Locus Coeruleus Acid-Sensing Ion Channels Modulate Sleep–Wakefulness and State Transition from NREM to REM Sleep in the Rat / 神经科学通报·英文版

The locus coeruleus (LC) is one of the essential chemoregulatory and sleep–wake (S–W) modulating centers in the brain. LC neurons remain highly active during wakefulness, and some implicitly become silent during rapid eye movement (REM) sleep. LC neurons are also involved in CO

The expression and function of acid-sensing ion channels in auditory system and vestibular system / 中华耳鼻咽喉头颈外科杂志

Acid-sensing ion channels are a class of extracellular H+ activated cation channels, belonging to the amiloride-sensitive epithelial Na+ channel/degenerin (ENaC/DEG) superfamily. During extracellular acidification, the channels are activated and produce corresponding action potential. Acid-sensing ion channels are extensively expressed in the peripheral and central nervous system. It plays an important in synaptic plasticity, mechanical sensation, injury sensation related to acidosis of local tissues, acid reception and retinal regulation. This article reviews the expression, biological characteristics and functions of acid-sensing ion channels in cochlea, vestibular tissue and auditory center, so as to improve the understanding of physiology and pathophysiology of auditory system.

Identification and Function of Acid-sensing Ion Channels in RAW 264.7 Macrophage Cells / 华中科技大学学报（医学）（英德文版）

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.

Identification and Function of Acid-sensing Ion Channels in RAW 264.7 Macrophage Cells / 华中科技大学学报（医学）（英德文版）

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.

Effect of low pH on acid-sensing ion channel 1a expression in vascular endothelial cell induced by serum IgA 1 from Henoch-Sch?nlein purpura children and its mechanism / 基础医学与临床

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 .

Anti-inflammation Effects of Cacumen Biotae Water Decoction on Mice with Auricle and Abdominal In-flammation / 中国药房

OBJECTIVE:To study the anti-inflammation effects of cacumen biotae water decoction on mice with auricle and ab-dominal inflammation. METHODS:Mice were randomized into a normal control group,a model group,a positive control group (0.25 g/L aspirin)and cacumen biotae high-dose,medium-dose and low-dose [1,0.5 and 0.25 g(medicinal materials)/L] groups, respectively marked as groups A,B,C,D,E and F,with 10 mice in each group. The mice were given drugs ig for 5 consecutive days. The models of auricle and abdominal inflammation were established for all groups except the normal control group. The con-tents of tumor necrosis factor α(TNF-α)and interleukin 1(IL-1)in the serum of mice with auricle inflammation were determined, and the swelling degree and swelling rate were calculated. The contents of TNF-α,IL-1 and acid-sensing ion channels 1a(ASIC1a) in the liver tissues of mice with abdominal inflammation and the concentration of proteins in the peritoneal lavage fluid(ΔA)there-of were detected. RESULTS:For mouse models of auricle inflammation,the contents of TNF-α and IL-1 in serum in group B were higher than in group A;the swelling degree and swelling rate and the contents of TNF-α and IL-1 in groups C,D,E and F were lower than in group B,and those of group E and F were higher than in group C. There were statistical differences(P<0.05). For mouse models of abdominal inflammation,the contents of TNF-α,IL-1 and ASIC1a in liver tissues and ΔA in group B were higher than in group A;the contents of TNF-α,IL-1 and ASIC1a as well as ΔA in groups C,D,E and F were lower than in group B. There were statistical differences(P<0.05). CONCLUSIONS:Cacumen biotae water decoction has anti-effect on acute auricle and abdominal inflammation by a mechanism which may be related to decreasing TNF-α,IL-1 and ASIC1a.

