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We showed previously that the autocrine activation of the FGFR-mediated pathway in GIST lacking secondary KIT mutations was a result of the inhibition of KIT signaling. We show here that the FGF2/FGFR pathway regulates VEGF-A/VEGFR signaling in IM-resistant GIST cells. Indeed, recombinant FGF2 increased the production of VEGF-A by IM-naive and resistant GIST cells. VEGF-A production was also increased in KIT-inhibited GIST, whereas the neutralization of FGF2 by anti-FGF2 mAb attenuated VEGFR signaling. Of note, BGJ 398, pan FGFR inhibitor, effectively and time-dependently inhibited VEGFR signaling in IM-resistant GIST T-1R cells, thereby revealing the regulatory role of the FGFR pathway in VEGFR signaling for this particular GIST cell line. This also resulted in significant synergy between BGJ 398 and VEGFR inhibitors (i.e., sunitinib and regorafenib) by enhancing their pro-apoptotic and anti-proliferative activities. The high potency of the combined use of VEGFR and FGFR inhibitors in IM-resistant GISTs was revealed by the impressive synergy scores observed for regorafenib or sunitinib and BGJ 398. Moreover, FGFR1/2 and VEGFR1/2 were co-localized in IM-resistant GIST T-1R cells, and the direct interaction between the aforementioned RTKs was confirmed by co-immunoprecipitation. In contrast, IM-resistant GIST 430 cells expressed lower basal levels of FGF2 and VEGF-A. Despite the increased expression VEGFR1 and FGFR1/2 in GIST 430 cells, these RTKs were not co-localized and co-immunoprecipitated. Moreover, no synergy between FGFR and VEGFR inhibitors was observed for the IM-resistant GIST 430 cell line. Collectively, the dual targeting of FGFR and VEGFR pathways in IM-resistant GISTs is not limited to the synergistic anti-angiogenic treatment effects. The dual inhibition of FGFR and VEGFR pathways in IM-resistant GISTs potentiates the proapoptotic and anti-proliferative activities of the corresponding RTKi. Mechanistically, the FGF2-induced activation of the FGFR pathway turns on VEGFR signaling via the overproduction of VEGF-A, induces the interaction between FGFR1/2 and VEGFR1, and thereby renders cancer cells highly sensitive to the dual inhibition of the aforementioned RTKs. Thus, our data uncovers the novel mechanism of the cross-talk between the aforementioned RTKs in IM-resistant GISTs lacking secondary KIT mutations and suggests that the dual blockade of FGFR and VEGFR signaling might be an effective treatment strategy for patients with GIST-acquired IM resistance via KIT-independent mechanisms.
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Mutations in GATA6 are associated with congenital heart disease, most notably conotruncal structural defects. However, how GATA6 regulates cardiac morphology during embryogenesis is undefined. We used knockout and conditional mutant zebrafish alleles to investigate the spatiotemporal role of gata6 during cardiogenesis. Loss of gata6 specifically impacts atrioventricular valve formation and recruitment of epicardium, with a prominent loss of arterial pole cardiac cells, including those of the ventricle and outflow tract. However, there are no obvious defects in cardiac progenitor cell specification, proliferation or death. Conditional loss of gata6 starting at 24â h is sufficient to disrupt the addition of late differentiating cardiomyocytes at the arterial pole, with decreased expression levels of anterior secondary heart field (SHF) markers spry4 and mef2cb. Conditional loss of gata6 in the endoderm is sufficient to phenocopy the straight knockout, resulting in a significant loss of ventricular and outflow tract tissue. Exposure to a Dusp6 inhibitor largely rescues the loss of ventricular cells in gata6-/- larvae. Thus, gata6 functions in endoderm are mediated by FGF signaling to regulate the addition of anterior SHF progenitor derivatives during heart formation.
