Department of Spinal Surgery, Orthopedic Medical Center, Zhujiang Hospital, Southern Medical University, Guangzhou, 510280, China.
Department of Histology and Embryology, Southern Medical University, Guangzhou, 510515, China.
Mol Neurobiol. 2023 Jan;60(1):51-67. doi: 10.1007/s12035-022-03041-9. Epub 2022 Oct 10.
Spinal cord injury (SCI) can lead to the destruction of the blood-spinal cord barrier (BSCB), causing various inflammatory cytokines, neutrophils, and macrophages to infiltrate the lesion area, resulting in secondary injury. Basement membranes (BMs) are maintained by all types of cells in the BSCB and contribute to BSCB maintenance. Perlecan is an important constituent of vascular BMs, maintaining vascular integrity and neuroprotection. However, it is not clear whether Perlecan is involved in BSCB repair after SCI. In this study, we found that Perlecan was specifically expressed in the BMs in the spinal cord and underwent degradation/remodeling after SCI. Subsequently, a CRISPR/Cas9-based SAM system was used to overexpress Perlecan in the injured spinal cord, resulting in significantly enhanced locomotor recovery and neural regeneration. Overexpression of Perlecan reduced BSCB permeability along with the neuroinflammatory response. Interestingly, Perlecan inhibited stress fiber formation by interacting with integrin β1 and inhibiting downstream ROCK/MLC signaling, resulting in reduced tight junctions (TJs) disassembly and improved BSCB integrity. Furthermore, the integrin receptor antagonist GRGDSP abolished the effects of Perlecan overexpression on BSCB permeability and TJs integrity. Overall, our findings suggest that Perlecan reduces BSCB permeability and the neuroinflammatory response by interacting with integrin β1 and inhibiting the downstream ROCK/MLC pathway to promote neurological recovery after SCI.
脊髓损伤 (SCI) 可导致血脊髓屏障 (BSCB) 的破坏，使各种炎症细胞因子、中性粒细胞和巨噬细胞浸润病变区域，导致继发性损伤。基膜 (BMs) 由 BSCB 中的所有类型的细胞维持，并有助于 BSCB 的维持。硫酸乙酰肝素蛋白聚糖是血管 BMs 的重要组成部分，维持血管完整性和神经保护。然而，尚不清楚硫酸乙酰肝素蛋白聚糖是否参与 SCI 后的 BSCB 修复。在本研究中，我们发现硫酸乙酰肝素蛋白聚糖特异性表达在脊髓中的 BMs 中，并在 SCI 后发生降解/重塑。随后，使用基于 CRISPR/Cas9 的 SAM 系统在损伤的脊髓中过表达硫酸乙酰肝素蛋白聚糖，导致明显增强的运动恢复和神经再生。硫酸乙酰肝素蛋白聚糖的过表达降低了 BSCB 的通透性以及神经炎症反应。有趣的是，硫酸乙酰肝素蛋白聚糖通过与整合素 β1 相互作用抑制下游的 ROCK/MLC 信号通路，从而抑制应力纤维形成，减少紧密连接 (TJ) 的解聚，改善 BSCB 的完整性。此外，整合素受体拮抗剂 GRGDSP 消除了硫酸乙酰肝素蛋白聚糖过表达对 BSCB 通透性和 TJ 完整性的影响。总之，我们的研究结果表明，硫酸乙酰肝素蛋白聚糖通过与整合素 β1 相互作用抑制下游的 ROCK/MLC 通路，降低 BSCB 的通透性和神经炎症反应，从而促进 SCI 后的神经恢复。
