Immunometabolism: Cellular Metabolism Turns Immune Regulator

Metabolic requirements of CD160 expressing memory-like NK cells in Gram-negative bacterial infection

Objective

Unique metabolic requirements accompany the development and functional fates of immune cells. How cellular metabolism is important in natural killer (NK) cells and their memory-like differentiation in bacterial infections remains elusive.

Methods

Here, we utilise our established NK cell memory assay to investigate the metabolic requirement for memory-like NK cell formation and function in response to the Gram-negative intracellular bacteria Burkholderia pseudomallei (BP), the causative agent of melioidosis.

Results

We demonstrate that CD160+ memory-like NK cells upon BP stimulation upregulate glucose and amino acid transporters in a cohort of recovered melioidosis patients which is maintained at least 3-month post-hospital admission. Using an in vitro assay, human BP-specific CD160+ memory-like NK cells show metabolic priming including increased expression of glucose and amino acid transporters with elevated glucose uptake, increased mTOR activation and mitochondrial membrane potential upon BP re-stimulation. Antigen-specific and cytokine-induced IFN-γ production of this memory-like NK cell subset are highly dependent on oxidative phosphorylation (OXPHOS) with some dependency on glycolysis, whereas the formation of CD160+ memory-like NK cells in vitro is dependent on fatty acid oxidation and OXPHOS and further increased by metformin.

Conclusion

This study reveals the link between metabolism and cellular function of memory-like NK cells, which can be exploited for vaccine design and for monitoring protection against Gram-negative bacterial infection.

Choice of medium affects PBMC quantification, cell size, and downstream respiratory analysis

High-resolution respirometry (HRR) can assess peripheral blood mononuclear cell (PBMC) bioenergetics, but no standardized medium for PBMC preparation and HRR analysis exist. Here, we study the effect of four different media (MiR05, PBS, RPMI, Plasmax) on the count, size, and HRR (Oxygraph-O2k) of intact PBMCs. Remarkably, the cell count was 21 % higher when PBMCs were resuspended in MiR05 than in PBS or Plasmax, causing O2 flux underestimation during HRR due to inherent adjustments. Moreover, smaller cell size and cell aggregation was observed in MiR05. Based on our findings, we propose that Plasmax, PBS or RPMI is more suitable than MiR05 for HRR of intact PBMCs. We provide oxygen solubility factors for Plasmax and PBS and encourage further optimization of a standardized HRR protocol for intact PBMCs.

Anandamide modulation of monocyte-derived Langerhans cells: implications for immune homeostasis and skin inflammation

Introduction

The endocannabinoid system (ECS), named after the chemical compounds found in the cannabis plant, is a regulatory network of neurotransmitters, receptors, and enzymes that plays crucial roles in skin health and disease. Endogenous ligands of the ECS, called endocannabinoids, have proven to be important regulators of immune responses. One of the most prevalent endocannabinoids, arachidonoylethanolamide (also known as anandamide), is known for its anti-inflammatory effects. Langerhans cells (LCs) are the sole antigen-presenting cells present in the human epidermis. They serve as the first line of defense against pathogens and are essential for the skin's specific immune responses and play a critical role in maintaining tissue homeostasis; however, little is known about the effect of endocannabinoids on these cells. Our research aimed to provide the connection between monocyte-derived Langerhans cells (moLCs) and the ECS, shedding light on their collaborative roles in immune homeostasis and inflammation.

Methods

Human monocytes were differentiated into moLCs using established protocols. Anandamide was applied during the differentiation process to test its effect on the viability, marker expression, and cytokine production of the cells, as well as in short term treatments for intracellular calcium measurement. TLR ligands applied after the differentiation protocol were used to activate moLCs. The impact of anandamide on the functionality of moLCs was further assessed using differential gene expression analysis of bulk RNA-Seq data, moLC-T cell cocultures, while ELISpot was employed to determine polarization of T cells activated in the aforementioned cocultures.

Results

Anandamide did not significantly affect the viability of moLCs up to 10 µM. When applied during the differentiation process it had only a negligible effect on CD207 expression, the prototypic marker of LCs; however, there was an observed reduction in CD1a expression by moLCs. Anandamide had no significant effects on the maturation status of moLCs, nor did it affect the maturation induced by TLR3 and TLR7/8 agonists. MoLCs differentiated in the presence of anandamide did however show decreased production of CXCL8, IL-6, IL-10 and IL-12 cytokines induced by TLR3 and TLR7/8 activation. Anandamide-treated moLCs showed an increased capability to activate naïve T cells; however, not to the level seen with combined TLR agonism. RNA sequencing analysis of moLCs differentiated with anandamide showed modest changes compared to control cells but did reveal an inhibitory effect on oxidative phosphorylation specifically in activated moLCs. Anandamide also promoted the polarization of naïve T cells towards a Th1 phenotype.

Discussion

Our results show that anandamide has nuanced effects on the differentiation, maturation, cytokine secretion, metabolism and function of activated moLCs. Among these changes the decrease in CD1a expression on moLCs holds promise to selectively dampen inflammation induced by CD1a restricted T cells, which have been implicated as drivers of inflammation in common inflammatory skin conditions such as psoriasis, atopic dermatitis and contact dermatitis.

Maternal consumption of fish oil protected breast-fed piglets against Escherichia coli lipopolysaccharide-induced damage through reshaping of intestinal fatty acids profile

It has been well documented that n-3 polyunsaturated fatty acids (n-3 PUFA) can alleviate inflammation caused by Escherichia coli (E. coli) lipopolysaccharides (LPS), the etiologic agents that causing yellow or white dysentery in young pigs. However, it remains unclear whether the increase in n-3 PUFA availability could enhance the ability of nursery pigs to resist invasion by E. coli. LPS. Twenty-four 21-day-old female piglets, each two of them from the same sow fed the beef tallow (BT) or fish oil (FO) diets, were allocated into four treatment groups: BT-CON, piglets from the BT-fed sows and intraperitoneally injected with saline (9 g/L); BT-LPS, piglets from the BT-fed sows and injected with LPS (100 μg/kg body weight); FO-CON, piglets from the FO-fed sows and injected with saline; FO-LPS, piglets from the FO-fed sows and injected with LPS. Following 2 h of LPS challenge, the magnitudes of increase in body temperature approached to a marked (p < 0.01) difference between the BT-CON and BT-LPS piglets, whereas the dramatic (p < 0.01) difference between the FO-CON and FO-LPS piglets was only observed at 4 h post LPS challenge. The body temperature averaged across the time points evaluated was about 0.2°C lower (p < 0.05) in the FO group than in the BT group. The FO group had lower (p < 0.05) mean corpuscular hemoglobin concentration, lower increase in serum interleukin (IL)-1β (p < 0.10) and IL-8 (p < 0.05) levels, higher (p < 0.01) serum albumin concentration, and higher (p = 0.10) ratios of jejunum villus height to crypt depth than the BT group. The FO group had much higher (p < 0.0001) ileal content of C20:5n3, C24:0, and C22:6n3, which were 2-4 times the content of the BT group. LPS challenge resulted in decreased (p < 0.05) intestinal C20:1 and C20:5n3 content, and the decrease (p < 0.05) in intestinal C20:3n6 and C24:1 content was observed in the BT-LPS piglets rather than in the FO-LPS piglets. Taken together, this study indicated that maternal consumption of fish oil protected breast-fed piglets against E. coli LPS-induced damage through reshaping of intestinal fatty acids profile, which sheds new light on the development of nutritional strategies to enhance the ability of young pigs to resist E. coli invasion.

13C-metabolic flux analysis reveals metabolic rewiring in HL-60 neutrophil-like cells through differentiation and immune stimulation

Neutrophils are innate immune cells and the first line of defense for the maintenance of homeostasis. However, our knowledge of the metabolic rewiring associated with their differentiation and immune stimulation is limited. Here, quantitative 13C-metabolic flux analysis was performed using HL-60 cells as the neutrophil model. A metabolic model for 13C-metabolic flux analysis of neutrophils was developed based on the accumulation of 13C in intracellular metabolites derived from 13C-labeled extracellular carbon sources and intracellular macromolecules. Aspartate and glutamate in the medium were identified as carbon sources that enter central carbon metabolism. Furthermore, the breakdown of macromolecules, estimated to be fatty acids and nucleic acids, was observed. Based on these results, a modified metabolic model was used for 13C-metabolic flux analysis of undifferentiated, differentiated, and lipopolysaccharide (LPS)-activated HL-60 cells. The glucose uptake rate and glycolytic flux decreased with differentiation, whereas the tricarboxylic acid (TCA) cycle flux remained constant. The addition of LPS to differentiated HL-60 cells activated the glucose uptake rate and pentose phosphate pathway (PPP) flux levels, resulting in an increased rate of total NADPH regeneration, which could be used to generate reactive oxygen species. The flux levels of fatty acid degradation and synthesis were also increased in LPS-activated HL-60 cells. Overall, this study highlights the quantitative metabolic alterations in multiple pathways via the differentiation and activation of HL-60 cells using 13C-metabolic flux analysis.

Advance in Multi-omics Research Strategies on Cholesterol Metabolism in Psoriasis

The skin is a complex and dynamic organ where homeostasis is maintained through the intricate interplay between the immune system and metabolism, particularly cholesterol metabolism. Various factors such as cytokines, inflammatory mediators, cholesterol metabolites, and metabolic enzymes play crucial roles in facilitating these interactions. Dysregulation of this delicate balance contributes to the pathogenic pathways of inflammatory skin conditions, notably psoriasis. In this article, we provide an overview of omics biomarkers associated with psoriasis in relation to cholesterol metabolism. We explore multi-omics approaches that reveal the communication between immunometabolism and psoriatic inflammation. Additionally, we summarize the use of multi-omics strategies to uncover the complexities of multifactorial and heterogeneous inflammatory diseases. Finally, we highlight potential future perspectives related to targeted drug therapies and research areas that can advance precise medicine. This review aims to serve as a valuable resource for those investigating the role of cholesterol metabolism in psoriasis.