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Diferenciación Celular , Endodermo , Factor de Transcripción GATA6 , Corazón , Proteínas de Pez Cebra , Pez Cebra , Animales , Pez Cebra/embriología , Pez Cebra/genética , Factor de Transcripción GATA6/metabolismo , Factor de Transcripción GATA6/genética , Proteínas de Pez Cebra/genética , Proteínas de Pez Cebra/metabolismo , Endodermo/metabolismo , Endodermo/embriología , Endodermo/citología , Diferenciación Celular/genética , Corazón/embriología , Organogénesis/genética , Regulación del Desarrollo de la Expresión Génica , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/citología , Transducción de Señal , Factores de Crecimiento de Fibroblastos/metabolismo , Factores de Crecimiento de Fibroblastos/genética , Fosfatasa 6 de Especificidad Dual/metabolismo , Fosfatasa 6 de Especificidad Dual/genética , Factores de Transcripción GATARESUMEN
Putatively, tooth agenesis was attributed to the initiation failure of tooth germs, though little is known about the histological and molecular alterations. To address if constitutively active FGF signaling is associated with tooth agenesis, we activated Fgf8 in dental mesenchyme with Osr-cre knock-in allele in mice (Osr2-creKI; Rosa26R-Fgf8) and found incisor agenesis and molar microdontia. The cell survival assay showed tremendous apoptosis in both the Osr2-creKI; Rosa26R-Fgf8 incisor epithelium and mesenchyme, which initiated incisor regression from cap stage. In situ hybridization displayed vanished Shh transcription, and immunostaining exhibited reduced Runx2 expression and enlarged mesenchymal Lef1 domain in Osr2-creKI; Rosa26R-Fgf8 incisors, both of which were suggested to enhance apoptosis. In contrast, Osr2-creKI; Rosa26R-Fgf8 molar germs displayed mildly suppressed Shh transcription, and the increased expression of Ectodin, Runx2 and Lef1. Although mildly smaller than WT controls prenatally, the Osr2-creKI; Rosa26R-Fgf8 molar germs produced a miniature tooth with impaired mineralization after a 6-week sub-renal culture. Intriguingly, the implanted Osr2-creKI; Rosa26R-Fgf8 molar germs exhibited delayed odontoblast differentiation and accelerated ameloblast maturation. Collectively, the ectopically activated Fgf8 in dental mesenchyme caused incisor agenesis by triggering incisor regression and postnatal molar microdontia. Our findings reported tooth agenesis resulting from the regression from the early bell stage and implicated a correlation between tooth agenesis and microdontia.
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Factor 8 de Crecimiento de Fibroblastos , Incisivo , Mesodermo , Diente Molar , Animales , Factor 8 de Crecimiento de Fibroblastos/genética , Factor 8 de Crecimiento de Fibroblastos/metabolismo , Ratones , Incisivo/anomalías , Incisivo/metabolismo , Mesodermo/metabolismo , Mesodermo/patología , Diente Molar/anomalías , Diente Molar/metabolismo , Anodoncia/genética , Anodoncia/metabolismo , Anodoncia/patología , Apoptosis , Proteínas Hedgehog/metabolismo , Proteínas Hedgehog/genética , Factor de Unión 1 al Potenciador Linfoide/metabolismo , Factor de Unión 1 al Potenciador Linfoide/genética , Subunidad alfa 1 del Factor de Unión al Sitio Principal/genética , Subunidad alfa 1 del Factor de Unión al Sitio Principal/metabolismo , Transducción de Señal , Regulación del Desarrollo de la Expresión Génica , Odontogénesis/genética , Ratones TransgénicosRESUMEN
Lymphoma positions as the fifth most common cancer, in the world, reporting remarkable deaths every year. Several promising strategies to counter this disease recently include utilizing small molecules that specifically target the lymphoma cellular proteins to overwhelm its progression. FGFBP1 is a soluble intracellular protein that progresses cancer cell proliferation and is upregulated in several cancers. Therefore, inhibiting FGFBP1 could significantly slow down lymphoma progression through triggering apoptosis. Thus, in this study, a flavonoid B4, isolated from Cajanus cajan, has been investigated for its effects of B4 on lymphoma, specifically as an FGFBP1 inhibitor. B4 could selectively hinder the growth of lymphoma cells by inducing caspase-dependent intrinsic apoptosis through G1/S transition phase cell cycle arrest. RNA sequencing analysis revealed that B4 regulates the genes involved in B-cell proliferation and DNA replication by inhibiting FGFBP1 in vitro. B4 increases the survival rate of lymphoma mice. B4 also represses the growth of patient-derived primary lymphoma cells through FGFBP1 inhibition. Drug affinity responsive target stability experimentations authorize that B4 powerfully binds to FGFBP1. The overexpression of FGFBP1 raises the pharmacological sensitivity of B4, supplementing its specific action on lymphoma cells. This study pioneers the estimation of B4 as a possible anticancer agent for lymphoma treatment. These outcomes highlight its selective inhibitory effects on lymphoma cell growth by downregulating FGFBP1 expression through intrinsic apoptosis, causing mitochondrial and DNA damage, ultimately leading to the inhibition of lymphoma progression. These suggest B4 may be a novel FGFBP1 inhibitor for the lymphoma treatment.
