Abstract
The parafollicular-cell (C-cell) hormone calcitonin (CT) can preserve or even augment skeletal mass by inhibiting osteoclast-mediated bone resorption. The possibility of an additional anabolic skeletal influence has also been raised: C cells might, via CT or other secretory products, affect osteoblast-mediated bone formation. The 57-residue amino-terminal procalcitonin cleavage peptide, N-proCT, has recently been identified in human and rat C cells, where it is made and secreted in equimolar amounts with CT. The coelaboration of N-proCT and CT and N-proCT's sequence conservation during evolution prompted us to investigate the potential skeletal bioactivity of N-proCT. We found that synthetic human N-proCT, at nanomolar concentrations, stimulated proliferation of normal and neoplastic human osteoblasts. At maximally effective doses, human N-proCT caused more than a 100% increase above the control rate of DNA synthesis, an effect comparable to the maximal growth effect of insulin, a potent mitogen for osteoblasts. Human N-proCT exerted a similar maximal mitogenic effect in chicken osteoblast cultures but at 1000-fold greater concentrations than in human bone-cell cultures. The bone-cell action of N-proCT was potentiated with insulin with a greater than 200% increase in DNA synthesis at high insulin concentrations. In sharp contrast to these findings for N-proCT, the other bioactive C-cell peptides, CT and somatostatin, showed no mitogenic effects in human or chicken osteoblast cultures. Our results indicate that the action of N-proCT on cultured bone cells is separate from and potentiated by insulin, a known growth factor. Unlike insulin and related growth factors such as insulin-like growth factor I, N-proCT is not mitogenic in skin fibroblast cultures. We propose that N-proCT is a C-cell hormone that promotes bone formation via stimulatory actions on osteoblasts and preosteoblasts.
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Selected References
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- Akil H., Young E., Walker J. M., Watson S. J. The many possible roles of opioids and related peptides in stress-induced analgesia. Ann N Y Acad Sci. 1986;467:140–153. doi: 10.1111/j.1749-6632.1986.tb14625.x. [DOI] [PubMed] [Google Scholar]
- Birnbaum R. S., O'Neil J. A., Muszynski M., Aron D. C., Roos B. A. A non-calcitonin secretory peptide derived from preprocalcitonin. J Biol Chem. 1982 Jan 10;257(1):241–244. [PubMed] [Google Scholar]
- Breimer L. H., MacIntyre I., Zaidi M. Peptides from the calcitonin genes: molecular genetics, structure and function. Biochem J. 1988 Oct 15;255(2):377–390. doi: 10.1042/bj2550377. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Burns D. M., Birnbaum R. S., Roos B. A. A neuroendocrine peptide derived from the amino-terminal half of rat procalcitonin. Mol Endocrinol. 1989 Jan;3(1):140–147. doi: 10.1210/mend-3-1-140. [DOI] [PubMed] [Google Scholar]
- Conlon J. M., Grimelius L., Thim L. Structural characterization of a high-molecular-mass form of calcitonin [procalcitonin-(60-116)-peptide] and its corresponding N-terminal flanking peptide [procalcitonin-(1-57)-peptide] in a human medullary thyroid carcinoma. Biochem J. 1988 Nov 15;256(1):245–250. doi: 10.1042/bj2560245. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Conover C. A., Hintz R. L., Rosenfeld R. G. Comparative effects of somatomedin C and insulin on the metabolism and growth of cultured human fibroblasts. J Cell Physiol. 1985 Jan;122(1):133–141. doi: 10.1002/jcp.1041220120. [DOI] [PubMed] [Google Scholar]