Mechanic study based on untargeted metabolomics of Pi-pa-run-fei-tang on pepper combined with ammonia induced chronic cough model mice

ETHNOPHARMACOLOGICAL RELEVANCE

Pi-pa-run-fei-tang (PPRFT), a traditional Chinese medicine formula with long-standing history, demonstrated beneficial effect on chronic cough. However, the mechanism underlying efficacy unclear. In current research, we explored the impact and molecular mechanism of chronic cough mouse stimulating with capsaicin combined with ammonia.

AIM OF THE STUDY

To investigate the metabolic modulating effects, and potential mechanisms underlying the therapeutic effect of PPRFT in chronic cough.

MATERIALS AND METHODS

Chronic cough mouse models were created by stimulating mice by capsaicin combined with ammonia. Number of coughs and cough latency within 2 min were recorded. With lung tissue and serum samples collected for histopathology, metabolomics, RT-qPCR, immunohistochemistry, and WB analysis. Lymphocytes were isolated and flow cytometric assays were conducted to evaluate the differentiation between Th17 and Treg cell among CD4+ cells.

RESULTS

Results indicated that PPRFT obviously reduced the number of coughs, prolonged cough latency, reduced inflammatory cell infiltration and lung tissues damage, and decreased the serum level of IL-6, IL-1β, TNF-α, and IL-17 while increasing IL-10 levels. Notably, PPRFT suppressed Th17 cell divergence and promoted Treg cell divergence. Furthermore, serum metabolomic assays showed that 46 metabolites differed significantly between group, with 35 pathways involved. Moreover, mRNA levels of IL-6, NF-κB, IL-17, RORγT, JAK2, STAT3, PI3K and AKT in lung tissues remarkably reduced and mRNA levels of IL-10 and FOXP3 were elevated after PPRFT pretreatment. Additionally, PPRFT treatments decreased the protein levels of IL-6, NF-κB, IL-17, RORγT, p-JAK2, p-STAT3, p-PI3K, and p-AKT and increased the protein levels of IL-10 and FOXP3, but no significantly effects to the levels on JAK2, STAT3, PI3K, and AKT in the lungs.

CONCLUSION

Conclusively, our result suggested the effect with PPRFT on chronic cough may be mediated through IL-6/JAK2/STAT3 and PI3K/AKT/NF-κB pathway, which regulate the differentiation between Th17 and Treg cell. This beneficial effect of PPRFT in capsaicin and ammonia-stimulated chronic cough mice indicates its potential application in treating chronic cough.

Nucleolin myocardial-specific knockout exacerbates glucose metabolism disorder in endotoxemia-induced myocardial injury

Background

Sepsis-induced myocardial injury, as one of the important complications of sepsis, can significantly increase the mortality of septic patients. Our previous study found that nucleolin affected mitochondrial function in energy synthesis and had a protective effect on septic cardiomyopathy in mice. During sepsis, glucose metabolism disorders aggravated myocardial injury and had a negative effect on septic patients.

Objectives

We investigated whether nucleolin could regulate glucose metabolism during endotoxemia-induced myocardial injury.

Methods

The study tested whether the nucleolin cardiac-specific knockout in the mice could affect glucose metabolism through untargeted metabolomics, and the results of metabolomics were verified experimentally in H9C2 cells. The ATP content, lactate production, and oxygen consumption rate (OCR) were evaluated.

Results

The metabolomics results suggested that glycolytic products were increased in endotoxemia-induced myocardial injury, and that nucleolin myocardial-specific knockout altered oxidative phosphorylation-related pathways. The experiment data showed that TNF-α combined with LPS stimulation could increase the lactate content and the OCR values by about 25%, and decrease the ATP content by about 25%. However, interference with nucleolin expression could further decrease ATP content and OCR values by about 10-20% and partially increase the lactate level in the presence of TNF-α and LPS. However, nucleolin overexpression had the opposite protective effect, which partially reversed the decrease in ATP content and the increase in lactate level.

Conclusion

Down-regulation of nucleolin can exacerbate glucose metabolism disorders in endotoxemia-induced myocardial injury. Improving glucose metabolism by regulating nucleolin was expected to provide new therapeutic ideas for patients with septic cardiomyopathy.

Hypoxia-inducible factor in breast cancer: role and target for breast cancer treatment

Globally, breast cancer stands as the most prevalent form of cancer among women. The tumor microenvironment of breast cancer often exhibits hypoxia. Hypoxia-inducible factor 1-alpha, a transcription factor, is found to be overexpressed and activated in breast cancer, playing a pivotal role in the anoxic microenvironment by mediating a series of reactions. Hypoxia-inducible factor 1-alpha is involved in regulating downstream pathways and target genes, which are crucial in hypoxic conditions, including glycolysis, angiogenesis, and metastasis. These processes significantly contribute to breast cancer progression by managing cancer-related activities linked to tumor invasion, metastasis, immune evasion, and drug resistance, resulting in poor prognosis for patients. Consequently, there is a significant interest in Hypoxia-inducible factor 1-alpha as a potential target for cancer therapy. Presently, research on drugs targeting Hypoxia-inducible factor 1-alpha is predominantly in the preclinical phase, highlighting the need for an in-depth understanding of HIF-1α and its regulatory pathway. It is anticipated that the future will see the introduction of effective HIF-1α inhibitors into clinical trials, offering new hope for breast cancer patients. Therefore, this review focuses on the structure and function of HIF-1α, its role in advancing breast cancer, and strategies to combat HIF-1α-dependent drug resistance, underlining its therapeutic potential.

Metabolic pathways in immune senescence and inflammaging: Novel therapeutic strategy for chronic inflammatory lung diseases. An EAACI position paper from the Task Force for Immunopharmacology

The accumulation of senescent cells drives inflammaging and increases morbidity of chronic inflammatory lung diseases. Immune responses are built upon dynamic changes in cell metabolism that supply energy and substrates for cell proliferation, differentiation, and activation. Metabolic changes imposed by environmental stress and inflammation on immune cells and tissue microenvironment are thus chiefly involved in the pathophysiology of allergic and other immune-driven diseases. Altered cell metabolism is also a hallmark of cell senescence, a condition characterized by loss of proliferative activity in cells that remain metabolically active. Accelerated senescence can be triggered by acute or chronic stress and inflammatory responses. In contrast, replicative senescence occurs as part of the physiological aging process and has protective roles in cancer surveillance and wound healing. Importantly, cell senescence can also change or hamper response to diverse therapeutic treatments. Understanding the metabolic pathways of senescence in immune and structural cells is therefore critical to detect, prevent, or revert detrimental aspects of senescence-related immunopathology, by developing specific diagnostics and targeted therapies. In this paper, we review the main changes and metabolic alterations occurring in senescent immune cells (macrophages, B cells, T cells). Subsequently, we present the metabolic footprints described in translational studies in patients with chronic asthma and chronic obstructive pulmonary disease (COPD), and review the ongoing preclinical studies and clinical trials of therapeutic approaches aiming at targeting metabolic pathways to antagonize pathological senescence. Because this is a recently emerging field in allergy and clinical immunology, a better understanding of the metabolic profile of the complex landscape of cell senescence is needed. The progress achieved so far is already providing opportunities for new therapies, as well as for strategies aimed at disease prevention and supporting healthy aging.

Threonine dehydrogenase regulates neutrophil homeostasis but not H3K4me3 levels in zebrafish

l-threonine dehydrogenase (Tdh) is an enzyme that links threonine metabolism to epigenetic modifications and mitochondria biogenesis. In vitro studies show that it is critical for the regulation of trimethylation of histone H3 lysine 4 (H3K4me3) levels and cell fate determination of mouse embryonic stem cells (mESCs). However, whether Tdh regulates a developmental process in vivo and, if it does, whether it also primarily regulates H3K4me3 levels in this process as it does in mESCs, remains elusive. Here, we revealed that, in zebrafish hematopoiesis, tdh is preferentially expressed in neutrophils. Knockout of tdh causes a decrease in neutrophil number and slightly suppresses their acute injury-induced migration, but, unlike the mESCs, the level of H3K4me3 is not evidently reduced in neutrophils sorted from the kidney marrow of adult tdh-null zebrafish. These phenotypes are dependent on the enzymatic activity of Tdh. Importantly, a soluble supplement of nutrients that are able to fuel the acetyl-CoA pool, such as pyruvate, glucose and branched-chain amino acids, is sufficient to rescue the reduction in neutrophils caused by tdh deletion. In summary, our study presents evidence for the functional requirement of Tdh-mediated threonine metabolism in a developmental process in vivo. It also provides an animal model for investigating the nutritional regulation of myelopoiesis and immune response, as well as a useful tool for high-throughput drug/nutrition screening.

