Biology subjects

Paolini, L.

Publications and source records attributed to Paolini, L..

7 recordsLinked to original sources

bioRxiv2026

Integrated Single-Fiber Multi-Omics Links an Inflammatory-Associated Myofiber State to Altered Myosin Dynamics in Patients with ICU-acquired weakness

Skeletal muscle dysfunction is a pervasive complication of critical illness that worsens survival and recovery, yet remains poorly explained by current clinical or molecular markers. To directly connect disease-associated molecular states to the contractile machinery, this study combined sequential functional, transcriptomic, and proteomic profiling of the same single human skeletal myofibers from critically ill patients in the intensive care unit with acquired weakness (ICU-AW) and controls. Despite marked donor-level heterogeneity, integrated analysis revealed a subtle yet conserved myofiber state enriched in ICU-AW, characterized by inflammatory and chemotactic gene programs, intracellular structural remodeling, and bioenergetic adaptation. Nineteen features were significantly altered at both RNA and protein levels from the same myofiber, linking an inflammatory transcriptional landscape to a proteomic shift toward mitochondrial and translational machinery and away from membrane-associated signaling. Functionally, fibers in this state displayed selectively disrupted myosin dynamics, evidenced by prolonged ATP turnover time of myosin heads in their super-relaxed conformation, implicating altered myosin energetics as a contributor to muscle dysfunction. These findings define a discrete, disease-associated myofiber state and establish an integrative single-fiber framework for connecting multi-omic heterogeneity to molecular motor function in complex human disease. Graphical AbstractSingle-fiber multi-omic and functional analysis reveals a stress-adapted myofiber state in ICU-AW. Specifically, for the present study, myofibers from ICU-AW donors and control donors were isolated and functionally profiled for myosin dynamics before being split for simultaneous transcriptomic and proteomic analysis. Integrated analysis then identified a reproducible fiber phenotype enriched in ICU-AW, characterized by inflammatory transcriptional signatures coordinated with mitochondrial proteomic remodeling and altered myosin super-relaxed state energetics. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=95 SRC="FIGDIR/small/706099v1_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@95715forg.highwire.dtl.DTLVardef@1462ff8org.highwire.dtl.DTLVardef@f74996org.highwire.dtl.DTLVardef@10055ec_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2025

Red blood Cell-derived Extracellular Vesicles as biomaterials: the opportunity of freezing-induced accelerated aging

Red blood cell-derived extracellular vesicles (RBC-EVs) are emerging as promising biomaterials for next-generation drug delivery, due to their inherent biocompatibility, immune evasion capabilities, and minimal oncogenic risk. However, their clinical translation remains limited by unresolved challenges related to heterogeneity, reproducibility, and long-term storage. This study proposes a method that leverages freezing-induced ageing for obtaining highly homogeneous RBC-EV batches, an important step towards using RBC-EVs as healthcare biomaterials and advancing their clinical translation in EV-based nanomedicine. This method was made possible thanks to the analytical support of discontinuous sucrose density gradient and high-resolution interferometric nanoparticle tracking analysis, which allowed the identification of a bimodal subpopulation distribution, in terms of vesicle size, interferometric contrast, and subpopulation profiles, in freshly prepared samples, and then tracked how long-term cold storage at -80 {degrees}C channeled this heterogeneity into a monomodal population. Finally, we evaluated the functionality of homogenized RBC-EV samples by assessing surface-associated enzymatic activity and uptake in cancer cell lines, demonstrating that freeze-thaw-induced accelerated-aging provides a viable strategy for producing RBC-EV preparations that retain membrane integrity and remain readily internalized by cells. These findings offer valuable insights into the optimization and standardization of RBC-EV handling and storage protocols, providing a foundation for their reliable integration into EV-based therapeutic applications.

cell biology↗

bioRxiv2025

Red Blood Cell-derived Extracellular Vesicles enable Cisplatin and Cetuximab Synergistic Therapy against Triple-Negative Breast Cancer

BackgroundTriple-negative breast cancer is an aggressive breast cancer subtype characterized by the absence of human epidermal growth factor receptor 2, estrogen and progesterone receptors, limiting targeted therapy options. Cisplatin, a chemotherapeutic agent, induces DNA damage and exhibits some efficacy against triple-negative breast cancer, but its effectiveness is often reduced by chemoresistance and systemic toxicity. A very promising strategy to augment cisplatin treatment can be based on combining it with the biologic Cetuximab, an epidermal growth factor receptor inhibitor, which boosts cisplatin efficacy by inducing ferroptosis. ResultsTo optimize this strategy in a biocompatible and precise manner, we developed a nanoplatform based on red blood cell-derived extracellular vesicles for the combined delivery of Cetuximab and cisplatin, enabling immune evasion, and the possibility of autologous personalization and GMP-compliant production. Owing to their DNA-free lumen and lack of EGFR, RBC-EVs preserve cisplatin activity and prevent interference with cetuximab. This formulation enhances cisplatins cytotoxicity by up to 50%, as shown in vitro and in patient-derived organoids. It effectively reduces chemoresistance by downregulating hypoxia-related genes and promoting ferroptosis, additionally, it improves cisplatins cytotoxic effects while reducing hemotoxicity compared to the administration of free cisplatin. ConclusionsThese findings highlight the potential of red blood cell-derived extracellular vesicles as a biocompatible delivery system enabling combined therapy and offering a promising strategy to overcome current limitations in TNBC treatment.

cell biology↗

bioRxiv2024

Differential predictive value of resident memory CD8+T cell subpopulations in non-small-cell lung cancer patients treated by immunotherapy

