Functional high-throughput analysis of the role of microRNAs in regulating Staphylococcus aureus infection

Informations projet

miRs4Staph

N° de convention de subvention: 893942

DOI

10.3030/893942

Projet clôturé

Date de signature de la CE 24 Mars 2020

Date de début 15 Octobre 2020

Date de fin 14 Octobre 2022

Financé au titre de

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Coût total

€ 147 815,04

Contribution de l’UE

€ 147 815,04

Coordonné par

CENTRO DE NEUROCIENCIAS E BIOLOGIACELULAR ASSOCIACAO
Portugal

Periodic Reporting for period 1 - miRs4Staph (Functional high-throughput analysis of the role of microRNAs in regulating Staphylococcus aureus infection)

Période du rapport: 2020-10-15 au 2022-10-14

Résumé du contexte et des objectifs généraux du projet

Staphylococcus aureus is a bacterium commonly found on the skin and nares of both humans and animals. However, it can become an opportunistic pathogen, causing a variety of clinical manifestations, from minor skin infections to life-threatening diseases, including pneumonia, osteomyelitis and endocarditis. The treatment of S. aureus infections has become increasingly difficult due to the emergence of antibiotic-resistant strains in clinical context and the spreading of these strains in the community.
Nowadays, it is known that S. aureus can live inside host cells and this intracellular lifestyle is crucial for infection dissemination and persistence. Also, intracellular bacteria may be protected from the activity of antimicrobials, leading to treatment failure and post-therapy relapse. In order to successfully invade and survive inside host cells, S. aureus needs to modulate host cell functions through several mechanisms. MiRNAs are small molecules present in host cells, which are capable of regulating cellular gene expression and, thus, influence the outcome of S. aureus infection.
In this context, the goal of this study was to discover miRNAs that regulate S. aureus invasion, survival, and replication within host cells. The knowledge of these factors may potentially reveal novel therapeutical targets to control S. aureus infection.

Travail effectué depuis le début du projet jusqu’à la fin de la période considérée dans le rapport et principaux résultats atteints jusqu’à présent

To discover host cell factors involved in S. aureus – host interplay, we used an in vitro S. aureus infection model, in which the effect of 2,042 individual miRNAs was evaluated in S. aureus infection of human epithelial cells. For that, we used innovative cell and molecular biology technologies, including high-throughput screening coupled to automated microscopy. As a result, we identified 87 miRNAs that strongly increased or decreased S. aureus infection and replication.
To increase the biological/clinical relevance of our findings, we validated the effect of this subset of 87 miRNAs on infection by S. aureus clinical isolates obtained from patients with different clinical manifestations, namely bone/joint infections, infective endocarditis and bacteraemia. We observed a strong conservation of the effect of the selected miRNAs on the infection and replication of the tested S. aureus isolates. We also performed time course experiments to determine which stages of S. aureus infection cycle were affected by specific miRNAs, and discovered that both the invasion and replication of S. aureus were regulated.
We have now selected two miRNAs that increase intracellular replication of S. aureus for detailed characterization, which is underway.
The results were presented by the Fellow at several advanced courses, meetings and conferences. An article describing the characterization of S. aureus intracellular lifestyles has been published, and additional manuscripts are expected. The Fellow participated in outreach activities, namely in the European Researcher’s Night.

Progrès au-delà de l’état des connaissances et impact potentiel prévu (y compris l’impact socio-économique et les conséquences sociétales plus larges du projet jusqu’à présent)

This study is revealing novel host molecular players that are important for S. aureus infection, which could be explored for the development of novel therapeutic approaches. This is particularly relevant at a time when antibiotic resistance is a major global health concern. In fact, the latest studies indicate that 4.95 million deaths worldwide were associated with infections caused by antimicrobial resistant bacteria in 2019. Among them, S. aureus is one of the most problematic multi-drug resistant pathogens, being the second most common cause of global deaths associated with bacterial antimicrobial resistance.
Therefore, the knowledge acquired from this project on host mechanisms relevant for S. aureus infection may reveal novel targets for therapeutic intervention and thus lead to the development of novel antimicrobial therapies based on host targets rather than aiming at the pathogen, which has high capacity of acquiring antibiotic resistance.

schematic representation of the project