Common and distinct metabolomic markers related to immune aging in Western European and East African populations

In old age, impaired immunity causes high susceptibility to infections and cancer, higher morbidity and mortality, and poorer vaccination efficiency. Many factors, such as genetics, diet, and lifestyle, impact aging. This study aimed to investigate how immune responses change with age in healthy Dutch and Tanzanian individuals and identify common metabolites associated with an aged immune profile. We performed untargeted metabolomics from plasma to identify age-associated metabolites, and we correlated their concentrations with ex-vivo cytokine production by immune cells, DNA methylation-based epigenetic aging, and telomere length. Innate immune responses were impacted differently by age in Dutch and Tanzanian cohorts. Age-related decline in steroid hormone precursors common in both populations was associated with higher systemic inflammation and lower cytokine responses. Hippurate and 2-phenylacetamide, commonly more abundant in older individuals, were negatively correlated with cytokine responses and telomere length and positively correlated with epigenetic aging. Lastly, we identified several metabolites that might contribute to the stronger decline in innate immunity with age in Tanzanians. The shared metabolomic signatures of the two cohorts suggest common mechanisms of immune aging, revealing metabolites with potential contributions. These findings also reflect genetic or environmental effects on circulating metabolites that modulate immune responses.

Alterations in metabolic pathways: a bridge between aging and weaker innate immune response

Aging is a time-dependent progressive physiological process, which results in impaired immune system function. Age-related changes in immune function increase the susceptibility to many diseases such as infections, autoimmune diseases, and cancer. Different metabolic pathways including glycolysis, tricarboxylic acid cycle, amino acid metabolism, pentose phosphate pathway, fatty acid oxidation and fatty acid synthesis regulate the development, differentiation, and response of adaptive and innate immune cells. During aging all these pathways change in the immune cells. In addition to the changes in metabolic pathways, the function and structure of mitochondria also have changed in the immune cells. Thereby, we will review changes in the metabolism of different innate immune cells during the aging process.

Emerging Issues and Initial Insights into Bacterial Biofilms: From Orthopedic Infection to Metabolomics

Bacterial biofilms, enigmatic communities of microorganisms enclosed in an extracellular matrix, still represent an open challenge in many clinical contexts, including orthopedics, where biofilm-associated bone and joint infections remain the main cause of implant failure. This study explores the scenario of biofilm infections, with a focus on those related to orthopedic implants, highlighting recently emerged substantial aspects of the pathogenesis and their potential repercussions on the clinic, as well as the progress and gaps that still exist in the diagnostics and management of these infections. The classic mechanisms through which biofilms form and the more recently proposed new ones are depicted. The ways in which bacteria hide, become impenetrable to antibiotics, and evade the immune defenses, creating reservoirs of bacteria difficult to detect and reach, are delineated, such as bacterial dormancy within biofilms, entry into host cells, and penetration into bone canaliculi. New findings on biofilm formation with host components are presented. The article also delves into the emerging and critical concept of immunometabolism, a key function of immune cells that biofilm interferes with. The growing potential of biofilm metabolomics in the diagnosis and therapy of biofilm infections is highlighted, referring to the latest research.

Jingfang Granules () alleviates bleomycin-induced acute lung injury through regulating PI3K/Akt/mTOR signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Acute lung injury is a kind of clinical emergency severe syndrome which might trigger acute respiratory distress syndrome. Jingfang Granules () is a traditional Chinese medicine which has been proven to improve acute lung injury induced by bleomycin through inhibiting recruitment and overactive of inflammation. However, the potential mechanisms are still not well evaluated.

AIM OF STUDY

The aim of this study was to evaluate the protective function of Jingfang Granules on bleomycin caused acute lung injury and further discuss the potential pharmacological mechanisms.

MATERIALS AND METHODS

C57BL/6J mice were intratracheal injected bleomycin to induce model with acute lung injury. The protective impact of Jingfang Granules on acute lung injury and lung fibrosis triggered by bleomycin were evaluated through detecting mice body weight, lung appearance, lung index, and histopathology. The potential pharmacological mechanism of Jingfang Granules in treating acute lung injury was further elucidated by the methods of network pharmacology, proteomics, metabolomics, as well as western blot. Additionally, the network pharmacology analysis and molecular docking technology were integrated to investigate the targets of Jingfang Granules improving acute lung injury.

RESULTS

Our results indicated that Jingfang Granules effectively protected mice from acute lung injury induced by bleomycin, which was confirmed by higher body weight, lower pulmonary edema and lung index, and improved pathology and fibrosis of lung tissue compared to model group. Proteomics, western blot, and metabolomics were integrated and the results confirmed that Jingfang Granules regulated the Glycolysis/Gluconogenesis and Pyruvate metabolism through downregulating the PI3K/Akt/mTOR signaling pathway. The network pharmacology analysis and molecular docking technology results showed that the targets of Jingfang Granules for treating acute lung injury were enriched in the PI3K/Akt signaling pathway, which included 7 target proteins such as MAPK1, MAPK3, JAK2, HRAS, EGFR, PIK3R1, and PIK3CA.

CONCLUSION

This study indicates that Jingfang Granules displays a markedly protective effect on acute lung injury caused by bleomycin through downregulating PI3K/Akt/mTOR signaling pathway, which in turn regulates Glycolysis/Gluconogenesis and Pyruvate metabolism.

GLUT-1/PKM2 loop dysregulation in patients with non-ST-segment elevation myocardial infarction promotes metainflammation

AIMS

The functional capacity of the immune cells is strongly dependent on their metabolic state and inflammatory responses are characterized by a greater use of glucose in immune cells. This study is aimed to establish the role of glucose metabolism and its players [glucose transporter 1 (GLUT-1) and pyruvate kinase isozyme M2 (PKM2)] in the dysregulation of adaptive immunity and inflammation observed in patients with non-ST-segment elevation myocardial infarction (NSTEMI).

METHODS AND RESULTS

We enrolled 248 patients allocated to three groups: NSTEMI patients, chronic coronary syndromes (CCS) patients, healthy subjects (HSs). NSTEMI patients showed higher expression of GLUT-1 and an enhanced glucose uptake in T cells when compared with CCS patients (P < 0.0001; P = 0.0101, respectively) and HSs (P = 0.0071; P = 0.0122, respectively). PKM2 had a prevalent nuclear localization in T lymphocytes in NSTEMI (P = 0.0005 for nuclear vs. cytoplasm localization), while in CCS and HS, it was equally distributed in both compartments. In addition, the nuclear fraction of PKM2 was significantly higher in NSTEMI compared with HS (P = 0.0023). In NSTEMI patients, treatment with Shikonin and Fasentin, which inhibits PKM2 enzyme activity and GLUT-1-mediated glucose internalization, respectively, led to a significant reduction in GLUT-1 expression along with the down-regulation of pro-inflammatory cytokine expression.

CONCLUSION

NSTEMI patients exhibit dysregulation of the GLUT-1/PKM2 metabolic loop characterized by nuclear translocation of PKM2, where it acts as a transcription regulator of pro-inflammatory genes. This detrimental loop might represent a new therapeutic target for personalized medicine.

Similarities and divergences in the metabolism of immune cells in cancer and helminthic infections

Energetic and nutritional requirements play a crucial role in shaping the immune cells that infiltrate tumor and parasite infection sites. The dynamic interaction between immune cells and the microenvironment, whether in the context of tumor or helminth infection, is essential for understanding the mechanisms of immunological polarization and developing strategies to manipulate them in order to promote a functional and efficient immune response that could aid in the treatment of these conditions. In this review, we present an overview of the immune response triggered during tumorigenesis and establishment of helminth infections, highlighting the transition to chronicity in both cases. We discuss the energetic demands of immune cells under normal conditions and in the presence of tumors and helminths. Additionally, we compare the metabolic changes that occur in the tumor microenvironment and the infection site, emphasizing the alterations that are induced to redirect the immune response, thereby promoting the survival of cancer cells or helminths. This emerging discipline provides valuable insights into disease pathogenesis. We also provide examples of novel strategies to enhance immune activity by targeting metabolic pathways that shape immune phenotypes, with the aim of achieving positive outcomes in cancer and helminth infections.

Therapeutic targeting of immunometabolism in Alzheimer's disease reveals a critical reliance on Hexokinase 2 dosage on microglial activation and disease progression

Microgliosis and neuroinflammation are prominent features of Alzheimer's disease (AD). Disease-responsive microglia meet their increased energy demand by reprogramming metabolism, specifically, switching to favor glycolysis over oxidative phosphorylation. Thus, targeting of microglial immunometabolism might be of therapeutic benefit for treating AD, providing novel and often well understood immune pathways and their newly recognized actions in AD. We report that in the brains of 5xFAD mice and postmortem brains of AD patients, we found a significant increase in the levels of Hexokinase 2 (HK2), an enzyme that supports inflammatory responses by rapidly increasing glycolysis. Moreover, binding of HK2 to mitochondria has been reported to regulate inflammation by preventing mitochondrial dysfunction and NLRP3 inflammasome activation, suggesting that its inflammatory role extends beyond its glycolytic activity. Here we report, that HK2 antagonism selectively affects microglial phenotypes and disease progression in a gene-dose dependent manner. Paradoxically, complete loss of HK2 fails to improve AD progression by exacerbating inflammasome activity while its haploinsufficiency results in reduced pathology and improved cognition in the 5XFAD mice. We propose that the partial antagonism of HK2, is effective in slowed disease progression and inflammation through a non-metabolic mechanism associated with the modulation of NFKβ signaling, through its cytosolic target IKBα. The complete loss of HK2 affects additional inflammatory mechanisms associated to mitochondrial dysfunction.

Highlights

Hexokinase 2, the first and rate-limiting enzyme of glycolysis, is specifically upregulated in plaque-associated microglia of AD mice models and in the postmortem cortex of human AD patients.Microglia haploinsufficient in HK2 exhibit reduced amyloid burden and inflammation as well as improved cognition in a mouse model of AD. Paradoxically, the complete loss of HK2 results in opposite effects, by exacerbating inflammation.Lonidamine, an anticancer drug that inhibits HK2, mimics the salutary effects of HK2 haploinsufficiency in the 5xFAD mice, but only in males during the early stages of disease.HK2 deletion induced mitochondrial dysfunction associated to increased expression of inflammasome elements and IL-1β.HK2 partial antagonism exerts beneficial effects independent of its energetic or mitochondrial role, likely through cytosolic stabilization of IκBα and inhibition of the NF-κB pathway, leading to reduced proinflammatory gene expression.

