Biology subjects

Bianchi, E.

Publications and source records attributed to Bianchi, E..

8 recordsLinked to original sources

bioRxiv2025

3D printing and bioprinting for miniaturized and scalable hanging-drop organoids culture

Three-dimensional (3D) cell culture systems rely on the manipulation of a biologically derived matrix, typically soluble Basement Membrane Extract (sBME), in which cells or cellular aggregates, such as organoids, are suspended. This matrix provides mechanobiological support, promoting cellular processes. However, the handling of sBME-based matrices containing cellular constructs poses significant challenges due to their rheological properties. We developed an integrated bioprinting system to surpass the conventional pipetting, seeding and culture in multiwell plates. The system combines a fluidic cartridge with innovative 3D-printed biocompatible culture tools designed to host and preserve high-throughput microcultures of Patient-Derived Organoids (PDOs) in sBME. The miniaturized hanging-drop configuration enables extended culture periods and high-throughput imaging screenings. This comprehensive approach overcomes common issues associated with sBME, including sedimentation of cellular aggregates, premature gelation, and structural collapse, which negatively impact culture quality and reproducibility throughout the entire 3D culture workflow, from seeding to culture maintenance, and post-culture analyses. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=133 SRC="FIGDIR/small/678315v1_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@19f976eorg.highwire.dtl.DTLVardef@8eeefcorg.highwire.dtl.DTLVardef@1ebe6c7org.highwire.dtl.DTLVardef@7c4403_HPS_FORMAT_FIGEXP M_FIG C_FIG Highlights- Miniaturized 3D hanging-drop matrix-embedded organoid culture in a 384-well plate - Custom cartridge enables homogeneous bioprinting of organoids in sBME-based matrix - 3D-printed tools support compact, scalable multiwell culture systems - System suited for miniaturized culture organoids for high-throughput drug screening - Scalable miniaturized culture system for extended periods of time

bioengineering↗

bioRxiv2024

Development of a high-throughput 3D culture microfluidic platform for multi-parameter phenotypic and omics profiling of patient-derived organoids

Patient-derived organoids (PDOs) are poised to become central tools both in clinical practice, to preemptively identify patient optimal treatments, and in drug discovery, overcoming the limitations of cancer cell lines. However, the use of PDOs in these settings has been hampered by several bottlenecks, including sample requirements, assay time, and handling in the context of high-throughput assays. We developed a Microfluidic Platform for Organoids culture (MPO) that miniaturises and simplifies PDOs cultures in a 384-plate format. Both retrospective and prospective clinical studies demonstrate MPO predictive value and the straightforward implementation in the clinical setting. MPO allows subcellular phenotypic screenings, as imaging-based applications like Cell Painting, target engagement analyses, alongside the comprehensive definition of PDOs genomic, transcriptomic, proteomic, lipidomic, and metabolomic landscapes. Harnessing the pleiotropic capabilities of MPO, we uncovered the role of EZH2 inhibitors to prevent the long-term emergence of resistance to RAS inhibitors in metastatic colon cancer. In all, we demonstrate the potential of MPO to impact clinical practice, alongside exploration of the mechanisms underlying compound response and resistance.

cancer biology↗

bioRxiv2024

IL-23 tunes inflammatory functions of human mucosal-associated invariant T (MAIT) cells

IL-23 signaling plays a key role in the pathogenesis of chronic inflammatory and infectious diseases, yet the cellular targets and signaling pathways affected by this cytokine remain poorly understood. We show that IL-23 receptors are expressed on the large majority of human MAIT, but not of conventional T cells. Protein and transcriptional profiling at the population and single cell level demonstrates that stimulation with IL-23 or the structurally related cytokine IL-12 drives distinct functional profiles, revealing a high level of plasticity of MAIT cells. IL-23, in particular, affects key molecules and pathways related to autoimmunity and cytotoxic functions. Integrated analysis of transcriptomic and chromatin accessibility, supported by CRISPR/Cas9 mediated deletion, shows that AP-1 transcription factors constitute a key regulatory node of the IL-23 pathway in MAIT cells. In conclusion, our findings indicate that MAIT cells are key mediators of IL-23 functions in immunity to infections and chronic inflammatory diseases.

immunology↗

bioRxiv2024

Head down tilt 15° increases cerebral perfusion before recanalization in acute ischemic stroke: a pre-clinical MRI study.

We investigated the therapeutic effect of head down positioning at -15{degrees} (head down tilt; HDT15) on cerebral collateral flow and infarct growth in a rat model of large vessel occlusion (LVO) stroke, using multi-modal MRI. Twenty-eight Wistar rats were randomly assigned to HDT15 or flat position for 60 minutes, starting 30 minutes after occlusion of the middle cerebral artery, followed by reperfusion. The perfusion shift analysis, comparing post- versus pre-treatment voxel-level changes in time-to-peak perfusion maps, showed a significant increase in cerebral perfusion in the HDT15 group (common odds ratio 1.50; 95% CI 1.41-1.60; p < 0.0001), but not in the flat group (common odds ratio 0.97; 95% CI 0.92-1.03; p = 0.3503). Infarct growth at 24 hours was + 31.4% in the flat group (343 versus 250 mm3; 95% CI 2.4 to 165.1; p = 0.0447) and + 15.4% in the HDT15 group (224 versus 192 mm3; 95% CI -26.9 to 85.9; p = 0.2272). Our findings indicate that HDT15 acutely increases cerebral perfusion in LVO acute ischemic stroke and provides a tissue-saving effect before recanalization. Further research is needed to develop HDT15 as an emergency therapy to acutely increase collateral flow in ischemic stroke prior to recanalization therapy.