- Deftos L. J., Krook L., Mayer G. P. Plasma calcitonin in the bovine species. Proc Soc Exp Biol Med. 1979 Oct;162(1):150–151. doi: 10.3181/00379727-162-40635. [DOI] [PubMed] [Google Scholar]
- Drivdahl R. H., Howard G. A., Baylink D. J. Extracts of bone contain a potent regulator of bone formation. Biochim Biophys Acta. 1982 Jan 12;714(1):26–33. doi: 10.1016/0304-4165(82)90123-4. [DOI] [PubMed] [Google Scholar]
- Eilon G., Perkins J., Viola M. V. Characteristics of a calcitonin-responsive cell line derived from a human osteosarcoma. Cancer Res. 1983 Aug;43(8):3763–3769. [PubMed] [Google Scholar]
- Ernst M., Froesch E. R. Growth hormone dependent stimulation of osteoblast-like cells in serum-free cultures via local synthesis of insulin-like growth factor I. Biochem Biophys Res Commun. 1988 Feb 29;151(1):142–147. doi: 10.1016/0006-291x(88)90570-0. [DOI] [PubMed] [Google Scholar]
- Ernst M., Schmid C., Froesch E. R. Enhanced osteoblast proliferation and collagen gene expression by estradiol. Proc Natl Acad Sci U S A. 1988 Apr;85(7):2307–2310. doi: 10.1073/pnas.85.7.2307. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Estivariz F. E., Carino M., Lowry P. J., Jackson S. Further evidence that N-terminal pro-opiomelanocortin peptides are involved in adrenal mitogenesis. J Endocrinol. 1988 Feb;116(2):201–206. doi: 10.1677/joe.0.1160201. [DOI] [PubMed] [Google Scholar]
- Farley J. R., Tarbaux N. M., Hall S. L., Linkhart T. A., Baylink D. J. The anti-bone-resorptive agent calcitonin also acts in vitro to directly increase bone formation and bone cell proliferation. Endocrinology. 1988 Jul;123(1):159–167. doi: 10.1210/endo-123-1-159. [DOI] [PubMed] [Google Scholar]
- Ferrier J., Ward-Kesthely A., Heersche J. N., Aubin J. E. Membrane potential changes, cAMP stimulation and contraction in osteoblast-like UMR 106 cells in response to calcitonin and parathyroid hormone. Bone Miner. 1988 Jun;4(2):133–145. [PubMed] [Google Scholar]
- Gkonos P. J., Born W., Jones B. N., Petermann J. B., Keutmann H. T., Birnbaum R. S., Fischer J. A., Roos B. A. Biosynthesis of calcitonin gene-related peptide and calcitonin by a human medullary thyroid carcinoma cell line. J Biol Chem. 1986 Nov 5;261(31):14386–14391. [PubMed] [Google Scholar]
- Hickman J., McElduff A. Insulin promotes growth of the cultured rat osteosarcoma cell line UMR-106-01: an osteoblast-like cell. Endocrinology. 1989 Feb;124(2):701–706. doi: 10.1210/endo-124-2-701. [DOI] [PubMed] [Google Scholar]
- Howard G. A., Turner R. T., Sherrard D. J., Baylink D. J. Human bone cells in culture metabolize 25-hydroxyvitamin D3 to 1,25-dihydroxyvitamin D3 and 24,25-dihydroxyvitamin D3. J Biol Chem. 1981 Aug 10;256(15):7738–7740. [PubMed] [Google Scholar]
- Höppener J. W., Steenbergh P. H., Slebos R. J., de Pagter-Holthuizen P., Roos B. A., Jansen M., Van den Brande J. L., Sussenbach J. S., Jansz H. S., Lips C. J. Expression of insulin-like growth factor-I and -II genes in rat medullary thyroid carcinoma. FEBS Lett. 1987 May 4;215(1):122–126. doi: 10.1016/0014-5793(87)80125-4. [DOI] [PubMed] [Google Scholar]
