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1.
对收集的16例未见血液雌激素水平升高的临床女孩性早熟患者的外周血样本,利用PCR—SSCP方法筛查了雌激素受体基因编码区的可能突变。结果在1例患者发现:其雌激素受体基因8号外显子编码精氨酸的548位密码子,1个C—T转换导致精氨酸残基被半胱氨酸所替代;这一突变使DNA序列中产生1个BtsⅠ酶切位点,通过PCR—RFLP实验证明此患者为Arg548/Cys548杂合体。为证明该突变在性早熟发生中的作用,构建了一个雌激素受体反应元件报道质粒pGL3-promoter—ERE;成功将野生型ESR1基因定点突变,并克隆于PCR3.1真核表达质粒。报道质粒和表达质粒共转染CMF-7细胞,Cys548突变能够增加萤火虫荧光素酶的产生。结果证明该突变雌激素受体在体外具有高活性特征,因而推测在体内也可能具有相应的过高活性,从而导致女孩的性早熟。  相似文献   

2.
肥胖基因和苗条蛋白——Leptin   总被引:4,自引:0,他引:4  
李铁 《生物学通报》1998,33(4):7-10
最近肥胖基因被克卫,发现它在脂肪组织特异表达,编码的蛋白--Leptin可作用于下丘脑,产生抑制摄食、减轻肥胖、减少体重的效应,在体重稳态的维持中个有重要作用,它还对生殖系统、造血系统等有调节作用。肥胖基因的突变或者Leptin受体基因的突变可引起小鼠和大鼠发生肥胖,但尚未发现人的肥胖与肥胖基因突变有关。  相似文献   

3.
目的:构建雌激素受体(ER)β潜在磷酸化位点突变体,并在人胚肾细胞293T中检测其对ERβ下游基因转录的影响。方法:通过ERα和ERβ序列同源性比对,寻找ERβ的潜在磷酸化位点;以pcDNA3-ERβ-FLAG为模板,通过重组PCR,将ERβ264位、469位Ser编码基因突变为Ala编码基因,将突变片段连接到同样双酶切的pcDNA3-FLAG载体中,Western blot检测其表达;将重组质粒转入293T细胞中,检测突变体对含雌激素应答元件(ERE)的报告基因转录活性的影响。结果:ERα和ERβ序列同源性比对发现ERβ的264位Ser和469位Ser可能是其潜在的磷酸化位点;构建了ERβ264位和469位2个点突变体载体pcDNA3-FLAG-ERβ(S264A)和pcDNA3-FLAG-ERβ(S469A),Western blot可检测到ERβ突变体融合蛋白在293T细胞中表达。萤光素酶活性检测表明,在没有雌激素刺激的情况下,2个突变体的活性较野生型没有变化;加入雌激素后,突变体的活性较野生型略有升高。结论:ERβ的264位和469位Ser位点的磷酸化可能不是ERβ调节下游基因转录所必需的,活性升高可能是由于ERβ构象变化造成的。  相似文献   

4.
《现代生物医学进展》2014,(7):I0004-I0004
据《自然一遗传学》上的两项独立研究显示,在某些转移性乳腺癌病例中,负责编码雌激素受体的基因会发生变异。这意味着雌激素受体对抗药物或对某些转移性乳腺癌病例具有疗效。Sarat Chandarlapaty等人选取了36个对激素疗法产生抗性的转移性乳腺癌肿瘤,对其中的230种基因进行测序,在9个肿瘤中发现ESRl基因突变。他们分析了44个转移性乳腺癌肿瘤中的ESRl基因,发现其中5个肿瘤存在基因突变。  相似文献   

5.
临床上常用的一种通过阻断β受体的抗心衰药物只对50%的病人有效。基因研究发现,β受体基因多形性与该药物的疗效有关。在人群中,β受体基因有两种常见表型,一种表型表达的受体在蛋白结构的特定部位含精氨酸,另一种表型表达的受体在蛋白结构的这一部位含有的是甘氨酸。每个人从父母那里遗传两套基因,因此人们有的有两条合成含精氨酸受体的基因;有人有两条合成含甘氨酸受体的基因;还有人有一条合成含精氨酸受体的基因,一条合成含甘氨酸受体的基因。将人的合成含精氨酸受体的基因转给小鼠,这种小鼠不仅易于发生心衰,而且对β受体阻断剂反应好。  相似文献   

