Astrocytic LRP1 enables mitochondria transfer to neurons and mitigates brain ischemic stroke by suppressing ARF1 lactylation

Metabolic reprogramming of astrocytes: Emerging roles of lactate

Lactate serves as a key energy metabolite in the central nervous system, facilitating essential brain functions, including energy supply, signaling, and epigenetic modulation. Moreover, it links epigenetic modifications with metabolic reprogramming. Nonetheless, the specific mechanisms and roles of this connection in astrocytes remain unclear. Therefore, this review aims to explore the role and specific mechanisms of lactate in the metabolic reprogramming of astrocytes in the central nervous system. The close relationship between epigenetic modifications and metabolic reprogramming was discussed. Therapeutic strategies for targeting metabolic reprogramming in astrocytes in the central nervous system were also outlined to guide future research in central nervous system diseases. In the nervous system, lactate plays an essential role. However, its mechanism of action as a bridge between metabolic reprogramming and epigenetic modifications in the nervous system requires future investigation. The involvement of lactate in epigenetic modifications is currently a hot research topic, especially in lactylation modification, a key determinant in this process. Lactate also indirectly regulates various epigenetic modifications, such as N6-methyladenosine, acetylation, ubiquitination, and phosphorylation modifications, which are closely linked to several neurological disorders. In addition, exploring the clinical applications and potential therapeutic strategies of lactic acid provides new insights for future neurological disease treatments.

Turning sour into sweet: Lactylation modification as a promising target in cardiovascular health

Lactylation, a recently identified posttranslational modification (PTM), has emerged as a critical regulatory mechanism in cardiovascular diseases (CVDs). This PTM involves the addition of lactyl groups to lysine residues on histones and nonhistone proteins, influencing gene expression and cellular metabolism. The discovery of lactylation has revealed new directions for understanding metabolic and immune processes, particularly in the context of CVDs. This review describes the intricate roles of specific lactylated proteins and enzymes, such as H3K18, HMGB1, MCT1/4, and LDH, in the regulation of cardiovascular pathology. This study also highlights the unique impact of lactylation on myocardial hypertrophy and distinguishes it from other PTMs, such as SUMOylation and acetylation, underscoring its potential as a therapeutic target. Emerging drugs targeting lactate transporters and critical enzymes involved in lactylation offer promising avenues for novel CVD therapies. This review calls for further research to elucidate the mechanisms linking lactylation to CVDs, emphasizing the need for comprehensive studies at the molecular, cellular, and organismal levels to pave the way for innovative preventive, diagnostic, and treatment strategies in cardiovascular medicine.

Astrocyte heterogeneity in ischemic stroke: Molecular mechanisms and therapeutic targets

Ischemic stroke is one of the major causes of death and disability in adults, bringing a significant economic burden to the society and families. Despite significant advancements in stroke treatment, focusing solely on neurons is insufficient for improving disease progression and prognosis. Astrocytes are the most ubiquitous cells in the brain, and they undergo morphological and functional changes after brain insults, which has been known as astrocyte reactivity. Transcriptomics have shown that reactive astrocytes (RA) are heterogeneous, and they can be roughly classified into neurotoxic and neuroprotective types, thereby affecting the development of central nervous system (CNS) diseases. However, the relationship between stroke and reactive astrocyte heterogeneity has not been fully elucidated, and regulating the heterogeneity of astrocytes to play a neuroprotective role may provide a new perspective for the treatment of stroke. Here we systematically review current advancements in astrocyte heterogeneity following ischemic stroke, elucidate the molecular mechanisms underlying their activation, and further summarize promising therapeutic agents and molecular targets capable of modulating astrocyte heterogeneity.

Single-cell RNA sequencing-guided engineering of mitochondrial therapies for intervertebral disc degeneration by regulating mtDNA/SPARC-STING signaling

Intervertebral disc degeneration (IVDD) is a leading cause of discogenic low back pain, contributing significantly to global disability and economic burden. Current treatments provide only short-term pain relief without addressing the underlying pathogenesis. Herein we report engineering of biomimetic therapies for IVDD guided by single-cell RNA-sequencing data from human nucleus pulposus tissues, along with validation using animal models. In-depth analyses revealed the critical role of mitochondrial dysfunction in fibrotic phenotype polarization of nucleus pulposus cells (NPCs) during IVDD progression. Consequently, mitochondrial transplantation was proposed as a novel therapeutic strategy. Transplanted exogeneous mitochondria improved mitochondrial quality control in NPCs under pathological conditions, following endocytosis, separate distribution or fusion with endogenous mitochondria, and transfer to neighboring cells by tunneling nanotubes. Correspondingly, intradiscal mitochondrial transplantation significantly delayed puncture-induced IVDD progression in rats, demonstrating efficacy in maintaining mitochondrial homeostasis and alleviating pathological abnormalities. Furthermore, exogenous mitochondria were engineered with a bioactive, mitochondrial-targeting macromolecule to impart anti-oxidative and anti-inflammatory activities. The obtained multi-bioactive biotherapy exhibited significantly enhanced benefits in IVDD treatment, in terms of reversing IVDD progression and restoring structural integrity through the mtDNA/SPARC-STING signaling pathways. Overall, our engineered mitochondrial therapies hold great promise for treating IVDD and other musculoskeletal diseases linked to mitochondrial dysfunction.

JZL-184 Alleviate Neurological Impairment through Regulation of Mitochondrial Transfer and Lipid Droplet Accumulation after Cardiac Arrest

Astrocytes are abundant glial cells in the central nervous system (CNS) that play important roles in brain injury following cardiac arrest (CA). Following brain ischemia, astrocytes trigger endogenous neuroprotective mechanisms, such as fatty acid transport. Lipid droplets (LDs) are cellular structures involved in neutral lipid storage and play essential roles in many biological processes. However, whether lipid droplet metabolism is related to the neurological prognosis after CA remains unclear. JZL-184 is a selective irreversible inhibitor of monoacylglycerol lipase (MAGL), and previous investigations revealed that JZL-184 confers neuroprotection in the brain following stroke. However, further investigations are warranted to explore the effect and mechanism of JZL-184 after CA. Here, we reveal that JZL-184 is neuroprotective after cardiac arrest, as it alleviates astroglial activation by upregulating the expression of transforming growth factor beta 1 (TGF-β1), promotes the transfer of mitochondria from astrocytes to neurons in the astrocyte‒neuron coculture system, and reduces lipid droplet accumulation in neurons. Mechanistically, this protective effect depends on the downstream genes DUSP4 and Rab27b. This study provides additional insights into strategies for inhibiting neurological impairment and suggests a potential therapeutic target after cardiac arrest.

