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  1. Article ; Online: A Common Polymorphism in RNASE6 Impacts Its Antimicrobial Activity toward Uropathogenic Escherichia coli

    Raul Anguita / Guillem Prats-Ejarque / Mohammed Moussaoui / Brian Becknell / Ester Boix

    International Journal of Molecular Sciences, Vol 25, Iss 1, p

    2024  Volume 604

    Abstract: Human Ribonuclease (RNase) 6 is a monocyte and macrophage-derived protein with potent antimicrobial activity toward uropathogenic bacteria. The RNASE6 gene is heterogeneous in humans due to the presence of single nucleotide polymorphisms (SNPs). RNASE6 ... ...

    Abstract Human Ribonuclease (RNase) 6 is a monocyte and macrophage-derived protein with potent antimicrobial activity toward uropathogenic bacteria. The RNASE6 gene is heterogeneous in humans due to the presence of single nucleotide polymorphisms (SNPs). RNASE6 rs1045922 is the most common non-synonymous SNP, resulting in a G to A substitution that determines an arginine (R) to glutamine (Q) transversion at position 66 in the protein sequence. By structural analysis we observed that R66Q substitution significantly reduces the positive electrostatic charge at the protein surface. Here, we generated both recombinant RNase 6-R66 and -Q66 protein variants and determined their antimicrobial activity toward uropathogenic Escherichia coli (UPEC), the most common cause of UTI. We found that the R66 variant, encoded by the major SNP rs1045922 allele, exhibited superior bactericidal activity in comparison to the Q66 variant. The higher bactericidal activity of R66 variant correlated with an increase in the protein lipopolysaccharide binding and bacterial agglutination abilities, while retaining the same enzymatic efficiency. These findings encourage further work to evaluate RNASE6 SNP distribution and its impact in UTI susceptibility.
    Keywords RNase ; RNase 6 ; RNase k6 ; single nucleotide polymorphisms ; antimicrobial peptides ; urinary tract infections ; Biology (General) ; QH301-705.5 ; Chemistry ; QD1-999
    Subject code 572
    Language English
    Publishing date 2024-01-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Structure-Based Design of an RNase Chimera for Antimicrobial Therapy

    Guillem Prats-Ejarque / Helena Lorente / Clara Villalba / Raúl Anguita / Lu Lu / Sergi Vázquez-Monteagudo / Pablo Fernández-Millán / Ester Boix

    International Journal of Molecular Sciences, Vol 23, Iss 95, p

    2022  Volume 95

    Abstract: Bacterial resistance to antibiotics urges the development of alternative therapies. Based on the structure-function of antimicrobial members of the RNase A superfamily, we have developed a hybrid enzyme. Within this family, RNase 1 exhibits the highest ... ...

    Abstract Bacterial resistance to antibiotics urges the development of alternative therapies. Based on the structure-function of antimicrobial members of the RNase A superfamily, we have developed a hybrid enzyme. Within this family, RNase 1 exhibits the highest catalytic activity and the lowest cytotoxicity; in contrast, RNase 3 shows the highest bactericidal action, alas with a reduced catalytic activity. Starting from both parental proteins, we designed a first RNase 3/1-v1 chimera. The construct had a catalytic activity much higher than RNase 3, unfortunately without reaching an equivalent antimicrobial activity. Thus, two new versions were created with improved antimicrobial properties. Both of these versions (RNase 3/1-v2 and -v3) incorporated an antimicrobial loop characteristic of RNase 3, while a flexible RNase 1-specific loop was removed in the latest construct. RNase 3/1-v3 acquired both higher antimicrobial and catalytic activities than previous versions, while retaining the structural determinants for interaction with the RNase inhibitor and displaying non-significant cytotoxicity. Following, we tested the constructs’ ability to eradicate macrophage intracellular infection and observed an enhanced ability in both RNase 3/1-v2 and v3. Interestingly, the inhibition of intracellular infection correlates with the variants’ capacity to induce autophagy. We propose RNase 3/1-v3 chimera as a promising lead for applied therapeutics.
    Keywords RNase ; protein engineering ; structure-function relationship ; antimicrobial proteins ; Biology (General) ; QH301-705.5 ; Chemistry ; QD1-999
    Subject code 500
    Language English
    Publishing date 2022-12-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: In Vivo Evaluation of ECP Peptide Analogues for the Treatment of Acinetobacter baumannii Infection

    Jiarui Li / Guillem Prats-Ejarque / Marc Torrent / David Andreu / Klaus Brandenburg / Pablo Fernández-Millán / Ester Boix

    Biomedicines, Vol 10, Iss 386, p

    2022  Volume 386

    Abstract: Antimicrobial peptides (AMPs) are alternative therapeutics to traditional antibiotics against bacterial resistance. Our previous work identified an antimicrobial region at the N-terminus of the eosinophil cationic protein (ECP). Following structure-based ...

