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Saverio Bellusci - One of the best experts on this subject based on the ideXlab platform.
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FGF10 identifies early lipofibroblast progenitors and controls their fate during embryonic lung development
European Respiratory Journal, 2013Co-Authors: Denise Al Alam, Elie El Agha, Virender K. Rehan, Soula Danopoulos, Saverio BellusciAbstract:Introduction: Lipofibroblasts (LIFs) are lipid-containing fibroblasts found in the late fetal and postnatal lung parenchyma. LIFs assimilate lipids and transfer triglycerides to adjacent alveolar epithelial type II cells to elaborate surfactant. Aims: Although LIFs have been studied in postnatal lungs, their cellular origin and mechanism of differentiation are unknown. We aim to determine the origin of LIFs and the molecular pathway that control their fate. Methods: Using FGF10-LacZ and FGF10iCre mouse lines, we analyzed the expression of LIFs markers in the FGF10-positive cells in situ and after sorting. In addition, we used in vivo knockdown of FGFR2b ligand activity from E14.5 to E18.5 and FGF10 hypomorphs as well as in vitro models (WI-38, NIH3T3-L1 cell lines and primary cultures of fibroblasts) to test whether FGF10 is capable on acting directly on the mesenchyme to promote LIFs differentiation. Results: We demonstrated that LIFs express FGF10 and that FGF10-positive cells permanently labeled at embryonic days E11.5 or E15.5 give rise to LIFs. In addition, in vivo knockdown of FGFR2b ligand activity as well as reduction of FGF10 expression led to decreased expression of LIF markers at E18.5. Using primary culture of lung mesenchyme as well as WI-38 human LIF progenitor cells and NIH3T3-L1 adipocyte progenitor cells, we demonstrate that recombinant FGF10 is capable of directly acting on the mesenchyme to trigger the commitment of these cells to the adipogenic lineage. Moreover, FGF10 also antagonizes TGFβ1-induced myofibroblast transdifferentiation of FGF10-positive cells. Conclusion: Our results demonstrate the essential role of FGF10 signaling in LIF formation.
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Characterization of a Novel Fibroblast Growth Factor 10 (FGF10) Knock-In Mouse Line to Target Mesenchymal Progenitors during Embryonic Development
PloS one, 2012Co-Authors: Elie El Agha, Stijn De Langhe, Denise Al Alam, Gianni Carraro, Breanne Mackenzie, Kerstin Goth, Robert Voswinckel, Mohammad K. Hajihosseini, Virender K. Rehan, Saverio BellusciAbstract:Fibroblast growth factor 10 (FGF10) is a key regulator of diverse organogenetic programs during mouse development, particularly branching morphogenesis. FGF10-null mice suffer from lung and limb agenesis as well as cecal and colonic atresia and are thus not viable. To date, the Mlcv1v-nLacZ-24 transgenic mouse strain (referred to as FGF10(LacZ)), which carries a LacZ insertion 114 kb upstream of exon 1 of FGF10 gene, has been the only strain to allow transient lineage tracing of FGF10-positive cells. Here, we describe a novel FGF10(Cre-ERT2) knock-in line (FGF10(iCre)) in which a Cre-ERT2-IRES-YFP cassette has been introduced in frame with the ATG of exon 1 of FGF10 gene. Our studies show that Cre-ERT2 insertion disrupts FGF10 function. However, administration of tamoxifen to FGF10(iCre); Tomato(flox) double transgenic embryos or adult mice results in specific labeling of FGF10-positive cells, which can be lineage-traced temporally and spatially. Moreover, we show that the FGF10(iCre) line can be used for conditional gene inactivation in an inducible fashion during early developmental stages. We also provide evidence that transcription factors located in the first intron of FGF10 gene are critical for maintaining FGF10 expression over time. Thus, the FGF10(iCre) line should serve as a powerful tool to explore the functions of FGF10 in a controlled and stage-specific manner.
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FGF10 expression identifies parabronchial smooth muscle cell progenitors and is required for their entry into the smooth muscle cell lineage.
Development (Cambridge England), 2005Co-Authors: Arnaud Mailleux, Stijn De Langhe, Jacqueline M. Veltmaat, Stéphane Zaffran, Robert Kelly, Jean Paul Thiery, Saverio BellusciAbstract:Lineage formation in the lung mesenchyme is poorly understood. Using a transgenic mouse line expressing LacZ under the control of FGF10 regulatory sequences, we show that the pool of FGF10 -positive cells in the distal lung mesenchyme contains progenitors of the parabronchial smooth muscle cells. FGF10 gene expression is slightly repressed in this transgenic line. This allowed us to create a hypomorphic FGF10 phenotype by expressing the LacZ transgene in a heterozygous FGF10 background. Hypomorphic FGF10 mutant lungs display a decrease inβ -galactosidase-positive cells around the bronchial epithelium associated with an accumulation of β-galactosidase-expressing cells in the distal mesenchyme. This correlates with a marked reduction of α smooth muscle actin expression, thereby demonstrating that FGF10 is mostly required for the entry of mesenchymal cells into the parabronchial smooth muscle cell lineage. The failure of exogenous FGF10 to phosphorylate its known downstream targets ERK and AKT in lung mesenchymal cultures strongly suggests that FGF10 acts indirectly on the progenitor population via an epithelial intermediate. We provide support for a role of epithelial BMP4 in mediating the formation of parabronchial smooth muscle cells.
