B cell-derived GABA elicits IL-10+ macrophages to limit anti-tumour immunity

Heterogeneity in advanced pulmonary sarcomatoid carcinoma and its efficacy to immune checkpoint inhibitors

BACKGROUND

Immune checkpoint inhibitors (ICIs) have improved the prognosis of patients with non-small cell lung cancer but rarely been explored in pulmonary sarcomatoid carcinoma (PSC). This multicenter study aimed to evaluate the effectiveness of ICIs for PSC and its underlying mechanism.

METHODS

Advanced PSC who received ICIs between August 2018 and May 2022 from 11 centers in China were included. Clinical characteristics and treatment information were collected. Whole-exome sequencing (WES) and whole transcriptome sequencing were conducted on pre-treatment samples to explore the mechanism.

RESULTS

113 patients with PSC were enrolled, the median PFS for patients receiving ICIs therapy was 8.77 months (95 % confidence interval, 4.21 to 13.32). Combining ICIs with anti-angiogenic agents significantly increased PFS (p = 0.04). Liver metastasis and combination therapy with anti-angiogenic agents were independent risk factors for PFS (Hazard Ratio [HR] = 3.652, p = 0.019 and HR = 0.435, p = 0.017, respectively). WES showed that PSC presented with a TMB of 6.3 mutations per million base pairs. High expression of TNFα signaling and glycolysis related gene showed a better prognosis.

CONCLUSIONS

ICIs showed promising benefits for advanced PSC, and the addition of anti-angiogenic therapy might be a more effective treatment strategy for this disease.

Prognostic value of a novel myeloid-to-lymphoid ratio biomarker in advanced gastric cancer

BACKGROUND

Currently, immune checkpoint inhibitors (ICIs) have excellent performance in the clinical treatment of advanced gastric cancer (AGC). However, precisely selecting AGC patients who can benefit from immunotherapy is an urgent difficulty. In this study, we investigated the immunoprognostic role of myeloid-to-lymphocyte ratio (M:L) in AGC patients.

METHODS

We collected information on 268 AGC patients who were hospitalized in the Department of Medical Oncology of PLA General Hospital from December 2014 to May 2021. The patients were divided into low M: L group (< 3.76) and high M:L group (≥ 3.76). Survival differences between different M: L level groups at baseline and after treatment were analyzed by methods such as Kaplan-Meier, Cox or Logistic regression model.

RESULTS

Progression free survival (PFS) (5.8 months vs. 3.4 months, p = 0.001) and overall survival (OS) (14.1 months vs. 9.0 months, p = 0.001) were significantly longer in the low M:L group than in the high M:L group. After analyses of Cox regression modeling it was concluded that M:L was an independent prognostic factor for PFS (HR 1.371 95%CI 1.057-1.777 p = 0.017) and OS (HR 1.352 95%CI 1.003-1.824 p = 0.048), respectively. Subsequent subgroup analyses performed across immunotherapy lines, regimens, PD-1 inhibitor agents, and age groups revealed a poorer prognosis in the high M:L group. Notably, an increase in the value of M:L after treatment significantly increased the risk of poor prognosis.

CONCLUSIONS

M:L ≥ 3.76 is associated with poor prognostic outcomes in AGC patients receiving immunotherapy and may be a predictive biomarker of prognosis. This result needs to be confirmed by larger prospective studies.

Tumor associated macrophages as key contributors and targets in current and future therapies for melanoma

INTRODUCTION

Despite the success of immunotherapies for melanoma in recent years, there remains a significant proportion of patients who do not yet derive benefit from available treatments. Immunotherapies currently licensed for clinical use target the adaptive immune system, focussing on Tcell interactions and functions. However, the most prevalent immune cells within the tumor microenvironment (TME) of melanoma are macrophages, a diverse immune cell subset displaying high plasticity, to which no current therapies are yet directly targeted. Macrophages have been shown not only to activate the adaptive immune response, and enhance cancer cell killing, but, when influenced by factors within the TME of melanoma, these cells also promote melanoma tumorigenesis and metastasis.

AREAS COVERED

We present a review of the most up-to-date literatureavailable on PubMed, focussing on studies from within the last 10 years. We also include data from ongoing and recent clinical trials targeting macrophages in melanoma listed on clinicaltrials.gov.

EXPERT OPINION

Understanding the multifaceted role of macrophages in melanoma, including their interactions with immune and cancer cells, the influence of current therapies on macrophage phenotype and functions and how macrophages could be targeted with novel treatment approaches, are all critical for improving outcomes for patients with melanoma.

The renoprotective activity of amikacin-gamma-amino butyric acid-chitosan nanoparticles: a comparative study

The development of nanoparticles (NPs) with active components with upgraded stability, and prolonged release helps in enhanced tissue regeneration. In addition, NPs are feasible strategy to boost antibiotic effectiveness and reduce drug side effects. Our study focuses on the use of amikacin (AMK) and gamma amino butyric acid (GABA) unloaded combinations or loaded on chitosan nanoparticles (CSNPs) for kidney protection. The AMK-GABA-CSNPs were prepared with the ionic gelation method, the morphology was studied using transmission electron microscopy (TEM), zetasizer and the Fourier transform-infrared spectroscopy (FT-IR) spectrum of the synthesized NPs was observed. The average size of AMK-GABA-CSNPs was 77.5 ± 16.5 nm. Zeta potential was + 38.94 ± 2.65 mV. AMK-GABA-CSNPs revealed significant in vitro antioxidant, anti-coagulation, non-hemolytic properties and good cell compatibility. To compare the effects of the unloaded AMK-GABA combination and AMK-GABA-CSNPs on the renal tissue, 42 healthy Sprague-Dawley rats were divided into seven groups. G1: normal control (NC), normal saline; G2: low-dose nephrotoxic group (LDN), AMK (20 mg/kg/day; i.p.); G3: unloaded AMK (20 mg/kg/day; i.p.) and GABA (50 mg/kg/day; i.p.); G4: AMK-GABA-CSNPs (20 mg/kg/day; i.p.); G5: high-dose nephrotoxic group (HDN), AMK (30 mg/kg/day; i.p.); G6: unloaded AMK (30 mg/kg/day; i.p.) and GABA (50 mg/kg/day; i.p.) and G7: AMK-GABA-CSNPs (30 mg/kg/day; i.p.). The results showed that AMK-GABA-CSNPs formulation is superior to unloaded AMK-GABA combination as it ameliorated kidney functions, oxidative stress and displayed a significant homeostatic role via suppression of inflammatory cytokines of Th1, Th2 and Th17 types. Hence, AMK-GABA-CSNPs could afford a potential nano-based therapeutic formula for the management of AMK-nephrotoxicity.

A GABAergic system in atrioventricular node pacemaker cells controls electrical conduction between the atria and ventricles

Physiologically, the atria contract first, followed by the ventricles, which is the prerequisite for normal blood circulation. The above phenomenon of atrioventricular sequential contraction results from the characteristically slow conduction of electrical excitation of the atrioventricular node (AVN) between the atria and the ventricles. However, it is not clear what controls the conduction of electrical excitation within AVNs. Here, we find that AVN pacemaker cells (AVNPCs) possess an intact intrinsic GABAergic system, which plays a key role in electrical conduction from the atria to the ventricles. First, along with the discovery of abundant GABA-containing vesicles under the surface membranes of AVNPCs, key elements of the GABAergic system, including GABA metabolic enzymes, GABA receptors, and GABA transporters, were identified in AVNPCs. Second, GABA synchronously elicited GABA-gated currents in AVNPCs, which significantly weakened the excitability of AVNPCs. Third, the key molecular elements of the GABAergic system markedly modulated the conductivity of electrical excitation in the AVN. Fourth, GABAA receptor deficiency in AVNPCs accelerated atrioventricular conduction, which impaired the AVN's protective potential against rapid ventricular frequency responses, increased susceptibility to lethal ventricular arrhythmias, and decreased the cardiac contractile function. Finally, interventions targeting the GABAergic system effectively prevented the occurrence and development of atrioventricular block. In summary, the endogenous GABAergic system in AVNPCs determines the slow conduction of electrical excitation within AVNs, thereby ensuring sequential atrioventricular contraction. The endogenous GABAergic system shows promise as a novel intervention target for cardiac arrhythmias.

