U937细胞表达成纤维细胞生长因子受体

以逆转录－ＤＮＡ聚合酶链反应（ＲＴ－ＰＣＲ）自Ｕ９３７细胞钓出了两条ｃＤＮＡ片段。将其克隆入ＴＡ克隆载体后进行ＤＮＡ测序。结果证明ｃＤＮＡ片段分别是人成纤维细胞生长因子受体１（ＦＧＦＲ１）的细胞外段和细胞内段ｃＤＮＡ。这一结果表明，Ｕ９３７细胞可以表达ＦＧＦＲ１ｍＲＮＡ。     

成纤维细胞生长因子受体1(FGFR1)基因在正常小鼠心脏组织中的变化

自人肺成纤维细胞以逆转录－ＤＮＡ聚合酶链式反应（ＲＴ－ＰＣＲ）钓取了人成纤维细胞生长因子受体１（ＦＧＦＲ１）细胞外段（含第２和第３免疫球蛋白结构域）ｃＤＮＡ。将此片段标记成非同位素探针，用其与ＳａｌⅠ消化的小鼠心脏等组织的基因组ＤＮＡ进行了Ｓｏｕｔｈｅｒｎ印迹杂交。结果表明：与其它组织相比，成年小鼠心脏组织显示ＦＧＦＲ１基因Ｓｏｕｔｈｅｒｎ印迹的带型发生了变化。经过分析，提出了产生这种变化的３种模式。     

成纤维细胞生长因子受体1（FGFR1）基因在正常小鼠心脏组织中变化

自人肺成纤维细胞以逆转录－ＤＮＡ聚合酶链式反应（ＲＴ－ＰＣＲ）钓取了人成纤维细胞生称因子受体１（ＦＧＦＲ１）细胞外段（含第２和第３免疫球蛋白结构域）ｃＤＮＡ。将此片段标记非同位素探针，用其与Ｓａｌ１消化的小鼠心脏等组织的基因组ＤＮＡ进行了Ｓｏｕｔｈｅｒｎ印迹技术，结果表明：与其它组织相比，成年小鼠心脏组织显示ＦＧＦＲ１基因Ｓｏｕｔｈｅｒｎ印迹的带型发生了变化，经过分析，提出了产生这种变化的３种模式     

人细胞色素p450IA1基因cDNA的克隆和鉴定

在用３－甲基胆蒽诱导培养人羊膜ＦＬ细胞２４ｈ后，抽提细胞总ＲＮＡ并直接合成ｃＤＮＡ第一链。利用人工合成的一对寡核苷酸引物，采用ＰＣＲ技术特异性地扩增Ｃｙｔ ｐ５０ＩＡ１ ｃＤＮＡ。３０个循环后琼脂糖凝胶电泳显示１．５Ｋｂ大小片段，长度与预计相符。Ｓｏｕｔｈｅｒｎ杂交结果证实此片段确为Ｃｙｔ ｐ４５０ＩＡ１ ｃＤＮＡ。将此片段克隆至质粒ｐＧＥＭ－３Ｚ并进行部份序列分析。结果显示克隆片段包含Ｃｙｔ ｐ     

以Bacmid-杆状病毒-昆虫细胞系统表达人FGF-9

目的：在Ｂａｃｍｉｄ－杆状病毒－昆虫细胞系统中表达人ＦＧＦ－９。方法：采用ＲＴ－ＰＣＲ技术,自新鲜人脑胶质瘤组织获取人ＦＧＦ－９全编码区ｃＤＮＡ,将其克隆入ｐＣＲ＾ＴＭⅡ质粒及ｐＹＥＸ４Ｔ－１真核表达质粒,经ＤＮＡ自动测序仪进行ＤＮＡ序列测定。将人ＦＧＦ－９ｃＤＮＡ定向克隆入ｐＦａｓｔＢａｃ质粒,进一步将其转座入Ｂａｃｍｉｄ中,在昆虫细胞Ｓｆ９中进行表达,采用ＳＤＳ－ＰＡＧＥ对表达产物进行分析。     

成纤维细胞生长因子受体1(FGFR-1)基因在人肠癌组织中的变化

为观察人ＦＧＦＲ－１基因变化与结肠癌发生的关系。采用ＲＴ－ＰＣＲ法从人肺成纤维细胞中钓取ＦＧＦＲ－１全编码区ｃＤＮＡ，用此ｃＤＮＡ探针与人肠癌及癌旁组织ＤＮＡ进行Ｓｏｕｔｈｅｒｎ印迹分析。结果表明：与癌旁组织相比结肠癌组织Ｓｏｕｔｈｅｒｎ印迹图谱发生了改变。提示ＰＧＦＲ－１基因变化与肠癌发生可能存在一定相关性。     

