Expression of fibroblast growth factor 9 in normal human lung and idiopathic pulmonary fibrosis.

The fibroblast growth factor (FGF) family of signaling ligands contributes significantly to lung development and maintenance in the adult. FGF9 is involved in control of epithelial branching and mesenchymal proliferation and expansion in developing lungs. However, its activity and expression in the normal adult lung and by epithelial and interstitial cells in fibroproliferative diseases like idiopathic pulmonary fibrosis (IPF) are unknown. Tissue samples from normal organ donor human lungs and those of a cohort of patients with mild to severe IPF were sectioned and stained for the immunolocalization of FGF9. In normal lungs, FGF9 was confined to smooth muscle surrounding airways, alveolar ducts and sacs, and blood vessels. In addition to these same sites, lungs of IPF patients expressed FGF9 in a population of myofibroblasts within fibroblastic foci, hypertrophic and hyperplastic epithelium of airways and alveoli, and smooth muscle cells surrounding vessels embedded in thickened interstitium. The results demonstrate that FGF9 protein increased in regions of active cellular hyperplasia, metaplasia, and fibrotic expansion of IPF lungs, and in isolated human lung fibroblasts treated with TGF-ß1 and/or overexpressing Wnt7B. The cellular distribution and established biologic activity of FGF9 make it a potentially strong candidate for contributing to the progression of IPF.

FGF9-induced proliferative response to eosinophilic inflammation in oesophagitis.

BACKGROUND: Oesophagitis is characterised by basal cell hyperplasia and activated eosinophils, which release mediators including major basic protein (MBP). MBP and its mimetic polyarginine activate the calcium sensing receptor (CaSR) on oesophageal epithelium. Fibroblast growth factor 9 (FGF9) is implicated in epithelial homeostasis and proliferative response to injury, but has not been characterised in the oesophagus. OBJECTIVE: To characterise FGF9 in oesophageal epithelium and oesophagitis, as the result of MBP activation of the CaSR. METHODS: Human oesophageal epithelial cells (HET-1A) were used to compare affects of calcium, polyarginine and MBP-peptide on FGF9. HET-1A were transfected with interfering RNA (siRNA(CaSR)). FGF9, FGF receptors 2 and 3, bone morphogenetic protein (BMP)-2, BMP-4 and noggin mRNA expression were detected by reverse transcriptase polymerase chain reaction. FGF9 was measured from HET-1A and from normal, gastro-oesophageal reflux and eosinophilic oesophagitis (EoE) patient biopsies using ELISA and immunohistochemistry. HET-1A proliferation was studied using bromodeoxyuridine and MTT. RESULTS: FGF9 was secreted by HET-1A cells treated with polyarginine and MBP-peptide, but not calcium. This effect was abrogated by siRNA(CaSR). FGF9 receptor mRNA was present. HET-1A cells proliferated following rhFGF9, but not MBP-peptide treatment, and rhFGF9 altered transcription of downstream proliferation-related genes (noggin, BMP-2 and BMP-4). FGF9 was increased in biopsies from patients with eosinophilic oesophagitis, which correlated with basal hyperplasia. CONCLUSION: Eosinophil-released MBP acts on the CaSR to increase FGF9 in oesophageal epithelial cells, leading to proliferation. Increased FGF9 is found in biopsies of EoE patients and may play a role in the pathogenesis of oesophagitis.

Clinical study of inflammatory factors in sputum induced early after lung volume reduction surgery.

BACKGROUND: The aim of this study was to prospectively study the changes in neutrophil elastase (NE), fibroblast growth factor 9 (Fgf9), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase 1 (TIMP-1) in sputum induced during the early period after lung volume reduction surgery (LVRS). METHODS: From April to October 2005, ten consecutive patients with chronic obstructive pulmonary disease (COPD) underwent LVRS. Ten non-small cell lung cancer patients (stage II - IIIa) received lobectomy as a control group. The induced sputum was collected from both groups at six different times (two weeks before operation and postoperatively at 1, 2, 4, 6 and 10 days). The level of NE, Fgf9, MMP-9 and TIMP-1 were measured using enzyme-linked immunosorbent assay. RESULTS: The pulmonary function (FEV(1)%) and arterial blood gases (PaO(2) and PaCO(2)) were significantly different between the groups. There were no significant differences in age, ejection fraction (EF), and operation duration, but hemoglobin in the LVRS group was statistically higher than in the controls. At certain times, there were significant differences in NE, MMP-9, TIMP-1 and MMP-9/TIMP-1 (P < 0.05) but not in Fgf9 between the two groups. The levels of NE and TIMP-1 were maximal at 2 days postoperatively and that of MMP-9 and MMP-9/TIMP-1 at 4 days postoperatively in the LVRS group. In the control group, maximal levels of NE and TIMP-1 occurred at 2 days postoperatively and that of MMP-9 and MMP-9/TIMP-1 at 1 day postoperatively. Ten days after surgery, all values of the control group were not significantly different from the baseline. In the LVRS group, the levels were significantly different from the pre-operative values (P < 0.05) apart from TIMP-1. CONCLUSION: The levels of NE, MMP-9, TIMP-1 and MMP-9/TIMP-1 of the LVRS group were different from those of the control group. The time course of these changes may be related to LVRS and the underlying process of COPD.

