Articles publicats en revistes (Institut de Bioenginyeria de Catalunya (IBEC))
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Targeted Covalent Photoswitch for Two-Photon Control of Endogenous Receptors(2026-04-01) Santini, Ramona; Malieieva, Galyna; Sortino, Rosalba; Pons Allés, Santiago; Ramos Guerra, Cristian; Matera, Carlo; Gorostiza Langa, PauThe study of intact cells and their signaling circuits with light requires a stimulation strategy that is focused, deeply penetrating, and does not damage them. Implanted optic fibers, light-emitting diodes, and luminescent materials operated externally with tissue-penetrating infrared (IR) light are invasive or limited by light attenuation around the illumination point. To overcome these barriers, two-photon pharmacology takes advantage of femtosecond-pulsed IR laser light to produce deep and spatiotemporally precise cellular stimulation using specially designed photoswitchable drugs. Compounds that can be covalently tethered to the target neuroreceptor perform particularly well. However, the tethered photoswitches reported to date require mutagenesis of the target protein, which prevents the use of photopharmacology to stimulate the nervous system in wild-type animals. Here, we report the first two-photon optimized targeted covalent photoswitch (TCP2P) that combines the efficient two-photon isomerization of ortho-fluoro-substituted azobenzene with the ability to conjugate to nucleophilic residues of endogenous proteins (AMPA and kainate ionotropic glutamate receptors in neurons). TCP2P is readily obtained by click coupling of two precursor compounds prior to use, and after simple incubation, it enables controlling neuronal activity at one- and two-photon excitation up to 800 nm without genetic modifications.Article
Hydrophilic Janus Micelles from an ABC Triblock Copolymer(Wiley-VCH, 2026-02-23) Muñoz López, José María; Hu, Lei; Wang, Haomin; Tian, Xiaohe; Ruiz-Perez, Lorena; Battaglia, GiuseppeWe describe the creation of an amphiphilic triblock copolymer that drives lateral phase separation within micelle coronas. The design combines a hydrophobic poly(lactide) (PLA) core ‑forming block with two distinct hydrophilic segments: poly(ethylene glycol) (PEG) and poly( N ‑vinylpyrrolidone) (PVP). In water, the copolymer assembles into spherical micelles, confirmed by cryogenic TEM and multi ‑angle light scattering. Selective end ‑labelling of PVP with an electron ‑dense iridium complex enabled unstained TEM imaging, revealing clear contrast asymmetry that locates PVP to a single hemisphere of the corona. Complementary 2D1 H-Nuclear Overhauser Effect Spectroscopy (1 H ‑NOESY) NMR confirmed this Janus ‑type segregation of PEG and PVP. These results demonstrate how molecular architecture can encode asymmetry into soft nanostructures, offering a versatile route to polymer ‑based Janus nanoparticles with dual surface functionality and broad technological potential.Article
Decoding the Conformation of Polylactic Acid in Block Copolymer Micelles(American Chemical Society, 2026-01-28) Muñoz López, José María; Tuveri, Gian Marco; Barbieri, Valentino; Basile, Marco; Cosenza, V.; Lorenz, Christian D.; Ruiz-Perez, Lorena; Battaglia, GiuseppeUnderstanding how molecular features dictate the self-assembly of amphiphilic block copolymers into well-defined nanostructures is essential for the rational design of advanced soft materials. However, the large number of interdependent parameters involved, such as particle size, aggregation number, interfacial curvature, and molecular weight, makes it challenging to establish general design principles. Here we establish a scaling-based framework for PEG-b-PLA micelles with a fixed hydrophilic–hydrophobic ratio. Systematic variation of molecular weights enables precise control of micelle size and aggregation number, quantified by DLS, cryo-TEM, and MALS.Article
Transferrin receptor 1-targeted polymersomes therapy for colorectal cancer(Elsevier, 2025-08-30) Pina, Ariana; Mastrantuono, Elisa; Silva, Marta Marques de Almeida e; Barbieri, Valentino; Muñoz López, José María; Battaglia, Giuseppe; Graça, Luís; Matias, DianaColorectal cancer (CRC) ranks among the most common cancers and is the second leading cause of cancer-relateddeaths. The high mortality associated with CRC is attributed mainly to difficulties in early detection and lack of effective targeted therapies. The Transferrin receptor 1 (TfR1) is particularly attractive as a therapy target given its notable overexpression in tumor cells, particularly in CRC. This study explored the potential of a polymeric nanoparticle (PSomes)-based drug delivery system targeting TfR1 to improve the precision and efficacy of CRC treatment. For this study, we used two human CRC cell lines (HT-29, and HCT116), a healthy human intestinal epithelial cell line (hIECs), and a murine CRC cell line (MC38). We engineered PSomes composed of poly (ethylene glycol) (PEG) and poly (lactic acid) (PLA), functionalized with the T7 peptide to enhance their specificity for TfR1-expressing cells. Targeting efficiency of these PSomes was assessed across all cell lines by evaluating the cellular uptake using flow cytometry. Upon establishing the optimal formulation for these NPs for TfR1-targeting, we encapsulated doxorubicin (DOX) to assess their therapeutic potential. Both in vitro and in vivo experiments demonstrated that DOX loaded TfR1-targeted PSomes delivered DOX to CRC cells, leading to efficient induction of CRC cell death, reducing tumor growth and improving survival rates, compared to the control groups. These results highlight the promise of TfR1-targeted PSomes as a precise strategy for CRCtherapy, offering enhanced treatment efficacy while reducing systemic toxicity. This novel approach could lead to more targeted and less harmful cancer treatments.
