Release of ATP during host cell killing by enteropathogenic E-coli and its role as a secretory mediator
Release of ATP during host cell killing by enteropathogenic E-coli and its role as a secretory mediator
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DOI：
10.1152/ajpgi.00484.2001
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发表时间：
2002-07-01
影响因子：
4.5
通讯作者：
Duffey, ME
中科院分区：
文献类型：
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作者：
Crane, JK;Olson, RA;Duffey, ME
肠致病性大肠杆菌（EPEC）可引起儿童严重的水样腹泻。我们研究了ATP释放过程中EPEC介导的人类细胞系的杀伤和是否释放腺嘌呤核苷酸作为分泌介质的功能。EPEC触发了从所有测试的人类细胞系中释放ATP：HeLa、COS-7和T84（结肠细胞），如使用荧光素酶试剂盒所测量的。如果加入5 '-外核苷酸酶抑制剂，则上清液培养基中ATP的积累增强，如果加入ATP再生系统，则ATP的积累进一步增强。在抑制剂/再生剂的存在下，ATP浓度在上清液培养基中达到1.5-2 μ M 4小时后，感染野生型EPEC菌株。在没有抑制剂/再生系统的情况下，细胞外ATP迅速分解为ADP、AMP和腺苷。条件培养基从EPEC感染的细胞引发了活跃的氯化物分泌反应，肠组织中研究的尤辛室（兔远端结肠和T84细胞单层），而条件培养基从未感染的细胞和无菌的EPEC细菌没有。对EPEC条件培养基的短路电流反应被腺苷受体阻断剂，如8-（对磺苯基）-茶碱和MRS 1754完全逆转。EPEC杀死宿主细胞释放ATP，ATP被分解为腺苷，腺苷又通过顶端腺苷A（2b）受体刺激分泌。这些发现为EPEC如何引起水样腹泻提供了新的见解。
Enteropathogenic Escherichia coli (EPEC) causes severe, watery diarrhea in children. We investigated ATP release during EPEC-mediated killing of human cell lines and whether released adenine nucleotides function as secretory mediators. EPEC triggered a release of ATP from all human cell lines tested: HeLa, COS-7, and T84 (colon cells) as measured using a luciferase kit. Accumulation of ATP in the supernatant medium was enhanced if an inhibitor of 5'-ectonucleotidase was included and was further enhanced if an ATP-regenerating system was added. In the presence of the inhibitor/regenerator, ATP concentrations in the supernatant medium reached 1.5-2 muM 4 h after infection with wild-type EPEC strains. In the absence of the inhibitor/regenerator system, extracellular ATP was rapidly broken down to ADP, AMP, and adenosine. Conditioned medium from EPEC-infected cells triggered a brisk chloride secretory response in intestinal tissues studied in the Ussing chamber (rabbit distal colon and T84 cell monolayers), whereas conditioned medium from uninfected cells and sterile filtrates of EPEC bacteria did not. The short-circuit current response to EPEC-conditioned medium was completely reversed by adenosine receptor blockers, such as 8-(p-sulfophenyl)-theophylline and MRS1754. EPEC killing of host cells releases ATP, which is broken down to adenosine, which in turn stimulates secretion via apical adenosine A(2b) receptors. These findings provide new insight into how EPEC causes watery diarrhea.