{"messages":[{"status":"ok","category":"cell biology","interval":"2025-04-10:2025-07-10","funder":"European Commission : https:\/\/ror.org\/00k4n6c32","cursor":0,"count":8,"count_new_papers":"7","total":"8"}], "collection":[{"title":"Tissue scarring provides a biomechanical framework to promote mammalian bile duct regeneration through the activation of integrin-SRC\/FAK signalling.","authors":"Walker, A.; Olaizola, P.; Brennan, E.; Jarman, E. J.; Yao, Y.; Carmichael, E.; Gradinaru, A.; Loftus, A. E. P.; Wilson, D. H.; Martinez Lyons, A.; Charlton, L.; Ober-Vliegen, K.; Mi, W.; Broeders, A.; Davies, K.; Carragher, N.; Unciti-Broceta, A.; Kendall, T. J.; J.W. van der Laan, L.; Verstegen, M.; Frame, M. C.; Waddell, S. H.; Boulter, L.","author_corresponding":"Luke Boulter","author_corresponding_institution":"University of Edinburgh","doi":"10.1101\/2025.04.21.649531","date":"2025-04-22","version":"1","type":"new results","license":"cc_by","category":"cell biology","jatsxml":"https:\/\/www.biorxiv.org\/content\/early\/2025\/04\/22\/2025.04.21.649531.source.xml","abstract":"Following chronic injury, the adult mammalian bile duct regenerates by forming new branches, essentially replumbing the ductular system to overcome blockages and breaks. To regenerate effectively, biliary epithelial cells (BECs) receive a range of pro-mitogenic signals from myofibroblasts, which concurrently deposit a collagen-rich scar around the duct as it regrows. Despite epithelial regeneration and scarring occurring side-by-side, whether the deposition of scar tissue regulates ductular regeneration per se remains unclear.\n\nBy inducing ductular fibrosis and regeneration in vivo, we show that the formation of collagen-I-rich scars around regenerating ducts changes the local biomechanical properties of these tissues, promoting the growth of ducts. Critically, this changing structural landscape is perceived by a spatially restricted population of biliary epithelial cells which forms a \"leading-tip\" of integrin-2-high cells. This leading-tip undergoes partial-EMT-type reprogramming, allowing it to become migratory and coordinate ductular regeneration. We show that this process is directly driven through an integrin-2-SRC\/FAK signalling axis; thereby connecting epithelial regeneration directly to the changing fibrotic environment in chronic ductular disease.\n\nHighlightsO_LIChronic liver disease results in the formation of stiff, collagen scars around ducts.\nC_LIO_LINew ducts acquire high levels of integrin-2 which is spatially localised to a \"leading-tip\", which loses epithelial features.\nC_LIO_LIIntegrin-2{beta}1-SRC\/FAK signalling regulates ductular migration by linking changes in the bio-structural composition of the liver with ductular cells.\nC_LI","funder":[{"name":"European Commission","id":"https:\/\/ror.org\/00k4n6c32","id-type":"ROR","award":"EP\/Y028546\/1;"},{"name":"Dutch Cancer Foundation","id":"","id-type":"ROR","award":"COCOON KWF-14364;"},{"name":"Chief Scientist Office","id":"https:\/\/ror.org\/01613vh25","id-type":"ROR","award":"EPD\/22\/12;"},{"name":"Carnegie Trust for the Universities of Scotland","id":"https:\/\/ror.org\/00dfrzy25","id-type":"ROR","award":"RIG012508;"},{"name":"Cancer Research UK","id":"https:\/\/ror.org\/054225q67","id-type":"ROR","award":"C52499\/A27948;"},{"name":"Medical Research Council","id":"https:\/\/ror.org\/03x94j517","id-type":"ROR","award":"MR\/Z506199\/1;"}],"published":"NA","server":"bioRxiv"},{"title":"Spindle-localized F-actin regulates polar MTOC organization and the fidelity of meiotic spindle formation","authors":"Soto-Moreno, E. J.; Ali, N. N.; Kuller, F.; Nasufovic, V.; Frolikova, M.; Tepla, O.; Masata, J.; Trauner, D.; Patterson, A. A.; Arndt, H.