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fibroblast growth factor 10 FGF10 invalidation results in anorectal malformation in mice
Journal of Pediatric Surgery, 2004Co-Authors: Timothy J Fairbanks, Frederic G. Sala, Kathryn D Anderson, Stijn De Langhe, Saverio Bellusci, David Warburton, Cartland R BurnsAbstract:Abstract Background/purpose Anorectal malformations occur in 1 per 4,000 live births and represent a surgical challenge. Although critically important, the basic mechanisms of normal anorectal union are incompletely understood. FGF10 signaling is known to serve a key role in mesenchymal/epithelial interactions in many organ systems including the gastrointestinal tract (GIT). The authors therefore hypothesized that FGF10 signaling has a central role in normal anorectal development. Methods FGF10 expression in wild-type (Wt) embryos was evaluated using whole-mount in situ hybridization. Wt and FGF10 −/− embryos were harvested from timed pregnant mothers at E12.5 through E17.5 and were analyzed for anorectal phenotype. Results Wt development of union between anorectal structures is completed between E12.5 and E13.5 with luminal communication between distal rectal epithelium and anus. FGF10 is discreetly expressed at E12.5 in the distal rectum. FGF10 −/− mutants show failure of union of the rectum and anus at an early stage (E13.5) and near term (E17.5). Conclusions FGF10 is expressed in the rectum at the time when anorectal continuity is established, indicating a role in normal anorectal development. FGF10 invalidation ( FGF10 −/− mutant) results in a genetically reproducible anorectal malformation phenotype. FGF10 function is critical for normal anorectal development.
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A genetic mechanism for cecal atresia: the role of the FGF10 signaling pathway.
The Journal of surgical research, 2004Co-Authors: Timothy J Fairbanks, Frederic G. Sala, Kathryn D Anderson, Stijn De Langhe, Saverio Bellusci, David Warburton, Robert Kanard, P. M. Del Moral, R.c. BurnsAbstract:Abstract Background Intestinal atresia represents a significant surgically correctable cause of intestinal obstruction in neonates. Intestinal development proceeds as a tube-like structure with differentiation along its axis. As the intestine differentiates, the cecum develops at the transition from small to large intestine. FGF10 is known to serve a key role in budding morphogenesis; however, little is known about its role in the development of this transitional structure. Here we evaluate the effect of FGF10 / Fgfr2b invalidation on the developing cecum. Materials and methods Wild-type C57Bl/6, FGF10 −/− , and Fgfr2b −/− embryos harvested from timed pregnant mothers were analyzed for cecal phenotype, FGF10 expression, and differentiation of smooth muscle actin. Results Wt cecal development is first evident at E11.5. FGF10 is discreetly expressed in the area of the developing cecum at early stages of development. One hundred percent of FGF10 −/− and Fgfr2b −/− mutant embryos demonstrate cecal atresia with absence of epithelial and muscular layers. The development of neighboring anatomical structures such as the ileocecal valve is not affected by FGF10 / Fgfr2b invalidation. Conclusions FGF10 expression is localized to the cecum early in the normal development of the cecum. FGF10 −/− and Fgfr2b −/− mutant embryos demonstrate cecal atresia with complete penetrance. Epithelial and muscular layers of the cecum are not present in the atretic cecum. The FGF10 −/− and Fgfr2b −/− mutants represent a genetically reproducible animal model of autosomal recessive intestinal atresia.
Stijn De Langhe - One of the best experts on this subject based on the ideXlab platform.
