Extracellular matrix influences hormone and protein production by human chorionic villi

Summary Increasing evidence confirms that the extracellular matrix greatly influences cell behaviour and function. Collagen and fibrin are in contact with trophoblast throughout pregnancy. To investigate whether these two matrices influence hormon production by the trophoblast, explants from first-trimester chorionic villi were cultured for up to 30 days either a) in medium with agitation, b) embedded in type-I collagen (three-dimensional gels), or c) embedded in fibrin (three-dimensional gels). The supernatant culture medium was changed every 48 h and tested by radioimmunoassay for hCG, progesterone and pregnancy-associated plasma protein A. In addition, after 3, 7, 15, and 30 days of culture villi were fixed and studied by light and electron microscopy. Embedding in the extracellular matrix showed higher and longer-lasting production rates of all measured products and superior structural preservation as compared to cultures with agitation. Collagen matrix proved to be superior to fibrin. As established by several tests, this difference was neither due to thrombin used to polymerize fibrinogen, nor to differences in the diffusion rates through the two different matrices used. We conclude that extracellular matrix, particularly collagen, influences the synthesis of trophoblastic products. Embedding of the villous explants in three-dimensional gels constitutes a new method for long-term cultures of chorionic villi.This study was presented at the workshop Placental-and decidual-specific protein synthesis and secretion: regulation, role and interaction, Zemun, Belgrade, Yugoslavia, 19–20 May, 1988 (Bischof and Castellucci 1988; see also J. Aplin 1989), and at the 11th Rochester Trophoblast Conference, Rochester, N.Y. USA, 9–12 October 1988 (Castellucci et al. 1988)     

Sialic acid moiety is responsible for the charge heterogeneity and the biological potency of rat lutropin

To elucidate a possible role of sialic acid moiety in the electrical heterogeneity of rat pituitary lutropin, seven components separated were individually treated with neuraminidase. Some intermediates with isoelectric points corresponding to the native components were concomitantly seen at the serial stages of the enzyme treatment. All the treated components showed an isoelectric point of about 10.0 which was the same to the isoelectric point of one of the seven components. Desialylation of the components with less biological activity caused enhancement of the in vitro cyclic AMP producing- and testosterone producing-activities as well as the binding activity to the receptor. It is concluded that the number of sialic acid moiety in lutropin is responsible for the charge heterogeneity and the biological potency of the hormone.     

人胎盘滋养层细胞培养与体外hCG释放的研究

本研究的目的是了解细胞滋养层细胞和合胞体滋养层细胞体外分化和生物学特性。方法:采用酶消化和Percoll密度梯度离心法,对人足月胎盘细胞滋养层细胞进行分离、纯化和体外培养。采用放射免疫法(RIA)检测细胞培养上清液hCG含量的变化。结果:经分离和纯化的细胞滋养层细胞在体外培养中生长良好,通过细胞分裂和融合形成合胞体滋养层细胞,随着合胞体滋养层细胞的生长,细胞培养上清液中hCG含量显著升高。我们认为从胎盘中分离和纯化的细胞滋养层细胞在体外培养中可分化和融合形成合胞体滋养层细胞,体外hCG含量的增加与合胞体滋养层细胞生长有关。     

大鼠卵巢绒毛膜促性腺激素受体在CHO中的表达和扩增

本文报道了利用二氢叶酸还原酶放大系统将大鼠ＬＨ／ｈＣＧ受体（记为Ｆ－ｈＣＧＲ）及其胞外肽段（记为Ｔ－ｈＣＧＲ）在中国苍鼠卵巢细胞（ＣＨＯ）中的表达。ＳＤＳ－ＰＡＧＥ分析表明,Ｆ－ｈＣＧＲ为一条蛋白质带,其表观分子量为９２ｋｄ,而Ｔ－ｈＣＧＲ为３５ｋｄ和３７ｋｄ两条带。表达受体对其配基ｈＣＧ表现出高的亲合力,Ｆ－ｈＣＧＲ的解离常数为７×１０－９ｍｏｌ／Ｌ,Ｔ－ｈＣＧＲ为６．４×１０－９ｍｏｌ／Ｌ。表达Ｆ－ｈＣＧＲ的转染ＣＨＯ细胞可结合１２５Ｉ－ｈＣＧ,而表达Ｔ－ｈＣＧＢ者不结合１２５Ｉ－ｈＣＧ。这提示Ｆ－ｈＣＧＲ主要存在于细胞质膜表面上。表达Ｆ－ｈＣＧＲ的转染ＣＨＯ细胞能刺激。ｃＡＭＰ的形成,而表达Ｔ－ｈＣＧＲ者不能刺激ｃＡＭＰ形成。免疫荧光定位结果表明,Ｔ－ｈＣＧＲ主要分布于质膜的细胞质侧以及胞内其他一些细胞器膜上。用免疫亲和层析可以得到纯化的Ｔ－ｈＣＧＲ。     

