Estrogen increases CD38 gene expression and leads to differential regulation of adenosine diphosphate (ADP)-ribosyl cyclase and cyclic ADP-ribose hydrolase activities in rat myometrium
Estrogen increases CD38 gene expression and leads to differential regulation of adenosine diphosphate (ADP)-ribosyl cyclase and cyclic ADP-ribose hydrolase activities in rat myometrium
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DOI：
10.1095/biolreprod66.3.596
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发表时间：
2002-03-01
影响因子：
3.6
通讯作者：
Kannan, MS
中科院分区：
文献类型：
--
作者：
Dogan, S;White, TA;Kannan, MS
激素通过对细胞内钙的作用影响子宫收缩力。子宫平滑肌中细胞内钙的调节通过几种机制实现，包括通过肌醇1，4，5-三磷酸和ryanodine敏感性通道从细胞内储存中动员。环ADP核糖（cADPR）是NAD（+）的代谢产物，已知通过兰尼碱受体通道介导钙释放。细胞表面糖蛋白CD 38催化cADPR的合成和分解，因此具有双功能酶活性。子宫肌层中激素对ADP-核糖基环化酶（环化酶）合成cADPR或cADP-核糖水解酶（水解酶）降解cADPR的调控知之甚少。我们研究了雌二醇-17 β对卵巢切除大鼠子宫平滑肌CD 38表达和cADPR合成和降解的影响。通过逆转录聚合酶链反应和Western印迹分析研究CD 38表达。在子宫微粒体组分中，分别使用烟酰胺鸟嘌呤二核苷酸和[P-32] cADPR作为底物测定环化酶和水解酶活性。微粒体蛋白亚分级SDS-PAGE和凝胶过滤，用于确定含有环化酶和水解酶活性的馏分。结果表明，环化酶和水解酶活性与单一蛋白组分相关，类似于卵巢切除和雌二醇治疗大鼠子宫中的CD 38，雌二醇-17 β导致1）CD 38 mRNA和蛋白表达增加，2）环化酶活性显著增强，但水解酶活性不增强。雌二醇-17 β对CD 38的差异调节，导致cADPR合成增加，对钙调节和子宫肌层收缩性有深远影响。
Hormones influence uterine contractility through their effects on intracellular calcium. The regulation of intracellular calcium in uterine smooth muscle is achieved by several mechanisms and includes mobilization from intracellular stores by inositol 1,4,5-trisphosphate and ryanodine-sensitive channels. Cyclic ADP-ribose (cADPR), a metabolite of NAD(+), is known to mediate calcium release through ryanodine receptor channels. A cell surface glycoprotein, CD38, catalyzes the synthesis and breakdown of cADPR and thus possesses bifunctional enzymatic activity. The regulation of cADPR synthesis by ADP-ribosyl cyclase (cyclase) or degradation by cADP-ribose hydrolase (hydrolase) by hormones in the myometrium is poorly understood. We investigated the effects of estradiol-17beta on CD38 expression and the synthesis and degradation of cADPR in myometrial smooth muscle obtained from ovariectomized rats. CD38 expression was studied by reverse transcription polymerase chain reaction and Western blot analyses. In uterine microsomal fractions, cyclase and hydrolase activities were measured using nicotinamide guanine dinucleotide and [P-32] cADPR as substrates, respectively. Microsomal proteins subfractionated by SDS-PAGE and gel filtration were used to determine the fractions containing cyclase and hydrolase activities. The results demonstrate that cyclase and hydrolase activities are associated with a single protein fraction, similar to CD38 in uteri from both ovariectomized and estradiol-treated rats, and estradiol-17beta causes 1) increased CD38 mRNA and protein expression and 2) significantly enhanced cyclase but not hydrolase activity. The differential regulation of CD38 by estradiol-17beta, resulting in increased cADPR synthesis, would have profound effects on calcium regulation and myometrial contractility.