Diversity of regulatory B cells: Markers and functions

Regulatory B cells (Bregs) are a functionally distinct B-cell subset involved in the maintenance of homeostasis and inhibition of inflammation. Studies, from the last two decades, have increased our understanding of cellular and molecular mechanisms involved in their generation, function, and to a certain extent phenotype. Current research endeavours to unravel the causes and consequences of Breg defects in disease, with increasing evidence highlighting the relevance of Bregs in promoting tumorigenic responses. Here we provide historical and emerging findings of the significance of Bregs in autoimmunity and transplantation, and how these insights have translated into the cancer field.

The significant role of amino acid metabolic reprogramming in cancer

Amino acid metabolism plays a pivotal role in tumor microenvironment, influencing various aspects of cancer progression. The metabolic reprogramming of amino acids in tumor cells is intricately linked to protein synthesis, nucleotide synthesis, modulation of signaling pathways, regulation of tumor cell metabolism, maintenance of oxidative stress homeostasis, and epigenetic modifications. Furthermore, the dysregulation of amino acid metabolism also impacts tumor microenvironment and tumor immunity. Amino acids can act as signaling molecules that modulate immune cell function and immune tolerance within the tumor microenvironment, reshaping the anti-tumor immune response and promoting immune evasion by cancer cells. Moreover, amino acid metabolism can influence the behavior of stromal cells, such as cancer-associated fibroblasts, regulate ECM remodeling and promote angiogenesis, thereby facilitating tumor growth and metastasis. Understanding the intricate interplay between amino acid metabolism and the tumor microenvironment is of crucial significance. Expanding our knowledge of the multifaceted roles of amino acid metabolism in tumor microenvironment holds significant promise for the development of more effective cancer therapies aimed at disrupting the metabolic dependencies of cancer cells and modulating the tumor microenvironment to enhance anti-tumor immune responses and inhibit tumor progression.

Decoding the spatiotemporal heterogeneity of tumor-associated macrophages

Tumor-associated macrophages (TAMs) are pivotal in cancer progression, influencing tumor growth, angiogenesis, and immune evasion. This review explores the spatial and temporal heterogeneity of TAMs within the tumor microenvironment (TME), highlighting their diverse subtypes, origins, and functions. Advanced technologies such as single-cell sequencing and spatial multi-omics have elucidated the intricate interactions between TAMs and other TME components, revealing the mechanisms behind their recruitment, polarization, and distribution. Key findings demonstrate that TAMs support tumor vascularization, promote epithelial-mesenchymal transition (EMT), and modulate extracellular matrix (ECM) remodeling, etc., thereby enhancing tumor invasiveness and metastasis. Understanding these complex dynamics offers new therapeutic targets for disrupting TAM-mediated pathways and overcoming drug resistance. This review underscores the potential of targeting TAMs to develop innovative cancer therapies, emphasizing the need for further research into their spatial characteristics and functional roles within the TME.

γ-aminobutyric acid receptor B signaling drives glioblastoma in females in an immune-dependent manner

Sex differences in immune responses impact cancer outcomes and treatment response, including in glioblastoma (GBM). However, host factors underlying sex specific immune-cancer interactions are poorly understood. Here, we identify the neurotransmitter γ-aminobutyric acid (GABA) as a driver of GBM-promoting immune response in females. We demonstrated that GABA receptor B (GABBR) signaling enhances L-Arginine metabolism and nitric oxide synthase 2 (NOS2) expression in female granulocytic myeloid-derived suppressor cells (gMDSCs). GABBR agonist and GABA analog promoted GBM growth in females in an immune-dependent manner, while GABBR inhibition reduces gMDSC NOS2 production and extends survival only in females. Furthermore, female GBM patients have enriched GABA transcriptional signatures compared to males, and the use of GABA analogs in GBM patients is associated with worse short-term outcomes only in females. Collectively, these results highlight that GABA modulates anti-tumor immune response in a sex-specific manner, supporting future assessment of GABA pathway inhibitors as part of immunotherapy approaches.

Crosstalk between the nervous system and tumor microenvironment: Functional aspects and potential therapeutic strategies

Recent advancements in understanding the tumor microenvironment (TME) have highlighted the critical role of the nervous system in cancer progression. This review comprehensively examines how the nervous system influences various aspects of tumorigenesis, including growth, motility, immune response, angiogenesis, and the behavior of cancer-associated fibroblasts (CAFs). We delineate the neurodevelopmental mechanisms associated with cancer, such as the secretion of neurotrophins and exosomes by cancer cells. Furthermore, we explore the emerging therapeutic strategy of targeting nerves associated with tumors. Evidence supporting this approach includes studies demonstrating direct tumor growth inhibition, enhanced efficacy of immunotherapy when combined with nervous system-modulating drugs, and the suppression of tumor blood vessel formation through nerve targeting. Finally, we discuss the current challenges in this field and emphasize the need for further exploration within cancer neuroscience.

The emerging role of tranexamic acid and its principal target, plasminogen, in skeletal health

The worldwide burden of skeletal diseases such as osteoporosis, degenerative joint disease and impaired fracture healing is steadily increasing. Tranexamic acid (TXA), a plasminogen inhibitor and anti-fibrinolytic agent, is used to reduce bleeding with high effectiveness and safety in major surgical procedures. With its widespread clinical application, the effects of TXA beyond anti-fibrinolysis have been noticed and prompted renewed interest in its use. Some clinical trials have characterized the effects of TXA on reducing postoperative infection rates and regulating immune responses in patients undergoing surgery. Also, several animal studies suggest potential therapeutic effects of TXA on skeletal diseases such as osteoporosis and fracture healing. Although a direct effect of TXA on the differentiation and function of bone cells in vitro was shown, few mechanisms of action have been reported. Here, we summarize recent findings of the effects of TXA on skeletal diseases and discuss the underlying plasminogen-dependent and -independent mechanisms related to bone metabolism and the immune response. We furthermore discuss potential novel indications for TXA application as a treatment strategy for skeletal diseases.

GABA-mediated inhibition of human CD4+ T cell functions is enhanced by insulin but impaired by high glucose levels

BACKGROUND

γ-aminobutyric acid (GABA), known as the main inhibitory neurotransmitter in the brain, exerts immunomodulatory functions by interaction with immune cells, including T cells. Metabolic programs of T cells are closely linked to their effector functions including proliferation, differentiation, and cytokine production. The physiological molecules glucose and insulin may provide environmental cues and guidance, but whether they coordinate to regulate GABA-mediated T cell immunomodulation is still being examined.

METHODS

CD4+ T cells that were isolated from blood samples from healthy individuals and from patients with type 1 diabetes (T1D) were activated in vitro. We carried out metabolic assays, multiple proximity extension assay (PEA), ELISA, qPCR, immunoblotting, immunofluorescence staining, flow cytometry analysis, MS-based proteomics, as well as electrophysiology and live-cell Ca2+ imaging.

FINDINGS

We demonstrate that GABA-mediated reduction of metabolic activity and the release of inflammatory proteins, including IFNγ and IL-10, were abolished in human CD4+ T cells from healthy individuals and patients with T1D when the glucose concentration was elevated above levels typically observed in healthy people. Insulin increased GABAA receptor-subunit ρ2 expression, enhanced the GABAA receptors-mediated currents and Ca2+ influx. GABA decreased, whereas insulin sustained, hexokinase activity and glycolysis in a glucose concentration-dependent manner.

INTERPRETATION

These findings support that metabolic factors, such as glucose and insulin, influence the GABA-mediated immunomodulation of human primary T cells effector functions.

FUNDING

The Swedish Children's Diabetes Foundation, The Swedish Diabetes Foundation, The Swedish Research Council 2018-02952, EXODIAB, The Ernfors Foundation, The Thurings Foundation and the Science for Life Laboratory.

Neurotransmitters: Impressive regulators of tumor progression

In contemporary times, tumors have emerged as the primary cause of mortality in the global population. Ongoing research has shed light on the significance of neurotransmitters in the regulation of tumors. It has been established that neurotransmitters play a pivotal role in tumor cell angiogenesis by triggering the transformation of stromal cells into tumor cells, modulating receptors on tumor stem cells, and even inducing immunosuppression. These actions ultimately foster the proliferation and metastasis of tumor cells. Several major neurotransmitters have been found to exert modulatory effects on tumor cells, including the ability to restrict emergency hematopoiesis and bind to receptors on the postsynaptic membrane, thereby inhibiting malignant progression. The abnormal secretion of neurotransmitters is closely associated with tumor progression, suggesting that focusing on neurotransmitters may yield unexpected breakthroughs in tumor therapy. This article presents an analysis and outlook on the potential of targeting neurotransmitters in tumor therapy.

