Background: Androgen deficiency (AD) is associated with increased risk of atherosclerosis, cardiovascular, and peripheral arterial disease. Although the biochemical and molecular mechanisms underlying this risk remain unclear, higher testosterone (TST) levels correlate to significant immunoprotective molecular and cellular responses. Our group has previously demonstrated that female sex hormones influence vascular pathogenesis via inflammatory-modulated matrix metalloproteinase (MMP) regulation. Here we investigated the role of AD and androgen replacement therapy in the modulation of these hormonally responsive pathways that could be playing a role in the development of vascular pathogenesis.Methods: Aged orchiectomized male rats underwent TST supplementation per controlled release pellet implantation (0-150 mg). Young and aged intact groups served as controls. Serum was collected at 0-4 wk and analyzed by enzyme-linked immunosorbent assays, qualitative cytokine screening, and quantitative multiplex analyses. Human aortic smooth muscle cells were treated with 4,5 alpha-dihydrotestosterone (DHT; 0-3000 nM) before or after interleukin 1 beta (IL-1 beta; 5 ng/mL) stimulation. Quantitative polymerase chain reaction and ingel zymography was used to assay the effect on MMP expression and activity.Results: Subphysiological, physiological, and supraphysiological levels of TST were achieved with 0.5, 2.5, and 35 mg TST pellet implants in vivo, respectively. Inflammatory arrays indicated that interleukin cytokines, specifically IL-2, IL-6, IL-10, IL-12, and IL-13, were elevated at subphysiological level of TST, whereas TST supplementation decreased interleukins. Supraphysiological TST resulted in a significant increase in MMP-9 and tissue inhibitor of metalloproteinase-1 (TIMP-1) in vivo. Pretreatment with IL-1b slightly increased membrane type 1-MMP (MT1-MMP) and MMP-2 expression at low to mid-level DHT exposure in vitro, although these trends were not statistically significant.Conclusions: Here we demonstrate AD is a proinflammatory modulator and indicate that MMP-independent mechanisms may play a role downstream of AD-induced inflammatory signaling in dysfunctional vascular remodeling. Future in vivo studies will examine AD and TST supplementation in acute inflammatory response to vascular injury and in MMP-modulated vascular disease. (C) 2014 Elsevier Inc. All rights reserved.

You have accessJournal of UrologySexual Function/Dysfunction/Andrology: Basic Research I1 Apr 2012812 TESTOSERONE MODULATES VASCULAR SMOOTH MUSCLE CELL MEDIATED MATRIX METALLOPROTEINASE EXPRESSION AND FUNCTION, IN VITRO John Beddies, James Bienvenu, Deidra Mountain, Stacy Kirkpatrick, Oscar Grandas, and Frederick Klein John BeddiesJohn Beddies Knoxville, TN More articles by this author , James BienvenuJames Bienvenu Knoxville, TN More articles by this author , Deidra MountainDeidra Mountain Knoxville, TN More articles by this author , Stacy KirkpatrickStacy Kirkpatrick Knoxville, TN More articles by this author , Oscar GrandasOscar Grandas Knoxville, TN More articles by this author , and Frederick KleinFrederick Klein Knoxville, TN More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.901AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES A strong association between serum testosterone levels and cardiovascular disease has been established. However, this relationship is complex, and the exact mechanism by which testosterone affects the vasculature system remains to be elucidated. Intimal hyperplasia (IH), the general response of a vessel to injury, is a well-established hallmark of atherosclerosis. An important component of this pathway involves matrix metalloproteinases (MMPs), implicated in vascular remodeling due to their ability to degrade components of the extracellular matrix. Previous studies have demonstrated a significant reduction of IH in the presence of testosterone, and our group has shown a positive correlation between female sex hormones and MMP activity. Therefore, we hypothesize testosterone reduces IH through modulation of MMP expression and function in male vascular smooth muscle cells (VSMCs). METHODS Male human aortic VSMCs were treated with low to high physiological concentrations of testosterone (TST; 0.3nM-3μM) or Dihydrotestosterone (DHT; 0.3nM-3μM) for 24hr. Control cells were incubated with delivery vehicle only. Total RNA was isolated and subjected to quantitative polymerase chain reaction (qPCR). Cell lysates were collected and subjected to Western blot analysis. MMP activities were measured in conditioned media using in-gel protease analysis. A modified MTT proliferation assay was used to investigate the role of TST and DHT on VSMC proliferation. Finally, VSMC migration was evaluated using a modified collagen type IV coated Boyden chamber assay. RESULTS qPCR revealed no significant change in the gene expression of MMPs. Western blot analysis and in-gel zymography demonstrated a significant change (P<0.05) in MMP-2 protein levels and enzymatic activity at higher physiological TST and DHT concentrations. Androgen stimulation at high physiological levels inhibited VSMC proliferation and migration through a collagen type IV lattice. CONCLUSIONS Dysfunctional remodeling underlies the pathogenesis of major vascular diseases, such as atherosclerosis. A key group of enzymes involved in these processes are MMPs. Testosterone affects the MMP pathway in a concentration-dependent manner. With increasing physiological levels of testosterone, MMP activity and VSMC migration are significantly inhibited, in vitro. Our data suggests the risk of developing IH may decrease with higher physiological testosterone concentrations via the downregulation of MMP activity. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187 Issue 4S April 2012 Page: e332 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.Metrics Author Information John Beddies Knoxville, TN More articles by this author James Bienvenu Knoxville, TN More articles by this author Deidra Mountain Knoxville, TN More articles by this author Stacy Kirkpatrick Knoxville, TN More articles by this author Oscar Grandas Knoxville, TN More articles by this author Frederick Klein Knoxville, TN More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Migration of vascular smooth muscle cells is a fundamental process in the development of intimal hyperplasia, a precursor to development of cardiovascular disease and a potential response to injury of an arterial wall. Boyden chamber experiments are used to quantify the motion of cell populations in response to a chemoattractant gradient (i.e., cell chemotaxis). We are developing a mathematical model of cell migration within the Boyden chamber, while simultaneously conducting experiments to obtain parameter values for the migration process. In the future, the model and parameters will be used as building blocks for a detailed model of the process that causes intimal hyperplasia. The cell migration model presented in this paper is based on the notion of a cell as a moving sensor that responds to an evolving chemoattractant gradient. We compare the results of our three-dimensional hybrid model with results from a one-dimensional continuum model. Some preliminary experimental data that is being used to refine the model is also presented.