Correlation between apoptosis induced by alumina and high molecular
weight polyethylene particles and the signal conduction of caspase 3*★

Abstract

AIM：To observe the dynamic changes in apoptosis involved in the biological response to alumina and high-molecular-weight polyethylene (HMWPE) particles, and the correlation between the apoptosis and signal conduction of caspase-3.

METHODS：The experiment was conducted in the animal experiment center and laboratory of the Department of Pathology, the Medical College of Nanchang University from September to December 2006. ①Totally 48 healthy Kunming mice were selected and divided into 3 groups according to the random table: control group, alumina particle group and HMWPE particle group with 16 mice in each group. ②The animal models of Air-pouch were established successfully if the injection site had no flare, pus, induration or exudation. The air pouches were injected with 3 mL alumina particles suspension into the alumina particle group, while 3 mL HMWPE particles suspension was injected in the HMWPE particle group; the control group was given matching phosphate buffered saline. ③Eight mice in each group were sacrificed respectively at 3 and 7 days after the injection to section the air-pouch capsule tissue. Histological changes were assessed by light microscope, TUNEL assays were conducted to quantify apoptotic cells and immunohistochemistry method was applied to detect the expression of caspase-3 in the pouch membrane.

RESULT:All 48 mice were involved in the result analysis. ①Histological changes of capsule wall: A great amount of macrophage infiltration and proliferation was detected in the alumina particle group and HMWPE particle group, and the cell number in the HMWPE group was significantly higher than the alumina particle group and control group at day 7 [(7 875±402), (5 134±256), (2 104±176) cells per mm2; P < 0.05, P < 0.01]. ②TUNEL result of apoptotic cells: TUNEL-positive cells were detected in the alumina particle group and HMWPE particle group, which were brown staining. No severe cellular reaction was found in the control group. ③Expression of caspase-3: The positive cell rates in each high fold field of the alumina particle group and HMWPE particle group were significantly higher than that in the control group, which was positively correlated with apoptotic index (r =0.752); At day 7, the expression of caspase-3 was highest in HMWPE particles group, about (28.57±5.62)%.

CONCLUSION：Both the allumina and HMWPE particles may result in cell apoptosis, and the latter one induces more severe apoptotic changes. Apoptosis involves in the pathogenesis of aseptic loosening, which is closely related with the activation of caspase-3.

摘要
目的：观察动物体内由高分子聚乙烯和氧化铝陶瓷磨损颗粒诱导的生物反应过程中细胞凋亡的动态变化，以及与半胱氨酸天冬氨酸蛋白酶3信号传导的相关性。
方法：实验于2005－09/12在南昌大学医学院病理科和动物实验中心完成。①选取健康昆明种小鼠48只，随机数字表法分成3组：模型对照组、氧化铝陶瓷磨损颗粒组、高分子聚乙烯磨损颗粒组，16只/组。②各组均建立Air-pouch动物模型，注射部位无红肿、流脓、硬结及渗出为模型构建成功。氧化铝陶瓷磨损颗粒组向air-pouch内注射经超声分散后的氧化铝陶瓷磨损颗粒悬液3 mL，高分子聚乙烯磨损颗粒组注射高分子聚乙烯磨损颗粒悬液3 mL，模型对照组注射等量磷酸盐缓冲盐水。③于术后第3，7天每组各处死8只小鼠，取air-pouch囊壁组织制备切片，光镜下观察囊壁组织结构的变化，TUNEL原位检测细胞凋亡情况，免疫组化染色检测半胱氨酸天冬氨酸蛋白酶3阳性细胞率的表达。
结果：48只小鼠均进入结果分析。①囊壁组织结构变化观察结果：光镜下氧化铝陶瓷磨损颗粒组、高分子聚乙烯磨损颗粒组均可见大量巨噬细胞浸润和增殖，术后第7天时囊壁组织细胞计数结果高分子聚乙烯磨损颗粒组明显高于氧化铝陶瓷磨损颗粒组、模型对照组[（7 875±402），（5 134±256），（2 104±176）个/mm2；P < 0.05，P < 0.01]。②凋亡细胞TUNEL原位检测结果：氧化铝陶瓷磨损颗粒组、高分子聚乙烯磨损颗粒组均存在TUNEL染色阳性细胞，细胞核着染成棕褐色或棕色，模型对照组未见明显组织细胞反应。③半胱氨酸天冬氨酸蛋白酶3的表达情况：每高倍视野阳性细胞率氧化铝陶瓷磨损颗粒组、高分子聚乙烯磨损颗粒组显著高于模型对照组，与凋亡指数均呈显著正相关（r =0.752）；高分子聚乙烯磨损颗粒组术后第7天时最多，达（28.57±5.62）%。
结论：高分子聚乙烯和氧化铝陶瓷磨损颗粒均能诱导细胞凋亡，并且高分子聚乙烯磨损颗粒诱导细胞凋亡程度高于氧化铝陶瓷磨损颗粒。细胞凋亡参与了假体无菌性松动的病理过程，且与半胱氨酸天冬氨酸蛋白酶3的激活有关。
关键词：聚乙烯类；氧化铝；细胞凋亡；半胱氨酸天冬氨酸蛋白酶

程涛，戴闽，帅浪，郝亮，范红先.高分子聚乙烯和氧化铝陶瓷磨损颗粒诱导细胞凋亡及与半胱氨酸天冬氨酸蛋白酶3信号传导的相关性[J].中国组织工程研究与临床康复，2007，11(1):127-129 [www.zglckf.com/zglckf/ejournal/upfiles/07-1/1k-127(ps).pdf]