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Hon, C. C.

Publications and source records attributed to Hon, C. C..

3 recordsLinked to original sources

DAP12-deficient microglia adopt a TREM2-independent antigen-presenting state with a glial-to-neuronal cascade in Nasu-Hakola disease

Nasu-Hakola disease (NHD), a dementia with about 200 cases worldwide, is caused by loss-of-function mutation of TYROBP, encoding DAP12, or its receptor TREM2. TREM2-DAP12 is the switch that converts microglia from a surveillant to a reactive state; what DAP12-deficient microglia become and to what extent they reshape their microenvironment is unknown. We profiled prefrontal cortex and hippocampus from an NHD donor and control by single-nucleus RNA sequencing and mapped the glial changes in situ by spatial transcriptomics. NHD microglia adopted a CIITA-driven, MHC class II-high antigen-presenting state with complement, iron and glycolytic programs and Fc receptors but not the TREM2-dependent lipid program. Astrocytes became pan-reactive and lost metallothionein expression, oligodendrocytes lost mature cells and cholesterol synthesis, and excitatory neurons lost presynaptic and activity programs, consistently between regions and across a published cohort. DAP12 deficiency left microglia in an antigen-presenting state short of the TREM2-dependent arm, accompanied by a glial-to-neuronal cascade.

neuroscience↗

Epigenomic and transcriptomic germ-free ageing atlas reveals sterile inflammation as an intrinsic ageing feature

Inflammageing is a hallmark of ageing. Commensal microbiota plays crucial roles in maintaining tissue homeostasis, yet its impact on cellular ageing and inflammageing remains poorly understood. Here we present a comprehensive single-cell epigenomic and transcriptomic atlas of tissues from mice aged under specific pathogen-free (SPF) or germ-free (GF) conditions. Microbiota conferred beneficial effects in young mice but accelerated various ageing features in old, such as age-related AP-1 pathway upregulation, senescence and transcriptomic alterations, likely due to age-associated dysbiosis. Strikingly, inflammatory signatures persisted across cell types in aged GF mouse tissues, establishing sterile inflammation as an intrinsic feature of ageing. Age-associated B cells expanded equally under GF and SPF conditions, raising the possibility that they function as intrinsic, microbiota-independent drivers of inflammageing and potential therapeutic targets. The atlas provides a resource for distinguishing intrinsic ageing features from those modulated by the microbiota, illuminating mechanisms of cellular ageing and potential anti-ageing interventions. HighlightsSterile inflammation and age-associated B cell expansion are prominent intrinsic ageing features The upregulation of age-associated AP-1 pathways and senescence of alveolar macrophages are attenuated in germ-free condition Germ-free condition induces premature ageing-like features in young mouse tissues but delays ageing features in old mice across multiple cell types

genomics↗

Recounting the FANTOM Cage Associated Transcriptome

Long non-coding RNAs (lncRNAs) have emerged as key coordinators of biological and cellular processes. Characterizing lncRNA expression across cells and tissues is key to understanding their role in determining phenotypes including human diseases. We present here FC-R2, a comprehensive expression atlas across a broadly-defined human transcriptome, inclusive of over 109,000 coding and non-coding genes, as described in the FANTOM CAGE-Associated Transcriptome (FANTOM-CAT) study. This atlas greatly extends the gene annotation used in the original recount2 resource. We demonstrate the utility of the FC-R2 atlas by reproducing key findings from published large studies and by generating new results across normal and diseased human samples. In particular, we (a) identify tissue specific transcription profiles for distinct classes of coding and non-coding genes, (b) perform differential expression analyses across thirteen cancer types, providing new insights linking promoter and enhancer lncRNAs expression to tumor pathogenesis, and (c) confirm the prognostic value of several enhancers in cancer. Comprised of over 70,000 samples, the FC-R2 atlas will empower other researchers to investigate functions and biological roles of both known coding genes and novel lncRNAs. Most importantly, access to the FC-R2 atlas is available from https://jhubiostatistics.shinyapps.io/recount/, the recount Bioconductor package, and http://marchionnilab.org/fcr2.html.

genomics↗