title: 1,25-dihydroxyvitamin D3 causes ADAM10-dependent ectodomain shedding of tumor necrosis factor receptor 1 in vascular smooth muscle cells.
abstract: 1,25-Dihydroxyvitamin D3 (1,25D3) has a potential antiatherosclerotic effect through anti-inflammatory actions. We investigated how 1,25D3 regulates tumor necrosis factor-α (TNF-α)-induced lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) expression in cultured human aortic smooth muscle cells. TNF-α activated Rac1/reactive oxygen species/spleen tyrosine kinase and transcriptional factors, activator protein-1, and nuclear factor κB, which led to LOX-1 expression. 1,25D3 inhibited TNF-α-induced LOX-1 expression by inhibiting Rac1 activation and thereby its downstream signals. 1,25D3 rapidly induced extracellular Ca(2+) influx. Verapamil, an inhibitor of L-type calcium channels, inhibited 1,25D3-induced Ca(2+) influx and counteracted the inhibitory effects of 1,25D3 on Rac1 activation, whereas Bay K8644 [1,4-dihydro-2,6-dimethyl-5-nitro-4-[2-(trifluoromethyl)phenyl]-3-pyridinecarboxylic acid, methyl ester], an L-type calcium channel agonist, attenuated TNF-α-induced Rac1 activation, as 1,25D3 did. 1,25D3 induced the ectodomain shedding of TNF receptor 1 (TNFR1), which was abolished by verapamil and in Ca(2+)-free media. Like 1,25D3, Bay K8644 induced the ectodomain shedding of TNFR1. Both 1,25D3 and Bay K8644 caused the translocation of a disintegrin and metalloprotease (ADAM) 10 from the cytoplasm to the plasma membrane, which was dependent on extracellular Ca(2+) influx. In contrast, depletion of ADAM10 by transfection of ADAM10-small interfering RNA prevented 1,25D3- or Bay K8644-induced ectodomain shedding of TNFR1 and abolished the suppressive effect of 1,25D3 on TNF-α-induced Rac1 activation. Taken together, these findings suggest that 1,25D3 induces extracellular Ca(2+) influx via L-type calcium channel, triggering ADAM10-mediated ectodomain shedding of TNFR1, and it thereby decreases responsiveness to TNF-α. By shedding TNFR1 from the cell surface, 1,25D3 may regulate inflammation and atherogenesis, whereas this effect could be attenuated by calcium channel blockers.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Korea (W.S.Y., S.-K.P.); Division of Nephrology, Department of Internal Medicine, Jeju National University School of Medicine, Jeju, Korea (H.W.K.); Asan Institute for Life Sciences, Seoul, Korea (J.M.L., N.J.H.); and Department of Pediatrics, College of Medicine, Dankook University, Cheonan, Korea (M.J.L.).
authors.forename: Won Seok
authors.initials: WS
authors.lastname: Yang
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Korea (W.S.Y., S.-K.P.); Division of Nephrology, Department of Internal Medicine, Jeju National University School of Medicine, Jeju, Korea (H.W.K.); Asan Institute for Life Sciences, Seoul, Korea (J.M.L., N.J.H.); and Department of Pediatrics, College of Medicine, Dankook University, Cheonan, Korea (M.J.L.).
authors.forename: Hyun Woo
authors.initials: HW
authors.lastname: Kim
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Korea (W.S.Y., S.-K.P.); Division of Nephrology, Department of Internal Medicine, Jeju National University School of Medicine, Jeju, Korea (H.W.K.); Asan Institute for Life Sciences, Seoul, Korea (J.M.L., N.J.H.); and Department of Pediatrics, College of Medicine, Dankook University, Cheonan, Korea (M.J.L.).
authors.forename: Joo Mi
authors.initials: JM
authors.lastname: Lee
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Korea (W.S.Y., S.-K.P.); Division of Nephrology, Department of Internal Medicine, Jeju National University School of Medicine, Jeju, Korea (H.W.K.); Asan Institute for Life Sciences, Seoul, Korea (J.M.L., N.J.H.); and Department of Pediatrics, College of Medicine, Dankook University, Cheonan, Korea (M.J.L.).
authors.forename: Nam Jeong
authors.initials: NJ
authors.lastname: Han
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Korea (W.S.Y., S.-K.P.); Division of Nephrology, Department of Internal Medicine, Jeju National University School of Medicine, Jeju, Korea (H.W.K.); Asan Institute for Life Sciences, Seoul, Korea (J.M.L., N.J.H.); and Department of Pediatrics, College of Medicine, Dankook University, Cheonan, Korea (M.J.L.).
authors.forename: Mee Jeong
authors.initials: MJ
authors.lastname: Lee
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Korea (W.S.Y., S.-K.P.); Division of Nephrology, Department of Internal Medicine, Jeju National University School of Medicine, Jeju, Korea (H.W.K.); Asan Institute for Life Sciences, Seoul, Korea (J.M.L., N.J.H.); and Department of Pediatrics, College of Medicine, Dankook University, Cheonan, Korea (M.J.L.) skpark@amc.seoul.kr.
authors.forename: Su-Kil
authors.initials: SK
authors.lastname: Park
mesh_terms: D051722:ADAM Proteins / Q000378:metabolism*; D000072197:ADAM10 Protein; D053829:Amyloid Precursor Protein Secretases / Q000378:metabolism*; D002117:Calcitriol / Q000494:pharmacology*; D002478:Cells, Cultured; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism*; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000378:metabolism*
chemical_list: D008565:Membrane Proteins; D047888:Receptors, Tumor Necrosis Factor, Type I; D053829:Amyloid Precursor Protein Secretases; D051722:ADAM Proteins; D000072197:ADAM10 Protein; C491236:ADAM10 protein, human; D002117:Calcitriol