Inflammation and Oxidative Stress Induced by Obesity, Gestational Diabetes, and Preeclampsia in Pregnancy: Role of High-Density Lipoproteins as Vectors for Bioactive Compounds

Inflammation and oxidative stress are essential components in a myriad of pathogenic entities that lead to metabolic and chronic diseases. Moreover, inflammation in its different phases is necessary for the initiation and maintenance of a healthy pregnancy. Therefore, an equilibrium between a necessary/pathologic level of inflammation and oxidative stress during pregnancy is needed to avoid disease development. High-density lipoproteins (HDL) are important for a healthy pregnancy and a good neonatal outcome. Their role in fetal development during challenging situations is vital for maintaining the equilibrium. However, in certain conditions, such as obesity, diabetes, and other cardiovascular diseases, it has been observed that HDL loses its protective properties, becoming dysfunctional. Bioactive compounds have been widely studied as mediators of inflammation and oxidative stress in different diseases, but their mechanisms of action are still unknown. Nonetheless, these agents, which are obtained from functional foods, increase the concentration of HDL, TRC, and antioxidant activity. Therefore, this review first summarizes several mechanisms of HDL participation in the equilibrium between inflammation and oxidative stress. Second, it gives an insight into how HDL may act as a vector for bioactive compounds. Third, it describes the relationships between the inflammation process in pregnancy and HDL activity. Consequently, different databases were used, including MEDLINE, PubMed, and Scopus, where scientific articles published in the English language up to 2023 were identified.

Fundamental Neurochemistry Review: Microglial immunometabolism in traumatic brain injury

Traumatic brain injury (TBI) is a devastating neurological disorder caused by a physical impact to the brain that promotes diffuse damage and chronic neurodegeneration. Key mechanisms believed to support secondary brain injury include mitochondrial dysfunction and chronic neuroinflammation. Microglia and brain-infiltrating macrophages are responsible for neuroinflammatory cytokine and reactive oxygen species (ROS) production after TBI. Their production is associated with loss of homeostatic microglial functions such as immunosurveillance, phagocytosis, and immune resolution. Beyond providing energy support, mitochondrial metabolic pathways reprogram the pro- and anti-inflammatory machinery in immune cells, providing a critical immunometabolic axis capable of regulating immunologic response to noxious stimuli. In the brain, the capacity to adapt to different environmental stimuli derives, in part, from microglia's ability to recognize and respond to changes in extracellular and intracellular metabolite levels. This capacity is met by an equally plastic metabolism, capable of altering immune function. Microglial pro-inflammatory activation is associated with decreased mitochondrial respiration, whereas anti-inflammatory microglial polarization is supported by increased oxidative metabolism. These metabolic adaptations contribute to neuroimmune responses, placing mitochondria as a central regulator of post-traumatic neuroinflammation. Although it is established that profound neurometabolic changes occur following TBI, key questions related to metabolic shifts in microglia remain unresolved. These include (a) the nature of microglial mitochondrial dysfunction after TBI, (b) the hierarchical positions of different metabolic pathways such as glycolysis, pentose phosphate pathway, glutaminolysis, and lipid oxidation during secondary injury and recovery, and (c) how immunometabolism alters microglial phenotypes, culminating in chronic non-resolving neuroinflammation. In this basic neurochemistry review article, we describe the contributions of immunometabolism to TBI, detail primary evidence of mitochondrial dysfunction and metabolic impairments in microglia and macrophages, discuss how major metabolic pathways contribute to post-traumatic neuroinflammation, and set out future directions toward advancing immunometabolic phenotyping in TBI.

Activated protein C modulates T-cell metabolism and epigenetic FOXP3 induction via α-ketoglutarate

A direct regulation of adaptive immunity by the coagulation protease activated protein C (aPC) has recently been established. Preincubation of T cells with aPC for 1 hour before transplantation increases FOXP3+ regulatory T cells (Tregs) and reduces acute graft-versus-host disease (aGVHD) in mice, but the underlying mechanism remains unknown. Because cellular metabolism modulates epigenetic gene regulation and plasticity in T cells, we hypothesized that aPC promotes FOXP3+ expression by altering T-cell metabolism. To this end, T-cell differentiation was assessed in vitro using mixed lymphocyte reaction or plate-bound α-CD3/CD28 stimulation, and ex vivo using T cells isolated from mice with aGVHD without and with aPC preincubation, or analyses of mice with high plasma aPC levels. In stimulated CD4+CD25- cells, aPC induces FOXP3 expression while reducing expression of T helper type 1 cell markers. Increased FOXP3 expression is associated with altered epigenetic markers (reduced 5-methylcytosine and H3K27me3) and reduced Foxp3 promoter methylation and activity. These changes are linked to metabolic quiescence, decreased glucose and glutamine uptake, decreased mitochondrial metabolism (reduced tricarboxylic acid metabolites and mitochondrial membrane potential), and decreased intracellular glutamine and α-ketoglutarate levels. In mice with high aPC plasma levels, T-cell subpopulations in the thymus are not altered, reflecting normal T-cell development, whereas FOXP3 expression in splenic T cells is reduced. Glutamine and α-ketoglutarate substitution reverse aPC-mediated FOXP3+ induction and abolish aPC-mediated suppression of allogeneic T-cell stimulation. These findings show that aPC modulates cellular metabolism in T cells, reducing glutamine and α-ketoglutarate levels, which results in altered epigenetic markers, Foxp3 promoter demethylation and induction of FOXP3 expression, thus favoring a Treg-like phenotype.

The role of macrophages polarization in sepsis-induced acute lung injury

Sepsis presents as a severe infectious disease frequently documented in clinical settings. Characterized by its systemic inflammatory response syndrome, sepsis has the potential to trigger multi-organ dysfunction and can escalate to becoming life-threatening. A common fallout from sepsis is acute lung injury (ALI), which often progresses to acute respiratory distress syndrome (ARDS). Macrophages, due to their significant role in the immune system, are receiving increased attention in clinical studies. Macrophage polarization is a process that hinges on an intricate regulatory network influenced by a myriad of signaling molecules, transcription factors, epigenetic modifications, and metabolic reprogramming. In this review, our primary focus is on the classically activated macrophages (M1-like) and alternatively activated macrophages (M2-like) as the two paramount phenotypes instrumental in sepsis' host immune response. An imbalance between M1-like and M2-like macrophages can precipitate the onset and exacerbate the progression of sepsis. This review provides a comprehensive understanding of the interplay between macrophage polarization and sepsis-induced acute lung injury (SALI) and elaborates on the intervention strategy that centers around the crucial process of macrophage polarization.

NAD + salvage governs mitochondrial metabolism, invigorating natural killer cell antitumor immunity

BACKGROUND AND AIMS

Natural killer (NK) cells are key players in tumor immunosurveillance, and metabolic adaptation manipulates their fate and functional state. The nicotinamide adenine dinucleotide (NAD + ) has emerged as a vital factor to link cellular metabolism and signaling transduction. Here, we identified NAD + metabolism as a central hub to determine the homeostasis and function of NK cells.

APPROACH AND RESULTS

NAD + level was elevated in activated NK cells. NAD + supplementation not only enhanced cytokine production and cytotoxicity but also improved the proliferation and viability of NK cells. Intriguingly, the salvage pathway was involved in maintaining NAD + homeostasis in activated NK cells. Genetic ablation or pharmacological blockade of nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in the NAD + salvage pathway, markedly destroyed the viability and function of NK cells. Mechanistically, NAD + salvage dictated the mitochondrial homeostasis and oxidative phosphorylation activity to support the optimal function of NK cells. However, in human HCC tissues, NAMPT expression and NAD + level were significantly down-regulated in tumor-infiltrating NK cells, which negatively correlated with patient survival. And lactate accumulation in the tumor microenvironment was at least partially responsible for the transcriptional repression of NAMPT in NK cells. Further, deficiency of Nampt in NK cells accelerated the growth of HCC and melanoma. Supplementation of the NAD + precursor nicotinamide mononucleotide (NMN) significantly improved NK antitumor response in both mouse and human cell-derived xenografts.

CONCLUSIONS

These findings reveal NAD + salvage as an essential factor for NK-cell homeostasis and function, suggesting a potential strategy for invigorating NK cell-based immunotherapy.

Peripheral blood mononuclear cells exhibit increased mitochondrial respiration after adjuvant chemo- and radiotherapy for early breast cancer

BACKGROUND

Adjuvant chemo- and radiotherapy cause cellular damage to tumorous and healthy dividing cells. Chemotherapy has been shown to cause mitochondrial respiratory dysfunction in non-tumorous tissues, but the effects on human peripheral blood mononuclear cells (PBMCs) remain unknown.

AIM

We aimed to investigate mitochondrial respiration of PBMCs before and after adjuvant chemo- and radiotherapy in postmenopausal patients with early breast cancer (EBC) and relate these to metabolic parameters of the patients.

METHODS

Twenty-three postmenopausal women diagnosed with EBC were examined before and shortly after chemotherapy with (n = 18) or without (n = 5) radiotherapy. Respiration (O2 flux per million PBMCs) was assessed by high-resolution respirometry of intact and permeabilized PBMCs. Clinical metabolic characteristics and mitochondrial DNA (mtDNA) content of PBMCs (mtDN relative to nuclear DNA) were furthermore assessed.

