Roszkowska Anna, Klimek Jerzy, Kaletha Krystian
Department of Biochemistry and Clinical Physiology, Medical University of Gdansk, Debinki 1, 80-211 Gdansk, Poland.
Mol Cell Biochem. 2008 Apr;311(1-2):249-51. doi: 10.1007/s11010-007-9699-8. Epub 2007 Dec 30.
Background AMP-deaminase (EC 3.5.4.6) and 5'-nucleotidase (EC 3.1.3.5) are enzymes responsible for the maintenance of cellular adenine nucleotides pool. Both exist in several isoforms that differ in kinetic properties and tissue distribution. Profile of isoforms of these enzymes in human placenta has not been analyzed so far while this could be important for understanding of pathology of placental ischemia such as in preeclampsia. Our aim was therefore to analyze expression of AMPD and CN-I genes in human term placenta. Methods RT-PCR analysis was used for determine expression of AMPD1, AMPD2, AMPD3 and CN-I. Results and conclusion The experimental results presented here indicate that genes coding "AMP-preferring", cytosolic isozyme of 5'-nucleotidase (cN-I) as well as "muscle-type" isozyme of AMP-deaminase (AMPD1) are not expressed in human term placenta. Among other AMPD family genes, only these coding "liver-type" isozyme (AMPD2) and, in lesser degree, "erythrocyte-type" isozyme (AMPD3) of AMP-deaminase are expressed in this organ. The expression level of AMPD3 was a half of that presented by AMPD2. We conclude that high abundance of AMP-deaminase 2 transcript suggest that this particular isoform is a predominant pathway of adenine nucleotides degradation in human term placenta that follows liver-type regulation of this process.
AMP脱氨酶(EC 3.5.4.6)和5'-核苷酸酶(EC 3.1.3.5)是负责维持细胞腺嘌呤核苷酸池的酶。两者都以几种同工型存在,这些同工型在动力学特性和组织分布上有所不同。到目前为止,尚未分析这些酶在人胎盘中的同工型概况,而这对于理解胎盘缺血(如子痫前期)的病理可能很重要。因此,我们的目的是分析人足月胎盘中AMPD和CN-I基因的表达。方法:采用RT-PCR分析来确定AMPD1、AMPD2、AMPD3和CN-I的表达。结果与结论:此处呈现的实验结果表明,编码“AMP偏好性”5'-核苷酸酶(cN-I)的胞质同工酶以及AMP脱氨酶(AMPD1)的“肌肉型”同工酶的基因在人足月胎盘中不表达。在其他AMPD家族基因中,只有编码AMP脱氨酶“肝型”同工酶(AMPD2)以及程度较轻的“红细胞型”同工酶(AMPD3)的基因在该器官中表达。AMPD3的表达水平是AMPD2的一半。我们得出结论,AMPD2转录本的高丰度表明这种特定的同工型是人类足月胎盘中腺嘌呤核苷酸降解的主要途径,该过程遵循肝型调节。