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BACKGROUND: Colon adenocarcinoma (COAD) is a malignant tumor of the digestive system. The mechanisms underlying COAD development and progression are still largely unknown. AIM: To identify the role of canopy FGF signaling regulator 3 (CNPY3) in the development and progression of COAD by using bioinformatic tools and functional experiments. METHODS: Bioinformatic data were downloaded from public databases. The associations of clinicopathological features, survival, and immune function with the expression of CNPY3 were analyzed. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses and Gene Set Enrichment Analysis were used to explore the related pathways. Then, quantitative real-time PCR and immunohistochemistry were used for validation of CNPY3 expression in clinical samples and tumor cell lines. Cell lines with CNPY3 knockdown were constructed to further analyze gene functions. The functional experiments included proliferation, invasion, migration and apoptosis assays. RESULTS: In both the TCGA cohort and the merged dataset, elevated CNPY3 expression was observed in tumor tissues. High CNPY3 expression correlated with adverse survival and compromised immune functions. Functional enrichment analysis suggested that the pro-oncogenic properties of CNPY3 might be linked to the PI3K-AKT signaling pathway. CNPY3 expression was validated at both the RNA and protein levels. Functional assays indicated that cell proliferation, invasion, and migration were inhibited and cell apoptosis was promoted after CNPY3 knockdown. Additionally, Western blot results revealed the downregulation of key proteins in the PI3K/AKT pathway following CNPY3 knockdown. PI3K/AKT pathway activator reversed the decrease in proliferation, invasion, and migration and the increase in apoptosis. Notably, CNPY3 knockdown still affected the cells when the pathway was inhibited. CONCLUSION: This study showed that CNPY3 is upregulated in COAD and might regulate COAD development and progression by the PI3K/AKT pathway. Thus, CNPY3 might be a promising therapeutic target.
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In vertebrates, Fgf signaling is essential for the development of pharyngeal pouches, which controls facial skeletal development. Genetically, fgf3 and fgf8 are required for pouch formation in mice and zebrafish. However, loss-of-function phenotypes of fgf3 and fgf8 are milder than expected in mice and zebrafish, which suggests that an additional fgf gene(s) would be involved in pouch formation. Here, we analyzed the expression, regulation, and function of three fgfs, fgf4, fgf24, and fgf17, during pouch development in zebrafish. We find that they are expressed in the distinct regions of pharyngeal endoderm in pouch formation, with fgf4 and fgf17 also being expressed in the adjacent mesoderm, in addition to previously reported endodermal fgf3 and mesodermal fgf8 expression. The endodermal expression of fgf4, fgf24, and fgf17 and the mesodermal expression of fgf4 and fgf17 are positively regulated by Tbx1 but not by Fgf3, in pouch formation. Fgf8 is required to express the endodermal expression of fgf4 and fgf24. Interestingly, however, single mutant, all double mutant combinations, and triple mutant for fgf4, fgf24, and fgf17 do not show any defects in pouches and facial skeletons. Considering a high degree of genetic redundancy in the Fgf signaling components in craniofacial development in zebrafish, our result suggests that fgf4, fgf24, and fgf17 have a potential role for pouch formation, with a redundancy with other fgf gene(s).
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Many growth factors and cytokines signal by binding to the extracellular domains of their receptors and driving association and transphosphorylation of the receptor intracellular tyrosine kinase domains, initiating downstream signaling cascades. To enable systematic exploration of how receptor valency and geometry affect signaling outcomes, we designed cyclic homo-oligomers with up to 8 subunits using repeat protein building blocks that can be modularly extended. By incorporating a de novo-designed fibroblast growth factor receptor (FGFR)-binding module into these scaffolds, we generated a series of synthetic signaling ligands that exhibit potent valency- and geometry-dependent Ca2+ release and mitogen-activated protein kinase (MAPK) pathway activation. The high specificity of the designed agonists reveals distinct roles for two FGFR splice variants in driving arterial endothelium and perivascular cell fates during early vascular development. Our designed modular assemblies should be broadly useful for unraveling the complexities of signaling in key developmental transitions and for developing future therapeutic applications.
