Androgen-Induced Progression of Arterial Calcification in Apolipoprotein E-Null Mice Is Uncoupled from Plaque Growth and Lipid Levels

Arterial calcification has prognostic significance for cardiovascular outcomes, but its pathogenesis remains unclear. Calcification increases with age, but its prevalence in men suggests hormonal influence. In this study we analyzed the effect of exogenous androgens on calcification of advanced atherosclerotic lesions in the arterial tree of gonadally intact 34-wk-old male and female apolipoprotein E-null mice. Testosterone (T) increased calcification 3- to 4-fold (P < 0.05) in lesions of the innominate artery and aortic sinus. A nonaromatizable androgen, dihydrotestosterone, also increased lesion calcification in the innominate artery (2.4-fold, P < 0.05) but not the aortic sinus. The androgen-induced effects were independent of sex and occurred despite corresponding reductions in plaque area, the latter correlating inversely with increased serum high-density lipoprotein cholesterol levels. Androgen-induced calcification in the innominate artery was observed with up-regulation of local androgen receptor (AR) expression in response to T and dihydrotestosterone for both males and females but neither androgen influenced innominate artery estrogen receptor (ER)-α or -β expression in either sex. Conversely, T-induced calcification in the aortic sinus was associated with down-regulation of ERα but not ERβ expression in both sexes, whereas androgen-induced AR expression was increased in female but decreased in male mice. This study demonstrates for the first time that calcification of advanced atherosclerotic lesions is an androgen-sensitive process and postulates potential roles for both AR- and ER-mediated pathways in androgen-induced vascular calcification. We demonstrate a novel direct link between vascular calcification and the major male hormone, T, uncoupled from conventional relationships with plaque growth and lipid levels. Calcification of advanced atherosclerotic lesions is an androgen-sensitive process whereby testosterone uncouples conventional relationships between plaque growth and lipid levels.

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Pravastatin attenuates atherosclerosis after myocardial infarction by inhibiting inflammatory Ly6Chigh monocytosis in apolipoprotein E knockout mice

Journal of International Medical Research ◽

10.1177/0300060520932816 ◽

2020 ◽

Vol 48 (7) ◽

pp. 030006052093281

Author(s):

Yufei Chen ◽

Hongqi Zhang ◽

Liang Hu ◽

Haiming Shi ◽

Xiaojin Liu ◽

...

Keyword(s):

Myocardial Infarction ◽

Cardiac Function ◽

Apolipoprotein E ◽

Monocyte Subset ◽

Aortic Sinus ◽

Aortic Lesion ◽

Atherosclerotic Lesions ◽

Apolipoprotein E Knockout Mice ◽

Oil Red O Staining ◽

Oil Red O

Objective To evaluate the protective effect of pravastatin on atherosclerotic development and inflammatory monocyte subset in atherosclerotic apolipoprotein E (ApoE)−/− mice after myocardial infarction (MI). Methods Male ApoE−/− mice (8 weeks old) were fed a high-fat diet for 14 weeks throughout the experiment. A MI model was produced using 18-week-old ApoE−/− mice. They were randomly divided into three groups: sham group, MI group, and MI+Pra group (40 mg/kg/day pravastatin). After 4 weeks (at the end of the study period), the mice were sacrificed and cardiac function was evaluated by echocardiography. Aortic lesion areas were evaluated using oil red O staining. Plaque macrophage in aortic sinus was analyzed by immunofluorescence staining. Flow cytometry was used to explore the proportions of monocyte subsets in the blood, spleen, and bone marrow． Results Pravastatin improved cardiac function and reduced lesion areas. It also attenuated the supply of monocytes in spleen, especially the inflammatory Ly6Chigh monocyte subset. Pravastatin also subsequently reduced macrophage accumulation in atherosclerotic lesions. Conclusions MI accelerated chronic atherosclerosis progress. Pravastatin suppressed atherosclerotic development and inhibited inflammatory monocytosis after MI in ApoE−/− mice.

