卡托普利对异丙肾上腺素诱导心力衰竭大鼠肠道菌群的影响

Effect of captopril on gut microbiota in isoproterenol-induced heart failure rats

目的 通过16S rRNA测序观察卡托普利对异丙肾上腺素(ISO)诱导慢性心衰大鼠肠道菌群的影响。方法 将26只大鼠分为造模组20只和对照组(CON组)6只,造模组大鼠使用5 mg/kg ISO皮下注射制备慢性心衰大鼠模型,CON组大鼠使用生理盐水皮下注射,持续14 d。最后,共有12只大鼠达到了慢性心衰大鼠模型成模标准,并分成模型组(MOD组)6只和卡托普利组(CAP组)6只。造模后,CON组和MOD组大鼠予以10 mL/kg蒸馏水灌胃,CAP组予以8.8 mg/kg的卡托普利片灌胃,连续15 d。给药结束后,采用超声心动图测量3组大鼠左室射血分数(LVEF)和左室短轴缩短率(LVFS),ELISA法检测血清氨基末端脑钠肽前体(NT-proBNP)水平,对心肌组织进行病理检查,收集肠道内容物提取细菌总DNA进行16S rRNA测序。结果 与CON组比较,MOD组LVEF(t=13.687,P<0.001)和LVFS(t=14.834,P<0.001)显著下降,血清NT-proBNP(t=-6.002,P<0.001)、心脏质量指数(t=-5.816,P<0.001)和左心室质量指数(t=-7.303,P<0.001)显著升高。经卡托普利治疗后,LVEF(t=-8.123,P<0.001)和LVFS(t=-6.968,P<0.001)显著升高,血清NT-proBNP(t=2.512,P=0.013)、心脏质量指数(t=4.235,P=0.002)和左心室质量指数(t=2.912,P=0.006)显著降低。HE染色显示MOD组心肌细胞体积明显增大且排列紊乱,伴随大量纤维结缔组织增生,经卡托普利治疗后纤维结缔组织和炎症细胞较MOD组大鼠明显减少。测序结果显示,CON组和MOD组在Shannon指数和Chao1指数无明显差异(P>0.05),经卡托普利干预后,CAP组的Shannon指数(t=-5.806,P<0.001)和Chao1指数(t=-6.100,P=0.001)较MOD组均明显升高。PCoA结果显示,CON组、MOD组和CAP组的肠道菌群有差异。在属水平上,与CON组比较,MOD组乳酸杆菌属(t=2.336,P=0.026)和Allobaculum(t=4.296,P=0.020)的相对丰度显著下降,Clostridium_sensu_stricto_1(t=-2.729,P=0.007)的相对丰度显著升高。与MOD组比较,CAP组Clostridium_sensu_stricto_1相对丰度显著下降(t=2.099,P=0.022),Allobaculum相对丰度显著升高(t=-4.361,P=0.022)。结论 卡托普利对慢性心衰大鼠心功能有显著的改善作用,可调节肠道菌群Clostridium_sensu_stricto_1和Allobaculum的相对丰度。

Objective To observe the effect of captopril on the intestinal flora of rats with isoproterenol(ISO)-induced chronic heart failure(CHF) by using 16S rRNA sequencing.Methods Twenty-six rats were divided into a modeling group(20 rats) and a control group(CON group,6 rats).The rats in the modeling group were injected subcutaneously 5mg/kg ISO to prepare a chronic heart failure model,while those in the CON group were injected with normal saline,for 14days.Finally,12 rats met the criteria for CHF rat model and were divided into a model group(MOD group,6 rats) and a captopril group(CAP group,6 rats).After modeling,the rats in the CON group and MOD group were given 10 mL/kg distilled water by gavage,while the CAP group was given 8.8 mg/kg captopril tablets by gavage for 15 consecutive days.After the administration,echocardiography was used to measure the left ventricular ejection fraction(LVEF) and left ventricular short-axis shortening(LVFS) of the three groups of rats,and the level of serum NT-proBNP(N-terminal probrain natriuretic peptide) was detected with ELISA.The pathological examination of myocardial tissue was performed,and intestinal contents were collected to extract total bacterial DNA for 16S rRNA sequencing.Results Compared with the CON group,the LVEF(t=13.687,P<0.001) and LVFS(t=14.834,P<0.001) of rats in the MOD group significantly decreased,and the level of serum NT-proBNP(t=-6.002,P<0.001),heart mass index(t=-5.816,P<0.001) and left ventricular mass index(t=-7.303,P<0.001) significantly increased.After treatment with captopril,the LVEF(t=-8.123,P<0.001) and LVFS(t=-6.968,P<0.001) significantly increased,and the level of NT-proBNP(t=2.512,P=0.013),heart mass index(t=4.235,P=0.002) and left ventricular mass index(t=2.912,P=0.006) significantly decreased.HE staining showed that the cardiomyocytes in the MOD group significantly increased in size and were disordered,accompanied by a large amount of fibrous connective tissue proliferation.After captopril treatment,the fibrous connective tissue and inflammatory cells significantly reduced compared with the MOD group.The sequencing results showed that there were no significant differences in the Shannon index and Chao1 index between the CON group and MOD group(P>0.05).After captopril intervention,the Shannon index(t=-5.806,P<0.001) and Chao1 index(t=-6.100,P=0.001) in the CAP group were significantly higher than those in the MOD group.The PCoA results showed that there were certain differences in the intestinal flora among the three groups.At the genus level,compared with the CON group,the relative abundances of Lactobacillus(t=2.336,P=0.026) and Allobaculum(t=4.296,P=0.020) in the MOD group significantly decreased,while that of Clostridium_sensu_stricto_1 increased significantly(t=-2.729,P=0.007).Compared with the MOD group,the relative abundance of Clostridium_sensu_stricto_1 in the CAP group significantly decreased(t=2.099,P=0.022) while that of Allobaculum increased significantly(t=-4.361,P=0.022).Conclusion Captopril can significantly improve cardiac function in rats with chronic heart failure and regulate the relative abundance of Clostridium_sensu_stricto_1 and Allobaculum in intestine.