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Diferenciación Celular , Factores de Crecimiento de Fibroblastos , Receptores de Factores de Crecimiento de Fibroblastos , Transducción de Señal , Animales , Humanos , Receptores de Factores de Crecimiento de Fibroblastos/metabolismo , Factores de Crecimiento de Fibroblastos/metabolismo , Ratones , Ligandos , Calcio/metabolismo , Sistema de Señalización de MAP QuinasasRESUMEN
Tumor heterogeneity, the presence of multiple distinct subpopulations of cancer cells between patients or among the same tumors, poses a major challenge to current targeted therapies. The way these different subpopulations interact among themselves and the stromal niche environment, and how such interactions affect cancer stem cell behavior has remained largely unknown. Here, it is shown that an FGF-BMP7-INHBA signaling positive feedback loop integrates interactions among different cell populations, including mammary gland stem cells, luminal epithelial and stromal fibroblast niche components not only in organ regeneration but also, with certain modifications, in cancer progression. The reciprocal dependence of basal stem cells and luminal epithelium is based on basal-derived BMP7 and luminal-derived INHBA, which promote their respective expansion, and is regulated by stromal-epithelial FGF signaling. Targeting this interaction loop, for example, by reducing the function of one or more of its components, inhibits organ regeneration and breast cancer progression. The results have profound implications for overcoming drug resistance because of tumor heterogeneity in future targeted therapies.
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Neoplasias de la Mama , Nicho de Células Madre , Humanos , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Neoplasias de la Mama/genética , Animales , Femenino , Nicho de Células Madre/fisiología , Células Madre Neoplásicas/metabolismo , Transducción de Señal , Ratones , Células Epiteliales/metabolismo , Proteína Morfogenética Ósea 7/metabolismo , Proteína Morfogenética Ósea 7/genética , Microambiente TumoralRESUMEN
PURPOSE OF REVIEW: To illustrate the value of using zebrafish to understand the role of the Fgf signaling pathway during craniofacial skeletal development under normal and pathological conditions. RECENT FINDINGS: Recent data obtained from studies on zebrafish have demonstrated the genetic redundancy of Fgf signaling pathway and have identified new molecular partners of this signaling during the early stages of craniofacial skeletal development. Studies on zebrafish models demonstrate the involvement of the Fgf signaling pathway at every stage of craniofacial development. They particularly emphasize the central role of Fgf signaling pathway during the early stages of the development, which significantly impacts the formation of the various structures making up the craniofacial skeleton. This partly explains the craniofacial abnormalities observed in disorders associated with FGF signaling. Future research efforts should focus on investigating zebrafish Fgf signaling during more advanced stages, notably by establishing zebrafish models expressing mutations responsible for diseases such as craniosynostoses.
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Anomalías Craneofaciales , Factores de Crecimiento de Fibroblastos , Transducción de Señal , Pez Cebra , Animales , Factores de Crecimiento de Fibroblastos/metabolismo , Factores de Crecimiento de Fibroblastos/genética , Anomalías Craneofaciales/genética , Anomalías Craneofaciales/metabolismo , Modelos Animales de Enfermedad , Cráneo , Huesos Faciales/crecimiento & desarrolloRESUMEN
Rising in popularity as a model organism in the classroom, zebrafish have numerous characteristics that make them ideal for teaching. In this study, we describe an experiment that helps students better understand the concept of tissue regeneration and the genes that control it. This experiment utilizes a dominant negative transgene for fgfr1 and allows students to observe the consequences of its activation. The first part of the laboratory is hands-on, and includes details of the amputation of caudal fins, heat shocking, general fish care, and visual observations. Over the course of a week, students observed the differences between the activated and unactivated transgene in the zebrafish. The second part was literature based, in which students tried to determine which gene is responsible for inhibiting regeneration. This encouraged students to sharpen their skills of deductive reasoning and critical thinking as they conduct research based on the information they receive about dominant negative receptors and transgenes. Having both a hands-on and critical thinking component in the laboratory helped synthesize the learning goals and allowed students to actively participate.
