Effect Of L Type Calcium Channel αl Subunit In Human Odontoblasts On Dentin Mineralization In Vitro

Dentin is a kind of highly calcified connective tissue, and odontoblasts play a critical role in dentin calcification. Studies have showed that many molecules participate in dentin calcification, such as L type calcium channels, Ca-ATPase, Na+/Ca2+ exchangers and calcium binding proteins. L type calcium channels play an important role in this process.L type calcium channel is a kind of macromolecule glycoprotein composed of five subunits,α1,α2,β,γandδ. The pore functional subunit of L type calcium channel, subunitα1, has three isformsα1 C,α1D andα1S. Study of the effects of L-type calcium channelα1 subunit on dentin calcification may have significant contribution in revealing the mechanism of dentin formation. The aim of this study was to investigate the effects of polyclonal antibody to L type calcium channelα1D subunit on human dentinogenesis by the method of human tooth slice organ culture in vitro and the possible calcium transport mechanism of L type calcium channel.1 Establishment of human tooth slice organ culture model in vitro Young healthy human premolars and the third molars were collected and cut into 2mm-thick transverse slices by low speed diamond-edged saw. The slices were embedded in 1% semisolid agarose-based medium and cultured in Trowel-type cultures for 2 to 14 days. Tooth slices were successfully cultured in vitro for two weeks, and the odontoblasts could maintain their original morphology within one week, and then gradually shrank, and the cell density decreased.2 Effects of nimodipine on human dentinogenesisTo study the effects of nimodipine on human dentinogenesis using human tooth slice organ culture in vitro. Agarose beads dipped in nimodipine solution and PBS were symmetrically placed on tooth slices, and the slices were then embedded in a semisolid agarose-based medium and cultured in Trowel-type cultures for 1 week. After treatment with nimodipine, the fluorescent band of tetracycline was narrow and weak, and globular calcification in predentine was decreased compared with the control. TEM showed that secretory vesicles in odontoblast were somewhat increased, but immunohistochemical staining for collagen I showed no difference between the two groups. The results suggested that nimodipine could influence the calcification of dentine, but had no obvious influence on the synthesis and secretion of dentine matrix.3 Effects of polyclonal antibody to L type calcium channelαlD subunit on human dentinogenesisTo study the effects of polyclonal antibody to L type calcium channelα1D subunit on human dentinogenesis using human tooth slice organ culture in vitro. Agarose beads dipped in polyclonal antibody to L type calcium channelα1D subunit and PBS were symmetrically placed on tooth slices, and the slices were then embedded in a semisolid agarose-based medium and cultured in Trowel-type cultures for 1 week. Fluorescent band of tetracycline in the experimental group was narrow, and globular calcification in predentine was decreased compared with the control group. Immunohistochemical staining for collagen I showed no obvious difference between the two groups. The results showed that polyclonal antibody to L type calcium channelα1D subunit could influence the calcification of dentine, but had no obvious influence on the synthesis and secretion of dentine matrix.