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Local delivery of polarized macrophages improves reperfusion recovery in a mouse hind limb ischemia model.

Jetten N, Donners MM, Wagenaar A, Cleutjens JP, van Rooijen N, de Winther MP, Post MJ - PLoS ONE (2013)

Bottom Line: Depletion of circulating monocytes by clodronate liposome injections did not hamper reperfusion recovery, however, treatment with exogenous polarized macrophages improved perfusion ratio after 14 days again.Deletion of the IL10-receptor (IL10R) in the myeloid lineage did not affect reperfusion recovery, yet the pro-arteriogenic effect of exogenously injected M2c macrophages was still present.This is the first study using local injection of macrophage subsets showing the pro-arteriogenic effect of polarized macrophages.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Genetics, Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands.

ABSTRACT

Aims: Enhancement of collateral development in coronary or peripheral artery disease is a therapeutic target, but it has proven difficult to achieve. Macrophages are key players in collateral remodeling, yet the effect of different macrophage subsets on arteriogenesis has not been investigated.

Methods and results: Murine macrophages were cultured from bone marrow and polarized into M1 (IFNγ), M2a (IL-4) or M2c (IL-10) subsets. C57BL/6 mice underwent femoral artery ligation followed by intramuscular injection of macrophage subsets. Using eGFP expressing macrophages, cells could be detected at least 6 days after ligation and were located in the perivascular space of collateral vessels. After 14 days, perfusion ratio was increased in animals treated with M1 as well as M2a and M2c macrophages compared to control. Depletion of circulating monocytes by clodronate liposome injections did not hamper reperfusion recovery, however, treatment with exogenous polarized macrophages improved perfusion ratio after 14 days again. We used IL10R(fl/fl)/LysMCre(+) mice to study the effect of inhibition of endogenous polarization towards specifically M2c macrophages on arteriogenesis. Deletion of the IL10-receptor (IL10R) in the myeloid lineage did not affect reperfusion recovery, yet the pro-arteriogenic effect of exogenously injected M2c macrophages was still present.

Conclusions: Local injection of polarized macrophages promotes reperfusion recovery after femoral artery ligation and is not influenced by depletion of circulatory monocytes. Preventing endogenous M2c polarization did not affect reperfusion recovery suggesting that M2c's are not required for collateralization, but are sufficient to induce collateral formation upon exogenous administration. This is the first study using local injection of macrophage subsets showing the pro-arteriogenic effect of polarized macrophages.

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Effect of inhibiting endogenous macrophage polarization (n=9).Reperfusion recovery in IL10R1fl/fl/LysMCre- (WT) and IL10R1fl/fl/LysMCre+ (KO) mice. Treatment with M2c macrophages improves reperfusion recovery in IL10R1fl/fl/LysMCre+ mice after 14 days compared to untreated animals (*: p<0.05).
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pone-0068811-g005: Effect of inhibiting endogenous macrophage polarization (n=9).Reperfusion recovery in IL10R1fl/fl/LysMCre- (WT) and IL10R1fl/fl/LysMCre+ (KO) mice. Treatment with M2c macrophages improves reperfusion recovery in IL10R1fl/fl/LysMCre+ mice after 14 days compared to untreated animals (*: p<0.05).

Mentions: In order to study the effect of endogenously polarized M2c macrophages we used mice with a conditional deletion for the IL10 receptor (IL10R1fl/fl/LysMCre+) on myeloid cells. Consequently, macrophages of these mice are not responsive to IL10 and cannot polarize towards an M2c phenotype. After 14 days, a slight delay in reperfusion recovery could be observed in IL10R1fl/fl/LysMCre+ (57.9% ± 0.195) compared to IL10R1fl/fl/LysMCre- animals (67.5% ± 0.146), although the effect was not significant. When exogenous M2c macrophages were injected into the adductor muscle of IL10R1fl/fl/LysMCre+ mice, reperfusion recovery improved significantly (76.2% ± 0.217, p<0.05) compared to the IL10R1fl/fl/LysMCre+ without macrophage treatment (Figure 5). This indicates that reperfusion recovery is not dependent on endogenous polarization of M2c macrophages and that treatment with exogenously polarized cells positively influences arteriogenesis.


