bims-medica 2026-02-15 papers

bims-medica

Biomed News

on Metabolism and diet in cancer

Issue of 2026–02–15
thirteen papers selected by
Brett Chrest, Wake Forest University

Lactylation fuels nucleotide biosynthesis and facilitates deuterium metabolic imaging of tumor proliferation in preclinical models of H3K27M-mutant gliomas.
Distinct effects of ketogenic and non-ketogenic weight-loss diets on hepatic steatosis and mitochondrial metabolism in MASLD.
Spatiotemporal metabolic mapping reveals diet-independent remodeling of the postnatal mouse brain.
Hepatic ketogenesis supports liver lipid homeostasis during acute exercise but is not required for exercise training to mitigate liver steatosis in mice.
CRIP1 knockdown enhances glycolytic dependence and increases sensitivity to 2-Deoxy-D-Glucose in acute myeloid leukemia.
Substrate availability and citrate alter TCA cycle metabolism and SLC13A3 in macrophage immune responses.
Metabolic permissiveness: how tissue context shapes cancer.
From Structure to Vulnerability: Mitochondrial Supercomplexes in Cancer Cells.
Therapeutic advances in acute myeloid leukemia: from LSD1 blockade to PROTAC-based strategies.
The Glutamine-α-Ketoglutarate Metabolic Axis Controls Vascular Smooth Muscle Cell Function.
The bottleneck of fat burning.
Impact of venetoclax trough levels on safety and efficacy in the treatment of acute myeloid leukemia.
Comprehensive Proteomics and β-Hydroxybutyrylation Profiling in Starvation-Induced Gastrocnemius Muscle Remodeling.

Sci Transl Med. 2026 Feb 11. 18(836): eadw0834

Lactylation fuels nucleotide biosynthesis and facilitates deuterium metabolic imaging of tumor proliferation in preclinical models of H3K27M-mutant gliomas.

Georgios Batsios, Céline Taglang, Suresh Udutha, Anne Marie Gillespie, Timothy Phoenix, Sabine Mueller, Sriram Venneti, Carl Koschmann, Pavithra Viswanath.

Hyperactivation of glucose metabolism to lactate is a metabolic hallmark of cancer. However, the functional role of lactate in pediatric diffuse midline glioma (DMG) cells is unclear. Here, using stable isotope tracing and loss-of-function studies in clinically relevant patient-derived DMG models, we show that the oncogenic histone H3K27M mutation epigenetically up-regulates the rate-limiting glycolytic enzyme phosphoglycerate kinase 1 (PGK1) and drives lactate production from [U-13C]-glucose in DMGs. Mechanistically, lactate posttranslationally activates the nucleoside diphosphate kinase NME1 through lactylation and facilitates the synthesis of nucleoside triphosphates that are essential for DNA replication and tumor proliferation. This mechanistic link between glycolysis and nucleotide biosynthesis provides the opportunity for deuterium metabolic imaging of tumor growth and response to therapy. Spatially mapping 2H-lactate production from [6,6-2H]-glucose allows visualization of the metabolically active tumor lesion and provides an early readout of response to standard of care and targeted therapy that precedes extended survival and reflects pharmacodynamic alterations in tumor tissues in preclinical DMG models in vivo at clinical field strength (3 T). Overall, we have identified an H3K27M-lactate-NME1 axis that drives DMG proliferation and facilitates noninvasive in vivo metabolic imaging of DMGs.

DOI: https://doi.org/10.1126/scitranslmed.adw0834
J Hepatol. 2026 Feb 06. pii: S0168-8278(26)00062-0. [Epub ahead of print]

Distinct effects of ketogenic and non-ketogenic weight-loss diets on hepatic steatosis and mitochondrial metabolism in MASLD.

Sami F Qadri, Kimmo Porthan, Sylvie Dufour, Tiina E Lehtimäki, Kitt Falk Petersen, Gerald I Shulman, Hannele Yki-Järvinen, Panu K Luukkonen.

