摘要
目的肥厚预适应(hypertrophic preconditioning,HP)是新近在小鼠模型上发现的一种抑制心肌肥厚的保护机制。但这一小鼠模型由于反复开胸缩窄/去缩窄主动脉,面临胸腔探查时间长、小鼠死亡率高等问题,制约了对HP进行在体水平的深入研究。我们拟对HP模型构建的关键环节进行改良,并使用超声生物显微镜无创评估心脏负荷程度,以确保模型的稳定高效建立。方法将雄性C57BL/6J小鼠(10~14周龄)分为肥厚预适应传统操作组(C‑HP组,N=40),肥厚预适应改良操作组(O‑HP组,N=40,留置长线头埋于胸廓皮下,使用显微镊解开缩窄线结),主动脉缩窄组(TAC组,N=20)及假手术组(Sham组,N=20)。各组最后一次术后4周,存活小鼠行超声生物显微镜以及心脏病理切片评估心脏肥大程度。超声检测室壁厚度和心腔内径。超声检查后对小鼠行安乐死取心脏,测量心脏重量/体重比,行病理切片检测心肌细胞横截面积和纤维化程度。结果在去缩窄和再缩窄过程中,O‑HP组较C‑HP组明显缩短手术时间,降低围手术期(从实验开始到手术结束6h)死亡率。再缩窄术后4周,O‑HP组小鼠存活率为67.5%(27/40),高于C‑HP组小鼠的37.5%(15/40),差别有统计学意义(P=0.007)。超声生物显微镜无创性检测主动脉缩窄处血流发现,O‑HP组与C‑HP组的缩窄处血流峰值在缩窄‑去缩窄‑再缩窄等关键环节的变化趋势类似,对HP模型进行改良不影响心脏承受的压力负荷水平。与Sham组小鼠对比,主动脉缩窄4周组(TAC 4W组)小鼠心室壁增厚、心功能受损、心肌细胞横截面积增大,纤维化增加,差别有统计学意义(P均<0.05)。主动脉再缩窄4周组(Re‑TAC 4W组)小鼠上述肥大反应明显减轻。此外,Re‑TAC 4W组小鼠与TAC 4W组小鼠相比,心房利钠肽及B型利钠肽表达减少,细胞外信号调节激酶(ERK1/2)激活程度明显减轻。结论我们成功构建优化并无创验证了一种心肌HP�
Objective Hypertrophic preconditioning(HP)was recently found to attenuate cardiac hypertrophy in the mouse.However,this mouse model of HP has encountered problems such as long thoracic exploration time and high mortality due to repeated thoracotomy and multiple banding/de‑banding of the aorta,which restricts the in‑depth study of HP in vivo.We intended to optimize the key aspects of establishment of HP and apply ultrasound biomicroscopy to non‑invasively assess cardiac load to ensure stable and efficient model establishment.Methods Male C57BL/6J mice(10‑14 weeks old)were divided into hypertrophic preconditioning conventional operation group(C‑HP,N=40),hypertrophic preconditioning optimized operation group(O‑HP,N=40,with long thread buried under the chest skin,and releasing the banding knot by microscopic tweezers),transverse aortic constriction(TAC)group(TAC,N=20),and sham operation group(Sham,N=20).Four weeks after the last operation in each group,the surviving mice underwent ultrasound biomicroscopy and pathological examination to assess cardiac hypertrophy.Echocardiography was used to detect wall thickness and left ventricular inner diameter.After ultrasound examination,the mice were euthanized,hearts were excised,and heart weight/body weight ratio was measured.The pathological section was used to measure the cross sectional area of the myocardial cells and cardiac fibrosis.Results In the process of de‑banding and re‑banding,O‑HP significantly shortens the operation time and reduces the mortality rate compared with C‑HP.Four weeks after re‑banding,the survival rate of mice in the O‑HP group was 67.5%(27/40),which was signficantly higher than that in the C‑HP group of 37.5%(15/40)(P=0.007).Non‑invasive detection of blood flow in the aortic constriction by ultrasound biomicroscopy revealed that the peak velocity of blood flow at the banding site in the O‑HP group and C‑HP were similar in the key points of banding‑de‑banding‑re‑banding,suggesting that the optimization of th
作者
吴剑
代方杰
黄家园
李璇
胡耀方
殷培培
杨春杰
李冰玉
张真中
游洁芸
王时俊
邹云增
Wu Jian;Dai Fangjie;Huang Jiayuan;Li Xuan;Hu Yaofang;Yin Peipei;Yang Chunjie;Li Bingyu;Zhang Zhenzhong;You Jieyun;Wang Shijun;Zou Yunzeng(Shanghai Institute of Cardiovascular Diseases,Zhongshan Hospital and Institutes of Biomedical Sciences,Fudan University,Shanghai 200032,China;Departement of Oncology,Southern Theater Air Force Hospital,Guangzhou 510062,China;Oriental Hospital of Shanghai(Oriental Hospital Affiliated to Tongji University),Shanghai,200120,China)
基金
国家自然科学基金(31430039,81670228)
上海市科委实验动物研究专项项目(16140901100)
上海市卫计委科研课题面上项目(201640044)
中山医院人才基金(No.014)
中山医院优秀青年计划(2017ZSYXQN09)
关键词
压力超负荷
肥厚预适应
优化
小鼠
Pressure overload
Hypertrophic preconditioning
Optimization
Mouse
