Lactate Regulates Metabolic and Pro-inflammatory Circuits in Control of T Cell Migration and Effector Functions

Histone lactylation-augmented IRF4 is implicated in arsenite-induced liver fibrosis via modulating Th17 cell differentiation

Arsenic, a ubiquitous environmental toxicant, has been implicated in causing liver fibrosis through chronic exposure. Histone lactylation is involved in various inflammatory diseases, among which liver fibrosis is included, and is also closely related to the regulation of immune cells. This work focuses on the mechanisms of histone lactylation and Th17 cell differentiation in arsenite-induced liver fibrosis through animal and cellular experiments. Chronic arsenite exposure of mice led to liver fibrosis, elevated glycolysis in liver, and increased lactate levels in both serum and liver, which promoted Th17 cell differentiation of CD4+ T cells and increased IL-17A secretion. Treatment with oxamate, a lactate dehydrogenase inhibitor, suppressed Th17 cell differentiation and alleviated fibrosis in the liver. For HepG2 cells, arsenite exposure enhanced glycolysis and lactate levels, leading to increased global lactylation (Kla), H3K18la, interferon-regulatory factor 4 (IRF4), retinoic acid receptor-related orphan receptor gamma t (RORγt), and IL-17A expression and secretion in co-cultured Jurkat cells. Furthermore, in Jurkat cells, reducing lactate production and transport decreased these protein levels, suppressed Th17 cell differentiation, decreased IL-17A secretion, and ultimately inhibited the activation of hepatic stellate cells (HSCs). These results indicate that lactate derived from hepatocytes promotes Th17 cell differentiation by upregulating IRF4 through H3K18la, thereby enhancing IL-17A secretion and the activation of HSCs, contributing to arsenite-induced liver fibrosis. Our work reveals a new mechanism of histone lactylation in arsenite-induced liver fibrosis and offers a fresh perspective for the development of strategies for prevention and treatment of this condition.

Lactate metabolism and acute kidney injury

ABSTRACT

Acute kidney injury (AKI) is a common clinically critical syndrome in hospitalized patients with high morbidity and mortality. At present, the mechanism of AKI has not been fully elucidated, and no therapeutic drugs exist. As known, glycolytic product lactate is a key metabolite in physiological and pathological processes. The kidney is an important gluconeogenic organ, where lactate is the primary substrate of renal gluconeogenesis in physiological conditions. During AKI, altered glycolysis and gluconeogenesis in kidneys significantly disturb the lactate metabolic balance, which exert impacts on the severity and prognosis of AKI. Additionally, lactate-derived posttranslational modification, namely lactylation, is novel to AKI as it could regulate gene transcription of metabolic enzymes involved in glycolysis or Warburg effect. Protein lactylation widely exists in human tissues and may severely affect non-histone functions. Moreover, the strategies of intervening lactate metabolic pathways are expected to bring a new dawn for the treatment of AKI. This review focused on renal lactate metabolism, especially in proximal renal tubules after AKI, and updated recent advances of lactylation modification, which may help to explore potential therapeutic targets against AKI.

Immunomodulatory behavior of CircRNAs in tumor microenvironment

Circular RNAs (circRNAs) are a type of non coding RNA that possess unique single stranded circular structures formed through reverse splicing mechanisms. Due to the lack of a free end that is typically susceptible to degradation by nucleases, circular RNAs exhibit resistance to ribonuclease R, making them highly stable in eukaryotic cells. The complex relationship between circRNA dysregulation and various pathophysiological conditions, especially cancer. Tumor microenvironment (TME) is a collective term for various components surrounding tumors and is an important factor affecting tumor development. Simultaneous infiltration of TME by different types of immune cells; These immune cells interact with the TME, collectively forming the so-called "tumor immune microenvironment". The complex interactions between tumor cells and TME profoundly affect the behavior of malignant tumors, and circRNAs derived from tumor cells and TME cell components have become important mediators of immune response and evasion within the TME. CircRNAs can directly or indirectly regulate immune cells, thereby modulating anti-tumor immunity. This review highlights how circRNAs, especially those encapsulated in extracellular vesicles like exosomes, influence the differentiation, chemotaxis, and anti-tumor immune functions of immune cells within the TME. Metabolic reprogramming plays an important role in this process. The process of circRNAs regulating tumor immunity is affected by multiple factors, such as hypoxia and viral infection. This review emphasizes the roles of the interaction between circRNAs and the TME in tumor immune regulation and prospects the guiding significance of circRNAs in tumor immune checkpoint therapy.

Lactate and Lactylation in AKI-to-CKD: Epigenetic Regulation and Therapeutic Opportunities

Lactate is not only a byproduct of glycolysis, but is also considered an energy source, gluconeogenic precursor, signalling molecule and protein modifier during the process of cellular metabolism. The discovery of lactylation reveals the multifaceted functions of lactate in cellular metabolism and opens new avenues for lactate-related research. Both lactate and lactylation have been implicated in regulating numerous biological processes, including tumour progression, ischemic-hypoxic injury, neurodevelopment and immune-related inflammation. The kidney plays a crucial role in regulating lactate metabolism, influencing lactate levels while also being regulated by lactate. Previous studies have demonstrated the importance of lactate in the pathogenesis of acute kidney injury (AKI) and chronic kidney disease (CKD). This review explores the role of lactate and lactylation in these diseases, comparing the function and metabolic mechanisms of lactate in normal and diseased kidneys from the perspective of lactylation. The key regulatory roles of lactylation in different organs, multiple systems, various pathological states and underlying mechanisms in AKI-to-CKD progression are summarised. Moreover, potential therapeutic targets and future research directions for lactate and lactylation across multiple kidney diseases are identified.

Lactylation-related molecular subtyping reveals the immune heterogeneity and clinical characteristics in ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is a chronic inflammatory disease linked to early-onset colorectal cancer and metabolic abnormalities. While intestinal lactate disturbances are observed in UC, the role of lactate and lactylation in its pathogenesis remains unclear. The lack of specific biomarkers reflecting these processes limits understanding of their biological significance.

METHODS

UC subtypes were classified using ConsensusClusterPlus and NMF based on LRGs. Immune infiltration was assessed with ssGSEA, xCell, and CIBERSORT. WGCNA identified subtype-specific gene modules, and Lasso regression pinpointed hub genes. Single-cell analysis determined cellular localization, while WB and IHC validated findings in clinical, mouse, and cell models. Prognostic machine learning models evaluated the clinical significance of these results.

RESULTS

LRGs distinguished UC patients from controls and stratified them into high and low immune infiltration groups. MSN and MAPRE1, strongly linked to UC, showed elevated expression in vitro and in vivo. They aid in diagnosing UC and UC-associated colorectal cancer and serve as predictors of UC severity and response to immunosuppressants.

CONCLUSION

Using high-throughput transcriptomic data, we identified hub LRGs and highlighted the role of lactate-mediated lactylation in UC. MSN and MAPRE1 were confirmed to be upregulated in an inflammatory environment, underscoring their potential for personalized UC diagnosis and treatment.

Regulatory T cell and endothelial cell crosstalk

Regulatory T (Treg) cells have a central role in the maintenance of immune surveillance and tolerance. They can migrate from lymphoid organs to blood and then into tissues and egress from tissues into draining lymph nodes. Specialized endothelial cells of blood and lymphatic vessels are the key gatekeepers for these processes. Treg cells that transmigrate across single-cell layers of endothelial cells engage in bidirectional crosstalk with these cells and regulate vascular permeability by promoting structural modifications of blood and lymphatic endothelial cells. In turn, blood and lymphatic endothelial cells can modulate Treg cell recirculation and residency. Here, we discuss recent insights into the cellular and molecular mechanisms of the crosstalk between Treg cells and endothelial cells and explore potential therapeutic strategies to target these interactions in autoimmunity, transplantation and cancer.