Article
Structure and mechanistic basis of NrdR, a bacterial master regulator of ribonucleotide reduction(Elsevier B.V., 2026-02-04) Pedraz López, Lucas; Szura, Arkadiusz; Schmitz, Claus; Rubio Canalejas, Alba; Martínez Mateos, Ángela; Santella, Anthony; Gomila Lluch, Gabriel; Calò, Annalisa; Solà, Maria; Torrents Serra, EduardRibonucleotide reductases (RNRs) are the essential enzymes responsible for synthesizing dNTPs, the building blocks of DNA. In bacteria, the entire RNR network is controlled by the master regulator NrdR. As a regulator of an essential pathway with no eukaryotic equivalent, NrdR is a promising antimicrobial target. Recent structural studies have outlined a mechanism of action for NrdR, in which ATP and dATP induce changes in the protein quaternary structure, regulating RNR repression. However, due to a lack of functional studies linking the known structures to their biological roles, the activation mechanism of NrdR is not yet fully understood. Here, we conducted a comprehensive study of NrdR in Escherichia coli and Pseudomonas aeruginosa. We delimited the NrdR regulon, combining transcriptomics and motif-based sequence analysis. We crystallized E. coli NrdR and identified the protein-protein interfaces involved in its oligomerization, including strong interactions between NrdR dimers to form tetramers, and less stable interfaces connecting such tetramers. We examined the variability of the quaternary structures of NrdR depending on the bound nucleotides by SEC-MALS and atomic force microscopy, and correlated structure to function using point mutations, EMSAs, and in vitro transcription assays. Overall, our results demonstrate the mechanism used by NrdR to modulate its quaternary structure and activity, deciphering essential interactions between subunits, and paving the way for targeted antimicrobial therapies.Article
Mapping mechanical stress in curved epithelia of designed size and shape(Nature Publishing Group, 2023-07-07) Marín Llauradó, Ariadna; Kale, Sohan; Ouzeri, Adam; Golde, Tom; Sunyer Borrell, Raimon; Torres Sánchez, Alejandro; Latorre Ibars, Ernest; Gómez González, Manuel; Roca-Cusachs Soulere, Pere; Arroyo, Marino; Trepat Guixer, XavierThe function of organs such as lungs, kidneys and mammary glands relies on the three-dimensional geometry of their epithelium. To adopt shapes such as spheres, tubes and ellipsoids, epithelia generate mechanical stresses that are generally unknown. Here we engineer curved epithelial monolayers of controlled size and shape and map their state of stress. We design pressurized epithelia with circular, rectangular and ellipsoidal footprints. We develop a computational method, called curved monolayer stress microscopy, to map the stress tensor in these epithelia. This method establishes a correspondence between epithelial shape and mechanical stress without assumptions of material properties. In epithelia with spherical geometry we show that stress weakly increases with areal strain in a size-independent manner. In epithelia with rectangular and ellipsoidal cross-section we find pronounced stress anisotropies that impact cell alignment. Our approach enables a systematic study of how geometry and stress influence epithelial fate and function in three-dimensions.Article
Competition for endothelial cell polarity drives vascular morphogenesis in the mouse retina(Elsevier, 2022-10-10) Barbacena, Pedro; Dominguez Cejudo, Maria; Fonseca, Catarina G.; Gómez González, Manuel; Faure, Laura M.; Zarkada, Georgia; Pena, Andreia; Pezzarossa, Anna; Ramalho, Daniela; Giarratano, Ylenia; Ouarné, Marie; Barata, David; Fortunato, Isabela Corina Santos; Henao Misikova, Lenka; Mauldin, Ian; Carvalho, Yulia; Trepat Guixer, Xavier; Roca-Cusachs Soulere, Pere; Eichmann, Anne; Bernabeu, Miguel O.; Franco, Claudio A.Blood-vessel formation generates unique vascular patterns in each individual. The principles governing the apparent stochasticity of this process remain to be elucidated. Using mathematical methods, we find that the transition between two fundamental vascular morphogenetic programs—sprouting angiogenesis and vascular remodeling—is established by a shift of collective front-to-rear polarity of endothelial cells in the mouse retina. We demonstrate that the competition between biochemical (VEGFA) and mechanical (blood-flow-induced shear stress) cues controls this collective polarity shift. Shear stress increases tension at focal adhesions overriding VEGFA-driven collective polarization, which relies on tension at adherens junctions. We propose that vascular morphogenetic cues compete to regulate individual cell polarity and migration through tension shifts that translates into tissue-level emergent behaviors, ultimately leading to uniquely organized vascular patterns.Article
