[Biological characteristic comparison between long junctional epithelium cells and junctional epithelium cells]

To culture long junctional epithelium (LJE) cells in vitro and compare its biological characteristics with junctional epithelium (JE) cells.

LJE samples were collected from the patients with chronic periodontitis during flap surgery. Sulcular parts of tissues were removed by sterile scissor then enzymatic method and keratinocyte-serum free medium (KSFM) were used for culturing. JE samples were obtained from healthy bicuspid premolars or third morlars for orthodontic or impaction reasons and the cells were cultured in the same way as LJE. The two types of cells were compared in cell morphology, dimension,viability, proliferation, apoptosis and cytokeratin expression by means of cytoanalyzer, confocal laser scanning microscope and flowcytometry. Statistical analysis was performed using SPSS11.5 software package for independent-samples t test.

LJE and JE cells exhibited similar cell morphology. Although the viability of LJE cells were lower than JE cells, there were no statistical significance (P>0.05). The mean diameter and volume of LJE cells were (19.03+/-0.19)microm and (4.29+/-0.19)x10(3) fL versus (17.16+/-0.95)microm and (3.20+/-0.52)x10(3)fL of JE cells (P<0.05). The doubling time of LJE cells, was longer than that of JE cells.CK19 expression of LJE cells was weaker than of JE cells and there were no difference in the expression pattern of CK6 and CK13. Compared with control cells, the early- and late-stage apoptosis ratio of LJE cells were (4.62+/-2.16)% and (9.46+/-1.84)%, respectively which were all higher than JE cells which were (0.47+/-0.63)% and (3.84+/-0.98)% (P<0.05).

There is difference between LJE and JE cells in dimension, CK19 expression, proliferation time and apoptosis. This study provides some clinical significance and aid in understanding the biological characteristics of LJE and the healing process of periodontitis.