   BACKGROUND & AIMS: Weight loss is the cornerstone therapy for metabolic dysfunction-associated steatotic liver disease (MASLD). However, the optimal dietary approach for reducing intrahepatic triglycerides (IHTG) and the mechanisms underlying steatosis resolution remain poorly defined. We investigated whether weight loss via a ketogenic diet (KD) differentially affects IHTG content, hepatic mitochondrial metabolism, and the circulating metabolome compared with a non-ketogenic diet (ND).
METHODS: Individuals with varying IHTG content underwent short-term hypocaloric KD and ND in a crossover design. Before and after each diet, IHTG was quantified by proton magnetic resonance spectroscopy and liver stiffness by magnetic resonance elastography. We used state-of-the-art isotope tracer methodology to compare KD and ND effects on in vivo rates of hepatic mitochondrial tricarboxylic acid (TCA) cycle oxidation, endogenous glucose production, and β-hydroxybutyrate production (ketogenesis). Targeted plasma metabolomics by NMR and LC-MS evaluated systemic metabolic responses.
RESULTS: Despite similar energy deficits and body fat loss, IHTG decreased 45% more with KD than ND (-29% vs. -20%), accompanied by a threefold greater improvement in hepatic insulin sensitivity (59% vs. 21%). KD, but not ND, markedly reduced serum insulin concentrations (-54%), thereby promoting lipolysis and intrahepatic fatty acid partitioning toward mitochondrial β-oxidation, increasing hepatic mitochondrial [NADH]/[NAD+] (redox state) (+51%), and decreasing rates of hepatic mitochondrial TCA cycle oxidation (-34%). KD, but not ND, increased plasma concentrations of branched-chain amino acids, acylcarnitines, and tricarboxylic acid cycle intermediates.
CONCLUSIONS: Both diets ameliorated MASLD, but KD produced a greater reduction in IHTG owing to a starvation-like metabolic state. However, the benefits of KD were accompanied by increased hepatic mitochondrial redox state and suppression of TCA cycle oxidation, which are features previously linked to progressive liver injury.
IMPACT AND IMPLICATIONS: This study provides mechanistic justification for considering dietary composition, in addition to caloric restriction, as a key determinant of steatosis resolution in MASLD. The findings highlight a potential trade-off between greater short-term reductions in liver fat and the emergence of metabolic features previously associated with increased susceptibility to liver injury. While a ketogenic diet may facilitate rapid liver fat reduction in selected clinical contexts, its use should be approached cautiously, particularly in individuals with advanced MASLD. These results underscore the need for systematic evaluation of dietary composition as a determinant of both efficacy and safety of nutritional interventions for MASLD.
CLINICAL TRIAL NUMBER: NCT03737071.

Keywords:  caloric restriction; citric acid cycle; cross-over study; energy metabolism; fatty liver; humans; insulin resistance; ketogenic diet; metabolome; redox state; weight loss

DOI:  https://doi.org/10.1016/j.jhep.2026.02.001
NPJ Metab Health Dis. 2026 Feb 10. 4(1): 7

Spatiotemporal metabolic mapping reveals diet-independent remodeling of the postnatal mouse brain.

Elisa M York, Anne Miller, Sylwia A Stopka, Nathalie Y R Agar, Gary Yellen.

Developing cells undergo extensive metabolic adaptations to support growth and differentiation. Here, using spatially resolved mass spectrometry imaging and stable isotope tracing, we systematically investigate metabolic remodeling in mouse brains at postnatal day 14 and day 28, a period coinciding with the transition from a maternal milk diet to solid food. Untargeted metabolomics reveals global shifts in lipid composition, and region-specific remodeling of central energy metabolism, including increased glycolytic intermediates in grey matter-enriched regions and a global decrease in tricarboxylic acid (TCA) cycle metabolites after weaning. Despite these marked changes in metabolite levels, the glucose incorporation rate remains constant across these developmental stages. Notably, weaning mice onto a milk-replacement diet demonstrates that the observed metabolic adaptations are largely diet-independent. Together, our data suggest that postnatal brain metabolic remodeling is an intrinsically programmed feature of maturation providing region-specific metabolic reorganization to support developmental demands.

