester.Homing of MSC-MVs in lung tissues was investigated by near-infrared live imaging.Immunohistochemical,western blotting,ELISA and other methods were used to detect expression of pulmonary fibrosis-related proteins and to compare effects on pulmonary fibrosis and fibrosis-related indicators.RESULTS The MSC-MVs gradually migrated and homed to damaged lung tissues in the ARDS model mice.Treatment with MSC-MVs significantly reduced lung injury and pulmonary fibrosis scores.However,low expression of HGF(siHGF-MSC-MVs)significantly inhibited the effects of MSC-MVs(P<0.05).Compared with the ARDS pulmonary fibrosis group,the MSC-MVs group exhibited suppressed expression of type I collagen antigen,type III collagen antigen,and the proteins transforming growth factor-βandα-smooth muscle actin,whereas the siHGF-MVs group exhibited significantly increased expression of these proteins.In addition,pulmonary compliance and the pressure of oxygen/oxygen inhalation ratio were significantly lower in the MSC-MVs group,and the effects of the MSC-MVs were significantly inhibited by low HGF expression(all P<0.05).CONCLUSION MSC-MVs improved lung ventilation functions and inhibited pulmonary fibrosis in ARDS mice partly via HGF mRNA transfer.

Generation of functional hepatocyte-like cells from human bone marrow mesenchymal stem cells by overexpression of transcription factor HNF4α and FOXA2

Background: Our previous study showed that overexpression of hepatocyte nuclear factor 4α(HNF4α) could directly promote mesenchymal stem cells(MSCs) to differentiate into hepatocyte-like cells. However, the efficiency of hepatic differentiation remains low. The purpose of our study was to establish an MSC cell line that overexpressed HNF4α and FOXA2 genes to obtain an increased hepatic differentiation efficiency and hepatocyte-like cells with more mature hepatocyte functions. Methods: Successful establishment of high-level HNF4α and FOXA2 co-overexpression in human induced hepatocyte-like cells(hi Hep cells) was verified by flow cytometry, immunofluorescence and RT-PCR. Measurements of albumin(ALB), urea, glucose, indocyanine green(ICG) uptake and release, cytochrome P450(CYP) activity and gene expression were used to analyze mature hepatic functions of hi Hep cells. Results: hi Hep cells efficiently express HNF4α and FOXA2 genes and proteins, exhibit typical epithelial morphology and acquire mature hepatocyte-like cell functions, including ALB secretion, urea production, ICG uptake and release, and glycogen storage. hi Hep cells can be activated by CYP inducers. The percentage of both ALB and α-1-antitrypsin(AAT)-positive cells was approximately 72.6%. The expression levels of hepatocyte-specific genes( ALB, AAT, and CYP1A1) and liver drug transport-related genes( ABCB1, ABCG2, and SLC22A18) in hi Hep cells were significantly higher than those in MSCs-Vector cells. The hi Hep cells did not form tumors after subcutaneous xenograft in BALB/c nude mice after 2 months. Conclusion: This study provides an accessible, feasible and efficient strategy to generate hi Hep cells from MSCs.

Derivation and applications of human hepatocyte-like cells

Human hepatocyte-like cells (HLCs) derived from human pluripotent stem cells (hPSCs) promise a valuable source of cells with human genetic background, physiologically relevant liver functions, and unlimited supply. With over 10 years’ efforts in this field, great achievements have been made. HLCs have been successfully derived and applied in disease modeling, toxicity testing and drug discovery. Large cohorts of induced pluripotent stem cells-derived HLCs have been recently applied in studying population genetics and functional outputs of common genetic variants in vitro. This has offered a new paradigm for genomewide association studies and possibly in vitro pharmacogenomics in the nearly future. However, HLCs have not yet been successfully applied in bioartificial liver devices and have only displayed limited success in cell transplantation. HLCs still have an immature hepatocyte phenotype and exist as a population with great heterogeneity, and HLCs derived from different hPSC lines display variable differentiation efficiency. Therefore, continuous improvement to the quality of HLCs, deeper investigation of relevant biological processes, and proper adaptation of recent advances in cell culture platforms, genome editing technology, and bioengineering systems are required before HLCs can fulfill the needs in basic and translational research. In this review, we summarize the discoveries, achievements, and challenges in the derivation and applications of HLCs.