Lactylation as a metabolic epigenetic modification: Mechanistic insights and regulatory pathways from cells to organs and diseases

In recent years, lactylation, a novel post-translational modification, has demonstrated a unique role in bridging cellular metabolism and epigenetic regulation. This modification exerts a dual-edged effect in both cancer and non-cancer diseases by dynamically integrating the supply of metabolic substrates and the activity of modifying enzymes: on one hand, it promotes tissue homeostasis and repair through the activation of repair genes; on the other, it exacerbates pathological progression by driving malignant phenotypes. In the field of oncology, lactylation regulates key processes such as metabolic reprogramming, immune evasion, and therapeutic resistance, thereby shaping the heterogeneity of the tumor microenvironment. In non-cancerous diseases, including neurodegeneration and cardiovascular disorders, its aberrant activation can lead to mitochondrial dysfunction, fibrosis, and chronic inflammation. Existing studies have revealed a dynamic regulatory network formed by the cooperation of modifying and demodifying enzymes, and have identified mechanisms such as subcellular localization and RNA metabolism intervention that influence disease progression. Nevertheless, several challenges remain in the field. This article comprehensively summarizes the disease-specific regulatory mechanisms of lactylation, with the aim of providing a theoretical foundation for its targeted therapeutic application.

GBE1 alleviates MPTP-induced PD symptoms in mice by enhancing glycolysis and oxidative phosphorylation

In Parkinson's disease (PD), the disturbance of energy metabolism due to glucose metabolic reprogramming may be a critical factor contributing to neuronal degeneration and death. Glycolysis, as the core process of glucose metabolism, not only serves as a fundamental source of energy but also integrates various metabolic pathways. However, the precise role of alterations in glycolysis-related pathways in the progression of PD remains elusive. We compared and analysed datasets from human databases of patients with PD and healthy controls to identify differentially expressed genes associated with glycolysis. Using the least absolute shrinkage and selection operator regression method and multivariate logistic regression analysis, we identified glucan-branching enzyme 1 (GBE1) as the most confident glycolytic gene implicated in PD. We validated the low expression of GBE1 in 1 - methyl - 4 - phenyl - 1,2,3,6 - tetrahydropyridine (MPTP)-induced PD animal models. Stereotaxic injection-mediated overexpression of GBE1 in striatal neurons improved motor dysfunction in these animal models. In vitro experiments demonstrated that GBE1 promotes the expression of lactate dehydrogenase A (LDHA) and lactate dehydrogenase B (LDHB), enhances cellular glycolytic flux, and thereby increases the viability of PC12 cells under MPP+ treatment. Additionally, GBE1 alleviates mitochondrial dysfunction and restores oxidative phosphorylation in PD. In summary, by integrating machine learning and bioinformatics approaches, we identified GBE1, a glycolysis-related gene with significant implications for PD, elucidating its crucial role in glucose metabolic reprogramming and identifying potential therapeutic targets for modulating glucose metabolism in PD.

The role of protein lactylation in brain health and disease: current advances and future directions

Lactate, the end product of glycolysis, plays a crucial role in cellular signaling and metabolism. The discovery of lactylation, a novel post-translational modification, has uncovered the role of lactate in regulating diseases, especially in the brain. Lactylation connects genetic encoding with protein function, thereby influencing key biological processes. Increasing evidence supports lactate-mediated lactylation as a critical modulator in neurological disorders. This review offers an overview of lactate metabolism and lactylation, highlighting recent advances in understanding the regulatory enzymes of lactylation and their role in the central nervous system. We investigate the impact of lactylation on brain dysfunctions, including neurodegenerative diseases, cerebrovascular disorders, neuroinflammation, brain tumors, and psychiatric conditions. Moreover, we highlight the therapeutic potential of targeting lactylation in treating brain disorders and outline key research gaps and future directions needed to advance this promising field.

Advances in research on mitochondrial dysfunction in neurodegenerative diseases

Given the high energy demand of the nervous system, mitochondrial dysfunction is a key factor in the pathogenesis of neurodegenerative diseases. Thus, a comprehensive understanding of its mechanisms and potential therapeutic targets is essential. This review discusses the roles of mitochondrial oxidative stress, mitochondrial dynamics alterations, and mtDNA damage in Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and multiple sclerosis (MS). In addition, it summarizes the contributions of novel technological approaches in detecting mitochondrial dysfunction, which assist in disease diagnosis. We also emphasize emerging therapeutic strategies and drugs aimed at enhancing mitochondrial quality control and reducing oxidative stress, thereby laying the groundwork for innovative therapeutic approaches in neurodegenerative disease treatment.

Targeting to miR-130b-5p/TLR4: How sodium danshensu suppresses inflammatory response of microglia in cerebral ischemia-reperfusion injury

Cerebral ischemia reperfusion injury (CIRI) is a crucial process in the inflammatory response. Sodium danshensu (SDSS) is of protective effects in cardiovascular and cerebrovascular diseases due to its anti-inflammatory properties. Studies have demonstrated that SDSS administration reduces infarct volume, attenuates neurological impairment, and inhibits microglia activation in rat models of CIRI. While it is well established that miRNAs play roles in a wide range of diseases through multiple pathways. However, the mechanism by which SDSS alleviates inflammatory injury after CIRI and its potential interaction with miRNAs remain unclear. Thus, we aimed to investigate the effectiveness and mechanism of SDSS in CIRI, and to verify whether it exerts anti-inflammatory effects by affecting miRNA. Through bioinformatics analysis and experimental validation, we identified miR-130b-5p is a key gene in the CIRI process, with SDSS administration leading to an upregulation of miR-130b-5p that is indispensable for its anti-inflammatory effects. Moreover, both SDSS and miR-130b-5p reduced the expression of TLR4. Overall, the beneficial effects of SDSS on CIRI can be attributed to the up-regulation of miR-130b-5p and the inhibition of TLR4, resulting in the attenuation of the inflammatory response.

Higher mitochondrial protein-Succinylation detected in lung tissues of idiopathic pulmonary fibrosis patients

A new pathogenic role for mitochondrial dysfunction has been associated with the development of idiopathic pulmonary fibrosis (IPF). Lysine succinylation (Ksucc) is involved in many energy metabolism pathways in mitochondria, making Ksucc highly valuable for studying IPF. We used liquid chromatography with tandem mass spectrometry (LC-MS/MS) to perform the first global profiling of Ksucc in fibrotic lung tissues from IPF patients, providing a proof of concept for the alteration of Ksucc in IPF and highlighting its potential as a therapeutic target. Selected candidate proteins were further verified by targeted proteomics using parallel reaction monitoring (PRM). In this study, we identified 1964 Ksucc sites on 628 modified proteins, with675 of these Ksucc sites on 124 modified proteins closely related to mitochondrial metabolism. 117 succinylated proteins were associated with energy metabolism in mitochondria by comparing these proteins with those previously reported in normal lung tissues. The Ksucc levels in KYAT3, HSD17B8, GRHPR, and IDH2 were different between control and IPF groups by Using PRM. This study provides insight into Ksucc profile alterations in IPF pathogenesis and Ksucc sites in proteins associated with mitochondrial energy metabolism can also serve as candidate molecules for future mechanism exploration and drug target selection in IPF.

