The glucose transporter GLUT3 controls T helper 17 cell responses through glycolytic-epigenetic reprogramming

METTL14 Mediates Glut3 m6A methylation to improve osteogenesis under oxidative stress condition

OBJECTIVES

Bone remodeling imbalance contributes to osteoporosis. Though current medications enhance osteoblast involvement in bone formation, the underlying pathways remain unclear. This study was aimed to explore the pathways involved in bone formation by osteoblasts, we investigate the protective role of glycolysis and N6-methyladenosine methylation (m6A) against oxidative stress-induced impairment of osteogenesis in MC3T3-E1 cells.

METHODS

We utilized a concentration of 200 μM hydrogen peroxide (H2O2) to establish an oxidative damage model of MC3T3-E1 cells. Subsequently, we examined the alterations in the m6A methyltransferases (METTL3, METTL14), glucose transporter proteins (GLUT1, GLUT3) and validated m6A methyltransferase overexpression in vitro and in an osteoporosis model. The osteoblast differentiation and osteogenesis-related molecules and serum bone resorption markers were measured by biochemical analysis, Alizarin Red S staining, Western blot and ELISA.

RESULTS

H2O2 treatment inhibited glycolysis and osteoblast differentiation in MC3T3-E1 cells. However, when METTL14 was overexpressed, these changes induced by H2O2 could be mitigated. Our findings indicate that METTL14 promotes GLUT3 expression via YTHDF1, leading to the modulation of various parameters in the H2O2-induced model. Similar positive effects of METTL14 on osteogenesis were observed in an ovariectomized mouse osteoporosis model.

DISCUSSION

METTL14 could serve as a potential therapeutic approach for enhancing osteoporosis treatment.

Targeting CD38 immunometabolic checkpoint improves metabolic fitness and cognition in a mouse model of Alzheimer's disease

Protective immunity, essential for brain maintenance and repair, may be compromised in Alzheimer's disease (AD). Here, using high-dimensional single-cell mass cytometry, we find a unique immunometabolic signature in circulating CD4+ T cells preceding symptom onset in individuals with familial AD, featured by the elevation of CD38 expression. Using female 5xFAD mice, a mouse model of AD, we show that treatment with an antibody directed to CD38 leads to restored metabolic fitness, improved cognitive performance, and attenuated local neuroinflammation. Comprehensive profiling across distinct immunological niches in 5xFAD mice, reveals a high level of disease-associated CD4+ T cells that produce IL-17A in the dural meninges, previously linked to cognitive decline. Targeting CD38 leads to abrogation of meningeal TH17 immunity and cortical IL-1β, breaking the negative feedback loop between these two compartments. Taken together, the present findings suggest CD38 as an immunometabolic checkpoint that could be adopted as a pre-symptomatic biomarker for early diagnosis of AD, and might also be therapeutically targeted alone or in combination with other immunotherapies for disease modification.

NIR-Activated Hollow Upconversion Nanocomposites for Tumor Therapy via GLUT1 Inhibition and Mitochondrial Function Disruption

Tumor remains a leading contributor to global mortality rates, necessitating urgent advancements in therapeutic interventions. Due to the intricate nature of the tumor microenvironment, individual differences make it difficult to achieve desired efficacy with a single strategy. To overcome these challenges, we develop for the first time hollow NaBiF4-based nanocomposites NaBiF4-W/R-D for tumor therapy by glucose transporter 1 (GLUT1) inhibition and mitochondrial function disruption. NaBiF4-W/R-D can inhibit GLUT1 function due to the presence of WZB117, which leads to a decrease in intracellular glucose in tumor cells, leaving them in a starved state. Meanwhile, the upconversion luminescence of NaBiF4-W/R-D under near-infrared (NIR) laser irradiation can stimulate the photosensitizer to efficiently generate singlet oxygen to disrupt the mitochondrial function and then kill the tumor cells. In addition, NIR-II emission from NaBiF4-W/R-D is used for fluorescence imaging to determine the optimal time point for tumor treatment. Finally, NaBiF4-W/R-D leads to mitochondrial membrane potential depolarization, impaired mitochondrial function, activation of caspase-3, and ultimately the amplification of apoptosis.

SENP1-SIRT3 axis mediates glycolytic reprogramming to suppress inflammation during Listeria monocytogenes infection

Listeria monocytogenes, a foodborne pathogen, has the ability to invade intestinal mucosal cells, undergo intracellular proliferation, activate host immune responses, and induce diseases such as colitis. We have demonstrated that sentrin-specific protease 1 (SENP1) functions as a protective gene in the host, suppressing the inflammatory response triggered by Listeria monocytogenes. The host's SENP1-SIRT3 axis plays a critical role in regulating inflammation during Listeria monocytogenes infection. Our findings reveal that overexpression of SENP1, particularly under Listeria monocytogenes infection conditions (MOI = 20), effectively suppresses inflammation through modulation of glycolysis. Mechanistically, during Listeria monocytogenes infection, SENP1 accumulates in the mitochondria, facilitating the de-SUMOylation and activation of sirtuin 3 (SIRT3). Activated SIRT3 then regulates the deacetylation of pyruvate kinase M2 (PKM2), leading to a decrease in glycolytic intermediates, downregulation of glycolysis-related gene expression, and suppression of inflammation. Taken together, our study provides a deeper understanding of the mechanistic role of the SENP1-SIRT3 axis in the regulation of inflammation, offering novel insights, and strategies for the treatment and prevention of inflammatory diseases.

IMPORTANCE

Sentrin-specific protease 1 (SENP1)-sirtuin 3 (SIRT3) has never been reported in the regulation of bacteria-induced inflammation. Our study demonstrated that SENP1 acted as a protective factor against Listeria-induced inflammation by promoting SIRT3 activation and subsequent metabolic reprogramming. The SENP1-SIRT3 axis served not only as an essential signaling pathway for regulating mitochondrial metabolic responses to metabolic stress but also responds to bacterial invasion and plays a protective role in the organism. Our findings provide a basis for further research into targeting the SENP1-SIRT3 signaling pathway for the treatment of bacterial infections.

The metabolic drivers of IFN-γ release: glycolysis and acetyl CoA ride in the front seat

Interferon gamma (IFN-γ) is a pleotropic cytokine which is a central mediator of the immune response to pathogen infection, while also playing important roles in tumour suppression and the pathogenesis of various autoimmune diseases. Consequently, there is potential utility in the treatment of a number of pathological conditions via being able to modify IFN-γ secretion. T cells and natural killer (NK) cells are the primary IFN-γ sources, with metabolic rewiring prior to their activation and IFN-γ secretion in both a unifying feature. The mechanisms by which metabolic changes, particularly increased glycolysis, drive enhanced IFN-γ production are multi-faceted, but are likely focused on epigenetic changes via increased acetyl CoA levels which fuels histone acetylation. Herein, we discuss the mechanisms by which metabolic changes drive altered IFN-γ synthesis by immune cells.

ACC1 is a dual metabolic-epigenetic regulator of Treg stability and immune tolerance

OBJECTIVE

Regulatory T cells (Tregs) are essential in maintaining immune tolerance and controlling inflammation. Treg stability relies on transcriptional and post-translational mechanisms, including histone acetylation at the Foxp3 locus and FoxP3 protein acetylation. Additionally, Tregs depend on specific metabolic programs for differentiation, yet the underlying molecular mechanisms remain elusive. We aimed to investigate the role of acetyl-CoA carboxylase 1 (ACC1) in the differentiation, stability, and function of regulatory T cells (Tregs).

METHODS

We used either T cell-specific ACC1 knockout mice or ACC1 inhibition via a pharmacological agent to examine the effects on Treg differentiation and stability. The impact of ACC1 inhibition on Treg function was assessed in vivo through adoptive transfer models of Th1/Th17-driven inflammatory diseases.