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Localized FGF10 expression is not required for lung branching morphogenesis but prevents differentiation of epithelial progenitors
Development (Cambridge England), 2013Co-Authors: Thomas Volckaert, Alice Campbell, Erik Dill, Parviz Minoo, Stijn De LangheAbstract:Localized FGF10 expression in the distal mesenchyme adjacent to sites of lung bud formation has long been thought to drive stereotypic branching morphogenesis even though isolated lung epithelium branches in the presence of non-directional exogenous FGF10 in Matrigel. Here, we show that lung agenesis in FGF10 knockout mice can be rescued by ubiquitous overexpression of FGF10, indicating that precisely localized FGF10 expression is not required for lung branching morphogenesis in vivo. FGF10 expression in the mesenchyme itself is regulated by Wnt signaling. Nevertheless, we found that during lung initiation simultaneous overexpression of FGF10 is not sufficient to rescue the absence of primary lung field specification in embryos overexpressing Dkk1, a secreted inhibitor of Wnt signaling. However, after lung initiation, simultaneous overexpression of FGF10 in lungs overexpressing Dkk1 is able to rescue defects in branching and proximal-distal differentiation. We also show that FGF10 prevents the differentiation of distal epithelial progenitors into Sox2-expressing airway epithelial cells in part by activating epithelial β-catenin signaling, which negatively regulates Sox2 expression. As such, these findings support a model in which the main function of FGF10 during lung development is to regulate proximal-distal differentiation. As the lung buds grow out, proximal epithelial cells become further and further displaced from the distal source of FGF10 and differentiate into bronchial epithelial cells. Interestingly, our data presented here show that once epithelial cells are committed to the Sox2-positive airway epithelial cell fate, FGF10 prevents ciliated cell differentiation and promotes basal cell differentiation.
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Characterization of a Novel Fibroblast Growth Factor 10 (FGF10) Knock-In Mouse Line to Target Mesenchymal Progenitors during Embryonic Development
PloS one, 2012Co-Authors: Elie El Agha, Stijn De Langhe, Denise Al Alam, Gianni Carraro, Breanne Mackenzie, Kerstin Goth, Robert Voswinckel, Mohammad K. Hajihosseini, Virender K. Rehan, Saverio BellusciAbstract:Fibroblast growth factor 10 (FGF10) is a key regulator of diverse organogenetic programs during mouse development, particularly branching morphogenesis. FGF10-null mice suffer from lung and limb agenesis as well as cecal and colonic atresia and are thus not viable. To date, the Mlcv1v-nLacZ-24 transgenic mouse strain (referred to as FGF10(LacZ)), which carries a LacZ insertion 114 kb upstream of exon 1 of FGF10 gene, has been the only strain to allow transient lineage tracing of FGF10-positive cells. Here, we describe a novel FGF10(Cre-ERT2) knock-in line (FGF10(iCre)) in which a Cre-ERT2-IRES-YFP cassette has been introduced in frame with the ATG of exon 1 of FGF10 gene. Our studies show that Cre-ERT2 insertion disrupts FGF10 function. However, administration of tamoxifen to FGF10(iCre); Tomato(flox) double transgenic embryos or adult mice results in specific labeling of FGF10-positive cells, which can be lineage-traced temporally and spatially. Moreover, we show that the FGF10(iCre) line can be used for conditional gene inactivation in an inducible fashion during early developmental stages. We also provide evidence that transcription factors located in the first intron of FGF10 gene are critical for maintaining FGF10 expression over time. Thus, the FGF10(iCre) line should serve as a powerful tool to explore the functions of FGF10 in a controlled and stage-specific manner.
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FGF10 dosage is critical for the amplification of epithelial cell progenitors and for the formation of multiple mesenchymal lineages during lung development.
Developmental biology, 2007Co-Authors: Suresh K. Ramasamy, Frederic G. Sala, Stijn De Langhe, Jacqueline M. Veltmaat, Arnaud Mailleux, Varsha V. Gupte, Francisca Mata, Pierre-marie Del Moral, Sara Parsa, Lisa K. KellyAbstract:The key role played by FGF10 during early lung development is clearly illustrated in FGF10 knockout mice, which exhibit lung agenesis. However, FGF10 is continuously expressed throughout lung development suggesting extended as well as additional roles for FGF10 at later stages of lung organogenesis. We previously reported that the enhancer trap Mlcv1v-nLacZ-24 transgenic mouse strain functions as a reporter for FGF10 expression and displays decreased endogenous FGF10 expression. In this paper, we have generated an allelic series to determine the impact of FGF10 dosage on lung development. We report that 80% of the newborn FGF10 hypomorphic mice die within 24 h of birth due to respiratory failure. These mutant mouse lungs display severe hypoplasia, dilation of the distal airways and large hemorrhagic areas. Epithelial differentiation and proliferation studies indicate a specific decrease in TTF1 and SP-B expressing cells correlating with reduced epithelial cell proliferation and associated with a decrease in activation of the canonical Wnt signaling in the epithelium. Analysis of vascular development shows a reduction in PECAM expression at E14.5, which is associated with a simplification of the vascular tree at E18.5. We also show a decrease in alpha-SMA expression in the respiratory airway suggesting defective smooth muscle cell formation. At the molecular level, these defects are associated with decrease in Vegfa and Pdgfa expression likely resulting from the decrease of the epithelial/mesenchymal ratio in the FGF10 hypomorphic lungs. Thus, our results indicate that FGF10 plays a pivotal role in maintaining epithelial progenitor cell proliferation as well as coordinating alveolar smooth muscle cell formation and vascular development.
