Janel Nathalie, Christophe Olivier, Aït Yahya-Graison Emilie, Hamelet Julien, Paly Evelyne, Prieur Marguerite, Delezoïde Anne-Lise, Delabar Jean Maurice
EA 3508, Université Paris 7--Denis Diderot, Paris, France.
Biochem Biophys Res Commun. 2006 Aug 11;346(4):1303-6. doi: 10.1016/j.bbrc.2006.06.048. Epub 2006 Jun 16.
Patients with Down syndrome appear to be protected from the development of atherosclerosis. On the contrary, hyperhomocysteinemia is associated with an increased risk for atherosclerosis. As hyperhomocysteinemia due to cystathionine beta synthase deficiency is associated with a decreased expression of paraoxonase-1, a major anti-atherosclerotic component secreted by the liver, we aimed to analyze the expression of paraoxonase-1 and cystathionine beta synthase in Down syndrome fetal liver by quantitative real-time reverse transcriptase-polymerase chain reaction. Paraoxonase-1 was up-regulated in Down syndrome fetal liver, while cystathionine beta synthase gene expression in Down syndrome fetuses was similar to the gene level in control fetuses. Moreover, there was no evidence for an association between paraoxonase-1 genotypes influencing paraoxonase-1 gene expression and Down syndrome. Since most serum paraoxonase-1 is synthesized in the liver, an increase of hepatic paraoxonase-1 expression might be one of the factors which could explain the low incidence of atherosclerotic vascular disease in Down syndrome.
唐氏综合征患者似乎对动脉粥样硬化的发展具有保护作用。相反，高同型半胱氨酸血症与动脉粥样硬化风险增加相关。由于胱硫醚β合酶缺乏导致的高同型半胱氨酸血症与对氧磷酶-1（肝脏分泌的一种主要抗动脉粥样硬化成分）表达降低有关，我们旨在通过定量实时逆转录聚合酶链反应分析唐氏综合征胎儿肝脏中对氧磷酶-1和胱硫醚β合酶的表达。对氧磷酶-1在唐氏综合征胎儿肝脏中上调，而唐氏综合征胎儿中胱硫醚β合酶基因表达与对照胎儿的基因水平相似。此外，没有证据表明影响对氧磷酶-1基因表达的对氧磷酶-1基因型与唐氏综合征之间存在关联。由于大多数血清对氧磷酶-1在肝脏中合成，肝脏对氧磷酶-1表达增加可能是解释唐氏综合征中动脉粥样硬化性血管疾病低发病率的因素之一。