Gamma-aminobutyric acid supplementation improves olanzapine-induced insulin resistance by inhibiting macrophage infiltration in mice subcutaneous adipose tissue

AIMS

To investigate whether gamma-aminobutyric acid (GABA) supplementation improves insulin resistance during olanzapine treatment in mice and to explore the underlying mechanisms.

MATERIALS AND METHODS

Insulin resistance and body weight gain were induced in mice by 10 weeks of olanzapine treatment. Simultaneously, the mice were administered GABA after 4 weeks of olanzapine administration.

RESULTS

We found that mice treated with olanzapine had lower GABA levels in serum and subcutaneous white adipose tissue (sWAT). GABA supplementation restored GABA levels and improved olanzapine-induced lipid metabolism disorders and insulin resistance. Chronic inflammation in adipose tissue is one of the main contributors to insulin resistance. We found that GABA supplementation inhibited olanzapine-induced adipose tissue macrophage infiltration and M1-like polarization, especially in sWAT. In vitro studies showed that stromal vascular cells, rather than adipocytes, were sensitive to GABA. Furthermore, the results suggested that GABA improves olanzapine-induced insulin resistance at least in part through a GABAB receptor-dependent pathway.

CONCLUSIONS

These findings suggest that targeting GABA may be a potential therapeutic approach for olanzapine-induced metabolic disorders.

B cells modulate lung antiviral inflammatory responses via the neurotransmitter acetylcholine

The rapid onset of innate immune defenses is critical for early control of viral replication in an infected host, yet it can also lead to irreversible tissue damage, especially in the respiratory tract. Intricate regulatory mechanisms must exist that modulate inflammation, while controlling the infection. Here, B cells expressing choline acetyl transferase (ChAT), an enzyme required for production of the metabolite and neurotransmitter acetylcholine (ACh) are identified as such regulators of the immediate early response to influenza A virus. Lung tissue ChAT + B cells are shown to interact with a7 nicotinic Ach receptor-expressing lung interstitial macrophages in mice within 24h of infection to control their production of TNFa, shifting the balance towards reduced inflammation at the cost of enhanced viral replication. Thus, innate-stimulated B cells are key participants of an immediate-early regulatory cascade that controls lung tissue damage after viral infection.

Secretome profiling reveals acute changes in oxidative stress, brain homeostasis, and coagulation following short-duration spaceflight

As spaceflight becomes more common with commercial crews, blood-based measures of crew health can guide both astronaut biomedicine and countermeasures. By profiling plasma proteins, metabolites, and extracellular vesicles/particles (EVPs) from the SpaceX Inspiration4 crew, we generated "spaceflight secretome profiles," which showed significant differences in coagulation, oxidative stress, and brain-enriched proteins. While >93% of differentially abundant proteins (DAPs) in vesicles and metabolites recovered within six months, the majority (73%) of plasma DAPs were still perturbed post-flight. Moreover, these proteomic alterations correlated better with peripheral blood mononuclear cells than whole blood, suggesting that immune cells contribute more DAPs than erythrocytes. Finally, to discern possible mechanisms leading to brain-enriched protein detection and blood-brain barrier (BBB) disruption, we examined protein changes in dissected brains of spaceflight mice, which showed increases in PECAM-1, a marker of BBB integrity. These data highlight how even short-duration spaceflight can disrupt human and murine physiology and identify spaceflight biomarkers that can guide countermeasure development.

Genomic and transcriptomic significance of multiple primary lung cancers detected by next-generation sequencing in clinical settings

Effective diagnosis and understanding of the mechanism of intrapulmonary metastasis (IM) from multiple primary lung cancers (MPLC) aid clinical management. However, the actual detection panels used in the clinic are variable. Current research on tumor microenvironment (TME) of MPLC and IM is insufficient. Therefore, additional investigation into the differential diagnosis and discrepancies in TME between two conditions is crucial. Two hundred and fourteen non-small cell lung cancer patients with multiple tumors were enrolled and 507 samples were subjected to DNA sequencing (NGS 10). Then, DNA and RNA sequencing (master panel) were performed on the specimens from 32 patients, the TME profiles between tumors within each patient and across patients and the differentially expressed genes were compared. Four patients were regrouped with NGS 10 results. Master panel resolved the classifications of six undetermined patients. The TME in MPLC exhibited a high degree of infiltration by natural killer (NK) cells, CD56dim NK cells, endothelial cells, etc., P < 0.05. Conversely, B cells, activated B cells, regulatory cells, immature dendritic cells, etc., P < 0.001, were heavily infiltrated in the IM. NECTIN4 and LILRB4 mRNA were downregulated in the MPLC (P < 0.0001). Additionally, NECTIN4 (P < 0.05) and LILRB4 were linked to improved disease-free survival in the MPLC. In conclusion, IM is screened from MPLC by pathology joint NGS 10 detections, followed by a large NGS panel for indistinguishable patients. A superior prognosis of MPLC may be associated with an immune-activating TME and the downregulation of NECTIN4 and LILRB4 considered as potential drug therapeutic targets.

GABA production induced by imipridones is a targetable and imageable metabolic alteration in diffuse midline gliomas

Diffuse midline gliomas (DMGs) are lethal primary brain tumors in children. The imipridones ONC201 and ONC206 induce mitochondrial dysfunction and have emerged as promising therapies for DMG patients. However, efficacy as monotherapy is limited, identifying a need for strategies that enhance response. Another hurdle is the lack of biomarkers that report on drug-target engagement at an early timepoint after treatment onset. Here, using 1 H-magnetic resonance spectroscopy, which is a non-invasive method of quantifying metabolite pool sizes, we show that accumulation of ψ-aminobutyric acid (GABA) is an early metabolic biomarker that can be detected within a week of ONC206 treatment, when anatomical alterations are absent, in mice bearing orthotopic xenografts. Mechanistically, imipridones activate the mitochondrial protease ClpP and upregulate the stress-responsive transcription factor ATF4. ATF4, in turn, upregulates glutamate decarboxylase, which synthesizes GABA, and downregulates ABAT , which degrades GABA, leading to GABA accumulation in DMG cells and tumors. Functionally, GABA secreted by imipridone-treated cells acts in an autocrine manner via the GABAB receptor to induce expression of superoxide dismutase (SOD1), which mitigates imipridone-induced oxidative stress and, thereby, curbs apoptosis. Importantly, blocking autocrine GABA signaling using the clinical stage GABAB receptor antagonist SGS-742 exacerbates oxidative stress and synergistically induces apoptosis in combination with imipridones in DMG cells and orthotopic tumor xenografts. Collectively, we identify GABA as a unique metabolic adaptation to imipridones that can be leveraged for non-invasive assessment of drug-target engagement and therapy. Clinical translation of our studies has the potential to enable precision metabolic therapy and imaging for DMG patients.

One Sentence Summary

Imipridones induce GABA accumulation in diffuse midline gliomas, an effect that can be leveraged for therapy and non-invasive imaging.

Increased GABA signaling in liver macrophage promotes HBV replication in HBV-carrier mice

Gamma-aminobutyric acid (GABA) signals in various non-neuronal cells including hepatocytes and some immune cells. Studies, including ours, show that type A GABA receptors (GABAARs)-mediated signaling occurs in macrophages regulating tissue-specific functions. Our recent study reveals that activation of GABAARs in liver macrophages promotes their M2-like polarization and increases HBV replication in mice. This short article briefly summarizes the GABA signaling system in macrophages and discusses potential mechanisms by which GABA signaling promotes HBV replication.

Gut microbial GABAergic signaling improves stress-associated innate immunity to respiratory viral infection

INTRODUCTION

Epidemiological evidences reveal that populations with psychological stress have an increased likelihood of respiratory viral infection involving influenza A virus (IAV) and SARS-CoV-2.

OBJECTIVES

This study aims to explore the potential correlation between psychological stress and increased susceptibility to respiratory viral infections and how this may contribute to a more severe disease progression.