6.
目的:通过观察雌激素对子宫内膜癌KLE细胞中Notch信号通路的影响,探讨过表达雌激素核受体(estrogenreceptor,ER)是否可以恢复雌激素对Notch信号通路的调控作用,继而调节细胞增殖活性。方法:MTT检测雌激素及Notch信号通路对细胞增殖活性的影响;RT.PCR及Westem.blotting检测雌激素及Notch通路抑制剂DAPT对Notch表达的影响;质粒的抽提及转染使KLE细胞中的雌激素核受体ER过表达。结果:雌激素呈剂量依赖效应促进KLE细胞的增殖活性,其中以雌激素浓度为1.0×10-9M时最明显(相对于对照组为1.25±0.026,P〈0.05);抑制Notch信号通路的表达可以明显下调KLE细胞的增殖活性(0.76±0.02,P〈0.05);在KLE细胞中,雌激素对Notch的表达没有明显的调控作用,但是将其雌激素核受体过表达后,雌激素可明显上调Notch的表达,并显著促进细胞的增殖活性(1.24±0.02,P〈0.05)。结论:在ER阴性的子宫内膜癌细胞中过表达ER,可以恢复雌激素对Notch信号通路的调控,从而进一步的调控细胞增殖活性。  相似文献   

7.
郭军  章双杰  汤青萍 《生命科学》2011,(10):975-979
垂体和性腺是生殖轴重要组成部分,两者之间的协同与制衡是动物维持正常生长发育的保证。性腺产生的雌激素可以反馈调控垂体神经内分泌活动。近年来,随着基因芯片和差异表达谱分析技术的发展,垂体内雌激素受体介导的基因调控网络不断取得进展,垂体生殖生理功能备受关注。通过综述雌激素及其受体在促性腺激素、催乳素、生长激素合成分泌中的调控作用,以及雌激素对垂体生长发育的影响,探讨雌激素受体通过垂体影响生殖过程,希望能为进一步研究雌激素及其受体的生殖生理作用开拓思路。  相似文献   

8.
雌激素受体β表达载体的构建及其转录活性测定   总被引:2,自引:2,他引:0  
为探索雌激素受体B(ERβ)在乳腺癌形成过程中的分子机制,构建出带HA标签的ERl3真核表达载体。首先将PCR扩增出的带HA标签的DNA片段连接到pcDNA3载体中,得到重组质粒pcDNA3-HA。再将ERβ完整编码区序列克隆到pcDNA3-HA中,得到重组质粒pcDNA3-HA—ERβ。Western印迹结果表明,转染pcDNA3-HA-ERβ重组质粒的293T细胞表达了与预期大小一致的HA—ERβ。用含雌激素应答元件的报告基因系统检测ERβ的转录活性表明。HA—ERβ在293T细胞中的表达激活了报告基因的表达。ERβ表达载体的成功构建为深入研究其生物学功能打下了坚实的基础。  相似文献   

9.
雌激素受体 β(ERβ) 是雌激素受体的另一亚型。众多体内外实验证明,ERβ 与乳腺癌的生长有密切联系。ERβ 低表达会促进乳腺 癌增殖,介导转移,还能抑制乳腺癌细胞的凋亡。临床数据证明,ERβ 在乳腺癌患者的癌旁组织中表达高于癌组织,且与乳腺癌患者的 总生存率相关。ERβ 与雌激素受体 α(ERα)、表皮生长因子受体(EGFR)、孕激素受体(PR)均有密切联系:ERα 和 ERβ mRNA 平 均表达水平比值(ERβ/ERα)升高,对抗癌药物有拮抗作用,反之则有协同作用;ERβ 的表达量受 PR 调节,并能通过 EGFR 及下游信 号通路,抑制上皮-间充质转化。临床乳腺癌样本表明,ERβ 低表达可能与启动子甲基化有关。因此,采用药物调节 ERβ 的表达以及敏感性, 是具有很大临床价值的潜在治疗手段。综述 ERβ 以及 ERβ 与相关受体之间的联系在乳腺癌生长中的作用。  相似文献   