Lactylation and regulated cell death

Lactylation, a newly identified post-translational modification, entails the attachment of lactate to lysine residues within proteins, profoundly modulating diverse cellular mechanisms underlying regulated cell death (RCD). This modification encompasses two primary categories: histone lactylation and non-histone lactylation. Histone lactylation assumes a pivotal regulatory function in the RCD process, primarily by modulating the transcriptional landscape of genes implicated in cell death. In contrast, non-histone lactylation exerts its influence by targeting transferases, transcription, cell cycle progression, death pathways, and metabolic processes that are intricately involved in RCD. This review provides a comprehensive overview of recent breakthroughs in understanding how lactylation regulates RCD, while also offering insights into potential avenues for future research, thereby deepening our comprehension of cellular fate determination.

Emerging roles of lysine lactyltransferases and lactylation

Given its various roles in cellular functions, lactate is no longer considered a waste product of metabolism and lactate sensing is a pivotal step in the transduction of lactate signals. Lysine lactylation is a recently identified post-translational modification that serves as an intracellular mechanism of lactate sensing and transfer. Although acetyltransferases such as p300 exhibit general acyl transfer activity, no bona fide lactyltransferases have been identified. Recently, the protein synthesis machinery, alanyl-tRNA synthetase 1 (AARS1), AARS2 and their Escherichia coli orthologue AlaRS, have been shown to be able to sense lactate and mediate lactyl transfer and are thus considered pan-lactyltransferases. Here we highlight the mechanisms and functions of these lactyltransferases and discuss potential strategies that could be exploited for the treatment of human diseases.

Lactylation in CNS disorders: mechanisms, cellular function, and disease relevance

Lactate, as a metabolic product or energy substrate, participates in various neurological processes within the physiological and pathological frameworks of the central nervous system (CNS). The groundbreaking application of multi-omics integration technologies has unveiled a novel role for lactate: lactylation, a unique post-translational modification (PTM) that covalently attaches lactate groups to lysine residues on proteins. This process precisely regulates protein function and gene expression, profoundly influencing the progression of various diseases. The lactylation process is meticulously regulated by a variety of key enzymes and metabolic pathways, forming a dynamic and intricate modification network. In this review, we summarize the key enzymes involved in lactylation, specifically "Writers," "Erasers," and "Readers." Furthermore, we systematically categorize lactylation observed in various cell types within the CNS and investigate its multifaceted roles in pathological processes, including neurodegenerative diseases, brain tumors, and brain injuries. By consolidating the latest research findings in this field, our review aims to highlight the significance of these discoveries for future research and explore their potential for translational applications.

Lactylation: A Novel Epigenetic Regulator of Cellular Senescence

Cellular senescence is the basic unit of organismal aging, a complicated biological process involving several cell types and tissues. It is also an important mechanism by which the body responds to damage and potential carcinogenesis. However, excessive or abnormal cellular senescence can lead to tissue functional degradation and the occurrence of diseases. In recent years, the role of epigenetic modifications in cellular senescence has received extensive attention. Lactylation, a novel post-translational modification derived from lactate, has recently gained significant attention as a key factor in cellular metabolism and epigenetic regulation, gradually demonstrating its importance in the regulation of cellular senescence. This review emphasizes the bidirectional causal relationship between lactylation and cellular senescence, highlighting its potential as a therapeutic target for aging-related diseases.

Protocol for investigating astrocytic mitochondria in neurons of adult mice using two-photon microscopy

Under pathological conditions, astrocytes can transfer mitochondria to neurons, where they exert neuroprotective effects. In this context, we present a protocol for capturing astrocytic mitochondria in neurons of adult mice using a two-photon microscope. We describe an approach for constructing a mouse model with combined labeling of astrocytic mitochondria and neurons. We then detail procedures for the preparation of a coverslip with a customized titanium ring and cranial window for two-photon microscopy scanning. For complete details on the use and execution of this protocol, please refer to Zhou et al. 1.

Mechanisms Associated with Mitophagy and Ferroptosis in Cerebral Ischemia-reperfusion Injury

Ischemic stroke (IS) constitutes a major threat to human health. Vascular recanalization by intravenous thrombolysis and mechanical thrombolysis remain the most significant and effective methods for relief of ischemia. Key elements of these treatments include achieving blood-vessel recanalization, restoring brain-tissue reperfusion, and preserving the ischemic penumbra. However, in achieving the therapeutic goals of vascular recanalization, secondary damage to brain tissue from cerebral ischemia-reperfusion injury (CIRI) must also be addressed. Despite advancements in understanding the pathological processes associated with CIRI, effective interventions to prevent its onset and progression are still lacking. Recent research has indicated that mitophagy and ferroptosis are critical mechanisms in the development of CIRI, and significantly contribute to the onset and progression of IS and CIRI because of common targets and co-occurrence mechanisms. Therefore, exploring and summarizing the potential connections between mitophagy and ferroptosis during CIRI is crucial. In the present review, we mainly focused on the mechanisms of mitochondrial autophagy and ferroptosis, and their interaction, in the development of CIRI. We believe that the data show a strong relationship between mitochondrial autophagy and ferroptosis with interactive regulation. This information may underpin new potential approaches for the prevention and treatment of IS and subsequent CIRI.

Lactylation: a promising therapeutic target in ischemia-reperfusion injury management

Ischemia-reperfusion injury (IRI) is a critical condition that poses a significant threat to patient safety. The production of lactate increases during the process of IRI, and lactate serves as a crucial indicator for assessing the severity of such injury. Lactylation, a newly discovered post-translational modification in 2019, is induced by lactic acid and predominantly occurs on lysine residues of histone or nonhistone proteins. Extensive studies have demonstrated the pivotal role of lactylation in the pathogenesis and progression of various diseases, including melanoma, myocardial infarction, hepatocellular carcinoma, Alzheimer's disease, and nonalcoholic fatty liver disease. Additionally, a marked correlation between lactylation and inflammation has been observed. This article provides a comprehensive review of the mechanism underlying lactylation in IRI to establish a theoretical foundation for better understanding the interplay between lactylation and IRI.

