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Impaired Vitamin D Signaling in Endothelial Cell Leads to an Enhanced Leukocyte-Endothelium Interplay: Implications for Atherosclerosis Development.

Bozic M, Álvarez Á, de Pablo C, Sanchez-Niño MD, Ortiz A, Dolcet X, Encinas M, Fernandez E, Valdivielso JM - PLoS ONE (2015)

Bottom Line: Inhibition of NF-κB activation with super-repressor IκBα blunted all signs of endothelial cell activation caused by downregulation of VDR in endothelial cells.In vivo, deletion of VDR led to significantly larger aortic arch and aortic root lesions in apoE-/- mice, with higher macrophage content. apoE-/-VDR-/-mice showed higher aortic expression of VCAM-1, ICAM-1 and IL-6 when compared to apoE-/-VDR+/+ mice.Our data demonstrate that lack of VDR signaling in endothelial cells leads to a state of endothelial activation with increased leukocyte-endothelial cell interactions that may contribute to the more severe plaque accumulation observed in apoE-/-VDR-/- mice.

View Article: PubMed Central - PubMed

Affiliation: Nephrology Research Department, IRB Lleida, Lleida, Spain.

ABSTRACT
Endothelial cell activation leading to leukocyte recruitment and adhesion plays an essential role in the initiation and progression of atherosclerosis. Vitamin D has cardioprotective actions, while its deficiency is a risk factor for the progression of cardiovascular damage. Our aim was to assess the role of basal levels of vitamin D receptor (VDR) on the early leukocyte recruitment and related endothelial cell-adhesion-molecule expression, as essential prerequisites for the onset of atherosclerosis. Knockdown of VDR in endothelial cells (shVDR) led to endothelial cell activation, characterized by upregulation of VCAM-1, ICAM-1 and IL-6, decreased peripheral blood mononuclear cell (PBMC) rolling velocity and increased PBMC rolling flux and adhesion to the endothelium. shVDR cells showed decreased IκBα levels and accumulation of p65 in the nucleus compared to shRNA controls. Inhibition of NF-κB activation with super-repressor IκBα blunted all signs of endothelial cell activation caused by downregulation of VDR in endothelial cells. In vivo, deletion of VDR led to significantly larger aortic arch and aortic root lesions in apoE-/- mice, with higher macrophage content. apoE-/-VDR-/-mice showed higher aortic expression of VCAM-1, ICAM-1 and IL-6 when compared to apoE-/-VDR+/+ mice. Our data demonstrate that lack of VDR signaling in endothelial cells leads to a state of endothelial activation with increased leukocyte-endothelial cell interactions that may contribute to the more severe plaque accumulation observed in apoE-/-VDR-/- mice. The results reveal an important role for basal levels of endothelial VDR in limiting endothelial cell inflammation and atherosclerosis.

No MeSH data available.


Related in: MedlinePlus

VDR deletion accelerates atherosclerosis in apoE-/- mice.apoE-/- and apoE-/-VDR-/- mice were fed a high fat-rescue diet (HFRD) for 8 weeks. (A) Aortas were stained with Oil-Red O, opened longitudinally and pinned onto a black wax surface. Luminal side of the aorta is displayed, showing red lipid-rich atherosclerotic lesions within aortic arch and thoracic aorta. (B) Quantitative analysis of atherosclerotic lesion size within aortic arch and thoracic aorta. Data presented are mean ± SEM of 14–15 mice/group. *p<0.05 vs. apoE-/-. (C) Quantitative analysis of atherosclerotic lesion size within aortic arch in males and females of apoE-/- and apoE-/-VDR-/- mice. Data presented are mean ± SEM of 10 mice/group *p<0.05 vs. apoE-/-. (D) Quantitative analysis of atherosclerotic lesion size within aortic root. Five cross sections (spanning 640 μm of the aortic root) were analyzed per mouse, as explained in Methods. Data presented are mean ± SEM of n = 10 mice/group. ##p<0.0005.
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pone.0136863.g004: VDR deletion accelerates atherosclerosis in apoE-/- mice.apoE-/- and apoE-/-VDR-/- mice were fed a high fat-rescue diet (HFRD) for 8 weeks. (A) Aortas were stained with Oil-Red O, opened longitudinally and pinned onto a black wax surface. Luminal side of the aorta is displayed, showing red lipid-rich atherosclerotic lesions within aortic arch and thoracic aorta. (B) Quantitative analysis of atherosclerotic lesion size within aortic arch and thoracic aorta. Data presented are mean ± SEM of 14–15 mice/group. *p<0.05 vs. apoE-/-. (C) Quantitative analysis of atherosclerotic lesion size within aortic arch in males and females of apoE-/- and apoE-/-VDR-/- mice. Data presented are mean ± SEM of 10 mice/group *p<0.05 vs. apoE-/-. (D) Quantitative analysis of atherosclerotic lesion size within aortic root. Five cross sections (spanning 640 μm of the aortic root) were analyzed per mouse, as explained in Methods. Data presented are mean ± SEM of n = 10 mice/group. ##p<0.0005.