METHODS

A chronic restraint stress (CRS) mouse model was used to infect IAV and estimate lung inflammation. Alveolar macrophages (AMs) were observed in the numbers, function and metabolic-epigenetic properties. To confirm the central importance of the gut microbiome in stress-exacerbated viral pneumonia, mice were conducted through microbiome depletion and gut microbiome transplantation.

RESULTS

Stress exposure induced a decline in Lactobacillaceae abundance and hence γ-aminobutyric acid (GABA) level in mice. Microbial-derived GABA was released in the peripheral and sensed by AMs via GABAAR, leading to enhanced mitochondrial metabolism and α-ketoglutarate (αKG) generation. The metabolic intermediator in turn served as the cofactor for the epigenetic regulator Tet2 to catalyze DNA hydroxymethylation and promoted the PPARγ-centered gene program underpinning survival, self-renewing, and immunoregulation of AMs. Thus, we uncover an unappreciated GABA/Tet2/PPARγ regulatory circuitry initiated by the gut microbiome to instruct distant immune cells through a metabolic-epigenetic program. Accordingly, reconstitution with GABA-producing probiotics, adoptive transferring of GABA-conditioned AMs, or resumption of pulmonary αKG level remarkably improved AMs homeostasis and alleviated severe pneumonia in stressed mice.

CONCLUSION

Together, our study identifies microbiome-derived tonic signaling tuned by psychological stress to imprint resident immune cells and defensive response in the lungs. Further studies are warranted to translate these findings, basically from murine models, into the individuals with psychiatric stress during respiratory viral infection.

New insights into immune cells in cancer immunotherapy: from epigenetic modification, metabolic modulation to cell communication

Cancer is one of the leading causes of death worldwide, and more effective ways of attacking cancer are being sought. Cancer immunotherapy is a new and effective therapeutic method after surgery, radiotherapy, chemotherapy, and targeted therapy. Cancer immunotherapy aims to kill tumor cells by stimulating or rebuilding the body's immune system, with specific efficiency and high safety. However, only few tumor patients respond to immunotherapy and due to the complex and variable characters of cancer immune escape, the behavior and regulatory mechanisms of immune cells need to be deeply explored from more dimensions. Epigenetic modifications, metabolic modulation, and cell-to-cell communication are key factors in immune cell adaptation and response to the complex tumor microenvironment. They collectively determine the state and function of immune cells through modulating gene expression, changing in energy and nutrient demands. In addition, immune cells engage in complex communication networks with other immune components, which are mediated by exosomes, cytokines, and chemokines, and are pivotal in shaping the tumor progression and therapeutic response. Understanding the interactions and combined effects of such multidimensions mechanisms in immune cell modulation is important for revealing the mechanisms of immunotherapy failure and developing new therapeutic targets and strategies.

TRPV1 inhibition suppresses non-small cell lung cancer progression by inhibiting tumour growth and enhancing the immune response

PURPOSE

TRPV1 is a nonselective Ca2+ channel protein that is widely expressed and plays an important role during the occurrence and development of many cancers. Activation of TRPV1 channels can affect tumour progression by regulating proliferation, apoptosis and migration. Some studies have also shown that activating TRPV1 can affect tumour progression by modulating tumour immunity. However, the effects of TRPV1 on the development of non-small cell lung cancer (NSCLC) have not been explored clearly.

METHOD

The Cancer Genome Atlas (TCGA) database and spatial transcriptomics datasets from 10 × Genomics were used to analyze TRPV1 expression in various tumour tissues. Cell proliferation and apoptosis were examined by cell counting kit 8 (CCK8), colony formation, and flow cytometry. Immunohistochemistry, qPCR, and western blotting were used to determine the mRNA and protein expression levels of TRPV1 and other related molecules. Tumour xenografts in BALB/C and C57BL/6J mice were used to determine the effects of TRPV1 on NSCLC development in vivo. Neurotransmitter content was examined by LC-MS/MS, ELISA and Immunohistochemistry. Immune cell infiltration was assessed by flow cytometry.

RESULTS

In this study, we found that TRPV1 expression was significantly upregulated in NSCLC and that patients with high TRPV1 expression had a poor prognosis. TRPV1 knockdown can significantly inhibit NSCLC proliferation and induce cell apoptosis through Ca2+-IGF1R signaling. In addition, TRPV1 knockdown resulted in increased infiltration of CD4+ T cells, CD8+ T cells, GZMB+CD8+ T cells and DCs and decreased infiltration of immunosuppressive MDSCs in NSCLC. In addition, TRPV1 knockout effectively decreased the expression of M2 macrophage markers CD163 and increased the expression of M1-associated, costimulatory markers CD86. Knockdown or knockout of TRPV1 significantly inhibit tumour growth and promoted an antitumour immune response through supressing γ-aminobutyric acid (GABA) secretion in NSCLC.

CONCLUSION

Our study suggests that TRPV1 acts as a tumour promoter in NSCLC, mediating pro-proliferative and anti-apoptotic effects on NSCLC through IGF1R signaling and regulating GABA release to affect the tumour immune response.

A GAD1 inhibitor suppresses osteosarcoma growth through the Wnt/β-catenin signaling pathway

Background

As a marker of the GABAergic system, the expression of glutamate decarboxylase 1 (GAD1) is mainly restricted to the central nervous system. Emerging studies have shown that aberrant expression of GAD1 in tumor tissues may promote tumor cell growth. The role of GAD1 in the development of osteosarcoma (OS) remains unclear, so this study sought to investigate the expression status of GAD1 and the effect of its specific inhibitor 3-mercaptopropionic acid (3-MPA) on OS.

Methods

The R2 database was used to analyze the relationship between the expression of GAD1 and clinical prognosis in OS patients. Immunohistochemistry was used to compare the expression profile of GAD1 between OS and matched neighboring tissues. The potential antitumor effects of 3-MPA on cell viability, colony formation and the cell cycle were examined. Moreover, the in vivo effect of 3-MPA on tumor growth was investigated using tumor-bearing nude mice.

Results

The expression level of GAD1 was aberrantly upregulated in OS tissues, but almost no expression of GAD1 was found in matched neighboring tissues. Western blotting analyses showed upregulation of GAD1 in OS cells compared to human osteoblast cells. In vitro and in vivo, 3-MPA significantly suppressed the growth of OS. Regarding the mechanism, 3-MPA inhibited β-catenin and cyclin D1 in OS cells, thereby inactivating the Wnt/β-catenin pathway.

Conclusions

OS displays increased expression of the GABAergic neuronal marker GAD1, and 3-MPA significantly reduces OS growth by inhibiting the Wnt/β-catenin pathway.

Experimental Validation and Multi-omics Analysis Identified ARPC1A as a Novel Oncogene and Potential Therapeutic Target in Glioblastoma

Actin-related protein 2/3 complex subunit 1A (ARPC1A) is implicated in several cancers due to its critical role in regulating actin polymerization. However, the exact mechanism of ARPC1A in cancer remains unclear. This study aims to investigate the biological role of ARPC1A in various cancers and the regulatory role of ARPC1A in glioblastoma multiforme (GBM). We analyzed the expression differences, prognostic value, mutations, immune infiltration, immune microenvironment, and single-cell level correlations of ARPC1A in various cancers. Furthermore, we employed gene set enrichment analysis (GSEA) and functional experiments to elucidate the regulatory mechanisms of ARPC1A on GBM. Importantly, we assessed the role of ARPC1A in temozolomide (TMZ) resistance of GBM. ARPC1A expression was up-regulated in most cancer tissues and was associated with poorer prognosis. Genomic mutation analysis revealed that the predominant type of ARPC1A mutation in tumors was amplification. ARPC1A expression was negatively correlated with B-cell and immune scores in most tumors. Both GSEA and single-cell sequencing have revealed that ARPC1A promotes tumor proliferation and epithelial-mesenchymal transition. In vitro experiments confirmed that ARPC1A knockdown inhibited the proliferation and metastatic ability of GBM cells. Notably, silencing ARPC1A reduced TMZ resistance in GBM cells. This study highlights the prognostic value of ARPC1A in various tumors and its potential for application in immunotherapy. Meanwhile, the modulation of GBM malignant behavior and TMZ resistance by ARPC1A provides a new approach for personalized and precise treatment of GBM.