L- and D-Lactate: unveiling their hidden functions in disease and health

Lactate, once considered a mere byproduct of anaerobic metabolism, is now recognized as a critical signaling molecule with diverse roles in physiology and pathology. There are two stereoisomers of lactate: L- and D-lactate. Recent studies have shown that disruptions in these two lactate stereoisomers have distinct effects on health and disease. L-lactate is central to glycolysis and energy transfer through the Cori cycle but also acts as the dominant lactylation isomer induced by glycolysis, influencing metabolism and cell survival. Although less studied, D-lactate is linked to metabolic disorders and plays a role in mitochondrial dysfunction and oxidative stress. This review focuses on both L- and D-lactate and examines their biosynthesis, transport, and expanding roles in physiological and pathological processes, particularly their functions in cancer, immune regulation, inflammation, neurodegeneration and other diseases. Finally, we assess the therapeutic prospects of targeting lactate metabolism, highlighting emerging strategies for intervention in clinical settings. Our review synthesizes the current understanding of L- and D-lactate, offering insights into their potential as targets for therapeutic innovation.

Lactylation and Central Nervous System Diseases

As the final product of glycolysis, lactate serves as an energy substrate, metabolite, and signaling molecule in various diseases and mediates lactylation, an epigenetic modification that occurs under both physiological and pathological conditions. Lactylation is a crucial mechanism by which lactate exerts its functions, participating in vital biological activities such as glycolysis-related cellular functions, macrophage polarization, and nervous system regulation. Lactylation links metabolic regulation to central nervous system (CNS) diseases, such as traumatic brain injury, Alzheimer's disease, acute ischemic stroke, and schizophrenia, revealing the diverse functions of lactylation in the CNS. In the future, further exploration of lactylation-associated enzymes and proteins is needed to develop specific lactylation inhibitors or activators, which could provide new tools and strategies for the treatment of CNS diseases.

The role of astrocyte metabolic reprogramming in ischemic stroke (Review)

Ischemic stroke, a leading cause of disability and mortality worldwide, is characterized by the sudden loss of blood flow in specific area of the brain. Intravenous thrombolysis with recombinant tissue plasminogen activator is the only approved pharmacological treatment for acute ischemic stroke; however, the aforementioned treatment has significant clinical limitations, thus there is an urgent need for the development of novel mechanisms and therapeutic strategies for ischemic stroke. Astrocytes, abundant and versatile cells in the central nervous system, offer crucial support to neurons nutritionally, structurally and physically. They also contribute to blood‑brain barrier formation and regulate neuronal extracellular ion concentrations. Accumulated evidence has revealed the involvement of astrocytes in the regulation of host neurotransmitter metabolism, immune response and tissue repair, and different metabolic characteristics of astrocytes can contribute to the process and development of ischemic stroke, suggesting that targeted regulation of astrocyte metabolic reprogramming may contribute to the treatment and prognosis of ischemic stroke. In the present review, the current understanding of the multifaceted mechanisms of astrocyte metabolic reprogramming in ischemic stroke, along with its regulatory factors and pathways, as well as the strategies to promote its polarization balance, which hold promise for astrocyte immunometabolism‑targeted therapies in the treatment of ischemic stroke, were summarized.

Multi-omic profiling of sarcopenia identifies disrupted branched-chain amino acid catabolism as a causal mechanism and therapeutic target

Sarcopenia is a geriatric disorder characterized by a gradual loss of muscle mass and function. Despite its prevalence, the underlying mechanisms remain unclear, and there are currently no approved treatments. In this study, we conducted a comprehensive analysis of the molecular and metabolic signatures of skeletal muscle in patients with impaired muscle strength and sarcopenia using multi-omics approaches. Across discovery and replication cohorts, we found that disrupted branched-chain amino acid (BCAA) catabolism is a prominent pathway in sarcopenia, which leads to BCAA accumulation and decreased muscle health. Machine learning analysis further supported the causal role of BCAA catabolic dysfunction in sarcopenia. Using mouse models, we validated that defective BCAA catabolism impairs muscle mass and strength through dysregulated mTOR signaling, and enhancing BCAA catabolism by BT2 protects against sarcopenia in aged mice and in mice lacking Ppm1k, a positive regulator of BCAA catabolism in skeletal muscle. This study highlights improving BCAA catabolism as a potential treatment of sarcopenia.

Global Profiling of Protein Lactylation in Human Hippocampi

PURPOSE

The hippocampus has long been associated with cognition and memory function, the implications of lysine lactylation (Kla), a recently identified post-translational modification (PTM), in the role of the hippocampus remain largely unexplored.

EXPERIMENTAL DESIGN

An LC-MS/MS bottom-up proteomics analysis of three human hippocampal tissue samples was applied to profile the lactylation map in human hippocampi under normal physiological conditions.

RESULTS

We identified 2579 quantifiable Class I lactylated sites in 853 proteins, of which contained four types of modification motifs. Cellular localization analysis implies that a majority of lactylated proteins were distributed in the cytoplasm. Functional enrichment analysis showed that lactylated proteins were mainly involved in energy metabolic pathways. In addition, we found that the lactylation on histones exhibits a certain degree of conservation across different tissues. Compared with previously reported lactylation databases, 213 lactylated proteins were identified for the first time in this study.

CONCLUSION AND CLINICAL RELEVANCE

The first global lactylated proteins atlas of human hippocampi was reported in this study. Our work provides a reliable foundation for further research on lactylation in the hippocampus under physiological conditions.

The Lactate-Primed KAT8‒PCK2 Axis Exacerbates Hepatic Ferroptosis During Ischemia/Reperfusion Injury by Reprogramming OXSM-Dependent Mitochondrial Fatty Acid Synthesis

Recipients often suffer from hyperlactatemia during liver transplantation (LT), but whether hyperlactatemia exacerbates hepatic ischemia-reperfusion injury (IRI) after donor liver implantation remains unclear. Here, the role of hyperlactatemia in hepatic IRI is explored. In this work, hyperlactatemia is found to exacerbate ferroptosis during hepatic IRI. Lactate-primed lysine acetyltransferase 8 (KAT8) is determined to directly lactylate mitochondrial phosphoenolpyruvate carboxykinase 2 (PCK2) at Lys100 and augments PCK2 kinase activity. By using gene-edited mice, evidence indicating that PCK2 exacerbates hepatic ferroptosis during IRI is generated. Mechanistically, PCK2 lactylate at Lys100 acts as a critical inducer of ferroptosis during IRI by competitively inhibiting the Parkin-mediated polyubiquitination of 3-oxoacyl-ACP synthase (OXSM), thereby leading to metabolic remodeling of mitochondrial fatty acid synthesis (mtFAS) and the potentiation of oxidative phosphorylation and the tricarboxylic acid cycle. More importantly, targeting PCK2 is demonstrated to markedly ameliorate hyperlactatemia-mediated ferroptosis during hepatic IRI. Collectively, the findings support the use of therapeutics targeting PCK2 to suppress hepatic ferroptosis and IRI in patients with hyperlactatemia during LT.