成纤维细胞生长因子受体1（FGFR—1）基因成人肠癌组织中的变化

为观察人ＦＧＦＲ－１基因变化与结肠癌发生的关系。采用ＲＴ－ＰＣＲ法从肺成纤维细胞中钓取ＦＧＦＲ－１全编码区ｃＤＮＡ,用此ｃＤＮＡ探针与人肠癌及癌旁组织进行Ｓｏｕｔｈｅｒｎ印迹分析。     

以Bacmid-杆状病毒-昆虫细胞系统表达人FGF-9

目的：在Ｂａｃｍｉｄ杆状病毒昆虫细胞系统中表达人ＦＧＦ９ 。方法：采用ＲＴＰＣＲ技术,自新鲜人脑胶质瘤组织获取人ＦＧＦ９ 全编码区ｃＤＮＡ,将其克隆入ｐＣＲＴＭ Ⅱ质粒及ｐＹＥＸ４Ｔ１ 真核表达质粒,经ＤＮＡ自动测序仪进行ＤＮＡ序列测定。将人ＦＧＦ９ ｃＤＮＡ 定向克隆入ｐＦａｓｔＢａｃ 质粒,进一步将其转座入Ｂａｃｍｉｄ 中,在昆虫细胞Ｓｆ９ 中进行表达,采用ＳＤＳＰＡＧＥ对表达产物进行分析。结果：在昆虫细胞表达系统中表达出人ＦＧＦ９ 重组蛋白。结论：人ＦＧＦ９ 在Ｂａｃｍｉｄ杆状病毒昆虫细胞系统中得到了表达。     

人神经生长因子β亚基cDNA的克隆及序列分析

目的：对国人神经生长因子β亚基（βＮＧＦ）ｃＤＮＡ 进行克隆及序列分析,为研究βＮＧＦ 的生理功能及其在临床应用提供基础与手段。方法：从人海马组织分离,纯化总ＲＮＡ,直接进行逆转录,用ＰＣＲ 扩增βＮＧＦ 的ｃＤＮＡ 得到６５０ｂｐ 的ＤＮＡ 片段,利用Ｔ－ Ａ 克隆载体法,制备重组质粒,克隆βＮＧＦｃＤＮＡ。结果：βＮＧＦ 的ｃＤＮＡ 全序列１０７４ ｂｐ ,其蛋白编码为６３０ ｂｐ ,由２１２ 个氨基酸组成,Ｎ 端为信号肽,中间区为前肽,Ｃ 端为成熟肽。结论：国人βＮＧＦ 序列分析结果与ｇｅｎｅ ｂａｎｋ 中的βＮＧＦ 序列完全一致,与外国人没有区别     

人整合素分子α4亚基片段的克隆及大肠杆菌的表达

目的 克隆并原核表达α４亚基笥段。方法 从ＩＬ－６细胞系中提取总ＲＮＡ,以ＲＴ－ＰＣＲ方法分两段扩增人整素分子α４亚基片段２．０ｋｂ ｃＤＮＡ,将两片段连接,并将其中的１．７ｋｂ基因片段亚克隆至表达载体ＰＧＥＸ－ＫＧ中,ＩＰＴＧ诱导表达。结果 ＲＴ－ＰＣＲ扩增并克隆了α４的两段ＣＤＮＡ,序列分析表明：与文献报道的μ４ＣＤＮＡ序列基本一致。两片段成功连接后将其中的１．７ｋｂ亚克隆至表达载体ＰＧＥＸ－     

成纤维细胞生长因子受体1配体精细结合位点的确定

目的 确定人成纤细胞生长因子受体1（FGFR1）的配体精细结合位点。方法 合成肽文库筛选，定向点突变,源核细胞重组蛋白质表达及受体－配体结合实验。结果 采用^125I标记的酸性成纤维细胞生生长因子（aFGF)，自合成肽文库中筛选到一个五肽序列（WGPGM），其序列及立体结构和FGFR1细胞外段的一个基序（WISPEKM）相似。为了证明FGFR1的WTSPEKM基序是结合FGF的重要结合，采用定向突变技术将WITSPEKM基序中的P（CCA）突变成A（GCA），并在原核细胞中表达了野生型和突变型FGFR1细胞外段重组蛋白质，受体－配体结合实验显示突变的GFFR1细胞外段结合aFGF的能力明显降低。结论 FGFR1的WISPEKM基序是配体结合的一个重要部位。     