Tumor infiltrating B lymphocytes (TIBs) associate with poor clinical outcomes, unfavorable therapeutic benefit and immunosuppressive context in metastatic clear cell renal cell carcinoma (mccRCC) patients treated with anti-PD-1 antibody plus Axitinib

PURPOSE

Immune checkpoint inhibitors (ICIs) plus tyrosine kinase inhibitors (TKIs) has become first-line therapy for metastatic renal cell carcinoma patients. This study aims to investigate the effect of tumor infiltrating B lymphocytes (TIBs) on the combination therapy.

METHODS

The retrospective analysis was conducted on the clinical records of 115 metastatic clear cell renal cell carcinoma (mccRCC) patients treated with anti-PD-1 antibody plus Axitinib between March 2020 and June 2023. Observation target: objective response rate (ORR), and overall survival (OS), progression-free survival (PFS) and immune profile.

RESULTS

Patients with high TIBs portended lower ORR of the combination therapy (p = 0.033). TIBs was an independent predictor for poorer OS (p = 0.013) and PFS (p = 0.021) in mccRCC patients with combination treatment. TIBs infiltration was associated with more CD4+T (p < 0.001), CD8+T (p < 0.001), M2 macrophages (p = 0.020) and regulatory T cells (Tregs) (p = 0.004). In TIBs high patients, the percentages of PD-1, CTLA-4 and TIM-3 positive rate were significantly increased in CD4+T (p = 0.038, 0.029 and 0.002 respectively) and CD8+T cells (p = 0.006, 0.026 and < 0.001 respectively).

CONCLUSIONS

Our study revealed TIBs infiltration predicted adverse outcomes in mccRCC patients treated with anti-PD-1 antibody plus Axitinib. As a corollary, TIBs positively associated with M2 macrophages and Tregs, leading to subsequent multiple immune checkpoints related exhaustion of T cells. Thus, only PD-1 blockade are inadequate to reverse T cells exhaustion effectively in high TIBs mccRCC patients.

Phytochemical Modulation of Ion Channels in Oncologic Symptomatology and Treatment

Modern chemotherapies offer a broad approach to cancer treatment but eliminate both cancer and non-cancer cells indiscriminately and, thus, are associated with a host of side effects. Advances in precision oncology have brought about new targeted therapeutics, albeit mostly limited to a subset of patients with an actionable mutation. They too come with side effects and, ultimately, 'self-resistance' to the treatment. There is recent interest in the modulation of ion channels, transmembrane proteins that regulate the flow of electrically charged molecules in and out of cells, as an approach to aid treatment of cancer. Phytochemicals have been shown to act on ion channels with high specificity regardless of the tumor's genetic profile. This paper explores the use of phytochemicals in cancer symptom management and treatment.

Prophylactic Supplementation with Lactobacillus Reuteri or Its Metabolite GABA Protects Against Acute Ischemic Cardiac Injury

The gut microbiome has emerged as a potential target for the treatment of cardiovascular disease. Ischemia/reperfusion (I/R) after myocardial infarction is a serious complication and whether certain gut bacteria can serve as a treatment option remains unclear. Lactobacillus reuteri (L. reuteri) is a well-studied probiotic that can colonize mammals including humans with known cholesterol-lowering properties and anti-inflammatory effects. Here, the prophylactic cardioprotective effects of L. reuteri or its metabolite γ-aminobutyric acid (GABA) against acute ischemic cardiac injury caused by I/R surgery are demonstrated. The prophylactic gavage of L. reuteri or GABA confers cardioprotection mainly by suppressing cardiac inflammation upon I/R. Mechanistically, GABA gavage results in a decreased number of proinflammatory macrophages in I/R hearts and GABA gavage no longer confers any cardioprotection in I/R hearts upon the clearance of macrophages. In vitro studies with LPS-stimulated bone marrow-derived macrophages (BMDM) further reveal that GABA inhibits the polarization of macrophages toward the proinflammatory M1 phenotype by inhibiting lysosomal leakage and NLRP3 inflammasome activation. Together, this study demonstrates that the prophylactic oral administration of L. reuteri or its metabolite GABA attenuates macrophage-mediated cardiac inflammation and therefore alleviates cardiac dysfunction after I/R, thus providing a new prophylactic strategy to mitigate acute ischemic cardiac injury.

Disulfiram treatment suppresses antibody-producing reactions by inhibiting macrophage activation and B cell pyrimidine metabolism

Antibody responses, involving B cells, CD4 + T cells, and macrophages, are implicated in autoimmune diseases and organ transplant rejection. We have previously shown that inhibiting FROUNT with disulfiram (DSF) suppresses macrophage activation and migration, effectively treating inflammatory diseases. In this study, we investigated the effectiveness of DSF in antibody-producing reactions. Using a heart transplantation mouse model with antibody-mediated rejection, we administered anti-CD8 antibody to exclude cellular rejection. DSF directly inhibited B cell responses in vitro and significantly reduced plasma donor-specific antibodies and graft antibody deposition in vivo, resulting in prolonged survival of the heart graft. DSF also mediated various effects, including decreased macrophage infiltration and increased Foxp3+ regulatory T-cells in the grafts. Additionally, DSF inhibited pyrimidine metabolism-related gene expression induced by B-cell stimulation. These findings demonstrate that DSF modulates antibody production in the immune response complexity by regulating B-cell and macrophage responses.

Tumor Immune Microenvironment and Its Clinicopathological and Prognostic Associations in Canine Splenic Hemangiosarcoma

Tumor cells can induce important cellular and molecular modifications in the tissue or host where they grow. The idea that the host and tumor interact with each other has led to the concept of a tumor microenvironment, composed of immune cells, stromal cells, blood vessels, and extracellular matrix, representing a unique environment participating and, in some cases, promoting cancer progression. The study of the tumor immune microenvironment, particularly focusing on the role of tumor-infiltrating lymphocytes (TILs), is highly relevant in oncology due to the prognostic and therapeutic significance of TILs in various tumors and their identification as targets for therapeutic intervention. Canine splenic hemangiosarcoma (HSA) is a common tumor; however, its immune microenvironment remains poorly understood. This retrospective study aimed to characterize the histological and immunohistochemical features of 56 cases of canine splenic HSA, focusing particularly on tumor-infiltrating lymphocytes (TILs). We assessed the correlations between the lymphocytic response, the macroscopic and histological characteristics of the tumor, and the survival data. Our study demonstrated that FoxP3 distribution was associated with tumor-related death and survival, while the CD20 count was associated with metastasis. This study provides an in-depth characterization of the tumor immune microenvironment in canine splenic HSA and describes potential prognostic factors.

Modulation of alveolar macrophage and mitochondrial fitness by medicinal plant-derived nanovesicles to mitigate acute lung injury and viral pneumonia

Acute lung injury (ALI) is generally caused by severe respiratory infection and characterized by overexuberant inflammatory responses and inefficient pathogens-containing, the two major processes wherein alveolar macrophages (AMs) play a central role. Dysfunctional mitochondria have been linked with distorted macrophages and hence lung disorders, but few treatments are currently available to correct these defects. Plant-derive nanovesicles have gained significant attention because of their therapeutic potential, but the targeting cells and the underlying mechanism remain elusive. We herein prepared the nanovesicles from Artemisia annua, a well-known medicinal plant with multiple attributes involving anti-inflammatory, anti-infection, and metabolism-regulating properties. By applying three mice models of acute lung injury caused by bacterial endotoxin, influenza A virus (IAV) and SARS-CoV-2 pseudovirus respectively, we showed that Artemisia-derived nanovesicles (ADNVs) substantially alleviated lung immunopathology and raised the survival rate of challenged mice. Macrophage depletion and adoptive transfer studies confirmed the requirement of AMs for ADNVs effects. We identified that gamma-aminobutyric acid (GABA) enclosed in the vesicles is a major molecular effector mediating the regulatory roles of ADNVs. Specifically, GABA acts on macrophages through GABA receptors, promoting mitochondrial gene programming and bioenergy generation, reducing oxidative stress and inflammatory signals, thereby enhancing the adaptability of AMs to inflammation resolution. Collectively, this study identifies a promising nanotherapeutics for alleviating lung pathology, and elucidates a mechanism whereby the canonical neurotransmitter modifies AMs and mitochondria to resume tissue homeostasis, which may have broader implications for treating critical pulmonary diseases such as COVID-19.

