Growth factor modulation of mitogenic responses and proteoglycan synthesis by human periodontal fibroblasts

Abstract

In order to understand the relationship between specific growth factors and matrix synthesis by periodontal cells, we have investigated the effects of platelet-derived growth factor BB (PDGF-BB), insulin-like growth factor-I (IGF-1), and growth hormone on DNA and proteoglycan synthesis by cultured human gingival and periodontal ligament fibroblasts in vitro. PDGF-BB and IGF-1, but not growth hormone, were mitogenic for both periodontal ligament fibroblasts and gingival fibroblasts, although the periodontal ligament cells responded more strongly. The mitogenic response was accompanied by alterations in expression of matrix proteoglycan mRNA. For both the gingival and periodontal ligament cells, there was a decrease in mRNA for decorin and an increase in mRNA for versican following exposure to IGF-1 and PDGF-BB. Although no change was seen in response to PDGF, biglycan mRNA level was increased by IGF-1 in periodontal ligament fibroblasts. With the gingival fibroblasts, biglycan mRNA levels were unaffected by IGF-1, PDGF-BB, or growth hormone. These findings suggest variable responses of fibroblasts to growth factors depending upon anatomical site within the periodontium. Moreover, there appears to be a correlation between cell proliferation and the types of proteoglycan synthesised with decorin expression being suppressed, and versican being increased during fibroblast proliferation.

Cytokine regulation of syndecan‐1 and ‐2 gene expression in human periodontal fibroblasts and osteoblasts

“…The bioactive molecules PDGF, TGF‐β 1 , and IL‐1β were chosen for this study because of their roles in both inflammation and tissue repair. PDGF‐BB induces gene expression of cell matrix‐related molecules, such as collagens and glycosaminoglycans (25, 32). In particular, PDGF‐BB upregulates the synthesis of versican, but downregulates decorin synthesis by PDLF and GF (25).…”

“…The cells were incubated for a further 8 h before the RNA was harvested. These concentrations were chosen on the basis of previous studies which have demonstrated these to be within the optimum range inducing biological responses by periodontal cells (23–25).…”

Tropoelastin Expression by Periodontal Fibroblasts

“…To examine tropoelastin mRNA expression, sample RNA was extracted from HGF and HPLF after culture for 4 wks by means of a RNeasy Mini Kit (Qiagen, Hilden, Germany), as described previously (Haase et al, 1998). Using the extracted RNA as a template, we carried out reverse-transcription reactions with a SuperScript TM First-Strand complementary DNA (cDNA) Synthesis System (Life Technologies, Grand Island, NY, USA).…”

IGF-1 Signaling Enhances Cell Survival in Periodontal Ligament Fibroblasts vs. Gingival Fibroblasts

“…Studies have suggested that periodontal ligament fibroblasts (PDLF) and gingival fibroblasts (GF) are heterogeneous (Lekic et al, 1997;Lackler et al, 2000) with extensive site-specific functional differences, including variations in responses to growth factors (Haase et al, 1998;Mumford et al, 2001). IGF-1 has been shown to regulate DNA and protein synthesis in PDLF in vitro and to enhance soft-tissue wound healing in vivo (Lynch et al, 1991;Ivanovski et al, 2001).…”

“…IGF-1 has been shown to regulate DNA and protein synthesis in PDLF in vitro and to enhance soft-tissue wound healing in vivo (Lynch et al, 1991;Ivanovski et al, 2001). It was suggested that PDLF respond to IGF-1 more strongly than GF, and this differential response to IGF-1 could stem from the tissue specificity of these cells within the periodontium (Haase et al, 1998). However, the role of IGF-1 in preventing apoptosis in PDLF compared with GF still remains unclear.…”