摘要
目的 研究诱导性ppp2r1a基因全身敲除对成年小鼠的主要生理功能影响并探讨相关机制.方法 将ppp2r1aflox/flox小鼠和CAGG-CreER小鼠杂交繁殖,获得20只CAGG-CreER ppp2r1aflox/flox小鼠,设立为纯合子组,并同时选取同窝野生型小鼠20只,采用单纯随机法,将纯合子、野生型小鼠分别分为4组,共8组,每组5只,腹腔注射他莫昔芬0、2、4、6 d,建立ppp2r1a基因诱导性敲除小鼠模型.采用Western blot法检测主要脏器中PP2A Aα（由ppp2r1a基因编码）的敲除效率,并观察小鼠体重、脏器病理改变以及外周血细胞计数和血生化,采用Real-time PCR法检测肝脏糖脂代谢相关基因的表达改变.结果 他莫昔芬注射6 d后,小鼠心脏、肝脏、脾脏、肺脏、肾脏和脑的PP2A Aα敲除效率分别约为35%、12%、15%、60%、69%和72%.他莫昔芬注射6 d后,纯合子小鼠体重[（17.42±1.76）g]低于野生型小鼠[（21.69±1.82）g]（P〈0.05）.纯合子小鼠活动减少,腹部和肾周脂肪少,存活不超过7 d.第6天后,纯合子小鼠脾脏的脏器系数[（0.36±0.05）%]低于野生型小鼠[（0.59±0.10）%]（P〈0.05）,组织病理HE染色显示脾脏萎缩明显,有核细胞明显减少.Tunel染色发现脾脏中淋巴细胞凋亡增多.纯合子小鼠血浆中谷丙转氨酶（ALT）和谷草转氨酶（AST）水平[（153.68±62.80）U/L和（193.2±44.28）U/L]均高于野生型小鼠[（41.02±12.91）U/L和（69.40±9.55）U/L]（P值均〈0.05）,提示ppp2r1a敲除导致肝损伤.纯合子血糖水平[（4.20±1.99）mmol/L]低于野生型[（8.88±0.65）mmol/L]（P〈0.05）,而总胆固醇、HDL-C和β-羟基丁酸（β-HB）水平[（3.12±0.39）、（1.53±0.38）和（2.49±0.89）mmol/L]均高于野生型小鼠[（1.69± 0.92）、（0.78±0.50）和（0.45±0.30）mmol/L]（P值均〈0.05）,表明ppp2r1a敲除会扰乱葡萄糖和胆固醇代谢.此外,纯合子小鼠白细胞计数（WBC）和淋巴细胞计数[（1.88±0.89）×10^9/L和（0.92±0.37�
Objective Investigate the effects of inducible ppp2r1a knockout on main physiological function in adult mice and study the mechanism.Methods Ppp2r1aflox/floxmice and CAGG-CreER mice were hybridized to obtain 20 CAGG-CreER ppp2r1aflox/floxand 20 mice in homozygous group.Two groups of mice were divided into 4 groups respectively,finally we got 8 groups with 5 mice in each group.Tamoxifen was injected intraperitoneally to acquire inducible ppp2r1a knockout mice.The knockout efficiency of PP2A Aα in vital organs was measured by Western blot. At 0, 2, 4 and 6 days after injection, we measured body weight, histopathological change, peripheral blood cell counts and blood biochemical. Real-time PCR was performed to measure expression of liver glucolipid metabolism genes. Results After tamoxifen injection for 6 days,the knockout efficiency of PP2A Aα in vital organs was 35%,12%,15%,60%,69% and 72%, respectively in heart,liver,spleen,lung,kidney and brain.After tamoxifen injection for 6 days,the weight of homozygous mice was lower than that of wild type mice,with values of（17.42±1.76）g and（21.69±1.82）g, respectively（P〈0.05）.Moreover,the activity level,abdominal and renal fat were significantly decreased in homozygous mice.Homozygous mice survived no more than 7 days.Compared with wild type mice,the organ coefficient of spleen of homozygous mice was decreased at the 6th day, with values of （0.59 ± 0.10）% and （0.36±0.05）% respectively （P〈0.05）. Obvious spleen atrophy and marked decrease of nucleated cells were showed by performing HE staining.Tunel staining revealed increased apoptosis ratio of splenic lymphocytes in homozygous mice. The levels of alanine aminotransferase （ALT） and aspartate transaminase （AST） of homozygous mice were higher than wild type mice （P〈0.05）. The values of ALT and AST in homozygous mice were （153.68 ± 62.80） U/L and （193.2 ± 44.28） U/L. The corresponding values in wild type mice were （41.02±12.91）U/L and（69.40±9.55）U/L.The above r
作者
樊俊灵
王方萍
王珊
柳晓玲
吴小嫩
陈雯
陈丽萍
李文学
Fan Junling, Wang Fangping, Wang Shan, Liu Xiaoling, Wu Xiaonen, Chen Wen, Chen Liping, Li Wenxue.(Faculty of Preventive Medicine, School of Public Health, Sun Yat-sen University, Guangzhou Key Laboratory of Environmental Pollution and Health Risk Assessment, Guangzhou 510080, Chin)
出处
《中华预防医学杂志》
CAS
CSCD
北大核心
2018年第5期530-537,共8页
Chinese Journal of Preventive Medicine
基金
广东省自然科学基金（2014A030313653）
国家自然科学基金青年项目（31401213）
关键词
小鼠
表型
蛋白磷酸酶2A
诱导性基因敲除
糖脂代谢紊乱
Mice
Phenotype
Protein phosphatase 2A
Inducible gene knockout
Glucose and lipid metabolism disorder