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MO750THE COMBINED PROGNOSTIC SIGNIFICANCE OF ALKALINE PHOSPHATASE AND INTRA-CRANIAL ARTERIAL CALCIFICATIONS IN HEMODIALYSIS PATIENTS

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gfab097.0030 ◽

2021 ◽

Vol 36 (Supplement_1) ◽

Author(s):

Keren Cohen Hagai ◽

Daniel Erez ◽

Tali Zitman-Gal ◽

Feda Fanadka ◽

Yael Einbinder ◽

...

Keyword(s):

Alkaline Phosphatase ◽

Vascular Calcification ◽

Bone Disease ◽

Prognostic Significance ◽

Elevated Serum ◽

Hemodialysis Patients ◽

Arterial Calcification ◽

Odds Ratios ◽

Risk Of Death ◽

All Cause Mortality

Abstract Background and Aims Intra-cranial arterial calcification (ICAC) in hemodialysis (HD) patients has a prevalence of about 90%, and its severity is correlated with age, hemodialysis vintage and mineral bone disease. Elevated concentrations of calcium and phosphorus are not sufficient to induce medial calcification because of inhibition by pyrophosphate. Alkaline Phosphatase (ALP) promotes vascular calcification by hydrolyzing pyrophosphate. Epigenetic mechanisms regulation by Apabetalone downregulates pathways involved in vascular calcification. This study assessed the combined impact of ICAC and elevated serum ALP on mortality among chronic HD patients. Method vascular calcifications represented by ICAC were measured simultaneous with mineral bone disease parameters including serum ALP of chronic HD patients who underwent non-contrast brain computerized tomography (CT) from 2015 to 2018 in our institution. Results This retrospective study included 153 hemodialysis patients (mean age 71.3±12.1 years, 60.1% male). Of the total cohort, 12(7.8%) had no brain calcifications and 69 (45.1%) had multiple intracranial calcifications. Considering the patients with normal ALP and no calcification as the reference group yielded adjusted odds ratios for all-cause mortality of 4.6 (95%CI 1.7-12.7) among patients with brain calcifications and normal ALP, p=0.003, and odds ratios for all-cause mortality of 6.1 (95%CI 2.1-17.7) among patients with brain calcifications and increased ALP. Conclusion We founded an independent association between ICAC and the risk of death among hemodialysis patients. The combined effect of ICAC and increased ALP was significantly associated with higher odds-ratio for all-cause mortality in chronic HD patients and may contribute to the risk stratification of these patients.

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The effects of miR-467b on lipoprotein lipase (LPL) expression, pro-inflammatory cytokine, lipid levels and atherosclerotic lesions in apolipoprotein E knockout mice

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2013.11.109 ◽

2014 ◽

Vol 443 (2) ◽

pp. 428-434 ◽

Cited By ~ 24

Author(s):

Guo-Ping Tian ◽

Yan-Yan Tang ◽

Ping-Ping He ◽

Yun-Cheng Lv ◽

Xin-Pin Ouyang ◽

...

Keyword(s):

Apolipoprotein E ◽

Lipoprotein Lipase ◽

Knockout Mice ◽

Inflammatory Cytokine ◽

Lipid Levels ◽

Atherosclerotic Lesions ◽

Apolipoprotein E Knockout Mice

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Faculty Opinions recommendation of Glucose-6-phosphate dehydrogenase deficiency decreases vascular superoxide and atherosclerotic lesions in apolipoprotein E(-/-) mice.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1031533.367722 ◽

2006 ◽

Author(s):

Fabio Recchia

Keyword(s):

Apolipoprotein E ◽

Dehydrogenase Deficiency ◽

Atherosclerotic Lesions ◽

Glucose 6 Phosphate Dehydrogenase

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Atherosclerotic plaque disruption induced by stress and lipopolysaccharide in apolipoprotein E knockout mice

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.01202.2008 ◽

2009 ◽

Vol 296 (5) ◽

pp. H1598-H1606 ◽

Cited By ~ 33

Author(s):

Mei Ni ◽

Yan Wang ◽

Mei Zhang ◽

Peng Fei Zhang ◽

Shi Fang Ding ◽

...

