Identification of SIRT3 as an eraser of H4K16la

Lactate metabolism and lactylation in kidney diseases: insights into mechanisms and therapeutic opportunities

The kidney is essential for lactate metabolism. Under normal conditions, the renal cortex mainly absorbs and metabolizes lactate, with minimal amounts excreted in urine. This process is part of a glucose-lactate recycling system between the cortex and medulla. In conditions such as acute kidney injury (AKI) and diabetic kidney disease (DKD), the kidney's ability to metabolize lactate is impaired, leading to lactate accumulation and exacerbated renal dysfunction. Novel post-translational modifications, such as lactylation, are critical in kidney disease pathophysiology by modulating gene transcription, protein function, and cellular metabolism. Lactylation is involved in inflammatory responses and tumor promotion in AKI, mitochondrial dysfunction in DKD, and tumor progression in clear cell renal cell carcinoma (ccRCC). The lactate-lactylation axis is central to the Warburg effect in ccRCC, where tumor cells preferentially rely on glycolysis rather than oxidative phosphorylation. Understanding the mechanisms of lactate metabolism and lactylation in kidney diseases may offer new therapeutic strategies. This review examines the role of lactate esters, especially lactylation, in kidney diseases, with a focus on their regulatory mechanisms and potential as therapeutic targets.

Magnesium-based implants accelerate femoral fracture healing through promoting histone lactylation-mediated osteoclastogenesis inhibition

AIMS

To investigate the molecular mechanisms by which magnesium (Mg)-based implants, specifically Mg-containing intramedullary nails (Mg-IMNs), promote femoral fracture healing.

MATERIALS AND METHODS

Rats with femoral fractures were treated with Mg-IMNs. In vitro experiments were conducted to assess the impact of Mg2+ on osteoclastogenesis and histone lactylation. Histological analysis, Western blotting, and qRT-PCR were employed to evaluate osteoclast maturation and the molecular pathways involved. In vivo, lactate was administered to replicate Mg-IMN effects, and lactate production was inhibited to observe potential reversal effects.

KEY FINDINGS

Mg-IMNs significantly enhanced fracture healing by inhibiting osteoclastogenesis. Mg2+ promoted intracellular lactate production, leading to histone lactylation, which suppressed osteoclast maturation by downregulating NFATc1. The P300/H3K18LA/HDAC1 pathway was identified as a key mediator in this process. Additionally, lactate administration mimicked the effects of Mg-IMNs, while blocking lactate reversed these effects.

SIGNIFICANCE

This study uncovers a novel mechanism by which Mg2+ promotes fracture healing through histone lactylation-mediated inhibition of osteoclastogenesis. These findings offer new therapeutic strategies for enhancing fracture repair via epigenetic regulation.

Long-term histone lactylation connects metabolic and epigenetic rewiring in innate immune memory

Trained immunity, a de facto innate immune memory characterized by enhanced responsiveness to future challenges, is underpinned by epigenetic and metabolic rewiring. In individuals vaccinated with Bacille Calmette-Guérin (BCG), lactate release was associated with enhanced cytokine responsiveness upon restimulation. Trained monocytes/macrophages are characterized by lactylation of histone H3 at lysine residue 18(H3K18la), mainly at distal regulatory regions. Histone lactylation was positively associated with active chromatin and gene transcription, persisted after the elimination of the training stimulus, and was strongly associated with "trained" gene transcription in response to a secondary stimulus. Increased lactate production upon induction of trained immunity led to enhanced production of proinflammatory cytokines, a process associated with histone lactylation. Pharmacological inhibition of lactate production or histone lactylation blocked trained immunity responses, while polymorphisms of LDHA and EP300 genes modulated trained immunity. Long-term histone lactylation persisted in vivo 90 days after vaccination with BCG, highlighting H3K18la as an epigenetic mark of innate immune memory.

