Fibroblast Growth Factor Receptor Inhibitors Reduce Adipogenesis of Orbital Fibroblasts and Enhance Myofibroblastic Differentiation in Graves' Orbitopathy.

Purpose: Orbital fibroblasts are involved in pathogenesis of Graves' orbitopathy (GO). Fibroblast growth factor (FGF) affects fibroblasts of GO. This study aims to investigate the roles of FGF and FGF receptor (FGFR) in GO.Methods: Serum FGF proteins and orbital fibroblast FGFR proteins and mRNAs were measured in GO patients and controls. Orbital fibroblasts of GO were cultured and accessed for changes in proliferation (by nuclei number and MTT), myofibroblastic differentiation (by α-SMA), and adipogenesis (by oil droplets using Oil Red O stain) under FGF1 with or without FGFR inhibitors (FGFRi).Results: Serum FGF1 and FGF2 were increased in GO patients. FGFR1 was the most abundantly expressed FGFR in GO orbital fibroblasts. FGF1 increased GO fibroblast proliferation/adipogenesis and suppressed myofibroblastic differentiation, while FGFRi reversed these effects.Conclusion: FGF signaling may be involved in GO pathogenesis. Manipulation of FGF-FGFR pathway for GO treatment is worthy of further investigation.Registration number on Clinicaltrials.gov: NCT03324022.

Plasma fibroblast growth factor 21 levels increase with ectopic fat accumulation and its receptor levels are decreased in the visceral fat of patients with type 2 diabetes.

Background: Fibroblast growth factor 21 (FGF21) is a novel metabolic regulator that has beneficial effects on glucose and lipid metabolism. However, plasma FGF21 levels are paradoxically increased in type 2 diabetes mellitus (T2DM) and obesity, suggesting resistance to this ligand. FGF21 acts mainly on adipose tissue and ectopic fat accumulation is a typical feature in metabolic deterioration such as diabetes, metabolic syndrome, and cardiovascular disease. Objective: To investigate the relationship between FGF21 resistance and ectopic fat accumulation. Research design and methods: Subjects who underwent 64-slice multidetector CT (MDCT) were enrolled (n=190). Plasma FGF21 levels and MDCT data of ectopic fats at various sites were analyzed. Human visceral and subcutaneous fat tissues from abdominal and coronary artery bypass surgery were obtained. FGF21 receptor expression and postreceptor signaling in different fat deposits of both control and T2DM subjects were analyzed. Results: Plasma FGF21 levels were significantly associated with body mass index, triglyceride, homeostatic model assessment of insulin resistance, and Matsuda index. Plasma FGF21 levels were significantly higher in patients with T2DM than in the pre-diabetes and normal glucose tolerance groups. The ectopic fat phenotypes (visceral, epicardial, intrahepatic, and intramuscular fat) of T2DM were significantly higher than controls. Plasma FGF21 levels were elevated and exhibited a strong positive correlation with ectopic fat accumulation in T2DM. The expression of genes comprising the FGF21 signaling pathway was also lower in visceral fat than in subcutaneous fat in this disease. Conclusions: Human FGF21 resistance in T2DM could result from increases in FGF21-resistant ectopic fat accumulation. Our study provides novel clinical evidence linking FGF21 resistance and T2DM pathogenesis.

[Effect of Ronghuang Granule on serum FGF23, FGFRs and Klotho in non-dialysis patients with CKD-MBD and kidney deficiency and damp-heat syndrome].

OBJECTIVE: To observe the effect of Ronghuang granule on serum fibroblast growth factor 23 (FGF23), fibroblast growth factor receptor (FGFRs) and Klotho protein levels in non-dialysis patients with chronic kidney disease-mineral and bone disorder (CKD-MBD) and kidney deficiency and damp heat syndrome. METHODS: Seventy non-dialysis CKD-MBD patients with kidney deficiency and dampness-heat syndrome were randomized into control group (n=35) and treatment group (n=35). All the patients were given routine treatment combined with traditional Chinese medicine retention enema, and the patients in the treatment group received additional Ronghuang granule treatment (3 times a day). After the 12-week treatments, the patients were examined for changes of TCM syndromes. Serum levels of Ca, P, parathyroid hormone (iPTH), FGF23, FGFRs and Klotho proteins were detected before and after treatment. These parameters were also examined in 20 healthy volunteers. RESULTS: Sixty-five patients completed the study, including 33 in the control group and 32 in the treatment group. The patients in the treatment group showed significantly better treatment responses than those in the control group (P < 0.05 or 0.01). At 4, 8, and 12 weeks of treatment, the patients in the treatment group had significantly lowered scores of TCM syndromes compared with the score before treatment (P < 0.05 or 0.01), while in the control group, significant reduction of the scores occurred only at 12 weeks (P < 0.05); at each of the time points, the treatment group had significantly greater reductions in the score than the control group (P < 0.01). Significant improvements in serum Ca, P and iPTH levels were observed at 4, 8, and 12 weeks in the treatment group (P < 0.05) but only at 12 weeks in the control group (P < 0.05). The patients in the control and treatment groups all showed elevated serum levels of FGF23, FGFRs and Klotho protein compared with the normal subjects (P < 0.01); FGF23, FGFRs and Klotho levels were significantly reduced in the treatment group (P < 0.05) but remained unchanged in the control group (P>0.05), showing significant differences between the two groups. CONCLUSIONS: Ronghuang granule improves the clinical symptoms of non-dialysis CKD-MBD patients with kidney deficiency and dampness heat syndrome by reducing serum levels of FGF23, FGFRs and Klotho, improving calcium and phosphorus metabolism disorder, and inhibiting secondary hyperparathyroidism.

