Investigating the role of CD44 and immune-neuro signaling mechanisms in neural stem cell responses after spinal cord injury

项目摘要 脊髓损伤(SCI)由于脊髓组织的丢失和局限性导致长期的功能损害。 再生。人类神经干细胞(HNSC)移植作为治疗癌症的一种令人兴奋的潜力 脊髓损伤，但hNSC与外部微环境之间的复杂相互作用较差 明白了。这项建议的目标是解决知识的这一差距，从而实现既优化 治疗性供者hNSC移植以及体内信号/转录的新见解 网络，以及这些网络对hNSC本地化和SCI后命运的影响。对这一点至关重要 IS的目标是阐明免疫-NSC信号转导机制。 脊髓损伤(SCI)导致血-脊髓屏障的破坏和血清的大量涌入 蛋白质，包括C1q.脊髓损伤还导致多相和长期的免疫反应，其中 浸润性免疫细胞和常驻免疫细胞也分泌C1q。我们已经证明了C1q的流入具有化学吸引力。 对于移植的hNSC，诱导hNSC向损伤中心迁移和聚集，并驱动 HNSC向星形胶质细胞方向发展。体内C1q的阻断释放了迁徙和血统选择， 促进脊髓损伤修复和运动功能恢复。我们还证明了C1q直接调节hNSC 通过受体介导的信号机制在体外进行迁移、增殖和分化。使用 无偏筛选，我们确定了C1q与5个候选受体之间的新相互作用，这些受体由 HNSC。CD44就是其中之一，它是一种在调节细胞行为方面具有既定作用的受体。我们的 已发表的数据表明，CD44是体外和体内hNSC对C1q化学吸引的主要介质， 结果表明，C1q-CD44信号对hNSC的命运也有调节作用。此外，急性期hNSC中CD44缺失 体内移植可促进脊髓损伤修复和运动功能恢复。 提出的目标的中心假设是NSC中的C1q-CD44信号改变NSC CD44-ICD异染色质调控转录组及移植人神经干细胞中CD44基因缺失 脊髓损伤后将加强修复。目的1研究CD44KO对人神经干细胞基因表达的影响。 基线和对CD44配体C1q、HA和骨桥蛋白的反应。Aim 2测试CD44的作用 移植入脊髓微环境的人神经干细胞修复能力的缺失及其依赖关系 对C1q的影响目的3探讨CD44KO在人神经干细胞中的定位及与命运的关系 对脊髓损伤后体内信号和转录网络的影响

Project Summary Spinal cord injury (SCI) results in long-term functional impairments due to loss of cord tissue and limited regeneration. Human neural stem cell (hNSC) transplantation has exciting potential as a treatment for SCI, but the complex interactions between hNSC and the extrinsic microenvironment are poorly understood. The objective of this proposal is to address this gap in knowledge, enabling both optimization of therapeutic donor hNSC transplantation, as well as new insights into in vivo signaling/transcriptional networks, and the consequence of these networks for hNSC localization and fate after SCI. Critical to this is goal is elucidating mechanisms of immune-NSC signaling. Spinal Cord Injury (SCI) causes disruption of the blood-spinal-cord barrier, and a robust influx of serum proteins, including C1q. SCI also results in a multiphasic and prolonged immune response, in which infiltrating and resident immune cells also secrete C1q. We have shown that C1q influx is chemoattractive for transplanted hNSC, inducing hNSC migration towards and clustering at the injury epicenter, and driving hNSC towards an astroglial lineage. Blockade of C1q in vivo releases both migration and lineage selection, and enhances SCI repair and locomotor recovery. We have also shown that C1q directly modulates hNSC migration, proliferation, and differentiation in vitro via a receptor-mediated signaling mechanism. Using an unbiased screen, we identified novel interactions between C1q and five candidate receptors expressed by hNSC. Among these is CD44, a receptor with an established role in regulating cellular behavior. Our published data identify CD44 as a principal mediator of hNSC chemoattraction to C1q in vitro and in vivo, and show that C1q-CD44 signaling also modulates hNSC fate. Further, CD44 deletion in hNSC in an acute transplantation paradigm in vivo enhances SCI repair and locomotor recovery. The central hypotheses of the proposed aims are that C1q-CD44 signaling in NSC alters the NSC transcriptome via CD44-ICD heterochromatin modulation, and that deletion of CD44 in transplanted hNSC after SCI will enhance repair. Aim 1 investigates the effect of CD44 KO on hNSC gene expression at baseline and in response to the CD44 ligands C1q, HA, and osteopontin. Aim 2 tests the effect of CD44 deletion on the repair capacity of hNSC transplanted into the SCI microenvironment, and the dependence of this effect on C1q. Aim 3 investigates the effect of CD44 KO in hNSC on localization and fate in relation to signaling and transcriptional networks in vivo after SCI