The regulatory role of protein lactylation in various diseases: Special focus on the regulatory role of non-histone lactylation

Lactylation, an emerging form of post-translational modification derived from lactate, plays a pivotal role in numerous cellular processes such as tumor proliferation, metabolism, inflammation, and embryonic development. However, the precise molecular mechanisms by which lactylation controls these biological functions in both physiological and pathological contexts remain elusive. This review summarizes the latest reported regulatory mechanisms of protein lactylation in various diseases since 2024, introducing the latest research progress regarding the regulatory functions of protein lactylation in pathological processes, with particular attention to the regulatory mechanisms of non-histone lactylation modification in diseases. Finally, it outlines the potential of targeted lactylation therapy, proposes the main directions for future research, and emphasizes its scientific significance for future studies.

SIRT3 Functions as an Eraser of Histone H3K9 Lactylation to Modulate Transcription for Inhibiting the Progression of Esophageal Cancer

Lysine lactylation (Kla) links lactate metabolism to epigenetic regulation, playing a key role in modulation of gene expression in tumor and immune microenvironment. Our recent study shows that HBO1-mediated histone H3K9la activates the transcription of genes encoding tumorigenesis, suggesting the potential significance of intervening in this Kla site for tumor therapy. Evidence so far indicates that traditional deacetylases can catalyze the removal of Kla; however, the precise demodifying enzyme to histone H3K9la in vivo and functional consequence remain elusive. Herein, we combined an antibody-based proximity labeling approach with mass spectrometry analysis to identify SIRT3 as a major binder to histone H3K9la and showed the specific catalysis of SIRT3 for the removal of lactylation. Molecular docking further revealed the molecular mechanism of the binding of histone H3K9la to SIRT3. More importantly, SIRT3 can specifically modulate gene transcription by regulating H3K9la, inhibiting the progression of esophageal squamous cancer cells. Together, our work identifies the specific delactylase of H3K9la and reveals an H3K9la-mediated molecular mechanism catalyzed by SIRT3 for gene transcription regulation in esophageal squamous cancer cells, and our findings provide an opportunity to investigate the physiological significance of Kla controlled by SIRT3 in cancer.

The role of protein lactylation: A kaleidoscopic post-translational modification in cancer

The recently discovered lysine lactylation represents a critical post-translational modification with widespread implications in epigenetics and cancer biology. Initially identified on histones, lysine lactylation has been also described on non-histone proteins, playing a pivotal role in transcriptional activation, protein function, and cellular processes. Two major sources of the lactyl moiety have been currently distinguished: L-lactyl-CoA (precursor of the L-lactyl moiety) and S-D-lactylglutathione (precursor of the D-lactyl moiety), which enable enzymatic and non-enzymatic mechanisms of lysine lactylation, respectively. Although the specific writers, erasers, and readers of this modification are still unclear, acetyltransferases and deacetylases have been proposed as crucial mediators of lysine lactylation. Remarkably, lactylation exerts significant influence on critical cancer-related pathways, thereby shaping cellular behavior during malignant transformation and the metastatic cascade. Hence, as recent insights into lysine lactylation underscore its growing potential in tumor biology, targeting this modification is emerging as a significant opportunity for cancer treatment.

Potential of lactylation as a therapeutic target in cancer treatment (Review)

Post‑translational modifications (PTMs) of proteins influence their functionality by altering the structure of precursor proteins. These modifications are closely linked to tumor progression through the regulation of processes such as cell proliferation, apoptosis, angiogenesis and invasion. Tumors produce large amounts of lactic acid through aerobic glycolysis. Lactic acid not only serves an important role in cell metabolism, but also serves an important role in cell communication. Lactylation, a PTM involving lactate and lysine residues as substrates, serves as an epigenetic regulator that modulates intracellular signaling, gene expression and protein function, thereby serving a crucial role in tumorigenesis and progression. The identification of lactylation provides a key breakthrough in elucidating the interaction between tumor metabolic reprogramming and epigenetic modification. The present review primarily summarizes the occurrence of lactylation, its effect on tumor progression, drug resistance, the tumor microenvironment and gut microbiota, and its potential as a therapeutic target for cancer. The aim of the present review was to provide novel strategies for potential cancer therapies.

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.

