Arginine-dependent immune responses

The immune response modulated by inoculation of commensal bacteria at birth impacts the gut microbiota and prevents Salmonella colonization

Super- and low-shedding phenomena have been observed in genetically homogeneous hosts infected by a single bacterial strain. To decipher the mechanisms underlying these phenotypes, we conducted an experiment with chicks infected with Salmonella Enteritidis in a non-sterile isolator, which prevents bacterial transmission between animals while allowing the development of the gut microbiota. We investigated the impact of four commensal bacteria called Mix4, inoculated at hatching, on chicken systemic immune response and intestinal microbiota composition and functions, before and after Salmonella infection. Our results revealed that these phenotypes were not linked to changes in cell invasion capacity of bacteria during infection. Mix4 inoculation had both short- and long-term effects on immune response and microbiota and promoted the low-shedder phenotype. Kinetic analysis revealed that Mix4 activated immune response from day 4, which modified the microbiota on day 6. This change promotes a more fermentative microbiota, using the aromatic compounds degradation pathway, which inhibited Salmonella colonization by day 11 and beyond. In contrast, control animals exhibited a delayed TNF-driven pro-inflammatory response and developed a microbiota using anaerobic respiration, which facilitates Salmonella colonization and growth. This strategy offers promising opportunities to strengthen the barrier effect against Salmonella and possibly other pathogens.

The flow cytometric analysis of depression focusing on modern-type depression and hikikomori: Exploring the link between subtypes of depression and immunological imbalances

INTRODUCTION

Depression includes different phenotypes. Modern-type depression (MTD) is a gateway disorder to pathological social withdrawal, known as hikikomori. Adverse childhood experiences (ACEs) are also important aetiologies of depression. Recently, immune imbalance has been proposed as a biological basis of depression. We hypothesised that peripheral immunological characteristics may be involved in subtyping of depression.

METHODS

21 patients with major depressive disorder (MDD) and 24 healthy controls (HC) were recruited. Peripheral blood mononuclear cells (PBMCs) were examined for surface antigens by flow cytometry. Participants were administered psychological scales such as Patient Health Questionnaire (PHQ)-9, Modern-Type Depression Trait Scale (TACS-22), Hikikomori Questionnaire (HQ-25), Child Abuse and Trauma Scale (CATS).

RESULTS

MDD group showed significantly higher percentage of B cells than HC group (p = 0.032). MDD group presented a negative correlation between: PHQ-9 and CD8 T effector memory cells (r= -0.639, p = 0.002), TACS-22 and monocytes (r= -0.459, p = 0.036), HQ-25 and NK T cells (r= -0.638, p = 0.004), CATS and Intermediate monocytes (r= -0.594, p = 0.009).

CONCLUSIONS

MTD traits, hikikomori tendencies, and ACEs were correlated with specific characteristics of peripheral immune cells. Our results suggest that immune imbalance influences the diverse presentations of depression. Further validation is warranted by large-scale prospective studies.

Unraveling the differential tolerance mechanisms of Acropora formosa and Montipora digitata to Benzo[a]pyrene (BaP) exposure via 4D proteomics

Coral reefs are suffering from environmental pollution worldwide, implying unprecedented survival challenges. In this paper we investigate the effects of the Benzo[a]pyrene (BaP) on the survival status of coral and explore its potential tolerance mechanism. By applying advanced 4D proteomics techniques, we systematically compared the differences in the protein expression profiles of Acropora formosa (A. formosa) and Montipora digitata (M. digitata) under BaP exposure conditions (50 μg/L, 72 h and 120 h). Under the same BaP exposure conditions, the bleaching rate of A. formosa was faster, and the zooxanthellae density and chlorophyll content were lower. M. digitata showed higher BaP tolerance than A. formosa, may attributed to significantly enhanced protein synthesis, folding, and stability in its host cells, as well as a more efficient energy metabolism mechanism. While A. formosa coral hosts showed low protein stability and high ferritin expression, and iron metabolism imbalance was aggravated under BaP stress, which increased oxidative stress damage. Specifically, the zooxanthellae of M. digitata without exposed to BaP showed stronger photosynthetic efficiency and glucose metabolism, especially the activation of the pyruvate metabolic pathway. However, these advantages were rapidly diminished after exposure to BaP. In response to BaP exposure, A. formosa's zooxanthellae may activated longevity related pathways and hypoxia-inducing factor signaling pathways, significantly enhancing energy metabolism pathways. This study is helpful to reveal the complex adaptive mechanism of coral reef ecosystem to environmental pollution.

L-Arginine and immune modulation: A pharmacological perspective on inflammation and autoimmune disorders

L- Arginine (2-Amino-5-guanidinovaleric acid, L-Arg) is a semi-essential amino acid that is mainly produced within the urea cycle. It acts as a key precursor in the synthesis of proteins, urea, creatine, prolamines (including putrescine, spermine, and spermidine), proline, and nitric oxide (NO). WhenL-Arg is metabolized, it produces NO, glutamate, and prolamines, which all play important regulatory roles in various physiological functions. In addition to its metabolic roles,L-Arg significantly influences immune responses, especially in the context of inflammation and autoimmune diseases. It affects the activity of immune cells by modulating T-cell function, the polarization of macrophages, and the release of cytokines. Importantly,L-Arg plays a dual role in immune regulation, functioning as both an immunostimulatory and immunosuppressive agent depending on the specific cellular and biochemical environments. This review examines the immunopharmacological mechanisms of L-Arg, emphasizing its involvement in inflammatory responses and its potential therapeutic uses in autoimmune conditions like rheumatoid arthritis, multiple sclerosis, and inflammatory bowel disease. By influencing the pathways of nitric oxide synthase (NOS) and arginase (ARG), L-Arg helps maintain immune balance and contributes to the pathophysiology of diseases. Gaining a better understanding of the pharmacological effects of L-Arg on immune regulation could yield new perspectives on targeted treatments for immune-related diseases. Exploring its impact on immune signaling and metabolic pathways may result in novel therapeutic approaches for chronic inflammatory and autoimmune disorders.

Different molecular responses of Mytilus mantle to lipopolysaccharide and peptidoglycan challenges

Mytilus live in water as sessile filter feeders, and the mantle tissue plays an important role in their immune defense. However, the overall knowledge of the immunity of this tissue remains limited. Peptidoglycan (PGN) and lipopolysaccharide (LPS) are the most representative microbe-associated molecular patterns (MAMPs) that play roles in the immune stimulation of host cells. In the present study, ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS)-based metabolomic analysis was performed to understand the precise regulatory mechanism at the molecular level in the Mytilus mantle in response to PGN and LPS stress. Moreover, the antioxidant ability and free amino acid composition of the mantle, and the antimicrobial activities of mantle mucus were evaluated. Our results revealed that LPS and PGN stresses had different effects on the mantle's free amino acid composition and antioxidant ability, and the mantle mucus' antimicrobial activity. Both PGN and LPS stress-induced alterations in amino acids, phospholipids, fatty acids, nucleotides, and their derivatives in the mantle. PGN injection activated the amino acid-related metabolism, and inhibited the lipid-related metabolisms in the mantle, while LPS injection activated the amino acid-related metabolisms and inhibited the arachidonic acid metabolism in the mantle compared to that in the control group. In addition, activation of the mTOR and FoxO signaling pathways and inhibition of lipid-related metabolism were observed in PGN vs. LPS. In addition, PGN injection induced the upregulation of fosfomycin and deoxynojirimycin in the mantle compared to LPS injection. Our study highlights the different responses at the metabolomic level of the mussel mantle to different MAMPs and the potential application of metabolites that specifically respond to PGN and LPS challenges in mussels as biomarkers.

BCAA metabolism in cancer progression and therapy resistance: The balance between fuel and cell signaling

Branched-chain amino acids (BCAAs), including leucine, isoleucine, and valine, play a crucial role in cellular metabolism and signaling. Recent studies have demonstrated that BCAA metabolic reprogramming is a key driver of tumor progression and treatment resistance in various cancers. BCAA metabolism supports cancer cell growth, survival, and proliferation by modulating pathways such as mTOR signaling and oxidative stress responses. By promoting immunosuppressive conditions and increasing the survival rate of cancer stem cells (CSCs), BCAAs contribute to immune evasion and resistance to therapies such as chemotherapy and immune checkpoint inhibitors. This article explores the different metabolic reprogramming patterns of BCAAs in various tumors and introduces BCAA-related metabolic targets for overcoming tumor resistance, offering new directions for precision cancer treatment, reducing resistance, and improving patient outcomes.

