DataSheet1_Caffeine Restores Neuronal Damage and Inflammatory Response in a Model of Intraventricular Hemorrhage of the Preterm Newborn.pdf

Germinal matrix-intraventricular hemorrhage (GM-IVH) is the most frequent intracranial hemorrhage in the preterm infant (PT). Long-term GM-IVH-associated sequelae include cerebral palsy, sensory and motor impairment, learning disabilities, or neuropsychiatric disorders. The societal and health burden associated with GM-IVH is worsened by the fact that there is no successful treatment to limit or reduce brain damage and neurodevelopment disabilities. Caffeine (Caf) is a methylxanthine that binds to adenosine receptors, regularly used to treat the apnea of prematurity. While previous studies support the beneficial effects at the brain level of Caf in PT, there are no studies that specifically focus on the role of Caf in GM-IVH. Therefore, to further understand the role of Caf in GM-IVH, we have analyzed two doses of Caf (10 and 20 mg/kg) in a murine model of the disease. We have analyzed the short (P14) and long (P70) effects of the treatment on brain atrophy and neuron wellbeing, including density, curvature, and phospho-tau/total tau ratio. We have analyzed proliferation and neurogenesis, as well as microglia and hemorrhage burdens. We have also assessed the long-term effects of Caf treatment at cognitive level. To induce GM-IVH, we have administered intraventricular collagenase to P7 CD1 mice and have analyzed these animals in the short (P14) and long (P70) term. Caf showed a general neuroprotective effect in our model of GM-IVH of the PT. In our study, Caf administration diminishes brain atrophy and ventricle enlargement. Likewise, Caf limits neuronal damage, including neurite curvature and tau phosphorylation. It also contributes to maintaining neurogenesis in the subventricular zone, a neurogenic niche that is severely affected after GM-IVH. Furthermore, Caf ameliorates small vessel bleeding and inflammation in both the cortex and the subventricular zone. Observed mitigation of brain pathological features commonly associated with GM-IVH also results in a significant improvement of learning and memory abilities in the long term. Altogether, our data support the promising effects of Caf to reduce central nervous system complications associated with GM-IVH.

生发基质-脑室内出血（Germinal matrix-intraventricular hemorrhage, GM-IVH）是早产儿（preterm infant, PT）中最常见的颅内出血类型。GM-IVH相关的长期后遗症包括脑瘫、感觉运动障碍、学习障碍以及神经精神疾病。目前尚无能够限制或减轻脑损伤与神经发育障碍的有效治疗手段，这一现状进一步加重了GM-IVH所带来的社会与医疗负担。
咖啡因（Caffeine, Caf）是一种可结合腺苷受体（adenosine receptors）的甲基黄嘌呤（methylxanthine）类物质，常规用于治疗早产儿呼吸暂停。尽管既往研究证实咖啡因对早产儿的脑部具有保护作用，但尚无专门探讨其在GM-IVH中作用的相关研究。因此，为进一步明确咖啡因在GM-IVH中的作用，本研究采用该疾病的小鼠模型（murine model），测试了两种剂量的咖啡因（10与20 mg/kg）。本研究分析了该治疗在短期（P14）与长期（P70）对脑萎缩与神经元状态的影响，包括神经元密度、神经突弯曲度以及磷酸化tau/总tau蛋白比值；同时分析了细胞增殖与神经发生（neurogenesis）情况，以及小胶质细胞（microglia）负荷与出血负荷。此外还评估了咖啡因治疗对认知功能的长期影响。
为构建GM-IVH模型，本研究向出生后第7天的CD1小鼠脑室内注射胶原酶（collagenase），并分别在短期（P14）与长期（P70）对实验动物进行检测分析。在本研究所用的早产儿GM-IVH小鼠模型中，咖啡因展现出了全面的神经保护作用。本研究结果显示，咖啡因给药可减轻脑萎缩与脑室扩张；同样，咖啡因可抑制神经元损伤，包括改善神经突弯曲度与tau蛋白磷酸化水平。此外，咖啡因有助于维持侧脑室下区（subventricular zone）的神经发生，而该神经发生微环境（neurogenic niche）在GM-IVH后会受到严重破坏。进一步而言，咖啡因可改善皮层与侧脑室下区的小血管出血及炎症反应。上述针对GM-IVH相关典型脑病理特征的改善作用，还可长期显著提升实验动物的学习与记忆能力。综上，本研究数据证实咖啡因可有效减轻GM-IVH相关的中枢神经系统并发症，具有良好的应用前景。