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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 stimulation of macrophages results in gene transcription, and surface protein expression consistent with a polarized M1 phenotype.Differentiated human monocyte-derived macrophage subtypes were either left untreated (-), treated with vehicle (control) or rh-gal-2 for 24 hours. Macrophages were analyzed for the indicated M1 markers by real-time PCR (A) or flow cytometry (B). Representative histograms for CD40 expression are shown in panel B. Expression levels are expressed relative to M0 untreated samples (set at 1) as mean ± SEM from at least 3 independent experiments. *P < 0.05, **P < 0.01.
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pone.0124347.g005: Human galectin-2 stimulation of macrophages results in gene transcription, and surface protein expression consistent with a polarized M1 phenotype.Differentiated human monocyte-derived macrophage subtypes were either left untreated (-), treated with vehicle (control) or rh-gal-2 for 24 hours. Macrophages were analyzed for the indicated M1 markers by real-time PCR (A) or flow cytometry (B). Representative histograms for CD40 expression are shown in panel B. Expression levels are expressed relative to M0 untreated samples (set at 1) as mean ± SEM from at least 3 independent experiments. *P < 0.05, **P < 0.01.

Mentions: To assess the capacity of galectin-2 to induce a proinflammatory phenotype in the different macrophages subtypes, we studied gene expression of several M1 cytokines (IL12p40, TNF-α, IL-6, IFN-β)[17–21] and of the costimulatoryM1 moleculeCD40 by real-time PCR (RT-PCR)in M0, M1, and M2 macrophages. Human galectin-2 treatment induced gene expression of TNF-α, IL-6, CD40in M0 and M2 macrophages, and further increased the expression of IL-12p40 and IL-6 in M1 macrophages, while IFN-β expression was not affected (Fig 5A). Increased protein expression of CD40on M0 and M2 macrophages by galectin-2 was established using flow cytometry (Fig 5B). These results indicate that galectin-2 switches M0- and M2 macrophages towards a proinflammatoryM1 state, with surface protein expression of CD40.


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 stimulation of macrophages results in gene transcription, and surface protein expression consistent with a polarized M1 phenotype.Differentiated human monocyte-derived macrophage subtypes were either left untreated (-), treated with vehicle (control) or rh-gal-2 for 24 hours. Macrophages were analyzed for the indicated M1 markers by real-time PCR (A) or flow cytometry (B). Representative histograms for CD40 expression are shown in panel B. Expression levels are expressed relative to M0 untreated samples (set at 1) as mean ± SEM from at least 3 independent experiments. *P < 0.05, **P < 0.01.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0124347.g005: Human galectin-2 stimulation of macrophages results in gene transcription, and surface protein expression consistent with a polarized M1 phenotype.Differentiated human monocyte-derived macrophage subtypes were either left untreated (-), treated with vehicle (control) or rh-gal-2 for 24 hours. Macrophages were analyzed for the indicated M1 markers by real-time PCR (A) or flow cytometry (B). Representative histograms for CD40 expression are shown in panel B. Expression levels are expressed relative to M0 untreated samples (set at 1) as mean ± SEM from at least 3 independent experiments. *P < 0.05, **P < 0.01.
Mentions: To assess the capacity of galectin-2 to induce a proinflammatory phenotype in the different macrophages subtypes, we studied gene expression of several M1 cytokines (IL12p40, TNF-α, IL-6, IFN-β)[17–21] and of the costimulatoryM1 moleculeCD40 by real-time PCR (RT-PCR)in M0, M1, and M2 macrophages. Human galectin-2 treatment induced gene expression of TNF-α, IL-6, CD40in M0 and M2 macrophages, and further increased the expression of IL-12p40 and IL-6 in M1 macrophages, while IFN-β expression was not affected (Fig 5A). Increased protein expression of CD40on M0 and M2 macrophages by galectin-2 was established using flow cytometry (Fig 5B). These results indicate that galectin-2 switches M0- and M2 macrophages towards a proinflammatoryM1 state, with surface protein expression of CD40.

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