Availability, Functionality, and Safety as well as Quality Control of Hepatocytes as Seeding Cells in Liver Regenerative Medicine: State of the Art and Challenges.

Hepatic disease is one of the most common causes of death worldwide and has become a global health problem. Liver transplantation is the only effective treatment strategy for patients with hepatic function failure, but the insufficient number of donated healthy livers is the main obstacle limiting this process. To alleviate the demand for donor's livers, alternative approaches are being actively explored using liver tissue engineering principles. Liver tissue engineering consists of three elements, including seeding cells, extracellular matrix, and bioreactors. Among them, seeding cell is the most key factor. In this regard, hepatocyte-based tissue engineering can overcome the above shortages for tissue repair and regeneration in hepatic disorders. Primary human hepatocytes in liver regenerative medicine are the most preferred seeding cells, although limited access to a sufficient number of functional hepatocytes are a major issue due to the difficulties in long-term function maintenance of hepatocyte as well as the lack of availability of healthy donors. Hepatocyte-like cells (HLCs), derived from various stem cells, including non-liver-derived stem cells and liver-derived stem cells, as well as trans-differentiation of other cell types, may provide adequate cell sources and could replace primary human hepatocytes as seeding cells. However, it is still a great difficulty that HLCs generated by stem cell differentiation meet the quality required for clinical therapy. Furthermore, none of the standardized protocols to generate high-quality HLCs is available. Whether primary hepatocytes or HLCs are from various sources, preventing the functional deterioration of hepatocytes or generating fully functional hepatocytes is also a big challenge, respectively. In addition, the adoptions of three-dimensional co-culture systems and some small-molecule compounds contribute to maintaining the hepatic functionality of primary hepatocytes and enhancing the liver-specific functions of HLCs. In short, hepatocyte-based liver regenerative medicine is an attractive alternative strategy for liver diseases, notwithstanding some challenges still exist from bench to bedside. This review summarizes the current status, issues, and challenges in availability, functionality, and safety, as well as quality control of seeding hepatocytes with regard to liver tissue engineering in regenerative medicine for the treatment of liver disorders.

Population Pharmacokinetics of Vancomycin in Kidney Transplant Recipients: Model Building and Parameter Optimization.

BACKGROUND: Depending on the renal function of patients and many other influencing factors, studies on vancomycin pharmacokinetics show significant inter- and intra-individual variability. The present study was conducted using a population pharmacokinetics method to investigate the pharmacokinetic parameters and identified their influencing covariates for intravenous vancomycin in adult kidney transplant recipients. METHODS: The drug monitoring data included 56 adult renal transplant recipients who received intravenous vancomycin as prophylactic medication. The analysis was performed by a population approach with NONMEM. Data were collected mainly during the first week after transplantation. Monitoring of vancomycin trough concentration in blood was initiated mainly 3-5 days after the initial administration. RESULTS: The one-compartment open model was optimal and adequately described the data. Body weight (WT) and estimated glomerular filtration rate (GFR) were identified as significant covariates of the pharmacokinetic parameters CL and V of intravenous vancomycin in the kidney transplant patients. The typical values of vancomycin CL and V were 2.08 L h-1 and 63.2 L, respectively. A dosage strategy scheme according to model results was also designed. CONCLUSION: Both WT and GFR of the kidney transplant patients positively influence the pharmacokinetic parameters CL and V for intravenous vancomycin. Our population pharmacokinetic model provides a reference for vancomycin dosage adjustment in kidney transplant recipients.

Myt1l induced direct reprogramming of pericytes into cholinergic neurons.

