Myeloid-specific ATP-citrate lyase deletion alters macrophage phenotype in vitro and in vivo without affecting tumor growth
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE169187 | GEO | 2021/06/30
REPOSITORIES: GEO
Similar Datasets
Project description:Macrophages represent a major immune cell population in atherosclerotic plaques and play central role in the progression of this lipid-driven chronic inflammatory disease. Targeting immunometabolism is proposed as a strategy to revert aberrant macrophage activation to improve disease outcome. Here, we show ATP citrate lyase (Acly) to be activated in inflammatory macrophages and human atherosclerotic plaques. We demonstrate that myeloid Acly deficiency induces a stable plaque phenotype characterized by increased collagen deposition and fibrous cap thickness, along with a smaller necrotic core. In-depth functional, lipidomic, and transcriptional characterization indicate deregulated fatty acid and cholesterol biosynthesis and reduced liver X receptor activation within the macrophages in vitro. This results in macrophages that are more prone to undergo apoptosis, whilst maintaining their capacity to phagocytose apoptotic cells. Together, our results indicate that targeting macrophage metabolism improves atherosclerosis outcome and we reveal Acly as a promising therapeutic target to stabilize atherosclerotic plaques.
2021-03-05 | MTBLS2159 | MetaboLights
Project description:Macrophages represent a major immune cell population in atherosclerotic plaques and play central role in the progression of this lipid-driven chronic inflammatory disease. Targeting immunometabolism is proposed as a strategy to revert aberrant macrophage activation to improve disease outcome. Here, we show ATP citrate lyase (Acly) to be activated in inflammatory macrophages and human atherosclerotic plaques. We demonstrate that myeloid Acly deficiency induces a stable plaque phenotype characterized by increased collagen deposition and fibrous cap thickness, along with a smaller necrotic core. In-depth functional, lipidomic, and transcriptional characterization indicate deregulated fatty acid and cholesterol biosynthesis and reduced liver X receptor (LXR) activation within the macrophages in vitro. This results in macrophages that are more prone to undergo apoptosis, whilst presenting increased phagocytosis of apoptotic cells. Together, our results indicate that targeting macrophage metabolism improves atherosclerosis outcome and we reveal Acly as a promising therapeutic target to stabilize atherosclerotic plaques.
2020-02-18 | GSE126690 | GEO
Project description:Macrophages are highly plastic, key regulators of inflammation. Deregulation of macrophage activation can lead to excessive inflammation as seen in inflammatory disorders like atherosclerosis, obesity, multiple sclerosis and sepsis. Targeting intracellular metabolism is considered as an approach to reshape deranged macrophage activation and to dampen the progression of inflammatory disorders. ATP citrate lyase (Acly) is a key metabolic enzyme and an important regulator of macrophage activation. Using a macrophage-specific Acly-deficient mouse model, we investigated the role of Acly in macrophages during acute and chronic inflammatory disorders. First, we performed RNA sequencing to demonstrate that Acly-deficient macrophages showed hyperinflammatory gene signatures in response to acute LPS stimulation in vitro. Next, we assessed endotoxin-induced peritonitis in myeloid-specific Acly-deficient mice and show that, apart from increased splenic Il6 expression, systemic and local inflammation were not affected by Acly deficiency. Also during obesity, both chronic low-grade inflammation and whole-body metabolic homeostasis remained largely unaltered in mice with Acly-deficient myeloid cells. Lastly, we show that macrophage-specific Acly deletion did not affect the severity of experimental autoimmune encephalomyelitis (EAE), an experimental model of multiple sclerosis. These results indicate that, despite increasing inflammatory responses in vitro, macrophage Acly deficiency does not worsen acute and chronic inflammatory responses in vivo. Together with our earlier observation that myeloid Acly deletion stabilizes atherosclerotic lesions, our findings highlight that therapeutic targeting of macrophage Acly can be beneficial in some, but not all, inflammatory disorders.
