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Wong, M.

Publications and source records attributed to Wong, M..

At least 19 recordsLinked to original sources

A single-plane electrical impedance tomography framework for integrated liver and kidney assessment

Chronic liver and kidney diseases frequently coexist, but their assessment typically requires separate clinical workflows involving serum-based estimated glomerular filtration rate (eGFR) testing and liver elastography-based controlled attenuation parameter (CAP). Electrical impedance tomography (EIT) has recently shown promise for providing portable, non-invasive proxies for both reference measurements. However, existing multi-organ EIT assessment still requires different acquisition protocols for each organ. To simplify this procedure, we assessed the feasibility of a single-plane EIT framework for reconstructing organ-specific images and estimating liver and kidney health from one abdominal belt placement. Across diverse abdominal belt locations, opposite-plane deviation was significantly greater for eGFREIT estimates (2.92%; IQR, 0.46-12.53%) than for CAPEIT estimates (0.94%; IQR, 0.66-1.70%) (p < 0.01). For both organs, compared to images acquired at the conventional organ-specific planes, image correlation significantly decreased (both, p < 0.05) and normalized root mean squared error significantly increased (both, p < 0.05) at the furthest imaging plane, with these differences being numerically larger for the kidney. Together, these results supported the kidney plane as the preferred location for multi-organ assessment. Test-retest evaluation after belt removal and reapplication demonstrated that the correlation between two repeated CAPEIT estimates was just as strong at the kidney plane (R2 = 0.98, p < 0.001) as it was at the conventional liver plane (R2 = 0.97, p < 0.001). Finally, in an independent clinical cohort, kidney-plane CAPEIT estimates were significantly higher in participants with a high metabolic liver-risk profile (i.e. diabetes and high blood pressure) (p < 0.005). CAPEIT estimates also distinguished high and low metabolic risk groups with an AUC of 0.756. Together, these findings support the feasibility of a portable multi-organ EIT imaging framework capable of extracting complementary liver and kidney information from a single belt placement.

bioengineering↗

Hyperexcitable but seizure-free: hippocampal network dysfunction in a Wolfram syndrome model

Wolfram syndrome (WS) is a rare, life-limiting progressive neurodegenerative disorder caused by pathogenic variants in the WFS1 gene. It is a prototype endoplasmic reticulum (ER) stress disorder, and the mechanisms underlying neurological phenotypes in WS remain incompletely understood. Although WFS1 protein is abundant in the hippocampus, the role of this region in WS remains relatively understudied. Here we characterize hippocampal function across scales in mice carrying a patient orthologous Wfs1 variant (p.W542*) on both alleles. Male mutants lose excitatory synapses, and dissociated hippocampal neurons are markedly hyperexcitable yet generate no increase in network bursting and no shift in network criticality, indicating that their additional firing is not recruited into coordinated population activity. This finding translates in vivo wherein intracranial electroencephalogram (EEG) recordings show no epileptiform activity or seizures in either sex, with no hippocampal astrogliosis, alongside a male-specific reduction in hippocampal low-gamma power. Additionally, EEG demonstrates a sex-specific disruption of sleep, which parallels a sex-divergent synaptic phenotype. Mutant male mice show impaired hippocampus-dependent fear memory and reduced voluntary motor activity. Taken together, we propose that cellular hyperexcitability in the WS hippocampus does not translate into increased network bursting, potentially due to disproportionate loss of excitatory synapses. This dissociation may provide a functional substrate for the neurological features of WS.

neuroscience↗

Inhibitors of HIV-1 maturation modulate conformational dynamics and heterogeneity of the immature Gag lattice

HIV-1 maturation requires the viral protease to cleave the Gag polyprotein into its constituent domains. Subsequent conformational and morphological changes result in a mature, infectious virion. Prior studies support a hypothesis in which Gag conformational dynamics and the heterogeneity of the immature Gag lattice enable proteolytic and morphological maturation. We developed a single-molecule Forster resonance energy transfer imaging approach to probe, in real time, the conformational dynamics of individual Gag molecules within immature HIV-1 virions. Our results capture Gag's conformational landscape and the spatial heterogeneity of the immature lattice. We evaluated inhibitors of maturation to identify immature lattice features that are modulated to disrupt maturation. Maturation inhibitors that act through diverse mechanisms, including lenacapavir and compounds that alter viral membrane composition, arrest Gag dynamics and reduce the spatial heterogeneity of the lattice. These observations support a model in which Gag dynamics and immature lattice organization regulate HIV-1 maturation.

