ABSTRACT
Objective The mechanisms of epimedium and Ligustrum Lucidum with glucocorticoid (GC) acting on asthma are closely related to the regulation of the JAKs / STATs pathway associated with the Th1/Th2 balance in the lung tissue of the asthmatic rats. This study aimed to investigate the synergistic effect of icariin and oleanolic acid with dexamethasone on the protein expressions of JAKs/STATs in GC-sensitive CEM-C7 and GC-resistant CEM-C1 cells.Methods We divided CEM-C7 and CEM-C1 cells into groups A (complete culture medium control), B (dexamethasone at 10-6mol/L), C (icarrin at 100 mg/mL), D (oleanolic acid at 100 mg/mL), E (icarrin+oleanolic acid both at 50 mg/mL), and F (icariin+oleanolic acid+dexamethasone at 50 mg/mL, 50 mg/mL and 10-6 mol/L, respectively), and treated them with corresponding agents for 24 hours. Then, we determined the protein expressions of JAKs (JAK1 and JAK2) and STATs (STAT1, STAT3, STAT5, and STAT6) in the CEM-C7 and CEM-C1 cells of different groups by Western blot.Results The protein expressions of JAK1 and JAK2 in the CEM-C1 cells were 0.22±0.01 and 0.23±0.01 in group A, 0.24±0.01 and 0.24±0.01 in group B, 0.23±0.01 and 0.22±0.01 in group C, 0.24±0.01 and 0.23±0.01 in group D, 0.22±0.01 and 0.21±0.01 in group E, and 0.18±0.01 and 0.19±0.01 in group F, both significantly lower in groups E and F than in B (P<0.01), and in groups C, D and F than in E (P<0.01). The expressions of STAT1 and STAT3 proteins were 0.23±0.01 and 0.23±0.01 in group A, 0.23±0.01 and 0.22±0.01 in group B, 0.23±0.01 and 0.22±0.01 in group C, 0.23±0.01 and 0.23±0.01 in group D, 0.18±0.01 and 0.20±0.02 in group E, and 0.17±0.01 and 0.16±0.01 in group F, both remarkably lower in groups E and F than in B (P<0.01), and that of STAT3 even lower in F than in E (P<0.01). The expressions of STAT5 and STAT6 were 0.24±0.01 and 0.24±0.01 in group A, 0.23±0.01 and 0.23±0.02 in group B, 0.23±0.01 and 0.24±0.01 in group C, 0.23±0.01 and 0.24±0.01 in group D, 0.19±0.01 and 0.19±0.01 in group E, and 0.16±0.01 and 0.20±0.02 in group F, both markedly lower in groups E and F than in B (P<0.01), and even lower in F than in E (P<0.01). The protein expressions of JAK1 and JAK2 in the CEM-C7 cells were 0.24±0.01 and 0.22±0.02 in group A, 0.12±0.01 and 0.49±0.01 in group B, 0.23±0.01 and 0.27±0.01 in group C, 0.25±0.01 and 0.25±0.02 in group D, 0.27±0.01 and 0.23±0.01 in group E, and 0.20±0.01 and 0.32±0.01 in group F, the former increased while the latter decreased significantly in groups B, C, D, E and F as compared with group A (P<0.01), the former even lower and the latter even higher in groups C and F than in E (P<0.01). The expressions of STAT1 and STAT3 were 0.23±0.01 and 0.23±0.01 in group A, 0.10±0.01 and 0.11±0.02 in group B, 0.27±0.01 and 0.26±0.01 in group C, 0.27±0.01 and 0.27±0.01 in group D, 0.28±0.01 and 0.27±0.01 in group E, and 0.21±0.01 and 0.23±0.02 in group F, both remarkably higher in groups C, D, E and F than in B (P<0.01), though lower in F than in E (P<0.01). The expressions of STAT5 and STAT6 were 0.24±0.01 and 0.24±0.01 in group A, 0.10±0.01 and 0.11±0.02 in group B, 0.23±0.01 and 0.23±0.02 in group C, 0.23±0.01 and 0.23±0.01 in group D, 0.24±0.01 and 0.24±0.01 in group E, and 0.20±0.01 and 0.21±0.05 in group F, both significantly upregulated in groups C, D, E and F as compared with B (P<0.01), though lower in F than in E (P<0.05).Conclusion In case of hormone resistance, icariin and oleanolic acid combined with dexamethasone may regulate the JAKs/STATs signaling pathway and improve the sensitivity to hormone action.