Intraventricular Administration Of Bmp-7 In Stroke Anima

中风和相关的血管事件会对中枢神经系统(CNS)造成广泛的损害，并导致严重的运动和认知障碍。有人认为，营养因子治疗可以减轻损伤的程度，并在损伤后恢复受损的神经元。我们先前已经测试了骨形态发生蛋白-7(BMP-7)在局灶性脑缺血损伤中的作用。骨形态发生蛋白-7是生长因子B超家族中的一员。我们发现BMP-7在脑室给药后具有深刻的神经保护作用。我们现在已经开始测试它在缺血脑中的分布，以确定BMP-7在脑实质中扩散的速度有多快。我们还确定了它是否在损伤后短期内对神经元中中间丝的表达产生影响，作为其恢复活性的部分基础。最后，我们检查了中风后对运动行为的影响。成年雄性SD大鼠右侧大脑中动脉闭塞60分钟，24小时后，侧脑室注射BMP-7或赋形剂，剂量为25微升(1微克/微升)。分别于注射BMP-7后1、3、6、24小时处死动物。在脑实质的定位方面，我们发现BMP-7在注射后1h主要出现在室管膜内，而在注射后3h已延伸到少数邻近神经元。然而，6小时组和24小时组在神经元中都有显著的BMP-7免疫反应标记，主要是在纹状体和丘脑。在接受赋形剂注射的动物中，注射侧的神经丝表达似乎相当弱，而在注射BMP-7后6小时和24小时观察到神经丝染色显著上调。24小时可见明显的轴突突起，并有明显的生长锥体，尤以腹侧纹状体和伏隔为甚。这些结果表明，注射BMP-7可能有助于缺血损伤后中间神经元细丝的表达，而且注射的因子可以整合到距离侧脑室几毫米处的神经元中。成年SD大鼠用水合氯醛麻醉。大脑中动脉(MCA)被一根穿过右侧颈内动脉的细丝短暂闭塞。缺血60分钟后取出细丝，允许再灌流。在大脑中动脉结扎(MCAO)后24小时处死动物，检测BMP-7mRNA的表达。其他动物在MCA闭塞后24小时接受单剂量静脉注射BMP-7或赋形剂，并用于随后的行为研究和BMP-7免疫组化染色。未处理组大鼠MCAO后24小时BMP-7基因表达上调。在接受静脉注射BMP-7的动物中，在MCAO后第6天，缺血侧海马/齿状回的BMP-7免疫反应呈剂量依赖性增加。接受BMP-7的动物在MCAO后第7天到第14天也显示出身体不对称性的减少，而在第14天运动活动增加。我们的数据表明，卒中后肠外注射BMP-7可以通过缺血侧的血脑屏障，并在更长的测试时间内诱导卒中动物的行为恢复。

Stroke and related vascular events can cause widespread damage to the central nervous system (CNS) and result in significant motor and cognitive impairments. It has been suggested that trophic factor treatment may reduce the extent of damage and restore damaged neurons following the injury. We have previously tested the effects of bone morphogenetic protein-7 (BMP-7), a member of the transforming growth factor-B superfamily of growth factors, in focal brain ischemic injury. We found BMP-7 to have profound neuroprotective effects after intraventricular administration. We have now proceeded to test its distribution in the ischemic brain, in order to determine how rapidly BMP-7 may diffuse through brain parenchyma. We also determined whether it has effects on expression of intermediate filaments in neurons short-term after the injury as a partial basis for its restorative activity. Finally we examined effects on motor behavior after stroke. Adult male Sprague-Dawley rats were subjected to a 60-minute occlusion of the right middle cerebral artery, and 24 hours thereafter, injections of BMP-7 or vehicle into the lateral ventricle on the ipsilateral side, at a dose of 25 ul (1 ug/ul), were performed. The animals were sacrificed 1, 3, 6, and 24 hours following the BMP-7 administration. In terms of localization in the brain parenchyma, we found that BMP-7 was mostly present in the ependyma 1 hour following injection, while it extended to a few adjacent neurons at 3 hours post-injection. However, the 6- and 24-hour groups both had significant BMP-7-immunoreactive labeling in neurons, primarily in the striatum and thalamus. Neurofilament expression appeared to be fairly weak on the injected side in animals that had received the vehicle injection, whereas a significant upregulation in neurofilament staining was observed at 6- and 24 hours post-injection of BMP-7. Significant neurite outgrowth, with obvious growth cones, was observed at 24 hours, particularly in the ventral striatum and accumbens. These results suggest that BMP-7 injection may aid in the expression of intermediate neuronal filaments following an ischemic injury, and furthermore that the injected factor can become incorporated into neurons located several millimeters from the lateral ventricle. Adult Sprague-Dawley rats were anesthetized with chloral hydrate. The middle cerebral artery (MCA) was transiently occluded by a filament, inserted through the right internal carotid artery. The filament was removed after 60-min ischemia to allow reperfusion. Some animals were killed 24 hours after MCA occlusion (MCAo) to examine BMP-7 mRNA expression. Other animals received a single dose of intravenous BMP-7 or vehicle at 24 hours after MCA occlusion and were used for subsequent behavioral studies and BMP-7 immunostaining. BMP-7 mRNA was upregulated 24 hours after MCAo in non-treated animals. BMP-7-immunoreactivity was dose-dependently increased on the ischemic side hippocampus/dentate on the 6th day after MCAo in animals receiving intravenous injection of BMP-7. Animals receiving BMP-7 also showed a decrease in body asymmetry from days 7 to day 14 and an increase in locomotor activity on day 14 after MCAo. Our data indicate that BMP-7, given parenterally after stroke, can pass through the blood brain barrier on the ischemic side and induce behavioral recovery in stroke animals at longer testing times.