RESULTS

Inhibition or genetic deletion of ACC1 led to an increase in acetyl-CoA availability, promoting enhanced histone and protein acetylation, and sustained FoxP3 transcription even under inflammatory conditions. Mice with T cell-specific ACC1 deletion exhibited an enrichment of double positive RORγt+FoxP3+ cells. Moreover, Tregs treated with an ACC1 inhibitor demonstrated superior long-term stability and an enhanced capacity to suppress Th1/Th17-driven inflammatory diseases in adoptive transfer models.

CONCLUSIONS

We identified ACC1 as a metabolic checkpoint in Treg biology. Our data demonstrate that ACC1 inhibition promotes Treg differentiation and long-term stability in vitro and in vivo. Thus, ACC1 serves as a dual metabolic and epigenetic hub, regulating immune tolerance and inflammation by balancing de novo lipid synthesis and protein acetylation.

Spermidine restricts neonatal inflammation via metabolic shaping of polymorphonuclear myeloid-derived suppressor cells

Newborns exhibit a heightened vulnerability to inflammatory disorders due to their underdeveloped immune system, yet the underlying mechanisms remain poorly understood. Here we report that plasma spermidine is correlated with the maturity of human newborns and reduced risk of inflammation. Administration of spermidine led to the remission of neonatal inflammation in mice. Mechanistic studies revealed that spermidine enhanced the generation of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) via downstream eIF5A hypusination. Genetic deficiency or pharmacological inhibition of deoxyhypusine synthase (DHPS), a key enzyme of hypusinated eIF5A (eIF5AHyp), diminished the immunosuppressive activity of PMN-MDSCs, leading to aggravated neonatal inflammation. The eIF5AHyp pathway was found to enhance the immunosuppressive function via histone acetylation-mediated epigenetic transcription of immunosuppressive signatures in PMN-MDSCs. These findings demonstrate the spermidine-eIF5AHyp metabolic axis as a master switch to restrict neonatal inflammation.

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.

Mitochondrial reactive oxygen species regulate acetyl-CoA flux between cytokine production and fatty acid synthesis in effector T cells

Genetic and environmental factors shape an individual's susceptibility to autoimmunity. To identify genetic variations regulating effector T cell functions, we used a forward genetics screen of inbred mouse strains and uncovered genomic loci linked to cytokine expression. Among the candidate genes, we characterized a mitochondrial inner membrane protein, TMEM11, as an important determinant of Th1 responses. Loss of TMEM11 selectively impairs Th1 cell functions, reducing autoimmune symptoms in mice. Mechanistically, Tmem11-/- Th1 cells exhibit altered cristae architecture, impaired respiration, and increased mitochondrial reactive oxygen species (mtROS) production. Elevated mtROS hindered histone acetylation while promoting neutral lipid accumulation. Further experiments using genetic, biochemical, and pharmacological tools revealed that mtROS regulate acetyl-CoA flux between histone acetylation and fatty acid synthesis. Our findings highlight the role of mitochondrial cristae integrity in directing metabolic pathways that influence chromatin modifications and lipid biosynthesis in Th1 cells, providing new insights into immune cell metabolism.

KLHL25-ACLY module functions as a switch in the fate determination of the differentiation of iTreg/Th17

The differentiation of Th17 and iTreg is tightly associated with fatty acid metabolism. TGFβ1-induced iTreg differentiation from Th0 relies on fatty acid oxidation (FAO), whereas IL-6 with TGFβ1 shifts metabolism to Th17-preferred fatty acid synthesis (FAS). However, how IL-6 reprograms fatty acid metabolism remains unclear. Here, we unveiled that TGFβ1-activated JNK is recruited to the Klhl25 promoter by NF-YA. JNK then phosphorylates histone H3 at Ser10 to activate Klhl25 transcription, leading to the ubiquitination-dependent degradation of ATP-citrate lyase (ACLY) and the switch from FAS to FAO, which supports iTreg generation. Whereas, upon IL-6 signaling, NF-YA is phosphorylated by ERK, losing its DNA binding ability, which shuts off TGFβ1-JNK-mediated Klhl25 transcription and ACLY ubiquitination, thereby increasing FAS and supporting Th17 differentiation. This study demonstrated that KLHL25-ACLY module functions as a switch in response to TGFβ1 and IL-6 signals, playing a decisive role in the fate determination of iTreg/Th17 differentiation.

Bridging epigenomics and tumor immunometabolism: molecular mechanisms and therapeutic implications

Epigenomic modifications-such as DNA methylation, histone acetylation, and histone methylation-and their implications in tumorigenesis, progression, and treatment have emerged as a pivotal field in cancer research. Tumors undergo metabolic reprogramming to sustain proliferation and metastasis in nutrient-deficient conditions, while suppressing anti-tumor immunity in the tumor microenvironment (TME). Concurrently, immune cells within the immunosuppressive TME undergo metabolic adaptations, leading to alterations in their immune function. The complicated interplay between metabolites and epigenomic modulation has spotlighted the significance of epigenomic regulation in tumor immunometabolism. In this review, characteristics of the epigenomic modification associated with tumors are systematically summarized alongside with their regulatory roles in tumor metabolic reprogramming and immunometabolism. Classical and emerging approaches are delineated to broaden the boundaries of research on the crosstalk research on the crosstalk between tumor immunometabolism and epigenomics. Furthermore, we discuss potential therapeutic strategies that target tumor immunometabolism to modulate epigenomic modifications, highlighting the burgeoning synergy between metabolic therapies and immunotherapy as a promising avenue for cancer treatment.

Cytometry at the Intersection of Metabolism and Epigenetics in Lymphocyte Dynamics

Landmark studies at the turn of the century revealed metabolic reprogramming as a driving force for lymphocyte differentiation and function. In addition to metabolic changes, differentiating lymphocytes must remodel their epigenetic landscape to properly rewire their gene expression. Recent discoveries have shown that metabolic shifts can shape the fate of lymphocytes by altering their epigenetic state, bringing together these two areas of inquiry. The ongoing evolution of high-dimensional cytometry has enabled increasingly comprehensive analyses of metabolic and epigenetic landscapes in lymphocytes that transcend the technical limitations of the past. Here, we review recent insights into the interplay between metabolism and epigenetics in lymphocytes and how its dysregulation can lead to immunological dysfunction and disease. We also discuss the latest technical advances in cytometry that have enabled these discoveries and that we anticipate will advance future work in this area.

Sweet regulation - The emerging immunoregulatory roles of hexoses

BACKGROUND

It is widely acknowledged that dietary habits have profound impacts on human health and diseases. As the most important sweeteners and energy sources in human diets, hexoses take part in a broad range of physiopathological processes. In recent years, emerging evidence has uncovered the crucial roles of hexoses, such as glucose, fructose, mannose, and galactose, in controlling the differentiation or function of immune cells.

AIM OF REVIEW

Herein, we reviewed the latest research progresses in the hexose-mediated modulation of immune responses, provided in-depth analyses of the underlying mechanisms, and discussed the unresolved issues in this field.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Owing to their immunoregulatory effects, hexoses affect the onset and progression of various types of immune disorders, including inflammatory diseases, autoimmune diseases, and tumor immune evasion. Thus, targeting hexose metabolism is becoming a promising strategy for reversing immune abnormalities in diseases.

