Kim Miri, Oh Seokmin, Kim Songyeon, Kim Il-Sun, Kim Joowon, Han Jungho, Ahn Ji Woong, Chung Seungsoo, Jang Jae-Hyung, Shin Jeong Eun, Park Kook In
Yonsei Biomedical Research Institute, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea.
Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, 50-1 Yonsei-Ro, Seodaemun-Gu, Seoul, 03722, Republic of Korea.
Inflamm Regen. 2024 Jul 16;44(1):33. doi: 10.1186/s41232-024-00349-y.
Neonatal hypoxic-ischemic brain injury (HIBI) is a significant contributor to neonatal mortality and long-term neurodevelopmental disability, characterized by massive neuronal loss and reactive astrogliosis. Current therapeutic approaches for neonatal HIBI have been limited to general supportive therapy because of the lack of methods to compensate for irreversible neuronal loss. This study aimed to establish a feasible regenerative therapy for neonatal HIBI utilizing in vivo direct neuronal reprogramming technology.
Neonatal HIBI was induced in ICR mice at postnatal day 7 by permanent right common carotid artery occlusion and exposure to hypoxia with 8% oxygen and 92% nitrogen for 90 min. Three days after the injury, NeuroD1 was delivered to reactive astrocytes of the injury site using the astrocyte-tropic adeno-associated viral (AAV) vector AAVShH19. AAVShH19 was engineered with the Cre-FLEX system for long-term tracking of infected cells.
AAVShH19-mediated ectopic NeuroD1 expression effectively converted astrocytes into GABAergic neurons, and the converted cells exhibited electrophysiological properties and synaptic transmitters. Additionally, we found that NeuroD1-mediated in vivo direct neuronal reprogramming protected injured host neurons and altered the host environment, i.e., decreased the numbers of activated microglia, reactive astrocytes, and toxic A1-type astrocytes, and decreased the expression of pro-inflammatory factors. Furthermore, NeuroD1-treated mice exhibited significantly improved motor functions.
This study demonstrates that NeuroD1-mediated in vivo direct neuronal reprogramming technology through AAV gene delivery can be a novel regenerative therapy for neonatal HIBI.
新生儿缺氧缺血性脑损伤（HIBI）是导致新生儿死亡和长期神经发育残疾的重要因素，其特征为大量神经元丢失和反应性星形胶质细胞增生。由于缺乏补偿不可逆神经元丢失的方法，目前针对新生儿HIBI的治疗方法仅限于一般支持性治疗。本研究旨在利用体内直接神经元重编程技术建立一种可行的新生儿HIBI再生治疗方法。
在出生后第7天的ICR小鼠中，通过永久性右侧颈总动脉闭塞并暴露于含8%氧气和92%氮气的缺氧环境90分钟诱导新生儿HIBI。损伤后三天，使用嗜星形胶质细胞腺相关病毒（AAV）载体AAVShH19将NeuroD1递送至损伤部位的反应性星形胶质细胞。AAVShH19采用Cre-FLEX系统构建，用于长期追踪感染细胞。
AAVShH19介导的异位NeuroD1表达有效地将星形胶质细胞转化为GABA能神经元，且转化后的细胞表现出电生理特性和突触递质。此外，我们发现NeuroD1介导的体内直接神经元重编程可保护受损的宿主神经元并改变宿主环境，即减少活化小胶质细胞、反应性星形胶质细胞和毒性A1型星形胶质细胞的数量，并降低促炎因子的表达。此外，接受NeuroD1治疗的小鼠运动功能有显著改善。
本研究表明，通过AAV基因递送的NeuroD1介导的体内直接神经元重编程技术可以成为新生儿HIBI的一种新型再生治疗方法。
