Aging and Innate immune system resilience in TBI

创伤性脑损伤（TBI）是神经系统并发症（包括慢性记忆）的主要原因 如痴呆症。老年TBI患者的预后恶化风险高于年轻患者。 对应物（Chou等人，2018; Early等人，2020; Morganti等人，2016; Ritzel等人，2019年，尽管 风险和更糟糕的结果，没有针对这一易感人群的靶向治疗， 很少有出版物关注这一弱势群体的治疗方法。数据显示， 老年受试者可能对治疗干预表现出较低的反应性（Tajiri等人，2014年），可能 表明老年人需要不同于年轻人的优化治疗。我们已经确定了一 来自人脂肪来源的干细胞（hASC exo）的治疗外泌体（Patel等人，（2018）A 在年轻啮齿类动物中，治疗窗口长达损伤后至少48小时（参见初步数据）。扩展 hASC exo的治疗窗口将是超过大多数当前实验治疗的主要进步， 治疗窗口只有几小时而不是几天。为了推动这一有前途的疗法，我们必须解决 我们对hASC exo的作用机制和有效性的认识存在重大差距， 对不同年龄人群的干预。我们的假设是这些hASC外泌体的主要作用是 通过与免疫系统相互作用来调节对损伤的二次免疫应答。已经很好了 在老年啮齿类动物中，先天免疫细胞对损伤的反应过度。 我们的初步数据证明了hASC exo改善行为和减少炎症反应的功效。 CCI后的标志物在老年啮齿动物中被改变。因此，一个悬而未决的问题是， 对治疗，特别是用hASC外泌体治疗的反应。

Traumatic brain injury (TBI) is a leading cause of neurological complications including chronic memory deficits such as dementia. Older TBI patients are at a higher risk for worsening of outcomes than their younger counterparts (Chou et al., 2018; Early et al., 2020; Morganti et al., 2016; Ritzel et al., 2019), despite the higher risk and worse outcomes, there are no targeted therapies targeted for this susceptible population, and only a few publications looking at therapeutics for this vulnerable population. This is compounded by data suggesting that older subjects may show less responsiveness to therapeutic interventions (Tajiri et al., 2014) which may indicate that aged individuals will require optimized treatments that differ from young. We have identified a therapy exosomes from human adipose derived stem cells (hASC exo) (Patel et al., 2018) that have a therapeutic window up to at least 48 hours post injury in young rodents (see preliminary data). The extended therapeutic window of hASC exo would be a major advancement over most current experimental therapeutics, with a treatment window of only hours and not days. To move this promising therapy forward we must address critical gaps in our knowledge regarding hASC exo’s mechanism of action, and effectiveness of the intervention in diverse age populations. Our hypothesis is that a major action of these hASC exosomes is to modulate the secondary immune response to injury by interacting with the immune system. It is already well established that in aged rodents aged there is an exaggerated response of innate immune cells to the injury. Our preliminary data demonstrates the efficacy of hASC exo to improve behavior and reduce inflammatory markers following CCI is modified in aged rodents . Thus, an unanswered question is how aging impacts the response to treatment, and specifically treatment with hASC exosomes.