Nonvesicular sterol transport is a metabolic immune checkpoint that guards dietary lipid uptake (scRNA-Seq)
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PROVIDER: PRJNA1160861 | ENA |
REPOSITORIES: ENA
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Project description:Nonvesicular sterol transport is a metabolic immune checkpoint that guards dietary lipid uptake
| PRJNA1160313 | ENA
Project description:The intrinsic pathways that control membrane organization in immune cells and the impact of such pathways on cellular functions are not well defined. Here we show that the nonvesicular cholesterol transporter Aster-A links plasma membrane (PM) cholesterol availability in T cells to immune signaling and systemic metabolism. Aster-A is recruited to the PM during T-cell receptor (TCR) activation, where it facilitates the removal of newly generated “accessible” cholesterol. Loss of Aster-A leads to excess PM cholesterol accumulation, resulting in enhanced TCR nano-clustering and signaling, and in Th17 cytokine production. Furthermore, Aster-A associates with STIM1 and negatively regulates STIM1-dependent calcium flux during activation of mouse and human T cells. Finally, mucosal Th17 response towards commensals is restrained by PM cholesterol remodeling. Ablation of Aster-A in T cells stimulates IL-22 production, which reduces intestinal fatty acid absorption, and confers resistance to diet-induced obesity. These findings delineate a multi-tiered regulatory scheme linking immune cell lipid flux to nutrient absorption and systemic physiology.
2025-07-20 | GSE277067 | GEO
Project description:The intrinsic pathways that control membrane organization in immune cells and the impact of such pathways on cellular functions are not well defined. Here we show that the nonvesicular cholesterol transporter Aster-A links plasma membrane (PM) cholesterol availability in T cells to immune signaling and systemic metabolism. Aster-A is recruited to the PM during T-cell receptor (TCR) activation, where it facilitates the removal of newly generated “accessible” cholesterol. Loss of Aster-A leads to excess PM cholesterol accumulation, resulting in enhanced TCR nano-clustering and signaling, and in Th17 cytokine production. Furthermore, Aster-A associates with STIM1 and negatively regulates STIM1-dependent calcium flux during activation of mouse and human T cells. Finally, mucosal Th17 response towards commensals is restrained by PM cholesterol remodeling. Ablation of Aster-A in T cells stimulates IL-22 production, which reduces intestinal fatty acid absorption, and confers resistance to diet-induced obesity. These findings delineate a multi-tiered regulatory scheme linking immune cell lipid flux to nutrient absorption and systemic physiology.
2025-07-20 | GSE277138 | GEO
Project description:Cooperation between ASTER-dependent nonvesicular transport and NPC1L1 facilitates dietary cholesterol uptake
| PRJNA852178 | ENA
Project description:Intestinal cholesterol absorption is an important determinant of systemic cholesterol homeostasis. Niemann-Pick C1 Like 1 (NPC1L1), the target of the drug ezetimibe, is a critical player in dietary cholesterol uptake. But how cholesterol moves within the cell downstream of NPC1L1 is unknown. Here we show that the nonvesicular sterol transporters Aster-B and -C cooperate with NPC1L1 to deliver dietary cholesterol from the gut lumen to the enterocyte ER for chylomicron packaging. Aster proteins are recruited to the enterocyte plasma membrane (PM) in response to NPC1L1-dependent cholesterol accumulation. Mice lacking Asters in intestine have impaired cholesterol absorption, and reduced plasma cholesterol. NanoSIMS imaging and tracer studies reveal delayed lipid trafficking into chylomicrons in Aster-deficient enterocytes. Interestingly, in addition to potently blocking NPC1L1, ezetimibe is also a low-affinity inhibitor of Aster-B and -C but not -A, and the structure of the Aster-C-ezetimibe complex reveals the basis for this selectivity. Our findings support a model in which NPC1L1 enriches dietary cholesterol at the apical PM, and ASTERs subsequently traffic this cholesterol to the ER. The findings identify the enterocyte Aster pathway as potential target for treatment of hypercholesterolemia. Alessandra Ferrari, PhD
2023-12-21 | GSE206780 | GEO
Project description:Expression profiling of guards brains as a function of individual genotype (AHB/EHB) and environment (AHB/EHB host colony)
2009-07-01 | E-TABM-606 | biostudies-arrayexpress
Project description:Project Abstract : Trimethylation of histone H3 lysine 4 (H3K4me3) is predominantly associated with transcriptional start sites (TSSs) and is believed to facilitate transcription initiation. Furthermore, H3K4me3 plays a role in defining cell fate and specific cellular functions. Nevertheless, the precise function of H3K4me3 in transcription activation remains a topic of ongoing debate. The Polymerase-associated factor 1 complex (Paf1C), which is integral to various transcription-related cellular processes, consists of five highly conserved subunits: Paf1, Ctr9, Rtf1, Cdc73, and Leo1. While all subunits of Paf1C are indispensable for the maintenance of H3K4 methylation levels, it is noteworthy that strains lacking Leo1 exhibited unaltered levels of H3K4me3. To elucidate the role of H3K4me3, we conducted a transcriptome analysis coupled with ChIP-sequencing of H3K4me3 in cells lacking Leo1. Our research uncovers a distinctive role of Leo1 in yeast, whereby it plays a pivotal role in maintaining sterol homeostasis through the suppression of Upc2 expression. Importantly, this role stands apart from the functions of other Paf1C subunits. H3K4me3 is essential for promoting the expression of sterol uptake genes that are Upc2-dependent when Leo1 is absent. Additionally, Set1 contributes to sterol homeostasis by regulating iron metabolism and mitochondrial functions rather than directly suppressing Upc2 expression. Therefore, our findings reveal a novel role for Leo1 in sterol homeostasis and highlight the importance of H3K4me3 in promoting transcription of response genes required for sterol uptake.