Conversion of mononuclear cells from human umbilical cord blood into hepatocyte-like cells

Objective： To evaluate the dltterentlatlon ot human umbilical cord blood ceils into hepatocyte-like cells. Methods： Mononuclear cells （MNCs） derived from human umbilical cord blood were isolated using Ficoll. The experiment was derived into 3 categories： （1） MNCs co-cultured with 50 mg minced liver tissue separated by a trans-well membrane and then collected at 0 h, 24 h, 48 h and 72 h; （2） MNCs cultured along supplemented with 100 ml/L FBS, 100 μ/ml penicillin, 100 μg/ml streptomycin, 4.7 μg/ml linoleic acid, 1×ITS, 10^-4 mol/L L-Ascorbic acid 2-P and a combination of FGF4 （100 ng/ml） and HGF （20 ng/mL）. Cells were then collected at 0 d and 16 d to examine the expression profile of hepatocyte correlating markers; （3） 0.2-0.3 ml of MNCs with a cell density of 2×10^7/ml were transplanted into prepared recipient mice [n=12, injected with 0.4 ml/kg （20%） CCl4 and 150 ng/kg 5-fluorouracil （5-Fu） prior the transplant 24 h and 48 h, respectively] via injection through tail vein. Mice were sacrificed 4 weeks after transplantation. The hepatocyte correlating mRNAs and proteins were determined by RT-PCR, immunohistochemical analysis and immunoflurence technique. Results： （1） After 72 h, a number of glycogen positive stained cells were observed with MNCs co-cultured with damaged mouse liver tissues. The expression of hepatocyte markers, human albumin （ALB）, α-fetal protein （AFP） and human GATA4 mRNA and proteins were detected by RT-PCR and immunohistochemistry as well. For the confirmation, the DNA sequencing of PCR products was performed. In control groups, MNCs co-cuhured with normal mouse hepatocytes or MNCs cultured alone, all markers remained negative. （2） In growth factor supplemented culture system, MNCs developed into larger volume with richer cytoplasm and binucleation after 16 d. Positive expression of ALB, AFP, CK18 and CK19 mRNA were detected with RT-PCR, and ALB positive staining was observed by immunocytochemistry as well. In contrast, MNCs cultured without exogenous growth factors scarcely attached to the culture dish and ALB mRNA was not detected. （3） In transplantation experiment, both of ALB and AFP mRNA were detected by RT-PCR and HSA, PCNA and ALB positive staining were observed in the livers of recipient mice by immunocytochemistry. Conclusion： MNCs from human umbilical cord blood could convert into hepatocyte-like ceils in 3 different ways, indicating their potential use in the clinic applications for the treatment of human liver diseases.

Autologous serum can induce mesenchymal stem cells into hepatocyte-like cells

Objective： To investigate whether the rabbit serum after radiofrequency ablation to liver tumor can induce mesenchymal stem cells （MSCs） differentiating into hepatocyte-like cells in order to find a new source and culture process for repairing liver injury. Methods： A tumor piece of 1 mm× 1mm×1 mm was transplanted into a tunnel at right liver of rabbits. The model of liver tumor was established after 2-3 weeks. The serum was collected from rabbits 72 h after being subjected to radiofrequency ablation of the liver tumor. Mesenchymal stem cells were isolated from rabbit bone marrow and cultured in DMEM containing autologous rabbit serum. Three kinds of media （L-DMEM） were tested respectively： ① containing 10% fetal calf serum （FCS）; ② containing 30% rabbit autologous serum after radiofrequency ablation of the liver tumor （ASRF）; ③ containing 30% rabbit autologous serum （AS）. MSCs were cultured on 12-well plates until passage 2 and examined under the light and electron microscopy at indicted intervals. The expression of albumin and CKl8 was detected using immunofluorescence to identify the characteristics of differentiated cells. Results： MSCs performed differently in the presence of fetal calf serum, rabbit autologous serum and rabbit autologous serum after radiofrequency ablation of the liver tumor. Induced by the serum after radiofrequency ablation to liver tumor for 7 d, the spindle-shaped MSCs turned into round shaped and resembled hepatocyte-like cells. The reactions were not found in MSCs cultured in FCS and AS groups. After induction for 14 d, slender microvilli, cell-cell junction structure and cholangiole emerged, and the differentiated cells expressed albumin and CKl 8. All those could not been observed in 10% FCS and 30% autologous serum groups. Conclusion： Mesenchymal stem cells differentiate into hepatocyte-like cells in the serum after radiofrequency ablation of liver tumor, providing us a potential cell source and culture process for clinical application in liver injury repairing.

