Intercellular Communication Research Articles

Exosomes derived from FN14-overexpressing BMSCs activate the NF-κB signaling pathway to induce PANoptosis in osteosarcoma.

Despite advances in treatment, the prognosis of osteosarcoma (OS) patients is unsatisfactory, and searching for possible targets is substantial. Fibroblast growth factor inducible type 14 (FN14), a plasma membrane protein, is involved in wound healing, angiogenesis, proliferation, apoptosis, and inflammation. However, its implication in OS development and progression has not been completely characterized. Herein, we explored the cell-to-cell communication of bone marrow mesenchymal stem cells (BMSCs) and OS cells mediated by FN14 in the tumor microenvironment of OS. To assess the interplay between FN14 expression levels and patient survival, FN14 expression was measured in both normal and OS tissues. The FN14 overexpressing BMSCs (OE) were constructed using lentivirus, and exosomes (EXO) were extracted. The uptake of FN14-containing EXO by OS cells was analyzed via flow cytometry and in vivo fluorescence imaging. In addition, high-throughput sequencing was performed to analyze the mechanisms by which EXO inhibits OS cell growth. Finally, the therapeutic effect of OE-EXO was evaluated in a mouse model of OS xenografts. The results showcased reduced FN14 expression in human and mouse OS tissues, suggesting its role may be involved in the malignant progression of OS. The FN14 expression was higher in BMSCs relative to OS cells, and FN14 was secreted and excreted by EXO. The OS cell progression was suppressed after the uptake of FN14-derived EXO from BMSCs. In addition, RNA sequencing revealed that FN14 in EXO activated NF-κB signaling, triggering PANoptosis in OS cells. In vivo, OE-EXO injection inhibited tumor growth in OS xenografts and significantly improved the long-term survival of mice. Our findings suggest that FN14 carried by EXO from BMSCs activates the NF-κB pathway to trigger PANoptosis in OS cells, providing a potential therapeutic strategy to inhibit OS progression.

Effects of Hyaluronic Acid on Three Different Cell Types of the Periodontium in a Novel Multi-Culture Cell Plate: An Exploratory Study.

Hyaluronic acid (HA) has received considerable attention in the reconstruction of lost periodontal tissues. HA has been proposed to play a role in cell proliferation, differentiation, migration, and cell-matrix as well as cell-cell interactions. Although various studies have been conducted, further research is needed to expand our knowledge based on HA such as its effects on cell proliferation and osteogenic differentiation. The aim of this study is to assess, in single- and multi-culture plate models, the effect of HA on the proliferation, viability, and function of periodontal ligament fibroblasts, osteoblasts, and gingival epithelial cells. A novel multi-culture cell plate was chosen to simulate a cell-cell communication as close as possible to a real clinical condition in an in vitro setting. We found that HA exclusively enhanced epithelial cell proliferation, while intercellular communication stimulated the proliferation and osteogenic potential of the osteoblasts, independently from HA use. The proliferation and function of the periodontal ligament fibroblasts were not changed by HA or the cellular interplay. The use of multi-culture plates could represent a promising method to investigate and compare dental biomaterials in experiments mimicking an in vivo environment.

Evaluation of unitary conductance of gap junction channels based on stationary fluctuation analysis.

Gap junction (GJ) channels, formed of connexin (Cx) protein, enable direct intercellular communication in most vertebrate tissues. One of the key biophysical characteristics of these channels is their unitary conductance, which can be affected by mutations in Cx genes and various biochemical factors, such as posttranslational modifications. Due to the unique intercellular configuration of GJ channels, recording single-channel currents is challenging, and precise data on unitary conductances of some Cx isoforms remain limited. In this study, we applied stationary noise analysis, a method successfully used for ion channels with very low unitary conductances, to GJ channels. We modified this technique to account for the residual conductance of GJ channels and present three strategies for estimating unitary conductance, including model-based evaluation of open-state probability and subtraction of residual conductance. To assess the validity, advantages, and limitations of these approaches, we performed mathematical analysis and simulation experiments. We also addressed practical issues such as the underestimation of sample variance in autocorrelated recordings and channel rundown, proposing solutions to these issues. Finally, we applied these strategies to electrophysiological data recorded from cells expressing Cx45. Our findings showed that noise-based estimates of Cx45 unitary conductance from macroscopic currents align well with those obtained from single-channel recordings.