RESULTS

Respiration of intact and permeabilized PBMCs from EBC patients significantly increased with adjuvant chemo- and radiotherapy (p = 6 × 10-5 and p = 1 × 10-7 , respectively). The oxygen flux attributed to specific mitochondrial complexes and respiratory states increased by 17-43% compared to before therapy initiation. Similarly, PBMC mtDNA content increased by 40% (p = 0.002). Leukocytes (p = 0.0001), hemoglobin (p = 0.0003), and HDL cholesterol (p = 0.003) concentrations decreased whereas triglyceride (p = 0.01) and LDL (p = 0.02) concentrations increased after treatment suggesting a worsened metabolic state. None of the metabolic parameters or the mtDNA content of PBMCs correlated significantly with PBMC respiration.

CONCLUSION

This study shows that mitochondrial respiration and mtDNA content in circulating PBMCs increase after adjuvant chemo- and radiotherapy in postmenopausal patients with EBC. Besides the increased mtDNA content, a shift in PBMC subpopulation proportions towards cells relying on oxidative phosphorylation, who may be less sensitive to chemotherapy, might influence the increased mitochondrial respiration observed iafter chemotherapy.

Amino Acid Catabolism: An Overlooked Area of Metabolism

Amino acids have been extensively studied in nutrition, mainly as key elements for maintaining optimal protein synthesis in the body as well as precursors of various nitrogen-containing compounds. However, it is now known that amino acid catabolism is an important element for the metabolic control of different biological processes, although it is still a developing field to have a deeper understanding of its biological implications. The mechanisms involved in the regulation of amino acid catabolism now include the contribution of the gut microbiota to amino acid oxidation and metabolite generation in the intestine, the molecular mechanisms of transcriptional control, and the participation of specific miRNAs involved in the regulation of amino acid degrading enzymes. In addition, molecules derived from amino acid catabolism play a role in metabolism as they are used in the epigenetic regulation of many genes. Thus, this review aims to examine the mechanisms of amino acid catabolism and to support the idea that this process is associated with the immune response, abnormalities during obesity, in particular insulin resistance, and the regulation of thermogenesis.

Influence of Maternal Immune Activation and Stressors on the Hippocampal Metabolome

Prenatal stress often results in maternal immune activation (MIA) that can impact prenatal brain development, molecular processes, and substrates and products of metabolism that participate in physiological processes at later stages of life. Postnatal metabolic and immunological stressors can affect brain metabolites later in life, independently or in combination with prenatal stressors. The effects of prenatal and postnatal stressors on hippocampal metabolites were studied using a pig model of viral MIA exposed to immunological and metabolic stressors at 60 days of age using gas chromatography mass spectrometry. Postnatal stress and MIA elicited effects (FDR-adjusted p-value < 0.1) on fifty-nine metabolites, while eight metabolites exhibited an interaction effect. The hippocampal metabolites impacted by MIA or postnatal stress include 4-aminobutanoate (GABA), adenine, fumarate, glutamate, guanine, inosine, ornithine, putrescine, pyruvate, and xanthine. Metabolites affected by MIA or postnatal stress encompassed eight significantly (FDR-adjusted p-value < 0.1) enriched Kyoto Encyclopedia of Genes and Genomes Database (KEGG) pathways. The enriched arginine biosynthesis and glutathione metabolism pathways included metabolites that are also annotated for the urea cycle and polyamine biosynthesis pathways. Notably, the prenatal and postnatal challenges were associated with disruption of the glutathione metabolism pathway and changes in the levels of glutamic acid, glutamate, and purine nucleotide metabolites that resemble patterns elicited by drugs of abuse and may underlie neuroinflammatory processes. The combination of MIA and postnatal stressors also supported the double-hit hypothesis, where MIA amplifies the impact of stressors later in life, sensitizing the hippocampus of the offspring to future challenges. The metabolites and pathways characterized in this study offer evidence of the role of immunometabolism in understanding the impact of MIA and stressors later in life on memory, spatial navigation, neuropsychiatric disorders, and behavioral disorders influenced by the hippocampus.

OXPHOS-targeting drugs in oncology: new perspectives

INTRODUCTION

Drugs targeting mitochondria are emerging as promising antitumor therapeutics in preclinical models. However, a few of these drugs have shown clinical toxicity. Developing mitochondria-targeted modified natural compounds and US FDA-approved drugs with increased therapeutic index in cancer is discussed as an alternative strategy.

AREAS COVERED

Triphenylphosphonium cation (TPP+)-based drugs selectively accumulate in the mitochondria of cancer cells due to their increased negative membrane potential, target the oxidative phosphorylation proteins, inhibit mitochondrial respiration, and inhibit tumor proliferation. TPP+-based drugs exert minimal toxic side effects in rodents and humans. These drugs can sensitize radiation and immunotherapies.

EXPERT OPINION

TPP+-based drugs targeting the tumor mitochondrial electron transport chain are a new class of oxidative phosphorylation inhibitors with varying antiproliferative and antimetastatic potencies. Some of these TPP+-based agents, which are synthesized from naturally occurring molecules and FDA-approved drugs, have been tested in mice and did not show notable toxicity, including neurotoxicity, when used at doses under the maximally tolerated dose. Thus, more effort should be directed toward the clinical translation of TPP+-based OXPHOS-inhibiting drugs in cancer prevention and treatment.

Impact of heat stress on dairy cattle and selection strategies for thermotolerance: a review

Climate change is a problem that causes many environmental issues that impact the productivity of livestock species. One of the major issues associated with climate change is an increase of the frequency of hot days and heat waves, which increases the risk of heat stress for livestock species. Dairy cattle have been identified as being susceptible to heat stress due to their high metabolic heat load. Studies have shown heat stress impacts several biological processes that can result in large economic consequences. When heat stress occurs, dairy cattle employ several physiological and cellular mechanisms in order to dissipate heat and protect cells from damage. These mechanisms require an increase and diversion in energy toward protection and away from other biological processes. Therefore, in turn heat stress in dairy cattle can lead numerous issues including reductions in milk production and reproduction as well as increased risk for disease and mortality. This indicates a need to select dairy cattle that would be thermotolerant. Various selection strategies to confer thermotolerance have been discussed in the literature, including selecting for reduced milk production, crossbreeding with thermotolerant breeds, selecting based on physiological traits and most recently selecting for enhanced immune response. This review discusses the various issues associated with heat stress in dairy cattle and the pros and cons to the various selection strategies that have been proposed to select for thermotolerance in dairy cattle.

Hepatic Global Transcriptomic Profiles of Holstein Cows According to Parity Reveal Age-Related Changes in Early Lactation

Cows can live for over 20 years, but their productive lifespan averages only around 3 years after first calving. Liver dysfunction can reduce lifespan by increasing the risk of metabolic and infectious disease. This study investigated the changes in hepatic global transcriptomic profiles in early lactation Holstein cows in different lactations. Cows from five herds were grouped as primiparous (lactation number 1, PP, 534.7 ± 6.9 kg, n = 41), or multiparous with lactation numbers 2-3 (MP2-3, 634.5 ± 7.5 kg, n = 87) or 4-7 (MP4-7, 686.6 ± 11.4 kg, n = 40). Liver biopsies were collected at around 14 days after calving for RNA sequencing. Blood metabolites and milk yields were measured, and energy balance was calculated. There were extensive differences in hepatic gene expression between MP and PP cows, with 568 differentially expressed genes (DEGs) between MP2-3 and PP cows, and 719 DEGs between MP4-7 and PP cows, with downregulated DEGs predominating in MP cows. The differences between the two age groups of MP cows were moderate (82 DEGs). The gene expression differences suggested that MP cows had reduced immune functions compared with the PP cows. MP cows had increased gluconeogenesis but also evidence of impaired liver functionality. The MP cows had dysregulated protein synthesis and glycerophospholipid metabolism, and impaired genome and RNA stability and nutrient transport (22 differentially expressed solute carrier transporters). The genes associated with cell cycle arrest, apoptosis, and the production of antimicrobial peptides were upregulated. More surprisingly, evidence of hepatic inflammation leading to fibrosis was present in the primiparous cows as they started their first lactation. This study has therefore shown that the ageing process in the livers of dairy cows is accelerated by successive lactations and increasing milk yields. This was associated with evidence of metabolic and immune disorders together with hepatic dysfunction. These problems are likely to increase involuntary culling, thus reducing the average longevity in dairy herds.