Keyword(s):

Apolipoprotein E ◽

High Fat Diet ◽

Morphological Analysis ◽

Fibrous Cap ◽

Atherosclerotic Lesions ◽

Plaque Disruption ◽

Apolipoprotein E Knockout Mice ◽

Fibrous Cap Thickness ◽

And Control ◽

Disruption Rate

To establish an animal model with disruptions of atherosclerotic plaques, 96 male apolipoprotein E knockout (apoE−/−) mice were randomly divided into stress, lipopolysaccharide (LPS), stress+LPS, and control groups ( n = 24 each). All mice were fed a high-fat diet throughout the experiment, and carotid atherosclerotic lesions were induced by placement of a constrictive perivascular collar. Four weeks after surgery, mice in the LPS and stress+LPS groups were intraperitoneally injected with LPS (1 mg/kg twice per week for 8 wk). Eight weeks after surgery, mice in the stress and stress+LPS groups were treated with intermittent physical stress (electric foot shock and noise stimulation) for 4 wk. Morphological analysis revealed a plaque disruption rate of 16.7% in control, 34.8% in LPS, 54.2% in stress, and 60.9% in stress+LPS groups. The disruption rates in stress and stress+LPS groups were both significantly higher than those of controls ( P = 0.007 and P = 0.002, respectively). Luminal thrombosis secondary to plaque disruption was observed only in the stress+LPS group. Both stress and LPS stimulation significantly decreased fibrous cap thickness and increased macrophage and lipid contents in plaques. Moreover, the combination of stress and LPS stimulation further lowered cap thickness and enhanced accumulation of macrophages and expression of inflammatory cytokines and matrix metalloproteinases. Stress activated the sympathetic nervous system, as manifested by increased blood pressure and flow velocity. Plasma fibrinogen levels were remarkably elevated in the stress and stress+LPS groups. In conclusion, stress- and LPS-costimulated apoE−/− mice provide a useful model for studies of plaque vulnerability and interventions.

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Macrophage P53 controls foam cell death in atherosclerotic lesions of apolipoprotein E deficient mice

Vascular Pharmacology ◽

10.1016/j.vph.2006.08.061 ◽

2006 ◽

Vol 45 (3) ◽

pp. e4

Author(s):

Marion J.J. Gijbels ◽

Lianne S.M. Boesten ◽

A. Suzanne M. Zadelaar ◽

Aart G. Jochemsen ◽

Bob van de Water ◽

...

Keyword(s):

Cell Death ◽

Apolipoprotein E ◽

Foam Cell ◽

Atherosclerotic Lesions ◽

Deficient Mice

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Abstract 518: In Vitro and in vivo Disease Modeling Using Patient Derived iPSCs to Characterize the Calcification Phenotype in Arterial Calcification Due to Deficiency of CD73

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.36.suppl_1.518 ◽

2016 ◽

Vol 36 (suppl_1) ◽

Author(s):

Cynthia St. Hilaire ◽

Hui Jin ◽

Yuting Huang ◽

Dan Yang ◽

Alejandra Negro ◽

...

Keyword(s):

