Development of a novel medium useful for hepatocyte studies

<p>Since the liver plays an important role in drug metabolism, in vitro tests using primary human hepatocytes (PHH) are one of the most important experimental tools of drug screening. However, in Japan, collecting PHH from humans raises ethical concerns, resulting that there is always a shortage of mature and normal PHH for research use. To solve this problem, hepatocytes derived from iPSCs (iPS-HEP) are promising as the alternative cell sources of PHH. Therefore, we focused on the culture medium for hepatocytes. In the first place, we evaluated the performance of the developed medium by measuring the amount of albumin secreted by PHH into the culture supernatant with ELISA. In the second place, we treated PHH with the drug-metabolizing enzyme inducer and the gene expression levels of the metabolizing enzyme were evaluated by RT-PCR. In the third place, we evaluated the function of iPS-HEP by ELISA and RT-PCR using this medium in the late stage of iPS-HEP differentiation induction. As a result, it was confirmed that there is no significant difference in the albumin secretion from PHH and gene expression levels of the metabolizing enzyme in both the commercially available media and the developed medium. However, when the drug-metabolizing enzyme inducer was added to iPS-HEP, a similar tendency of the drug response was observed even though the gene expression levels were significantly lower than PHH. In conclusion, we report that our developed medium can be used for PHH and iPS-HEP and could be a promising medium for various hepatocyte studies.</p>