engleski

Intracellular distribution of galectin-3 in LPS-activated macrophage-like cells

Galectin-3, a β -galactoside binding lectin exerts important roles in many biological and (pato)physiological processes (adhesion, proliferation, differentiation, apoptosis, inflammation, neoplastic transformation, spreading metastases). Being one of the key lectins of innate and acquired immunity, galectin-3 is considered a powerful pro-inflammatory signal. It triggers/promotes respiratory burst in monocytes, acts as a monocyte/macrophage chemoattractant and promotes survival of inflammatory cells through its anti-apoptotic activity. Expression of galectin-3 was suggested to be regulated through MAPK signaling pathway and NF-κ B and AP-1 transcription factors. The aim of this study was to ascertain the level of galectin-3 expression in physiological and patophysiological processes of monocytes. Flow cytometry (Beckmann Coulter FC500) was used to determine the level of membrane and intracellular galectin-3 expression. As a model, we used lipopolysaccharide (LPS) activated and phorbol 12-myristate-13-acetate (PMA) differentiated THP-1 monocytic cell-line, cultured in RPMI 1640, supplemented with 10% FCS and antibiotics. Galectin-3 was detected using anti-human galectin-3 antibodies, following FITC-labeled secondary antibody. Dead cells were excluded as 7AAD positive. Macrophage-like morphology was confirmed by an elevated CD14 stain and surface adhesion. THP-1 cells, activated by E. coli LPS, have markedly up-regulated expression of intracellular galectin-3, while the surface level remains largely unchanged, in respect to the controls. Differentiation of monocytes to macrophages is associated with an increase of surface galectin-3 in respect to control cells. Given the importance of galectin-3 in monocyte/macrophage physiology, further experiments are necessary to elucidate the regulatory pathways governing its expression in immune cells.

galectin-3; monocyte/macrophages; flow cytometry

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