Tetra-O-methyl-nordihydroguaiaretic acid inhibits energy metabolism and synergistically induces anticancer effects with temozolomide on LN229 glioblastoma tumors implanted in mice while preventing obesity in normal mice that consume high-fat diets

Tetra-O-methyl-nordihydroguaiaretic acid (terameprocol; M4N), a global transcription inhibitor, in combination with a second anticancer drug induces strong tumoricidal activity and has the ability to suppress energy metabolism in cultured cancer cells. In this study, we showed that after continuous oral consumption of high-fat (HF) diets containing M4N, the M4N concentration in most of the organs in mice reached ~1 μM (the M4N concentration in intestines and fat pads was as high as 20-40 μM) and treatment with the combination of M4N with temozolomide (TMZ) suppressed glycolysis and the tricarboxylic acid cycle in LN229 human glioblastoma implanted in xenograft mice. Combination treatment of M4N with TMZ also reduced the levels of lactate dehydrogenase A (LDHA), a key enzyme for glycolysis; lactate, a product of LDHA-mediated enzymatic activity; nicotinamide phosphoribosyltransferase, a rate-limiting enzyme for nicotinamide adenine dinucleotide plus hydrogen (NADH)/NAD+ salvage pathway; and NAD+, a redox electron carrier essential for energy metabolism. It was also shown that M4N suppressed oxygen consumption in cultured LN229 cells, indicating that M4N inhibited oxidative phosphorylation. Treatment with M4N and TMZ also decreased the level of hypoxia-inducible factor 1A, a major regulator of LDHA, under hypoxic conditions. The ability of M4N to suppress energy metabolism resulted in induction of the stress-related proteins activating transcription factor 4 and cation transport regulator-like protein 1, and an increase in reactive oxygen species production. In addition, the combination treatment of M4N with TMZ reduced the levels of oncometabolites such as 2-hydroxyglutarate as well as the aforementioned lactate. M4N also induced methylidenesuccinic acid (itaconate), a macrophage-specific metabolite with anti-inflammatory activity, in tumor microenvironments. Meanwhile, the ability of M4N to suppress energy metabolism prevented obesity in mice consuming HF diets, indicating that M4N has beneficial effects on normal tissues. The dual ability of combination treatment with M4N to suppress both energy metabolism and oncometabolites shows that it is potentially an effective therapy for cancer.

Role of T cells in the pathogenesis of systemic lupus erythematous: Focus on immunometabolism dysfunctions

Evidence demonstrates that T cells are implicated in developing SLE, and each of them dominantly uses distinct metabolic pathways. Indeed, intracellular enzymes and availability of specific nutrients orchestrate fate of T cells and lead to differentiation of regulatory T cells (Treg), memory T cells, helper T cells, and effector T cells. The function of T cells in inflammatory and autoimmune responses is determined by metabolic processes and activity of their enzymes. Several studies were conducted to determine metabolic abnormalities in SLE patients and clarify how these modifications could control the functions of the involved T cells. Metabolic pathways such as glycolysis, mitochondrial pathways, oxidative stress, mTOR pathway, fatty acid and amino acid metabolisms are dysregulated in SLE T cells. Moreover, immunosuppressive drugs used in treating autoimmune diseases, including SLE, could affect immunometabolism. Developing drugs to regulate autoreactive T cell metabolism could be a promising therapeutic approach for SLE treatment. Accordingly, increased knowledge about metabolic processes paves the way to understanding SLE pathogenesis better and introduces novel therapeutic options for SLE treatment. Although monotherapy with metabolic pathways modulators might not be sufficient to prevent autoimmune disease, they may be an ideal adjuvant to reduce administration doses of immunosuppressive drugs, thus reducing drug-associated adverse effects. This review summarized emerging data about T cells that are involved in SLE pathogenesis, focusing on immunometabolism dysregulation and how these modifications could affect the disease development.

Chronic alcohol administration alters metabolomic profile of murine bone marrow

Introduction

People with hazardous alcohol use are more susceptible to viral, bacterial, and fungal infections due to the effect of alcohol on immune system cell function. Metabolized ethanol reduces NAD+ to NADH, affecting critical metabolic pathways. Here, our aim was to investigate whether alcohol is metabolized by bone marrow cells and if it impacts the metabolic pathways of leukocyte progenitor cells. This is said to lead to a qualitative and quantitative alteration of key metabolites which may be related to the immune response.

Methods

We addressed this aim by using C57BL/6 mice under chronic ethanol administration and evaluating the metabolomic profile of bone marrow total cells by gas chromatography-coupled mass spectrometry (GC-MS).

Results

We identified 19 metabolites. Our data demonstrated that chronic ethanol administration alters the metabolomic profile in the bone marrow, resulting in a statistically diminished abundance of five metabolites in ethanol-treated animals: uracil, succinate, proline, nicotinamide, and tyrosine.

Discussion

Our results demonstrate for the first time in the literature the effects of alcohol consumption on the metabolome content of hematopoietic tissue and open a wide range of further studies to investigate mechanisms by which alcohol compromises the cellular function of the immune system.

Interactions between Macrophages and Biofilm during Staphylococcus aureus-Associated Implant Infection: Difficulties and Solutions

Staphylococcus aureus (S. aureus) biofilm is the major cause of failure of implant infection treatment that results in heavy social and economic burden on individuals, families, and communities. Planktonic S. aureus attaches to medical implant surfaces where it proliferates and is wrapped by extracellular polymeric substances, forming a solid and complex biofilm. This provides a stable environment for bacterial growth, infection maintenance, and diffusion and protects the bacteria from antimicrobial agents and the immune system of the host. Macrophages are an important component of the innate immune system and resist pathogen invasion and infection through phagocytosis, antigen presentation, and cytokine secretion. The persistence, spread, or clearance of infection is determined by interplay between macrophages and S. aureus in the implant infection microenvironment. In this review, we discuss the interactions between S. aureus biofilm and macrophages, including the effects of biofilm-related bacteria on the macrophage immune response, roles of myeloid-derived suppressor cells during biofilm infection, regulation of immune cell metabolic patterns by the biofilm environment, and immune evasion strategies adopted by the biofilm against macrophages. Finally, we summarize the current methods that support macrophage-mediated removal of biofilms and emphasize the importance of considering multi-dimensions and factors related to implant-associated infection such as immunity, metabolism, the host, and the pathogen when developing new treatments.

Metabolomics meets systems immunology

Metabolic processes play a critical role in immune regulation. Metabolomics is the systematic analysis of small molecules (metabolites) in organisms or biological samples, providing an opportunity to comprehensively study interactions between metabolism and immunity in physiology and disease. Integrating metabolomics into systems immunology allows the exploration of the interactions of multilayered features in the biological system and the molecular regulatory mechanism of these features. Here, we provide an overview on recent technological developments of metabolomic applications in immunological research. To begin, two widely used metabolomics approaches are compared: targeted and untargeted metabolomics. Then, we provide a comprehensive overview of the analysis workflow and the computational tools available, including sample preparation, raw spectra data preprocessing, data processing, statistical analysis, and interpretation. Third, we describe how to integrate metabolomics with other omics approaches in immunological studies using available tools. Finally, we discuss new developments in metabolomics and its prospects for immunology research. This review provides guidance to researchers using metabolomics and multiomics in immunity research, thus facilitating the application of systems immunology to disease research.

Targeting immunometabolism against acute lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are life-threatening conditions triggered by multiple intra- and extra-pulmonary injury factors, characterized by complicated molecular mechanisms and high mortality. Great strides have been made in the field of immunometabolism to clarify the interplay between intracellular metabolism and immune function in the past few years. Emerging evidence unveils the crucial roles of immunometabolism in inflammatory response and ALI. During ALI, both macrophages and lymphocytes undergo robust metabolic reprogramming and discrete epigenetic changes after activated. Apart from providing ATP and biosynthetic precursors, these metabolic cellular reactions and processes in lung also regulate inflammation and immunity.In fact, metabolic reprogramming involving glucose metabolism and fatty acidoxidation (FAO) acts as a double-edged sword in inflammatory response, which not only drives inflammasome activation but also elicits anti-inflammatory response. Additionally, the features and roles of metabolic reprogramming in different immune cells are not exactly the same. Here, we outline the evidence implicating how adverse factors shape immunometabolism in differentiation types of immune cells during ALI and summarize key proteins associated with energy expenditure and metabolic reprogramming. Finally, novel therapeutic targets in metabolic intermediates and enzymes together with current challenges in immunometabolism against ALI were discussed.

Shouhui Tongbian Capsules induce regression of inflammation to improve intestinal barrier in mice with constipation by targeted binding to Prkaa1: With no obvious toxicity

Constipation arising from the poor bowel movement is a rife enteric health problem. Shouhui Tongbian Capsule (SHTB) is a traditional Chinese medicine (TCM) which effectively improve the symptoms of constipation. However, the mechanism has not been fully evaluated. The purpose of this study was to evaluate the effect of SHTB on the symptoms and intestinal barrier of mice with constipation. Our data showed that SHTB effectively improved the constipation induced by diphenoxylate, which was confirmed by shorter first defecation time, higher internal propulsion rate and fecal water content. Additionally, SHTB improved the intestinal barrier function, which was manifested by inhibiting the leakage of Evans blue in intestinal tissues and increasing the expression of occludin and ZO-1. SHTB inhibited NLRP3 inflammasome signaling pathway and TLR4/NF-κB signaling pathway, reduced the number of proinflammatory cell subsets and increased the number of immunosuppressive cell subsets to relieve inflammation. The photochemically induced reaction coupling system combined with cellular thermal shift assay and central carbon metabolomics technology confirmed that SHTB activated AMPKα through targeted binding to Prkaa1 to regulate Glycolysis/Gluconeogenesis and Pentose Phosphate Pathway, and finally inhibited intestinal inflammation. Finally, no obvious toxicity related to SHTB was found in a repeated drug administration toxicity test for consecutive 13 weeks. Collectively, we reported SHTB as a TCM targeting Prkaa1 for anti-inflammation to improve intestinal barrier in mice with constipation. These findings broaden our knowledge of Prkaa1 as a druggable target protein for inflammation inhibition, and open a new avenue to novel therapy strategy for constipation injury.

Metabolomic Profiling of Lungs from Mice Reveals the Variability of Metabolites in Pneumocystis Infection and the Metabolic Abnormalities in BAFF-R-Deficient Mice

Purpose

The incidence of Pneumocystis pneumonia (PCP) in patients without human immunodeficiency virus (HIV) has been increasing. In this study, we aimed to investigate the metabolic changes in Pneumocystis infection and the metabolic abnormalities in B-cell-activating factor receptor (BAFF-R)-deficient mice with Pneumocystis infection.