Effect of Danhong injection on respiratory inhibition induced by hypoxia / 中国病理生理杂志

AIM: To investigate the effect of Danhong injection on respiratory inhibition induced by hypoxia and its related mechanism .METHODS:The electromyogram of the diaphragm was monitored to observe the respiratory re-sponses of the rats to hypoxia .The expression of acid-sensingion channel 1a (ASIC1a) in the brainstem after hypoxia was detected by the technique of immunohistochemical staining .RESULTS: The respiratory responses of the rats to hypoxia were initiatory excitation and consequent inhibition .In contrast to pre-hypoxia, the respiration of the rats in hypoxia group was inhibited 30 min after hypoxia (P<0.05), but the respiration of the rats in hypoxia plus Danhong group was still ex-cited (P<0.05), indicating that the respiration of the rats in hypoxia plus Danhong group was not yet depressed at the same time.The ASIC1a positive neurons were detected in the nuclei of trapezoid body and solitary tract .Compared with control group, the expression of ASIC1a was obviously enhanced after hypoxia .In contrast to hypoxia group , the expression of ASIC1a in the rats in hypoxia plus Danhong group was remarkably reduced (P<0.05).CONCLUSION:Danhong in-jection resists the occurrence of respiratory inhibition after hypoxia , and ASIC1a may participate in this process .

Antinociceptive Effects of Amiloride and Benzamil in Neuropathic Pain Model Rats

Amiloride and benzamil showed antinocicepitve effects in several pain models through the inhibition of acid sensing ion channels (ASICs). However, their role in neuropathic pain has not been investigated. In this study, we investigated the effect of the intrathecal amiloride and benzamil in neuropathic pain model, and also examined the role of ASICs on modulation of neuropathic pain. Neuropathic pain was induced by L4-5 spinal nerve ligation in male Sprague-Dawley rats weighing 100-120 g, and intrathecal catheterization was performed for drug administration. The effects of amiloride and benzamil were measured by the paw-withdrawal threshold to a mechanical stimulus using the up and down method. The expression of ASICs in the spinal cord dorsal horn was also analyzed by RT-PCR. Intrathecal amiloride and benzamil significantly increased the paw withdrawal threshold in spinal nerve-ligated rats (87%+/-12% and 76%+/-14%, P=0.007 and 0.012 vs vehicle, respectively). Spinal nerve ligation increased the expression of ASIC3 in the spinal cord dorsal horn (P=0.01), and this increase was inhibited by both amiloride and benzamil (P<0.001 in both). In conclusion, intrathecal amiloride and benzamil display antinociceptive effects in the rat spinal nerve ligation model suggesting they may present an alternative pharmacological tool in the management of neuropathic pain at the spinal level.

Effects of acid sensing ion channels inhibitor amiloride on pain behavior in a rat model of post-incision pain / 中华行为医学与脑科学杂志

ObjectiveTo explore the effects and underlying mechanisms of acid sensing ion channels (ASICs) on pain behavior in a rat model of post-incision pain.MethodsFifty-eight adult male Sprague Dawley rats were used in this study,four rats were used for immunofluorescence test,thirty rats were employed for pain behavior test,and twenty-four rats were used for Western blot.Rats used for pain behavior test and Western blot were randomly divided into 3 groups:control group ( C group),incision pain model group ( I group) and amiloride group (A group).Plantar skin of rats in A group were infiltrated with 20 μl(200 μg)amiloride solution.Paw withdrawal mechanical threshold(PWMT) and paw withdrawal thermal latency(PWTL) of all rats in pain behavior test was tested at 24 h preoperative,2 h,4 h,8 h,12 h,24 h postoperative.Western blot was tested at 4 h postoperative.ResultsImmunofluorescence test displayed ASIC3 was expressed in plantar skin of all rats.The basal level of PWMT and PWTL of all rats in three groups was C group( (23.15 ± 5.10) g,( 11.32 ± 1.21 ) s),I group ( (23.26 ± 5.69) g,( 11.75 ± 2.01 ) s),A group ( (23.63 ± 4.96 ) g,( 11.47 ± 1.96) s) respectively,which was no significantly difference (P ＞ 0.05 ).PWMT and PWTL of I group and A group was significantly lower than that of C group at all time points postoperative (P ＜ 0.05) ; PWMT and PWTL of A group was at 2 h( ( 13.75 ±3.25)g,(9.96±1.32)s),4h((14.05±3.75)g,(9.17±2.11)s),8 h((9.75 ±2.74)g,(8.11 ±1.22)s)postoperative,which was significantly higher than that of I group (P ＜ 0.05 ).Compared with that of C group,the level of pERK1/2 expression was significantly increased in I group at 4 h postoperative (P ＜ 0.05 ),which could be inhibited by amiloride local infiltration (P ＜ 0.05 ).ConclusionASIC3 can mediate incision pain in a rat model of post-incision pain,through pERK1/2 signaling pathway,which can be inhibited by amiloride.

