Title:Toll-Like Receptors: Sensor Molecules for Detecting Damage to the Nervous System
Volume: 14
Issue: 1
Author(s): Hyunkyoung Lee, Soojin Lee, Ik-Hyun Cho and Sung Joong Lee
Affiliation:
Keywords:
Toll-like receptor, Stroke, Spinal cord injury, Peripheral nerve injury, Neuropathic pain
Abstract: 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.