Lactate dehydrogenase B deficiency-dependent hyperlactatemia coordinates with necroptosis to worsen septic liver and kidney injuries

Hyperlactatemia is intimately correlated with severity and poor prognosis of patients with sepsis. However, little experimental evidence on this process is known. We report here that lactate dehydrogenase B (LDHB), the glycolytic enzyme that catalyzes conversion of lactate to pyruvate, is transcriptionally downregulated in blood samples of hyperlactatemic patients, while mice receiving lactate injection have reduced LDHB activity in liver and kidney. LDHB knockout (Ldhb-/-) mice with hyperlactatemia are vulnerable to lethality, hypotension and vascular leakage. The hyperlactatemic Ldhb-/- mice develop severe liver and kidney injuries accompanied by increased hepatic and renal SLC16A1 abundance but unaltered morphology. Pharmacological targeting of SLC16A1 with AZD3965 in Ldhb-/- mice rescues the hyperlactatemia-induced lethality, liver and kidney injuries. Loss of LDHB renders hyperlactatemia, lethality, vascular leakage, liver and kidney injuries in response to abdominal sepsis. AZD3965 treatment partially abrogates liver and kidney injuries of septic Ldhb-/- mice without affecting necrosis. Blockade of necroptosis significantly protects Ldhb-/- mice against septic liver and kidney injuries, enabling a compensation towards the therapeutic efficacy of AZD3965. Our study together unearth the coordination of hyperlactatemia and necroptosis in septic liver and kidney injuries in the context of LDHB deficiency, and support further investigation of combined targeting SLC16A1 and necroptosis for clinical treatment of sepsis with low LDHB activity.

Ferroptosis: CD8+T cells' blade to destroy tumor cells or poison for self-destruction

Ferroptosis represents an emerging, iron-dependent form of cell death driven by lipid peroxidation. In recent years, it has garnered significant attention in the realm of cancer immunotherapy, particularly in studies involving immune checkpoint inhibitors. This form of cell death not only enhances our comprehension of the tumor microenvironment but is also considered a promising therapeutic strategy to address tumor resistance, investigate immune activation mechanisms, and facilitate the development of cancer vaccines. The combination of immunotherapy with ferroptosis provides innovative targets and fresh perspectives for advancing cancer treatment. Nevertheless, tumor cells appear to possess a wider array of ferroptosis evasion strategies compared to CD8+T cells, which have been conclusively shown to be more vulnerable to ferroptosis. Furthermore, ferroptosis in the TME can create a favorable environment for tumor survival and invasion. Under this premise, both inducing tumor cell ferroptosis and inhibiting T cell ferroptosis will impact antitumor immunity to some extent, and even make the final result run counter to our therapeutic purpose. This paper systematically elucidates the dual-edged sword role of ferroptosis in the antitumor process of T cells, briefly outlining the complexity of ferroptosis within the TME. It explores potential side effects associated with ferroptosis-inducing therapies and critically considers the combined application of ferroptosis-based therapies with ICIs. Furthermore, it highlights the current challenges faced by this combined therapeutic approach and points out future directions for development.

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.

Tumor Microenvironment: Obstacles and Opportunities for T Cell-Based Tumor Immunotherapies

The complex composition and dynamic change of the tumor microenvironment (TME), mainly consisting of tumor cells, immune cells, stromal cells, and extracellular components, significantly impede the effector function of cytotoxic T lymphocytes (CTL), thus representing a major obstacle for tumor immunotherapies. In this review, we summarize and discuss the impacts and underlying mechanisms of major elements in the TME (different cell types, extracellular matrix, nutrients and metabolites, etc.) on the infiltration, survival, and effector functions of T cells, mainly CD8+ CTLs. Moreover, we also highlight recent advances that may potentiate endogenous antitumor immunity and improve the efficacy of T cell-based immunotherapies in patients with cancer by manipulating components inside/outside of the TME. A deeper understanding of the effects and action mechanisms of TME components on the tumor-eradicating ability of CTLs may pave the way for discovering new targets to augment endogenous antitumor immunity and for designing combinational therapeutic regimens to enhance the efficacy of tumor immunotherapies in the clinic.

Metabolic Reprogramming of Anti-cancer T Cells: Targeting AMPK and PPAR to Optimize Cancer Immunotherapy

Cancer treatment era has been revolutionized by the novel therapeutic methods such as immunotherapy in recent years. Immunotherapy-based approaches are considered effective and reliable methods that has brought hope to eradicate certain cancers. Nonetheless, there are some issues, considered as critical obstacles in successful cancer immunotherapy. Such issues are attributed to the ability of the tumor cells in providing a tolerant microenvironment that impairs the immune responses, and help the cancer cells evade the immunogenic cell death. It has been suggested that the re-activation and maintenance of effector immune cells may become possible by metabolic reprogramming. Several signaling pathways have been noticed with the possibility of metabolic reprogramming of tumor-specific T cells, to overcome the metabolic restrictions in the tumor microenvironment; and among them, AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptors (PPAR) have been investigated the most as the main energy sensors and regulators of mitochondrial biogenesis. The synergic effects of AMPK activators and/or PPAR agonists in cancer immunotherapy have been reported. In this review, we compare the roles of AMPK activators and PPAR agonists, and the efficacy of their combination in metabolic reprogramming of cytotoxic T cells in favoring cancer immunotherapy.

T cell-based cancer immunotherapy: opportunities and challenges

T cells play a central role in the cancer immunity cycle. The therapeutic outcomes of T cell-based intervention strategies are determined by multiple factors at various stages of the cycle. Here, we summarize and discuss recent advances in T cell immunotherapy and potential barriers to it within the framework of the cancer immunity cycle, including T-cell recognition of tumor antigens for activation, T cell trafficking and infiltration into tumors, and killing of target cells. Moreover, we discuss the key factors influencing T cell differentiation and functionality, including TCR stimulation, costimulatory signals, cytokines, metabolic reprogramming, and mechanistic forces. We also highlight the key transcription factors dictating T cell differentiation and discuss how metabolic circuits and specific metabolites shape the epigenetic program of tumor-infiltrating T cells. We conclude that a better understanding of T cell fate decision will help design novel strategies to overcome the barriers to effective cancer immunity.

Intranuclear TCA and mitochondrial overload: The nascent sprout of tumors metabolism

Abnormal glucose metabolism in tumors is a well-known form of metabolic reprogramming in tumor cells, the most representative of which, the Warburg effect, has been widely studied and discussed since its discovery. However, contradictions in a large number of studies and suboptimal efficacy of drugs targeting glycolysis have prompted us to further deepen our understanding of glucose metabolism in tumors. Here, we review recent studies on mitochondrial overload, nuclear localization of metabolizing enzymes, and intranuclear TCA (nTCA) in the context of the anomalies produced by inhibition of the Warburg effect. We provide plausible explanations for many of the contradictory points in the existing studies, including the causes of the Warburg effect. Furthermore, we provide a detailed prospective discussion of these studies in the context of these new findings, providing new ideas for the use of nTCA and mitochondrial overload in tumor therapy.