Constructing a Prognostic Model for Non-Small-Cell Lung Cancer Risk Based on Genes Characterising the Differentiation of Myeloid-Derived Suppressor Cells

Cancer is the most common malignancy, with over 2 million new cases and nearly 1.8 million deaths worldwide annually. Non-small-cell lung cancer (NSCLC) is the predominant subtype, accounting for the majority of cases. Myeloid-derived suppressor cells (MDSCs), which originate from monocytes and typically differentiate into macrophages and granulocytes, possess potent immunosuppressive capabilities. MDSCs regulate immune responses in various pathological conditions and are strongly associated with poor prognosis in cancer patients. This study aims to elucidate the complex interplay between MDSCs, immune cells, and tumours in the NSCLC tumour microenvironment (TME). By integrating single-cell RNA sequencing (scRNA-seq) data with bulk RNA sequencing (Bulk RNA-seq) data, we identified MDSCs as the target cell population and used Monocle software (v2.22.0) to infer their developmental trajectories. We identified key genes associated with MDSCs differentiation processes and classified MDSCs into seven distinct states based on their functional roles. Furthermore, we constructed a prognostic risk model based on the impact of MDSCs differentiation on NSCLC prognosis, utilizing Elastic Net regression and multivariate Cox regression analysis of Bulk RNA-seq data. The model's performance and accuracy were validated using both internal and external validation sets. Additionally, we compared risk scores with clinical pathological features and the relationship between risk scores and key immune cells in the immune microenvironment, demonstrating the model's clinical predictive value. We also explored how prognostic genes contribute to poor prognosis in NSCLC. Moreover, small molecule compounds targeting these prognostic genes were screened, and their anti-tumour effects were evaluated as potential therapeutic strategies for NSCLC treatment. This study not only reveals the complex regulatory mechanisms of MDSCs in the NSCLC immune microenvironment but also successfully constructs a prognostic risk model based on MDSCs differentiation states. The model demonstrates excellent clinical performance in predicting patient prognosis, effectively identifying high-risk patients and providing robust support for individualized treatment and immunotherapy decisions. Through association analyses with key immune cells in the immune microenvironment and clinical pathological features, our model can assist clinicians in formulating more precise treatment plans based on patients' immune status and tumour characteristics. Furthermore, we identified small molecule compounds targeting these prognostic genes, providing novel and promising therapeutic targets for NSCLC, which could further enhance treatment efficacy and improve patients' survival quality.

Unveiling the role of the upper respiratory tract microbiome in susceptibility and severity to COVID-19

It is argued that commensal bacteria in the upper respiratory tract (URT) protect against pathogen colonization and infection, including respiratory viruses. Given that the microbiome can mediate immune modulation, a link between the URT microbiome (URTM) and COVID-19 susceptibility and severity is expected. This 16S metagenomics cross-sectional study assessed URTM composition, metabolic prediction, and association with laboratory biomarkers in non-COVID-19 pneumonia (NO-CoV), moderate (M-CoV), severe (S-CoV) COVID-19 patients, as well as COVID-19-negative, asymptomatic (NC) patients. The S-CoV group exhibited reduced URTM diversity, primarily due to a decreased abundance of eubiotic taxa. Some of these taxa (e.g., Haemophilus sp., Neisseria sp.) were also associated with inflammatory biomarkers. Multiple metabolic pathways (e.g., short-chain fatty acids, vitamin B12) linked to immune response, antiviral activity, and host susceptibility showed decreased abundance in S-CoV. These pathways could suggest potential alternatives for the therapeutic arsenal against COVID-19, providing reassurance about the progress in understanding and treating this disease.

Metabolic reprogramming in cancer therapy-related cardiovascular toxicity: Mechanisms and intervention strategies

Cancer therapy-related cardiovascular toxicity (CTR-CVT) poses a major challenge in managing cancer patients, contributing significantly to morbidity and mortality among survivors. CTR-CVT includes various cardiovascular issues, such as cardiomyopathy, myocardial ischemia, arrhythmias, and vascular dysfunction, which significantly impact patient prognosis and quality of life. Metabolic reprogramming, characterized by disruptions in glucose, lipid, and amino acid metabolism, represents a shared pathophysiological feature of cancer and cardiovascular diseases; however, the precise mechanisms underlying CTR-CVT remain inadequately understood. In recent years, strategies targeting metabolic pathways have shown promise in reducing cardiovascular risks while optimizing cancer treatment efficacy. This review systematically summarizes metabolic reprogramming characteristics in both cancer and cardiovascular diseases, analyzes how anticancer therapies induce cardiovascular toxicity through metabolic alterations, and explores emerging therapeutic strategies targeting metabolic dysregulation. By integrating current research advancements, this review aims to enhance the understanding of CTR-CVT and provide groundwork for the development of safer and more effective cancer approaches.

Antipyretic effects of Xiangqin Jiere granules on febrile young rats revealed by combining pharmacodynamics, metabolomics, network pharmacology, molecular biology experiments and molecular docking strategies

Xiangqin Jiere granules (XQJRG) is a proprietary Chinese medicine treating children's colds and fevers, but its mechanism of action is unclear. The aim of this study was to explore the antipyretic mechanisms of XQJRG based on pharmacodynamics, non-targeted metabolomics, network pharmacology, molecular biology experiments, molecular docking, and molecular dynamics (MD) simulation. Firstly, the yeast-induced fever model was constructed in young rats to study antipyretic effect of XQJRG. Metabolomics and network pharmacology studies were performed to identify the key compounds, targets and pathways involved in the antipyretic of XQJRG. Subsequently, MetScape was used to jointly analyze targets from network pharmacology and metabolites from metabolomics. Finally, the key targets were validated by enzyme-linked immunosorbent assay (ELISA), and the affinity and stability of key ingredient and targets were evaluated by molecular docking and MD simulation. The animal experimental results showed that after XQJRG treatment, body temperature of febrile rats was significantly reduced, 13 metabolites were significantly modulated, and pathways of differential metabolite enrichment were mainly related to amino acid and lipid metabolism. Network pharmacology results indicated that quercetin and kaempferol were the key active components of XQJRG, TNF, AKT1, IL6, IL1B and PTGS2 were core targets. ELISA confirmed that XQJRG significantly reduced the plasma concentrations of IL-1β, IL-6, and TNF-α, and the hypothalamic concentrations of COX-2 and PGE2. Molecular docking demonstrated that the binding energies of kaempferol to the core targets were all below -5.0 kcal/mol. MD simulation results showed that the binding free energies of TNF-kaempferol, IL6-kaempferol, IL1B-kaempferol and PTGS2-kaempferol were -87.86 kcal/mol, -70.41 kcal/mol, -69.95 kcal/mol and -106.67 kcal/mol, respectively. In conclusion, XQJRG has antipyretic effects on yeast-induced fever in young rats, and its antipyretic mechanisms may be related to the inhibition of peripheral pyrogenic cytokines release by constituents such as kaempferol, the reduction of hypothalamic fever mediator production, and the amelioration of disturbances in amino acid and lipid metabolism.

l-Arginine: A multifaceted regulator of diabetic cardiomyopathy

In diabetes mellitus, dysregulated glucose and lipid metabolism lead to diabetic cardiomyopathy (DCM) by imparting pathological myocardial remodeling and cellular injury. Accelerated glycation, oxidative stress, and activated inflammatory pathways culminate in cardiac fibrosis and hypertrophy in DCM. The regulatory effects of l-Arginine (L-Arg) have been elucidated in the pathological changes of DCM, including myocardial fibrosis, hypertrophy, and apoptosis, by inhibiting glycation and oxidative stress-induced inflammation. Disturbed L-Arg metabolism and decreased intracellular L-Arg pool are correlated with the progression of DCM; therefore, L-Arg supplementation has been prescribed for various cardiovascular dysfunctions. This review expands the therapeutic potential of L-Arg supplementation in DCM by elucidating its molecular mechanism of action and exploring potential clinical outcomes.

Immunosuppression of Tumor-Derived Factors Modulated Neutrophils in Upper Tract Urothelial Carcinoma Through Upregulation of Arginase-1 via ApoA1-STAT3 Axis

Upper tract urothelial carcinoma (UTUC) presents aggressive features and a tumor microenvironment with T cell depletion. However, the role of tumor-associated neutrophils in UTUC remains unclear. This study aimed to investigate how UTUC tumor-derived factors modulate neutrophils and their impact on T cell immune responses. Our findings demonstrate that UTUC secreted tumor-derived factors, with apolipoprotein A1 (Apo-A1) being the predominant factor, which upregulated arginase-1 expression in neutrophils. STAT3 activation was responsible for the upregulation of arginase-1 in neutrophils. Blocking the interactions between Apo-A1 and its receptors reduced arginase-1 expression in neutrophils treated with tumor tissue culture supernatant (TTCS). Moreover, both CD4+ T and CD8+ T cell proliferation were inhibited by neutrophils treated with Apo-A1 or TTCS. Importantly, blocking Apo-A1 signaling in neutrophils reversed the inhibitory effects on T cells. In UTUC patients, the neutrophil-to-lymphocyte ratio was higher than that in healthy subjects. The expression of arginase-1 in neutrophils and the level of Apo-A1 within UTUC tumors were negatively correlated with tumor-infiltrating CD4+ T cells. Additionally, neutrophils from UTUC patients showed increased expression of arginase-1 and exhibited inhibitory effects of T cell functions. These findings suggest that UTUC orchestrates an immune-suppressive microenvironment through Apo-A1-mediated upregulation of arginase-1 in neutrophils, ultimately leading to the inhibition of T cell proliferation.