Glioblastoma-derived migrasomes promote migration and invasion by releasing PAK4 and LAMA4

Almost all high-grade gliomas, particularly glioblastoma (GBM), are highly migratory and aggressive. Migrasomes are organelles produced by highly migratory cells capable of mediating intercellular communication. Thus, GBM cells may produce migrasomes during migration. However, it remains unclear whether migrasomes can influence GBM migration and invasion. In this study, we observed the presence and formation of migrasomes in GBM cells. We found that expression levels of key migrasome formation factor, tetraspanin 4 (TSPAN4), correlated positively with pathological grade and poor prognosis of GBM based on the databases and clinical samples analysis. Subsequently, we knocked down TSPAN4 and found that GBM cell migration and invasion were significantly inhibited due to the reduced formation of migrasomes. We further confirmed that migrasomes are enriched in extracellular matrix (ECM)-related proteins such as p21-activating kinase 4 (PAK4) and laminin alpha 4 (LAMA4). Our experimental results suggest that migrasomes promote GBM cells migration by releasing such proteins into the extracellular space. Overall, we identified migrasomes in GBM and the molecular mechanisms by which they regulate them, providing potential targets for treating GBM.

MiR-519d-3p from Placenta-Derived Exosomes Induce Immune Intolerance Regulating Immune Cells, Contributing to the Pathogenesis of Preeclampsia

ABSTRACT Background MiR-519d-3p, also called specific placenta biomarkers, is a member of the Chromosome 19 miRNA Cluster (C19MC) with the highest concentrations of miRNAs in human placenta and maternal serum. These miRNAs are secreted by fetal trophoblast cells within extracellular vesicles (EVs) and interact with the mother’s immune cells, which has been proposed to be crucial for immunological tolerance at the placental-maternal interface. A key mechanism in preeclampsia, a multifactorial, multipath hypertensive pregnancy illness, is an immunological imbalance between the mother and the fetus. Methods Using Next Generation Sequencing, we determined that the placenta-derived Exosomes (pEXOs) of preeclamptic patients had elevated expression of miR-519. To further develop an in vitro model of trophoblast-immune cell communication, HTR-8/Svneo cells and Jurkat T cells were employed and we utilized experiments such as Western blot (WB), Real-Time Quantitative Reverse Transcription Polymerase Chain Reaction (RT-qPCR), Cell-Counting-Kit-8 (CCK-8) cell proliferation analysis, cell apoptosis analysis, and other techniques to accomplish research. Results It was discovered that miR-519d-3p in pEXOs promoted Jurkat T cell proliferation, inhibited apoptosis, and induced Jurkat T cell differentiation toward Th17. Conclusion MiR-519d-3p in pEXOs disrupts immune tolerance at the maternal-placental interface by encouraging Jurkat T cell proliferation, preventing Jurkat T cell apoptosis, and creating an imbalance in Th17/Treg differentiation. This likely leads to SIRS and unfavorable pregnancy complications like preeclampsia.

Unraveling the Connection Between Ion Channels and Pancreatic Stellate Cell Activation.

Quiescent pancreatic stellate cells (PSCs) represent only a very low proportion of the pancreatic tissue, but their activation leads to stroma remodeling and fibrosis associated with pathologies such as chronic pancreatitis and pancreatic ductal adenocarcinoma (PDAC). PSC activation can be induced by various stresses, including acidosis, growth factors (PDGF, TGFβ), hypoxia, high pressure, or intercellular communication with pancreatic cancer cells. Activated PSC targeting represents a promising therapeutic strategy, but little is known regarding the molecular mechanisms underlying the activation of PSCs. Identification of new biomarkers of PSC activation associated with desmoplasia in chronic pancreatitis and PDAC could lead to new therapeutic targets for exocrine pancreatic disease treatments. Ion channels and transporters are transmembrane proteins involved in numerous physiological and pathological processes, including PDAC. They are well known to act as biosensors of the tissue microenvironment, and they can be easily accessible for drugs. However, their role in PSC activation is not fully understood. In this review, we briefly discuss the role of activated PSCs in pancreas inflammation and pathological fibrosis (associated with chronic pancreatitis and PDAC), and we describe the role of specific ion channels and transporters (Ca2+, K+, Na+ and Cl-) in these processes in the light of recent literature.

