Biology subjects

Jiu, Y.

Publications and source records attributed to Jiu, Y..

7 recordsLinked to original sources

bioRxiv2023

Vaccinia virus induces EMT-like transformation and RhoA-mediated mesenchymal migration

The emerging outbreak of monkeypox is closely associated with the viral infection and spreading, threatening global public health. Virus-induced cell migration facilitates viral transmission. However, high-resolution dynamics and mechanisms underlying this type of cell migration remain unclear. Here, we investigate the motility of cells infected by vaccinia virus (VACV), a close relative of monkeypox, through combining multi-omics analyses and high-resolution live-cell imaging. We find that, upon VACV infection, the epithelial cells undergo EMT-like transformation, during which they lose intercellular junctions and acquire the migratory capacity to promote viral spreading. After transformation, VACV-induced mesenchymal migration is highly dependent on the actin cytoskeleton and RhoA signaling, which is responsible for the depolymerization of robust actin stress fibers, the leading-edge protrusion formation, and the rear-edge recontraction. Our study reveals how poxviruses alter the epithelial phenotype and regulate RhoA signaling to induce fast migration, providing a unique perspective to understand the pathogenesis of poxviruses.

cell biology↗

bioRxiv2022

Enhancing detectable fluorescence fluctuation for high-throughput and four-dimensional live-cell super-resolution imaging

Super-resolution (SR) imaging with high-throughput is invaluable to fast and high-precision profiling in a wide range of biomedical applications. However, prevalent SR methods require sophisticated acquisition devices and specific imaging control, and may cost a fairly long time on a single field-of-view. These essentially increase the construction difficulty, including challenges in imaging throughput, system establishment, and automation. Using the natural photophysics of fluorescence, fluctuation-based microscopy techniques can routinely break the diffraction limit with no need for additional optical components, but its long acquisition time still poses a challenge for high-throughput imaging or visualizing transient organelle dynamics. Here, we propose an SR method based on the Auto-Correlation with two-step Deconvolution (SACD) that reduces the number of frames required by maximizing the detectable fluorescence fluctuation behavior in each measurement, with further removal of tunable parameters by a Fourier ring correlation analysis. It only needs 20 frames for twofold lateral and axial resolution improvements, while the SR optical fluctuation imaging (SOFI) needs more than 1000 frames. By capturing raw images for [~]10 minutes, we record an SR image with [~]128 nm resolution that contains 2.4 gigapixels covering an area of [~]2.0 mm x 1.4 mm, including more than 2,000 cells. Beyond that, by applying continuity and sparsity joint constraint, the Sparse deconvolution-assisted SACD enables 4D live-cell SR imaging of events such as mitochondrial fission and fusion. Overall, as an open-sourced module, we anticipate SACD can offer direct access to SR, which may facilitate the biology studies of cells and organisms with high-throughput and low-cost.

biophysics↗

bioRxiv2022

Quantitatively mapping local quality of super-resolution microscopy by rolling Fourier ring correlation

In fluorescence microscopy, computational algorithms have been developed to suppress noise, enhance contrast, and even enable super-resolution (SR). However, the local quality of the images may vary on multiple scales, and these differences can lead to misconceptions, which is especially intractable in emerging deep-learning ones. Current mapping methods fail to finely estimate the local quality, challenging to associate the SR scale content. Here, we develop a rolling Fourier ring correlation (rFRC) framework to evaluate the reconstruction uncertainties down to SR scale. To visually pinpoint regions with low reliability, a filtered rFRC is combined with a modified resolution scaled error map (RSM), offering a comprehensive and concise map for further examination. We demonstrate their performances on various SR imaging modalities, and the resulting quantitative maps enable better SR images integrated from different reconstructions. Beyond that, we provide a strategy for learning-based restorations, allowing a direct detection of both data and model uncertainties, and expect the representative cases can inspire further advances in this rapidly developing field.

biophysics↗

bioRxiv2022

Microsecond pulse electrical stimulation modulates cell migration

Wound healing is a complicated process for maintaining skin integrity after injury, for which electrical stimulations (ES) are ascribed to promote wound healing by facilitating cell migration. Time-shortening of the stimulation treatment from current hours to minutes for efficient wound healing but free of cell damage in return, is however rather a challenge. Here, a novel mechanism of ultrashort pulse electric field (PEF), microsecond PEF at higher voltage, is proposed and realized to promote wound healing under a much short time (seconds) for the total treatment. We revealed that microsecond PEF regulated actin cytoskeleton reorganization and focal adhesion turnover, promoting fibroblasts migration in 2D cell cultures under the pulse stimulation. This accelerated fibroblast migration was accompanied by the mutual promotion with extracellular matrix (ECM) alignment in 3D microenvironments, which cooperatively benefit the eventual wound healing, and these findings were further confirmed by the enhanced skin wound healing in a classic mouse model. Additionally, we coined an actin- and collagen-dependent mechanism of microsecond PEF-mediated wound healing. The quantitative mechanism proposed here for our novel microsecond pulse electric filed (sPEF) methodology orients the new practical electric treatment in a wide range of biomedical applications, such as wound healing, regenerative medicine, and tissue engineering.