Nutrition-induced changes in the microbiota can cause dysbiosis and disease development

Eukaryotic organisms are associated with complex microbial communities. Changes within these communities have been implicated in disease development. Nonetheless, it remains unclear whether these changes are a cause or a consequence of disease. Here, we report a causal link between environment-induced shifts in the microbiota and disease development. Using the model organism Hydra, we observed changes in microbial composition when transferring laboratory-grown Hydra to natural lake environments. These shifts were caused not only by new colonizers, through the process of community coalescence (merging of previously separate microbial communities), but also by lake water nutrients. Moreover, selective manipulation of the nutrient environment induced compound-specific shifts in the microbiota followed by disease development. Finally, L-arginine supplementation alone caused a transition in Pseudomonas from symbiotic to pathogenic, leading to an upregulation of immune response genes, tissue degradation, and host death. These findings challenge the notion that the host-associated microbiota is exclusively controlled by the host, highlighting the dynamic interplay between host epithelial environment, microbial colonizer pool, and nutrient conditions of the surrounding water. Furthermore, our results show that overfeeding of the microbiota allows for uncontrolled microbial growth and versatile interactions with the host. Environmental conditions may thus render symbionts a potential hazard to their hosts, blurring the divide between pathogenic and non-pathogenic microbes.IMPORTANCEThis study highlights the critical need to understand the dynamic interplay between host-associated microbiota and environmental factors to obtain a holistic view on organismal health. Our results demonstrate that ecosystem-wide microbial trafficking (community coalescence) and environmental nutrient conditions reshape microbial communities with profound implications for host health. By exploring nutrient-driven changes in microbial composition, our research finds experimental support for the "overfeeding hypothesis," which states that overfeeding alters the functionality of the host microbiota such that an overabundance in nutrients can facilitate disease development, transforming non-pathogenic microbes into pathogens. These findings emphasize the critical role of metabolic interactions driving microbial pathogenicity. Furthermore, our research provides empirical evidence for the "pathogenic potential" concept, challenging traditional distinctions between pathogenic and non-pathogenic microbes and supporting the idea that any microbe can become pathogenic under certain conditions.

Neutrophils and Neutrophil-Based Drug Delivery Systems in Anti-Cancer Therapy

Neutrophils, the most abundant white blood cells, play a dual role in cancer progression. While they can promote tumor growth, metastasis, and immune suppression, they also exhibit anti-tumorigenic properties by attacking cancer cells and enhancing immune responses. This review explores the complex interplay between neutrophils and the tumor microenvironment (TME), highlighting their ability to switch between pro- and anti-tumor phenotypes based on external stimuli. Pro-tumorigenic neutrophils facilitate tumor growth through mechanisms such as neutrophil extracellular traps (NETs), secretion of pro-inflammatory cytokines, and immune evasion strategies. They contribute to angiogenesis, tumor invasion, and metastasis by releasing vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs). Conversely, anti-tumor neutrophils enhance cytotoxicity by generating reactive oxygen species (ROS), promoting antibody-dependent cell-mediated cytotoxicity (ADCC), and activating other immune cells such as cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. Recent advances in neutrophil-based drug delivery systems have harnessed their tumor-homing capabilities to improve targeted therapy. Neutrophil-mimicking nanoparticles and membrane-coated drug carriers offer enhanced drug accumulation in tumors, reduced systemic toxicity, and improved therapeutic outcomes. Additionally, strategies to modulate neutrophil activity, such as inhibiting their immunosuppressive functions or reprogramming them towards an anti-tumor phenotype, are emerging as promising approaches in cancer immunotherapy. Understanding neutrophil plasticity and their interactions with the TME provides new avenues for therapeutic interventions. Targeting neutrophil-mediated mechanisms could enhance existing cancer treatments and lead to the development of novel immunotherapies, ultimately improving patient survival and clinical outcomes.

Cancer cell-derived arginine fuels polyamine biosynthesis in tumor-associated macrophages to promote immune evasion

Arginine metabolism reshapes the tumor microenvironment (TME) into a pro-tumor niche through complex metabolic cross-feeding among various cell types. However, the key intercellular metabolic communication that mediates the collective effects of arginine metabolism within the TME remains unclear. Here, we reveal that the metabolic interplay between cancer cells and macrophages plays a dominant role in arginine-driven breast cancer progression. Within the TME, breast cancer cells serve as the primary source of arginine, which induces a pro-tumor polarization of tumor-associated macrophages (TAMs), thereby suppressing the anti-tumor activity of CD8+ T cells. Notably, this cancer cell-macrophage interaction overrides the arginine-mediated enhancement of CD8+ T cell anti-tumor activity. Mechanistically, polyamines derived from arginine metabolism enhance pro-tumor TAM polarization via thymine DNA glycosylase (TDG)-mediated DNA demethylation, regulated by p53 signaling. Importantly, targeting the arginine-polyamine-TDG axis between cancer cells and macrophages significantly suppresses breast cancer growth, highlighting its therapeutic potential.

SCFA biotherapy delays diabetes in humanized gnotobiotic mice by remodeling mucosal homeostasis and metabolome

Type 1 diabetes (T1D) is linked to an altered gut microbiota characterized by reduced short-chain fatty acid (SCFA) production. Oral delivery of a SCFA-yielding biotherapy in adults with T1D was followed by increased SCFAs, altered gut microbiota and immunoregulation, as well as delaying diabetes in preclinical models. Here, we show that SCFA-biotherapy in humans is accompanied by remodeling of the gut proteome and mucosal immune homeostasis. Metabolomics showed arginine, glutamate, nucleotide and tryptophan metabolism were enriched following the SCFA-biotherapy, and found metabolites that correlated with glycemic control. Fecal microbiota transfer demonstrated that the microbiota of SCFA-responders delayed diabetes progression in humanized gnotobiotic mice. The protected mice increased similar metabolite pathways to the humans including producing aryl-hydrocarbon receptor ligands and reducing inflammatory mucosal immunity and increasing IgA production in the gut. These data demonstrate that a potent SCFA immunomodulator promotes multiple beneficial pathways and supports targeting the microbiota as an approach against T1D. Trial registration: Australia New Zealand Clinical Trials Registry ACTRN12618001391268.

Longitudinal analysis of rhesus macaque metabolome during acute SIV infection reveals disruption in broad metabolite classes

Persons living with HIV experience significant metabolic dysregulation, frequently resulting in immune and other cellular dysfunction. However, our understanding of metabolism and its relationship to immunity in the context of HIV remains incompletely understood, especially as it relates to the acute and early chronic phases of HIV infection. Herein, we employed mass spectrometry and a simian immunodeficiency virus (SIV)-infected rhesus macaque model to characterize changes in over 500 plasma metabolites throughout SIV infection. This broad metabolomic approach recapitulated known pathogenic signatures of HIV, such as a perturbed tryptophan/kynurenine ratio, but also identified novel metabolic changes. We observed a general decrease in plasma amino acid concentrations, with the notable exceptions of elevated aspartate and glutamate. Acute infection was marked by a transient increase in lactate dehydrogenase activity, indicating a shift toward anaerobic metabolism. Indoleamine 2,3-dioxygenase activity, defined by the kynurenine/tryptophan ratio, was significantly increased in both acute and chronic phases and strongly correlated with viral load. These results provide a comprehensive characterization of metabolic fluctuations during early lentiviral infection, furthering our understanding of the crucial interplay between metabolism and immune response. Our findings highlight systemic metabolic consequences of infection and provide potential targets for therapeutic intervention or biomarkers of disease progression.

IMPORTANCE

Despite significant advances in antiretroviral therapy and pre-exposure prophylaxis, HIV remains a global challenge. Understanding the underlying immune mechanisms is critical for improving HIV control and therapeutic development. Cellular metabolism represents a crucial yet underappreciated area of immune system function. Metabolite availability and metabolic pathway preferences directly influence the functional response capacity of immune cells and are highly dysregulated during HIV infection. To further the understanding of metabolic impacts of HIV infection, we utilized cutting-edge mass spectrometry-based metabolome interrogation to measure over 500 metabolites using an acute simian immunodeficiency virus infection model in rhesus macaques. Our comprehensive analysis provides insights into the dynamic metabolic landscape throughout early infection, revealing both known and novel metabolic signatures. These findings enhance our understanding of the complex interplay between metabolism and immunity in lentiviral infections, potentially informing new strategies for early detection, prevention, and treatment of HIV.

The impact of sleeve gastrectomy on MASH development by regulating the composition of gut microbiota and metabolic homeostasis

The prevalence of metabolic dysfunction-associated steatohepatitis (MASH) is increasing annually, which is a global public health issue. Although clinical trials are lacking, observational studies indicate that bariatric surgery can alleviate the progression of MASH. Here, we performed sleeve gastrectomy (SG) and Sham surgery on 8-week-old mice, and then fed a AMLN diet for 24 weeks to construct a diet-inducted MASH mice model after 4-week post-surgery recovery. Applying a multi-omics approach combining metagenomics, metabolomics, and transcriptomics, we found that SG prevents the development of hepatic steatosis, inflammation, and fibrosis in MASH mice not only by significantly altering the structure of gut microbiota including s_Akkermansia muciniphila, s_Alistiples dispar, g_Helicobacter and s_uc_Oscillospiraceae, but also by modulating the levels of serum metabolites including l-arginine and taurocholic acid (TCA). These results suggest that SG and the alteration of gut microbiota and its related serum metabolites can be served as the effective therapeutic strategies for MASH.

