title: Increased activity of TNAP compensates for reduced adenosine production and promotes ectopic calcification in the genetic disease ACDC.
abstract: ACDC (arterial calcification due to deficiency of CD73) is an autosomal recessive disease resulting from loss-of-function mutations in NT5E, which encodes CD73, a 5'-ectonucleotidase that converts extracellular adenosine monophosphate to adenosine. ACDC patients display progressive calcification of lower extremity arteries, causing limb ischemia. Tissue-nonspecific alkaline phosphatase (TNAP), which converts pyrophosphate (PPi) to inorganic phosphate (Pi), and extracellular purine metabolism play important roles in other inherited forms of vascular calcification. Compared to cells from healthy subjects, induced pluripotent stem cell-derived mesenchymal stromal cells (iMSCs) from ACDC patients displayed accelerated calcification and increased TNAP activity when cultured under conditions that promote osteogenesis. TNAP activity generated adenosine in iMSCs derived from ACDC patients but not in iMSCs from control subjects, which have CD73. In response to osteogenic stimulation, ACDC patient-derived iMSCs had decreased amounts of the TNAP substrate PPi, an inhibitor of extracellular matrix calcification, and exhibited increased activation of AKT, mechanistic target of rapamycin (mTOR), and the 70-kDa ribosomal protein S6 kinase (p70S6K), a pathway that promotes calcification. In vivo, teratomas derived from ACDC patient cells showed extensive calcification and increased TNAP activity. Treating mice bearing these teratomas with an A2b adenosine receptor agonist, the mTOR inhibitor rapamycin, or the bisphosphonate etidronate reduced calcification. These results show that an increase of TNAP activity in ACDC contributes to ectopic calcification by disrupting the extracellular balance of PPi and Pi and identify potential therapeutic targets for ACDC.
authors.affiliation: Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Jin
authors.affiliation: Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Cynthia
authors.initials: C
authors.lastname: St Hilaire
authors.affiliation: Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Yuting
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Dan
authors.initials: D
authors.lastname: Yang
authors.affiliation: Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Natalia I
authors.initials: NI
authors.lastname: Dmitrieva
authors.affiliation: Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Negro
authors.affiliation: Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Robin
authors.initials: R
authors.lastname: Schwartzbeck
authors.affiliation: Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Yangtengyu
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Yu
authors.affiliation: Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Avram
authors.initials: A
authors.lastname: Walts
authors.affiliation: Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Davaine
authors.affiliation: Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 10 Center Drive, Bethesda, MD 20892, USA.|Biochemistry Facility, NHLBI, NIH, Bethesda, MD 20892, USA.
authors.forename: Duck-Yeon
authors.initials: DY
authors.lastname: Lee
authors.affiliation: Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 10 Center Drive, Bethesda, MD 20892, USA.|Mouse Imaging Facility, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD 20892, USA.
authors.forename: Danielle
authors.initials: D
authors.lastname: Donahue
authors.affiliation: Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 10 Center Drive, Bethesda, MD 20892, USA.|Medical Genetics Branch, National Human Genome Research Institute, NIH, Building 10, Room 10C103, Bethesda, MD 20892, USA.
authors.forename: Kevin S
authors.initials: KS
authors.lastname: Hsu
authors.affiliation: Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Jessica
authors.initials: J
authors.lastname: Chen
authors.forename: Tao
authors.initials: T
authors.lastname: Cheng
authors.affiliation: Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 10 Center Drive, Bethesda, MD 20892, USA.|Medical Genetics Branch, National Human Genome Research Institute, NIH, Building 10, Room 10C103, Bethesda, MD 20892, USA.
authors.forename: William
authors.initials: W
authors.lastname: Gahl
authors.affiliation: Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 10 Center Drive, Bethesda, MD 20892, USA. boehmm@nhlbi.nih.gov chengb@nhlbi.nih.gov.
authors.forename: Guibin
authors.initials: G
authors.lastname: Chen
authors.affiliation: Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 10 Center Drive, Bethesda, MD 20892, USA. boehmm@nhlbi.nih.gov chengb@nhlbi.nih.gov.
authors.forename: Manfred
authors.initials: M
authors.lastname: Boehm
mesh_terms: D015720:5'-Nucleotidase / Q000172:deficiency; D000241:Adenosine / Q000235:genetics / Q000378:metabolism; D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D058851:GPI-Linked Proteins / Q000172:deficiency; D030342:Genetic Diseases, Inborn / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000201:enzymology* / Q000473:pathology; D059630:Mesenchymal Stem Cells / Q000201:enzymology* / Q000473:pathology; D051379:Mice; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D058570:TOR Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D061205:Vascular Calcification / Q000201:enzymology* / Q000235:genetics / Q000473:pathology
chemical_list: D058851:GPI-Linked Proteins; C546842:MTOR protein, human; D051057:Proto-Oncogene Proteins c-akt; D038762:Ribosomal Protein S6 Kinases, 70-kDa; D058570:TOR Serine-Threonine Kinases; C548267:ALPL protein, human; D000469:Alkaline Phosphatase; D015720:5'-Nucleotidase; C548241:NT5E protein, human; D000241:Adenosine