Mentions: To study the functional role of VDR in atherosclerosis, we generated animals lacking both VDR (VDR-/-) and apoE (apoE-/-) gene. Three months old apoE-/-VDR-/- double knockout mice (DKO) and corresponding apoE-/-VDR+/+ mice (from now on termed apoE-/-) were fed a high fat rescue diet (HFRD) and drinking water containing 1% Ca-gluconate for 8 weeks. Atherosclerosis burden was quantified by planimetric analysis of whole-mounted oil Red-O-stained aortic arch and thoracic aorta and by analyzing cross-sections through the valve area of the aortic root. apoE-/-VDR-/- mice demonstrated significantly enhanced atherosclerotic lesion formation in the aortic arch region (1.7-fold, p<0.0103), compared with apoE-/-mice (Fig 4A and 4B). The size of the plaque was also evaluated within each gender. Quantitative analysis showed significant increases in the lesion area of 2.5-fold in DKO males and 1.7-fold in DKO females compared with apoE-/- counterparts (Fig 4C). In contrast, VDR deletion did not affect atheroma size in the thoracic aorta (Fig 4A and 4B). Consistent with the data from the en face method, cross-sectional examination of the valve area of the aortic root revealed that VDR deletion markedly accelerated atherosclerotic plaque formation in this highly susceptible region (2.04-fold, p<0,0002) (Fig 4D). Under the conditions of HFRD, both groups of mice maintained normal serum levels of calcium (8.8–10 mg/dL) and phosphate (5.5–6.01 mg/dL) (S1 Fig). Nevertheless, serum calcium concentrations of apoE-/-VDR-/- mice were significantly lower than those of single apoE-/- animals (S1 Fig).


Impaired Vitamin D Signaling in Endothelial Cell Leads to an Enhanced Leukocyte-Endothelium Interplay: Implications for Atherosclerosis Development.

Bozic M, Álvarez Á, de Pablo C, Sanchez-Niño MD, Ortiz A, Dolcet X, Encinas M, Fernandez E, Valdivielso JM - PLoS ONE (2015)

VDR deletion accelerates atherosclerosis in apoE-/- mice.apoE-/- and apoE-/-VDR-/- mice were fed a high fat-rescue diet (HFRD) for 8 weeks. (A) Aortas were stained with Oil-Red O, opened longitudinally and pinned onto a black wax surface. Luminal side of the aorta is displayed, showing red lipid-rich atherosclerotic lesions within aortic arch and thoracic aorta. (B) Quantitative analysis of atherosclerotic lesion size within aortic arch and thoracic aorta. Data presented are mean ± SEM of 14–15 mice/group. *p<0.05 vs. apoE-/-. (C) Quantitative analysis of atherosclerotic lesion size within aortic arch in males and females of apoE-/- and apoE-/-VDR-/- mice. Data presented are mean ± SEM of 10 mice/group *p<0.05 vs. apoE-/-. (D) Quantitative analysis of atherosclerotic lesion size within aortic root. Five cross sections (spanning 640 μm of the aortic root) were analyzed per mouse, as explained in Methods. Data presented are mean ± SEM of n = 10 mice/group. ##p<0.0005.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4556440&req=5