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FGF10 expression identifies parabronchial smooth muscle cell progenitors and is required for their entry into the smooth muscle cell lineage.
Development (Cambridge England), 2005Co-Authors: Arnaud Mailleux, Stijn De Langhe, Jacqueline M. Veltmaat, Stéphane Zaffran, Robert Kelly, Jean Paul Thiery, Saverio BellusciAbstract:Lineage formation in the lung mesenchyme is poorly understood. Using a transgenic mouse line expressing LacZ under the control of FGF10 regulatory sequences, we show that the pool of FGF10 -positive cells in the distal lung mesenchyme contains progenitors of the parabronchial smooth muscle cells. FGF10 gene expression is slightly repressed in this transgenic line. This allowed us to create a hypomorphic FGF10 phenotype by expressing the LacZ transgene in a heterozygous FGF10 background. Hypomorphic FGF10 mutant lungs display a decrease inβ -galactosidase-positive cells around the bronchial epithelium associated with an accumulation of β-galactosidase-expressing cells in the distal mesenchyme. This correlates with a marked reduction of α smooth muscle actin expression, thereby demonstrating that FGF10 is mostly required for the entry of mesenchymal cells into the parabronchial smooth muscle cell lineage. The failure of exogenous FGF10 to phosphorylate its known downstream targets ERK and AKT in lung mesenchymal cultures strongly suggests that FGF10 acts indirectly on the progenitor population via an epithelial intermediate. We provide support for a role of epithelial BMP4 in mediating the formation of parabronchial smooth muscle cells.
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fibroblast growth factor 10 FGF10 invalidation results in anorectal malformation in mice
Journal of Pediatric Surgery, 2004Co-Authors: Timothy J Fairbanks, Frederic G. Sala, Kathryn D Anderson, Stijn De Langhe, Saverio Bellusci, David Warburton, Cartland R BurnsAbstract:Abstract Background/purpose Anorectal malformations occur in 1 per 4,000 live births and represent a surgical challenge. Although critically important, the basic mechanisms of normal anorectal union are incompletely understood. FGF10 signaling is known to serve a key role in mesenchymal/epithelial interactions in many organ systems including the gastrointestinal tract (GIT). The authors therefore hypothesized that FGF10 signaling has a central role in normal anorectal development. Methods FGF10 expression in wild-type (Wt) embryos was evaluated using whole-mount in situ hybridization. Wt and FGF10 −/− embryos were harvested from timed pregnant mothers at E12.5 through E17.5 and were analyzed for anorectal phenotype. Results Wt development of union between anorectal structures is completed between E12.5 and E13.5 with luminal communication between distal rectal epithelium and anus. FGF10 is discreetly expressed at E12.5 in the distal rectum. FGF10 −/− mutants show failure of union of the rectum and anus at an early stage (E13.5) and near term (E17.5). Conclusions FGF10 is expressed in the rectum at the time when anorectal continuity is established, indicating a role in normal anorectal development. FGF10 invalidation ( FGF10 −/− mutant) results in a genetically reproducible anorectal malformation phenotype. FGF10 function is critical for normal anorectal development.
Arnaud Mailleux - One of the best experts on this subject based on the ideXlab platform.
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FGF10 dosage is critical for the amplification of epithelial cell progenitors and for the formation of multiple mesenchymal lineages during lung development.
Developmental biology, 2007Co-Authors: Suresh K. Ramasamy, Frederic G. Sala, Stijn De Langhe, Jacqueline M. Veltmaat, Arnaud Mailleux, Varsha V. Gupte, Francisca Mata, Pierre-marie Del Moral, Sara Parsa, Lisa K. KellyAbstract:The key role played by FGF10 during early lung development is clearly illustrated in FGF10 knockout mice, which exhibit lung agenesis. However, FGF10 is continuously expressed throughout lung development suggesting extended as well as additional roles for FGF10 at later stages of lung organogenesis. We previously reported that the enhancer trap Mlcv1v-nLacZ-24 transgenic mouse strain functions as a reporter for FGF10 expression and displays decreased endogenous FGF10 expression. In this paper, we have generated an allelic series to determine the impact of FGF10 dosage on lung development. We report that 80% of the newborn FGF10 hypomorphic mice die within 24 h of birth due to respiratory failure. These mutant mouse lungs display severe hypoplasia, dilation of the distal airways and large hemorrhagic areas. Epithelial differentiation and proliferation studies indicate a specific decrease in TTF1 and SP-B expressing cells correlating with reduced epithelial cell proliferation and associated with a decrease in activation of the canonical Wnt signaling in the epithelium. Analysis of vascular development shows a reduction in PECAM expression at E14.5, which is associated with a simplification of the vascular tree at E18.5. We also show a decrease in alpha-SMA expression in the respiratory airway suggesting defective smooth muscle cell formation. At the molecular level, these defects are associated with decrease in Vegfa and Pdgfa expression likely resulting from the decrease of the epithelial/mesenchymal ratio in the FGF10 hypomorphic lungs. Thus, our results indicate that FGF10 plays a pivotal role in maintaining epithelial progenitor cell proliferation as well as coordinating alveolar smooth muscle cell formation and vascular development.
