Establishment of a human neonatal hepatocyte cell line

Oral fecal transplantation enriches Lachnospiraceae and butyrate to mitigate acute liver injury

While fecal microbiota transplantation (FMT) shows promise in treating human diseases, oral capsule FMT is more accepted and accessible to patients. However, microbe selection in the upper gastrointestinal tract (UGIT) through oral administration remains unclear. Here, we demonstrate that short-term oral fecal gavage (OFG) alleviates acetaminophen-induced acute liver injury (AILI) in mice, regardless of the divergent effects of commensal gut microbes. Pasteurized fecal gavage yields similar therapeutic effects. OFG enriches gut Lachnospiraceae and butyrate compared to donor feces. Butyrate mitigates AILI-induced ferroptosis via AMPK-ULK1-p62 signaling to simultaneously induce mitophagy and Nrf2 antioxidant responses. Combined N-acetylcysteine and butyrate administration significantly improves AILI mouse survival rates. These observations indicate the significance of the UGIT in modulating the implanted fecal microbes through oral administration and its potential biological and clinical impacts. Our findings also highlight a possible strategy for applying microbial metabolites to treat acute liver injury.

Engineering H2 O2 and O2 Self-Supplying Nanoreactor to Conduct Synergistic Chemiexcited Photodynamic and Calcium-Overloaded Therapy in Orthotopic Hepatic Tumors

Photodynamic therapy (PDT) is traditionally ineffective for deeply embedded tumors due to the poor penetration depth of the excitation light. Chemiluminescence resonance energy transfer (CRET) has emerged as a promising mode of PDT without external light. To date, related research has frequently used endogenous hydrogen peroxide (H₂ O₂ ) and oxygen (O₂ ) inside the solid tumor microenvironment to trigger CRET-mediated PDT. Unfortunately, this significantly restricts treatment efficacy and the development of further biomedical applications because of the limited amounts of endogenous H₂ O₂ and O₂ . Herein, a nanohybrid (mSiO₂ /CaO₂ /CPPO/Ce6: mSCCC) nanoparticle (NP) is designed to achieve synergistic CRET-mediated PDT and calcium (Ca²⁺ )-overload-mediated therapy. The calcium peroxide (CaO₂ ) formed inside mesoporous SiO₂ (mSC) with the inclusion of the chemiluminescent agent (CPPO) and photosensitizer (Ce6) self-supplies H₂ O₂ , O₂ , and Ca²⁺ allowing for the subsequent treatments. The Ce6 in mSCCC NPs is excited by chemical energy in situ following the supply of H₂ O₂ and O₂ to produce singlet oxygen (¹ O₂ ). The nanohybrid NPs are coated with stearic acid to avoid decomposition during blood circulation through contact with aqueous environment. This nanohybrid shows promising performance in the generation of ¹ O₂ for external light-free PDT and the release of Ca²⁺ ions for Ca²⁺ -overloaded therapy against orthotopic hepatocellular carcinoma.

In Vivo and In Vitro Models of Hepatocellular Carcinoma: Current Strategies for Translational Modeling

Hepatocellular carcinoma (HCC) is the sixth most common cancer worldwide and the third leading cause of cancer-related death globally. HCC is a complex multistep disease and usually emerges in the setting of chronic liver diseases. The molecular pathogenesis of HCC varies according to the etiology, mainly caused by chronic hepatitis B and C virus infections, chronic alcohol consumption, aflatoxin-contaminated food, and non-alcoholic fatty liver disease associated with metabolic syndrome or diabetes mellitus. The establishment of HCC models has become essential for both basic and translational research to improve our understanding of the pathophysiology and unravel new molecular drivers of this disease. The ideal model should recapitulate key events observed during hepatocarcinogenesis and HCC progression in view of establishing effective diagnostic and therapeutic strategies to be translated into clinical practice. Despite considerable efforts currently devoted to liver cancer research, only a few anti-HCC drugs are available, and patient prognosis and survival are still poor. The present paper provides a state-of-the-art overview of in vivo and in vitro models used for translational modeling of HCC with a specific focus on their key molecular hallmarks.

