Abstract
Preptin, a newly isolated 34-amino-acid peptide hormone that is cosecreted with insulin and amylin from pancreatic beta-cells, has emerged as a regulatory element in bone metabolism, but its mechanism remains unclear. We assessed the effects of preptin on proliferation and differentiation of human osteoblasts and investigated the mechanism involved. Our results demonstrated that preptin promoted human osteoblasts proliferation and alkaline phosphatase activity. Suppression of connective tissue growth factor (CTGF), which was upregulated by preptin in a dose- and time-dependent manner, with small interfering RNA (siRNA) abolished the preptin-induced human osteoblasts proliferation and differentiation. Preptin induced activation of ERK mitogen-activated protein kinase (MAPK), but not p38 or JNK in human osteoblasts. Furthermore, pretreatment of human osteoblasts with the ERK inhibitor PD98059 abolished the preptin-induced CTGF secretion and blocked the promoting effect of preptin on osteoblasts proliferation and differentiation. These data demonstrated that preptin is involved in bone anabolism mediated by ERK/CTGF in human osteoblasts and may contribute to the preservation of bone mass observed in hyperinsulinemic states, such as obesity.
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Arnott JA, Nuglozeh E, Rico MC, Arango-Hisijara I, Odgren PR, Safadi FF, Popoff SN (2007) Connective tissue growth factor (CTGF/CCN2) is a downstream mediator for TGF-beta1-induced extracellular matrix production in osteoblasts. J Cell Physiol 210:843–852. doi:10.1002/jcp.20917
Buchanan CM, Phillips AR, Cooper GJ (2001) Preptin derived from proinsulin-like growth factor II (proIGF-II) is secreted from pancreatic islet beta-cells and enhances insulin secretion. Biochem J 360:431–439. doi:10.1042/0264-6021:3600431
Cooper GJ, Willis AC, Clark A, Turner RC, Sim RB, Reid KB (1987) Purification and characterization of a peptide from amyloid-rich pancreases of type 2 diabetic patients. Proc Natl Acad Sci USA 84:8628–8632. doi:10.1073/pnas.84.23.8628
Cornish J, Callon KE, Cooper GJ, Reid IR (1995) Amylin stimulates osteoblasts proliferation and increases mineralized bone volume in adult mice. Biochem Biophys Res Commun 207:133–139. doi:10.1006/bbrc.1995.1163
Cornish J, Callon KE, Reid IR (1996) Insulin increases histomorphometric indices of bone formation In vivo. Calcif Tissue Int 59:492–495
Cornish J, Callon KE, King AR, Cooper GJ, Reid IR (1998) Systemic administration of amylin increases bone mass, linear growth, and adiposity in adult male mice. Am J Physiol 275(4 Pt 1):E694–E699
Cornish J, Callon KE, Bava U, Watson M, Xu X, Lin JM, Chan VA, Grey AB, Naot D, Buchanan CM, Cooper GJ, Reid IR (2007) Preptin, another peptide product of the pancreatic beta-cell, is osteogenic in vitro and in vivo. Am J Physiol Endocrinol Metab 292:E117–E122. doi:10.1152/ajpendo.00642.2005
Guney E, Kisakol G, Ozgen G, Yilmaz C, Yilmaz R, Kabalak T (2003) Effect of weight loss on bone metabolism: comparison of vertical banded gastroplasty and medical intervention. Obes Surg 13:383–388. doi:10.1381/096089203765887705
Hla MM, Davis JW, Ross PD, Wasnich RD, Yates AJ, Ravn P, Hosking DJ, McClung MR (1996) Early Postmenopausal Intervention Cohort (EPIC) Study Group, a multicenter study of the influence of fat and lean mass on bone mineral content: evidence for differences in their relative influence at major fracture sites. Am J Clin Nutr 64:354–360
