大鼠ASIC2a和ASIC3同聚體離子通道電生理學(xué)特性的研究
發(fā)布時(shí)間:2018-06-12 21:10
本文選題:酸感受離子通道2a + 酸感受離子通道3; 參考:《沈陽(yáng)藥科大學(xué)》2007年碩士論文
【摘要】: 酸感受離子通道(acid-sensing ion channels,,ASICs)是一類由胞外酸化所激活的陽(yáng)離子通道,屬于真皮鈉離子通道家族。至今已經(jīng)克隆出這個(gè)家族7個(gè)不同亞基:ASIC1a;ASIC1b;ASIC1b2;ASIC2a;ASIC2b;ASIC3和ASIC4。ASICs在體內(nèi)分布廣泛,功能復(fù)雜。其中ASIC2a和ASIC3因在酸味覺、觸覺、疼痛等方面具有重要的生理學(xué)功能和病理學(xué)意義而逐漸成為研究熱點(diǎn)。 本實(shí)驗(yàn)應(yīng)用分子生物學(xué)技術(shù),成功構(gòu)建大鼠ASIC2a和ASIC3全長(zhǎng)表達(dá)質(zhì)粒。將編碼ASIC2a和ASIC3亞基的cRNA分別注射到爪蟾卵母細(xì)胞中,使其表達(dá)并組成ASIC2a和ASIC3的同聚體離子通道,使用雙電極電壓鉗技術(shù)記錄H~+誘發(fā)電流,分析電流的藥理學(xué)和門控動(dòng)力學(xué)特征,觀察Ca~(2+)、Na~+及K~+離子對(duì)H~+誘發(fā)電流的影響。研究發(fā)現(xiàn):降低胞外液pH值可誘導(dǎo)出內(nèi)向電流,pH值越小H~+誘發(fā)的電流幅度越大。ASIC2a的pH_(50)為5.12,ASIC3的pH_(50)為5.83。ASIC2a的內(nèi)向電流具有穩(wěn)態(tài)失活成分,ASIC3的內(nèi)向電流具有快速和穩(wěn)態(tài)失活兩種成分。提高胞外Ca~(2+)濃度可降低H~+誘發(fā)的電流幅度。胞外Ca~(2+)對(duì)ASIC2a和ASIC3抑制作用的IC_(50)分別為11.98 mmol/L和9.16 mmol/L。ASIC2a和ASIC3除了對(duì)Na~+通透外,對(duì)K~+也具有一定程度的通透。 本實(shí)驗(yàn)以爪蟾卵母細(xì)胞為表達(dá)載體,成功建立了ASIC2a和ASIC3離子通道表達(dá)細(xì)胞模型,系統(tǒng)的觀察了ASIC2a和ASIC3同聚體離子通道的電生理學(xué)特性及不同離子對(duì)其功能的影響。本研究結(jié)果不僅有利于進(jìn)一步加深對(duì)ASICs生物學(xué)特性的了解,而且也為靶向ASICs類藥物的研發(fā)提供了較為理想的篩選和評(píng)價(jià)技術(shù)平臺(tái)。
[Abstract]:Acid-sensing ion channels are a kind of cationic channels activated by extracellular acidification and belong to the dermal sodium ion channel family. Up to now, seven different subunits of this family have been cloned: ASIC1b, ASIC1b2, ASIC2b2, ASIC2b, ASIC3 and ASIC4.ASICs, which are widely distributed and have complex functions in vivo. Among them, ASIC2a and ASIC3 have become the research focus because of their important physiological function and pathological significance in acid sense, tactile sense, pain and so on. In this study, the full length expression plasmids ASIC2a and ASIC3 were successfully constructed by molecular biology. The cRNA encoding ASIC2a and ASIC3 subunits were injected into Xenopus oocytes to express and form the homopolymer ion channels of ASIC2a and ASIC3 respectively. The H- induced currents were recorded by double electrode voltage clamp technique, and the pharmacological and gated characteristics of the currents were analyzed. The effects of Na ~ and K ~ + on H ~ -induced currents were observed. It was found that the lower the pH value of extracellular solution was, the greater the amplitude of inward current was. The pH of ASIC2a was 5.12 and the pH of ASIC3 was 5.83. The inward current of ASIC2a had two components: fast and steady-state inactivation. The increase of extracellular Caan2 concentration can reduce the amplitude of H- induced currents. The inhibitory effects of extracellular Caanzao 2 on ASIC2a and ASIC3 were 11.98 mmol / L and 9.16 mmol / L ASIC2a and ASIC3, respectively. The ASIC2a and ASIC3 ion channel expression cell models were successfully established using Xenopus oocytes as expression vector. The electrophysiological characteristics of ASIC2a and ASIC3 homopolymer ion channels and the effects of different ions on their function were systematically observed. The results of this study not only help to further understand the biological characteristics of ASICs, but also provide an ideal platform for screening and evaluation of targeted ASICs drugs.
【學(xué)位授予單位】:沈陽(yáng)藥科大學(xué)
【學(xué)位級(jí)別】:碩士
【學(xué)位授予年份】:2007
【分類號(hào)】:R33
【參考文獻(xiàn)】
相關(guān)期刊論文 前6條
1 田輝凱,李學(xué)軍;爪蟾卵母細(xì)胞表達(dá)體系在功能基因組學(xué)研究中的應(yīng)用[J];國(guó)外醫(yī)學(xué)(分子生物學(xué)分冊(cè));2002年04期
2 伍龍軍,徐天樂;酸敏感離子通道的功能及其相關(guān)調(diào)控[J];生物化學(xué)與生物物理進(jìn)展;2003年03期
3 伍龍軍,徐天樂;組織酸化參與外周痛覺傳遞的離子通道機(jī)制[J];生物化學(xué)與生物物理進(jìn)展;2004年05期
4 伍龍軍;徐天樂;;大鼠脊髓背角神經(jīng)元中酸敏感離子通道的特性和功能研究[J];生理科學(xué)進(jìn)展;2006年02期
5 張曉東,臧益民,謝安;用于離子通道基因表達(dá)的爪蟾卵母細(xì)胞的分離和培養(yǎng)[J];心臟雜志;2001年02期
6 艾平;劉振偉;戴薇薇;張樹卓;鄭建全;;大鼠背根神經(jīng)節(jié)酸感受離子通道(ASICs)的藥理學(xué)特性研究[J];中國(guó)藥理學(xué)通報(bào);2007年01期
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