10.
目的:构建雌激素受体α(ERα)高效真核表达载体,并检测其转录活性。方法:用常规PCR方法特异扩增带有Flag标签的人ERα全长编码序列,经双酶切后将其克隆到真核表达载体pIRESpuro2中,构建重组质粒pIRESpuro2-Flag-ERα;用Westernblot鉴定该重组质粒介导的Flag-ERα在人胚肾细胞株293T中的表达情况;用含雌激素应答元件的报告基因系统检测ERα的转录活性。结果:构建了pIRESpuro2-Flag-ERα重组质粒,该质粒介导的融合蛋白在293T细胞中得到表达,并可以激活含雌激素应答元件的报告基因的活性。结论:ERα高效真核表达载体的构建为进一步研究ERα在乳腺癌中的作用奠定了基础。  相似文献   

11.
INTRODUCTION: Symptoms of precocious puberty (PP) in children always arouse anxiety in their parents. Many children with PP are being hospitalized for the detailed diagnostic work-up. The aim of our study was to analyze the frequency of the variants of PP in children referred to our department. MATERIAL: Retrospective analysis of 119 children (103 girls and 16 boys) referred for hospitalization in the years 2003-2005 due to signs of precocious puberty was performed. RESULTS: Premature thelarche, benign variant of puberty, was diagnosed in 62 (53%) girls, in the mean age of 3.39 (+/- 2.33) years. Their mean height was within 0.7 +/- 1.1 SD. Premature pubarche was diagnosed 30 (25%) children--22 girls and 8 boys in the mean age was 7.24 (+/- 0.81) years. Their mean height was 1.3 +/- 1.0 SD and was significantly higher than normal (p < 0.0001). Premature menarche was diagnosed in 8 (7%) girls in the mean age 4.81 +/-2.26 years. Mean height in this group was normal for age (0.9+/-0.8 SD). PP was diagnosed in 19 (16%) children (11 girls and 8 boys) in the mean age 5.91 +/- 1.63 years. Mean height in this group was 1.6 +/- 0.7 SD, and was significantly higher than the mean for age (p<0.0005). GnRH-dependent type was present in 15 children, diagnosed as idiopathic in 9 girls and 1 boy. In 5 children (4 boys and 1 girl) pathology of central nervous system was found. In 4 children GnRH-independent precocious puberty was diagnosed--in 3 caused by congenital adrenal hyperplasia and in 1 boy by tumour of testis (leydigioma). CONCLUSIONS: Girls with precocious thelarche without growth acceleration present the benign variant of puberty and need clinical follow up only. Boys with clinical signs of precocious puberty should be carefully evaluated to rule out the organic cause.  相似文献   

12.
Congenital hypogonadotropic hypogonadism (CHH) is characterized by low gonadotropins and failure to progress normally through puberty. Mutations in the gene encoding the GnRH receptor (GNRHR1) result in CHH when present as compound heterozygous or homozygous inactivating mutations. This study identifies and characterizes the properties of two novel GNRHR1 mutations in a family in which three brothers display normosmic CHH while their sister was unaffected. Molecular analysis in the proband and the affected brothers revealed two novel non-synonymous missense GNRHR1 mutations, present in a compound heterozygous state, whereas their unaffected parents possessed only one inactivating mutation, demonstrating the autosomal recessive transmission in this kindred and excluding X-linked inheritance equivocally suggested by the initial pedigree analysis. The first mutation at c.845 C>G introduces an Arg substitution for the conserved Pro 282 in transmembrane domain (TMD) 6. The Pro282Arg mutant is unable to bind radiolabeled GnRH analogue. As this conserved residue is important in receptor conformation, it is likely that the mutation perturbs the binding pocket and affects trafficking to the cell surface. The second mutation at c.968 A>G introduces a Cys substitution for Tyr 323 in the functionally crucial N/DPxxY motif in TMD 7. The Tyr323Cys mutant has an increased GnRH binding affinity but reduced receptor expression at the plasma membrane and impaired G protein-coupling. Inositol phosphate accumulation assays demonstrated absent and impaired Gα(q/11) signal transduction by Pro282Arg and Tyr323Cys mutants, respectively. Pretreatment with the membrane permeant GnRHR antagonist NBI-42902, which rescues cell surface expression of many GNRHR1 mutants, significantly increased the levels of radioligand binding and intracellular signaling of the Tyr323Cys mutant but not Pro282Arg. Immunocytochemistry confirmed that both mutants are present on the cell membrane albeit at low levels. Together these molecular deficiencies of the two novel GNRHR1 mutations lead to the CHH phenotype when present as a compound heterozygote.  相似文献   