Light-Triggered Protease-Mediated Release of Actin-Bound Cargo from Synthetic Cells.

Synthetic cells offer a versatile platform for addressing biomedical and environmental challenges, due to their modular design and capability to mimic cellular processes such as biosensing, intercellular communication, and metabolism. Constructing synthetic cells capable of stimuli-responsive secretion is vital for applications in targeted drug delivery and biosensor development. Previous attempts at engineering secretion for synthetic cells have been confined to non-specific cargo release via membrane pores, limiting the spatiotemporal precision and specificity necessary for selective secretion. Here, a protein-based platform termed TEV Protease-mediated Releasable Actin-binding Protein (TRAP) is designed and constructed for selective, rapid, and triggerable secretion in synthetic cells. TRAP is designed to bind tightly to reconstituted actin networks and is proteolytically released from bound actin, followed by secretion via cell-penetrating peptide membrane translocation. TRAP's efficacy in facilitating light-activated secretion of both fluorescent and luminescent proteins is demonstrated. By equipping synthetic cells with a controlled secretion mechanism, TRAP paves the way for the development of stimuli-responsive biomaterials, versatile synthetic cell-based biosensing systems, and therapeutic applications through the integration of synthetic cells with living cells for targeted delivery of protein therapeutics.

Microsporocytic ARF17 misexpression leads to an excess callose deposition and male sterility in Arabidopsis.

The accurate callose deposition plays important roles in pollen wall formation and pollen fertility. As a direct target of miRNA160, ARF17 participate in the formation of the callose wall. However, the impact of ARF17 misexpression in microsporocytes on callose wall formation and pollen fertility remains unknown. Here, the SDS promoter, which is capable of specifically driving gene expression in microsporocytes, was employed to drive the expression of 5mARF17. The pSDS:5mARF17#3 transgenic line were male sterile. TEM revealed that sporopollenin substance was embedded in a thicker callose layer, which resulted in the complete loss of exine structure and pollen abortion in the pSDS:5mARF17#3 line. Consistently, RT-qPCR revealed an increase in the expression of several Cals genes in pSDS:5mARF17#3. EMSA assay demonstrated that ARF17 could bind to the promoter of Cals4 gene, which further suggest that ARF17 could regulate several Cals genes expression. It is notable that the expression of several exine formation-related genes increased significantly in pSDS:5mARF17#3. In conclusion, our findings highlight that the regulation of miRNA160-ARF17 in microsporocytes modulates the thickness of the callose wall, which is crucial for pollen exine formation and intercellular communication.

Nourishment of nerves and innervation: A novel approach for the treatment of myocardial infarction.

Autonomic innervation of the heart plays a pivotal role not only in regulating the heart rate but also in modulating the cardiac cell microenvironment via cell-cell interactions and influencing the heart's repair capabilities. Currently, the primary clinical approach for treating myocardial infarction (MI) is percutaneous coronary intervention. However, the myocardial salvage rate remains low for patients with advanced disease. MI is recognized as an autonomic nervous system disorder, marked by sympathetic hyperactivity and the loss of parasympathetic nerves. Following MI, ventricular sympathetic nerve sprouting occurs, leading to an increase in ventricular sympathetic innervation and, consequently, an increased risk of ventricular arrhythmia, which is the primary cause of sudden cardiac death in patients with a history of MI. The vagus nerve positively regulates cardiomyocyte proliferation and regeneration, enhancing ventricular remodeling and cardiac function post-MI. This process is highly significant in the treatment and rehabilitation of MI. Cardiac autonomic nerves are influenced by factors such as inflammation, immunity, intercellular communication, metabolism, genetics, epigenetics, and cytokine secretion related to cardiac mesenchymal nerves. In recent years, significant advancements have been made regarding treatment for MI, specifically in the fields of autonomic nervous system therapies, stem cell and extracellular vesicle treatments, traditional Chinese medicine acupuncture and moxibustion, and peripheral electrophysiological stimulation and bioengineering materials. The balance of dominance between the sympathetic and parasympathetic nervous systems in the heart affects tissue regeneration and cardiac remodeling after MI. The secretion of neurons regulates the microenvironment of cardiac repair. The neural therapy of MI involves multiple fields such as traditional Chinese medicine, biomaterials, stem cell therapy, and drug research and development, and has broad development prospects Key Messages: The regulation exerted by the cardiac autonomic nervous system on the heart significantly influences the prognosis of MI. This involves nervous system modulation of inflammation and heart rate and complex interactions between neurons and cardiomyocytes, immune cells, fibroblasts, adipocytes, stem cells, and other cellular components. Genetic and epigenetic modifications, as well as shifts in energy metabolism, also play crucial roles.

