bims-meprid Biomed News
on Metabolic-dependent epigenetic reprogramming in differentiation and disease
Issue of 2024–07–28
five papers selected by
Alessandro Carrer, Veneto Institute of Molecular Medicine
  1. Nuclear pyruvate dehydrogenase complex regulates histone acetylation and transcriptional regulation in the ethylene response.
  2. Citrate metabolism controls the senescent microenvironment via the remodeling of pro-inflammatory enhancers.
  3. Metabolic determinants of germinal center B cell formation and responses.
  4. Phospholipid biosynthesis modulates nucleotide metabolism and reductive capacity.
  5. Nucleoside Diphosphate Kinases Are ATP-Regulated Carriers of Short-Chain Acyl-CoAs.
  1. Sci Adv. 2024 Jul 26. 10(30): eado2825
    Nuclear pyruvate dehydrogenase complex regulates histone acetylation and transcriptional regulation in the ethylene response.
    Zhengyao Shao, Liangqiao Bian, Shyon K Ahmadi, Tyler J Daniel, Miguel A Belmonte, Jackson G Burns, Prashanth Kotla, Yang Bi, Zhouxin Shen, Shou-Ling Xu, Zhi-Yong Wang, Steven P Briggs, Hong Qiao.
      Ethylene plays its essential roles in plant development, growth, and defense responses by controlling the transcriptional reprograming, in which EIN2-C-directed regulation of histone acetylation is the first key step for chromatin to perceive ethylene signaling. But how the nuclear acetyl coenzyme A (acetyl CoA) is produced to ensure the ethylene-mediated histone acetylation is unknown. Here we report that ethylene triggers the accumulation of the pyruvate dehydrogenase complex (PDC) in the nucleus to synthesize nuclear acetyl CoA to regulate ethylene response. PDC is identified as an EIN2-C nuclear partner, and ethylene triggers its nuclear accumulation. Mutations in PDC lead to an ethylene hyposensitivity that results from the reduction of histone acetylation and transcription activation. Enzymatically active nuclear PDC synthesizes nuclear acetyl CoA for EIN2-C-directed histone acetylation and transcription regulation. These findings uncover a mechanism by which PDC-EIN2 converges the mitochondrial enzyme-mediated nuclear acetyl CoA synthesis with epigenetic and transcriptional regulation for plant hormone response.
    DOI:  https://doi.org/10.1126/sciadv.ado2825
  2. Cell Rep. 2024 Jul 17. pii: S2211-1247(24)00825-8. [Epub ahead of print] 114496
    Citrate metabolism controls the senescent microenvironment via the remodeling of pro-inflammatory enhancers.
    Kan Etoh, Hirotaka Araki, Tomoaki Koga, Yuko Hino, Kanji Kuribayashi, Shinjiro Hino, Mitsuyoshi Nakao.
      The senescent microenvironment and aged cells per se contribute to tissue remodeling, chronic inflammation, and age-associated dysfunction. However, the metabolic and epigenomic bases of the senescence-associated secretory phenotype (SASP) remain largely unknown. Here, we show that ATP-citrate lyase (ACLY), a key enzyme in acetyl-coenzyme A (CoA) synthesis, is essential for the pro-inflammatory SASP, independent of persistent growth arrest in senescent cells. Citrate-derived acetyl-CoA facilitates the action of SASP gene enhancers. ACLY-dependent de novo enhancers augment the recruitment of the chromatin reader BRD4, which causes SASP activation. Consistently, specific inhibitions of the ACLY-BRD4 axis suppress the STAT1-mediated interferon response, creating the pro-inflammatory microenvironment in senescent cells and tissues. Our results demonstrate that ACLY-dependent citrate metabolism represents a selective target for controlling SASP designed to promote healthy aging.
    Keywords:  ACLY; CP: Cell biology; CP: Metabolism; H3K27 acetylation; SASP; acetyl-CoA; citrate metabolism; senescence; senostatics
    DOI:  https://doi.org/10.1016/j.celrep.2024.114496
  3. Nat Chem Biol. 2024 Jul 26.
    Metabolic determinants of germinal center B cell formation and responses.