3D Micropatterned Traction Force Microscopy: A Technique to Control 3D Cell Shape While Measuring Cell-Substrate Force Transmissio(Wiley-VCH Verlag, 2024-10-23) Faure, Laura M.; Gómez González, Manuel; Baguer, Ona; Comelles Pujadas, Jordi; Martínez, Elena; Arroyo, Marino; Trepat Guixer, Xavier; Roca-Cusachs Soulere, PereCell shape and function are intimately linked, in a way that is mediated by the forces exerted between cells and their environment. The relationship between cell shape and forces has been extensively studied for cells seeded on flat 2D substrates, but not for cells in more physiological 3D settings. Here, a technique called 3D micropatterned traction force microscopy (3D-µTFM) to confine cells in 3D wells of defined shape, while simultaneously measuring the forces transmitted between cells and their microenvironment is demonstrated. This technique is based on the 3D micropatterning of polyacrylamide wells and on the calculation of 3D traction force from their deformation. With 3D-µTFM, it is shown that MCF10A breast epithelial cells exert defined, reproducible patterns of forces on their microenvironment, which can be both contractile and extensile. Cells switch from a global contractile to extensile behavior as their volume is reduced are further shown. The technique enables the quantitative study of cell mechanobiology with full access to 3D cellular forces while having accurate control over cell morphology and the mechanical conditions of the microenvironment.Article
Who arrived first? Priority effects on Candida albicans and Pseudomonas aeruginosa dual biofilms(Springer Nature, 2025-02-03) Arévalo Jaimes, Betsy Verónica; Admella, Joana; Torrents Serra, EduardHistorical processes in community assembly, such as species arrival order, influence interactions, causing priority effects. Candida albicans and Pseudomonas aeruginosa often co-occur in biofilm-based infections of the skin, lungs, and medical devices. Their predominantly antagonistic relationship involves complex physical and chemical interactions. However, the presence and implications of priority effects among these microorganisms remain largely unexplored. Here, we investigate the presence and impact of priority effect in dual-species biofilms using clinical isolates. By varying inoculation order, we observe significant changes in biofilm composition, structure, virulence, and antimicrobial susceptibility. The first colonizer has an advantage for surface colonization. Consecutive colonization increases biofilm virulence and negates C. albicans' protective effect on P. aeruginosa PAET1 against meropenem treatment. Finally, we propose N-acetylcysteine as an adjuvant for treating C. albicans and P. aeruginosa interkingdom infections, working independently of priority effects.Article
Improving neuroblastoma therapy with a new p53 family-activating agent(Elsevier B.V., 2025-11-15) Almeida, Joana; Resende, Diana I. S. P.; Silva, R.; Villasante Bermejo, Aranzazu; Murphy, Catherine; Zingales, Veronica; Palmeira, Andreia; Skoda, Jan; Broso, Francesca; Vadivellu, Aiswariya; Oliveira, Paula A.; Reis, Salette; Nunes, Claudia; Loh, Amos H.P.; Ferreira, Joana Margarida; Martins, Eduarda P.; Costa, Bruno M.; Inga, Alberto; Samitier i Martí, Josep; Sousa, Emilia P.; Saraiva, LucíliaNeuroblastoma (NB) is among the most common malignancies in children and represents a therapeutic challenge in pediatric oncology. p53 family proteins play a critical role in protecting cells from genomic instability and malignant transformation. However, in NB, their activities are often inhibited by interacting proteins such as MDM2. The interplay between p53 family pathway and N-Myc, a key biomarker of poor prognosis, is also a critical factor in NB pathogenesis. Herein, we disclose 1-(dibromomethyl)-3,4,6-trimethoxy-9H-xanthen-9-one (LEM3) as a new p53 family-activating agent with