neuroscience↗

bioRxiv2023

Deep learning insights into the architecture of the mammalian egg-sperm fusion synapse

A crucial event in sexual reproduction is when haploid sperm and egg fuse to form a new diploid organism at fertilization. In mammals, direct interaction between egg JUNO and sperm IZUMO1 mediates gamete membrane adhesion, yet their role in fusion remains enigmatic. We used AlphaFold to predict the structure of other extracellular proteins essential for fertilization to determine if they could form a complex that may mediate fusion. We first identified TMEM81, whose gene is expressed by mouse and human spermatids, as a protein having structural homologies with both IZUMO1 and another sperm molecule essential for gamete fusion, SPACA6. Using a set of proteins known to be important for fertilization and TMEM81, we then systematically searched for predicted binary interactions using an unguided approach and identified a pentameric complex involving sperm IZUMO1, SPACA6, TMEM81 and egg JUNO, CD9. This complex is structurally consistent with both the expected topology on opposing gamete membranes and the location of predicted N-glycans not modeled by AlphaFold-Multimer, suggesting that its components could organize into a synapse-like assembly at the point of fusion. Finally, the structural modeling approach described here could be more generally useful to gain insights into transient protein complexes difficult to detect experimentally. Impact statementStructural modeling with AlphaFold-Multimer was used to investigate extracellular protein interactions involved in mammalian egg-sperm recognition, suggesting a putative pentameric complex that includes TMEM81, a sperm protein not previously involved in gamete recognition.

biophysics↗

bioRxiv2023

Camouflaging Endovascular Stents with an Endothelial Coat Using CD31 Domain 1-mimetic Peptides

BackgroundEndovascular stents and flow diverters have become widely used for the treatment of vascular diseases; however, their effectiveness is often limited by the deposition and activation of blood platelets and leukocytes. The foreignness of these devices often triggers pathologic local reactions that impede their integration and compromise their efficacy. In this study, we developed a method to camouflage endovascular stents and flow diverters by coating them with a surface that mimics healthy endothelium, in order to promote more effective device integration and prevent the activation of blood cells. MethodsWe designed peptides using domain 1 and/or domain 2 of human CD31 and synthesized the chosen peptide to coat clinical-grade nitinol flow diverters and cobalt chromium balloon expandable stents. The coated stents were implanted in adult rabbits and included control groups of uncoated devices and drug-eluting CoCr stents. The rabbits were monitored for 60 days, during which we assessed the integration of the devices under a physiologic confluence of endothelial cells. ResultsOur results demonstrated that the stents coated with the CD31-Domain 1 mimicking peptide promoted a smooth integration of the devices under a physiologic confluence of endothelial cells. By day 7, the coated stents were entirely covered by a smooth endothelium, unlike bare-metal and drug-eluting stents which remained largely exposed to the flowing blood. By day 60, the coated stents demonstrated superiority over both bare-metal and drug-eluting stents, as they resulted in the formation of a "neo-arterial" wall at the entrance of the aneurysmal sac. ConclusionOur method provides a promising step towards the development of more effective and biocompatible endovascular devices. The CD31 domain 1 coating prevented the pathologic local reaction at the site of stent implantation and promoted faster and more effective device integration. Further studies are necessary to investigate the efficacy and safety of CD31 domain 1 coatings on a larger scale, as well as their long-term durability and potential clinical applications.

bioengineering↗

bioRxiv2020

Mutated clones driving leukemic transformation are already detectable at the single cell level in CD34-positive cells in the chronic phase of primary myelofibrosis

Disease progression of myeloproliferative neoplasms is the result of increased genomic complexity. Since the ability to predict disease evolution is crucial for clinical decision, we studied single cell genomics and transcriptomics of CD34-positive cells from a primary myelofibrosis (PMF) patient who progressed to acute myeloid Leukemia (AML) while receiving Ruxolitinib. Single cell genomics allowed the reconstruction of clonal hierarchy and demonstrated that TET2 was the first mutated gene while FLT3 was the last one. Disease evolution was accompanied by increased clonal heterogeneity and mutational rate, but clones carrying TP53 and FLT3 mutations were already present in chronic phase. Single cell transcriptomics unraveled repression of interferon signaling suggesting an immunosuppressive effect exerted by Ruxolitinib. Moreover, AML transformation was associated with a differentiative block and immune escape. These results suggest that single cell analysis can unmask tumor heterogeneity and provide meaningful insights about PMF progression that might guide personalized therapy.

cancer biology↗

bioRxiv2020

Control of fluid flow by Adgrd1 is essential for mammalian oviductal embryo transport

Dysfunction of oviductal embryo transport can lead to ectopic pregnancy which affects 1 to 2% of all conceptions in the United States and Europe, and is the most common cause of pregnancy-related death in the first trimester1, 2. Ectopic pregnancies almost always occur in the Fallopian tube, emphasizing the critical role of oviductal transport in human reproduction3. Oviductal transit is regulated and involves a valve-like "tubal-locking" phenomenon that temporarily arrests oocytes at the ampullary-isthmic junction (AIJ) where fertilization occurs4. Here, we show that female mice lacking the orphan adhesion G-protein coupled receptor Adgrd1 are sterile because they are unable to unlock the restraining mechanism at the AIJ, inappropriately retaining embryos within the oviduct. Adgrd1 is expressed on the oviductal epithelium and the post-ovulatory attenuation of tubal fluid production is dysregulated in Adgrd1-deficient mice. We identified Plxdc2 as an activating ligand for Adgrd1 displayed on the surface of cumulus cells. Our findings suggest that regulating oviductal luminal fluid production by Adgrd1 controls embryo transit, and provides important insights into the genetic regulation and molecular mechanisms involved embryo tubal transport.

molecular biology↗