Neutrophil contribution to spinal cord injury and repair

Abstract

Spinal cord injuries remain a critical issue in experimental and clinical research nowadays, and it is now well accepted that the immune response and subsequent inflammatory reactions are of significant importance in regulating the damage/repair balance after injury. The role of macrophages in such nervous system lesions now becomes clearer and their contribution in the wound healing process has been largely described in the last few years. Conversely, the contribution of neutrophils has traditionally been considered as detrimental and unfavorable to proper tissue regeneration, even if there are very few studies available on their precise impact in spinal cord lesions. Indeed, recent data show that neutrophils are required for promoting functional recovery after spinal cord trauma. In this review, we gathered recent evidence concerning the role of neutrophils in spinal cord injuries but also in some other neurological diseases, highlighting the need for further understanding the different mechanisms involved in spinal cord injury and repair.Electronic supplementary materialThe online version of this article (doi:10.1186/s12974-014-0150-2) contains supplementary material, which is available to authorized users.

The role of neutrophil granulocytes in immune-to-brain communication

“…As such, inhibition of neutrophil recruitment by neutralizing antibodies against the chemokine receptor CXCR2, which is for example activated by CINC1, ameliorated the disease in an animal model for atypical autoimmune encephalomyelitis [58]. Others investigated the role for neutrophil granulocytes during spinal cord injury and found mixed results; detrimental for tissue regeneration but also beneficial for promoting functional recovery [59] most likely depending on the timing during programing of the inflammatory process [60]. Interestingly, induction of neutropenia by a neutralizing antibody during severe LPS-induced systemic inflammation (i.p., 2.5mg/kg) revealed that such IL-1β-expressing neutrophils contribute to the induction and/or maintenance of depressionlike behaviours 48h after LPS-stimulation [56].…”

Metformin ameliorates BSCB disruption by inhibiting neutrophil infiltration and MMP‐9 expression but not direct TJ proteins expression regulation

“…Emerging evidence indicated that infiltrated neutrophils are the major source of the MMP-9 in SCI [15][16][17]. As the first inflammatory cells, neutrophils infiltrate the site of injury following traumatic CNS injury, and it peaks at 24 hrs after injury [18]. The infiltration of neutrophils is regulated by intercellular adhesion molecule-1 (ICAM-1), which expresses on endothelial cells, and high expression of ICAM-1 facilitates neutrophil adhesion and tissue infiltration [18].…”

“…As the first inflammatory cells, neutrophils infiltrate the site of injury following traumatic CNS injury, and it peaks at 24 hrs after injury [18]. The infiltration of neutrophils is regulated by intercellular adhesion molecule-1 (ICAM-1), which expresses on endothelial cells, and high expression of ICAM-1 facilitates neutrophil adhesion and tissue infiltration [18]. The infiltrated neutrophils accumulates in the inflammatory core of a tissue lesion to secret MMPs, which are oxidative and tissue-degrading enzymes [19].…”

Effect of Boswellia serrata extract on tissue inflammation and white blood cells responses of spinal cord injury in rat model

“…Similar other studies, our data reveal that neutrophils are needed for encouraging functional recovery after spinal cord damage. They are initial inflammatory cells which appear at the lesion site and act by different mechanisms, such as releasing angiogenic factors, to induce inflammation-mediated tissue remodeling (29,30). We did not find any studies that investigate effects of B. serrata extract on the neuronal cells in traumatic SCI.…”