- Kalu D. N., Cockerham R., Yu B. P., Roos B. A. Lifelong dietary modulation of calcitonin levels in rats. Endocrinology. 1983 Dec;113(6):2010–2016. doi: 10.1210/endo-113-6-2010. [DOI] [PubMed] [Google Scholar]
- Krook L., Lutwak L., McEntee K. Dietary calcium, ultimobranchial tumors and osteopetrosis in the bull. Syndrome of calcitonin excess? Am J Clin Nutr. 1969 Feb;22(2):115–118. doi: 10.1093/ajcn/22.2.115. [DOI] [PubMed] [Google Scholar]
- Lasmoles F., Jullienne A., Day F., Minvielle S., Milhaud G., Moukhtar M. S. Elucidation of the nucleotide sequence of chicken calcitonin mRNA: direct evidence for the expression of a lower vertebrate calcitonin-like gene in man and rat. EMBO J. 1985 Oct;4(10):2603–2607. doi: 10.1002/j.1460-2075.1985.tb03977.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MacIntyre I., Hillyard C. J., Murphy P. K., Reynolds J. J., Das R. E., Craig R. K. A second plasma calcium-lowering peptide from the human calcitonin precursor. Nature. 1982 Dec 2;300(5891):460–462. doi: 10.1038/300460a0. [DOI] [PubMed] [Google Scholar]
- Pfeifle B., Boeder H., Ditschuneit H. Interaction of receptors for insulin-like growth factor I, platelet-derived growth factor, and fibroblast growth factor in rat aortic cells. Endocrinology. 1987 Jun;120(6):2251–2258. doi: 10.1210/endo-120-6-2251. [DOI] [PubMed] [Google Scholar]
- Puzas J. E., Drivdahl R. H., Howard G. A., Baylink D. J. Endogenous inhibitor of bone cell proliferation. Proc Soc Exp Biol Med. 1981 Jan;166(1):113–122. doi: 10.3181/00379727-166-41032. [DOI] [PubMed] [Google Scholar]
- Raisz L. G. Local and systemic factors in the pathogenesis of osteoporosis. N Engl J Med. 1988 Mar 31;318(13):818–828. doi: 10.1056/NEJM198803313181305. [DOI] [PubMed] [Google Scholar]
- Robey P. G., Termine J. D. Human bone cells in vitro. Calcif Tissue Int. 1985 Sep;37(5):453–460. [PubMed] [Google Scholar]
- Roos B. A., Fischer J. A., Pignat W., Alander C. B., Raisz L. G. Evaluation of the in vivo and in vitro calcium-regulating actions of noncalcitonin peptides produced via calcitonin gene expression. Endocrinology. 1986 Jan;118(1):46–51. doi: 10.1210/endo-118-1-46. [DOI] [PubMed] [Google Scholar]
- Roos B. A., Huber M. B., Birnbaum R. S., Aron D. C., Lindall A. W., Lips K., Baylin S. B. Medullary thyroid carcinomas secrete a noncalcitonin peptide corresponding to the carboxyl-terminal region of preprocalcitonin. J Clin Endocrinol Metab. 1983 Apr;56(4):802–807. doi: 10.1210/jcem-56-4-802. [DOI] [PubMed] [Google Scholar]
- Roos B. A., Okano K., Deftos L. J. Evidence for a pro-calcitonin. Biochem Biophys Res Commun. 1974 Oct 8;60(3):1134–1140. doi: 10.1016/0006-291x(74)90430-6. [DOI] [PubMed] [Google Scholar]
- Shamonki I. M., Frumar A. M., Tataryn I. V., Meldrum D. R., Davidson B. H., Parthemore J. G., Judd H. L., Deftos L. J. Age-related changes of calcitonin secretion in females. J Clin Endocrinol Metab. 1980 Mar;50(3):437–439. doi: 10.1210/jcem-50-3-437. [DOI] [PubMed] [Google Scholar]
- Zaidi M., Chambers T. J., Bevis P. J., Beacham J. L., Gaines Das R. E., MacIntyre I. Effects of peptides from the calcitonin genes on bone and bone cells. Q J Exp Physiol. 1988 Jul;73(4):471–485. doi: 10.1113/expphysiol.1988.sp003168. [DOI] [PubMed] [Google Scholar]