Effects Of Titanium Ions On The Activation And TRPV1 Channel Of T Lymphocytes

Objective: To investigate the role of titanium ions on the regulation of bone metabolism surrounding dental implant from the point of bone immunology by studying the effects of titanium ions on the activation and TRPV1 channel of T lymphocytes.Methods: 1.Jurkat T lymphocytes were cultured in vitro with or without phytohemagglutinin（PHA）pre-stimulation and exposed to 0μ mol/L 、 25μmol/L、50μmol/L and 100μmol/L titanium ions for 24 h.The expression of CD69 was measured by flow cytometry（FCM）.The expression of NF-κB mRNA and TRPV1 mRNA were detected by quantitative real-time polymerase chain reaction（qRT-PCR）.2.After TRPV1 channel was blocked thirty minutes by BCTC,T lymphocytes were exposed to 0μmol/L、 50μmol/L titanium ions with or without PHA pre-stimulation for 24 h.The intracellular Ca²⁺ concentration was analyzed by FCM.The expression of bone metabolism-related factors IL-1β、TNF-α and RANKL were measured by enzyme-linked immuno sorbent assay（ELISA）.Results: 1.Compared with the control group,25μmol/L、50μmol/L and100 μ mol/L titanium ions could enhance the expression of CD69,NF-κ B mRNA and TRPV1 mRNA in pre-stimulation or non-stimulation groups（P<0.05）.The expression of CD69 between 25μmol/L and 50μmol/L titanium ions groups in pre-stimulation T lymphocytes was not statistically significant（P> 0.05）.The difference of the expression of NF-κ B mRNA was not statistically significant between 5μmol/L and 50μmol/L titanium ions groups with or without PHA stimulation（P>0.05）.There was statistically significant about TRPV1 m RNA expression in 25μmol/L,50μmol/L,and 100 μmol/L titanium ions with or without PHA stimulation（P<0.05）.2.The difference of intracellular Ca²⁺ concentration was not statistically significant compared with control group in 50μmol/L titanium ions group after TRPV1 channel was blocked（P > 0.05）,and there was not significant of intracellular Ca²⁺ concentration between pre-blocked group and non-blocked group（P>0.05）.The intracellular Ca²⁺ concentration in 50μmol/L titanium ions group in pre-stimulation T lymphocytes was significantly higher than control group（P<0.05）,and which in pre-blocked groups were lower than in non-blocked groups（P<0.05）.3.After TRPV1 channel was blocked,the expression of bone metabolism-related factors IL-1βand TNF-αin 50μmol/L titanium ions group with or without PHA stimulation were higher than control group,and which in pre-blocked groups were lower than in non-blocked groups.The difference of RANKL expression was not statistically significant compared with control group in 50 μ mol/L titanium ions group in non-stimulation T lymphocyte after TRPV1 channel was blocked;the expression of RANKL in 50μ mol/L titanium ions group with PHA stimulation were higher than control group,and which in pre-blocked groups were lower than in non-blockedgroups（P<0.05）.Conclusions: 1.Titanium ions could enhance the expression of CD69 and NF-κB that induce activation effects of T lymphocytes.2.TRPV1 channel could affect that titanium ions regulate secretion of bone metabolism related factor IL-1β、TNF-αand RANKL in T lymphocytes,which may be related to the change of intracellular Ca²⁺ concentrations.