EXPRESSION OF CYP1A1 AND CYP1A2 GENES IN HUMAN LIVER
EXPRESSION OF CYP1A1 AND CYP1A2 GENES IN HUMAN LIVER
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DOI：
10.1097/00008571-199310000-00003
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发表时间：
1993-10-01
期刊：
影响因子：
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通讯作者：
GOLDSTEIN, JA
中科院分区：
文献类型：
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作者：
SCHWEIKL, H;TAYLOR, JA;GOLDSTEIN, JA
使用大鼠CYP 1A 2的单特异性抗体对人肝脏进行的免疫印迹分析表明，CYP 1A 2蛋白在人肝脏中的表达是高度可变的。然后采用定量PCR分析来检查人肝脏中CYP 1A 1和CYP 1A 2 mRNA的个体间变异性。免疫印迹分析显示，肝脏CYP 1A 2 mRNA含量与蛋白水平显著相关（r = 0.58; p < 0.01）。CYP 1A 2 mRNA含量在个体之间变化>40倍，而CYP 1A 1含量变化>20倍。在不同个体的肝脏中，CYP 1A 2 mRNA高于CYP 1A 1 mRNA（约2至30倍）。具有最高CYP 1A 1和CYP 1A 2 mRNA量的个体是当前吸烟者，但另外两个吸烟者的mRNA表达在非吸烟者中观察到的范围内。两种CYP 1A mRNA的表达高度相关（r = 0. 001）。72; p < 0.0005），但在非吸烟者中相关性不太显著（r = 0.62; p < 0.05）。我们通过PCR从表达极少量CYP 1A 2蛋白的肝脏中扩增了全长CYP 1A 2 cDNA克隆。序列分析表明，该克隆缺失了外显子4，但未发现其他序列变化; PCR分析表明，正常剪接和异常剪接的mRNA在所有人肝组织中都能检测到，但正常剪接的mRNA比剪接变异体的含量高。因此，CYP 1A 2编码区的序列变化不能解释该个体中CYP 1A 2的低表达。
Immunoblot analysis of human livers using a monospecific antibody to rat CYP1A2 demonstrated that the expression of CYP1A2 protein is highly variable in human liver. Quantitative PCR analysis was then employed to examine the interindividual variability of both CYP1A1 and CYP1A2 mRNAs in human liver. Hepatic content of CYP1A2 mRNA correlated significantly with levels of CYP1A2 protein as analysed by immunoblot analysis (r = 0.58; p < 0.01). CYP1A2 mRNA content varied >40-fold among individuals while CYP1A1 content varied >20-fold. CYP1A2 mRNA was higher than CYP1A1 mRNA (approximately two to 30-fold) in livers of different individuals. The individual with the highest CYP1A1 and CYP1A2 mRNA amounts was a current smoker, but mRNA expression in two other smokers was within the range observed among nonsmokers. The expression of the two CYP1A mRNAs correlated highly (r = 0. 72; p < 0.0005) when smokers were included, but the correlation was less significant (r = 0.62; p < 0.05) in nonsmokers. We amplified a full-length CYP1A2 cDNA clone by PCR from a liver which expressed extremely low amounts of CYP1A2 protein. Sequence analysis indicated that exon 4 was missing in this clone, but no other sequence changes were found. PCR analysis demonstrated that both the normally spliced mRNA and abnormally spliced mRNA could be detected in all human livers examined, but the normally spliced mRNA was more abundant than the splice variant. Therefore, sequence changes in the coding region of CYP1A2 did not account for the poor expression of CYP1A2 in this individual.