人重组FGFR1在昆虫细胞膜上的表达

目的：将人重组成纤维细胞生长因子受体1（FGFR1）表达在昆明细胞膜表面,有作筛选成纤维细胞生长因子（FGFs）损抗肽抗针。方法：将人FGFR1 cDNA克隆入昆虫病毒的转递质粒pFastBac Ⅰ上,然后转座到昆虫病毒Bacmid上。以重组Bacmid转染昆虫细胞Sf9并表达人FGFR1,以Western印迹和ELISA对表达出的蛋白质进行鉴定。结果：FGFR1 cDNA片段2100bp,重组FGFR1表达产物分子量78kD。ELISA结果显示,人重组FGFR1高效地在昆虫细胞Sf9膜表达。结论：这个表达系统能很好地表达出人重组FGFR1,并能准确地将其定位到昆虫细胞膜的表面。     

Promotion of neurite outgrowth by fibroblast growth factor receptor 1 overexpression and lysosomal inhibition of receptor degradation in pheochromocytoma cells and adult sensory neurons

Basic fibroblast growth factor (FGF-2) is up-regulated in response to a nerve lesion and promotes axonal regeneration by activation of the tyrosine kinase receptor fibroblast growth factor receptor 1 (FGFR1). To determine the effects of elevated FGFR1 levels on neurite outgrowth, overexpression was combined with lysosomal inhibition of receptor degradation. In pheochromocytoma (PC12) cells, FGFR1 overexpression resulted in flattened morphology, increased neurite outgrowth and activation of extracellular signal-regulated kinase (ERK) and AKT. Degradation of FGFR1 was inhibited by the lysosomal inhibitor leupeptin and by the proteasomal inhibitor lactacystin. In rat primary adult neurons, FGFR1 overexpression enhanced FGF-2-induced axon growth which was further increased by co-treatment with leupeptin. Lysosomal inhibition of receptor degradation concomitant with ligand stimulation of neurons overexpressing FGFR1 provides new insight in tyrosine kinase receptor-mediated promotion of axon regeneration and demonstrates that adult sensory neurons express sub-optimal levels of tyrosine kinase receptors for neurotrophic factors.     

Distinct craniofacial-skeletal-dermatological dysplasia in a patient with W290C mutation in FGFR2

Mutations in the fibroblast growth factor receptor genes (FGFR) have been known to be associated with many craniosynostosis syndromes with overlapping phenotypes. We studied a 15-year-old Thai boy with an unspecified craniosynostosis syndrome characterized by multiple suture craniosynostoses, a persistent anterior fontanel, corneal scleralization, choanal stenosis, atresia of the auditory meatus, broad thumbs and great toes, severe scoliosis, acanthosis nigricans, hydrocephalus, and mental retardation. Radiography revealed bony ankyloses of vertebral bodies of T9-12, humero-radio-ulnar joints, intercarpal joints, distal interphalangeal joints of fifth fingers, fibulo-tibial joints, intertarsal joints, and distal interphalangeal joints of the first toes. The patient was a heterozygous for a 870G --> T change resulting in a W290C amino acid substitution in the extracellular domain of the fibroblast growth factor receptor 2 gene (FGFR2). This mutation has previously been reported in a patient with severe Pfeiffer syndrome type 2 that is distinct from the craniosynostosis in our patient. These findings emphasize locus, allelic, and phenotypic heterogeneity of craniofacial-skeletal-dermatological syndrome due to FGFR2 mutations.     

Epigenetic silencing through DNA and histone methylation of fibroblast growth factor receptor 2 in neoplastic pituitary cells

Four members of the fibroblast growth factor receptor (FGFR) family of tyrosine kinases transduce signals of a diverse group of more than 23 fibroblast growth factor (FGF) ligands. Each prototypic receptor is composed of three immunoglobulin-like extracellular domains, two of which are involved in ligand binding. Alternative RNA splicing of one of two exons results in two different forms of the second half of the third immunoglobulin-like domain, the IIIb or IIIc isoforms. The contribution of each receptor and their isoforms in tumorigenesis remains unknown. In the pituitary, FGFR2 is expressed primarily as the IIIb isoform in normal adenohypophysial cells. In contrast, FGFR2 is significantly down-regulated in mouse corticotroph AtT20 tumor cells where the 5' promoter is methylated. Treatment of AtT20 cells with 5'-azacytidine resulted in FGFR2 re-expression, mainly as the FGFR2-IIIb isoform. Chromatin immunoprecipitation revealed evidence of histone methylation, but not of deacetylation, in the silencing of FGFR2 in AtT20 cells. Exposure of these cells to the cognate FGFR2-IIIb ligand FGF-7 resulted in diminished Rb phosphorylation and accumulation of p21 and p27, indicating diminished cell cycle progression. Examination of primary human pituitary adenomas revealed FGFR2 down-regulation in 52% (11 of 21) of samples and FGFR2 promoter DNA methylation in 45% (10 of 22) of samples. These data highlight the contribution from DNA and histone methylation as epigenetic mechanisms responsible for FGFR2 silencing in pituitary neoplasia.     

