In situ quantification of osmotic pressure within living embryonic tissues

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Nov. 2, 2023

Abstract Mechanics is known to play a fundamental role in many cellular and developmental processes. Beyond active forces material properties, osmotic pressure believed control essential cell tissue characteristics. However, it remains very challenging perform situ vivo measurements of pressure. Here we introduce double emulsion droplet sensors that enable local intra- extra-cellularly within 3D multicellular systems, including living tissues. After generating calibrating the sensors, measure blastomeres early zebrafish embryos as well interstitial fluid between cells blastula by monitoring size droplets previously inserted embryo. Our results show balance intracellular pressures, with values approximately 0.7 MPa, but large imbalance inside outside The ability developing organoids, will help improve our understanding its biological

Language: Английский

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Viscosity-dependent control of protein synthesis and degradation

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: March 8, 2024

Abstract It has been proposed that the concentration of proteins in cytoplasm maximizes speed important biochemical reactions. Here we have used Xenopus egg extracts, which can be diluted or concentrated to yield a range cytoplasmic protein concentrations, test effect on mRNA translation and degradation. We find synthesis rates are maximal ~1x cytoplasm, whereas degradation continues rise higher optimal ~1.8x. show this difference optima attributed greater sensitivity viscosity. The different could produce negative feedback homeostatic system, where increasing above 1x physiological level increases viscosity selectively inhibits drives system back toward set point.

Language: Английский

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Cytoplasmic fluidization contributes to breaking spore dormancy in fission yeast

Proceedings of the National Academy of Sciences, Journal Year: 2024, Volume and Issue: 121(26)

Published: June 18, 2024

The cytoplasm is a complex, crowded environment that influences myriad cellular processes including protein folding and metabolic reactions. Recent studies have suggested changes in the biophysical properties of play key role homeostasis adaptation. However, it still remains unclear how cells control their cytoplasmic response to environmental cues. Here, we used fission yeast spores as model system dormant elucidate mechanisms underlying regulation properties. By tracking fluorescent tracer particles, found particle mobility decreased compared vegetative rapidly increased at onset dormancy breaking upon glucose addition. This fluidization depended on glucose-sensing via cyclic adenosine monophosphate-protein kinase A pathway. PKA activation led trehalose degradation through trehalase Ntp1, thereby increasing amount decreased. In contrast, rapid did not require de novo synthesis, cytoskeletal dynamics, or cell volume increase. Furthermore, measurement diffusion coefficients with particles different sizes suggests spore impedes movement larger complexes (40 150 nm) such ribosomes, while allowing free smaller molecules (~3 second messengers signaling proteins. Our experiments thus uncovered series events enable quickly fluidize breaking.

Language: Английский

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Scaling behaviour and control of nuclear wrinkling

Nature Physics, Journal Year: 2023, Volume and Issue: 19(12), P. 1927 - 1935

Published: Sept. 18, 2023

Language: Английский

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Eukaryotic cell size regulation and its implications for cellular function and dysfunction

Physiological Reviews, Journal Year: 2024, Volume and Issue: 104(4), P. 1679 - 1717

Published: June 20, 2024

Depending on cell type, environmental inputs, and disease, the cells in human body can have widely different sizes. In recent years, it has become clear that size is a major regulator of function. However, we are only beginning to understand how optimization function determines given cell’s optimal size. Here, review currently known control strategies eukaryotic intricate link intracellular biomolecular scaling, organelle homeostasis, cycle progression. We detail size-dependent regulation early development impact differentiation. Given importance for normal cellular physiology, must account changing conditions. describe sense stimuli, such as nutrient availability, accordingly adapt their by regulating growth Moreover, discuss correlation pathological states with misregulation long time this was considered downstream consequence dysfunction. newer studies reveal reversed causality, misregulated leading pathophysiological phenotypes senescence aging. summary, highlight important roles dysfunction, which could implications both diagnostics treatment clinic.

