Abstract
Shortage of functional hepatocytes hampers drug safety testing and therapeutic applications because mature hepatocytes cannot be expanded and maintain functions in vitro. Recent studies have reported that liver progenitor cells can originate from mature hepatocytes in vivo. Derivation of proliferating progenitor cells from mature hepatocytes, and re-differentiation into functional hepatocytes in vitro has not been successful. Here we report the derivation of novel mesenchymal-like stem cells (arHMSCs) from adult rat hepatocytes. Immunofluorescence and flow cytometry characterization of arHMSCs found expression of mesenchymal markers CD29, CD44, CD90, vimentin and alpha smooth muscle actin. These arHMSCs proliferated in vitro for 4 passages yielding 104 fold increase in cell number in 28 days, and differentiated into hepatocyte-like cells (arHMSC-H). The arHMSC-H expressed significantly higher level of hepatocyte-specific markers (200 fold for albumin and 6 fold for Cyp450 enzymes) than arHMSCs. The arHMSC-H also demonstrated dose response curves similar to primary hepatocytes for 3 of the 6 paradigm hepatotoxicants tested, demonstrating utility in drug safety testing applications.
Highlights
In vitro and applied for drug-testing applications[9,10,11,12]
ArHMSCs in our study were positive for mesenchymal markers such as alpha-smooth muscle actin (SMA), Vimentin, CD44, CD29 and CD90. adult rat hepatocyte-derived mesenchymal-like stem cells (arHMSCs) were vastly different in morphology compared to the liver-derived progenitor cells (LDPCs) derived by Sahin et al.[14] and did not express CD45. arHMSCs were derived directly from hepatocytes but not from the clonal selection and LDPC repopulation as described by Sahin and Chen et al.[13,14]
We studied the morphological changes in the primary rat hepatocytes cultured for seven days in culture using continuous live cell imaging
Summary
In this study we have derived adult rat hepatocyte-derived mesenchymal-like stem cells (arHMSCs) from rat hepatocytes, and re-differentiated them into hepatocyte-like cells and characterized them for drug-testing applications[13,14]. Over fourteen days in culture arHMSCs differentiated to an epithelial lineage and expressed liver-specific phenotypes such as ureagenesis, albumin secretion, expression of hepatic nuclear factors and cytochrome P450 enzymes. They exhibited dose-dependent hepatotoxicity similar to that seen in mature hepatocytes for half of the tested hepatotoxicants. ArHMSC-H in our study demonstrated hepatocyte-like liver-specific functions and exhibited dose-dependent toxicity to selected paradigm hepatotoxicants, with dose response curves similar to that observed in mature hepatocytes. By bypassing embryonic stem cell reprogramming and avoiding the use of viral vectors in induced pluripotent stem cells, our approach can be adapted to generate patient-specific progenitors for individualized toxicity screens
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