The role of lactylation in virology

Lactylation, a novel post-translational protein modification, is increasingly recognized for its widespread occurrence on lysine residues in both histone and non-histone proteins. Recent research has primarily focused on its implications in specific human diseases, particularly cancer progression, metabolic disorders, neurodegenerative diseases, and immune responses. However, it is crucial to acknowledge the significant roles played by viruses as pathogens in both clinical and veterinary medicine, as well as in zoological and phytopathological studies. This review highlights the latest advancements in understanding the mechanisms underlying lactylation and its regulation, emphasizing the role of lactylation in certain viruses. We discuss its involvement in essential biological functions, the pathogenic mechanisms of various viruses, host-virus interactions, and practical applications, including the potential for lactylation to serve as a therapeutic target in disease pathogenesis. Exploring the interactions between viruses and lactylation presents a promising research direction that may help refine the emerging concept of lactylation.

The emerging role of protein L-lactylation in metabolic regulation and cell signalling

L-Lactate has emerged as a crucial metabolic intermediate, moving beyond its traditional view as a mere waste product. The recent discovery of L-lactate-driven protein lactylation as a post-translational modification has unveiled a pathway that highlights the role of lactate in cellular signalling. In this Perspective, we explore the enzymatic and metabolic mechanisms underlying protein lactylation and its impacts on both histone and non-histone proteins in the contexts of physiology and diseases. We discuss growing evidence suggesting that this modification regulates a wide range of cellular functions and is involved in various physiological and pathological processes, such as cell-fate determination, development, cardiovascular diseases, cancer and autoimmune disorders. We propose that protein lactylation acts as a pivotal mechanism, integrating metabolic and signalling pathways to enable cellular adaptation, and highlight its potential as a therapeutic target in various diseases.

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.

Potential role of lactylation in intrinsic immune pathways in lung cancer

Lung cancer, one of the most lethal malignancies, has seen its therapeutic strategies become a focal point of significant scientific attention. Intrinsic immune signaling pathways play crucial roles in anti-tumor immunity but face clinical application challenges despite promising preclinical outcomes. Lactylation, an emerging research focus, may influences lung cancer progression by modulating the functions of histones and non-histone proteins. Recent findings have suggested that lactylation regulates key intrinsic immune molecules, including cGAS-STING, TLR, and RIG-I, thereby impacting interferon expression. However, the precise mechanisms by which lactylation governs intrinsic immune signaling in lung cancer remain unclear. This review presents a comprehensive and systematic analysis of the relationship between lactylation and intrinsic immune signaling pathways in lung cancer and emphasizes the innovative perspective of linking lactylation-mediated epigenetic modifications with immune regulation. By thoroughly examining current research findings, this review uncovers potential regulatory mechanisms and highlights the therapeutic implications of targeting lactylation in lung cancer. Future investigations into the intricate interactions between lactylation and intrinsic immunity are anticipated to unveil novel therapeutic targets and strategies, potentially improving patient survival outcomes.

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.

Protein lactylation in cancer: mechanisms and potential therapeutic implications

Increased glycolysis, which leads to high lactate production, is a common feature of cancer cells. Recent evidence suggests that lactate plays a role in the post-translational modification of histone and nonhistone proteins via lactylation. In contrast to genetic mutations, lactylation in cancer cells is reversible. Thus, reversing lactylation can be exploited as a pharmacological intervention for various cancers. Here we discuss recent advances in histone and nonhistone lactylation in cancer, including L-, D- and S-lactylation, as well as alanyl-tRNA synthetase as a novel lactyltransferase. We also discuss potential approaches for targeting lactylation as a therapeutic opportunity in cancer treatment.

The curious case of mitochondrial sirtuin in rewiring breast cancer metabolism: Mr Hyde or Dr Jekyll?

