Biology subjects

Vader, P.

Publications and source records attributed to Vader, P..

9 recordsLinked to original sources

bioRxiv2026

Degenerated intervertebral disc environment impairs notochordal cell-derived extracellular vesicles release and their matrix anabolic effect

At the onset of intervertebral disc degeneration, within the disc core, the pH and osmolarity decrease, and the residing notochordal cells (NCs) gradually transition towards nucleus pulposus cells (NPCs). How these microenvironmental cues shape the NCs extracellular vesicles (EV)-enriched secretome, and thus EV-mediated communication with NPCs during this transition, remains poorly understood. To study this, we collected the secretome from pig NC-rich tissue cultured for 4 days in either healthy or degenerate disc media to mimic these changes. In both conditions, NC-rich tissues were largely comparable at the histological and biochemical levels. Despite, tissues released glycosaminoglycans (GAGs), depleting the extracellular matrix. Surprisingly, degenerative media did not differentially release inflammatory regulators, though it reduced PGE2 release. We asked whether this extended to EV-enriched secretome media (SM_EV+), and found that the degenerative media reduced the number of EVs without altering their morphology or size. We then determined NC-EV association of inflammatory and matrix regulators. NC-EV isolation enriched MMP1, IL6 and IL10 and depleted soluble GAGs. Conversely, EV-depletion (SM_EV-) removed most GAGs without affecting MMP1, IL6, and IL10, suggesting that they contribute to the NC-EV soft corona. Functionally, healthy SM_EV+ improved GAG production by NPCs, but attenuated TBXT expression. Degenerate SM_EV+ did not elicit detectable EV-specific effects. These findings suggest that, in health, secretome-mediated communication from NCs to NPCs is only partially EV-mediated. At the onset of IVD degeneration, low pH and osmolarity impair the release of NC-EVs and negate the EV-specific beneficial matrix-anabolic effects on NPCs, contributing to the NC-to-NPC transition.

cell biology↗

bioRxiv2026

NEO-AAV: an engineered extracellular vesicle-enveloped AAV platform for activation-coupled T cell transduction and CAR-T cell generation

Efficient delivery of genetic cargo to primary human T cells remains a critical barrier for cell-based immunotherapies. AAVs are widely used but limited by immune neutralization and poor T cell transduction efficiency. We present NEO-AAV, an engineered fusion protein (PH-ALG2-PKD12) that recruits AAV capsids into endogenous extracellular vesicles (EVs) via PI(4,5)P2-directed membrane targeting, multivalent PKD12-capsid clustering, and ALG2-mediated ESCRT machinery recruitment, yielding EV-enveloped particles with improved AAV loading compared with passive EV-AAV controls. NEO-AAV displayed enhanced resistance to an anti-AAV6 neutralizing antibody (ADK6), maintaining transduction at concentrations that neutralized naked AAV6 and outperformed passively formed EV-AAV6. Surface display of a CD7/CD3/CD28 tri-chimera enabled single-step activation and transduction of CD7 T cells within PBMCs, reaching [~]38% eGFP cells without exogenous pre-activation. As a proof-of-concept, NEO-AAV generated functional CAR-T cells from primary human PBMCs, exhibiting antigen-specific IFN-{gamma} release and cytotoxicity against CD19+ target cells. CAR expression peaked at day 5 and declined by day 15, consistent with episomal AAV kinetics, framing NEO-AAV as an activation-coupled delivery module rather than a durable solution. Together, NEO-AAV provides a programmable EV-enveloped AAV platform with improved immune shielding and single-step T cell transduction, offering a building block for immune cell engineering with in vivo potential.

bioengineering↗

bioRxiv2026

An extracellular vesicle biogenesis-inspired engineering platform for efficient protein delivery and therapeutic base editing

Efficient and controllable delivery of genome-editing proteins remains a central challenge for therapeutic translation of gene-editing technologies. Extracellular vesicles (EVs) offer an attractive non-viral delivery modality due to their biocompatibility and large capacity for cytosolic cargo delivery. Yet, rational strategies to achieve controlled and programmable protein loading are still lacking. Here, we present NEO-TOP-EVs, an EV biogenesis-guided engineering platform that systematically integrates key features of three design principles inspired by vesicle formation: 1) PI(4,5)P2-mediated plasma membrane targeting, 2) ESCRT-dependent membrane scission, and 3) self-assembly-driven cargo clustering for enabling efficient encapsulation of genome-editing ribonucleoproteins. Together, the NEO design increased cargo incorporation and enhanced functional delivery of gene editing modalities under particle-normalized conditions. Using NEO-TOP-EVs, we achieve efficient delivery of Cas9 and adenine base editor ribonucleoproteins without nucleic acid templates. In an in vitro proof-of-concept, delivery of an adenine base editor targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) induces efficient splice-site disruption, resulting in reduced PCSK9 expression and enhanced LDL receptor activity. Proof-of-concept in vivo experiments provide preliminary evidence of functional Cre protein delivery to the liver. Together, these findings establish NEO-TOP-EVs as a modular platform for protein-based genome editing, demonstrating how biogenesis-informed EV engineering yields functional protein delivery at levels relevant to therapeutic development.

