细胞周期蛋白D1基因敲除对小鼠脑缺血边缘区胶质细胞增殖及神经元凋亡的影响  

Effects of cyclin D1 gene knock-out on astrocyte proliferation and neuronal apoptosis in boundary zone following the focal cerebral ischemia

作　　者：张强[1] 王伟[1] 徐运兰[1] 谢敏杰[1] 杜鹏[1] 陈晨[1] 朱舟[1] 王萍[1] 杜一星[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院神经内科,武汉430030

出　　处：《中华神经科杂志》2005年第9期570-574,共5页Chinese Journal of Neurology

基　　金：国家自然科学基金重点项目(30230140)

摘　　要：目的观察细胞周期调控对局灶性脑缺血边缘区胶质细胞增殖及神经元凋亡的影响。方法选用细胞周期蛋白D1(cyclin D1)基因敲除小鼠,建立光化学诱导小鼠局灶性脑缺血模型,随机将实验动物分为脑缺血组和假手术组,采用尼氏染色显示脑梗死灶并计算梗死灶面积;应用免疫荧光化学方法检测胶质纤维酸性蛋白(GFAP)的表达;并通过TUNEL方法检测神经元凋亡。结果缺血后3、7、28d cyclin D1基因敲除纯合子小鼠梗死灶面积占脑片总面积比值(1·00±0·28,1·00±0·16,1·10±0·16)明显小于杂合子(3·60±0·47,3·80±0·28,4·20±0·24)及野生型小鼠(3·60±0·51,3·90±0·21,4·30±0·47,均P<0·05);缺血后各时间组缺血边缘区GFAP表达明显增强,但缺血后7、28d纯合子小鼠缺血边缘区GFAP的表达明显弱于杂合子及野生型小鼠(缺血后7、28d纯合子小鼠缺血边缘区GFAP的吸光度值依次为0·612±0·069,0·622±0·146,杂合子为0·838±0·089,0·998±0·172,野生型为0·863±0·076,1·054±0·124,均P<0·05);缺血后3d于缺血边缘区可见大量TUNEL阳性染色细胞,而且杂合子、野生型小鼠缺血区细胞凋亡数目明显多于纯合子小鼠(缺血3d后纯合子、杂合子、野生型TUNEL阳性率依次为7·00±3·01,23·30±7·59,25·50±8·77,P<0·05);纯合子小鼠抗神经元特异性核蛋白(NeuN)+TUNEL双标阳性的结果明显弱于杂合子和野生型小鼠(P<0·05)。结论通过cyclin D1基因敲除,可部分抑制缺血边缘区胶质细胞增殖,同时减少神经元凋亡和脑梗死面积。该结果提示调控细胞周期可能是脑缺血新的治疗方向。Objective To observe the effects of cell cycle modification on astrocyte proliferation and neuronal apoptosis by using focal cerebral ischemia model on cyclin D1 gene knock-out mouse. Methods A photothrombotic model of focal brain ischemia was established in cyclin D1 gene knock-out mouse for studying the effects of cyclin D1 gene knock-out on average ratio of infarction area by using Nissl staining, as to observing the effects on optical density of glial fibrillary acidic protein （GFAP） , and studying the neuronal apoptosis by TUNEL method. Results The average ratio of infarction area of cyclin D1 gene knock-out mouse （KO） was found smaller than that of hemizygous mouse （HG） and wild type mouse （WT） （P 〈 0. 05） , and the average ratio of infarction area of KO after ischemia 3, 7 and 28 days was 1.00 ± 0. 28, 1.00 ± 0. 16 and 1.10 ± 0. 16 respectively; those of HG were 3. 60 ± 0.47, 3.80 ± 0. 28 and 4. 20 ± 0. 24 ; and those of WT were 3.60 ±0.51,3.90 ±0. 21 and 4. 30 ±0.47. The optical density of GFAP in KO was decreased significantly as compared with those in WT and HG 7 and 28 days after focal cerebral ischemia （P 〈0.05）, the optical density of GFAP on KO was 0. 612 ±0. 069, 0. 622 ±0. 146 respectively; those of HG were 0. 838 ±0.089, 0.998 ±0.172; and those of WT were 0.863 ±0.076, 1.054 ±0.124. The percent of apoptosis cell of KO was inhibited 3 days after ischemia （ P 〈 0. 05 ） , the percent of apoptosis cell of KO, HG and WT were 0. 070 ±0. 0301, 0. 233± 0. 0759 and 0. 255 ± 0. 0877 respectively, and the positive rates of TUNEL ＋ NeuN of KO, HG and WT were 2. 59 ± 0. 10,24. 31 ± 0. 10 and 25.00 ± 0. 10 respectively. Conclusion Cyclin D1 gene knock-out might partially inhibit the activation and decrease the proliferation of astrocyte and neuronal apoptosis after focal cerebral ischemia.

关 键 词：细胞周期蛋白D1 小鼠 基因敲除 神经胶质 细胞凋亡 脑缺血 胶质纤维酸性蛋白 基因敲除小鼠 缺血边缘区 神经元凋亡 细胞增殖 

分 类 号：R743.3[医药卫生—神经病学与精神病学]