Asparagine Endopeptidase Inhibition Attenuates Tissue Plasminogen Activator-Induced Brain Hemorrhagic Transformation After Ischemic Stroke

BACKGROUND

Thrombolytic treatment with tissue plasminogen activator (tPA) is one of the approved pharmacological therapies for acute ischemic stroke. However, the use of tPA is limited due to hemorrhagic transformation (HT) and the narrow therapeutic time window. Previous studies demonstrated that asparagine endopeptidase (AEP), a widely expressed pH-dependent endo-lysosomal cysteine protease, can induce neuronal death during ischemia-reperfusion injury. But whether AEP is engaged in HT during ischemia-reperfusion injury is unclear. In the current study, we expanded the role of AEP on HT after delayed tPA administration.

METHODS

In order to investigate the effects of AEP on HT after delayed tPA administration following ischemic stroke, the middle cerebral artery occlusion/reperfusion (MCAO/R) was performed in wild-type (WT) and AEP knockout (KO) transgenic mice, followed by delayed administration of tPA (10 mg/kg, 3 h after occlusion). Additionally, we explored the potential of R13, a specific TrkB agonist with a strong inhibitory impact on AEP, to mitigate injury induced by tPA. 24 h after tPA administration, the following parameters were assessed: infarct volume, behavioral tests, hemorrhagic levels, Evans blue leakage, tight and adherens junction protein expression, blood-brain barrier (BBB) function, cerebral vascular structure, matrix metalloproteinases (MMPs), and BBB-regulated protein low-density lipoprotein receptor-related protein 1 (LRP-1) expression. To construct an in vitro model to examine the effects of AEP on ischemia-reperfusion injury after tPA treatment, human umbilical vein endothelial cells (HUVECs) were exposed to 4 h of oxygen-glucose deprivation (OGD), followed by treatment with tPA (500 ng/mL). 7,8-dihydroxyflavone (7,8-DHF), a natural TrkB agonist with an inhibitory effect on AEP, was applied before OGD.

RESULTS

Compared with tPA-treated WT mice, AEP KO mice treated with tPA showed improved infarct volume, neurological function, brain edema, brain hemoglobin levels, Evans blue leakage, vascular tight junctions, and basement membrane structure combined with reduced AEP expression and activity within the peri-infarct area. In addition, the mice treated with R13 exhibited protective effects on the BBB. Furthermore, we found that the expression of MMP2, MMP9, and LRP-1 in the brain was inhibited by both AEP knockout and R13 treatment. Moreover, HUVECs treated with 7,8-DHF showed improvements in tight and adherens junction proteins and suppressed levels of MMP2, MMP9, and LRP-1.

CONCLUSION

Our findings demonstrate that AEP exacerbates HT induced by delayed tPA treatment in acute ischemic stroke by activating LRP-1, MMP2, and MMP9, which disrupts BBB integrity. We further confirmed R13 as a preventive therapy to attenuate HT induced by delayed tPA treatment in acute ischemic stroke. The present study suggests AEP inhibition may serve as a promising strategy to enhance the safety of delayed tPA thrombolysis for ischemic stroke.

Lactylation of PLBD1 Facilitates Brain Injury Induced by Ischemic Stroke

BACKGROUND

Ischemic stroke is a prevalent global condition and its associated brain damage poses a significant threat to patient survival and outcomes. The underlying mechanisms of ischemic stroke-induced brain injury remain elusive, necessitating further investigation.

METHODS

Ischemic stroke models were established using middle cerebral artery occlusion (MCAO) in animals and oxygen-glucose deprivation and reperfusion (OGD-R) in cells. Phospholipase B domain-containing protein 1 (PLBD1) expression in these models was assessed via western blotting analysis, reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR), and cell immunofluorescence. A comprehensive evaluation, incorporating cellular lactate dehydrogenase (LDH) release assays, glycolysis metabolism kits, RT-qPCR, western blotting, triphenyl tetrazolium chloride (TTC) staining, neurological scoring, brain tissue water content measurement, and creatine kinase-MB (CK-MB) analysis, was conducted to determine the impact of PLBD1 on brain injury. Potential lactylation sites in PLBD1 were predicted using the DeepKla database, with western blotting and co-immunoprecipitation (Co-IP) confirming the lactylation site.

RESULTS

PLBD1 was significantly upregulated in the brain tissue of MCAO animal models and OGD-R-treated cells. PLBD1 knockdown markedly mitigated OGD-R-induced cellular injury, suppressed glycolysis in vitro, and reversed MCAO-induced brain damage in vivo. Furthermore, lactylation at the K155 site of PLBD1 enhanced its expression in response to elevated lactate levels following OGD-R treatment. These results indicated that the upregulation of PLBD1 via K155 site lactylation plays a pivotal role in exacerbating ischemic stroke-induced brain damage.

CONCLUSION

Targeting the lactate/PLBD1 axis presents a promising therapeutic strategy for ischemic stroke management.

GLA deficiency causes cardiac hypertrophy via enhanced autophagy

Fabry disease is a monogenic disease characterized by a deficiency or loss of α-galactosidase A (GLA). Cardiomyopathy is the leading cause of death in Fabry patients; however, a lack of understanding of the pathological mechanism impedes the development of effective therapies. Here, we used a Gla knockout (KO) mouse model and investigated its impact on cardiomyopathy. We found that globotriaosylceramide (Gb3) increased the uptake and accumulation of fatty acids in KO hearts by increasing the expression levels of CD36 and ACC2. The augmented fatty acid metabolism further increased autophagy activity, leading to age-related late-onset cardiac hypertrophy. Additionally, increased autophagy facilitates disturbances in fatty acid metabolism. The inhibition of autophagy by supplementation with 3-methyladenine (3-MA) or the overexpression of GLA by the cardiomyocyte-specific adeno-associated virus for 2 months could rebalance abnormal fatty acid metabolism and ameliorate cardiac hypertrophy and dysfunction in KO hearts, suggesting a central role of autophagy in GLA deficiency-related cardiomyopathy.

