Abstract:
Objective To study the effects of ethyl pyruvate (EP) on expression of inflammatory factor IL-1β in macrophages stimulated by oxidized low-density lipoprotein (ox-LDL).
Methods THP-1 cells weredifferentiated into macrophages by stimulation of phorbol ester (PMA, 100 ng/ml) and then incubated with ox-LDL (50 mg/L) only or added with EP (5 mmol/L) for 6 h, 12 h, 24 h and 48 h for RNA. The expression level of HMGB1, TLR4 and IL-1β were quantified by real-time PCR.
Results The expression of HMGB1 and TLR4 began to increase after stimulated by ox-LDL for 12 h in macrophages. The HMGB1 expression in macrophages stimulated by ox-LDL for 12 h, 24 h and 48 h was 3.23, 6.95, 8.96 times of control group, and the TLR4 expression in macrophages stimulated by ox-LDL for 12 h, 24 h and 48 h was 3.35, 5.65, 5.98 times of control group. Ethyl pyruvate could inhibit the expression of HMGB1 and TLR4 in macrophages. Compared with ox-LDL group, the inhibition rate of HMGB1 in macrophages treated by EP for 12 h, 24 h and 48 h was 64.4%, 83.8%, 77.5%, respectively, and the inhibition rate of TLR4 in macrophages treated by EP for 12 h, 24 h and 48 h was 54.9%, 42.6%, 65.6%, respectively. The expression of IL-1β began to increase after stimulated by ox-LDL for 6 h. The IL-1β expression in macrophages stimulated by ox-LDL for 6 h, 12 h, 24 h and 48 h was 2.24, 2.88, 3.36, 3.73 times of control group. Compared with ox-LDL group, the inhibition rate of IL-1β in macrophages treated by EP for 6 h, 12 h, 24 h and 48 h was 31.6%, 48.6%, 49.3%, 51.2%, respectively.
Conclusion EP is an effective agent which reduces the expression of IL-1β by inhibiting the HMGB1 in macrophages stimulated by ox-LDL.