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Proteínas de Pez Cebra , Pez Cebra , Animales , Pez Cebra/fisiología , Proteínas de Pez Cebra/genética , Cola (estructura animal)/fisiología , Aletas de Animales/fisiologíaRESUMEN
Phenotype switching of vascular smooth muscle cells (VSMCs) is a pathological process in various vascular diseases. Canopy FGF signaling regulator 2 (CNPY2) has previously been found to be abnormally expressed in ApoE-/- mice and aortic endothelial cells, indicating it may have an important role in vascular diseases. The present study aimed to determine the role and mechanism of CNPY2 in VSMC phenotype switching. Following stimulation with platelet-derived growth factor type BB (PDGF-BB), the expression of CNPY2 in VSMCs was detected using reverse transcription-quantitative PCR and western blot analysis. Subsequently, to explore the regulatory effects of CNPY2 on VSMCs, CNPY2 expression was knocked down by transfection with short hairpin RNA and cell viability, proliferation, migration and phenotypic transformation indicators were detected. Western blot analysis was also used to detect the phosphorylation of Akt/mTOR/GSK-3ß pathway-associated proteins downstream of CNPY2. In addition, pretreatment with the Akt pathway activator SC79 was performed to further explore the regulatory mechanisms of CNPY2. The results revealed that CNPY2 expression was upregulated in PDGF-BB-stimulated VSMCs. In addition, the knockdown of CNPY2 inhibited PDGF-BB-induced VSMC hyperproliferation, cell cycle arrest, migration and phenotypic transformation, as well the activation of Akt/mTOR/GSK-3ß pathway-associated proteins. Pretreatment with SC79 significantly reversed the inhibitory effects of CNPY2 knockdown on the proliferation, cell cycle arrest, migration and phenotypic transformation of the model cells. In summary, the present study indicates that CNPY2 regulates the abnormal proliferation, migration and phenotypic transformation of PDGF-BB-stimulated VSMCs via activation of the Akt/mTOR/GSK-3ß signaling pathway.
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The molecular basis for cortical expansion during evolution remains largely unknown. Here, we report that fibroblast growth factor (FGF)-extracellular signal-regulated kinase (ERK) signaling promotes the self-renewal and expansion of cortical radial glial (RG) cells. Furthermore, FGF-ERK signaling induces bone morphogenic protein 7 (Bmp7) expression in cortical RG cells, which increases the length of the neurogenic period. We demonstrate that ERK signaling and Sonic Hedgehog (SHH) signaling mutually inhibit each other in cortical RG cells. We provide evidence that ERK signaling is elevated in cortical RG cells during development and evolution. We propose that the expansion of the mammalian cortex, notably in human, is driven by the ERK-BMP7-GLI3R signaling pathway in cortical RG cells, which participates in a positive feedback loop through antagonizing SHH signaling. We also propose that the relatively short cortical neurogenic period in mice is partly due to mouse cortical RG cells receiving higher SHH signaling that antagonizes ERK signaling.
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Células Ependimogliales , Quinasas MAP Reguladas por Señal Extracelular , Animales , Ratones , Humanos , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Células Ependimogliales/metabolismo , Proliferación Celular , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Transducción de Señal , Factores de Crecimiento de Fibroblastos , Mamíferos/metabolismoRESUMEN
Peripheral sensory neurons are a critical part of the nervous system that transmit a multitude of sensory stimuli to the central nervous system. During larval and juvenile stages in zebrafish, this function is mediated by Rohon-Beard somatosensory neurons (RBs). RBs are optically accessible and amenable to experimental manipulation, making them a powerful system for mechanistic investigation of sensory neurons. Previous studies provided evidence that RBs fall into multiple subclasses; however, the number and molecular makeup of these potential RB subtypes have not been well defined. Using a single-cell RNA sequencing (scRNA-seq) approach, we demonstrate that larval RBs in zebrafish fall into three, largely nonoverlapping classes of neurons. We also show that RBs are molecularly distinct from trigeminal neurons in zebrafish. Cross-species transcriptional analysis indicates that one RB subclass is similar to a mammalian group of A-fiber sensory neurons. Another RB subclass is predicted to sense multiple modalities, including mechanical stimulation and chemical irritants. We leveraged our scRNA-seq data to determine that the fibroblast growth factor (Fgf) pathway is active in RBs. Pharmacological and genetic inhibition of this pathway led to defects in axon maintenance and RB cell death. Moreover, this can be phenocopied by treatment with dovitinib, an FDA-approved Fgf inhibitor with a common side effect of peripheral neuropathy. Importantly, dovitinib-mediated axon loss can be suppressed by loss of Sarm1, a positive regulator of neuronal cell death and axonal injury. This offers a molecular target for future clinical intervention to fight neurotoxic effects of this drug.