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Gli3-mediated somitic FGF10 expression gradients are required for the induction and patterning of mammary epithelium along the embryonic axes
Development (Cambridge England), 2006Co-Authors: Jacqueline M. Veltmaat, Frederic G. Sala, Frédéric Relaix, Klaus Kratochwil, Wendy Van Veelen, Ritva Rice, Bradley Spencer-dene, Arnaud Mailleux, David P. RiceAbstract:Little is known about the regulation of cell fate decisions that lead to the formation of five pairs of mammary placodes in the surface ectoderm of the mouse embryo. We have previously shown that fibroblast growth factor 10 (FGF10) is required for the formation of mammary placodes 1, 2, 3 and 5. Here, we have found that FGF10 is expressed only in the somites underlying placodes 2 and 3, in gradients across and within these somites. To test whether somitic FGF10 is required for the formation of these two placodes, we analyzed a number of mutants with different perturbations of somitic FGF10 gradients for the presence of WNT signals and ectodermal multilayering, markers for mammary line and placode formation. The mammary line is displaced dorsally, and formation of placode 3 is impaired in Pax3ILZ/ILZ mutants, which do not form ventral somitic buds. Mammary line formation is impaired and placode 3 is absent in Gli3Xt-J/Xt-J and hypomorphic FGF10 mutants, in which the somitic FGF10 gradient is shortened dorsally and less overall FGF10 is expressed, respectively. Recombinant FGF10 rescued mammogenesis in FGF10(-/-) and Gli3Xt-J/Xt-J flanks. We correlate increasing levels of somitic FGF10 with progressive maturation of the surface ectoderm, and show that full expression of somitic FGF10, co-regulated by GLI3, is required for the anteroposterior pattern in which the flank ectoderm acquires a mammary epithelial identity. We propose that the intra-somitic FGF10 gradient, together with ventral elongation of the somites, determines the correct dorsoventral position of mammary epithelium along the flank.
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FGF10 expression identifies parabronchial smooth muscle cell progenitors and is required for their entry into the smooth muscle cell lineage.
Development (Cambridge England), 2005Co-Authors: Arnaud Mailleux, Stijn De Langhe, Jacqueline M. Veltmaat, Stéphane Zaffran, Robert Kelly, Jean Paul Thiery, Saverio BellusciAbstract:Lineage formation in the lung mesenchyme is poorly understood. Using a transgenic mouse line expressing LacZ under the control of FGF10 regulatory sequences, we show that the pool of FGF10 -positive cells in the distal lung mesenchyme contains progenitors of the parabronchial smooth muscle cells. FGF10 gene expression is slightly repressed in this transgenic line. This allowed us to create a hypomorphic FGF10 phenotype by expressing the LacZ transgene in a heterozygous FGF10 background. Hypomorphic FGF10 mutant lungs display a decrease inβ -galactosidase-positive cells around the bronchial epithelium associated with an accumulation of β-galactosidase-expressing cells in the distal mesenchyme. This correlates with a marked reduction of α smooth muscle actin expression, thereby demonstrating that FGF10 is mostly required for the entry of mesenchymal cells into the parabronchial smooth muscle cell lineage. The failure of exogenous FGF10 to phosphorylate its known downstream targets ERK and AKT in lung mesenchymal cultures strongly suggests that FGF10 acts indirectly on the progenitor population via an epithelial intermediate. We provide support for a role of epithelial BMP4 in mediating the formation of parabronchial smooth muscle cells.
Jacqueline M. Veltmaat - One of the best experts on this subject based on the ideXlab platform.
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FGF10 dosage is critical for the amplification of epithelial cell progenitors and for the formation of multiple mesenchymal lineages during lung development.
