The present study investigates the effects of high external calcium
concentration ([Ca2+]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.
A large (>8 µm in diameter) and a small (<8 µm) cell line
were cultured in medium containing: 1) low
[Ca2+]o (0.37 mM); 2) high
[Ca2+]o (2.87 mM); 3) NPS R-467 (3
µM) in presence of high [Ca2+]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
[Ca2+]o. Growth/proliferation rates
were compared between groups. In large cells, the addition of NPS R-467
significantly increased cell growth whereas increasing
[Ca2+]o was not effective in this
cell line. In small cells, both higher
[Ca2+]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 [Ca2+]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.
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.
Publisher: Public Library of Science
Date Published: 17-March-2011
Author(s): Martino N., Lange-Consiglio A., Cremonesi F., Valentini L., Caira M., Guaricci A., Ambruosi B., Sciorsci R., Lacalandra G., Reshkin S., Dell’Aquila M.