Exosomes in Autoimmune Diseases: A Review of Mechanisms and Diagnostic Applications.

Exosomes, small extracellular vesicles secreted by various cell types, have emerged as key players in the pathophysiology of autoimmune diseases. These vesicles serve as mediators of intercellular communication, facilitating the transfer of bioactive molecules such as proteins, lipids, and nucleotide. In autoimmune diseases, exosomes have been implicated in modulating immune responses, oxidative stress, autophagy, gut microbes, and the cell cycle, contributing to disease initiation, progression, and immune dysregulation. Recent advancements in exosome isolation techniques and their molecular characterization have paved the way for exploring their clinical potential as biomarkers and therapeutic targets. This review focuses on the mechanisms by which exosomes influence autoimmune disease development and their potential clinical applications, particularly in diagnosis. The role of exosomes in autoimmune diseases, including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), type 1 diabetes mellitus (T1DM), inflammatory bowel disease (IBD), and Sjögren's syndrome (SS), is discussed in relation to their involvements in antigen presentation, T-cell activation, and the induction of inflammatory pathways. Additionally, exosome-based biomarkers offer promising non-invasive diagnostic tools for early diagnostic, disease monitoring, and therapeutic response assessment. However, challenges such as standardization of exosome isolation protocols and validation of their clinical significance remain. This review highlights the potential of exosomes as both diagnostic biomarkers and therapeutic targets in autoimmune diseases, emphasizing the need for further research to overcome current limitations and fully harness their clinical value.

Endometrial stromal cell signaling and microRNA exosome content in women with adenomyosis.

Adenomyosis is a chronic, estrogen-driven disorder characterized by the presence of endometrial glands and stroma within the myometrium. Despite its significant impact on reproductive health and quality of life, the pathogenesis of the disease remains unclear. Both the glandular and stromal compartments of eutopic endometrium from women with adenomyosis show alterations compared to healthy subjects. However, the molecular mechanisms driving crosstalk between stromal cells and epithelial glands, along with paracrine signaling underlying lesion development and progression, are still poorly understood. Exosomes, small cell-derived carriers and microRNAs, namely non-coding RNA molecules, are crucial to intercellular communication within the endometrium and may elucidate interactions between the two compartments that contribute to adenomyotic lesion formation. To our knowledge, this is the first foundational study to comprehensively isolate and characterize stroma-derived exosomes from women with adenomyosis. Exosome isolation by means of differential ultracentrifugation was validated in 22 samples, including 11 healthy subjects and 11 women with adenomyosis, using nanoparticle tracking analysis, transmission electron microscopy, and flow cytometry. Profiling of microRNA in secreted exosomes revealed 10 microRNAs with significantly altered expression in adenomyosis subjects during the menstrual phase compared to controls. Thorough investigations into menstruation-specific molecular mechanisms, as well as predicted target genes and enriched pathways of exosomal microRNAs, offer promising insights into the pathogenesis of adenomyosis, shedding light on the potential mechanisms underlying stromal cell signaling and adenomyotic lesion establishment. This work does, however, have certain drawbacks, including modest sample size and limited representation due to a lack of readily available endometrial biopsies in the menstrual phase. Having done the groundwork in this study, future research should seek to validate these findings in larger cohorts and apply functional assays. Indeed, our findings can serve as a resource to elucidate the role of menstruation-specific stroma-derived microRNA-mediated signaling and its potential impact on adenomyosis development.

Decoding the MMP14 Integrin Link: Key Player in the Secretome Landscape.