Developmental biology, 2007Co-Authors: Suresh K. Ramasamy, Frederic G. Sala, Stijn De Langhe, Jacqueline M. Veltmaat, Arnaud Mailleux, Varsha V. Gupte, Francisca Mata, Pierre-marie Del Moral, Sara Parsa, Lisa K. KellyAbstract:The key role played by FGF10 during early lung development is clearly illustrated in FGF10 knockout mice, which exhibit lung agenesis. However, FGF10 is continuously expressed throughout lung development suggesting extended as well as additional roles for FGF10 at later stages of lung organogenesis. We previously reported that the enhancer trap Mlcv1v-nLacZ-24 transgenic mouse strain functions as a reporter for FGF10 expression and displays decreased endogenous FGF10 expression. In this paper, we have generated an allelic series to determine the impact of FGF10 dosage on lung development. We report that 80% of the newborn FGF10 hypomorphic mice die within 24 h of birth due to respiratory failure. These mutant mouse lungs display severe hypoplasia, dilation of the distal airways and large hemorrhagic areas. Epithelial differentiation and proliferation studies indicate a specific decrease in TTF1 and SP-B expressing cells correlating with reduced epithelial cell proliferation and associated with a decrease in activation of the canonical Wnt signaling in the epithelium. Analysis of vascular development shows a reduction in PECAM expression at E14.5, which is associated with a simplification of the vascular tree at E18.5. We also show a decrease in alpha-SMA expression in the respiratory airway suggesting defective smooth muscle cell formation. At the molecular level, these defects are associated with decrease in Vegfa and Pdgfa expression likely resulting from the decrease of the epithelial/mesenchymal ratio in the FGF10 hypomorphic lungs. Thus, our results indicate that FGF10 plays a pivotal role in maintaining epithelial progenitor cell proliferation as well as coordinating alveolar smooth muscle cell formation and vascular development.
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Gli3-mediated somitic FGF10 expression gradients are required for the induction and patterning of mammary epithelium along the embryonic axes
Development (Cambridge England), 2006Co-Authors: Jacqueline M. Veltmaat, Frederic G. Sala, Frédéric Relaix, Klaus Kratochwil, Wendy Van Veelen, Ritva Rice, Bradley Spencer-dene, Arnaud Mailleux, David P. RiceAbstract:Little is known about the regulation of cell fate decisions that lead to the formation of five pairs of mammary placodes in the surface ectoderm of the mouse embryo. We have previously shown that fibroblast growth factor 10 (FGF10) is required for the formation of mammary placodes 1, 2, 3 and 5. Here, we have found that FGF10 is expressed only in the somites underlying placodes 2 and 3, in gradients across and within these somites. To test whether somitic FGF10 is required for the formation of these two placodes, we analyzed a number of mutants with different perturbations of somitic FGF10 gradients for the presence of WNT signals and ectodermal multilayering, markers for mammary line and placode formation. The mammary line is displaced dorsally, and formation of placode 3 is impaired in Pax3ILZ/ILZ mutants, which do not form ventral somitic buds. Mammary line formation is impaired and placode 3 is absent in Gli3Xt-J/Xt-J and hypomorphic FGF10 mutants, in which the somitic FGF10 gradient is shortened dorsally and less overall FGF10 is expressed, respectively. Recombinant FGF10 rescued mammogenesis in FGF10(-/-) and Gli3Xt-J/Xt-J flanks. We correlate increasing levels of somitic FGF10 with progressive maturation of the surface ectoderm, and show that full expression of somitic FGF10, co-regulated by GLI3, is required for the anteroposterior pattern in which the flank ectoderm acquires a mammary epithelial identity. We propose that the intra-somitic FGF10 gradient, together with ventral elongation of the somites, determines the correct dorsoventral position of mammary epithelium along the flank.
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FGF10 expression identifies parabronchial smooth muscle cell progenitors and is required for their entry into the smooth muscle cell lineage.
Development (Cambridge England), 2005Co-Authors: Arnaud Mailleux, Stijn De Langhe, Jacqueline M. Veltmaat, Stéphane Zaffran, Robert Kelly, Jean Paul Thiery, Saverio BellusciAbstract:Lineage formation in the lung mesenchyme is poorly understood. Using a transgenic mouse line expressing LacZ under the control of FGF10 regulatory sequences, we show that the pool of FGF10 -positive cells in the distal lung mesenchyme contains progenitors of the parabronchial smooth muscle cells. FGF10 gene expression is slightly repressed in this transgenic line. This allowed us to create a hypomorphic FGF10 phenotype by expressing the LacZ transgene in a heterozygous FGF10 background. Hypomorphic FGF10 mutant lungs display a decrease inβ -galactosidase-positive cells around the bronchial epithelium associated with an accumulation of β-galactosidase-expressing cells in the distal mesenchyme. This correlates with a marked reduction of α smooth muscle actin expression, thereby demonstrating that FGF10 is mostly required for the entry of mesenchymal cells into the parabronchial smooth muscle cell lineage. The failure of exogenous FGF10 to phosphorylate its known downstream targets ERK and AKT in lung mesenchymal cultures strongly suggests that FGF10 acts indirectly on the progenitor population via an epithelial intermediate. We provide support for a role of epithelial BMP4 in mediating the formation of parabronchial smooth muscle cells.
