Biology subjects

Manor, U.

Publications and source records attributed to Manor, U..

At least 19 recordsLinked to original sources

bioRxiv2026

Spatial imprints of emergent cardiomyocyte states in the pressure-overloaded heart

Resilience to cardiac stress is essential for health, yet the relationship between cardiomyocyte (CM) stress response and local microenvironment remains unclear. Here, we combined MERFISH spatial transcriptome profiling with Cellouette, an improved cell segmentation method, to determine CM-microenvironment relationships in a mouse model of ventricular pressure overload. We report the shape, transcription profile, spatial organization, and physical connectivity for >400,000 cells across stressed and healthy tissues. Under stress, CMs adopted a spectrum of emergent transcriptional states, with advanced states marked by a metabolic and pro-fibrotic shift. To discover CM-environment relationships, we performed a network analysis of physical cell connectivity combined with cell-type-specific profiling. We found that pro-fibrotic CM progression was tightly linked to distinct local microenvironments, and CM metabolic shifts could be inferred from transcriptional patterns in neighboring non-CM cells, revealing microenvironmental imprints of disease. We thus provide a resource for understanding the heterogeneity of outcome during cardiac pressure overload. HighlightsO_LICellouette provides accurate segmentation for single-cell spatial transcriptomics in cardiac tissue. C_LIO_LIPressure overload creates spatial gradients of cardiomyocyte pro-fibrotic states. C_LIO_LICardiomyocyte pro-fibrotic progression is linked to changes in local cell composition and gene expression. C_LIO_LITranscriptional states of non-muscle cells predict metabolic state of adjacent cardiomyocytes. C_LI

genomics↗

bioRxiv2026

The COX2-PGE2-PKA Axis Suppresses Antiviral Immunity by Inhibiting mtDNA-Dependent STING Activation.

The innate immune cGAS-STING pathway is activated by cytosolic double-stranded DNA (dsDNA) to induce type I interferon (IFN) response, which is essential for mounting the antiviral response. However, STING activation during viral infection is often insufficient to achieve complete viral clearance, suggesting the existence of additional mechanisms that evade its activity. Here, we identified COX2/PGE2 as a negative regulator of STING activation, particularly in response to arising cytosolic mitochondrial DNA (mtDNA) generated during HSV-1 infection. Mechanistically, PGE2, through the EP4-cAMP-PKA axis, induces mitophagy to remove defective mitochondria and hence prevent the accumulation of immunostimulatory cytosolic mtDNA, thereby dampening STING-mediated type I IFN and antiviral response. Furthermore, we identified STOML2 as a downstream target of PKA that connects mitochondrial quality control with the regulation of innate immune signaling. Together, our findings establish the COX2/PGE2/PKA axis as a negative regulator of mtDNA-STING signaling that may be targeted to potentiate STING-mediated type I IFN and innate immunity. O_FIG O_LINKSMALLFIG WIDTH=166 HEIGHT=200 SRC="FIGDIR/small/716411v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@1c39d56org.highwire.dtl.DTLVardef@18e7c0eorg.highwire.dtl.DTLVardef@172b353org.highwire.dtl.DTLVardef@15b215a_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical abstractC_FLOATNO C_FIG

cell biology↗

bioRxiv2025

Pcdh20 is a POU2F3 target gene required for proper tuft cell microvillus formation

BACKGROUND & AIMSTuft cells play protective roles in infection, inflammation, and tumorigenesis through the secretion of cytokines and eicosanoids. Tuft cells are known for their tall, blunt microvilli, thought to be analogous to mechanosensory hair cell stereocilia; however, a functional role for the microvillar apparatus has not been identified. POU2F3 is the master regulator transcription factor for tuft cells, yet how POU2F3 drives formation of this unique structure is unknown. Here, we aimed to identify POU2F3 target genes and commonalities between tuft and hair cells to better understand this unique structure. METHODSPOU2F3 ChIP-seq was performed on tuft cells and compared to the hair cell transcriptome. Tuft cell RNA-seq datasets were interrogated for hair cell structural and mechanosensory genes; expression was validated. Intestinal and gallbladder tuft cells were examined using multiple light and electron microscopy (EM) modalities. PCDH20 was knocked down in mouse models and ultrastructural analyses were performed. The tuft cell cytoskeleton was modeled using AlphaFold3 prediction. RESULTSGenes encoding structural and mechanosensory proteins common to both tuft and hair cells, including Pcdh20, were identified. Imaging localized PCDH20 to tuft cell microvilli and hair cell stereocilia. Genetic ablation of Pcdh20 in mice resulted in structural defects in tuft cell microvilli, including loss of rigidity and organization. Molecular modeling suggests PCDH20 homodimers link adjacent microvilli. CONCLUSIONSPcdh20 is a POU2F3 target gene in tuft cells, critical to maintain the rigid microvillar apparatus. These findings, together with the shared expression of mechanosensory components like TMC1, support the hypothesis that tuft cells could have mechanosensory capabilities analogous to cochlear hair cells.