2021-04-19 | GSE169189 | GEO
Project description:ATP-citrate lyase (ACLY) is a key enzyme provoking metabolic and epigenetic gene regulation. Molecularly, these functions are exerted by the provision of acetyl-coenzyme A, which is then used as a substrate for de novo lipogenesis or as an acetyl-group donor in acetylation reactions. It has been demonstrated that ACLY activity can be positively regulated via phosphorylation at serine 455 by Akt and protein kinase A. Nonetheless, the impact of phosphorylation on ACLY function in human myeloid cells is poorly understood. In this study we reconstituted ACLY knockout human monocytic THP-1 cells with a wild type ACLY as well as catalytically inactive H760A, and phosphorylation-deficient S455A mutants. Using these cell lines, we determined the impact of ACLY activity and phosphorylation on histone acetylation and pro-inflammatory gene expression in response to lipopolysaccharide (LPS). Our results show that ACLY serine 455 phosphorylation does not influence the proper enzymatic function of ACLY, since both, wild type ACLY and phosphorylation-deficient mutant, exhibited increased cell growth and histone acetylation as compared to cells with a loss of ACLY activity. Transcriptome analysis revealed enhanced expression of pro-inflammatory and interferon response genes in ACLY knockout and H760A THP-1 cells under unstimulated or LPS-treated conditions. At the same time, S455A ACLY-expressing cells showed a phenotype very similar to wild type cells. Contrary to ACLY knockout, pharmacological inhibition of ACLY in THP-1 cells or in primary human macrophages does not enhance LPS-triggered pro-inflammatory gene expression. Our data thus suggest that ACLY retains functionality in the absence of Akt/PKA-mediated phosphorylation in human myeloid cells. Furthermore, loss of ACLY activity may elicit long-term adaptive mechanisms, increasing inflammatory responses.
2022-11-30 | GSE216003 | GEO
Project description:Our study explores the previously uncharted role of ATP-citrate lyase (ACLY) in vascular remodeling within the pulmonary and coronary circulations, providing novel insights into the pathogenesis of pulmonary hypertension and coronary artery diseases. ACLY, known for its involvement in de novo lipid synthesis and histone acetylation, emerges as a key regulator in sustaining vascular smooth muscle cell proliferation and survival. Utilizing rare human coronary and pulmonary artery tissues, our findings reveal an upregulation of ACLY expression during vascular remodeling processes. Inhibition of ACLY, achieved through pharmacological and molecular interventions in humans primary cultured vascular smooth muscle cells, leads to decreased proliferation, migration, and resistance to apoptosis. Mechanistically, these effects are associated with diminished glycolysis, lipid synthesis, GCN5-dependent histone acetylation, and FOXM1 activation. In vivo experiments, combining pharmacological and VSMC-specific ACLY knockout mice, ACLY inhibition demonstrate its efficacy in mitigating systemic vascular remodeling and reducing pulmonary hypertension. Notably, initiating ACLY inhibition post-disease onset reverses pathological conditions, positioning ACLY as a promising therapeutic target. Human ex-vivo tissue culture further supports our findings, showcasing reduced vascular remodeling in cultured human coronary artery rings and a reversal of pulmonary artery remodeling in precision-cut lung slices upon ACLY inhibition. This study introduces a groundbreaking concept, linking disparate abnormalities in vascular diseases to a common pathogenetic denominator, ACLY. The identified "multiple-hit" therapeutic approach presents potential targets for addressing complex vascular diseases, offering avenues for future clinical interventions.
2024-11-14 | GSE254952 | GEO
Project description:Autophagy is a cellular and energy homeostatic mechanism that contributes to maintain the number of primordial follicles, germ cell survival, and anti-ovarian aging. However, it remains unknown whether autophagy in granulosa cells affects the oocyte maturation. Here, we show a clear tendency of reduced autophagy level in human granulosa cell from women of advanced maternal age, implying a potential negative correlation between autophagy level and oocyte quality. We therefore established a co-culture system and show that either pharmacological inhibition or genetic ablation of autophagy in granulosa cells negatively affect the oocyte quality and fertilization ability. Moreover, our metabolomics analysis indicates that the adverse impact of autophagy impairment on oocyte quality is mediated by downregulated citrate levels, while exogenous supplementation of citrate can significantly restore the oocyte maturation. In molecular level, we found ATP citrate lyase (Acly), which is a crucial enzyme catalyzing the cleavage of citrate, was preferentially associated with K63-linked ubiquitin chains and recognized by the autophagy receptor protein SQSTM1/p62 for the selective autophagic degradation. In human follicles, autophagy levels in granulosa cells was downregulated with maternal aging, accompanied by decreased citrate in the follicular fluid, implying a potential correlation between citrate metabolism and oocyte quality. We also show that elevated citrate levels in porcine follicular fluid promote oocyte maturation. Collectively, our data reveal that autophagy in granulosa cells is a beneficial mechanism to maintain a certain degree of citrate by selectively targeting Acly during oocyte maturation.