potent NB anticancer activity. At 0.13–2.1 μM, LEM3 inhibited the growth of several NB cell lines. Its activity was further evidenced in spheroids, patient-derived NB cells, and in a vasculature stiffness-based model of MYCN-amplified NB cells. This growth-inhibitory effect was associated with cell cycle arrest and apoptosis, in SH-SY5Y and SK-N-BE(2) NB cells, without apparent acquisition of resistance. LEM3 inhibited cell migration and invasion and reduced the expression of NB-related prognostic markers, particularly MYCN mRNA and protein levels. LEM3 released p53, TAp63, and TAp73 from their interaction with MDM2 both in a yeast-based assay and NB cells; for p53, this led to increased protein stabilization, DNA-binding ability, and transcriptional activity. Fluorescence quenching and docking analyses suggested that LEM3 binds to p53, TAp63, and TAp73 at the MDM2-binding site within their transactivation domain. LEM3 also synergies with doxorubicin and cisplatin in NB cells. Given the central role of the p53 family-MDM2-MYCN axis in NB pathogenesis, our findings support LEM3 as a promising compound for advancing NB targeted therapy.Article
PEGylated PLGA nanoparticles prepared from nano-emulsion templates as versatile platforms to cross blood-brain barrier models(Elsevier B.V., 2025-08-01) López Mitjavila, Joan Josep; Palma Florez, Sujey; Lagunas, Anna; Mir, Mònica; Samitier i Martí, Josep; Rodriguez-Abreu, C.; Grijalvo, S.PEGylation prevents aggregation and enhances the systemic circulation of nanoparticles (NPs), improving the delivery of actives to targeted cells. In this study, a conjugation reaction was used to attach polyethylene glycol (PEG) chains of molecular weights 750 and 5000 Da onto the surface of poly(lactic-co-glycolic acid) (PLGA) NPs obtained using the phase inversion composition methods, with carbodiimide/N-hydroxysuccinimide (NHS) and carbodiimide/sulfo-NHS activation reactions. Proton nuclear magnetic resonance indicated a higher degree of decoration (ca. 44.7 %) when carbodiimide/sulfo-NHS activation and PEG low molecular weight (750 Da) were used. Short incubation times (2 h at 37 ◦C) in the presence of 10 % fetal bovine serum showed no significant changes in particle size compared to pristine NPs. After 5 h of incubation, PEGylated NPs exhibited increase size (101.4 ± 15.3 nm) and polydispersity (0.6 ± 0.01). The presence of PEG chains decorating NPs reduced antioxidant release from NPs to ca. 10 % after 24 h at 37 ◦C following the Korsmeyer–Peppas model and governed by a Fickian diffusion mechanism. The antioxidant capacity of NPs showed a dose-activity relationship with ca. 60 % inhibition at 0.16 mg mL− 1 NP concentration and an EC50 of 51.7 ± 3.3 μg mL− 1 . Cell culture studies indicated no cytotoxicity for PLGA and PEGylated NPs up to 0.05 mg mL− 1 . Internalization studies confirmed cellular uptake into SHSY5Y cells. The impact of PEGylated NPs on blood-brain barrier (BBB) permeabilization was evaluated in a BBB-on-chip model, showing that PLGA encapsulation and PEGylated NPs, though to a lesser extent, facilitated crossing and permeabilization through the endothelial layer, demonstrating their potential for effective brain delivery.Article
Geometry-driven migration efficiency of autonomous epithelial cell clusters(Nature Publishing Group, 2024-09-01) Vercurysse, Eléonore; Brückner, David B.; Gómez González, Manuel; Remson, Alexandre; Luciano, Marine; Kalukula, Yohalie; Rossetti, Leone; Trepat Guixer, Xavier; Hannezo, Edouard; Gabriele, SylvainThe directed migration of epithelial cell collectives through coordinated movements plays a crucial role in various physiological processes and is increasingly understood at the level of large confluent monolayers. However, numerous processes rely on the migration of small groups of polarized epithelial clusters in complex environments, and their responses to external geometries remain poorly understood. To address this, we cultivate primary epithelial keratocyte tissues on adhesive microstripes to create autonomous epithelial clusters with well-defined geometries. We show that their migration efficiency is strongly influenced by the contact geometry and the orientation of cell–cell contacts with respect to the direction of migration. A combination of velocity and polarity alignment with contact regulation of locomotion in an active matter model captures quantitatively the experimental data. Furthermore, we predict that this combination of rules enables efficient navigation in complex geometries, which we confirm experimentally. Altogether, our findings provide a conceptual framework for extracting the interaction rules of active systems from their interaction with physical boundaries, as well as design principles for collective navigation in complex microenvironments.Article