B cells and the stressed brain: emerging evidence of neuroimmune interactions in the context of psychosocial stress and major depression

The immune system has emerged as a key regulator of central nervous system (CNS) function in health and in disease. Importantly, improved understanding of immune contributions to mood disorders has provided novel opportunities for the treatment of debilitating stress-related mental health conditions such as major depressive disorder (MDD). Yet, the impact to, and involvement of, B lymphocytes in the response to stress is not well-understood, leaving a fundamental gap in our knowledge underlying the immune theory of depression. Several emerging clinical and preclinical findings highlight pronounced consequences for B cells in stress and MDD and may indicate key roles for B cells in modulating mood. This review will describe the clinical and foundational observations implicating B cell-psychological stress interactions, discuss potential mechanisms by which B cells may impact brain function in the context of stress and mood disorders, describe research tools that support the investigation of their neurobiological impacts, and highlight remaining research questions. The goal here is for this discussion to illuminate both the scope and limitations of our current understanding regarding the role of B cells, stress, mood, and depression.

Pancreatic β-cell failure, clinical implications, and therapeutic strategies in type 2 diabetes

ABSTRACT

Pancreatic β-cell failure due to a reduction in function and mass has been defined as a primary contributor to the progression of type 2 diabetes (T2D). Reserving insulin-producing β-cells and hence restoring insulin production are gaining attention in translational diabetes research, and β-cell replenishment has been the main focus for diabetes treatment. Significant findings in β-cell proliferation, transdifferentiation, pluripotent stem cell differentiation, and associated small molecules have served as promising strategies to regenerate β-cells. In this review, we summarize current knowledge on the mechanisms implicated in β-cell dynamic processes under physiological and diabetic conditions, in which genetic factors, age-related alterations, metabolic stresses, and compromised identity are critical factors contributing to β-cell failure in T2D. The article also focuses on recent advances in therapeutic strategies for diabetes treatment by promoting β-cell proliferation, inducing non-β-cell transdifferentiation, and reprograming stem cell differentiation. Although a significant challenge remains for each of these strategies, the recognition of the mechanisms responsible for β-cell development and mature endocrine cell plasticity and remarkable advances in the generation of exogenous β-cells from stem cells and single-cell studies pave the way for developing potential approaches to cure diabetes.

Gut microbiome-metabolites axis: A friend or foe to colorectal cancer progression

An expanding corpus of research robustly substantiates the complex interrelation between gut microbiota and the onset, progression, and metastasis of colorectal cancer. Investigations in both animal models and human subjects have consistently underscored the role of gut bacteria in a variety of metabolic activities, driven by dietary intake. These activities include amino acid metabolism, carbohydrate fermentation, and the generation and regulation of bile acids. These metabolic derivatives, in turn, have been identified as significant contributors to the progression of colorectal cancer. This thorough review meticulously explores the dynamic interaction between gut bacteria and metabolites derived from the breakdown of amino acids, fatty acid metabolism, and bile acid synthesis. Notably, bile acids have been recognized for their potential carcinogenic properties, which may expedite tumor development. Extensive research has revealed a reciprocal influence of gut microbiota on the intricate spectrum of colorectal cancer pathologies. Furthermore, strategies to modulate gut microbiota, such as dietary modifications or probiotic supplementation, may offer promising avenues for both the prevention and adjunctive treatment of colorectal cancer. Nevertheless, additional research is imperative to corroborate these findings and enhance our comprehension of the underlying mechanisms in colorectal cancer development.

The cancer-immune dialogue in the context of stress

Although there is little direct evidence supporting that stress affects cancer incidence, it does influence the evolution, dissemination and therapeutic outcomes of neoplasia, as shown in human epidemiological analyses and mouse models. The experience of and response to physiological and psychological stressors can trigger neurological and endocrine alterations, which subsequently influence malignant (stem) cells, stromal cells and immune cells in the tumour microenvironment, as well as systemic factors in the tumour macroenvironment. Importantly, stress-induced neuroendocrine changes that can regulate immune responses have been gradually uncovered. Numerous stress-associated immunomodulatory molecules (SAIMs) can reshape natural or therapy-induced antitumour responses by engaging their corresponding receptors on immune cells. Moreover, stress can cause systemic or local metabolic reprogramming and change the composition of the gastrointestinal microbiota which can indirectly modulate antitumour immunity. Here, we explore the complex circuitries that link stress to perturbations in the cancer-immune dialogue and their implications for therapeutic approaches to cancer.

Navigating the blurred path of mixed neuroimmune signaling

Evolution has created complex mechanisms to sense environmental danger and protect tissues, with the nervous and immune systems playing pivotal roles. These systems work together, coordinating local and systemic reflexes to restore homeostasis in response to tissue injury and infection. By sharing receptors and ligands, they influence the pathogenesis of various diseases. Recently, a less-explored aspect of neuroimmune communication has emerged: the release of neuropeptides from immune cells and cytokines/chemokines from sensory neurons. This article reviews evidence of this unique neuroimmune interplay and its impact on the development of allergy, inflammation, itch, and pain. We highlight the effects of this neuroimmune signaling on vital processes such as host defense, tissue repair, and inflammation resolution, providing avenues for exploration of the underlying mechanisms and therapeutic potential of this signaling.

Neuroimmune recognition and regulation in the respiratory system

Neuroimmune recognition and regulation in the respiratory system is a complex and highly coordinated process involving interactions between the nervous and immune systems to detect and respond to pathogens, pollutants and other potential hazards in the respiratory tract. This interaction helps maintain the health and integrity of the respiratory system. Therefore, understanding the complex interactions between the respiratory nervous system and immune system is critical to maintaining lung health and developing treatments for respiratory diseases. In this review, we summarise the projection distribution of different types of neurons (trigeminal nerve, glossopharyngeal nerve, vagus nerve, spinal dorsal root nerve, sympathetic nerve) in the respiratory tract. We also introduce several types of cells in the respiratory epithelium that closely interact with nerves (pulmonary neuroendocrine cells, brush cells, solitary chemosensory cells and tastebuds). These cells are primarily located at key positions in the respiratory tract, where nerves project to them, forming neuroepithelial recognition units, thus enhancing the ability of neural recognition. Furthermore, we summarise the roles played by these different neurons in sensing or responding to specific pathogens (influenza, severe acute respiratory syndrome coronavirus 2, respiratory syncytial virus, human metapneumovirus, herpes viruses, Sendai parainfluenza virus, Mycobacterium tuberculosis, Pseudomonas aeruginosa, Staphylococcus aureus, amoebae), allergens, atmospheric pollutants (smoking, exhaust pollution), and their potential roles in regulating interactions among different pathogens. We also summarise the prospects of bioelectronic medicine as a third therapeutic approach following drugs and surgery, as well as the potential mechanisms of meditation breathing as an adjunct therapy.

Periampullary cancer and neurological interactions: current understanding and future research directions

Periampullary cancer is a malignant tumor occurring around the ampullary region of the liver and pancreas, encompassing a variety of tissue types and sharing numerous biological characteristics, including interactions with the nervous system. The nervous system plays a crucial role in regulating organ development, maintaining physiological equilibrium, and ensuring life process plasticity, a role that is equally pivotal in oncology. Investigations into nerve-tumor interactions have unveiled their key part in controlling cancer progression, inhibiting anti-tumor immune responses, facilitating invasion and metastasis, and triggering neuropathic pain. Despite many mechanisms by which nerve fibers contribute to cancer advancement still being incompletely understood, the growing emphasis on the significance of nerves within the tumor microenvironment in recent years has set the stage for the development of groundbreaking therapies. This includes combining current neuroactive medications with established therapeutic protocols. This review centers on the mechanisms of Periampullary cancer's interactions with nerves, the influence of various types of nerve innervation on cancer evolution, and outlines the horizons for ongoing and forthcoming research.