Differentiation of Mesenchymal Stem Cells into Hepatocyte-Like Cells by Autologous Serum after Radiofrequency Ablation of Liver Tumor

Mesenchymal stem cells?(MSCs) have been shown to differentiate into liver cells in serum of part-resection liver, but it was hardly feasible in clinical use. Our studies revealed that MSCs could differentiate into hepatocyte-like cells in autologous serum after radiofrequency ablation (RFA) therapy of the liver tumor. Rabbits with liver tumor subsequently treated with RFA therapy. Serum was collected from those rabbits before RFA therapy and 72 hours after RFA therapy. MSCs were isolated from each rabbit’s bone marrow and cultured in DMEM medium containing the following different supplements: 30% fetal calf serum (FCS group), 30% rabbit autologous serum (AS group) or 30% autologous serum after RFA treatment of the liver tumor (ASRF group), observed by electron microscopy, flow cytometry, immunofluorescence. Seven days later, most of the spindle-shaped MSCs in the ASRF group transformed into polygon or round-shaped cells resembling hepatocytes, and the percentage in S/G2/M phase was higher than in the FCS or AS groups. Fourteen days later, slender microvilli, cell-cell junction structures and cholangiole emerged in the cells belonging to the ASRF group, the expression of albumin and CK18 was observed only in the differentiated cells from the ASRF group. These changes were not observed in the FCS group or the AS group. This study may provide a potential cell source and culture process for clinical application in liver injury treatment.

Hepatocyte growth factor promotes retinal pigment epithelium cell activity through MET/AKT signaling pathway

AIM:To explore the effects of hepatocyte growth factor(HGF)on retinal pigment epithelium(RPE)cell behaviors.METHODS:The human adult retinal pigment epithelial cell line-19(ARPE-19)were treated by HGF or mesenchymalepithelial transition factor(MET)inhibitor SU11274 in vitro.Cell viability was detected by a Cell Counting Kit-8 assay.Cell proliferation and motility was detected by a bromodeoxyuridine incorporation assay and a wound healing assay,respectively.The expression levels of MET,phosphorylated MET,protein kinase B(AKT),and phosphorylated AKT proteins were determined by Western blot assay.The MET and phosphorylated MET proteins were also determined by immunofluorescence assay.RESULTS:HGF increased ARPE-19 cells’viability,proliferation and migration,and induced an increase of phosphorylated MET and phosphorylated AKT proteins.SU11274 significantly reduced cell viability,proliferation,and migration and decreased the expression of MET and AKT proteins.SU11274 suppressed HGF-induced increase of viability,proliferation,and migration in ARPE-19 cells.Additionally,SU11274 also blocked HGF-induced phosphorylation of MET and AKT proteins.CONCLUSION:HGF enhances cellular viability,proliferation,and migration in RPE cells through the MET/AKT signaling pathway,whereas this enhancement is suppressed by the MET inhibitor SU11274.HGF-induced MET/AKT signaling might be a vital contributor of RPE cells survival.

