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
Our previous study found that some trigeminal ganglion (TG) nerve endings in the inner walls of rat anterior chambers were mechanosensitive, and transient receptor potential ankyrin 1 (TRPA1) was an essential mechanosensitive channel in the membrane. To address the effect of cannabinoids on the mechanosensitive TG nerve endings in the inner walls of anterior chambers of rat eye, we investigated the effect of the (R)-(+)-WIN55, 212-2 mesylate salt (WIN), a synthetic cannabinoid on their cell bodies in vitro. Rat TG neurons innervating the inner walls of the anterior chambers were labeled by 1,1'-dilinoleyl-3,3,3',3'-tetramethylindocarbocyanine, 4-chlorobenzenesulfona (FAST DiI). Whole cell patch clamp was performed to record the currents induced by drugs and mechanical stimulation. Mechanical stimulation was applied to the neurons by buffer ejection. WIN evoked inward currents via TRPA1 activation in FAST DiI-labeled TG neurons. WIN enhanced mechanosensitive currents via TRPA1 activation in FAST DiI-labeled TG neurons. Our results indicate that cannabinoids can enhance the mechanosensitivity of TG endings in the inner walls of anterior chambers of rat eye via TRPA1 activation.
Subject(s)
Animals , Rats , Action Potentials , Anterior Chamber , Cannabinoids , Eye , Neurons , Patch-Clamp Techniques , Rats, Sprague-Dawley , TRPA1 Cation Channel , TRPC Cation Channels , Genetics , Trigeminal Ganglion , PhysiologyABSTRACT
<p><b>AIM</b>To study the effects of hydrocortisone sodium succinate on sodium current in human atrial myocytes and in guinea pig ventricular myocytes.</p><p><b>METHODS</b>Single cardiac myocytes were isolated by enzyme. The effects of hydrocortisone sodium succinate on sodium current (INa) were assessed by applying whole-cell patch clamp techniques.</p><p><b>RESULTS</b>Hydrocortisone sodium succinate (1, 3, 10 micromol x L(-1)) was shown to inhibit INa of both human atrial myocytes and guinea pig ventricular myocytes in concentration dependent manner and the IC50 were 6.97 and 8.74 micromol x L(-1), respectively. The inhibition effects acted quickly (1-3 min) and the maximal activating voltage of INa was not changed in both human and guinea pig cardiac myocytes.</p><p><b>CONCLUSION</b>Hydrocortisone sodium succinate can exhibit inhibitory effects on INa in both human and guinea pig cardiac myocytes, and its inhibitory effects act rapidly, which are not consistent with genomic effects, so there may be nongenomic effects.</p>