近期,，由中科院水生所淡水生態(tài)與生物技術(shù)國(guó)家重點(diǎn)實(shí)驗(yàn)室桂建芳研究員等完成的魚(yú)類(lèi)低氧反應(yīng)基因研究成果被《自然·中國(guó)》列為研究亮點(diǎn),。
低氧是生物生存的重要環(huán)境壓力,。對(duì)于人類(lèi)和其他陸生脊椎動(dòng)物而言，低氧壓力可以導(dǎo)致很多代謝方面的改變以達(dá)到快速適應(yīng)的目的,。然而在水里,，氧氣溶解度相對(duì)較低且沒(méi)有良好的擴(kuò)散,，所以許多魚(yú)類(lèi)不得不在行為、生理,、生化,、分子等方面發(fā)展良好的適應(yīng)機(jī)制以應(yīng)付水環(huán)境不斷發(fā)生的低氧危機(jī)。鯽是少數(shù)強(qiáng)耐低氧脊椎動(dòng)物之一,，但因其不同個(gè)體和不同組織對(duì)低氧反應(yīng)存在差異,，因而給系統(tǒng)研究魚(yú)類(lèi)抗低氧的分子機(jī)制帶來(lái)許多不便。為此,，水生所淡水生態(tài)與生物技術(shù)國(guó)家重點(diǎn)實(shí)驗(yàn)室桂建芳研究員等以鯽囊胚細(xì)胞為材料,，通過(guò)抑制性差減雜交技術(shù)建立了一個(gè)適于系統(tǒng)研究魚(yú)類(lèi)抗低氧分子機(jī)制的細(xì)胞模型系統(tǒng)。他們?cè)诎l(fā)現(xiàn)血紅素加氧酶—1（HO—1）在低氧條件下具有明顯上調(diào)表達(dá)的基礎(chǔ)上,，克隆并特征分析了該基因,。他們發(fā)現(xiàn)該血紅素加氧酶—1基因廣泛表達(dá)于健康鯽魚(yú)的后腎、頭腎,、鰓和腸中，且在后腎組織中有明顯的低氧誘導(dǎo)表達(dá)增強(qiáng),。GFP融合蛋白亞細(xì)胞定位分析表明該基因的蛋白不但定位在細(xì)胞質(zhì)中而且與結(jié)構(gòu)預(yù)測(cè)相吻合,，同時(shí)定位在細(xì)胞膜上。接下來(lái)他們構(gòu)建了穩(wěn)定表達(dá)HO—1的細(xì)胞系CAB/pcDNA3.1—HO—1 和空白對(duì)照細(xì)胞系CAB/pcDNA3.1,，經(jīng)4天低氧處理（1% O2）后發(fā)現(xiàn)CAB/pcDNA3.1—HO—1細(xì)胞系較對(duì)照細(xì)胞系CAB/pcDNA3.1 可以很好的抑制低氧處理所引起的大量細(xì)胞脫落死亡,。另外，利用CCK—8試劑盒檢測(cè)兩種細(xì)胞系在低氧處理和常氧恢復(fù)實(shí)驗(yàn)中細(xì)胞生存力狀況時(shí)也發(fā)現(xiàn)了兩種細(xì)胞耐受低氧方面的明顯不同,。因此建議血紅素加氧酶—1基因可能對(duì)CAB細(xì)胞抵抗低氧應(yīng)激反應(yīng)方面起到重要的保護(hù)作用,。
該研究成果的實(shí)驗(yàn)工作主要由該實(shí)驗(yàn)室的研究生王丹和博士后鐘雪萍等完成，研究論文發(fā)表在《實(shí)驗(yàn)生物學(xué)雜志》（Journal of Experimental Biology）,?！蹲匀?middot;中國(guó)》評(píng)論的題目是“Hydrobiology: Out of air, but not out of action”。（生物谷Bioon.com）
生物谷推薦原始出處：
Journal of Experimental Biology,，211, 2700-2706 (2008),，Dan Wang，Jian-Fang Gui
Inductive transcription and protective role of fish heme oxygenase-1 under hypoxic stress
Dan Wang, Xue-Ping Zhong, Zhi-Xian Qiao and Jian-Fang Gui*
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Wuhan 430072, China
Heme oxygenase-1 is the rate-limiting enzyme in the degradation of heme into biliverdin, carbon monoxide and free divalent iron. In this study, we cloned heme oxygenase isoform 1 (CaHO-1) from a hypoxia-tolerant teleost fish Carassius auratus. The full-length cDNA of CaHO-1 is 1247 bp and encodes a protein of 272 amino acids. RT-PCR and real-time PCR analysis indicated that CaHO-1 was predominantly transcribed in posterior kidney, head kidney, gill and intestine, and induction of gene transcription was observed predominantly in posterior kidney under hypoxic stress. Moreover, the hypoxia-induced transcription was confirmed in goldfish larvae and in in vitro cultured CAB cells. Fluorescence of the HO-1-GFP fusion protein revealed a cytoplasmic and plasma membrane localization, which was consistent with the putative transmembrane structure. Subsequently, we established a stably transfected CAB/pcDNA3.1-HO-1 cell line and a control CAB/pcDNA3.1 cell line, and found that the number of dead cells was obviously reduced in the pcDNA3.1-HO-1-transfected group following 4 days of hypoxic (1% O2) treatment in comparison with numerous detached dead cells in the control pcDNA3.1-transfected cells. Furthermore, a significant cell viability difference between the two kinds of transfected cells during hypoxia–reoxygenation was revealed. Therefore, the data suggest that fish HO-1 might play a significant protective role in cells in response to hypoxic stress.
