Biology subjects

You, W.-K.

Publications and source records attributed to You, W.-K..

5 recordsLinked to original sources

bioRxiv2026

Systemic and Local Delivery of siRNA to the CNS and Periphery via Anti-IGF1R Antibody Conjugation

siRNA delivery platforms capable of accessing both central and peripheral tissues are critically needed to expand the therapeutic potential of oligonucleotides. To address this, we developed a novel siRNA-antibody conjugate by attaching an Hprt-targeting siRNA to an engineered antibody shuttle. This shuttle targets the insulin-like growth factor 1 receptor (IGF1R) using a fused antibody fragment (Clone F) and utilizes an antibody backbone with no tissue-relevant binding in this study. The resulting conjugate, designated Clone F-Hprt, demonstrated robust in vivo knockdown across multiple tissues. Clone F-Hprt demonstrated enhanced penetration into central nervous system (CNS) tissues compared to unconjugated siRNA following intracerebroventricular (ICV) and intravenous (IV) administration. In peripheral tissues, Clone F-Hprt achieved widespread knockdown in muscle, heart, and lung, consistent with IGF1R expression. The conjugate was well tolerated across all routes, including with repeated dosing. Although several receptor-mediated approaches for CNS delivery are progressing to the clinic (e.g., targeting the transferrin receptor), clinical validation remains to be demonstrated. Our findings highlight IGF1R as an alternative receptor capable of supporting delivery across both central and peripheral tissues, offering a complementary strategy for expanding the therapeutic landscape of oligonucleotide delivery.

neuroscience↗

bioRxiv2024

A brain-shuttled antibody targeting alpha synuclein aggregates for the treatment of synucleinopathies

Parkinsons disease and multiple system atrophy are members of a class of devastating neurodegenerative diseases called synucleinopathies, which are characterized by the presence of alpha-synuclein (-Syn) rich aggregates in the brains of patients. Passive immunotherapy targeting these aggregates is an attractive disease-modifying strategy. Such an approach must not only demonstrate target selectivity towards -Syn aggregates, but also achieve appropriate brain exposure to have the desired therapeutic effect. Here we present preclinical data for a next-generation antibody for the treatment of synucleinopathies. SAR446159 (ABL301) is a bispecific antibody composed of an -Syn-binding immunoglobulin (IgG) and an engineered insulin-like growth factor receptor 1 (IGF1R) binding single-chain variable fragment (scFv), acting as a shuttle to transport an antibody across the blood-brain barrier (BBB). SAR446159 binds tightly and preferentially to -Syn aggregates and prevents their seeding capacity in vitro and in vivo. Incubation with SAR446159 reduced -Syn preformed fibrils (PFFs) uptake in neurons and facilitated uptake and clearance by microglia. In wild type mice injected in the striatum with -Syn PFFs, treatment with SAR446159 reduced the spread of aSyn pathology as measured by phosphorylated -Syn staining and lessened the severity of motor phenotypes. Additionally, in 9-month-old transgenic mice overexpressing -Syn (mThy1--Syn, Line 61), repeated treatment with SAR446159 reduced markers of -Syn aggregation in the brain. SAR446159 had significantly higher brain and CSF penetration over a sustained period than its monospecific counterpart (1E4) in rats and monkeys. The binding properties of SAR446159 combined with its brain-shuttle technology make it a potent, next-generation immunotherapeutic for treating synucleinopathies.

neuroscience↗

bioRxiv2022

Ancient midbrain inhibitory neurons control selective spatial attention

To behave adaptively in complex environments, animals must selectively process the most important information in space while ignoring distractors. Contrary to the dominant cortico-centric view, we report that an evolutionarily old group of inhibitory neurons in the brainstem, called PLTi, is critical for this function of selective spatial attention. In freely behaving mice performing a human-like spatial attention task, we found that bilateral silencing of PLTi severely disrupted target selection without causing perceptual or motor impairments. PLTis effects depended necessarily on goal-relevant, rather than just physical salience-based signals, together revealing it as a dedicated brain site for priority-driven attentional target selection. PLTis core computational function is its explicit implementation of the abstract cognitive decision boundary separating target from distracters: it controlled the accuracy and categorical precision of this decision boundary, doing so by shaping neural representations of competing stimuli in the superior colliculus, a major sensorimotor hub. PLTi may, therefore, be a conserved brainstem engine across vertebrates for winner-take-all-like spatial decisions in goal-driven behavior.

neuroscience↗

bioRxiv2020

Visual psychophysics and limits of visual discrimination performance in freely behaving mice

Studying the temporal dynamics of perceptual decisions offers key insights into the cognitive processes contributing to it. Conducting such investigation in a genetically tractable animal model can facilitate the subsequent unpacking of the mechanistic basis of different stages in perceptual dynamics. Here, we investigated the time course as well as fundamental psychophysical constants governing visual perceptual decision-making in freely behaving mice. We did so by analyzing response accuracy against reaction time (i.e., conditional accuracy), in a series of 2-AFC orientation discrimination tasks in which we varied target size, luminance, duration, and presence of a foil. Our results quantified two distinct stages in the time course of mouse visual decision-making - a sensory encoding stage, in which conditional accuracy exhibits a classic tradeoff with response speed, and a subsequent short term memory-dependent stage in which conditional accuracy exhibits a classic asymptotic decay following stimulus offset. We estimated the duration of visual sensory encoding as 200-320 ms across tasks, the lower bound of the duration of short-term memory as ~1700 ms, and the briefest duration of visual stimulus input that is informative as [≤]50 ms. Separately, by varying stimulus onset delay, we demonstrated that the conditional accuracy function and RT distribution can be independently modulated, and found that the duration for which mice naturally withhold from responding is a quantitative metric of impulsivity. Taken together, our results establish a quantitative foundation for investigating the neural circuit bases of visual decision dynamics in mice. SIGNIFICANCE STATEMENTThis study presents a quantitative breakdown of the time course of visual decision-making in mice during naturalistic behavior. It demonstrates parallel stages in mouse visual perceptual decision dynamics to those in humans, estimates their durations, and shows that mice are able to discriminate well under challenging visual conditions - with stimuli that are brief, low luminance, and small. These results set the stage for investigating the neural bases of visual perceptual decision dynamics and their dysfunction in mice.

neuroscience↗

bioRxiv2019

Endogenous and exogenous control of visuospatial selective attention in freely behaving mice

Selective spatial attention, the ability to dynamically prioritize the most important spatial location, is essential for adaptive behavior. It has been studied primarily in head-fixed animals, and almost exclusively in primates. Here, we report the development of two human-inspired, discrimination-based behavioral paradigms for studying selective visuospatial attention in the freely behaving mouse: the spatial probability task, and the flanker task. In the spatial probability task, we found enhanced response accuracy, perceptual discriminability, and rates of sensory evidence accumulation at the location with higher probability of target occurrence, and opposite effects at the lower probability location. In the absence of systematic differences in sensory input, motor biases, and trial structure, these results demonstrated endogenous expectation-driven shifts of spatial attention. In the flanker task, we found that a second, flanker stimulus presented with the target, but with incongruent information, caused switch-like decrements in response accuracy and perceptual discriminability as a function of flanker contrast, as well as a reduced rate of evidence accumulation. These results demonstrated exogenous capture of spatial attention. The innovation of behavioral tasks for selective visuospatial attention in unrestrained mice opens up a rich avenue for future research dissecting the neural circuit mechanisms underlying this critical executive function.

neuroscience↗