bims-medebr Biomed News
on Metabolism of the developing brain
Issue of 2025–12–21
fourteen papers selected by
Regina F. Fernández, Johns Hopkins University



  1. Nat Commun. 2025 Dec 14.
      The brain is a lipid-rich organ that experiences rapid growth and development after birth in a period hallmarked by extensive lipid synthesis. We still lack a fundamental understanding of lipid metabolism during this critical time of brain development and how these dynamics occur in infants born extremely preterm (<28 weeks of gestation) suffering from brain injuries. Using an established model of neonatal brain injury due to intermittent hypoxemia, we recapitulate hippocampal-dependent cognitive impairments and examine the extent of changes in the brain's lipid profile. Our results show changes in hippocampal lipid composition and abnormal fatty acid profile. Furthermore, we provide evidence of an increase in mitochondrial fatty acid β-oxidation, a process that is not classically thought of occurring in the developing brain. We find that a specific alternative fuel, acetate, spares fatty acids from mitochondrial β-oxidation. Here, we show that treatment with acetate in vivo in the form of glycerol-triacetate promotes functional recovery and restores hippocampal fatty acid profile after neonatal brain injury.
    DOI:  https://doi.org/10.1038/s41467-025-67542-6
  2. Metab Brain Dis. 2025 Dec 17. 41(1): 3
      Brain energy metabolism primarily depends on glucose, which serves as the primary energy source for neuronal activity. Glucose entry into the brain is mediated by glucose transporters, the major isoforms of which are GLUT1 and GLUT3. GLUT1 is responsible for delivering glucose to the brain parenchyma, while GLUT3, with its high affinity for glucose, ensures glucose uptake by neurons. Growing evidence indicates that disturbed glucose metabolism is closely associated with impaired brain function and the progression of neurological diseases, and regulating these transporters may be a potential therapeutic strategy to restore metabolic balance. This review focuses on the current understanding of the functions and regulation of GLUT1 and GLUT3. We first examine their distribution and their distinct contributions to glucose utilization, then summarize how pathological factors such as ischemia, hypoxia, oxidative stress, and neuroinflammation alter the expression and activity of these transporters. At the molecular level, we highlight the multiple signaling pathways involved in the regulation of glucose transporters. The PI3K/Akt, HIF-1α, AMPK, and mTOR pathways, along with microRNA-mediated mechanisms, influence the expression and activity of GLUT1 or GLUT3, respectively, in diverse physiological and pathological contexts. We also discuss evidence for pathway crosstalk, including interactions between PI3K/Akt, mTOR, and HIF-1α, as well as AMPK-mTOR coupling, which may provide additional regulatory insights. In summary, despite significant progress, critical gaps remain in linking upstream signaling to transporter dynamics and therapeutic effects. A deeper understanding of the regulatory networks underlying glucose metabolism will more accurately capture the complexity of disease-related metabolic regulation and may reveal novel therapeutic targets for intervening in glucose metabolism disorders.
    Keywords:  Brain; GLUT-1; GLUT-3; Glucose metabolism; Glucose transporter
    DOI:  https://doi.org/10.1007/s11011-025-01753-0
  3. Glia. 2026 Feb;74(2): e70128
      Oligodendrocytes are the myelinating cells of the central nervous system. Regulation of the early stages of oligodendrocyte development is critical to the function of the cell. Specifically, myelin sheath formation is an energetically demanding event that requires precision, as alterations may lead to dysmyelination. Fatty acid β-oxidation has been shown to be critical for the function of oligodendrocytes. We previously showed that myeloid cell leukemia-1 (MCL-1), a well-characterized anti-apoptotic protein, is required for the development of murine oligodendrocytes in vivo. Further, MCL-1 regulates long-chain fatty acid β-oxidation in cancer cells through its interaction with Acyl-CoA synthetase long-chain family member 1 (ACSL1), an enzyme responsible for the conversion of free long-chain fatty acids into fatty acyl-CoA esters. Here, we introduce an in vitro system to isolate human stem cell-derived oligodendrocyte progenitor cells (OPCs) and investigate the involvement of MCL-1 during human oligodendrocyte development. Using this system, we pharmacologically inhibited MCL-1 in OPCs to investigate its non-apoptotic function at this developmental stage. We also used a motor neuron-oligodendrocyte co-culture system to examine the downstream effects of MCL-1 at later developmental stages when oligodendrocytes begin to contact axons and generate myelin. We demonstrate that the mitochondrial network changes in human oligodendrocyte development resemble those reported in mouse tissue. Our findings point to MCL-1 as a critical factor essential for proper oligodendrocyte morphogenesis.