OBJECTIVE: The cholinergic deficit is thought to underlie progressed cognitive decline in Alzheimer Disease. The lineage reprogramming of somatic cells into cholinergic neurons may provide strategies toward cell-based therapy of neurodegenerative diseases. METHODS AND RESULTS: Here, we found that a combination of neuronal transcription factors, including Ascl1, Myt1l, Brn2, Tlx3, and miR124 (5Fs) were capable of directly converting human brain vascular pericytes (HBVPs) into cholinergic neuronal cells. Intriguingly, the inducible effect screening of reprogramming factors showed that a single reprogramming factor, Myt1l, induced cells to exhibit similarly positive staining for Tuj1, MAP2, ChAT, and VAChT upon lentivirus infection with the 5Fs after 30 days. HBVP-converted neurons were rarely labeled even after long-term incubation with BrdU staining, suggesting that induced neurons were directly converted from HBVPs rather than passing through a proliferative state. In addition, the overexpression of Myt1l induced the elevation of Ascl1, Brn2, and Ngn2 levels that contributed to reprogramming. CONCLUSIONS: Our findings provided proof of the principle that cholinergic neurons could be produced from HBVPs by reprogramming factor-mediated fate instruction. Myt1l was a critical mediator of induced neuron cell reprogramming. HBVPs represent another excellent alternative cell resource for cell-based therapy to treat neurodegenerative disease.

Impact of high fat diet on long non-coding RNAs and messenger RNAs expression in the aortas of ApoE(-/-) mice.

Atherosclerosis is a chronic multifactorial inflammatory disease with high prevalence worldwide, and has become the leading cause of death. The present study was designed to investigate the impact of high-fat diet on ApoE(-/-) mice exhibiting atherosclerosis by detecting the genome-wide expression profile of lncRNAs and mRNAs. A total of 354 differentially expressed lncRNAs were identified (≥2.0 folds). Simultaneously, 357 differentially expressed mRNAs from the same chip were found. The expression differences of lncRNAs and mRNAs were consistent in both qPCR and microarray detection. Annotation results of the mRNAs which correlated with lncRNAs showed that the commonly related pathways were metabolism and inflammation. Hypergeometric distribution analysis indicated that the differentially expressed lncRNAs had been mostly regulated by transcription factors (TFs) such as Myod1, Rxra, Pparg, Tcf3, etc. Additional lncRNA-target-TFs network analysis was conducted for the top 20 differentially expressed lncRNAs. The results indicated Hnf4a, Ppara, Vdr, and Runx3 as the TFs most likely to regulate the production of these lncRNAs, and might play roles in inflammatory and metabolic processes in atherosclerosis. In a nutshell, the present study identified a panel of dysregulated lncRNAs and mRNAs that may be potential biomarkers or drug targets relevant to the high-fat diet related atherogenesis.

[Characteristics of microsomal phase II metabolic enzymes in mouse embryonic stem cell-derived liver tissue].

OBJECTIVE: To investigate the characteristics of phase II metabolic enzymes in mouse embryonic stem (ES) cell-derived liver tissue. METHODS: Mature hepatocytes were differentiated from embryonic stem cells in cultured mouse embryoid bodies (EB) at d18. Western blot was used to detect the expression of uridine 5'-diphosphate glucronosyl transferase (UGT1a1,UGT1a6) and microsomal glutathione S-transferases 1(mGST1) during the differentiation course.The derived liver tissue was incubated with UDPGA and 7-HFC,the formation of 7-HFC glucuronide was detected by HPLC to examine the total activities of UGT1a1 and UGT1a6. Furthermore, the microsomes were incubated with CDNB and GSH,and the mGST1 activity was measured by spectrometry. RESULTS: An increase tendency of UGT1a1 expression was noticed during the differentiation course. UGT1a6 and mGST1 were not detected in the earlier stage until d18 of differentiation. The metabolic activity of mGST1 in the derived hepatocytes was 7.65 nmol/min/mg on d18. CONCLUSION: The ES cell-derived liver tissue possesses partial metabolic function of phase II enzymes on d18 of differentiation,which might be used as a model for in vitro research on hepatic pathophysiology and phase II drug metabolism.

The role of ursodeoxycholic acid in non-alcoholic steatohepatitis: a systematic review.

