Human pluripotent stem cell-derived mesenchymal stem cells regenerate injured GUNN rat liver

Gunn rats bear a mutation within the uridine diphosphate glucuronosyltransferase-1A1 (Ugt1A1) gene resulting in high serum bilirubin levels as seen in Crigler-Najjar syndrome. In the present study, the Gunn rat was used as an animal model for heritable liver dysfunction. Human pluripotent stem cell-derived mesenchymal stem cells (iMSCs) were transplanted into Gunn rats after partial hepatectomy. The iMSCs engrafted and survived in the liver for up to 2 months without the need for immunosuppression. The transplanted iMSCs differentiated into functional hepatocytes and partially suppressed hyperbilirubinemia. Furthermore, human Albumin as well as the human immunomodulatory factors, RANTES and SERPINE1, were detected in the rat serum upon iMSC transplantation. The differentiation of iMSCs into hepatocytes was confirmed by qPCR and/or immunohistochemistry, detecting expression of human hepatocyte nuclear factor 4α, UGT1A1, cytokeratin 18, α-fetoprotein and Albumin. These findings indicate transplanted iMSCs differentiated into hepatocytes and thus contributed to tissue repair in an injury model of hepatocyte-based liver regeneration. The transcriptomes of iMSCs from human fetal MSC-dervied iPSCs and human ESC line H1 were compared to native human fetal MSCs as well as to the pluripotent prcursor ESCs and fetal MSC-derived iPSC by microarray analysis (PrimeView Human Gene Expression Array, Affymetrix, Thermo Fisher Scientific).