Real-Time Force Monitoring of Electrically Stimulated 3D-Bioengineered Muscle Bioactuators Using Organic Sensors with Tunable Sensitivity(2025-10-14) Lai, Stefano; Fuentes Llanos, Judith; Guix Noguera, Maria; Casula, Giulia; Cosseddu, Piero; Sánchez Ordóñez, SamuelThe contractile nature of skeletal muscle tissue makes it especially attractive for powering biohybrid actuators. Significant efforts have been dedicated to the improvement and control of contraction force, going one step forward toward the automation of these biohybrid platforms. Herein, 3D-bioengineered skeletal muscle tissues are integrated with organic transistor-based sensors to define a soft bioactuator with real-time force monitoring capabilities. The muscle tissue is electrically stimulated while the organic sensor ensures transduction of the exerted force into an electrical signal that allows direct monitoring of the bioactuator performance. Sensor calibration is carried out to define its sensitivity at different biasing conditions: as opposed to standard, two-terminal piezoresistive devices, transistor-based strain sensors show tunable sensitivity by acting on the voltage applied to a third terminal-the gate. A complete evaluation of sensing performances is provided, demonstrating that real-time monitoring is effective under different conditions, including stimulation signal frequency and chemical modulation of the bioactuator contraction, demonstrating its potential use as a drug testing platform. In the reported results, the way is paved for a complete exploitation of organic devices in soft robotic applications and to the development of novel biohybrid machines in bioengineering and biomedicine. The integration of sensing elements in bioengineered actuators is key to obtain real-time information about their performance and further control/automation. By coupling flexible organic field-effect transistor to a skeletal muscle actuator we demonstrate the feasibility to record in real-time its contractile behavior when stimulated by electrical pulses, showing both high sensitivity absence of cross talk between stimulation and readout.Article
Cancer-associated fibroblasts actively compress cancer cells and modulate mechanotransduction(Nature Publishing Group, 2023-11-01) Barbazán, Jorge; Pérez González, Carlos; Gómez González, Manuel; Dedenon, Mathieu; Richon, Sophie; Latorre, Ernest; Serra, Marco; Mariani, Pascale; Descroix, Stéphanie; Sens, Pierre; Trepat Guixer, Xavier; Matic Vignjevic, DanijelaDuring tumor progression, cancer-associated fibroblasts (CAFs) accumulate in tumors and produce an excessive extracellular matrix (ECM), forming a capsule that enwraps cancer cells. This capsule acts as a barrier that restricts tumor growth leading to the buildup of intratumoral pressure. Combining genetic and physical manipulations in vivo with microfabrication and force measurements in vitro, we found that the CAFs capsule is not a passive barrier but instead actively compresses cancer cells using actomyosin contractility. Abrogation of CAFs contractility in vivo leads to the dissipation of compressive forces and impairment of capsule formation. By mapping CAF force patterns in 3D, we show that compression is a CAF-intrinsic property independent of cancer cell growth. Supracellular coordination of CAFs is achieved through fibronectin cables that serve as scaffolds allowing force transmission. Cancer cells mechanosense CAF compression, resulting in an altered localization of the transcriptional regulator YAP and a decrease in proliferation. Our study unveils that the contractile capsule actively compresses cancer cells, modulates their mechanical signaling, and reorganizes tumor morphology.- ArticleThe role of strategy units in guiding research institutions through complexity(Springe Nature, 2026-02-13) Bertero, Michela Giulia; Sonne-Hansen, Katrine; Wegener, Anna-Lynn; Sanchis Estruch, Teresa
