This study aimed to comprehend the largely unknown role of voltage-gated potassium channel 1.3 （Kvl.3） in the phagocytic function of macrophages. We found that blocking of the Kv 1.3 channel with 100 pmol L 1 Sticho...This study aimed to comprehend the largely unknown role of voltage-gated potassium channel 1.3 （Kvl.3） in the phagocytic function of macrophages. We found that blocking of the Kv 1.3 channel with 100 pmol L 1 Stichodactyla helianthus neurotoxin （ShK） enhanced the phagocytic capacities of both resting and lipopolysaccharide （LPS）-stimulated RAW264.7 macrophages in the chicken erythrocyte system. In the fluorescein isothiocyanate （FITC）-labeled Escherichia coli k-12 system, ShK increased the phagocytic capacities of resting RAW264.7 cells, but not of the LPS-stimulated cells, as LPS alone stimulated almost satu- rated phagocytosis of the macrophages. ShK increased the nitric oxide （NO） production in LPS-activated cells, but not in rest- ing RAW264.7 cells. There was no effect of ShK alone on the cytokine secretions in resting RAW264.7 cells, but it suppressed IL-113 secretion in LPS-stimulated RAW264.7 cells. At a concentration of 100 pmol L 1, ShK did not affect the viability of the tested cells. Kv 1.3 was expressed in RAW264.7 cells; this expression was downregulated by LPS, but significantly upregulat- ed by disrupting caveolin-dependent endocytosis with filipin III. In addition, cytochalasin D, an inhibitor of actin polymeriza- tion, did not affect the Kvl.3 expression. Thus, blocking of the Kvl.3 channel enhances the phagocytic capacity and NO pro- duction of this cell line. Our results suggest that Kv 1.3 channel serves as a negative regulator of phagocytosis in macrophages and can therefore be a potential target in the treatment of macrophage dysfunction.展开更多
基金supported by the National Key Basic Research Program of China(2011CB93350)National Natural Science Foundation of China(31171088,31471126,81470540,81300139)
文摘This study aimed to comprehend the largely unknown role of voltage-gated potassium channel 1.3 （Kvl.3） in the phagocytic function of macrophages. We found that blocking of the Kv 1.3 channel with 100 pmol L 1 Stichodactyla helianthus neurotoxin （ShK） enhanced the phagocytic capacities of both resting and lipopolysaccharide （LPS）-stimulated RAW264.7 macrophages in the chicken erythrocyte system. In the fluorescein isothiocyanate （FITC）-labeled Escherichia coli k-12 system, ShK increased the phagocytic capacities of resting RAW264.7 cells, but not of the LPS-stimulated cells, as LPS alone stimulated almost satu- rated phagocytosis of the macrophages. ShK increased the nitric oxide （NO） production in LPS-activated cells, but not in rest- ing RAW264.7 cells. There was no effect of ShK alone on the cytokine secretions in resting RAW264.7 cells, but it suppressed IL-113 secretion in LPS-stimulated RAW264.7 cells. At a concentration of 100 pmol L 1, ShK did not affect the viability of the tested cells. Kv 1.3 was expressed in RAW264.7 cells; this expression was downregulated by LPS, but significantly upregulat- ed by disrupting caveolin-dependent endocytosis with filipin III. In addition, cytochalasin D, an inhibitor of actin polymeriza- tion, did not affect the Kvl.3 expression. Thus, blocking of the Kvl.3 channel enhances the phagocytic capacity and NO pro- duction of this cell line. Our results suggest that Kv 1.3 channel serves as a negative regulator of phagocytosis in macrophages and can therefore be a potential target in the treatment of macrophage dysfunction.