A murine groin site cardiac transplantation model-applicable tool for studying roles of peripheral lymph nodes in transplantation

The murine heterotopic cardiac transplantation model has been widely used to study antigen-specific immune responses or new immunosuppressive agents, which have a strong correlation with peripheral lymph nodes. Thus, a new organ transplantation model that is applicable to related studies is needed. Here, we describe a groin-site murine heart transplantation model using a cuff technique, in which the donor aorta and pulmonary artery are anastomosed to the truncated femoral vessels of the recipient. The mean survival time (MST) of the grafts in BALB/c-to-C57BL/6 allo-transplant group was 7.2 ± 0.3 days, and 1.9 ± 0.2 days in BALB/c-to-Sprague-Dawley (SD) rat xeno-transplant group. H&E results show that donor hearts from both groups demonstrate typical pathological features at the endpoint. Evans Blue tracing revealed that the popliteal lymph nodes of the grafted side hindlimb are larger than those of the contralateral side. Moreover, IHC staining for CD3, CD20 shows that the germinal center and cortex region of the grafted side of popliteal lymph nodes is apparently increased than that of the contralateral side. To sum up, this model may serve as an ideal model to study the role of peripheral lymph nodes in organ transplant rejection. In addition, extra-peritoneal grafting makes a step forward in animal welfare under the 3Rs' principle (Replacement, Reduction, Refinement).

Perineural invasion in colorectal cancer: mechanisms of action and clinical relevance

BACKGROUND

In recent years, the significance of the nervous system in the tumor microenvironment has gained increasing attention. The bidirectional communication between nerves and cancer cells plays a critical role in tumor initiation and progression. Perineural invasion (PNI) occurs when tumor cells invade the nerve sheath and/or encircle more than 33% of the nerve circumference. PNI is a common feature in various malignancies and is associated with tumor invasion, metastasis, cancer-related pain, and unfavorable clinical outcomes. The colon and rectum are highly innervated organs, and accumulating studies support PNI as a histopathologic feature of colorectal cancer (CRC). Therefore, it is essential to investigate the role of nerves in CRC and comprehend the mechanisms of PNI to impede tumor progression and improve patient survival.

CONCLUSION

This review elucidates the clinical significance of PNI, summarizes the underlying cellular and molecular mechanisms, introduces various experimental models suitable for studying PNI, and discusses the therapeutic potential of targeting this phenomenon. By delving into the intricate interactions between nerves and tumor cells, we hope this review can provide valuable insights for the future development of CRC treatments.

Neuromedin U regulates the anti-tumor activity of CD8+ T cells and glycolysis of tumor cells in the tumor microenvironment of pancreatic ductal adenocarcinoma in an NMUR1-dependent manner

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with a poor prognosis, which is lethal in approximately 90% of cases despite advanced standard therapies. A typical feature of PDAC is the immunosuppressive tumor microenvironment with multiple immunosuppressive factors including neurotransmitters. Recently, neuromedin U (NMU), a highly conserved neuropeptide with many physiological functions, has attracted attention for its roles in tumorigenesis and metastasis in several types of cancers. However, whether NMU affects PDAC progression remains unclear. In this study, using an orthotopic mouse model of PDAC in combination with bioinformatics analysis, we found that NMU was upregulated in tumor tissues from the patients with PDAC and positively correlated with a poor prognosis of the disease. Interestingly, knockout of the Nmu gene in mice enhanced the anti-tumor functions of tumor-infiltrating CD8+ T cells in an NMU receptor 1-dependent manner. Additionally, NMU promoted the glycolytic metabolism of mouse PDAC tumors. The activities of pyruvate kinase (PK) and lactate dehydrogenase (LDH), pivotal enzymes involved in the regulation of lactate production, were markedly reduced in tumor tissues from NMU-knockout mice. In vitro the presence of LDHA inhibitor can reduce the production of lactic acid stimulated by NMU, which can increase the anti-tumor activity of CD8+ T cells. Moreover, treatment of the pancreatic cancer cells with a phosphoinositide 3-kinase (PI3K) inhibitor diminished NMU-induced lactate production and the activities of PK and LDH, suggesting that NMU might regulate glycolysis via the PI3K/AKT pathway.

Tumor Neurobiology in the Pathogenesis and Therapy of Head and Neck Cancer

The neurobiology of tumors has attracted considerable interest from clinicians and scientists and has become a multidisciplinary area of research. Neural components not only interact with tumor cells but also influence other elements within the TME, such as immune cells and vascular components, forming a polygonal relationship to synergistically facilitate tumor growth and progression. This review comprehensively summarizes the current state of the knowledge on nerve-tumor crosstalk in head and neck cancer and discusses the potential underlying mechanisms. Several mechanisms facilitating nerve-tumor crosstalk are covered, such as perineural invasion, axonogenesis, neurogenesis, neural reprogramming, and transdifferentiation, and the reciprocal interactions between the nervous and immune systems in the TME are also discussed in this review. Further understanding of the nerve-tumor crosstalk in the TME of head and neck cancer may provide new nerve-targeted treatment options and help improve clinical outcomes for patients.

Fipronil disturbs the antigen-specific immune responses and GABAergic gene expression in the ovalbumin-immunized BALB/c mice

BACKGROUND

Fipronil (FPN) is a broad-spectrum pesticide and commonly known as low toxicity to vertebrates. However, increasing evidence suggests that exposure to FPN might induce unexpected adverse effects in the liver, reproductive, and nervous systems. Until now, the influence of FPN on immune responses, especially T-cell responses has not been well examined. Our study is designed to investigate the immunotoxicity of FPN in ovalbumin (OVA)-sensitized mice. The mice were administered with FPN by oral gavage and immunized with OVA. Primary splenocytes were prepared to examine the viability and functionality of antigen-specific T cells ex vivo. The expression of T cell cytokines, upstream transcription factors, and GABAergic signaling genes was detected by qPCR.

RESULTS

Intragastric administration of FPN (1-10 mg/kg) for 11 doses did not show any significant clinical symptoms. The viability of antigen-stimulated splenocytes, the production of IL-2, IL-4, and IFN-γ by OVA-specific T cells, and the serum levels of OVA-specific IgG1 and IgG2a were significantly increased in FPN-treated groups. The expression of the GABAergic signaling genes was notably altered by FPN. The GAD67 gene was significantly decreased, while the GABAR β2 and GABAR δ were increased.

CONCLUSION

FPN disturbed antigen-specific immune responses by affecting GABAergic genes in vivo. We propose that the immunotoxic effects of FPN may enhance antigen-specific immunity by dysregulation of the negative regulation of GABAergic signaling on T cell immunity.

Tumor-derived GABA promotes lung cancer progression by influencing TAMs polarization and neovascularization

BACKGROUND

Gamma-aminobutyric acid (GABA), a common neurotransmitter, has been found in various cancers but its origin and its role in the tumor immune microenvironment remains unclear.

METHODS

Here, we reported the expression of glutamate decarboxylase 1 (GAD1, converting glutamate into GABA) in lung cancer tissues based on the publicly available database, and explored the effects and underlying mechanism of GABA on lung cancer progression.

RESULTS

Compared with normal tissues, GAD1 was aberrantly overexpressed in lung adenocarcinoma (LUAD) based on TCGA database. Furthermore, the LUAD patients' overall survival was negatively correlated with the GAD1 expression levels. Our work found that a GABAa receptor inhibitor had a therapeutic effect on mouse tumors and significantly reduced tumor size and weight. Further experiments showed that GABA derived from tumor cells promoted tumor progression not by directly affecting cancer cells but by affecting macrophages polarization in the tumor microenvironment. We found that GABA inhibited the NF-κB pathway and STAT3 pathway to prevent macrophages from polarizing towards M1 type, while promoting macrophage M2 polarization by activating the STAT6 pathway. GABA was also found to promote tumor neovascularization by increasing the expression of FGF2 in macrophages.

CONCLUSIONS

These results suggest that GABA affects tumor progression by regulating macrophage polarization, and targeting GABA and its signaling pathway may represent a potential therapy for lung cancer.

Breg-Mediated Immunoregulation in the Skin

Wound healing is a complex process involving a coordinated series of events aimed at restoring tissue integrity and function. Regulatory B cells (Bregs) are a subset of B lymphocytes that play an essential role in fine-tuning immune responses and maintaining immune homeostasis. Recent studies have suggested that Bregs are important players in cutaneous immunity. This review summarizes the current understanding of the role of Bregs in skin immunity in health and pathology, such as diabetes, psoriasis, systemic sclerosis, cutaneous lupus erythematosus, cutaneous hypersensitivity, pemphigus, and dermatomyositis. We discuss the mechanisms by which Bregs maintain tissue homeostasis in the wound microenvironment through the promotion of angiogenesis, suppression of effector cells, and induction of regulatory immune cells. We also mention the potential clinical applications of Bregs in promoting wound healing, such as the use of adoptive Breg transfer.