Vascular Calcification ◽

Disease Modeling ◽

Induced Pluripotent Stem Cell ◽

Dermal Fibroblasts ◽

In Vivo Studies ◽

Arterial Calcification ◽

Patient Specific ◽

And Control

Objective: The objective of this study was to develop a patient-specific induced pluripotent stem cell (iPSC)-based disease model to understand the process by which CD73-deficiency leads to vascular calcification in the disease, Arterial Calcification due to Deficiency of CD73 (ACDC). Approach & Results: ACDC is an autosomal recessive disease resulting from mutations in the gene encoding for CD73, which converts extracellular AMP to adenosine. CD73-deficiency manifests with tortuosity and vascular calcification of the medial layer of lower-extremity arteries, a pathology associated with diabetes and chronic kidney disease. We previously identified that dermal fibroblasts isolated from ACDC patients calcify in vitro, however in vivo studies of the vasculature are limited, as murine models of CD73 deficiency do not recapitulate the human disease phenotype. Thus, we created iPSCs from ACDC patients and control fibroblasts. ACDC and Control iPSCs form teratomas when injected in immune-compromised mice, however ACDC iPSC teratomas exhibit extensive calcifications. Control and ACDC iPSCs were differentiated down the mesenchymal lineage (MSC) and while there was no difference in chondrogenesis and adipogenesis, ACDC iMSCs underwent osteogenesis sooner than control iPSC, have higher activity of tissue-nonspecific alkaline phosphatase (TNAP), and lower levels of extracellular adenosine. During osteogenic simulation, TNAP activity in ACDC cells significantly increased adenosine levels, however, not to levels needed for functional compensatory stimulation of the adenosine receptors. Inhibition of TNAP with levimisole ablates this increase in adenosine. Treatment with an A2b adenosine receptor (AR) agonist drastically reduced TNAP activity in vitro, and calcification in ACDC teratomas, as did treatment with etidronate, which is currently being tested in a clinical trial on ACDC patients. Conclusions: These results illustrate a pro-osteogenic phenotype in CD73-deficient cells whereby TNAP activity attempts to compensate for CD73 deficiency, but subsequently induces calcification that can be reversed by activation of the A2bAR. The iPSC teratoma model may be used to screen other potential therapeutics for calcification disorders.

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Abstract 276: SR-BI Suppresses Apoptosis by Reducing Endoplasmic Reticulum Stress and Promoting Akt Activity in Macrophages

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.34.suppl_1.276 ◽

2014 ◽

Vol 34 (suppl_1) ◽

Author(s):

Huan Tao ◽

Patricia G Yancey ◽

Sean S Davies ◽

L Jackson Roberts ◽

John L Blakemore ◽

...

Keyword(s):

Endoplasmic Reticulum ◽

Apolipoprotein E ◽

Er Stress ◽

Cell Apoptosis ◽

Free Cholesterol ◽

Oxidized Ldl ◽

Tunel Staining ◽

Type I ◽

Apoptotic Cells ◽

Atherosclerotic Lesions

Objective: Macrophage apoptosis contributes to atherosclerotic plaque necrosis, inflammation, development and rupture. Scavenger receptor class B type I (SR-BI) is a key regulator of HDL metabolism and cellular cholesterol homeostasis. Here we examined the hypothesis that macrophage SR-BI modulates lipid-associated cellular stress and apoptosis. Methods and Results: In vitro cell apoptosis assays were performed in primary macrophages, and for in vivo evidence, we examined TUNEL staining of atherosclerotic lesions of LDLR -/- mice that were reconstituted with SR-BI -/- or WT bone marrow after 16 weeks on a Western diet. We found that SR-BI deficiency led to ~64.3% more apoptotic cells induced by oxidized LDL or free cholesterol in primary macrophages, and 6-fold more lesional apoptotic cells in SR-BI -/- →LDLR -/- mice compared to WT recipient mice. In macrophages, SR-BI deficiency caused significant accumulations of cellular free cholesterol and elevated markers of endoplasmic reticulum (ER) stress. These were exacerbated by feeding mice a high-cholesterol diet or inactivating the apolipoprotein E gene. Peroxidation of lipoproteins and cell membranes leads to modification of phosphatidylethanolamine by lipid aldehydes including isolevuglandins (IsoLG-PE). Treatment of macrophages with IsoLG-PE induced 52.6% more apoptotic cells in SR-BI -/- macrophages compared to WT. Transgenic expression of SR-BI by transfection of SR-BI -/- macrophages rescued oxidative stress-induced ER stress and cell apoptosis. SR-BI deficiency inhibited the Akt pathway compromising macrophage survival and increasing lesion necrosis. Moreover, Akt Activator was able to rescue SR-BI deficiency associated apoptosis in macrophages. Apolipoprotein E interacts with SR-BI in macrophages, co-operating for cellular lipid homeostasis and cell survival signaling. Conclusion: SR-BI protects against cell apoptosis induced by lipid stress in macrophages and atherosclerotic lesions. The underlying mechanisms are, at least in part, through reducing lipid-associated ER stress and promoting Akt activity in macrophages. Thus, we identify macrophage SR-BI-mediated apoptosis pathways as molecular targets for the prevention of atherosclerotic cardiovascular events.

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