Amino Acid Metabolism and Immune Dysfunction in Urea Cycle Disorders: T and B Cell Perspectives

Urea cycle disorders (UCDs) are a group of genetic metabolic conditions characterized by enzyme deficiencies responsible for detoxifying ammonia. Hyperammonemia, the accumulation of intermediate metabolites, and a deficiency of essential amino acids-due to a protein-restrictive diet and the use of ammonia scavengers-can increase the risk of infections, particularly during metabolic crises. While the underlying mechanisms of immune suppression are still being fully elucidated, hyperammonemia may impair the function of immune cells, particularly T cells and macrophages, inhibiting the proliferation of T cells and cytokine production. Arginine, which is essential for T-cell activation and function, may also be limited in these patients, and its depletion can increase their vulnerability to infections. Twenty-four UCD patients and 31 healthy donors were recruited for the study. Peripheral lymphocyte subset analysis, intracellular protein and cytokine staining, and proliferation assays were performed by flow cytometry. Amino acid levels were measured using the HPLC method. The UCD patients exhibited low lymphocyte-proliferation capacity in both proximal and distal defects in response to phytohaemagglutinin (PHA) and anti-CD2, anti-CD3, and anti-CD28 (CD-mix), which was lower than healthy controls. Proximal-UCD patients exhibited a significantly higher response for IFN-γ compared to both distal-UCD patients and healthy controls. The different amino acids in the culture medium were changed significantly in the groups. This study highlights significant immune dysfunctions in UCD patients, particularly impaired T-cell proliferation and altered amino acid metabolism. Proximal UCD patients exhibited a higher IFN-γ response, indicating a potential for hyperinflammation. Despite this, infection rates did not significantly differ between proximal UCD and distal UCD patients, although distal UCD patients had higher hospitalization rates. Amino acid analysis revealed distinct metabolic disruptions, emphasizing the complex interplay between metabolism and immune function. These findings suggest that UCDs cause profound immune alterations, necessitating further research to develop targeted therapeutic strategies.

ArgR-dependent bacterial resistance to host lipid droplets in Edwardsiella piscicida

Lipid droplets (LDs), as innate immune hubs, function in the front line of antimicrobial defense involved in the host-pathogen arms race. Particularly for intracellular bacterial pathogens, the endowed capacity to resist host LDs can effectively facilitate pathogen in vivo colonization and evasion from the host's innate immune response. Here, to investigate the genetic mechanisms of intracellular bacteria response to host LDs, we utilized transposon insertion sequencing to dissect critical fitness determinants of Edwardsiella piscicida under the treatment of LDs isolated from its native host, turbot. Targeted metabolomics indicated that LD challenge resulted in the accumulation of intracellular arginine. The core arginine metabolism regulatory factor, ArgR, was found to play a pivotal role in combating LDs, emphasizing the importance of orchestrating intracellular arginine levels for bacterial LD adaptation. Specifically, ArgR enhanced the expressions of genes involved in arginine catabolism (speA/B and arcC) and diminished gene transcripts associated with arginine import (artP) and synthesis (argD/E/H). Furthermore, ArgR contributed to the pathogenesis of E. piscicida, promoting the proliferation in host cells and virulence in turbot. Collectively, our results shed light on the underlying mechanism of intracellular pathogens resisting LDs during bacterial infections and highlighting the crucial role of arginine in the host-pathogen interactions.

Arginine and colorectal cancer: Exploring arginine-related therapeutic strategies and novel insights into cancer immunotherapies

Concerning the progression of societies and the evolution of lifestyle and dietary habits, the potential for the development of human malignancies, particularly colorectal cancer (CRC), has markedly escalated, positioning it as one of the most prevalent and lethal forms of cancer globally. Empirical evidence indicates that the metabolic processes of cancerous and healthy cells can significantly impact immune responses and the fate of tumors. Arginine, a multifaceted amino acid, assumes a crucial and paradoxical role in various metabolic pathways, as certain tumors exhibit arginine auxotrophy while others do not. Notably, CRC is classified as arginine non-auxotrophic, possessing the ability to synthesize arginine from citrulline. Systemic arginine deprivation and the inhibition of arginine uptake represent two prevalent therapeutic strategies in oncological treatment. However, given the divergent behaviors of tumors concerning the metabolism and synthesis of arginine, one of these therapeutic approaches-namely systemic arginine deprivation-does not apply to CRC. This review elucidates the characteristics of arginine uptake inhibition and systemic arginine deprivation alongside their respective benefits and limitations in CRC. Furthermore, the involvement of arginine in immunotherapeutic strategies is examined in light of the most recent discoveries on various human malignancies.

L-Arginine and Nitric Oxide in Vascular Regulation-Experimental Findings in the Context of Blood Donation

This narrative review provides an analysis of the role of nitric oxide (NO) and its precursors, particularly L-arginine, in vascular regulation and health, with an emphasis on findings from our experimental research in animal models. NO serves as a critical mediator of vascular function, contributing to vasodilation, the regulation of blood flow, and the prevention of thrombosis. As a primary precursor of NO, L-arginine is essential for maintaining endothelial integrity, modulating mitochondrial function, and reducing oxidative damage. This review synthesises the data and contextualises these findings within the physiological challenges faced by blood donors, such as repeated blood donation and associated oxidative stress. It examines the effects of L-arginine supplementation on mitochondrial respiration, lipid peroxidation, and microsomal oxidation in different conditions, including differences in age, gender, and dietary interventions. The mechanisms by which L-arginine enhances NO production, improves vascular elasticity, and alleviates endothelial dysfunction caused by reduced NO bioavailability are also investigated. By integrating experimental findings with insights from the existing literature, this review provides a perspective on the potential of L-arginine supplementation to address the specific physiological needs of blood donors. It highlights the importance of personalised nutritional approaches in enhancing donor recovery and vascular resilience. In addition, this review assesses the wider implications of L-arginine supplementation in mitigating oxidative stress and preserving vascular function. The interplay between NO bioavailability, dietary factors, and physiological adaptation in blood donors is highlighted, along with the identification of current knowledge gaps and recommendations for future research. By presenting both original experimental evidence and a critical synthesis of the literature, this article highlights the therapeutic potential of NO precursors, particularly L-arginine, in promoting vascular health in the context of blood donation.

Harnessing amino acid pathways to influence myeloid cell function in tumor immunity

Amino acids are pivotal regulators of immune cell metabolism, signaling pathways, and gene expression. In myeloid cells, these processes underlie their functional plasticity, enabling shifts between pro-inflammatory, anti-inflammatory, pro-tumor, and anti-tumor activities. Within the tumor microenvironment, amino acid metabolism plays a crucial role in mediating the immunosuppressive functions of myeloid cells, contributing to tumor progression. This review delves into the mechanisms by which specific amino acids-glutamine, serine, arginine, and tryptophan-regulate myeloid cell function and polarization. Furthermore, we explore the therapeutic potential of targeting amino acid metabolism to enhance anti-tumor immunity, offering insights into novel strategies for cancer treatment.

Hempseed Water-Soluble Protein Fraction and Its Hydrolysate Display Different Biological Features

Hempseeds, from the Cannabis sativa plant, and its derivates are a versatile food option for various dietary preferences. Due to their aminoacidic profile, researchers have studied the presence of bioactive peptides in hempseed proteins. In this study, the water-soluble fraction of hempseed protein was extracted, and the derived peptides were analyzed. The investigation focused on their biological function, particularly their antioxidant activity. Several biological functions have arisen, such as angiotensin-converting enzyme inhibition activity, dipeptidyl-peptidase IV, dipeptidyl-peptidase III inhibition, and ubiquitin-mediated proteolysis activation. The hydrolysates show greater 2,2-azinobis-[3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical scavenging activity compared to the proteins (97.95 ± 4.48 versus 81.04 ± 10.63). Furthermore, the impact of these proteins and peptides on the U937 cell line was evaluated to assess cell viability and their potential role in modulating inflammation associated with gastrointestinal autoimmune diseases. Protein treatment resulted in a significant reduction in cell viability, as opposed to hydrolysates, which did not affect it.

New formulation of ibuprofen-arginate reduces oxidative stress and prevents macrophage polarization toward M1 phenotype

A hypertonic solution of Ibuprofen (Ibu) was designed to nebulize, associating a low concentration of Ibu with L-Arginine (AR), to increase solubility and serve as a nitric oxide donor. To provide preclinical research human bronchial epithelial cells derived from a cystic fibrosis patient homozygous for the ΔF508 CFTR mutation (CFBE41o-) and mouse RAW 264.7 macrophages were pre-treated with Ibu (10-100 μM), AR (20 and 200 μM), or the combination Ibu-AR (10-100 μM). After Angiotensin II (AngII) or LPS/Interferon ϒ (IFN) stimulation, Reactive Oxygen Species (ROS) generation, Nitric Oxide (NO) formation, and the expression of inflammatory markers were determined. Ibu-AR (10/20 μM) significantly reduced ROS generation stimulated by AngII (p < 0.01) in CFBE41o- cells preserved the NO pathway and inhibited LPS-stimulated nitrite generation (p < 0.001). In macrophages, the combination Ibu-Ar, in a ratio of 1:2-1:6, efficiently scavenged excessive ROS generated by LPS, and significantly induced NO generation (p < 0.001), but inhibited nitrite formation. In LPS/IFNϒ-activated Raw, gene signature of M1polarization including tumor necrosis factor (TNF-α), NADPH Oxidase 2 (NOX-2), MCP-1, and inducible nitric oxide synthase (iNOS) were significantly downregulated by Ibu-AR, as well TNF-α, IL-6, and iNOS protein expressions. The inhibitory effect produced by Ibu-AR on M1 macrophages was associated with the inhibition of p-ERK1/2 and p-STAT3. Ibu-AR represents an effective therapeutic strategy for reducing oxidative stress, preserving NO bioavailability, and modulating inflammation in chronic inflammatory diseases.