    Abstract Antimicrobial peptides (AMPs) are alternative therapeutics to traditional antibiotics against bacterial resistance. Our previous work identified an antimicrobial region at the N-terminus of the eosinophil cationic protein (ECP). Following structure-based analysis, a 30mer peptide (ECPep-L) was designed that combines antimicrobial action against Gram-negative species with lipopolysaccharides (LPS) binding and endotoxin-neutralization activities. Next, analogues that contain non-natural amino acids were designed to increase serum stability. Here, two analogues were selected for in vivo assays: the all-D version (ECPep-D) and the Arg to Orn version that incorporates a D-amino acid at position 2 (ECPep-2D-Orn). The peptide analogues retained high LPS-binding and anti-endotoxin activities. The peptides efficacy was tested in a murine acute infection model of Acinetobacter baumannii . Results highlighted a survival rate above 70% following a 3-day supervision with a single administration of ECPep-D. Moreover, in both ECPep-D and ECPep-2D-Orn peptide-treated groups, clinical symptoms improved significantly and the tissue infection was reduced to equivalent levels to mice treated with colistin, used as a last resort in the clinics. Moreover, treatment drastically reduced serum levels of TNF-α inflammation marker within the first 8 h. The present results support ECP-derived peptides as alternative candidates for the treatment of acute infections caused by Gram-negative bacteria.
    Keywords ECP ; AMPs ; infection ; murine model ; Gram-negative bacteria ; LPS ; Biology (General) ; QH301-705.5
    Subject code 630 ; 540
    Language English
    Publishing date 2022-02-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Insight into the Antifungal Mechanism of Action of Human RNase N-terminus Derived Peptides

    Vivian A. Salazar / Javier Arranz-Trullén / Guillem Prats-Ejarque / Marc Torrent / David Andreu / David Pulido / Ester Boix

    International Journal of Molecular Sciences, Vol 20, Iss 18, p

    2019  Volume 4558

    Abstract: Candida albicans is a polymorphic fungus responsible for mucosal and skin infections. Candida cells establish themselves into biofilm communities resistant to most currently available antifungal agents. An increase of severe infections ensuing in fungal ... ...

    Abstract Candida albicans is a polymorphic fungus responsible for mucosal and skin infections. Candida cells establish themselves into biofilm communities resistant to most currently available antifungal agents. An increase of severe infections ensuing in fungal septic shock in elderly or immunosuppressed patients, along with the emergence of drug-resistant strains, urge the need for the development of alternative antifungal agents. In the search for novel antifungal drugs our laboratory demonstrated that two human ribonucleases from the vertebrate-specific RNaseA superfamily, hRNase3 and hRNase7, display a high anticandidal activity. In a previous work, we proved that the N-terminal region of the RNases was sufficient to reproduce most of the parental protein bactericidal activity. Next, we explored their potency against a fungal pathogen. Here, we have tested the N-terminal derived peptides that correspond to the eight human canonical RNases (RN1-8) against planktonic cells and biofilms of C. albicans . RN3 and RN7 peptides displayed the most potent inhibitory effect with a mechanism of action characterized by cell-wall binding, membrane permeabilization and biofilm eradication activities. Both peptides are able to eradicate planktonic and sessile cells, and to alter their gene expression, reinforcing its role as a lead candidate to develop novel antifungal and antibiofilm therapies.
    Keywords antimicrobial peptides ; Candida albicans ; biofilms ; antifungal activity ; RNaseA superfamily ; Biology (General) ; QH301-705.5 ; Chemistry ; QD1-999
    Subject code 616
    Language English
    Publishing date 2019-09-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: Insights into the Antimicrobial Mechanism of Action of Human RNase6

    David Pulido / Javier Arranz-Trullén / Guillem Prats-Ejarque / Diego Velázquez / Marc Torrent / Mohammed Moussaoui / Ester Boix

    International Journal of Molecular Sciences, Vol 17, Iss 4, p

    Structural Determinants for Bacterial Cell Agglutination and Membrane Permeation

    2016  Volume 552

    Abstract: Human Ribonuclease 6 is a secreted protein belonging to the ribonuclease A (RNaseA) superfamily, a vertebrate specific family suggested to arise with an ancestral host defense role. Tissue distribution analysis revealed its expression in innate cell ... ...

    Abstract Human Ribonuclease 6 is a secreted protein belonging to the ribonuclease A (RNaseA) superfamily, a vertebrate specific family suggested to arise with an ancestral host defense role. Tissue distribution analysis revealed its expression in innate cell types, showing abundance in monocytes and neutrophils. Recent evidence of induction of the protein expression by bacterial infection suggested an antipathogen function in vivo. In our laboratory, the antimicrobial properties of the protein have been evaluated against Gram-negative and Gram-positive species and its mechanism of action was characterized using a membrane model. Interestingly, our results indicate that RNase6, as previously reported for RNase3, is able to specifically agglutinate Gram-negative bacteria as a main trait of its antimicrobial activity. Moreover, a side by side comparative analysis with the RN6(1–45) derived peptide highlights that the antimicrobial activity is mostly retained at the protein N-terminus. Further work by site directed mutagenesis and structural analysis has identified two residues involved in the protein antimicrobial action (Trp1 and Ile13) that are essential for the cell agglutination properties. This is the first structure-functional characterization of RNase6 antimicrobial properties, supporting its contribution to the infection focus clearance.
    Keywords RNases ; host defence ; antimicrobial peptides ; cell agglutination ; infectious diseases ; Biology (General) ; QH301-705.5 ; Chemistry ; QD1-999
    Subject code 572
    Language English
    Publishing date 2016-04-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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