Milk growth factors and expression of small intestinal growth factor receptors during the perinatal period in mice.

BACKGROUND: Growth factors (GFs) are milk bioactive components contributing to the regulation of neonatal small intestinal maturation, and their receptors on the small intestinal epithelium play essential roles in mediating the functions of GFs. There is limited data correlating milk GFs and their receptors in the neonatal small intestine during the perinatal period. METHODS: Small intestines of C57BL/6N mouse pups were collected at regular intervals during fetal life and up to postnatal day (PD) 60. Gene expression of GF receptors was determined by real-time qPCR. Milk GF concentrations up to PD21 were analyzed by enzyme-linked immunosorbent assay. RESULTS: The majority of GF receptors showed significantly greater expression in the fetus than in postnatal life, and a sharp decrease occurred from PD14 extending to PD60; solid food restriction (PD14 and PD18) did not affect this decrease. Concentrations of five detected milk GFs demonstrated that GFs and the corresponding small intestinal receptors exhibited different correlations, with only milk transforming growth factor ß1 (TGF-ß1) having a significant positive correlation with TGF-ß receptor 1 mRNA. CONCLUSION: Gene expression of small intestinal GF receptors is likely a process of neonatal intestinal maturation that is affected concurrently by milk GFs and additional endogenous factors.

Growth inhibition and induction of apoptosis in acute myeloid leukemia cells by new indolinone derivatives targeting fibroblast growth factor, platelet-derived growth factor, and vascular endothelial growth factor receptors.

In acute myeloid leukemia (AML), receptor tyrosine kinase ligands promote growth and survival and contribute to AML-associated marrow neoangiogenesis. We have tested simultaneous inhibition of vascular endothelial growth factor, fibroblast growth factor, and platelet-derived growth factor receptor signaling by novel indolinone derivatives using 14 myeloid, including 11 human leukemic, cell lines. Compounds inhibited colony formation of all cell lines in a dose-dependent fashion. Inhibitory concentrations for 50% of the colony formation/survival (IC50) for BIBF1000 were <100 nmol/L for 3 of 11,

Anti-tumor angiogenesis therapy using soluble receptors: enhanced inhibition of tumor growth when soluble fibroblast growth factor receptor-1 is used with soluble vascular endothelial growth factor receptor.

We have shown that a soluble receptor for vascular endothelial growth factor (sVEGFR), which adsorbs VEGF and may function as a dominant-negative receptor, suppresses tumor angiogenesis and enhances apoptosis of cancer cells, thereby inhibiting tumor growth [Cancer Res 60 (2000) 2169-2177]. In the present study, using as many as 11 cancer cell lines, we tested two hypotheses: (a) that a soluble fibroblast growth factor receptor-1 (sFGFR1) might inhibit tumor angiogenesis and growth in sVEGFR-resistant cancers, and (b) that combining sFGFR1 with sVEGFR might produce an enhanced inhibitory effect. In two cell lines derived from human lung cancer, H460 and A549, both of which produce a considerable amount of FGF-2, sVEGFR and a soluble receptor for angiopoietin-1 were both ineffective; however, sFGFR1 inhibited tumor angiogenesis and growth, demonstrating the critical role that FGFs play in some cancers. In three cell lines (QG56 from lung cancer, T3M4 and Panc1 from pancreatic cancer), which produced both VEGF and FGF-2 at detectable levels, combined sVEGFR and sFGFR1 produced an enhanced inhibitory effect compared to their individual effects. The combined usage of sVEGFR plus sFGFR1 suppressed tumor growth in all cancer cell lines tested, suggesting possible effectiveness of this strategy against a wide range of cancers.

Structural characterization of the circulating soluble FGF receptors reveals multiple isoforms generated by secretion and ectodomain shedding.

Soluble fibroblast growth factor receptors (FGFRs) have been identified in multiple biological fluids, including blood. Efforts to examine the biological properties of these proteins have been hampered by the incomplete chemical characterization of the receptors within the second half of the third immunoglobulin (Ig)-like domain, where alternative splicing leads to receptor variants with different ligand binding properties. Using mass spectrometry techniques, we have mapped the soluble FGFRs to the secreted receptor, FGFR1(IIIa), the two and three Ig-like domain isoforms of FGFR1(IIIc) and a carboxyl-terminal cleavage peptide from the two and three Ig-like domain isoforms of FGFR1(IIIb). The secreted FGFR is produced by the translation of an alternatively spliced transcript and the cleaved receptors are released by ectodomain shedding of the transmembrane receptors.