title: Role of inflammatory cytokines in peripheral nerve injury.
abstract: Inflammatory events occurring in the distal part of an injured peripheral nerve have, nowadays, a great resonance. Investigating the timing of action of the several cytokines in the important stages of Wallerian degeneration helps to understand the regenerative process and design pharmacologic intervention that promotes and expedites recovery. The complex and synergistic action of inflammatory cytokines finally promotes axonal regeneration. Cytokines can be divided into pro- and anti-inflammatory cytokines that upregulate and downregulate, respectively, the production of inflammatory mediators. While pro-inflammatory cytokines are expressed in the first phase of Wallerian degeneration and promote the recruitment of macrophages, anti-inflammatory cytokines are expressed after this recruitment and downregulate the production of all cytokines, thus determining the end of the process. In this review, we describe the major inflammatory cytokines involved in Wallerian degeneration and the early phases of nerve regeneration. In particular, we focus on interleukin-1, interleukin-2, interleukin-6, tumor necrosis factor-β, interleukin-10 and transforming growth factor-β.
authors.affiliation: Department of Clinical and Biological Sciences, University of Turin, Orbassano 10043, Turin, Italy ; Neuroscience Institute of the "Cavalieri Ottolenghi" Foundation, Orbassano 10043, Turin, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Fregnan
authors.affiliation: Department of Clinical and Biological Sciences, University of Turin, Orbassano 10043, Turin, Italy ; Neuroscience Institute of the "Cavalieri Ottolenghi" Foundation, Orbassano 10043, Turin, Italy.
authors.forename: Luisa
authors.initials: L
authors.lastname: Muratori
authors.affiliation: Department of Clinical and Biological Sciences, University of Turin, Orbassano 10043, Turin, Italy.
authors.forename: Anabel Rodriguez
authors.initials: AR
authors.lastname: Simões
authors.affiliation: Department of Clinical and Biological Sciences, University of Turin, Orbassano 10043, Turin, Italy.
authors.forename: Maria Giuseppina
authors.initials: MG
authors.lastname: Giacobini-Robecchi
authors.affiliation: Department of Clinical and Biological Sciences, University of Turin, Orbassano 10043, Turin, Italy ; Neuroscience Institute of the "Cavalieri Ottolenghi" Foundation, Orbassano 10043, Turin, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Raimondo
keywords: Schwann cells; anti-inflammatory cytokines; axonal regeneration; inflammatory reaction; macrophage; myelin; nerve injury; neural regeneration; peripheral nervous system; pro-inflammatory cytokines; wallerian degeneration