Effect of vitamin D on endothelial progenitor cells function

BackgroundEndothelial progenitor cells (EPCs) are a population of bone marrow-derived cells, which have an important role in the process of endothelialization and vascular repair following injury. Impairment of EPCs, which occurs in patients with diabetes, was shown to be related to endothelial dysfunction, coronary artery disease (CAD) and adverse clinical outcomes. Recent evidence has shown that calcitriol, the active hormone of vitamin D, has a favorable impact on the endothelium and cardiovascular system. There is limited data on the effect of vitamin D on EPCs function.AimTo examine the in vitro effects of Calcitriol on EPCs from healthy subjects and patients with diabetes.MethodsFifty-one patients with type 2 diabetes (60±11 years, 40% women, HbA1C: 9.1±0.8%) and 23 healthy volunteers were recruited. EPCs were isolated and cultured with and without calcitriol. The capacity of the cells to form colony-forming units (CFUs), their viability (measured by MTT assay), KLF-10 levels and angiogenic markers were evaluated after 1 week of culture.ResultsIn diabetic patients, EPC CFUs and cell viability were higher in EPCs exposed to calcitriol vs. EPCs not exposed to calcitriol [EPC CFUs: 1.25 (IQR 1.0–2.0) vs. 0.5 (IQR 0.5–1.9), p ConclusionIn patients with diabetes mellitus, in vitro vitamin D supplementation improved EPCs capacity to form colonies and viability. Further studies regarding the mechanisms by which vitamin D exerts its effect are required.研究背景：内皮祖细胞（Endothelial progenitor cells, EPCs）是一类骨髓来源的细胞群体，在机体损伤后的内皮化进程与血管修复过程中发挥关键作用。糖尿病患者体内出现的内皮祖细胞功能损伤，已被证实与内皮功能障碍、冠状动脉疾病（coronary artery disease, CAD）及不良临床结局密切相关。近年来的研究证据表明，维生素D的活性激素骨化三醇（calcitriol）对内皮组织与心血管系统具有积极的调控作用，但目前关于维生素D对内皮祖细胞功能影响的相关研究数据仍较为匮乏。 研究目的：本研究旨在探讨骨化三醇对健康受试者与糖尿病患者来源的内皮祖细胞的体外干预效应。 研究方法：本研究共招募51例2型糖尿病患者（年龄60±11岁，女性占比40%，糖化血红蛋白（HbA1C）：9.1±0.8%）及23名健康志愿者。分离获取内皮祖细胞后，分别在添加与不添加骨化三醇的条件下进行体外培养。于培养1周后，评估细胞的集落形成能力、细胞活性（采用MTT法检测）、KLF-10表达水平及血管生成标志物的表达情况。 研究结果：相较于未暴露于骨化三醇的内皮祖细胞，糖尿病患者来源的经骨化三醇处理的内皮祖细胞，其集落形成能力与细胞活性均有所提升[EPC集落形成单位：1.25（四分位距1.0–2.0） vs 0.5（四分位距0.5–1.9），p]。 研究结论：对于糖尿病患者，体外补充维生素D可改善其内皮祖细胞的集落形成能力与细胞活性。未来仍需开展进一步研究，以阐明维生素D发挥上述调控作用的具体分子机制。