Effects of Fuzhenghuayu decoction on collagen synthesis of cultured hepatic stellate cells,hepatocytes and fibroblasts in rats

AIM To study the mechanism of Fuzhenghuayu (FZHY) decoction on anti liver fibrosis. METHODS FZHY 10% decoction sera was incubated with rat normal subcultured hepatic stellate cells (HSC) and fibrotic primarily cultured HSC, normal and fibrotic hepatocytes and subcultured skin fibroblasts separately. Cell intracellular and extracellular collagen synthesis rates were measured by the method of Proline impulse and collagenase digestion. RESULTS For primarily cultured HSC and hepatocytes, both of intracellular and extracellular collagen synthesis rates decreased in the drug sera group. For the normal subcultured HSC and primarily cultured hepatocytes, the extracellular collagen secretion was decreased obviously by the drug sera, and intracellular collagen synthesis rates were inhibited to some extents. For fibroblasts, both intracellular and extracellular collagen synthesis rates were inhibited some what, but no significant differences were found. CONCLUSION The mechanism of FZHY decoction on anti liver fibrosis may be associated with inhibition of liver collagen production.

Fibroblast growth factor-4 and hepatocyte growth factor induce differentiation of human umbilical cord blood-derived mesenchymal stem cells into hepatocytes

AIM： To investigate the differentiation of human umbilical cord blood （HUCB）-derived mesenchymal stem cells （MSCs） into hepatocytes by induction of fibroblast growth factor-4 （FGF-4） and hepatocyte growth factor （HGF）, and to find a new source of cell types for therapies of hepatic diseases. METHODS： MSCs were isolated by combining gradient density centrifugation with plastic adherence. When HUCB-derived MSCs reached 70% confluence, they were cultured in Iscove modified Dulbecco medium （IMDM） supplemented with 10 mL/L FBS, 20 ng/mL HGF and 10 ng/mL FGF-4. The medium was changed every 4 d and stored for albumin, alpha-fetoprotein （AFP） and urea assay. Expression of CK-18 was detected by immunocytochemistry. Glycogen storage in hepatocytes was determined by PAS staining. RESULTS： By combining gradient density centrifugation with plastic adherence, we could isolate MSCs from 25.6% of human umbilical cord blood. When MSCs were cultured with FGF-4 and HGF, approximately 63.6% of cells became small, round and epithelioid on d 28 by morphology. Compared with the control, the level of AFP increased significantly from d 12 to 18.20：1=1.16 μg/L （t = 2.884, P〈0.05） in MSCs cultured with FGF-4 and HGF, and was higher （54.28±3.11 μg/L） on d 28 （t = 13.493, P〈0.01）. Albumin increased significantly on d 16 （t = 6.68, P〈0.01） to 1.02±0.15 μg/mL, and to 3.63±0.30 μg/mL on d 28 （t = 11.748, P〈0.01）. Urea （4.72±1.03 μmol/L） was detected on d 20 （t = 4.272, P〈0.01）, and continued to increase to 10.28±1.06 μmol/L on d 28 （t = 9.276, P〈0.01）. Cells expressed CK-18 on d 16. Glycogen storage was observed on d 24. CONCLUSION： HUCB-derived MSCs can differentiate into hepatocytes by induction of F-GF-4 and HGF. HUCB derived MSCs are a new source of cell types for cell transplantation therapy of hepatic diseases.

