Effect of dexamethasone and formoterol on expression of TLR4 in macrophages differentiated from THP-1 cell line / 中国医师杂志

ABSTRACT

Objective Inhaled corticosteroids combined with long β2-adrenoceptor agonist are widely used in treatment of chronic obstructive pulmonary disease,but mechanisms remain unclear.Methods Macrophage cells differentiated from THP-1 cell line were stimulated with dexamethasone and/or formoterol with or without lipopolysaccharide (LPS).TLR4 mRNA and protein were examined by reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting.Results A dose-dependent up regulation in TLR4 mRNA and protein expression in the presence of LPS was found.Treatment with dexamethasone (10-10 ～ 10-6mol/L) resulted in a dose-dependent reduction in TLR4 mRNA and protein.Stimulation with formeterol (10-7 mol/L and 10-6 mol/L) caused up regulation of TLR4.Formoterol (10-6mol/L)partially reversed the inhibitory effect of dexamethasone (10-6 mol/L) on TLR4 expression in the presence of LPS.Conclusions Modulation of TLR4 in macrophages by dexamethasone and/or formoterol may be one of the mechanisms for combination and have important implications for the treatment of airway inflammation in response to gram-negative bacteria.