title: Cystathionine γ-lyase accelerates osteoclast differentiation: identification of a novel regulator of osteoclastogenesis by proteomic analysis.
abstract: OBJECTIVE
  Clinical evidence has linked vascular calcification in advanced atherosclerotic plaques with overt cardiovascular disease and mortality. Bone resorbing monocyte-derived osteoclast-like cells are sparse in these plaques, indicating that their differentiation capability could be suppressed. Here, we seek to characterize the process of osteoclastogenesis by identifying novel regulators and pathways, with the aim of exploring possible strategies to reduce calcification.
  
  
  RESULTS
  We used a quantitative mass spectrometry strategy, tandem mass tagging, to quantify changes in the proteome of osteoclast-like cells differentiated from RAW264.7 cells in response to, receptor activator of nuclear factor κ-B ligand induction, a common in vitro model for osteogenesis. More than 4000 proteins were quantified, of which 138 were identified as novel osteoclast-related proteins. We selected 5 proteins for subsequent analysis (cystathionine γ-lyase [Cth/CSE], EGF-like repeat and discoidin I-like domain-containing protein 3, integrin α FG-GAP repeat containing 3, adseverin, and serpinb6b) and show that gene expression levels are also increased. Further analysis of the CSE transcript profile reveals an early onset of an mRNA increase. Silencing of CSE by siRNA and dl-propargylglycine, a CSE inhibitor, attenuated receptor activator of nuclear factor κ-B ligand-induced tartrate-resistant acid phosphatase type 5 activity and pit formation, suggesting that CSE is a potent inducer of calcium resorption. Moreover, knockdown of CSE suppressed expression of osteoclast differentiation markers.
  
  
  CONCLUSIONS
  Our large-scale proteomics study identified novel candidate regulators or markers for osteoclastogenesis and demonstrated that CSE may act in early stages of osteoclastogenesis.
authors.affiliation: From the Division of Cardiovascular Medicine, Center for Interdisciplinary Cardiovascular Sciences (T.I., N.M., I.Y., C.G., J.M., M.A., S.S., E.A.), Channing Division of Network Medicine (M.A.), and Division of Cardiovascular Medicine, Center for Excellence in Vascular Biology (M.A., E.A.), Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Kowa Company, Ltd, Tokyo, Japan (T.I., I.Y., J.M.).
authors.forename: Takahiro
authors.initials: T
authors.lastname: Itou
authors.forename: Natalia
authors.initials: N
authors.lastname: Maldonado
authors.forename: Iwao
authors.initials: I
authors.lastname: Yamada
authors.forename: Claudia
authors.initials: C
authors.lastname: Goettsch
authors.forename: Jiro
authors.initials: J
authors.lastname: Matsumoto
authors.forename: Masanori
authors.initials: M
authors.lastname: Aikawa
authors.forename: Sasha
authors.initials: S
authors.lastname: Singh
authors.forename: Elena
authors.initials: E
authors.lastname: Aikawa
mesh_terms: D000480:Alkynes / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000378:metabolism; D001057:Apolipoproteins E / Q000172:deficiency; D015415:Biomarkers; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D003542:Cystathionine gamma-Lyase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D004041:Dietary Fats / Q000633:toxicity; D020869:Gene Expression Profiling; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D008264:Macrophages / Q000166:cytology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D016328:NF-kappa B / Q000378:metabolism; D010010:Osteoclasts / Q000166:cytology / Q000201:enzymology* / Q000378:metabolism; D040901:Proteomics; D053245:RANK Ligand / Q000494:pharmacology; D034622:RNA Interference; D012333:RNA, Messenger / Q000096:biosynthesis; D034741:RNA, Small Interfering / Q000494:pharmacology; D021241:Spectrometry, Mass, Electrospray Ionization; D014158:Transcription, Genetic
chemical_list: D000480:Alkynes; D001057:Apolipoproteins E; D015415:Biomarkers; D004041:Dietary Fats; D016328:NF-kappa B; D053245:RANK Ligand; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C505689:Tnfsf11 protein, mouse; C009055:propargylglycine; D016173:Macrophage Colony-Stimulating Factor; D003542:Cystathionine gamma-Lyase; D005998:Glycine
keywords: RANKL protein; macrophages; osteoclast; proteomics; vascular calcification