CD4+ T-cell metabolism in the pathogenesis of Sjogren's syndrome

The abnormal effector function of CD4+ T cells plays a key role in the pathogenesis of Sjogren's syndrome (SS) and its associated systematic autoimmune response. Cellular metabolism, including glucose metabolism, lipid metabolism and amino acid metabolism, supports proliferation, migration, survival and differentiation into distinct CD4+ T-cell subsets. Different subtypes of T cells have significantly different demands for related metabolic processes, which enables us to finely regulate CD4+ T cells through different metabolic processes in autoimmune diseases such as SS. In this review, we summarize the effects of disturbances in distinct metabolic processes, such as glycolysis, fatty acid metabolism, glutamine decomposition, mitochondrial dynamics, and ferroptosis, on how to support the effector functions of CD4+ T cells in the SS. We also discuss potential drugs with high value in the treatment of SS through metabolic normalization in CD4+ T cells. Finally, we propose possible directions for future targeted therapy for immunometabolism in SS.

Impact of lactate on immune cell function in the tumor microenvironment: mechanisms and therapeutic perspectives

Lactate has emerged as a key regulator in the tumor microenvironment (TME), influencing both tumor progression and immune dynamics. As a byproduct of aerobic glycolysis, lactate satisfies the metabolic needs of proliferating tumor cells while reshaping the TME to facilitate immune evasion. Elevated lactate levels inhibit effector immune cells such as CD8+ T and natural killer cells, while supporting immunosuppressive cells, such as regulatory T cells and myeloid-derived suppressor cells, thus fostering an immunosuppressive environment. Lactate promotes epigenetic reprogramming, stabilizes hypoxia-inducible factor-1α, and activates nuclear factor kappa B, leading to further immunological dysfunction. In this review, we examined the role of lactate in metabolic reprogramming, immune suppression, and treatment resistance. We also discuss promising therapeutic strategies targeting lactate metabolism, including lactate dehydrogenase inhibitors, monocarboxylate transporter inhibitors, and TME neutralization methods, all of which can restore immune function and enhance immunotherapy outcomes. By highlighting recent advances, this review provides a theoretical foundation for integrating lactate-targeted therapies into clinical practice. We also highlight the potential synergy between these therapies and current immunotherapeutic strategies, providing new avenues for addressing TME-related challenges and improving outcomes for patients with cancer.

CD38-mediated metabolic reprogramming promotes the stability and suppressive function of regulatory T cells in tumor

In the tumor microenvironment (TME), regulatory T cells (Tregs) adapt their metabolism to thrive in low-glucose, high-lactate conditions, but the mechanisms remain unclear. Our study identifies CD38 as a key regulator of this adaptation by depleting nicotinamide adenine dinucleotide (oxidized form) (NAD+), redirecting lactate-derived pyruvate toward phosphoenolpyruvate and bypassing the tricarboxylic acid (TCA) cycle. This prevents accumulation of α-ketoglutarate, which destabilizes Tregs by inducing hypermethylation at the Foxp3 locus. Restoring NAD+ with nicotinamide mononucleotide reverses this adaptation, pushing Tregs back to the TCA cycle and reducing their suppressive function. In YUMM1.7 melanoma-bearing mice, small-molecule CD38 inhibition selectively destabilizes intratumoral Tregs, sparking robust antitumor immunity. These findings reveal that targeting the CD38-NAD+ axis disrupts Tregs metabolic adaptation and offers a strategy to enhance antitumor responses.

The Role of Lactate and Lactylation in the Dysregulation of Immune Responses in Psoriasis

Historically, lactate has been considered merely a metabolic byproduct. However, recent studies have revealed that lactate plays a much more dynamic role, acting as an immune signaling molecule that influences cellular communication, through the process of "lactate shuttling." Lactylation, a novel post-translational modification, is directly derived from lactate and represents an emerging mechanism through which lactate exerts its effects on cellular function. It has been shown to directly affect immune cells by modulating the activation of pro-inflammatory and anti-inflammatory pathways. This modification influences the expression of key immune-related genes, thereby impacting immune cell differentiation, cytokine production, and overall immune response. In this review, we focused on the role of lactate and lactylation in the dysregulation of immune responses in psoriasis and its relapse. Additionally, we discuss the potential applications of targeting lactate metabolism and lactylation modifications in the treatment of psoriasis, alongside the investigation of artificial intelligence applications in advancing lactate and lactylation-focused drug development, identifying therapeutic targets, and enabling personalized medical decision-making. The significance of this review lies in its comprehensive exploration of how lactate and lactylation contribute to immune dysregulation, offering a novel perspective for understanding the metabolic and epigenetic changes associated with psoriasis. By identifying the roles of these pathways in modulating immune responses, this review provides a foundation for the development of new therapeutic strategies that target these mechanisms.

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.

Lactate: A key regulator of the immune response

Lactate, the end product of both anaerobic and aerobic glycolysis in proliferating and growing cells-with the latter process known as the Warburg effect-is historically considered a mere waste product of cell and tissue metabolism. However, research over the past ten years has unveiled multifaceted functions of lactate that critically shape and impact cellular biology. Beyond serving as a fuel source, lactate is now known to influence gene expression through histone modification and to function as a signaling molecule that impacts a wide range of cellular activities. These properties have been particularly studied in the context of both adaptive and innate immune responses. Here, we review the diverse roles of lactate in the regulation of the immune system during homeostasis and disease pathogenesis (including cancer, infection, cardiovascular diseases, and autoimmunity). Furthermore, we describe recently proposed therapeutic interventions for manipulating lactate metabolism in human diseases.

Immunomodulatory role of the stem cell circadian clock in muscle repair

Circadian rhythms orchestrate physiological processes such as metabolism, immune function, and tissue regeneration, aligning them with the optimal time of day (TOD). This study identifies an interplay between the circadian clock within muscle stem cells (SCs) and their capacity to modulate the immune microenvironment during muscle regeneration. We reveal that the SC clock triggers TOD-dependent inflammatory gene transcription after injury, particularly genes related to neutrophil activity and chemotaxis. These responses are driven by cytosolic regeneration of the signaling metabolite nicotinamide adenine dinucleotide (oxidized form) (NAD+), as enhancing cytosolic NAD+ regeneration in SCs is sufficient to induce inflammatory responses that influence muscle regeneration. Mononuclear single-cell sequencing of the regenerating muscle niche further implicates the cytokine CCL2 in mediating SC-neutrophil cross-talk in a TOD-dependent manner. Our findings highlight the intersection between SC metabolic shifts and immune responses within the muscle microenvironment, dictated by circadian rhythms, and underscore the potential for targeting circadian and metabolic pathways to enhance tissue regeneration.

Lactate promotes premature aging of preeclampsia placentas through histone lactylation-regulated GADD45A

BACKGROUND

Premature placental aging has been linked to preeclampsia (PE), with lactate identified as a promoter of cellular senescence in various cell types. In this study, we explored the role and underlying mechanisms of lactate in driving premature placental aging associated with PE.

METHODS

To evaluate senescence markers in placental samples or trophoblast cells, we conducted SA-β-Gal staining, western blotting, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and immunofluorescence assays. SiRNA transfection was used to reduce GADD45A expression in HTR-8/SVneo cells exposed to lactate. Additionally, chromatin immunoprecipitation-qPCR (ChIP-qPCR) was used to analyze histone lactylation at the GADD45A promoter region.