Role of major cardiovascular surgery-induced metabolic reprogramming in acute kidney injury in critical care

PURPOSE

Major cardiovascular surgery imposes high physiologic stress, often causing severe organ dysfunction and poor outcomes. The underlying mechanisms remain unclear. This study investigated metabolic changes induced by major cardiovascular surgery and the potential role of identified metabolic signatures in postoperative acute kidney injury (AKI).

METHODS

A prospective observational study included 53 patients undergoing major cardiovascular surgery in 3 groups: cardiac surgery with cardiopulmonary bypass (CPB n = 33), without CPB (n = 10), and major vascular surgery (n = 10). For each patient, peripheral blood samples were collected pre-surgery, and at 6 h and 24 h post-surgery. Untargeted metabolomics using mass spectrometry quantified 8668 metabolic features in serum samples. Linear mixed-effect models (adjusted for age, sex, and body mass index) and pathway analyses were performed.

RESULTS

In the cardiac surgery with CPB group, 772 features were significantly altered (P < 2.8E - 05) across the 3 time points. These features were enriched in five classes, all related to protein metabolism, with glycine and serine metabolism being the most represented. Cardiac surgery with CPB showed a distinct metabolic signature compared to other groups. Patients who developed postoperative AKI exhibited increased protein catabolism (including valine, leucine, and isoleucine degradation), disruptions in the citric acid cycle, and plasmatic accumulation of acylcarnitines.

CONCLUSION

Major cardiovascular surgery, particularly with CPB, induces significant changes in protein metabolism. Patients developing postoperative AKI exhibited specific metabolic signatures. These findings may be critical for designing interventions to minimize organ dysfunction, including AKI, and improve outcomes in major cardiovascular surgery.

Arginine metabolism in myeloid cells in health and disease

Metabolic flexibility is key for the function of myeloid cells. Arginine metabolism is integral to the regulation of myeloid cell responses. Nitric oxide (NO) production from arginine is vital for the antimicrobial and pro-inflammatory responses. Conversely, the arginase 1 (ARG1)-dependent switch between the branch of NO production and polyamine synthesis downregulates inflammation and promotes recovery of tissue homeostasis. Creatine metabolism is key for energy supply and proline metabolism is required for collagen synthesis. Myeloid ARG1 also regulates extracellular arginine availability and T cell responses in parasitic diseases and cancer. Cancer, surgery, sepsis and persistent inflammation in chronic inflammatory diseases, such as neuroinflammatory diseases or arthritis, are associated with dysregulation of arginine metabolism in myeloid cells. Here, we review current knowledge on arginine metabolism in different myeloid cell types, such as macrophages, neutrophils, microglia, osteoclasts, tumor-associated macrophages (TAMs), tumor-associated neutrophils (TANs) and myeloid-derived suppressor cells (MDSCs). A deeper understanding of the function of arginine metabolism in myeloid cells will improve our knowledge on the pathology of several diseases and may set the platform for novel therapeutic applications.

Aqueous humor metabolomic profiling identifies a distinct signature in pseudoexfoliation syndrome

Purpose

PEXS was first described in 1917, yet its etiology still needs clarification. An imbalance between oxidants and antioxidants plays a significant role. PEXS leads to various ocular complications, including increased risk during cataract surgery due to weak zonules, lens dislocation, and reduced visual outcomes. Our study investigates whether metabolomics can provide insights into this ocular pathology.

Methods

The study included 183 patients undergoing cataract surgery at Pauls Stradins Clinical University Hospital. 104 patients did not have PEXS, while 79 were diagnosed with the condition. Intraocular fluid samples from these patients were analyzed using targeted metabolite analysis, performed through HILIC liquid chromatography coupled with mass spectrometry detection.

Results

The aqueous humor of PEXS patients contains statistically significant higher levels of cystine (p < 0.001), citrulline (p < 0.001), phenylalanine (p = 0.041), tyrosine (p = 0.025), serine (p = 0.030), arginine (p = 0.017), lactic acid (p = 0.055), tryptophan (p = 0.055), and creatinine (p = 0.022). These results suggest a potential link to ferroptosis.

Conclusion

Ferroptosis is a form of programmed cell death characterized by iron-dependent LPO. The inhibition of the antiporter system Xc - leads to increased oxidative stress, suggesting that the changes seen in PEXS could be linked to ferroptosis. Our findings indicate that cysteine synthesis occurs via the transsulfation pathway, attributable to inhibiting the antiporter system Xc -. Treatment of pseudoexfoliation should lower the oxidative stress inside the anterior chamber by reducing the uptake of PUFAs, lower iron levels, and cysteine supplementation.

Promising Cellular Immunotherapy for Colorectal Cancer Using Classical Dendritic Cells and Natural Killer T Cells

Colorectal cancer (CRC) remains one of the leading causes of cancer-related morbidity and mortality around the world. Despite advances in surgery, chemotherapy, and targeted therapies, the prognosis for patients with metastatic or advanced CRC remains poor. Immunotherapies comprising immune checkpoint inhibitors showed disappointing responses in metastatic CRC (mCRC). However, cellular immunotherapy, specifically using classical dendritic cells (cDCs), may hold unique promise in immune recognition for CRC antigens. cDCs are substantial players in immune recognition and are instrumental in orchestrating innate and adaptive immune responses by processing and presenting tumor antigens to effector cells. Natural killer T (NKT) cells are insufficiently studied but unique effector cells because of their ability to bridge innate and adaptive immune reactions and the crosstalk with dendritic cells in cancer. This review explores the therapeutic potential of using both cDCs and NKT cells as a synergistic therapy in CRC, focusing on their biological roles, strategies for harnessing their capabilities, clinical applications, and the challenges within the tumor microenvironment. Both cDCs and NKT cells can be used as a new effective approach for cell-based therapies in cancers to provide a new hope for CRC patients that are challenging to treat.

GlutaR: A High-Performance Fluorescent Protein-Based Sensor for Spatiotemporal Monitoring of Glutamine Dynamics In Vivo

Glutamine is the most abundant amino acid in human blood and muscle, and is integral to a wide variety of functions in cancer cells. However, the inability to monitor the subcellular distribution of glutamine in real-time has obscured understanding of glutamine metabolism under physiological and pathological conditions. Here, we report the development of a genetically encoded fluorescent sensor and demonstrate how this GlnBP-cpYFP fusion "GlutaR sensor" undergoes glutamine-induced conformational changes reflected in detectable fluorescence responses. Obtained after iterative screening of approximately 1,600 variants, GlutaR exhibits a ratiometric readout, fast response kinetics, and high responsivity (R488/405 of ~1000 %), and we demonstrate its selectivity for monitoring glutamine fluctuations in multiple cell types. Additionally, using digitonin permeabilization of GlutaR HeLa cells, we generated a calibration curve and performed in situ titration to quantify free glutamine concentrations in subcellular compartments (cytosol, nucleus, mitochondria). Subsequently, we applied GlutaR to investigate how chemical and genetic inhibition of glutamine synthetase (GS) and glutaminase (GLS) differentially alter glutamine levels in subcellular compartments. Finally, we demonstrate GlutaR's ability to monitor dynamic glutamine levels in muscle and liver tissues of diabetic mice in vivo. These findings collectively demonstrate GlutaR as a versatile tool for the spatiotemporal characterization of glutamine metabolism in living cells and tissues.

In Vivo Assessment of Healing Potential of Ointments Containing Bee Products, Vegetal Extracts, and Polymers on Skin Lesions

Background/Objectives: The present experiment aimed to formulate four ointments that included mixtures of plant extracts (Hippophae rhamnoides, Calendula officinalis, Arctium lappa, and Achillea millefolium), apitherapy products (honey, propolis, and apilarnil) and natural polymers (collagen, chitosan, and the lyophilisate of egg white) in an ointment base. Methods: In order to investigate the therapeutic properties of the ointments, experimental in vivo injury models (linear incision, circular excision, and thermal burns) were performed on laboratory animals, namely Wistar rats. The treatment was applied topically, once a day, for 21 days. Clinical and macroscopic evaluation, determination of lesion shrinkage rate, re-epithelialization period, and histopathological examination were performed. Results: The results demonstrate that the tested ointments have a significant effect in healing skin lesions. On the ninth day of treatment, the wound contraction rate was 98.17 ± 0.15% for the mixed ointment group, compared to the negative control group's rate of 14.85 ± 2.95%. At day 21, dermal collagenization and restoration of histological structure occurred for all treated groups. Conclusions: The tested ointments exerted in vivo wound healing and re-epithelialization effects on incision, excision, and thermal burn injuries.