Inhibition of ATP-citrate lyase by bempedoic acid protects against abdominal aortic aneurysm formation in mice

Abdominal aortic aneurysm (AAA) is a prevalent degenerative disease characterized by an exacerbated inflammation and destructive vascular remodeling. Unfortunately, effective pharmacological tools for the treatment of this disease remain a challenge. ATP-citrate lyase (ACLY), the primary enzyme responsible for acetyl-CoA biosynthesis, is a key regulator of inflammatory signaling in macrophages and lymphocytes. Here, we found increased levels of the active (phosphorylated) form of ACLY (p-ACLY) in the inflammatory infiltrate of AAA from patients and in aneurysmal lesions from angiotensin II (Ang II)-infused apolipoprotein E-deficient mice (ApoE-/-). Furthermore, plasma ACLY levels positively correlates with IL6 and IFNγ levels in patients with AAA, while inflammatory stimuli strongly upregulated ACLY expression in macrophages and Jurkat cells. The administration of the ACLY inhibitor bempedoic acid (BemA) protected against Ang II-induced AAA formation in ApoE-/- mice, limiting the progression of aortic dilatation and reducing mortality due to aortic rupture. BMS-303141, another ACLY inhibitor, also ameliorated AAA formation, although to a lesser extent. BemA attenuated vascular remodeling and the disorganization and rupture of elastic fibers induced by Ang II, as well as vascular inflammation, decreasing the recruitment of macrophages (CD68 +) and neutrophils (Ly-6G+) into the aortic wall. Moreover, BemA shifted splenic monocytes toward a functionally anti-inflammatory phenotype, and increased the percentage of CD4+CD69+ cells. Taken together, these results support the contribution of ACLY to AAA and point to BemA as a promising tool to be considered for future clinical trials addressing the management of this disease which is quite often associated with disorders of lipoprotein metabolism.

Dexamethasone has profound influence on the energy metabolism of porcine blood leukocytes and prevents the LPS-induced glycolytic switch

In farm animals, little is known about the relationship between energy metabolism of immune cells and their activation state. Moreover, there has recently been evidence that dexamethasone, a powerful glucocorticoid-based drug, can exert its anti-inflammatory effects by interfering with the energy metabolism of immune cells, but the mechanisms are not yet fully understood. To address these knowledge gaps, we explored the connection between the energy metabolism of porcine peripheral blood mononuclear cells (PBMCs) and their response to pro- and anti-inflammatory stimulation with lipopolysaccharide (LPS) and dexamethasone (DEX) in vitro. Interventions in the metabolism of PBMCs with the glycolysis inhibitor 2-deoxy-D-glucose or the HIF-1α inhibitor KC7F2 reduced the LPS-induced TNF-α production, but the mitochondrial ATP synthesis inhibitor oligomycin showed no significant effect. The anti-inflammatory action of DEX was not affected by any of the inhibitors. To investigate the metabolic actions of LPS and DEX in PBMCs, we evaluated glycolysis and mitochondrial respiration following 24 hours stimulation using the Seahorse XFe96 flux analyzer. Our results revealed significantly higher glycolysis in LPS-treated PBMCs, but provided no evidence for a change in mitochondrial respiration. In contrast, DEX reduced LPS-induced glycolysis and, especially when administered alone, significantly lowered mitochondrial respiration. Pretreatment with KC7F2 counteracted the effects of LPS and DEX on glycolysis, and reduced mitochondrial respiration regardless of the inflammatory state of the PBMCs. Gene expression analysis identified the glucose transporter SLC2A3, and the tricarboxylic acid cycle genes IDH1 and SDHB as the main switches for the antagonistic metabolic actions of LPS and DEX, which are closely associated with the inflammatory state of PBMCs.

Energy metabolism in health and diseases

Energy metabolism is indispensable for sustaining physiological functions in living organisms and assumes a pivotal role across physiological and pathological conditions. This review provides an extensive overview of advancements in energy metabolism research, elucidating critical pathways such as glycolysis, oxidative phosphorylation, fatty acid metabolism, and amino acid metabolism, along with their intricate regulatory mechanisms. The homeostatic balance of these processes is crucial; however, in pathological states such as neurodegenerative diseases, autoimmune disorders, and cancer, extensive metabolic reprogramming occurs, resulting in impaired glucose metabolism and mitochondrial dysfunction, which accelerate disease progression. Recent investigations into key regulatory pathways, including mechanistic target of rapamycin, sirtuins, and adenosine monophosphate-activated protein kinase, have considerably deepened our understanding of metabolic dysregulation and opened new avenues for therapeutic innovation. Emerging technologies, such as fluorescent probes, nano-biomaterials, and metabolomic analyses, promise substantial improvements in diagnostic precision. This review critically examines recent advancements and ongoing challenges in metabolism research, emphasizing its potential for precision diagnostics and personalized therapeutic interventions. Future studies should prioritize unraveling the regulatory mechanisms of energy metabolism and the dynamics of intercellular energy interactions. Integrating cutting-edge gene-editing technologies and multi-omics approaches, the development of multi-target pharmaceuticals in synergy with existing therapies such as immunotherapy and dietary interventions could enhance therapeutic efficacy. Personalized metabolic analysis is indispensable for crafting tailored treatment protocols, ultimately providing more accurate medical solutions for patients. This review aims to deepen the understanding and improve the application of energy metabolism to drive innovative diagnostic and therapeutic strategies.

Glycolytic reprogramming shapes the histone acetylation profile of activated CD4+ T cells in juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is an autoimmune disease characterized by accumulation of activated CD4+ T cells in the synovial fluid (SF) of affected joints. JIA CD4+ T cells exhibit a unique inflammation-associated epigenomic signature, but the underlying mechanisms remain unclear. We demonstrate that CD4+ T cells from JIA SF display heightened glycolysis upon activation and JIA-specific H3K27 acetylation, driving transcriptional reprogramming. Pharmacological inhibition of glycolysis altered the expression of genes associated with these acetylated regions. Healthy CD4+ T cells exposed to JIA SF exhibited increased glycolytic activity and transcriptomic changes marked by heightened histone 3 lysine 27 acetylation (H3K27ac) at JIA-specific genes. Elevated H3K27ac was dependent on glycolytic flux, while inhibiting glycolysis or pyruvate dehydrogenase (PDH) impaired transcription of SF-driven genes. These findings demonstrate a key role of glycolysis in JIA-specific gene expression, offering potential therapeutic targets for modulating inflammation in JIA.

Human Genetic GLUT1 Deficiency Results in Impaired T Cellular IFN-γ Production

GLUT1 deficiency prevents glucose uptake in T cells resulting in lower intracellular ATP generation and IFNy production.

Calcium Release-Activated Calcium Modulator ORAI1-Sensitive Serine Dehydratase Regulates Fatty Acid-Induced CD4+ Th17/Treg Imbalance in Dairy Cows

High concentrations of free fatty acids (FFAs) caused by negative energy balance render the cow more prone to inflammatory diseases in part due to an imbalance in the types of immune cells and their specific functions. We previously demonstrated that ORAI calcium release-activated calcium modulator 1 (ORAI1) was associated with increased CD4+ Th17 content, but the precise mechanisms remain unclear. The purpose of this study was to evaluate the efficacy of FFAs on CD4+ T cell inflammatory response. High FFAs in dairy cows caused the transcript level of the pro-inflammatory factor IL-17A, plasma concentration of IL-17A, and amount of intracellular IL-17A to increase while the transcript levels and intracellular amount of the anti-inflammatory factor FOXP3 were downregulated. These changes indicated Th17/Treg imbalance and inflammation in dairy cows with high FFA. Moreover, ORAI1 and SDS abundance was elevated in dairy cows with high FFAs by transcriptomics, QPCR, and Western blot. Knockdown of SDS (siSDS) did not alter ORAI1 expression in CD4+ T cells from high-FFA cows, while it decreased the expression of inflammatory factors. Transfection of CD4+ T cells using siRNA knockdown for ORAI1 (siORAI1) revealed that SDS and inflammatory factor abundance decreased. Serine can be catabolized to pyruvate by the action of serine dehydratase (SDS). Data from this study suggested that high FFAs caused by negative energy balance after calving regulates the Th17/Treg balance via SDS, but SDS does not regulate ORAI1 abundance. The above data suggested a pro-inflammatory mechanism in CD4+ T cells regulated by the ORAI1-sensitive SDS pathway in early postpartum cows experiencing high-FFA conditions. Thus, targeting this pathway may represent a new therapeutic and interventional approach for preventing immune-related disorders around parturition.