A high density of resident memory T cells (TRM) in tumors correlates with improved clinical outcomes in immunotherapy-treated patients. However, in preclinical models, only some subpopulations of TRM are associated with cancer vaccine efficacy. We identified two main TRM subpopulations in tumor-infiltrating lymphocytes derived from non-small cell lung cancer (NSCLC) patients: one co-expressing CD103 and CD49a (DP), and the other expressing only CD49a (MP); both exhibiting additional TRM surface markers like CD69. DP TRM exhibited greater functionality compared to MP TRM. Analysis of T-cell receptor (TCR) repertoire and of the stemness marker TCF-1 revealed shared TCRs between populations, with the MP subset appearing more progenitor-like phenotype. In two NSCLC patient cohorts, only DP TRM predicted PD-1 blockade response. Multivariate analysis, including various biomarkers (CD8, TCF1+CD8+T cells, and PD-L1) associated with responses to anti-PD(L)1, showed that only intra-tumoral infiltration by DP TRM remained significant. This study highlights the non-equivalence of TRM populations and emphasizes the importance of distinguishing between them to better define their role in antitumor immunity and as a biomarker of response to immunotherapy.

immunology↗

bioRxiv2024

Biogenic nanoparticles from liquid and solid matrices: biochemical and biophysical properties of Extracellular Vesicles-enriched samples from human plasma and skeletal muscle tissue.

AimStudies on extracellular vesicles (EVs) focused on samples enriched from liquid matrices, such as cell culture media and blood. Recent research highlights the roles of EVs derived from the extracellular matrix of solid tissues, and how investigating these specific EVs offers insights into their microenvironment and potential biological influences on surrounding cells. This study presents a shared method to separate and compare EV enriched from solid (human skeletal muscle biopsy) and liquid (human plasma) matrices, addressing technical challenges and minimizing biases in separation techniques. MethodsPlasma and skeletal muscle-EVs were obtained combining serial centrifugation steps and discontinuous sucrose density gradient. EVs characterization employed advanced analytical techniques such as Western Blot, Colorimetric Nanoplasmonic assay, Atomic Force Miscoscopy, Nanoparticle Tracking Analysis and Dynamic Light Scattering to focus on biomolecular composition, nanomechanical properties, particle yield, size distribution, and colloidal stability. ResultsThe analysis revealed distinct differences between skeletal muscle-EVs and plasma-EVs including: molecular composition, physical and nanomechanical properties, as well as particle size distribution. Skeletal muscle-EVs exhibited unique colloidal behavior compared to their plasma counterparts, suggesting tissue-specific features that may influence their biological activity and stability. ConclusionsThe findings demonstrate that EVs from skeletal muscle tissue possess unique biochemical and biophysical characteristics when compared to those derived from plasma. These differences reflect their diverse biological origins and microenvironments. Understanding these distinctions could advance the development of EV-based diagnostic tools, particularly for muscular disorders, and broaden our knowledge of EV roles across various tissue contexts. HIGHLIGHTSO_LIShared protocol to enrich and compare extracellular vesicles (EVs) from both solid (skeletal muscle biopsy) and liquid (plasma) human samples, reducing methodological bias across matrices. C_LIO_LISkeletal muscle-derived EVs differ significantly from plasma EVs in biochemical and biophysical properties such as molecular composition, size distribution, nanomechanical properties, and colloidal stability. C_LIO_LIEV heterogeneity across microenvironments emerged as a key biological feature, highlighting their potential for specific diagnostic applications. C_LI

cell biology↗

bioRxiv2023

A synthetic delivery vector for mucosal vaccination

The success of mRNA-based vaccines during the Covid-19 pandemic has highlighted the value of this new platform for vaccine development against infectious disease. However, the CD8+ T cell response remains modest with mRNA vaccines, and these do not induce mucosal immunity, which would be needed to prevent viral spread in the healthy population. To address this drawback, we developed a dendritic cell targeting mucosal vaccination vector, the homopentameric STxB. Here, we describe the highly efficient chemical synthesis of the protein, and its in vitro folding. This straightforward preparation led to a synthetic delivery tool whose biophysical and intracellular trafficking characteristics were largely indistinguishable from recombinant STxB. The chemical approach allowed for the generation of new variants with bioorthogonal handles. Selected variants were chemically coupled to several types of antigens derived from the mucosal viruses SARS-CoV-2 and type 16 human papillomavirus. Upon intranasal administration in mice, mucosal immunity, including resident memory CD8+ T cells and IgA antibodies was induced against these antigens. Our study thereby identifies a novel synthetic antigen delivery tool for mucosal vaccination with an unmatched potential to respond to an urgent medical need.

biochemistry↗

bioRxiv2019

AFM-based High-Throughput Nanomechanical Screening of Single Extracellular Vesicles

We herein describe an Atomic Force Microscopy (AFM)-based experimental procedure which allows the simultaneous mechanical and morphological characterization of several hundred individual nanosized vesicles within the hour timescale. When deposited on a flat rigid surface from aqueous solution, vesicles are deformed by adhesion forces into oblate spheroids whose geometry is a direct consequence of their mechanical stiffness. AFM image analysis can be used to quantitatively measure the contact angle of individual vesicles, which is a size-independent descriptor of their deformation and, consequently, of their stiffness. The same geometrical measurements can be used to infer vesicle diameter in its original, spherical shape. We demonstrate the applicability of the proposed approach to natural vesicles obtained from different sources, recovering their size and stiffness distributions by simple AFM imaging in liquid. We show how the combined EV stiffness/size readout is able to discriminate between subpopulations of vesicular and non-vesicular objects in the same sample, and between populations of vesicles with similar sizes but different mechanical characteristics. We also discuss a force spectroscopy calibration procedure to quantitatively link the stiffness of EVs to their average contact angle. Finally, we discuss expected extensions and applications of the methodology.

biophysics↗