新生小鼠脑组织caspase-3表达变化研究

［摘要］目的　观察caspase-3在新生儿缺氧缺血性脑病(NHIE)小鼠模型脑组织中表达的变化。方法　选取7 d CD1新生小鼠30只，分为假手术组(9只)和NHIE模型组(21只)。采用右侧颈总动脉结扎，并给予8%低氧100min制备新生儿缺氧缺血性脑病小鼠模型。用TTC染色法检查两组的脑组织梗死面积，DAPI染色观察脑组织病理变化，原位末端标记技术(TUNEL)检测脑组织细胞凋亡，荧光免疫组化法检测脑组织半胱氨酸天冬氨酸蛋白酶(caspase)-3表达水平。结果　假手术组小鼠脑组织未见梗死灶，脑组织细胞排列致密整齐，TUNEL阳性细胞数［(18.57±4.98)个］和caspase-3阳性细胞数［(9.17±2.14)个］明显低于NHIE模型组的TUNEL阳性细胞数［(209.57±41.27)个］和caspase-3阳性细胞数［(63.33±16.22)个］；与假手术组相比，NHIE模型组小鼠的右侧半球可见梗死灶，脑组织细胞大量坏死脱落、周围组织间隙变大。结论　NHIE模型鼠出现的脑组织损伤，可能与caspase-3表达增加、脑组织细胞凋亡增加有关。

［关键词］缺氧缺血；脑梗死；细胞凋亡；半胱氨酸天冬氨酸蛋白酶3；小鼠；缺氧缺血性脑病

Change of the expression of caspase-3 in ipsilateral brain of neonatal hypoxic-ischemia encephalopathy model mice

［Abstract］Objective To observe apoptotic cells and caspase-3-positive cells in ipsilateral brain of neonatal hypoxic-ischemia encephalopathy(NHIE)model mice.Methods7 d CD1 mice were randomly divided into two groups，sham group and model group.NHIE model was induced by right common carotid artery ligation followed by 8%oxygen hypoxia for 100 min.TTC staining was used to examine brain infarction，DAPI staining was used to examine brain pathological change，TUNEL was used to detect apoptotic cells and fluorescence immunohistochemistry was used to detect caspase-3 expression in the ipsilateral brain.Results No infarct was detected in sham group.Cells were densely and orderly arranged in brain.TUNEL-positive cells(18.57±4.98)and caspase-3-positive cells(9.17±2.14)in the ipsilateral brain were both less than those in the ipsilateral brain of mice in model group(209.57±41.27)and(63.33±16.22)respectively.Mice in model group presented infarct in the right hemisphere with more dead cells and wider interstitial space compared with sham group.Conclusion Brain injury in NHIE model might be related to the increasing caspase-3 expression thus leads to apoptosis.(www.xing528.com)

［Key words］hypoxia-ischemia；cerebral infarction； apoptosis； caspase-3；mice；hypoxic-ischemic encephalopathy

新生儿缺氧缺血性脑病(neonatal hypoxic-ischemic encephalopathy，NHIE)指各种围生期窒息引起的部分或完全缺氧、脑血流减少或暂停而导致的胎儿或新生儿脑损伤［1］，是新生儿窒息后的严重并发症，较为常见，病情重且病死率高；并可产生永久性神经功能障碍，如智力低下、癫痫、脑性瘫痪、痉挛和共济失调等，严重影响患儿的生活质量，给社会和家庭造成沉重的负担。研究报道细胞凋亡参与了缺氧缺血性脑损伤的发病过程［2-3］。而半胱氨酸天冬氨酸蛋白酶(caspase)-3是细胞凋亡的主要执行者，研究发现，NHIE模型鼠脑组织中caspase-3活性增加［4-5］，而NHIE模型鼠脑组织中caspase-3表达量是否增加尚不清楚。本研究通过建立NHIE小鼠模型，观察脑组织损伤程度、细胞凋亡及caspase-3表达情况，为下一步研究药物的作用机制奠定实验基础。