biophysics↗

USP15 REGULATES NEUROINFLAMMATION AND DRIVES PATHOGENESIS IN SYNUCLEINOPATHIES

Neuroinflammation strongly contributes to the pathogenesis of neurological and neurodegenerative diseases, including Parkinson's disease. We show that ablation of Usp15 in astrocytes and in microglia protects against lethal neuroinflammation in vivo. In a mouse model of synucleinopathy, Usp15 deletion diminishes alpha-syn deposits in the brain, slows disease progression, and increases survival time. The neuroprotective effect of Usp15 is associated with differential expression of inflammatory pathways in situ including interferon stimulated genes. These USP15-dependent effects in vivo are recapitulated in vitro in primary human microglia and astrocytes. We detect high USP15 expression in microglia from Parkinson's patients with strong co-expression with LRRK2 and SNCA. In humans, we detect a strong cis-acting eQTL directing high USP15 expression in CD14+ myeloid cells. The allele driving this eQTL is itself associated with increased disease risk, linking myeloid USP15 expression, elevated USP15 plasma levels in Parkinson's patients, to genetic susceptibility.

neuroscience↗

Senataxin loss induces cGAS–STING-mediated mitochondrial dysfunction

Ataxia with oculomotor apraxia type 2 (AOA2) is a rare neurodegenerative disease caused by loss-of-function mutations in Senataxin, which encodes an RNA:DNA helicase. Many studies on Senataxin loss focus on its putative roles in regulating transcription and RNA transcript localization. However, several phenotypes remain underexplored, including metabolic dysregulation associated with ataxias. Using Senataxin-deficient mouse cells, we observed increased nuclear and genomic instability, as well as innate immune activation via the cGAS-STING axis. We also observed elevated ROS levels, decreased mitochondrial function, and hyperfused mitochondria. Importantly, mitochondrial dysfunction depends on cGAS/STING activity, indicating that the two phenotypes are functionally connected. Senataxin-deficient mice and AOA2 patient cells similarly exhibit spontaneous innate immune activation, and AOA2 patient cells also show decreased mitochondrial function. Our work identifies a previously unseen phenotype for AOA2 in which loss of Senataxin results in mitochondrial dysfunction promoted by cGAS and STING. SummaryThis study demonstrates a previously unidentified phenotype in AOA2 and Senataxin research in which cGAS-STING promotes mitochondrial dysregulation in Setx-/- MEFs. Further, these innate immune activation and mitochondrial dysregulated phenotypes are recapitulated in AOA2 patient cells.

Cell Biology↗

STING-STAT3-SOX18 Axis Drives EndMT and Epigenetic Reprogramming in SAVI Lung Fibrosis

A high prevalence of early-onset interstitial lung disease, including pulmonary fibrosis, in pediatric patients with Stimulator of interferon genes (STING)-Associated Vasculopathy with onset in infancy (SAVI) suggests a critical role for the cGAS-STING pathway in the pathogenesis of pulmonary fibrosis. We identified an endothelial-to-mesenchymal transition (EndMT) signature in lesional lung biopsies from SAVI patients, marked by a loss of endothelial and acquisition of mesenchymal markers. Consistently, induced pluripotent stem cell-derived endothelial cells (iECs) from SAVI patients harboring gain-of-function STING1 mutations spontaneously undergo EndMT, a process rescued in isogenic-correction. In endothelial cells, STING activation induces IRF3-independent STAT3 phosphorylation, initiating a SLUG-dependent mesenchymal transcriptional program while repressing SOX18 and an epigenetically-regulated endothelial maintenance network. Our studies define a non-canonical cGAS-STING-STAT3 signaling axis that couples a mesenchymal transcriptional program with epigenetic silencing of an endothelial maintenance program, promoting TGF{beta}-independent STING-mediated EndMT and endothelial dysfunction, and suggesting STING as a therapeutic target for inflammatory pulmonary fibrosis.