The role of lactylation in tumor growth and cancer progression

Background

Lactate's perception of lactate has changed over the last 30 years from a straightforward metabolic byproduct to a complex chemical with important biological activities, such as signal transduction, gluconeogenesis, and mitochondrial respiration. In addition to its metabolic contributions, lactate has far-reaching repercussions. This review highlights the role of lactate in the course of cancer by highlighting lactylation as a unique epigenetic alteration. The purpose of this review is to clarify the functions of lactate in the biology of tumors, with a particular focus on the translational potential of lactylation pathways in cancer diagnosis and treatment approaches.

Methods

This review summarizes research on the relationship between lactate and cancer, with an emphasis on histone lactylation, its effect on gene expression, and its influence on the tumor microenvironment. By establishing a connection between metabolic byproducts and epigenetic gene regulation, we investigated how lactylation affects immune regulation, inflammation, and cellular repair.

Findings

Histone lactylation, or the addition of lactate to lysine residues on histone proteins, increases transcriptional activity and facilitates the expression of genes involved in homeostasis and repair. These findings have important implications for cancer treatment. Lactylation, for example, activates genes such as Arg1, which is a hallmark of the M2 macrophage phenotype implicated in immunosuppression and tumor growth. The ability of lactate to dynamically alter gene expression is further supported by its function as a histone deacetylase(HDAC)inhibitor and its impact on histone acetylation. Its wide-ranging involvement in cellular metabolism and epigenetic control has been demonstrated by the discovery of particular lactylation sites on histones in various cell types, including cancer cells.

Lactylation modification in cardio-cerebral diseases: A state-of-the-art review

Cardio-cerebral diseases (CCDs), encompassing conditions such as coronary heart disease, myocardial infarction, stroke, Alzheimer's disease, et al., represent a significant threat to human health and well-being. These diseases are often characterized by metabolic abnormalities and remodeling in the process of pathology. Glycolysis and hypoxia-induced lactate accumulation play critical roles in cellular energy dynamics and metabolic imbalances in CCDs. Lactylation, a post-translational modification driven by excessive lactate accumulation, occurs in both histone and non-histone proteins. It has been implicated in regulating protein function across various pathological processes in CCDs, including inflammation, angiogenesis, lipid metabolism dysregulation, and fibrosis. Targeting key proteins involved in lactylation, as well as the enzymes regulating this modification, holds promise as a therapeutic strategy to modulate disease progression by addressing these pathological mechanisms. This review provides a holistic picture of the types of lactylation and the associated modifying enzymes, highlights the roles of lactylation in different pathological processes, and synthesizes the latest clinical evidence and preclinical studies in a comprehensive view. We aim to emphasize the potential of lactylation as an innovative therapeutic target for preventing and treating CCD-related conditions.

Lactylation: The metabolic accomplice shaping cancer's response to radiotherapy and immunotherapy

Protein lactylation, an emerging post-translational modification, is providing new insights into tumor biology and challenging our current understanding of cancer mechanisms. Our review illuminates the intricate roles of lactylation in carcinogenesis, tumor progression, and therapeutic responses, positioning it as a critical linchpin connecting metabolic reprogramming, epigenetic modulation, and treatment outcomes. We provide an in-depth analysis of lactylation's molecular mechanisms and its far-reaching impact on cell cycle regulation, immune evasion strategies, and therapeutic resistance within the complex tumor microenvironment. Notably, this review dissects the paradoxical nature of lactylation in cancer immunotherapy and radiotherapy. While heightened lactylation can foster immune suppression and radioresistance, strategically targeting lactylation cascades opens innovative avenues for amplifying the efficacy of current treatment paradigms. We critically evaluate lactylation's potential as a robust diagnostic and prognostic biomarker and explore frontier therapeutic approaches targeting lactylation. The synergistic integration of multi-omics data and artificial intelligence in lactylation research is catalyzing significant strides towards personalized cancer management. This review not only consolidates current knowledge but also charts a course for future investigations. Key research imperatives include deciphering tumor-specific lactylation signatures, optimizing synergistic strategies combining lactylation modulation with immune checkpoint inhibitors and radiotherapy, and comprehensively assessing the long-term physiological implications of lactylation intervention. As our understanding of lactylation's pivotal role in tumor biology continues to evolve, this burgeoning field promises to usher in transformative advancements in cancer diagnosis, treatment modalitie.

Proteomic analysis of whole blood to investigate the therapeutic effects of nervonic acid on cerebral ischemia-reperfusion injury in rats

Introduction

Blood proteomics offers a powerful approach for identifying disease-specific biomarkers. However, no reliable blood markers are currently available for the diagnosis stroke. Nervonic acid (NA), a vital long-chain monounsaturated fatty acid found in mammalian nervous tissue, shows promising therapeutic potential in neurological disorders. This study aimed to develop a reliable methodology for whole blood proteomics to identify early warning biomarkers and evaluate drug treatment efficacy.

Methods

After modeling via the classic thread embolization method, whole blood samples were collected from the rats. Morphological assessments of brain tissue indicated that NA significantly mitigated brain and neuronal damage in rats. The differential protein expression profile was analyzed using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) whole blood proteomics.

Results

ZZZGene Ontology (GO) analysis revealed that, compared to ginkgo biloba extract (EGb), the proteins differentially expressed under NA intervention were predominantly involved in oxidative stress response and calcium-dependent adhesion processes. Key targets of NA in the treatment of middle cerebral artery occlusion (MCAO) models included ENO1, STAT3, NME2, VCL, and CCT3.

Discussion

This whole blood proteomic approach provides a comprehensive understanding of protein profiles associated with disease states, offering valuable insights into potential therapeutic targets and enabling the evaluation of NA and EGb intervention efficacy. Our findings underscore the protective effects of NA against cerebral ischemia-reperfusion injury and highlight its potential as a treatment for stroke.

The impact of glycolysis on ischemic stroke: from molecular mechanisms to clinical applications

Ischemic stroke (IS), a leading cause of disability and mortality worldwide, remains a significant challenge due to its complex pathogenesis. Glycolysis, a central metabolic pathway, plays a critical role in bridging the gap between metabolic dysfunction and neurological impairment. During ischemic conditions, glycolysis replaces oxidative phosphorylation as the primary energy source for brain tissue. However, in the ischemia-reperfusion state, neuronal cells show a particular reliance on aerobic glycolysis. Immune cells, such as monocytes, also contribute to atheromatous plaque formation and thrombi through increased aerobic glycolysis. Given glycolysis's involvement in various pathological stages of IS, it offers the potential for improved diagnosis, treatment, and prevention. This review comprehensively explores the role of glycolysis in different phases of IS, addresses existing controversies, and discusses its diagnostic and therapeutic applications. By elucidating the intricate relationship between glycolysis and IS, this review aims to provide novel insights for future research and clinical advancements.

