Role of PLC/PIP2 signaling pathway in radiation-induced NRP1 + Treg cells / 中华放射医学与防护杂志

ABSTRACT

Objective To explore the role of PLC/PIP2 signal pathway in the changes of mouse thymus CD4 + CD25 + NRP1 + Treg and TGF-β1 after different doses of X-ray irradiation Methods 36 ICR mice were randomly divided into 6 groups according to the irradiation doses of 0,0.5,1.0,2.0,4.0 and 6.0 Gy,respectively.Flow cytometry was used to detect the expression of NRP1 + Treg,and ELISA was used to detect the expression of TGF-β1 in mouse thymocytes at 16 h post-irradiation.The EL-4 cells were irradiated by X-rays at the dose of 4.0 Gy after co-cultured with the PMA and TMB-8 for 2 hours.Flow cytometry was used to detect the expression of NRP1 + Treg,and ELISA was used to detect the changes of TGF-β1 at 48 h post-irradiation.Results The NRP1 + Treg appeared a transient decrease at both 0.5 and 1.0 Gy irradiation and reached its valley value at 1.0 Gy (t =6.96,P ＜ 0.01),then showed a dosedependent increase and reached its peak at 6.0 Gy (t =6.70,P ＜ 0.01).The TGF-β1 level decreased after 0.5 Gy X-rays (t =12.53,P ＜0.01),then increased at a dose-dependent manner and reached its peak at 4.0 Gy (t =10.40-19.56,P ＜ 0.01).Compared with the sham-irradiation,NRP1 + Treg was decreased significantly after PMA treatment (t =3.06,P ＜ 0.01),while it was up-regulated significantly after irradiation in the presence of PMA (t =8.27,P ＜ 0.01).TGF-β1 was reduced in the presence of PMA with or without irradiation (t =10.46-39.69,P ＜ 0.01).NRP1 + Treg and TGF-β1 were increased significantly after TMB-8 treatment (t =5.53-44.26,P ＜ 0.01).Conclusions NRP1 + Treg cells and TGF-β1 were up-regulated after a high dose radiation,and the PLC/PIP2 signal pathway may participate in the regulation.