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Células Receptoras Sensoriales , Pez Cebra , Animales , Pez Cebra/metabolismo , Animales Modificados Genéticamente , Supervivencia Celular , Células Receptoras Sensoriales/fisiología , Axones/fisiología , Análisis de la Célula Individual , MamíferosRESUMEN
Canopy FGF signaling regulator 2 (CNPY2) is a novel angiogenic growth factor. In recent years, increasing evidence highlights that CNPY2 has important functions in health and disease. Many new blood vessels need to be formed to meet the nutrient supply in the process of tumor growth. CNPY2 can participate in the development of tumors by promoting angiogenesis. CNPY2 also enhances neurite outgrowth in neurologic diseases and promotes cell proliferation and tissue repair, thereby improving cardiac function in cardiovascular diseases. Regrettably, there are few studies on CNPY2 in various diseases. At the same time, its biological function and molecular mechanism in the process and development of disease are still unclear. This paper reviews the recent studies on CNPY2 in cervical cancer, renal cell carcinoma, prostate cancer, colorectal cancer, lung cancer, gastric cancer, hepatocellular carcinoma, cerebral ischemia-reperfusion injury, spinal cord ischemia-reperfusion injury, Parkinson's disease, ischemic heart disease, myocardial ischemiareperfusion injury, myocardial infarction, heart failure, and non-alcoholic fatty liver disease. The biological function and molecular mechanism of CNPY2 in these diseases have been summarized in this paper. Many drugs that play protective roles in tumors, cardiovascular diseases, non-alcoholic fatty liver disease, and neurologic diseases by targeting CNPY2, have also been summarized in this paper. In addition, the paper also details the biological functions and roles of canopy FGF signaling regulator 1 (CNPY1), canopy FGF signaling regulator 3 (CNPY3), canopy FGF signaling regulator 4 (CNPY4), and canopy FGF signaling regulator 5 (CNPY5). The mechanism and function of CNPY2 should be continued to study in order to accelerate disease prevention in the future.
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Enfermedades Cardiovasculares , Neoplasias Hepáticas , Neoplasias Pulmonares , Enfermedad del Hígado Graso no Alcohólico , Daño por Reperfusión , Masculino , Humanos , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Neoplasias Pulmonares/patologíaRESUMEN
Nerves play important roles in organ development and tissue homeostasis. Stem/progenitor cells differentiate into different cell lineages responsible for building the craniofacial organs. The mechanism by which nerves regulate stem/progenitor cell behavior in organ morphogenesis has not yet been comprehensively explored. Here, we use tooth root development in mouse as a model to investigate how sensory nerves regulate organogenesis. We show that sensory nerve fibers are enriched in the dental papilla at the initiation of tooth root development. Through single cell RNA-sequencing analysis of the trigeminal ganglion and developing molar, we reveal several signaling pathways that connect the sensory nerve with the developing molar, of which FGF signaling appears to be one of the important regulators. Fgfr2 is expressed in the progenitor cells during tooth root development. Loss of FGF signaling leads to shortened roots with compromised proliferation and differentiation of progenitor cells. Furthermore, Hh signaling is impaired in Gli1-CreER;Fgfr2fl/fl mice. Modulation of Hh signaling rescues the tooth root defects in these mice. Collectively, our findings elucidate the nerve-progenitor crosstalk and reveal the molecular mechanism of the FGF-SHH signaling cascade during tooth root morphogenesis.