RESULTS

SA-β-Gal staining indicated a significant increase in senescent cell proportions in placentas from PE patients compared to controls. Treatment with lactate enhanced senescence in trophoblast cells, leading to an increase in P16 expression. RNA sequencing analysis showed that genes differentially expressed in lactate-treated cells were involved in pathways linked to cellular senescence. Additionally, lactate augmented GADD45A expression and increased histone lactylation at its promoter region, while knocking down GADD45A in trophoblast cells mitigated the senescence induced by lactate.

CONCLUSIONS

Lactate promotes trophoblast senescence through epigenetic upregulation of GADD45A expression, offering fresh perspectives on the molecular mechanisms and potential treatment targets for PE.

Oncogenic activation of PI K3 CA in cancers: Emerging targeted therapies in precision oncology

Phosphoinositide 3-kinases (PI3Ks) are heterodimers consisting of a p110 catalytic subunit and a p85 regulatory subunit. The PIK3CA gene, which encodes the p110α, is the most frequently mutated oncogene in cancer. Oncogenic PIK3CA mutations activate the PI3K pathway, promote tumor initiation and development, and mediate resistance to anti-tumor treatments, making the mutant p110α an excellent target for cancer therapy. PIK3CA mutations occur in two hotspot regions: one in the helical domain and the other in the kinase domain. The PIK3CA helical and kinase domain mutations exert their oncogenic function through distinct mechanisms. For example, helical domain mutations of p110α gained direct interaction with insulin receptor substrate 1 (IRS-1) to activate the downstream signaling pathways. Moreover, p85β proteins disassociate from helical domain mutant p110α, translocate into the nucleus, and stabilize enhancer of zeste homolog 1/2 (EZH1/2). Due to the fundamental role of PI3Kα in tumor initiation and development, PI3Kα-specific inhibitors, represented by FDA-approved alpelisib, have developed rapidly in recent decades. However, side effects, including on-target side effects such as hyperglycemia, restrict the maximum dose and thus clinical efficacy of alpelisib. Therefore, developing p110α mutant-specific inhibitors to circumvent on-target side effects becomes a new direction for targeting PIK3CA mutant cancers. In this review, we briefly introduce the function of the PI3K pathway and discuss how PIK3CA mutations rewire cell signaling, metabolism, and tumor microenvironment, as well as therapeutic strategies under development to treat patients with tumors harboring a PIK3CA mutation.

How oxygenation shapes immune responses: emerging roles for physioxia and pathological hypoxia

Most eukaryotes require oxygen for their survival and, with increasing multicellular complexity, oxygen availability and delivery rates vary across the tissues of complex organisms. In humans, healthy tissues have markedly different oxygen gradients, ranging from the hypoxic environment of the bone marrow (where our haematopoietic stem cells reside) to the lungs and their alveoli, which are among the most oxygenated areas of the body. Immune cells are therefore required to adapt to varying oxygen availability as they move from the bone marrow to peripheral organs to mediate their effector functions. These changing oxygen gradients are exaggerated during inflammation, where oxygenation is often depleted owing to alterations in tissue perfusion and increased cellular activity. As such, it is important to consider the effects of oxygenation on shaping the immune response during tissue homeostasis and disease conditions. In this Review, we address the relevance of both physiological oxygenation (physioxia) and disease-associated hypoxia (where cellular oxygen demand outstrips supply) for immune cell functions, discussing the relevance of hypoxia for immune responses in the settings of tissue homeostasis, inflammation, infection, cancer and disease immunotherapy.

Targeting metabolic dysfunction of CD8 T cells and natural killer cells in cancer

The importance of metabolic pathways in regulating immune responses is now well established, and a mapping of the bioenergetic metabolism of different immune cell types is under way. CD8 T cells and natural killer (NK) cells contribute to cancer immunosurveillance through their cytotoxic functions and secretion of cytokines and chemokines, complementing each other in target recognition mechanisms. Several immunotherapies leverage these cell types by either stimulating their activity or redirecting their specificity against tumour cells. However, the anticancer activity of CD8 T cells and NK cells is rapidly diminished in the tumour microenvironment, closely linked to a decline in their metabolic capacities. Various strategies have been developed to restore cancer immunosurveillance, including targeting bioenergetic metabolism or genetic engineering. This Review provides an overview of metabolic dysfunction in CD8 T cells and NK cells within the tumour microenvironment, highlighting current therapies aiming to overcome these issues.

Identification of a Lactate Accumulation Model to Explain the Heterogeneity in Prognosis, Immune Landscape, and Tumor Environment for HNSCC patients

Head and neck squamous cell carcinoma (HNSCC) is one of the most frequent cancers with a high mortality rate. Lactate accumulation, a hallmark of cancer, has received extensive attention, but its role in HNSCC remains underexplored. Therefore, we identified 33 prognostic genes related to lactate accumulation. By consensus clustering, we separated all HNSCC samples into cluster_A or cluster_B and explored the difference of clinicopathological characteristics and genomics landscape. Next, we performed LASSO analysis and RSF to calculate the lactate-related gene score (LRGS) and constructed a risk model with high accuracy for predicting survival, as estimated by ROC, nomogram, and calibration curve. Then, through OncoPredict algorithm and TCIA, we filter the suitable drugs, especially immunology with diverse LRGS. GSEA analysis showed that the DEGs of LRGS were enriched in activation of immune response and positive regulation of immune response. Moreover, we developed a tumor-infiltrating immune-related lncRNA signature (TILSig) through a combination of 115 immune cell lines from 16 GEO datasets and DealGPL570. Subsequently, we identified the 9 tumor-infiltrating immune-related lncRNAs and calculated the TIL_score. The correlations among these tumor-infiltrating immune-related lncRNAs, hub lactate-related genes and LRGS levels were visualized. According to validation using multiple datasets including TCGA, GSE65858, GSE41613, GSE27020, and the IMvigor 210 database, CARS2, NFU1, and SYNJ1 were identified as hub genes. In light of a comprehensive pan-cancer study, we analyzed these genes to detect the potential clinical value. In conclusion, the constructed LRGS provides important insights for subsequent mechanistic research and can guide clinicians in proposing therapeutic strategies for HNSCC patients.

Lactic acid inhibits the interaction between PD-L1 protein and PD-L1 antibody in the PD-1/PD-L1 blockade therapy-resistant tumor

Immune checkpoint blockade therapy targeting the programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) axis has shown remarkable clinical impact in multiple cancer types. Nonetheless, despite the recent success of PD-1/PD-L1 blockade therapy, such response rates in cancer patients have been limited to tumors encompassing specific tumor microenvironment characteristics. The altered metabolic activity of cancer cells shapes the anti-tumor immune response by affecting the activity of immune cells. However, it remains mostly unknown how the altered metabolic activity of cancer cells impacts their resistance to PD-1/PD-L1 blockade therapy. Here, we found that tumor cell-derived lactic acid renders the immunosuppressive tumor microenvironment in the PD-1/PD-L1 blockade-resistant tumors by inhibiting the interaction between the PD-L1 protein and anti-PD-L1 antibody. Furthermore, we showed that the combination therapy of targeting PD-L1 with our PD-L1 antibody-drug conjugate (PD-L1-ADC) and reducing lactic acid with the monocarboxylate transporter 1 (MCT-1) inhibitor, AZD3965, can effectively treat the PD-1/PD-L1 blockade-resistant tumors. The findings of this study provide a new mechanism of how lactic acid induces an immunosuppressive tumor microenvironment and suggest a potential combination treatment to overcome the tumor resistance to PD-1/PD-L1 blockade therapy.

