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Galectin-2 induces a proinflammatory, anti-arteriogenic phenotype in monocytes and macrophages.

Yıldırım C, Vogel DY, Hollander MR, Baggen JM, Fontijn RD, Nieuwenhuis S, Haverkamp A, de Vries MR, Quax PH, Garcia-Vallejo JJ, van der Laan AM, Dijkstra CD, van der Pouw Kraan TC, van Royen N, Horrevoets AJ - PLoS ONE (2015)

Bottom Line: The inhibiting effect of galectin-2 on arteriogenesis was confirmed in vivo, but the mechanism is largely unknown.Furthermore, galectin-2 skews human macrophages to a M1-like proinflammatory phenotype, characterized by a reduced motility and expression of an anti-arteriogenic cytokine/growth factor repertoire.This is accompanied by a switch in surface protein expression to CD40-high and CD206-low (M1).

View Article: PubMed Central - PubMed

Affiliation: Dept of Molecular Cell Biology and Immunology, VU University Medical Centre, Amsterdam, the Netherlands.

ABSTRACT
Galectin-2 is a monocyte-expressed carbohydrate-binding lectin, for which increased expression is genetically determined and associated with decreased collateral arteriogenesis in obstructive coronary artery disease patients. The inhibiting effect of galectin-2 on arteriogenesis was confirmed in vivo, but the mechanism is largely unknown. In this study we aimed to explore the effects of galectin-2 on monocyte/macrophage phenotype in vitro and vivo, and to identify the receptor by which galectin-2 exerts these effects. We now show that the binding of galectin-2 to different circulating human monocyte subsets is dependent on monocyte surface expression levels of CD14. The high affinity binding is blocked by an anti-CD14 antibody but not by carbohydrates, indicating a specific protein-protein interaction. Galectin-2 binding to human monocytes modulated their transcriptome by inducing proinflammatory cytokines and inhibiting pro-arteriogenic factors, while attenuating monocyte migration. Using specific knock-out mice, we show that galectin-2 acts through the CD14/toll-like receptor (TLR)-4 pathway. Furthermore, galectin-2 skews human macrophages to a M1-like proinflammatory phenotype, characterized by a reduced motility and expression of an anti-arteriogenic cytokine/growth factor repertoire. This is accompanied by a switch in surface protein expression to CD40-high and CD206-low (M1). In a murine model we show that galectin-2 administration, known to attenuate arteriogenesis, leads to increased numbers of CD40-positive (M1) and reduced numbers of CD206-positive (M2) macrophages surrounding actively remodeling collateral arteries. In conclusion galectin-2 is the first endogenous CD14/TLR4 ligand that induces a proinflammatory, non-arteriogenic phenotype in monocytes/macrophages. Interference with CD14-Galectin-2 interaction may provide a new intervention strategy to stimulate growth of collateral arteries in genetically compromised cardiovascular patients.

No MeSH data available.


Related in: MedlinePlus

Human galectin-2 induces proinflammatory- and reduces proarteriogenic gene expression in monocytes.Human monocytes were incubated with rh-gal-2 or LPS for three hours in the presence or absence of PMB. Proinflammatory (A) and proarteriogenic (B) gene expression was determined by real-time PCR. (C) Lactose does not influence rh-gal-2-induced expression of proinflammatory genes, quantified relative to untreated sample (set at 1). Results represent mean ± SEM from at least 3 independent experiments. *P < 0.05, **P < 0.01, ****P< 0.0001.
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pone.0124347.g003: Human galectin-2 induces proinflammatory- and reduces proarteriogenic gene expression in monocytes.Human monocytes were incubated with rh-gal-2 or LPS for three hours in the presence or absence of PMB. Proinflammatory (A) and proarteriogenic (B) gene expression was determined by real-time PCR. (C) Lactose does not influence rh-gal-2-induced expression of proinflammatory genes, quantified relative to untreated sample (set at 1). Results represent mean ± SEM from at least 3 independent experiments. *P < 0.05, **P < 0.01, ****P< 0.0001.

Mentions: To study the biological consequences of monocyte/galectin-2 interaction, we determined the effect of galectin-2 on pro- and anti-inflammatory gene expression. We observed a significant increase in the expression of proinflammatory genes such as TNF-α, IL-6, IL12-p40 and IFN-β upon incubation of monocytes with human galectin-2. In contrast to LPS-induced expression of these cytokines, their galectin-2 induced expression was not affected by polymyxin B (Fig 3A). Consistently, involvement of LPS in binding of galectin-2 to monocytes was excluded by FACS analysis, as binding was not affected by Polymyxin B (data not shown). These results show that the observed proinflammatory effects specifically result from galectin-2 and do not result from the presence of LPS contaminations in the galectin-2 preparations used.


