Limits...
PI3K p110γ deletion attenuates murine atherosclerosis by reducing macrophage proliferation but not polarization or apoptosis in lesions.

Zotes TM, Arias CF, Fuster JJ, Spada R, Pérez-Yagüe S, Hirsch E, Wymann M, Carrera AC, Andrés V, Barber DF - PLoS ONE (2013)

Bottom Line: Atherosclerosis is an inflammatory disease regulated by infiltrating monocytes and T cells, among other cell types.We analyzed atherosclerosis development in LDLR(-/-)p110γ(+/-) and LDLR(-/-)p110γ(-/-) mice, and performed expression and functional assays in tissues and primary cells from these and from p110γ(+/-) and p110γ(-/-) mice.Lack of p110γ in LDLR(-/-) mice reduces the atherosclerosis burden.

View Article: PubMed Central - PubMed

Affiliation: Department of Immunology and Oncology, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas (CNB-CSIC), Madrid, Spain.

ABSTRACT
Atherosclerosis is an inflammatory disease regulated by infiltrating monocytes and T cells, among other cell types. Macrophage recruitment to atherosclerotic lesions is controlled by monocyte infiltration into plaques. Once in the lesion, macrophage proliferation in situ, apoptosis, and differentiation to an inflammatory (M1) or anti-inflammatory phenotype (M2) are involved in progression to advanced atherosclerotic lesions. We studied the role of phosphoinositol-3-kinase (PI3K) p110γ in the regulation of in situ apoptosis, macrophage proliferation and polarization towards M1 or M2 phenotypes in atherosclerotic lesions. We analyzed atherosclerosis development in LDLR(-/-)p110γ(+/-) and LDLR(-/-)p110γ(-/-) mice, and performed expression and functional assays in tissues and primary cells from these and from p110γ(+/-) and p110γ(-/-) mice. Lack of p110γ in LDLR(-/-) mice reduces the atherosclerosis burden. Atherosclerotic lesions in fat-fed LDLR(-/-)p110γ(-/-) mice were smaller than in LDLR(-/-)p110γ(+/-) controls, which coincided with decreased macrophage proliferation in LDLR(-/-)p110γ(-/-) mouse lesions. This proliferation defect was also observed in p110γ(-/-) bone marrow-derived macrophages (BMM) stimulated with macrophage colony-stimulating factor (M-CSF), and was associated with higher intracellular cyclic adenosine monophosphate (cAMP) levels. In contrast, T cell proliferation was unaffected in LDLR(-/-)p110γ(-/-) mice. Moreover, p110γ deficiency did not affect macrophage polarization towards the M1 or M2 phenotypes or apoptosis in atherosclerotic plaques, or polarization in cultured BMM. Our results suggest that higher cAMP levels and the ensuing inhibition of macrophage proliferation contribute to atheroprotection in LDLR(-/-) mice lacking p110γ. Nonetheless, p110γ deletion does not appear to be involved in apoptosis, in macrophage polarization or in T cell proliferation.

Show MeSH

Related in: MedlinePlus

Macrophage proliferation in aortic plaque is impaired in LDLR−/−p110γ−/− mice whereas T cell proliferation is unaffected.Atherosclerotic plaques were studied in LDLR−/−p110γ+/− (female, n = 5) and LDLR−/−p110γ−/− (female, n = 6) mice after two months on a high-fat diet. (A) Representative photomicrographs of immunofluorescent staining for macrophage proliferation in aortic sections. Bar = 30 μm. (B) Percentage of proliferating relative to total macrophages in lesion area. (C) Representative photomicrographs of immunofluorescent staining for T cell proliferation in aortic sections. Bar = 50 μm. (D) Percentage of proliferating T cells relative to total T cells in lesion area, quantified with ImageJ. (E) Percentage of bone marrow-derived macrophages (BMM) in G2/M, S and G0/G1 phases at 26 h post-M-CSF stimulation in LDLR−/−p110γ+/− and LDLR−/−p110γ−/− mice (n = 3 experiments, each with a pool of 3 mice/genotype). Mean ± SD; Student’s t-test, p<0.05 (for B, D, E).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3750002&req=5