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Diente , Animales , Ratones , Diente Molar , Morfogénesis/genética , Odontogénesis/genética , Raíz del DienteRESUMEN
The D-quadrant organizer sets up the dorsal-ventral (DV) axis and regulates mesodermal development of spiralians. Studies have revealed an important role of mitogen-activated protein kinase (MAPK) signaling in organizer function, but the related molecules have not been fully revealed. The association between fibroblast growth factor receptor (FGFR) and MAPK signaling in regulating organizer specification has been established in the annelid Owenia fusiformis. Now, comparable studies in other spiralian phyla are required to decipher whether this organizer-inducing function of FGFR is prevalent in Spiralia. Here, we indicate that treatment with the FGFR inhibitor SU5402 resulted in deficiency of organizer specification in the mollusk Lottia peitaihoensis. Subsequently, the bone morphogenetic protein (BMP) signaling gradient and DV patterning were disrupted, suggesting the roles of FGFR in regulating organizer function. Changes in multiple aspects of organizer function (the morphology of vegetal blastomeres, BMP signaling gradient, expression of DV patterning markers, etc.) indicate that these developmental functions have different sensitivities to FGFR/MAPK signaling. Our results reveal a functional role of FGFR in organizer specification as well as DV patterning of Lottia embryos, which expands our knowledge of spiralian organizers. Supplementary Information: The online version contains supplementary material available at 10.1007/s42995-023-00194-x.
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Fibroblast growth factor 10 (FGF10) is a major morphoregulatory factor that plays essential signaling roles during vertebrate multiorgan development and homeostasis. FGF10 is predominantly expressed in mesenchymal cells and signals though FGFR2b in adjacent epithelia to regulate branching morphogenesis, stem cell fate, tissue differentiation and proliferation, in addition to autocrine roles. Genetic loss of function analyses have revealed critical requirements for FGF10 signaling during limb, lung, digestive system, ectodermal, nervous system, craniofacial and cardiac development. Heterozygous FGF10 mutations have been identified in human genetic syndromes associated with craniofacial anomalies, including lacrimal and salivary gland aplasia. Elevated Fgf10 expression is associated with poor prognosis in a range of cancers. In addition to developmental and disease roles, FGF10 regulates homeostasis and repair of diverse adult tissues and has been identified as a target for regenerative medicine.
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Nkx2.3, a transcription factor, plays important roles in various developmental processes. However, the mechanisms underlying nkx2.3's regulation of pouch and pharyngeal arch development in zebrafish remain unclear. In this study, we demonstrated that knockdown or knockout of nkx2.3 resulted in the absence of posterior ceratobranchial cartilages in zebrafish. The absence of posterior pharyngeal cartilages is a consequence of the compromised proliferation and differentiation and survival of cranial neural crest cells (CNCCs). Notably, we found that nkx2.3 was not involved in endoderm pouch formation. Additionally, our findings suggested that nkx2.3 negatively regulated Fibroblast growth factor (Fgf) signaling, as overexpression of fgf8 could mimic the phenotype observed in nkx2.3 morphants, suppressing CNCC differentiation. Moreover, inhibiting Fgf signaling restored the abnormalities in posterior cartilages induced by nkx2.3 knockdown. These findings establish the essential role of nkx2.3 in the development of posterior ceratobranchial cartilages through the inhibition of fgf8.
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Chen et al. have derived cryogenic electron microscopy (cryo-EM) structures of signaling complexes of the endocrine hormone fibroblast growth factor 23 (FGF23) with fibroblast growth factor receptor (FGFR), α-Klotho, and heparin sulfate. These structures are asymmetric, leading to questions concerning in vivo function, and will facilitate structure-based drug design to modulate FGF23 signaling.
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Factores de Crecimiento de Fibroblastos , Proteínas Klotho , Humanos , Factores de Crecimiento de Fibroblastos/química , Glucuronidasa/metabolismo , Transducción de Señal/fisiología , Receptores de Factores de Crecimiento de Fibroblastos/metabolismoRESUMEN
Extracellular signal-regulated kinase (Erk) signaling dynamics elicit distinct cellular responses in a variety of contexts. The early zebrafish embryo is an ideal model to explore the role of Erk signaling dynamics in vivo, as a gradient of activated diphosphorylated Erk (P-Erk) is induced by fibroblast growth factor (Fgf) signaling at the blastula margin. Here, we describe an improved Erk-specific biosensor, which we term modified Erk kinase translocation reporter (modErk-KTR). We demonstrate the utility of this biosensor in vitro and in developing zebrafish and Drosophila embryos. Moreover, we show that Fgf/Erk signaling is dynamic and coupled to tissue growth during both early zebrafish and Drosophila development. Erk activity is rapidly extinguished just prior to mitosis, which we refer to as mitotic erasure, inducing periods of inactivity, thus providing a source of heterogeneity in an asynchronously dividing tissue. Our modified reporter and transgenic lines represent an important resource for interrogating the role of Erk signaling dynamics in vivo.