Galectin-2 induces a proinflammatory, anti-arteriogenic phenotype in monocytes and macrophages.

Yıldırım C, Vogel DY, Hollander MR, Baggen JM, Fontijn RD, Nieuwenhuis S, Haverkamp A, de Vries MR, Quax PH, Garcia-Vallejo JJ, van der Laan AM, Dijkstra CD, van der Pouw Kraan TC, van Royen N, Horrevoets AJ - PLoS ONE (2015)

Human galectin-2 induces proinflammatory- and reduces proarteriogenic gene expression in monocytes.Human monocytes were incubated with rh-gal-2 or LPS for three hours in the presence or absence of PMB. Proinflammatory (A) and proarteriogenic (B) gene expression was determined by real-time PCR. (C) Lactose does not influence rh-gal-2-induced expression of proinflammatory genes, quantified relative to untreated sample (set at 1). Results represent mean ± SEM from at least 3 independent experiments. *P < 0.05, **P < 0.01, ****P< 0.0001.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4401781&req=5

pone.0124347.g003: Human galectin-2 induces proinflammatory- and reduces proarteriogenic gene expression in monocytes.Human monocytes were incubated with rh-gal-2 or LPS for three hours in the presence or absence of PMB. Proinflammatory (A) and proarteriogenic (B) gene expression was determined by real-time PCR. (C) Lactose does not influence rh-gal-2-induced expression of proinflammatory genes, quantified relative to untreated sample (set at 1). Results represent mean ± SEM from at least 3 independent experiments. *P < 0.05, **P < 0.01, ****P< 0.0001.
Mentions: To study the biological consequences of monocyte/galectin-2 interaction, we determined the effect of galectin-2 on pro- and anti-inflammatory gene expression. We observed a significant increase in the expression of proinflammatory genes such as TNF-α, IL-6, IL12-p40 and IFN-β upon incubation of monocytes with human galectin-2. In contrast to LPS-induced expression of these cytokines, their galectin-2 induced expression was not affected by polymyxin B (Fig 3A). Consistently, involvement of LPS in binding of galectin-2 to monocytes was excluded by FACS analysis, as binding was not affected by Polymyxin B (data not shown). These results show that the observed proinflammatory effects specifically result from galectin-2 and do not result from the presence of LPS contaminations in the galectin-2 preparations used.

Bottom Line: The inhibiting effect of galectin-2 on arteriogenesis was confirmed in vivo, but the mechanism is largely unknown.Furthermore, galectin-2 skews human macrophages to a M1-like proinflammatory phenotype, characterized by a reduced motility and expression of an anti-arteriogenic cytokine/growth factor repertoire.This is accompanied by a switch in surface protein expression to CD40-high and CD206-low (M1).

View Article: PubMed Central - PubMed

Affiliation: Dept of Molecular Cell Biology and Immunology, VU University Medical Centre, Amsterdam, the Netherlands.

ABSTRACT
Galectin-2 is a monocyte-expressed carbohydrate-binding lectin, for which increased expression is genetically determined and associated with decreased collateral arteriogenesis in obstructive coronary artery disease patients. The inhibiting effect of galectin-2 on arteriogenesis was confirmed in vivo, but the mechanism is largely unknown. In this study we aimed to explore the effects of galectin-2 on monocyte/macrophage phenotype in vitro and vivo, and to identify the receptor by which galectin-2 exerts these effects. We now show that the binding of galectin-2 to different circulating human monocyte subsets is dependent on monocyte surface expression levels of CD14. The high affinity binding is blocked by an anti-CD14 antibody but not by carbohydrates, indicating a specific protein-protein interaction. Galectin-2 binding to human monocytes modulated their transcriptome by inducing proinflammatory cytokines and inhibiting pro-arteriogenic factors, while attenuating monocyte migration. Using specific knock-out mice, we show that galectin-2 acts through the CD14/toll-like receptor (TLR)-4 pathway. Furthermore, galectin-2 skews human macrophages to a M1-like proinflammatory phenotype, characterized by a reduced motility and expression of an anti-arteriogenic cytokine/growth factor repertoire. This is accompanied by a switch in surface protein expression to CD40-high and CD206-low (M1). In a murine model we show that galectin-2 administration, known to attenuate arteriogenesis, leads to increased numbers of CD40-positive (M1) and reduced numbers of CD206-positive (M2) macrophages surrounding actively remodeling collateral arteries. In conclusion galectin-2 is the first endogenous CD14/TLR4 ligand that induces a proinflammatory, non-arteriogenic phenotype in monocytes/macrophages. Interference with CD14-Galectin-2 interaction may provide a new intervention strategy to stimulate growth of collateral arteries in genetically compromised cardiovascular patients.

No MeSH data available.


Related in: MedlinePlus