Fgf9 signalling stimulates Spred and Sprouty expression in embryonic mouse pancreas mesenchyme
Section snippets
Embryonic mouse pancreas mesenchyme express FGF receptor IIIc splice forms and Fgf9
To begin to understand the potential for mesenchymal Fgf signalling we first analyzed the expression of FGFR splice forms and candidate Fgf ligands in embryonic mouse pancreas epithelium and mesenchyme by qPCR. We separated E11.5 dorsal pancreatic epithelia from their surrounding mesenchyme and isolated RNA from both fractions, which was subsequently processed for qPCR analysis. To determine the purity of each fraction we analyzed the expression of epithelium-specific markers (Cdh1
Discussion
To investigate the possible involvement of Spred and Sprouty members in murine pancreas development, we undertook a PCR screen for all known members of this family. Among them, Spry2 and Spred1 were the most highly expressed as measured by qPCR and the only ones detectable at the protein level. By two independent methods of separation, we found their expression to be preferentially localized to the pancreatic mesenchyme. The same pattern of expression has been described for Spred genes in the
Mice
Pdx1-eGFP transgenic mice were generated by pronuclear microinjection of a 6.3 kb-long transgene, which was cloned by replacing the Cre coding region of Pdx1-Cre (Herrera, 2000) by the coding sequence of eGFP. Two different families were established from separate founder mice, displaying the same phenotype. Only one was used in these studies.
Culture of pancreatic buds
Dorsal pancreatic rudiments were dissected from embryonic day (E)11.5 NMRI mice, and cultivated in 40 μl hanging drops. Culture medium was DMEM/F12 + Glutamax
Acknowledgements
We thank Heidi Ingemann Jensen and Søren Refsgaard Lindskog for excellent technical support, R. Scott Heller and members of Department of Developmental Biology for critical reading of the manuscript. We want to thank K. Schuh and A. Yoshimura for sharing of antibodies and plasmids. This work was made possible by support from the EU 6th Framework Program (to P.S.).
References (29)
- et al.
Sonic hedgehog directs specialised mesoderm differentiation in the intestine and pancreas
Curr. Biol.
(1997) - et al.
FGFR1-IIIb is a putative marker of pancreatic progenitor cells
Mech. Dev.
(2002) - et al.
Epitheliomesenchymal interaction in pancreatic morphogenesis
Dev. Biol.
(1962) - et al.
Expression of Spred and Sprouty in developing rat lung
Mech. Dev.
(2002) - et al.
Evolution of the Fgf and Fgfr gene families
Trends Genet.
(2004) - et al.
Evidence that SPROUTY2 functions as an inhibitor of mouse embryonic lung growth and morphogenesis
Mech. Dev.
(2001) - et al.
FGF10 signaling maintains the pancreatic progenitor cell state revealing a novel role of Notch in organ development
Dev. Biol.
(2003) - et al.
Receptor specificity of the fibroblast growth factor family
J. Biol. Chem.
(1996) - et al.
ERK pathway positively regulates the expression of Sprouty genes
Biochem. Biophys. Res. Commun.
(2001) - et al.
Early pancreas organogenesis: morphogenesis, tissue interactions, and mass effects
Dev. Biol.
(1967)
Receptor specificity of the fibroblast growth factor family. The complete mammalian FGF family
J. Biol. Chem.
Fgf10 is essential for maintaining the proliferative capacity of epithelial progenitor cells during early pancreatic organogenesis
Development
Genomic organization and embryonic expression of the mouse fibroblast growth factor 9 gene
Dev. Dyn.
Lung hypoplasia and neonatal death in Fgf9-null mice identify this gene as an essential regulator of lung mesenchyme
Development
Cited by (19)
Mesodermal induction of pancreatic fate commitment
2019, Seminars in Cell and Developmental BiologyCitation Excerpt :Together with pancreatic mesenchyme being unperturbed by Fgf10 deficiency and exogenous Fgf10 being able to rescue growth of both pancreatic buds in explanted E9.5 Fgf10−/− guts, this suggests that mesenchymal Fgf10 acts as a mitogen for the bud-stage pancreatic endoderm [60]. This is consistent with the cognate receptor, Fgfr2b, being expressed by the primary transition pancreatic endoderm [100–102]. However, the more mild pancreatic hypoplasia of Fgfr2b−/− mice [103,104] implies that Fgf10 signaling is not transduced exclusively through Fgfr2b during early pancreatic morphogenesis.
Quantification of type II procollagen splice forms using alternative transcript-qPCR (AT-qPCR)
2012, Matrix BiologyCitation Excerpt :There are few practical methods for the routine quantitative analysis of alternative mRNA splice forms. Most commonly, PCR-based, co-amplification approaches, generating multiple PCR products have been used, with primers that flank alternative exon–exon junctions (Kafert et al., 1999; Dalski et al., 2000; Davis-Taber et al., 2000; Favy et al., 2000; Brown et al., 2004; Connell et al., 2005; Meidan et al., 2005; Yoong et al., 2005; Nygard et al., 2010; Long et al., 2011; Sylvestersen et al., 2011). Although convenient, the co-amplification approach, is semi-quantitative at best, and may under- or over-estimate relative quantities of alternative splice forms.
Signaling pathways regulating murine pancreatic development
2012, Seminars in Cell and Developmental BiologyCitation Excerpt :FGF10 (and FGF7) signaling to FGFR2b induces pancreatic epithelial proliferation, both in vitro and in vivo. Moreover, exogenous FGF's suppresses endocrine development and enhances the development of amylase-positive cells in explant cultures suggesting that FGF10 signaling biases the epithelium towards an acinar fate [10–12]. Similarly, two groups showed that ectopic Fgf10 expression driven by the Pdx1 promoter results in enhanced proliferation of undifferentiated pancreatic epithelial cells, while suppressing both endocrine and exocrine differentiation [13,14].