重组人粒细胞集落刺激因子修复大鼠动脉损伤

背景:有研究显示大鼠皮下注射粒细胞集落刺激因子后,外周血CD34 细胞明显增高。并发现运用粒细胞集落刺激因子不仅动员了骨髓干细胞,而且加速损伤血管段的再内皮化,抑制了新生内膜增生。目的:观察重组人粒细胞集落刺激因子对大鼠损伤动脉的再内皮化及抑制新生内膜增生作用。设计:随机对照动物实验。单位:南京医科大学附属南京第一医院。材料:实验于2005-12/2006-04于南京市第一医院完成。选用40只雄性SD大鼠,8～12周龄SPF级,体质量200～250g,购于国家啮齿类实验动物种子中心上海分中心。重组人粒细胞集落刺激因子购于山东齐鲁制药有限公司,2F动脉取栓导管购于Edwards Lifesciences公司,CD34单克隆抗体、CD45单克隆抗体购于联科生物有限公司。方法:用Excel软件随机将大鼠分成治疗组及对照组,每组20只。治疗组给予皮下注射重组人粒细胞集落刺激因子(100μg/kg),1次/d,共8d。对照组皮下注射等量生理盐水,1次/d,共8d。治疗5d后,腹腔注射麻醉大鼠,颈外动脉做一切口,将2F动脉取栓导管插入至左颈总动脉分叉处,注入200μL空气使球囊扩张,然后回拉球囊至肩胛舌骨肌处,回抽空气后重新送回导管,反复3次后拔出导管,结扎颈外动脉。①治疗前和治疗5d后,所有大鼠均取1mL静脉血进行白细胞和CD34 细胞计数。②球囊损伤后14和28d,每组分别麻醉后处死大鼠10只,取左颈总动脉。每组各5只用于暴露动脉内膜腔,应用图形分析软件计算再内皮化面积,再内皮化面积=未被伊文氏蓝着色区域/损伤总面积;每组另有5只,取左颈总动脉,取血管横切面,经HE染色后用图像分析软件计算新生内膜与中膜比(I/M),评估新生内膜增生程度。③采用免疫组化方法检测血管内膜CD31 与vWF (Ⅷ因子)细胞,推测损伤后内皮修复程度。主要观察指标:①大鼠外周血白细胞及CD34 细胞表达。②球囊损伤后血管再内皮化程度。③新生内膜增生程度(新生内膜与中膜比)。④血管内膜CD31 与vWF (Ⅷ因子)细胞检测结果。结果:纳入SD大鼠40只均进入结果分析。①外周血白细胞及CD34 细胞表达:治疗5d后,治疗组大鼠白细胞总数高于对照组(27.60±2.45)×109L-1,(10.11±1.81)×109L-1,P<0.01],CD34 细胞数量高于对照组(38.31×107L-1,3.14×107L-1,P<0.01)。②血管再内皮化程度:球囊损伤后14和28d,治疗组再内皮化面积分别为(68.3±8.3)%,(97.6±4.1)%,高于对照组(33.8±6.3)%,(76.1±5.2)%,P<0.01]。③新生内膜增生程度:球囊损伤后14,28d,治疗组新生内膜与中膜比分别为0.39±0.11,0.45±0.09,均低于对照组(0.87±0.15,1.26±0.16,P<0.01),治疗组血管新生内膜增生程度被显著抑制。④血管内膜CD31 与vWF (Ⅷ因子)细胞检测:球囊损伤后28d,治疗组血管内膜被接近于连续完整的CD31 与vWF 细胞覆盖,对照组血管内膜仅见零星、分散的CD31 与vWF 细胞。结论:重组人粒细胞集落刺激因子可促进大鼠血管损伤后外周血中CD34 细胞表达及血管内膜再内皮化,抑制新生内膜增生。