Tanshinone I reprograms glycolysis metabolism to regulate histone H3 lysine 18 lactylation (H3K18la) and inhibits cancer cell growth in ovarian cancer

Salvia miltiorrhiza, the anticancer properties of these components are multifaceted, encompassing the inhibition of tumor growth, prevention of the metastatic spread of cancer cells, enhancement of the sensitivity of cancer cells to chemotherapy and radiation therapy, and the suppression of angiogenesis, which is crucial for tumor growth and survival. In the context of our recent study, we have discovered that tanshinone I, one of the active components of Salvia miltiorrhiza, possesses the ability to inhibit the proliferation of ovarian cancer cells, both in laboratory settings and within living organisms. To further understand the molecular mechanisms behind this effect, we conducted a comprehensive transcriptomic analysis. Our findings indicated that tanshinone I exerts its inhibitory action by downregulating the expression of genes associated with glycolysis. Specifically, tanshinone I decreased the expression of glycolysis-related genes such as HK2 (hexokinase 2), PFK (phosphofructokinase), ENO2 (enolase 2), and LDHA (lactate dehydrogenase A). Inhibiting lactate production by tanshinone I application reduced the level of histone H3 lysine 18 lactylation (H3K18la), which reduced the expression of tumor-associated genes, such as TTK, PDGFRβ, YTHDF2 and RUBCNL. In addition, tanshinone I alleviated the immunosuppressive tumor microenvironment. In summary, tanshinone I blocks glycolysis to regulate histone H3 lysine 18 lactylation (H3K18la), which inhibits ovarian cancer cell growth, revealing the anticancer mechanism of tanshinone I.

D-sodium lactate promotes the activation of NF-κB signaling pathway induced by lipopolysaccharide via histone lactylation in bovine mammary epithelial cells

Lactate is a glycolytic end product that is further metabolized as an energy source. This end product has been associated with certain diseases, including sepsis and tumors, and it can regulate the transition of macrophages to an anti-inflammatory state. This study aimed to explore the effects of lactate on the inflammatory responses of mammary gland epithelial cells, which constitute the first line of defense against pathogens in mammary glands. Bovine mammary epithelial cells (BMECs) were challenged with lipopolysaccharide (LPS) in the presence or absence of D-sodium lactate (D-nala). LPS exposure increased the concentration of lactate both inside and outside the cells. Further, inhibiting glycolysis diminished the LPS-induced production of proinflammatory cytokines. Treatment with LPS, exogenous D-nala, and their combination upregulated the expression levels of MCT1, increased the intracellular levels of lactate and histone H3 lysine 18 lactylation (H3K18la), and activated the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) signaling pathway. The lactylation of H3K18 was mediated by p300/CBP. The p300/CBP inhibitor C646 decreased the level of H3K18la, reversing the activation of the NF-κB signaling pathway and release of proinflammatory cytokines. Therefore, LPS increased the intracellular level of lactate by upregulating MCT1 and glycolysis. D-nala exacerbated the LPS-induced inflammatory responses in BMECs. Moreover, intracellular lactate enhanced the activation of the NF-κB signaling pathway through the p300/CBP-mediated lactylation of H3K18. Thus, the findings of this study expand our understanding of lactate function in immune regulation.

T Cell Dysregulation in Rheumatoid Arthritis: from Genetic Susceptibility to Established Disease

PURPOSE OF REVIEW

Rheumatoid arthritis (RA) is a complex autoimmune disease characterized by chronic inflammation of the synovial tissue, where T cells play a central role in pathogenesis. Recent research has identified T peripheral helper (Tph) cells as critical mediators of local B cell activation in inflamed tissues. This review synthesizes the latest advancements in our understanding the of the role of T cells in RA, from initiation to established disease.

RECENT FINDINGS

We explore recent advances regarding the genetic and epigenetic factors that predispose individuals to RA, the mechanisms of T cell activation and differentiation, and the interactions between T cells and other immune and stromal cells within the synovial microenvironment. The emergence of Tph cells as key drivers of RA pathobiology is highlighted, along with their potential as therapeutic targets. We also discuss the heterogeneity of T cell responses and their interplay with synovial cells, while addressing critical research gaps such as the drivers of T cell recruitment and the plasticity of synovial phenotypes. A deeper understanding of T cell dynamics in RA will provide valuable insights for developing targeted therapies to modulate T cell-mediated inflammation and improve patient outcomes.

Hospitalised older adults with community-acquired pneumonia and sepsis have dysregulated neutrophil function but preserved glycolysis

OBJECTIVE

Community-acquired pneumonia (CAP) is a leading cause of hospitalisation in older adults and is associated with a high likelihood of adverse outcomes. Given the ageing population and lack of therapeutic advances in CAP, new strategies to manage the burden of this disease are needed. Neutrophil dysfunction has been widely demonstrated in CAP and is associated with poor outcomes. We hypothesised that impaired glycolytic metabolism was driving neutrophil dysfunction in older adults with CAP.

METHODS

To investigate the mechanism underlying neutrophil dysfunction in CAP, we recruited older adults with CAP and sepsis, age-matched controls and healthy young adults to assess neutrophil function and glycolytic metabolism in peripheral blood neutrophils.

RESULTS

We demonstrate that neutrophils from older donors with CAP display a broad range of functional defects, including inaccurate migration to interleukin 8, impaired respiratory burst in response to phorbol 12-myristate 13-acetate and increased spontaneous degranulation compared with age-matched controls. Glycolysis (assessed by extracellular flux and RNA-sequencing) was not significantly altered between age-matched groups; however, basal rates of neutrophil glycolysis were significantly higher in patients with CAP and older adult controls compared with healthy young adults, and stimulated glycolysis was significantly higher in young adults compared with older adults with and without CAP.

CONCLUSIONS

Our findings suggest that neutrophil dysfunction in older adults with CAP may be implicated in poor outcomes, irrespective of glycolytic metabolism.

Mannose metabolism reshapes T cell differentiation to enhance anti-tumor immunity

Cellular metabolic status profoundly influences T cell differentiation, persistence, and anti-tumor efficacy. Our single-cell metabolic analyses of T cells reveal that diminished mannose metabolism is a prominent feature of T cell dysfunction. Conversely, experimental augmentation/restoration of mannose metabolism in adoptively transferred T cells via D-mannose supplementation enhances anti-tumor activity and restricts exhaustion differentiation both in vitro and in vivo. Mechanistically, D-mannose treatment induces intracellular metabolic programming and increases the O-GlcNAc transferase (OGT)-mediated O-GlcNAcylation of β-catenin, which preserves Tcf7 expression and epigenetic stemness, thereby promoting stem-like programs in T cells. Furthermore, in vitro expansion with D-mannose supplementation yields T cell products for adoptive therapy with stemness characteristics, even after extensive long-term expansion, that exhibits enhanced anti-tumor efficacy. These findings reveal cell-intrinsic mannose metabolism as a physiological regulator of CD8+ T cell fate, decoupling proliferation/expansion from differentiation, and underscoring the therapeutic potential of mannose modulation in cancer immunotherapy.

