Stem Cell-Derived Hepatocyte-Like Cells as Model for Viral Hepatitis Research

Figure 1

Stem cell-derived hepatocyte-like cells support virus research of HBV, HCV, and HEV. (a) During differentiation, iPSC or hESC undergo definitive endoderm induction, hepatic specification, hepatoblast expansion, and hepatic maturation to become HLCs that are permissive for infection with hepatitis viruses. (b) For HBV infection, cells are treated with activin A and Wnt-3A enhancer for 4 days and HGF and Rock inhibitor Y-27632 for one day, followed by HGF for 1 week. Hepatoblast cells are administered with DEX for 3 days and can be used for HBV infection at this point. The infected cells can be maintained in the presence of insulin, HC, and DMSO for another 1 month [19]. (c) For HCV application, iPSC/hESC is differentiated using two methods. Upper: this arm is similar to (b) (a, [17]). Lower: cells are treated with activin A and FGF-2 until day 4 when FGF-10 is added for 2 days and then coadded with retinoic acid and TGF-β inhibitor SB431542 until day 10. Cells are further treated with FGF-4, HGF, and EGF for about 10 days [65]. (d) On day 5, endoderm is formed by activin A, FGF-2, and bFGF and further differentiated by BMP4 and bFGF until day 10. Cells are terminally differentiated by EGF and HGF to hepatocyte-like cells. Cells can be infected with HEV or maintained in the medium containing oncostatin-M [18, 75]. Abbreviations: AAT: α-1-antitrypsin; AFP: alpha fetoprotein; APOB: apolipoprotein B; BMP4: bone morphogenetic protein 4; Cd81: cluster of differentiation 81; CK-7: cytokeratin 7; CLDN1: claudin-1; CXCR4: C-X-C chemokine receptor type 4; CYP: cytochrome 450 enzyme; DEX: dexamethasone; DMSO: dimethyl sulfoxide; EGF: epidermal growth factor; FGF: fibroblast growth factor; FOXA2: forkhead box protein A2 (also known as hepatocyte nuclear factor 3-beta); GATA4: GATA-binding protein 4; HC: hydrocortisone; hESC: human embryonic stem cells; HGF: hepatocyte growth factor; HNF: hepatocyte nuclear factor; iPSC: induced pluripotent stem cells; KRT19: cytokeratin 19; NANOG: Nanog homeobox; NTCP: sodium taurocholate cotransporting polypeptide; OCT4: octamer-binding transcription factor 4; PROM1: prominin 1; RXR: retinoid X receptor; SOX17: sex determining region Y-box 17; TGF: tumor growth factor.

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