Metabolic reprogramming driven by EZH2 inhibition depends on cell-matrix interactions

EZH2 (Enhancer of Zeste Homolog 2), a subunit of Polycomb Repressive Complex 2 (PRC2), catalyzes the trimethylation of histone H3 at lysine 27 (H3K27me3), which represses expression of genes. It also has PRC2-independent functions, including transcriptional coactivation of oncogenes, and is frequently overexpressed in lung cancers. Clinically, EZH2 inhibition can be achieved with the FDA-approved drug EPZ-6438 (tazemetostat). To realize the full potential of EZH2 blockade, it is critical to understand how cell-cell/cell-matrix interactions present in 3D tissue and cell culture systems influences this blockade in terms of growth-related metabolic functions. Here, we show that EZH2 suppression reduced growth of human lung adenocarcinoma A549 cells in 2D cultures but stimulated growth in 3D cultures. To understand the metabolic underpinnings, we employed [13C6]-glucose stable isotope-resolved metabolomics to determine the effect of EZH2 suppression on metabolic networks in 2D versus 3D A549 cultures. The Krebs cycle, neoribogenesis, γ-aminobutyrate metabolism, and salvage synthesis of purine nucleotides were activated by EZH2 suppression in 3D spheroids but not in 2D cells, consistent with the growth effect. Using simultaneous 2H7-glucose + 13C5,15N2-Gln tracers and EPZ-6438 inhibition of H3 trimethylation, we delineated the effects on the Krebs cycle, γ-aminobutyrate metabolism, gluconeogenesis, and purine salvage to be PRC2-dependent. Furthermore, the growth/metabolic effects differed for mouse Matrigel versus self-produced A549 extracellular matrix. Thus, our findings highlight the importance of the presence and nature of extracellular matrix in studying the function of EZH2 and its inhibitors in cancer cells for modeling the in vivo outcomes.

Amino acid catabolite markers for early prognostication of pneumonia in patients with COVID-19

Effective early-stage markers for predicting which patients are at risk of developing SARS-CoV-2 infection have not been fully investigated. Here, we performed comprehensive serum metabolome analysis of a total of 83 patients from two cohorts to determine that the acceleration of amino acid catabolism within 5 days from disease onset correlated with future disease severity. Increased levels of de-aminated amino acid catabolites involved in the de novo nucleotide synthesis pathway were identified as early prognostic markers that correlated with the initial viral load. We further employed mice models of SARS-CoV2-MA10 and influenza infection to demonstrate that such de-amination of amino acids and de novo synthesis of nucleotides were associated with the abnormal proliferation of airway and vascular tissue cells in the lungs during the early stages of infection. Consequently, it can be concluded that lung parenchymal tissue remodeling in the early stages of respiratory viral infections induces systemic metabolic remodeling and that the associated key amino acid catabolites are valid predictors for excessive inflammatory response in later disease stages.

GABA induced by sleep deprivation promotes the proliferation and migration of colon tumors through miR-223-3p endogenous pathway and exosome pathway

BACKGROUND

Research has indicated that long-term sleep deprivation can lead to immune dysfunction and participate in the occurance and progression of tumors. However, the relationship between sleep deprivation and colon cancer remains unclear. This study explored the specific mechanism through which sleep deprivation promotes the proliferation and migration of colon cancer, with a focus on the neurotransmitter GABA.

METHODS

Chronic sleep deprivation mice model were used to investigate the effect of sleep disorder on tumors. We detected neurotransmitter levels in the peripheral blood of mice using ELISA. CCK-8 assay, colony formation assay, wound healing assay, and transwell assay were performed to investigate the effect of GABA on colon cancer cells, while immunofluorescence showed the distribution of macrophages in lung metastatic tissues. We isolated exosomes from a GABA-induced culture medium to explore the effects of GABA-induced colon cancer cells on macrophages. Gain- and loss-of-function experiments, luciferase report analysis, immunohistochemistry, and cytokine detection were performed to reveal the crosstalk between colon cancer cells and macrophages.

RESULTS

Sleep deprivation promote peripheral blood GABA level and colon cancer cell proliferation and migration. Immunofluorescence analysis revealed that GABA-induced colon cancer metastasis is associated with enhanced recruitment of macrophages in the lungs. The co-culture results showed that GABA intensified M2 polarization of macrophage induced by colon cancer cells. This effect is due to the activation of the macrophage MAPK pathway by tumor-derived exosomal miR-223-3p. Furthermore, M2-like macrophages promote tumor proliferation and migration by secreting IL-17. We also identified an endogenous miR-223-3p downregulation of the E3 ligase CBLB, which enhances the stability of cMYC protein and augments colon cancer cells proliferation and migration ability. Notably, cMYC acts as a transcription factor and can also regulate the expression of miR-223-3p.

CONCLUSION

Our results suggest that sleep deprivation can promote the expression of miR-223-3p in colon cancer cells through GABA, leading to downregulation of the E3 ligase CBLB and inhibition of cMYC ubiquitination. Simultaneously, extracellular miR-223-3p promotes M2-like macrophage polarization, which leads to the secretion of IL-17, further enhancing the proliferation and migration of colon cancer cells.

Magnaporthe oryzae effector MoSPAB1 directly activates rice Bsr-d1 expression to facilitate pathogenesis

Fungal pathogens typically use secreted effector proteins to suppress host immune activators to facilitate invasion. However, there is rarely evidence supporting the idea that fungal secretory proteins contribute to pathogenesis by transactivating host genes that suppress defense. We previously found that pathogen Magnaporthe oryzae induces rice Bsr-d1 to facilitate infection and hypothesized that a fungal effector mediates this induction. Here, we report that MoSPAB1 secreted by M. oryzae directly binds to the Bsr-d1 promoter to induce its expression, facilitating pathogenesis. Amino acids 103-123 of MoSPAB1 are required for its binding to the Bsr-d1 promoter. Both MoSPAB1 and rice MYBS1 compete for binding to the Bsr-d1 promoter to regulate Bsr-d1 expression. Furthermore, MoSPAB1 homologues are highly conserved among fungi. In particular, Colletotrichum fructicola CfSPAB1 and Colletotrichum sublineola CsSPAB1 activate kiwifruit AcBsr-d1 and sorghum SbBsr-d1 respectively, to facilitate pathogenesis. Taken together, our findings reveal a conserved module that may be widely utilized by fungi to enhance pathogenesis.

CD24hiCD27+ Bregs within Metastatic Lymph Nodes Promote Multidrug Resistance in Breast Cancer

PURPOSE

Axillary lymph nodes (LN) are the primary and dominant metastatic sites in breast cancer. However, the interaction between tumor cells and immune cells within metastatic LNs (mLN) remains poorly understood. In our study, we explored the effect of CD24hiCD27+ regulatory B cells (Breg) within mLNs on orchestrating drug resistance of breast cancer cells.

EXPERIMENTAL DESIGN

We collected mLN samples from patients with breast cancer who had received standard neoadjuvant therapy (NAT) and analyzed the spatial features of CD24hiCD27+ Bregs through multicolor immunofluorescence staining. The effect of CD24hiCD27+ Bregs on drug resistance of breast cancer cells was evaluated via in vitro experiments. A mouse model with mLNs was used to evaluate the strategies with blocking the interactions between Bregs and breast cancer for improving tumor regression within mLNs.

RESULTS

In patients with breast cancer who had received NAT, there is a close spatial correlation between activated CD24hiCD27+ Bregs and residual tumor cells within mLNs. Mechanistically, CD24hiCD27+ Bregs greatly enhance the acquisition of multidrug resistance and stem-like features of breast cancer cells by secreting IL6 and TNFα. More importantly, breast cancer cells further promote the activation of CD24hiCD27+ Bregs via CD40L-dependent and PD-L1-dependent proximal signals, forming a positive feedback pattern. PD-L1 blockade significantly attenuates the drug resistance of breast cancer cells induced by CD24hiCD27+ Bregs, and addition of anti-PD-L1 antibody to chemotherapy improves tumor cell remission in mLNs.

CONCLUSIONS

Our study reveals the pivotal role of CD24hiCD27+ Bregs in promoting drug resistance by interacting with breast cancer cells in mLNs, providing novel evidence for an improved strategy of chemoimmunotherapy combination for patients with breast cancer with mLNs.