Induction Of Hepatocyte-like Cellsby Overexpression Of FOXA3 And HNF4α In IPSCS And BMSCs

Liver is the body’s central station of metabolism with a variety of physiological and biochemical functions, which are necessary to maintain the body’s healthy functioning. Hepatocytes are the basic units of the liver to perform these functions. Needless to say, the value of researches about hepatocytes is great. Primary hepatocytes are difficult to maintain substantial growth in its form and function when cultured in vitro. Thus, the usual sources of hepatocytes rely on donation. This problem has been a major constraint in basic research, drug development, treatment of liver diseases and other related fields. How to obtain proliferative and functional hepatocyte-like cells in vitro is the urgent problem need to be solved. Normally, stem cells can self-renew and maintain a pluripotent. In some specific inducing environment, stem cells can differentiate into a variety of other adult cell types with functions. Inducted hepatocytes from stem cells, which were easy to obtain or be cultured, are considered the most practical way. In the present, researches in this area have made many significant advances, but there are still many inevitable limitations. Different starting cell selections and induction methods of differentiation have their own advantages and disadvantages. The emerging induced pluripotent stem cells(iPSCs) and bone marrow mesenchymal stem cells(BMSCs) have many obvious advantages and are considered to be the ideal source of inducted hepatocytes.Inspired by reports of somatic cells directly differentiated by using tissue-specific transcription factors, we attempt to induct iPSCs and BMSCs into hepatocyte-like cells(HLCs) directly by overexpressing FOXA3 and HNF4α, two liver-enriched transcription factors, in this study. The results showed that these HLCs from iPSCs had the typical hepatocyte morphology with the unique hepatocyte markers such as ALB, KRT18, KRT19 and AFP. Except for the above, these HLCs from BMSCs also expressed markers of mature hepatocytes such as G6 P, TAT, TTR. Simultaneously, they also exhibited hepatic functions such as glycogen storage, indocyanine green(ICG) absorption, and cytoplasmic accumulation of neutral triglycerides and lipids. Regrettably, HLCs derived fromr i PSCs only exhibited glycogen storage and a weak ICG uptake.In addition of that, these functions of both the two HLCs could be maintained in the process of cell culture, thus suggesting that FOXA3 and HNF4α are powerful transcription factors for inducing functional HLCs.Comparingthe initial source of cells from several aspects, the complexity of the operational processes, the experimental period andthe hepatocyte-like phenotype and function,the method of the HLCs induced from BMSCs has more obvious advantages, higher feasibility, shorter induction period, higher efficiency, simpler operation, more comprehensive function. This study will provide novel methods to generate HLCs and new research resources for hepatocyte and liver related researches.