DOI: https://doi.org/10.1038/s44324-025-00098-7
bioRxiv. 2026 Jan 26. pii: 2026.01.24.701392. [Epub ahead of print]

Hepatic ketogenesis supports liver lipid homeostasis during acute exercise but is not required for exercise training to mitigate liver steatosis in mice.

Cha Mee Vang, Andres F Ortega, Ruth E Pfeiffer, Jared L Hartmann, Griffin S Hampton, Hu Wang, Eric D Queathem, Peter A Crawford, Xianlin Han, Curtis C Hughey.

The acceleration of hepatic lipid disposal during acute exercise has been proposed as a contributor to the anti-steatotic effects of exercise training. Ketogenesis, which produces acetoacetate (AcAc) and β-hydroxybutyrate (βOHB) from fatty acids, is among the lipid disposal pathways stimulated by exercise. This study tested the hypothesis that hepatic ketogenesis is necessary for exercise training to lower liver lipids. Liver-specific 3-hydroxymethylglutaryl-CoA synthase 2 knockout (HMGCS2 KO) mice and wild type (WT) littermates underwent sedentary, acute exercise, and exercise training protocols. Liver ketone bodies and lipids were determined via mass spectrometry platforms. Stable isotope infusions in conscious, unrestrained mice defined mitochondrial oxidative fluxes at rest and during exercise. Loss of hepatic HMGCS2 decreased liver AcAc and βOHB concentrations and impaired their increase during exercise. Liver triacylglycerides (TAGs) were comparable between genotypes at rest (i.e., ad libitum fed and short fasted conditions). In contrast, liver TAGs were elevated in HMGCS2 KO mice following acute, non-exhaustive exercise. Liver TCA cycle flux was higher in KO mice at rest. During exercise, TCA cycle flux increased in both WT and KO mice but was not different between genotypes with greater exercise duration. This suggests that enhanced disposal of lipids via the TCA cycle may prevent liver lipid accumulation in HMGCS2 KO mice under sedentary conditions, but not during exercise. Unexpectedly, exercise training decreased liver TAGs similarly in both HMGCS2 KO and WT mice. In conclusion, hepatic ketogenesis supports liver lipid homeostasis during acute exercise, but is not required for exercise training to lower liver lipids.
NEW & NOTEWORTHY: Exercise training has been proposed to mitigate liver steatosis partly through enhanced hepatic lipid disposal. During acute exercise, the disposal of fatty acids to ketone bodies is stimulated. This study tested the hypothesis that hepatic ketogenesis was required for exercise training to reduce liver fat in mice. The results show that hepatic ketogenesis is needed to prevent lipid accumulation during acute exercise, but is not necessary for exercise training to lower liver lipids.

DOI: https://doi.org/10.64898/2026.01.24.701392
Mol Biol Rep. 2026 Feb 11. 53(1): 382

CRIP1 knockdown enhances glycolytic dependence and increases sensitivity to 2-Deoxy-D-Glucose in acute myeloid leukemia.

Muhammad Asif Zeb, Faryal Mehwish Awan, Aamir Ali Khan, Sadiq Noor Khan.