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Neuromechanobiology: Bridging Mechanobiology and Neuroscience Through Evidence and Open Questions(MDPI, 2026-01-19) Zimkowska, Karolina; Riu-Villanueva, Marc; Río Fernández, José Antonio delNeuromechanobiology has emerged as a multidisciplinary field at the interface of neuroscience and mechanobiology, aiming to elucidate how mechanical forces influence the development, organization, and function of the nervous system. This review offers a comprehensive overview of the historical evolution of the discipline, its molecular and biophysical foundations, and the experimental strategies employed to investigate it. Recent advances have revealed the pivotal roles of substrate stiffness, mechanical signaling, and force transduction in neural stem proliferation, axon guidance, synapse formation, and neural circuit maturation. All these effects originate at the molecular level and extend to the mesoscopic scale. Disrupted mechanotransduction has been increasingly implicated in neurodevelopmental disorders and neurodegenerative diseases, underscoring its clinical relevance. Key unresolved questions and future directions are also highlighted, with emphasis on the need for integrative approaches to decipher the complex interplay between mechanical forces and neural function.Altres
Liposomal sprays for nasal vaccination: a comparative study of cationic and anionic formulations involving stability upon nebulization, sprayability, and in vitro immune activation(Elsevier, 2025-09-07) Aroffu, Matteo; Fulgheri, Federica; Rached, Rita Abi; Castangia, Ines; Corteggio, Annunziata; Italiani, Paola; D'Apice, Luciana; Sainz-Ramos, Myriam; García-Villén, Fátima; Fernàndez Busquets, Xavier; Manconi, Maria; Pedraz, José Luis; Manca, Maria Letizia; Fadda, Anna MariaNasal immunization is a promising non-invasive route, enabling needle-free self-administration and activating immune cells in the mucosal tissue of the upper airways. This vaccination method is particularly appealing when paired with biocompatible and biodegradable nanocarriers like liposomes, which serve as an effective tool for the nasal delivery of antigenic molecules. In the present study, the model antigen ovalbumin was encapsulated in liposomes using an eco-friendly method. Negative and positive liposomes were formulated with Phospholipon®90 G alone (anionic liposomes) or combined with 1,2-dioleoyl-3-trimethylammonium-propane (cationic DOTAPliposomes). These liposomes were smaller than 130 nm and remained stable for up to 3 months. Their sprayability was assessed based on criteria established by the European Medicines Agency and the Food and Drug Administration for nasal products. Both formulations were easily sprayable, generating droplets larger than 5 μm, which are expected to deposit in the nose while avoiding the lungs. Furthermore, after nebulization, they retained their dimensions, structures, and high encapsulation efficiencies (>70 %). In a co-culture system of dendritic cells and B3Z OT-I hybridoma cells, it was shown that they enhanced antigen elivery and presentation,producing approximately 6–9 times more interleukin-2 compared to the ovalbumin solution. Lastly, when tested on macrophages, they did not induce any proinflammatory effect. However, due to their higher mucoadhesiveness (~88 % vs ~8 %) and better deposition in the posterior nasal cavity (~52 % vs ~43 %) compared to anionic liposomes, cationic DOTAP-liposomes appeared more suitable for nasal administration.Article
FleQ-Dependent regulation of the ribonucleotide reductase repressor NrdR in Pseudomonas aeruginosa during biofilm growth and infection(Springer Nature, 2025-11-27) Marchan del Pino, Domingo ; Rubio Canalejas, Alba; Pedraz López, Lucas; Hernández, José María; Admella Pedrico, Joana; Blanco Cabra, Núria; Torrents Serra, EduardRibonucleotide reductases (RNRs) are essential enzymes that catalyze the conversion of ribonucleotides to deoxyribonucleotides (dNTPs), a critical step in DNA synthesis and repair. While all organisms encode for at least one RNR class, Pseudomonas aeruginosa harbors three, providing a competitive advantage that allows it to adapt and colonize various environments. Despite their importance, the mechanisms coordinating the