Background: Several studies have demonstrated techniques in differentiating human adipose-derived stem cells (hADSCs) into hepatocytes. Unfortunately, transdifferentiation is inefficient, and the function of these induced hepatocyte-like cells (which we termed ‘iHeps’) is low compared with that of real hepatocytes.
Aims: We aimed to identify transcriptional deficiencies in iHeps that are critical to hepatocyte development, which may provide insights into improving the efficiency of transdifferentiation.
Methods: hADSCs were differentiated into iHeps, and iHeps were assayed for hepatocyte-like activity. iHeps were then screened for expression of several growth factors, receptors and transcription factors (TFs) critical to liver development using reverse transcription-polymerase chain reaction (RT-PCR). Deficient TFs were transduced into hADSCs and hepatocyte function was reassessed after hepatic differentiation.
Results: Differentiation of hADSCs into iHeps resulted in the upregulation of hepatic proteins. However, the levels of expression of hepatocyte-specific proteins in these iHeps were well below those of Huh 7.5 hepatoma cells, used in comparison. Five developmental TFs were notably absent on the RT-PCR screen. Lentiviral transduction of these TFs into hADSCs followed by culture in hepatocyte induction medium resulted in increased albumin expression compared with untransduced hADSCs treated in a parallel fashion.
Conclusions: These five missing TFs are known to regulate hepatocyte differentiation and some are required to establish the competence of the foregut endoderm. Presumably due to their mesenchymal lineage, hADSCs do not express these endodermal TFs and are not fully competent to respond to critical developmental signals. Supplementation of these TFs may induce competency and enhance the differentiation of hADSCs into hepatocytes.