Frederic G. Sala - One of the best experts on this subject based on the ideXlab platform.
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FGF10 overexpression enhances the formation of tissue engineered small intestine
Journal of Tissue Engineering and Regenerative Medicine, 2016Co-Authors: Yasuhiro Torashima, Frederic G. Sala, Daniel E. Levin, Erik R. Barthel, Allison L. Speer, Xiaogang Hou, Tracy C. GrikscheitAbstract:Short bowel syndrome (SBS) is a morbid and mortal condition characterized in most patients by insufficient intestinal surface area. Current management strategies are inadequate, but tissue-engineered small intestine (TESI) offers a potential therapy. A barrier to translation of TESI is the generation of scalable mucosal surface area to significantly increase nutritional absorption. Fibroblast growth factor 10 (FGF10) is a critical growth factor essential for the development of the gastrointestinal tract. We hypothesized that overexpression of FGF10 would improve the generation of TESI. Organoid units, the multicellular donor tissue that forms TESI, were derived from Rosa26(rtTA/+), tet(o)FGF10/(-) or FGF10(Mlc-nlacZ-v24) (hereafter called FGF10(lacZ)) mice. These were implanted into the omentum of NOD/SCID γ-chain-deficient mice and induced with doxycycline in the case of tet(o)FGF10/(-). Resulting TESI were explanted at 4 weeks and studied by histology, quantitative RT-PCR and immunofluorescence. Four weeks after implantation, FGF10 overexpressing TESI was larger and weighed more than the control tissues. Within the mucosa, the villus height was significantly longer and crypts contained a greater percentage of proliferating epithelial cells. A fully differentiated intestinal epithelium with enterocytes, goblet cells, enteroendocrine cells and Paneth cells was identified in the FGF10-overexpressing TESI, comparable to native small intestine. β-Galactosidase expression was found in both the epithelium and the mesenchyme of the TESI derived from the FGF10(LacZ) duodenum. However, this was not the case with TESI generated from jejunum and ileum. We conclude that FGF10 enhances the formation of TESI.
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FGF10 overexpression enhances the formation of tissue‐engineered small intestine
Journal of tissue engineering and regenerative medicine, 2013Co-Authors: Yasuhiro Torashima, Frederic G. Sala, Daniel E. Levin, Erik R. Barthel, Allison L. Speer, Xiaogang Hou, Tracy C. GrikscheitAbstract:Short bowel syndrome (SBS) is a morbid and mortal condition characterized in most patients by insufficient intestinal surface area. Current management strategies are inadequate, but tissue-engineered small intestine (TESI) offers a potential therapy. A barrier to translation of TESI is the generation of scalable mucosal surface area to significantly increase nutritional absorption. Fibroblast growth factor 10 (FGF10) is a critical growth factor essential for the development of the gastrointestinal tract. We hypothesized that overexpression of FGF10 would improve the generation of TESI. Organoid units, the multicellular donor tissue that forms TESI, were derived from Rosa26(rtTA/+), tet(o)FGF10/(-) or FGF10(Mlc-nlacZ-v24) (hereafter called FGF10(lacZ)) mice. These were implanted into the omentum of NOD/SCID γ-chain-deficient mice and induced with doxycycline in the case of tet(o)FGF10/(-). Resulting TESI were explanted at 4 weeks and studied by histology, quantitative RT-PCR and immunofluorescence. Four weeks after implantation, FGF10 overexpressing TESI was larger and weighed more than the control tissues. Within the mucosa, the villus height was significantly longer and crypts contained a greater percentage of proliferating epithelial cells. A fully differentiated intestinal epithelium with enterocytes, goblet cells, enteroendocrine cells and Paneth cells was identified in the FGF10-overexpressing TESI, comparable to native small intestine. β-Galactosidase expression was found in both the epithelium and the mesenchyme of the TESI derived from the FGF10(LacZ) duodenum. However, this was not the case with TESI generated from jejunum and ileum. We conclude that FGF10 enhances the formation of TESI.
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FGF10 dosage is critical for the amplification of epithelial cell progenitors and for the formation of multiple mesenchymal lineages during lung development.
