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| Hind Limb Unloading Depresses Corneal Epithelial Wound Healing in Mice |
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| 作者：Li Zhiji… 文章来源：Section of Leukocyte Biology, Departments of Pediatrics, Medicine and Immunology, Baylor College of Medicine, Houston, Texas, USA. 点击数1780 更新时间：2004/6/15 文章录入：毛进 责任编辑：毛进 |
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| C57Bl/6 mice were subjected to hindlimb unloading (HU) for a period of three
weeks to determine the possible effects on epithelial wound healing. A
standardized corneal epithelial wound was performed and parameters of the
inflammatory response and re-epithelialization were analyzed over an
observation period of 96 hours. Wound closure was significantly retarded in
mice during HU with re-epithelialization being delayed by approximately 12
hours. Both epithelial migration and cell division were significantly
depressed and delayed. The inflammatory response to epithelial wounding was
also significantly altered during HU. Neutrophils as detected by the Gr-1
marker were initially elevated above normal levels prior to wounding and
during the first few hours afterwards, but there was a significant reduction
in neutrophil response to wounding at times where neutrophil influx and
migration in controls were vigorous. A similar pattern was seen with
CD11b+CD11c+ cells (monocyte lineage). Langerhans cells (LC) are normally
resident within the peripheral corneal epithelium. They respond to injury by
initially leaving the epithelial site within 6 hours and returning to normal
levels by 96 hours, 2 days after re-epithelialization is complete. During HU
this pattern is distinctly different, with LC numbers slowing diminishing,
reaching a nadir at 96 hours, significantly below normal. Evidence for
systemic effects of HU is provided by findings that collagen deposition within
subcutaneous sponges was significantly reduced during HU. In conclusion, hind
limb unloading, a ground-based model simulating some physiologic aspects of
space flight, impairs wound repair of corneas. Multiple factors both local and
systemic likely contribute to this delayed wound healing.
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