Rat bone marrow mesenchymal stem cells differentiate into hepatocytes in vitro

AIM: To investigate the mechanism and regulation of differentiation from bone marrow mesenchymal stem cells (MSCs) into hepatocytes and to find a new source of celltypes for therapies of hepatic diseases. METHODS: MSCs were isolated by combining gradient density centrifugation with plastic adherence. The cells were cultured in osteogenic or adipogenic differentiation medium and determined by histochemical staining. MSCs were plated in plastic culture flasks that were not coated with components of extracellular matrix (ECM). When MSCs reached 70% confluence, they were cultured in low glucose Dulbecco's modified Eagle's medium supplemented with 10 mL/L fetal bovine serum, 20 ng/mL hepatocyte growth factor (HGF) and 10 ng/mL fibroblast growth factor-4 (FGF-4). The medium was changed every 3 d and stored for albumin, alpha-fetoprotein (AFP) and urea assay. Glycogen store of hepatocytes was determined by periodic acid-Schiff staining.RESULTS: By combining gradient density centrifugation with plastic adherence, we isolated a homogeneous population of cells from rat bone marrow and differentiated them into osteocytes and adipocytes. When MSCs were cultured withFGF-4 and HGF, approximately 56.6% of cells became smallround and epithelioid on d 24 by morphology. Compared with the control, levels of AFP increased significantly from d 12 to 15.5±1.4 μg/L (t = 2.31, P＜0.05) in MSCs cultured with FGF-4and HGF, and were higher (46.2±1.5 μg/L)ond 21 (t = 41.926, P＜0.01), then decreased to 24.8±2.2 μg/L on d 24 (t = 10.345, P＜0.01). Albumin increased significantly on d 21 (t= 3.325, P＜0.01) to 1.4±0.2 μg/mL,and to 2.1±0.7 μg/mL on d 24 (t= 3.646, P＜0.01). Urea(2.3±0.4 mmol/L) was first detected on d 21 (t = 6.739, P＜0.01), and continued to increase to 2.6±0.9 mmol/Lon d 24 (t= 4.753, P＜0.01). Glycogen storage was first seen on d 21.CONCLUSION: The method combining gradient density centrifugation with plastic adherence can isolate MSCs. Rat MSCs may be differentiated into hepatocytes by FGF-4 and HGF. Cytokines may play a more important role in differentiation from rat MSCs into hepatocytes.

Studies on the mechanism of SIRT1/AMPK signaling pathway between hepatocytes and hepatic stellate cells

OBJECTIVE To investigate the mechanism of SIRT1/AMPK signaling pathway between hepatocytes and hepatic stellate cells(HSCs).METHODS Normal human Chang liver cells and human hepatic stellate cell line,LX-2 cells were treated with SRT1720(10μmol·L^(-1))and AICAR(500μmol·L^(-1))prior to ethanol(50 mmol·L^(-1)) for 24 and 48 h.Cell viability was analyzed by methyl thiazolyl tetrazolium assay.SIRT1,AMPK and p-AMPK m RNA levels for 24 h and 48 h were analyzed by RT-PCR,SIRT1,AMPK and p-AMPK protein expressions in the supernatant at 24 and 48 h was detected by Western blot.RESULTS SRT1720 and AICAR effectively decreased LX-2 cell viabilities and exhibited scarcely little toxicity in human Chang liver cells.SRT1720 and AICAR attenuated collagen-I,α-smooth muscle actin(α-SMA)levels,activated liver kinase B-1(LKB1)and AMPK phosphorylation in ethanol treated LX-2 cells.Meanwhile,SRT1720 and AICAR enhanced SIRT1 expression mediated by ethanol both in Chang liver cells and LX-2 cells.Furthermore,SRT1720 and AICAR suppressed the expression of sterol regulatory element-binding protein-1(SREBP-1)to regulate fatty acid synthesis.CONCLUSION SIRT1 agonist and AMPK agonist blocked the crosstalk between hepatocytes and HSCs via SIRT1/AMPK signaling pathway to modulate hepatocytes accumulation of lipid and HSCs activation.

Effect of glycyrrhizic acid and 18β-glycyrrhetinic acid on the differentiation of human umbilical cord-mesenchymal stem cells into hepatocytes

