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RGS1 regulates myeloid cell accumulation in atherosclerosis and aortic aneurysm rupture through altered chemokine signalling.

Patel J, McNeill E, Douglas G, Hale AB, de Bono J, Lee R, Iqbal AJ, Regan-Komito D, Stylianou E, Greaves DR, Channon KM - Nat Commun (2015)

Bottom Line: Regulator of G-Protein Signalling-1 (RGS1) deactivates G-protein signalling, reducing the response to sustained chemokine stimulation.Rgs1 reduces macrophage chemotaxis and desensitizes chemokine receptor signalling.Collectively, these data reveal a role for Rgs1 in leukocyte trafficking and vascular inflammation and identify Rgs1, and inhibition of chemokine receptor signalling as potential therapeutic targets in vascular disease.

View Article: PubMed Central - PubMed

Affiliation: 1] Division of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK [2] Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK.

ABSTRACT
Chemokine signalling drives monocyte recruitment in atherosclerosis and aortic aneurysms. The mechanisms that lead to retention and accumulation of macrophages in the vascular wall remain unclear. Regulator of G-Protein Signalling-1 (RGS1) deactivates G-protein signalling, reducing the response to sustained chemokine stimulation. Here we show that Rgs1 is upregulated in atherosclerotic plaque and aortic aneurysms. Rgs1 reduces macrophage chemotaxis and desensitizes chemokine receptor signalling. In early atherosclerotic lesions, Rgs1 regulates macrophage accumulation and is required for the formation and rupture of Angiotensin II-induced aortic aneurysms, through effects on leukocyte retention. Collectively, these data reveal a role for Rgs1 in leukocyte trafficking and vascular inflammation and identify Rgs1, and inhibition of chemokine receptor signalling as potential therapeutic targets in vascular disease.

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Rgs1 is upregulated by inflammatory stimuli in activated monocytes.(a) Confirmation of Rgs1 mRNA changes in thoracic aortas of ApoE−/− mice and wild-type controls on a high-fat diet (n=5 per group) by qRT–PCR. (b) Rgs1 expression is correlated with the expression of the macrophage marker Cd68 in thoracic aortas of ApoE−/− mice and wild-type controls on a high-fat diet. Each symbol represents an individual mouse (n=5 per group) by qRT–PCR. (c) qRT–PCR analysis of Rgs1 mRNA in primary cells isolated from ApoE−/− mice (n=5–6; BC, B cells; BM, bone marrow cells; EC, endothelial cells; MΦ, macrophages; S, splenocytes). (d) qRT-PCR analysis of Rgs1 expression in human tissue and cells. (Mo; Blood monocytes, plaque macrophages from carotid endarterectomies (n=3), SV; Saphenous vein and IMA; internal mammary artery from CABGs (n=8), OA; omental artery and AAA; abdominal aortic aneurysm from AAA repair patients (n=8–11)). (e) SV and IMA are from CABGs. qRT–PCR analysis of Rgs1 mRNA in Ly6G-7/4hi BM monocytes and peritoneal monocytes isolated from zymosan-induced peritonitis (ZIP) in ApoE−/− mice (n=6–7 per group). (f) qRT–PCR analysis of Rgs1 mRNA in bone marrow-derived macrophages from ApoE−/− mice stimulated with IFN-γ and lipopolysaccharide (M1) and unstimulated (M0) over 24 h presented relative to mRNA in unstimulated cells, set as 1. *P<0.05, **P<0.01 calculated using the Student’s t-test (Data in a are expressed as mean±s.d. and data in c–f as mean±s.e.m.).
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f1: Rgs1 is upregulated by inflammatory stimuli in activated monocytes.(a) Confirmation of Rgs1 mRNA changes in thoracic aortas of ApoE−/− mice and wild-type controls on a high-fat diet (n=5 per group) by qRT–PCR. (b) Rgs1 expression is correlated with the expression of the macrophage marker Cd68 in thoracic aortas of ApoE−/− mice and wild-type controls on a high-fat diet. Each symbol represents an individual mouse (n=5 per group) by qRT–PCR. (c) qRT–PCR analysis of Rgs1 mRNA in primary cells isolated from ApoE−/− mice (n=5–6; BC, B cells; BM, bone marrow cells; EC, endothelial cells; MΦ, macrophages; S, splenocytes). (d) qRT-PCR analysis of Rgs1 expression in human tissue and cells. (Mo; Blood monocytes, plaque macrophages from carotid endarterectomies (n=3), SV; Saphenous vein and IMA; internal mammary artery from CABGs (n=8), OA; omental artery and AAA; abdominal aortic aneurysm from AAA repair patients (n=8–11)). (e) SV and IMA are from CABGs. qRT–PCR analysis of Rgs1 mRNA in Ly6G-7/4hi BM monocytes and peritoneal monocytes isolated from zymosan-induced peritonitis (ZIP) in ApoE−/− mice (n=6–7 per group). (f) qRT–PCR analysis of Rgs1 mRNA in bone marrow-derived macrophages from ApoE−/− mice stimulated with IFN-γ and lipopolysaccharide (M1) and unstimulated (M0) over 24 h presented relative to mRNA in unstimulated cells, set as 1. *P<0.05, **P<0.01 calculated using the Student’s t-test (Data in a are expressed as mean±s.d. and data in c–f as mean±s.e.m.).

