Biology subjects

Poupardin, R.

Publications and source records attributed to Poupardin, R..

5 recordsLinked to original sources

bioRxiv2024

EV-Checklist: A fast documentation tool for enhancing transparency and accessibility in extracellular vesicle research.

Extracellular vesicle (EV) research has experienced rapid growth in the past decade. While community-driven efforts, such as the MISEV guidelines (2014, 2018, 2023), have aimed to standardize reporting and enhance experimental rigor, these have not yet been universally adopted in daily EV research practices. The complexity and time commitment required by existing reporting tools can deter researchers from fully embracing them, leading to incomplete or inconsistent documentation in EV studies. Therefore, we created EV-checklist, a complementary digital tool to streamline documentation during manuscript submission and increase transparency for the reviewers, editors and readers. Our tool guides researchers through a straightforward checklist covering nomenclature, source, isolation, characterization, and functional studies of EVs. It generates a concise two-page PDF formatted table for easy integration into manuscripts and provides editors, reviewers, and readers with a clear overview of the conducted studies. EV-Checklist intends to complement existing comprehensive registries as a fast-and-easy tool to enhance clarity and accessibility of methodological and functional insights. It may also promote higher adherence to documentation standards and in EV studies. Our tool is available on https://ev-zone.org.

scientific communication and education↗

bioRxiv2021

Adherence to minimal experimental requirements for defining extracellular vesicles and their functions: a systematic review

Rigorous measures are required to cope with the advance of extracellular vesicle (EV) research, from 183 to 2,309 studies/year, between 2012-2020. The MISEV guidelines requested standardizing methods, thereby assuring and improving of EV research quality. We investigated how EV research improved over time. We conducted a keyword search in 5,093 accessible publications over the period 2012-2020 and analyzed the methodology used for EV isolation and characterization. We found a significant improvement over the years particularly regarding EV characterization where recent papers used a higher number of methods and EV markers to check for quantity and purity. Interestingly, we also found that EV papers using more methods and EV markers were cited more frequently cited. Papers citing MISEV criteria were more prone to use a higher number of characterization methods. We therefore established a concise checklist summarizing MISEV criteria to support EV researchers towards reaching the highest standards in the field. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=88 SRC="FIGDIR/small/441160v1_ufig1.gif" ALT="Figure 1"> View larger version (20K): org.highwire.dtl.DTLVardef@1362fe8org.highwire.dtl.DTLVardef@83657dorg.highwire.dtl.DTLVardef@7bf4e2org.highwire.dtl.DTLVardef@a300a_HPS_FORMAT_FIGEXP M_FIG Graphical abstract C_FIG

bioinformatics↗

bioRxiv2020

Self-assembly of progenitor cells under the aegis of platelet factors facilitates human skin organoid formation and vascularized wound healing

Stem/progenitor cells can self-organize into organoids modelling tissue function and regeneration. Here we demonstrate that human platelet-derived factors can orchestrate 3D self-assembly of clonally expanded adult skin fibroblasts, keratinocytes and endothelial progenitors forming skin organoids within three days. Organoids showed distinct signaling patterns in response to inflammatory stimuli that clearly differed from separated cell types. Human induced pluripotent stem cell (hiPSC)-derived skin cell progenitors also self-assembled into stratified human skin within two weeks, healing deep wounds of immune-deficient mice. Co-transplantation of endothelial progenitors significantly accelerated vascularization. Mechanistically, platelet-derived extracellular vesicles mediated the platelet-derived trophic effects. Long-term fitness of epidermal cells was accelerated further by keratinocyte growth factor mRNA transfection. No tumorigenesis was observed upon xenografting. This permits novel rapid 3D skin-related pharmaceutical testing opportunities and facilitates development of iPSC-based skin regeneration strategies.

cell biology↗

bioRxiv2020

Extra-hematopoietic immunomodulatory role of the SCID-susceptibility gene DOCK-2 identified by stepwise maturation of human iPSCs into clonogenic mesodermal stromal progenitors

