Biology subjects

Hung, Y.

Publications and source records attributed to Hung, Y..

6 recordsLinked to original sources

bioRxiv2026

PV interneuron-targeted CRISPRa rescue of SCN1A haploinsufficiency in Dravet syndrome

Dravet syndrome is a severe epileptic encephalopathy caused by SCN1A haploinsufficiency, which leads to reduced NaV1.1 expression in parvalbumin (PV)-expressing interneurons and disrupted excitatory-inhibitory balance in the brain. We developed an AAV-based CRISPR activation system (AAV9-E2-dCas9-VP64) to selectively upregulate SCN1A from its endogenous locus in PV interneurons. An in vitro saturating guide RNA (gRNA) screen across the human SCN1A promoter identified a lead guide with robust and highly specific engagement of the SCN1A locus. This lead gRNA was validated in human Dravet syndrome model GABAergic neurons, where dose-dependent and specific SCN1A upregulation was observed. Intracerebroventricular (ICV) administration in a mouse model of Dravet syndrome produced dose-dependent improvement in survival as well as reduced susceptibility to hyperthermia-induced seizures and increased NaV1.1 protein expression, with maintained PV interneuron selectivity and minimal off-target expression. In a study in juvenile cynomolgus macaques, MRI-guided ICV administration of the vector was well tolerated, achieved broad cortical biodistribution, and maintained strong detargeting of peripheral tissues, with substantially lower peripheral dCas9 expression relative to the brain. These results support PV interneuron-selective SCN1A gene modulation via CRISPR activation as a promising therapeutic strategy for Dravet syndrome. AAV9-E2-dCas9-VP64 (RT101) is currently in preclinical development and is being advanced toward evaluation in the clinic.

neuroscience↗

bioRxiv2025

In Situ Photoactivated Hydrogel Adhesive Dressings for Post Colon Polypectomies (PolypCures)

Colon polypectomy is a widely performed endoscopic procedure that reduces the incidence of colorectal cancer but leaves exposed colonic wounds susceptible to bleeding, perforation, and infection. The current standard of wound care, mechanical clips, is limited by technical complexity, high cost, and poor efficacy for large (> 2 cm in diameter) or difficult-to-access lesions. Here, we present PolypCure, an in situ photoactivated hydrogel adhesive dressing delivered via a single catheter, through either oozing or spraying methods, to achieve rapid, spatiotemporally controlled sealing and hemostasis (within 2 min) of colon lesions using the white light source integrated into standard endoscopic instruments. The hydrogel, composed of norbornene- and thiol-functionalized polyethylene glycol, carboxymethyl cellulose, and Eosin Y, exhibits mechanical properties comparable to colon tissue (G [~] 6 kPa), strong shear strength (> 15 kPa), low swelling (< 200%), and small pore size ([~] 20 {micro}m), ensuring long-term stability (up to 30 days) and protection against bacterial infiltration. The formulation also demonstrates biocompatibility and hemocompatibility. In an in vivo pig colon endoscopic mucosal resection (EMR) model, PolypCure fully adheres to large lesions for at least 3 days and promotes early-stage wound healing. Overall, PolypCure is a promising solution to wound management post-polypectomy.