Function study of acid-sensing ion channels in non-neuronal tissues / 中国药理学通报

Acid-sensing ion channels(ASICs) are a novel class of ligand-gated cation channels activated by extracellular acidification and belong to the epithelial sodium channels(DEG/ENaC) superfamily.Their biological functions have recently been found not only in the central nervous system but also relevant to the physiology and pathology of non-neuronal tissues such as taste buds, cardiovascular system and bones.This review concerns the latest research on the expression and functions of ASICs in non-neuronal tissues so as to promote the understanding of their physiological and pathological functions.

Expression of acid sensing ion channel 3 in the lung tissue of rats with, acute lung injury / 中华急诊医学杂志

Objective To explore the expression of acid seining ion channels-3 (ASIC3) in lung tissue in rats with acute lung injury (ALI). Method Twenty four male Sprague-Dawley (SD) rats were randomly divided into four groups: LPS groups (LPS 2 h, LPS 4 h, LPS 6 h group, n=6), stimulated by LPS for 2, 4, 6 hours, respectively; normal control group, injected with saline (NS group, n=6). The ALI models were produced through venous injection of LPS, and the criteria was the characteristic pathological changes in the lung tissue. Ar-terial blood gas analysis was observed, lung wet and dry weight ratio (W/D), lung histopathology and ASIC3 ex-pression were detected. Data were expressed as mean±standard deviation. Independent Sample T test and One-way ANOVA and Kendall's tau_b were used for comparison in SPSS 13.0, and changes were considered as statistieal-ly significant if P value was less than 0.05. Results The partial pressure of oxygen (PaO2) in LPS 2 h, LPS 4 h, LPS 6 h group was (67.47±6.01), (59.17±7.18), (52.54±7.62) , respecively, and was significantly lower than that in eontrol group (98.15±1.06) (P<0.01). Compare with control group, pH was significantly lower in LPS4 h group (7.28±0.04), LPS6 h group (7.24±0.03) (P<0.01). Inflammation cells gradually increased, alveolar septum was widened, edema existed in interstitial spaces, and pulmonary structures gradually destroyed in LPS groups.The expression of ASIC3 in LPS4 h, LPS 6 h group was (205.91±10.12), (196.51± 18.60), respectively, and was significantly lower thanthat in control group (220.23±10.11) (P<0.05). The W/D in LPS 6 h group was (5.18±0.21), and was significantly higher than that in the control group (4.45± 0.18) (P<0.05). Conclusions ASIC3 is expressed in alveolar epithelial cells and bronchial epithehal cells in LPS-induced ALI rats.

Growing insights into acid-sensing ion channels / 中国药理学通报

Acid-sensing ion channels( ASICs )are ubiquitously expressed both in periphery nervous system, where they are involved in nociception,mechanosensation,inflammation ,cardiac angina, and in central nervous system,where they are essential to a variety of physiologic and pathophysiologic processes,such as synaptic plasticity ,learning ,memory and ischemic brain injury. Here in the article, we present a collection of key points about ASICs, ranging from molecular identity and expression, regulatory mechanisms responsible for channel gating to their multiple functions. Finally, a future prospect for the investigation of ASICs is outlined.