The responses of cells to the distinct PDGF isoforms have been correlated directly to the relative numbers of specific PDGF receptor subunits on the cell surface. The modulation of PDGF-a receptor subunits, the major subunit expressed in human periodontal ligament (PDL) cells, by cytokines present in the periodontal wound site, such as interleukin-1 (IL-1), may be an important factor influencing regenerative outcomes. The purpose of the present study was to examine the effects of IL-1β on PDGF-a receptor subunit expression in human PDL cells. Primary cultures of human PDL cells were treated with IL-1β over a range of concentrations. We assessed PDGF-a receptor subunits by examining the mitogenic responses of cells to PDGF-AA, specific binding of 125I-labeled PDGF-AA, immunofluorescent analysis of PDGF-a receptor subunits, and PDGF-a receptor subunit mRNA levels using Northern blot analysis. The results demonstrate a significant concentration-dependent decrease in 3H-thymidine incorporation in response to PDGF-AA following IL-1β treatment (p < 0.001). This decreased response correlated directly with IL-1-induced decreases in 125I-labeled PDGF-AA binding (p < 0.01), the numbers of immunolabeled PDGF-a receptor subunits, and in PDGF-a receptor subunit mRNA levels. However, when combined with TGF-β, IL-1β did not show additional down-regulation in proliferative response to PDGF-AA or PDGF-a receptor subunits beyond that achieved with these factors individually. These experiments identify IL-1 (3, along with TGF-β, as significant inhibitors of PDGF stimulation in human PDL cells, acting through the down-regulation of PDGF-a receptor subunit expression.
Blanco FJ, Geng Y., Lotz M. ( 1995). Differentiation-dependent effects of IL-1 and TGF-beta on human articular chondrocyte proliferation are related to inducible nitric oxide synthase expression. J Immunol154:4018-4026.
2.
Bolander ME (1992). Regulation of fracture repair by growth factors . Proc Soc Exp Biol Med200:165-170.
3.
Boyce BF, Aufdemorte TB, Garrett IR, Yates AJ, Mundy GR (1989). Effects of interleukin-1 on bone turnover in normal mice. Endocrinol125:1142-1150.
4.
Centrella M., McCarthy TL, Kusmik WF, Canalis E. (1992). Isoform-specific regulation of platelet-derived growth factor activity and binding in osteoblast-enriched cultures from fetal rat bone. J Clin Invest89:1076-1084.
5.
Cho MI, Lin W.-L, Genco RJ (1995). Platelet-derived growth factor-modulated guided tissue regenerative therapy. J Periodontol66:522-530.
6.
Chomczynski P., Sacchi N. (1987). Single-step method of RNA isolation by acid guanidinium thiocyanate-phenolchloroform extraction. Anal Biochem162:156-159.
7.
Collins JM, Grogan WM (1989). Comparison between flow cytometry and fluorometry for the kinetic measurement of membrane fluidity parameters. Cytometry10:44-49.
8.
Giannobile WV, Finkelman RD, Lynch SE (1994). Comparison of canine and non-human primate animal models for periodontal regenerative therapy: Results following a single administration of PDGF/IGF-I. J Periodontol65:1158-1168.
9.
Gilardetti RS, Chaibi MS, Stroumza J., Williams SR, Antoniades HN, Carnes DC, et al. (1991). High-affinity binding of PDGF-AA and PDGF-BB to normal human osteoblastic cells and modulation by interleukin-1. Am J Physiol261:C980-C985.
Heldin CH, Backstrom G., Ostman A., Hammacher A., Ronnstrand L., Rubin K., et al. (1988). Binding of different dimeric forms of PDGF to human fibroblasts: Evidence for two separate receptor types. EMBO J7:1387-1397.
12.
Jandinski JJ, Stashenko P., Feder LS, Leung CC, Peros WJ, Rynar JE, et al. (1991). Localization of interleukin-1β in human periodontal tissue. J Periodontol62:36-43.
13.
Kose KN, Xie JF, Carnes DL, Graves DT (1996). Pro-inflammatory cytokines down regulate platelet-derived growth factor-a receptor gene expression in human osteoblastic cells. J Cell Physiol166:188-197.
14.
Lynch SE, Williams RC, Polson AM, Howell TH, Reddy MS, Zappa VE, et al. (1989). A combination of platelet-derived and insulin-like growth factors enhance periodontal regeneration. J Clin Periodontol16:545-548.
15.
Lynch SE, deCastilla GR, Williams RC, Kiritsy CP, Howell TH, Reddy MS, et al. (1991). The effects of short-term application of a combination of platelet-derived and insulin-like growth factors on periodontal wound healing. J Periodontol62:458-467.
