phytoestrogens and Vascular-Calcification

Postmenopausal women are at an increased risk of vascular calcification which is defined as the pathological deposition of minerals in the vasculature, and is strongly linked with increased cardiovascular disease risk. Since estrogen-replacement therapy is associated with increased cancer risk, there is a strong need for safer therapeutic approaches. In this study we aimed to investigate the protective and therapeutic effects of the phytoestrogen resveratrol against vascular calcification in ovariectomized rats, a preclinical model of postmenopause. Furthermore, we aimed to compare the effects of resveratrol to those of estrogen and to explore the mechanisms underpinning those effects. Treatment with resveratrol or estrogen ameliorated aortic calcification in ovariectomized rats, as shown by reduced calcium deposition in the arterial wall. Mechanistically, the effects of resveratrol and estrogen were mediated via the activation of SIRT1 signaling. SIRT1 protein expression was downregulated in the aortas of ovariectomized rats, and upregulated in rats treated with resveratrol or estrogen. Moreover, resveratrol and estrogen reduced the levels of the osteogenic markers: runt-related transcription factor 2 (RUNX2), osteocalcin and alkaline phosphatase (ALP) which have been shown to play a role during vascular calcification. Additionally, the senescence markers (p53, p16 and p21) which were also reported to play a role in the pathogenesis of vascular calcification, were reduced upon treatment with resveratrol and estrogen. In conclusion, the phytoestrogen resveratrol may be a safer alternative to estrogen, as a therapeutic approach against the progression of vascular calcification during postmenopause.

Topics: Animals; Aorta; Core Binding Factor Alpha 1 Subunit; Female; Osteogenesis; Ovariectomy; Phytoestrogens; Postmenopause; Rats; Resveratrol; Signal Transduction; Sirtuin 1; Vascular Calcification

Although soy phytoestrogen are proposed to prevent or improve postmenopausal vascular and bone diseases, the currently available data are controversial and unclear. In this study we evaluated the molecular and biochemical action of genistein on the cellular events involved in vascular calcification. Rat monocytes, aortic vascular cell and osteoblasts cultures in vitro exposed to Gen were employed. Gen down regulated the expression of cell adhesion molecules involved in stable leukocyte attachment. Using flow cytometry we found that the PE significantly diminished monocyte integrins CD11b, CD11c and CD18 expression either under basal and pro-inflammatory environment. At endothelial level, Gen also reduced Intercellular Adhesion Molecule 1 mRNA expression. On vascular muscle cells, the PE markedly reduced cell proliferation and migration. When vascular calcification was studied, muscle cells transdifferentiation into osteoblasts like cells was evaluated. Cells were cultured in osteogenic medium for 21 days. The expression of alkaline phosphatase and the presence of calcified nodules in the extracellular matrix were selected as features of muscle transdifferentiation. Calcified muscle cells exhibited higher levels of alkaline phosphatase activity and enhanced deposition of calcium nodules respect to native cells. Both osteoblastic markers were significantly reduced after Gen treatment. In contrast to this anti-osteogenic action, on bone cells Gen promoted osteoblasts growth, enhanced alkaline phosphatase activity and increased matrix mineralization. Its mitogenic action on osteoblasts directly depends on nitric oxide endothelial production stimulated by the PE. The data presented suppose a beneficial role of Gen on bone and vascular cells, with a cross link between both systems.

Topics: Animals; Animals, Newborn; Aorta; Biomarkers; Cell Movement; Cell Proliferation; Cell Transdifferentiation; Cells, Cultured; Dietary Supplements; Endothelium, Vascular; Female; Gene Expression Regulation; Genistein; Intercellular Adhesion Molecule-1; Monocytes; Muscle, Smooth, Vascular; Osteoblasts; Osteogenesis; Phytoestrogens; Rats, Wistar; Skull; Vascular Calcification

Several studies demonstrate that estradiol can prevent arterial calcification. However, little is known regarding the effect of puerarin, a phytoestrogen extracted from Radix Puerariae, on arterial calcification. The aim of the present study was to determine whether puerarin reduced osteoblastic differentiation of calcifying vascular smooth muscle cells (CVSMCs). The CVSMCs were isolated from mice aorta and treated with different concentrations of puerarin. The alkaline phosphatase (ALP) activity, osteocalcin secretion and Runx2 expression were determined. To examine whether estrogen receptors (ERs) PI3K and Akt play a role in this effect, ICI182789, phosphoinositide 3-kinase (PI3K) inhibitor, LY294002, or the Akt inhibitor, 1L-6-hydroxymethyl-chiro-inositol 2-(R)-2-O-methyl-3-O-octadecylcarbonate (HIMO) was used. Our results showed puerarin could inhibit ALP activity, osteocalcin secretion and Runx2 expression in CVSMCs. Puerarin could induce the activation of Akt. Furthermore, pretreatment of ICI182780, LY294002, HIMO could abolish the effect of puerarin on ALP activity in CVSMCs. Our experiment demonstrated that puerain could attenuate the osteoblastic differentiation of VSMCs through the ER/PI3K-Akt signal pathway.

Topics: Alkaline Phosphatase; Animals; Aorta; Cell Differentiation; Cells, Cultured; Core Binding Factor Alpha 1 Subunit; Endoplasmic Reticulum Stress; Isoflavones; Mice; Muscle, Smooth, Vascular; Osteoblasts; Osteocalcin; Phosphatidylinositol 3-Kinases; Phytoestrogens; Phytotherapy; Plant Roots; Proto-Oncogene Proteins c-akt; Pueraria; Signal Transduction; Vascular Calcification