BACKGROUND: Non-alcoholic steatohepatitis (NASH) is a condition that occurs during the progression of non-alcoholic fatty liver disease. Effective therapy for NASH is still lacking. In this study, we investigated the effects of Ursodeoxycholic acid (UDCA) in the treatment of NASH. METHODS: Western and Chinese databases were searched by independent investigators using appropriate MESH headings to identify randomized, controlled Western and Chinese clinical trials, published between January 1990 and October 2012, testing the effects of UDCA in patients with NASH. Patient characteristics and trial endpoints were analyzed, with quality assessment according to widely acknowledged criteria. P < 0.05 was defined as statistically significant in all trials. RESULTS: Twelve qualified randomized clinical trials, including six from China and involving 1160 subjects, were selected. Seven of these trials assessed the effects of UDCA Monotherapy, with the other five testing combinations of UDCA with vitamin E, polyene phosphatidylcholine, silymarin, glycyrrhizin and tiopronin. The duration of therapy ranged from 3 to 24 months, with two studies using high doses of UDCA (23-35 mg/kg/d). The average quality point was 2.69, and was significantly lower in articles from China than in those from Western countries (2.2 ± 0.4 vs. 3.8 ± 1.1, respectively, p < 0.05). UDCA Monotherapy significantly improved liver function in five studies and improved steatosis and fibrosis in two studies. All five studies assessing UDCA combination therapy showed significant improvements liver function, while two studies also improved steatosis and inflammation. One study of high-dose UDCA showed significant improvements in ALT, γGT and liver fibrosis, whereas the other study showed no significant change in ALT and liver pathology. CONCLUSIONS: UDCA therapy is effective in NASH, especially when combined with other drugs. However, the low quality of these studies and the heterogeneity of their results precluded further meta-analysis. Additional carefully designed clinical trials are needed, especially in China.

Impact of pharmacist antimicrobial dosing adjustments in septic patients on continuous renal replacement therapy in an intensive care unit.

BACKGROUND: Correct dosing of antimicrobial drugs in septic patients receiving continuous renal replacement therapy (CRRT) is complex. This study aimed to evaluate the effects of dosing adjustments performed by pharmacists on the length of intensive care unit (ICU) stay, ICU cost, and antimicrobial adverse drug events (ADEs). METHODS: A single-center, 2-phase (pre-/post-intervention) study was performed in an ICU of a university-affiliated hospital. Septic patients receiving CRRT in the post-intervention phase received a specialized antimicrobial dosing service from critical care pharmacists, whereas patients in the pre-intervention phase received routine medical care without involving pharmacists. The 2 phases were compared to evaluate the outcomes of pharmacist interventions. RESULTS: Pharmacists made 183 antimicrobial dosing adjustment recommendations for septic patients receiving CRRT. Changes in CRRT-related variables (116, 63.4%) were the most common risk factors for dosing errors, and ß-lactams (101, 55.2%) were the antimicrobials most commonly associated with dosing errors. Dosing adjustments were related to a reduced length of ICU stay from 10.7 ± 11.1 days to 7.7 ± 8.3 days (p = 0.037) in the intervention group, and to cost savings of $3525 (13,463 ± 12,045 vs. 9938 ± 8811, p = 0.038) per septic patient receiving CRRT in the ICU. Suspected antimicrobial adverse drug events in the intervention group were significantly fewer than in the pre-intervention group (19 events vs. 8 events, p = 0.048). CONCLUSIONS: The involvement of pharmacists in antimicrobial dosing adjustments in septic patients receiving CRRT is associated with a reduced length of ICU stay, lower ICU costs, and fewer ADEs. Hospitals may consider employing clinical pharmacists in ICUs.

Helicobacter pylori and Crohn's disease: a retrospective single-center study from China.