cell biology↗

YAP disrupts bile acid homeostasis to drive cancer-associated cachexia

Cancer-associated cachexia is a severe metabolic syndrome marked by dramatic loss of adipose and muscle mass. Although preclinical models have advanced our understanding of cachexia, there are still no approved therapies due to the limited insights into the mechanisms underlying tissue wasting. Here, we utilise a YAP-driven model of liver cancer in zebrafish, which rapidly develops cachexia, to uncover an evolutionarily conserved role for bile acid disruption in the onset of cachexia. Spatial transcriptomic analysis revealed that YAP induces a bi-lineage cholangiocarcinoma phenotype, which was associated with bile acid dysregulation. Mechanistically, we establish that both bile acid synthesis (via CYP7A1) and signalling through the bile acid receptor TGR5 are essential for cachexia induction. Notably, we find that the promotion of bile acid excretion with odevixibat ameliorates cachexia. Together, our findings reveal an evolutionarily conserved mechanism by which YAP promotes cachexia and suggest a potential therapeutic strategy to treat the syndrome.

cancer biology↗

Splitting and filling the gaps: a reorganization of Corymbiglomeraceae and new taxa from trans-Pacific tropical regions

Diversisporales comprises species with worldwide distribution that produce glomoid, otosporoid, or tricisporoid spores. The recent reorganization of the order by Oehl et al. (2016) recognizes two families, Diversisporaceae and Corymbiglomeraceae, comprising one and five genera, respectively. Several Glomeromycotan specimens collected in northern and southeastern Mexico and in French Polynesian atolls were characterized using both morphological and molecular analyses. Phylogenetic inference revealed that they represent new members in the Diversisporales, supporting the reorganization of the genus Redeckera into three independent lineages: Albocarpum gen. nov., with A. arenaceum sp. nov., A. leptohyphum sp. nov., and A. fulvum comb. nov., Pulvinocarpum pulvinatum gen. et comb. nov., and Redeckera, which retains five species, including R. varelae sp. nov. In addition, we described Melanocarpum mexicanum gen. et sp. nov. and Diversispora papillosa sp. nov. A broader phylogeny, based on eDNA sequences and representative of Diversisporales species, including the newly described taxa, further supported the split of Redeckera and suggested three additional clades likely corresponding to a new family and two new genera, awaiting the discovery of representative morphospecies to be formally described. Using eDNA sequences metadata, the occurrences of the newly described taxa were mapped, allowing to recognize distribution patterns, mostly in the pantropical zone, distinguish widespread and rare species, and suggest possible endemisms. Finally, the coexistence of species forming large sporocarps (A. fulvum and A. leptohyphum) alongside species forming spores in loose aggregates (A. arenaceum), prompted us to propose a possible sporulation dimorphism in Albocarpum, an argument previously raised to explain the nested placement of Corymbiglomus and Paracorymbiglomus within the Redeckera clade.

evolutionary biology↗

Development of the Early Childhood Duodenum across Ancestry, Geography and Environment

During early childhood, the proximal small intestinal mucosa plays a central role in growth, metabolism, immune priming, and neuronal development. Yet the cellular architecture and environmental responsiveness of the human small intestinal mucosa during this period remain poorly defined. Here, we generate a comprehensive cellular and spatial map of the duodenum from 87 children aged 6 months to 13 years, representing diverse ancestries and geographic contexts. This atlas integrates single-cell transcriptomic and spatial profiling with data on diet, social drivers of health, and environmental exposures. Using these data, we define mucosal cellular composition and chart its developmental trajectory in early childhood. Comparative analyses of children residing in the United States (US) and Pakistan reveal a differentiated enterocyte subset expressing the aquaglyceroporin, AQP10 (AQP10+ enterocyte), that is enriched in children from the US. We show that emergence of this enterocyte state depends on lipid exposure to intestinal stem cells and correlates with dietary fat intake. We also identify a previously-undescribed thyrotropin-releasing hormone (TRH+) enteroendocrine cell and provide evidence for a local endocrine-epithelial-lymphocyte circuit. Our work establishes a detailed framework for pediatric duodenal mucosal development and illuminates how intestinal cellular dynamics are shaped by age and environment.