13.
Marfan syndrome is an autosomal dominant disease caused by mutations in the gene encoding for fibrillin-1 (FBN1). More than 1,000 FBN1 mutations have been identified, which may lead to multiple organ involvement, particularly of the ocular, skeletal, and cardiovascular systems. Mutations in exons 59–65 have been reported in the past to cause mild Marfan-like fibrillinopathies. We report a family with a mutation in exon 63 that manifests with significant cardiovascular system involvement such as aortic root dilatations, dissection of the aorta, and sudden death at a young age. Genetic analysis revealed that four related individuals are positive for a novel heterozygous Cys2633Arg mutation in exon 63. Their genotype–phenotype profile (based on the revised Ghent nosology) is described. We postulate that the Cys2633Arg mutation may manifest with significant and progressive enlargement of the aortic root, risk of aortic dissections, and minor skeletal abnormalities, without involving the ocular system (i.e., ectopia lentis).  相似文献   

14.
Precocious puberty associated with profound hypothyroidism is a rare condition. It is usually characterized by breast development, vaginal bleeding, lack of pubic hair and delayed bone age. Multicystic ovaries in profound hypothyroid patients with precocious puberty have been rarely described. Vaginal bleeding in adolescent girls should be considered as a clinical significance particularly when it is prolonged or heavy, whereas vaginal bleeding in younger girls, regardless of its duration and quantity is always of clinical importance. Bleeding in such patients could be caused by local causes such as vulvar or vaginal lesions, or it could be from the endometrium, which is usually a sign of systemic hormonal disturbance [1]. In this report a rare case of vaginal bleeding, large, multicystic ovaries, precocious puberty and delayed bone age in a 7 years old girl with profound hypothyroidism is described.  相似文献   

15.
Twenty years ago it was believed that pubertal growth was stimulated by testicular androgen in boys and by adrenal androgen in girls. Estrogen, which was used to inhibit growth in excessively tall girls, was not thought to have growth-promoting effects. We hypothesized that estrogen has a biphasic effect on epiphyseal growth, with maximal stimulation at low levels. We showed that the administration of low doses of estrogen, corresponding to a serum estradiol level of about 4 pg/ml (15 pmol/l) caused more than a 60% increase over the prepubertal growth rate in both boys and girls. To test the hypothesis that estrogen is the principal mediator of the pubertal growth spurt in boys, we administered the aromatase inhibitor, testolactone, to boys with familial male-limited precocious puberty. Testolactone produced near normalization of both growth velocity and bone maturation, despite levels of serum testosterone that remained within the adult male range. The observation that low levels of estrogen stimulate growth and bone maturation suggested that estrogen might explain the more rapid epiphyseal maturation of prepubertal girls compared to boys. To determine whether prepubertal girls have higher estrogen levels than prepubertal boys, we developed an ultrasensitive recombinant cell bioassay for estrogen with a sensitivity of 0.02 pg/ml (0.07 pmol/l) estradiol equivalents. Prepubertal girls had approximately eight-fold higher levels of serum estradiol than did prepubertal boys (0.6 ± 0.6 pg/ml (SD) (2.2 ± 2.2 pmol/l) vs 0.08 ± 0.2 pg/ml (0.29 ± 0.73 pmol/l), P < 0.05). We concluded that the pubertal growth spurt of both sexes is driven primarily by estrogen, and that the more rapid epiphyseal maturation of prepubertal girls (vs boys) may be explained by their higher estradiol levels.  相似文献   

16.
The molecular basis of familial chylomicronemia (type I hyperlipoproteinemia), a rare autosomal recessive trait, was investigated in six unrelated individuals (five of Spanish descent and one of Northern European extraction). DNA amplification by polymerase chain reaction (PCR) followed by single strand conformation polymorphism (SSCP) analysis allowed rapid identification of the underlying mutations. Six different mutant alleles (three of which are previously undescribed) of the gene encoding lipoprotein lipase (LPL) were discovered in the five LPL-deficient patients. These included an 11 bp deletion in exon 2, and five missense mutations: Trp 86 Arg (exon 3), His 136 Arg (exon 4), Gly 188 Glu (exon 5), Ile 194 Thr (exon 5), and Ile 205 Ser (exon 5). The Trp 86 Arg mutation is the only known missense mutation in exon 3. The other missense mutations lie in the highly conserved "central homology region" in close proximity with the catalytic site of LPL. These and other previously reported missense mutations provide insight into structure/function relationships in the lipase family. The missense mutations point to the important role of particular highly conserved helices and beta-strands in proper folding of the LPL molecule, and of certain connecting loops in the catalytic process. A nonsense mutation (Arg 19 Term) in the gene encoding apolipoprotein C-II (apoC-II), the cofactor of LPL, was found to underlie chylomicronemia in the sixth patient who had normal LPL but was apoC-II-deficient.  相似文献   