cell biology↗

bioRxiv2024

Dark Microglia Are Abundant in Normal Postnatal Development, where they Remodel Synapses via Phagocytosis and Trogocytosis, and Are Dependent on TREM2

This study examined dark microglia--a state linked to central nervous system pathology and neurodegeneration--during postnatal development in the mouse ventral hippocampus, finding that dark microglia interact with blood vessels and synapses and perform trogocytosis of pre-synaptic axon terminals. Furthermore, we found that dark microglia in development notably expressed C-type lectin domain family 7 member A (CLEC7a), lipoprotein lipase (LPL) and triggering receptor expressed on myeloid cells 2 (TREM2) and required TREM2, differently from other microglia, suggesting a link between their role in remodeling during development and central nervous system pathology. Together, these results point towards a previously under-appreciated role for dark microglia in synaptic pruning and plasticity during normal postnatal development.

neuroscience↗

bioRxiv2024

INF2-mediated actin polymerization at ER-organelle contacts regulates organelle size and movement

Proper regulation of organelle dynamics is critical for cellular function, but the mechanisms coordinating multiple organelles remain poorly understood. Here we show that actin polymerization mediated by the endoplasmic reticulum (ER)-anchored formin INF2 acts as a master regulator of organelle morphology and movement. Using high-resolution imaging, we demonstrate that INF2-polymerized actin filaments assemble at ER contact sites on mitochondria, endosomes, and lysosomes just prior to their fission. Genetic manipulation of INF2 activity alters the size, shape and motility of all three organelles. Our findings reveal a conserved mechanism by which the ER uses actin polymerization to control diverse organelles, with implications for understanding organelle dysfunction in neurodegenerative and other diseases. This work establishes INF2-mediated actin assembly as a central coordinator of organelle dynamics and inter-organelle communication.

cell biology↗

bioRxiv2024

An Open-Source Deep Learning-Based GUI Toolbox For Automated Auditory Brainstem Response Analyses (ABRA)

Hearing loss is a pervasive global health challenge with profound impacts on communication, cognitive function, and quality of life. Recent studies have established age-related hearing loss as a significant risk factor for dementia, highlighting the importance of hearing loss research. Auditory brainstem responses (ABRs), which are electrophysiological recordings of acoustically evoked synchronized neural activity from the auditory nerve and brainstem, serve as in vivo correlates for sensory hair cell and synaptic function, hearing sensitivity, and other critical readouts of auditory pathway physiology, making them highly valuable for both basic neuroscience and clinical research. Despite their utility, traditional ABR analyses rely heavily on subjective manual interpretation, which may introduce variability and pose challenges for reproducibility across studies. Here, we introduce Auditory Brainstem Response Analyzer (ABRA), a novel suite of open-source ABR analysis tools powered by deep learning, which automates and standardizes ABR waveform analysis. ABRA employs convolutional neural networks trained on diverse datasets collected from multiple experimental settings, achieving rapid and unbiased extraction of key ABR metrics, including peak amplitude, latency, and auditory threshold estimates. We demonstrate that ABRAs deep learning models provide performance comparable to expert human annotators while dramatically reducing analysis time and enhancing reproducibility across datasets from different laboratories. By bridging hearing research, sensory neuroscience, and advanced computational techniques, ABRA facilitates broader interdisciplinary insights into auditory function. An online version of the tool is available for use at no cost at https://abra.ucsd.edu.

neuroscience↗

bioRxiv2024

VASCilia (Vision Analysis StereoCilia): A Napari Plugin for Deep Learning-Based 3D Analysis of Cochlear Hair Cell Stereocilia Bundles

