Neuroprotective and regenerative effects of small molecules and their receptors

小分子及其受体的神经保护和再生作用

• 批准号: 8553240
• 负责人: Yun Wang
• 金额: $ 45.54万
• 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/8553240
• 关键词: 3,4-Dihydroxyphenylacetic Acid; 3-nitropropionate; Ablation; Adenosine; Adenosine A3 Receptor; Adult; Aftercare; Agonist; Amphetamines; Animals; Anisotropy; Anoxia; Apoptosis; Apoptotic; Attenuated; Behavioral; Binding; Biochemical; Blood - brain barrier anatomy; Brain; Brain Injuries; Brain-Derived Neurotrophic Factor; Calcium Binding; Carbon Dioxide; Cell Death; Cell Nucleus; Cell Survival; Cells; Cerebral Infarction; Cerebrum; Cleaved cell; Contralateral; Corpus striatum structure; Cultured Cells; DNA; Data; Development; Diffusion Magnetic Resonance Imaging; Dopamine; Dose; Embolism; Exposure to; FOS gene; Fiber; Follow-Up Studies; Glucose; Growth; Heart; High Pressure Liquid Chromatography; Hippocampus (Brain); Hour; Hydrogen Peroxide; Hypoxia; Image; Immune response; Immune system; In Situ Nick-End Labeling; Infarction; Inflammation; Inflammatory; Injection of therapeutic agent; Injury; Intoxication; Ipsilateral; Ischemia; Ischemic Brain Injury; Isomerism; JUN gene; Label; Lesion; Lung; MAPK8 gene; Matrix Metalloproteinases; Measures; Mediating; Mediator of activation protein; Methamphetamine; Microglia; Middle Cerebral Artery Occlusion; Mitochondria; Motor Activity; Mus; Mutant Strains Mice; Naloxone; Nerve Degeneration; Neurites; Neurodegenerative Disorders; Neurologic; Neuronal Dysfunction; Neurons; Neurotoxins; PC12 Cells; Parkinsonian Disorders; Pharmaceutical Preparations; Play; Process; Rattus; Recovery; Reporting; Reserpine; Rodent Model; Role; Saline; Side; Signal Transduction; Site; Slice; Stroke; Synaptophysin; TNF gene; Tissues; Toxic effect; Transplantation; Tretinoin; Up-Regulation; Vitamin A; Weight; alitretinoin; body asymmetry; bone morphogenetic protein 7; brain tissue; caspase-3; density; deprivation; dopaminergic neuron; immunoreactivity; improved; in vivo; inflammatory marker; inhibitor/antagonist; mRNA Expression; male; mesangial cell; middle cerebral artery; nervous system disorder; neurofilament; novel therapeutic intervention; pifithrin; post stroke; preconditioning; prevent; protective effect; receptor; regenerative; reinnervation; relating to nervous system; repaired; research study; response; small molecule; synaptogenesis

(1) Amphetamine in neuroregeneration: AM post-treatment significantly reduced neurological deficits, as measured by body asymmetry and Bedersons score in stroke rats. T2WI and diffusion tensor imaging (DTI) were used to examine the size of infarction and axonal reinnervation, respectively, before and following treatment on days 2, 10 and 25 after stroke. AM treatment reduced the volume of tissue loss on days 10 and 25. A significant increase in fractional anisotropy ratio was found in the ipislateral cortex after repeated AM administration, suggesting a possible increase in axonal outgrowth in the lesioned side cortex. Western analysis indicated that AM significantly increased the expression of synaptophysin ipsilaterally and neurofilament bilaterally. AM also enhanced matrix metalloproteinase (MMP) enzymatic activity, determined by MMP zymography in the lesioned side cortex. qRT-PCR was used to examine the expression of trophic factors after the 1st and 2nd doses of AM or saline injection. The expression of BDNF, but not BMP7 or CART, was significantly enhanced by AM in the lesioned side cortex. In conclusion, post-stroke treatment with AM facilitates behavioral recovery, which is associated with an increase in fractional anisotropy activity, enhanced fiber growth in tractography, synaptogenesis, upregulation of BDNF, and MMP activity mainly in the lesioned cortex. Our data suggest that the ipsilateral cortex may be the major target of action in stroke brain after AM treatment. (2) adenosine A3R receptor: We reported that high doses of Meth suppressed locomotor activity in adult male A3R null mutant (-/-) mice and their controls (+/+), with a greater reduction being found in the -/- mice. Brain tissues were collected at 3 days after the Meth or saline injections. Meth treatment reduced striatal dopamine (DA) levels in both +/+ and -/- mice, examined by HPLC, with an increase in DOPAC/DA ratio being found only in -/- animals after Meth treatment. Meth also significantly increased ionized calcium-binding adaptor molecule 1 (Iba-1) and cleaved caspase-3 level in striatum as well as Iba-1 and TNF mRNA expression in nigra in -/-, compared to +/+, mice. Previous studies have shown that pharmacological suppression of VMAT2 by reserpine enhanced Meth toxicity by increasing cytosolic DA and inflammation. A significant reduction in striatal VMAT2 expression was found in -/- mice, compared to +/+ mice, suggesting that increase in sensitivity to Meth injury in -/- mice may be related to a reduction in VMAT2 expression in these mice. Our data suggest that A3R -/- mice are more sensitive to high doses of Meth. (3) pifithrin-a (PFT-a): (A) We found that PFTa has protective against Meth -mediated injury in dopaminergic neurons. High dose of Meth reduced TH immunoreactivity and fiber density in primary dopaminergic neuronal culture. Co-treatment with PFTa significantly attenuated these degenerative changes. Our data suggest that treatment with a p53 inhibitor or suppression of p53 expression limits neuronal dysfunction and cell death induced by exposure to dopaminergic neurotoxins. (B) Systemic administration of PFT- enhanced the survival of dopaminergic neuronal transplants in vivo. PFT- treatment suppressed cell death, increased survival of TH (+) cells, enhanced TH neurite outgrowth from ventromesencephalic grafts, and augmented behavioral recovery in Parkinsonian rats. In conclusion, our data suggest that activation of p53 is an important mediator for cell death after injury or during neural repair. Transient suppression of p53 may increase the survival of neurons or NPCs after brain injury. (4) Retinoic acid (RA): Pretreatment with 9 cis RA (9cRA) increased locomotor activity, attenuated neurological deficits, and reduced cerebral infarction and TUNEL labeling in stroke rats. 9cRA increased the expression of bone morphogenetic protein 7 (BMP7) in brain. The protective response of 9cRA can be antagonized by BMP antagonist noggin. Our data suggest that RA can induce protective responses against Meth toxicity in cultured cells and in vivo, possibly through BMP7 mechanism. (5) (-)Naloxone: Neurodegeneration can occur through the activation of inflammatory processes. From experiments conducted this past year, we have observed improved behavioral recovery (body asymmetery and neurological score) following stroke when (+)naloxone was administered daily for 1 week starting one day after middle cerebral artery occlusion in rats. We are currently following up these studies comparing (-)naloxone as well as examining changes in markers of inflammation that are upregulated following ischemia of the stroke.