Non-histone lactylation: unveiling its functional significance

Lactylation, a newly discovered protein posttranslational modification (PTM) in 2019, primarily occurs on lysine residues. Lactylation of histones was initially identified, and subsequent studies have increasingly demonstrated its widespread presence on non-histone proteins. Recently, high-throughput proteomics studies have identified a large number of lactylated proteins and sites, revealing their global regulatory role in disease development. Notably, this modification is catalyzed by lactyltransferase and reversed by delactylase, with numerous new enzymes, such as AARS1/2, reported to be involved. Specifically, these studies have revealed how lactylation exerts its influence through alterations in protein spatial conformation, molecular interactions, enzyme activity and subcellular localization. Indeed, lactylation is implicated in various physiological and pathological processes, including tumor development, cardiovascular and cerebrovascular diseases, immune cell activation and psychiatric disorders. This review provides the latest advancements in research on the regulatory roles of non-histone protein lactylation, highlighting its crucial scientific importance for future studies.

Exploring the prognostic significance of lactate-mitochondria-related genes in prostate cancer

Prostate cancer (PCa) is a common and serious health issue among older men globally. Metabolic reprogramming, particularly involving lactate and mitochondria, plays a key role in PCa progression, but studies linking these factors to prognosis are limited. To identify novel prognostic markers of PCa based on lactate-mitochondria-related genes (LMRGs), RNA sequencing data and clinical information of PCa from The Cancer Genome Atlas (TCGA) and the cBioPortal database were used to construct a lactate-mitochondria-related risk signature. Here, we established a novel nine-LMRG risk signature for PCa, and Kaplan-Meier curves confirmed a worse prognosis for high-risk subgroups in the TCGA dataset. Meanwhile, a nomogram that effectively predicts the prognosis of PCa patients was also constructed. Next, close associations between the lactate-mitochondria-related signature and the immune microenvironment were examined to clarify the role of LMRGs in shaping the immune landscape. Furthermore, as the only lactate-related gene among the nine key prognostic risk genes, myeloperoxidase (MPO) was identified as a key factor that mediates lactate production in vitro and in vivo through attenuation of the glycolytic pathway. More importantly, MPO significantly inhibited PCa cell migration, invasion, and epithelial-mesenchymal transition (EMT), indicating its potential as an anticancer gene. Additionally, PCa with high MPO expression is highly sensitive to chemotherapeutic agents and mitochondrial inhibitors, highlighting its potential as an improved therapeutic strategy for PCa management.

APP lysine 612 lactylation ameliorates amyloid pathology and memory decline in Alzheimer's disease

Posttranslational modification (PTM) of the amyloid precursor protein (APP) plays a critical role in Alzheimer's disease (AD). Recent evidence reveals that lactylation modification, as a novel PTM, is implicated in the occurrence and development of AD. However, whether and how APP lactylation contributes to both the pathogenesis and cognitive function in AD remains unknown. Here, we observed a reduction in APP lactylation in AD patients and AD model mice and cells. Proteomic mass spectrometry analysis further identified lysine 612 (APP-K612la) as a crucial site for APP lactylation, influencing APP amyloidogenic processing. A lactyl-mimicking mutant (APPK612T) reduced amyloid-β peptide (Aβ) generation and slowed down cognitive deficits in vivo. Mechanistically, APPK612T appeared to facilitate APP trafficking and metabolism. However, lactylated APP entering the endosome inhibited its binding to BACE1, suppressing subsequent cleavage. Instead, it promoted protein interaction between APP and CD2-associated protein (CD2AP), thereby accelerating the endosomal-lysosomal degradation pathway of APP. In the APP23/PS45 double-transgenic mouse model of AD, APP-Kla was susceptible to L-lactate regulation, which reduced Aβ pathology and repaired spatial learning and memory deficits. Thus, these findings suggest that targeting APP lactylation may be a promising therapeutic strategy for AD in humans.

Recommendations for mitochondria transfer and transplantation nomenclature and characterization

Intercellular mitochondria transfer is an evolutionarily conserved process in which one cell delivers some of their mitochondria to another cell in the absence of cell division. This process has diverse functions depending on the cell types involved and physiological or disease context. Although mitochondria transfer was first shown to provide metabolic support to acceptor cells, recent studies have revealed diverse functions of mitochondria transfer, including, but not limited to, the maintenance of mitochondria quality of the donor cell and the regulation of tissue homeostasis and remodelling. Many mitochondria-transfer mechanisms have been described using a variety of names, generating confusion about mitochondria transfer biology. Furthermore, several therapeutic approaches involving mitochondria-transfer biology have emerged, including mitochondria transplantation and cellular engineering using isolated mitochondria. In this Consensus Statement, we define relevant terminology and propose a nomenclature framework to describe mitochondria transfer and transplantation as a foundation for further development by the community as this dynamic field of research continues to evolve.

Electroacupuncture Pretreatment Reduces Ischemic Brain Injury by Inhibiting the Lactate Production and Its Derived Protein Lactylation Formation

AIM

Given that electroacupuncture (EA) pretreatment inhibits lactate production and lactate-derived lysine lactation (Kla) aggravates ischemic brain injury, we aimed to investigate whether the formation of Kla protein is involved in EA pretreatment to alleviate ischemic brain injury.

METHODS

EA was performed on the Baihui acupoint (GV20) of male C57BL/6J mice before receiving the permanent middle cerebral artery occlusion (pMCAO) surgery. Western blot and immunofluorescent staining were used to observe neuronal survival, astrocyte activation, and protein Kla levels, and the lactate levels in ischemic brains were assayed with a commercial kit. TTC staining and neurological function scores are performed to evaluate the brain damage in mice.

RESULTS

We found that the increased lactate content and protein Kla levels were significantly decreased in ischemic brain tissue of mice after receiving EA pretreatment, and accompanied by the reduction of astrocyte activation and neuronal injury and death. Meantime, we found that EA pretreatment was effective in reversing the worsening of ischemic brain injury caused by lactate supplementation. However, EA pretreatment did not further reduce the lactate content and protein Kla levels and ameliorate brain injury in ischemic stroke mice after inhibition of glycolysis.

CONCLUSION

Our study reveals that EA pretreatment reduced ischemic brain damage by inhibiting lactate production and its derived protein Kla formation in mice with ischemic stroke.