    Jun Wu, Jiawen Zhou, Gen Li, Xuan Sun, Chen Xiang, Haiyan Chen, Peng Jiang.
      Germinal center (GC) B cells are crucial for the generation of GCs and long-lived humoral immunity. Here we report that one-carbon metabolism determines the formation and responses of GC B cells. Upon CD40 stimulation, GC B cells selectively upregulate methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) expression to generate purines and the antioxidant glutathione. MTHFD2 depletion reduces GC B cell frequency and antigen-specific antibody production. Moreover, supplementation with nucleotides and antioxidants suffices to promote GC B cell formation and function in vitro and in vivo through activation of the mammalian target of rapamycin complex 1 signaling pathway. Moreover, we found that antigen stimulation enhances YY1 binding to the Mthfd2 promoter and promotes MTHFD2 transcription. Interestingly, these findings can be generalized to the pentose phosphate pathway, which is another major source of reducing power and nucleotides. Therefore, these results suggest that an increased capacity for nucleotide synthesis and redox balance is required for GC B cell formation and responses, revealing a key aspect of GC B cell fate determination.
    DOI:  https://doi.org/10.1038/s41589-024-01690-6
  4. Nat Chem Biol. 2024 Jul 26.
    Phospholipid biosynthesis modulates nucleotide metabolism and reductive capacity.
    Yibing Zhu, Xiaomeng Tong, Jingyuan Xue, Hong Qiu, Dan Zhang, Dao-Qiong Zheng, Zong-Cai Tu, Cunqi Ye.
      Phospholipid and nucleotide syntheses are fundamental metabolic processes in eukaryotic organisms, with their dysregulation implicated in various disease states. Despite their importance, the interplay between these pathways remains poorly understood. Using genetic and metabolic analyses in Saccharomyces cerevisiae, we elucidate how cytidine triphosphate usage in the Kennedy pathway for phospholipid synthesis influences nucleotide metabolism and redox balance. We find that deficiencies in the Kennedy pathway limit nucleotide salvage, prompting compensatory activation of de novo nucleotide synthesis and the pentose phosphate pathway. This metabolic shift enhances the production of antioxidants such as NADPH and glutathione. Moreover, we observe that the Kennedy pathway for phospholipid synthesis is inhibited during replicative aging, indicating its role in antioxidative defense as an adaptive mechanism in aged cells. Our findings highlight the critical role of phospholipid synthesis pathway choice in the integrative regulation of nucleotide metabolism, redox balance and membrane properties for cellular defense.
    DOI:  https://doi.org/10.1038/s41589-024-01689-z
  5. Int J Mol Sci. 2024 Jul 09. pii: 7528. [Epub ahead of print]25(14):
    Nucleoside Diphosphate Kinases Are ATP-Regulated Carriers of Short-Chain Acyl-CoAs.
    Domenico Iuso, Julie Guilliaumet, Uwe Schlattner, Saadi Khochbin.
      Nucleoside diphosphate (NDP) kinases 1 and 2 (NME1/2) are well-characterized enzymes known for their NDP kinase activity. Recently, these enzymes have been shown by independent studies to bind coenzyme A (CoA) or acyl-CoA. These findings suggest a hitherto unknown role for NME1/2 in the regulation of CoA/acyl-CoA-dependent metabolic pathways, in tight correlation with the cellular NTP/NDP ratio. Accordingly, the regulation of NME1/2 functions by CoA/acyl-CoA binding has been described, and additionally, NME1/2 have been shown to control the cellular pathways consuming acetyl-CoA, such as histone acetylation and fatty acid synthesis. NME1/2-controlled histone acetylation in turn mediates an important transcriptional response to metabolic changes, such as those induced following a high-fat diet (HFD). This review discusses the CoA/acyl-CoA-dependent NME1/2 activities and proposes that these enzymes be considered as the first identified carriers of CoA/short-chain acyl-CoAs.
    Keywords:  acyl-CoAs; fatty acid synthesis; histone acetylation; nucleoside diphosphate (NDP) kinases 1 and 2 (NME1/2)
    DOI:  https://doi.org/10.3390/ijms25147528
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