RESUMO
BACKGROUND: A key player in the fibrotic process is the transforming growth factor ß (TGF-ß) which enhances extracellular matrix production by increasing the transcription of matrix proteins. The cytokine TGF-ß first binds to the TGFßRII receptor (dimer), resulting in the recruitment of the TGFßRI receptor (dimer). The complex thus formed leads to the phosphorylation of the kinase domain of TGFßRI, which in turn results in activation of the Smad pathway. This is therefore a targeted pathway for research into the application of peptide inhibitors in blocking the TGF-ß-Smad signaling pathway. The aim of this study was to design a peptide inhibitor (homologous to the cytokine TGF-ß) which, after binding to the TGFßRI/TGFßRII receptor, would block the cytokine binding and thus prevent the formation of an activating complex. METHODS: Preliminary work on the design and synthesis of inhibitors for TGFßRI/TGFßRII has allowed us to identify and describe five key regions of the TGF-ß-TGFßRI/TGFßRII interface. The following five peptide inhibitors were synthesized for Region 1: 1.1 ALDAAYCFR, 1.2 LDAAYCFRN, 1.3 DAAYCFRNV, 1.4 AAYCFRNVQ, 1.5 AYCFRNVQD. The expression of the SEAP reporter gene, Smad2, Smad3, Smad4, and JNK1 gene was measured using quantitative real-time polymerase chain reaction. RESULTS: For Region 1 peptide inhibitors tested for TGFßRI/TGFßRII, reduced SEAP (reporter gene) expression was observed in cells of the MFB-F11 line, which suggests inhibited the formation of cytokine-receptor complexes. CONCLUSIONS: For IP1_2, 1_3 and 1_5 Region 1 peptides tested for TGFßRI/TGFßRII, reduced cytokine-receptor signal by adding newly designed inhibitors. The study revealed an impact of these peptide inhibitors on the reduction of mRNA expression of Smad2, Smad3, Smad4 and JNK1 genes.
RESUMO
BACKGROUND: TGF-ß and its receptors play a crucial role in asthma pathogenesis, bronchial hyperreactivity, and bronchial remodeling. Expression of isoforms 1-3 of TGFß cytokine is influenced by tagging polymorphisms in the TGFß1, TGFß2 and TGFß3 gene, and these SNPs may be associated with the risk of asthma development and severity as well as with other diseases. Polymorphic forms of TGF-ß1, TGF-ß2 and TGF-ß3 genes regulate the degree of bronchial inflammation, deterioration of lung functional parameters in spirometry and elevated level of total IgE. All this results in intensification of disease symptoms. According to current GINA 2020 guidelines, the Asthma Control Test (ACT™) should be applied to assess asthma symptoms. METHODS: An analysis of polymorphisms localized in TGF-ß1, TGF-ß2 and TGF-ß3 genes was conducted on 652 DNA samples with an application of the MassARRAY® system using the mass spectrometry technique MALDI TOF MS. The degree of asthma control was evaluated with ACT™. RESULTS: The occurrence of the T / C genotype in rs8109627 (p = 0.0171) in the TGF-ß1 gene is significantly associated with a higher ACT result (controlled asthma) in a multivariate linear regression analysis model after using backward stepwise selection of variables. In addition, in the linear model for prediction of ACT score we showed SNP rs8109627 (p = 0.0497) in the TGF-ß1 gene (improvement of the disease control - controlled asthma) and rs2796822 (p = 0.0454) in the TGF-ß2 gene (deterioration of the diseases control - uncontrolled asthma) significantly modify the degree of asthma control. DISCUSSION: We described clinical significance of two SNPs in two genes TGF-ß1 and TGF-ß2, as yet unknown. We proved that the use of both genotypes and MAC allows to create a moderately correct prognostic model which is about 70% efficient on the entire set of analyzed SNPs in TGF-ß1, TGF-ß2, and TGF-ß3 genes.
