The Cultivation And Identification Of Mandibular Condylar Cartilage Cells Of The Rats And The Effect On Apoptotic Protein Under Hydrostatic Pressure

Objectives: To explore the cultivative method of mandibular condylar cartilage cells of the rats and observe its biological characteristics and study the law of the expression of Fas and TRPM7 protein under different hydrostatic pressure in mandibular condylar cartilage cells(MCCs).Discuss whether the pathways of Fas and TRPM7 have something with apoptosis of MCCs.Methods: The rats were dissect-ed to obtain the condylar cartilage.To obtain stem cells by digestion of collagena-se II combined with the method of tissue blocks.Tested the growth curve of MC-Cs by MTT.Identification of MCCs by toluidine blue staining and Immunohistoch-emistry and immunofluorescence of collagen II were applied.The third generation cells was selected and divided into two groups randomly.Different hydrostatic pres-sure and duration were given to experimental group.The control group was cultur-ed under the same condition without pressure.The expression of TRPM7 and Fas protein was detected by Western Blot to observe the change of apoptin under di-fferent pressure and duration in vitro.Results: The digestion of collagenase II combined with tissue block could get the most cells which were digesting for 18-20 hours.The cells mainly showed polygonal in vitro.The cells of 1 to 4 generation with the stable biological characteristics like the original cells,of which 3 generation was best.After the 5th generation,cells were turning to old.The positive expression of MCCs prompted the reliability that cells derived from cartilage through toluidine blue staining and immunohistochemical staining and immuneofluorescence s-taining of collagen II.The expression of Fas protein decreased with the increase o-f pressure(6Kpa,8Kpa,10Kpa)under the same duration of pressure lasting 1h,o-r 2h.Fas protein in experimental group was compared with control group,P<0.05.Fas protein expressed increasely with the increase of pressure(20Kpa/2h,30Kpa/1h,30Kpa/2h).The difference was statistically significant compared between contro-l group and each experimental group,P<0.05.When the pressure was 20Kpa/1h,the difference was not statistically significant compared between control group and experimental group,P>0.05.The expression of TRPM7 protein decreased with the increase of pressure(6Kpa,8Kpa,10 Kpa,20Kpa)under the same duration of pressure lasting 1h or 2h.TRPM7 protein in experimental group was compared with control group,P<0.05.TRPM7 protein expressed more than control group under the pressure of 30Kpa/2h.The difference was statistically significant compared betw-een control group experimental group,P<0.05.But the group of 30Kpa/1h was n-ot.Conclusion: The digestion of collagenase II combined with tissue block was o-ne method obtaining MCCs.Within a scope of a certain pressure and time,the bi-gger the pressure was,the less the apoptin expressed which meant the cells might present depressed apoptotic status.Above the scope of the certain pressure,the bi-gger the pressure was,the more the apoptin expressed which meant the cells mig ht present increased apoptotic status.The study laid the theoretical foundation for r-esearching pathological mechanism of TMD.