Lu Hao, Wu Xiaoyue, Wang Zejing, Li Li, Chen Wen, Yang Mingcan, Huo Da, Zeng Wen, Zhu Chuhong
Department of Anatomy, National & Regional Engineering Laboratory of Tissue Engineering, Key Lab for Biomechanics of Chongqing, Third Military Medical University, Chongqing, China.
Department of Anatomy, National & Regional Engineering Laboratory of Tissue Engineering, Key Lab for Biomechanics of Chongqing, Third Military Medical University, Chongqing, China.
J Surg Res. 2016 Oct;205(2):464-473. doi: 10.1016/j.jss.2016.06.086. Epub 2016 Jul 5.
Mesenchymal stem cell (MSC) transplantation is an effective treatment therapy for ischemic ulcers. However, in high-glucose microenvironment, the original inflammation-inhibiting function of MSCs leads to turns into secreting large amounts of inflammatory mediators, such as tumor necrosis factor alpha, for example, which decreases their capacity and becomes poor quality stem cells over inflammation cells for diabetic foot ulcers repair in the healing of diabetic foot ulcers. Erythropoietin (EPO) is an anti-inflammatory, proangiogenic cytokine. It is unclear whether EPO-activated MSCs with biomaterials can promote the effective healing of diabetic foot ulcers.
Cultivated MSCs in MSC-L, MSC-H, EPO-G, Akt-G, and mTOR-G, then separated the supernatant-conditioned medium of these groups to stimulate human umbilical vein endothelial cells on proliferation and migration experiments; a new type of biomaterial planted with the EPO-activated MSCs was applied to the diabetic foot ulcers of the C57 mice.
In vitro experiments showed that EPO could stimulate MSCs to secrete vascular endothelial growth factor in high-glucose microenvironment. More importantly, EPO could reduce the damage to MSCs by high-glucose microenvironment, promote their proliferation and migration functions, and inhibit the high-glucose-induced MSCs from secreting the inflammatory mediator tumor necrosis factor alpha. In vivo experiments showed greater angiogenesis in EPO-MSC group than in control group, ulcer healing in EPO-MSC group was significantly better than that in control group, and MSCs partially differentiated into endothelial cells. EPO-activated MSCs could inhibit the monocyte invasion of localized diabetic foot ulcers.
Our results indicate that EPO-activated MSCs can promote the effective healing of diabetic foot ulcers. The mechanism is that EPO can change stem cells from excessive inflammation into general inflammation and improved diabetic foot ulcers inflammatory microenvironment.
间充质干细胞（MSC）移植是治疗缺血性溃疡的有效方法。然而，在高糖微环境中，MSC原本的抗炎功能会转变为分泌大量炎性介质，如肿瘤坏死因子α，这会降低其在糖尿病足溃疡愈合过程中修复糖尿病足溃疡的能力，使其相较于炎症细胞而言成为质量较差的干细胞。促红细胞生成素（EPO）是一种抗炎、促血管生成的细胞因子。目前尚不清楚EPO激活的MSC与生物材料联合使用是否能促进糖尿病足溃疡的有效愈合。
培养MSC-L、MSC-H、EPO-G、Akt-G和mTOR-G组的MSC，然后分离这些组的上清条件培养基，用于刺激人脐静脉内皮细胞进行增殖和迁移实验；将种植有EPO激活的MSC的新型生物材料应用于C57小鼠的糖尿病足溃疡。
体外实验表明，EPO能刺激MSC在高糖微环境中分泌血管内皮生长因子。更重要的是，EPO能减轻高糖微环境对MSC的损伤，促进其增殖和迁移功能，并抑制高糖诱导的MSC分泌炎性介质肿瘤坏死因子α。体内实验表明，EPO-MSC组的血管生成比对照组更明显，EPO-MSC组的溃疡愈合明显优于对照组，且MSC部分分化为内皮细胞。EPO激活的MSC能抑制局部糖尿病足溃疡处的单核细胞浸润。
我们的结果表明，EPO激活的MSC能促进糖尿病足溃疡的有效愈合。其机制是EPO能使干细胞从过度炎症转变为一般炎症，改善糖尿病足溃疡的炎性微环境。