Mammalian sirtuins are class III histone deacetylases involved in the regulation of multiple biological processes including senescence, DNA repair, apoptosis, proliferation, caloric restriction, and metabolism. Among the mammalian sirtuins, SIRT3, SIRT4, and SIRT5 are localized in the mitochondria and collectively termed the mitochondrial sirtuins. Mitochondrial sirtuins are NAD+-dependent deacetylases that play a central role in cellular metabolism and function as epigenetic regulators by performing post-translational modification of cellular proteins. Several studies have identified the role of mitochondrial sirtuins in age-related pathologies and the rewiring of cancer metabolism. Mitochondrial sirtuins regulate cellular functions by contributing to post-translational modifications, including deacetylation, ADP-ribosylation, demalonylation, and desuccinylation of diverse cellular proteins to maintain cellular homeostasis. Here, we review and discuss the structure and function of the mitochondrial sirtuins and their role as metabolic regulators in breast cancer. Altered breast cancer metabolism may promote tumor progression and has been an essential target for therapy. Further, we discuss the potential role of targeting mitochondrial sirtuin and its impact on breast cancer progression using sirtuin inhibitors and activators as anticancer agents.

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.

Recent advances of lysine lactylation in prokaryotes and eukaryotes

Lysine lactylation is a newly discovered protein post-translational modification that plays regulatory roles in cell metabolism, growth, reprogramming, and tumor progression. It utilizes lactate as the modification precursor, which is an end product of glycolysis while functioning as a signaling molecule in cells. Unlike previous reviews focused primarily on eukaryotes, this review aims to provide a comprehensive summary of recent knowledge about lysine lactylation in prokaryotes and eukaryotes. The current identification and enrichment strategies for lysine lactylation are introduced, and the known readers, writers, and erasers of this modification are summarized. In addition, the physiological and pathological implications of lysine lactylation are reviewed for different organisms, especially in prokaryotic cells. Finally, we end with a discussion of the limitations of the studies so far and propose future directions for lysine lactylation investigations.

The TRIM33 Bromodomain Recognizes Histone Lysine Lactylation

Histone lysine lactylation (Kla) regulates inflammatory gene expression in activated macrophages and mediates the polarization of inflammatory (M1) to reparative (M2) macrophages. However, the molecular mechanisms and key protein players involved in Kla-mediated transcriptional changes are unknown. As Kla is structurally similar to lysine acetylation (Kac), which is bound by bromodomains, we hypothesized that bromodomain-containing proteins bind histone Kla. Here, we screened 28 recombinantly expressed bromodomains for binding to histone Kla peptides via AlphaScreen assays. TRIM33 was the sole bromodomain tested that bound histone Kla peptides. TRIM33 attenuates inflammatory genes during late-stage macrophage activation; thus, TRIM33 provides a potential link between histone Kla and macrophage polarization. Orthogonal biophysical techniques, including isothermal titration calorimetry and protein-detected nuclear magnetic resonance, confirmed the submicromolar binding affinity of the TRIM33 bromodomain to both Kla and Kac histone post-translational modifications. Sequence alignments of human bromodomains revealed a unique glutamic acid residue within the TRIM33 binding pocket that we found confers TRIM33 specificity for binding Kla compared with other bromodomains. Molecular modeling of interactions of Kla with the TRIM33 bromodomain binding pocket and site-directed mutagenesis of glutamic acid confirmed the critical role of this residue in the selective recognition of Kla by TRIM33. Collectively, our findings implicate TRIM33, a bromodomain-containing protein, as a novel reader of histone Kla, potentially bridging the gap between histone Kla and macrophage polarization. This study enhances our understanding of the regulatory role of histone Kla in macrophage-mediated inflammation and offers insights into the underlying structural and biophysical mechanisms.

Chromatin lysine acylation: On the path to chromatin homeostasis and genome integrity

The fundamental role of cells in safeguarding the genome's integrity against DNA double-strand breaks (DSBs) is crucial for maintaining chromatin homeostasis and the overall genomic stability. Aberrant responses to DNA damage, known as DNA damage responses (DDRs), can result in genomic instability and contribute significantly to tumorigenesis. Unraveling the intricate mechanisms underlying DDRs following severe damage holds the key to identify therapeutic targets for cancer. Chromatin lysine acylation, encompassing diverse modifications such as acetylation, lactylation, crotonylation, succinylation, malonylation, glutarylation, propionylation, and butyrylation, has been extensively studied in the context of DDRs and chromatin homeostasis. Here, we delve into the modifying enzymes and the pivotal roles of lysine acylation and their crosstalk in maintaining chromatin homeostasis and genome integrity in response to DDRs. Moreover, we offer a comprehensive perspective and overview of the latest insights, driven primarily by chromatin acylation modification and associated regulators.

