FGF20 modulates gut microbiota to mitigate dextran sodium sulfate-induced ulcerative colitis in mouse models.

Ulcerative colitis (UC), a prevalent form of inflammatory bowel disease (IBD), presents a significant clinical challenge due to the lack of optimal therapeutic strategies. Emerging evidence suggests that fibroblast growth factor 20 (FGF20) may play a crucial role in mitigating UC symptoms, though the mechanistic underpinnings remain elusive. In this study, a mouse model of UC was established using dextran sodium sulfate (DSS) to investigate the potential role of FGF20. Our findings revealed a marked reduction in FGF20 expression in the serum and colonic tissues of DSS-treated mice. Furthermore, FGF20 knockout did not exacerbate colonic damage in these mice. Conversely, overexpression of FGF20 via adeno-associated virus (AAV) significantly alleviated UC-associated symptoms. This alleviation was evidenced by attenuated intestinal shortening, mitigated weight loss, increased colonic goblet cell density and crypt formation, reduced inflammation severity and inflammatory cell infiltration, and enhanced expression of tight junction and mucin proteins. Moreover, FGF20 significantly ameliorated the dysbiosis of gut microbiota in DSS-treated mice by increasing the abundance of beneficial bacteria and decreasing the abundance of harmful bacteria. The beneficial effects of FGF20 were notably attenuated following gut microbiota depletion with an antibiotic regimen. Fecal microbiota transplantation experiments further supported the critical role of gut microbiota in mediating the effects of FGF20 on DSS-treated mice. In conclusion, these findings highlight the potential involvement of gut microbiota in the therapeutic effects of FGF20 in UC.

Glioma cell-derived FGF20 suppresses macrophage function by activating ß-catenin.

Macrophages, which are the main regulators of the tumor-associated microenvironment, play a crucial role in the progression of various tumors. The anti-inflammatory role of ß-catenin in macrophages has been extensively studied in recent years. However, the association between macrophages and ß-catenin with regards to the development of glioma has not yet been investigated, at least to the best of our knowledge. The present study found that fibroblast growth factor 20 (FGF20), as a paracrine cytokine, was secreted by glioma cells and acted on macrophages. FGF20 treated macrophages exhibited a decreased pro-inflammatory phenotype upon LPS and IFN-γ stimulation, characterized by the decreased the level of M1 macrophage markers and the reduced production of pro-inflammatory cytokines. Mechanistic analysis revealed that FGF20 interacted with FGF receptor 1 isoform of macrophages, and subsequently increased the stability of ß-catenin via phosphorylating GSK3ß, which suppressed macrophage polarization to the M1-phenotype. Finally, it was found that FGF20 of glioma cells expression was upregulated by the glucocorticoids (GCs) treatment, and decreased FGF20 expression of glioma cells markedly blocked the effects of GCs on the polarization of macrophages. On the whole, the present study demonstrates that FGF20, secreted from glioma cells, participates the GCs regulated macrophage function and exerts anti-inflammatory effects during the treatment of glioma by GCs. Moreover, a molecular link was identified between glioma cells and macrophages, demonstrating that FGF20 modulates the GCs-induced dysfunction of macrophages during glioma development.

Fibroblast Growth Factor 20 Gene Polymorphism in Parkinson's Disease in Asian Population: A Meta-Analysis.

Parkinson's disease (PD) is a neurodegenerative disease with the pathological hallmark of Lewy bodies and Lewy neurites composed of α-synuclein. The SNP rs591323 is one of the risk loci located near the FGF20 gene that has been implicated in PD. The variation of FGF20 in the 3' untranslated region was shown to increase α-synuclein expression. We examined the association of rs591323 with the risk of PD in a Taiwanese population and conducted a meta-analysis, including our study and two other studies from China, to further confirm the role of this SNP in Taiwanese/Chinese populations. A total of 586 patients with PD and 586 health controls (HCs) were included in our study. We found that the minor allele (A) and the AA + GA genotype under the dominant model are significantly less frequent in PD than in controls. The meta-analysis consisted of 1950 patients with PD and 2073 healthy controls from three studies. There was significant association between rs591323 and the risk of PD in the additive (Z = -3.96; p < 0.0001) and the dominant models (Z = -4.01; p < 0.0001). Our study results and the meta-analysis support the possible protective role of the rs591323 A allele in PD in Taiwanese/Chinese populations.

