Assessment of the effectiveness of the peptide inhibitor homologous to the transforming growth factor ß cytokine blocking the TGFßRI/TGFßRII receptor complex-pilot study.

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.

New insights into the regulation of TGF-ß/Smad and MPK signaling pathway gene expressions by nasal allergen and methacholine challenge test in asthma.

Background: Asthma is a heterogeneous chronic inflammatory disease of the bronchi, the course of which is significantly influenced by extrinsic factors (specific and non-specific). Methods: The aim of this study was to evaluate the effect of these factors represented by nasal allergen challenge (specific factors) and methacholine challenge test (non-specific) on changes in mRNA expression of genes encoding the TGF-ß (TGF-ß1 and TGF-ß3)‒Smad (mitogen-activated protein kinase 1/3 [MPK1/3], Smad1/3/6/7) signaling pathway in asthmatic patients. Results: Seventy-five subjects were included in the study, of whom 27 were applied an intranasal allergen provocation and 48 a methacholine provocation. There were 9 men and 18 women in the intranasal provocation group, and 17 men and 31 women in the methacholine test group. We found that both examined the types of challenges contributed to changes in the relative expression of genes of the TGF-ß (TGF-ß1 and TGF-ß3)‒Smad (MPK1/3, Smad1/3/6/7) signaling pathway in asthmatic patients. A decrease was noted for MAPK1, MAPK3, Smad3, Smad6, and Smad7 genes and an increase of up to 2.5 times for TGF-ß1 gene. Conclusions: Our experiment allows us to conclude that the change in the mRNA expression of the TGF-ß1-MPK1/3 and Smad3/6/7 genes occurs after an intranasal allergen and bronchial methacholine challenge.