Brief communication The primate MHC contains sequences related to the fibroblast growth factor receptor gene family

We have cloned and sequenced a genomic region centromeric of the HLA-B locus from different MHC ancestral haplotypes. These haplotypes are associated with several diseases. The sequences were analyzed for coding potential and their relevance to disease associations were assessed with respect to the level of polymorphism. Analysis of sequences located approximately 25kb centromeric of HLA-B reveals the existence of fibroblast growth factor receptor related sequences. These sequences designated PERB1 (FGFR6 ) reveal 80% homology, at both nucleic acid and amino acid level, to the immunoglobulin domain 1 (Ig-1) of the human fibroblast growth factor receptor 3 ( FGFR3 ) gene. Amino acid comparison of the Ig-1 domain of PERB1 to those of other FGFR molecules indicates that PERB1 is more closely related to FGFR3 and FGFR5 than to FGFR1 , FGFR2 or FGFR4 . Genomic sequence analysis, however, reveals no consensus splice sites and indicates the existence of inframe premature stop codons in the putative coding sequences. The results suggest that these sequences may represent FGFR gene fragments existing within the central MHC. Sequence analysis of the Mhc in 6 chimpanzee and one orangutan indicates that the existence of PERB 1 predates the spe-ciation of the three species. The fact that the MHC contains a mixture of functional and nonfunctional (pseudo) genes suggests that a functional copy of PERB1 (FGFR6 ) may exist within or in close proximity to the MHC.     

Sorting polyclonal antibodies into functionally distinct fractions using peptide phage display: 'a library on top of a library'

A general approach for sorting antibodies (Abs) to a restricted protein domain was developed using phage-displayed peptide libraries. The method is demonstrated by fractionating polyclonal antibodies (pAbs), raised against a short peptide derived from the extracellular, juxtamembrane region of fibroblast growth factor receptor 1 (FGFR1) into fractions with distinct chemical and biological characteristics. Screening two combinatorial peptide libraries, with the pAb, several sequences, homologous to different regions within the original peptide, were identified. Four of the corresponding peptides were synthesized and used as peptide-conjugated affinity columns for the fractionation of the pAbs. The fractions obtained were unique in their recognition patterns and in their capacity to immunoprecipitate and immunoblot, as well as to modulate the activity of FGFR1. This technique is, therefore, highly sufficient in separating pAbs to monospecific fractions and may also be used for fine mapping of different, even overlapping, sequences within a restricted peptide or protein domain.     

Endocytosis and Transport of Growth Factor Receptors in Peripheral Axon Regeneration: Novel Lessons from Neurons Expressing Lysine-Deficient FGF Receptor Type 1 in vitro

In the course of peripheral nerve regeneration, axons encounter different extracellular growth factors secreted by non-neuronal cells at the injury site and retrogradely transported after binding to neuronal membrane receptor tyrosine kinases. The present study reviews the role of receptor transport in peripheral axon outgrowth and provides novel data on trafficking of fibroblast growth factor receptor type 1 (FGFR1). Differences in receptor transport are determined by different numbers of lysine residues acting as ubiquitination sites in the intracellular receptor domain. We previously demonstrated that overexpression of mutant FGFR1-25R (25 out of 29 intracellular lysines replaced with arginine) results in enhanced receptor recycling as compared to wild-type FGFR1 followed by strong stimulation of elongative axon growth in vitro. Here, the effects of lysine-deficient FGFR1 (FGFR1-29R lacking all 29 cytoplasmic lysine residues) or of only 15 lysine mutations (FGFR1-15R) on axon outgrowth and concomitant changes in signal pathway activation were investigated by immunocytochemistry and morphometry of cultured primary neurons. Overexpression of FGFR1-15R in adult sensory neurons resulted in enhanced receptor recycling, which was accompanied by increased axon elongation without stimulating axon branching. By contrast, FGFR1-29R was neither endocytosed nor axon outgrowth affected. Although overexpression of FGFR1-15R or FGFR1-25Ra strongly promoted elongation, we did not detect increased signal pathway activation (ERK, AKT, PLC, or STAT3) in neurons expressing mutant FGFR1 as compared with wild-type neurons raising the possibility that other signaling pathways or signaling independent mechanisms may be involved in the axon outgrowth effects of recycled FGF receptors. Anat Rec, 302:1268–1275, 2019. © 2019 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.