AIM: To investigate the association between Helicobacter pylori (H. pylori) infection and the prevalence of Crohn's disease (CD). METHODS: Subjects were selected from patients admitted the gastrointestinal (GI) department at The First Affiliated Hospital School of Medicine (Zhejiang University) for abdominal pain, hematochezia, diarrhea and other GI symptoms between January 2008 and September 2012. CD was diagnosed by endoscopy and biopsy. H. pylori infection was detected by a (14)C-urea breath test and culturing of the biopsy sample. Demographic, anthropometric and serologic data were collected for each patient. H. pylori infection rate was compared between CD and control groups, followed by a subgroup analysis based on extent and severity of CD. Student's t, Mann-Whiney U, and χ(2) tests were used to analyze the data. RESULTS: A total of 447 patients were analyzed, including 229 in the CD group and 248 in the control group. There were no significant differences in age, sex, and rates of hypertension or diabetes. However, the CD group showed significantly higher rates of smoking history (34.9% vs 18.1%), alcohol intake (17.4% vs 8.1%), white blood cell count (9.7 ± 2.9 × 10(9)/L vs 4.3 ± 0.9 × 10(9)/L), and C-reactive protein (36.3 ± 20.8 mg/L vs 5.5 ± 2.3 mg/L) but lower body mass index (24.5 ± 2.0 kg/m(2) vs 26.0 ± 2.2 kg/m(2)) than the control group. The H. pylori infection rate in the CD group was 27.1%, significantly lower than that of 47.9% in the control group. Furthermore, the H. pylori infection rates in patients with colonic, small intestine, ileocolonic and extensive CD were 31.1%, 28.9%, 26.8% and 25.9% respectively, all of which were significantly lower than in the control group. Finally, the H. pylori infection rates in patients with remission, moderate and severe CD were 34.3%, 30.7% and 22.0% respectively, which were also significantly lower than in the control group. CONCLUSION: Lower H. pylori infection in CD patients suggests a correlation between bacterial infection and CD, suggesting caution when considering H. pylori eradication in CD patients.

Uncoupling protein and nonalcoholic fatty liver disease.

OBJECTIVE: To review the current advances on the role of uncoupling protein (UCP) in the pathogenesis and progress of nonalcoholic fatty liver disease (NAFLD). DATA SOURCES: A comprehensive search of the PubMed literature without restriction on the publication date was carried out using keywords such as UCP and NAFLD. STUDY SELECTION: Articles containing information related to NAFLD and UCP were selected and carefully analyzed. RESULTS: The typical concepts, up-to-date findings, and existing controversies of UCP2 in NAFLD were summarized. Besides, the effect of a novel subtype of UCP (hepatocellular down regulated mitochondrial carrier protein, HDMCP) in NAFLD was also analyzed. Finally, the concept that any mitochondrial inner membrane carrier protein may have, more or less, the uncoupling ability was reinforced. CONCLUSIONS: Considering the importance of NAFLD in clinics and UCP in energy metabolism, we believe that this review may raise research enthusiasm on the effect of UCP in NAFLD and provide a novel mechanism and therapeutic target for NAFLD.

MAPEG expression in mouse embryonic stem cell-derived hepatic tissue system.

The expressions of membrane-associated proteins in eicosanoid and glutathione metabolism (MAPEG), a superfamily involved in both inflammation and cell protection, were investigated in an in vitro system of mouse embryonic stem (ES) cell-derived hepatic tissue. Gene expressions of all MAPEG members were demonstrated in a developmental-dependent manner in the derived hepatic tissue. The protein expression of microsomal glutathione S-transferase 1 (MGST1) was not detected until differentiating day 14. It gradually increased by maturation of hepatic tissue. The microsomes of ES cell-derived hepatic tissue possessed the MGST1-like catalytic activity. However, MGST1 from the microsome preparation could not form dimers as usual when exposed to reactive nitrogen species ONOO. Among the other members in MAPEG, weak expressions of leukotriene C(4) synthase (LTC(4)S) and microsomal prostaglandin E synthase 1 (mPGES-1) were observed. A stable expression of 5-Lipoxygenase activating protein (FLAP) appeared during the entire course of differentiation. MGST2 and MGST3 failed to express in the derived hepatic tissue, although mRNA of them do existed. In conclusion, ES cell-derived hepatic tissue possess MAPEG gene expression features, but not all protein expression could be detected, which helps to understand not only the nature of the tissue derived, but also the fate of bioartificial liver system, and may as well provide a valuable in vitro model for research in both inflammation process and toxic events in hepatological fields.

Enhanced expressions and activations of leukotriene C4 synthesis enzymes in D-galactosamine/lipopolysaccharide-induced rat fulminant hepatic failure model.