Histone Modifications and DNA Methylation in Psoriasis: A Cellular Perspective

In recent years, epigenetic modifications have attracted significant attention due to their unique regulatory mechanisms and profound biological implications. Acting as a bridge between environmental stimuli and changes in gene activity, they reshape gene expression patterns, providing organisms with regulatory mechanisms to respond to environmental changes. A growing body of evidence indicates that epigenetic regulation plays a crucial role in the pathogenesis and progression of psoriasis. A deeper understanding of these epigenetic mechanisms not only helps unveil the molecular mechanisms underlying the initiation and progression of psoriasis but may also provide new insights into diagnostic and therapeutic strategies. Given the unique roles and significant contributions of various cell types involved in the process of psoriasis, a thorough analysis of specific epigenetic patterns in different cell types becomes a key entry point for elucidating the mechanisms of disease development. Although epigenetic modifications encompass multiple complex layers, this review will focus on histone modifications and DNA methylation, describing how they function in different cell types and subsequently impact the pathophysiological processes of psoriasis. Finally, we will summarize the current problems in research concerning histone modifications and DNA methylation in psoriasis and discuss the clinical application prospects and challenges of targeting epigenetic modifications as therapeutic strategies for psoriasis.

Metabolic regulation of myeloid-derived suppressor cells in tumor immune microenvironment: targets and therapeutic strategies

Cancer remains a major challenge to global public health, with rising incidence and high mortality rates. The tumor microenvironment (TME) is a complex system of immune cells, fibroblasts, extracellular matrix (ECM), and blood vessels that form a space conducive to cancer cell proliferation. Myeloid-derived suppressor cells (MDSCs) are abundant in tumors, and they drive immunosuppression through metabolic reprogramming in the TME. This review describes how metabolic pathways such as glucose metabolism, lipid metabolism, amino acid metabolism, and adenosine metabolism have a significant impact on the function of MDSCs by regulating their immunosuppressive activity and promoting their survival and expansion in tumors. The review also explores key metabolic targets in MDSCs and strategies to modulate MDSC metabolism to improve the tumor immune microenvironment and enhance anti-tumor immune responses. Understanding these pathways can provide insight into potential therapeutic targets for modulating MDSC activity and improving outcomes of cancer immunotherapies.

Metabolic Profiling of Activated T Lymphocytes Using Single-Cell Energetic Metabolism by Profiling Translation Inhibition (SCENITH)

Metabolic reprogramming is increasingly recognized as a fundamental aspect of T cell activation, influencing the differentiation, proliferation, and effector functions of lymphocytes. Measuring and screening the metabolic states of activated T cells provide insights into the dynamic interplay between cellular metabolism and immune function. In the following chapter, we provide a simple protocol based on the publication of Argüello et al. [1] to analyze the metabolic state of activated T cells at the single-cell level using standard flow cytometry.

Why and how citrate may sensitize malignant tumors to immunotherapy

Immunotherapy, either alone or in combination with chemotherapy, has demonstrated limited efficacy in a variety of solid cancers. Several factors contribute to explaining primary or secondary resistance. Among them, cancer cells, whose metabolism frequently relies on aerobic glycolysis, promote exhaustion of cytotoxic immune cells by diverting the glucose in the tumor microenvironment (TME) to their own profit, while secreting lactic acid that sustains the oxidative metabolism of immunosuppressive cells. Here, we propose to combine current treatment based on the use of immune checkpoint inhibitors (ICIs) with high doses of sodium citrate (SCT) because citrate inhibits cancer cell metabolism (by targeting both glycolysis and oxidative metabolism) and may active anti-tumor immune response. Indeed, as showed in preclinical studies, SCT reduces cancer cell growth, promoting cell death and chemotherapy effectiveness. Furthermore, since the plasma membrane citrate carrier pmCIC is mainly expressed in cancer cells and low or not expressed in immune and non-transformed cells, we argue that the inhibition of cancer cell metabolism by SCT may increase glucose availability in the TME, thus promoting functionality of anti-tumor immune cells. Concomitantly, the decrease in the amount of lactic acid in the TME may reduce the functionality of immunosuppressive cells. Preclinical studies have shown that SCT can enhance the anti-tumor immune response through an enhancement of T cell infiltration and activation, and a repolarization of macrophages towards a TAM1-like phenotype. Therefore, this simple and cheap strategy may have a major impact to increase the efficacy of current immunotherapies in human solid tumors and we encourage testing it in clinical trials.

Metabolic Screening of T Lymphocytes During Activation via SEAHORSE Extracellular Flux (XF) Analysis

Upon activation, T cells undergo a profound reconfiguration of their metabolic profile, transitioning from a quiescent to a metabolically active state characterized by an increase in both aerobic glycolysis and mitochondrial respiration. Seahorse extracellular flux (XF) analysis is a powerful method for measuring the changes in fundamental metabolic pathways in real-time, including aerobic glycolysis and mitochondrial respiration of live T cells. This method allows a precise determination of mitochondrial performance and lactate secretion, which is measured as oxygen consumption rate (OCR) and glycolytic proton efflux rate (ECAR), respectively. By dynamically monitoring these metabolic changes, Seahorse XF analysis provides comprehensive insights into the metabolic dynamics of (activated) T cells across diverse experimental conditions or treatments.

TAGLN-RhoA/ROCK2-SLC2A3-mediated Mechano-metabolic Axis Promotes Skin Fibrosis

Skin fibrotic diseases are characterized by abnormal fibroblast function and excessive deposition of extracellular matrix. Our previous single-cell sequencing results identified an enriched fibroblast subcluster in skin fibrotic tissues that highly expresses the actin cross-linking cytoskeletal protein Transgelin (TAGLN), which bridges the mechanical environment of tissues and cellular metabolism. Therefore, we aimed to investigate the role of TAGLN in the pathogenesis of skin fibrosis. Transwell, wound healing, collagen gel contraction assay, immunofluorescence and RNA-seq analyses were used to validate and explore the potential mechanisms of the TAGLN-RhoA/ROCK2-SLC2A3-mediated mechano-metabolic axis in dermal fibrosis. The therapeutic efficacy of targeting TAGLN was validated using a bleomycin-induced mouse model of skin fibrosis. Functional assays revealed that downregulation of TAGLN inhibited motility and secretory function of fibroblasts, including invasion, migration, contraction, and collagen secretion. The glucose carrier SLC2A3 was identified as one of the downstream targets of TAGLN by RNA-sequencing analysis and further validation. We further demonstrated that TAGLN regulates the expression of SLC2A3 through the RhoA/ROCK2 pathway, a key pathway of mechanotransduction, thereby affecting glycolysis and motility of fibroblasts. This study reveals the existence of the TAGLN-RhoA/ROCK2-SLC2A3 mechano-metabolic axis in skin fibrotic diseases and provides a promising target for its clinical treatment.

T cell metabolism in kidney immune homeostasis

Kidney immune homeostasis is intricately linked to T cells. Inappropriate differentiation, activation, and effector functions of T cells lead to a spectrum of kidney disease. While executing immune functions, T cells undergo a series of metabolic rewiring to meet the rapid energy demand. The key enzymes and metabolites involved in T cell metabolism metabolically and epigenetically modulate T cells' differentiation, activation, and effector functions, thereby being capable of modulating kidney immune homeostasis. In this review, we first summarize the latest advancements in T cell immunometabolism. Second, we outline the alterations in the renal microenvironment under certain kidney disease conditions. Ultimately, we highlight the metabolic modulation of T cells within kidney immune homeostasis, which may shed light on new strategies for treating kidney disease.