2024-08-01 | GSE244733 | GEO
Project description:Project Abstract : Trimethylation of histone H3 lysine 4 (H3K4me3) is predominantly associated with transcriptional start sites (TSSs) and is believed to facilitate transcription initiation. Furthermore, H3K4me3 plays a role in defining cell fate and specific cellular functions. Nevertheless, the precise function of H3K4me3 in transcription activation remains a topic of ongoing debate. The Polymerase-associated factor 1 complex (Paf1C), which is integral to various transcription-related cellular processes, consists of five highly conserved subunits: Paf1, Ctr9, Rtf1, Cdc73, and Leo1. While all subunits of Paf1C are indispensable for the maintenance of H3K4 methylation levels, it is noteworthy that strains lacking Leo1 exhibited unaltered levels of H3K4me3. To elucidate the role of H3K4me3, we conducted a transcriptome analysis coupled with ChIP-sequencing of H3K4me3 in cells lacking Leo1. Our research uncovers a distinctive role of Leo1 in yeast, whereby it plays a pivotal role in maintaining sterol homeostasis through the suppression of Upc2 expression. Importantly, this role stands apart from the functions of other Paf1C subunits. H3K4me3 is essential for promoting the expression of sterol uptake genes that are Upc2-dependent when Leo1 is absent. Additionally, Set1 contributes to sterol homeostasis by regulating iron metabolism and mitochondrial functions rather than directly suppressing Upc2 expression. Therefore, our findings reveal a novel role for Leo1 in sterol homeostasis and highlight the importance of H3K4me3 in promoting transcription of response genes required for sterol uptake.
2024-08-01 | GSE244788 | GEO
Project description:Ergosterol is a prominent component of the yeast plasma membrane and essential for yeast cell viability. It is synthesized in the endoplasmic reticulum and transported to the plasma membrane by non-vesicular mechanisms requiring carrier proteins. Oxysterol binding protein homologues and yeast StARkin proteins have been proposed to function as sterol carriers. Although many of these proteins are capable of transporting sterols between synthetic lipid vesicles in vitro, they are not essential for ergosterol transport in cells, indicating that they may be functionally redundant with each other or with additional - as yet unidentified - sterol carriers. To address this point we hypothesized that sterol transport proteins are also sterol binding proteins (SBPs), and used an in vitro chemo-proteomic strategy to identify all cytosolic SBPs. We generated a cytosol fraction enriched in SBPs and captured the proteins with a photoreactive clickable cholesterol analog. Quantitative proteomics of the captured proteins identified 342 putative SBPs. Analysis of these identified proteins based on their annotated function, reported drug phenotypes, interactions with proteins regulating lipid metabolism, gene ontology, and presence of mammalian orthologs revealed a subset of 62 characterized and nine uncharacterized candidates. Five of the uncharacterized proteins play a role in maintaining plasma membrane integrity as their absence affects the ability of cells to grow in the presence of nystatin or myriocin. We anticipate that the dataset reported here will be a comprehensive resource for functional analysis of sterol binding/transport proteins and provide insights into novel aspects of non-vesicular sterol trafficking.
2019-11-25 | PXD014555 | Pride
Project description:Statins are cholesterol lowering drugs that inhibit cholesterol synthesis and reduce intracellular sterol levels, stimulating a transcriptional response. We sought to identify genes that were statin responsive in the HepG2 human hepatoma cell line and determine which of those genes were sterol responsive using sterol addback conditions. Though the vast majority of statin responsive genes are sterol responsive, we identified a subset of statin responsive genes whose gene expression changes are not reversed upon sterol addback.
2024-12-10 | GSE190736 | GEO