bioengineering↗

bioRxiv2025

Flexible gaze reinstatement during working memory for natural scenes

The information we hold in mind with working memory (WM) may propagate beyond the cortex and out to the peripheral motor system. For instance, directionally biased hand and eye movements can express simple visuo-spatial features during WM maintenance. If such sensorimotor inflections are a form of WM representation, they may also express more multifaceted and task-adaptive information than just spatial location. Here, we ask whether gaze patterns carry item-specific detail about complex stimuli held in mind, and whether gaze prospectively adapts to the behavioral task demands. To do this, we tracked human eye movements (male and female) during WM for naturalistic images, and we manipulated which image features were most task-relevant (visual or semantic). In two experiments, we found that the eyes moved in complex, item-specific spatiotemporal sequences during WM maintenance. Delay period gaze patterns retraced the scanpaths from stimulus encoding, echoing the gaze reinstatement that aligns with neural pattern reactivation during long-term memory retrieval. Therefore, gaze patterns during WM may reinstate visual encoding processes for maintenance. We also used time-resolved representational similarity analyses, guided by convolutional neural network modeling, to test the specificity of WM gaze patterns across a trial. We found that gaze representations were more distinct when the task prioritized visual detail, and also ramped up in anticipation of the WM probe. Therefore, oculomotor WM signals are malleable to when and how the content will be used. These results suggest that the earliest levels of visual processing reflect prospectively-oriented and functionally flexible WM content representations. SignificanceThe eyes are an outwardly accessible extension of the brain. They are the first stop for visual processing, but may also offer a rich window into underlying cognition. For instance, pupil dilation can reflect changing cognitive load, and eye movement biases can reflect basic spatial information about content held in mind with working memory. Working memory is a critical neuro-cognitive function, but its physiological bases remain under debate. Here, we show that eye movements code for more than simple spatial WM, and instead express intricate patterns that read out the complex, real-world stimuli held in mind. This work shows how cognitive states influence oculomotor functions, and also advances theories of WM representation to include the earliest stages of sensory processing.

neuroscience↗

bioRxiv2024

Massively parallel jumping assay decodes Alu retrotransposition activity

The human genome contains millions of retrotransposons, several of which could become active due to somatic mutations having phenotypic consequences, including disease. However, it is not thoroughly understood how nucleotide changes in retrotransposons affect their jumping activity. Here, we developed a novel massively parallel jumping assay (MPJA) that can test the jumping potential of thousands of transposons en masse. We generated nucleotide variant library of selected four Alu retrotransposons containing 165,087 different haplotypes and tested them for their jumping ability using MPJA. We found 66,821 unique jumping haplotypes, allowing us to pinpoint domains and variants vital for transposition. Mapping these variants to the Alu-RNA secondary structure revealed stem-loop features that contribute to jumping potential. Combined, our work provides a novel high-throughput assay that assesses the ability of retrotransposons to jump and identifies nucleotide changes that have the potential to reactivate them in the human genome.

genomics↗

bioRxiv2021

Macropinosomes host TLR9 signaling and regulation of inflammatory responses in microglia

To support their innate immune and scavenging functions in the brain, microglia are equipped with Toll-like receptors (TLRs), including the intracellular receptor TLR9, which is activated by microbial CpG-rich DNA. Macropinocytosis is an abundant and inducible pathway in microglia for fluid-phase uptake and ingestion of microbes and cell debris. TLR9 signaling has been ascribed to endolysosomes, particularly lysosomes, which it accesses through direct transport or via internalization from the surface. Here, TLR9 and exogenous CpG-DNA are localized during uptake into fluid-filled macropinosomes, upon upregulated macropinocytosis, where acidic and proteolytic environments support MyD88-induced signaling. Macropinosomes represent an abundant pathway for endolysosomal traffic of TLR9 but are also a much more exposed site for nucleic acid activation of the receptor with a risk of excessive inflammation. To constrain TLR9 inflammation, macropinosomes also house the TLR9 co-receptor LRP1 and regulators Rab8a and PI3K{gamma} which augment Akt signaling and favor anti-inflammatory cytokine production. Macropinosomes and their inflammatory regulators are therefore important components of TLR9 pathways in microglia that are poised for surveillance and protection in the CNS.

cell biology↗

bioRxiv2019

Environmental reservoirs of Mycobacterium bovis and Mycobacterium tuberculosis in the Ruaha region, Tanzania

This study was designed to investigate the prevalence of members of the Mycobacterium tuberculosis complex (MTBC) in the environment of pastoralists and villagers in the Iringa district, adjacent to the Ruaha National Park in Tanzania. Utilising specific qPCR assays, both Mycobacterium bovis and Mycobacterium tuberculosis were detected in cattle faeces, boma soil, water and household dust. M. bovis was also found in goat faeces and goat boma soil. This is the first report of faecal shedding of M. bovis in goats and the first molecular survey of faecal shedding in cattle. The prevalence of both bacterial species varied by village, area, season and sample type. Geographical and temporal correlations across sample types were suggestive of cross species transmission. This non-invasive test has previously been rigorously validated for screening other mammals; in this study it has successfully been applied to detect M. bovis and M. tuberculosis in livestock faeces and the environment.

microbiology↗