Stromal cells contribute to organ integrity as fibroblasts and to vascular stability as pericytes, in addition to their enigmatic niche function in many tissues. Their inherent immunomodulatory capacity attracted particular attention, initiating numerous clinical trials, particularly testing trophic regeneration and immunomodulation. Key stromal immune functions are still enigmatic. Here we show that dedicator of cytokinesis (DOCK-2) previously described for causing immune cell dysfunction plays a role in extra-hematopoietic immunity by regulating stromal/fibroblast immunomodulatory function. We used three independent strategies including iPSC-derived mesodermal stromal cell (MSC) lineage maturation, severe combined immunodeficiency (SCID) patient-derived cells and CRISPR/Cas9 knockout to support our findings. Human induced pluripotent stem cells (iPSCs) were generated from healthy bone marrow and umbilical cord blood-derived fibroblasts by Sendai virus-mediated transient expression of Yamanaka factors. After mesoderm induction, stromal differentiation was induced by platelet-derived growth factors under animal serum-free conditions. Under feeder-free defined conditions, iPSCs differentiated into expandable and cryo-preservable CD73+/CD105+/Tra-1-81- early iPS-MSCs lacking immunosuppressive potential. Successive maturation was required for reaching the canonical MSC phenotype and immunomodulatory competence over time, while maintaining clonogenicity, comparable to parental MSCs. Sequential RNAseq revealed acquisition of a spectrum of immune-related genes significantly expressed in mature iPS-MSCs and resembling parental MSCs immune gene expression. The DOCK-2 gene attracted our attention because mutations can cause SCID. Interestingly, SCID patient-derived fibroblast lines harboring bi-allelic DOCK-2 mutations showed significantly reduced immunomodulatory capacity compared to non-mutated control fibroblasts. CRISPR/Cas9-mediated DOCK-2 knockout in healthy iPSCs resulted in iPS-MSCs that also displayed reduced immunomodulatory capacity, thus confirming a role of DOCK-2 in stromal immune function. At a mechanistic level, DOCK-2 deficiency resulted in disturbed subcellular localization of CDC42. This provides first evidence for an extra-hematopoietic immunomodulatory role of DOCK-2 in stromal cells, previously considered restricted to hampering immune cell migration/function resulting in SCID. We may speculate that some of the signs and symptoms of persisting immune disease after successful hematopoietic stem cell transplantation in SCID patients could at least in part be due to mutations, like DOCK-2-/-, permissive outside the hematopoietic immune system, as evidenced also by the increased virus infection susceptibility of DOCK-2 deficient fibroblasts.

immunology↗

bioRxiv2019

Extracellular vesicles from therapeutic grade allogeneic human placental stromal cells induce angiogenesis and modulate immunity

Nanoparticles can acquire a protein corona defining their biological identity. Corona functions were not yet considered for cell-derived extracellular vesicles (EVs). Here we demonstrate that nanosized EVs from therapy-grade human placental-expanded (PLX) stromal cells are surrounded by an imageable and functional protein corona when enriched with permissive technology. Scalable EV separation from cell-secreted soluble factors via tangential flow-filtration and subtractive tandem mass-tag proteomics revealed significant enrichment of predominantly immunomodulatory and proangiogenic proteins. Western blot, calcein-based flow cytometry, super-resolution and electron microscopy verified EV identity. PLX-EVs protected corona proteins from protease digestion. EVs significantly ameliorated human skin regeneration and angiogenesis in vivo, induced differential signaling in immune cells, and dose-dependently inhibited T cell proliferation in vitro. Corona removal by size-exclusion or ultracentrifugation abrogated angiogenesis. Re-establishing an artificial corona by cloaking EVs with defined proangiogenic proteins served as a proof-of-concept. Understanding EV corona formation will improve rational EV-inspired nanotherapy design.

cell biology↗