Alleviation of chronic TBI through modulation of calcium signaling

通过调节钙信号传导缓解慢性 TBI

• 批准号: 10700780
• 负责人: Bidhan Chandra Bandyopadhyay
• 金额: --
• 依托单位: U.S. DEPT/VETS AFFAIRS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-10-01 至 2025-09-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10700780
• 关键词: Affect; Afghanistan; Agonist; Anterior Pituitary Gland; Anxiety; Area; Attenuated; Behavior; Behavioral; Botulinum Toxins; Brain; Brain region; Calcium Signaling; Calcium ion; Cell Survival; Cells; Chronic; Clinical; Complex; Data; Disease; Fatigue; Feedback; Functional disorder; Future; Genetic; Goals; Hormonal; Hormone replacement therapy; Hormone secretion; Hormones; Hypopituitarism; Hypothalamic structure; Image; Impaired cognition; Impairment; Inflammation; Inflammatory Response; Injury; Investigation; Ion Channel; Iraq; Measures; Mediating; Medical; Memory; Memory impairment; Mental Depression; Modeling; Molecular; Mus; Natural regeneration; Neuronal Injury; Neurons; Neurosecretory Systems; Outcome; Oxidative Stress; Pathogenesis; Pathway interactions; Patients; Pituitary Gland; Posttraumatic growth; Process; Proteins; Publishing; Quality of life; Rattus; Reagent; Recovery; Rehabilitation therapy; Research Personnel; Resources; Role; SNAP receptor; Series; Serum; Signal Transduction; Signs and Symptoms; Site; Somatostatin; Somatotropin; Somatotropin-Releasing Hormone; Survivors; Synaptic Vesicles; TBI Patients; TRP channel; Testing; Therapeutic; Time; Traumatic Brain Injury; Vesicle; Veterans; Walking; War; axon growth; axon injury; axon regeneration; behavior test; behavioral study; controlled cortical impact; experimental study; functional restoration; ghrelin; growth hormone deficiency; hypothalamic pituitary axis; improved; injured; innovation; morris water maze; motor learning; mouse model; neurobehavioral; neurochemistry; neurotropic; novel; novel therapeutics; patch clamp; pharmacologic; postsynaptic; protein complex; psychologic; receptor; repaired; restoration; side effect; targeted delivery; technology platform; tool

Project Summary: Growth hormone deficiency (GHD) due to chronic traumatic brain injury (TBI) is common among the veterans from the wars in Iraq and Afghanistan. Such condition develops as a result of hypothalamic-pituitary axis (HPA) dysfunction leading to reduced growth hormone (GH) levels, which pose a significant impact on their quality of life due to medical, psychological, and psychiatric consequences. The GH replacement therapy in post-traumatic GHD, in most cases, do not produce the desired clinical outcome. Analysis of the signs and symptoms of HPA dysfunction suggests that compromise in GH secretion may be as a result of defective upstream hypothalamic signaling. Thus, we propose to restore the hypothalamic- neurotropic stimulation by endogenous GH secretion from the surviving (post-TBI) anterior pituitary cells (somatotrophs), leading to axonal regeneration of TBI-damaged neurons. Although intracellular calcium ion (Ca2+) concentration ([Ca2+]i) can regulate hormone release, the ion channel responsible for increasing [Ca2+]i the GH release in pituitary somatotrophs is unknown. Our ongoing studies have identified that activation of Transient Receptor Potential Canonical 3 (TRPC3), a Ca2+ influx channel, facilitates vesicle-associated soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein complex interactions, which is necessary for hormonal release. Moreover, disruption of TRPC3 markedly attenuated [Ca2+]i entry, which is essential for GH secretion and axonal regeneration. Thus, our central hypothesis is that the agonist activation of TRPC3 in pituitary cells triggers Ca2+ entry, resulting in enhanced GH secretion, which will help to regenerate those damaged axons in the adjacent HPA region. We propose to study the following two Aims using an established controlled cortical impact (CCI)-induced injury mouse model of TBI: (1) Characterization of the role of TRPC3 in regulating GH secretion by examining the functional restoration of hypothalamic neurotropic connections in TBI; and (2) Determine that TRPC3 activation stimulates axonal regeneration in TBI-damaged neurons and examine a “proof of concept” that augmenting TRPC3 expression/activation ameliorates chronic neurobehavioral abnormalities. We will perform a series of behavioral tests such as Morris water maze for memory and beam walk test to assess sensorimotor coordination and motor learning for correlating the behavior with brain neurochemistry. The results of the present study will: i) find the novel mechanism of TRPC3-induced GH secretion essential for axonal growth and regeneration that can be used as a tool to identify potential new therapeutic options; ii) elucidate the molecular pathogenesis of GH secretion following chronic TBI; and iii) help to plan and execute future investigations to improve and manage TBI- induced GHD and neurobehavioral abnormalities in both veterans and civilians.

项目摘要：由于慢性创伤性脑损伤（TBI）引起的生长激素缺乏症（GHD）是常见的 在伊拉克和阿富汗战争的退伍军人中。这种情况的发展是由于 下丘脑-垂体轴（HPA）功能障碍导致生长激素（GH）水平降低，这构成了 由于医疗、心理和精神方面的后果，对他们的生活质量产生重大影响。的GH 在大多数情况下，创伤后GHD的替代疗法不能产生期望的临床结果。 HPA功能障碍的体征和症状的分析表明，GH分泌的妥协可能是因为 这是下丘脑上游信号缺陷的结果因此，我们建议恢复下丘脑- 脑外伤后存活的垂体前叶细胞内源性GH分泌的亲神经性刺激 （生长激素），导致TBI损伤的神经元的轴突再生。虽然细胞内钙离子 (Ca2[Ca ~（2+）]i）可以调节激素的释放，负责增加[Ca ~（2+）]i的离子通道 垂体生长激素细胞中GH释放是未知的。我们正在进行的研究已经确定， 瞬时受体电位经典3（TRPC 3），一种Ca 2+内流通道，促进囊泡相关可溶性 N-乙基马来酰亚胺敏感因子附着蛋白受体（SNARE）蛋白复合物相互作用， 荷尔蒙释放所必需的。此外，TRPC 3的破坏显著减弱了[Ca 2 +]i内流，这是由于[Ca 2 +]i内流的抑制。 对生长激素分泌和轴突再生至关重要。因此，我们的中心假设是， TRPC 3在垂体细胞触发Ca 2+内流，导致GH分泌增强，这将有助于 再生邻近HPA区受损的轴突。我们建议研究以下两个目的 使用已建立的TBI的受控皮质撞击（CCI）诱导的损伤小鼠模型：（1）表征 TRPC 3在调节GH分泌中的作用，通过检查下丘脑的功能恢复， TBI中的亲神经性连接;以及（2）确定TRPC 3激活刺激TBI中的轴突再生。 TBI损伤的神经元，并检查增加TRPC 3表达/激活的“概念证明” 改善慢性神经行为异常。我们会进行一系列的行为测试，比如莫里斯 水迷宫记忆和平衡木行走试验，以评估感觉运动协调和运动学习， 将行为与大脑神经化学联系起来。本研究的结果将：i）发现小说 TRPC 3诱导的GH分泌机制对轴突生长和再生至关重要，可用作 一个工具，以确定潜在的新的治疗选择; ii）阐明GH分泌的分子发病机制 慢性TBI后;和iii）帮助计划和执行未来的调查，以改善和管理TBI- 在退伍军人和平民中诱发GHD和神经行为异常。