背景:粒细胞集落刺激因子(G-CSF)是中性粒细胞浸润的关键介质,并且在肝脏中具有促纤维化作用,肺,和梗塞的心脏,但其在血管紧张素II(AngII)诱导的高血压和心脏重塑中的作用尚未完全确定。因此,我们试图研究G-CSF与C57BL/6J小鼠中性粒细胞募集和心肌纤维化之间的因果关系.
方法:在接受持续输注AngII(1,500ng/kg/min)的野生型(WT)小鼠中诱导高血压和心脏纤维化。7天后,心脏切片用苏木精和伊红染色,马森的三色,和免疫组织化学。通过实时聚合酶链反应分析检测细胞因子的mRNA表达。通过蛋白质印迹分析测量蛋白质水平。
结果:AngII输注后,心肌G-CSF表达在心脏中显著升高.此外,WT小鼠表现出血压升高,明显的中性粒细胞积累,促炎细胞因子表达,活性氧的产生,AngII输注7天后和心脏纤维化。然而,施用抗G-CSF中和抗体,但不是对照免疫球蛋白G,显著减弱了这些影响。此外,中和G-CSF抗体可逆转AngII诱导的心脏ERK1/2、STAT3和AKT信号通路激活.
结论:本研究表明,G-CSF在高血压和心肌纤维化中起关键作用,靶向该细胞因子可能是改善高血压性心脏病的一种新的治疗策略。
BACKGROUND: Granulocyte colony stimulating factor (G-CSF) is a key mediator of neutrophil infiltration and is profibrotic in the liver, lung, and infarcted heart, but its roles in angiotensin II (Ang II)-induced hypertension and cardiac remodeling have not been fully determined. Thus, we sought to investigate the causal relation of G-CSF to neutrophil recruitment and cardiac fibrosis in C57BL/6J mice.
METHODS: Hypertension and cardiac fibrosis were induced in wild-type (WT) mice receiving continuous infusion of Ang II (1,500ng/kg/min). After 7 days, heart sections were stained with hematoxylin and eosin, Masson\'s trichrome, and immunohistochemistry. The mRNA expression of cytokines was detected by real-time polymerase chain reaction analysis. The protein levels were measured by Western blot analysis.
RESULTS: After Ang II infusion, myocardial G-CSF expression was significantly elevated in the hearts. Moreover, WT mice exhibited increased blood pressure, marked neutrophil accumulation, proinflammatory cytokine expression, reactive oxygen species production, and cardiac fibrosis after 7 days of Ang II infusion. However, administration of anti-G-CSF neutralizing antibody, but not with control immunoglobulin G, significantly attenuated these effects. In addition, neutralizing G-CSF antibody reversed Ang II-induced activation of ERK1/2, STAT3, and AKT signaling pathways in the hearts.
CONCLUSIONS: This study demonstrates that G-CSF plays a critical role in hypertension and cardiac fibrosis and targeting this cytokine may be a novel therapeutic strategy to ameliorate hypertensive heart disease.