Study on Stimulatory factor(s) of IL-6 dependent plasmimogen activator activity in dental pulp cells

IL-6可能通过刺激牙髓细胞中的PA-纤溶酶系统参与细胞外基质的降解。本研究旨在探讨IL-6对牙髓细胞和牙龈细胞中PA-纤溶酶系统的影响，并阐明这种影响是否是牙髓细胞的特异性事件。牙髓细胞和牙龈细胞取自同一供体，用IL-6处理。结果表明，IL-6处理后的牙髓细胞PA活性明显增强，而牙龈细胞PA活性无明显增强。为了阐明培养基中存在的一些因素可能导致这种观察结果，牙龈细胞用从IL-6处理的牙髓细胞培养物获得的条件培养基生长。牙髓细胞条件培养液能刺激牙龈细胞的PA活性。可溶性IL-6受体（sIL-6 r）或抗sIL-6 r抗体对这种刺激作用无影响。施加条件培养基级分，并用0.05M磷酸盐、0.15M氯化钠洗脱12 kDa以下的IL-6刺激牙龈细胞纤溶酶原激活剂的活性，提示牙髓细胞和牙龈细胞对IL-6对PA-纤溶酶系统的反应不同，牙髓细胞条件培养液中可能含有刺激牙龈细胞PA活性的未知因子。

IL-6 may be involved in the extracellular matrix degradation through the stimulation of the PA-plasmin system in dental pulp cells. The purpose of this study is to evaluate the effect of IL-6 on PA-plasmin system in both dental pulp and gingival cells and, to clarify whether this effect is the specific event in dental pulp cells. Dental pulp and gingival cells were obtained from same donor, and treated with IL-6. It was observed that the PA activity of dental pulp cells treated with IL-6 was enhanced significantly compared to control, however gingival cells showed no such increase. To elucidate that some factors present in the medium might result in this observation, the gingival cells was grown with conditioned medium obtained from cultures of IL-6-treated dental pulp cells. The conditioned medium resulted from dental pulp cells enabled to stimulate the PA activity of gingival cells. Soluble IL-6 receptor(slL-6r) or anti-sIL-6r did not affect on this stimulatery effect. The conditioned medium fraction was applied and eluted with O.05M phosphate, 0.15M sodium chloride (pH 6.8) onto a gel filtration column The flaction of under the 12 kDa stimulated activity of plasminogen activator of gingival cells.These findings suggest that dental pulp cells were differrent from gingival cells with respect to the response of IL-6 toward the PA-plasmin system, and the conditioned medium from dental pulp cells may containe unknown factor(s) which stimulate PA activity of gingival cells.