   BACKGROUND: Acute Myeloid Leukemia (AML) is an aggressive hematologic malignancy with suboptimal treatment outcomes, necessitating the development of novel therapeutic strategies. Metabolic reprogramming, particularly a dependency on glycolysis, is a hallmark of cancer cells. The cysteine-rich intestinal protein 1 (CRIP1) gene exhibits dual roles in cancer, but its function in AML metabolism remains unexplored. This study investigated the metabolic consequences of CRIP1 knockdown and the subsequent efficacy of the glycolytic inhibitor 2-deoxy-D-glucose (2-DG) compared to the oxidative phosphorylation (OXPHOS) inhibitor IACS-010759.
METHODS: Stable CRIP1 knockdown (CRIP1-KD) was established in the OCI-AML3 cell line using lentiviral shRNA. Metabolic changes were assessed by measuring glucose consumption and lactate secretion. Expression of lactate dehydrogenase A (LDHA) was evaluated by Western blot. The cytotoxic effects of 2-DG and IACS-010759 were determined via flow cytometry using 7-AAD staining.
RESULTS: CRIP1-KD cells demonstrated an 87% reduction in CRIP1 expression (*p*<0.001) and a significant increase in both glucose uptake (*p*=0.04) and lactate production (*p*=0.01) compared to scramble control (SCR) cells. This glycolytic phenotype was corroborated by a 3.3-fold upregulation in LDHA protein expression. Treatment with 2-DG resulted in a more pronounced suppression of glucose consumption and lactate production than IACS-010759 in CRIP1-KD cells (*p*=0.01). Consequently, CRIP1-KD cells exhibited significantly higher cell death after 2-DG treatment (29.10%) compared to IACS-010759 treatment (17.25%; *p*=0.003).
CONCLUSION: Our findings indicate that CRIP1 knockdown induces a glycolytic switch in AML cells, rendering them exquisitely sensitive to glycolytic inhibition by 2-DG. This suggests that CRIP1 status could serve as a biomarker for predicting response to metabolic therapies and highlights 2-DG as a promising therapeutic agent for a subset of AML characterized by glycolytic dependency.

Keywords:  2-Deoxy-D-Glucose; Acute glycolysis Cysteine-Rich protein 1 (CRIP1); Leukemia; Myeloid; Oxidative phosphorylation

DOI:  https://doi.org/10.1007/s11033-026-11546-y
Immunol Lett. 2026 Feb 09. pii: S0165-2478(26)00020-9. [Epub ahead of print] 107147

Substrate availability and citrate alter TCA cycle metabolism and SLC13A3 in macrophage immune responses.

Lea Woyciechowski, Hanna F Willenbockel, Thekla Cordes.

  Cell culture media are commonly formulated to enhance cell growth and often lack the physiological nutrient composition found in human blood plasma. The impact of substrate availability on immune cell metabolism and function remains incompletely understood. Here, we demonstrate that changes in culture medium composition affect mitochondrial metabolic pathways, immune responses, and transport in macrophages. Using mass spectrometry and stable isotope tracing, we identify citrate as a mediator linking extracellular substrate availability to intracellular metabolism. We also observe increased IL-6 secretion and elevated expression of plasma membrane transporter NaDC3 (SLC13A3) under physiological carbon source conditions that are reversed when citrate is excluded from the medium. Our findings demonstrate that extracellular substrate composition influences macrophage immunometabolism and identify citrate as an extracellular signal that modulates immune responses. This work highlights the importance of physiologically relevant nutrient availability in studying and targeting immunometabolic pathways.

Keywords:  SLC13A3; citrate; immunometabolism; itaconate; mass spectrometry; mitochondrial metabolism; substrate availability; tracing

DOI:  https://doi.org/10.1016/j.imlet.2026.107147
Genes Dev. 2026 Feb 09.

Metabolic permissiveness: how tissue context shapes cancer.

Chrysanthi Moschandrea, Christian Frezza.

