McCully James D, Cowan Douglas B, Pacak Christina A, Toumpoulis Ioannis K, Dayalan Haripriya, Levitsky Sidney
Division of Cardiothoracic Surgery, Beth Israel Deaconess Medical Center, Harvard Institutes of Medicine, 77 Ave. Louis Pasteur, Rm. 144, Boston, MA 02115, USA.
Am J Physiol Heart Circ Physiol. 2009 Jan;296(1):H94-H105. doi: 10.1152/ajpheart.00567.2008. Epub 2008 Oct 31.
Previously, we demonstrated that ischemia induces mitochondrial damage and dysfunction that persist throughout reperfusion and impact negatively on postischemic functional recovery and cellular viability. We hypothesized that viable respiration-competent mitochondria, isolated from tissue unaffected by ischemia and then injected into the ischemic zone just before reperfusion, would enhance postischemic functional recovery and limit infarct size. New Zealand White rabbits (n = 52) were subjected to 30 min of equilibrium and 30 min of regional ischemia (RI) induced by snaring the left anterior descending coronary artery. At 29 min of RI, the RI zone was injected with vehicle (sham control and RI vehicle) or vehicle containing mitochondria (7.7 x 10(6) +/- 1.5 x 10(6)/ml) isolated from donor rabbit left ventricular tissue (RI-Mito). The snare was released at 30 min of RI, and the hearts were reperfused for 120 min. Our results show that left ventricular peak developed pressure and systolic shortening in RI-Mito hearts were significantly enhanced (P < 0.05 vs. RI-vehicle) to 75% and 83% of equilibrium value, respectively, at 120 min of reperfusion compared with 57% and 62%, respectively, in RI-vehicle hearts. Creatine kinase-MB, cardiac troponin I, and infarct size relative to area at risk were significantly decreased in RI-Mito compared with RI-vehicle hearts (P < 0.05). Confocal microscopy showed that injected mitochondria were present and viable after 120 min of reperfusion and were distributed from the epicardium to the subendocardium. These results demonstrate that viable respiration-competent mitochondria, isolated from tissue unaffected by ischemia and then injected into the ischemic zone just before reperfusion, significantly enhance postischemic functional recovery and cellular viability.
此前，我们证明缺血会诱导线粒体损伤和功能障碍，这种损伤和功能障碍在整个再灌注过程中持续存在，并对缺血后功能恢复和细胞活力产生负面影响。我们推测，从未受缺血影响的组织中分离出具有活性且能进行呼吸作用的线粒体，然后在再灌注前注入缺血区域，将会增强缺血后功能恢复并限制梗死面积。将52只新西兰白兔通过结扎左前降支冠状动脉诱导30分钟平衡期和30分钟局部缺血（RI）。在RI 29分钟时，向RI区域注射载体（假手术对照组和RI载体组）或含有从供体兔左心室组织分离的线粒体（7.7×10⁶±1.5×10⁶/ml）的载体（RI-线粒体组）。在RI 30分钟时松开结扎线，心脏再灌注120分钟。我们的结果显示，与RI载体组心脏相比，RI-线粒体组心脏在再灌注120分钟时左心室峰值收缩压和收缩期缩短率显著增强（与RI载体组相比，P<0.05），分别达到平衡值的75%和83%，而RI载体组心脏分别为57%和62%。与RI载体组心脏相比，RI-线粒体组心脏中的肌酸激酶-MB、心肌肌钙蛋白I以及相对于危险区域的梗死面积显著降低（P<0.05）。共聚焦显微镜检查显示，注射的线粒体在再灌注120分钟后仍然存在且具有活性，并且从心外膜分布至心内膜下。这些结果表明，从未受缺血影响的组织中分离出具有活性且能进行呼吸作用的线粒体，然后在再灌注前注入缺血区域，可显著增强缺血后功能恢复和细胞活力。
