Rotoli B M, Bussolati O, Dall' Asta V, Hoffmann E K, Cabrini G, Gazzola G C
Istituto di Patologia Generale, Università degli Studi di Parma, Italy.
Biochem Biophys Res Commun. 1996 Oct 23;227(3):755-61. doi: 10.1006/bbrc.1996.1581.
In this study we have employed three lines of C127 murine cells. C127 CFTR w/t, C127 CFTR delta F508 and C127 mock, transfected with, respectively, wild type, delta F508 mutant human CFTR cDNA or the vector only. In the first 10 minutes of a Cl(-)-free incubation the three cell lines exhibit a significant shrinkage due to a loss of K+ and Cl-. However, C127 CFTR w/t cells shrink more than C127 CFTR delta F508 and the mock cells. The supplementation of Cl(-)-free medium with ATP causes a marked decrease in the cell volume of C127 CFTR delta F508 and of the mock cells but not of C127 CFTR w/t cells. ATP effect is mimicked by adenosine 5'-O-(3-thiotriphosphate), but neither by adenosine nor by UTP. Measurements of extracellular ATP indicate that during the Cl(-)-free incubation C127 CFTR w/t cells extrude more ATP than the other two cell lines. The results are consistent with the hypothesis that CFTR enhances K+ and Cl- permeabilities by promoting the extrusion of ATP.
在本研究中，我们使用了三株C127小鼠细胞系。分别用野生型、ΔF508突变型人CFTR cDNA或仅用载体转染的C127 CFTR野生型/野生型（w/t）、C127 CFTR ΔF508和C127空载体(mock)细胞系。在无Cl⁻孵育的前10分钟，这三株细胞系由于K⁺和Cl⁻的丢失而出现明显的皱缩。然而，C127 CFTR w/t细胞比C127 CFTR ΔF508和空载体细胞皱缩得更厉害。用ATP补充无Cl⁻培养基会导致C127 CFTR ΔF508和空载体细胞的细胞体积显著减小，但不会使C127 CFTR w/t细胞的细胞体积减小。5'-O-(3-硫代三磷酸)腺苷可模拟ATP的作用，但腺苷和尿苷三磷酸（UTP）均无此作用。细胞外ATP的测量表明，在无Cl⁻孵育期间，C127 CFTR w/t细胞比其他两株细胞系排出更多的ATP。这些结果与CFTR通过促进ATP的排出增强K⁺和Cl⁻通透性这一假说一致。