Rapid progress has been made in the exciting field of secretome research in health and disease. The tumor secretome, which is a significant proportion of the tumor proteome, is secreted into the extracellular space to promote intercellular communication and thus tumor progression. Among the many molecules of the secretome, integrins and matrix metalloproteinase 14 (MMP14) stand out as the interplay of adhesion and proteolysis drives invasion. Integrins serve as mechanosensors that mediate the contact of cells with the scaffold of the extracellular matrix and are significantly involved in the precise positioning and activity control of the membrane-bound collagenase MMP14. As a secretome proteinase, MMP14 influences and modifies the secretome itself. While integrins and MT-MMPs are membrane bound, but can be released and are therefore border crossers between the cell surface and the secretome, the extracellular matrix is not constitutively cell-bound, but its binding to integrins and other cell receptors is a stringently regulated process. To understand the mutual interactions in detail, we first summarize the structure and function of MMP14 and how it is regulated at the enzymatic and cellular level. In particular, the mutual interactions between integrins and MMP14 include the proteolytic cleavage of integrins themselves by MMP14. We then review the biochemical, cell biological and physiological effects of MMP14 on the composition and associated functions in the tumor secretome when either bound to the cell membrane, or located on extracellular microvesicles, or as a proteolytically shed non-membrane-bound ectodomain. Novel methods of proteomics, including the analysis of extravesicular vesicles, and new methods for the quantification of MMP14 will provide new research and diagnostic tools. The proteolytic modification of the tumor secretome, especially by MMP14, may bring an additional aspect to tumor secretome studies and will have an impact on the diagnosis and most likely also on the therapy of cancer patients.

Mesenchymal stem cell-derived extracellular vesicles in periodontal bone repair.

Periodontitis is a chronic inflammatory disease that destroys tooth-supporting structures and poses significant public health challenges due to its high prevalence and links to systemic health conditions. Traditional treatments are effective in reducing the inflammatory response and improving the clinical symptoms of periodontitis. However, these methods are challenging to achieve an ideal treatment effect in alveolar bone repair. Mesenchymal stem cells (MSCs) represent a potential alternative for the treatment of periodontal bone defects due to their self-renewal and differentiation capabilities. Recent research indicates that MSCs exert their effects primarily through paracrine mechanisms. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) serve as pivotal mediators in intercellular communication, transferring microRNAs (miRNAs), messenger RNAs (mRNAs), proteins, and cytokines to recipient cells, thereby emulating the therapeutic effects of MSCs. In periodontitis, MSC-EVs play a pivotal role in immunomodulation and bone remodeling, thereby facilitating periodontal bone repair. As a cell-free therapy, MSC-EVs demonstrate considerable clinical potential due to their specialized membrane structure, minimal immunogenicity, low toxicity, high biocompatibility, and nanoscale size. This review indicates that MSC-EVs represent a promising approach for periodontitis treatment, with the potential to overcome the limitations of traditional therapies and offer a more effective solution for bone repair in periodontal disease. In this review, we introduce MSC-EVs, emphasizing their mechanisms and clinical applications in periodontal bone repair. It synthesizes recent advances, existing challenges, and future prospects to present up-to-date information and novel techniques for periodontal regeneration and to guide the improvement of MSC-EV therapy in clinical practice.

Using the Key Characteristics Framework to Unlock the Mysteries of Aryl Hydrocarbon Receptor-Mediated Effects on the Immune System.

Initially discovered for its role mediating the deleterious effects of environmental contaminants, the aryl hydrocarbon receptor (AHR) is now known to be a crucial regulator of the immune system. The expanding list of AHR ligands includes synthetic and naturally derived molecules spanning pollutants, phytochemicals, pharmaceuticals, and substances derived from amino acids and microorganisms. The consequences of engaging AHR vary, depending on factors such as the AHR ligand, cell type, immune challenge, developmental state, dose, and timing of exposure relative to the immune stimulus. This review frames this complexity using the recently identified key characteristics of agents that affect immune system function (altered cell signaling, proliferation, differentiation, effector function, communication, trafficking, death, antigen presentation and processing, and tolerance). The use of these key characteristics provides a scaffold for continued discovery of how AHR and its myriad ligands influence the immune system, which will help harness the power of this enigmatic receptor to prevent or treat disease.