Lactate-induced protein lactylation in cancer: functions, biomarkers and immunotherapy strategies

Lactate, long viewed as a byproduct of glycolysis and metabolic waste. Initially identified within the context of yogurt fermentation, lactate's role extends beyond culinary applications to its significance in biochemical processes. Contemporary research reveals that lactate functions not merely as the terminal product of glycolysis but also as a nexus for initiating physiological and pathological responses within the body. Lysine lactylation (Kla), a novel post-translational modification (PTM) of proteins, has emerged as a pivotal mechanism by which lactate exerts its regulatory influence. This epigenetic modification has the potential to alter gene expression patterns, thereby impacting physiological and pathological processes. Increasing evidence indicates a correlation between lactylation and adverse prognosis in various malignancies. Consequently, this review article aims to encapsulate the proteins that interact with lactate, elucidate the role of lactylation in tumorigenesis and progression, and explore the potential therapeutic targets afforded by the modulation of lactylation. The objective of this review is to clarify the oncogenic significance of lactylation and to provide a strategic framework for future research directions in this burgeoning field.

Immunosenescence, Physical Exercise, and their Implications in Tumor Immunity and Immunotherapy

Aging is associated with a decline in immune function, termed immunosenescence, which compromises host defences and increases susceptibility to infections and cancer. Physical exercise is widely recognized for its myriad health benefits, including the potential to modulate the immune system. This review explores the bidirectional relationship between immunosenescence and physical exercise, focusing on their interplay in shaping antitumor immunity. We summarize the impact of aging on innate and adaptive immune cells, highlighting alterations that contribute to immunosenescence and cancer development. We further delineate the effects of exercise on immune cell function, demonstrating its potential to mitigate immunosenescence and enhance antitumor responses. We also discuss the implications of immunosenescence for the efficacy of immunotherapies, such as immune checkpoint inhibitors and adoptive T cell therapy, and explore the potential benefits of combining exercise with these interventions. Collectively, this review underscores the importance of understanding the complex relationship between immunosenescence, physical exercise, and antitumor immunity, paving the way for the development of innovative strategies to improve cancer outcomes in the aging population.

Metabolic Signaling in the Tumor Microenvironment

Cancer cells must reprogram their metabolism to sustain rapid growth. This is accomplished in part by switching to aerobic glycolysis, uncoupling glucose from mitochondrial metabolism, and performing anaplerosis via alternative carbon sources to replenish intermediates of the tricarboxylic acid (TCA) cycle and sustain oxidative phosphorylation (OXPHOS). While this metabolic program produces adequate biosynthetic intermediates, reducing agents, ATP, and epigenetic remodeling cofactors necessary to sustain growth, it also produces large amounts of byproducts that can generate a hostile tumor microenvironment (TME) characterized by low pH, redox stress, and poor oxygenation. In recent years, the focus of cancer metabolic research has shifted from the regulation and utilization of cancer cell-intrinsic pathways to studying how the metabolic landscape of the tumor affects the anti-tumor immune response. Recent discoveries point to the role that secreted metabolites within the TME play in crosstalk between tumor cell types to promote tumorigenesis and hinder the anti-tumor immune response. In this review, we will explore how crosstalk between metabolites of cancer cells, immune cells, and stromal cells drives tumorigenesis and what effects the competition for resources and metabolic crosstalk has on immune cell function.

New Posttranslational Modification Lactylation Brings New Inspiration for the Treatment of Rheumatoid Arthritis

Lactic acid (LA) is an essential glycolytic metabolite and energy source in the body, which is present in high levels in the synovial fluid of patients with rheumatoid arthritis (RA) and is a reliable indicator for identifying inflammatory arthritis. LA not only acts as an inflammatory amplifier in RA, recent studies have found that novel posttranslational modification (PTM) lactylation mediated by LA may also play a key role in RA. Single-cell sequencing showed that the RA lactylation score of patients with RA was significantly increased, and core lactylation-promoting genes, including NDUFB3, NGLY1, and other genes, were found to be potential biomarkers of RA. More studies have shown that lactylation can regulate genes in various cells, such as fibroblast-like synoviocytes (FLSs) and macrophages, thus playing a special role in the development and occurrence of autoimmune diseases, neurological diseases, and cancer diseases. In this paper, we review the research on lactylation in RA-related cells and mechanisms and bring new insights into the pathogenesis, diagnosis, and treatment of RA.

Important Role of Mitochondrial Dysfunction in Immune Triggering and Inflammatory Response in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease, primarily characterized by chronic symmetric synovial inflammation and erosive bone destruction.Mitochondria, the primary site of cellular energy production, play a crucial role in energy metabolism and possess homeostatic regulation capabilities. Mitochondrial function influences the differentiation, activation, and survival of both immune and non-immune cells involved in RA pathogenesis. If the organism experiences hypoxia, genetic predisposition, and oxidative stress, it leads to mitochondrial dysfunction, which further affects immune cell energy metabolism, synovial cell proliferation, apoptosis, and inflammatory signaling, causing the onset and progression of RA; and, mitochondrial regulation is becoming increasingly important in the treatment of RA.In this review, we examine the structure and function of mitochondria, analyze the potential causes of mitochondrial dysfunction in RA, and focus on the mechanisms by which mitochondrial dysfunction triggers chronic inflammation and immune disorders in RA. We also explore the effects of mitochondrial dysfunction on RA immune cells and osteoblasts, emphasizing its key role in the immune response and inflammatory processes in RA. Furthermore, we discuss potential biological processes that regulate mitochondrial homeostasis, which are of great importance for the prevention and treatment of RA.

Targeting metabolic pathway enhance CAR-T potency for solid tumor

Chimeric antigen receptor (CAR) T cells have great potential in cancer therapy, particularly in treating hematologic malignancies. However, their efficacy in solid tumors remains limited, with a significant proportion of patients failing to achieve long-term complete remission. One major challenge is the premature exhaustion of CAR-T cells, often due to insufficient metabolic energy. The survival, function and metabolic adaptation of CAR-T cells are key determinants of their therapeutic efficacy. We explore how targeting metabolic pathways in the tumor microenvironment can enhance CAR-T cell therapy by addressing metabolic competition and immunosuppression that impair CAR-T cell function. Tumors undergo metabolically reprogrammed to meet their rapid proliferation, thereby modulating metabolic pathways in immune cells to promote immunosuppression. The distinct metabolic requirements of tumors and T cells create a competitive environment, affecting the efficacy of CAR-T cell therapy. Recent research on glucose, lipid and amino acid metabolism, along with the interactions between tumor and immune cell metabolism, has revealed that targeting these metabolic processes can enhance antitumor immune responses. Combining metabolic interventions with existing antitumor therapies can fulfill the metabolic demands of immune cells, providing new ideas for tumor immunometabolic therapies. This review discusses the latest advances in the immunometabolic mechanisms underlying tumor immunosuppression, their implications for immunotherapy, and summarizes potential metabolic targets to improve the efficacy of CAR-T therapy.