developmental biology↗

CBL mutations in pediatric solid and CNS tumors are a marker of receptor tyrosine kinase activation and a potential therapeutic target

Mutations in CBL, an E3 ubiquitin ligase that negatively regulates receptor tyrosine kinases (RTKs) and potentiates intracellular signaling, have been extensively characterized in hematological malignancies. However, the impacts are unknown in other cancer types. We have identified established and novel aberrations in CBL in molecularly diverse pediatric CNS and solid tumors. Additionally, we present novel CBL splice mutations, including in the germline of a high-grade glioma patient, and alternative CBL splicing without corresponding genomic alterations. Functionally, we demonstrate that CBL exon 8/9{Delta}, typically associated with acute myeloid leukemia, is RTK activating in neuroblastoma and that novel CBL variants, CBL E366_E373del and CBL C384G, can cooperate with overexpression of EGFR to transform Ba/F3 cells. Collectively, these data represent a novel form of RTK activation in pediatric patients with solid and CNS tumors who might benefit from RTK-targeted therapies. Statement of significanceMolecularly targeted therapies improve childhood cancer outcomes. Therapies targeting genes called receptor tyrosine kinases are particularly effective. We have identified new genetic alterations that may be a marker for receptor tyrosine kinase activation and drug sensitivity, enabling more patients to benefit from targeted treatments.

cancer biology↗

DySTrack: a modular smart microscopy tool for live tracking of dynamic samples on modern commercial microscopes

Advances in microscopy and bioimage analysis are enabling unprecedented quantitative observation of dynamic biological systems. Smart microscopy closes the loop by feeding back image-derived information to control image acquisition on the fly, paving the way for increasingly autonomous and sophisticated experiments. However, adoption of smart microscopy remains limited primarily to specialists, and even simple tasks such as live tracking of moving samples are still widely handled manually. Here we describe DySTrack, a modular open-source python tool that serves as a minimal bridge between commercial acquisition software and arbitrary image analysis pipelines, allowing users to stick with familiar vendor-developed user interfaces for microscope configuration whilst leveraging the powerful and platform-agnostic python ecosystem for image analysis. DySTrack comes with detailed documentation and with ready-to-use, easy-to-adapt example pipelines that track moving tissues (namely the zebrafish lateral line primordium and the chick Hensens node) during embryonic development. We hope DySTrack will contribute to a recent push to make smart microscopy more widely accessible.

developmental biology↗

Chronic oral cannabidiol delays or prevents seizures in a mouse model of CLN2 disease

A growing body of literature describes the anti-inflammatory, neuroprotective, and anti-epileptic properties of the cannabis sativa constituent cannabidiol, suggesting that it might play a useful role in the treatment of neurodegenerative diseases. Late infantile neuronal ceroid lipofuscinosis (CLN2 disease) is a rare pediatric neurodegenerative disorder resulting from an inherited dysfunction of the lysosome. CLN2 disease, and its representative animal models, display neuroimmune response, neuroinflammation, neurodegeneration, and epileptic seizures, and these symptoms are all touted as potential targets of cannabidiol therapeutic benefit. Here, we treated a valid model of CLN2 disease with long-term daily cannabidiol (300mg/kg) from 1 month of age until disease end stage and evaluated epileptic seizures, lifespan, and markers of neuroimmune response. Chronic cannabidiol treatment significantly delayed or fully eliminated seizures in CLN2 mice compared to those treated with vehicle only, and the treatment led to a nearly significant extension of lifespan. These effects occurred in the absence of any therapeutic benefit to physiological markers of disease such as GFAP, CD68, and cytokine/chemokine reactivity. Taken together, we show that chronic treatment with cannabidiol confers significant anti-seizure benefit to the mouse model of CLN2 disease, and that it does not appear to do so by altering the inflammatory and neuroimmune markers traditionally used to track CLN2 disease progression.

neuroscience↗

A splice-switching antisense oligonucleotide approach for pediatric genetic epilepsies