Advances in the regulation of the role of Myeloid-derived suppressor cells in the Tumor microenvironment by Tumor-derived exosomes

In the progression of malignancies, myeloid-derived suppressor cells (MDSCs) play a crucial role in modulating tumor immunology within the tumor microenvironment (TME), which is often characterized by the extensive infiltration of immune cells. These cells are abnormally activated and demonstrate strong immunosuppressive properties under pathological conditions such as cancer. Recent research highlights the importance of tumor-derived exosomes (TEXs) as key mediators of this immunosuppressive activity. TEXs, small extracellular vesicles released by tumor cells, carry a diverse array of bioactive molecules such as proteins, lipids, and RNA, which modulate the behavior of recipient cells within the TME. The assembly and release of TEXs are tightly regulated by the TME, and accumulating evidence suggests that TEXs facilitate MDSC activation, expansion, and enhancement of their immunosuppressive functions. This study aims to investigate the role of TEXs in mediating intercellular communication between tumor cells and MDSCs. By understanding these mechanisms, it is possible to develop strategies to regulate MDSC behavior, including promoting their differentiation into mature myeloid cells, reducing their expansion and accumulation, and impairing their suppressive activity. Ultimately, these insights will provide a foundation for targeting MDSCs as a therapeutic approach to inhibit tumor growth, invasion, and metastasis, offering promising directions for future clinical applications.

Role of Acorus calamus extract in reducing exosome secretion by targeting Rab27a and nSMase2: a therapeutic approach for breast cancer.

Exosomes are extracellular vesicles released by cells that mediate intercellular communication and actively participate in cancer progression, metastasis, and regulation of immune response within the tumour microenvironment. Inhibiting exosome release from cancer cells could be employed as a therapeutic against cancer. In the present study, we have studied the effects of Acorus calamus in inhibiting exosome secretion via targetting Rab27a and neutral sphingomyelinase 2 (nSMase2) in HER2-positive (MDA-MB-453), hormone receptor-positive (MCF-7) and triple-negative breast cancer (MDA-MB-231) cells. We observed that treatment with A. calamus significantly downregulated the expression of Rab27a and nSMase2 in all tested cells. NTA analysis showed that inhibition of Rab27a and nSMase2 reduced exosome secretion from breast cancer cells. We conducted metabolic profiling of A. calamus extract to reveal the phytochemicals present and docked them on Rab27a and nSMase2 to decipher the compounds responsible for protein inhibition. Molecular dynamic simulations were conducted on lead compounds, and we observed that calcitriol lactone showed the most stable binding interactions with nSMase2. Treatment of breast cancer cells with calcitriol lactone significantly downregulated nSMase2 expression. Our study demonstrates that A. calamus significantly inhibits exosome secretion in HER2-positive, hormone receptor-positive, and triple-negative breast cancer cells by targeting key regulatory proteins Rab27a and neutral sphingomyelinase 2 (nSMase2). These findings suggest that A. calamus holds therapeutic potential in inhibiting exosome-mediated cancer progression by targeting the exosome secretion pathway. Further investigations are warranted to explore the clinical applications of these findings in breast cancer treatment.

Effect of Kinases in Extracellular Vesicles from HIV-1-Infected Cells on Bystander Cells.

As of 2023, there were 39.9 million people living with Human Immunodeficiency Virus type 1 (HIV-1). Although great strides have been made in treatment options for HIV-1, and our understanding of the HIV-1 life cycle has vastly improved since the start of this global health crisis, a functional cure remains elusive. One of the main barriers to a cure is latency, which allows the virus to persist despite combined antiretroviral therapy (cART). Recently, we have found that exosomes, which are small, membrane-enclosed particles released by virtually all cell types and known to mediate intercellular communication, caused an increase in RNA Polymerase II loading onto the HIV-1 promoter. This resulted in the production of both short- and long-length viral transcripts in infected cells under cART. This current study examines the effects of exosome-associated kinases on bystander cells. The phospho-kinase profiling of exosomes revealed differences in the kinase payload of exosomes derived from uninfected and HIV-1-infected cells, with CDK10, GSK3β, and MAPK8 having the largest concentration differences. These kinases were shown to be biologically active and capable of phosphorylating substrates, and they modulated changes in the cell cycle dynamics of exposed cells. Given the relevance of such effects for the immune response, our results implicate exosome-associated kinases as new possible key contributors to HIV-1 pathogenesis that affect bystander cells. These findings may guide new therapeutic avenues to improve the current antiretroviral treatment regimens.

Immunometabolic alterations in type 2 diabetes mellitus revealed by single-cell RNA sequencing: insights into subtypes and therapeutic targets.