16.
Majack RA, Grieshaber NA, Cook CL, Weiser MC, McFall RC, Grieshaber SS, et al. (1996). Smooth muscle cells isolated from the neointima after vascular injury exhibit altered responses to platelet-derived growth factor and other stimuli. J Cell Physiol167:106-112.
17.
Matsuda N., Lin WL, Kumar NM, Cho MI, Genco RJ (1992). Mitogenic, chemotactic, and synthetic responses of rat periodontal ligament fibroblastic cells to polypeptide growth factors in vitro. J Periodontol63:515-525.
18.
Matsui T., Heideran M., Miki T., Popescu N., La Rochelle W., Kraus M., et al. (1989). Isolation of a novel receptor cDNA establishes the existence of two PDGF receptor genes. Science243:800-802.
19.
Mundy GR (1993). Cytokines and growth factors in the regulation of bone remodeling. J Bone Miner Res8:S505-S510.
20.
Oates TW, Rouse CA, Cochran DL (1993). Mitogenic effects of growth factors on human periodontal ligament cells in vitro. J Periodontol64:142-148.
21.
Oates TW, Kose KN, Xie JF, Graves DT, Collins JM, Cochran DL (1995). Receptor binding of PDGF-AA and PDGF-BB, and the modulation of PDGF receptors by TGF-β, in human periodontal ligament cells . J Cell Physiol162:359-366.
22.
Park J.-B, Matsuura M., Han K.-Y. Norderyd 0, Lin W.-L, Genco RJ, et al. (1995). Periodontal regeneration in class III furcation defects of beagle dogs using guided tissue regenerative therapy with platelet-derived growth factor. J Periodontol66:462-477.
23.
Rutherford RB, Niekrash CE, Kennedy JE, Charette MF (1992). Platelet-derived and insulin-like growth factors stimulate regeneration of periodontal attachment in monkeys. J Periodont Res27:285-290.
24.
Rutherford RB, Ryan ME, Kennedy JE, Tucker MM, Charette MF (1993). Platelet-derived growth factor and dexamethasone combined with a collagen matrix induce regeneration of the periodontium in monkeys. J Clin Periodontol20:537-544.
25.
Seifert RA, Hart CE, Phillips PE, Forstrom JW, Ross R., Murray MJ, et al. (1989). Two different subunits associate to create isoform-specific platelet-derived growth factor receptors. J Biol Chem264:8771-8778.
26.
Seifert RA, vanKoppen A., Bowen-Pope DF (1993). PDGF-AB requires PDGF receptor a-subunits for high-affinity, but not for low affinity, binding and signal transduction. J Biol Chem268:4473-4480.
27.
Somerman MJ, Archer SY, Imm GR, Foster RA (1988). A comparative study of human periodontal ligament cells and gingival fibroblasts in vitro. J Dent Res67:66-70.
28.
Stashenko P., Jandinski JJ, Fujiyoshi P., Rynar J., Socransky SS (1991a). Tissue levels of bone resorptive cytokines in periodontal disease. J Periodontol62:504-509.
29.
Stashenko P., Fujiyoshi P., Obernesser MS, Prostak L., Haffajee AD, Socransky SS (1991b). Levels of interleukin-1 beta in tissue from sites of active periodontal disease. J Clin Periodontol18:548-554.
30.
Taichman RS, Hauschka PV (1992). Effects of interleukin-1 beta and tumor necrosis factor-alpha on osteoblastic expression of osteocalcin and mineralized extracellular matrix in vitro. Inflammation16:587-601.
31.
Takeshita A., Nui ZG, Hanazawa S., Takara I., Higushi H., Katayama I., et al. (1992). Effect of interleukin-1 β on gene expressions and functions of fibro-blastic cells derived from human periodontal ligament . J Periodont Res27 :250-255.
32.
Tsukamoto T., Matsui T., Nakata H., Ito M., Natazuka T., Fukase M., et al. (1991). Interleukin-1 enhances the response of osteoblasts to platelet-derived growth factor through the alpha receptor-specific up-regulation. J Biol Chem266:10143-10147.
33.
Wilton JM, Bampton JL, Griffiths GS, Curtis MA, Life JS, Johnson NW, et al. (1992). Interleukin-1 beta (IL-1β) levels in gingival crevicular fluid from adults with previous evidence of destructive periodontitis; a cross sectional study. J Clin Periodontol19:53-57.
34.
Xie JF, Stroumza J., Graves DT (1994). 11-1 down-regulates PDGF-a receptor gene expression at the transcriptional level in human osteoblastic cells. J Immunol153:378-383.
