Analysis of the Role of CX3CL1 (Fractalkine) and Its Receptor CX3CR1 in Traumatic Brain and Spinal Cord Injury: Insight into Recent Advances in Actions of Neurochemokine Agents

CX3CL1, also known as fractalkine, is a unique chemokine that acts as both a chemoattractant and an adhesion molecule. It interacts with the CX3CR1 receptor and is involved in communication within the central nervous system (CNS). The CX3CL1/CX3CR1 axis plays a role in various physiological processes in the CNS, including interactions between neurons, microglia, and immune cells. It has also been implicated in neuropathologies like traumatic brain injury (TBI) and spinal cord injury (SCI). This review summarizes current knowledge about the CX3CL1/CX3CR1 axis in TBI and SCI, exploring potential molecular and cellular mechanisms that could be targeted for therapeutic interventions.

• 1
  CX3CL1 is mainly produced by endothelial cells and neurons, with its expression elevated in highly vascularized and innervated organs, including the CNS.
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  CX3CR1 is primarily expressed by microglial cells in the brain and spinal cord, which do not demonstrate mRNA expression for CX3CL1.
• 3
  After TBI, CX3CL1 levels increase in the cerebrospinal fluid (CSF) while decreasing in the serum, correlating with blood-brain barrier (BBB) dysfunction.