Characterization of early and terminal complement proteins associated with polymorphonuclear leukocytes in vitro and in vivo after spinal cord injury.
Characterization of early and terminal complement proteins associated with polymorphonuclear leukocytes in vitro and in vivo after spinal cord injury.
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DOI：
10.1186/1742-2094-5-26
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发表时间：
2008-06-25
影响因子：
9.3
通讯作者：
Anderson AJ
中科院分区：
文献类型：
--
作者：
Nguyen HX;Galvan MD;Anderson AJ
补体系统被认为通过调节许多生理事件和途径来影响中枢神经系统（CNS）的损伤或疾病。中枢神经系统创伤后补体的激活也会导致 C5b-9 膜攻击复合物 (C5b-9/MAC) 的形成和沉积，从而对重要的中枢神经系统细胞造成细胞裂解或亚溶解效应。尽管源自血清/血脑屏障破坏的补体蛋白可能导致损伤或疾病，但浸润性免疫细胞可能代表损伤后重要的局部补体来源。作为损伤后数小时内渗入中枢神经系统的第一个免疫细胞，多形核白细胞 (PMN) 可能通过与补体介导的事件相关的机制影响损伤。然而，PMN 的早期和终末补体蛋白的表达/关联尚未在体外得到充分表征，并且之前在创伤性脊髓损伤（SCI）后的体内也未观察到。我们使用 rt-PCR 研究了补体 mRNA 的表达，并使用免疫荧光和定量流式细胞术研究了与 PMN 相关的补体蛋白的存在。在培养物中，受刺激或未受刺激的 PMN 表达编码 C1q、C3 和 C4 的 mRNA，但不表达 C5、C6、C7 或 C9。在不到 30% 的培养 PMN 中也检测到了补体蛋白 C1q 或 C3。相比之下，SCI 后 3 天，超过 70% 的浸润受损脊髓的 PMN 与 C1q、C3、C7 和 C5b-9/MAC 相关。 C7 或 C5b-9/MAC 与受损脊髓中浸润性 PMN 的定位/关联表明，C7 或 C5b-9/MAC 结合的细胞碎片通过浸润性 PMN 掺入或内化，因为 C7 和 C5b-9/MAC 大部分定位于脊髓中心区域 PMN 内的颗粒囊泡。此外，在 SCI 后数周内观察到损伤脊髓中 PMN 的存在，表明这种浸润细胞群可能长期影响补体介导的事件和创伤后 SCI 发病机制。这里提供的数据提供了 SCI 后体外和体内与 PMN 相关的早期和终末补体蛋白的首次表征。数据还表明，PMN 在 SCI 后环境中补体的局部内化或传递以及补体激活中发挥作用。
The complement system has been suggested to affect injury or disease of the central nervous system (CNS) by regulating numerous physiological events and pathways. The activation of complement following traumatic CNS injury can also result in the formation and deposition of C5b-9 membrane attack complex (C5b-9/MAC), causing cell lysis or sublytic effects on vital CNS cells. Although complement proteins derived from serum/blood-brain barrier breakdown can contribute to injury or disease, infiltrating immune cells may represent an important local source of complement after injury. As the first immune cells to infiltrate the CNS within hours post-injury, polymorphonuclear leukocytes (PMNs) may affect injury through mechanisms associated with complement-mediated events. However, the expression/association of both early and terminal complement proteins by PMNs has not been fully characterized in vitro, and has not observed previously in vivo after traumatic spinal cord injury (SCI). We investigated the expression of complement mRNAs using rt-PCR and the presence of complement proteins associated with PMNs using immunofluroescence and quantitative flow cytometry. Stimulated or unstimulated PMNs expressed mRNAs encoding for C1q, C3, and C4, but not C5, C6, C7 or C9 in culture. Complement protein C1q or C3 was also detected in less than 30% of cultured PMNs. In contrast, over 70% of PMNs that infiltrated the injured spinal cord were associated with C1q, C3, C7 and C5b-9/MAC 3 days post-SCI. The localization/association of C7 or C5b-9/MAC with infiltrating PMNs in the injured spinal cord suggests the incorporation or internalization of C7 or C5b-9/MAC bound cellular debris by infiltrating PMNs because C7 and C5b-9/MAC were mostly localized to granular vesicles within PMNs at the spinal cord epicenter region. Furthermore, PMN presence in the injured spinal cord was observed for many weeks post-SCI, suggesting that this infiltrating cell population could chronically affect complement-mediated events and SCI pathogenesis after trauma. Data presented here provide the first characterization of early and terminal complement proteins associated with PMNs in vitro and in vivo after SCI. Data also suggest a role for PMNs in the local internalization or deliverance of complement and complement activation in the post-SCI environment.