bims-meprid 2023-11-05 papers

Issue of 2023‒11‒05
five papers selected by
Alessandro Carrer, Veneto Institute of Molecular Medicine

J Cachexia Sarcopenia Muscle. 2023 Nov 02.

Lactate promotes myogenesis via activating H3K9 lactylation-dependent up-regulation of Neu2 expression.

Weilong Dai, Gang Wu, Ke Liu, Qianqian Chen, Jingli Tao, Honglin Liu, Ming Shen.

BACKGROUND: Lactate, a glycolytic metabolite mainly produced in muscles, has been suggested to regulate myoblast differentiation, although the underlying mechanism remains elusive. Recently, lactate-mediated histone lactylation is identified as a novel epigenetic modification that promotes gene transcription.METHODS: We used mouse C2C12 cell line and 2-month-old male mice as in vitro and in vivo models, respectively. These models were treated with lactate to explore the biological function and latent mechanism of lactate-derived histone lactylation on myogenic differentiation by quantitative real-time PCR, western blotting, immunofluorescence staining, chromatin immunoprecipitation, cleavage under targets and tagmentation assay and RNA sequencing.
RESULTS: Using immunofluorescence staining and western blotting, we proposed that lactylation might occur in the histones. Inhibition of lactate production or intake both impaired myoblast differentiation, accompanied by diminished lactylation in the histones. Using lactylation site-specific antibodies, we demonstrated that lactate preferentially increased H3K9 lactylation (H3K9la) during myoblast differentiation (CT VS 5, 10, 15, 20, 25 mM lactate treatment, P = 0.0012, P = 0.0007, and the rest of all P < 0.0001). Notably, inhibiting H3K9la using P300 antagonist could block lactate-induced myogenesis. Through combined omics analysis using cleavage under targets and tagmentation assay and RNA sequencing, we further identified Neu2 as a potential target gene of H3K9la. IGV software analysis (P = 0.0013) and chromatin immunoprecipitation-qPCR assay (H3K9la %Input, LA group = 9.0076, control group = 2.7184, IgG = 0.3209) confirmed that H3K9la is enriched in the promoter region of Neu2. Moreover, siRNAs or inhibitors against Neu2 both abrogated myoblast differentiation despite lactate treatment, suggesting that Neu2 is required for lactate-mediated myoblast differentiation.
CONCLUSIONS: Our findings provide novel understanding of histone lysine lactylation, suggesting its role in myogenesis, and as potential therapeutic targets for muscle diseases.

Keywords: Histone lactylation; Lactate; Myoblast differentiation

DOI: https://doi.org/10.1002/jcsm.13363

Science. 2023 Nov 03. 382(6670): eabp9201

Formaldehyde regulates S-adenosylmethionine biosynthesis and one-carbon metabolism.

Vanha N Pham, Kevin J Bruemmer, Joel D W Toh, Eva J Ge, Logan Tenney, Carl C Ward, Felix A Dingler, Christopher L Millington, Carlos A Garcia-Prieto, Mia C Pulos-Holmes, Nicholas T Ingolia, Lucas B Pontel, Manel Esteller, Ketan J Patel, Daniel K Nomura, Christopher J Chang.

One-carbon metabolism is an essential branch of cellular metabolism that intersects with epigenetic regulation. In this work, we show how formaldehyde (FA), a one-carbon unit derived from both endogenous sources and environmental exposure, regulates one-carbon metabolism by inhibiting the biosynthesis of S-adenosylmethionine (SAM), the major methyl donor in cells. FA reacts with privileged, hyperreactive cysteine sites in the proteome, including Cys120 in S-adenosylmethionine synthase isoform type-1 (MAT1A). FA exposure inhibited MAT1A activity and decreased SAM production with MAT-isoform specificity. A genetic mouse model of chronic FA overload showed a decrease n SAM and in methylation on selected histones and genes. Epigenetic and transcriptional regulation of Mat1a and related genes function as compensatory mechanisms for FA-dependent SAM depletion, revealing a biochemical feedback cycle between FA and SAM one-carbon units.

DOI: https://doi.org/10.1126/science.abp9201

Exp Hematol. 2023 Oct 26. pii: S0301-472X(23)01739-3. [Epub ahead of print]

Metabolic regulation in erythroid differentiation by systemic ketogenesis in fasted mice.

Wenjuan Ma, Yuichiro Arima, Terumasa Umemoto, Tomomasa Yokomizo, Yuqing Xu, Kenichi Miharada, Yosuke Tanaka, Toshio Suda.

