Ni Yingying, Liang Degang, Tian Yikui, Kron Irving L, French Brent A, Yang Zequan
Department of Cardiovascular Surgery, Tianjin Medical University General Hospital, Tianjin, P.R. of China.
Department of Cardiovascular Surgery, Tianjin Medical University General Hospital, Tianjin, P.R. of China.
J Surg Res. 2018 Dec;232:442-449. doi: 10.1016/j.jss.2018.06.042. Epub 2018 Jul 23.
Adenosine A2B receptor (AAR) agonist reduces myocardial reperfusion injury by acting on inflammatory cells. Recently, a cardiosplenic axis was shown to mediate the myocardial postischemic reperfusion injury. This study aimed to explore whether the infarct-squaring effect of AAR agonist was primarily due to its action on splenic leukocytes.
C57BL6 (wild type [WT]) mice underwent 40 min of left coronary artery occlusion followed by 60 min of reperfusion. AAR knockout (KO) and interleukin (IL)-10KO mice served as donors for splenic leukocytes. Acute splenectomy was performed 30 min before ischemia. The acute splenic leukocyte adoptive transfer was performed by injecting 5 × 10 live splenic leukocytes into splenectomized mice. BAY 60-6583, an AAR agonist, was injected by i.v. 15 min before ischemia. The infarct size (IS) was determined using 2,3,5-triphenyltetrazolium chloride and Phthalo blue staining. The expression of p-Akt and IL-10 was estimated by Western blotting. Immunofluorescence staining assessed the localization of IL-10 expression.
BAY 60-6583 reduced the myocardial IS in intact mice but failed to reduce the same in splenectomized mice, which had a smaller IS than intact mice. BAY 60-6583 reduced the IS in splenectomized mice with the acute transfer of WT splenic leukocytes; however, it did not protect the heart of splenectomized mice with the acute transfer of ARKO splenic leukocytes. Furthermore, BAY 60-6583 increased the levels of p-Akt and IL-10 in the WT spleen. Moreover, it did not exert any protective effect in IL-10KO mice.
AAR activation before ischemia stimulated the IL-10 production in splenic leukocytes via a PI3K/Akt pathway, thereby exerting anti-inflammatory effects that limited the myocardial reperfusion injury.
腺苷A2B受体（AAR）激动剂通过作用于炎症细胞减轻心肌再灌注损伤。最近，心脾轴被证明可介导心肌缺血后再灌注损伤。本研究旨在探讨AAR激动剂的梗死面积缩小效应是否主要归因于其对脾白细胞的作用。
C57BL6（野生型[WT]）小鼠接受40分钟的左冠状动脉闭塞，随后再灌注60分钟。AAR基因敲除（KO）小鼠和白细胞介素（IL）-10基因敲除小鼠作为脾白细胞供体。在缺血前30分钟进行急性脾切除术。通过向脾切除小鼠注射5×10个活脾白细胞进行急性脾白细胞过继转移。在缺血前15分钟静脉注射AAR激动剂BAY 60-6583。使用2,3,5-三苯基氯化四氮唑和酞菁蓝染色测定梗死面积（IS）。通过蛋白质印迹法评估p-Akt和IL-10的表达。免疫荧光染色评估IL-10表达的定位。
BAY 60-6583可缩小完整小鼠的心肌梗死面积，但不能缩小脾切除小鼠的梗死面积，脾切除小鼠的梗死面积小于完整小鼠。BAY 60-6583可缩小急性转移野生型脾白细胞的脾切除小鼠的梗死面积；然而，它不能保护急性转移ARKO脾白细胞的脾切除小鼠的心脏。此外，BAY 60-6583可增加野生型脾脏中p-Akt和IL-10的水平。此外，它在IL-10基因敲除小鼠中未发挥任何保护作用。
缺血前激活AAR通过PI3K/Akt途径刺激脾白细胞产生IL-10，从而发挥抗炎作用，限制心肌再灌注损伤。