Establishment and characterization of immortalized porcine neonatal hepatocytes without the use of viral components

Porcine hepatocytes are a promising option for xenotransplantation in light of the critical shortage of orthotopic donor livers. Because primary hepatocytes have limited ability to proliferate in vitro, several immortalized hepatocyte lines have been established. However, these cells have typically been generated using a virus-dependent transfection methodology and express viral oncogenes that introduce potential risks in clinical applications. In our study, we established immortalized porcine neonatal hepatocytes by introduction of a plasmid-based hTERT gene expression system by electroporation, without the use of viral components. We detected stable expression of hTERT by RT-PCR and Western blot. The immortalized hepatocytes exhibit a high growth rate, but retain the normal morphology of freshly isolated primary hepatocytes. To date, these immortalized hepatocytes have been expanded for over 80 passages. In addition, no significant differences were detected in glycogen synthesis, secretion of serum albumin, or lipid accumulation between the primary hepatocytes and our immortalized hepatocytes. The cells also exhibit serum-dependent growth and have no capacity for anchorage-independent growth in vitro, demonstrating that they have not been transformed in vitro. Our immortalized porcine hepatocytes will be useful for elucidating the pathogenesis of liver disease and developing efficient treatments. Furthermore, these immortalized hepatocytes may provide a safer source of cells for application in xenotransplantation, compared with immortalized cells generated using viral components.

Coagulant activity of recombinant human factor VII produced by lentiviral human F7 gene transfer in immortalized hepatocyte-like cell line

Human mesenchymal stem cells (hMSCs) have the potential to differentiate into hepatocyte-like cells, indicating that these cells may be the new target cell of interest to produce biopharmaceuticals. Our group recently established a hMSC-derived immortalized hepatocyte-like cell line (imHC) that demonstrates several liver-specific phenotypes. However, the ability of imHC to produce coagulation factors has not been characterized. Here, we examined the potential for imHC as a source of coagulation protein production by investigating the ability of imHC to produce human factor VII (FVII) using a lentiviral transduction system. Our results showed that imHC secreted a low amount of FVII (~22 ng/mL) into culture supernatant. Moreover, FVII from the transduced imHC (0.11 ± 0.005 IU/mL) demonstrated a similar coagulant activity compared with FVII from transduced HEK293T cells (0.12 ± 0.004 IU/mL) as determined by chromogenic assay. We demonstrate for the first time, to the best of our knowledge, that imHC produced FVII, albeit at a low level, indicating the unique characteristic of hepatocytes. Our study suggests the possibility of using imHC for the production of coagulation proteins.

Potential for Isolation of Immortalized Hepatocyte Cell Lines by Liver-Directed In Vivo Gene Delivery of Transposons in Mice

Isolation of hepatocytes and their culture in vitro represent important avenues to explore the function of such cells. However, these studies are often difficult to perform because of the inability of hepatocytes to proliferate in vitro. Immortalization of isolated hepatocytes is thus an important step toward continuous in vitro culture. For cellular immortalization, integration of relevant genes into the host chromosomes is a prerequisite. Transposons, which are mobile genetic elements, are known to facilitate integration of genes of interest (GOI) into chromosomes in vitro and in vivo. Here, we proposed that a combination of transposon- and liver-directed introduction of nucleic acids may confer acquisition of unlimited cellular proliferative potential on hepatocytes, enabling the possible isolation of immortalized hepatocyte cell lines, which has often failed using more traditional immortalization methods.

Evaluation of the hepatocyte-derived cell line BFH12 as an in vitro model for bovine biotransformation

The knowledge of drug metabolising enzymes (DMEs) in cattle is rather limited. The capability of the bovine foetal hepatocyte-derived cell line BFH12 to serve as model for biotransformation was evaluated. Gene expression analysis of DMEs was performed by reverse transcription PCR (RT-PCR). The presence of efflux transporters was visualised by immunocytochemistry, and functional induction of cytochrome P450 (CYP) 1A was assessed by the ethoxyresorufin-O-deethylase (EROD) assay. The production of bile acids was measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). RT-PCR revealed the expression of cytochromes 1A1, 1A2, 3A4 and phase II enzymes UGT1A1, UGT1A6 and GSTM1. Immunofluorescence demonstrated efflux transporters ABCG2 and ABCC1. The EROD assay revealed a dose-dependent CYP1A induction after treatment with benzo[a]pyrene (BP). LC-MS/MS analysis of cell culture supernatants showed the production of bile acids including taurocholic acid, tauro-chenodeoxycholic acid, taurodeoxycholic acid and taurolithocholic acid. The results strongly suggest the applicability of the cell line BFH12 for subsequent experiments in the emerging field of bovine biotransformation.