BACKGROUND End-stage liver disease is a global health complication with high prevalence and limited treatment options.Cell-based therapies using mesenchymal stem cells(MSCs)emerged as an alternative approach to support hepatic regeneration.In vitro preconditioning strategies have been employed to strengthen the regenerative and differentiation potential of MSCs towards hepatic lineage.Chemical compounds of the triterpene class;glycyrrhizic acid(GA)and 18β-glycyrrhetinic acid(GT)possess diverse therapeutic properties including hepatoprotection and anti-fibrosis characteristics.They are capable of modulating several signaling pathways that are crucial in hepatic regeneration.Preconditioning with hepato-protective triterpenes may stimulate MSC fate transition towards hepatocytes.AIM To explore the effect of GA and GT on hepatic differentiation of human umbilical cord-MSCs(hUC-MSCs).METHODS hUC-MSCs were isolated and characterized phenotypically by flow cytometry and immunocytochemistry for the expression of MSC-associated surface molecules.Isolated cells were treated with GA,GT,and their combination for 24 h and then analyzed at three time points;day 7,14,and 21.qRT-PCR was performed for the expression of hepatic genes.Expression of hepatic proteins was analyzed by immunocytochemistry at day 21.Periodic acid Schiff staining was performed to determine the functional ability of treated cells.RESULTS The fusiform-shaped morphology of MSCs in the treatment groups in comparison with the untreated control,eventually progressed towards the polygonal morphology of hepatocytes with the passage of time.The temporal transcriptional profile of preconditioned MSCs displayed significant expression of hepatic genes with increasing time of differentiation.Preconditioned cells showed positive expression of hepatocyte-specific proteins.The results were further corroborated by positive periodic acid Schiff staining,indicating the presence of glycogen in their cytoplasm.Moreover,bi-nucleated cells,which is the typical feature of hepatocytes,were also seen in the preconditioned cells.CONCLUSION Preconditioning with glycyrrhizic acid,18β-glycyrrhetinic acid and their combination,successfully differentiates hUC-MSCs into hepatic-like cells.These MSCs may serve as a better therapeutic option for degenerative liver diseases in future.

Differentiation of Menstrual Blood Derived Stem Cell (MensSCs) to Hepatocyte-Liked Cell on Three Dimensional Nanofiberscaffold: Poly Caprolacton (PCL)

Menstrual blood stem cells (MensSCs) have enormous potential as a source for cell replacement therapies. Since there is a major concern in utilization of nanofibers in tissue engineering of stem cells, we examined the potential of MensSCs to differentiate into hepatocytes, using different protocols and compare cells, with two-dimensional (2D) and three-dimensional (3D) culture systems. Cell characterization experiments of MensSCs have demonstrated that they are multipotent stem cells similar to mesenchymal stem cells, which can successfully differentiate into osteogenic and adipogenic lineages. The efficiency of the cells on the scaffold was appraised by scanning electron microscopy (SEM), MTT assay, and hematoxylin and eosin (H&E) staining. Thereafter, the differentiation protocols were developed by hepatocyte growth factor (HGF) and oncostatin M (OSM) with serum-supplemented or serum-free culture media up to 30 days. Immunofluorescence analysis and ELISA assay revealed the expression of albumin (ALB) in differentiated cells. Hepatocyte-like cells expressed liver-specific gene such as albumin(ALB), α-fetoprotein (AFP), tyrosine aminotransferase (TAT) and cytochrome P450 subunit 7a1 (Cyp7a1) at mRNA levels. In conclusion, the evidences presented in this study show that the nanofiber scaffold and MensSCs may provide a source of differentiated cells for treatment of liver diseases.

Study of nennatolysosomes in mouse hepatocytes and pancreatic exocrine acinar cells

Acid phosphatase(ACPase)-positive nematolysosomes in mouse hepatocytes and thepancreatic exocrine acinar cells were studied with ultracytoehemical method.The nematolyso-somes were 2～8μm in length,0.1～0.3μm in diameter.Some branched and some did notbranch,and most of them winded through the organelles.

