2026 年第 9 期 第 21 卷

混合谱系激酶3对血管紧张素Ⅱ诱导的高血压小鼠心脏重塑的抑制作用

Inhibitory effect of mixed lineage kinase 3 on angiotensin Ⅱ-induced cardiac remodeling in hypertensive mice

作者：田烨璇高诗娟李玉琳

英文作者：Tian Yexuan Gao Shijuan Li Yulin

单位：首都医科大学附属北京安贞医院北京市心肺血管疾病研究所心血管生物学研究室，北京100029

英文单位：Laboratory of Cardiovascular Biology Beijing Institute of Heart Lung and Blood Vessel Diseases Beijing Anzhen Hospital Capital Medical University Beijing 100029 China

关键词：高血压；心脏重塑；纤维化；混合谱系激酶3

英文关键词：Hypertension;Cardiacremodeling;Fibrosis;Mixedlineagekinase3

• 摘要：

• 目的 研究混合谱系激酶3（MLK3）对血管紧张素Ⅱ（AngⅡ）诱导的高血压小鼠模型心脏重塑的抑制作用。方法 选取无特定病原体级10～12周龄雄性C57BL/6J野生型（WT）及Mlk3基因敲除（Mlk3KO）小鼠各12只，根据基因型及处理方式将小鼠随机分为4组：WT+生理盐水组、WT+AngⅡ组、Mlk3KO+生理盐水组和Mlk3KO+AngⅡ组，每组6只。WT+AngⅡ组和Mlk3KO+AngⅡ组通过皮下植入渗透压缓释泵持续输注AngⅡ，剂量为1 000 ng/（kg·min），持续给药28 d，构建高血压模型。WT+生理盐水组和Mlk3KO+生理盐水组输注等体积生理盐水。尾套法检测小鼠收缩压及舒张压；小动物超声评估心功能；麦胚凝集素荧光染色检测心肌细胞横截面积；Masson三色染色法量化心肌胶原沉积；实时荧光定量逆转录聚合酶链反应技术检测小鼠心脏组织中心肌肥大标志基因［心房钠尿肽（Anp）、肌球蛋白重链7（Myh7）］以及纤维化标志基因［Ⅰ型胶原蛋白α1链（Col1a1）、Ⅲ型胶原蛋白α1链（Col3a1）］mRNA表达水平。结果 与WT+生理盐水组相比，WT+AngⅡ组小鼠收缩压与舒张压均显著升高，左心室射血分数（LVEF）和左心室短轴缩短率（LVFS）均降低，心脏质量指数、心肌细胞横截面积、心肌间质纤维化面积均增加，心肌肥大标志基因Anp、Myh7及纤维化标志基因Col1a1、Col3a1的mRNA表达水平均上调（均P＜0.05），提示AngⅡ诱导的高血压心脏重塑模型构建成功。与WT+生理盐水组相比，Mlk3KO+生理盐水组小鼠收缩压与舒张压升高（均P＜0.05），提示Mlk3基因缺失可升高基础血压水平。与WT+AngⅡ组相比，Mlk3KO+AngⅡ组小鼠收缩压与舒张压进一步升高［（175±5）mmHg（1 mmHg=0.133 kPa）比（154±10）mmHg、（119±6）mmHg比（105±5）mmHg］，LVEF和LVFS进一步降低，心脏质量指数增大，心肌细胞横截面积增加，Anp和Myh7的mRNA表达水平升高；同时，心肌间质纤维化面积增加，Col1a1和Col3a1的mRNA表达水平升高（均P＜0.05）。结论 Mlk3KO加剧AngⅡ诱导的高血压小鼠病理性心脏重塑。

• Objective To investigate the inhibitory effect of mixed lineage kinase 3 (MLK3) on angiotensin Ⅱ (AngⅡ)-induced cardiac remodeling in a hypertensive mouse model. Methods Twelve specific pathogen-free male C57BL/6J wild-type (WT) mice and twelve Mlk3 knockout (Mlk3KO) mice aged 10-12 weeks were selected. The mice were randomly divided into four groups according to genotype and treatment: WT+normal saline group, WT+AngⅡ group, Mlk3KO+normal saline group and Mlk3KO+AngⅡ group, with 6 mice in each group. Mice in the WT+AngⅡ group and Mlk3KO+AngⅡ group received continuous infusion of AngⅡ at a dose of 1 000 ng/(kg·min) for 28 d via subcutaneously implanted osmotic minipumps to establish the hypertension model. Mice in the WT+normal saline group and Mlk3KO+normal saline group were infused with an equal volume of normal saline. Tail-cuff method was used to detect systolic and diastolic blood pressure; small-animal echocardiography was applied to evaluate cardiac function; wheat germ agglutinin fluorescence staining was performed to detect cardiomyocyte cross-sectional area; Masson′s trichrome staining was used to quantify myocardial collagen deposition; real-time fluorescent quantitative reverse transcription polymerase chain reaction was adopted to detect the mRNA expression levels of myocardial hypertrophy marker genes ［atrial natriuretic peptide (Anp), myosin heavy chain 7 (Myh7)］ and fibrosis marker genes ［collagen type Ⅰ α1 chain (Col1a1), collagen type Ⅲ α1 chain (Col3a1)］ in mouse cardiac tissues. Results Compared with the WT+normal saline group, the WT+AngⅡ group exhibited significantly elevated systolic and diastolic blood pressure, decreased left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS), increased cardiac mass index, enlarged cardiomyocyte cross-sectional area and myocardial interstitial fibrosis area, as well as upregulated mRNA expression of hypertrophy marker genes Anp, Myh7 and fibrosis marker genes Col1a1, Col3a1 (all P＜0.05), indicating successful establishment of the AngⅡ-induced hypertensive cardiac remodeling model. Compared with the WT+normal saline group, the Mlk3KO+normal saline group showed elevated systolic and diastolic blood pressure (both P＜0.05), suggesting that Mlk3 gene deletion could increase basal blood pressure. Compared with the WT+AngⅡ group, the Mlk3KO+AngⅡ group presented further elevated systolic and diastolic blood pressure ［(175±5)mmHg (1 mmHg=0.133 kPa) vs (154±10)mmHg, (119±6)mmHg vs (105±5)mmHg］, further reduced LVEF and LVFS, increased cardiac mass index, enlarged cardiomyocyte cross-sectional area, and elevated mRNA expression of Anp and Myh7; meanwhile, myocardial interstitial fibrosis area was increased and mRNA expression of Col1a1 and Col3a1 was upregulated (all P＜0.05). Conclusions Mlk3KO exacerbates AngⅡ-induced pathological cardiac remodeling in hypertensive mice.