Neuroprotective and neuroregenerative effects of Bone morphogenetic proteins

骨形态发生蛋白的神经保护和神经再生作用

• 批准号: 7593265
• 负责人: Yun Wang
• 金额: $ 82.03万
• 依托单位: NATIONAL INSTITUTE ON DRUG ABUSE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7593265
• 关键词: Adult; Alleles; Animals; Behavioral; Blood Vessels; Bone Morphogenetic Proteins; Brain; Bromodeoxyuridine; Cells; Cerebral Ventricles; Chloral Hydrate; Contralateral; Corpus Callosum; Corpus striatum structure; Data; Dose; Embryo; Event; Galactosidase; Hour; Impaired cognition; In Situ Nick-End Labeling; Injury; Intraventricular; Ischemia; Ischemic Brain Injury; Label; LacZ Genes; Lesion; Measures; Mediating; Methamphetamine; Middle Cerebral Artery Occlusion; Motor; Motor Activity; Mus; Nerve Degeneration; Neuraxis; Neurologic; Neurons; Neurotoxins; Oxidopamine; Parkinson Disease; Purpose; Rattus; Recovery; Reperfusion Injury; Reporter; Rodent Model; Sprague-Dawley Rats; Stroke; Surgical sutures; Techniques; Testing; Tissues; Toxic effect; Treatment Factor; Tyrosine 3-Monooxygenase; body asymmetry; bone morphogenetic protein 7; day; dopaminergic neuron; drug of abuse; immunoreactivity; in vivo; middle cerebral artery; nestin protein; neurogenesis; neurotoxicity; nigrostriatal pathway

Methamphetamine (MA) is a drug of abuse as well as a dopaminergic neurotoxin. We previously demonstrated that pretreatment with bone morphogenetic protein 7 (BMP7) reduced 6-hydroxydopamine mediated neurodegeneration in a rodent model of Parkinsons disease. In this study, we examined the neuroprotective effects of BMP7 against MA-mediated toxicity in dopaminergic neurons. Primary dopaminergic neurons, prepared from rat embryonic ventral mesencephalic tissue, were treated with MA. High doses of MA decreased tyrosine hydroxylase immunoreactivity (THir) while increasing TUNEL labeling. These toxicities were significantly antagonized by BMP7. Interaction of BMP7 and MA in vivo was first examined in CD1 mice. High doses of MA (10 mg/kg x 4 s.c.) significantly reduced locomotor activity and THir in striatum. Intra-cerebroventricular administration of BMP7 antagonized these changes. In BMP7 +/- mice, MA suppressed locomotor activity and reduced TH immunoreactivity in nigra reticulata to a greater degree than in wild type BMP7 +/+ mice, suggesting that deficiency in BMP7 expression increases vulnerability to MA insults. Since BMP7 +/- mice also carry a LacZ-expressing reporter allele at the BMP7 locus, the expression of BMP7 was indirectly measured through the enzymatic activity of -galactosidase (-gal) in BMP7 +/- mice. High doses of MA significantly suppressed -gal activity in striatum, suggesting that MA may inhibit BMP7 expression at the terminals of nigrostriatal pathway. In conclusion, our data indicate that MA can cause lesioning in the nigrostriatal dopaminergic terminals and that BMP7 is protective against MA mediated neurotoxicity in central dopaminergic neurons. 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 BMP-7 in focal brain ischemic injury. We found BMP-7 to have profound neuroprotective effects after intraventricular administration. The purpose of this study was to examine neuroregenerative effects of BMP7 after ischemia /reperfusion injury. Adult Sprague-Dawley rats were anesthetized with chloral hydrate. Right middle cerebral artery (MCA) was transiently ligated with 10-O suture for one hour. One day after MCA occlusion, vehicle or BMP7 was infused to the contralateral cerebral ventricle. To identify possible neurogenesis, bromodeoxyurindine (BrdU) was systemically injected on the 4th and 5th days after MCA occlusion. Animals treated with BMP7 showed a rapid correction of body asymmetry and neurological deficits, suggesting BMP7 facilitates recovery after stroke. Animals were sacrificed at one month after stroke and brains were analyzed using immunohistological techniques. BMP7 treatment enhanced immunoreactivity of BrdU in the subventricular zone, lesioned cortex, and corpus callosum. These BrdU positive cells co-labeled with nestin and NeuN. Our behavioral and anatomical data suggest that BMP7 promotes neuroregeneration in stroke animals, possibly through the proliferation of new neuronal precursors after ischemia.

甲基苯丙胺（MA）是一种滥用药物，也是一种多巴胺能神经毒素。我们先前证明，在帕金森病啮齿动物模型中，骨形态发生蛋白7（BMP 7）预处理可减少6-羟基多巴胺介导的神经变性。在这项研究中，我们研究了BMP 7对MA介导的多巴胺能神经元毒性的神经保护作用。原代多巴胺能神经元，从大鼠胚胎腹侧中脑组织制备，用MA处理。高剂量的MA降低酪氨酸羟化酶免疫反应性（THir），同时增加TUNEL标记。这些毒性被BMP 7显著拮抗。首先在CD 1小鼠中检查BMP 7和MA的体内相互作用。高剂量MA（10 mg/kg x 4皮下注射）显著降低纹状体中的运动活性和THir。脑室内注射BMP 7可拮抗这些变化。在BMP 7 +/-小鼠中，MA抑制运动活性，并降低网状黑质中TH免疫反应性的程度大于野生型BMP 7 +/+小鼠，表明BMP 7表达的缺陷增加了对MA损伤的脆弱性。由于BMP 7 +/-小鼠在BMP 7基因座处也携带LacZ表达报告基因等位基因，因此通过BMP 7 +/-小鼠中β-半乳糖苷酶（β-gal）的酶活性间接测量BMP 7的表达。 高剂量的MA显著抑制纹状体的-gal活性，表明MA可能抑制黑质纹状体通路末端的BMP 7表达。 总之，我们的数据表明，MA可以引起黑质纹状体多巴胺能末梢的病变，BMP 7对MA介导的中枢多巴胺能神经元的神经毒性具有保护作用。 中风和相关血管事件可导致中枢神经系统（CNS）的广泛损伤，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程度并恢复损伤后受损的神经元。我们先前已经测试了BMP-7在局灶性脑缺血损伤中的作用。我们发现BMP-7在脑室内给药后具有深刻的神经保护作用。本研究的目的是检查缺血/再灌注损伤后BMP 7的神经再生作用。用水合氯醛麻醉成年Sprague-Dawley大鼠。用10-O缝线短暂结扎右侧大脑中动脉（MCA）1小时。在MCA闭塞后一天，将媒介物或BMP 7输注到对侧脑室。 为了确定可能的神经发生，在MCA闭塞后第4和第5天全身注射溴脱氧尿苷（BrdU）。用BMP 7治疗的动物显示出身体不对称和神经缺陷的快速纠正，表明BMP 7促进中风后的恢复。中风后一个月处死动物，并使用免疫组织学技术分析大脑。BMP 7处理增强了室管膜下区、受损皮质和胼胝体中BrdU的免疫反应性。 这些BrdU阳性细胞与Nestin和NeuN共标记。我们的行为和解剖学数据表明，BMP 7促进中风动物的神经再生，可能是通过缺血后新的神经元前体细胞的增殖。