Cochlear hair cells are essential for hearing, and their stereocilia bundles are critical for mechanotransduction. However, analyzing the 3D morphology of these bundles can be challenging due to their complex organization and the presence of other cellular structures in the tissue. To address this, we developed VASCilia (Vision Analysis StereoCilia), a Napari plugin suite that automates the analysis of 3D confocal microscopy datasets of phalloidin-stained cochlear hair cell bundles. VASCilia includes five deep learning-based models that streamline the analysis process, including: (1) Z-Focus Tracker (ZFT) for selecting relevant slices in a 3D image stack; (2) PCPAlignNet (Planar Cell Polarity Alignment Network) for automated orientation of image stacks; (3) a segmentation model for identifying and delineating stereocilia bundles; (4) a tonotopic Position Prediction tool; and (5) a classification tool for identifying hair cell subtypes. In addition, VASCilia provides automated computational tools and measurement capabilities. Using VASCilia, we demonstrate its utility on challenging datasets, including neonatal wildtype and Eps8 KO 5-day old mice), revealing that total actin content does not necessarily scale with bundle height. We further showcase its power by quantifying complex bundle disorganization in Cdh23-/- cochleae via texture analysis, which revealed systematically more heterogeneous and less regular bundles than in controls. These novel biological findings demonstrate the power of VASCilia in facilitating detailed quantitative analysis of stereocilia. VASCilia also provides a user-friendly interface that allows researchers to easily navigate and use the tool, with the added capability to reload all their analyses for review or sharing purposes. We believe that VASCilia will be a valuable resource for researchers studying cochlear hair cell development and function, addressing a longstanding need in the hair cell research community for specialized deep learning-based tools capable of high-throughput image quantitation. We have released our code along with a manually annotated dataset that includes approximately 55 3D stacks featuring instance segmentation (https://github.com/ucsdmanorlab/Napari-VASCilia). This dataset comprises a total of 502 inner and 1,703 outer hair cell bundles annotated in 3D. As the first open-source dataset of its kind, we aim to establish a foundational resource for constructing a comprehensive atlas of cochlea hair cell images. Ultimately, this initiative will support the development of foundational models adaptable to various species, markers, and imaging scales to accelerate advances within the hearing research community.

bioinformatics↗

bioRxiv2024

PSSR2: a user-friendly Python package for democratizing deep learning-based point-scanning super-resolution microscopy

PSSR2 improves and expands on the previously established PSSR (Point-Scanning Super-Resolution) workflow for simultaneous super-resolution and denoising of undersampled microscopy data. PSSR2 is designed to put state-of-the-art technology into the hands of the general microscopy and biology research community, enabling user-friendly implementation of PSSR workflows with little to no programming experience required, especially through its integrated CLI and Napari plugin.

bioinformatics↗

bioRxiv2024

A deep learning-based strategy for producing dense 3D segmentations from sparsely annotated 2D images

Analyzing volumetric microscopy data requires dense segmentation, yet training accurate machine learning models demands prohibitively expensive 3D ground-truth. To overcome this bottleneck, we present a lightweight framework that bootstraps dense 3D instance segmentations directly from sparse 2D annotations. A 2D network trained on sparse labels predicts complete boundaries on every section, and a 3D network pre-trained on synthetic data infers inter-section connectivity to build coherent 3D volumes. We validated this 2D[->]3D method across diverse datasets spanning electron, expansion, and live-cell microscopy. Strikingly, 3D models trained on these rapidly generated pseudo ground-truths achieve accuracy comparable to those trained on dense expert annotations, yielding up to a 1,000-fold reduction in human annotation time. Even accounting for downstream proofreading, total reconstruction costs drop by an order of magnitude. This approach democratizes the generation of dense 3D training data, seamlessly extending 2D foundation models into the third dimension.

neuroscience↗

bioRxiv2023

Large-scale annotated dataset for cochlear hair cell detection and classification

Our sense of hearing is mediated by cochlear hair cells, localized within the sensory epithelium called the organ of Corti. There are two types of hair cells in the cochlea, which are organized in one row of inner hair cells and three rows of outer hair cells. Each cochlea contains a few thousands of hair cells, and their survival is essential for our perception of sound because they are terminally differentiated and do not regenerate after insult. It is often desirable in hearing research to quantify the number of hair cells within cochlear samples, in both pathological conditions, and in response to treatment. However, the sheer number of cells along the cochlea makes manual quantification impractical. Machine learning can be used to overcome this challenge by automating the quantification process but requires a vast and diverse dataset for effective training. In this study, we present a large collection of annotated cochlear hair-cell datasets, labeled with commonly used hair-cell markers and imaged using various fluorescence microscopy techniques. The collection includes samples from mouse, human, pig and guinea pig cochlear tissue, from normal conditions and following in-vivo and in-vitro ototoxic drug application. The dataset includes over 90,000 hair cells, all of which have been manually identified and annotated as one of two cell types: inner hair cells and outer hair cells. This dataset is the result of a collaborative effort from multiple laboratories and has been carefully curated to represent a variety of imaging techniques. With suggested usage parameters and a well-described annotation procedure, this collection can facilitate the development of generalizable cochlear hair cell detection models or serve as a starting point for fine-tuning models for other analysis tasks. By providing this dataset, we aim to supply other groups within the hearing research community with the opportunity to develop their own tools with which to analyze cochlear imaging data more fully, accurately, and with greater ease.