    Keywords:  MCL‐1; fatty acid oxidation; hESCs; iPSCs; mitochondria; oligodendrocytes
    DOI:  https://doi.org/10.1002/glia.70128
  4. Cell Death Dis. 2025 Dec 15.
      AGC1 deficiency is a rare, early-onset encephalopathy caused by mutations in the SLC25A12 gene, encoding the mitochondrial aspartate/glutamate carrier isoform 1 (AGC1). Patients exhibit epileptic encephalopathy, cerebral hypomyelination, severe hypotonia, and global developmental delay. A hallmark biochemical feature of AGC1 deficiency is reduced brain N-acetylaspartate (NAA), a key metabolite involved in myelin lipid synthesis. However, the underlying mechanisms leading to the hypomyelinating phenotype remain unclear. In this study, we generated neuronal progenitors (NPs) derived from human-induced pluripotent stem cells (hiPSCs) of AGC1-deficient patients to investigate the metabolic and bioenergetic consequences of AGC1 loss. We demonstrated that AGC1-deficient NPs exhibit impaired proliferation, increased apoptosis, and a metabolic shift toward a hyperglycolytic phenotype due to defective mitochondrial pyruvate oxidation. RNA sequencing revealed downregulation of mitochondrial pyruvate carrier MPC1/2, limiting pyruvate-driven oxidative phosphorylation (OXPHOS) and reinforcing glycolysis as the primary energy source. Despite this metabolic shift, AGC1-deficient mitochondria retained the potential for OXPHOS when alternative anaplerotic substrates were provided. Notably, the administration of ketone bodies, in combination with glutamine, fully restored mitochondrial respiration, suggesting a mechanistic basis for the clinical improvements observed in AGC1-deficient patients undergoing ketogenic diet therapy. Our study highlights the importance of alternative metabolic pathways in maintaining neuronal energy homeostasis in AGC1 deficiency and offers insights into potential therapeutic strategies aimed at bypassing the mitochondrial pyruvate oxidation defect.
    DOI:  https://doi.org/10.1038/s41419-025-08314-4
  5. Glia. 2026 Feb;74(2): e70112
      CD38 is an ectoenzyme that converts NAD+ to NAM to help maintain bioenergetic homeostasis. CD38 dysregulation and gene variation is reported in neurodegenerative conditions such as Parkinson's disease (PD) and Alzheimer's disease (AD), highlighting the need to better understand CD38 biology within the brain. Here, we demonstrate enrichment of Cd38 in midbrain astrocytes and describe how CD38 deficiency influences brain metabolism, astrocytic gene expression, and bioenergetics. We demonstrate increased NAD content, decreased NAM content, and increased NAD/NAM in the midbrain and striatum of CD38-deficient (Cd38-/-) mice, indicating the dependence on CD38 for NAD to NAM conversion in the brain. RNA-sequencing of isolated astrocytes revealed numerous differentially expressed genes in Cd38+/- and Cd38-/- mice, with alterations in mitochondrial, metabolic, senescence-related, astrocyte reactivity, and other genes involved in PD and AD etiology. Furthermore, functional metabolic analysis of midbrain revealed changes in pyruvate oxidation, age-dependent increase of citrate synthase (CS) activity, and reduction of cytochrome c oxidase-to-CS ratio in Cd38 deficiency. These findings identify a novel role for astrocytes in the regulation of CD38-dependent NAD/NAM homeostasis in the brain and provide a framework for future studies evaluating the relationship between CD38 dysfunction, aging, and vulnerability of neuronal populations in neurodegenerative disease. Importantly, these studies underscore the necessity to better resolve the impact of CD38 deficiency on brain metabolism, considering ongoing clinical trials and discussions related to the use of CD38 modulators for the treatment of cancers, age-related decline, and neurodegenerative disease.