Establishment of an immortalized intestinal epithelial cell line from tree shrews by lentivirus-mediated hTERT gene transduction

The intestinal epithelium has an average lifespan of 4–5 days. Normally, primary intestinal epithelial cells can be cultured for about 15 days in vitro. The aim of this study was to explore methods to isolate and immortalize intestinal epithelial cells (IECs) of tree shrews in order to establish a new resource of experimental material and to provide a cell model for drug development and infection mechanism research. Tissue from the small intestine of tree shrews was digested with collagenase XI, neutral protease I, and dithiothreitol. The human telomerase reverse transcriptase gene (hTERT) was transferred into tree shrew IECs using the pHBLV-CMVIE-ZsGreen-Puro vector. The level of hTERT mRNA was detected by quantitative reverse transcription polymerase chain reaction. Immunofluorescence and western blot assays were performed to detect biochemical markers of IECs. The micromorphology of cells was observed with electron microscopy. We then conducted experiments to assess proliferative activity and analyze the karyotype of isolated cells. The results showed the immortalized cell line that we established and screened, maintained the characteristics and biochemical markers of primary IECs. Our results showed that the cell line we established can be considered an alternative cell model for intestinal drug research and for studies on intestinal infection and cell signaling.

Intrahepatic hepatitis B virus large surface antigen induces hepatocyte hyperploidy via failure of cytokinesis

Hepatitis B virus (HBV) is an aetiological factor for liver cirrhosis and hepatocellular carcinoma (HCC). Despite current antiviral therapies that successfully reduce the viral load in patients with chronic hepatitis B, persistent hepatitis B surface antigen (HBsAg) remains a risk factor for HCC. To explore whether intrahepatic viral antigens contribute directly to hepatocarcinogenesis, we monitored the mitotic progression of HBV-positive cells. Cytokinesis failure was increased in HBV-positive HepG2.2.15 and 1.3ES2 cells, as well as in HuH-7 cells transfected with a wild-type or X-deficient HBV construct, but not in cells transfected with an HBsAg-deficient construct. We show that expression of viral large surface antigen (LHBS) was sufficient to induce cytokinesis failure of immortalized hepatocytes. Premitotic defects with DNA damage and G2 /M checkpoint attenuation preceded cytokinesis in LHBS-positive cells, and ultimately resulted in hyperploidy. Inhibition of polo-like kinase-1 (Plk1) not only restored the G2 /M checkpoint in these cells, but also suppressed LHBS-mediated in vivo tumourigenesis. Finally, a positive correlation between intrahepatic LHBS expression and hepatocyte hyperploidy was detected in >70% of patients with chronic hepatitis B. We conclude that HBV LHBS provokes hyperploidy by inducing DNA damage and upregulation of Plk1; the former results in atypical chromatin structures, and the latter attenuates the function of the G2 /M DNA damage checkpoint. Our data uncover a mechanism by which genomic integrity of hepatocytes is disrupted by viral LHBS. These findings highlight the role of intrahepatic surface antigen as an oncogenic risk factor in the development of HCC. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Hepatitis B virus PreS2-mutant large surface antigen activates store-operated calcium entry and promotes chromosome instability

Hepatitis B virus (HBV) is a driver of hepatocellular carcinoma, and two viral products, X and large surface antigen (LHBS), are viral oncoproteins. During chronic viral infection, immune-escape mutants on the preS2 region of LHBS (preS2-LHBS) are gain-of-function mutations that are linked to preneoplastic ground glass hepatocytes (GGHs) and early disease onset of hepatocellular carcinoma. Here, we show that preS2-LHBS provoked calcium release from the endoplasmic reticulum (ER) and triggered stored-operated calcium entry (SOCE). The activation of SOCE increased ER and plasma membrane (PM) connections, which was linked by ER- resident stromal interaction molecule-1 (STIM1) protein and PM-resident calcium release- activated calcium modulator 1 (Orai1). Persistent activation of SOCE induced centrosome overduplication, aberrant multipolar division, chromosome aneuploidy, anchorage-independent growth, and xenograft tumorigenesis in hepatocytes expressing preS2- LHBS. Chemical inhibitions of SOCE machinery and silencing of STIM1 significantly reduced centrosome numbers, multipolar division, and xenograft tumorigenesis induced by preS2-LHBS. These results provide the first mechanistic link between calcium homeostasis and chromosome instability in hepatocytes carrying preS2-LHBS. Therefore, persistent activation of SOCE represents a novel pathological mechanism in HBV-mediated hepatocarcinogenesis.

