Biology subjects

Strunk, D.

Publications and source records attributed to Strunk, D..

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

The NLRP3/eIF2 axis drives cell cycle progression in acute myeloid leukemia

Aberrant activation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome mediates numerous inflammatory diseases. Oncogenes can activate the NLRP3 inflammasome and thereby promote myeloproliferative neoplasia, suggesting a crucial role of NLRP3 in the malignant transformation of hematopoietic cells. Here, we show that bone marrow-derived mononuclear cells of AML patients display enhanced expression of NLRP3, IL-1{beta} and IL-18 and that high-level expression of NLRP3 is linked to poor survival of AML patients. Pharmacological and genetic inhibition of NLRP3 inflammasome activation attenuated cell proliferation of MOLM-13 AML cells in vitro. In vivo, genetic inhibition of NLRP3 in MOLM-13 AML cells resulted in reduced engraftment potential in xenografts, along with reduced splenomegaly and organ infiltration. Differential proteomic analysis revealed the eIF2 pathway as potential target of NLRP3 in AML, with a significant increase of eIF2 phosphorylation upon NLRP3 inhibition. NLRP3 inhibition also caused a strong decrease in cyclin - dependent kinases CDK4 and CDK6, accompanied by an upregulation of the CDK inhibitor p21 (CDKN1A) and a marked arrest of cell cycle progression in the G0/G1 phase, consistent with the role of eIF2 phosphorylation as negative cell cycle regulator. Taken together, we show that inhibition of the NLRP3 inflammasome reduces AML cell proliferation by promoting eIF2 phosphorylation, which in turn enhances the expression of cell cycle arrest genes such as p21. Thus, the study uncovers the NLRP3/eIF2 axis as new driver of AML proliferation and proposes a novel therapeutic treatment of AML by targeted inhibition of NLRP3 activation.

immunology↗

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

MiRNA-10b marks aggressive squamous cell carcinomas, and confers a cancer stem cell-like phenotype

BackgroundCutaneous squamous cell carcinomas (cSCC) are the primary cause of premature deaths in patients suffering from the rare skin-fragility disorder recessive dystrophic epidermolysis bullosa, which is in marked contrast to the rarely metastasizing nature of these carcinomas in the general population. This remarkable difference is attributed to the frequent development of chronic wounds caused by an impaired skin integrity. However, the specific molecular and cellular changes to malignancy, and whether there are common players in different types of aggressive cSCCs, remain relatively undefined. MethodsMiRNA expression profiling was performed across various cell types isolated from skin and cSCCs. Microarray results were confirmed by qPCR and by an optimized in situ hybridization protocol. Functional impact of overexpression of a dysregulated miRNA was assessed in migration and 3D spheroid assays. Sample-matched transcriptome data was generated to support the identification of disease relevant miRNA targets. ResultsSeveral miRNAs were identified as dysregulated in cSCCs as compared to controls. These included the metastasis-linked miR-10b, which was significantly upregulated in primary cell cultures and in archival biopsies. At the functional level, overexpression of miR-10b conferred the stem cell-characteristic of 3D-spheroid formation capacity to keratinocytes, and impaired their mobility. Analysis of miR-10b downstream effects identified a novel putative target of miR-10b, the actin- and tubulin cytoskeleton-associated protein DIAPH2. ConclusionThe discovery that miR-10b confers an aspect of cancer stemness - that of enhanced tumor cell adhesion, known to facilitate metastatic colonization - provides an important avenue for future development of novel therapies targeting this metastasis-linked miRNA.

cancer biology↗

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↗