Exposure of cultured fibroblasts to the peptide PR-11 for the identification of induced proteome alterations and discovery of novel potential ligands

• Published in: Biochimica et biophysica acta Vol. 1864; no. 12; pp. 1775 - 1786
• Main Authors: Breguez, Gustavo Silveira, Neves, Leandro Xavier, Silva, Karina Taciana Santos, de Freitas, Lorran Miranda Andrade, de Oliveira Faria, Gabriela, Isoldi, Mauro César, Castro-Borges, William, de Andrade, Milton Hércules Guerra
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-12-2016
• Subjects: Animals; Antimicrobial Cationic Peptides - metabolism; Antimicrobial Cationic Peptides - pharmacology; Carrier Proteins - metabolism; Cells, Cultured; Fibroblasts - drug effects; Fibroblasts - metabolism; Hypoxia-Inducible Factor 1, alpha Subunit - metabolism; Immobilized Proteins - metabolism; Immobilized Proteins - pharmacology; Label-free shotgun; Ligands; Mass Spectrometry; Mitochondrial Proteins - metabolism; NF-kappa B - metabolism; Peptide Fragments - metabolism; Peptide Fragments - pharmacology; PR-11; PR-11 binding proteins; PR-39; Proline rich-peptides; Proteasome Inhibitors - metabolism; Proteasome Inhibitors - pharmacology; Proteome - drug effects; Proteome - metabolism; Proteomics; Rats; Rats, Wistar; Swine; Proline rich-peptides; Label-free shotgun; PR-11 binding proteins; PR-39; PR-11
• ISSN: 1570-9639; 0006-3002; 1878-1454
• DOI: 10.1016/j.bbapap.2016.09.017

The PR-11 peptide corresponds to the N-terminal and active region of the endogenously synthesized PR-39 molecule, of porcine origin. It is known to possess various biological effects including antimicrobial properties, angiogenic and anti-inflammatory activities. Apart from its reported activity as a proteasome inhibitor, a more comprehensive understanding of its function, at the molecular level, is still lacking. In this study, we used a label-free shotgun strategy to evaluate the proteomic alterations caused by exposure of cultured fibroblasts to the peptide PR-11. This approach revealed that more than half of the identified molecules were related to signalling, transcription and translation. Proteins directly associated to regulation of angiogenesis and interaction with the hypoxia-inducible factor 1-α (HIF-1α) were significantly altered. In addition, at least three differentially expressed molecules of the NF-κB pathway were detected, suggesting an anti-inflammatory property of PR-11. At last, we demonstrated novel potential ligands of PR-11, through its immobilization for affinity chromatography. Among the eluted molecules, gC1qR, a known complement receptor, appeared markedly enriched. This provided preliminary evidence of a PR-11 ligand possibly involved in the internalization of this peptide. Altogether, our findings contributed to a better understanding of the cellular pathways affected by PR-39 derived molecules.
•Alterations caused by PR-11 on fibroblast culture were revealed by shotgun proteomics.•Signalling and transcription/translation represents over 50% of altered proteins.•Proteins associated to regulation of the HIF-1α and NF-κB pathways were detected.•The gC1qR protein was identified as a ligand of PR-11 by affinity chromatography.