Bronchial epithelium repair by Esculentin-1a-derived antimicrobial peptides: involvement of metalloproteinase-9 and interleukin-8, and evaluation of peptides\u2019 immunogenicity

Floriana Cappiello,Loretta Ferrera,Y. Peter Di,Bruno Casciaro,Han-Tang Chen,Veronica Carnicelli,Danilo Ranieri,Maria Luisa Mangoni

doi:10.1038/s41598-019-55426-x

Abstract

The airway epithelium is seriously damaged upon pulmonary Pseudomonas aeruginosa infection, especially in cystic fibrosis (CF) sufferers. Therefore, the discovery of novel anti-infective agents accelerating healing of infected injured tissues is crucial. The antipseudomonal peptides esculentin-1a(1–21)NH2 and its diastereomer Esc(1–21)-1c (Esc peptides) hold promise in this respect. In fact, they stimulate airway epithelial wound repair, but no mechanistic insights are available. Here we demonstrated that this process occurs through promotion of cell migration by an indirect activation of epidermal growth factor receptor mediated by metalloproteinases. Furthermore, we showed an increased expression of metalloproteinase 9, at both gene and protein levels, in peptide-treated bronchial epithelial cells with a functional or mutated form of CF transmembrane conductance regulator. In addition, the two peptides counteracted the inhibitory effect of Pseudomonas lipopolysaccharide (mimicking an infection condition) on the wound healing activity of the airway epithelium, and they enhanced the production of interleukin-8 from both types of cells. Finally, no immunogenicity was discovered for Esc peptides, suggesting their potential safety for clinical usage. Besides representing a step forward in understanding the molecular mechanism underlying the peptide-induced wound healing activity, these studies have contributed to highlight Esc peptides as valuable therapeutics with multiple functions.

Highlights

The respiratory epithelium is damaged after exposure to microbial pathogens such as Pseudomonas aeruginosa[1]
We recently showed that both Esc peptides promoted the restitution of the pseudo-wound produced in wt-CFBE and F508del-CFBE monolayers within 20 h, at an optimal concentration of 10 μM or 1 μM for Esc(1–21) or its diastereomer, respectively[17]
We discovered that treatment of CFBE with both Esc peptides in serum-free medium led to a clear change of the cytoskeleton arrangement, with a cellular shape that is typical of cell motility and that mainly consists in the formation of lamellipodia at the front edge

Summary

Introduction

The respiratory epithelium is damaged after exposure to microbial pathogens such as Pseudomonas aeruginosa[1]. Both Esc(1–21) and its diastereomer (Esc peptides) were able to advance the healing of a pseudo-wound produced in a monolayer of wt-CFBE and F508del-CFBE, by activation of epidermal growth factor receptor (EGFR), with a higher efficacy for the diastereomer[17] This function is extremely advantageous, considering that the recovery of an injured infected tissue does require elimination of microorganisms and retrieval of tissue integrity and its barrier function preventing pathogens penetration. Considering the potential usage of Esc peptides as therapeutic agents, their immunogenicity was evaluated This is the first report showing the involvement of MMP-9 in the AMPs-induced migration of bronchial epithelial cells, either wt-CFBE or F508del-CFBE, as well as the induction of IL-8 production from Esc peptides-stimulated bronchial cells in bacterial infection-mimicking conditions. We demonstrated for the first time that Esc peptides are not immunogenic

Methods

Results

Conclusion