  An emerging paradox in cancer metabolism is that identical oncogenic mutations produce profoundly different metabolic phenotypes depending on tissue context, with many mutations exhibiting striking tissue-restricted distributions. Here we introduce metabolic permissiveness as the inherent capacity of a tissue to tolerate, adapt to, or exploit metabolic disruptions, providing a unifying framework for explaining this selectivity. We examine tissue-specific metabolic rewiring driven by canonical oncogenes (MYC and KRAS), tumor suppressors (p53, PTEN, and LKB1), and tricarboxylic acid (TCA) cycle enzymes (FH, SDH, and IDH), demonstrating that baseline metabolic architecture, nutrient microenvironment, redox buffering, and compensatory pathways determine whether mutations confer a selective advantage or metabolic crisis. We further discuss how the tumor microenvironment shapes metabolic adaptation and therapeutic vulnerability. This framework reveals shared principles of tissue-specific metabolic vulnerability in cancer and provides a mechanistic basis for precision metabolic therapies.

Keywords:  cancer; metabolism; permissiveness

DOI:  https://doi.org/10.1101/gad.353516.125
Cells. 2026 Jan 29. pii: 258. [Epub ahead of print]15(3):

From Structure to Vulnerability: Mitochondrial Supercomplexes in Cancer Cells.

Corinne E Griguer, Susanne Flor, Claudia R Oliva.

  Mitochondrial respiratory supercomplexes are emerging as key regulators of bioenergetics, redox homeostasis, and metabolic plasticity in cancer. Their assembly enhances electron transport efficiency, limits reactive oxygen species production, and supports the high oxidative and biosynthetic demands of tumor growth. Cancer cells remodel supercomplex organization in response to hypoxia, nutrient limitation, and therapeutic stress, enabling rapid metabolic adaptation. Multiple assembly factors-including COX subunits, HIGD1A/2A, COX7A2L (SCAF1), cardiolipin remodeling enzymes, and Complex I assembly factors such as NDUFAF1 and NDUFAF2-contribute to supercomplex stabilization and can be dysregulated in malignancy. Alterations in these factors enhance respiratory flexibility and therapy resistance, particularly in aggressive tumors such as glioblastoma. However, critical gaps remain, including incomplete understanding of the molecular mechanisms controlling supercomplex assembly and remodeling, limited validation of functional findings in primary patient-derived cells or clinical samples, and uncertainty regarding the contribution of supercomplex to therapy resistance and metabolic adaptation across tumor types. Advances in structural biology and functional imaging have uncovered tumor-specific vulnerabilities within supercomplex architecture that may be exploited therapeutically. Targeting supercomplex assembly, cardiolipin-protein interactions, or electron flux through individual supercomplex modules represents a promising approach to disrupt cancer metabolism and sensitize tumors to treatment. This review synthesizes current knowledge on supercomplex regulation, function, and therapeutic potential in cancer, and outlines key unanswered questions that remain to be addressed.

Keywords:  bioenergetics; cancer metabolism; mitochondrial supercomplexes; respiratory chain assembly factors; therapeutic resistance

DOI:  https://doi.org/10.3390/cells15030258
Ann Med Surg (Lond). 2026 Feb;88(2): 2166-2167

Therapeutic advances in acute myeloid leukemia: from LSD1 blockade to PROTAC-based strategies.

Sarum A Khan, Muhammad A Qamar, Muhammad T Feroze.

  Acute myeloid leukemia (AML) is a fast-progressing blood cancer marked by immature myeloid cells and poor survival rates. Most AML subtypes resist standard treatments, especially in older adults, highlighting the need for new targeted therapies. A hallmark of AML is LSD1 overexpression, which blocks blood cell maturation. Though some LSD1 inhibitors can trigger differentiation, their use is limited by toxicity and incomplete target inhibition. PROTAC degraders like MS9117 offer a promising solution by eliminating LSD1. This halts leukemia growth, promotes robust cell differentiation, and restores sensitivity to agents like all-trans retinoic acid, benefits not seen with traditional inhibitors. PROTACs can also target previously undruggable proteins, such as transcription factors, potentially enabling lower doses and fewer side effects. Several PROTAC therapies are now in AML trials. LSD1-targeted degradation is promising, but further research is needed to confirm its safety, overcome resistance, and identify optimal drug combinations for AML treatment.