pone-0072674-g002: Macrophage proliferation in aortic plaque is impaired in LDLR−/−p110γ−/− mice whereas T cell proliferation is unaffected.Atherosclerotic plaques were studied in LDLR−/−p110γ+/− (female, n = 5) and LDLR−/−p110γ−/− (female, n = 6) mice after two months on a high-fat diet. (A) Representative photomicrographs of immunofluorescent staining for macrophage proliferation in aortic sections. Bar = 30 μm. (B) Percentage of proliferating relative to total macrophages in lesion area. (C) Representative photomicrographs of immunofluorescent staining for T cell proliferation in aortic sections. Bar = 50 μm. (D) Percentage of proliferating T cells relative to total T cells in lesion area, quantified with ImageJ. (E) Percentage of bone marrow-derived macrophages (BMM) in G2/M, S and G0/G1 phases at 26 h post-M-CSF stimulation in LDLR−/−p110γ+/− and LDLR−/−p110γ−/− mice (n = 3 experiments, each with a pool of 3 mice/genotype). Mean ± SD; Student’s t-test, p<0.05 (for B, D, E).

Mentions: Macrophage proliferation in lesions enhances atherosclerosis progression to more advanced disease stages [15]. To determine whether the reduced atherosclerosis burden in LDLR−/−p110γ−/− mice correlated with cell proliferation defects in lesions, we performed double immunofluorescence experiments in aortic cross-sections from high-fat diet-fed mice to test whether p110γ deficiency affected macrophage and T cell in situ proliferation (as assessed by Ki67 expression). These studies showed a significant reduction in the number of proliferating neointimal macrophages in LDLR−/−p110γ−/− compared to LDLR−/−p110γ +/− mice (Figure 2A, 2B). In contrast, p110γ deletion did not affect T cell proliferation (Figure 2C, 2D).


PI3K p110γ deletion attenuates murine atherosclerosis by reducing macrophage proliferation but not polarization or apoptosis in lesions.

Zotes TM, Arias CF, Fuster JJ, Spada R, Pérez-Yagüe S, Hirsch E, Wymann M, Carrera AC, Andrés V, Barber DF - PLoS ONE (2013)

Macrophage proliferation in aortic plaque is impaired in LDLR−/−p110γ−/− mice whereas T cell proliferation is unaffected.Atherosclerotic plaques were studied in LDLR−/−p110γ+/− (female, n = 5) and LDLR−/−p110γ−/− (female, n = 6) mice after two months on a high-fat diet. (A) Representative photomicrographs of immunofluorescent staining for macrophage proliferation in aortic sections. Bar = 30 μm. (B) Percentage of proliferating relative to total macrophages in lesion area. (C) Representative photomicrographs of immunofluorescent staining for T cell proliferation in aortic sections. Bar = 50 μm. (D) Percentage of proliferating T cells relative to total T cells in lesion area, quantified with ImageJ. (E) Percentage of bone marrow-derived macrophages (BMM) in G2/M, S and G0/G1 phases at 26 h post-M-CSF stimulation in LDLR−/−p110γ+/− and LDLR−/−p110γ−/− mice (n = 3 experiments, each with a pool of 3 mice/genotype). Mean ± SD; Student’s t-test, p<0.05 (for B, D, E).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3750002&req=5

