Galanin is a potent modulator of cytokine and chemokine expression in human macrophages

Sci Rep. 2019 May 10;9(1):7237. doi: 10.1038/s41598-019-43704-7.

Abstract

The regulatory peptide galanin is broadly distributed in the central- and peripheral nervous systems as well as in non-neuronal tissues, where it exerts its diverse physiological functions via three G-protein-coupled receptors (GAL1-3-R). Regulatory peptides are important mediators of the cross-communication between the nervous- and immune systems and have emerged as a focus of new therapeutics for a variety of inflammatory diseases. Studies on inflammatory animal models and immune cells revealed both pro- and anti-inflammatory functions of galanin. Here, we probed specific immune-related functions of the galanin system and found galanin and GAL1-R and GAL2-R mRNA to be expressed in a range of human immune cells. In particular, macrophages displayed differentiation- and polarization-dependent expression of galanin and its receptors. Exposure to exogenous galanin affected the cytokine/chemokine expression profile of macrophages differently, depending on their differentiation and polarization, and mainly modulated the expression of chemokines (CCL2, CCL3, CCL5 and CXCL8) and anti-inflammatory cytokines (TGF-β, IL-10 and IL-1Ra), especially in type-1 macrophages. Cytokine/chemokine expression levels in interferon-gamma- and lipopolysaccharide-polarized macrophages were upregulated whereas in unpolarized macrophages they were downregulated upon galanin treatment for 20 hours. This study illuminates the regulation of important cytokines/chemokines in macrophages by galanin, depending on specific cell activation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Differentiation / physiology
  • Cell Polarity / physiology
  • Cells, Cultured
  • Chemokines / metabolism*
  • Cytokines / metabolism*
  • Galanin / metabolism*
  • Humans
  • Macrophage Activation / physiology
  • Macrophages / metabolism*
  • RNA, Messenger / metabolism

Substances

  • Chemokines
  • Cytokines
  • RNA, Messenger
  • Galanin