-D.; Komrskova, K.; Zernicka-Goetz, M.; Glover, D. M.; Balboula, A. Z.","author_corresponding":"Ahmed Z. Balboula","author_corresponding_institution":"University of Missouri","doi":"10.1101\/2025.05.07.652730","date":"2025-05-11","version":"1","type":"new results","license":"cc_by_nc","category":"cell biology","jatsxml":"https:\/\/www.biorxiv.org\/content\/early\/2025\/05\/11\/2025.05.07.652730.source.xml","abstract":"Mammalian oocytes are notoriously prone to chromosome segregation errors leading to aneuploidy. The spindle provides the machinery for accurate chromosome segregation during cell division. Mammalian oocytes lack centrioles and, therefore, the meiotic spindle relies on the organization of numerous acentriolar microtubule organizing centers into two poles (polar MTOCs, pMTOCs). The traditional view is that, in mammalian oocytes, microtubules are the sole cytoskeletal component responsible for regulating pMTOC organization and spindle assembly. We identified a novel F-actin pool that surrounds pMTOCs, forming F-actin cage-like structure. We demonstrated that F-actin localization on the spindle depends on unconventional myosins X and VIIb. Selective disruption of spindle-localized F-actin, using myosin X\/VIIb knockdown oocytes or photoswitchable Optojasp-1, perturbed pMTOC organization, leading to unfocused spindle poles and chromosome missegregation. Here, we unveil an important function of F-actin in regulating pMTOC organization, a critical process for ensuring the fidelity of meiotic spindle formation and proper chromosome segregation.","funder":[{"name":"National Institute of General Medical Sciences","id":"https:\/\/ror.org\/04q48ey07","id-type":"ROR","award":"R35 GM142537;"},{"name":"European Commission","id":"https:\/\/ror.org\/00k4n6c32","id-type":"ROR","award":"Marie Sklodowska-Curie Fellowship 706170;"},{"name":"Czech Grant Agency","id":"","id-type":"ROR","award":"GA22-30494S;"},{"name":"Czech Health Research Council","id":"","id-type":"ROR","award":"NW24-08-00048;"},{"name":"BIOCEV","id":"","id-type":"ROR","award":"CZ.1.05\/1.1.00\/02.0109;"},{"name":"Institute of Biotechnology of the Czech Academy of Sciences","id":"","id-type":"ROR","award":"RVO 86652036;"},{"name":"Deutsche Forschungsgemeinschaft","id":"https:\/\/ror.org\/018mejw64","id-type":"ROR","award":"390713860;"},{"name":"MEYS \u2013 LM2023050 and RVO","id":"","id-type":"ROR","award":""}],"published":"10.1038\/s41467-025-63586-w","server":"bioRxiv"},{"title":"Cryo-Correlative Light and X-ray microscopies: Expanding the Intracellular Chemical Map","authors":"Karpov, D.; Cuau, L.; Shishkov, R.; Gramaccioni, C.; Dallerba, E.; Schwehr, B.; Hackett, M.; Plush, S.; Massi, M.; Lerouge, F.; Cloetens, P.; Bohic, S.","author_corresponding":"Sylvain Bohic","author_corresponding_institution":"ESRF, The European Synchrotron, Grenoble, France; University Grenoble Alpes, Synchrotron Radiation for Biomedical Research, Grenoble, France","doi":"10.1101\/2025.05.23.655741","date":"2025-05-23","version":"1","type":"new results","license":"cc_by","category":"cell biology","jatsxml":"https:\/\/www.biorxiv.org\/content\/early\/2025\/05\/23\/2025.05.23.655741.source.xml","abstract":"We introduce a powerful, integrated workflow that fuses cryo-optical fluorescence microscopy with cryogenic synchrotron radiation X-ray fluorescence nanoimaging to unlock unprecedented nanoscale insights into cellular ultrastructure and composition. Our method delivers sharp 2D and 3D visualizations enabling simultaneous elemental mapping, nanoparticle tracking, and imaging of mitochondrial features via a luminescent cyclometalated iridium complex. We further demonstrated that combining well-chosen molecular probes possessing different heavy elements (e.g. rhenium, iridium, bromine and iodine) allows elemental multiplex \"painting\" of different organelle to provide X-ray fluorescent elemental contrast of some intracellular