Amyloid-β oligomers increase the binding and internalization of tau oligomers in human synapses

In Alzheimer's disease (AD), the propagation and spreading of CNS tau pathology closely correlates with cognitive decline, positioning tau as an attractive therapeutic target. Amyloid beta (Aβ) has been strongly implicated in driving tau spread, whereas primary tauopathies such as primary age-related tauopathy (PART)-which lack Aβ pathology-exhibit limited tau spread and minimal-to-no cognitive decline. Emerging evidence converges on a trans-synaptic mechanism of tau spread, facilitated by the transfer of misfolded tau aggregates (e.g. soluble oligomers). However, it is unclear whether Aβ oligomers modulate the binding and internalization of tau oligomers in human synapses. Our translationally focused paradigms utilize post-mortem brain specimens from Control, PART, and AD patients. Synaptosomes isolated from the temporal cortex of all three groups were incubated with preformed recombinant tauO (rtauO), ± preformed recombinant AβO (rAβO), and oligomer binding/internalization was quantified via flow cytometry following proteinase K (PK) digestion of surface-bound oligomers. TauO-synapse interactions were visualized using EM immunogold. Brain-derived tau oligomers (BDTO) from AD and PART PBS-soluble hippocampal fractions were co-immunoprecipitated and analyzed via mass spectrometry to compare synaptic tauO interactomes in primary and secondary tauopathies, thereby inferring the role of Aβ. AD synaptosomes, enriched in endogenous Aβ pathology, exhibited increased rtauO internalization compared to PART synaptosomes. This observation was mirrored in Control synaptosomes, where recombinant rAβO significantly increased rtauO binding and internalization. PK pre-treatment abolished this effect, implicating synaptic membrane proteins in AβO-mediated tauO internalization. While both PART and AD BDTO were broadly enriched in synaptic proteins, AD BDTO exhibited differential enrichment of endocytic proteins across pre- and post-synaptic compartments, whereas PART BDTO showed no significant synaptic enrichment. This study demonstrates that Aβ oligomers enhance tau oligomer binding and drive its internalization through synaptic membrane proteins. These findings offer novel mechanistic insights underlying pathological tau spreading directly within human synapses and emphasize the therapeutic potential of targeting Aβ-tau interactions.

Progress of Astrocyte-Neuron Crosstalk in Central Nervous System Diseases

Neurons are the primary cells responsible for information processing in the central nervous system (CNS). However, they are vulnerable to damage and insult in a variety of neurological disorders. As the most abundant glial cells in the brain, astrocytes provide crucial support to neurons and participate in synapse formation, synaptic transmission, neurotransmitter recycling, regulation of metabolic processes, and the maintenance of the blood-brain barrier integrity. Though astrocytes play a significant role in the manifestation of injury and disease, they do not work in isolation. Cellular interactions between astrocytes and neurons are essential for maintaining the homeostasis of the CNS under both physiological and pathological conditions. In this review, we explore the diverse interactions between astrocytes and neurons under physiological conditions, including the exchange of neurotrophic factors, gliotransmitters, and energy substrates, and different CNS diseases such as Alzheimer's disease, Parkinson's disease, stroke, traumatic brain injury, and multiple sclerosis. This review sheds light on the contribution of astrocyte-neuron crosstalk to the progression of neurological diseases to provide potential therapeutic targets for the treatment of neurological diseases.

Progress in Lactate Metabolism and Its Regulation via Small Molecule Drugs

Lactate, once viewed as a byproduct of glycolysis and a metabolic "waste", is now recognized as an energy-providing substrate and a signaling molecule that modulates cellular functions under pathological conditions. The discovery of histone lactylation in 2019 marked a paradigm shift, with subsequent studies revealing that lactate can undergo lactylation with both histone and non-histone proteins, implicating it in the pathogenesis of various diseases, including cancer, liver fibrosis, sepsis, ischemic stroke, and acute kidney injury. Aberrant lactate metabolism is associated with disease onset, and its levels can predict disease outcomes. Targeting lactate production, transport, and lactylation may offer therapeutic potential for multiple diseases, yet a systematic summary of the small molecules modulating lactate and its metabolism in various diseases is lacking. This review outlines the sources and clearance of lactate, as well as its roles in cancer, liver fibrosis, sepsis, ischemic stroke, myocardial infarction, and acute kidney injury, and summarizes the effects of small molecules on lactate regulation. It aims to provide a reference and direction for future research.

Lactylation in cancer: Current understanding and challenges

Lactylation, a recently identified post-translational modification, has initially been linked to gene transcription regulation through epigenetic mechanisms. However, its role in tumorigenesis-whether as a major driver or a minor regulator-remains uncertain. Here, we summarize the current understanding of lactylation and discuss the inherent challenges in definitively attributing specific biological roles to this modification. We emphasize the necessity for precise methodologies to manipulate lactylation levels within pathophysiologically relevant conditions. Further investigation is required to determine whether lactylation plays a critical role in tumor biology or merely reflects secondary metabolic alterations.

Lactylation: A Novel Post-Translational Modification with Clinical Implications in CNS Diseases

Lactate, an important metabolic product, provides energy to neural cells during energy depletion or high demand and acts as a signaling molecule in the central nervous system. Recent studies revealed that lactate-mediated protein lactylation regulates gene transcription and influences cell fate, metabolic processes, inflammation, and immune responses. This review comprehensively examines the regulatory roles and mechanisms of lactylation in neurodevelopment, neuropsychiatric disorders, brain tumors, and cerebrovascular diseases. This analysis indicates that lactylation has multifaceted effects on central nervous system function and pathology, particularly in hypoxia-induced brain damage. Highlighting its potential as a novel therapeutic target, lactylation may play a significant role in treating neurological diseases. By summarizing current findings, this review aims to provide insights and guide future research and clinical strategies for central nervous system disorders.

Lactylation of histone by BRD4 regulates astrocyte polarization after experimental subarachnoid hemorrhage

Under subarachnoid hemorrhage (SAH) conditions, astrocytes undergo a marked intensification of glycolytic activity, resulting in the generation of substantial amounts of lactate to maintain the energy demand for neurons and other brain cells. Lactate has garnered increasing attention in recent years because of its emerging role in critical biological processes such as inflammation regulation and neuroprotection, particularly through its histone lactylation. Bromodomain-containing protein 4 (BRD4) plays a crucial role in maintaining neural development and promoting memory formation in the central nervous system. Nonetheless, the function and regulatory mechanism of BRD4 and histone lactylation in astrocytes following SAH remain elusive. Our findings indicate that BRD4, a crucial epigenetic regulator, plays a definitive role in histone lactylation. Both in vitro and in vivo, these results demonstrated that targeted silencing of BRD4 in astrocytes can significantly reduce H4K8la lactylation, thereby aggravating the A1 polarization of astrocytes and ultimately affecting the recovery of neural function and prognosis in mice after SAH. In summary, BRD4 plays a pivotal role in modulating astrocyte polarization following SAH via histone lactylation. Targeting this mechanism might offer an efficient therapeutic strategy for SAH.