大鼠卵巢促黄体激素/人绒毛膜促性腺激素受体cDNA的克隆和在昆虫细胞中的高效表达

促黄体激素/人绒毛膜促性腺激素受体(LH/hCG receptor)是一种与G-蛋白偶联的糖蛋白。本文报道了从大鼠卵巢cDNA库中筛选LH/hCG受体cDNA及其在昆虫细胞中的高效表达。LH/hCG受体cDNA全长2403bp,编码受体信号肽和成熟受体674个氨基酸。用多角体病毒表达载体pVL1393,LH/hCG受体cDNA在昆虫细胞中得到高效表达。在非还原和还原条件下的SDS-PAGE分析显示,用亲和层析分离纯化的受体表观分子量分别为120Kd和92Kd。经配基结合和Scatchard Plot分析表明,其与hCG反应的Kd为8.4×10~(-9)mol/L,与CHO细胞表达产物相似。     

Existence and Functions of Neurotens in Human Early Placental Villi

ＥｘｉｓｔｅｎｃｅａｎｄＦｕｎｃｔｉｏｎｓｏｆＮｅｕｒｏｔｅｎｓｉｎＨｕｍａｎＥａｒｌｙＰｌａｃｅｎｔａｌＶｉｌｌｉＺＨＡＮＧＣｈｏｎｇ－ｌｉ（张崇理）;ＣＨＥＮＧＬｉ－ｒｅｎ（程丽仁）,ＳＨＥＮＷｅｉ－ｂｉｎ（沈卫斌）;ＹＩＮＨｏｎｇ（殷红）;ＨＵ...     

Regulation of the synthesis of human chorionic gonadotropin by strains of HeLa cells in culture

Summary Thirty-seven strains of HeLa cells were examined for their ability to synthesize human chorionic gonadotropin (hCG) and its alpha subunit (hCG-α) in culture. Synthesis of hCG-α and hCG also was investigated in the presence of sodium butyrate and 5-bromo-2′-deoxyuridine (BrdUrd). All HeLa strains synthesized hCG-α in culture. Sodium butyrate increased the synthesis of hCG-α in all HeLa cells; BrdUrd increased synthesis in 32 of the 37 strains examined. Although few HeLa strains synthesized hCG in the absence of inducers, hCG was detected in most strains in the presence of sodium butyrate. The synthesis of hCG and its alpha subunit is, therefore, a stable genetic characteristics of HeLa cells. Certain preparations of hCG and its subunits were generously provided through the Center for Population Research of the National Institute of Child Health and Human Development, NIH.     

Stimulation of leydig cell testoterone secretion in vitro and in vivo in hypophysectomized rats by an agonist of luteinizing hormone releasing hormone

Injection of a luteinizing hormone-releasing hormone (LHRH) agonist into 55-day-old male rats which had been hypophysectomized 3 days earlier resulted in a 10- to 30-fold increase in the levels of testosterone in serum and testicular interstitial fluid (IF) in the 4h following injection. The levels achieved were within or above the normal range for intact untreated rats of this age. In similar animals, injection of LHRH agonist also enhanced the serum testosterone response to injected hCG at $\text{1}\text{1}\text{2}\text{h}$, but not at later times after injection, and by 24h reduced IF levels of testosterone suggested that LHRH agonist had begun to inhibit stimulation by hCG. $\text{In vitro}$, dispersed Leydig cells from untreated hypophysectomized rats showed a 2-fold increase in testosterone responsiveness to LHRH agonist when compared to cells from intact rats, and this change was associated with an 80% increase in the number of Leydig cell LHRH-receptors.     

Predominance of gonadotropin α-subunit resulting from preferential loss of hCGβ production in an established cell line

Summary The BeWo line of trophoblastic cells, maintained in continuous culture since 1966, was employed to investigate the phenomenon of gonadotropin α-subunit predominance that exists in several cell lines. The secretion of complete human chorionic gonadotropin (hCG) relative to α-subunit was compared in several different BeWo sublines, all of which were derived from BeWo stock roller tube colonies. In all of the BeWo sublines, secretion of hCG originally exceeded secretion of α-subunit. With time in culture, however, there was a marked decline in production of hCG/hCGβ, but not in α-subunit. Thus it appears that the production of hCGβ by BeWo choriocarcinoma cells is more labile than the production of the α-subunit.