ABSTRACT
Trefoil factor family domain peptides (TFF) are thought to be involved in mucosal epithelial restitution and wound healing of the gastrointestinal tract and are up-regulated in ulceration and in a variety of solid tumours. It was hypothesized that TFFs are also expressed on mucosal surfaces of the human respiratory tract. Lung tissue, nasal polyps, and sputum samples from seven patients with cystic fibrosis (CF), two with chronic and acute bronchitis, and non-dysplastic material from two cases of bronchial adenocarcinoma were analysed for TFF expression by immunohistochemistry, immunofluorescence, western blot and RT-PCR. Expression of TFF1 and TFF3 was observed in material from all patients. TFFs were localized in goblet and ciliated cells, as well as in some submucosal cells of tracheobronchial tissues and nasal polyps from normal and CF individuals. In sputa of patients with CF and with chronic or acute bronchitis, TFF1 and TFF3 were detected by western blotting. Freshly cultivated nasal epithelial cells transcribed and secreted TFFs and mucins, whereas nasal cells cultivated for 6 weeks still expressed mucins, but not TFFs. Secreted TFFs and mucins also bound to the surface of Staphylococcus aureus in infected CF airways. In conclusion, TFF1 and TFF3 are expressed and secreted in normal and inflamed airways. The association of TFFs with bacteria may contribute to the anti-microbial mucociliary defence system.
Subject(s)
Mucins , Muscle Proteins , Neuropeptides , Proteins/metabolism , Respiratory Tract Diseases/metabolism , Adenocarcinoma/metabolism , Aged , Bronchitis/metabolism , Chronic Disease , Cystic Fibrosis/metabolism , Female , Fluorescent Antibody Technique, Indirect , Growth Substances/metabolism , Humans , Immunoenzyme Techniques , Lung Neoplasms/metabolism , Male , Middle Aged , Nasal Polyps/metabolism , Peptides/metabolism , Sinusitis/metabolism , Sputum/metabolism , Staphylococcus aureus/metabolism , Trefoil Factor-1 , Trefoil Factor-2 , Trefoil Factor-3 , Tumor Suppressor ProteinsABSTRACT
The winged helix transcription factors HNF-3/FKH (forkhead homologs) activate endodermal-derived and acute-phase gene expression and control gut development in Drosophila. Trefoil factor family (TFFs) peptides are vertebrate products secreted by mucin-producing epithelial cells of the gastrointestinal tract involved in restitution and repair of the mucosa. They are positively regulated in ulcerative and neoplastic conditions. We describe a consensus sequence in human and rodent TFF promoters close to the TATAA box showing striking similarity to the binding site of the HNF-3/FKH family. In gel retardation assays, HNF-3 alpha and beta bound predominantly to the site in TFF1 (formerly pS2) and, to a lesser extent, to the sites in TFF2 or TFF3. Mutations generated in this motif severely impaired transcription of TFF1 reporter genes. Cotransfection with expression vectors of HNF-3alpha and beta, but not the related HFH 11A and B, specifically activated the wild-type TFF1 reporter genes. Activation of endogenous expression of TFF1 by HNF-3 alpha and beta gene products was more than 1000 fold in the pancreatic cell line Capan-2 and fivefold in the gastric cell line MKN-45, whereas the intestinal cell lines HUTU 80 and HT-29 displayed no effect. Thus, HNF-3/FKH factors contribute causally to cell-specific regulation of TFF genes and may explain the acute-phase response of TFF peptides.
Subject(s)
Growth Substances/genetics , Mucins , Muscle Proteins , Neuropeptides , Peptides/genetics , Proteins/genetics , Trans-Activators/genetics , Animals , Base Sequence , Binding Sites , Cell Nucleus/chemistry , Cell Nucleus/metabolism , Cell-Free System/chemistry , Cell-Free System/metabolism , DNA-Binding Proteins/genetics , Forkhead Box Protein M1 , Forkhead Transcription Factors , Gene Expression Regulation, Neoplastic , Genes, Reporter/genetics , Growth Substances/metabolism , Hepatocyte Nuclear Factor 3-alpha , Hepatocyte Nuclear Factor 3-beta , Humans , Molecular Sequence Data , Mutagenesis , Nuclear Proteins/genetics , Peptides/metabolism , Promoter Regions, Genetic , Protein Binding , Proteins/metabolism , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Sequence Homology, Nucleic Acid , TATA Box , Trans-Activators/metabolism , Transcription Factors/genetics , Trefoil Factor-1 , Trefoil Factor-2 , Trefoil Factor-3 , Tumor Cells, Cultured/chemistry , Tumor Cells, Cultured/cytology , Tumor Cells, Cultured/metabolism , Tumor Suppressor ProteinsABSTRACT
Peptides belonging to the trefoil factor family (TFF) protect the gastrointestinal epithelia. Overexpression of TFFs was observed in pathological conditions such as gastritis, ulceration, metaplasia and neoplasia of the gastrointestinal tract. The aims of this work were to investigate the recently described TFF2 gene polymorphism in different European populations. DNA samples from blood of healthy individuals and gastric cancer patients were genotyped using the polymerase chain reaction. They were compared to a gastric cancer population. The results do not show any significant difference in allelic frequencies between gastric cancer patients and healthy individuals from Portugal. However, the frequency of the two alleles found varies considerably among Europeans.
