title: Impact of estrogens on atherosclerosis and bone in the apolipoprotein E-deficient mouse model.
abstract: OBJECTIVE
  The common inflammatory pathophysiology has nourished the hypothesis of a relationship between osteoporosis and cardiovascular disease. Estrogens are key agents in the modulation of both processes. We investigated whether induction of atherosclerosis affects bone and whether estrogens modulate both processes.
  
  
  METHODS
  Female apolipoprotein E-deficient mice (a well-established model of atherogenesis) were ovariectomized or falsely operated and fed either standard diet or high-fat diet (HFD). Six animals were included in each of the four groups. To clarify mechanisms, we treated preosteoblastic MC3T3-E1 cells with mouse serum.
  
  
  RESULTS
  Physiological levels of estrogens in falsely operated mice limited atherosclerotic burden in the thoracic aorta, but not in the aortic arch. Bone resorption, as assessed by C-telopeptides, was increased by ovariectomy in animals fed standard diet, but not in animals fed HFD. Bone microstructural properties at the distal femur showed deteriorated trabecular architecture in bone volumetric fraction and trabecular number after ovariectomy, but trabecular pattern factor, trabecular thickness, trabecular spacing, or the structural model index remained unchanged. Changes in cortical parameters were not significant. Volumetric bone mineral density was reduced in trabecular bone, but not in cortical bone, in ovariectomized mice fed standard diet. Preosteoblastic MC3T3-E1 cells exhibited increased cellular proliferation and viability and alkaline phosphatase activity after treatment with sera from animals fed HFD.
  
  
  CONCLUSIONS
  Endogenous estrogens partially reduce atherogenic burden in female apolipoprotein E-deficient mice. Ovariectomy increases bone resorption, but not under exacerbated proatherogenic conditions induced by HFD. The absence of apolipoprotein E might have an influence on the asymmetric responses of atherogenesis and bone resorption.
authors.affiliation: From the 1Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana, Valencia, Spain; 2Vascular Biology Unit, Department of Molecular and Cellular Pathology and Therapy, Instituto de Biomedicina de Valencia, Valencia, Spain; 3Service of Orthopedic Surgery, Complexo Hospitalario Universitario de Santiago de Compostela, A Coruña, Spain; 4Trabeculae SL, San Cibrao das Viñas, Ourense, Spain; 5Department of Functional Biology and Physical Anthropology, Faculty of Biological Sciences, University of Valencia, Valencia, Spain; 6Laboratory of Molecular and Genetic Cardiovascular Pathophysiology, Department of Epidemiology, Atherothrombosis, and Imaging, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain; 7Department of Pediatrics, Obstetrics, and Gynecology, University of Valencia, Valencia, Spain; and 8Service of Obstetrics and Gynecology, Hospital Universitario Dr. Peset, Valencia, Spain.
authors.forename: María Leonor
authors.initials: ML
authors.lastname: Fernández-Murga
authors.forename: Ángela
authors.initials: Á
authors.lastname: Vinué
authors.forename: José Ramón
authors.initials: JR
authors.lastname: Caeiro
authors.forename: David
authors.initials: D
authors.lastname: Guede
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Tarín
authors.forename: Vicente
authors.initials: V
authors.lastname: Andrés
authors.forename: Antonio
authors.initials: A
authors.lastname: Cano
mesh_terms: D000818:Animals; D001057:Apolipoproteins E / Q000172:deficiency*; D050197:Atherosclerosis / Q000378:metabolism / Q000517:prevention & control*; D015519:Bone Density; D001862:Bone Resorption; D059305:Diet, High-Fat; D004195:Disease Models, Animal; D004967:Estrogens / Q000502:physiology*; D005260:Female; D006801:Humans; D051379:Mice; D010024:Osteoporosis / Q000517:prevention & control*; D010052:Ovariectomy
chemical_list: D001057:Apolipoproteins E; D004967:Estrogens