title: Zoledronate upregulates MMP-9 and -13 in rat vascular smooth muscle cells by inducing oxidative stress.
abstract: BACKGROUND
  Bisphosphonates, including zoledronate, target osteoclasts and are widely used in the treatment of osteoporosis and other bone resorption diseases, despite side effects that include damaging the stomach epithelium. Beneficial and adverse effects on other organ systems, including the cardiovascular system, have also been described and could impact on the use of bisphosphonates as therapeutic agents. Vascular smooth muscle cells (VSMCs) are major constituents of the normal vascular wall and have a key role in intimal thickening and atherosclerosis, in part by secreting MMPs that remodel the extracellular matrix and cleave cell surface proteins or secreted mediators. In this study, we investigated the effects of zoledronate on MMP expression.
  
  
  METHODS
  Rat VSMCs were stimulated by PDGF (50 ng/mL) plus TNF-α (10 ng/mL) or left unstimulated for a further 24 hours in serum-free medium. In other series of experiments, cells were pre-treated either with SC-514 (50 μM) or with apocynin (20 nM) for 2 hours, then zoledronate (100 μM) was added into 2% fetal calf serum containing medium for 24 hours.
  
  
  CONCLUSIONS
  Using isolated rat VSMCs in culture, zoledronate (100 μM) increased MMP-9 and -13 mRNA expressions but inhibited MMP-2 expression. MMP-9 and MMP-13 up-regulation was shown to depend on the NF-κB pathway; and this was activated by zoledronate. Furthermore, zoledronate elevated the levels of reactive oxygen species detected by either dichlorofluorescein in isolated VSMCs or lucigenin enhanced chemiluminescence in rat aortic rings in vitro. Apocynin, an inhibitor of NADPH oxidase, reversed NF-κB activation and MMP-9 and MMP-13 up-regulation by zoledronate.
  
  
  CONCLUSIONS
  We conclude that zoledronate increases MMP-9 and MMP-13 expressions in rat VSMCs dependent upon stimulation of the NF-κB pathway by reactive oxygen species. Effects on MMP expression may contribute to the pharmacologic profile of bisphosphonates.
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, Ege University, Izmir, Turkey.
authors.forename: Mehmet Zuhuri
authors.initials: MZ
authors.lastname: Arun
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, Ege University, Izmir, Turkey.
authors.forename: Buket
authors.initials: B
authors.lastname: Reel
authors.affiliation: Bristol Heart Institute, University of Bristol, Bristol Royal Infirmary, Bristol, UK.
authors.forename: Graciela B
authors.initials: GB
authors.lastname: Sala-Newby
authors.affiliation: Bristol Heart Institute, University of Bristol, Bristol Royal Infirmary, Bristol, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Bond
authors.affiliation: Bristol Heart Institute, University of Bristol, Bristol Royal Infirmary, Bristol, UK.
authors.forename: Aikaterini
authors.initials: A
authors.lastname: Tsaousi
authors.affiliation: Bristol Heart Institute, University of Bristol, Bristol Royal Infirmary, Bristol, UK.
authors.forename: Perry
authors.initials: P
authors.lastname: Maskell
authors.affiliation: Bristol Heart Institute, University of Bristol, Bristol Royal Infirmary, Bristol, UK.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Newby
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004164:Diphosphonates / Q000494:pharmacology*; D007093:Imidazoles / Q000494:pharmacology*; D008297:Male; D053509:Matrix Metalloproteinase 13 / Q000235:genetics / Q000378:metabolism*; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects*; D000077211:Zoledronic Acid
chemical_list: D004164:Diphosphonates; D007093:Imidazoles; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D000077211:Zoledronic Acid; D053509:Matrix Metalloproteinase 13; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9
keywords: bisphosphonate; matrix metalloproteinase; reactive oxygen species; vascular smooth muscle cell; zoledronate