Cytokine profile in synovial fluid from patients with internal derangement of the temporomandibular joint: a preliminary study.

OBJECTIVES: Temporomandibular joint disorders (TMD) comprise a group of chronic painful conditions of mastication in the temporomandibular joint (TMJ). Although the association between TMD and internal derangement of the TMJ is well documented, the functional relevance is still unclear. Increased concentrations of inflammatory mediators have been identified in the synovial fluid of affected patients with TMD, suggesting an underlying degenerative or inflammatory process. The aim of this study was to generate a comprehensive cytokine expression profile in TMD. METHODS: 15 samples from patients with internal derangement of TMJ were analysed using a novel cytokine array that enables the analysis of 79 different cytokines simultaneously. RESULTS: Cytokine levels were correlated with the presence of joint effusion (JE) determined by MRI. In the majority of synovial fluid samples, angiogenin (Ang), fibroblast growth factor (FGF)-9, insulin-like growth factor-binding protein (IGFBP)-3, interleukin (IL)-1alpha, IL-1beta, IL-8, inducible protein (IP)-10, macrophage inflammatory protein (MIP)-1beta, osteoprotegerin (OPG), transforming growth factor (TGF)-beta2, tissue inhibitor of metalloproteinase (TIMP)-1, TIMP-2, tumour necrosis factor (TNF)-beta and vascular endothelial growth factor (VEGF) were detectable. Furthermore, the expression levels of Ang, brain-derived neurotrophic factor (BDNF), FGF-4, FGF-9, IGFBP-2, IL-8, MIP-1beta, OPG, pulmonary and activation-regulated protein (PARC), TGF-beta2, TIMP-2 and VEGF were significantly associated with the presence of JE; among these, nine cytokines (Ang, BDNF, FGF-4, FGF-9, IGFBP-2, MIP-1beta, PARC, TGF-beta2 and TIMP-2) were hitherto not described in TMD. CONCLUSIONS: This study confirmed previous reports of elevated cytokine levels in TMD. Additionally, we identified previously undescribed cytokines that were upregulated and correlated significantly with the presence of JE. We were able to identify novel cytokines that have hitherto not been described in TMD. Strategies targeting the identified cytokines may represent a novel therapy option in TMD.

Fibroblast growth factor 9: cloning and immunolocalisation during tooth development in Didelphis albiventris.

There are no reports in literature about functional roles of fibroblast growth factor 9 (FGF-9) in tooth development in animals with complete tooth pattern. The classical model for studying tooth development is the mouse, which has small number of teeth and distinctive incisor and molar patterns. The opossum Didelphis albiventris with five upper and four lower incisors, one canine, three premolars, and four molars, on each side of the jaw, seems to be a convenient model to test results obtained in the mouse. Molecular expression studies indicate that FGF-9 participates in murine tooth initiation and regulation of morphogenesis. Searching for similarities and differences in FGF-9 expression between the opossum and the mouse, amino acid sequence and expression pattern of FGF-9 in the developing first molars of D. albiventris were characterised. FGF-9 cDNA sequence was obtained using RT-PCR and expressed in bacterial system for recombinant protein production and analysis of immunoreactivity. FGF-9 expression during tooth development was investigated by immunoperoxidase method. FGF-9 protein consists in a 209-residue polypeptide with a predicted molecular mass of 23.5 kDa. FGF-9 amino acid sequence has 98% of sequence identity to human and 97% to rodents. During tooth development, epithelial FGF-9 expression was seen at the dental lamina stage. Mesenchymal expression was seen at the bud stage and at the cap stage. No significant expression was found in the enamel knot. While in rodents FGF-9 is involved in initiation and regulation of tooth shape, it is suggested that it is only involved in tooth initiation in D. albiventris.