The Therapeutic Potential of Physical Exercise in Cancer: The Role of Chemokines

The global increase in cancer cases and mortality has been associated with inflammatory processes, in which chemokines play crucial roles. These molecules, a subfamily of cytokines, are essential for the migration, adhesion, interaction, and positioning of immune cells throughout the body. Chemokines primarily originate in response to pathogenic stimuli and inflammatory cytokines. They are expressed by lymphocytes in the bloodstream and are divided into four classes (CC, CXC, XC, and CX3C), playing multifaceted roles in the tumor environment (TME). In the TME, chemokines regulate immune behavior by recruiting cells such as tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs), which promote tumor survival. Additionally, they directly influence tumor behavior, promoting pathological angiogenesis, invasion, and metastasis. On the other hand, chemokines can also induce antitumor responses by mobilizing CD8+ T cells and natural killer (NK) cells to the tumor, reducing pro-inflammatory chemokines and enhancing essential antitumor responses. Given the complex interaction between chemokines, the immune system, angiogenic factors, and metastasis, it becomes evident how important it is to target these pathways in therapeutic interventions to counteract cancer progression. In this context, physical exercise emerges as a promising strategy due to its role modulating the expression of anti-inflammatory chemokines and enhancing the antitumor response. Aerobic and resistance exercises have been associated with a beneficial inflammatory profile in cancer, increased infiltration of CD8+ T cells in the TME, and improvement of intratumoral vasculature. This creates an environment less favorable to tumor growth and supports the circulation of antitumor immune cells and chemokines. Therefore, understanding the impact of exercise on the expression of chemokines can provide valuable insights for therapeutic interventions in cancer treatment and prevention.

Lactate and Lactylation: Dual Regulators of T-Cell-Mediated Tumor Immunity and Immunotherapy

Lactate and its derivative, lactylation, play pivotal roles in modulating immune responses within the tumor microenvironment (TME), particularly in T-cell-mediated cancer immunotherapy. Elevated lactate levels, a hallmark of the Warburg effect, contribute to immune suppression through CD8+ T cell functionality and by promoting regulatory T cell (Treg) activity. Lactylation, a post-translational modification (PTM), alters histone and non-histone proteins, influencing gene expression and further reinforcing immune suppression. In the complex TME, lactate and its derivative, lactylation, are not only associated with immune suppression but can also, under certain conditions, exert immunostimulatory effects that enhance cytotoxic responses. This review describes the dual roles of lactate and lactylation in T-cell-mediated tumor immunity, analyzing how these factors contribute to immune evasion, therapeutic resistance, and immune activation. Furthermore, the article highlights emerging therapeutic strategies aimed at inhibiting lactate production or disrupting lactylation pathways to achieve a balanced regulation of these dual effects. These strategies offer new insights into overcoming tumor-induced immune suppression and hold the potential to improve the efficacy of cancer immunotherapies.

Dual impacts of serine/glycine-free diet in enhancing antitumor immunity and promoting evasion via PD-L1 lactylation

The effect of the serine/glycine-free diet (-SG diet) on colorectal cancer (CRC) remains unclear; meanwhile, programmed death-1 (PD-1) inhibitors are less effective for most CRC patients. Here, we demonstrate that the -SG diet inhibits CRC growth and promotes the accumulation of cytotoxic T cells to enhance antitumor immunity. Additionally, we also identified the lactylation of programmed death-ligand 1 (PD-L1) in tumor cells as a mechanism of immune evasion during cytotoxic T cell-mediated antitumor responses, and blocking the PD-1/PD-L1 signaling pathway is able to rejuvenate the function of CD8+ T cells recruited by the -SG diet, indicating the potential of combining the -SG diet with immunotherapy. We conducted a single-arm, phase I study (ChiCTR2300067929). The primary outcome suggests that the -SG diet is feasible and safe for regulating systemic immunity. Secondary outcomes include patient tolerability and potential antitumor effects. Collectively, our findings highlight the promising therapeutic potential of the -SG diet for treating solid tumors.

Metabolic drives affecting Th17/Treg gene expression changes and differentiation: impact on immune-microenvironment regulation

The CD4+ T-cell population plays a vital role in the adaptive immune system by coordinating the immune response against different pathogens. A significant transformation occurs in CD4+ cells during an immune response, as they shift from a dormant state to an active state. This transformation leads to extensive proliferation, differentiation, and cytokine production, which contribute to regulating and coordinating the immune response. Th17 and Treg cells are among the most intriguing CD4+ T-cell subpopulations in terms of genetics and metabolism. Gene expression modulation processes rely on and are linked to metabolic changes in cells. Lactylation is a new model that combines metabolism and gene modulation to drive Th17/Treg differentiation and functional processes. The focus of this review is on the metabolic pathways that impact lymphocyte gene modulation in a functionally relevant manner.

microRNAs: critical targets for treating rheumatoid arthritis angiogenesis

Vascular neogenesis, an early event in the development of rheumatoid arthritis (RA) inflammation, is critical for the formation of synovial vascular networks and plays a key role in the progression and persistence of chronic RA inflammation. microRNAs (miRNAs), a class of single-stranded, non-coding RNAs with approximately 21-23 nucleotides in length, regulate gene expression by binding to the 3' untranslated region (3'-UTR) of specific mRNAs. Increasing evidence suggests that miRNAs are differently expressed in diseases associated with vascular neogenesis and play a crucial role in disease-related vascular neogenesis. However, current studies are not sufficient and further experimental studies are needed to validate and establish the relationship between miRNAs and diseases associated with vascular neogenesis, and to determine the specific role of miRNAs in vascular development pathways. To better treat vascular neogenesis in diseases such as RA, we need additional studies on the role of miRNAs and their target genes in vascular development, and to provide more strategic references. In addition, future studies can use modern biotechnological methods such as proteomics and transcriptomics to investigate the expression and regulatory mechanisms of miRNAs, providing a more comprehensive and in-depth research basis for the treatment of related diseases such as RA.

Liver type 1 innate lymphoid cells undergo apoptosis in murine models of macrophage activation syndrome and are dispensable for disease

Macrophage activation syndrome (MAS) exemplifies a severe cytokine storm disorder with liver inflammation. In the liver, classical natural killer (cNK) cells and liver-resident type 1 innate lymphoid cells (ILC1s) dominate the ILC population. Thus far, research has primarily focused on the corresponding role of cNK cells. Considering the liver inflammation and cytokine storm in MAS, liver-resident ILC1s represent an interesting population to explore due to their rapid cytokine production upon environmental triggers. By utilizing a Toll-like receptor (TLR)9- and TLR3:4-triggered MAS model, we showed that ILC1s highly produce IFN-γ and TNF-α. However, activated ILC1s undergo apoptosis and are strongly reduced in numbers, while cNK cells resist inflammation-induced apoptosis. Signs of mitochondrial stress suggest that this ILC1 apoptosis may be driven by inflammation-induced mitochondrial impairment. To study whether early induction of highly cytokine-producing ILC1s influences MAS development, we used Hobit KO mice due to their paucity of liver ILC1s but unaffected cNK cell numbers. Nevertheless, neither the severity of MAS features nor the total inflammatory cytokine levels were affected in these Hobit KO mice, indicating that ILC1s are dispensable for MAS pathogenesis. Collectively, our data demonstrate that ILC1s undergo apoptosis during TLR-triggering and are dispensable for MAS pathogenesis.

Urinary Tract Infections Detection with Molecular Biomarkers

Urinary tract infection (UTI) is the most prevalent kind of pathogenic bacteria infection, and the midstream urine culture is regarded as the gold standard in UTI diagnosis. Recently, even with modern media and techniques such as polymerase chain reaction (PCR), urinary cultures still create a considerable workload for hospital laboratories. Other UTI-detecting methods, such as flow cytometry and lateral flow immunoassay, suffer from various drawbacks like long time consumption and low sensitivity. Therefore, looking for reliable biomarkers in UTI is urgently needed. In this review, the current definitions of UTI can be basically divided into two main categories: uncomplicated UTI and complicated UTI. In light of anatomical sites, it can be classified as either lower UTI or upper UTI. We take the classification of UTI as a clue and review the reported extensive literature to classify the existing studied markers into the following three categories: Biomarkers used clinically; Promising biomarkers; and Controversial biomarkers. Particularly, the nucleic acid-associated, metabolomic, and lipidomic biomarkers are highlighted. At the end, we discuss the challenges and prospects of biomarkers in UTI, hoping to further inspire the diagnosis of UTI.

