Hypoxia inducible microRNA 210 attenuates keratinocyte proliferation and impairs closure in a murine model of ischemic wounds
Hypoxia inducible microRNA 210 attenuates keratinocyte proliferation and impairs closure in a murine model of ischemic wounds
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DOI：
10.1073/pnas.1001653107
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发表时间：
2010-04-13
影响因子：
11.1
通讯作者：
Sen, Chandan K.
中科院分区：
文献类型：
--
作者：
Biswas, Sabyasachi;Roy, Sashwati;Sen, Chandan K.
局部缺血使伤口闭合复杂化。在这里，我们提出了一个独特的小鼠缺血性伤口模型，是基于双蒂皮瓣的方法。使用这种缺血性伤口模型，我们试图阐明microRNA如何参与限制缺氧（缺血的主要组成部分）下的伤口上皮再生。通过激光多普勒和高光谱成像评估的缺血限制了血流并降低了组织氧饱和度。EPR血氧测定显示缺血创面组织pO（2）< 10 mm Hg。缺血性伤口遭受受损的巨噬细胞募集和延迟的伤口上皮形成。具体而言，如通过Ki 67染色确定的上皮增殖受到损害。体内成像显示缺血性伤口中大量缺氧诱导因子-1 α（HIF-1 α）稳定，其中HIF-1 α诱导miR-210表达，进而沉默其靶E2 F3，E2 F3在缺血性伤口的伤口边缘组织中显著下调。E2 F3被认为是细胞增殖的关键促进剂。在角质形成细胞中，E2 F3的敲低限制了细胞增殖。在常氧条件下使用Ad-VP 16-HIF-1 α强制稳定HIF-1 α上调miR-210表达，下调E2 F3，并限制细胞增殖。使用miR-210的细胞递送的研究证明了miR-210在限制角质形成细胞增殖中的关键作用。总之，这些结果是独特的，证明缺血的缺氧成分可能通过稳定HIF-1 α来限制伤口再上皮化，HIF-1 α诱导miR-210表达，导致细胞周期调节蛋白E2 F3下调。
Ischemia complicates wound closure. Here, we are unique in presenting a murine ischemic wound model that is based on bipedicle flap approach. Using this model of ischemic wounds we have sought to elucidate how microRNAs may be implicated in limiting wound re-epithelialization under hypoxia, a major component of ischemia. Ischemia, evaluated by laser Doppler as well as hyperspectral imaging, limited blood flow and lowered tissue oxygen saturation. EPR oximetry demonstrated that the ischemic wound tissue had pO(2) < 10 mm Hg. Ischemic wounds suffered from compromised macrophage recruitment and delayed wound epithelialization. Specifically, epithelial proliferation, as determined by Ki67 staining, was compromised. In vivo imaging showed massive hypoxia inducible factor-1 alpha (HIF-1 alpha) stabilization in ischemic wounds, where HIF-1 alpha induced miR-210 expression that, in turn, silenced its target E2F3, which was markedly down-regulated in the wound-edge tissue of ischemic wounds. E2F3 was recognized as a key facilitator of cell proliferation. In keratinocytes, knock-down of E2F3 limited cell proliferation. Forced stabilization of HIF-1 alpha using Ad-VP16-HIF-1 alpha under normoxic conditions upregulated miR-210 expression, down-regulated E2F3, and limited cell proliferation. Studies using cellular delivery of miR-210 antagomir and mimic demonstrated a key role of miR-210 in limiting keratinocyte proliferation. In summary, these results are unique in presenting evidence demonstrating that the hypoxia component of ischemia may limit wound re-epithelialization by stabilizing HIF-1 alpha, which induces miR-210 expression, resulting in the down-regulation of the cell-cycle regulatory protein E2F3.