Summary ParagraphVariants in ion channel genes are common causes of pediatric epilepsy, often leading to intractable seizures, developmental delay and other comorbidities, which increases risk of death. Pathogenic variants in the SCN8A gene, which encodes a voltage-gated sodium channel critical for action potential generation in the brain, account for [~]1% of genetic epilepsies. The voltage sensor in SCN8A domain 1 is encoded by one of two developmentally-regulated mutually exclusive alternative exons, 5N and 5A. We observe that variants in these exons are more likely to cause infantile spasms, a severe seizure type, than variants elsewhere in SCN8A, and that some pathogenic variants affect exon 5 splicing, impacting patient phenotype. Molecular and evolutionary analyses implicate the exon sequences of these and other voltage-gated ion channel alternative exons in splicing regulation. We identified antisense oligonucleotides (ASOs) that shift splicing of SCN8A exon 5N to 5A or vice versa. These ASOs normalize neuronal activity in patient-derived iPSC neurons, and reduce seizures and motor impairment and extend lifespan in a new exon 5N mutant mouse model. Our results demonstrate that splice-switching ASOs can effectively reduce the expression of pathogenic isoforms and rescue both seizure and non-seizure phenotypes. Similar approaches should be applicable to pediatric genetic epilepsies caused by mutations in other ion channel alternative exons.

neuroscience↗

Persistence of vestibular function in the absence of glutamatergic transmission from hair cells

Quantal synaptic transmission in vestibular end-organs is glutamatergic. Although genetic deletion of Slc17a8 (termed Vglut3) leads to deafness in mice, the dependence of vestibular function on VGLUT3-mediated quantal transmission is unknown. Here, we investigated the vestibular phenotype of Vglut3-/- mice at the cellular, systems, and behavioral levels. The type-II vestibular hair cells (VHCs) in Vglut3+/+mice were strongly immunoreactive for VGLUT3, while type-I VHCs showed poor immunoreactivity. In Vglut3-/- mice quantal synaptic transmission in utricular calyces was reduced in rate and amplitude by > 95%. In vivo recordings of spontaneous activity in the vestibular nerve revealed similar action potential rates and regularity in Vglut3+/+and Vglut3-/- mice, suggesting a divergent underlying mechanism compared to the silent Vglut3-/- auditory nerve. In behavioral studies, Vglut3-/- mice did not exhibit considerable sensorimotor or balance deficits. Collectively, these data support the view that non-quantal transmission is the predominant mode of neurotransmission between type I VHCs and vestibular calyceal afferent neurons. We propose that non-quantal transmission alone underlies the apparently normal vestibular nerve physiology and behavioral function in Vglut3-/- mice.

neuroscience↗

Unraveling the Toxicological Effects of Hydroxyacetone - A Reaction Product in Electronic Cigarette Aerosols

Hydroxyacetone has been detected at high concentrations (up to [~]12 mg/mL) in electronic cigarette (EC) aerosols, including those derived from products associated with adverse health effects. Given the limited understanding of its inhalation toxicology, we investigated hydroxyacetones impact on human airway epithelial cells. Acute exposures at the air-liquid interface (ALI) using 3D EpiAirway tissues--a surrogate for human tracheobronchial epithelium--were analyzed via proteomics. Differential expression analysis identified numerous affected proteins, with enrichment pointing to alterations in mitochondrial function and actin cytoskeletal disruption as major targets. Ingenuity Pathway Analysis (IPA) highlighted "Mitochondrial Dysfunction" and "NRF2-Mediated Oxidative Stress" among top toxicological categories, and "Nuclear Cytoskeletal Signaling" as a key canonical pathway. To validate and extend these findings, submerged cultures of BEAS-2B cells were exposed to hydroxyacetone (0.01-10 mg/mL) and assessed for mitochondrial activity, oxidative stress, and F-actin integrity. At 1 mg/mL, mitochondrial membrane potential and reactive oxygen species (ROS) increased, with elevated hydrogen peroxide detected in the culture medium. At 10 mg/mL, mitochondrial activity declined significantly, accompanied by cell rounding and apoptotic blebbing within 2 hours. F-actin destabilization occurred at 1, 3.33, and 10 mg/mL, with cytoplasmic and perinuclear filaments more affected than cortical actin. Findings from ALI and submerged models were concordant, supporting hydroxyacetone-induced mitochondrial stress, oxidative damage, and cytoskeletal disruption. These results suggest that hydroxyacetone concentrations found in EC aerosols may contribute to respiratory toxicity and warrant further investigation.