    Keywords:  RNA‐sequencing; aging; astrocyte; brain metabolism; mitochondria; neurodegeneration
    DOI:  https://doi.org/10.1002/glia.70112
  6. Redox Biol. 2025 Dec 15. pii: S2213-2317(25)00491-4. [Epub ahead of print]89 103978
      Lipid droplet accumulation in microglia has been implicated in inflammatory functions associated with aging and demyelinating diseases. However, the molecular mechanisms driving lipid droplet formation under pathological conditions remain unrevealed. It is demonstrated herein that the acetylation of fatty acid synthase (FASN) plays a key regulatory role in the accumulation of lipid droplets in microglia following traumatic brain injury (TBI). Through mass spectrometry analysis, we identified hyperacetylation at lysine K673 of FASN as a critical driver of lipid droplet formation in microglia. Notably, this acetylation event not only promotes lipid droplet accumulation but also enhances pro-inflammatory cytokine production and phagocytic activity in microglia. Additionally, we found that HDAC3 may be the enzyme responsible for deacetylation of FASN K673. Importantly, observation of a mouse model carrying the FASN K673R mutation revealed a reduction in microglial lipid droplet accumulation and neuroinflammatory responses following TBI relative to wild-type mice. Thus, FASN acetylation is a pivotal regulator of post-TBI microglial lipid droplet formation and neuroinflammation. This positions the targeting of deacetylation pathways as a novel therapeutic strategy for TBI.
    Keywords:  Acetylation; Fatty acid synthase; Microglia; Neuroinflammation; Traumatic brain injury
    DOI:  https://doi.org/10.1016/j.redox.2025.103978
  7. Ibrain. 2025 ;11(4): 457-475
      With the intensification of the aging society, the incidence of various neurodegenerative diseases is on the rise. The hippocampus is susceptible to age-related neuronal decline and is the earliest and crucial region affected in the transition from healthy aging to neurodegenerative diseases. Before the diagnosis of neurodegenerative diseases, there is already a decline in brain energy metabolism, with the disruption of energy metabolism serving as the primary mechanism leading to neuronal damage. This triggers complex signaling mechanisms both inside and outside the brain during the aging process. Glucose serves as the primary energy source for brain tissues, and a decrease in glucose metabolism is an early indicator of age-related functional changes in the brain. Therefore, understanding the pathophysiological basis of glucose metabolism in the aging hippocampus, as well as the underlying mechanisms, is crucial in comprehending cognitive aging. Such understanding is integral for early intervention and the mitigation of memory and learning impairments caused by energy metabolism. In this review, we have delved into the characteristics of energy metabolism, focusing specifically on glucose metabolism, as well as exploring the molecular foundations and associated mechanisms present within hippocampal neuronal cells under both normal and aging conditions. Notably, our investigation has highlighted the vital roles played by ALG5 and STT3A, key molecules involved in N-glycosylation, in influencing GLUT expression and the rate of membrane transport, regulating glucose metabolism, and thereby influencing cellular glucose uptake. The exploration of this study direction holds considerable promise for future endeavors.
    Keywords:  ALG5; STT3A; aging; glucose metabolism; hippocampus
    DOI:  https://doi.org/10.1002/ibra.12201
  8. bioRxiv. 2025 Nov 27. pii: 2025.11.25.690197. [Epub ahead of print]
      The structure and function of cellular and intracellular membranes are critically governed by the fatty acid (FA) composition of phospholipids (PLs), which is dynamically regulated by a network of enzymes that fine-tune lipid species according to cellular demands. In this study, we identify a mechanism through which the formation of mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) modulates the activity of the acyl-CoA synthetase long-chain family member 4 (ACSL4), an enzyme that channels polyunsaturated fatty acids (PUFAs) into phosphatidylcholine (PC) via the Lands cycle. Through integrated biochemical, proteomic, and lipidomic analyses in both cellular and animal models, we demonstrate that MAM formation enhances ACSL4 activity, promoting arachidonic acid (AA) activation and its preferential incorporation into PC in concert with the MAM-localized lysophospholipid acyltransferase 4 (LPCAT4). Our findings further uncover an unexpected link between this pathway and the pathogenesis of Alzheimer's disease (AD). We show that elevated levels of C99-the β-secretase cleavage product of amyloid precursor protein (APP)-induce MAM remodeling through cholesterol clustering, which in turn activates ACSL4 and alters PC composition. This effect is mirrored in AD models as well as in fibroblasts, neurons, and immune cells derived from both familial and sporadic AD patients, all of which exhibit chronically increased C99 levels, heightened ACSL4 activity, and enrichment of PUFA-containing PC species, leading to lipid imbalance and membrane dysfunction. Together, these results establish MAMs as dynamic lipid-regulatory hubs that coordinate ACSL4-dependent membrane remodeling and highlight the contribution of MAM dysregulation to lipid abnormalities observed in AD.
