Sakiyama Shoji, dePerrot Marc, Han Bing, Waddell Thomas K, Keshavjee Shaf, Liu M
University Health Network Toronto General Hospital, Department of Surgery, University of Toronto, Toronto, Ontario, Canada.
J Heart Lung Transplant. 2003 Mar;22(3):338-46. doi: 10.1016/s1053-2498(02)00553-3.
Dramatic alterations of protein tyrosine phosphorylation have been found during the ischemia-reperfusion (IR) period of human lung transplantation. IR also induces activation of p38 mitogen-activated protein kinase (p38) in the heart and kidney. The objective of the present study was to determine whether these changes exist in a rat single-lung transplant model for further mechanistic investigations.
Isogeneic lung transplantation was performed from Lewis (LEW) to LEW rats, whereas allogeneic transplantation was from LEW to Brown Norway (BN) rats. Blood gases and peak airway pressure were monitored. Lung tissues were collected after 6 hours of cold ischemic preservation, after 30 minutes of warm ischemia for lung implantation, and after 2 hours of reperfusion. Protein tyrosine kinase (PTK) and phosphatase (PTP) activities were measured. Protein tyrosine phosphorylation, Src PTK and p38 expression and p38 phosphorylation were examined by western blotting.
In both iso- and allografts, the lung function of transplants was very well preserved. Protein tyrosine phosphorylation, PTK and PTP activities were decreased significantly after 2 hours of reperfusion. Src protein level and phosphorylation of p38 were reduced after 2 hours of reperfusion.
During the early IR period of lung transplantation, decreased protein tyrosine phosphorylation may be involved in apoptosis and other biologic changes. The lack of p38 activation suggests that activity of mitogen-activated protein kinase pathways in the lung transplantation setting may be different from other IR processes.
在人类肺移植的缺血再灌注（IR）期间，已发现蛋白质酪氨酸磷酸化发生显著改变。IR还会诱导心脏和肾脏中的p38丝裂原活化蛋白激酶（p38）激活。本研究的目的是确定在大鼠单肺移植模型中是否存在这些变化，以便进行进一步的机制研究。
从Lewis（LEW）大鼠到LEW大鼠进行同基因肺移植，而从LEW大鼠到Brown Norway（BN）大鼠进行异基因移植。监测血气和气道峰值压力。在冷缺血保存6小时后、肺植入温缺血30分钟后以及再灌注2小时后收集肺组织。测量蛋白质酪氨酸激酶（PTK）和磷酸酶（PTP）活性。通过蛋白质印迹法检测蛋白质酪氨酸磷酸化、Src PTK和p38表达以及p38磷酸化。
在同基因和异基因移植中，移植肺的功能均得到很好的保留。再灌注2小时后，蛋白质酪氨酸磷酸化、PTK和PTP活性显著降低。再灌注2小时后，Src蛋白水平和p38磷酸化降低。
在肺移植的早期IR期间，蛋白质酪氨酸磷酸化降低可能参与细胞凋亡和其他生物学变化。缺乏p38激活表明肺移植环境中丝裂原活化蛋白激酶途径的活性可能与其他IR过程不同。
