ABSTRACT
This study evaluated the attachment, chemo-attractive, proliferative and mineralization inductive potential of a bovine cementum extract (CPE) on newborn murine dental follicle cells (MDFC) in vitro. Cementum extract was partially purified by DEAE-cellulose chromatografy. A band representing and Mr of 55,000 was excised form the fel and the protein (s) were electroeluted. Attachment assays revealed that CPE (1.0 µg/ml) promoted MDFC attachment by 96 percent in comparison with collagen type I (5 µg/ml), and was five-fold greater compared with serum-free media (SFM), (p<0.05). Between 1 and 5 days CPE at 1.0 µg/ml and collagen type I at 5 µg/ml sustained more than 75 percent attachement and spreading of MDFC when compared to SFM (P<0.05). Contrary to other reports, fibronectin (0.5 µg/ml) was more potent than CPE in promoting MDFC chemoattraction (P<0.05). MDFC proliferation was stimulated by CPE (0.125 µg/ml), but this response was elicited only when CPE was used together with 10 percent FBS (37.3 percent) or 0.2 percent FBS (76 percent) (p<0.05). Alkaline phosphatase expression by MDFC was increased by CPE (1.0 µg/ml), in comparison to the control. Calcium deposits were detected by von Kossa staining in 14-day MDFC cultures treated with CPE. Nodule formation and its mineralization in long-term MDFC cultures were induced by CPE (1.0 µg/ml). Molecules(s) contained in CPE appear to regulate various biological activities in MDFC, indicating that CPE could play a key role in selecting progenitor cells required for the process of cementogenesis during development
Subject(s)
Animals , Cell Adhesion Molecules , Chemotaxis/drug effects , Dental Cementum/chemistry , Dental Sac/cytology , Dental Sac/drug effects , Cell Division , In Vitro Techniques , Proteins/pharmacology , Tissue Extracts/pharmacologyABSTRACT
Hertwing's epithelial root sheath (HERS) cells were isolated and recombined with ectomesenchymal cells in vitro utilizing extracellular matrix components as substrate. After 14 days in culture, HERS cells were differnetiated and exhibited a stratified organization. These features resembled those observed in vivo as epithelial rests of Malassez. A mineralization process was also present in HERS cells, in which calcium salts were deposited. This mineralization was correlated with the strong immunoexpression of osteopontin by HERS. The results obtained add support to the possible role of HERS in the secretion of Hypocalcified material on the root during early cementogenesis