    DOI:  https://doi.org/10.1101/2025.11.25.690197
  9. Mol Aspects Med. 2025 Dec 18. pii: S0098-2997(25)00102-5. [Epub ahead of print]107 101438
      Once considered a non-essential amino acid, L-serine (L-Ser) is now recognized as conditionally essential in the brain, orchestrating a complex network of metabolic and signalling pathways. L-Ser provides carbon units to the one-carbon metabolism, supporting nucleotide synthesis and methylation reactions, and serves as a precursor for phosphatidylserine and sphingolipids. L-Ser plays crucial roles in glutathione and heme metabolism and interfaces with mitochondrial one-carbon pathways, thereby linking it to energy production, redox homeostasis, and epigenetic regulation. Its conversion into glycine and D-serine further supports neurotransmission, synaptic plasticity, and cognitive functions. Throughout the lifespan, L-Ser and its derivatives contribute to maintaining neuronal and glial homeostasis. However, fundamental questions remain regarding how L-Ser biosynthesis, transport, and compartmentalization are coordinated in the intact brain and how their dysregulation contributes to disease. Current knowledge largely derives from cancer biology or in vitro models, and translating these insights to the central nervous system poses major challenges. The lack of specific tools to monitor L-Ser flux in vivo, limited understanding of post-translational regulation of key enzymes and incomplete mapping of transport mechanisms across the blood-brain barrier still hampers deeper mechanistic and translational insight. This review compiles the most recent evidence, emphasizing the translational relevance of L-Ser-based interventions and underscoring the urgent need for systematic clinical trials to fully evaluate its therapeutic potential.
    Keywords:  D-serine; L-serine; Metabolism; Neurotransmission; Phosphorylated pathway; Serinosome
    DOI:  https://doi.org/10.1016/j.mam.2025.101438
  10. bioRxiv. 2025 Dec 14. pii: 2025.12.14.694212. [Epub ahead of print]
      The two greatest risk factors for Alzheimer's Disease (AD) are aging and Apolipoprotein E4 (APOE4) polymorphism, yet how these factors interact remain unclear. In this study, we investigate how bone morphogenetic protein (BMP) signaling, which increases with age, contributes to APOE4-induced lipid metabolic dysfunctions using induced-pluripotent stem cell (iPSC)-derived astrocytes and cocultured neurons. Surprisingly, BMP signaling differentially altered lipid droplet formation, cholesterol synthesis and breakdown, and fatty acid-oxidation in APOE4 compared to APOE3 astrocytes, and increased secretion of oxidized LDL (oxLDL). Furthermore, neurons cocultured with BMP4-treated APOE4 astrocytes showed altered transcriptomic profiles based on scRNA-seq as well as increased tau phosphorylation (p-tau). oxLDL treatment similarly increased p-tau and reduced neuronal survival. Conversely, lipid uptake inhibition in neurons rescued the BMP4/APOE4 astrocyte-induced neuronal phenotype. These data demonstrate key interactions between APOE4 and aging-associated molecular signaling in AD pathogenesis and establish a causal linkage between astrocytic lipid metabolism and neuronal tau hyperphosphorylation.
    DOI:  https://doi.org/10.64898/2025.12.14.694212
  11. bioRxiv. 2025 Dec 09. pii: 2025.12.05.692675. [Epub ahead of print]
       Background: Anemia is a common medical condition in preterm infants. Previous studies show that neurodevelopmental outcomes of preterm infants are dependent in part on the degree of anemia. In a developmentally appropriately-timed neonatal mouse model, phlebotomy induced anemia (PIA) of the degree commonly seen in hospitalized preterm infants results in brain iron deficiency and hypoxia and significant short-term and long-term brain dysfunction, especially in the hippocampus. Iron and oxygen are critical for mitochondrial oxidative phosphorylation-mediated ATP production and thus energetically demanding brain developmental processes (e.g., axon/dendrite growth, myelination, synaptogenesis).
    Objective: To test the hypothesis that neonatal PIA acutely impairs mitochondrial respiratory capacity and electron transport chain (ETC) complex function in the developing hippocampus.
    Methods: Neonatal mice were phlebotomized daily beginning on postnatal day 3 (P3). On P14, mitochondria were isolated from the hippocampus of male and female PIA and non-bled mice. Seahorse bioenergetic analyses were performed to determine the effects of PIA on mitochondrial oxidative phosphorylation activity and ETC complex functional capacity.
