Human pulp cells respond to calcitonin gene-related peptide in vitro.
Cell monolayers derived from human pulpal explants were passaged 3 to 4 times before characterization of the response of the cells to calcitonin gene-related peptide (CGRP). Northern blot analysis of mRNA revealed the presence of transcripts for bone morphogenetic protein-2 (BMP-2). Stimulation with CGRP produced a 1.8-fold increase in BMP-2 mRNA expression by the cells. Analysis of binding of CGRP to whole cells indicated that unlabeled human CGRP competed with labeled CGRP in a dose dependent fashion with a KD, estimated from the EC50, in the range of 5 x 10(-8)M. Binding of labeled CGRP was greatly reduced by the presence of 10(-6)M CGRP but was unaffected by the presence of 10(-6)M Human PTH(1-34) or 10(-6)M calcitonin. CGRP produced a 2.8-fold increase in cyclic AMP over basal levels, which was similar to the increase produced by PTH(1-34) (2.6 fold) but slightly more than the increase produced by calcitonin (1.9 fold). The pulp-derived cells displayed a high basal level of alkaline phosphatase enzyme activity, which was not altered by treatment with CGRP or either PTH(1-34) or 1,25(OH)2D3. Stimulation with 2.5 x 10(-8)M 1,25(OH)2D3 did produce a 7.6-fold increase in osteocalcin. These results indicate that pulp cells possess the cellular machinery to respond to CGRP and that stimulation of the production of BMP-2, a factor known to be associated with induction of dentin formation, is a component of the response.
Calland
J W
JW
Department of Endodontics, University of Texas Health Science Center at San Antonio 78284-7892, USA.
Harris
S E
SE
Carnes
D L
DL
D015152:Blotting, Northern; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000096:biosynthesis / Q000187:drug effects; D002116:Calcitonin / Q000494:pharmacology; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism / Q000494:pharmacology*; D002478:Cells, Cultured; D003470:Culture Media; D000242:Cyclic AMP / Q000378:metabolism; D003782:Dental Pulp / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D008964:Molar, Third; D012333:RNA, Messenger / Q000032:analysis / Q000187:drug effects; D011869:Radioligand Assay; D013268:Stimulation, Chemical; D019379:Teriparatide / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000096:biosynthesis / Q000187:drug effects
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D003470:Culture Media; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D019379:Teriparatide; D002116:Calcitonin; D000242:Cyclic AMP; D015740:Calcitonin Gene-Related Peptide