探讨FGFR3在骨骼发育和疾病中的作用

成纤维细胞生长因子受体（fibroblast growth factor receptors FGFRs）属于免疫球蛋白基因超家族成员,它们与其相应配体成纤维细胞生长因子（fibroblast-growth factors,FGFs）结合,在组织器官发育及损伤修复过程中发挥重要作用。     

骨骼疾病中FGFR的激活

近两年来，成纤维细胞生长因子受体（ＦＧＦＲ）家庭的４个成员中的３个有越来越多的突变被证实为骨骼和头颅发育过程中的常染色体性疾病的原因。这些突变定位于这些受体的细胞外结构域，跨膜结构域或酪氨酸激酶结构域。最后的研究表明，受体信号的组成性激活这一共同机制，构成了绝大多数这类疾病的基础，这表明在骨骼生长的负调控中的ＦＧＦＲ起正常的作用。     

FGFR3突变与软骨发育不全的研究进展

软骨发育不全(achondroplasia,ACH,MIM100800)是人类侏儒症最常见的形式,是非致死性的一种常染色体显性遗传疾病。他以短肢、躯干相对正常和巨头为特征。新生儿的发病率大约为1∶20 000。近年来ACH的基因分子诊断取得了突破性的进展,揭示软骨发育不全与成纤维细胞生长因子受体3(fibroblast growth factor receptor,FGFR3,MIM134934)基因跨膜区的突变密切相关。这种突变有突变热点,95%以上的患者,380位密码子的错义突变,精氨酸替代了甘氨酸。     

FGFS／FGFRS在骨骼发育与疾病中的作用

成纤维细胞生长因子(fibroblast growth factors．FGFs)及其受体成纤维细胞生长因子受体(fibroblast growth factor receptors,FGFRs)在许多组织、器官的发育和疾病发生、发展过程中有重要作用。现代分子生物、分子遗传技术包括转基因和基因敲除技术等的应用极大地加深了对FGFs、FGFRs的结构和功能，尤其是它们在人体遗传性骨骼疾病(侏儒和囟门早闭)中作用和机制的认识。本综述将介绍FGFS／FGFRS在骨骼发育与疾病中的作用。     

FGFS/FGFRS在骨骼发育与疾病中的作用

成纤维细胞生长因子 (fibroblast growth factors,FGFs)及其受体成纤维细胞生长因子受体 (fibroblast growthfactor receptors,FGFRs)在许多组织、器官的发育和疾病发生、发展过程中有重要作用。现代分子生物、分子遗传技术包括转基因和基因敲除技术等的应用极大地加深了对 FGFs、FGFRs的结构和功能 ,尤其是它们在人体遗传性骨骼疾病 (侏儒和囟门早闭 )中作用和机制的认识。本综述将介绍 FGFS/ FGFRS在骨骼发育与疾病中的作用。     

FGFR3基因突变分析鉴别软骨发育不全及类似遗传性侏儒

目的 了解中国人软骨发育不全患者（ａｃｈｏｎｄｒｏｐｌａｓｉａ,ＡＣＨ）的基因突变情况,建立一种快速简便的从分子水平鉴别ＡＣＨ及类似遗传性侏儒的方法。方法 对２１例ＡＣＨ患者及６例颖似ＡＣＨ患者的干血滤纸片进行成纤维细胞成长因子受体３（ｆｉｂｒｏｂｌａｓｔ ｇｒｏｗｔｈ ｆａｃｔｏｒ ｒｅｃｅｐｔｏｒ３,ＦＧＦＲ３）基因跨膜区特异性扩增,通过限性内切酶分析、单链构象多态和变性梯度凝胶电泳检测基因突     

成纤维细胞生长因子受体3突变与疾病

成纤维细胞生长因子受体3(FGFR3)在细胞的增殖、分化、血管形成、骨骼发育及与生长和发育相关的过程中起着十分重要的作用。本文概述了FGFR3突变与遗传性侏儒症、膀胱癌等肿瘤的发生和发展的关系。     

与FGFR3基因有关的遗传性侏儒研究进展

生长长骨两端的内软骨持续性骨化,可以引起骨骼的纵向生长.当此过程发生障碍时,可以导致侏儒.与FGFR3基因有关的遗传性侏儒主要有ACH、HCH、TD.过去曾将这些引起身材矮小的疾病都不合适地统称作ACH.随着临床医学和分子遗传学的发展,人们对这几种疾病有了进一步的认识.     