    Results: PIA hippocampal mitochondria demonstrated an overall reduced oxygen consumption rate (OCR) compared to non-bled controls when ETC oxygen consumption was coupled to ATP production. PIA reduced hippocampal mitochondrial OCR that was not due to the ETC in females not males. Basal respiration, proton leak, and maximal respiratory capacity were significantly reduced in PIA hippocampal mitochondria, an effect that did not differ by sex. When mitochondrial ETC oxygen consumption was uncoupled from ATP production with the protonophore FCCP, a mild reduction in OCR was observed across all ETC complexes, with only complex I-mediated OCR being significantly lower than non-bled controls.
    Conclusions: These findings suggest that impaired mitochondrial energetic capacity may mechanistically contribute to the persistent neurobehavioral deficits caused by PIA, through dysregulation of energy-demanding neurodevelopmental processes (e.g., neuron structural maturation).
    DOI:  https://doi.org/10.64898/2025.12.05.692675
  12. Biochim Biophys Acta Mol Basis Dis. 2025 Dec 11. pii: S0925-4439(25)00480-6. [Epub ahead of print]1872(3): 168130
      McArdle disease, caused by mutations in the pygm encoding myophosphorylase, impairs muscle glycogenolysis and lactate production during exercise, leading to severe energy deficits. Here, we report that the decreased lactate production in McArdle disease regulates mitochondrial magnesium (mMg2+) uptake, with major metabolic consequences in skeletal muscle. Using a CRISPR/Cas9-generated pygm knockout (KO) rat model, we demonstrate that KO rats fail to elevate lactate during static muscle contraction and exhibit diminished mMg2+ uptake, disrupted ATP synthesis, and impaired mitochondrial respiration. In vitro, caffeine-stimulated KO myotubes showed preserved Ca2+ oscillations but lacked lactate production and mMg2+ uptake. Restoration of lactate levels via glucose supplementation rescued mMg2+ transport and improved metabolic output. These findings underscore the significance of lactate as a crucial regulator of mMg2+ homeostasis and provide valuable mechanistic insights into the metabolic dysfunction observed in McArdle disease.
    Keywords:  Glycogen storage disease type V; Lactate signaling; Lactate-Mg(2+) axis; McArdle disease; Metabolic myopathy; Mitochondrial Mg(2+) mobilization; Myophosphorylase deficiency
    DOI:  https://doi.org/10.1016/j.bbadis.2025.168130
  13. bioRxiv. 2025 Nov 25. pii: 2025.11.24.690227. [Epub ahead of print]
      Neurons rely on glial lactate shuttling for metabolic support, which declines with aging and in neurodegenerative disease. Full disruption of lactate shuttling in peripheral nerves causes progressive axon degeneration, but we were interested to understand how partial disruption, a scenario more relevant to aging and disease, contributes to neurodegeneration risk. Pyruvate and lactate are interconverted by lactate dehydrogenases (LDHA and LDHB) in both lactate producing and consuming cells. We therefore began by investigating Ldhb knockout mice (loss of LDHA, the dominant LDH in liver and muscle, caused embryonic lethality), and discovered that they develop progressive neuromuscular junction atrophy and functional decline without axon degeneration. Because even Ldhb+/- heterozygosity significantly affects motor behavior, we also wondered about a potential link to congenital disease and pursued this by identifying rare loss-of-function LDHB variants among ALS patients. Next, to better understand how LDHB loss leads to motor decline, we selectively deleted it in defined cell types. SC-specific deletion caused robust motor defects, whereas motor neuron-specific deletion has little effect. Reasoning that neuronal LDHB deficiency could model age-associated decline in lactate metabolism, we asked whether it would interact with ALS genetic risk. Indeed, motor-neuron LDHB deficiency synergizes with relatively mild ALS risk variants, TDP43-Q331K and Sod1-D83G knock-in alleles, to produce early motor neuropathy, indicating that LDHB loss enhances disease risk. These findings establish lactate metabolism as a modifier of motor system vulnerability and highlight it as a therapeutic target in peripheral as well as central neurodegeneration.
    DOI:  https://doi.org/10.1101/2025.11.24.690227
  14. Front Neurosci. 2025 ;19 1745196
      
    Keywords:  autophagosomes; bipolar disease; disulupidptosis; glioma; lactate; micronutraceuticals; migraine; neuroenergetics
    DOI:  https://doi.org/10.3389/fnins.2025.1745196