Expression of CFTR and presence of cAMP-mediated fluid secretion in human fetal lung.
Expression of CFTR and presence of cAMP-mediated fluid secretion in human fetal lung.
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人胎肺中 CFTR 的表达和 cAMP 介导的液体分泌的存在。
DOI：
10.1152/ajplung.1992.262.4.l472
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Bastacky,J
中科院分区：
文献类型：
--
作者：
McCrayJr,PB;Reenstra,WW;Louie,E;Johnson,J;Bettencourt,JD;Bastacky,J
我们研究了囊性纤维化（CF）基因在正常和CF影响胎儿肺组织中的发育表达。研究了两个不相关的CF胎儿，均为F508缺失的纯合子。利用聚合酶链反应扩增逆转录总RNA来评估囊性纤维化跨膜传导调节因子（CFTR） mRNA在妊娠中期CF肺和妊娠早期和中期正常肺中存在。采用免疫沉淀法对正常妊娠中期胎儿肺移植体中CFTR蛋白进行鉴定。为了评估CF对胎儿可能的功能影响，肺组织外植体在浸泡器官培养中生长。光镜和电镜下，CF胎儿肺外植体表现正常。当正常胎儿肺的外植体暴露于8-（4-氯苯硫基）腺苷3‘,-5’环单磷酸（CPT-cAMP）和3-异丁基-1-甲基黄嘌呤（IBMX） 24小时时，腔内液体含量增加，通过测量截面直径增加40 +/- 4%来评估。相比之下，相同处理的CF外植体外植体直径没有显著变化（3 +/- 1.6%）。用微电极测定胎儿肺移植体的上皮传导电位（psi t）。在正常的妊娠中期外植体中，CPT-cAMP和IBMX引起psi -t超极化（-0.93 +/- 14 mV至-4.3 +/- 1.2 mV）；相比之下，CPT-cAMP和IBMX对CF胎儿肺移植体的psi t无显著影响（-0.84 +/- 0.07 mV至-1.21 +/- 0.26 mV）。本研究证实了CFTR mRNA和蛋白在人胎肺中的存在，提示虽然CF胎肺形态正常，但CF胎儿肺中camp介导的分泌液分泌存在缺陷。
We studied the developmental expression of the cystic fibrosis (CF) gene in human lung tissue from normal and CF-affected fetuses. Two unrelated CF fetuses, both homozygous for the delta F508 deletion, were examined. Cystic fibrosis transmembrane conductance regulator (CFTR) mRNA was present in second-trimester CF lung and in first- and second-trimester normal lung as assessed by amplification of reverse transcribed total RNA with the use of the polymerase chain reaction. CFTR protein was identified by immunoprecipitation in normal second-trimester fetal lung explants. To evaluate possible functional consequences of CF in the fetus, lung tissue explants were grown in submersion organ culture. By light and electron microscopy, the CF fetal lung explants appeared normal. When explants from normal fetal lung were exposed to 8-(4-chlorophenylthio) adenosine 3',-5'cyclic monophosphate (CPT-cAMP), and 3-isobutyl-1-methylxanthine (IBMX) for 24 h, the intraluminal fluid content increased, as assessed by a 40 +/- 4% increase in cross-sectional diameter. In contrast, identically treated CF explants showed no significant change in explant diameter (3 +/- 1.6%). The transepithelial potential (psi t) across fetal lung explants was measured with microelectrodes. In normal second-trimester explants, CPT-cAMP and IBMX caused hyperpolarization of psi t (-0.93 +/- 14 mV to -4.3 +/- 1.2 mV); in contrast, CF fetal lung explants showed no significant change in psi t with CPT-cAMP and IBMX (-0.84 +/- 0.07 mV to -1.21 +/- 0.26 mV). This study confirms the presence of CFTR mRNA and protein in human fetal lung and suggests that although the CF fetal lung appears normal morphologically, there is a defect in cAMP-mediated fluid secretion in the lung of the CF fetus.