Role of macrophages in peripheral nerve injury and repair

• Published in: Neural regeneration research Vol. 14; no. 8; pp. 1335 - 1342
• Main Authors: Liu, Ping, Peng, Jiang, Han, Gong-Hai, Ding, Xiao, Wei, Shuai, Gao, Gang, Huang, Kun, Chang, Feng, Wang, Yu
• Format: Journal Article
• Language: English
• Published: India Wolters Kluwer India Pvt. Ltd 01.08.2019; Medknow Publications and Media Pvt. Ltd; Medknow Publications & Media Pvt. Ltd; Shanxi Medical University, Taiyuan, Shanxi Province, China; Institute of Orthopedics, Chinese PLA General Hospital, Beijing, China%Institute of Orthopedics, Chinese PLA General Hospital, Beijing, China%Kunming Medical University, Kunming, Yunnan Province, China%Shihezi University Medical College, Shihezi, Xinjiang Uygur Autonomous Region, China%Department of Orthopaedic Surgery, Shanxi Provincial People's Hospital, Shanxi Medical University, Taiyuan, Shanxi Province, China%Anhui Medical University Air Force Clinical College, Hefei, Anhui Province, China; Wolters Kluwer - Medknow; Wolters Kluwer Medknow Publications
• Subjects: Angiogenesis; Anti-inflammatory agents; Care and treatment; Cell growth; Chemokines; Cytokines; Disease; Extracellular matrix; Genotype & phenotype; Homeostasis; Immune system; Inflammation; Insulin-like growth factors; Ligands; Macrophages; nerve regeneration; macrophage; origin; polarization; function; nerve injury; nerve repair; tissue engineering; neural regeneration; Nervous system; Nitric oxide; Obesity; Osteoarthritis; Peripheral nervous system diseases; Recruitment; Review; Tissue engineering; Tumor necrosis factor-TNF; Vascular endothelial growth factor; Wound healing; tissue engineering; neural regeneration; function; nerve injury; origin; macrophage; nerve regeneration; nerve repair; polarization
• ISSN: 1673-5374; 1876-7958
• DOI: 10.4103/1673-5374.253510

Resident and inflammatory macrophages are essential effectors of the innate immune system. These cells provide innate immune defenses and regulate tissue and organ homeostasis. In addition to their roles in diseases such as cancer, obesity and osteoarthritis, they play vital roles in tissue repair and disease rehabilitation. Macrophages and other inflammatory cells are recruited to tissue injury sites where they promote changes in the microenvironment. Among the inflammatory cell types, only macrophages have both pro-inflammatory (M1) and anti-inflammatory (M2) actions, and M2 macrophages have four subtypes. The co-action of M1 and M2 subtypes can create a favorable microenvironment, releasing cytokines for damaged tissue repair. In this review, we discuss the activation of macrophages and their roles in severe peripheral nerve injury. We also describe the therapeutic potential of macrophages in nerve tissue engineering treatment and highlight approaches for enhancing M2 cell-mediated nerve repair and regeneration.