Biology subjects

Cheung, S. W.

Publications and source records attributed to Cheung, S. W..

4 recordsLinked to original sources

bioRxiv2025

β2AR Agonists Sustain Thermogenesis and Leanness via Sympathofacilitation

Human thermogenesis depends on {beta}2-adrenoceptors ({beta}2AR) expressed in thermogenic adipocytes, which are activated by norepinephrine released from sympathetic neurons. Whether {beta}2AR also modulates thermogenesis via direct presynaptic action within sympathetic neurons has remained unclear. Here, we identify Adrb2 expression in human and rodent cervical sympathetic neurons. {beta}2AR agonism exerts neurotrophic effects and facilitates cholinergic responsiveness in mouse sympathetic neurons, indicating a sympathofacilitatory role. Selective deletion of {beta}2AR in sympathetic neurons leads to impaired nerve activity in brown adipose tissue, sympathetic neuropathy, worsened fasting-induced hypothermia, and progressive obesity in chow-fed mice--without changes in food intake. These findings uncover a presynaptic role for {beta}2AR in sustaining thermogenesis and regulating adiposity, suggesting sympathofacilitation as a therapeutic avenue for obesity. HighlightsO_LIHuman and mouse cervical sympathetic neurons express adrenoceptor beta 2 (Adrb2) C_LIO_LI{beta}2-adrenoceptor ({beta}2AR) activation is neurotrophic and facilitates sympathetic neuronal excitability C_LIO_LILoss of {beta}2AR in sympathetic neurons leads to neuropathy in brown adipose tissue and reduced sympathetic activity C_LIO_LIDeletion of {beta}2AR in sympathetic neurons exacerbates fasting-induced hypothermia and promotes obesity independently of food intake C_LI

physiology↗

bioRxiv2023

The Association between Commensal Flagellated Bacteria and Cardiovascular Benefits in Humans

BackgroundIncreasing evidence has shown associations between gut microbiota and cardiovascular risks. However, whether sex influences the cardiovascular outcome of gut microbiota remains elusive. MethodsThe gut microbiota metagenomic data from two previous population-based cohorts and the proteomics data from human liver samples were analyzed. ResultsThrough a sex-based analysis of 500 Functional Genomics Project (500FG) cohort, we found that the capacity of producing flagellin in Eubacterium rectale, Roseburia Intestinalis and Roseburia inulinivorans partially explained the levels of high-density lipoprotein-cholesterol (HDL-C) and apolipoprotein A1 in female participants. By comparing the bacterial species showing positive correlations with HDL-C and the flagellin species found in human liver samples, we found that E. rectale and R. inulinivorans appeared to be the major prevalent flagellated species in gut microbiota contributed to the hosts HDL-C level. The analysis of the Chinese-based cohort in which the male participants had relatively higher abundance of these two bacteria, the abovementioned positive correlation was also observed. ConclusionsThe flagellin-producing function of E. rectale and R. inulinivorans in the gut microbiota partially explained the HDL-C level in the host, and there is a sex-specific difference in the sensitivity of this beneficial interaction. Our findings suggest a potential interaction between commensal bacteria and the host that yields a cardiovascular benefit. Clinical PerspectiveO_ST_ABSWhat is new?C_ST_ABSO_LIThe flagellin-producing capacity of certain species in gut microbiota is positively associated with the HDL-C and ApoA1 levels in human. C_LIO_LIBy comparing the flagellated bacteria in the gut and flagellin species in the liver, Eubacterium rectale and Roseburia inulinivorans are shown to be the most prevalent species contributing to such cardiovascular benefits. C_LIO_LIThe sensitivity of such beneficial interaction with the gut flagellated bacteria is different between male and female. C_LI What are the clinical implications? (maximum 100 words, formatted as 2-3 bullets)O_LIBeside the role in metabolic inflammation, gut microbiota can be beneficial against cardiovascular risk by modulating HDL-C level through certain flagellated species. C_LIO_LIThe interaction between flagellated bacteria in the gut and the host provide a different insight in exploring potential therapeutic targets to increase HDL-C level. C_LI

systems biology↗

bioRxiv2022

Multi-tasking Deep Network for Tinnitus Classification and Severity Prediction from Multimodal Structural Images

Subjective tinnitus is an auditory phantom perceptual disorder without an objective biomarker. Fast and efficient diagnostic tools will advance clinical practice by detecting or confirming the condition, tracking change in severity, and monitoring treatment response. Motivated by evidence of subtle anatomical or functional morphological information in magnetic resonance images (MRI) of the brain, we examined data-driven machine learning methods for joint tinnitus classification (tinnitus or no tinnitus) and tinnitus severity prediction. We propose a deep multi-task multi-modal framework for joint functionalities using structural MRI (sMRI) data. To leverage cross-information multimodal neuroimaging data, we integrated two modalities of 3-dimensional sMRI - T1 weighted (T1w) and T2 weighted (T2w) images. To explore the key components in the MR images that drove task performance, we segmented both T1w and T2w images into three different components - cerebrospinal fluid (CSF), grey matter (GM) and white matter (WM), and examined performance of each segmented image. Results demonstrate that our multimodal framework capitalizes on the information across both modalities (T1w and T2w) for the joint task of tinnitus classification and severity prediction. Our model outperforms existing learning-based and conventional methods in terms of accuracy, sensitivity, specificity, and negative predictive value.

neuroscience↗

bioRxiv2018

Rare variants in the genetic background modulate the expressivity of neurodevelopmental disorders

PurposeTo assess the contribution of rare variants in the genetic background towards variability of neurodevelopmental phenotypes in individuals with rare copy-number variants (CNVs) and gene-disruptive mutations.\n\nMethodsWe analyzed quantitative clinical information, exome-sequencing, and microarray data from 757 probands and 233 parents and siblings who carry disease-associated mutations.\n\nResultsThe number of rare secondary mutations in functionally intolerant genes (second-hits) correlated with the expressivity of neurodevelopmental phenotypes in probands with 16p12.1 deletion (n=23, p=0.004) and in probands with autism carrying gene-disruptive mutations (n=184, p=0.03) compared to their carrier family members. Probands with 16p12.1 deletion and a strong family history presented more severe clinical features (p=0.04) and higher burden of second-hits compared to those with mild/no family history (p=0.001). The number of secondary variants also correlated with the severity of cognitive impairment in probands carrying pathogenic rare CNVs (n=53) or de novo mutations in disease genes (n=290), and negatively correlated with head size among 80 probands with 16p11.2 deletion. These second-hits involved known disease-associated genes such as SETD5, AUTS2, and NRXN1, and were enriched for genes affecting cellular and developmental processes.\n\nConclusionAccurate genetic diagnosis of complex disorders will require complete evaluation of the genetic background even after a candidate gene mutation is identified.

genomics↗