Mechanisms by which fibroblast growth factor 20 improves motor performance in a mouse model of Parkinson's disease.

Genome-wide studies have reported that Parkinson's disease is associated with abnormal expression of various growth factors. In this study, male C57BL/6 mice aged 10 weeks were used to establish Parkinson's disease models using an intraperitoneal injection of 60 mg/kg 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. 28 days later, 10 or 100 ng fibroblast growth factor 20 was injected intracerebroventricularly. The electrophysiological changes in the mouse hippocampus were recorded using a full-cell patch clamp. Expression of Kv4.2 in the substantia nigra was analyzed using a western blot assay. Serum malondialdehyde levels were analyzed by enzyme-linked immunosorbent assay. The motor coordination of mice was evaluated using the rotarod test. The results showed that fibroblast growth factor 20 decreased A-type potassium current in neurons of the substantia nigra, increased long-term potentiation amplitude in the hippocampus, and downregulated Kv4.2 expression. A high dose of fibroblast growth factor 20 reduced serum malondialdehyde levels and enhanced the motor coordination of mice. These findings confirm that fibroblast growth factor 20 has a therapeutic effect on the toxicity induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, and its mechanism of action is associated with the inhibition of A-type K+ currents and Kv4.2 expression. All animal procedures were approved by the Animal Care and Use Committee of Qilu Hospital of Shandong University, China in 2017 (approval No. KYLL-2017-0012).

Stimulation of mouse vibrissal follicle growth by recombinant human fibroblast growth factor 20.

OBJECTIVES: To explore potential effects of recombinant human fibroblast growth factor 20 (rhFGF20) in the growth of cultured mouse vibrissal follicles. RESULTS: The growth of cultured mouse vibrissal follicles was significantly induced by rhFGF20 in a dose dependent pattern in the in vitro vibrissal follicle organ culture model. However, too high concentration of rhFGF20 could inhibit the growth of vibrissal follicles. We further demonstrated that rhFGF20 stimulated the proliferation of hair matrix cells and activated Wnt/ß-catenin signaling pathway. CONCLUSIONS: The rhFGF20 might be a potential therapeutic agent to treat hair loss disorders.

Fibroblast growth factor 20 is protective towards dopaminergic neurons in vivo in a paracrine manner.

Neuroprotective strategies are an unmet medical need for Parkinson's disease. Fibroblast growth factor 20 (FGF20) enhances survival of cultured dopaminergic neurons but little is known about its in vivo potential. We set out to examine whether manipulation of the FGF20 system affected nigrostriatal tract integrity in rats, to identify which fibroblast growth factor receptors (FGFRs) might reside on dopaminergic neurons and to discover the source of endogenous FGF20 in the substantia nigra (SN). Male Sprague Dawley rats were subject to a partial 6-OHDA lesion alongside treatment with exogenous FGF20 or an FGFR antagonist. Behavioural readouts and tyrosine-hydroxylase (TH) immunohistochemistry were used to evaluate nigrostriatal tract integrity. Fluorescent immunohistochemistry was used to examine FGFR subtype expression on TH-positive dopamine neurons and FGF20 cellular localisation within the SN. FGF20 (2.5 µg/day) significantly protected TH-positive cells in the SN and terminals in the striatum, while reducing the development of motor asymmetry at 5, 8 and 11 days post lesion. Conversely, the FGFR antagonist PD173074 (2 mg/kg) significantly worsened both the 6-OHDA lesion and resultant motor asymmetry. Within the SN, TH-positive cells expressed FGFR1, 3 and 4 while FGF20 co-localised with GFAP-positive astrocytes. In conclusion, FGF20 protects dopaminergic neurons in vivo, an action likely mediated through activation of FGFRs1, 3 or 4 found on these neurons. Given FGF20 is localised to astrocytes in the adult SN, endogenous FGF20 provides its protection of dopamine neurons through a paracrine action. Boosting the endogenous FGF20 production might offer potential as a future therapeutic strategy in Parkinson's disease.