pharmacology and toxicology↗

Population genomics highlight the vulnerability of coral-dwelling gobies to ecological losses due to climatic disturbances

Predicting species resilience to climate change generally focuses on species life history and ecology, overlooking genomic changes following disturbances. After consecutive cyclones and heatwaves, coral-dwelling Gobiodon gobies have experienced extreme population and group size reductions, and slower recovery rates than their coral hosts. To assess genomic contributions to this vulnerability, we analyzed multiple Gobiodon species for population structure (1) among three locations in western Oceania and (2) pre- and post-disturbances at the central location that underwent the same cyclones and heatwaves that reduced populations and group sizes. Species compared among locations all exhibited population structure. Post-disturbances, two species (G. fuscoruber, G. rivulatus) were extirpated, two species (G. histrio, G. quinquestrigatus) exhibited genetic bottlenecks, one species had no change to genetic diversity (G. brochus), and another species had consistently low diversity (G. erythrospilus). Our results highlight that coral-dwelling gobies face compounding ecological and genomic losses from climatic disturbances, warranting targeted conservation.

genomics↗

Considerations for the use of contrast agents with diffuse in vivo flow cytometry to detect circulating cancer cell populations

SignificanceMetastasis is a leading cause of cancer-related deaths. Disseminated circulating tumor cells (CTCs) through the bloodstream seed metastatic tumors at distant sites. Most methods for enumerating CTCs in humans clinically rely on drawing and analyzing small blood samples, but these may yield inaccurate estimates of CTC burden and cannot measure CTC changes over time. Identification and enumeration of CTCs for experimental or clinical purposes largely rely on marker-driven analyses by flow cytometry. AimIn principle, non-invasive fluorescence enumeration of CTCs directly in vivo could provide a more accurate method for enumerating CTCs. However, this will require specific contrast agent for CTCs. The goal of this work is to define characteristics of useful CTC contrast agents and perform preliminary testing of candidate contrast agents used for fluorescence guided surgery (FGS). ApproachWe evaluated a clinical small-molecule folate receptor targeted contrast agent (OTL38, pafolacianine), a fluorogenic pan-cathepsin contrast agent (VGT-309, abenacianine), and a set of custom designed, small-molecule prostate specific membrane antigen (PSMA) targeted contrast agents. We tested these contrast agents using in vitro cell culture models and in in vivo murine models. ResultsAll tested contrast agents showed high uptake and labeling by target cell lines, but also small but significant labeling of non-cancer blood cells. Contrast agents that exhibited rapid clearance from circulation and the fluorogenic approach resulted in significantly reduced non-specific interfering background fluorescence signals. ConclusionsAlthough the fluorescence contrast agents tested have properties useful for labeling of CTCs, as yet none exhibited the required high specificity. This resulted in some labeling of non-cancer blood cells which presented false-positive CTC counts. Improved contrast agent design and multiplexed use of more than one contrast agent may improve this specificity.

bioengineering↗

Synovial fibroblasts support vascular function in an acute injury-on-a-chip model

Most patients who sustain an acute joint injury develop degenerative joint disease, or osteoarthritis (OA). Animal models have informed the design of OA therapeutics; however, no disease-modifying therapy has successfully translated to human patients. Thus, there is a strong motivation to develop humanized in vitro platforms to fill a critical gap in knowledge of disease progression post-injury. Here, we develop an acute injury-on-a-chip model of the synovium, a vascularized, joint-lining tissue that has been implicated in OA progression and as a key driver of joint disease. We apply this chip-based system to investigate crosstalk between endothelial cells, lining an engineered vessel, and synovial fibroblasts, embedded within an extracellular matrix hydrogel. Our data indicate that synovial fibroblasts, rather than initiating disease, attempt to support and maintain vascular function in the presence of acute inflammation (i.e., interleukin-1{beta}). Such knowledge may provide new targets for OA therapeutics, preventing the progression from joint injury to disease in patients. TeaserIn the presence of inflammation, a hallmark of acute injury, synovial fibroblasts work to maintain vascular health.

bioengineering↗