Keywords:  E3 ligase; GFL1B; LSD1 inhibitors; acute myeloid leukemia (AML); bomedemstat; epigenetic dysregulation; hematological toxicity; immature blood cells; lysine-specific demethylase (LSD1); proteolysis targeting chimeras (PROTAC); repressor complex

DOI:  https://doi.org/10.1097/MS9.0000000000004650
Cells. 2026 Jan 26. pii: 230. [Epub ahead of print]15(3):

The Glutamine-α-Ketoglutarate Metabolic Axis Controls Vascular Smooth Muscle Cell Function.

Kelly J Peyton, Xiao-Ming Liu, Giovanna L Durante, William Durante.

  Glutamine is a known regulator of vascular smooth muscle cell (VSMC) function, but the molecular pathways underlying this response remain incompletely understood. This study investigated how glutamine metabolism influences VSMC behavior and identified the responsible enzymes and metabolites. Glutamine deprivation markedly reduced VSMC proliferation, migration, and collagen synthesis, while modestly decreasing viability. Pharmacological inhibition of glutaminase-1 (GLS1) or aminotransferases (AT) similarly suppressed these cellular functions, whereas inhibiting glutamate dehydrogenase 1 (GLUD1) had no effect. Metabolite analysis revealed that glutamine deprivation or AT inhibition, but not GLUD1 inhibition, reduced intracellular α-ketoglutarate (αKG) concentrations, establishing AT as the primary enzyme converting glutamine-derived glutamate to αKG. To identify which metabolite drives VSMC responses, glutamine-starved cells were supplemented with various glutamine-derived molecules. The cell-permeable αKG analog dimethyl-αKG significantly restored VSMC proliferation, migration, collagen synthesis, and survival, while ammonia only enhanced viability, demonstrating αKG's primary role in mediating glutamine-dependent functions. These findings establish that glutamine metabolism via the GLS1-AT-αKG pathway is a critical driver of VSMC activation and survival. Targeting this glutamine-αKG metabolic axis through GLS1 inhibition, AT blockade, or downstream αKG disruption offers a compelling therapeutic strategy for ameliorating fibroproliferative vascular diseases, including atherosclerosis, post-angioplasty restenosis, and pulmonary hypertension.

Keywords:  aminotransferase; collagen; glutaminase; glutamine; migration; proliferation; vascular smooth muscle cells; viability; α-ketoglutarate

DOI:  https://doi.org/10.3390/cells15030230
Science. 2026 Feb 12. 391(6786): 659-660

The bottleneck of fat burning.

Angela M Ramos-Lobo, Pierre Maechler.

A mitochondrial transport protein promotes carnitine synthesis in mice when fat consumption is needed.

DOI: https://doi.org/10.1126/science.aef2173
Sci Rep. 2026 Feb 07.

Impact of venetoclax trough levels on safety and efficacy in the treatment of acute myeloid leukemia.

Hiromi Hayashi, Takeo Yamagiwa, Junya Kanda, Takayuki Ishikawa, Masashi Sawa, Yasuko Miyahara, Takayoshi Tachibana, Mitsumasa Watanabe, Yasunori Ueda, Yasuhiko Tsutsumi, Kazunori Imada, Shin-Ichiro Fujiwara, Tomomi Toubai, Kota Yoshifuji, Hirokazu Hirata, Hiroshi Kawabata, Masaaki Tsuji, Satoshi Wakita, Hiroki Yokoyama, Toshiyuki Kitano, Kazunori Murai, Yoshihisa Kataoka, Eri Kawata, Shun-Ichi Kimura, Ryusuke Yamamoto, Kotaro Miyao, Daisuke Nakayama, Akihiko Izumi, Takahito Kawata, Yoshiyuki Onda, Takashi Sakamoto, Chisaki Mizumoto, Toshio Kitawaki, Kouhei Yamashita, Atsushi Yonezawa, Tomoya Kawakami, Shunsaku Nakagawa, Risa Taniguchi, Tomohiro Terada, Akifumi Takaori-Kondo.