Advances in cell sources of hepatocytes for bioartificial liver

BACKGROUND: Orthotopic liver transplantation (OLT) is the most effective therapy for liver failure. However, OLT is severely limited by the shortage of liver donors. Bioartificial liver (BAL) shows great potential as an alternative therapy for liver failure In recent years, progress has been made in BAL regarding genetically engineered cell lines, immortalized human hepatocytes, methods for preserving the phenotype of primary human hepatocytes, and other functional hepatocytes derived from stem cells. DATA SOURCES: A systematic search of PubMed and ISI Web of Science was performed to identify relevant studies in English language literature using the Key words such as liver failure bioartificial liver, hepatocyte, stem cells, differentiation, and immortalization. More than 200 articles related to the cell sources of hepatocyte in BAL were systematically reviewed. RESULTS: Methods for preserving the phenotype of primary human hepatocytes have been successfully developed. Many genetically engineered cell lines and immortalized human hepatocytes have also been established. Among these cell lines the incorporation of BAL with GS-HepG2 cells or alginate encapsulated HepG2 cells could prolong the survival time and improve pathophysiological parameters in an animal model of liver failure. The cBAL111 cells were evaluated using the AMC-BAL bioreactor, which could eliminate ammonia and lidocaine, and produce albumin. Importantly, BAL loading with HepLi-4 cells could significantly improve the blood biochemical parameters, and prolong the survival time in pigs with liver failure. Other functional hepatocytes differentiated from stem cells, such as human liver progenitor cells, have been successfully achieved. CONCLUSIONS: Aside from genetically modified liver cell lines and immortalized human hepatocytes, other functionalhepatocytes derived from stem cells show great potential as cell sources for BAL. BAL with safe and effective liver cells may be achieved for clinical liver failure in the near future.

Inhibitory effects of grape procyanidins on free radical-induced cell damage in rat hepatocytes in vitro

AIM： To study the protective effect of grape procyanidins on oxidative injury induced by ethanol and carbon tetrachloride in rat hepatocytes. METHODS： Normal rat hepatocytes as well as cells damaged by ethanol or carbon tetrachloride were incubated with different doses of grape procyanidins for 24 h. Cell proliferation, apoptosis and TNFα mRNA expression were subsequently determined using MTT assay, cell death ELISA and in situ hybridization. RESULTS： Proliferative levels of the control cells from ethanol and CCh injury groups significantly decreased while apoptosis and TNFα mRNA expression significantly increased compared to the normal control and grape procyanidins co-treatment groups （0.455 ± 0.051 vs 0.318 ±0.045, P 〈 0.05）. In comparison with the normal control, 50 and 100 mg/L grape procyanidins significantly stimulated cell growth, with a better effect observed with 100 mg/L grape procyanidins. CONCLUSION： Grape procyanidins inhibit the hepatocyte damage induced by ethanol and carbon tetrachloride, and stimulate normal hepatocyte proliferation.

Hepatocyte Growth Factor Gene-modified Bone Marrow-derived Mesenchymal Stem Cells Transplantation Promotes Angiogenesis in a Rat Model of Hindlimb Ischemia

Summary： Angiogenic gene therapy and cell-based therapy for peripheral arterial disease （PAD） have been studied intensively currently. This study aimed to investigate whether combining mesenchymal stem cells （MSCs）transplantation with ex vivo human hepatocyte growth factor （HGF） gene transfer was more therapeutically efficient than the MSCs therapy alone in a rat model of hindlimb ischemia. One week after establishing hindlimb ischemia models, Sprague-Dawley （SD） rats were randomized to receive HGF gene-modified MSCs transplantation （HGF-MSC group）, untreated MSCs transplantation （MSC group）, or PBS injection （PBS group）, respectively. Three weeks after injection, angiogenesis was significantly induced by both MSCs and HGF-MSCs transplantation, and capillary density was the highest in the HGF-MSC group. The number of transplanted cell-derived endothelial cells was greater in HGF-MSC group than in MSC group after one week treatment. The expression of angiogenic cytokines such as HGF and VEGF in local ischemic muscles was more abundant in HGF-MSC group than in the other two groups. In vitro, the conditioned media obtained from HGF-MSCs cultures exerted proproliferative and promigratory effects on endothelial cells. It is concluded that HGF gene-modified MSCs transplantation therapy may induce more potent angiogenesis than the MSCs therapy alone. Engraftment of MSCs combined with angiogenic gene delivery may be a promising therapeutic strategy for the treatment of severe PAD.