Résumé
Objective To explore the relationship of the ADP-ribosylation factor-like 8A (Arl8a)with TLR4-TRIF-GEFH1 -RhoB pathway in dendritic cells(DCs). Methods DCs were prepared from wildtype and TRIF-knockout (TRIFKO) mice. After LPS stimulation, the cells were collected for cDNA amplification. Real-time PCR method was used to detect Arl8a mRNA levels. DCs from wild-type mice were transfected with guanine nucleotide-exchange factors H1 ( GEFH1 ) small interference RNA ( siRNA ), Arl8a mRNA levels were examined with or without LPS stimulation. Then RhoB mRNA expression was analyzed in DCs transfected with the siRNA of GEFH1 and Arl8a gene, respectively. Results LPS induced the up-regulation of Arl8a mRNA in DCs from control mice but not in DCs from TRIFKO, indicating that LPS-mediated up-regulation of Arl8a was suppressed in TRIFKO DCs. In addition, siRNA of GEFH1 significantly suppressed the LPS-mediated up-regulation of Arl8a mRNA, RNAi of Arl8a and GEFH1 significantly decreased RhoB mRNA level in DCs after LPS stimulation ( P ＜ 0. 01 ). Conclusion The expression of Arl8a is involved in the TLR4-TRIF pathway in DCs, and Arl8a is closely associated with GEFH1 and RhoB at transcriptional level.