Sirtuin 1/sirtuin 3 are robust lysine delactylases and sirtuin 1-mediated delactylation regulates glycolysis

Lysine lactylation (Kla), an epigenetic mark triggered by lactate during glycolysis, including the Warburg effect, bridges metabolism and gene regulation. Enzymes such as p300 and HDAC1/3 have been pivotal in deciphering the regulatory dynamics of Kla, though questions about additional regulatory enzymes, their specific Kla substrates, and the underlying functional mechanisms persist. Here, we identify SIRT1 and SIRT3 as key "erasers" of Kla, shedding light on their selective regulation of both histone and non-histone proteins. Proteomic analysis in SIRT1/SIRT3 knockout HepG2 cells reveals distinct substrate specificities toward Kla, highlighting their unique roles in cellular signaling. Notably, we highlight the role of specific Kla modifications, such as those on the M2 splice isoform of pyruvate kinase (PKM2), in modulating metabolic pathways and cell proliferation, thereby expanding Kla's recognized functions beyond epigenetics. Therefore, this study deepens our understanding of Kla's functional mechanisms and broadens its biological significance.

Small Molecule-Induced Post-Translational Acetylation of Catalytic Lysine of Kinases in Mammalian Cells

Reversible lysine acetylation is an important post-translational modification (PTM). This process in cells is typically carried out enzymatically by lysine acetyltransferases and deacetylases. The catalytic lysine in the human kinome is highly conserved and ligandable. Small-molecule strategies that enable post-translational acetylation of the catalytic lysine on kinases in a target-selective manner therefore provide tremendous potential in kinase biology. Herein, we report the first small molecule-induced chemical strategy capable of global acetylation of the catalytic lysine on kinases from mammalian cells. By surveying various lysine-acetylating agents installed on a promiscuous kinase-binding scaffold, Ac4 was identified and shown to effectively acetylate the catalytic lysine of >100 different protein kinases from live Jurkat/K562 cells. In order to demonstrate that this strategy was capable of target-selective and reversible chemical acetylation of protein kinases, we further developed six acetylating compounds on the basis of VX-680 (a noncovalent inhibitor of AURKA). Among them, Ac13/Ac14, while displaying excellent in vitro potency and sustained cellular activity against AURKA, showed robust acetylation of its catalytic lysine (K162) in a target-selective manner, leading to irreversible inhibition of endogenous kinase activity. The reversibility of this chemical acetylation was confirmed on Ac14-treated recombinant AURKA protein, followed by deacetylation with SIRT3 (a lysine deacetylase). Finally, the reversible Ac13-induced acetylation of endogenous AURKA was demonstrated in SIRT3-transfected HCT116 cells. By disclosing the first cell-active acetylating compounds capable of both global and target-selective post-translational acetylation of the catalytic lysine on kinases, our strategy could provide a useful chemical tool in kinase biology and drug discovery.

Advances in the interaction of glycolytic reprogramming with lactylation

Lactylation is a novel post-translational modification (PTM) involving proteins that is induced by lactate accumulation. Histone lysine lactylation alters chromatin spatial configuration, influencing gene transcription and regulating the expression of associated genes. This modification plays a crucial role as an epigenetic regulatory factor in the progression of various diseases. Glycolytic reprogramming is one of the most extensively studied forms of metabolic reprogramming, recognized as a key hallmark of cancer cells. It is characterized by an increase in glycolysis and the inhibition of the tricarboxylic acid (TCA) cycle, accompanied by significant lactate production and accumulation. The two processes are closely linked by lactate, which interacts in various physiological and pathological processes. On the one hand, lactylation levels generally correlate positively with the extent of glycolytic reprogramming, being directly influenced by the lactate concentration produced during glycolytic reprogramming. On the other hand, lactylation can also regulate glycolytic pathways by affecting the transcription and structural functions of essential glycolytic enzymes. This review comprehensively outlines the mechanisms of lactylation and glycolytic reprogramming and their interactions in tumor progression, immunity, and inflammation, with the aim of elucidating the relationship between glycolytic reprogramming and lactylation.