bioengineering↗

bioRxiv2022

SARS-CoV-2 infected cells sprout actin-rich filopodia that facilitate viral invasion

Emerging COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a great threat to human health and economics. Although SARS-CoV-2 entry mechanism has been explored, little is known about how SARS-CoV-2 regulates the host cell remodeling to facilitate virus invasion process. Here we unveil that SARS-CoV-2 boosts and repurposes filopodia for entry to the target cells. Using SARS-CoV-2 virus-like particle (VLP), real-time live-cell imaging and simulation of active gel model, we reveal that VLP-induced Cdc42 activation leads to the formation of filopodia, which reinforce the viral entry to host cells. By single-particle tracking and sparse deconvolution algorithm, we uncover that VLP particles utilize filopodia to reach the entry site in two patterns, surfing and grabbing, which are more efficient and faster than entry via flat plasma membrane regions. Furthermore, the entry process via filopodia is dependent on the actin cytoskeleton and actin-associated proteins fascin, formin, and Arp2/3. Importantly, either inhibition the actin cross-linking protein fascin or the active level of Cdc42 could significantly hinders both the VLP and the authentic SARS-CoV-2 entry. Together, our results highlight that the spatial-temporal regulation of the actin cytoskeleton by SARS-CoV-2 infection makes filopodia as a highway for virus entry, which emerges as an antiviral target. Significance StatementRevealing the mechanism of SARS-CoV-2 invasion is of great significance to explain its high pathogenic and rapid transmission in the world. We discovered a previously unknown route of SARS-CoV-2 entry. SARS-CoV-2 virus-like particles boost cellular filopodia formation by activating Cdc42. Using state-of-art-technology, we spatial-temporally described how virus utilize filopodia to enter the target cell in two modes: surfing and grabbing. Filopodia can directly transport the virus to endocytic hot spots to avoid the virus from disorderly searching on the plasma membrane. Our study complements current knowledge of SARS-CoV-2 that filopodia and its components not only play an important role in virus release and cell-cell transmission, but also in the entry process, and provides several potential therapeutic targets for SARS-CoV-2. HighlightsO_LISARS-CoV-2 VLP infection promotes filopodia formation by activating Cdc42 C_LIO_LISARS-CoV-2 VLP utilizes filopodia to enter target cell via two modes, surfing and grabbing C_LIO_LIFilopodia disruption compromises the invasion of both VLP and authentic SARS-CoV-2 C_LI

cell biology↗

bioRxiv2022

Vimentin supports directional cell migration by controlling focal adhesions

Persistent cell migration requires focal adhesions to assemble and disassemble locally while maintaining global front-rear alignment. The mechanism that enforces this long-range spatial coherence remains unresolved. Here we identify the intermediate filament protein vimentin as a cell-scale organizer that stabilizes focal adhesion alignment during directed fibroblast migration. Using quantitative live-cell imaging, we show that vimentin-deficient fibroblasts lose directional persistence and a complete collapse of global focal adhesion alignment. Quantitative analysis reveals that vimentin stabilizes focal adhesion alignment by constraining angular fluctuations and preserving the periodic bias of adhesion birth across the adhesion field. Loss of vimentin results in smaller, rapidly turning-over adhesions with disrupted orientation. Trajectory analysis reveals a mechanically anchored adhesion state selectively associated with vimentin recruitment, distinguishing mechanical stabilization from biochemical maturation. Super-resolution and iPALM imaging further show that vimentin integrates within the focal adhesion nanoarchitecture near the force-transduction layer. Together, our findings establish that vimentin intermediate filaments impose spatial coherence on adhesion dynamics, converting locally stochastic adhesion assembly, turnover, and disassembly into globally coordinated adhesions and persistent directional migration.

cell biology↗

bioRxiv2021

Host cytoskeletal vimentin serves as a structural organizer and an RNA-binding protein regulator to facilitate Zika viral replication

Emerging microbe infections such as Zika virus (ZIKV) pose an increasing threat to human health. Current investigations on ZIKV replication have revealed the construction of replication compartments (RCs) and the utilization of host cellular endomembranes, without careful examination of the cytoskeletal network. Here, we investigated the function of vimentin, one of the intermediate filaments (IFs) that play a central role in basic cellular functions and diseases, in the life cycle of ZIKV infection. Using advanced imaging techniques, we uncovered that vimentin filaments have drastic reorganization upon viral protein synthesis, to form a perinuclear cage-like structure that embraces and concentrates RCs. Genetically removal of vimentin markedly reduced viral genome replication, viral protein production and infectious virions release, without interrupting viral binding and entry. Furthermore, proteomics and transcriptome screens by mass spectrometry and RNA sequencing identified intense interaction and regulation between vimentin and hundreds of endoplasmic reticulum (ER)-resident RNA-binding proteins. Among them, the cytoplasmic-region of ribosome receptor binding protein 1 (RRBP1), an ER transmembrane protein directly binds viral RNA, can interact with vimentin, resulting in modulation of ZIKV replication. Together, our work discovered a dual role for vimentin as being not only a structural element for RCs but also an RNA-binding-regulating hub in the ZIKV infection model, unveiling another layer of the complexity between host and virus interaction.

cell biology↗