Fibroblast Growth Factor 9 Suppresses Striatal Cell Death Dominantly Through ERK Signaling in Huntington’s Disease

• Published in: Cellular physiology and biochemistry Vol. 48; no. 2; pp. 605 - 617
• Main Authors: Yusuf, Issa Olakunle, Cheng, Pei-Hsun, Chen, Hsiu-Mei, Chang, Yu-Fan, Chang, Chih-Yi, Yang, Han-In, Lin, Chia-Wei, Tsai, Shaw-Jenq, Chuang, Jih-Ing, Wu, Chia-Ching, Huang, Bu-Miin, Sun, H. Sunny, Yang, Shang-Hsun
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland S. Karger AG 01-01-2018; Cell Physiol Biochem Press GmbH & Co KG
• Subjects: Alzheimer's disease; Animals; Apoptosis; Apoptosis - drug effects; bcl-X Protein - metabolism; Butadienes - pharmacology; Caspase 3 - metabolism; Cell death; Cell Line; Cell signaling; Enzymes; Extracellular Signal-Regulated MAP Kinases - antagonists & inhibitors; Extracellular Signal-Regulated MAP Kinases - metabolism; Fibroblast Growth Factor 9; Fibroblast Growth Factor 9 - pharmacology; Fibroblasts; Gene expression; Glial cell line-derived neurotrophic factor; Glial Cell Line-Derived Neurotrophic Factor - metabolism; Growth factors; Huntington Disease - metabolism; Huntington Disease - pathology; Huntingtons disease; Huntington’s disease; JNK Mitogen-Activated Protein Kinases - metabolism; Kinases; MAP Kinase Signaling System - drug effects; Mice; Mice, Transgenic; Neurodegeneration; Nitriles - pharmacology; Original Paper; Parkinson's disease; Pathogenesis; Proteins; Proto-Oncogene Proteins c-akt - metabolism; Rodents; Stem cells; Striatal cell death; Transgenic animals; Visual Cortex - cytology; Visual Cortex - drug effects; Visual Cortex - metabolism; Glial cell line-derived neurotrophic factor; Huntington’s disease; Striatal cell death; Fibroblast Growth Factor 9; Cell signaling
• ISSN: 1015-8987; 1421-9778
• DOI: 10.1159/000491889

Background/Aims: Huntington’s disease (HD) is a heritable neurodegenerative disorder, and there is no cure for HD to date. A type of fibroblast growth factor (FGF), FGF9, has been reported to play prosurvival roles in other neurodegenerative diseases, such as Parkinson’s disease and Alzheimer’s disease. However, the effects of FGF9 on HD is still unknown. With many similarities in the cellular and pathological mechanisms that eventually cause cell death in neurodegenerative diseases, we hypothesize that FGF9 might provide neuroprotective functions in HD. Methods: In this study, STHdh Q7/Q7 (WT) and STHdh Q111/Q111 (HD) striatal knock-in cell lines were used to evaluate the neuroprotective effects of FGF9. Cell proliferation, cell death and neuroprotective markers were determined via the MTT assay, propidium iodide staining and Western blotting, respectively. The signaling pathways regulated by FGF9 were demonstrated using Western blotting. Additionally, HD transgenic mouse models were used to further confirm the neuroprotective effects of FGF9 via ELISA, Western blotting and immunostaining. Results: Results show that FGF9 not only enhances cell proliferation, but also alleviates cell death as cells under starvation stress. In addition, FGF9 significantly upregulates glial cell line-derived neurotrophic factor (GDNF) and an anti-apoptotic marker, Bcl-xL, and decreases the expression level of an apoptotic marker, cleaved caspase 3. Furthermore, FGF9 functions through ERK, AKT and JNK pathways. Especially, ERK pathway plays a critical role to influence the effects of FGF9 toward cell survival and GDNF production. Conclusions: These results not only show the neuroprotective effects of FGF9, but also clarify the critical mechanisms in HD cells, further providing an insight for the therapeutic potential of FGF9 in HD.