Rashidi Hassan, Alhaque Sharmin, Szkolnicka Dagmara, Flint Oliver, Hay David C
MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, EH16 4UU, UK.
Arch Toxicol. 2016 Jul;90(7):1757-61. doi: 10.1007/s00204-016-1689-8. Epub 2016 Mar 15.
Freshly isolated human adult hepatocytes are considered to be the gold standard tool for in vitro studies. However, primary hepatocyte scarcity, cell cycle arrest and the rapid loss of cell phenotype limit their widespread deployment. Human embryonic stem cells and induced pluripotent stem cells provide renewable sources of hepatocyte-like cells (HLCs). Despite the use of various differentiation methodologies, HLCs like primary human hepatocytes exhibit unstable phenotype in culture. It has been shown that the functional capacity can be improved by adding back elements of human physiology, such as cell co-culture or through the use of natural and/or synthetic surfaces. In this study, the effect of fluid shear stress on HLC performance was investigated. We studied two important liver functions, cytochrome P450 drug metabolism and serum protein secretion, in static cultures and those exposed to fluid shear stress. Our study demonstrates that fluid shear stress improved Cyp1A2 activity by approximately fivefold. This was paralleled by an approximate ninefold increase in sensitivity to a drug, primarily metabolised by Cyp2D6. In addition to metabolic capacity, fluid shear stress also improved hepatocyte phenotype with an approximate fourfold reduction in the secretion of a foetal marker, alpha-fetoprotein. We believe these studies highlight the importance of introducing physiologic cues in cell-based models to improve somatic cell phenotype.
新鲜分离的成人肝细胞被认为是体外研究的金标准工具。然而，原代肝细胞的稀缺、细胞周期停滞以及细胞表型的快速丧失限制了它们的广泛应用。人类胚胎干细胞和诱导多能干细胞提供了可再生的肝样细胞（HLCs）来源。尽管使用了各种分化方法，但与原代人肝细胞一样，HLCs在培养中表现出不稳定的表型。研究表明，通过加入人体生理学元素，如细胞共培养或使用天然和/或合成表面，可以提高其功能能力。在本研究中，研究了流体剪切应力对HLC性能的影响。我们在静态培养和暴露于流体剪切应力的培养中研究了两种重要的肝功能，细胞色素P450药物代谢和血清蛋白分泌。我们的研究表明，流体剪切应力使Cyp1A2活性提高了约五倍。这与对主要由Cyp2D6代谢的药物的敏感性增加约九倍相平行。除代谢能力外，流体剪切应力还改善了肝细胞表型，使胎儿标志物甲胎蛋白的分泌减少了约四倍。我们认为这些研究突出了在基于细胞的模型中引入生理线索以改善体细胞表型的重要性。