Plasmonic Supramolecular Nanozyme-Based Bio-Cockleburs for Synergistic Therapy of Infected Diabetic Wounds

Diabetic wounds are a major devastating complication of diabetes due to hyperglycemia, bacterial invasion, and persistent inflammation, and the current antibiotic treatments can lead to the emergence of multidrug-resistant bacteria. Herein, a bimetallic nanozyme-based biomimetic bio-cocklebur (GNR@CeO2@GNPs) is designed and synthesized for diabetic wound management by depositing spiky ceria (CeO2) shells and gold nanoparticles (GNPs) on a gold nanorod (GNR) nanoantenna. The plasmonic-enhanced nanozyme catalysis and self-cascade reaction properties simultaneously boost the two-step enzyme-mimicking catalytic activity of GNR@CeO2@GNPs, leading to a significant improvement in overall therapeutic efficacy rather than mere additive effects. Under the glucose activation and 808 nm laser irradiation, GNR@CeO2@GNPs material captures photons and promotes the transfer of hot electrons from GNR and GNPs into CeO2, realizing a "butterfly effect" of consuming local glucose, overcoming the limited antibacterial efficiency of an individual PTT modality, and providing substantial reactive oxygen species. In vitro and in vivo experiments demonstrate the material's exceptional antibacterial and antibiofilm properties against Gram-negative and Gram-positive bacteria, which can reduce inflammation, promote collagen deposition, and facilitate angiogenesis, thereby accelerating wound healing. This study provides a promising new strategy to develop plasmonic-enhanced nanozymes with a catalytic cascade mode for the antibiotic-free synergistic treatment of infected diabetic wounds.

A two-way relationship between histone acetylation and metabolism

A link between epigenetics and metabolism was initially recognized because the cellular metabolic state is communicated to the genome through the concentration of intermediary metabolites that are cofactors of chromatin-modifying enzymes. Recently, an additional interaction was postulated due to the capacity of the epigenome to store substantial amounts of metabolites that could become available again to cellular metabolite pools. Here, we focus on histone acetylation and review recent evidence illustrating this reciprocal relationship: in one direction, signaling-induced acetyl-coenzyme A (acetyl-CoA) changes influence histone acetylation levels to regulate genomic functions, and in the opposite direction histone acetylation acts as an acetate reservoir to directly affect downstream acetyl-CoA-mediated metabolism. This review highlights the current understanding, experimental challenges, and future perspectives of this bidirectional interplay.

Glut3 promotes cellular O-GlcNAcylation as a distinctive tumor-supportive feature in Treg cells

Regulatory T cells (Tregs) establish dominant immune tolerance but obstruct tumor immune surveillance, warranting context-specific mechanistic insights into the functions of tumor-infiltrating Tregs (TIL-Tregs). We show that enhanced posttranslational O-linked N-acetylglucosamine modification (O-GlcNAcylation) of cellular factors is a molecular feature that promotes a tumor-specific gene expression signature and distinguishes TIL-Tregs from their systemic counterparts. We found that altered glucose utilization through the glucose transporter Glut3 is a major facilitator of this process. Treg-specific deletion of Glut3 abrogates tumor immune tolerance, while steady-state immune homeostasis remains largely unaffected in mice. Furthermore, by employing mouse tumor models and human clinical data, we identified the NF-κB subunit c-Rel as one such factor that, through Glut3-dependent O-GlcNAcylation, functionally orchestrates gene expression in Tregs at tumor sites. Together, these results not only identify immunometabolic alterations and molecular events contributing to fundamental aspects of Treg biology, specifically at tumor sites but also reveal tumor-specific cellular properties that can aid in the development of Treg-targeted cancer immunotherapies.

Metabolic footprint and logic through the T cell life cycle

A simple definition of life is a system that can self-replicate (proliferation) and self-sustain (metabolism). At the cellular level, metabolism has evolved to drive proliferation, which requires energy and building blocks to duplicate cellular biomass before division. T lymphocytes (or T cells) are required for adaptive immune responses, protecting us against invading and malignant agents capable of hyper-replication. To gain a competitive advantage over these agents, activated T cells can duplicate their biomass and divide into two daughter cells in as short as 2-6 hours, considered the fastest cell division among all cell types in vertebrates. Thus, the primary task of cellular metabolism has evolved to commit available resources to drive T cell hyperproliferation. Beyond that, the T cell life cycle involves an ordered series of fate-determining events that drive cells to transition between discrete cell states. At the life stages not involved in hyperproliferation, T cells engage metabolic programs that are more flexible to sustain viability and maintenance and sometimes are fine-tuned to support specific cellular activities. Here, we focus on the central carbon metabolism, which is most relevant to cell proliferation. We provide examples of how the changes in the central carbon metabolism may or may not change the fate of T cells and further explore a few conceptual frameworks, such as metabolic flexibility, the Goldilocks Principle, overflow metabolism, and effector-signaling metabolites, in the context of T cell fate transitions.

Control of T-cell immunity by fatty acid metabolism

Fatty acids play critical roles in maintaining the cellular functions of T cells and regulating T-cell immunity. This review synthesizes current research on the influence of fatty acids on T-cell subsets, including CD8+ T cells, TH1, TH17, Treg (regulatory T cells), and TFH (T follicular helper) cells. Fatty acids impact T cells by modulating signaling pathways, inducing metabolic changes, altering cellular structures, and regulating gene expression epigenetically. These processes affect T-cell activation, differentiation, and function, with implications for diseases such as autoimmune disease and cancer. Based on these insights, fatty acid pathways can potentially be modulated by novel therapeutics, paving the way for novel treatment approaches for immune-mediated disorders and cancer immunotherapy.

SLC2A3 promotes head and neck squamous cancer developing through negatively regulating CD8+ T cell in tumor microenvironment

Recent studies have identified SLC2A3 as being abnormally upregulated in multiple tumor types, correlating with poor survival and disrupted microenvironments. However, its prognostic significance in head and neck squamous cell carcinoma (HNSC) remains underexplored. In this study, SLC2A3 was screened as a potential risk gene influencing both immune and tumor components within the tumor microenvironment (TME) of 504 HNSC patients from the TCGA database. Immune infiltration analyses and clinical significance on SLC2A3 were conducted using ESTIMATE, CIBERSORT, ssGSEA, TIMER and clinical prognosis parameters. Additionally, the single-cell dataset is used to analyze the expression of SLC2A3 in various subpopulations. The magnetic activated cell sorting (MACS) is used to isolate CD8+ T cells from PBMCs or tumor tissues. Flow cytometry is used to identify purified and activated CD8+ T cells. GSEA and WB were used to investigate the molecular mechanism of SLC2A3 in CD8+ T cells. The co-culture system of CD8+ T cells and TU686 was used to investigate the effects of SLC2A3 on immune cells and tumor development. In this study, SLC2A3 was identified as a potential risk gene affecting both immune cells and tumor components within the TME of 504 HNSC patients derived from the TCGA database. We conducted immune infiltration analyses and assessed the clinical significance of SLC2A3 using various bioinformatics tools, including ESTIMATE, CIBERSORT, ssGSEA, and TIMER, along with clinical prognosis parameters. The single-cell RNA sequencing dataset was utilized to examine SLC2A3 expression across different cellular subpopulations. Magnetic activated cell sorting (MACS) was employed to isolate CD8+ T cells from peripheral blood mononuclear cells (PBMCs) or tumor tissues. Flow cytometry was implemented to confirm the purity and activation state of the isolated CD8+ T cells. GSEA and Western blot were applied to explore the molecular mechanisms underlying SLC2A3's role in CD8+ T cells. Lastly, a co-culture system involving CD8+ T cells and TU686 tumor cells was established to study the impact of SLC2A3 on immune cell function and tumor progression. SLC2A3 emerges as an actively variable gene within the immune and stromal components of the TME, linked to aggravated immune infiltration and poor clinical outcomes. The upregulated expression of SLC2A3 is predominantly enriched in immune-related biological processes and linked to the suppression of CD8+ T cells, which are crucial for the survival of HNSC patients. Furthermore, SLC2A3 exhibits specific overexpression in CD8+ T cells and may potentially trigger ferroptosis. Knockdown of SLC2A3 led to a significant increase in the proliferation of CD8+ T cells compared to those without knockdown. In co-culture systems, CD8+ T cells with SLC2A3 knockdown demonstrated an enhanced ability to eliminate tumor cells compared to those without the knockdown. SLC2A3 is associated with changes in the TME and prognostic indicators. Moreover, high SLC2A3 expression in CD8+ T cells may drive cell death through ferroptosis, fostering tumor progression.

