Expression of the murine fibroblast growth factor 5 gene in the adult central nervous system.

Abstract

The murine homolog of the fibroblast growth factor-5 (FGF-5) gene has been cloned, and the sequence of the gene's three exons has been determined. The murine gene and the previously isolated human FGF-5 gene are substantially homologous within the coding sequences and in upstream sequences, which contain an additional open reading frame. We have used a portion of the murine gene as probe to detect FGF-5 RNA in adult mouse tissues by both Northern blot and in situ hybridization methods. FGF-5 RNA is present at low levels in widely distributed areas of the central nervous system. Several loci of FGF-5 expression could be localized by in situ hybridization and include portions of the cerebral cortex, hippocampus, and thalamus. Neuronal expression accounts for at least some of the FGF-5 RNA synthesized in the central nervous system. Fibroblast growth factors (FGFs) constitute a family of mitogenic proteins with related primary structures. Each mammalian factor, of which seven are now known, is encoded by a distinct gene (1)(2)(3)(4)(5)(6)(7)(8). FGFs are mitogenic towards a broad spectrum of mesodermal and ectodermal cells (9) and can act also as inducers (10-13) and inhibitors (14) of developmental pathways. Fibroblasts and endothelial cells can respond to several different FGFs (9). By contrast, keratinocyte growth factor, the most recently characterized FGF, does not stimulate fibroblast growth (15). Hence, FGFs may have overlapping but distinct spectra of activities.FGF-5 is a growth factor discovered in our laboratory as the product of a human oncogene detected by DNA transfection assays (6, 16). The protein is mitogenic towards fibroblasts and endothelial cells in vitro (6), but the natural targets for FGF-5 action in vivo have yet to be ascertained. As a first step towards an understanding of Genomic Library Screening. Murine NIH 3T3 DNA partially digested with Sau3aI was cloned into EMBL4 A phage DNA to generate one library, while another consisting of mouse spleen DNA cloned into A phage EMBL3 was obtained from F. Costantini. Libraries were screened by a standard procedure (17) using as probe human FGF-5 cDNA (6) labeled with 32P by random hexamer priming (18 RNA Filter Blot Hybridization. Tissues were dissected from 8-week-old C57BL/6 mice, and the RNA was isolated after solubilization in guanidinium isothiocyanate (21). RNA was also isolated from seven components of brain dissected by standard procedure (22). RNA filter blot hybridization after agarose gel electrophoresis followed a standard protocol (23) using a 32P-labeled Pst I/Sac I 450-bp DNA fragment containing exon 3 of the murine FGF-5 gene (see Fig. 1 *The sequences reported in this paper have been deposited in the GenBank data base (accession nos. M37821-4 for the murine FGF-5 gene and M37825 for the corrected human FGF-5 cDNA). 8022The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this f...

Fibroblast growth factor-5 stimulates mitogenic signaling and is overexpressed in human pancreatic cancer: evidence for autocrine and paracrine actions

“…A 306 bp BamHI/HindIII cDNA fragment, corresponding to nt 128 to 433 of the human FGF-5 cDNA sequence (Haub et al, 1990), was generated by RT ± PCR from human placenta RNA. The primers used for the FGF-5 cDNA preparation were: 5'-CTC-GGATCCGCGGCTG-GAAGAATGA corresponding to nt 128 to 143 of the human FGF-5 cDNA, and 5'-GCG-AAGCTTACC-GATGCCCACTCTGCA corresponding to nt 416 to 433.…”

Pattern of keratinocyte growth factor and keratinocyte growth factor receptor expression during mouse fetal development suggests a role in mediating morphogenetic mesenchymal‐epithelial interactions

“…In particular, various members of the fibroblast growth factor (FGF) gene family have been implicated in mesoderm induction in amphibians, and appear to play a role in early pattern formation (Kimelman and Kirschner, 1987;Slack et al, 1987;Paterno et al, 1989). Furthermore, expression of these genes in later stages of mouse embryonic development implies a role in tissue differentiation and organogenesis (Wilkinson et al, 1989;Hebert et al, 1990;Haub and Goldfarb, 1991;Niswander and Martin, 1992;Drucker and Goldfarb, 1993;deLapeyriere et al, 1993). However, since most of the FGF family members have broad target cell specificities, and are expressed by multiple cell types, it is unclear what role they may play in the induction of specific epithelial components by the mesenchyme.…”

Evidence that fibroblast growth factor 5 is a major muscle-derived survival factor for cultured spinal motoneurons

“…Indeed, the most prominent embryonic expression of FGF-5 mRNA beyond gastrulation in the mouse occurs at E12.5-E14.5 in a patch of mesenchyme at the base of the hindlimb (Haub and Goldfarb, 1991). It may be that FGF-5 protein similarly expressed in the developing rat is deposited in the surrounding muscle and thus contributes to the observed FGF-5-like activity in E17 muscle extracts.…”

“…The membranes were hybridized overnight in 50% formamide as described (Castren et aI., 1992) with a 500 bp cRNA probe to FGF-S. The probe (specific activity 10" cpm/Ilg) wa~ made by run-on transcription of a pBluescript SK+ vector containing a 2.2 kb mouse Fgf-S cDNA fragment (Haub and Goldfarb, 1991) linear· ized with BglIl.…”

“…FGF-5 contains a hydrophobic N-terminal leader sequence typical of a secreted protein (Zhan et al, 1988) and is released into the medium of transformed NIH 3T3 cells . mRNA for FGF-5 can be found prior to gastrulation in mouse embryos, suggesting that this factor may have an important function during very early stages of embryonic development (Hebert et al, 1991;Haub and Goldfarb, 1991). We demonstrate here that recombinant human FGF-5 is able to support the survival of chick spinal motoneurons in culture and that both FGF-5 50 mRNA and immunoprecipitable activity are present in embryonic rat skeletal muscle during the period of naturally occurring motoneuron death as well as in adult muscle.…”