ABSTRACT
Activation of acid-sensing ion channels (ASICs) plays an important role in neuroinflammation.Macrophage recruitment to the sites of inflammation is an essential step in host defense.ASIC 1 and ASIC3 have been reported to mediate the endocytosis and maturation of bone marrow derived macrophages.However,the expression and inflammation-related functions of ASICs in RAW 264.7 cells,another common macrophage,are still elusive.In the present study,we first demonstrated the presence of ASIC 1,ASIC2a and ASIC3 in RAW 264.7 macrophage cell line by using reverse transcriptase polymerase chain reaction (RT-PCR),Western blotting and immunofluorescence experiments.The non-specific ASICs inhibitor amiloride and specific homomeric ASIC 1 a blocker PcTx 1 reduced the production of iNOS and COX-2 by LPS-induced activating RAW 264.7 cells.Furthermore,not only amiloride but also PcTx 1 inhibited the migration and LPS-induced apoptosis of RAW 264.7 cells.Taken together,our findings suggest that ASICs promote the inflammatory response and apoptosis of RAW 264.7 cells,and ASICs may serve as a potential novel target for immunological disease therapy.
ABSTRACT
Activation of acid-sensing ion channels (ASICs) plays an important role in neuroinflammation.Macrophage recruitment to the sites of inflammation is an essential step in host defense.ASIC 1 and ASIC3 have been reported to mediate the endocytosis and maturation of bone marrow derived macrophages.However,the expression and inflammation-related functions of ASICs in RAW 264.7 cells,another common macrophage,are still elusive.In the present study,we first demonstrated the presence of ASIC 1,ASIC2a and ASIC3 in RAW 264.7 macrophage cell line by using reverse transcriptase polymerase chain reaction (RT-PCR),Western blotting and immunofluorescence experiments.The non-specific ASICs inhibitor amiloride and specific homomeric ASIC 1 a blocker PcTx 1 reduced the production of iNOS and COX-2 by LPS-induced activating RAW 264.7 cells.Furthermore,not only amiloride but also PcTx 1 inhibited the migration and LPS-induced apoptosis of RAW 264.7 cells.Taken together,our findings suggest that ASICs promote the inflammatory response and apoptosis of RAW 264.7 cells,and ASICs may serve as a potential novel target for immunological disease therapy.
ABSTRACT
Objective To investigate the effect of low pH on acid-sensing ion channel 1a( ASIC1a) expression in vascular endothelial cells induced by serum IgA 1 from Henoch-Sch?nlein purpura ( HSP ) children and regulatory role of ASIC1a in it.Methods Human dermal microvascular endothelial cells ( HDMECs) treated by serum IgA1 from children with HSP were incubated in different pH medium .ASIC1a, destrin and α-SM mRNA expressions in HDMECs were evaluated by real-time quantitative polymerase chain reaction (q-PCR).The level of inflammatory cytokines released by vascular endothelial cells was detected by ELISA .Moreover destrin and α-SM protein expres-sion in HDMECs was evaluated by Western blot .Results The results showed that in low pH condition , IgA1 from HSP children could induce the upregulation of ASIC 1a mRNA expression , stimulate IL-8, NO and TM release of vascular endothelial cells of HSP children .And blockers of ASICs could reduce acid-induced cytokine release of vascular endothelial cells .Moreover destrin and α-SM mRNA and protein expression in HDMECs of HSP children significantly decreased when exposure to extracellular acidosis .However blockers of ASICs increased destrin and α-SM mRNA and protein expression in vascular endothelial cells of HSP children .Conclusions These findings showed that activation of ASIC 1a could be involved in the vascular endothelial cell injury of HSP children .Blocking ASIC1a may have a significant protective effect on the inflammatory injury of vascular endothelial cells .