Khosla S, Hassoun AA, Baker BK, Liu F, Zein NN, Whyte MP, Reasner CA, Nippoldt TB, Tiegs RD, Hintz RL, Conover CA (1998) Insulin-like growth factor system abnormalities in hepatitis C-associated osteosclerosis. Potential insights into increasing bone mass in adults. J Clin Invest 101:2165–2173. doi:10.1172/JCI1111
Kubota S, Takigawa M (2007) Role of CCN2/CTGF/Hcs24 in bone growth. Int Rev Cytol 257:1–41. doi:10.1016/S0074-7696(07)57001-4
Leivonen SK, Hakkinen L, Liu D, Kahari VM (2005) Smad3 and extracellular signal-regulated kinase 1/2 coordinately mediate transforming growth factor-beta-induced expression of connective tissue growth factor in human fibroblasts. J Invest Dermatol 124:1162–1169. doi:10.1111/j.0022-202X.2005.23750.x
Luo XH, Guo LJ, Xie H, Yuan LQ, Wu XP, Zhou HD, Liao EY (2006) Adiponectin stimulates RANKL and inhibits OPG expression in human osteoblasts through the MAPK signaling pathway. J Bone Miner Res 21:1648–1656. doi:10.1359/jbmr.060707
Nishida T, Nakanishi T, Asano M, Shimo T, Takigawa M (2000) Effects of CTGF/Hcs24, a hypertrophic chondrocyte‐specific gene product, on the proliferation and differentiation of osteoblastic cells in vitro. J Cell Physiol 184:197–206. doi:10.1002/1097-4652(200008)184:2<197::AID-JCP7>3.0.CO;2-R
Parisi MS, Gazzerro E, Rydziel S, Canalis E (2006) Expression and regulation of CCN genes in murine osteoblasts. Bone 38:671–677. doi:10.1016/j.bone.2005.10.005
Radak TL (2004) Caloric restriction and calcium’s effect on bone metabolism and body composition in overweight and obese premenopausal women. Nutr Rev 62:468–481. doi:10.1111/j.1753-4887.2004.tb00019.x
Safadi FF, Xu J, Smock SL, Kanaan RA, Selim AH, Odgren PR, Marks SC Jr, Owen TA, Popoff SN (2003) Expression of connective tissue growth factor in bone: Its role in osteoblasts proliferation and differentiation in vitro and bone formation in vivo. J Cell Physiol 196:51–62. doi:10.1002/jcp.10319
Smerdel-Ramoya A, Zanotti S, Deregowski V, Canalis E (2008) Connective tissue growth factor enhances osteoblastogenesis in vitro. J Biol Chem 283:22690–22699. doi:10.1074/jbc.M710140200
Takigawa M, Nakanishi T, Kubota S, Nishida T (2003) Role of CTGF/HCS24/ecogenin in skeletal growth control. J Cell Physiol 194:256–266. doi:10.1002/jcp.10206
Wardlaw GM (1996) Putting body weight and osteoporosis into perspective. Am J Clin Nutr 63:433S–436S
Xie H, Yuan LQ, Luo XH, Huang J, Cui RR, Guo LJ, Zhou HD, Wu XP, Liao EY (2007) Apelin suppresses apoptosis of human osteoblasts. Apoptosis 12:247–254. doi:10.1007/s10495-006-0489-7
Yuan LQ, Xie H, Luo XH, Wu XP, Zhou HD, Lu Y, Liao EY (2006) Taurine transporter is expressed in osteoblasts. Amino Acids 31:157–163. doi:10.1007/s00726-005-0313-7
Yuan LQ, Lu Y, Luo XH, Xie H, Wu XP, Liao EY (2007) Taurine promotes connective tissue growth factor (CTGF) expression in osteoblasts through the ERK signal pathway. Amino Acids 32:425–430. doi:10.1007/s00726-006-0380-4
Acknowledgments
This work was supported by Grant from Chinese National Key Basic ‘973’ Research Project (No. 2006CB503808), and the National Natural Science Foundation of China (No. 30801174, No. 30871191 and No. 30572078).
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Y.-S. Liu and Y. Lu contributed equally to this work.
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Liu, YS., Lu, Y., Liu, W. et al. Connective tissue growth factor is a downstream mediator for preptin-induced proliferation and differentiation in human osteoblasts. Amino Acids 38, 763–769 (2010). https://doi.org/10.1007/s00726-009-0281-4
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DOI: https://doi.org/10.1007/s00726-009-0281-4