neuroscience↗

bioRxiv2023

Altered Fhod3 Expression Involved in Progressive High-Frequency Hearing Loss via Dysregulation of Actin Polymerization Stoichiometry in The Cuticular Plate

Age-related hearing loss (ARHL) is a common sensory impairment with complex underlying mechanisms. In our previous study, we performed a meta-analysis of genome-wide association studies (GWAS) in mice and identified a novel locus on chromosome 18 associated with ARHL specifically linked to a 32 kHz tone burst stimulus. Consequently, we investigated the role of Formin Homology 2 Domain Containing 3 (Fhod3), a newly discovered candidate gene for ARHL based on the GWAS results. We observed Fhod3 expression in auditory hair cells (HCs) and primarily localized at the cuticular plate (CP). To understand the functional implications of Fhod3 in the cochlea, we generated Fhod3 overexpression mice (Pax2-Cre+/-; Fhod3Tg/+) (TG) and HC-specific conditional knockout mice (Atoh1-Cre+/-; Fhod3fl/fl) (KO). Audiological assessments in TG mice demonstrated progressive high-frequency hearing loss, characterized by predominant loss of outer hair cells, and a decreased phalloidin intensities of CP. Ultrastructural analysis revealed shortened stereocilia in the basal turn cochlea. Importantly, the hearing and HC phenotype in TG mice were replicated in KO mice. These findings indicate that Fhod3 plays a critical role in regulating actin dynamics in CP and stereocilia. Further investigation of Fhod3 related hearing impairment mechanisms may facilitate the development of therapeutic strategies for ARHL in humans.

neuroscience↗

bioRxiv2023

Mitochondria- and ER-associated actin are required for mitochondrial fusion

Mitochondria play a crucial role in the regulation of cellular metabolism and signalling. Mitochondrial activity is modulated by the processes of mitochondrial fission and fusion, which are required to properly balance respiratory and metabolic functions, transfer material between mitochondria, and remove defective mitochondria. Mitochondrial fission occurs at sites of contact between the endoplasmic reticulum (ER) and mitochondria, and is dependent on the formation of actin filaments that drive mitochondrial constriction and the recruitment and activation of the dynamin-related GTPase fission protein DRP1. The requirement for mitochondria- and ER-associated actin filaments in mitochondrial fission remains unclear, and the role of actin in mitochondrial fusion remains entirely unexplored. Here we show that preventing the formation of actin filaments on either mitochondria or the ER disrupts both mitochondrial fission and fusion. We show that fusion but not fission is dependent on Arp2/3, whereas both fission and fusion are dependent on INF2 formin-dependent actin polymerization. We also show that mitochondria-associated actin marks fusion sites prior to the dynamin family GTPase fusion protein MFN2. Together, our work introduces a novel method for perturbing organelle-associated actin filaments, and demonstrates a previously unknown role for actin in mitochondrial fusion.

cell biology↗

bioRxiv2023

Mutant Prion Protein Endoggresomes are Hubs for Local Axonal Organelle-Cytoskeletal Remodeling

Dystrophic axons comprising misfolded mutant prion protein (PrP) aggregates are a characteristic pathological feature in the prionopathies. These aggregates form inside endolysosomes -called endoggresomes-, within swellings that line up the length of axons of degenerating neurons. The pathways impaired by endoggresomes that result in failed axonal and consequently neuronal health, remain undefined. Here, we dissect the local subcellular impairments that occur within individual mutant PrP endoggresome swelling sites in axons. Quantitative high-resolution light and electron microscopy revealed the selective impairment of the acetylated vs tyrosinated microtubule cytoskeleton, while micro-domain image analysis of live organelle dynamics within swelling sites revealed deficits uniquely to the MT-based active transport system that translocates mitochondria and endosomes toward the synapse. Cytoskeletal and defective transport results in the retention of mitochondria, endosomes, and molecular motors at swelling sites, enhancing mitochondria-Rab7 late endosome contacts that induce mitochondrial fission via the activity of Rab7, and render mitochondria dysfunctional. Our findings point to mutant Pr Pendoggresome swelling sites as selective hubs of cytoskeletal deficits and organelle retention that drive the remodeling of organelles along axons. We propose that the dysfunction imparted locally within these axonal micro-domains spreads throughout the axon over time, leading to axonal dysfunction in prionopathies.