Sgo1 is a potential therapeutic target for hepatocellular carcinoma

Shugoshin-like protein 1 (Sgo1) is an essential protein in mitosis; it protects sister chromatid cohesion and thereby ensures the fidelity of chromosome separation. We found that the expression of Sgo1 mRNA was relatively low in normal tissues, but was upregulated in 82% of hepatocellular carcinoma (HCC), and correlated with elevated alpha-fetoprotein and early disease onset of HCC. The depletion of Sgo1 reduced cell viability of hepatoma cell lines including HuH7, HepG2, Hep3B, and HepaRG. Using time-lapse microscopy, we showed that hepatoma cells were delayed and ultimately die in mitosis in the absence of Sgo1. In contrast, cell viability and mitotic progression of immortalized cells were not significantly affected. Notably, mitotic cell death induced upon Sgo1 depletion was suppressed upon inhibitions of cyclin-dependent kinase-1 and Aurora kinase-B, or the depletion of mitotic arrest deficient-2. Thus, mitotic cell death induced upon Sgo1 depletion in hepatoma cells is mediated by persistent activation of the spindle assembly checkpoint. Together, these results highlight the essential role of Sgo1 in the maintenance of a proper mitotic progression in hepatoma cells and suggest that Sgo1 is a promising oncotarget for HCC.

Development and characterization of a new human hepatic cell line

The increasing demand and hampered use of primary human hepatocytes for research purposes have urged scientists to search for alternative cell sources, such as immortalized hepatic cell lines. The aim of this study was to develop a human hepatic cell line using the combined overexpression of TERT and the cell cycle regulators cyclin D1 and mutant isoform CDK4R24C. Following transduction of adult human primary hepatocytes with the selected immortalization genes, cell growth was triggered and a cell line was established. When cultured under appropriate conditions, the cell line expressed several hepatocytic markers and liver-enriched transcription factors at the transcriptional and/or translational level, secreted liver-specific proteins and showed glycogen deposition. These results suggest that the immortalization strategy applied to primary human hepatocytes could generate a novel hepatic cell line that seems to retain some key hepatic characteristics.

Lysine Demethylase LSD1 Coordinates Glycolytic and Mitochondrial Metabolism in Hepatocellular Carcinoma Cells

The hallmark of most cancer cells is the metabolic shift from mitochondrial to glycolytic metabolism for adapting to the surrounding environment. Although epigenetic modification is intimately linked to cancer, the molecular mechanism, by which epigenetic factors regulate cancer metabolism, is poorly understood. Here, we show that lysine-specific demethylase-1 (LSD1, KDM1A) has an essential role in maintaining the metabolic shift in human hepatocellular carcinoma cells. Inhibition of LSD1 reduced glucose uptake and glycolytic activity, with a concurrent activation of mitochondrial respiration. These metabolic changes coexisted with the inactivation of the hypoxia-inducible factor HIF1α, resulting in a decreased expression of GLUT1 and glycolytic enzymes. In contrast, during LSD1 inhibition, a set of mitochondrial metabolism genes was activated with the concomitant increase of methylated histone H3 at lysine 4 in the promoter regions. Consistently, both LSD1 and GLUT1 were significantly overexpressed in carcinoma tissues. These findings demonstrate the epigenetic plasticity of cancer cell metabolism, which involves an LSD1-mediated mechanism.

Immortalized Human Hepatic Cell Lines for In Vitro Testing and Research Purposes

The ubiquitous shortage of primary human hepatocytes has urged the scientific community to search for alternative cell sources, such as immortalized hepatic cell lines. Over the years, several human hepatic cell lines have been produced, whether or not using a combination of viral oncogenes and human telomerase reverse transcriptase protein. Conditional approaches for hepatocyte immortalization have also been established and allow generation of growth-controlled cell lines. A variety of immortalized human hepatocytes have already proven useful as tools for liver-based in vitro testing and fundamental research purposes. The present chapter describes currently applied immortalization strategies and provides an overview of the actually available immortalized human hepatic cell lines and their in vitro applications.