Comprehensive review of histone lactylation: Structure, function, and therapeutic targets

Histone lysine lactylation (Kla) has emerged as a distinct epigenetic modification that differs markedly from established acylation modifications through the unique addition of a lactyl group to a lysine residue. Such modifications not only alter nucleosome structure but also significantly impact chromatin dynamics and gene expression, thus playing a crucial role in cellular metabolism, inflammatory responses, and embryonic development. The association of histone Kla with various metabolic processes, particularly glycolysis and glutamine metabolism, underscores its pivotal role in metabolic reprogramming, including in cancerous tissues, where it contributes to tumorigenesis, immune evasion, and angiogenesis. In addition, histone Kla is involved in the pathogenesis of various diseases, particularly several cancers and neurodegenerative diseases. The identification of histone Kla opens new avenues for therapeutic interventions targeting specific Kla sites. In this review, we summarize the differences between histone Kla modifications and other acylation modifications, discuss the mechanisms and roles of histone Kla in disease, and conclude by describing existing drugs and potential targets. This study provides new insights into the mechanisms linking histone Kla to diseases and into the discovery of new drugs and targets.

Role of histone modifications in neurogenesis and neurodegenerative disease development

Progressive neuronal dysfunction and death are key features of neurodegenerative diseases; therefore, promoting neurogenesis in neurodegenerative diseases is crucial. With advancements in proteomics and high-throughput sequencing technology, it has been demonstrated that histone post-transcriptional modifications (PTMs) are often altered during neurogenesis when the brain is affected by disease or external stimuli and that the degree of histone modification is closely associated with the development of neurodegenerative diseases. This review aimed to show the regulatory role of histone modifications in neurogenesis and neurodegenerative diseases by discussing the changing patterns and functional significance of histone modifications, including histone methylation, acetylation, ubiquitination, phosphorylation, and lactylation. Finally, we explored the control of neurogenesis and the development of neurodegenerative diseases by artificially modulating histone modifications.

Lactate enhances NMNAT1 lactylation to sustain nuclear NAD+ salvage pathway and promote survival of pancreatic adenocarcinoma cells under glucose-deprived conditions

The aim of this study was to investigate the underlying molecular mechanism behind the promotion of cell survival under conditions of glucose deprivation by l-lactate. To accomplish this, we performed tissue microarray and immunohistochemistry staining to analyze the correlation between the abundance of pan-Lysine lactylation and prognosis. In vivo evaluations of tumor growth were conducted using the KPC and nude mice xenograft tumor model. For mechanistic studies, multi-omics analysis, RNA interference, and site-directed mutagenesis techniques were utilized. Our findings robustly confirmed that l-lactate promotes cell survival under glucose deprivation conditions, primarily by relying on GLS1-mediated glutaminolysis to support mitochondrial respiration. Mechanistically, we discovered that l-lactate enhances the NMNAT1-mediated NAD+ salvage pathway while concurrently inactivating p-38 MAPK signaling and suppressing DDIT3 transcription. Notably, Pan-Kla abundance was significantly upregulated in patients with Pancreatic adenocarcinoma (PAAD) and associated with poor prognosis. We identified the 128th Lysine residue of NMNAT1 as a critical site for lactylation and revealed EP300 as a key lactyltransferase responsible for catalyzing lactylation. Importantly, we elucidated that lactylation of NMNAT1 enhances its nuclear localization and maintains enzymatic activity, thereby supporting the nuclear NAD+ salvage pathway and facilitating cancer growth. Finally, we demonstrated that the NMNAT1-dependent NAD+ salvage pathway promotes cell survival under glucose deprivation conditions and is reliant on the activity of Sirt1. Collectively, our study has unraveled a novel molecular mechanism by which l-lactate promotes cell survival under glucose deprivation conditions, presenting a promising strategy for targeting lactate and NAD+ metabolism in the treatment of PAAD.