structure. By eliminating the need for separate sample preparations, this streamlined approach maximizes limited synchrotron beamtime and dramatically accelerates data acquisition, setting a new benchmark for advanced cryo-nanoscale imaging studies.","funder":[{"name":"European Commission","id":"https:\/\/ror.org\/00k4n6c32","id-type":"ROR","award":"Horizon 2020, Grant Agreement No. 899549;"},{"name":"Australian Research Council","id":"https:\/\/ror.org\/05mmh0f86","id-type":"ROR","award":"DP220103901;"},{"name":"European Synchrotron Radiation Facility","id":"https:\/\/ror.org\/02550n020","id-type":"ROR","award":"IN-1118;IHLS-3625;"}],"published":"10.1021\/acsnano.5c10637","server":"bioRxiv"},{"title":"Ciliary and non-ciliary functions of CEP104 in Xenopus","authors":"Louka, P.; Potamiti, L.; Panayiotidis, M. I.; Skourides, P.","author_corresponding":"Panagiota Louka","author_corresponding_institution":"University of Cyprus","doi":"10.1101\/2025.06.12.659327","date":"2025-06-15","version":"1","type":"new results","license":"cc_by_nc_nd","category":"cell biology","jatsxml":"https:\/\/www.biorxiv.org\/content\/early\/2025\/06\/15\/2025.06.12.659327.source.xml","abstract":"Cep104 is a conserved protein essential for centriole and cilia function, with mutations linked to Joubert Syndrome. We investigated its role in Xenopus embryonic development, revealing that Cep104 is crucial for neural tube closure (NTC) through regulating apical constriction. We show that the role of Cep104 in cilia and hedgehog signaling cannot alone explain the elicited defects. We go on to show that Cep104 localizes to the ends of cytoplasmic microtubules, influencing their stability. Downregulation of CEP104 led to microtubule instability and defects in multiciliated cell intercalation, a process dependent on stable microtubules. Our findings demonstrate that Cep104 functions beyond cilia, playing a significant role in cytoplasmic microtubule dynamics, suggesting that both ciliary and non-ciliary roles are important for neurodevelopment and the pathogenesis of ciliopathies.","funder":[{"name":"European Commission","id":"https:\/\/ror.org\/00k4n6c32","id-type":"ROR","award":"MarieSkłodowska-Curie Actions #893418;"}],"published":"NA","server":"bioRxiv"},{"title":"Ciliary and non-ciliary functions of CEP104 in Xenopus","authors":"Louka, P.; Potamiti, L.; Panayiotidis, M. I.; Skourides, P.","author_corresponding":"Panagiota Louka","author_corresponding_institution":"University of Cyprus","doi":"10.1101\/2025.06.12.659327","date":"2025-06-16","version":"2","type":"new results","license":"cc_by_nc_nd","category":"cell biology","jatsxml":"https:\/\/www.biorxiv.org\/content\/early\/2025\/06\/16\/2025.06.12.659327.source.xml","abstract":"Cep104 is a conserved protein essential for centriole and cilia function, with mutations linked to Joubert Syndrome. We investigated its role in Xenopus embryonic development, revealing that Cep104 is crucial for neural tube closure (NTC) through regulating apical constriction. We show that the role of Cep104 in cilia and hedgehog signaling cannot alone explain the elicited defects. We go on to show that Cep104 localizes to the ends of cytoplasmic microtubules, influencing their stability. Downregulation of CEP104 led to microtubule instability and defects in multiciliated cell intercalation, a process dependent on stable microtubules. Our findings demonstrate that Cep104 functions beyond cilia, playing a significant role in cytoplasmic microtubule dynamics, suggesting that both ciliary and non-ciliary roles are important for neurodevelopment and the pathogenesis of ciliopathies.","funder":[{"name":"European Commission","id":"https:\/\/ror.org\/00k4n6c32","id-type":"ROR","award":"MarieSkłodowska-Curie Actions #893418;"}],"published":"NA","server":"bioRxiv"},{"title":"Cholesteryl