Cameron Stella H, Alwakeel Amr J, Goddard Liping, Hobbs Catherine E, Gowing Emma K, Barnett Elizabeth R, Kohe Sarah E, Sizemore Rachel J, Oorschot Dorothy E
Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand.
Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand.
Mol Cell Neurosci. 2015 Sep;68:56-72. doi: 10.1016/j.mcn.2015.03.019. Epub 2015 Mar 28.
Perinatal hypoxia-ischemia is a major cause of striatal injury and may lead to cerebral palsy. This study investigated whether delayed administration of bone marrow-derived mesenchymal stem cells (MSCs), at one week after neonatal rat hypoxia-ischemia, was neurorestorative of striatal medium-spiny projection neurons and improved motor function. The effect of a subcutaneous injection of a high-dose, or a low-dose, of MSCs was investigated in stereological studies. Postnatal day (PN) 7 pups were subjected to hypoxia-ischemia. At PN14, pups received treatment with either MSCs or diluent. A subset of high-dose pups, and their diluent control pups, were also injected intraperitoneally with bromodeoxyuridine (BrdU), every 24h, on PN15, PN16 and PN17. This permitted tracking of the migration and survival of neuroblasts originating from the subventricular zone into the adjacent injured striatum. Pups were euthanized on PN21 and the absolute number of striatal medium-spiny projection neurons was measured after immunostaining for DARPP-32 (dopamine- and cAMP-regulated phosphoprotein-32), double immunostaining for BrdU and DARPP-32, and after cresyl violet staining alone. The absolute number of striatal immunostained calretinin interneurons was also measured. There was a statistically significant increase in the absolute number of DARPP-32-positive, BrdU/DARPP-32-positive, and cresyl violet-stained striatal medium-spiny projection neurons, and fewer striatal calretinin interneurons, in the high-dose mesenchymal stem cell (MSC) group compared to their diluent counterparts. A high-dose of MSCs restored the absolute number of these neurons to normal uninjured levels, when compared with previous stereological data on the absolute number of cresyl violet-stained striatal medium-spiny projection neurons in the normal uninjured brain. For the low-dose experiment, in which cresyl violet-stained striatal medium-spiny neurons alone were measured, there was a lower statistically significant increase in their absolute number in the MSC group compared to their diluent controls. Investigation of behavior in another cohort of animals showed that delayed administration of a high-dose of bone marrow-derived MSCs, at one week after neonatal rat hypoxia-ischemia, improved motor function on the cylinder test. Thus, delayed therapy with a high- or low-dose of adult MSCs, at one week after injury, is effective in restoring the loss of striatal medium-spiny projection neurons after neonatal rat hypoxia-ischemia and a high-dose of MSCs improved motor function.
围产期缺氧缺血是纹状体损伤的主要原因，可能导致脑瘫。本研究调查了新生大鼠缺氧缺血一周后延迟给予骨髓间充质干细胞（MSC）是否对纹状体中等棘状投射神经元具有神经修复作用并改善运动功能。在体视学研究中，研究了皮下注射高剂量或低剂量MSC的效果。出生后第7天的幼崽遭受缺氧缺血。在出生后第14天，幼崽接受MSC或稀释剂治疗。高剂量幼崽及其稀释剂对照幼崽的一个亚组在出生后第15天、第16天和第17天每24小时还腹腔注射溴脱氧尿苷（BrdU）。这允许追踪源自脑室下区的神经母细胞向相邻损伤纹状体的迁移和存活情况。幼崽在出生后第21天安乐死，在对多巴胺和cAMP调节的磷蛋白-32（DARPP-32）进行免疫染色、对BrdU和DARPP-32进行双重免疫染色以及单独进行甲酚紫染色后，测量纹状体中等棘状投射神经元的绝对数量。还测量了纹状体免疫染色的钙视网膜蛋白中间神经元的绝对数量。与稀释剂对照组相比，高剂量间充质干细胞（MSC）组中DARPP-32阳性、BrdU/DARPP-32阳性和甲酚紫染色的纹状体中等棘状投射神经元的绝对数量有统计学意义的增加，而纹状体钙视网膜蛋白中间神经元较少。与正常未受伤大脑中甲酚紫染色的纹状体中等棘状投射神经元绝对数量的先前体视学数据相比，高剂量的MSC将这些神经元的绝对数量恢复到正常未受伤水平。对于低剂量实验，其中仅测量甲酚紫染色的纹状体中等棘状神经元，与稀释剂对照组相比，MSC组中其绝对数量的增加在统计学上具有较低的显著性。对另一组动物的行为研究表明，新生大鼠缺氧缺血一周后延迟给予高剂量骨髓源性MSC可改善圆柱体试验中的运动功能。因此，损伤一周后延迟给予高剂量或低剂量的成年MSC可有效恢复新生大鼠缺氧缺血后纹状体中等棘状投射神经元的损失，且高剂量的MSC改善了运动功能。
