Conclusion
TRIM21 caused abnormal expression of IL-6 in OLP via regulating TRIB2-MAPK signal axis, leading to the disrupted Th1/Th2 balance in T lymphocytes.
Methods
Western bolt and qPCR assays were used to detect the effects of TRIM21 on cellular levels of ERK, p-ERK, AP-1, IL-6, TRIB2, IRF3, and IRF7, while co-immunoprecipitation was performed to verify the interaction between Trim21 and TRIB2 protein. The TRIM21 effect on TH1/TH2 balance in T cells was also evaluated using ELISA.
Results
The results of western blot showed that TRIM21 overexpression significantly increased p-ERK, c-fos, c-jun, IL-6 and TRIB2 levels in H9 cells (P<0.01 and P<0.001), however, inhibited the IRF3 and IRF7 levels (P<0.05). On the other hand, TRIM21 did not regulate the phosphorylation of ERK and the mRNA expression of AP-1 and TRIB2. In addition, TRIM21 was in relation to the proteasome degradation in TRIB2-ERK. TRIM21 also regulated the level of TRIB2 not only by inhibiting the ubiquitination of TRIB2, but also by affecting IL-6 through the ERK pathway.