Department of Pediatrics I, Neonatology and Experimental Perinatal Neurosciences, Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, University Duisburg-Essen, Essen, Germany.
Institute for Transfusion Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
J Neuroinflammation. 2023 Nov 27;20(1):280. doi: 10.1186/s12974-023-02961-0.
Neonatal encephalopathy following hypoxia-ischemia (HI) is a leading cause of childhood death and morbidity. Hypothermia (HT), the only available but obligatory therapy is limited due to a short therapeutic window and limited efficacy. An adjuvant therapy overcoming limitations of HT is still missing. Mesenchymal stromal cell (MSC)-derived extracellular vesicles (EVs) have shown promising therapeutic effects in various brain injury models. Challenges associated with MSCs' heterogeneity and senescence can be mitigated by the use of EVs from clonally expanded immortalized MSCs (ciMSCs). In the present study, we hypothesized that intranasal ciMSC-EV delivery overcomes limitations of HT.
Nine-day-old C57BL/6 mice were exposed to HI by occlusion of the right common carotid artery followed by 1 h hypoxia (10% oxygen). HT was initiated immediately after insult for 4 h. Control animals were kept at physiological body core temperatures. ciMSC-EVs or vehicle were administered intranasally 1, 3 and 5 days post HI/HT. Neuronal cell loss, inflammatory and regenerative responses were assessed via immunohistochemistry, western blot and real-time PCR 7 days after insult. Long-term neurodevelopmental outcome was evaluated by analyses of cognitive function, activity and anxiety-related behavior 5 weeks after HI/HT.
In contrast to HT monotherapy, the additional intranasal therapy with ciMSC-EVs prevented HI-induced cognitive deficits, hyperactivity and alterations of anxiety-related behavior at adolescence. This was preceded by reduction of striatal neuronal loss, decreased endothelial, microglia and astrocyte activation; reduced expression of pro-inflammatory and increased expression of anti-inflammatory cytokines. Furthermore, the combination of HT with intranasal ciMSC-EV delivery promoted regenerative and neurodevelopmental processes, including endothelial proliferation, neurotrophic growth factor expression and oligodendrocyte maturation, which were not altered by HT monotherapy.
Intranasal delivery of ciMSC-EVs represents a novel adjunct therapy, overcoming limitations of acute HT thereby offering new possibilities for improving long-term outcomes in neonates with HI-induced brain injury.
缺氧缺血（HI）后新生儿脑病是儿童死亡和发病的主要原因。作为唯一可用的强制性治疗方法，低温（HT）由于治疗窗短和疗效有限而受到限制。一种克服 HT 局限性的辅助治疗方法仍然缺失。间充质基质细胞（MSC）衍生的细胞外囊泡（EVs）在各种脑损伤模型中显示出有希望的治疗效果。使用从克隆扩增的永生化 MSC（ciMSC）衍生的 EVs 可以减轻 MSC 异质性和衰老相关的挑战。在本研究中，我们假设鼻内 ciMSC-EV 递药可克服 HT 的局限性。
9 天大的 C57BL/6 小鼠通过阻断右侧颈总动脉然后进行 1 小时缺氧（10%氧气）来暴露于 HI。HI 后立即开始 HT，持续 4 小时。对照动物保持生理核心体温。在 HI/HT 后 1、3 和 5 天，通过鼻内给予 ciMSC-EV 或载体。通过免疫组织化学、western blot 和实时 PCR 评估 7 天后的神经元细胞丢失、炎症和再生反应。HI/HT 后 5 周通过分析认知功能、活动和焦虑相关行为来评估长期神经发育结局。
与 HT 单药治疗相比，额外的鼻内 ciMSC-EV 治疗可预防 HI 诱导的认知缺陷、青春期多动和焦虑相关行为改变。这是通过减少纹状体神经元丢失、减少内皮细胞、小胶质细胞和星形胶质细胞激活、减少促炎细胞因子的表达和增加抗炎细胞因子的表达来实现的。此外，HT 联合鼻内 ciMSC-EV 给药促进了再生和神经发育过程，包括内皮细胞增殖、神经营养生长因子表达和少突胶质细胞成熟，而 HT 单药治疗并未改变这些过程。
鼻内递 ciMSC-EVs 代表一种新的辅助治疗方法，克服了急性 HT 的局限性，为改善 HI 诱导的脑损伤新生儿的长期结局提供了新的可能性。
