Cementum specific components which influence periodontal connective tissue cells

We have isolated two polypeptides from cementum one of which promotes the growth and the other the attachment of periodontal cells. One polypeptide, the cementum derived growth factor (CGF), was extracted from healthy human and bovine teeth by 1 M CH₃COOH and purified by heparin-affinity chromatography and HPLC. The CGF is a 23' kDa polypeptide which is mitogenic to fibroblasts and smooth muscle cells. It is active alone, but its activity is highly potentiated by plasma-derived serum or EGF. It induces classical mitogenic signaling events, which include Ca^+plus; mobilization, inositol phosphate hydrolysis, activation of phosphokinase C (PKC) and transcription of cellular protooncogenes c-fos and jun-B. The magnitude and pattern of activation of signaling events and their susceptibility to PKC inhibitors and pertussis toxin indicated that the CGF may be a distinct molecular species. The CAP is a 55 kDa polypeptide which promotes the attachment and spreading of fibroblasts, smooth muscle cells, bone cells and endothelial cells, but not epithelial cells. Antibodies to CAP immunostain cementum, but not other tissues. Root surfaces bind CAP. The CGF and CAP do not appear to be present in adjacent periodontal structures. Our data show that the CAP and CGF selectively interact with periodontal cell populations and affect their biological activities, and thus may influence the formation and regeneration of periodontal connective tissues.