Methods

The important function of B cells during Pneumocystis infection is increasingly recognized. In this study, a Pneumocystis-infected mouse model was constructed in BAFF-R^-/- mice and wild-type (WT) mice. Lungs of uninfected WT C57BL/6, WT Pneumocystis-infected, and BAFF-R^-/- Pneumocystis-infected mice were used for metabolomic analyses to compare the metabolomic profiles among the groups, with the aim of exploring the metabolic influence of Pneumocystis infection and the influence of mature B-cell deficiency during infection.

Results

The results indicated that many metabolites, mainly lipids and lipid-like molecules, were dysregulated in Pneumocystis-infected WT mice compared with uninfected WT C57BL/6 mice. The data also demonstrated significant changes in tryptophan metabolism, and the expression levels of key enzymes of tryptophan metabolism, such as indoleamine 2,3-dioxygenase 1 (IDO1), were significantly upregulated. In addition, B-cell development and function might be associated with lipid metabolism. We found a lower level of alitretinoin and the abnormalities of fatty acid metabolism in BAFF-R^-/- Pneumocystis-infected mice. The mRNA levels of enzymes associated with fatty acid metabolism in the lung were upregulated in BAFF-R^-/- Pneumocystis-infected mice and positively correlated with the level of IL17A, thus suggesting that the abnormalities of fatty acid metabolism may be associated with greater inflammatory cell infiltration in the lung tissue of BAFF-R^-/- Pneumocystis-infected mice compared with the WT Pneumocystis-infected mice.

Conclusion

Our data revealed the variability of metabolites in Pneumocystis-infected mice, suggesting that the metabolism plays a vital role in the immune response to Pneumocystis infection.

α-Mangostin Inhibited M1 Polarization of Macrophages/Monocytes in Antigen-Induced Arthritis Mice by Up-Regulating Silent Information Regulator 1 and Peroxisome Proliferators-Activated Receptor γ Simultaneously

Background

α-Mangostin (MG) showed the potentials in alleviating experimental arthritis, inhibiting inflammatory polarization of macrophages/monocytes, and regulating peroxisome proliferators-activated receptor γ (PPAR-γ) and silent information regulator 1 (SIRT1) signals. The aim of this study was to analyze the correlations among the above-mentioned properties.

Methods

Antigen-induced arthritis (AIA) was established in mouse, which was treated with MG in combination with SIRT1/PPAR-γ inhibitors to clarify the role of the two signals in the anti-arthritic actions. Pathological changes were systematically investigated. Phenotypes of cells were investigated by flow cytometry. Expression and co-localization of SIRT1 and PPAR-γ proteins in joint tissues were observed by the immunofluorescence method. Finally, clinical implications from the synchronous up-regulation of SIRT1 and PPAR-γ were validated by experiments in vitro.

Results

SIRT1 and PPAR-γ inhibitors (nicotinamide and T0070097) reduced the therapeutic effects of MG on AIA mice, and abrogated MG-induced up-regulation of SIRT1/PPAR-γ and inhibition of M1 polarization in macrophages/monocytes. MG has a good binding affinity to PPAR-γ, and MG promoted the co-expression of SIRT1 and PPAR-γ in joints. Synchronously activating SIRT1 and PPAR-γ was revealed to be necessary by MG to repress inflammatory responses in THP-1 monocytes.

Conclusion

MG binds PPAR-γ and excites this signaling to initiate ligand-dependent anti-inflammatory activity. Due to certain unspecified signal transduction crosstalk mechanism, it then promoted SIRT1 expression and further limited inflammatory polarization of macrophages/monocytes in AIA mice.

Development of an Untargeted Metabolomics Strategy to Study the Metabolic Rewiring of Dendritic Cells upon Lipopolysaccharide Activation

Dendritic cells (DCs) are essential immune cells for defense against external pathogens. Upon activation, DCs undergo profound metabolic alterations whose precise nature remains poorly studied at a large scale and is thus far from being fully understood. The goal of the present work was to develop a reliable and accurate untargeted metabolomics workflow to get a deeper insight into the metabolism of DCs when exposed to an infectious agent (lipopolysaccharide, LPS, was used to mimic bacterial infection). As DCs transition rapidly from a non-adherent to an adherent state upon LPS exposure, one of the leading analytical challenges was to implement a single protocol suitable for getting comparable metabolomic snapshots of those two cellular states. Thus, a thoroughly optimized and robust sample preparation method consisting of a one-pot solvent-assisted method for the simultaneous cell lysis/metabolism quenching and metabolite extraction was first implemented to measure intracellular DC metabolites in an unbiased manner. We also placed special emphasis on metabolome coverage and annotation by using a combination of hydrophilic interaction liquid chromatography and reverse phase columns coupled to high-resolution mass spectrometry in conjunction with an in-house developed spectral database to identify metabolites at a high confidence level. Overall, we were able to characterize up to 171 unique meaningful metabolites in DCs. We then preliminarily compared the metabolic profiles of DCs derived from monocytes of 12 healthy donors upon in vitro LPS activation in a time-course experiment. Interestingly, the resulting data revealed differential and time-dependent activation of some particular metabolic pathways, the most impacted being nucleotides, nucleotide sugars, polyamines pathways, the TCA cycle, and to a lesser extent, the arginine pathway.

A Critical Appraisal of the Diagnostic and Prognostic Utility of the Anti-Inflammatory Marker IL-37 in a Clinical Setting: A Case Study of Patients with Diabetes Type 2

BACKGROUND

The role of the cytokine interleukin-37 (IL-37) has been recognized in reversing inflammation-mediated metabolic costs. The aim was to evaluate the clinical utility of this cytokine as a diagnostic and prognostic marker in patients with type 2 diabetes (T2D).

METHODS

We included 170 older (median: 66 years) individuals with T2D (females: 95) and classified as primary care attenders to assess the association of factors that describe patients with plasma IL-37 levels (expressed as quartiles) using multinomial regression models. We determined the diagnostic ability of IL-37 cut-offs to identify diabetes-related complications or patient subgroups by using Receiver Operating Characteristic analysis (c-statistics).

RESULTS

Frailty status was shown to have a suppressive effect on IL-37 circulating levels and a major modifying effect on associations of metabolic and inflammatory factors with IL-37, including the effects of treatments. Situations in which IL-37 reached a clinically significant discriminating ability included the model of IL-37 and C-Reactive Protein in differentiating among diabetic patients with low-normal/high BMI ((<25/≥25 kg/m2), and the model of IL-37 and Thyroid Stimulating Hormone in discriminating between women with/without metabolic syndrome.

CONCLUSIONS

The study has revealed limitations in using classical approaches in determining the diagnostic and prognostic utility of the cytokine IL-37 in patients with T2D and lain a foundation for new methodology approaches.

Jingfang Granules improve glucose metabolism disturbance and inflammation in mice with urticaria by up-regulating LKB1/AMPK/SIRT1 axis

ETHNOPHARMACOLOGICAL RELEVANCE

Jingfang Granule (JFG) is a Traditional Chinese Medicine prescription to empirically treat skin disease such as urticaria in clinical practice. However, the potential mechanisms of JFG on urticaria are not fully defined.

AIM OF STUDY

The aim of this study is to investigate the mechanisms of JFG in treating urticaria through an OVA/aluminum hydroxide induced urticaria mice model.

MATERIALS AND METHODS

KM mice were injected intraperitoneally (i.p.) with OVA/aluminium hydroxide to establish the model with urticaria. After the mice were administered JFG, itching degree and hematoxylin and eosin (H&E) staining were used to assess the protective effect of JFG on mice with urticaria. The regulatory networks were investigated by proteomics and central carbon metabolomics. Spleen T lymphocyte subsets were detected by flow cytometry. Peripheral blood cytokines were detected using ELISA kits or Cytometric Bead Array (CBA) kits. The protein expression of skin tissue was detected by western blot or immunohistochemical staining.

RESULTS

JFG significantly relived skin tissue lesions and skin pruritus in mice with urticaria. Meanwhile, JFG significantly decreased IgE, IL-1β, IL-6, IL-4, TNF-α and IL-17A levels and increased IFN-γ levels in the serum of urticaria mice by inhibiting the expression of inflammation associated proteins including TLR4 and p-NF-κB p65, p-ERK1/2, p-JNK and p-p38, NLRP3, ASC and cleaved caspase-1. The results of proteomics, central carbon metabolomics, western blot and immunohistochemical staining confirmed that JFG inhibited Glycolysis/Gluconeogenesis and Pentose phosphate pathway in the skin tissue of urticaria mice by activating the LKB1/AMPK/SIRT1 axis and then downregulating the protein expressions of Glut1, TORC2, p-CREB, PEPCK, HNF4α and G6Pase.

CONCLUSION

The current study demonstrates that JFG is effective in treating OVA/aluminum hydroxide-induced skin lesions and inflammation in mice, and JFG exhibits the clinical benefits via modulating LKB1/AMPK/SIRT1 axis, which in turn inhibits Glycolysis/Gluconeogenesis and Pentose phosphate pathway.

Innate sensing and cellular metabolism: role in fine tuning antiviral immune responses

Several studies over the last decade have identified intimate links between cellular metabolism and macrophage function. Metabolism has been shown to both drive and regulate macrophage function by producing bioenergetic and biosynthetic precursors as well as metabolites (and other bioactive molecules) that regulate gene expression and signal transduction. Many studies have focused on lipopolysaccharide-induced reprogramming, assuming that it is representative of most inflammatory responses. However, emerging evidence suggests that diverse pathogen-associated molecular patterns (PAMPs) are associated with unique metabolic profiles, which may drive pathogen specific immune responses. Further, these metabolic pathways and processes may act as a rheostat to regulate the magnitude of an inflammatory response based on the biochemical features of the local microenvironment. In this review, we will discuss recent work examining the relationship between cellular metabolism and macrophage responses to viral PAMPs and describe how these processes differ from lipopolysaccharide-associated responses. We will also discuss how an improved understanding of the specificity of these processes may offer new insights to fine-tune macrophage function during viral infections or when using viral PAMPs as therapeutics.