The photothermal effect of silica–carbon hollow sphere–concanavalin A on liver cancer cells

We used silica–carbon hollow spheres (SCHSs) as material for thermal production under NIR laser irradiation. Concanavalin A (ConA), a lectin, was applied to enhance binding on the cell surface of liver cancer cells. We demonstrated that ConA conjugated SCHSs killed liver cancer cells efficiently.

Strategies for immortalization of primary hepatocytes

The liver has the unique capacity to regenerate in response to a damaging event. Liver regeneration is hereby largely driven by hepatocyte proliferation, which in turn relies on cell cycling. The hepatocyte cell cycle is a complex process that is tightly regulated by several well-established mechanisms. In vitro, isolated hepatocytes do not longer retain this proliferative capacity. However, in vitro cell growth can be boosted by immortalization of hepatocytes. Well-defined immortalization genes can be artificially overexpressed in hepatocytes or the cells can be conditionally immortalized leading to controlled cell proliferation. This paper discusses the current immortalization techniques and provides a state-of-the-art overview of the actually available immortalized hepatocyte-derived cell lines and their applications.

Higher-order chromatin regulation and differential gene expression in the human tumor necrosis factor/lymphotoxin locus in hepatocellular carcinoma cells

The three-dimensional context of endogenous chromosomal regions may contribute to the regulation of gene clusters by influencing interactions between transcriptional regulatory elements. In this study, we investigated the effects of tumor necrosis factor (TNF) signaling on spatiotemporal enhancer-promoter interactions in the human tumor necrosis factor (TNF)/lymphotoxin (LT) gene locus, mediated by CCCTC-binding factor (CTCF)-dependent chromatin insulators. The cytokine genes LTα, TNF, and LTβ are differentially regulated by NF-κB signaling in inflammatory and oncogenic responses. We identified at least four CTCF-enriched sites with enhancer-blocking activities and a TNF-responsive TE2 enhancer in the TNF/LT locus. One of the CTCF-enriched sites is located between the early-inducible LTα/TNF promoters and the late-inducible LTβ promoter. Depletion of CTCF reduced TNF expression and accelerated LTβ induction. After TNF stimulation, via intrachromosomal dynamics, these insulators mediated interactions between the enhancer and the LTα/TNF promoters, followed by interaction with the LTβ promoter. These results suggest that insulators mediate the spatiotemporal control of enhancer-promoter associations in the TNF/LT gene cluster.

Telomerase Reverse Transcriptase Upregulation Attenuates Astrocyte Proliferation and Promotes Neuronal Survival in the Hypoxic–Ischemic Rat Brain

Background and Purpose—

Telomerase reverse transcriptase (TERT) is tightly related to the resistance of cells to stress and injury. However, little is known about the roles of TERT in the nervous system. We try to investigate the effects of TERT on the function of astrocytes in developing rat brains subjected to hypoxia–ischemia.

Methods—

TERT expression was detected in rat brains with hypoxia–ischemia. In in vitro study, the function of astrocytes with TERT overexpression was measured, and the effects of astrocyte on neuronal apoptosis were examined. Moreover, overexpression or inhibition of TERT was conducted in vivo by gene transduction. Astrocyte proliferation was examined through Ki67 staining. Terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling staining and brain infarct volume calculation were used to detect neuronal injury.

Results—

Both TERT mRNA and protein were upregulated in neurons within 2 days but shifted to astrocytes at Day 3 after hypoxia–ischemia. Astrocyte proliferation was inhibited with TERT overexpression due to the upregulation of cell-cycle regulatory protein p15. Meanwhile, the apoptosis of neurons increased, whereas neurons were cocultured with conditioned media from astrocytes with TERT inhibition compared with TERT overexpression due to the decrease of neurotrophin-3 expression in astrocytes. Furthermore, Ki67-positive astrocytes and neuronal injury were found to be inhibited in TERT-overexpressing rat brains with hypoxia–ischemia.

Conclusions—

TERT attenuates astrocyte proliferation and promotes neuronal survival in the developing rat brain after hypoxia–ischemia, partly through its enhancement of p15 and neurotrophin-3 expression in astrocytes.