STEROID REGULATION OF ONCOFETAL FIBRONECTIN EXPRESSION IN HUMAN CYTOTROPHOBLASTS
STEROID REGULATION OF ONCOFETAL FIBRONECTIN EXPRESSION IN HUMAN CYTOTROPHOBLASTS
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DOI：
10.1016/0960-0760(93)90202-8
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发表时间：
1993-07-01
影响因子：
4.1
通讯作者：
LOCKWOOD, CJ
中科院分区：
文献类型：
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作者：
GULLER, S;LACROIX, NC;LOCKWOOD, CJ
肿瘤胎儿纤连蛋白（onfFN）是FN的一种独特的糖基化形式，被认为在妊娠期间的子宫/胎盘粘附中起关键作用。在本研究中，我们研究了类固醇激素调节的onfFN在高度纯化的制剂（大于或等于95%）的细胞滋养层细胞分离自人类足月胎盘。基于免疫测定，相对于对照，用10（-6）M醋酸甲羟孕酮（MPA）处理细胞滋养层在第1、2、3和4天分别使onfFN的培养基水平下调25、53、59和62%。类固醇调节的模式和总FN水平与onfFN几乎相同，表明长期类固醇治疗调节FN的合成，而不是其癌胚糖基化。MPA治疗诱导2倍刺激介质水平的hCG，表明胎盘功能的增加与类固醇介导的FN表达的变化。类固醇特异性实验表明，MPA，皮质醇和地塞米松是onfFN表达的有效抑制剂，而雌二醇（E2），脱氧皮质酮，睾酮，孕酮和合成的孕酮OD-14，不是。这表明，糖皮质激素，而不是孕激素可能是胎盘FN表达的生理调节剂，MPA可能通过糖皮质激素样机制介导其基质修饰活性。用地塞米松（10（-7）M）处理细胞不会影响总蛋白质合成水平或人胎盘催乳素向培养基的释放。这表明类固醇介导的细胞滋养层中onfFN表达的下调不是由于蛋白质合成的普遍减少。基于蛋白质印迹的光密度扫描，MPA和地塞米松处理使onfFN的培养基水平相对于对照水平下调70%。北方印迹显示，MPA和地塞米松介导的FN mRNA的稳态水平在存在或不存在E2的情况下降低60-90%。我们的体外模型可以提供一个独特的系统来评估类固醇对细胞外基质（ECM）蛋白表达的影响。此外，我们认为类固醇激素可能会严重调节胎盘ECM蛋白的合成，从而影响整个妊娠期间滋养层/子宫的粘附以及胎儿分娩后胎盘和膜的排出。
Oncofetal fibronectin (onfFN) is a uniquely glycosylated form of FN suggested to play a critical role in uterine/placental adherence during pregnancy. In the present study we have examined steroid regulation of onfFN in highly purified preparations (greater-than-or-equal-to 95%) of cytotrophoblasts isolated from human term placentas. Based on immunoassays, relative to controls, treatment of cytotrophoblasts with 10(-6) M medroxyprogesterone acetate (MPA) down-regulated media levels of onfFN 25, 53, 59, and 62% on days 1, 2, 3 and 4, respectively. The pattern of steroid regulation and levels of total FN were nearly identical to that of onfFN suggesting that chronic steroid treatment regulates synthesis of FN and not its oncofetal glycosylation. MPA treatment induced a 2-fold stimulation in media levels of hCG indicating that increased placental function was associated with steroid-mediated changes in FN expression. Steroid specificity experiments demonstrated that MPA, cortisol, and dexamethasone were potent inhibitors of onfFN expression whereas estradiol (E2), deoxycorticosterone, testosterone, progesterone, and the synthetic progestin OD-14, were not. This suggested that glucocorticoids and not progestins may be the physiologic regulators of placental FN expression and that MPA may mediate its matrix-modifying activity through a glucocorticoid-like mechanism. Treatment of cells with dexamethasone (10(-7) M) did not affect the levels of total protein synthesis or the release of human placental lactogen to the culture medium. This indicated that steroid-mediated down-regulation of onfFN expression in cytotrophoblasts did not result from a general reduction of protein synthesis. Based on densitometric scanning of Western blots, MPA and dexamethasone treatments down-regulated media levels of onfFN 70% relative to control levels. Northern blotting revealed that MPA and dexamethasone mediated a 60-90% reduction in steady state levels of FN mRNA in the presence or absence of E2. Our in vitro model may provide a unique system to evaluate steroidal effects on extracellular matrix (ECM) protein expression. In addition, we suggest that steroids may critically regulate placental ECM protein synthesis, and thus affect trophoblast/uterine adherence throughout pregnancy and expulsion of the placenta and membranes following delivery of the fetus.