(1)苯丙胺在神经再生中的作用：根据中风大鼠的身体不对称性和Bedersons评分，AM治疗后显著减少了神经功能缺陷。分别于治疗前和治疗后第2、10、25天进行T2WI和弥散张量成像(DTI)检查脑梗塞面积和轴突再支配情况。AM治疗在第10天和第25天减少了组织丢失的体积。反复给药后，同侧皮质各向异性分数显著增加，提示患侧皮质轴突突起增多。Western分析显示，黄芪能显著增加同侧突触素和双侧神经丝的表达。AM还能增强受损侧皮质中基质金属蛋白酶(MMP)的酶活性，这是通过对损伤侧皮质中的MMP酶谱测定得出的。采用定量逆转录聚合酶链式反应(QRT-PCR法)检测注射AM或生理盐水第1、2次后营养因子的表达。AM可显著增强BDNF的表达，但对BMP7和CART的表达无明显影响。综上所述，卒中后应用AM可促进行为恢复，这与各向异性活动增加、纤维生长增强、突触形成、脑源性神经营养因子表达上调以及主要在皮损皮质的基质金属蛋白酶活性有关。我们的数据表明，AM治疗后，同侧皮质可能是卒中脑的主要作用靶点。 (2)腺苷A3R受体：我们报道，高剂量的Meth抑制成年雄性A3R缺失突变(-/-)小鼠及其对照(+/+)小鼠的运动活动，在-/-小鼠中发现更大的减少。于注射甲基强的松龙或生理盐水后3d取脑组织。经高效液相色谱检测，冰毒治疗降低了+/+和-/-小鼠的纹状体多巴胺(DA)水平，而DOPAC/DA比率仅在冰毒治疗后的-/-动物中发现。与+/+小鼠相比，METH还显著增加了纹状体离子钙结合接头分子1(Iba-1)和裂解caspase-3的水平，以及黑质Iba-1和TNF的mRNA表达。先前的研究表明，利血平对VMAT2的药理抑制通过增加胞内DA和炎症来增强Meth的毒性。与+/+小鼠相比，-/-小鼠纹状体VMAT2的表达显著降低，这表明-/-小鼠对Meth损伤的敏感性增加可能与这些小鼠的VMAT2表达减少有关。我们的数据表明，A3R-/-小鼠对高剂量的Meth更敏感。 (3)匹非菊酯-a(PFT-a)：(A)我们发现PFTa对甲基溴介导的多巴胺能神经元损伤具有保护作用。大剂量Meth可降低原代培养的多巴胺能神经元的TH免疫反应性和纤维密度。与PFTA联合治疗显著减轻了这些退行性改变。我们的数据表明，使用P53抑制剂或抑制P53表达可以限制因暴露于多巴胺能神经毒素而导致的神经元功能障碍和细胞死亡。(B)全身应用PFT可提高体内多巴胺能神经元移植的存活率。PFT治疗抑制了帕金森病大鼠的细胞死亡，增加了TH(+)细胞的存活率，促进了从腹中脑移植物中长出的TH轴突，并促进了行为恢复。总之，我们的数据表明，P53的激活是损伤后或神经修复过程中细胞死亡的重要中介。短暂抑制P53可能会增加脑损伤后神经元或神经前体细胞的存活率。 (4)维甲酸(RA)：9顺式维甲酸(9cRA)可增加卒中大鼠的运动能力，减轻神经功能缺失，减少脑梗塞和TUNEL标记。9cRA可增加脑内骨形态发生蛋白7(BMP7)的表达。BMP拮抗剂noggin可拮抗9cRA的保护作用。我们的数据提示，RA在培养细胞和体内均能诱导对Meth毒性的保护性反应，可能是通过BMP7机制。 (5)(-)纳洛酮：神经变性可通过激活炎症过程发生。从过去一年进行的实验中，我们观察到，在大鼠大脑中动脉闭塞后的一天开始，每天服用(+)纳洛酮1周，可以改善中风后的行为恢复(身体不对称和神经评分)。我们目前正在跟进这些研究，比较(-)纳洛酮以及检测中风缺血后上调的炎症标志物的变化。