Local delivery of polarized macrophages improves reperfusion recovery in a mouse hind limb ischemia model.

Jetten N, Donners MM, Wagenaar A, Cleutjens JP, van Rooijen N, de Winther MP, Post MJ - PLoS ONE (2013)

Effect of inhibiting endogenous macrophage polarization (n=9).Reperfusion recovery in IL10R1fl/fl/LysMCre- (WT) and IL10R1fl/fl/LysMCre+ (KO) mice. Treatment with M2c macrophages improves reperfusion recovery in IL10R1fl/fl/LysMCre+ mice after 14 days compared to untreated animals (*: p<0.05).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3722193&req=5

pone-0068811-g005: Effect of inhibiting endogenous macrophage polarization (n=9).Reperfusion recovery in IL10R1fl/fl/LysMCre- (WT) and IL10R1fl/fl/LysMCre+ (KO) mice. Treatment with M2c macrophages improves reperfusion recovery in IL10R1fl/fl/LysMCre+ mice after 14 days compared to untreated animals (*: p<0.05).
Mentions: In order to study the effect of endogenously polarized M2c macrophages we used mice with a conditional deletion for the IL10 receptor (IL10R1fl/fl/LysMCre+) on myeloid cells. Consequently, macrophages of these mice are not responsive to IL10 and cannot polarize towards an M2c phenotype. After 14 days, a slight delay in reperfusion recovery could be observed in IL10R1fl/fl/LysMCre+ (57.9% ± 0.195) compared to IL10R1fl/fl/LysMCre- animals (67.5% ± 0.146), although the effect was not significant. When exogenous M2c macrophages were injected into the adductor muscle of IL10R1fl/fl/LysMCre+ mice, reperfusion recovery improved significantly (76.2% ± 0.217, p<0.05) compared to the IL10R1fl/fl/LysMCre+ without macrophage treatment (Figure 5). This indicates that reperfusion recovery is not dependent on endogenous polarization of M2c macrophages and that treatment with exogenously polarized cells positively influences arteriogenesis.

Bottom Line: Depletion of circulating monocytes by clodronate liposome injections did not hamper reperfusion recovery, however, treatment with exogenous polarized macrophages improved perfusion ratio after 14 days again.Deletion of the IL10-receptor (IL10R) in the myeloid lineage did not affect reperfusion recovery, yet the pro-arteriogenic effect of exogenously injected M2c macrophages was still present.This is the first study using local injection of macrophage subsets showing the pro-arteriogenic effect of polarized macrophages.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Genetics, Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands.

ABSTRACT

Aims: Enhancement of collateral development in coronary or peripheral artery disease is a therapeutic target, but it has proven difficult to achieve. Macrophages are key players in collateral remodeling, yet the effect of different macrophage subsets on arteriogenesis has not been investigated.

Methods and results: Murine macrophages were cultured from bone marrow and polarized into M1 (IFNγ), M2a (IL-4) or M2c (IL-10) subsets. C57BL/6 mice underwent femoral artery ligation followed by intramuscular injection of macrophage subsets. Using eGFP expressing macrophages, cells could be detected at least 6 days after ligation and were located in the perivascular space of collateral vessels. After 14 days, perfusion ratio was increased in animals treated with M1 as well as M2a and M2c macrophages compared to control. Depletion of circulating monocytes by clodronate liposome injections did not hamper reperfusion recovery, however, treatment with exogenous polarized macrophages improved perfusion ratio after 14 days again. We used IL10R(fl/fl)/LysMCre(+) mice to study the effect of inhibition of endogenous polarization towards specifically M2c macrophages on arteriogenesis. Deletion of the IL10-receptor (IL10R) in the myeloid lineage did not affect reperfusion recovery, yet the pro-arteriogenic effect of exogenously injected M2c macrophages was still present.

Conclusions: Local injection of polarized macrophages promotes reperfusion recovery after femoral artery ligation and is not influenced by depletion of circulatory monocytes. Preventing endogenous M2c polarization did not affect reperfusion recovery suggesting that M2c's are not required for collateralization, but are sufficient to induce collateral formation upon exogenous administration. This is the first study using local injection of macrophage subsets showing the pro-arteriogenic effect of polarized macrophages.

Show MeSH