Drug Repurposing to Accelerate Progress in Neonatal Neuroprotection

摘要 在儿童时期，急性脑损伤的风险在新生儿期达到高峰。围产期脑的主要机制 损伤包括缺氧缺血（HI）和子宫内炎症（如绒毛膜炎），或 新生儿（如坏死性小肠结肠炎）感染。在足月儿中，先前的缺氧缺血事件可 在早产儿中，多因素的作用机制通常更难识别， 确认身份。考虑到围产期脑损伤的神经系统发病率， 对于早产儿，非常需要有效的神经保护干预。许多药物可以减少脑损伤 并改善新生啮齿动物缺氧缺血性（HI）脑损伤模型的功能结果。一个主要 翻译的挑战是选择那些优先发展的补充较大的动物围产期 损伤模型，并最终用于早期人类新生儿试验。鉴于新药上市的时间滞后， 我们的策略是优先评估潜在的神经保护药物， 已经批准用于其他适应症，即"再利用"，并利用"自适应平台设计模型"， 功效比较研究。这项建议建立在我们最近的发现，治疗与临床 现有的抗生素阿奇霉素（AZ），减少脑损伤，改善功能结果，在多个 新生啮齿动物缺氧缺血性（HI）脑损伤模型。我们的目的是比较神经保护功效 在临床上可用的药物中，包括AZ，在类似的新生啮齿动物模型中具有神经保护作用， 帮助优先考虑进入人体试验的最佳候选人。将在充分表征的 大鼠缺氧缺血性脑损伤模型和炎症放大缺氧缺血性脑损伤模型。我们将合并 两个年龄组的研究，出生后第7天（P7），以模拟足月脑发育，P3，以模拟 早产儿为了引起单侧前脑损伤，动物接受单侧颈动脉结扎， 随后定时（45 - 90分钟）暴露于8%氧气;这导致可量化的感觉运动缺陷， 单侧脑组织损伤促炎刺激，例如注射TLR-4（脂多糖，LPS） 或TLR-2（Pam3CSK 4）激动剂，放大HI损伤。我们的初步研究表明， 与HI和炎症相比，AZ治疗在两个年龄段都具有剂量和时间依赖性神经保护作用。 扩大HI损伤。我们目前的目标是比较多种临床治疗中的神经保护功效。 P7（Aim 1）和P3（Aim 2）大鼠中可用药物（AZ、促红细胞生成素、褪黑素、西地那非、咖啡因、托吡酯） 缺氧缺血性和炎症放大的缺氧缺血性脑损伤模型。我们量化保护性 结合偏侧感觉运动功能、记忆和神经病理学的复合评分的疗效 措施，并将死亡视为可能的伤害结果。我们假设这些比较 有效性研究将确定一种或两种药物在每个年龄段具有最高的优越性， 加快进展，将安全有效的药物推向足月和早产儿的临床试验。

Abstract In childhood, the risks of acute brain injury peak in the neonatal period. Major mechanisms of perinatal brain injury include hypoxia-ischemia (HI) and inflammation in response to intrauterine (e.g. chorioamnionitis) or neonatal (e.g. necrotizing enterocolitis) infections. In term infants, antecedent hypoxic-ischemic events can often be discerned; in premature neonates, multifactorial contributing mechanisms are often more difficult to identify. In view of the significant neurologic morbidity associated with perinatal brain injury in both term and preterm infants, effective neuroprotective interventions are greatly needed. Many drugs decrease brain injury and improve functional outcome in neonatal rodent hypoxic-ischemic (HI) brain injury models. A major translational challenge is to select those to prioritize for advancement to complementary larger animal perinatal injury models, and ultimately to early stage human neonatal trials. In view of the time lag from new drug development to clinical trials, our strategy is to prioritize evaluation of potentially neuroprotective drugs that are already approved for other indications i.e. “repurposing”, and utilize an “adaptive platform design model” for comparative efficacy studies. This proposal builds upon our recent findings that treatment with a clinically available antibiotic, azithromycin (AZ), reduces brain damage and improves functional outcomes in multiple neonatal rodent hypoxic-ischemic (HI) brain injury models. Our aims are to compare neuroprotective efficacy among clinically available drugs, including AZ, that are neuroprotective in similar neonatal rodent models, to help prioritize the best candidate(s) to advance to human trials. Efficacy will be compared in well-characterized rat models of hypoxic-ischemic and inflammation-amplified hypoxic-ischemic brain injury. We will incorporate studies in two age groups, post-natal day 7 (P7), to model term brain development, and P3, to model premature neonates. To elicit unilateral forebrain injury, animals undergo unilateral carotid artery ligation and subsequent timed (45-90 min) exposure to 8% oxygen; this results in quantifiable sensorimotor deficits and unilateral brain tissue damage. Pro-inflammatory stimuli, e.g. injections of a TLR-4 (lipopolysaccharide, LPS) or a TLR-2 (Pam3CSK4) agonist prior to lesioning, amplify HI injury. Our preliminary studies showed that treatment with AZ confers dose and time-dependent neuroprotection, at both ages, vs. HI and inflammation- amplified HI injury. Our current goals are to compare the neuroprotective efficacy among multiple clinically available drugs (AZ, erythropoietin, melatonin, sildenafil, caffeine, topiramate) in P7 (Aim 1) and P3 (Aim 2) rat hypoxic-ischemic and inflammation-amplified hypoxic-ischemic brain injury models. We quantify protective efficacy with composite scores that incorporate lateralizing sensorimotor function, memory and neuropathology measures, and also account for death as a possible injury outcome. We hypothesize that these comparative efficacy studies will identify one or two drugs with the highest probability of superiority at each age, and thus accelerate progress towards advancing safe and effective drugs to clinical trials in term and preterm neonates.