Evaluation of FGF 20 variants for susceptibility to Parkinson's disease in Eastern Indians.

BACKGROUND: Parkinson's disease (PD) is the second most common neurodegenerative disease and has a complex etiology. Single nucleotide polymorphisms in the 3'-untranslated region of Fibroblast growth factor 20 (FGF 20) have been reported to be associated with PD; however, the results are controversial. Although FGF20 enhances the survival of dopaminergic neurons, it may also result in PD susceptibility by altering alpha-synuclein expression. MATERIALS AND METHODS: To identify and characterize genetic risk variants in FGF 20 in Eastern Indian PD patients, 2 SNPs of FGF 20 (rs1721100 and rs2720208) were genotyped in 336 PD cases and 313 ethnically matched controls by PCR-RFLP. RESULTS: We observed statistically significant differences in genotypic and allelic frequencies of rs1721100 between PD cases and controls but not for rs12720208. Haplotype G-C showed a significant protective effect against PD. A functional assay revealed that the risk allele C at rs1721100 has little or no effect on relative luciferase activity from a reporter construct in the presence of miR-3189-3p, whereas allele G results in significant dose-dependent reduction. CONCLUSION: Our results suggest that FGF 20 is a susceptibility gene for PD in Eastern Indians.

Association between FGF20 rs12720208 gene polymorphism and Parkinson's disease: a meta-analysis.

Previous studies have claimed the association of rs12720208 polymorphism in the fibroblast growth factor 20 (FGF20) gene with the increased risk of Parkinson's disease (PD), but results from the published data were controversial. The aim of our present meta-analysis was to estimate the overall association between FGF20 rs12720208 polymorphism and the risk of PD. Case-control studies with sufficient data evaluating the association between rs12720208 C/T polymorphism and PD susceptibility were systematically identified in PubMed, OVID, SinoMed, Chinese National Knowledge Infrastructure (CNKI) up to July 10, 2015. A total of 3402 PD patients and 3739 controls from seven case-control studies were collected for this meta-analysis. The pooled odds ratio (OR) with its 95 % confidence interval (CI) was calculated to assess the genetic association between FGF20 rs12720208 polymorphism and the risk of PD. In this study, no enough proof was found to prove the association in any genetic models with random-effects model (CT+TT vs. CC: OR = 1.147, 95 % CI: 0.883-1.489, P = 0.304; TT vs. CC+CT: OR = 1.754, 95 % CI: 0.878-3.505, P = 0.112; T vs. C: OR = 1.169, 95 % CI = 0.919-1.487, P = 0.204; TT+CC vs. CT: OR = 0.906, 95 % CI = 0.694-1.182, P = 0.466). Our results suggest that there is no sufficient evidence to support the association between rs12720208 polymorphism and PD risk. Studies with larger sample size across diverse populations and subgroup analyses are necessary in the future.

Effects of temperature and additives on stability and spectrum of a therapeutic fibroblast growth factor.

BACKGROUND AND THE PURPOSE OF THE STUDY: Human fibroblast growth factor 20 (FGF20) is a 16.5 kDa protein containing 154 amino acid residues with reportedly poor thermal stability, and low stability, which are considered to be major factors that can limit its pharmacological applications. Thus, the aim of this study was to enhance the thermal stability and bio activity of a therapeutic FGF20 by addition of sucrose or heparin as additives and also at different temperatures. METHODS: A variety of biophysical techniques such as far-UV circular dichroism (CD), fluorescence and high resolution derivative UV absorption spectroscopy, were employed to characterize FGF20 and study the effects of heparin and sucrose on its thermal stability and bio activity at pH 7.0. RESULTS: Results of this study suggest that human FGF20 is significantly unstable and induction of heat by increased temperatures results in aggregation and precipitation at pH 7.0. Great changes in the fluorescence intensity and shape were achieved by addition of heparin and sucrose at different temperatures compared to the control. From 10 °C to 60 °C, no significant changes were observed in far-UV CD spectrum compared to the control, but significant changes were observed by adding sucrose when these temperatures are above 45 °C. Upon addition of heparin and sucrose, the mitogenic activity increased significantly at all tested temperatures, and these changes may be related to the roles of heparin and sucrose on the structure and conformation of FGF20. CONCLUSION: Results of this study suggest that heparin and sucrose as additives seems to benjm sufficient to prevent thermal inactivation of FGF20 and also maintain its conformation stability and bio activity.