Lactate metabolism and lactylation in cardiovascular disease: novel mechanisms and therapeutic targets

Cardiovascular disease (CVD) is responsible for approximately 30% of annual global mortality rates, yet existing treatments for this condition are considered less than ideal. Despite being previously overlooked, lactate, a byproduct of glycolysis, is now acknowledged for its crucial role in the cellular functions of the cardiovascular system. Recent studies have shown that lactate influences the proliferation, differentiation, and activation of immune cells through its modulation of post-translational protein modifications, thereby affecting the development and prognosis of cardiovascular disease. Consequently, there has been a notable increase in interest towards drug targets targeting lactylation in immune cells, prompting further exploration. In light of the swift advancements in this domain, this review article is dedicated to examining lactylation in cardiovascular disease and potential drug targets for regulating lactylation, with the aim of enhancing comprehension of this intricate field.

Targeting the tumor microenvironment with biomaterials for enhanced immunotherapeutic efficacy

The tumor microenvironment (TME) is a complex system characterized by low oxygen, low pH, high pressure, and numerous growth factors and protein hydrolases that regulate a wide range of biological behaviors in the tumor and have a profound impact on cancer progression. Immunotherapy is an innovative approach to cancer treatment that activates the immune system, resulting in the spontaneous killing of tumor cells. However, the therapeutic efficacy of these clinically approved cancer immunotherapies (e.g., immune checkpoint blocker (ICB) therapies and chimeric antigen receptor (CAR) T-cell therapies) is far from satisfactory due to the presence of immunosuppressive TMEs created in part by tumor hypoxia, acidity, high levels of reactive oxygen species (ROS), and a dense extracellular matrix (ECM). With continuous advances in materials science and drug-delivery technologies, biomaterials hold considerable potential for targeting the TME. This article reviews the advances in biomaterial-based targeting of the TME to advance our current understanding on the role of biomaterials in enhancing tumor immunity. In addition, the strategies for remodeling the TME offer enticing advantages; however, the represent a double-edged sword. In the process of reshaping the TME, the risk of tumor growth, infiltration, and distant metastasis may increase.

Lactate: a rising star in tumors and inflammation

Lactate has been traditionally regarded as a mere byproduct of glycolysis or metabolic waste. However, an increasing body of literature suggests its critical role in regulating various physiological and pathological processes. Lactate is generally associated with hypoxia, inflammation, viral infections, and tumors. It performs complex physiological roles by activating monocarboxylate transporter (MCT) or the G protein-coupled receptor GPR81 across the cell membrane. Lactate exerts immunosuppressive effects by regulating the functions of various immune cells (such as natural killer cells, T cells, dendritic cells, and monocytes) and its role in macrophage polarization and myeloid-derived suppressor cell (MDSC) differentiation in the tumor microenvironment. Lactic acid has also recently been found to increase the density of CD8+ T cells, thereby enhancing the antitumor immune response. Acute or chronic inflammatory diseases have opposite immune states in the inflammatory disease microenvironment. Factors such as cell types, transcriptional regulators, ionic mediators, and the microenvironment all contribute to the diverse functions lactate exhibits. Herein, we reviewed the pleiotropic effects of lactate on the regulation of various functions of immune cells in the tumor microenvironment and under inflammatory conditions, which may help to provide new insights and potential targets for the diagnosis and treatment of inflammatory diseases and malignancies.

From metabolic byproduct to immune modulator: the role of lactate in tumor immune escape

Lactic acid, a key metabolic byproduct within the tumor microenvironment, has garnered significant attention for its role in immune evasion mechanisms. Tumor cells produce and release large amounts of lactic acid into the tumor microenvironment through aberrant glycolysis via the Warburg effect, leading to a drop in pH. Elevated lactic acid levels profoundly suppress proliferation capacity, cytotoxic functions, and migratory abilities of immune effector cells such as macrophages and natural killer cells at the tumor site. Moreover, lactic acid can modulate the expression of surface molecules on immune cells, interfering with their recognition and attack of tumor cells, and it regulates signaling pathways that promote the expansion and enhanced function of immunosuppressive cells like regulatory T cells, thereby fostering immune tolerance within the tumor microenvironment. Current research is actively exploring strategies targeting lactic acid metabolism to ameliorate tumor immune evasion. Key approaches under investigation include inhibiting the activity of critical enzymes in lactic acid production to reduce its synthesis or blocking lactate transporters to alter intracellular and extracellular lactate distribution. These methods hold promise when combined with existing immunotherapies such as immune checkpoint inhibitors and chimeric antigen receptor T-cell therapies to enhance the immune system's ability to eliminate tumor cells. This could pave the way for novel combinatorial treatment strategies in clinical cancer therapy, effectively overcoming tumor immune evasion phenomena, and ultimately improving overall treatment efficacy.

Small Leucine Zipper Protein Regulates Glucose Metabolism of Prostate Cancer Cells via Induction of Phosphoglycerate Kinase 1

BACKGROUND

Cancer cells exhibit altered metabolism whereby glucose is preferentially utilized to produce lactate through aerobic glycolysis. The increase in lactate production creates an acidic microenvironment that supports tumor progression and metastasis. Human small leucine zipper protein (sLZIP) is involved in the transcriptional regulation of genes related to migration and invasion of prostate cancer. However, the role of sLZIP in modulating glucose metabolism in prostate cancer remains unknown. This study investigates whether sLZIP regulates the transcription of glycolysis-related genes to promote metabolic reprogramming in prostate cancer.

METHODS

Depletion of sLZIP resulted in the downregulation of several glycolytic genes, including glucose transporter 1, phosphofructokinase liver type, phosphoglycerate kinase 1 (PGK1), and lactate dehydrogenase. Among these, only PGK1 showed a prominent dose-dependent decrease in mRNA and protein expression after sLZIP silencing.

RESULTS

Mechanistically, increasing or decreasing sLZIP affected the promoter activity of PGK1 in a similar manner. Moreover, the absence of sLZIP attenuated the maximum glycolytic rate in prostate cancer cells. These results were further supported by a reduction in lactate secretion, glucose uptake, and ATP production in sLZIP-knockout prostate cancer cells. sLZIP deficiency hindered cancer growth, as demonstrated by proliferation assays. However, overexpression of PGK1 in sLZIP knockout cells resulted in recovery of aerobic glycolysis. Results of the xenograft experiment revealed that mice injected with sLZIP knockout cells exhibited a decrease in tumor mass compared to those injected with control cells.

CONCLUSION

These findings suggest that sLZIP contributes to the metabolic reprogramming of prostate cancer cells via the transcriptional regulation of PGK1.

Similarities in B Cell Defects between Aging and Obesity

The aging population is increasing worldwide, and there is also an increase in the aging population living with overweight and obesity, due to changes in lifestyle and in dietary patterns that elderly individuals experience later in life. Both aging and obesity are conditions of accelerated metabolic dysfunction and dysregulated immune responses. In this review, we summarize published findings showing that obesity induces changes in humoral immunity similar to those induced by aging and that the age-associated B cell defects are mainly due to metabolic changes. We discuss the role of the obese adipose tissue in inducing dysfunctional humoral responses and autoimmune Ab secretion.