esters and high protein-to-lipid ratios distinguish Non-Vesicular Extracellular Particles from Extracellular Vesicles","authors":"Ghosal, S.; Leporati, R.; Varga, A.; Susanszki, P.; Fekete, N.; Laszlo, T.; Barkai, T.; Grebecz, F. K.; Khamari, D.; Magyar, T. Z.; Hoering, M.; Vukman, K. V.; Bodnar, B. R.; Kestecher, B. M.; Fattah, M. A.; Bodor, C.; Maleth, J.; Liebisch, G.; Orso, E.; Buzas, E. I.; Osteikoetxea, X.","author_corresponding":"Xabier Osteikoetxea","author_corresponding_institution":"HCEMM-SU Extracellular Vesicle Research Group, Budapest, 1089, Hungary.; Institute of Genetics, Cell- and Immunobiology, Semmelweis University, Budapest, 1089, ","doi":"10.1101\/2025.07.01.662358","date":"2025-07-03","version":"1","type":"new results","license":"cc_by","category":"cell biology","jatsxml":"https:\/\/www.biorxiv.org\/content\/early\/2025\/07\/03\/2025.07.01.662358.source.xml","abstract":"Extracellular vesicles (EVs) are central to intercellular communication, yet the mechanisms underlying their biogenesis and diversity remain incompletely understood. Here, we integrate meta-analysis, advanced lipidomic, protein-to-lipid profiling, and super-resolution imaging to define the fundamental principles governing EV heterogeneity. Our meta-analysis of published transmission electron microcrographs across kingdoms reveals a highly conserved 110 nm average diameter and 200 nm upper size limit for intraluminal vesicles (ILVs), which are secreted as exosomes. Besides classical EV populations, we also characterize a distinct nanoparticle class: 167000 xg pellet of non-vesicular extracellular particles (167k-NVEPs), which exhibit a significantly higher protein-to-lipid ratio than 14000 xg pellet of large EVs (14k-lEVs) and 100000 xg pellet of small EVs (100k-sEVs), as measured by both biochemical assays and Raman spectroscopy. Lipid profiling demonstrates that 167k-NVEPs exhibit significant enrichment in cholesteryl esters and triacylglycerols, lipids typically associated with lipid droplets and the endosome\/lysosome system. Analysis of lipid carbon-chain lengths reveals distinct signatures: 167k-NVEPs show pronounced enrichment at 16 and 18 carbons, while 100k-sEVs display enrichment at 32 and 34 carbons. This divergence indicates a potential connection to flexible biogenesis pathways. Marker heterogeneity across EV populations, confirmed by confocal and super-resolution microscopy, further underscores the limitations of relying on canonical tetraspanins for EV classification. Notably, 167k-NVEPs (likely exomeres) exhibit enrichment of Arf6 and CD63. Together, our findings provide compositional, biophysical, and molecular evidence supporting the formal recognition of 167k-NVEPs as a distinct class of extracellular particles and enabling exploring in disease biology and therapeutic delivery.\n\nSignificance StatementExtracellular vesicles (EVs) are critical mediators of intercellular communication, yet their classification remains clouded by ambiguity in terms of their composition and biogenesis. This study resolves critical uncertainties through a cross-kingdom meta-analysis, establishing a conserved [~]110nm diameter and [~]200 nm upper size limit for intraluminal vesicles (ILVs), the precursors to exosomes. More significantly, we identify non-vesicular extracellular particles (167k-NVEPs) as a distinct class based on their unique sterol-rich lipidome, enrichment in lipids of 16 and 18 carbon chain length, elevated protein-to-lipid ratio, and functional cargo delivery. These features, alongside evidence of non-canonical origin and functional cargo delivery, establish NVEPs as a discrete class of extracellular particles.","funder":[{"name":"European Commission","id":"https:\/\/ror.org\/00k4n6c32","id-type":"ROR","award":"Horizon 2020  Grant agreement 739593;"},{"name":"Hungarian