Huffman Lynn C, Koch Sheryl E, Butler Karyn L
Department of Surgery, Division of Trauma/Critical Care, Institute of Molecular Pharmacology and Biophysics, University of Cincinnati, 231 Albert B. Sabin Way, Cincinnati, OH 45267-0828, USA.
Am J Physiol Heart Circ Physiol. 2008 Jan;294(1):H257-62. doi: 10.1152/ajpheart.00769.2007. Epub 2007 Nov 2.
Preconditioning (PC) protects against ischemia-reperfusion (I/R) injury via the activation of the JAK-STAT pathway. We hypothesized that the mediators responsible for PC can be transferred to naive myocardium through the coronary effluent. Langendorff-perfused hearts from male Sprague-Dawley rats were randomized to paired donor/acceptor protocols with or without PC in the presence or absence of the JAK-2 inhibitor AG-490 (n = 6 for each group). Warmed, oxygenated coronary effluent collected during the reperfusion phases of PC (3 cycles of 5 min ischemia and 5 min reperfusion) was administered to acceptor hearts. The hearts were then subjected to 30 min ischemia and 40 min reperfusion. The left ventricles were analyzed for phosphorylated (p)STAT-1, pSTAT-3, Bax, Bcl, Bcl-X(L)/Bcl-2-associated protein (BAD), and caspase-3 expression by Western blot. A separate group of hearts (n = 6) was analyzed for STAT activation immediately after the transfer of the PC effluent (no I-R). Baseline cardiodynamics were not different among the groups. End-reperfusion maximal change in pressure over time (+dP/dt(max)) was significantly (P < 0.05) improved in acceptor PC (3,637 +/- 199 mmHg/s) and donor PC (4,304 +/- 347 mmHg/s) hearts over non-PC donor (2,020 +/- 363 mmHg/s) and acceptor (2,624 +/- 345 mmHg/s) hearts. Similar differences were seen for minimal change in pressure over time (-dP/dt(min)). STAT-3 activation was significantly increased in donor and acceptor PC hearts compared with non-PC hearts. Conversely, pSTAT-1 and Bax expression was decreased in donor and acceptor PC hearts compared with non-PC hearts. No differences in Bcl, BAD, or caspase-3 expression were observed. Treatment with AG-490 attenuated the recovery of +/-dP/dt in acceptor PC hearts and significantly reduced pSTAT-3 expression. The PC coronary effluent activates JAK-STAT signaling, limits apoptosis, and protects myocardial performance from I/R injury.
预处理（PC）通过激活JAK-STAT信号通路来保护心肌免受缺血再灌注（I/R）损伤。我们推测，负责预处理的介质可通过冠状动脉流出液转移至未处理的心肌。将雄性Sprague-Dawley大鼠的Langendorff灌注心脏随机分为配对的供体/受体组，在有或无JAK-2抑制剂AG-490的情况下进行或不进行预处理（每组n = 6）。在预处理的再灌注阶段（5分钟缺血和5分钟再灌注的3个周期）收集温热、充氧的冠状动脉流出液，并注入受体心脏。然后使心脏经历30分钟缺血和40分钟再灌注。通过蛋白质免疫印迹法分析左心室中磷酸化（p）STAT-1、pSTAT-3、Bax、Bcl、Bcl-X(L)/Bcl-2相关蛋白（BAD）和半胱天冬酶-3的表达。在转移预处理流出液后（无I/R），立即对另一组心脏（n = 6）进行STAT激活分析。各组之间的基线心脏动力学无差异。与未预处理的供体（2,020 +/- 363 mmHg/s）和受体（2,624 +/- 345 mmHg/s）心脏相比，预处理受体（3,637 +/- 199 mmHg/s）和预处理供体（4,304 +/- 347 mmHg/s）心脏在再灌注结束时压力随时间的最大变化（+dP/dt(max)）显著改善（P < 0.05）。压力随时间的最小变化（-dP/dt(min)）也有类似差异。与未预处理的心脏相比，预处理供体和受体心脏中的STAT-3激活显著增加。相反，与未预处理的心脏相比，预处理供体和受体心脏中的pSTAT-1和Bax表达降低。未观察到Bcl、BAD或半胱天冬酶-3表达的差异。用AG-490处理可减弱预处理受体心脏中+/-dP/dt的恢复，并显著降低pSTAT-3表达。预处理冠状动脉流出液可激活JAK-STAT信号，限制细胞凋亡，并保护心肌功能免受I/R损伤。