Mentions: To identify genes that are specifically regulated with atherosclerosis progression, we used a whole mouse genome array to profile the gene expression in the thoracic aortas from ApoE−/− mice, comparing older atherosclerotic ApoE−/− mice with young littermate animals before plaque development (Supplementary Table 1). Among a number of genes already known to play major roles in the development of atherosclerosis such as Ccl2 (MCP-1), Rgs1 was identified as one of the novel candidate genes with higher expression in aortas from older ApoE−/− mice than in aortas from younger ApoE−/− mice. We confirmed that Rgs1 mRNA was upregulated in aortas from atherosclerotic ApoE−/− mice compared with younger ApoE−/− mice (8 weeks, male mice) or wild-type C57BL/6 mice of the same age (16 weeks, male mice) by quantitative reverse transcriptase-PCR (qRT–PCR) (Fig. 1a). The high expression of Rgs1 was associated with the high expression of the macrophage marker Cd68 in individual animals, suggesting that macrophages may be the source of RGS1 in atherosclerotic plaques (Fig. 1b). To test this hypothesis, we quantified Rgs1 expression in different primary cells isolated from ApoE−/− mice and found high Rgs1 mRNA levels in CD68 positive macrophages compared with B cells where Rgs1 is known to have a non-redundant role (Fig. 1c). In contrast, we did not detect Rgs1 mRNA in either vascular smooth muscle cells (VSMCs) or endothelial cells, which are also known to be involved in atherosclerotic plaque progression (Fig. 1c).


RGS1 regulates myeloid cell accumulation in atherosclerosis and aortic aneurysm rupture through altered chemokine signalling.

Patel J, McNeill E, Douglas G, Hale AB, de Bono J, Lee R, Iqbal AJ, Regan-Komito D, Stylianou E, Greaves DR, Channon KM - Nat Commun (2015)

