Department of Clinical and Experimental Medicine, University of Padova, Medical School, Via Giustiniani, 2. 35100 Padova, Italy.
Diabetologia. 2011 Apr;54(4):945-53. doi: 10.1007/s00125-010-2007-2. Epub 2010 Dec 17.
AIMS/HYPOTHESIS: Bone marrow (BM)-derived endothelial progenitor cells (EPC) promote tissue healing and angiogenesis, whereas altered EPC biology may favour diabetic complications. We tested the hypothesis that diabetes impairs the contribution of BM-derived cells at sites of wound healing.
Four weeks after induction of diabetes in C57BL/6 mice, hindlimb skin wounds were created and monitored by digital imaging and histology. Circulating EPCs were quantified by flow cytometry before and after wounding. In separate experiments, bone marrow from C57BL/6 mice constitutively producing green fluorescent protein (GFP) was transplanted into myeloablated wild-type mice before induction of diabetes. We quantified proliferation, apoptosis and endothelial differentiation of tissue GFP(+) cells. Net recruitment of GFP(+) cells was estimated by correcting the number of tissue GFP(+) cells at each time point for basal levels, apoptosis and proliferation rates.
Diabetes delayed wound healing, with reduced granulation tissue thickness and vascularity, and increased apoptosis. Circulating EPC levels were not modified by 4 week diabetes and/or skin wounding. BM-derived EPCs (GFP(+)vWf(+) [von Willebrand factor] cells) within the granulation tissue were significantly reduced in diabetic compared with control mice. BM-derived GFP(+) cells showed increased apoptosis and decreased proliferation in diabetic versus non-diabetic wound tissues. Estimated net recruitment of BM-derived GFP(+) cells was reduced on day 1 after wounding in diabetic mice.
CONCLUSIONS/INTERPRETATION: Diabetic-delayed wound healing was associated with defective recruitment, survival and proliferation of BM-derived progenitor cells. Local treatments aimed at restoring EPC homing and survival might improve tissue healing in diabetes.
目的/假设：骨髓（BM）衍生的内皮祖细胞（EPC）促进组织愈合和血管生成，而 EPC 生物学的改变可能有利于糖尿病并发症的发生。我们检验了这样一个假设，即糖尿病会损害 BM 来源细胞在伤口愈合部位的贡献。
在 C57BL/6 小鼠诱导糖尿病 4 周后，创建并通过数字成像和组织学监测后肢皮肤伤口。在创伤前后通过流式细胞术定量循环 EPC。在单独的实验中，在诱导糖尿病之前，将来自持续产生绿色荧光蛋白（GFP）的 C57BL/6 小鼠的骨髓移植到骨髓清除的野生型小鼠中。我们量化了组织 GFP（+）细胞的增殖、凋亡和内皮分化。通过校正每个时间点组织 GFP（+）细胞的数量，以纠正基础水平、凋亡和增殖率，来估计 GFP（+）细胞的净募集。
糖尿病延迟了伤口愈合，导致肉芽组织厚度和血管减少，凋亡增加。4 周糖尿病和/或皮肤创伤并未改变循环 EPC 水平。与对照小鼠相比，糖尿病小鼠肉芽组织中的 BM 衍生 EPC（GFP（+）vWf（+）[血管性血友病因子]细胞）明显减少。与非糖尿病伤口组织相比，BM 衍生的 GFP（+）细胞在糖尿病伤口组织中表现出更高的凋亡和更低的增殖。在糖尿病小鼠中，创伤后第 1 天，BM 衍生的 GFP（+）细胞的估计净募集减少。
结论/解释：糖尿病延迟的伤口愈合与 BM 衍生祖细胞的募集、存活和增殖缺陷有关。旨在恢复 EPC 归巢和存活的局部治疗可能会改善糖尿病中的组织愈合。
