title: May BDNF Be Implicated in the Exercise-Mediated Regulation of Inflammation? Critical Review and Synthesis of Evidence.
abstract: BACKGROUND
  Exercise attenuates inflammation and enhances levels of brain-derived neurotrophic factor (BDNF). Exercise also enhances parasympathetic tone, although its role in activating the cholinergic anti-inflammatory pathway is unclear. The physiological pathways of exercise's effect on inflammation are obscure.
  
  
  OBJECTIVE
  To critically review the evidence on the role of BDNF in the anti-inflammatory effects of exercise and its potential involvement in the cholinergic anti-inflammatory pathway.
  
  
  METHODS
  Critical literature review of studies published in MEDLINE, PubMed, CINAHL, Embase, and Cochrane databases.
  
  
  RESULTS
  BDNF is critically involved in the bidirectional signaling between immune and neurosensory cells and in the regulation of parasympathetic system responses. BDNF is also intricately involved in the inflammatory response: inflammation induces BDNF production, and, in turn, BDNF exerts pro- and/or anti-inflammatory effects. Although exercise modulates BDNF and its receptors in lymphocytes, data on BDNF's immunoregulatory/anti-inflammatory effects in relation to exercise are scarce. Moreover, BDNF increases cholinergic activity and is modulated by parasympathetic system activation. However, its involvement in the cholinergic anti-inflammatory pathway has not been investigated.
  
  
  CONCLUSIONS
  Converging lines of evidence implicate BDNF in exercise-mediated regulation of inflammation; however, data are insufficient to draw concrete conclusions. We suggest that there is a need to investigate BDNF as a potential modulator/mediator of the anti-inflammatory effects of exercise and of the cholinergic anti-inflammatory pathway during exercise. Such research would have implications for a wide range of inflammatory diseases and for planning targeted exercise protocols.
authors.affiliation: Department of Nursing, Cyprus University of Technology, Limassol, Cyprus e.papathanassoglou@cut.ac.cy.
authors.forename: Elizabeth D E
authors.initials: ED
authors.lastname: Papathanassoglou
authors.affiliation: Department of Nursing, Cyprus University of Technology, Limassol, Cyprus.
authors.forename: Panagiota
authors.initials: P
authors.lastname: Miltiadous
authors.affiliation: Department of Nursing, Cyprus University of Technology, Limassol, Cyprus.
authors.forename: Maria N
authors.initials: MN
authors.lastname: Karanikola
mesh_terms: D019208:Brain-Derived Neurotrophic Factor / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007249:Inflammation / Q000276:immunology* / Q000517:prevention & control*
chemical_list: D019208:Brain-Derived Neurotrophic Factor; C579455:BDNF protein, human
keywords: brain-derived neurotrophic factor; cholinergic anti-inflammatory pathway; critical illness; early progressive mobility; exercise; immunity; inflammation; parasympathetic nervous system; physical activity