expression of different RNRs in microorganisms with multiple RNR classes remain poorly understood. The transcriptional regulator NrdR controls the expression of all three RNR classes by binding to conserved motifs (NrdR boxes) in their promoters. However, the regulation of nrdR itself remains unknown. In this study, we investigated the transcriptional regulation of nrdR using a combination of bioinformatics and experimental approaches we identified potential transcription factors (TF) involved in nrdR regulation. Our analysis identified four potential TF that could regulate nrdR, and we experimentally confirmed that specifically, FleQ is responsible for regulating nrdR expression under aerobic and anaerobic conditions. Furthermore, we explored nrdR regulation under biofilm-forming conditions and in the Galleria mellonella infection model to gain insights into how nrdR might be regulated in vivo.Altres
Disclosure of cinnamic acid/4,9-diaminoacridine conjugates as multi-stage antiplasmodial hits(Elsevier, 2024-04-15) Fonte, Mélanie ; Rôla, Catarina; Santana, Sofia; Avalos Padilla, Yunuen; Fernàndez Busquets, Xavier; Prudêncio, Miguel ; Gomes, Paula A. C ; Teixeira, Catia Marlene4,9-diaminoacridines with reported antiplasmodial activity were coupled to different trans-cinnamic acids, delivering a new series of conjugates inspired by the covalent bitherapy concept. The new compounds were more potent than primaquine against hepatic stages of Plasmodium berghei, although this was accompanied by cytotoxic effects on Huh-7 hepatocytes. Relevantly, the conjugates displayed nanomolar activities against blood stage P. falciparum parasites, with no evidence of hemolytic effects below 100 mu M. Moreover, the new compounds were at least 25-fold more potent than primaquine against P. falciparum gametocytes. Thus, the new antiplasmodial hits disclosed herein emerge as valuable templates for the development of multi-stage antiplasmodial drug candidates.Article
Circulating metabolic markers after surgery identify patients at risk for severe postoperative complications: a prospective cohort study in colorectal cancer(Elsevier, 2024-03-01) Montcusí, Blanca; Pera Román, Miguel; Madrid Gambín, Francisco Javier; Pozo Mendoza, Óscar J., 1975-; Marco Colás, Santiago; Marín Martínez, Silvia; Mayol, Xavier; Pascual Damieta, Marta; Alonso-Gonçalves, Sandra; Silvia Salvans Ruiz; Jiménez-Toscano, Marta; Cascante i Serratosa, MartaBackground: Early detection of postoperative complications after colorectal cancer (CRC) surgery is associated with improved outcomes. The aim was to investigate early metabolomics signatures capable to detect patients at risk for severe postoperative complications after CRC surgery. Materials and methods: Prospective cohort study of patients undergoing CRC surgery from 2015 to 2018. Plasma samples were collected before and after surgery, and analyzed by mass spectrometry obtaining 188 metabolites and 21 ratios. Postoperative complications were registered with Clavien–Dindo Classification and Comprehensive Complication Index. Results: One hundred forty-six patients were included. Surgery substantially modified metabolome and metabolic changes after surgery were quantitatively associated with the severity of postoperative complications. The strongest positive relationship with both Clavien–Dindo and Comprehensive Complication Index (β=4.09 and 63.05, P<0.001) corresponded to kynurenine/tryptophan, against an inverse relationship with lysophosphatidylcholines (LPCs) and phosphatidylcholines (PCs). Patients with LPC18:2/PCa36:2 below the cut-off 0.084 µM/µM resulted in a sevenfold higher risk of major complications (OR=7.38, 95% CI: 2.82–21.25, P<0.001), while kynurenine/tryptophan above 0.067 µM/µM a ninefold (OR=9.35, 95% CI: 3.03–32.66, P<0.001). Hexadecanoylcarnitine below 0.093 µM displayed a 12-fold higher risk of anastomotic leakage-related complications (OR=11.99, 95% CI: 2.62–80.79, P=0.004). Conclusion: Surgery-induced phospholipids and amino acid dysregulation is associated with the severity of postoperative complications after CRC surgery, including anastomotic leakage-related outcomes. The authors provide quantitative insight on metabolic markers, measuring vulnerability to postoperative morbidity that might help guide early decision-making and improve surgical outcomes.