title: Involvement of nitric oxide in iodine deficiency-induced microvascular remodeling in the thyroid gland: role of nitric oxide synthase 3 and ryanodine receptors.
abstract: Iodine deficiency (ID) induces microvascular changes in the thyroid gland via a TSH-independent reactive oxygen species-hypoxia inducible factor (HIF)-1α-vascular endothelial growth factor (VEGF) pathway. The involvement of nitric oxide (NO) in this pathway and the role of calcium (Ca(2+)) and of ryanodine receptors (RYRs) in NO synthase 3 (NOS3) activation were investigated in a murine model of goitrogenesis and in 3 in vitro models of ID, including primary cultures of human thyrocytes. ID activated NOS3 and the production of NO in thyrocytes in vitro and increased the thyroid blood flow in vivo. Using bevacizumab (a blocking antibody against VEGF-A) in mice, it appeared that NOS3 is activated upstream of VEGF-A. L-nitroarginine methyl ester (a NOS inhibitor) blocked the ID-induced increase in thyroid blood flow in vivo and NO production in vitro, as well as ID-induced VEGF-A mRNA and HIF-1α expression in vitro, whereas S-nitroso-acetyl-penicillamine (a NO donor) did the opposite. Ca(2+) is involved in this pathway as intracellular Ca(2+) flux increased after ID, and thapsigargin activated NOS3 and increased VEGF-A mRNA expression. Two of the 3 known mammalian RYR isoforms (RYR1 and RYR2) were shown to be expressed in thyrocytes. RYR inhibition using ryanodine at 10μM decreased ID-induced NOS3 activation, HIF-1α, and VEGF-A expression, whereas RYR activation with ryanodine at 1nM increased NOS3 activation and VEGF-A mRNA expression. In conclusion, during the early phase of TSH-independent ID-induced microvascular activation, ID sequentially activates RYRs and NOS3, thereby supporting ID-induced activation of the NO/HIF-1α/VEGF-A pathway in thyrocytes.
authors.affiliation: Pôle de Morphologie (J.C., C.W., B.D.J., J.V., M.-C.M., I.M.C.), de Pharmacologie et Thérapeutique (V.J., I.L., J.-L.B., P.S.), et d'Endocrinologie, Diabète et Nutrition (P.G.), Institut de Recherche Expérimentale et Clinique, Secteur des Sciences de la Santé, Faculté de Médecine, Université catholique de Louvain, 1200, Brussels, Belgium; and Service d'Endocrino-Diabétologie (A.-C.G., I.M.C.), Centre Hospitalier Régional, 7000, Mons-Hainaut, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Craps
authors.forename: C
authors.initials: C
authors.lastname: Wilvers
authors.forename: V
authors.initials: V
authors.lastname: Joris
authors.forename: B
authors.initials: B
authors.lastname: De Jongh
authors.forename: J
authors.initials: J
authors.lastname: Vanderstraeten
authors.forename: I
authors.initials: I
authors.lastname: Lobysheva
authors.forename: J-L
authors.initials: JL
authors.lastname: Balligand
authors.forename: P
authors.initials: P
authors.lastname: Sonveaux
authors.forename: P
authors.initials: P
authors.lastname: Gilon
authors.forename: M-C
authors.initials: MC
authors.lastname: Many
authors.forename: A-C
authors.initials: AC
authors.lastname: Gérard
authors.forename: I M
authors.initials: IM
authors.lastname: Colin
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D005260:Female; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D007455:Iodine / Q000172:deficiency*; D008297:Male; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism*; D013961:Thyroid Gland / Q000098:blood supply*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D017382:Reactive Oxygen Species; D019837:Ryanodine Receptor Calcium Release Channel; D042461:Vascular Endothelial Growth Factor A; D009569:Nitric Oxide; D007455:Iodine; D052250:Nitric Oxide Synthase Type III; D002118:Calcium