检测FGFR3基因鉴别诊断先天性软骨发育不全

目的 建立一种基因水平上鉴别诊断先天性软骨发育不全的方法。方法 采用PCR—RFLP技术对1例临床确诊的ACH患者，1例临床怀疑为ACH患者的FGFR3基因第10外显子1138位核苷酸作突变型分析。结果 确诊的ACH患者1138核苷酸存在C→A的转换，而临床怀疑为ACH患者的1138核苷酸无任何改变。结论 检测FCFR3基因突变可从分子水平上鉴别诊断先天性软管发育不全，准确率达95％。     

利用基因芯片技术研究FGFR3在小鼠胚胎肢芽不同发育阶段的表达

目的 检测在软骨发育分化过程中具有重要作用的成纤维细胞生长因子受体3(FGFR3)在小鼠胚胎肢芽发育过程中的表达. 方法 采用小鼠全基因组Affymetrix mouse 430 2.0芯片检测小鼠胚胎肢芽发育不同阶段的基因表达,并进行组织学染色观察. 结果 FGFR3在E12.5d开始呈现明显的表达上调,在E13.5d达到上调顶峰,E14.5d后FGFR3表达逐渐下调. 结论 FGFR3的表达与胚胎肢芽软骨发育过程密切相关,在软骨的发育分化过程中发挥着重要的作用,并可作为前软骨细胞的特异件标记物.     

Description of a new mutation and characterization of FGFR1, FGFR2, and FGFR3 mutations among Brazilian patients with syndromic craniosynostoses

Dominant mutations in three fibroblast growth factor receptor genes (FGFRs1-3) cause Crouzon, Jackson-Weiss, Pfeiffer, and Apert syndromes. In the present study, 50 Brazilian patients with these four syndromes (27 Apert, 17 Crouzon, 5 Pfeiffer, and 1 Jackson-Weiss patients) were screened for mutations in the FGFR1-3 genes. Except for one, all the Apert patients had either S252W (n = 16) or P253R (n = 10) mutations. The remaining Apert case is atypical with a mutation altering the splice site of FGFR2 exon IIIc. The Pfeiffer patients had mutations in one of the FGFR genes: three in FGFR2, one in FGFR1, and one in FGFR3. In contrast, only 8 of the 17 Crouzon patients studied had a mutation in either FGFR2 (n = 7) or FGFR3 locus (n = 1). Mutations in the FGFR2 locus account for most (93%) of our syndromic craniosynostotic cases, whereas 5% had mutations in the FGFR3 locus and only 2% had mutations in the FGFR1 gene. Except for one, all the other mutations were reported previously in craniosynostotic patients from other populations. Interestingly, the mutation C278F, previously described in Crouzon and Pfeiffer cases, was here identified in a familial case with Jackson-Weiss. Also, unexpectedly, a common mutation altering the splice site of the FGFR2 exon IIIc was found in one Apert and two Pfeiffer patients. In addition, we identified a new mutation (A337P) in the FGFR2 exon IIIc associated with Crouzon phenotype. Am. J. Med. Genet. 78:237–241, 1998. © 1998 Wiley-Liss, Inc.     

小鼠FGFR3可控性RNAi载体的构建和抑制效率验证

目的 构建小鼠成纤维细胞生长因子受体3(fibroblast growth factor receptor 3,FGFR3)可控性RNAi载体及RNAi载体,并在体外验证后者效率.方法 以含有pLoxPneo基因的pBSK/U6载体为骨架,首先构建针对FGFR3的可控性RNAi载体pBSU6/FGFR3i,然后经Cre重组酶去除neo基因后得到RNAi载体FGFR3-RNAi.将FGFR3-RNAi与FGFR3表达载体分别共转染RAW264.7和HEK293T细胞株,经半定量RT-PCR和Western blot分别检测FGFR3 mRNA和蛋白表达情况.结果 成功构建针对FGFR3的可控性敲低载体和RNAi载体;FGFR3载体在细胞水平可明显降低FGFR3 mRNA的丰度及蛋白表达.结论 为进一步获得FGFR3可控性敲低的小鼠模型奠定基础.     

