title: Galectin-1 and galectin-3 expression profiles in classically and alternatively activated human macrophages.
abstract: BACKGROUND
  Galectins have been identified as modulators of many monocyte/macrophage functions. In the response to a wide range of environmental cues macrophages may exhibit different biochemical and biological characteristics, but two main subtypes, classically (M1) and alternatively (M2) activated macrophages have been recognized. To contribute to elucidation of role and regulation of galectin-1 and galectin-3 in differently activated macrophages we explored their expression profiles in these cells.
  
  
  METHODS
  Human monocytes obtained from blood donors were differentiated into classically (M1) and alternatively (M2a/M2c) activated macrophages. Gene and protein expression levels of intra- and extracellular galectins were investigated by qRT-PCR, Western-blot, flow cytometry, and ELISA while cytokine and surface receptor expression profiling was performed by flow cytometry.
  
  
  RESULTS
  Differentiation/polarization of human monocytes into classically (M1) and alternatively (M2a/M2c) activated macrophages was followed by profound changes of galectin-3 expression and its proteolytic cleavage. Expression and secretion of Gal-3 was tightly regulated and significantly differed among classically (M1) and alternatively (M2a/M2c) activated macrophages, while the differences of galectin-1 expression profiles were not as pronounced. Human monocytes exhibited high amount of free galectin-3 receptors, while on both types of activated macrophages were fully saturated.
  
  
  CONCLUSIONS
  Galectin-3 is more distinctive descriptor of macrophages differentiation/activation than galectin-1. Its specific expression and secretion pattern in M1 vs. M2a/M2c macrophages contributes to better understanding of its role and regulation in these cells.
  
  
  CONCLUSIONS
  Recognition of distinct galectin-1 and galectin-3 expression profiles in differently activated macrophages provides a new insight on biological characteristics of these cells and sheds a new light of galectin-3 as a modulator of individual macrophage subset. This article is part of a Special Issue entitled Glycoproteomics.
authors.affiliation: University of Zagreb, Faculty of Pharmacy and Biochemistry, Department of Biochemistry and Molecular Biology, Zagreb, Croatia.
authors.forename: Ruder
authors.initials: R
authors.lastname: Novak
authors.forename: Sanja
authors.initials: S
authors.lastname: Dabelic
authors.forename: Jerka
authors.initials: J
authors.lastname: Dumic
mesh_terms: D000328:Adult; D002454:Cell Differentiation / Q000235:genetics; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D037483:Galectin 1 / Q000235:genetics* / Q000378:metabolism; D037502:Galectin 3 / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008262:Macrophage Activation / Q000235:genetics* / Q000502:physiology; D008264:Macrophages / Q000378:metabolism* / Q000502:physiology; D055442:Metabolome / Q000502:physiology; D009000:Monocytes / Q000378:metabolism / Q000502:physiology; D011485:Protein Binding / Q000235:genetics; D059467:Transcriptome; D015854:Up-Regulation / Q000235:genetics
chemical_list: D037483:Galectin 1; D037502:Galectin 3