Scientific Research Fund","id":"https:\/\/ror.org\/00v349e63","id-type":"ROR","award":"OTKA FK 147023;EXCELLENCE  151417;Advanced Grant 150767;2019-2.1.7-ERA-NET-2021-00015;NVKP_16- 1-2016-0004;TKP2021-EGA-23;"},{"name":"Hungarian National Research, Development and Innovation Office (NKFIH)","id":"","id-type":"ROR","award":"TKP2021-EGA-23;RRF-2.3.121-2022-00003;VEKOP-2.3.2-162016-00002;VEKOP-2.3.3-15- 2017-00016,;EK\u00d6P-2024-237;"},{"name":"Hungarian Government","id":"","id-type":"ROR","award":"Stipendium Hungaricum Scholarship 2021;"}],"published":"NA","server":"bioRxiv"},{"title":"Mechanical Coordination of Intestinal Cell Extrusion by Supracellular 3D Force Patterns","authors":"Matejcic, M.; Wang, M.; Lopez Serrano, E.; Perez-Gonzalez, C.; Houtekamer, R.; Ceada, G.; Roca-Cusachs, P.; Gloerich, M.; Trepat, X.","author_corresponding":"Xavier Trepat","author_corresponding_institution":"Institute for Bioengineering of Catalonia","doi":"10.1101\/2025.07.03.661686","date":"2025-07-03","version":"1","type":"new results","license":"cc_by_nc_nd","category":"cell biology","jatsxml":"https:\/\/www.biorxiv.org\/content\/early\/2025\/07\/03\/2025.07.03.661686.source.xml","abstract":"Every day, the mammalian intestinal epithelium extrudes millions of cells to sustain tissue self-renewal. Despite its fundamental role in intestinal homeostasis, the mechanisms that trigger, compartmentalize, and execute intestinal cell extrusion remain largely unknown. Here, using intestinal organoids, we map the three-dimensional forces and cytoskeletal dynamics that drive intestinal cell extrusion. We show that, unlike in other epithelia, extrusion is initiated by the sudden dissolution of a contractile myosin 2A meshwork triggered by a calcium influx. Following meshwork dissolution, the extruding cell and its neighbors generate an upwards traction force that requires myosin contractility but is generated by lamellipodial protrusions in neighboring cells. Importantly, these lamellipodia not only act as force generators but also determine whether extrusion occurs apically or basally, serving as symmetry breakers of the process. Finally, we show that compartmentalization of cell extrusion to the outside of the intestinal crypt does not require curvature and instead depends on myosin 2A. Our findings reveal that the intestinal epithelium exhibits a distinctive mode of extrusion, in which tension differentials--rather than compressive stresses from crowding--trigger and compartmentalize cell removal.","funder":[{"name":"Spanish Ministry for Science and Innovation","id":"","id-type":"ROR","award":"FJC2018-037440-I;PID2022-142672NB-I00;PID2021-128635NB-I00 MCIN\/AEI\/ 10.13039\/501100011033;ERDF-EU A way of making Europe;"},{"name":"EMBO","id":"","id-type":"ROR","award":"ALTF-1169;"},{"name":"European Research Council","id":"https:\/\/ror.org\/0472cxd90","id-type":"ROR","award":"Adv-101097753;Adv-883739;"},{"name":"Generalitat de Catalunya","id":"https:\/\/ror.org\/01bg62x04","id-type":"ROR","award":"2017-SGR-1602;AGAUR SGR-2017-01602;"},{"name":"ICREA Academia","id":"","id-type":"ROR","award":""},{"name":"Fundaci\u00f3 la Marat\u00f3 de TV3","id":"","id-type":"ROR","award":"201903-30-31-32;"},{"name":"European Commission","id":"https:\/\/ror.org\/00k4n6c32","id-type":"ROR","award":"H2020-FETPROACT-01-2016-731957;"},{"name":"La Caixa Foundation","id":"","id-type":"ROR","award":"LCF\/PR\/HR24\/00326;"},{"name":"Human Frontiers Science Program","id":"","id-type":"ROR","award":"HFSPRGP022\/2024;"}],"published":"NA","server":"bioRxiv"},{"title":"Identification of transporters essential for survival of Leishmania promastigotes in the digestive tract of sand flies","authors":"Sadlova, J.; Vojtkova, B.; Becvar, T.; Dobramysl, U.; Moeri, S.; Alagoez, C.; Wheeler, R. J.; Volf, P.; Gluenz, E.; Albuquerque-Wendt, A.","author_corresponding":"Andreia