蓝斑核促肾上腺皮质激素释放激素系统对肠易激综合征大鼠内脏敏感性的影响  

Activation of corticotropin-releasing hormone system in the locus ceruleus induces the visceral sensitivity of irritable bowel syndrome rats

作　　者：王曦[1] 李蒙[1] 胡玥[1] 戴春艳 傅宇斐 金威洋 陈喆[1] 吕宾[1] Wang Xi;Li Meng;Hu Yue;Dai Chunyan;Fu Yufei;Jin Weiyang;Chen Zhe;Lyu Bin(Key Laboratory of Digestive Pathophysiology of Zhejiang Province,The First Affiliated Hospital of Zhejiang Chinese Medical University,Hangzhou 310006,China;College of Life and Environmental Sciences,Hangzhou Normal University,Hangzhou 310036,China)

机构地区：[1]浙江中医药大学附属第一医院浙江省消化道疾病病理生理研究重点实验室,杭州310006 [2]杭州师范大学生命与环境科学学院,310036

出　　处：《中华消化杂志》2020年第1期40-44,共5页Chinese Journal of Digestion

基　　金：国家自然科学基金(81400594、81503297、81603340、81600426、81770535、81773945)。

摘　　要：目的研究中枢蓝斑区促肾上腺皮质激素释放激素(CRH)系统在IBS中的作用,探索影响其改变的分子机制。方法采用母婴分离联合出生后复合应激构建大鼠IBS模型,后采用脑核团微取样的方法获得大鼠蓝斑区的组织样本。应用实时荧光定量PCR技术检测对照组和IBS组大鼠蓝斑核内细胞癌基因Fos(c-Fos),以及CRH和其相应受体促肾上腺皮质激素释放激素受体(CRHR)1、CRHR2的mRNA表达;同时检测DNA甲基转移酶(DNMT)1、DNMT3a和DNMT3b的mRNA表达;采用蛋白质印迹法检测组蛋白甲基转移酶——ASH2样蛋白(ASH2L),以及SET核癌基因和MYND域2蛋白(SMYD2)的表达。统计学分析采用t检验。结果IBS组的直肠充气压低于对照组[(69.82±5.47)mmHg比(86.86±5.98)mmHg(1 mmHg=0.133 kPa)],c-Fos基因的mRNA水平较对照组升高(2.11±0.44比1.00±0.19),CRH的mRNA水平较对照组升高(1.99±0.35比1.00±0.13),SMYD2的蛋白表达水平较对照组上调(1.04±0.21比0.61±0.12),差异均有统计学意义(t=6.215、2.321、2.797、4.451,P均<0.05)。IBS组大鼠CRHR1、CRHR2、DNMT1、DNMT3a、DNMT3b的mRNA水平以及ASH2L的表达与对照组比较(分别为0.96±0.13比1.00±0.26、1.35±0.63比1.00±0.43、1.40±0.61比1.00±0.19、1.39±0.58比1.00±0.21、1.45±0.71比1.00±0.39和0.80±0.19比1.05±0.26),差异均无统计学意义(P均>0.05)。结论母婴分离联合出生后复合应激通过影响蓝斑核内Crh基因的转录进而造成CRH系统和去甲肾上腺能系统应激调控网络的激活,导致大鼠内脏敏感性增加。Crh基因转录异常可能与SMYD2介导的组蛋白H3K36的甲基化有密切关系,而与DNA的甲基化修饰无关。Objective To study the role of corticotropin-releasing hormone(CRH)system in locus ceruleus(LC)in irritable bowel syndrome(IBS)and to explore its molecular mechanism.Methods The IBS rat was established by maternal separation following with postnatal stress.The tissues sample of LC was obtained by micropunched nuclei.The expression of c-Fos,CRH and its receptors including corticotropin-releasing hormone receptor(CRHR)1 and CRHR2 of rats’LC tissues of control group and IBS group was detected by quantitative polymerase chain reaction(PCR).The expression of DNA methyltransferase(DNTM)1,DNMT3a and DNMT3b at the mRNA level were also measured.In addition,the expression of histone methyltransferase ASH2-like protein(ASH2L)and SET and MYND domain containing 2(SMYD2)was determined by Western blotting.T test was used for statistical analysis.Results The rectal pneumatic pressure of IBS group was lower than that of control group((69.82±5.47)mmHg vs.(86.86±5.98)mmHg;1 mmHg=0.133 kPa),however compared with that of control group,the expression of c-Fos at the mRNA level increased(2.11±0.44 vs.1.00±0.19),and the differences were statistically significant(t=6.215 and 2.321,P<0.01 and 0.05).In addition,compared with that of control group,the expression of CRH at the mRNA level increased(1.99±0.35 vs.1.00±0.13),and the difference was statistically significant(t=2.797,P<0.05).Compared with that of control group,the expression of SMYD2 at the protein level up-regulated(1.04±0.21 vs.0.61±0.12),and the difference was statistically significant(t=4.451,P<0.01).However,there were no statistically significant differences in the expression of CRHR-1,CRHR2,DNMT1,DNMT3a,DNMT3b at the mRNA level,and the expression of ASH2L between IBS group and control group(0.96±0.13 vs.1.00±0.26,1.35±0.63 vs.1.00±0.43,1.40±0.61 vs.1.00±0.19,1.39±0.58 vs.1.00±0.21,1.45±0.71vs.1.00±0.39 and 0.80±0.19 vs.1.05±0.26,respectively;all P>0.05).Conclusions Maternal separation combined with postnatal stress affect the transcription of Crh gene in

关 键 词：肠易激综合征 蓝斑 母婴分离应激 促肾上腺皮质激素释放激素系统 表观遗传学 

分 类 号：R574.4[医药卫生—消化系统]