2015年3月11日訊 /生物谷BIOON/ --近日,來自德國的科學家在著名國際期刊nature medicine在線發表了他們的最新研究進展,他們發現Reg3β對於巨噬細胞向心肌損傷部位遷移具有重要調控作用,Reg3β缺失會嚴重影響心肌損傷部位的巨噬細胞累積,阻礙心肌修復過程。
心肌缺血後的心肌癒合依賴於對骨髓細胞尤其是巨噬細胞的招募和局部擴張。研究人員發現Reg3β對於巨噬細胞向心肌損傷部位的遷移具有非常重要的調控作用。通過基於質譜(MS)的分泌蛋白組分析發現去分化的心肌細胞能夠釋放Reg3β對細胞因子OSM進行應答,OSM能夠激活細胞內的JAK1和STAT3信號通路。Reg3β缺失會導致心臟缺血部位的巨噬細胞數目大量下降,同時伴隨心室擴張和對中性粒細胞的清除不足,對中性粒細胞清除不充分會引起基質降解增強,延緩膠原沉積,同時增加心臟破裂的敏感性。
研究證明OSM能夠通過細胞內不同信號通路發揮作用,調節心肌細胞去分化和心肌依賴性的巨噬細胞遷移。浸潤性中性粒細胞和巨噬細胞釋放的OSM能夠誘導一個正反饋迴路:OSM誘導心肌細胞產生Reg3β,吸引更多具有OSM分泌功能的巨噬細胞。這一反饋迴路的活性能夠控制心臟巨噬細胞的積累程度,對心肌修復具有重要意義。
綜上所述,該項研究發現了Reg3β在心肌修復過程中對巨噬細胞遷移和積累的重要調控作用,對預防和治療相關心臟疾病具有重要意義。(生物谷Bioon.com)
Myocardial healing requires Reg3β-dependent accumulation of macrophages in the ischemic heart
Holger Lorchner,Jochen P?ling,Praveen Gajawada,Yunlong Hou,Viktoria Polyakova, Sawa Kostin,Juan M Adrian-Segarra,Thomas Boettger,Astrid Wietelmann,Henning Warnecke,Manfred Richter,Thomas Kubin& Thomas Braun
Cardiac healing after myocardial ischemia depends on the recruitment and local expansion of myeloid cells, particularly macrophages. Here we identify Reg3β as an essential regulator of macrophage trafficking to the damaged heart. Using mass spectrometry-based secretome analysis, we found that dedifferentiating cardiomyocytes release Reg3β in response to the cytokine OSM, which signals through Jak1 and Stat3. Loss of Reg3β led to a large decrease in the number of macrophages in the ischemic heart, accompanied by increased ventricular dilatation and insufficient removal of neutrophils. This defect in neutrophil removal in turn caused enhanced matrix degradation, delayed collagen deposition and increased susceptibility to cardiac rupture. Our data indicate that OSM, acting through distinct intracellular pathways, regulates both cardiomyocyte dedifferentiation and cardiomyocyte-dependent regulation of macrophage trafficking. Release of OSM from infiltrating neutrophils and macrophages initiates a positive feedback loop in which OSM-induced production of Reg3β in cardiomyocytes attracts additional OSM-secreting macrophages. The activity of the feedback loop controls the degree of macrophage accumulation in the heart, which is instrumental in myocardial healing.