Albuquerque-Wendt","author_corresponding_institution":"Swiss TPH, PCU","doi":"10.1101\/2025.07.07.663555","date":"2025-07-10","version":"1","type":"new results","license":"cc_by","category":"cell biology","jatsxml":"https:\/\/www.biorxiv.org\/content\/early\/2025\/07\/10\/2025.07.07.663555.source.xml","abstract":"Leishmania amastigotes ingested by female phlebotomine sand flies are exposed to a harsh and dynamic environment that differs markedly from the intracellular niche in the mammalian host in temperature, pH and nutrient availability. Membrane transporter proteins, channels and pumps play a crucial role in maintaining cellular physiology under changing environments. A systematic loss-of-function screen of the L. mexicana transporter deletion mutants in macrophage and mouse infections previously identified transporter genes important for the amastigote stage. To test which transporters are important for the promastigote stage in the insect vector, we measured the fitness of gene deletion mutants in Lu. longipalpis sand flies. Pooled libraries of different complexities, consisting of 71 to 317 barcoded parasite lines allowed for an estimation of the bottleneck size in experimental infections, providing a foundation for similar experimental bar-seq studies. The fitness of each mutant parasite line was measured by tracking population composition over a course of 9 days in the sand flies and compared with the growth fitness of promastigotes over 7 days in laboratory cultures. There was a high correlation of fitness scores in vitro and in vivo, but 34 mutants showed a loss of fitness only in vivo, including deletion mutants of vacuolar H+ ATPase (V-ATPase) subunits. V-ATPase deletion mutants expressed low levels of the metacyclic-specific transcript sherp in vitro and failed to generate metacyclic promastigotes in sand flies, indicating that V-ATPase function is required for parasite differentiation and progression through the Leishmania life cycle.\n\nAuthor SummaryLeishmania parasites cause leishmaniases - a group of neglected tropical diseases that affect millions of people worldwide. These parasites must survive in two radically different environments: inside a mammalian host and within the gut of a blood-feeding sand fly. To thrive in the sand fly, Leishmania undergo extensive physiological changes and depend on transporter proteins to move nutrients and other molecules across their cell membranes. In this study, we focused on identifying which of these transporters are critical for the parasites survival inside the sand fly. We used a library of genetically engineered Leishmania promastigotes - the parasite form adapted to the insect vector - to assess the importance of more than 300 different transporter genes. We discovered that 34 of these transporters are essential for successful colonization of the sand fly. Among them, one key protein complex - the vacuolar H+ ATPase (V-ATPase) pump - was found to be crucial for parasite survival in the insect vector. Our findings deepen our understanding of how Leishmania adapts to life within the sand fly and highlight potential molecular targets for disrupting its transmission.","funder":[{"name":"European Commission","id":"https:\/\/ror.org\/00k4n6c32","id-type":"ROR","award":"trans-LEISHion-EU FP7, No. 798736;LeishBlock-Horizon, No. 101148623;"},{"name":"Wellcome Trust","id":"https:\/\/ror.org\/029chgv08","id-type":"ROR","award":"104111\/Z\/14\/Z;104627\/Z\/14\/Z;200807\/Z\/16\/Z;211075\/Z\/18\/Z;221944\/A\/20\/Z;"},{"name":"Medical Research Council","id":"https:\/\/ror.org\/03x94j517","id-type":"ROR","award":"MR\/V000446\/1;"},{"name":"Swiss National Science Foundation","id":"https:\/\/ror.org\/00yjd3n13","id-type":"ROR","award":"310030_220011;"}],"published":"NA","server":"bioRxiv"}]}