bioengineering↗

bioRxiv2025

Visualizing extracellular vesicle-mediated RNA transfer using a novel metabolic labeling approach

Extracellular vesicles (EVs) are key players in intercellular communication, facilitated by the transfer of RNA and other molecular cargo between cells. However, how EV-RNA is processed in recipient cells remains poorly understood, particularly the uptake and intracellular trafficking pathways leading to functional transfer remains elusive. Visualizing EV-RNA in recipient cells may help to address these knowledge gaps. Although EV labeling methods are well-established, tracking endogenous RNA cargo within EVs and in recipient cells is challenging due to its low abundance, requiring highly sensitive labeling methods. Existing RNA labeling methods often lack sensitivity, specificity for donor cell-derived RNA, or are limited to labeling long RNA species. In this study, we propose a novel metabolic labeling approach to track RNA in donor cells, EVs and recipient cells using 5-ethynyl uridine (5-EU). 5-EU is a nucleoside analog of uridine that is incorporated into nascent RNA and can be detected through click chemistry with a fluorescent azide. To enhance RNA labeling efficiency, we overexpressed Uridine-Cytidine Kinase 2 (UCK2) in MDA-MB-231 donor cells, which increased 5-EU incorporation into nascent RNA chains. This approach allowed visualization and quantification of RNA in isolated EVs. Furthermore, co-culturing MDA-MB-231 UCK2+ donor cells expressing a CD63-HaloTag fusion protein with HMEC1-eGFP+ recipient cells enabled visualization and quantification of intercellular transfer of EVs and their endogenous RNA cargo. This novel approach offers a sensitive and specific tool for studying physiological EV-RNA transfer, thereby advancing our understanding of the biological roles of EVs in intercellular communication.

cell biology↗

bioRxiv2024

Tissue-specific modulation of CRISPR activity by miRNA-sensing guide RNAs

Nucleic acid nanostructures offer unique opportunities for biomedical applications due to their sequence-programmable structures and functions, which enable the design of complex responses to molecular cues. Control of the biological activity of therapeutic cargoes based on endogenous molecular signatures holds the potential to overcome major hurdles in translational research: cell specificity and off-target effects. Endogenous microRNAs can be used to profile cell type and cell state and are ideal inputs for RNA nanodevices. Here we present CRISPR MiRAGE (miRNA-activated genome editing), a tool comprising a dynamic single-guide RNA that senses miRNA complexed with Argonaute proteins and controls downstream CRISPR activity based on the detected miRNA signature. We study the operation of the miRNA-sensing single-guide RNA and attain muscle-specific activation of gene editing through CRISPR MiRAGE in models of Duchenne muscular dystrophy. By enabling RNA-controlled gene editing activity, this technology creates opportunities to advance tissue-specific CRISPR treatments for human diseases.

bioengineering↗

bioRxiv2024

A modular strategy for extracellular vesicle-mediated CRISPR-Cas9 delivery through aptamer-based loading and UV-activated cargo release

CRISPR-Cas9 gene editing technology offers the potential to permanently repair genes containing pathological mutations. However, efficient intracellular delivery of the Cas9 ribonucleoprotein complex remains one of the major hurdles in its therapeutic application. Extracellular vesicles (EVs) are biological nanosized membrane vesicles released by cells, that play an important role in intercellular communication. Due to their innate capability of intercellular transfer of proteins, RNA, and various other biological cargos, EVs have emerged as a novel promising strategy for the delivery of macromolecular biotherapeutics, including CRISPR-Cas9 ribonucleoproteins. Here, we present a versatile, modular strategy for the loading and delivery of Cas9. We leverage the high affinity binding of MS2 coat proteins (MCPs) fused to EV-enriched proteins to MS2 aptamers incorporated into single guide RNAs (sgRNAs), in combination with a UV-activated photocleavable linker domain, PhoCl. Combined with the Vesicular stomatitis virus G (VSV-G) protein this modular platform enables efficient loading and subsequent delivery of the Cas9 ribonucleoprotein complex, which shows critical dependence on the incorporation and activation of the photocleavable linker domain. As this approach does not require any direct fusion of Cas9 to EV-enriched proteins, we demonstrate that Cas9 can readily be exchanged for other variants, including transcriptional activator dCas9-VPR and adenine base editor ABE8e, as confirmed by various sensitive fluorescent reporter assays. Taken together, we describe a robust and modular strategy for successful Cas9 delivery, which can be applied for CRISPR-Cas9-based genetic engineering as well as transcriptional regulation, underlining the potential of EV-mediated strategies for the treatment of genetic diseases.

molecular biology↗

bioRxiv2024

Hypoxia and TNF-alpha modulate extracellular vesicle release from human induced pluripotent stem cell-derived cardiomyocytes