Venetoclax-azacitidine chemotherapy is a key treatment for older or medically unfit patients with acute myeloid leukemia (AML). As venetoclax is metabolized via cytochrome P450 3 A, dose adjustments are required when combined with antifungal agents. However, data on venetoclax concentrations and their impact on safety and efficacy remain limited. This study analyzed the association between venetoclax trough levels and treatment outcomes in 152 AML patients (median age: 70 years). The median trough level was 1,518 ng/mL (range: 60-11,328 ng/mL), with significant interindividual variability, even after adjusting for antifungal use. High venetoclax trough levels were significantly associated with elevated creatinine and total bilirubin levels. Patients with trough levels below 1857.3 ng/mL had lower rates of hematologic toxicity during the first treatment cycle (92.9% vs. 100%, P = 0.041). In the second cycle, hematologic toxicity was lower in patients with concentrations below 1,299.3 ng/mL (68% vs. 90%, P = 0.009). In the treatment-naïve group, trough levels above 1857.3 ng/mL were associated with a higher composite complete remission rate (77.3% vs. 47.8%, P = 0.042). These findings highlight the need for venetoclax dose optimization based on drug levels to improve both safety and efficacy in AML treatment.

DOI: https://doi.org/10.1038/s41598-026-38587-4
Biology (Basel). 2026 Feb 06. pii: 289. [Epub ahead of print]15(3):

Comprehensive Proteomics and β-Hydroxybutyrylation Profiling in Starvation-Induced Gastrocnemius Muscle Remodeling.

Leilei Cui, Chunping Huang, Yu Su, Shiqi Xu, Liang Zha, Qiuyuan Zhao, Wu Quan, Xinqiang Lan, Yang Xiang, Qiquan Wang.

  Starvation elicits profound metabolic adaptations in skeletal muscle, enabling survival during nutrient scarcity. While global proteomic changes underpinning muscle atrophy have been studied, the role of lysine β-hydroxybutyrylation (Kbhb), a novel metabolite-derived post-translational modification linked to ketone metabolism, remains largely unexplored. In this study, we subjected mice to 72 h of food deprivation and performed integrative quantitative proteomics and Kbhb-modified peptide profiling on gastrocnemius muscle. Starvation induced significant body weight and muscle mass loss, accompanied by increased systemic β-hydroxybutyrate levels and widespread Kbhb modification of muscle proteins. Proteomic analysis revealed extensive downregulation of ribosomal and translation-associated proteins, coupled with upregulation of autophagy and lipid catabolism pathways, highlighting a coordinated shift from anabolic processes to catabolic and oxidative metabolism. Deep Kbhb profiling identified over 7500 modified lysine sites across 2000 proteins, with starvation triggering a global increase in Kbhb on key metabolic enzymes involved in glycolysis, TCA cycle, fatty acid β-oxidation, and amino acid metabolism. Notably, starvation-enhanced Kbhb preferentially targeted evolutionarily conserved lysines proximal to catalytic or cofactor-binding domains, implicating a regulatory role in enzymatic activity modulation. Conversely, Kbhb on structural and contractile proteins was downregulated, suggesting functional reprioritization of muscle physiology during fasting. Our findings uncover lysine β-hydroxybutyrylation as a dynamic, metabolically responsive PTM mediating gastrocnemius muscle adaptation to energy deficiency, expanding the paradigm of potentially metabolite-driven epigenetic and non-epigenetic regulatory mechanisms in muscle metabolism.

Keywords:  ketone body; lysine β-hydroxybutyrylation (Kbhb); proteomics; skeletal muscle; starvation

DOI:  https://doi.org/10.3390/biology15030289