Reversible transition between hepatocytes and liver progenitors for in vitro hepatocyte expansion

In Vitro Expansion of Primary Human Hepatocytes with Efficient Liver Repopulation Capacity

“…The expression of ALB and AAT proteins was validated by immunofluorescent staining, showing that over 97% of ProliHHs were positive for both ALB and AAT at passage 3 (P3) and P4 (Figures 2B and S3C). These data were different from expandable rodent hepatocytes (Katsuda et al, 2017;Wu et al, 2017), which showed almost undetectable expression of hepatocyte genes. It is noteworthy that ProliHHs expressed hepatic genes at comparable levels under normoxia and hypoxia ( Figures S3D and S3E).…”

“…Hepatocyte-to-HepPD conversion is likely to take place through a bi-phenotypic ''intermediate'' status characterized by the co-expression of hepatocyte markers and progenitor-associated markers (Tanimizu et al, 2014;Yanger et al, 2013). Two recent studies have respectively demonstrated the generation of expandable progenitor-like cells and duct-like cells from rodent hepatocytes in vitro (Katsuda et al, 2017;Wu et al, 2017). Despite the cessation of expression of hepatocyte genes in vitro, these cells could extensively repopulate mouse livers and regain features of mature hepatocytes, indicating that this may be a means of producing transplantable hepatocytes on a large scale (Katsuda et al, 2017;Wu et al, 2017).…”

“…Two recent studies have respectively demonstrated the generation of expandable progenitor-like cells and duct-like cells from rodent hepatocytes in vitro (Katsuda et al, 2017;Wu et al, 2017). Despite the cessation of expression of hepatocyte genes in vitro, these cells could extensively repopulate mouse livers and regain features of mature hepatocytes, indicating that this may be a means of producing transplantable hepatocytes on a large scale (Katsuda et al, 2017;Wu et al, 2017). Notably, in chronic liver diseases, HHs with expression of progenitor-associated markers were also documented in regenerative nodules (Michalopoulos and Khan, 2015;Yoon et al, 2011), indicating this may be a suitable strategy for expanding HHs at the ''intermediate'' status in vitro.…”

The breakthrough in primary human hepatocytes in vitro expansion

“…Meanwhile, the RNA-sequencing data provided in this article accompanied with additional data in previous studies 8,9 allow us to characterize PHHs, ProliHHs, HLCs and LPCs. Taken together, these data show us a whole picture of where these cells locate in the transcriptome level respectively, further offering insights into critical molecular mechanisms involved in hepatocytes expansion and repopulation.…”

“…More recently, it was recognized that adding ROCK, TGFβ and GSK3 inhibitors to the medium can achieve the long-term in vitro expansion of mature mouse hepatocytes and turn these cells into bipotent liver progenitor cells with regenerative capacity 8 . Meanwhile, another laboratory has demonstrated that mouse hepatocytes could be converted to liver progenitor-like cells when cultured in the transition and expansion medium (TEM) with the ability to passage for more than 30 times without apparent morphological changes 9 . Nevertheless, these methods do not seem to be promising when applied on human hepatocytes.…”