title: Contrasting mechanisms by which social isolation and restraint impair healing in male mice.
abstract: Stress modulates vital aspects of immune functioning in both human and non-human animals, including tissue repair. For example, dermal wounds heal more slowly and are associated with prolonged inflammation and increased bacterial load in mice that experience chronic physical restraint. Social stressors also negatively affect healing; however, previous studies suggest that the affected healing mechanisms may be stress model-specific. Here, the effects of either social isolation or physical restraint on dermal wound healing (3.5 mm wounds on the dorsum) were compared in hairless male mice. Social isolation beginning 3 weeks prior to wounding delayed healing comparably to physical restraint (12 h/day for eight days), in spite of marked differences in metabolic and hormonal consequences (i.e. body mass) between the two stress models. Additionally, isolated mice exhibited reductions in wound bacterial load and inflammatory gene expression (interleukin-1beta [IL-1β], monocyte chemoattractant protein [MCP]), whereas restraint significantly increased both of these parameters relative to controls. Experimentally augmenting bacterial concentrations in wounds of isolated mice did not ameliorate healing, whereas this treatment accelerated healing in controls. This work indicates that social isolation and restraint stressors comparably impair healing, but do so through disparate mechanisms and at different phases of healing.
authors.affiliation: Department of Periodontics, College of Dentistry, University of Illinois at Chicago (UIC) , Chicago, IL , USA .
authors.forename: Leah M
authors.initials: LM
authors.lastname: Pyter
authors.forename: Linglan
authors.initials: L
authors.lastname: Yang
authors.forename: Cassandra
authors.initials: C
authors.lastname: McKenzie
authors.forename: José M
authors.initials: JM
authors.lastname: da Rocha
authors.forename: C Sue
authors.initials: CS
authors.lastname: Carter
authors.forename: Bin
authors.initials: B
authors.lastname: Cheng
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Engeland
mesh_terms: D000818:Animals; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D053583:Interleukin-1beta / Q000096:biosynthesis; D008297:Male; D008812:Mice, Hairless; D018945:Monocyte Chemoattractant Proteins / Q000096:biosynthesis; D010913:Pituitary-Adrenal System / Q000502:physiology; D012149:Restraint, Physical; D012934:Social Isolation; D013315:Stress, Psychological / Q000503:physiopathology*; D014945:Wound Healing / Q000502:physiology*; D014946:Wound Infection / Q000503:physiopathology
chemical_list: D053583:Interleukin-1beta; D018945:Monocyte Chemoattractant Proteins