Rg3-lipo biomimetic delivery of paclitaxel enhances targeting of tumors and myeloid-derived suppressor cells

Liposomal drug delivery systems have revolutionized traditional cytotoxic drugs. However, the relative instability and toxicity of the existing liposomal drug delivery systems compromised their efficacy. Herein, we present Rg3-lipo, an innovative drug delivery system using a glycosyl moiety-enriched ginsenoside (Rg3). This system is distinguished by its glycosyl moieties exposed on the liposomal surface. These moieties imitate human cell membranes to stabilize and evade phagocytic clearance. The Rg3-lipo system loaded with paclitaxel (PTX-Rg3-lipo) demonstrated favorable bioavailability and safety in Sprague-Dawley rats, beagle dogs, and cynomolgus monkeys. With its glycosyl moieties recognizing tumor cells via the glucose transporter Glut1, PTX-Rg3-lipo inhibited gastric, breast, and esophageal cancers in human cancer cell lines, tumor-bearing mice, and patient-derived xenograft models. These glycosyl moieties selectively targeted myeloid-derived suppressor cells (MDSCs) through the glucose transporter Glut3 to attenuate their immunosuppressive effect. The mechanism study revealed that Rg3-lipo suppressed glycolysis and downregulated the transcription factors c-Maf and Mafb overcoming the MDSC-mediated immunosuppressive microenvironment and enhancing PTX-Rg3-lipo's antitumor effect. Taken together, we supply substantial evidence for its advantageous bioavailability and safety in multiple animal models, including nonhuman primates, and Rg3-lipo's dual targeting of cancer cells and MDSCs. Further investigation regarding Rg3-lipo's druggability will be conducted in clinical trials.

Association between dietary inflammatory index and adolescent myopia based on the National Health and Nutrition Examination Survey

The prevalence of adolescent myopia is remarkably increasing. Previous studies have indicated that an unhealthy diet is a risk factor for myopia. However, the link between diet-related inflammation and myopia is unclear. To explore their correlation, we used dietary inflammation index (DII) that is a parameter to quantify the inflammatory potential of diet, to reveal the relationship between DII and myopia in adolescents. We extracted sociodemographic data, information of diets and eye refractive status of adolescents from National Health and Nutrition Examination Survey (NHANES) for period 1999-2008. Dietary intake data was used to calculate DII scores, which were then categorized into quartiles. Multivariable regression models and subgroup analyses were conducted to investigate the association between DII and myopia. Subsequently, smoothed curve analyses were conducted to discern the trend of correlation between DII and myopia across diverse population. A total of 7191 juveniles aged at 12 to 18 years with complete information were included in our study, consisting 3367 participants with diagnosis of myopia. Among these participants, a trend towards an increasing prevalence of myopia was observed with a higher DII. After adjusting for all covariates, stratified logistic regression analyses showed that among the population aged in 16 to 18 years old or with 9-11th grade educational level, the prevalence of myopia was significantly increased with higher DII score (OR = 1.06, 95% CI = 1.01, 1.11, P = 0.006; OR = 1.06, 95% CI = 1.01, 1.11, P = 0.010). In the two subgroups, participants in the highest quartile of DII had a 31.00% higher risk of myopia and a higher 27.00% risk of myopia respectively, compared to those in the lowest quartile of DII. Our results revealed an increasing trend in the prevalence of myopia with increased DII score in adolescents. Particularly, DII was positively associated with the risk of myopia among the population aged in 16 to 18 years old and with 9-11th grade educational level.

Transcription factor TCF1 binds to RORγt and orchestrates a regulatory network that determines homeostatic Th17 cell state

T helper (Th) 17 cells encompass a spectrum of cell states, including cells that maintain homeostatic tissue functions and pro-inflammatory cells that can drive autoimmune tissue damage. Identifying regulators that determine Th17 cell states can identify ways to control tissue inflammation and restore homeostasis. Here, we found that interleukin (IL)-23, a cytokine critical for inducing pro-inflammatory Th17 cells, decreased transcription factor T cell factor 1 (TCF1) expression. Conditional deletion of TCF1 in mature T cells increased the pro-inflammatory potential of Th17 cells, even in the absence of IL-23 receptor signaling, and conferred pro-inflammatory potential to homeostatic Th17 cells. Conversely, sustained TCF1 expression decreased pro-inflammatory Th17 potential. Mechanistically, TCF1 bound to RORγt, thereby interfering with its pro-inflammatory functions, and orchestrated a regulatory network that determined Th17 cell state. Our findings identify TCF1 as a major determinant of Th17 cell state and provide important insight for the development of therapies for Th17-driven inflammatory diseases.

RBM25 is required to restrain inflammation via ACLY RNA splicing-dependent metabolism rewiring

Spliceosome dysfunction and aberrant RNA splicing underline unresolved inflammation and immunopathogenesis. Here, we revealed the misregulation of mRNA splicing via the spliceosome in the pathogenesis of rheumatoid arthritis (RA). Among them, decreased expression of RNA binding motif protein 25 (RBM25) was identified as a major pathogenic factor in RA patients and experimental arthritis mice through increased proinflammatory mediator production and increased hyperinflammation in macrophages. Multiomics analyses of macrophages from RBM25-deficient mice revealed that the transcriptional enhancement of proinflammatory genes (including Il1b, Il6, and Cxcl10) was coupled with histone 3 lysine 9 acetylation (H3K9ac) and H3K27ac modifications as well as hypoxia inducible factor-1α (HIF-1α) activity. Furthermore, RBM25 directly bound to and mediated the 14th exon skipping of ATP citrate lyase (Acly) pre-mRNA, resulting in two distinct Acly isoforms, Acly Long (Acly L) and Acly Short (Acly S). In proinflammatory macrophages, Acly L was subjected to protein lactylation on lysine 918/995, whereas Acly S did not, which influenced its affinity for metabolic substrates and subsequent metabolic activity. RBM25 deficiency overwhelmingly increased the expression of the Acly S isoform, enhancing glycolysis and acetyl-CoA production for epigenetic remodeling, macrophage overactivation and tissue inflammatory injury. Finally, macrophage-specific deletion of RBM25 led to inflammaging, including spontaneous arthritis in various joints of mice and inflammation in multiple organs, which could be relieved by pharmacological inhibition of Acly. Overall, targeting the RBM25-Acly splicing axis represents a potential strategy for modulating macrophage responses in autoimmune arthritis and aging-associated inflammation.

Metabolic and ionic control of T cells in asthma endotypes

CD4+ T cells play a central role in orchestrating the immune response in asthma, with dysregulated ion channel profiles and altered metabolic signatures contributing to disease progression and severity. An important classification of asthma is based on the presence of T-helper cell type 2 (Th2) inflammation, dividing patients into Th2-high and Th2-low endotypes. These distinct endotypes have implications for disease severity, treatment response, and prognosis. By elucidating how ion channels and energy metabolism control Th cells in asthma, this review contributes to the pathophysiological understanding and the prospective development of personalized therapeutic treatment strategies for patients suffering from distinct asthma endotypes.

Enhanced ROS Production and Mitochondrial Metabolic Shifts in CD4+ T Cells of an Autoimmune Uveitis Model

Equine recurrent uveitis (ERU) is a spontaneously occurring autoimmune disease and one of the leading causes of blindness in horses worldwide. Its similarities to autoimmune-mediated uveitis in humans make it a unique spontaneous animal model for this disease. Although many aspects of ERU pathogenesis have been elucidated, it remains not fully understood and requires further research. CD4+ T cells have been a particular focus of research. In a previous study, we showed metabolic alterations in CD4+ T cells from ERU cases, including an increased basal oxygen consumption rate (OCR) and elevated compensatory glycolysis. To further investigate the underlying reasons for and consequences of these metabolic changes, we quantified reactive oxygen species (ROS) production in CD4+ T cells from ERU cases and compared it to healthy controls, revealing significantly higher ROS production in ERU-affected horses. Additionally, we aimed to define mitochondrial fuel oxidation of glucose, glutamine, and long-chain fatty acids (LCFAs) and identified significant differences between CD4+ T cells from ERU cases and controls. CD4+ T cells from ERU cases showed a lower dependency on mitochondrial glucose oxidation and greater metabolic flexibility for the mitochondrial oxidation of glucose and LCFAs, indicating an enhanced ability to switch to alternative fuels when necessary.

