外周血单核细胞表达PEDF在2型糖尿病视网膜病变中的意义

Level of PEDF Increased in Monocytes in Diabetic Retinopathy

【目的】色素上皮衍生因子(PEDF)通过抗血管增生、抗炎、抗氧化应激等影响糖尿病视网膜病变(DR)发生发展,而单核/巨噬细胞(CD14+)与慢性炎症关系密切。本研究拟通过观察外周血CD14+细胞中PEDF的表达水平,为进一步探讨DR发病机制提供线索。【方法】选取2011年10月至2013年4月在我院内分泌科住院确诊为2型糖尿病患者(DM组)108例,分为无糖尿病视网膜病变组(NDR组)52例和糖尿病视网膜病变组(DR组)56例,同期健康体检者作为对照组(NC组)52例。收集患者外周血白细胞及其分类细胞计数相关指标;密度梯度离心法收集患者PBMC,免疫磁珠分离法提取CD14+细胞;剩余PBMC提取总蛋白,western blot比较总PBMC(t PBMC)与分离掉CD14+细胞的PBMC[PBMC(ex CD14+)]中PEDF蛋白表达水平。【结果】DR组和NDR组单核细胞绝对值较NC组升高(P<0.05),但DR组和NDR组间单核细胞绝对值的差异无统计学意义(P>0.05);DR组淋巴细胞绝对值较NDR组明显减低(P<0.05);与t PBMC相比,PBMC(ex CD14+)中PEDF蛋白表达水平明显下降(P<0.05)。【结论】DR患者外周血单核细胞数量增加。单核细胞是PBMC中表达PEDF的主要细胞。

【Objective】 Pigment epithelium derived factor（PEDF） has been widely implicated in Diabetic retinopathy（DR） via inhibition of angiogenesis and inflammation.Monocyte/macrophage（CD14＋cell） is closely associated with chronic inflammation.The present study is aimed to investigate whether PEDF is mainly expressed in monocytes in DR patients.【Methods】 Type 2 diabetic patients served as DM group（n = 108）,which were sub-divided into non-diabetic retinopathy group（NDR group,n = 52） and diabetic retinopathy group（DR group,n = 56） by angiography.52 healthy persons were enrolled in the study as normal control group（NC group）.CD14＋cells were isolated from PBMC using density-gradient centrifugation and immunomagnetic beads.The protein level of PEDF in the t PBMC and PBMC（ex CD14＋） was determined by western blot.The content of white blood cell count was measured.【Results】 The counts of monocytes were similar in NDR and DR groups（P〈0.05） but lower in NC group（P〈0.05）.The counts of lymphocytes in DR groups were lower in NDR groups（P〈0.05）.The level of PEDF in PBMC excluding CD14 positive cells was significantly lower than that of total PBMC（P〈0.05）.【Conclusion】 Monocytes are the main cells to secret PEDF in PBMC.