Carbonic anhydrase gene expression in CA II-deficient (Car2-/-) and CA IX-deficient (Car9-/-) mice
Carbonic anhydrase gene expression in CA II-deficient (Car2-/-) and CA IX-deficient (Car9-/-) mice
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DOI：
10.1113/jphysiol.2005.102590
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发表时间：
2006-03-01
影响因子：
5.5
通讯作者：
Parkkila, S
中科院分区：
文献类型：
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作者：
Pan, PW;Leppilampi, M;Parkkila, S
使用实时PCR和免疫组织化学，我们已经检查了表达的碳酸酐酶同工酶（CA）I，II，III，IV，IX，XII，XIII和XIV在脑，肾，胃和结肠的野生型，CA II缺陷（Car 2（-/-）），和CA IX缺陷（Car 9（-/-））小鼠。Car 4、Car 12、Car 13和Car 14 mRNA的表达在三组小鼠之间没有显示出任何显著差异，而两组CA缺陷小鼠的结肠中的Car 1和肾脏中的Car 3的表达水平均降低。Car 2 mRNA水平大大降低，但没有完全消除在所有四个组织中的Car 2（-/-）小鼠，其中没有CA II蛋白的表达。对从C57 BL 6 Car 2（-/-）小鼠分离的Car 2 cDNA进行测序，揭示了与野生型C57 BL 6小鼠的两个核苷酸差异。一种是在野生型DBA小鼠的Car 2 mRNA中发现的沉默多态性，该小鼠是提供原始诱变染色体的品系。第二个变化是导致密码子155（Gln 155 X）过早终止翻译的突变。在Car 2（-/-）小鼠的胃中，Car 9 mRNA和CA IX蛋白表达水平分别上调约2.5倍和3.6倍。这些结果表明，Car 2（-/-）小鼠胃中胞质CA II功能的丧失导致细胞外CA即CA IX的上调，其在胃上皮的细胞表面上表达。
Using real-time PCR and immunohistochemistry, we have examined the expression of carbonic anhydrase isozymes (CA) I, II, III, IV, IX, XII, XIII and XIV in the brain, kidney, stomach and colon of the wild-type, CA II-deficient (Car2(-/-)), and CA IX deficient (Car9(-/-)) mice. The expression of Car4, Car12, Car13 and Car14 mRNAs did not show any significant deviations between the three groups of mice, whereas both groups of CA deficient mice showed decreased expression levels of Car1 in the colon and Car3 in the kidney. The Car2 mRNA level was greatly reduced but not completely abolished in all four tissues from the Car2(-/-) mice in which no CA II protein was expressed. Sequencing the Car2 cDNA isolated from C57BL6 Car2(-/-) mice revealed two nucleotide differences from the wild-type C57BL6 mice. One is a silent polymorphism found in Car2 mRNA from wild-type DBA mice, which is the strain that provided the original mutagenized chromosome. The second change is a mutation that causes prematurely terminated translation at codon 155 (Gln155X). Car9 mRNA and CA IX protein expression levels were up-regulated about 2.5- and 3.6-fold, respectively, in the stomach of the Car2(-/-) mice. These results suggest that the loss of function of cytosolic CA II in the stomach of Car2(-/-) mice leads to up-regulation of an extracellular CA, namely CA IX, which is expressed on the cell surface of the gastric epithelium.