PLoS ONE：有助于帮助干细胞恢复肢体损伤的酶

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2014年5月16日讯 /生物谷BIOON/--虽然恢复受伤腿部的血流是一个好的方面，但它实际上会导致额外伤害，阻碍恢复。近日，佐治亚大学Babak Baban博士等人证实：恢复血流实际上加剧炎症和细胞死亡，而不是帮助许多患者恢复。同时研究揭示在一种酶帮助下，一种干细胞疗法似乎干预损伤恢复，相关研究发表在PLOS ONE杂志上。
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此前的研究表明，干细胞可能都通过启用新的血管生长和通过降低现有严重的炎症，来提高恢复，Baban说：这项新的研究表明吲哚胺2，3二氧化酶或简称IDO（广为人知能抑制免疫反应），在调节炎症反应中起重要作用。干细胞和许多其他类型细胞系都表达IDO。该研究的通讯作者解释：我们不希望关闭免疫系统，我们希望把它恢复正常。
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甚至是短期内血和养分不足，都可导致破坏性的酸性代谢产物、自由基的快速积累，导致破坏细胞结构，Yu表示：细胞“发电站”称为线粒体，它应该产生能量来源三磷酸腺苷，缺血过程中，线粒体损伤是早期伤亡事件，线粒体会迅速成为丰满，渗漏和不正常的。线粒体是病态的，当血流恢复后，它可以给予病态线粒体更大的附加应力。& U$ [! e' y" p0 A1 w( `7 a  d$ s2 c

7 K% l3 ^# M; F# y( ]- p) K线粒体开始泄漏不应该存在于线粒体外的物质，他说：如此细胞会迅速被压垮。炎症反应，本是正常愈合过程的一部分，能升级帮助收拾残局，但这种情况下反而进一步加剧了这一问题。接下来的研究步骤是分析是否IDO越高越好。- j4 L  Q0 s; [# s' w3 Q
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研究人员指出，干细胞疗法还没有用来帮助患者肢体受伤恢复，但正在临床研究中，以帮助中风和心脏发作恢复。眼下，大多数医生所能做的就是恢复血流，并给予广谱抗生素。
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坤明

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doi:10.1371/journal.pone.00957207 y- x4 e% `4 B
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9 E0 p  N# \" d9 d$ i5 q1 \! ^The Role of Indoleamine 2,3 Dioxygenase in Beneficial Effects of Stem Cells in Hind Limb Ischemia Reperfusion Injury
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Mohamad Masoumy,et al.6 S& _' Q' P( r$ L0 V, P4 h

2 m$ B- @$ z2 n; JIschemia-Reperfusion (IR) injury of limb remains a significant clinical problem causing secondary complications and restricting clinical recovery, despite rapid restoration of blood flow and successful surgery. In an attempt to further improve post ischemic tissue repair, we investigated the effect of a local administration of bone marrow derived stem cells (BMDSCs) in the presence or absence of immune-regulatory enzyme, IDO, in a murine model. A whole limb warm ischemia-reperfusion model was developed using IDO sufficient (WT) and deficient (KO) mice with C57/BL6 background. Twenty-four hours after injury, 5×105 cells (5×105 cells/200 μL of PBS solution) BMDSCs (Sca1 + cells) were injected intramuscularly while the control group received just the vehicle buffer (PBS). Forty-eight to seventy-two hours after limb BMDSC injection, recovery status including the ratio of intrinsic paw function between affected and normal paws, general mobility, and inflammatory responses were measured using video micrometery, flow cytometry, and immunohistochemistry techniques. Additionally, MRI/MRA studies were performed to further study the inflammatory response between groups and to confirm reconstitution of blood flow after ischemia. For the first time, our data, showed that IDO may potentially represent a partial role in triggering the beneficial effects of BMDSCs in faster recovery and protection against structural changes and cellular damage in a hind limb IR injury setting (P = 0.00058).
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