Reprint of: M1 macrophage-targeted curcumin nanocrystals with l-arginine-modified for acute lung injury by inhalation

Acute Lung Injury/Acute Respiratory Distress Syndrome (ALI/ARDS) with clinical manifestations of respiratory distress and hypoxemia remains a significant cause of respiratory failure, boasting a persistently high incidence and mortality rate. Given the central role of M1 macrophages in the pathogenesis of acute lung injury (ALI), this study utilized the anti-inflammatory agent curcumin as a model drug. l-arginine (L-Arg) was employed as a targeting ligand, and chitosan was initially modified with l-arginine. Subsequently, it was utilized as a surface modifier to prepare inhalable nano-crystals loaded with curcumin (Arg-CS-Cur), aiming for specific targeting of pulmonary M1 macrophages. Compared with unmodified chitosan-curcumin nanocrystals (CS-Cur), Arg-CS-Cur exhibited higher uptake in vitro by M1 macrophages, as evidenced by flow cytometry showing the highest fluorescence intensity in the Arg-CS-Cur group (P < 0.01). In vivo accumulation was greater in inflamed lung tissues, as indicated by small animal imaging demonstrating higher lung fluorescence intensity in the DiR-Arg-CS-Cur group compared to the DiR-CS-Cur group in the rat ALI model (P < 0.05), peaking at 12 h. Moreover, Arg-CS-Cur demonstrated enhanced therapeutic effects in both LPS-induced RAW264.7 cells and ALI rat models. Specifically, treatment with Arg-CS-Cur significantly suppressed NO release and levels of TNF-α and IL-6 in RAW264.7 cells (p < 0.01), while in ALI rat models, expression levels of TNF-α and IL-6 in lung tissues were significantly lower than those in the model group (P < 0.01). Furthermore, lung tissue damage was significantly reduced, with histological scores significantly lower than those in the CS-Cur group (P < 0.01). In conclusion, these findings underscore the targeting potential of l-arginine-modified nanocrystals, which effectively enhance curcumin concentration in inflammatory environments by selectively targeting M1 macrophages. This study thus introduces novel perspectives and theoretical support for the development of targeted therapeutic interventions for acute inflammatory lung diseases, including ALI/ARDS.

Biochemistry, pharmacology, and in vivo function of arginases

The enzyme arginase catalyzes the hydrolysis of l-arginine into l-ornithine and urea. The 2 existing isoforms Arg1 and Arg2 exhibit different cellular localizations and metabolic functions. Arginase activity is crucial for nitrogen detoxification in the urea cycle, synthesis of polyamines, and control of l-arginine bioavailability and nitric oxide (NO) production. Despite significant progress in the understanding of the biochemistry and function of arginases, several open questions remain. Recent studies have revealed that the regulation and function of Arg1 and Arg2 are cell type-specific, species-specific, and profoundly different in mice and humans. The main differences are in the distribution and function of Arg1 and Arg2 in immune and erythroid cells. Contrary to what was previously thought, Arg1 activity appears to be only partially related to vascular NO signaling under homeostatic conditions in the vascular wall, but its expression is increased under disease conditions and may be targeted by treatment with arginase inhibitors. Arg2 appears to be mainly a catabolic enzyme involved in the synthesis of l-ornithine, polyamine, and l-proline but may play a putative role in blood pressure control, at least in mice. The immunosuppressive role of arginase-mediated arginine depletion is a promising target for cancer treatment. This review critically revises and discusses the biochemistry, pharmacology, and in vivo function of arginases, focusing on the insights gained from the analysis of cell-specific Arg1 and Arg2 knockout mice and human studies using arginase inhibitors or pegylated recombinant arginase. SIGNIFICANCE STATEMENT: Further basic and translational research is needed to deepen our understanding of the regulation of Arg1 and Arg2 in different cell types in consideration of their localization, species-specificity, and multiple biochemical and physiological roles. This will lead to better pharmacological strategies to target arginase activity in liver, cardiovascular, hematological, immune/infectious diseases, and cancer.

Genetically Confirmed Optimal Causal Association of Cerebrospinal Fluid Metabolites With Hemorrhagic Stroke

Hemorrhagic stroke (HS) mainly includes intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH), both of which seriously affect the patient's prognosis. Cerebrospinal fluid (CSF) metabolites and HS showed a link in observational studies. However, the causal association between them is not clear. We aimed to establish the optimal causality of CSF metabolites with HS. Mendelian randomization (MR) was employed to identify associations between CSF metabolites and different sources of HS. Univariable MR and false discovery rates (FDR) were used to identify initial causal associations. Linkage disequilibrium score regression determined genetic correlations. Multiple sensitive analyses ensured the reliability of the results. Multivariable MR and MR Bayesian Model Averaging were used to identify the optimal causal associations. The combined effects of metabolites and HS were assessed by meta-analyses. Pathway analyses were performed to identify potential pathways of action. Reverse MR was also conducted to identify reverse causal associations. Finally, Corresponding blood metabolites were used to explore the multiple roles of metabolites. We identified 20 CSF metabolites and six metabolic pathways associated with ICH; 15 CSF metabolites and three metabolic pathways associated with SAH. Nineteen and seven metabolites were causally associated with deep and lobar ICH, respectively. CSF levels of mannose (OR 0.63; 95% CI 0.45-0.88; Pcombined = 0.0059) and N-acetyltaurine (OR 0.68; 95% CI 0.47-0.98; Pcombined = 0.0395) may serve as the optimal exposures for ICH and SAH, respectively. Additionally, CSF ascorbic acid 3-sulfate levels significantly decrease the risk of deep ICH (OR 0.79; 95% CI 0.66-0.94; p = 0.0065; PFDR = 0.091). Supplemental analysis of blood metabolites suggested multiple roles for CSF and blood N-formylanthranilic acid and hippurate. There are significant causal associations between CSF metabolites and HS, which provides a further rationale for the prevention and monitoring of ICH and SAH.

Metabolic-Modulating Effects of Radiation: Undetectable Yet Deadly-A Review on Radiotherapy

From a cancer-centric perspective, radiotherapy has been primarily viewed as a localised treatment modality, targeting cancer tissues with ionising radiation to induce DNA damage and cell death [...].

The Role of Macronutrients and Gut Microbiota in Neuroinflammation Post-Traumatic Brain Injury: A Narrative Review

Traumatic brain injury (TBI) represents a multifaceted pathological condition resulting from external forces that disrupt neuronal integrity and function. This narrative review explores the intricate relationship between dietary macronutrients, gut microbiota (GM), and neuroinflammation in the TBI. We delineate the dual aspects of TBI: the immediate mechanical damage (primary injury) and the subsequent biological processes (secondary injury) that exacerbate neuronal damage. Dysregulation of the gut-brain axis emerges as a critical factor in the neuroinflammatory response, emphasizing the role of the GM in mediating immune responses. Recent evidence indicates that specific macronutrients, including lipids, proteins, and probiotics, can influence microbiota composition and in turn modulate neuroinflammation. Moreover, specialized dietary interventions may promote resilience against secondary insults and support neurological recovery post-TBI. This review aims to synthesize the current preclinical and clinical evidence on the potential of dietary strategies in mitigating neuroinflammatory pathways, suggesting that targeted nutrition and gut health optimization could serve as promising therapeutic modalities in TBI management.

Pathway Thermodynamic Analysis Postulates Change in Glutamate Metabolism as a Key Factor in Modulating Immune Responses

Background

Temperature, as seen during fever, plays a pivotal role in modulating immune responses and maintaining cellular homeostasis. Shifts in temperature influence the thermodynamic feasibility of metabolic reactions, with Gibbs free energy (ΔG) serving as a key indicator of the spontaneity of reactions under specific conditions. By altering ΔG in response to temperature changes across various metabolite concentrations and cell types, we can gain insights into the thermodynamic properties of metabolic pathways and identify critical factors involved in metabolism and immune function. Using Max-Min Driving Force (MDF) analysis, we can assess changes in ΔG by varying temperature and metabolite concentrations, allowing for a detailed examination of thermodynamic feasibility at both the pathway and individual reaction levels.

Results

In this study, MDF analysis is applied to measure the changes in the driving force of pathways and the ΔG of each reaction at normal human core temperature (310.15 K) and elevated temperatures (up to 315.15 K). Additionally, we explore how shifts in the thermodynamic feasibility of reactions under immune activation, compared to normal physiological conditions, highlight key metabolic intermediates-such as fructose-1,6-bisphosphate, glucose-6-phosphate, and several steps in glutamate metabolism-as important regulators of metabolic processes and immune responses.

Conclusion

The goal of this study is to underscore the value of thermodynamic parameters such as ΔG, concentration, and temperature in identifying potential therapeutic targets, with the aim of mitigating the detrimental effects of fever while preserving its beneficial aspects.

Myeloid effector cells in cancer

The role of myeloid cells in tumor immunity is multifaceted. While dendritic cells support T cell-mediated tumor control, the highly heterogenous populations of macrophages, neutrophils, and immature myeloid cells were generally considered immunosuppressive. This view has led to effective therapies reinvigorating tumor-reactive T cells; however, targeting the immunosuppressive effects of macrophages and neutrophils to boost the cancer immunity cycle was clinically less successful. Recent studies interrogating the role of immune cells in the context of successful immunotherapy affirm the key role of T cells, but simultaneously challenge the idea that the cytotoxic function of T cells is the main contributor to therapy-driven tumor regression. Rather, therapy-activated intra-tumoral T cells recruit and activate or reprogram several myeloid effector cell types, the presence of which is necessary for tumor rejection. Here, we reappreciate the key role of myeloid effector cells in tumor rejection as this may help to shape future successful immunotherapies.

