Department of Neuroscience and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, 110-749, Korea.
Curr Protein Pept Sci. 2013 Feb;14(1):33-42. doi: 10.2174/1389203711314010006.
Toll-like receptors (TLRs) are type I transmembrane signaling molecules that are expressed in cells of the innate immune system. In these cells, TLRs function as pattern recognition receptors (PRR) that recognize specific molecular patterns derived from microorganisms. Upon activation, TLRs trigger a cascade of intracellular signaling pathways in innate immune cells, leading to the induction of inflammatory and innate immune responses, which in turn regulate adaptive immune responses. In the nervous system, different members of the TLR family are expressed on glial cells (astrocytes, microglia, oligodendrocytes, and Schwann cells) and neurons. Recently, increasing evidence has supported the idea that TLRs also recognize endogenous molecules that are released from damaged tissue, thereby regulating inflammatory responses and subsequent tissue repair. These findings imply that TLRs on glial cells may also be involved in the inflammatory response to tissue damage in the nervous system. In this review, we discuss recent studies on TLR expression in the cells of the nervous system and their roles in acute neurological disorders involving tissue damage such as strokes, traumatic spinal cord and brain injuries, and peripheral nerve injuries.
Toll 样受体（TLRs）是一类Ⅰ型跨膜信号分子，表达于固有免疫系统的细胞表面。在这些细胞中，TLRs 作为模式识别受体（PRR），可以识别来自微生物的特定分子模式。TLRs 被激活后，会在固有免疫细胞中引发一系列的细胞内信号通路，导致炎症和固有免疫反应的诱导，进而调节适应性免疫反应。在神经系统中，TLR 家族的不同成员表达于神经胶质细胞（星形胶质细胞、小胶质细胞、少突胶质细胞和施万细胞）和神经元。最近，越来越多的证据支持这样一种观点，即 TLR 还可以识别来自受损组织释放的内源性分子，从而调节炎症反应和随后的组织修复。这些发现表明，神经胶质细胞上的 TLR 也可能参与神经系统组织损伤的炎症反应。在这篇综述中，我们讨论了 TLR 在神经系统细胞中的表达及其在涉及组织损伤的急性神经疾病中的作用的最新研究，这些疾病包括中风、创伤性脊髓和颅脑损伤以及周围神经损伤。