AIM: To investigate the expression and activity of leukotriene C4 (LTC4) synthesis enzymes and their underlying relationship with cysteinyl leukotriene (cys-LT) generation in a rat fulminant hepatic failure (FHF) model induced by D-galactosamine/lipopolysaccharide (D-GalN/ LPS). METHODS: Rats were treated with D-GalN (300 mg/kg) plus LPS (0.1 mg/kg) for 1, 3, 6, and 12 h. Enzyme immunoassay was used to determine the hepatic cys-LT content. Reverse transcription-polymerase chain reaction (RT-PCR), Western blot or immunohistochemical assay were employed to assess the expression or location of LTC4 synthesis enzymes, which belong to membrane associated proteins in eicosanoid and glutathione (MAPEG) metabolism superfamily. Activity of LTC4 synthesis enzymes was evaluated by determination of the products of LTA4 after incubation with liver microsomes using high performance liquid chromatography (HPLC). RESULTS: Livers were injured after treatment with D-GalN/LPS, accompanied by cys-LT accumulation at the prophase of liver injury. Both LTC4 synthase (LTC4S) and microsomal glutathione-S-transferase (mGST) 2 were expressed in the rat liver, while the latter was specifically located in hepatocytes. Their mRNA and protein expressions were up-regulated at an earlier phase after treatment with D-GalN/LPS. Meantime, a higher activity of LTC4 synthesis enzymes was detected, although the activity of LTC4S played the main role in this case. CONCLUSION: The expression and activity of both LTC4S and mGST2 are up regulated in a rat FHF model, which are, at least, partly responsible for cys-LT hepatic accumulation.

[Gene expressions of LTC4 synthase homologs in Con A-induced mouse hepatitis and regulative effect of cyclosporine A].

OBJECTIVE: To explore the gene expressions of LTC4 synthase homologs in concanavalin A (Con A)-induced mouse hepatitis and regulation role of cyclosporine A (Cs A) treatment. METHODS: Male Balb/c mouse liver injury model was developed by iv injection of Con A (20 mg/kg) and protected by Cs A pretreatment (150 mg/kg) before Con A administration. Blood samples were collected at indicated times after Con A treatment with or without Cs A pretreatment. Liver damage was assessed by serum transaminase ALT and AST measurement and histological evaluation. Meantime, three LTC4 synthase homolog gene expressions were determined by RT-PCR. RESULTS: Serum ALT and AST upregulation were accompanied with histological damage at 2 h after Con A administration, and further aggravated at 8 h. mGST2 gene expression increased 1.7 fold at 2 h and 1.9 fold at 8 h, while the expression of LTC4 S and mGST3 changed little. Pretreatment with Cs A prevented mouse liver from injury by Con A and partly inhibited the mGST2 gene expression upregulation. CONCLUSIONS: Administration of Con A in mouse lead to a significant increase of mGST2 gene expression without any significant effect on LTC4 S and mGST3 mRNA levels. Cs A pretreatment results in protection of liver damage, whereas fails to fully inhibit the increase of mGST2 gene expression.

[Protective effects of triterpenoids on primarily cultured rat hepatocytes injured by D-galactosamine and carbon tetrachloride].

OBJECTIVE: To investigate the protective effects and mechanism of triterpenoids on primarily cultured rat hepatocytes injured by D-galactosamine (D-GalN) or carbon tetrachloride (CCl4). METHODS: Rat hepatocytes were isolated by two-step collagenase perfusion and cultured in RPMI 1640 medium. Protective effects of asiatic acid (AA) and beta-glycyrrhetinic acid (GA) were evaluated on hepatocytes injured by D-GalN (2 mmol/L) or CCl4 (10 mmol/L). Cell morphology was observed by light microscope, cell viability was measured by MTT assay, AST and LDH were determined by an automatic analyzer. Fluorescence assay was applied to test reactive oxygen species (ROS), nitric oxide end products (NOx) and reduced glutathione (GSH), and JC-1 staining was used to determine mitochondria membrane potential (DeltaPsim). RESULTS: AST and LDH in medium were decreased when treated with AA and GA after D-GalN injury (P<0.05), furthermore AA enhanced the hepatocyte viability (P<0.05). Moreover, AA and GA significantly reduced ROS and NOx generation, and ameliorated DeltaPsim lost induced by D-GalN. AA also inhibited GSH decrease due to D-GalN and CCl4 treatment. CONCLUSION: Both AA and GA could protect hepatocytes from D-GalN and CCl4 injuries, which is associated with reducing intracellular ROS and NOx, reversing GSH depression and ameliorating DeltaPsim lost.