FGFR3 biology and skeletal disease

Fibroblast Growth Factor Receptor 3 (FGFR3) is one of four high-affinity receptors for canonical FGF ligands. It acts in many tissues and plays a special role in skeletal development, especially post-embryonic bone growth, where it inhibits chondrocyte proliferation and differentiation. Gain of function mutations cause the most common forms of dwarfism in humans, and they are also detected in cancer. Triggered by ligand binding or in some cases mutation, FGFR3 activation involves dimerization of receptor monomers, phosphorylation of specific tyrosine residues in the receptor’s kinase domain and in the tightly linked scaffold protein Fibroblast Receptor Factor Substrate 2 (FRS2). Signaling molecules recruited to these phosphorylation sites propagate signals through cascades that are subject to modulation. Signal output is also regulated by the fate of the receptor and the interval between its activation and degradation. Trafficking pathways have been identified for both lysosomal and proteasomal degradation, as well as, an alternative fate that involves intramembrane cleavage that produces an intracellular domain fragment capable of nuclear transport and potential function.     

Compound heterozygosity for the achondroplasia-hypochondroplasia FGFR3 mutations: Prenatal diagnosis and postnatal outcome

We report on a male newborn infant, a compound carrier of heterozygous mutations in the FGFR3 gene causing achondroplasia and hypochondroplasia. The mother has achondroplasia and carries the common G1138 (G380R) mutation in the FGFR3 gene; the father has hypochondroplasia due to the C1620A (N540K) mutation in the same gene. The fetus was found to carry both mutations diagnosed prenatally by amniocentesis at 17.6 weeks of gestation, following maternal serum screening which showed an increased risk for Down syndrome (1:337). Detailed fetal ultrasound studies showed a large head, short limbs, and a small chest at 22 weeks of gestation. The changes were more severe than those of either achondroplasia or hypochondroplasia. The patient was born by cesarean section at 38 weeks of gestation and had rhizomelic shortness of the upper and lower limbs with excess skin folds, large head, enlarged fontanelles, frontal bossing, lumbar gibbus, trident position of the fingers, and a narrow chest with a horizontal line of demarcation at the narrowest area of the chest. Skeletal radiographs showed shortness of the long bones and flare of metaphyses. He had respiratory difficulties and was treated with nasal prongs. Seizures developed on day 2 of life and recurred on day 9 and responded to treatment with phenobarbital. Brain computed tomographic scan showed possible grey matter heterotopia, partial agenesis of the corpus callosum, and cortical dysplasia. To our knowledge, there are only two previously published cases of compound heterozygous achondroplasia-hypochondroplasia patients. The diagnosis was confirmed by DNA mutation analysis of the FGFR3 gene in both cases. Am. J. Med. Genet. 84:401–405, 1999. © 1999 Wiley-Liss, Inc.     

FGFR3基因突变导致软骨发育不全的产前分子诊断

目的本研究对FGFR3（fibroblast growth factor receptor 3,FGFR3）基因突变导致的软骨发育不全（ACH）家系的1例中期妊娠者进行产前分子诊断,以达到优生的目的。方法患者妻子于20孕周在B超下进行羊膜囊穿刺,抽取羊水20ml,提取羊水细胞基因组DNA,对FGFR3基因外显子10进行PCR扩增并测序。结果该例胎儿FGFR3基因外显子10测序结果显示,胎儿带有与父亲一样的FGFR3基因突变（c.1138G〉A）,B超监测显示双顶径与孕周不相符,双顶径（PBD）值偏低,进一步证实了ACH,目前在医生的指导下已经顺利引产。结论软骨发育不全是一种少见的常染色体显性遗传病,对于有ACH风险的胎儿进行产前分子诊断非常重要,从而有效地避免患儿出生。     

An improved methodology for the detection of the common mutation in the FGFR3 gene responsible for achondroplasia

Homozygous achondroplasia is a neonatal lethal condition which can only be diagnosed in the first trimester of pregnancy by molecular analysis. The vast majority of patients with achondroplasia have a G→A substitution at position 1138 of the fibroblast growth factor receptor (FGFR3) cDNA sequence, resulting in the substitution of an arginine for a glycine residue at position 380 of the FGFR3 protein. This mutation has typically been detected by SfcI digestion of amplified genomic DNA. We have demonstrated that the SfcI digestion protocol does not consistently distinguish between DNA samples heterozygous and homozygous for the G1138A substitution, and illustrates how the misdiagnosis of a homozygous affected fetus for one carrying only one copy of the G1138A mutation could occur. We report here an improved, simple nonradioactive technique which can reliably and consistently detect the presence of the G1138A mutation both in the heterozygous and homozygous state. Hum Mutat 10:496–499, 1997. © 1997 Wiley-Liss, Inc.