PRMT6 Epigenetically Drives Metabolic Switch from Fatty Acid Oxidation toward Glycolysis and Promotes Osteoclast Differentiation During Osteoporosis

Epigenetic regulation of metabolism profoundly influences cell fate commitment. During osteoclast differentiation, the activation of RANK signaling is accompanied by metabolic reprogramming, but the epigenetic mechanisms by which RANK signaling induces this reprogramming remain elusive. By transcriptional sequence and ATAC analysis, this study identifies that activation of RANK signaling upregulates PRMT6 by epigenetic modification, triggering a metabolic switching from fatty acids oxidation toward glycolysis. Conversely, Prmt6 deficiency reverses this shift, markedly reducing HIF-1α-mediated glycolysis and enhancing fatty acid oxidation. Consequently, PRMT6 deficiency or inhibitor impedes osteoclast differentiation and alleviates bone loss in ovariectomized (OVX) mice. At the molecular level, Prmt6 deficiency reduces asymmetric dimethylation of H3R2 at the promoters of genes including Ppard, Acox3, and Cpt1a, enhancing genomic accessibility for fatty acid oxidation. PRMT6 thus emerges as a metabolic checkpoint, mediating metabolic switch from fatty acid oxidation to glycolysis, thereby supporting osteoclastogenesis. Unveiling PRMT6's critical role in epigenetically orchestrating metabolic shifts in osteoclastogenesis offers a promising target for anti-resorptive therapy.

RNA methyltransferase NSUN2-mediated m5C methylation promotes Cr(VI)-induced malignant transformation and lung cancer by accelerating metabolism reprogramming

Hexavalent chromium [Cr(VI)], one common environmental contaminant, has long been recognized as a carcinogen associated with lung cancer, but roles and mechanisms of Cr(VI)-induced epigenetic dysregulations in carcinogenesis remain to be investigated. In this study, we identified that RNA m5C methyltransferase NSUN2 was significantly upregulated in Cr(VI)-transformed cells and lung tissues of Cr(VI)-exposed mice. Inhibition of NSUN2 reduced cell proliferation, migration, colony formation and tube formation abilities. We found NSUN2-mediated m5C modification induced metabolic reprogramming and cell cycle by promoting the mRNA stabilities of ME1, GLUT3 and CDK2. In addition, knockdown of NSUN2 attenuated tumorigenesis and angiogenesis in vivo. RNA m5C reader ALYREF was identified to be involved in NSUN2-mediated m5C modification in Cr (VI)-induced carcinogenesis. Further study showed that EP300 induced NSUN2 upregulation through transcriptional activation by inducing histone modification at H3K27ac site for regulating Cr(VI) carcinogenesis. Our findings demonstrated novel role and mechanism of NSUN2 and epigenetic changes by increasing the RNA m5C modification that are important for Cr (VI)-induced carcinogenesis through NSUN2/ALYREF pathway. NSUN2, ALYREF, ME1, GLUT3 or/and CDK2 may be used as potential new biomarkers or/and therapeutic target(s) in the future.

Twin study identifies early immunological and metabolic dysregulation of CD8+ T cells in multiple sclerosis

Multiple sclerosis (MS) is an inflammatory neurological disease of the central nervous system with a subclinical phase preceding frank neuroinflammation. CD8+ T cells are abundant within MS lesions, but their potential role in disease pathology remains unclear. Using high-throughput single-cell RNA sequencing and single-cell T cell receptor analysis, we compared CD8+ T cell clones from the blood and cerebrospinal fluid (CSF) of monozygotic twin pairs in which the cotwin had either no or subclinical neuroinflammation (SCNI). We identified peripheral MS-associated immunological and metabolic alterations indicative of an enhanced migratory, proinflammatory, and activated CD8+ T cell phenotype, which was also evident in cotwins with SCNI and in an independent validation cohort of people with MS. Together, our in-depth single-cell analysis indicates a disease-driving proinflammatory role of infiltrating CD8+ T cells and identifies potential immunological and metabolic therapeutic targets in both prodromal and definitive stages of the disease.

Polymeric nanoformulations aimed at cancer metabolism reprogramming with high specificity to inhibit tumor growth

Metabolic disorders of cancer cells create opportunities for metabolic interventions aimed at selectively eliminating cancer cells. Nevertheless, achieving this goal is challenging due to cellular plasticity and metabolic heterogeneity of cancer cells. This study presents a dual-drug-loaded, macrophage membrane-coated polymeric nanovesicle designed to reprogram cancer metabolism with high specificity through integrated extracellular and intracellular interventions. This nanoformulation can target cancer cells and largely reduce their glucose intake, while the fate of intracellular glucose internalized otherwise is redirected at the specially introduced oxidation reaction instead of inherent cancer glycolysis. Meanwhile, it inhibits cellular citrate intake, further reinforcing metabolic intervention. Furthermore, the nanoformulation causes not only H2O2 production, but also NADPH down-regulation, intensifying redox damage to cancer cells. Consequently, this nanoformulation displays highly selective toxicity to cancer cells and minimal harm to normal cells mainly due to metabolic vulnerability of the former. Once administered into tumor-bearing mice, this nanoformulation is found to induce the transformation of pro-tumor tumor associated macrophages into the tumor-suppressive phenotype and completely inhibit tumor growth with favourable biosafety.

Histone lactylation dynamics: Unlocking the triad of metabolism, epigenetics, and immune regulation in metastatic cascade of pancreatic cancer

Cancer cells rewire metabolism to sculpt the immune tumor microenvironment (TME) and propel tumor advancement, which intricately tied to post-translational modifications. Histone lactylation has emerged as a novel player in modulating protein functions, whereas little is known about its pathological role in pancreatic ductal adenocarcinoma (PDAC) progression. Employing a multi-omics approach encompassing bulk and single-cell RNA sequencing, metabolomics, ATAC-seq, and CUT&Tag methodologies, we unveiled the potential of histone lactylation in prognostic prediction, patient stratification and TME characterization. Notably, "LDHA-H4K12la-immuno-genes" axis has introduced a novel node into the regulatory framework of "metabolism-epigenetics-immunity," shedding new light on the landscape of PDAC progression. Furthermore, the heightened interplay between cancer cells and immune counterparts via Nectin-2 in liver metastasis with elevated HLS unraveled a positive feedback loop in driving immune evasion. Simultaneously, immune cells exhibited altered HLS and autonomous functionality across the metastatic cascade. Consequently, the exploration of innovative combination strategies targeting the metabolism-epigenetics-immunity axis holds promise in curbing distant metastasis and improving survival prospects for individuals grappling with challenges of PDAC.

Activation and antitumor immunity of CD8+ T cells are supported by the glucose transporter GLUT10 and disrupted by lactic acid

CD8+ T cell activation leads to the rapid proliferation and differentiation of effector T cells (Teffs), which mediate antitumor immunity. Although aerobic glycolysis is preferentially activated in CD8+ Teffs, the mechanisms that regulate CD8+ T cell glucose uptake in the low-glucose and acidic tumor microenvironment (TME) remain poorly understood. Here, we report that the abundance of the glucose transporter GLUT10 is increased during CD8+ T cell activation and antitumor immunity. Specifically, GLUT10 deficiency inhibited glucose uptake, glycolysis, and antitumor efficiency of tumor-infiltrating CD8+ T cells. Supplementation with glucose alone was insufficient to rescue the antitumor function and glucose uptake of CD8+ T cells in the TME. By analyzing tumor environmental metabolites, we found that high concentrations of lactic acid reduced the glucose uptake, activation, and antitumor effects of CD8+ T cells by directly binding to GLUT10's intracellular motif. Disrupting the interaction of lactic acid and GLUT10 by the mimic peptide PG10.3 facilitated CD8+ T cell glucose utilization, proliferation, and antitumor functions. The combination of PG10.3 and GLUT1 inhibition or anti-programmed cell death 1 antibody treatment showed synergistic antitumor effects. Together, our data indicate that GLUT10 is selectively required for glucose uptake of CD8+ T cells and identify that TME accumulated lactic acid inhibits CD8+ T cell effector function by directly binding to GLUT10 and reducing its glucose transport capacity. Last, our study suggests disrupting lactate-GLUT10 binding as a promising therapeutic strategy to enhance CD8+ T cell-mediated antitumor effects.