Serum Metabolites as Diagnostic Biomarkers in Patients with Endometriosis

Endometriosis diagnosis is usually delayed. The gold standard for diagnosing endometriosis is laparoscopy, which is invasive and accompanied by several risks. Currently, there are no effective non-invasive biomarkers for diagnosing endometriosis. Here, we investigated whether metabolites whose levels are altered in patients with endometriosis hold potential as diagnostic biomarkers for the disease. This case-control study involved 32 patients with endometriosis and 29 patients with other benign gynecological disease. The diagnosis of all patients was confirmed through postoperative histopathological examination, and the patients were divided into two groups: an endometriosis group (EM) and a control group. Fasting blood was collected and used for non-targeted metabolomic-based detection. The data were processed through principal component analysis, orthogonal partial least squares discriminant analysis, and significance analysis of microarrays. A univariate receiver operating characteristic curve was used to evaluate the diagnostic value of the metabolites. The metabolite profiles of patients with endometriosis were markedly different compared with those of the controls. In addition, several metabolic pathways, including biosynthesis of unsaturated fatty acids, arginine biosynthesis, and glutathione metabolism, were altered. Ornithine and medorinone showed better potential as biomarkers for endometriosis diagnosis than CA125. We analyzed the altered metabolic profiles in patients with endometriosis and found ornithine and medorinone as potential non-invasive biomarkers for endometriosis diagnosis, whereas the combined ornithine-medorinone diagnosis is more valuable. These findings may help advance research on non-invasive diagnostic biomarkers for endometriosis. Further research with an improved study design and a larger cohort should be performed to confirm the diagnostic potential and clinical application of these biomarkers.

Anti-inflammatory effects of 1,7-dihydroxy-3,4-dimethoxyxanthone through inhibition of M1-phenotype macrophages via arginine/mitochondrial axis

It is known that 1,7-dihydroxy-3,4-dimethoxyxanthone (XAN), derived from Securidaca inappendiculata Hassk., exhibits anti-inflammatory and analgesic activities and inhibits M1 polarization of macrophages. However, its ability to alleviate inflammation induced by pro-inflammatory cytokines in THP-1 cells and its anti-inflammatory mechanisms remain unclear. THP-1 cells were treated with phorbol 12-myristate-13-acetate to differentiate and divided into three groups. They were stimulated with lipopolysaccharide (LPS) and interferon-γ (IFN-γ). The toxicity of XAN was assessed using Cell Counting Kit-8, and the expression of various genes and proteins was analyzed using real-time quantitative polymerase chain reaction, flow cytometry, and western blotting. Transmission electron microscopy was used to observe changes in mitochondrial structure. XAN at concentrations ≤ 10 µg/mL did not affect THP-1 cell viability and reduced the mRNA expression of pro-inflammatory factors, including interleukin (IL)-1β, inducible nitric oxide synthase (iNOS), NOD-like receptor thermal protein domain protein 3 (NLRP3), and tumor necrosis factor-α (TNF-α). XAN also increased the levels of anti-inflammatory factors, including chemokine ligand 22, mannose receptor (CD206), IL-10, peroxisome proliferator-activated receptor-γ, and transglutaminase 2. Additionally, XAN downregulated the expression of inflammation-related proteins iNOS, NLRP3, and IL-1β; significantly increased the expression of arginase 1, ornithine decarboxylase, and arginine metabolism-related proteins and genes; inhibited mitochondrial damage; and reduced reactive oxygen species (ROS) generation. XAN enhanced the arginine metabolism pathway, prevented mitochondrial damage, reduced ROS levels, and provided an effective defensive response against LPS/IFN-γ-induced inflammation.

Nanocarriers for Delivery of Anticancer Drugs: Current Developments, Challenges, and Perspectives

Cancer, the most common condition worldwide, ranks second in terms of the number of human deaths, surpassing cardiovascular diseases. Uncontrolled cell multiplication and resistance to cell death are the traditional features of cancer. The myriad of treatment options include surgery, chemotherapy, radiotherapy, and immunotherapy to treat this disease. Conventional chemotherapy drug delivery suffers from issues such as the risk of damage to benign cells, which can cause toxicity, and a few tumor cells withstand apoptosis, thereby increasing the likelihood of developing tolerance. The side effects of cancer chemotherapy are often more pronounced than its benefits. Regarding drugs used in cancer chemotherapy, their bioavailability and stability in the tumor microenvironment are the most important issues that need immediate addressing. Hence, an effective and reliable drug delivery system through which both rapid and precise targeting of treatment can be achieved is urgently needed. In this work, we discuss the development of various nanobased carriers in the advancement of cancer therapy-their properties, the potential of polymers for drug delivery, and recent advances in formulations. Additionally, we discuss the use of tumor metabolism-rewriting nanomedicines in strengthening antitumor immune responses and mRNA-based nanotherapeutics in inhibiting tumor progression. We also examine several issues, such as nanotoxicological studies, including their distribution, pharmacokinetics, and toxicology. Although significant attention is being given to nanotechnology, equal attention is needed in laboratories that produce nanomedicines so that they can record themselves in clinical trials. Furthermore, these medicines in clinical trials display overwhelming results with reduced side effects, as well as their ability to modify the dose of the drug.

Regionalization of intestinal microbiota and metabolites in the small intestine of the Bactrian camel

Introduction

Peyer's patches (PPs) are crucial antigen-inductive sites of intestinal mucosal immunity. Prior research indicated that, in contrast to other ruminants, PPs in the small intestine of Bactrian camels are found in the duodenum, jejunum, and ileum and display polymorphism. Using this information, we analyzed the microbial and metabolic characteristics in various segments of the Bactrian camel's small intestine to further elucidate how the immune system varies across different regions.

Methods

In this study, the microbiota and metabolite of 36 intestinal mucosal samples, including duodenal (D-PPs), jejunal (J-PPs), and ileal PPs (I-PPs), were profiled for six Bactrian camels using 16S rRNA gene sequencing and liquid chromatography with tandem mass spectrometry (LC-MS/MS). To confirm meaningful associations, we conducted connection analyses on the significantly different objects identified in each group's results. ELISA was used to analyze the levels of IgA, IgG, and IgM in the same tissues.

Results

The microbiota and metabolite profiles of J-PPs and I-PPs were found to be similar, whereas those of D-PPs were more distinct. In J-PPs and I-PPs, the dominant bacterial genera included Clostridium, Turicibacter, and Shigella. In contrast, D-PPs had a significant increase in the abundance of Prevotella, Fibrobacter, and Succinobacter. Regarding the metabolomics, D-PPs exhibited high levels of polypeptides, acetylcholine, and histamine. On the other hand, J-PPs and I-PPs were characterized by an enrichment of free amino acids, such as L-arginine, L-glutamic acid, and L-serine. These metabolic differences mainly involve amino acid production and metabolic processes. Furthermore, the distribution of intestinal immunoglobulins highlighted the specificity of D-PPs. Our results indicated that proinflammatory microbes and metabolites were significantly enriched in D-PPs. In contrast, J-PPs and I-PPs contained substances that more effectively enhance immune responses, as evidenced by the differential distribution of IgA, IgG, and IgM.

Discussion

The intestinal microenvironment of Bactrian camels displays distinct regional disparities, which we propose are associated with variations in immunological function throughout different segments of the small intestine. This study highlights the specific traits of the intestinal microbiota and metabolites in Bactrian camels, offering a valuable reference for understanding the relationship between regional intestinal immunity and the general health and disease of the host.

Green Microfluidic Method for Sustainable and High-Speed Analysis of Basic Amino Acids in Nutritional Supplements

Amino acids (AAs) have broad nutritional, therapeutic, and medical significance and thus are one of the most common active ingredients of nutritional supplements. Analytical strategies for determining AAs are high-priced and often limited to methods that require modification of AA polarity or incorporation of an aromatic moiety. The aim of this work was to develop a new method for the determination of L-arginine, L-ornithine, and L-lysine on low-cost microchip electrophoresis instrumentation conjugated with capacitively coupled contactless conductivity detection. A solution consisting of 0.3 M acetic acid and 1 × 10-5 M iminodiacetic acid has been identified as the optimal background electrolyte, ensuring the shortest possible analysis time. The short migration times of amino acids (t ≤ 64 s) and method simplicity resulted in high analysis throughput with high precision and linearity (R2≥ 0.9971). The limit of detection values ranged from 0.15 to 0.19 × 10-6 M. The accuracy of the proposed method was confirmed by recovery measurements. The results were compared with CE-UV-VIS and HPLC-DAD methods and showed good agreement. This work represents the first successful demonstration of the ME-C4D analysis of L-arginine, L-ornithine, and L-lysine in real samples.

