人巨细胞病毒感染致颈动脉粥样硬化机制的探讨

Study on the mechanism of internal carotid artery atherosclerosis induced by HCMV infection

目的比较颈动脉粥样硬化斑块与正常颈动脉中的人巨细胞病毒核酸(HCMV DNA)、血凝素样氧化低密度脂蛋白受体-1(LOX-1)、基质金属蛋白酶(MMP)-2、MMP-9的表达情况,探讨人巨细胞病毒感染与颈动脉粥样硬化的关系。方法收集31例行颈动脉内膜剥脱术后的颈动脉粥样硬化斑块标本作为动脉粥样硬化组,所有标本均于手术后12 h内取材。另选择性别、年龄与动脉粥样硬化组相匹配的28例正常颅内动脉标本作为对照组,均于死亡后12 h内行尸体解剖并取材。应用原位杂交技术检测2组标本中HCMV DNA表达情况,利用免疫组化法检测LOX-1、MMP-2、MMP-9表达情况;统计颈动脉粥样硬化组伴及不伴危险因素者HCMV DNA阳性细胞计数,HCMV DNA阳性与阴性表达者、血脂水平正常与异常者LOX-1、MMP-2、MMP-9阳性细胞计数。结果动脉粥样硬化组HCMV DNA、LOX-1、MMP-2、MMP-9阳性表达率及LOX-1、MMP-2、MMP-9阳性染色面积中位数和OD值中位数均明显高于对照组(P均<0.05)。颈动脉粥样硬化组中高TG血症、血清LDL水平>2.60 mmol/L和既往吸烟者HCMV DNA阳性细胞计数高于相应不伴危险因素者(P均<0.05)。动脉粥样硬化组中HCMV阳性者LOX-1阳性细胞计数明显高于HCMV阴性者(P均<0.05),而HCMV阳性者与HCMV阴性者MMP-2、MMP-9阳性细胞计数比较差异均无统计学意义(P均>0.05)。TG正常与升高者LOX-1、MMP-2和MMP-9阳性细胞数比较差异均无统计学意义(P均>0.05);LDL>2.6 mmol/L者LOX-1阳性细胞数明显高于LDL正常者(P<0.05)。结论HCMV感染是动脉粥样硬化危险因素之一,LOX-1、MMP-2及MMP-9参与颈动脉粥样硬化的病理过程,HCMV感染可能通过上调LOX-1基因表达从而促进动脉粥样硬化的发生、发展。

Objective It is to compare the expression of human cytomegalovirus nucleic acid（HCMV DNA）,hemagglutinin-like oxidized low-density lipoprotein receptor-1（LOX-1）,matrix metalloproteinase-2（MMP-2）,MMP-9 in carotid atherosclerotic plaques and normal carotid arteries,and to explore the relationship between HCMV infection and atherosclerosis.Methods Thirty-one specimens of carotid atherosclerotic plaque after carotid endarterectomy were collected as atherosclerosis group.Another 28 normal intracranial artery specimens matched with gender and age were selected as the control group.All of them were autopsied and taken within 12 hours after death.The expression of HCMV DNA was detected by situ hybridization methods.The expression of MMP-2,MMP-9,LOX-1 were detected by immunohistochemistry.The numbers of HCMV DNA positive cells in the carotid atherosclerosis group with and without risk factors,the positive and negative expression of HCMV DNA,the normal and abnormal blood lipid levels,the counts of LOX-1,MMP-2 and MMP-9 positive cells were calculated.Results The positive expression rates of HCMV DNA,LOX-1,MMP-2 and MMP-9 in the atherosclerosis group and the median and OD values of LOX-1,MMP-2 and MMP-9 positive staining areas were significantly higher than those in the control group（P0.05）.In patients with carotid atherosclerosis,high TG and serumLDL levels2.60 mmol/L and HCMV DNA positive cells in previous smokers were higher than those without risk factors（P0.05）.The number of LOX-1 positive cells in HCMV-positive patients was significantly higher than that in HCMV-negative patients（P0.05）,but there was no statistical difference in HCMV-positive and HCMV-negative MMP-2 and MMP-9 positive cell counts（P0.05）.There were no significant differences in the number of LOX-1,MMP-2 and MMP-9 positive cells between normal and high TG patients（P0.05）.The number of LOX-1 positive cells was significantly higher in the patients with LDL2.6 mmol/L than that in normal LDL ones（P0.05）.Conclusion HCMV infection is one of the risk factors of atherosclerosis.LOX-1,MMP-2 and MMP-9 are involved in the pathological process of carotid atherosclerosis.HCMV infection may promote occurrence and development of atherosclerosis by up-regulating LOX-1 gene expression.