Erythroid terminal differentiation and maturation depends on enormous energy supply. During periods of fasting, ketone bodies from the liver are transported into circulation and utilized as crucial fuel for peripheral tissues. However, effects of fasting or ketogenesis on erythroid behavior remain unknown. Here, we generated a mouse model with insufficient ketogenesis by conditionally knocking out the gene encoding the hepatocyte-specific ketogenic enzyme hydroxymethylglutary-CoA synthase 2 (Hmgcs2 KO). Intriguingly, erythroid maturation was enhanced with boosted fatty acid synthesis in bone marrow of hepatic Hmgcs2 KO mouse under fasting condition, suggesting that systemic ketogenesis has a profound effect on erythropoiesis. Moreover, we observed significantly activated fatty acids synthesis and mevalonate pathway along with reduced histone acetylation in immature erythrocytes under less systemic ketogenesis condition. Our findings revealed a new insight to erythroid differentiation, in which metabolic homeostasis and histone acetylation mediated by ketone bodies are essential factors in adaptation towards nutrient deprivation and stressed erythropoiesis.

DOI: https://doi.org/10.1016/j.exphem.2023.10.003

JCI Insight. 2023 Oct 31. pii: e164968. [Epub ahead of print]

Signaling metabolite succinylacetone activates HIF-1α and promotes angiogenesis in GSTZ1-deficient hepatocellular carcinoma.

Huating Luo, Qiujie Wang, Fan Yang, Rui Liu, Qingzhu Gao, Bin Cheng, Xue Lin, Luyi Huang, Chang Chen, Jin Xiang, Kai Wang, Bo Qin, Ni Tang.

Aberrant angiogenesis in hepatocellular carcinoma (HCC) is associated with tumor growth, progression, and local or distant metastasis. Hypoxia-inducible factor 1α (HIF-1α) is a transcription factor that plays a major role in regulating angiogenesis during adaptation of tumor cells to nutrient-deprived microenvironment. Genetic defects in Krebs cycle enzymes, such as succinate dehydrogenase and fumarate hydratase, result in elevation of oncometabolites succinate and fumarate, thereby increasing HIF-1α stability and activating the HIF-1α signaling pathway. However, whether other metabolites regulate HIF-1α stability remains unclear. Here, we reported that the enzyme in phenylalanine/tyrosine catabolism glutathione S-transferase zeta 1 (GSTZ1) deficiency led to accumulation of succinylacetone, which was structurally similar to α-ketoglutarate. Succinylacetone competed with α-ketoglutarate for PHD2 binding and inhibited PHD2 activity, preventing hydroxylation of HIF-1α, thus resulting in its stabilization and consequent expression of vascular endothelial growth factor (VEGF). Our findings suggest that GSTZ1 may serve as an important tumor suppressor owing to its ability to inhibit the HIF-1α/VEGFA axis in HCC. Moreover, we explored the therapeutic potential of HIF-1α inhibitor combined with anti-PD-L1 therapy to effectively prevent HCC angiogenesis and tumorigenesis in Gstz1-knockout mice, suggesting a potentially actionable strategy for HCC treatment.

Keywords: Liver cancer; Oncology

DOI: https://doi.org/10.1172/jci.insight.164968

Nat Metab. 2023 Oct 30.

PDK4-dependent hypercatabolism and lactate production of senescent cells promotes cancer malignancy.

Xuefeng Dou, Qiang Fu, Qilai Long, Shuning Liu, Yejun Zou, Da Fu, Qixia Xu, Zhirui Jiang, Xiaohui Ren, Guilong Zhang, Xiaoling Wei, Qingfeng Li, Judith Campisi, Yuzheng Zhao, Yu Sun.

Senescent cells remain metabolically active, but their metabolic landscape and resulting implications remain underexplored. Here, we report upregulation of pyruvate dehydrogenase kinase 4 (PDK4) upon senescence, particularly in some stromal cell lines. Senescent cells display a PDK4-dependent increase in aerobic glycolysis and enhanced lactate production but maintain mitochondrial respiration and redox activity, thus adopting a special form of metabolic reprogramming. Medium from PDK4+ stromal cells promotes the malignancy of recipient cancer cells in vitro, whereas inhibition of PDK4 causes tumor regression in vivo. We find that lactate promotes reactive oxygen species production via NOX1 to drive the senescence-associated secretory phenotype, whereas PDK4 suppression reduces DNA damage severity and restrains the senescence-associated secretory phenotype. In preclinical trials, PDK4 inhibition alleviates physical dysfunction and prevents age-associated frailty. Together, our study confirms the hypercatabolic nature of senescent cells and reveals a metabolic link between cellular senescence, lactate production, and possibly, age-related pathologies, including but not limited to cancer.

DOI: https://doi.org/10.1038/s42255-023-00912-w