pone-0072674-g002: Macrophage proliferation in aortic plaque is impaired in LDLR−/−p110γ−/− mice whereas T cell proliferation is unaffected.Atherosclerotic plaques were studied in LDLR−/−p110γ+/− (female, n = 5) and LDLR−/−p110γ−/− (female, n = 6) mice after two months on a high-fat diet. (A) Representative photomicrographs of immunofluorescent staining for macrophage proliferation in aortic sections. Bar = 30 μm. (B) Percentage of proliferating relative to total macrophages in lesion area. (C) Representative photomicrographs of immunofluorescent staining for T cell proliferation in aortic sections. Bar = 50 μm. (D) Percentage of proliferating T cells relative to total T cells in lesion area, quantified with ImageJ. (E) Percentage of bone marrow-derived macrophages (BMM) in G2/M, S and G0/G1 phases at 26 h post-M-CSF stimulation in LDLR−/−p110γ+/− and LDLR−/−p110γ−/− mice (n = 3 experiments, each with a pool of 3 mice/genotype). Mean ± SD; Student’s t-test, p<0.05 (for B, D, E).
Mentions: Macrophage proliferation in lesions enhances atherosclerosis progression to more advanced disease stages [15]. To determine whether the reduced atherosclerosis burden in LDLR−/−p110γ−/− mice correlated with cell proliferation defects in lesions, we performed double immunofluorescence experiments in aortic cross-sections from high-fat diet-fed mice to test whether p110γ deficiency affected macrophage and T cell in situ proliferation (as assessed by Ki67 expression). These studies showed a significant reduction in the number of proliferating neointimal macrophages in LDLR−/−p110γ−/− compared to LDLR−/−p110γ +/− mice (Figure 2A, 2B). In contrast, p110γ deletion did not affect T cell proliferation (Figure 2C, 2D).

Bottom Line: Atherosclerosis is an inflammatory disease regulated by infiltrating monocytes and T cells, among other cell types.We analyzed atherosclerosis development in LDLR(-/-)p110γ(+/-) and LDLR(-/-)p110γ(-/-) mice, and performed expression and functional assays in tissues and primary cells from these and from p110γ(+/-) and p110γ(-/-) mice.Lack of p110γ in LDLR(-/-) mice reduces the atherosclerosis burden.

View Article: PubMed Central - PubMed

Affiliation: Department of Immunology and Oncology, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas (CNB-CSIC), Madrid, Spain.

ABSTRACT
Atherosclerosis is an inflammatory disease regulated by infiltrating monocytes and T cells, among other cell types. Macrophage recruitment to atherosclerotic lesions is controlled by monocyte infiltration into plaques. Once in the lesion, macrophage proliferation in situ, apoptosis, and differentiation to an inflammatory (M1) or anti-inflammatory phenotype (M2) are involved in progression to advanced atherosclerotic lesions. We studied the role of phosphoinositol-3-kinase (PI3K) p110γ in the regulation of in situ apoptosis, macrophage proliferation and polarization towards M1 or M2 phenotypes in atherosclerotic lesions. We analyzed atherosclerosis development in LDLR(-/-)p110γ(+/-) and LDLR(-/-)p110γ(-/-) mice, and performed expression and functional assays in tissues and primary cells from these and from p110γ(+/-) and p110γ(-/-) mice. Lack of p110γ in LDLR(-/-) mice reduces the atherosclerosis burden. Atherosclerotic lesions in fat-fed LDLR(-/-)p110γ(-/-) mice were smaller than in LDLR(-/-)p110γ(+/-) controls, which coincided with decreased macrophage proliferation in LDLR(-/-)p110γ(-/-) mouse lesions. This proliferation defect was also observed in p110γ(-/-) bone marrow-derived macrophages (BMM) stimulated with macrophage colony-stimulating factor (M-CSF), and was associated with higher intracellular cyclic adenosine monophosphate (cAMP) levels. In contrast, T cell proliferation was unaffected in LDLR(-/-)p110γ(-/-) mice. Moreover, p110γ deficiency did not affect macrophage polarization towards the M1 or M2 phenotypes or apoptosis in atherosclerotic plaques, or polarization in cultured BMM. Our results suggest that higher cAMP levels and the ensuing inhibition of macrophage proliferation contribute to atheroprotection in LDLR(-/-) mice lacking p110γ. Nonetheless, p110γ deletion does not appear to be involved in apoptosis, in macrophage polarization or in T cell proliferation.

Show MeSH
Related in: MedlinePlus