Lactylation Modification in Cardiometabolic Disorders: Function and Mechanism

Cardiovascular disease (CVD) is recognized as the primary cause of mortality and morbidity on a global scale, and developing a clear treatment is an important tool for improving it. Cardiometabolic disorder (CMD) is a syndrome resulting from the combination of cardiovascular, endocrine, pro-thrombotic, and inflammatory health hazards. Due to their complex pathological mechanisms, there is a lack of effective diagnostic and treatment methods for cardiac metabolic disorders. Lactylation is a type of post-translational modification (PTM) that plays a regulatory role in various cellular physiological processes by inducing changes in the spatial conformation of proteins. Numerous studies have reported that lactylation modification plays a crucial role in post-translational modifications and is closely related to cardiac metabolic diseases. This article discusses the molecular biology of lactylation modifications and outlines the roles and mechanisms of lactylation modifications in cardiometabolic disorders, offering valuable insights for the diagnosis and treatment of such conditions.

Histone lactylation: from tumor lactate metabolism to epigenetic regulation

The Warburg Effect is one of the most well-known cancer hallmarks. This metabolic pattern centered on lactate has extremely complex effects on various aspects of tumor microenvironment, including metabolic remodeling, immune suppression, cancer cell migration, and drug resistance development. Based on accumulating evidence, metabolites are likely to participate in the regulation of biological processes in the microenvironment and to form a feedback loop. Therefore, further revealing the key mechanism of lactate-mediated oncological effects is a reasonable scientific idea. The discovery and refinement of histone lactylation in recent years has laid a firm foundation for the above idea. Histone lactylation is a post-translational modification that occurs at lysine sites on histones. Specific enzymes, known as "writers" and "erasers", catalyze the addition or removal, respectively, of lactacyl group at target lysine sites. An increasing number of investigations have reported this modification as key to multiple cellular procedures. In this review, we discuss the close connection between histone lactylation and a series of biological processes in the tumor microenvironment, including tumorigenesis, immune infiltration, and energy metabolism. Finally, this review provides insightful perspectives, identifying promising avenues for further exploration and potential clinical application in this field of research.

SIRT3 Activation a Promise in Drug Development? New Insights into SIRT3 Biology and Its Implications on the Drug Discovery Process

Sirtuins catalyze deacetylation of lysine residues with a NAD+-dependent mechanism. In mammals, the sirtuin family is composed of seven members, divided into four subclasses that differ in substrate specificity, subcellular localization, regulation, as well as interactions with other proteins, both within and outside the epigenetic field. Recently, much interest has been growing in SIRT3, which is mainly involved in regulating mitochondrial metabolism. Moreover, SIRT3 seems to be protective in diseases such as age-related, neurodegenerative, liver, kidney, heart, and metabolic ones, as well as in cancer. In most cases, activating SIRT3 could be a promising strategy to tackle these health problems. Here, we summarize the main biological functions, substrates, and interactors of SIRT3, as well as several molecules reported in the literature that are able to modulate SIRT3 activity. Among the activators, some derive from natural products, others from library screening, and others from the classical medicinal chemistry approach.

The (patho)physiological roles of the individual deacylase activities of a sirtuin

Since the discovery of the sirtuin family founding member (i.e., the yeast silent information regulator 2 (sir2) protein) in 2000, more and more sirtuin proteins have been identified and are currently known to be present in organisms from all the three kingdoms of life (i.e., bacteria, archaea, and eukarya). Seven sirtuin proteins have been identified in mammals including humans, that is, SIRT1/2/3/4/5/6/7. Sirtuin proteins are a class of enzymes with primary catalytic activity being the β-nicotinamide adenine dinucleotide (β-NAD+ or NAD+)-dependent deacylation from the Nε-acyl-lysine residues on cellular proteins. Many sirtuins (e.g., human SIRT1/2/3/4/5/6/7) have been found to each possess multiple individual deacylase activities acting on Nε-acyl-lysine substrates with different acyl groups ranging from the simple formyl and acetyl to the more complex groups like succinyl and myristoyl; however, our current knowledge on the (patho)physiological roles of these individual deacylase activities is still limited, which could be due to the currently still thin research toolbox for investigation (i.e., the deacylase-selective sirtuin mutant and inhibitor/activator). In this article, an updated account on the subject matter will be presented with biochemical and medicinal chemistry perspectives.