Growth factors and feeder cells promote differentiation of human embryonic stem cells into dopaminergic neurons: a novel role for fibroblast growth factor-20.

Human embryonic stem cells (hESCs) are a potential source of dopaminergic neurons for treatment of patients with Parkinson's disease (PD). Dopaminergic neurons can be derived from hESCs and display a characteristic midbrain phenotype. Once transplanted, they can induce partial behavioral recovery in animal models of PD. However, the potential research field faces several challenges that need to be overcome before clinical application of hESCs in a transplantation therapy in PD can be considered. These include low survival of the hESC-derived, grafted dopaminergic neurons after transplantation; unclear functional integration of the grafted neurons in the host brain; and, the risk of teratoma/tumor formation from the transplanted cells. This review is focused on our recent efforts to improve the survival of hESC-dervied dopaminergic neurons. In a recent study, we examined the effect of fibroblast growth factor (FGF)-20 in the differentiation of hESCs into dopaminergic neurons. We supplemented cultures of hESCs with FGF-20 during differentiation on PA6 mouse stromal cells for 3 weeks. When we added FGF-20 the yield of neurons expressing tyrosine hydroxylase increased. We demonstrated that at least part of the effect is contributed by enhanced cell differentiation towards the dopaminergic phenotype as well as reduced cell death. We compare our results with those obtained in other published protocols using different sets of growth factors. Taken together, our data indicate that FGF-20 has potent effects to generate large number of dopaminergic neurons derived from hESCs, which may be useful for hESC-based therapy in PD.

Fibroblast growth factor-20 increases the yield of midbrain dopaminergic neurons derived from human embryonic stem cells.

In the central nervous system, fibroblast growth factor (FGF)-20 has been reported to act preferentially on midbrain dopaminergic neurons. It also promotes the dopaminergic differentiation of stem cells. We have analyzed the effects of FGF-20 on human embryonic stem cells (hESCs) differentiation into dopaminergic neurons. We induced neuronal differentiation of hESCs by co-culturing those with PA6 mouse stromal cells for 3 weeks. When we supplemented the culture medium with FGF-20, the number of tyrosine hydroxylase (TH)-expressing neurons increased fivefold, from 3% to 15% of the hESC-derived cells. The cultured cells also expressed other midbrain dopaminergic markers (PITX3, En1, Msx1, and Aldh1), suggesting that some had differentiated into midbrain dopaminergic neurons. We observed no effect of FGF-20 on the size of the soma area or neurite length of the TH-immunopositive neurons. Regardless of whether FGF-20 had been added or not, 17% of the hESC-derived cells expressed the pan-neuronal marker b-III-Tubulin. The proportion of proliferating cells positive for Ki-67 was also not affected by FGF-20 (7% of the hESC-derived cells). By contrast, after 3 weeks in culture FGF-20 significantly reduced the proportion of cells undergoing cell death, as revealed by immunoreactivity for cleaved caspase-8, Bcl-2 associated X protein (BAX) and cleaved caspase-3 (2.5% to 1.2% of cleaved caspase-3-positive cells out of the hESC-derived cells). Taken together, our results indicate that FGF-20 specifically increases the yield of dopaminergic neurons from hESCs grown on PA6 feeder cells and at least part of this effect is due to a reduction in cell death.