Rgs1 is upregulated by inflammatory stimuli in activated monocytes.(a) Confirmation of Rgs1 mRNA changes in thoracic aortas of ApoE−/− mice and wild-type controls on a high-fat diet (n=5 per group) by qRT–PCR. (b) Rgs1 expression is correlated with the expression of the macrophage marker Cd68 in thoracic aortas of ApoE−/− mice and wild-type controls on a high-fat diet. Each symbol represents an individual mouse (n=5 per group) by qRT–PCR. (c) qRT–PCR analysis of Rgs1 mRNA in primary cells isolated from ApoE−/− mice (n=5–6; BC, B cells; BM, bone marrow cells; EC, endothelial cells; MΦ, macrophages; S, splenocytes). (d) qRT-PCR analysis of Rgs1 expression in human tissue and cells. (Mo; Blood monocytes, plaque macrophages from carotid endarterectomies (n=3), SV; Saphenous vein and IMA; internal mammary artery from CABGs (n=8), OA; omental artery and AAA; abdominal aortic aneurysm from AAA repair patients (n=8–11)). (e) SV and IMA are from CABGs. qRT–PCR analysis of Rgs1 mRNA in Ly6G-7/4hi BM monocytes and peritoneal monocytes isolated from zymosan-induced peritonitis (ZIP) in ApoE−/− mice (n=6–7 per group). (f) qRT–PCR analysis of Rgs1 mRNA in bone marrow-derived macrophages from ApoE−/− mice stimulated with IFN-γ and lipopolysaccharide (M1) and unstimulated (M0) over 24 h presented relative to mRNA in unstimulated cells, set as 1. *P<0.05, **P<0.01 calculated using the Student’s t-test (Data in a are expressed as mean±s.d. and data in c–f as mean±s.e.m.).
© Copyright Policy - open-access
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f1: Rgs1 is upregulated by inflammatory stimuli in activated monocytes.(a) Confirmation of Rgs1 mRNA changes in thoracic aortas of ApoE−/− mice and wild-type controls on a high-fat diet (n=5 per group) by qRT–PCR. (b) Rgs1 expression is correlated with the expression of the macrophage marker Cd68 in thoracic aortas of ApoE−/− mice and wild-type controls on a high-fat diet. Each symbol represents an individual mouse (n=5 per group) by qRT–PCR. (c) qRT–PCR analysis of Rgs1 mRNA in primary cells isolated from ApoE−/− mice (n=5–6; BC, B cells; BM, bone marrow cells; EC, endothelial cells; MΦ, macrophages; S, splenocytes). (d) qRT-PCR analysis of Rgs1 expression in human tissue and cells. (Mo; Blood monocytes, plaque macrophages from carotid endarterectomies (n=3), SV; Saphenous vein and IMA; internal mammary artery from CABGs (n=8), OA; omental artery and AAA; abdominal aortic aneurysm from AAA repair patients (n=8–11)). (e) SV and IMA are from CABGs. qRT–PCR analysis of Rgs1 mRNA in Ly6G-7/4hi BM monocytes and peritoneal monocytes isolated from zymosan-induced peritonitis (ZIP) in ApoE−/− mice (n=6–7 per group). (f) qRT–PCR analysis of Rgs1 mRNA in bone marrow-derived macrophages from ApoE−/− mice stimulated with IFN-γ and lipopolysaccharide (M1) and unstimulated (M0) over 24 h presented relative to mRNA in unstimulated cells, set as 1. *P<0.05, **P<0.01 calculated using the Student’s t-test (Data in a are expressed as mean±s.d. and data in c–f as mean±s.e.m.).
Mentions: To identify genes that are specifically regulated with atherosclerosis progression, we used a whole mouse genome array to profile the gene expression in the thoracic aortas from ApoE−/− mice, comparing older atherosclerotic ApoE−/− mice with young littermate animals before plaque development (Supplementary Table 1). Among a number of genes already known to play major roles in the development of atherosclerosis such as Ccl2 (MCP-1), Rgs1 was identified as one of the novel candidate genes with higher expression in aortas from older ApoE−/− mice than in aortas from younger ApoE−/− mice. We confirmed that Rgs1 mRNA was upregulated in aortas from atherosclerotic ApoE−/− mice compared with younger ApoE−/− mice (8 weeks, male mice) or wild-type C57BL/6 mice of the same age (16 weeks, male mice) by quantitative reverse transcriptase-PCR (qRT–PCR) (Fig. 1a). The high expression of Rgs1 was associated with the high expression of the macrophage marker Cd68 in individual animals, suggesting that macrophages may be the source of RGS1 in atherosclerotic plaques (Fig. 1b). To test this hypothesis, we quantified Rgs1 expression in different primary cells isolated from ApoE−/− mice and found high Rgs1 mRNA levels in CD68 positive macrophages compared with B cells where Rgs1 is known to have a non-redundant role (Fig. 1c). In contrast, we did not detect Rgs1 mRNA in either vascular smooth muscle cells (VSMCs) or endothelial cells, which are also known to be involved in atherosclerotic plaque progression (Fig. 1c).

Bottom Line: Regulator of G-Protein Signalling-1 (RGS1) deactivates G-protein signalling, reducing the response to sustained chemokine stimulation.Rgs1 reduces macrophage chemotaxis and desensitizes chemokine receptor signalling.Collectively, these data reveal a role for Rgs1 in leukocyte trafficking and vascular inflammation and identify Rgs1, and inhibition of chemokine receptor signalling as potential therapeutic targets in vascular disease.

View Article: PubMed Central - PubMed

Affiliation: 1] Division of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK [2] Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK.

ABSTRACT
Chemokine signalling drives monocyte recruitment in atherosclerosis and aortic aneurysms. The mechanisms that lead to retention and accumulation of macrophages in the vascular wall remain unclear. Regulator of G-Protein Signalling-1 (RGS1) deactivates G-protein signalling, reducing the response to sustained chemokine stimulation. Here we show that Rgs1 is upregulated in atherosclerotic plaque and aortic aneurysms. Rgs1 reduces macrophage chemotaxis and desensitizes chemokine receptor signalling. In early atherosclerotic lesions, Rgs1 regulates macrophage accumulation and is required for the formation and rupture of Angiotensin II-induced aortic aneurysms, through effects on leukocyte retention. Collectively, these data reveal a role for Rgs1 in leukocyte trafficking and vascular inflammation and identify Rgs1, and inhibition of chemokine receptor signalling as potential therapeutic targets in vascular disease.

Show MeSH
Related in: MedlinePlus