Developmental biology, 2007Co-Authors: Suresh K. Ramasamy, Frederic G. Sala, Stijn De Langhe, Jacqueline M. Veltmaat, Arnaud Mailleux, Varsha V. Gupte, Francisca Mata, Pierre-marie Del Moral, Sara Parsa, Lisa K. KellyAbstract:The key role played by FGF10 during early lung development is clearly illustrated in FGF10 knockout mice, which exhibit lung agenesis. However, FGF10 is continuously expressed throughout lung development suggesting extended as well as additional roles for FGF10 at later stages of lung organogenesis. We previously reported that the enhancer trap Mlcv1v-nLacZ-24 transgenic mouse strain functions as a reporter for FGF10 expression and displays decreased endogenous FGF10 expression. In this paper, we have generated an allelic series to determine the impact of FGF10 dosage on lung development. We report that 80% of the newborn FGF10 hypomorphic mice die within 24 h of birth due to respiratory failure. These mutant mouse lungs display severe hypoplasia, dilation of the distal airways and large hemorrhagic areas. Epithelial differentiation and proliferation studies indicate a specific decrease in TTF1 and SP-B expressing cells correlating with reduced epithelial cell proliferation and associated with a decrease in activation of the canonical Wnt signaling in the epithelium. Analysis of vascular development shows a reduction in PECAM expression at E14.5, which is associated with a simplification of the vascular tree at E18.5. We also show a decrease in alpha-SMA expression in the respiratory airway suggesting defective smooth muscle cell formation. At the molecular level, these defects are associated with decrease in Vegfa and Pdgfa expression likely resulting from the decrease of the epithelial/mesenchymal ratio in the FGF10 hypomorphic lungs. Thus, our results indicate that FGF10 plays a pivotal role in maintaining epithelial progenitor cell proliferation as well as coordinating alveolar smooth muscle cell formation and vascular development.
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Gli3-mediated somitic FGF10 expression gradients are required for the induction and patterning of mammary epithelium along the embryonic axes
Development (Cambridge England), 2006Co-Authors: Jacqueline M. Veltmaat, Frederic G. Sala, Frédéric Relaix, Klaus Kratochwil, Wendy Van Veelen, Ritva Rice, Bradley Spencer-dene, Arnaud Mailleux, David P. RiceAbstract:Little is known about the regulation of cell fate decisions that lead to the formation of five pairs of mammary placodes in the surface ectoderm of the mouse embryo. We have previously shown that fibroblast growth factor 10 (FGF10) is required for the formation of mammary placodes 1, 2, 3 and 5. Here, we have found that FGF10 is expressed only in the somites underlying placodes 2 and 3, in gradients across and within these somites. To test whether somitic FGF10 is required for the formation of these two placodes, we analyzed a number of mutants with different perturbations of somitic FGF10 gradients for the presence of WNT signals and ectodermal multilayering, markers for mammary line and placode formation. The mammary line is displaced dorsally, and formation of placode 3 is impaired in Pax3ILZ/ILZ mutants, which do not form ventral somitic buds. Mammary line formation is impaired and placode 3 is absent in Gli3Xt-J/Xt-J and hypomorphic FGF10 mutants, in which the somitic FGF10 gradient is shortened dorsally and less overall FGF10 is expressed, respectively. Recombinant FGF10 rescued mammogenesis in FGF10(-/-) and Gli3Xt-J/Xt-J flanks. We correlate increasing levels of somitic FGF10 with progressive maturation of the surface ectoderm, and show that full expression of somitic FGF10, co-regulated by GLI3, is required for the anteroposterior pattern in which the flank ectoderm acquires a mammary epithelial identity. We propose that the intra-somitic FGF10 gradient, together with ventral elongation of the somites, determines the correct dorsoventral position of mammary epithelium along the flank.
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fibroblast growth factor 10 FGF10 invalidation results in anorectal malformation in mice
Journal of Pediatric Surgery, 2004Co-Authors: Timothy J Fairbanks, Frederic G. Sala, Kathryn D Anderson, Stijn De Langhe, Saverio Bellusci, David Warburton, Cartland R BurnsAbstract:Abstract Background/purpose Anorectal malformations occur in 1 per 4,000 live births and represent a surgical challenge. Although critically important, the basic mechanisms of normal anorectal union are incompletely understood. FGF10 signaling is known to serve a key role in mesenchymal/epithelial interactions in many organ systems including the gastrointestinal tract (GIT). The authors therefore hypothesized that FGF10 signaling has a central role in normal anorectal development. Methods FGF10 expression in wild-type (Wt) embryos was evaluated using whole-mount in situ hybridization. Wt and FGF10 −/− embryos were harvested from timed pregnant mothers at E12.5 through E17.5 and were analyzed for anorectal phenotype. Results Wt development of union between anorectal structures is completed between E12.5 and E13.5 with luminal communication between distal rectal epithelium and anus. FGF10 is discreetly expressed at E12.5 in the distal rectum. FGF10 −/− mutants show failure of union of the rectum and anus at an early stage (E13.5) and near term (E17.5). Conclusions FGF10 is expressed in the rectum at the time when anorectal continuity is established, indicating a role in normal anorectal development. FGF10 invalidation ( FGF10 −/− mutant) results in a genetically reproducible anorectal malformation phenotype. FGF10 function is critical for normal anorectal development.