IPS from fsc and ESC Display Comparable Potential for Derivation of Hepatocytes

huangcong1988

ScienceDaily (Jan. 10, 2011) — Numerous patients suffering from chronic liver diseases are currently receiving inadequate treatment due to the lack of organs donated for transplantation. However, hepatocytes derived from induced pluripotent stem cells (iPSCs) could offer an alternative for the future. Scientists from the Max Planck Institute for Molecular Genetics in Berlin compared hepatocytes from embryonic stem cells with hepatocytes from iPS cells and found that their gene expression is very similar.
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: P9 [# K7 U8 M7 fNevertheless, in comparison to "real" hepatocytes, just under half of the genes exhibited a different gene expression. Therefore, the gene expression of hepatocytes derived from iPS cells still requires adaptation before the cells could be used in the treatment of liver diseases.6 Q& k% o5 n, a2 e* ^5 f9 \
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The research is published in Stem Cells and Development (Dec. 20, 2010).
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  w! X, ^7 u. v, K# ^Induced pluripotent stem cells can be derived from different cell types and have the same genetic background as their progenitors. Hepatocytes derived from iPSCs therefore constitute an ideal point of departure for future regenerative therapy, as immune rejection between donor and host cells can be avoided.
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In their study, the Max Planck scientists compared hepatocyte-like cells derived from iPS cells and embryonic stem cells with "real" hepatocytes in early and later stages of development. Justyna Jozefczuk from the Max Planck Institute for Molecular Genetics explains: "It is the only way to determine actual differences between the cell types, and any flaws still present in the 'synthetic' hepatocytes." The scientists were able to show that the gene expression of hepatocytes based on embryonic stem cells and iPSCs is about 80 per cent similar. However, compared to isolated cells from the foetal human liver, the gene expression match is only 53 per cent.
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, p$ S7 Q9 R; s2 b2 w+ E% gHepatocyte-like cells from iPSCs and embryonic stem cells activate many of the typical liver proteins, e.g., albumin, alpha-fetoprotein and cytokeratin 18. Moreover, the "synthetic" hepatocytes can store glycogen and produce urea, just like the "real" hepatocytes. In addition, they are able to absorb and break down foreign molecules. In contrast, the genes around the enzyme group cytochrome P450 in the iPSCs and in real hepatocytes display different expression levels. These enzymes metabolise, among other things, drugs and foreign substances.
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; z; s2 [& p+ o- g9 V. q& k"This knowledge not only helps us better understand the causes of liver diseases; it also allows us to develop more efficient, patient-specific drugs," says James Adjaye from the Max Planck Institute for Molecular Genetics.
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always_wp

皮肤及血液中所提取干细胞可修复肝脏% L9 A8 J: J2 G0 j2 F, g. g, ]
In Vivo Liver Regeneration Potential of Human Induced Pluripotent Stem Cells from Diverse Origins
8 N$ d' ^. e# U  U$ |据英国《每日电讯报》5月12日（北京时间）报道，美国科学家首次使用由成人的皮肤及血液中提取的干细胞培育出成熟的肝脏细胞，并用其来治疗罹患肝硬化的老鼠，结果显示，这些细胞的表现可媲美正常的肝脏细胞。科学家表示，未来，肝病患者有望利用自身皮肤或血液中提取出的干细胞进行治疗，不需苦苦等待他人的肝脏来进行移植手术。
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huangcong1988

回复 always_wp 的帖子& a( ~4 m  N  [
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呵呵，最近看到太多关于ips的负面消息，有时候觉得很做ips没前途，但一想到ips的机制机理还没研究清楚，而且其真正的身份还没界定，我就觉得ips还是那个神秘的ips！