2023-01-09 | GSE190697 | GEO
Project description:Differentiation of cardiac fibroblasts (CFs) to myofibroblasts is necessary for matrix remodeling and fibrosis in heart failure. We previously reported mitochondrial calcium signaling drives α-ketoglutarate-dependent histone demethylation, promoting the myofibroblast gene program. Here, we investigated the role of ATP-citrate lyase (ACLY), a key enzyme for acetyl-CoA biosynthesis, in histone acetylation regulating myofibroblast formation and persistence in cardiac fibrosis. Inactivation of ACLY prevented, and importantly reversed, myofibroblasts towards quiescence. Genetic deletion of Acly in activated myofibroblasts prevented fibrosis and preserved cardiac function in murine pressure-overload. TGFβ stimulation enhanced ACLY nuclear localization and increased H3K27ac at fibrotic gene loci. Pharmacological inhibition of ACLY or forced nuclear expression of dominant-negative ACLY mutant prevented myofibroblast formation and H3K27ac. Our data indicate nuclear ACLY activity is necessary for myofibroblast differentiation and persistence by maintaining histone acetylation at TGFβ-induced myofibroblast genes. These findings provide novel clinical rational to prevent and reverse pathological fibrosis. CUT&RUN Sequencing for H3K27ac on the role of ACLY in myofibroblast differentiaton.
2024-05-16 | GSE232010 | GEO
Project description:TLR activation induces inflammatory responses in macrophages by activating temporally defined transcriptional cascades within the first hours after stimulation. Whether concurrent changes in the cellular metabolism that occur upon TLR activation influence the quality of the transcriptional responses remain unknown. Here we investigated how macrophages adopt their metabolism early after activation to regulate TLR-inducible gene induction. Macrophages increase glucose metabolism and adopt fluxes through the TCA cycle to foster Citrate synthesis. We concomitantly observe activation of ATP-Citrate Lyase (Acly), resulting in augmented acetyl-CoA synthesis and histone acetylation. To investigate which genes and genes classes require ATP-citrate lyase activity for induction we stimulated bone marrow derived macrophages with LPS after ATP-citrate lyase inhibition.
2019-12-16 | GSE129497 | GEO
Project description:Microtubule (MT)-based transport is an evolutionary conserved processed finely tuned by posttranslational modifications. Among them, tubulin acetylation, which is catalyzed by the α-tubulin N-acetyltransferase 1, Atat1, facilitates the recruitment and processivity of molecular motors along MT tracks. However, the mechanisms that controls Atat1 activity remains poorly understood. Here we show that a pool of vesicular ATP-citrate lyase Acly acts as a rate limiting enzyme to modulate Atat1 activity by controlling availability of Acetyl-CoA. In addition, we showed that Acly expression is reduced upon loss of Elongator activity, further connecting Elongator to Atat1 in the pathway regulating -tubulin acetylation and MT-dependent transport in projection neurons across species. Remarkably, comparable defects occur in fibroblasts from Familial Dysautonomia (FD) patients bearing an autosomal recessive mutation in the gene coding for the Elongator subunit ELP1. Our data may thus shine new light on the pathophysiological mechanisms underlying FD.
2022-02-16 | PXD021186 | Pride
Project description:Glioblastoma multiforme (GBM), the most common and aggressive primary brain tumor in adults, can be divided into several molecular subtypes including proneural GBM. Most clinical strategies aimed at directly targeting glioma cells in these tumors have failed. A promising alternative is to target stromal cells in the brain microenvironment, such as tumor-associated microglia and macrophages (TAMs). Macrophages are dependent upon colony stimulating factor (CSF)-1 for differentiation and survival; therefore, we used an inhibitor of its receptor, CSF-1R, to target macrophages in a mouse proneural GBM model. CSF-1R inhibition dramatically increased survival in mice and regressed established GBMs. Tumor cell apoptosis was significantly increased, and proliferation and tumor grade markedly decreased. Surprisingly, TAMs were not depleted in tumors treated with the CSF-1R inhibitor. Instead, analysis of gene expression in TAMs isolated from treated tumors revealed a decrease in alternatively activated/ M2 macrophage markers, consistent with impaired tumor-promoting functions. These gene signatures were also associated with better survival specifically in the proneural subtype of patient gliomas. Collectively, these results establish macrophages as valid therapeutic targets in proneural gliomas, and highlight the clinical potential for CSF-1R inhibitors in GBM. RNA was isolated from sorted tumor associated macrophages (TAMs) from murine gliomas following either 7 days of vehicle or BLZ945 treatment. Samples were collected from 16 total tumor burdened mice, with 8 replicates for each treatment group. BLZ945: a Colony-Stimulating Factor 1 Receptor (CSF-1R) inhibitor
2013-09-20 | E-GEOD-37475 | biostudies-arrayexpress