Combined transcriptome and metabolome analysis reveals the mechanism of high nitrite tolerance in freshwater mussel Anodonta woodiana

Nitrite contamination and stress on aquatic organisms are increasingly emphasized in freshwater ecosystems. Freshwater bivalves exhibit high tolerance to nitrite; however, the underlying mechanism is unknown. Accordingly, this study investigated the tolerance mechanism of the globally occurring freshwater bivalve Anodonta woodiana. A. woodiana were exposed to nominal concentrations of 0, 250, 500, 1000, 2000, and 4000 mg/L nitrite for 96 h to calculate the 96-h median lethal concentration (96-h LC50). A combined transcriptome and metabolome analysis of the hemolymph (the most vital component of the bivalve immune system) was performed after exposing A. woodiana to 300 mg/L nitrite (approximately half the 96-h LC50) for 96 h. The 96-h LC50 of nitrite in A. woodiana was 618.7 mg/L. Transcriptome analysis identified 5600 differentially expressed genes (DEGs) primarily related to ribosomes, lysosomes, DNA replication, and nucleotide excision repair. Metabolome analysis identified 216 differentially expressed metabolites (DEMs) primarily involved in biosynthesis of amino acids, 2-oxocarboxylic acid metabolism, protein digestion and absorption, aminoacyl-tRNA biosynthesis, nucleotide metabolism, ABC transporters, and valine, leucine and isoleucine degradation. Combined transcriptome and metabolome analysis revealed that DEGs and DEMs were primarily associated with nucleotide (purine and pyrimidine) and amino acid metabolism (including aminoacyl-tRNA biosynthesis, cysteine and methionine metabolism, arginine and proline metabolism, and valine, leucine and isoleucine degradation) as well as the immune system (necroptosis and glutathione metabolism). This study is the first to describe the high tolerance of A. woodiana to nitrite and elucidate the molecular mechanisms underlying high nitrite tolerance in mussels.

Rosini Silva A, Brites C, Angelo da Silva Miyaguti N, Raposo Passos Mansoldo F, Vaz Nunes S, Henrique Godoy Sanches P, Regiani Cataldi T, Pais de Carvalho C, Reis da Silva A, Ribeiro da Rosa J, Magalhães Borges M, Vilarindo Oliveira W, Canevari TC, Beatriz Vermelho A, Nogueira Eberlin M, M. Porcari A. Mass Spectrometry-Based Metabolomics Reveals a Salivary Signature for Low-Severity COVID-19

Omics approaches were extensively applied during the coronavirus disease 2019 (COVID-19) pandemic to understand the disease, identify biomarkers with diagnostic and prognostic value, and discover new molecular targets for medications. COVID-19 continues to challenge the healthcare system as the virus mutates, becoming more transmissible or adept at evading the immune system, causing resurgent epidemic waves over the last few years. In this study, we used saliva from volunteers who were negative and positive for COVID-19 when Omicron and its variants became dominant. We applied a direct solid-phase extraction approach followed by non-target metabolomics analysis to identify potential salivary signatures of hospital-recruited volunteers to establish a model for COVID-19 screening. Our model, which aimed to differentiate COVID-19-positive individuals from controls in a hospital setting, was based on 39 compounds and achieved high sensitivity (85%/100%), specificity (82%/84%), and accuracy (84%/92%) in training and validation sets, respectively. The salivary diagnostic signatures were mainly composed of amino acids and lipids and were related to a heightened innate immune antiviral response and an attenuated inflammatory profile. The higher abundance of thyrotropin-releasing hormone in the COVID-19 positive group highlighted the endocrine imbalance in low-severity disease, as first reported here, underscoring the need for further studies in this area.

Metabolism and epigenetics: drivers of tumor cell plasticity and treatment outcomes

Emerging evidence indicates that metabolism not only is a source of energy and biomaterials for cell division but also acts as a driver of cancer cell plasticity and treatment resistance. This is because metabolic changes lead to remodeling of chromatin and reprogramming of gene expression patterns, furthering tumor cell phenotypic transitions. Therefore, the crosstalk between metabolism and epigenetics seems to hold immense potential for the discovery of novel therapeutic targets for various aggressive tumors. Here, we highlight recent discoveries supporting the concept that the cooperation between metabolism and epigenetics enables cancer to overcome mounting treatment-induced pressures. We discuss how specific metabolites contribute to cancer cell resilience and provide perspective on how simultaneously targeting these key forces could produce synergistic therapeutic effects to improve treatment outcomes.

Chemical Screening, Identification, and Comparison of Tripterygium Hypoglaucum Hutch Preparations by Ultra-High-Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry Combined With Multivariate Statistical Analysis

Colquhounia root tablets (CRT) and Tripterygium hypoglaucum hutch tablets (THHT), two major Tripterygium hypoglaucum hutch (THH) commercial preparations, have been used to treat chronic kidney diseases or rheumatic diseases. However, there have been no reports on the chemical comparison between CRT and THHT, greatly hindering the understanding of their pharmacological difference as well as their rational application in clinical practice. In the present study, ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry combined with automated data analysis by MS-DIAL software and MS-FLO website was employed to systematically screen and characterize the components in CRT and THHT. Multivariate statistical analysis was used to compare the differences between these two preparations. As a result, up to 92 components were tentatively identified, and 17 of them were characterized for the first time in THH preparations. According to the criteria of variable importance in projection (VIP) >1, p < 0.05, and fold change (FC) > 1.2, 46 components could be screened as major differential chemical components. Among them, phenolic acids, organic acids, amino acids, and diterpenoids were higher in CRT, while the sesquiterpene alkaloids were relatively higher in THHT. This study clarified the chemical material basis and the difference between CRT and THHT, providing a valuable reference for quality control and clinical rational use of THH preparations.

Cervical mucus can be used for metabolite screening in cervical cancer

Approximately 660,000 women are diagnosed with cervical cancer annually. Current screening options such as cytology or human papillomavirus testing have limitations, creating a need to identify more effective ancillary biomarkers for triage. Here, we evaluated whether metabolomic analysis of cervical mucus metabolism could be used to identify biomarkers of cervical intraepithelial neoplasia (CIN) and cervical cancer. The case-control group consisted of 181 CIN, 69 squamous cell carcinoma (SCC) patients, and 48 healthy controls in the primary cohort. We undertook metabolomic analyses using ultra-HPLC-tandem mass spectrometry. Univariate and multivariate analyses were carried out to profile metabolite characteristics, and receiver operating characteristic (ROC) analysis identified biomarker candidates. Five metabolites conferred the highest discriminatory power for SCC: oxidized glutathione (GSSG) (area under the ROC curve, 0.924; 95% confidence interval, 0.877-0.971), malic acid (0.914, 0.859-0.968), kynurenine (0.884, 0.823-0.945), GSSG/glutathione (GSH) (0.936, 0.892-0.979), and kynurenine/tryptophan (0.909, 0.856-0.961). Malic acid was the best marker for detection of CIN2 or worse (0.858, 0.793-0.922) and was a clinically useful metabolite. We confirmed the reproducibility of the results by validation cohort. Additionally, metabolomic analyses revealed eight pathways strongly associated with cervical neoplasia. Of these, only the tricarboxylic acid cycle was strongly associated with all CINs and cancer, indicating active energy production. Aberrant arginine metabolism by decreasing arginine and increasing citrulline might reduce tumor immunity. Changes in cysteine-methionine and GSH pathways might drive the initiation and progression of cervical cancer. These results suggest that metabolic analysis can identify ancillary biomarkers and could improve our understanding of the pathophysiological mechanisms underlying cervical neoplasia.

ARG2 knockdown promotes G0/G1 cell cycle arrest and mitochondrial dysfunction in adenomyosis via regulation NF-κB and Wnt/Β-catenin signaling cascades

BACKGROUND

Adenomyosis is a common gynecological disease, characterized by overgrowth of endometrial glands and stroma in the myometrium, however its exact pathophysiology still remains uncertain. Emerging evidence has demonstrated the elevated level of arginase 2 (ARG2) in endometriosis and adenomyosis. This study aimed to determine whether ARG2 involved in mitochondrial function and epithelial to mesenchymal transition (EMT) in adenomyosis and its potential underlying mechanisms.

MATERIALS AND METHODS

RNA interference was used to inhibit ARG2 gene, and then Cell Counting Kit (CCK-8) assay and flow cytometery were performed to detect the cell proliferation capacity, cell cycle, and apoptosis progression, respectively. The mouse adenomyosis model was established and RT-PCR, Western blot analysis, mitochondrial membrane potential (Δψm) detection and mPTP opening evaluation were conducted.

RESULTS

Silencing ARG2 effectively down-regulated its expression at the mRNA and protein levels in endometrial cells, leading to decreased enzyme activity and inhibition of cell viability. Additionally, ARG2 knockdown induced G0/G1 cell cycle arrest, promoted apoptosis, and modulated the expression of cell cycle- and apoptosis-related regulators. Notably, the interference with ARG2 induces apoptosis by mitochondrial dysfunction, ROS production, ATP depletion, decreasing the Bcl-2/Bax ratio, releasing Cytochrome c, and increasing the expression of Caspase-9/-3 and PARP. In vivo study in a mouse model of adenomyosis demonstrated also elevated levels of ARG2 and EMT markers, while siARG2 treatment reversed EMT and modulated inflammatory cytokines. Furthermore, ARG2 knockdown was found to modulate the NF-κB and Wnt/β-catenin signaling pathways in mouse adenomyosis.

CONCLUSION

Consequently, ARG2 silencing could induce apoptosis through a mitochondria-dependent pathway mediated by ROS, and G0/G1 cell cycle arrest via suppressing NF-κB and Wnt/β-catenin signaling pathways in Ishikawa cells. These findings collectively suggest that ARG2 plays a crucial role in the pathogenesis of adenomyosis and may serve as a potential target for therapeutic intervention.