17.
A female chimpanzee developed premature sex skin swelling, breast budding, advanced bone age, and moderate estrogen effect of the vaginal cytology. Extensive radiographic and hormonal studies excluded all the known causes of precocious puberty and pseudopuberty, yielding a diagnosis of idiopathic true precocious puberty. To our knowledge this is the first observation of idiopathic true precocious puberty in a chimpanzee.  相似文献   

18.
BACKGROUND: Thirty-six mutations that cause Gaucher disease, the most common glycolipid storage disorder, are known. Although both alleles of most patients with the disease contain one of these mutations, in a few patients one or both disease-producing alleles have remained unidentified. Identification of mutations in these patients is useful for genetic counseling. MATERIALS AND METHODS: The DNA from 23 Gaucher disease patients in whom at least one glucocerebrosidase allele did not contain any of the 36 previously described mutations has been examined by single strand conformation polymorphism (SSCP) analysis, followed by sequencing of regions in which abnormalities were detected. RESULTS: Eight previously undescribed mutations were detected. In exon 3, a deletion of a cytosine at cDNA nt 203 was found. In exon 6, three missense mutations were identified: a C-->A transversion at cDNA nt 644 (Ala176-->Asp), a C-->A transversion at cDNA nt 661 that resulted in a (Pro182-->Thr), and a G-->A transition at cDNA nt 721 (Gly202-->Arg). Two missense mutations were found in exon 7: a G-->A transition at cDNA nt 887 (Arg257-->Gln) and a C-->T at cDNA nt 970 (Arg285-->Cys). Two missense mutations were found in exon 9: a T-->G at cDNA nt 1249 (Trp378-->Gly) and a G-->A at cDNA nt 1255 (Asp380-->Asn). In addition to these disease-producing mutations, a silent C-->G transversion at cDNA nt 1431, occurring in a gene that already contained the 1226G mutation, was found in one family. CONCLUSIONS: The mutations described here and previously known can be classified as mild, severe, or lethal, on the basis of their effect on enzyme production and on clinical phenotype, and as polymorphic or sporadic, on the basis of the haplotype in which they are found. Rare mutations such as the new ones described here are sporadic in nature.  相似文献   

19.
Autosomal recessive congenital ichthyosis (ARCI) is a rare, heterogenous keratinization disorder of the skin, classically divided into two clinical subtypes, lamellar ichthyosis (LI) and nonbullous congenital ichthyosiformis erythroderma (CIE). Recently, strong evidence for the involvement of the transglutaminase 1 gene (TGM1) in LI has evolved. We have studied ARCI in the isolated Finnish population, in which recessive disorders are often caused by single mutations enriched by a founder effect. Surprisingly, five different mutations of TGM1 (Arg141His, Arg142Cys, Gly217Ser, Val378Leu, and Arg395Leu) were found in Finnish ARCI patients. In addition to affected LI patients, we also identified TGM1 mutations in CIE patients. Moreover, haplotype analysis of the chromosomes carrying the most common mutation, a C-->T transition changing Arg142 to Cys, revealed that the same mutation has been introduced twice in the Finnish population. In addition to this Arg142Cys mutation, three other mutations, in Arg141 and Arg142, have been described elsewhere, in other populations. These findings suggest that this region of TGM1 is more susceptible to mutation. The corresponding amino acid sequence is conserved in other transglutaminases, but, for example, coagulation factor XIII (FXIII) mutations do not cluster in this region. Protein modeling of the Arg142Cys mutation suggested disruption or destabilization of the protein. In transfection studies, the closely related transglutaminase FXIII protein with the corresponding mutation was shown to be susceptible to degradation in COS cells, further supporting evidence of the destabilizing effect of the Arg142Cys mutation in TGM1.  相似文献   

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