bims-meprid 2025-04-27 papers

Neuron. 2025 Apr 14. pii: S0896-6273(25)00247-8. [Epub ahead of print]

Alpha-synuclein mutations mislocalize cytoplasmic p300 compromising autophagy, which is rescued by ACLY inhibition.

Sung Min Son, Farah H Siddiqi, Ana Lopez, Rizwan Ansari, Sylwia D Tyrkalska, So Jung Park, Tilo Kunath, Emmanouil Metzakopian, Angeleen Fleming, David C Rubinsztein.

Triplications and certain point mutations in the SNCA gene, encoding alpha-synuclein (α-Syn), cause Parkinson's disease (PD). Here, we demonstrate that the PD-causing A53T α-Syn mutation and elevated α-Syn expression perturb acetyl-coenzyme A (CoA) and p300 biology in human neurons and in the CNS of zebrafish and mice. This dysregulation is mediated by activation of ATP-citrate lyase (ACLY), a key enzyme that generates acetyl-CoA in the cytoplasm, via two mechanisms. First, ACLY activity increases acetyl-CoA levels, which activate p300. Second, ACLY activation increases LKB1 acetylation, which inhibits AMPK, leading to increased cytoplasmic and decreased nuclear p300. This lowers histone acetylation and increases acetylation of cytoplasmic p300 substrates, like raptor, which causes mechanistic target of rapamycin complex 1 (mTORC1) hyperactivation, thereby impairing autophagy. ACLY inhibitors rescue pathological phenotypes in PD neurons, organoids, zebrafish, and mouse models, suggesting that this pathway is a core feature of α-Syn toxicity and that ACLY may be a suitable therapeutic target.

Keywords: ACLY; AMPK; Parkinson's disease; acetyl-CoA; acetylation; alpha-synuclein; autophagy; mTORC1; nucleocytoplasmic shuttling of p300

DOI: https://doi.org/10.1016/j.neuron.2025.03.028

Nat Cell Biol. 2025 Apr 23.

α-Ketoglutarate promotes trophectoderm induction and maturation from naive human embryonic stem cells.

Karlien Van Nerum, Anne Wenzel, Lidia Argemi-Muntadas, Eleni Kafkia, Antar Drews, Ida Sophie Brun, Viktoria Lavro, Annina Roelofsen, Nikolaos Stamidis, Sandra Bages Arnal, Cheng Zhao, Simone di Sanzo, Moritz Völker-Albert, Sophie Petropoulos, Thomas Moritz, Jan Jakub Żylicz.

Development and lineage choice are driven by interconnected transcriptional, epigenetic and metabolic changes. Specific metabolites, such as α-ketoglutarate (αKG), function as signalling molecules affecting the activity of chromatin-modifying enzymes. However, how metabolism coordinates cell-state changes, especially in human pre-implantation development, remains unclear. Here we uncover that inducing naive human embryonic stem cells towards the trophectoderm lineage results in considerable metabolic rewiring, characterized by αKG accumulation. Elevated αKG levels potentiate the capacity of naive embryonic stem cells to specify towards the trophectoderm lineage. Moreover, increased αKG levels promote blastoid polarization and trophectoderm maturation. αKG supplementation does not affect global histone methylation levels; rather, it decreases acetyl-CoA availability, reduces histone acetyltransferase activity and weakens the pluripotency network. We propose that metabolism functions as a positive feedback loop aiding in trophectoderm fate induction and maturation, highlighting that global metabolic rewiring can promote specificity in cell fate decisions through intricate regulation of signalling and chromatin.

DOI: https://doi.org/10.1038/s41556-025-01658-1

Cell Metab. 2025 Apr 12. pii: S1550-4131(25)00209-8. [Epub ahead of print]

Circulating glycerate predicts resilience to fructose-induced hepatic steatosis.

Excessive intake of dietary fructose increases the risk of metabolic-dysfunction-associated steatotic liver disease (MASLD), cirrhosis, and cancers. However, what host factors determine disease vulnerability is incompletely understood. Here, we leverage genetically divergent mouse strains, mass spectrometry-based metabolomics, and in vivo isotope tracing, identifying circulating glycerate as a biomarker that predicts resilience to fructose-induced hepatic steatosis in both sexes. We found that the surge of circulating glycerate after an oral fructose provision reflects strong small-intestinal fructose catabolism. Such fructose clearance by the small intestine is linked to a weaker induction of hepatic de novo lipogenesis and steatosis upon chronic fructose exposure across strains. These data indicate the potential utility of an oral fructose tolerance test and circulating glycerate measurements to predict an individual's susceptibility to fructose-elicited steatotic liver and provide personalized dietary recommendations.

Keywords: MASLD; fructose; in vivo isotope tracing; liquid chromatography spectrometry

DOI: https://doi.org/10.1016/j.cmet.2025.03.017

Nat Cell Biol. 2025 Apr 21.

Metabolites in tumour interstitial fluid directly suppress T cells.

DOI: https://doi.org/10.1038/s41556-025-01652-7

Cancer Immunol Res. 2025 Apr 22.

NEDDylation regulates CD8+ T cell metabolism and anti-tumor immunity.

NEDDylation is a post-translational modification whereby the ubiquitin-like molecule NEDD8 is attached to protein substrates in a process dependent on NEDD8 activating enzyme regulatory subunit (NAE1). NEDDylation is emerging as a regulator of cancer biology, but its precise role in antitumor immunity has not been thoroughly characterized. Here, we study the impact of NEDDylation in CD8+ T cell-mediated antitumor responses. Analysis of publicly available single-cell RNA sequencing databases revealed that CD8+ tumor-infiltrating lymphocytes (TILs) showed increased expression of NEDD8 during their differentiation into effector memory cells. In vitro activation of mouse and human CD8+ T cells drove the upregulation of the NEDDylation enzymatic pathway, resulting in an enrichment of NEDDylated proteins. In vivo tumor challenge assays demonstrated that CD8+ T cells lacking NAE1 (NAE1-KO) exhibited reduced antitumor capability and a less activated phenotype with compromised differentiation into effector cells. Upregulating NEDDylation by knocking out deNEDDylase sentrin-specific protease 8 (SENP8) increased the in vitro cytotoxic capability of CD8+ CAR T cells. In addition, LC MS/MS proteomic analyses of NAE1-KO CD8+ T cells and CD8+ T cells treated with the NEDDylation inhibitor MLN4924, showed a pronounced impairment in metabolic pathways, including glycolysis and oxidative phosphorylation. In this context, we validated lactate dehydrogenase A, α-enolase and hexokinase 1, which are relevant glycolytic enzymes, as NEDD8 targets. In line with this, NEDDylation-deficient CD8+ T cells demonstrated reduced transcription, protein expression and enzymatic activity of lactate dehydrogenase. In summary, we uncover NEDDylation as a critical regulator of CD8+ T cell-mediated antitumor immunity.

DOI: https://doi.org/10.1158/2326-6066.CIR-24-0127