Hypoxia and Intestinal Inflammation: Common Molecular Mechanisms and Signaling Pathways

The gastrointestinal tract (GI) has a unique oxygenation profile. It should be noted that the state of hypoxia can be characteristic of both normal and pathological conditions. Hypoxia-inducible factors (HIF) play a key role in mediating the response to hypoxia, and they are tightly regulated by a group of enzymes called HIF prolyl hydroxylases (PHD). In this review, we discuss the involvement of inflammation hypoxia and signaling pathways in the pathogenesis of inflammatory bowel disease (IBD) and elaborate in detail on the role of HIF in multiple immune reactions during intestinal inflammation. We emphasize the critical influence of tissue microenvironment and highlight the existence of overlapping functions and immune responses mediated by the same molecular mechanisms. Finally, we also provide an update on the development of corresponding therapeutic approaches that would be useful for treatment or prophylaxis of inflammatory bowel disease.

Deletion of Glycogen Synthase Kinase 3 Beta Reprograms NK Cell Metabolism

Loss of cytotoxicity and defective metabolism are linked to glycogen synthase kinase 3 beta (GSK3β) overexpression in natural killer (NK) cells from patients with acute myeloid leukemia or from healthy donors after expansion ex vivo with IL-15. Drug inhibition of GSK3β in these NK cells improves their maturation and cytotoxic activity, but the mechanisms of GSK3β-mediated dysfunction have not been well studied. Here, we show that expansion of NK cells with feeder cells expressing membrane-bound IL-21 maintained normal GSK3β levels, allowing us to study GSK3β function using CRISPR gene editing. We deleted GSK3B and expanded paired-donor knockout and wild-type (WT) NK cells and then assessed transcriptional and functional alterations induced by loss of GSK3β. Surprisingly, our data showed that deletion of GSK3B did not alter cytotoxicity, cytokine production, or maturation (as determined by CD57 expression). However, GSK3B-KO cells demonstrated significant changes in expression of genes related to rRNA processing, cell proliferation, and metabolic function, suggesting possible metabolic reprogramming. Next, we found that key genes downregulated in GSK3B-KO NK cells were upregulated in GSK3β-overexpressing NK cells from AML patients, confirming this correlation in a clinical setting. Lastly, we measured cellular energetics and observed that GSK3B-KO NK cells exhibited 150% higher spare respiratory capacity, a marker of metabolic fitness. These findings suggest a role for GSK3β in regulating NK cell metabolism.

MAITabolism2 - the emerging understanding of MAIT cell metabolism and their role in metabolic disease

Mucosal associated invariant T (MAIT) cells are a population of unconventional innate T cells due to their non-MHC restriction and rapid effector responses. MAIT cells can recognise bacterial derived antigens presented on the MHC-like protein via their semi-restricted T cell receptor (TCR). Upon TCR triggering MAIT cells rapidly produce a range of effector molecules including cytokines, lytic granules and chemokines. This rapid and robust effector response makes MAIT cells critical in host responses against many bacterial pathogens. MAIT cells can also respond independent of their TCR via innate cytokines such as interleukin (IL)-18, triggering cytokine production, and are important in anti-viral responses. In addition to their protective role, MAIT cells have been implicated in numerous inflammatory diseases, including metabolic diseases often contributing to the pathogenesis via their robust cytokine production. Effector cells such as MAIT cells require significant amounts of energy to support their potent responses, and the type of nutrients available can dictate the functionality of the cell. Although data on MAIT cell metabolism is just emerging, several recent studies are starting to define the intrinsic metabolic requirements and regulators of MAIT cells. In this review we will outline our current understanding of MAIT cell metabolism, and outline their role in metabolic disease, and how disease-related changes in extrinsic metabolism can alter MAIT cell responses.

Specificity of the innate immune responses to different classes of non-tuberculous mycobacteria

Mycobacterium avium is the most common nontuberculous mycobacterium (NTM) species causing infectious disease. Here, we characterized a M. avium infection model in zebrafish larvae, and compared it to M. marinum infection, a model of tuberculosis. M. avium bacteria are efficiently phagocytosed and frequently induce granuloma-like structures in zebrafish larvae. Although macrophages can respond to both mycobacterial infections, their migration speed is faster in infections caused by M. marinum. Tlr2 is conservatively involved in most aspects of the defense against both mycobacterial infections. However, Tlr2 has a function in the migration speed of macrophages and neutrophils to infection sites with M. marinum that is not observed with M. avium. Using RNAseq analysis, we found a distinct transcriptome response in cytokine-cytokine receptor interaction for M. avium and M. marinum infection. In addition, we found differences in gene expression in metabolic pathways, phagosome formation, matrix remodeling, and apoptosis in response to these mycobacterial infections. In conclusion, we characterized a new M. avium infection model in zebrafish that can be further used in studying pathological mechanisms for NTM-caused diseases.

Cartilage calcification in osteoarthritis: mechanisms and clinical relevance

Pathological calcification of cartilage is a hallmark of osteoarthritis (OA). Calcification can be observed both at the cartilage surface and in its deeper layers. The formation of calcium-containing crystals, typically basic calcium phosphate (BCP) and calcium pyrophosphate dihydrate (CPP) crystals, is an active, highly regulated and complex biological process that is initiated by chondrocytes and modified by genetic factors, dysregulated mitophagy or apoptosis, inflammation and the activation of specific cellular-signalling pathways. The links between OA and BCP deposition are stronger than those observed between OA and CPP deposition. Here, we review the molecular processes involved in cartilage calcification in OA and summarize the effects of calcium crystals on chondrocytes, synovial fibroblasts, macrophages and bone cells. Finally, we highlight therapeutic pathways leading to decreased joint calcification and potential new drugs that could treat not only OA but also other diseases associated with pathological calcification.

A novel, accurate, and non-invasive liquid biopsy test to measure cellular immune responses as a tool to diagnose early-stage lung cancer: a clinical trials study

INTRODUCTION

Lung cancer remains the leading cause of death from cancer, worldwide. Developing early detection diagnostic methods, especially non-invasive methods, is a critical component to raising the overall survival rate and prognosis for lung cancer. The purpose of this study is to evaluate two protocols of a novel in vitro cellular immune response test to detect lung cancer. The test specifically quantifies the glycolysis metabolism pathway, which is a biomarker for the activation level of immune cells. It summarizes the results of two clinical trials, where each deploys a different protocol's version of this test for the detection of lung cancer. In the later clinical trial, an improved test protocol is applied.

METHOD

The test platform is based on changes in the metabolic pathways of the immune cells following their activation by antigenic stimuli associated with Lung cancer. Peripheral Blood Mononuclear Cells are loaded on a multiwell plate together with various lung tumor associated antigens and a fluorescent probe that exhibits a pH-dependent absorption shift. The acidification process in the extracellular fluid is monitored by a commercial fluorescence plate reader device in continuous reading for 3 h at 37 °C to document the fluorescent signal received from each well.

RESULTS

In the later clinical trial, an improved test protocol was applied and resulted in increased test accuracy. Specificity of the test increased to 94.0% and test sensitivity increased to 97.3% in lung cancer stage I, by using the improved protocol.

CONCLUSION

The improved protocol of the novel cellular immune metabolic response based test detects stage I and stage II of lung cancer with high specificity and sensitivity, with low material costs and fast results.

Abnormal glucose metabolism in virus associated sepsis

Sepsis is identified as a potentially lethal organ impairment triggered by an inadequate host reaction to infection (Sepsis-3). Viral sepsis is a potentially deadly organ impairment state caused by the host's inappropriate reaction to a viral infection. However, when a viral infection occurs, the metabolism of the infected cell undergoes a variety of changes that cause the host to respond to the infection. But, until now, little has been known about the challenges faced by cellular metabolic alterations that occur during viral infection and how these changes modulate infection. This study concentrates on the alterations in glucose metabolism during viral sepsis and their impact on viral infection, with a view to exploring new potential therapeutic targets for viral sepsis.

Inflammation driven metabolic regulation and adaptation in macrophages

Macrophages are a diverse population of phagocytic immune cells involved in the host defense mechanisms and regulation of homeostasis. Usually, macrophages maintain healthy functioning at the cellular level, but external perturbation in their balanced functions can lead to acute and chronic disease conditions. By sensing the cues from the tissue microenvironment, these phagocytes adopt a plethora of phenotypes, such as inflammatory or M1 to anti-inflammatory (immunosuppressive) or M2 subtypes, to fulfill their spectral range of functions. The existing evidence in the literature supports that in macrophages, regulation of metabolic switches and metabolic adaptations are associated with their functional behaviors under various physiological and pathological conditions. Since these macrophages play a crucial role in many disorders, therefore it is necessary to understand their heterogeneity and metabolic reprogramming. Consequently, these macrophages have also emerged as a promising target for diseases in which their role is crucial in driving the disease pathology and outcome (e.g., Cancers). In this review, we discuss the recent findings that link many metabolites with macrophage functions and highlight how this metabolic reprogramming can improve our understanding of cellular malfunction in the macrophages during inflammatory disorders. A systematic analysis of the interconnecting crosstalk between metabolic pathways with macrophages should inform the selection of immunomodulatory therapies for inflammatory diseases.