Dahuang Lingxian Prescription Regulates Effect of TAK1 and TRAF6 Interaction and Co-localization on Inflammatory Response of Bile Duct Cells / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo observe the repair effect of Dahuanglingxian prescription （DHLX） on bile duct epithelial cells of rats. To explore whether its mechanism of action is to adjust the mutual binding of transforming growth factor -β （TGF-β） activated kinase 1（TAK1） and tumor necrosis factor receptor-associated factor 6 （TRAF6）， and regulate the activation of the nuclear transcription factor -κB （NF-κB）/mitogen-activated protein kinase （MAPK） signaling pathway. MethodThe 20 SD rats were randomly divided into normal group and DHLX group， 10 rats in each group， were given saline and DHLX （320 mg·kg-1·d-1） for 8 days， to prepare normal serum and DHLX serum. Biliary epithelial cells were extracted from normal SD rats and divided into 9 groups： Normal group， model group （20 mg·L-1）， LPS+DHLX group （20 mg·L-1+10% DHLX）， LPS+PDTC group （20 mg·L-1+200 μmol·L-1）， LPS+SB203580 group （20 mg·L-1+0.5 μmol·L-1）， LPS+PDTC+SB203580 group （20 mg·L-1+200 μmol·L-1+0.5 μmol·L-1）， LPS+PDTC+DHLX group （20 mg·L-1+200 μmol·L-1+10% DHLX serum）， LPS+SB203580+DHLX group （20 mg·L-1+0.5 μmol·L-1+10% DHLX serum）， LPS+PDTC+SB203580 +DHLX group （20 mg·L-1+200 μmol·L-1+0.5 μmol·L-1+10% DHLX serum）. The microscopic observation of morphological changes in each group of cells after drug intervention. Enzyme-linked immunosorbent assay（ELISA） was used to detect the expression of （IL）-1β and IL-6 in each group of cells. Western blot detected the expression levels of TAK1 and TRAF6 proteins in each group of cells， Co-IP detected the interaction between TAK1 and TRAF6， and further observed the distribution and co-localization of TAK1 and TRAF6 using Laser confocal microscope. ResultAfter the action of LPS， the cell synapses are reduced， the cell body becomes significantly rounded and smaller， but the cell morphology of each group tends to be normal after medication. Compared with normal group， the expression levels of IL-1β and IL-6 in model group were significantly increased （P<0.05）， while the expression level of TAK1 was decreased while the expression level of TRAF6 was increased （P<0.05）. The content of TAK1-TRAF6 protein complex showed a decreasing trend， and the two proteins co-located in the cytoplasm. Compared with model group， the expression levels of IL-1β and IL-6 in LPS+DHLX group were significantly decreased （P<0.05）， the expression level of TAK1 was increased and the expression level of TRAF6 was decreased （P<0.05）， the content of TAK1-TRAF6 protein complex was significantly increased （P<0.01）， and the two proteins were significantly co-located in cytoplasm. Compared with LPS+DHLX group， the expression levels of IL-1β and IL-6 in other groups were significantly decreased （P<0.05，P<0.01）. TAK1-TRAF6 protein complex content in each group was significantly decreased after pathway blocker intervention （P<0.05）， while TAK1-TRAF6 protein complex content in each group was significantly increased after pathway blocker combined with DHLX intervention （P<0.05）. Co-localization of the TAK1-TRAF6 in cytoplasm was not obvious. ConclusionIn the LPS-induced inflammatory response of bile duct cells， the binding of TAK1 and TRAF6 showed a weakening trend， but DHLX could reverse the phenomenon， we think the mechanism of action may be related to promoting the mutual binding of TAK1 and TARF6 to inhibit the activation of the NF-κB/MAPK signaling pathway.