Fgf20, or Fibroblast growth factor 20, is a neurotrophic factor and a member of the FGF9 subfamily. Its receptors include FGFR4, FGFR3b, FGFR2b, and FGFRc splice forms. It plays significant roles in development and homeostasis, and is associated with multiple signaling pathways such as MAPK, PI3K, and Wnt/β -catenin pathways [1,3,7]. Fgf20 is crucial for various biological processes and is linked to human diseases including Parkinson's Disease, cancer, and hereditary deafness [1].

In Fgf20 mouse mutants, phenotypes like congenital deafness, lack of hair, small kidneys, and delayed mammary ductal outgrowth are observed, indicating its importance in these developmental processes [1]. In the cochlea, FGF20-FGFR1 signaling through MAPK and PI3K controls sensory progenitor differentiation into hair cells and supporting cells [3]. In glioma, glioma-derived FGF20 acts on macrophages, suppressing their pro-inflammatory phenotype via β-catenin activation [2]. In ulcerative colitis mouse models, overexpression of FGF20 alleviates symptoms by modulating gut microbiota [4]. Also, in spinal cord injury and traumatic brain injury mouse models, FGF20 shows neuroprotective effects, promoting repair and protecting the blood-brain barrier respectively [5,6].

In conclusion, Fgf20 is essential for multiple biological functions including embryonic development, neuronal homeostasis, and tissue repair. Studies using Fgf20-related mouse models have provided insights into its role in diseases such as neurological disorders, cancer, and inflammatory bowel diseases, highlighting its potential as a therapeutic target.

References:

1. Van Greenen, Justine D, Hockman, Dorit. 2023. FGF20. In Differentiation; research in biological diversity, 139, 100737. doi:10.1016/j.diff.2023.10.005. https://pubmed.ncbi.nlm.nih.gov/38007375/

2. Cai, Xue, Tao, Weichen, Li, Lei. 2021. Glioma cell-derived FGF20 suppresses macrophage function by activating β-catenin. In Cellular signalling, 89, 110181. doi:10.1016/j.cellsig.2021.110181. https://pubmed.ncbi.nlm.nih.gov/34757019/

3. Su, Yutao, Yang, Lu M, Ornitz, David M. 2020. FGF20-FGFR1 signaling through MAPK and PI3K controls sensory progenitor differentiation in the organ of Corti. In Developmental dynamics : an official publication of the American Association of Anatomists, 250, 134-144. doi:10.1002/dvdy.231. https://pubmed.ncbi.nlm.nih.gov/32735383/

4. Jin, Zhongqian, Liu, Zhaoyang, Pan, Jiaxuan, Yu, Xiang, Gong, Fanghua. 2024. FGF20 modulates gut microbiota to mitigate dextran sodium sulfate-induced ulcerative colitis in mouse models. In International immunopharmacology, 142, 113044. doi:10.1016/j.intimp.2024.113044. https://pubmed.ncbi.nlm.nih.gov/39217880/

5. Cai, Xiong, Xie, Zhenwen, Zhao, Juan, Xu, Jiake, Zhu, Sipin. . FGF20 promotes spinal cord injury repair by inhibiting the formation of necrotic corpuscle P-MLKL/P-RIP1/P-RIP3 in neurons. In Journal of cellular and molecular medicine, 28, e70109. doi:10.1111/jcmm.70109. https://pubmed.ncbi.nlm.nih.gov/39676730/

6. Chen, Jun, Wang, Xue, Hu, Jian, Lin, Li, Li, Xiaokun. 2021. FGF20 Protected Against BBB Disruption After Traumatic Brain Injury by Upregulating Junction Protein Expression and Inhibiting the Inflammatory Response. In Frontiers in pharmacology, 11, 590669. doi:10.3389/fphar.2020.590669. https://pubmed.ncbi.nlm.nih.gov/33568994/

7. Yang, Lu M, Huh, Sung-Ho, Ornitz, David M. 2018. FGF20-Expressing, Wnt-Responsive Olfactory Epithelial Progenitors Regulate Underlying Turbinate Growth to Optimize Surface Area. In Developmental cell, 46, 564-580.e5. doi:10.1016/j.devcel.2018.07.010. https://pubmed.ncbi.nlm.nih.gov/30100263/