pone.0136863.g004: VDR deletion accelerates atherosclerosis in apoE-/- mice.apoE-/- and apoE-/-VDR-/- mice were fed a high fat-rescue diet (HFRD) for 8 weeks. (A) Aortas were stained with Oil-Red O, opened longitudinally and pinned onto a black wax surface. Luminal side of the aorta is displayed, showing red lipid-rich atherosclerotic lesions within aortic arch and thoracic aorta. (B) Quantitative analysis of atherosclerotic lesion size within aortic arch and thoracic aorta. Data presented are mean ± SEM of 14–15 mice/group. *p<0.05 vs. apoE-/-. (C) Quantitative analysis of atherosclerotic lesion size within aortic arch in males and females of apoE-/- and apoE-/-VDR-/- mice. Data presented are mean ± SEM of 10 mice/group *p<0.05 vs. apoE-/-. (D) Quantitative analysis of atherosclerotic lesion size within aortic root. Five cross sections (spanning 640 μm of the aortic root) were analyzed per mouse, as explained in Methods. Data presented are mean ± SEM of n = 10 mice/group. ##p<0.0005.
Mentions: To study the functional role of VDR in atherosclerosis, we generated animals lacking both VDR (VDR-/-) and apoE (apoE-/-) gene. Three months old apoE-/-VDR-/- double knockout mice (DKO) and corresponding apoE-/-VDR+/+ mice (from now on termed apoE-/-) were fed a high fat rescue diet (HFRD) and drinking water containing 1% Ca-gluconate for 8 weeks. Atherosclerosis burden was quantified by planimetric analysis of whole-mounted oil Red-O-stained aortic arch and thoracic aorta and by analyzing cross-sections through the valve area of the aortic root. apoE-/-VDR-/- mice demonstrated significantly enhanced atherosclerotic lesion formation in the aortic arch region (1.7-fold, p<0.0103), compared with apoE-/-mice (Fig 4A and 4B). The size of the plaque was also evaluated within each gender. Quantitative analysis showed significant increases in the lesion area of 2.5-fold in DKO males and 1.7-fold in DKO females compared with apoE-/- counterparts (Fig 4C). In contrast, VDR deletion did not affect atheroma size in the thoracic aorta (Fig 4A and 4B). Consistent with the data from the en face method, cross-sectional examination of the valve area of the aortic root revealed that VDR deletion markedly accelerated atherosclerotic plaque formation in this highly susceptible region (2.04-fold, p<0,0002) (Fig 4D). Under the conditions of HFRD, both groups of mice maintained normal serum levels of calcium (8.8–10 mg/dL) and phosphate (5.5–6.01 mg/dL) (S1 Fig). Nevertheless, serum calcium concentrations of apoE-/-VDR-/- mice were significantly lower than those of single apoE-/- animals (S1 Fig).

Bottom Line: Inhibition of NF-κB activation with super-repressor IκBα blunted all signs of endothelial cell activation caused by downregulation of VDR in endothelial cells.In vivo, deletion of VDR led to significantly larger aortic arch and aortic root lesions in apoE-/- mice, with higher macrophage content. apoE-/-VDR-/-mice showed higher aortic expression of VCAM-1, ICAM-1 and IL-6 when compared to apoE-/-VDR+/+ mice.Our data demonstrate that lack of VDR signaling in endothelial cells leads to a state of endothelial activation with increased leukocyte-endothelial cell interactions that may contribute to the more severe plaque accumulation observed in apoE-/-VDR-/- mice.

View Article: PubMed Central - PubMed

Affiliation: Nephrology Research Department, IRB Lleida, Lleida, Spain.

ABSTRACT
Endothelial cell activation leading to leukocyte recruitment and adhesion plays an essential role in the initiation and progression of atherosclerosis. Vitamin D has cardioprotective actions, while its deficiency is a risk factor for the progression of cardiovascular damage. Our aim was to assess the role of basal levels of vitamin D receptor (VDR) on the early leukocyte recruitment and related endothelial cell-adhesion-molecule expression, as essential prerequisites for the onset of atherosclerosis. Knockdown of VDR in endothelial cells (shVDR) led to endothelial cell activation, characterized by upregulation of VCAM-1, ICAM-1 and IL-6, decreased peripheral blood mononuclear cell (PBMC) rolling velocity and increased PBMC rolling flux and adhesion to the endothelium. shVDR cells showed decreased IκBα levels and accumulation of p65 in the nucleus compared to shRNA controls. Inhibition of NF-κB activation with super-repressor IκBα blunted all signs of endothelial cell activation caused by downregulation of VDR in endothelial cells. In vivo, deletion of VDR led to significantly larger aortic arch and aortic root lesions in apoE-/- mice, with higher macrophage content. apoE-/-VDR-/-mice showed higher aortic expression of VCAM-1, ICAM-1 and IL-6 when compared to apoE-/-VDR+/+ mice. Our data demonstrate that lack of VDR signaling in endothelial cells leads to a state of endothelial activation with increased leukocyte-endothelial cell interactions that may contribute to the more severe plaque accumulation observed in apoE-/-VDR-/- mice. The results reveal an important role for basal levels of endothelial VDR in limiting endothelial cell inflammation and atherosclerosis.

No MeSH data available.


Related in: MedlinePlus