cell biology↗

bioRxiv2023

Astrocyte glypican 5 regulates synapse maturation and stabilization

The maturation and stabilization of appropriate synaptic connections is a vital step in the development of neuronal circuits, however the molecular signals underlying these processes are not fully understood. We show that astrocytes, through production of glypican 5 (GPC5), are required for maturation and refinement of synapses in the developing mouse cortex. In the absence of astrocyte GPC5 thalamocortical synapses in the visual cortex show structural immaturity during the critical period, including smaller presynaptic terminals, decreased postsynaptic density area, and presence of more postsynaptic partners at multisynaptic connections. This structural immaturity is accompanied by a delay in developmental incorporation of GLUA2-containing calcium impermeable AMPARs at intracortical synapses. The functional impact of this is that mice lacking astrocyte GPC5 exhibit increased levels of ocular dominance plasticity in adulthood. This shows astrocyte GPC5 is necessary for maturation and stabilization of synaptic connections in typical development, with implications for understanding disorders with altered synaptic function, including Alzheimers disease, where GPC5 levels are altered.

neuroscience↗

bioRxiv2022

Violation of the ultrastructural size principle in the dorsolateral prefrontal cortex underlies working memory impairment in the aged common marmoset (Callithrix jacchus)

Working memory relies critically on the dorsolateral prefrontal cortex (dlPFC). Morphology and function of the dlPFC, and corresponding working memory performance, are affected early in the aging process. However, these effects are heterogeneous, with nearly half of aged individuals spared of working memory deficits. Translationally relevant model systems are critical for investigating the neurobiological drivers of this variability and identifying why some people experience age-related working memory impairment while others do not. The common marmoset (Callithrix jacchus) is advantageous as a model in which to investigate the biological underpinnings of aging because, as a nonhuman primate, marmosets have a clearly defined dlPFC facilitating investigations of prefrontal-dependent cognitive functions, including working memory, and their short (~10 year) lifespan facilitates longitudinal studies of aging. Here, we conduct the first investigation of synaptic ultrastructure in the dlPFC of the marmoset and investigate whether there are changes to synaptic ultrastructure that are unique to aging with and without working memory impairment. To do this, we characterized working memory capacity in a cohort of marmosets that collectively covered their short lifespan, and found age-related working memory impairment. We also found a remarkable degree of heterogeneity in performance, similar to that found in humans. Utilizing three dimensional reconstruction from serial section electron microscopy, we visualized structural correlates of synaptic efficacy including boutons, mitochondria, and synapses in layer III of the dlPFC of three marmosets: one young adult (YA), one aged cognitively unimpaired (AU), and one aged cognitively impaired (AI). We find that aged marmosets have fewer synapses in dlPFC than young, and this is due to selective vulnerability of small synapses. Next, we tested the hypothesis that violation of the ultrastructural size principle underlies age-related working memory impairment. The ultrastructural size principle states that synaptic efficacy relies on coordinated scaling of synaptic components (e.g., synapses, mitochondria) with presynaptic boutons. While synapses and mitochondria scaled proportionally and were strongly correlated with presynaptic boutons in the YA and AU marmosets, the ultrastructural characteristics of the AI marmoset were alarmingly different. We found that age-related working memory impairment was associated with disproportionately large synapses compared to presynaptic boutons, specifically in those with mitochondria. Remarkably, presynaptic mitochondria and these boutons were completely decorrelated. We posit that this decorrelation results in mismatched energy supply and demand, leading to impaired synaptic transmission. This is the first report of age-related synapse loss in the marmoset, and the first demonstration that violation of the ultrastructural size principle underlies age-related working memory impairment.

neuroscience↗

bioRxiv2022

Endosomal removal and disposal of dysfunctional, immunostimulatory mitochondrial DNA

