Fibroblast growth factors (FGFs) control organ morphogenesis during development as well as tissue homeostasis and repair in the adult organism. Despite their importance, many mechanisms that regulate FGF function are still poorly understood. Interestingly, the thermodynamic stability of 22 mammalian FGFs varies widely, with some FGFs remaining stable at body temperature for more than 24 h, while others lose their activity within minutes. How thermodynamic stability contributes to the function of FGFs during development remains unknown. Here we show that FGF10, an important limb and lung morphogen, exists as an intrinsically unstable protein that is prone to unfolding and is rapidly inactivated at 37 °C. Using rationally driven directed mutagenesis, we have developed several highly stable (STAB) FGF10 variants with a melting temperature of over 19 °C more than that of wildtype FGF10. In cellular assays in vitro, the FGF10-STABs did not differ from wildtype FGF10 in terms of binding to FGF receptors, activation of downstream FGF receptor signaling in cells, and induction of gene expression. In mouse embryonal lung explants, FGF10-STABs, but not wildtype FGF10, suppressed branching, resulting in increased alveolarization and expansion of epithelial tissue. Similarly, FGF10-STAB1, but not FGF10 wildtype, inhibited the growth of mouse embryonic tibias and markedly altered limb morphogenesis when implanted into chicken limb buds, collectively demonstrating that thermal instability should be considered an important regulator of FGF function that prevents ectopic signaling. Furthermore, we show enhanced differentiation of human iPSC-derived lung organoids and improved regeneration in ex vivo lung injury models mediated by FGF10-STABs, suggesting an application in cell therapy.

• Klíčová slova
• Development, FGF10, Fibroblast growth factor, Lung, Morphogen, Stability,
• MeSH
• fibroblastový růstový faktor 10 * metabolismus   genetika   chemie   MeSH
• lidé MeSH
• myši MeSH
• plíce metabolismus   embryologie   MeSH
• receptory fibroblastových růstových faktorů metabolismus   MeSH
• signální transdukce * MeSH
• stabilita proteinů MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• Fgf10 protein, mouse MeSH Prohlížeč
• fibroblastový růstový faktor 10 * MeSH
• receptory fibroblastových růstových faktorů MeSH

The FGF system is the most complex of all receptor tyrosine kinase signaling networks with 18 FGF ligands and four FGFRs that deliver morphogenic signals to pattern most embryonic structures. Even when a single FGFR is expressed in the tissue, different FGFs can trigger dramatically different biological responses via this receptor. Here we show both quantitative and qualitative differences in the signaling of one of the FGF receptors, FGFR1c, in response to different FGFs. We provide an overview of the recent discovery that FGFs engage in biased signaling via FGFR1c. We discuss the concept of ligand bias, which represents qualitative differences in signaling as it is a measure of differential ligand preferences for different downstream responses. We show how FGF ligand bias manifests in functional data in cultured chondrocyte cells. We argue that FGF-ligand bias contributes substantially to FGF-driven developmental processes, along with known differences in FGF expression levels, FGF-FGFR binding coefficients and differences in FGF stability in vivo.

• Klíčová slova
• Bias, FGF, FGFR, Signaling,
• MeSH
• chondrocyty metabolismus   MeSH
• fibroblastové růstové faktory * metabolismus   MeSH
• lidé MeSH
• ligandy MeSH
• receptor fibroblastových růstových faktorů, typ 1 * metabolismus   MeSH
• receptory fibroblastových růstových faktorů * metabolismus   MeSH
• signální transdukce * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• fibroblastové růstové faktory * MeSH
• ligandy MeSH
• receptor fibroblastových růstových faktorů, typ 1 * MeSH
• receptory fibroblastových růstových faktorů * MeSH