The glycolytic reaction PGAM unexpectedly restrains Th17 pathogenicity and Th17-dependent autoimmunity

Glucose metabolism is a critical regulator of T cell function, largely thought to support their activation and effector differentiation. Here, we investigate the relevance of individual glycolytic reactions in determining the pathogenicity of T helper 17 (Th17) cells using single-cell RNA-seq and Compass, an algorithm we previously developed for estimating metabolic flux from single-cell transcriptomes. Surprisingly, Compass predicted that the metabolic shunt between 3-phosphoglycerate (3PG) and 2-phosphoglycerate (2PG) is inversely correlated with pathogenicity in these cells, whereas both its upstream and downstream reactions were positively correlated. Perturbation of phosphoglycerate mutase (PGAM), an enzyme required for 3PG to 2PG conversion, resulted in an increase in protein expression of IL2, IL17, and TNFa, as well as induction of a pathogenic gene expression program. Consistent with PGAM playing a pro-regulatory role, inhibiting PGAM in Th17 cells resulted in exacerbated autoimmune responses in the adoptive transfer model of experimental autoimmune encephalomyelitis (EAE). Finally, we further investigated the effects of modulating glucose concentration on Th17 cells in culture. Th17 cells differentiated under high- and low-glucose conditions substantially differed in their metabolic and effector transcriptomic programs, both central to Th17 function. Importantly, the PGAM-dependent gene module marks the least pathogenic state of Th17 cells irrespective of glucose concentration. Overall, our study identifies PGAM, contrary to other glycolytic enzymes, as a negative regulator of Th17 pathogenicity.

Inhibition of BCAT1-mediated cytosolic leucine metabolism regulates Th17 responses via the mTORC1-HIF1α pathway

Branched-chain amino acids (BCAAs), particularly leucine, are indispensable AAs for immune regulation through metabolic rewiring. However, the molecular mechanism underlying this phenomenon remains unclear. Our investigation revealed that T-cell receptor (TCR)-activated human CD4+ T cells increase the expression of BCAT1, a cytosolic enzyme responsible for BCAA catabolism, and SLC7A5, a major BCAA transporter. This upregulation facilitates increased leucine influx and catabolism, which are particularly crucial for Th17 responses. Activated CD4+ T cells induce an alternative pathway of cytosolic leucine catabolism, generating a pivotal metabolite, β-hydroxy β-methylbutyric acid (HMB), by acting on BCAT1 and 4-hydroxyphenylpyruvate dioxygenase (HPD)/HPD-like protein (HPDL). Inhibition of BCAT1-mediated cytosolic leucine metabolism, either with BCAT1 inhibitor 2 (Bi2) or through BCAT1, HPD, or HPDL silencing using shRNA, attenuates IL-17 production, whereas HMB supplementation abrogates this effect. Mechanistically, HMB contributes to the regulation of the mTORC1-HIF1α pathway, a major signaling pathway for IL-17 production, by increasing the mRNA expression of HIF1α. This finding was corroborated by the observation that treatment with L-β-homoleucine (LβhL), a leucine analog and competitive inhibitor of BCAT1, decreased IL-17 production by TCR-activated CD4+ T cells. In an in vivo experimental autoimmune encephalomyelitis (EAE) model, blockade of BCAT1-mediated leucine catabolism, either through a BCAT1 inhibitor or LβhL treatment, mitigated EAE severity by decreasing HIF1α expression and IL-17 production in spinal cord mononuclear cells. Our findings elucidate the role of BCAT1-mediated cytoplasmic leucine catabolism in modulating IL-17 production via HMB-mediated regulation of mTORC1-HIF1α, providing insights into its relevance to inflammatory conditions.

Oligoclonal CD4+CXCR5+ T cells with a cytotoxic phenotype appear in tonsils and blood

In clinical situations, peripheral blood accessible CD3+CD4+CXCR5+ T-follicular helper (TFH) cells may have to serve as a surrogate indicator for dysregulated germinal center responses in tissues. To determine the heterogeneity of TFH cells in peripheral blood versus tonsils, CD3+CD4+CD45RA-CXCR5+ cells of both origins were sorted. Transcriptomes, TCR repertoires and cell-surface protein expression were analysed by single-cell RNA sequencing, flow cytometry and immunohistochemistry. Reassuringly, all blood-circulating CD3+CD4+CXCR5+ T-cell subpopulations also appear in tonsils, there with some supplementary TFH characteristics, while peripheral blood-derived TFH cells display markers of proliferation and migration. Three further subsets of TFH cells, however, with bona fide T-follicular gene expression patterns, are exclusively found in tonsils. One additional, distinct and oligoclonal CD4+CXCR5+ subpopulation presents pronounced cytotoxic properties. Those 'killer TFH (TFK) cells' can be discovered in peripheral blood as well as among tonsillar cells but are located predominantly outside of germinal centers. They appear terminally differentiated and can be distinguished from all other TFH subsets by expression of NKG7 (TIA-1), granzymes, perforin, CCL5, CCR5, EOMES, CRTAM and CX3CR1. All in all, this study provides data for detailed CD4+CXCR5+ T-cell assessment of clinically available blood samples and extrapolation possibilities to their tonsil counterparts.

Re-establishing immune tolerance in multiple sclerosis: focusing on novel mechanisms of mesenchymal stem cell regulation of Th17/Treg balance

The T-helper 17 (Th17) cell and regulatory T cell (Treg) axis plays a crucial role in the development of multiple sclerosis (MS), which is regarded as an immune imbalance between pro-inflammatory cytokines and the maintenance of immune tolerance. Mesenchymal stem cell (MSC)-mediated therapies have received increasing attention in MS research. In MS and its animal model experimental autoimmune encephalomyelitis, MSC injection was shown to alter the differentiation of CD4+T cells. This alteration occurred by inducing anergy and reduction in the number of Th17 cells, stimulating the polarization of antigen-specific Treg to reverse the imbalance of the Th17/Treg axis, reducing the inflammatory cascade response and demyelination, and restoring an overall state of immune tolerance. In this review, we summarize the mechanisms by which MSCs regulate the balance between Th17 cells and Tregs, including extracellular vesicles, mitochondrial transfer, metabolic reprogramming, and autophagy. We aimed to identify new targets for MS treatment using cellular therapy by analyzing MSC-mediated Th17-to-Treg polarization.

Genetically engineering glycolysis in T cells increases their antitumor function

BACKGROUND

T cells play a central role in the antitumor response. However, they often face numerous hurdles in the tumor microenvironment, including the scarcity of available essential metabolites such as glucose and amino acids. Moreover, cancer cells can monopolize these resources to thrive and proliferate by upregulating metabolite transporters and maintaining a high metabolic rate, thereby outcompeting T cells.

METHODS

Herein, we sought to improve T-cell antitumor function in the tumor vicinity by enhancing their glycolytic capacity to better compete with tumor cells. To achieve this, we engineered human T cells to express a key glycolysis enzyme, phosphofructokinase, in conjunction with Glucose transporter 3, a glucose transporter. We co-expressed these, along with tumor-specific chimeric antigen or T-cell receptors.

RESULTS

Engineered cells demonstrated an increased cytokine secretion and upregulation of T-cell activation markers compared with control cells. Moreover, they displayed superior glycolytic capacity, which translated into an improved in vivo therapeutic potential in a xenograft model of human tumors.

CONCLUSION

In summary, these findings support the implementation of T-cell metabolic engineering to enhance the efficacy of cellular immunotherapies for cancer.