title: Functional expression of the extracellular calcium sensing receptor (CaSR) in equine umbilical cord matrix size-sieved stem cells.
abstract: BACKGROUND
  The present study investigates the effects of high external calcium concentration ([Ca(2+)](o)) and the calcimimetic NPS R-467, a known calcium-sensing receptor (CaSR) agonist, on growth/proliferation of two equine size-sieved umbilical cord matrix mesenchymal stem cell (eUCM-MSC) lines. The involvement of CaSR on observed cell response was analyzed at both the mRNA and protein level.
  
  
  RESULTS
  A large (>8 µm in diameter) and a small (<8 µm) cell line were cultured in medium containing: 1) low [Ca(2+)](o) (0.37 mM); 2) high [Ca(2+)](o) (2.87 mM); 3) NPS R-467 (3 µM) in presence of high [Ca(2+)](o) and 4) the CaSR antagonist NPS 2390 (10 µM for 30 min.) followed by incubation in presence of NPS R-467 in medium with high [Ca(2+)](o). Growth/proliferation rates were compared between groups. In large cells, the addition of NPS R-467 significantly increased cell growth whereas increasing [Ca(2+)](o) was not effective in this cell line. In small cells, both higher [Ca(2+)](o) and NPS R-467 increased cell growth. In both cell lines, preincubation with the CaSR antagonist NPS 2390 significantly inhibited the agonistic effect of NPS R-467. In both cell lines, increased [Ca(2+)](o) and/or NPS R-467 reduced doubling time values.Treatment with NPS R-467 down-regulated CaSR mRNA expression in both cell lines. In large cells, NPS R-467 reduced CaSR labeling in the cytosol and increased it at cortical level.
  
  
  CONCLUSIONS
  In conclusion, calcium and the calcimimetic NPS R-467 reduce CaSR mRNA expression and stimulate cell growth/proliferation in eUCM-MSC. Their use as components of media for eUCM-MSC culture could be beneficial to obtain enough cells for down-stream purposes.
authors: Department of Animal Production, Faculty of Biotechnological Sciences, University of Bari, Valenzano, Bari, Italy. nicmartino@libero.it
authors: Nicola Antonio
authors: NA
authors: Martino
authors: Anna
authors: A
authors: Lange-Consiglio
authors: Fausto
authors: F
authors: Cremonesi
authors: Luisa
authors: L
authors: Valentini
authors: Michele
authors: M
authors: Caira
authors: Antonio Ciro
authors: AC
authors: Guaricci
authors: Barbara
authors: B
authors: Ambruosi
authors: Raffaele Luigi
authors: RL
authors: Sciorsci
authors: Giovanni Michele
authors: GM
authors: Lacalandra
authors: Stephan Joel
authors: SJ
authors: Reshkin
authors: Maria Elena
authors: ME
authors: Dell'Aquila
mesh_terms: D000814:Aniline Compounds / Q000494:pharmacology; D000818:Animals; D057966:Calcimimetic Agents / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism*; D005110:Extracellular Space / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006736:Horses; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D044169:Receptors, Calcium-Sensing / Q000235:genetics / Q000378:metabolism*; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism; D014470:Umbilical Cord / Q000166:cytology*
chemical_list: D000814:Aniline Compounds; D057966:Calcimimetic Agents; C111654:NPS R-467; D012333:RNA, Messenger; D044169:Receptors, Calcium-Sensing; D002118:Calcium