Extracellular vesicles (EVs) have emerged as important mediators of intercellular communication in the heart under homeostatic and pathological conditions, such as myocardial infarction (MI). However, the basic mechanisms driving cardiomyocyte-derived EV (CM-EV) production following stress are poorly understood. In this study, we generated human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) that express NanoLuc-tetraspanin reporters. These modified hiPSC-CMs allow for robust quantification of CM-EV secretion from small numbers of cells without the need for time-consuming EV isolation techniques. We subjected these cells to a panel of small molecules to study their effect on CM-EV biogenesis and secretion under basal and stress-associated conditions. We observed that EV biogenesis is context-dependent in hiPSC-CMs. Nutrient starvation decreases CM-EV secretion while hypoxia increases the production of CM-EVs in a nSmase2-dependent manner. Moreover, the inflammatory cytokine TNF- increased CM-EV secretion through a process involving NLRP3 inflammasome activation and mTOR signaling. Here, we detailed for the first time the regulatory mechanisms of EV biogenesis in hiPSC-CMs upon MI-associated stressors.

cell biology↗

bioRxiv2023

Multimodal engineering of extracellular vesicles for efficient intracellular protein delivery

Extracellular vesicles (EVs) are promising tools to transfer macromolecular therapeutic molecules to recipient cells, however, efficient functional intracellular protein delivery by EVs remains challenging. Here, we have developed novel and versatile systems that leverage selected molecular tools to engineer EVs for robust cytosolic protein delivery both in vitro and in vivo. These systems, termed VSV-G plus EV-sorting Domain-Intein-Cargo (VEDIC) and VSV-G-Foldon-Intein-Cargo (VFIC), exploit an engineered mini-intein (intein) protein with self-cleavage activity to link cargo to an EV-sorting domain and release it from the EV membrane inside the EV lumen. In addition, we utilize the fusogenic protein VSV-G to facilitate endosomal escape and cargo release from the endosomal system to the cytosol of recipient cells. Importantly, we demonstrate that the combination of the self-cleavage intein, fusogenic protein and EV-sorting domain are indispensable for efficient functional intracellular delivery of cargo proteins by engineered EVs. As such, nearly 100% recombination and close to 80% genome editing efficiency in reporter cells were observed by EV-transferred Cre recombinase and Cas9/sgRNA RNPs, respectively. Moreover, EV-mediated Cre delivery by VEDIC or VFIC engineered EVs resulted in significant in vivo recombination in Cre-LoxP R26-LSL-tdTomato reporter mice following both local and systemic injections. Finally, we applied these systems for improved treatment of LPS-induced systemic inflammation by delivering a super-repressor of NF-B activity. Altogether, this study describes a platform by which EVs can be utilized as a vehicle for the efficient intracellular delivery of macromolecular therapeutics for treatments of disease. Graphic summary: Development of VEDIC and VFIC systems for high-efficiency intracellular protein delivery in vitro and in vivo.Intein in tripartite fusion protein (EV-sorting Domain-Intein-Cargo) performs C-terminal cleavage during the process of EV-biogenesis, resulting in enriched free cargo proteins inside of vesicles. Together with fusogenic protein, VSV-G, these engineered EVs achieve high-efficiency intracellular delivery of cargo protein (Cre and super repressor of NF-B) or protein complex (Cas9/sgRNA RNPs) both in reporter cells and in mice models. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=142 SRC="FIGDIR/small/535834v4_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@d0da37org.highwire.dtl.DTLVardef@1a6514corg.highwire.dtl.DTLVardef@235c9aorg.highwire.dtl.DTLVardef@194bbfa_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2020

Profiling of extracellular small RNAs highlights a strong bias towards non-vesicular secretion

Extracellular environment consists of a plethora of different molecules, including extracellular miRNA that can be secreted in association with extracellular vesicles (EVs) or soluble protein complexes (non-EVs). Yet, it is generally accepted that most of the biological activity is attributed to EV-associated miRNAs. The capability of EVs to transport cargoes has attracted much interest towards developing EVs as therapeutic short RNA carriers by using endogenous loading strategies for miRNA enrichment. Here, by overexpressing miRNA and shRNA sequences of interest in source cells and using size exclusion liquid chromatography (SEC) to separate the cellular secretome into EV and non-EV fractions, we saw that strikingly, <2% of all secreted overexpressed miRNA were found in association with EVs. To see whether the prominent non-EV miRNA secretion also holds true at the basal expression level of native miRNA transcripts, both fractions were further analysed by small RNA sequencing. This revealed a global correlation of EV and non-EV miRNA abundance to that of their parent cells and showed an enrichment only for miRNAs with a relatively low cellular expression level. Further quantification showed that similarly to the transient overexpression context, an outstanding 96.2-99.9% of total secreted miRNA at its basal level was secreted to the non-EV fraction. Yet, even though EVs contain only a fraction of secreted miRNAs, these molecules were found stable at 37{degrees}C in serum-containing environment, indicating that if sufficient miRNA loading to EVs is achieved, EVs can remain miRNA delivery-competent for a prolonged period of time. This study suggests that the passive endogenous EV loading strategy can be a relatively wasteful way of loading miRNA to EVs and active miRNA loading approaches are needed for developing advanced EV miRNA therapies in the future.

molecular biology↗