Rapid orderly migration of neutrophils after traumatic brain injury depends on MMP9/13

• Published in: Biochemical and biophysical research communications Vol. 579; pp. 161 - 167
• Main Authors: Zou, Dandan, Hu, Wenlong, Qin, Jie, Wei, Zongfang, Wang, Danyang, Li, Li
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 19-11-2021
• Subjects: Animals; Apoptosis; Brain - metabolism; Brain Injuries, Traumatic - metabolism; Cell Movement; Green Fluorescent Proteins - metabolism; Injury; Interleukin-1beta - metabolism; Leukocyte Count; Macrophage; Macrophages - metabolism; Matrix Metalloproteinase 13 - metabolism; Matrix Metalloproteinase 9 - metabolism; Mice; Migration; MMP13; MMP9; Neutrophil; Neutrophils - metabolism; Zebrafish; MMP13; Neutrophil; MMP9; Migration; Injury; Macrophage
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2021.09.044

Macrophages and granulocytes play an important role in various injuries and post-traumatic repair. Due to the limited number of neutrophils in the brain, their role in traumatic brain injury has rarely been mentioned. Here, neutrophils were found to take over the role of macrophages after brain injury in the absence of macrophages. Neutrophils have the characteristics of long residence time and number advantage to actively remove the apoptotic debris. The number of neutrophils recruited was effectively reduced by inhibiting IL-1β. Interestingly, neutrophils migrated regularly and rapidly to the wound during the early stages of brain injury through three paths. They first infiltrated the wound mainly through blood circulation around the eyes, then became unscrupulous and began to move directly across the brain. In addition, MMP9 and MMP13 were found to be related to the migration of neutrophils, and inhibition of MMP could significantly inhibit the number and speed of neutrophils’ migration. Our study showed that neutrophils rely on MMP9 and MMP13 for a rapid and orderly response to brain injury to maintain central nervous system stability in the absence or decrease of macrophages.
•When macrophages become less effective after injury, neutrophils immediately take their place.•In the early stage of craniocerebral injury, neutrophils migrate to the site of injury in an orderly and regular manner.•The expression of MMP9 and MMP13 increased after brain injury.•MMP9 and MMP13 contribute to the mobility of neutrophils' migration.