Granulocyte-colony stimulating factor for repair of injured arteries in rats

BACKGROUND:It has been reported that treatment with granulocyte-colony stimulating factor (G-CSF) increases the abundance of circulating CD34+ cells in rats. Data from the study, more important, suggested that mobilized by G-CSF may enhance rapid reendothelization and reduce neointimal formation after vascular injury.OBJECTIVE: To evaluate whether BM-derived CD34+ cells could enhance rapid reendothelization and reduce neointimal formation after balloon-injured carotid artery in an intact rat model.DESIGN: Randomized control animal study.SETTING: Nanjing First Hospital Affiliated to Nanjing Medical University.MATERIALS: The experiment was carried out in Nanjing First Hospital from December 2005 to April 2006. A total of 40 male Sprague-Dawley rats, weighing 200-250 g and of SPF grade, were purchased from National Rodent Laboratory Animal Resources, Shanghai Branch. The recombinant human G-CSF was purchased from Qilu Pharmaceutical. The 2F Fogarty arterial embolectomy catheters were purchased from Edwards Lifesciences. Anti-human CD34 and anti-human CD45 were purchased from Multi Sciences.METHODS: SD rats were divided randomly into treated group (n =20) and control group (n =20). Subcutaneous injection of recombinant human G-CSF (100 μg/kg/day) once daily for 8 days for treated group. Control group as treated with subcutaneous injection of saline. Five days after initiation of G-CSF treatment or saline, the rats were anesthetized by intraperitoneal injection with ketamine. The left common carotid artery was exposed through a midline incision of the ventral side of the neck. A 2F Fogarty arterial embolectomy catheter was inserted through the external carotid artery,inflated with 200 μL air, and passed 3 times along the length of the segment, which was defined proximally by the carotid bifurcation and distally by the edge of the omohyoid muscle. After removal of the catheter, the proximal ligature of the external carotid artery was tied off. ① An average of 1 mL venous blood per rat was collected for enumeration of the white blood wells (WBCs) and CD34+ cells before and 5 days after initiating G-CSF or saline treatment. ② Ten rats in each group were killed with overdose ketamine at 14 and 28 days after balloon injury and left common carotid arteries were harvested. The luminal surface of carotid arteries (n =5, each group) was exposed to calculate the reendothelialized area, which was manually traced with software (Image ProPlus). Reendothelialized area = non-stained with Evans blue area/the total area of balloon-injuried. The cross sections of carotid arteries (n =5, each group) were stained with hematoxylin and eosin (HE) and calculated intima-to-media area ratio (I/M) with software (Image ProPlus) to assess the extent of neointimal thickening. ③ To evaluate the extent of reendothelialization of arteries injury, sections were stained with CD31 and vWF by immunohistochemistry analysis.MAIN OUTCOME MEASURES: ① The number of WBCs and CD34+ cells; ② the extent of reendothelialization of arteries injury; ③ the extent of neointimal hyperplasia (I/M); ④ CD31 + and vWF+ endothelial cells.RESULTS: A total of 40 rats were involved in the final analysis. ① The number of WBCs and CD34+ cells: After 5 days of treatment, the number of WBCs in the treated rats increased more than 2.7-fold compared with control group (27.60±2.45) ×109 L-1, (10.11±1.81) ×109 L-1, P ＜ 0.01], CD34+ cells increased more than 12.2-fold compared with control group (38.31×107 L-1, 3.14×107 L-1, P ＜ 0.01). ② The extent of reendothelialization: At 14 and 28 days after balloon injury,carotid artery of reendothelialization in the treated group were (68.3±8.3)％ and (97.6±4.1)％, superior than the control group (33.8±6.3)％ and (76.1±5.2)％ (P ＜ 0.01). ③ The extent of neointimal hyperplasia: At 14 and 28 days after balloon injury, the neointima-media (I/M) ratios in the treated rats were 0.39±0.11 and 0.45±0.09, less than the control group 0.87±0.15,1.26±0.16 (P ＜ 0.01). A highly significant inhibition of neointimal hyperplasia was observed in the treated group. ④ CD31+ and vWF+ endothelial cells: At 28 days after injury, sections from G-CSF treated group showed almost complete and continuous monolayer of CD31 and vWF positive cells.In contrast, a patchy and interrupted CD31 and vWF positive cells were found lining the lumen of control group.CONCLUSION:Treatment with G-CSF significantly increases the number of CD34+ cells and accelerates the rate of reendothelialization of injured vessels, leading to marked inhibition of neointimal formation after vascular injury in rats.