Maternally inherited mitochondrial DNA (mtDNA) encodes essential subunits of the mitochondrial oxidative phosphorylation system, but is also a major damage-associated molecular pattern (DAMP) that engages innate immune sensors when released into the cytoplasm, outside of cells or into circulation1. This function of mtDNA contributes to antiviral resistance, but unfortunately also causes pathogenic inflammation in many disease contexts2. Cells experiencing mtDNA stress due to depletion of the mtDNA-packaging protein, Transcription Factor A, Mitochondrial (TFAM), or HSV-1 infection exhibit elongated mitochondria, mtDNA depletion, enlargement of nucleoids (mtDNA-protein complexes), and activation of cGAS/STING innate immune signaling via mtDNA released into the cytoplasm3. However, the relationships between altered mitochondrial dynamics and mtDNA-mediated activation of the cGAS-STING pathway remain unclear. Here, we show that entire enlarged nucleoids are released from mitochondria that remain bound to TFAM and colocalize with cGAS. These nucleoids arise at sites of mtDNA replication due to a block in mitochondrial fission at a stage when endoplasmic reticulum (ER) actin polymerization would normally commence, which we propose is a fission checkpoint to ensure that mtDNA has completed replication and is competent for segregation into daughter mitochondria. Released nucleoids also colocalize with the early endosomal marker RAB5 as well as the late endosomal marker RAB7 in TFAM-deficient cells and in response to mtDNA stress caused by the HSV-1 UL12.5 protein. Loss of RAB7 increases interferon stimulated gene (ISG) expression. Thus, we propose that defects in mtDNA replication and/or segregation enact a late mitochondrial fission checkpoint that, if persistent, leads to selective removal of dysfunctional nucleoids by a mitochondrial-endosomal pathway. Early steps in this pathway are prone to mtDNA release and cGAS-STING activation, but the immunostimulatory mtDNA is ultimately disposed of through a mechanism involving RAB7-containing late endosomes to prevent excessive innate immune signaling. This mtDNA quality control pathway might represent a therapeutic target to prevent mtDNA-mediated inflammation and associated pathology.

cell biology↗

bioRxiv2022

Long-term NAD+ supplementation prevents the progression of age-related hearing loss in mice

Age-related hearing loss (ARHL) is the most common sensory disability associated with human aging. Yet, there are no approved measures for preventing or treating this debilitating condition. With its slow progression, continuous and safe approaches are critical for ARHL treatment. Nicotinamide Riboside (NR), a NAD+ precursor, is well tolerated even for long-term use and is already shown effective in various disease models including Alzheimers and Parkinsons Disease. It has also been beneficial against noise induced hearing loss and in hearing loss associated with premature aging. However, its beneficial impact on ARHL is not known. Using two different wild-type mouse strains, we show that long-term NR administration prevents the progression of ARHL. Through transcriptomic and biochemical analysis, we find that NR administration restores age-associated reduction in cochlear NAD+ levels, upregulates biological pathways associated with synaptic transmission and PPAR signaling, and reduces the number of orphan ribbon synapses between afferent auditory neurons and inner hair cells. We also find that NR targets a novel pathway of lipid droplets in the cochlea by inducing the expression of CIDEC and PLIN1 proteins that are downstream of PPAR signaling and are key for lipid droplet growth. Taken together, our results demonstrate the therapeutic potential of NR treatment for ARHL and provide novel insights into its mechanism of action.

animal behavior and cognition↗

bioRxiv2021

Content-aware frame interpolation (CAFI): Deep Learning-based temporal super-resolution for fast bioimaging

The development of high-resolution microscopes has made it possible to investigate cellular processes in 4D (3D over time). However, observing fast cellular dynamics remains challenging as a consequence of photobleaching and phototoxicity. These issues become increasingly problematic with the depth of the volume acquired and the speed of the biological events of interest. Here, we report the implementation of two content-aware frame interpolation (CAFI) deep learning networks, Zooming SlowMo (ZS) and Depth-Aware Video Frame Interpolation (DAIN), based on combinations of recurrent neural networks, that are highly suited for accurately predicting images in between image pairs, therefore improving the temporal resolution of image series as a post-acquisition analysis step. We show that CAFI predictions are capable of understanding the motion context of biological structures to perform better than standard interpolation methods. We benchmark CAFIs performance on six different datasets, obtained from three different microscopy modalities (point-scanning confocal, spinning-disk confocal and confocal brightfield microscopy). We demonstrate its capabilities for single-particle tracking methods applied to the study of lysosome trafficking. CAFI therefore allows for reduced light exposure and phototoxicity on the sample and extends the possibility of long-term live-cell imaging. Both DAIN and ZS as well as the training and testing data are made available for use by the wider community via the ZeroCostDL4Mic platform.

cell biology↗