Language: Английский

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A deep learning-based toolkit for 3D nuclei segmentation and quantitative analysis in cellular and tissue context

Development, Journal Year: 2024, Volume and Issue: 151(14)

Published: July 15, 2024

ABSTRACT We present a new set of computational tools that enable accurate and widely applicable 3D segmentation nuclei in various digital organs. have developed an approach for ground truth generation iterative training nuclear models, which we applied to popular CellPose, PlantSeg StarDist algorithms. provide two high-quality models trained on plant datasets obtained from fixed or live samples, acquired different animal tissues, stained with stains fluorescent protein-based reporters. also share diverse dataset about 10,000 nuclei. Furthermore, advanced the MorphoGraphX analysis visualization software by, among other things, providing method linking segmented their surrounding cells found nuclear-to-cell volume ratio varies between ovule tissues during development tissue. Finally, extended pipeline proofreading tool uses as seeds correct cell errors difficult-to-segment tissues.

Language: Английский

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Conserved nucleocytoplasmic density homeostasis drives cellular organization across eukaryotes

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: Sept. 6, 2023

Abstract The packing and confinement of macromolecules in the cytoplasm nucleoplasm has profound implications for cellular biochemistry. How intracellular density distributions vary affect physiology remains largely unknown. Here, we show that nucleus is less dense than living systems establish maintain a constant ratio between these compartments. Using label-free biophotonics theory, nuclear set by pressure balance across envelope vitro , vivo during early development. Nuclear transport establishes specific proteome exerts colloid osmotic pressure, which, assisted entropic chromatin draws water into nucleus. C. elegans while nuclear-to-cytoplasmic (N/C) volume ratios change development, N/C robustly maintained. We propose maintenance biophysical driver one oldest tenets cell biology: ratio. In summary, this study reveals previously unidentified homeostatic coupling macromolecular densities drives organization with pathophysiologies such as senescence cancer.

Language: Английский

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Macromolecular crowding: Sensing without a sensor

Current Opinion in Cell Biology, Journal Year: 2023, Volume and Issue: 85, P. 102269 - 102269

Published: Oct. 26, 2023

Language: Английский

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N2FXm, a method for joint nuclear and cytoplasmic volume measurements, unravels the osmo-mechanical regulation of nuclear volume in mammalian cells

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Feb. 7, 2024

Abstract In eukaryotes, cytoplasmic and nuclear volumes are tightly regulated to ensure proper cell homeostasis. However, current methods measure volumes, including confocal 3D reconstruction, have limitations, such as relying on two-dimensional projections or poor vertical resolution. Here, overcome these we describe a method, N2FXm, jointly in single cultured adhering human cells, real time, across cycles. We find that this method accurately provides joint size over dynamic measurements at different time resolutions. Moreover, by combining several experimental perturbations analyzing mathematical model osmotic effects tension, show N2FXm can give relevant insights how mechanical forces exerted the cytoskeleton envelope affect growth of nucleus volume biasing import. Our allowing for accurate resolutions, highlights non-constancy nucleus/cytoplasm ratio along cycle.

Language: Английский

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Size Scaling of Condensates in Multicomponent Phase Separation

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(23), P. 16000 - 16009

Published: May 29, 2024

Constant proportionalities between cells and their intracellular organelles have been widely observed in various types of cells, known as size scaling. However, the mechanism underlying scaling its modulation by environmental factors multicomponent systems remain poorly understood. Here, we study membrane-less condensates using microdroplet-encapsulated minimalistic formed droplet microfluidics mean-field theory. We demonstrate that is an inherent characteristic liquid–liquid phase separation. This concept supported experiments showing occurrence phenomena condensate a generic lever rule acquired from Moreover, it found condensate-to-microdroplet ratio can be affected solute salt concentrations, with good agreement predictions Notably, identify noise buffering whereby composed large macromolecules effectively maintain constant volumes counteract concentration fluctuations small molecules. achieved through dynamic rearrangement molecules out membrane-free interfaces. Our work provides crucial insights into understanding mechanistic principles govern well associated biological functions.

Language: Английский

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