bioRxiv Science⌕ Search

Biology subjects

Dontaine, J.

Publications and source records attributed to Dontaine, J..

2 recordsLinked to original sources

O-GlcNAcylation and low glycolysis underpin Th2 polarization by dendritic cells

Activation of dendritic cells (DCs) is dependent on rewiring of their cellular metabolism. However, the metabolic requirements for DCs to prime T helper 2 (Th2) responses are still poorly understood. Using unbiased transcriptomics and non-targeted metabolomics we find that helminth antigen-conditioned human DCs suppress glycolysis while increasing hexosamine biosynthesis to fuel protein O-GlcNAcylation. Functionally, glycolytic inhibition of DCs selectively enhanced, while blocking O-GlcNAcylation impaired, Th2-priming capacity. In helminth infection and allergic challenge, Th2 responses were also attenuated in vivo in mice with specific deletion of O-GlcNAc Transferase (OGT) in CD11c-expressing cells. Mechanistically, through proteomic analysis and functional validation, we identified O-GlcNAcylation as a critical negative regulator of immune synapse formation by controlling cytoskeletal organization via Fascin-1 and Zyxin, thereby dampening TCR signalling to promote Th2 polarization. Altogether we reveal a novel metabolic program in DCs that governs Th2 polarization, that could potentially be harnessed to treat type 2 mediated inflammatory diseases.

immunology↗

skNAC is a Key Driver of Cardiomyocyte Integrity Against Pathological Cardiac Hypertrophy and Heart Failure

Chronic pressure overload induces cardiac hypertrophy and heart failure through coordinated alterations in proteome homeostasis, metabolism and sarcomere organisation. The muscle-specific -isoform of the nascent polypeptide-associated complex (skNAC) is essential for sarcomere assembly during development, but its role in adult hearts remains largely unknown. Here, we show that skNAC expression is reduced in hypertrophic cardiomyocytes, mouse models of pressure overload, and human hypertrophic hearts, in association with disease severity. Cardiomyocyte-specific skNAC deletion results in basal hypertrophy, systolic dysfunction, and premature death, and exacerbates pressure overload-induced heart failure. At the molecular level, skNAC associates with ribosomes and is required for sarcomere organisation maintenance, while its loss induces autophagy and ultrastructural defects. Integrated transcriptomic and proteomic analyses reveal early downregulation of metabolic gene expression despite increased abundance of corresponding proteins, indicating compensatory metabolic responses. Gain-of-function studies confirm a protective role against hypertrophy. Together, these data establish skNAC as a key regulator of cardiac proteome homeostasis and metabolic adaptation during pathological remodelling.

physiology↗