Type 2 Diabetes Mellitus (T2DM) represents a major global health challenge, marked by chronic hyperglycemia, insulin resistance, and immune system dysfunction. Immune cells, including T cells and monocytes, play a pivotal role in driving systemic inflammation in T2DM; however, the underlying single-cell mechanisms remain inadequately defined. Single-cell RNA sequencing of peripheral blood mononuclear cells (PBMCs) from 37 patients with T2DM and 11 healthy controls (HC) was conducted. Immune cell types were identified through clustering analysis, followed by differential expression and pathway analysis. Metabolic heterogeneity within T cell subpopulations was evaluated using Gene Set Variation Analysis (GSVA). Machine learning models were constructed to classify T2DM subtypes based on metabolic signatures, and T-cell-monocyte interactions were explored to assess immune crosstalk. Transcription factor (TF) activity was analyzed, and drug enrichment analysis was performed to identify potential therapeutic targets. In patients with T2DM, a marked increase in monocytes and a decrease in CD4+ T cells were observed, indicating immune dysregulation. Significant metabolic diversity within T cell subpopulations led to the classification of patients with T2DM into three distinct subtypes (A-C), with HC grouped as D. Enhanced intercellular communication, particularly through the MHC-I pathway, was evident in T2DM subtypes. Machine learning models effectively classified T2DM subtypes based on metabolic signatures, achieving an AUC > 0.84. Analysis of TF activity identified pivotal regulators, including NF-kB, STAT3, and FOXO1, associated with immune and metabolic disturbances in T2DM. Drug enrichment analysis highlighted potential therapeutic agents targeting these TFs and related pathways, including Suloctidil, Chlorpropamide, and other compounds modulating inflammatory and metabolic pathways. This study underscores significant immunometabolic dysfunction in T2DM, characterized by alterations in immune cell composition, metabolic pathways, and intercellular communication. The identification of critical TFs and the development of drug enrichment profiles highlight the potential for personalized therapeutic strategies, emphasizing the need for integrated immunological and metabolic approaches in T2DM management.

Host cell responses to Candida albicans biofilm-derived extracellular vesicles.

Candida albicans is a prevalent fungal pathogen responsible for infections in humans. As described recently, nanometer-sized extracellular vesicles (EVs) produced by C. albicans play a crucial role in the pathogenesis of infection by facilitating host inflammatory responses and intercellular communication. This study investigates the functional properties of EVs released by biofilms formed by two C. albicans strains-3147 (ATCC 10231) and SC5314-in eliciting host responses. We demonstrate the capability of C. albicans EVs to trigger reactions in human epithelial and immune cells. The involvement of EVs in pathogenesis was evidenced from the initial stages of infection, specifically in adherence to epithelial cells. We further established the capacity of these EVs to induce cytokine production in the epithelial A549 cell line, THP-1 macrophage-like cells, and blood-derived monocytes differentiated into macrophages. Internalization of EVs by THP-1 macrophage-like cells was confirmed, identifying macropinocytosis and phagocytosis as the most probable mechanisms, as demonstrated using various inhibitors that target potential vesicle uptake pathways in human cells. Additionally, C. albicans EVs and their cargo were identified as chemoattractants for blood-derived neutrophils. After verification of the in vivo effect of biofilm-derived EVs on the host, using Galleria mellonella larvae as an alternative model, it was demonstrated that vesicles from C. albicans SC5314 increased mortality in the injected larvae. In conclusion, for both types of EVs a predominantly pro-inflammatory effect on host was observed, highlighting their significant role in the inflammatory response during C. albicans infection.

Metabolically activated and highly polyfunctional intratumoral VISTA+ regulatory B cells are associated with tumor recurrence in early-stage NSCLC

B cells have emerged as central players in the tumor microenvironment (TME) of non-small cell lung cancer (NSCLC). However, although there is clear evidence for their involvement in cancer immunity, scanty data exist on the characterization of B cell phenotypes, bioenergetic profiles and possible interactions with T cells in the context of NSCLC. In this study, using polychromatic flow cytometry, mass cytometry, and spatial transcriptomics we explored the intricate landscape of B cell phenotypes, bioenergetics, and their interaction with T cells in NSCLC. Our analysis revealed that TME contains diverse B cell clusters, including VISTA+ Bregs, with distinct metabolic and functional profiles. Target liquid chromatography-tandem mass spectrometry confirmed the expression of VISTA on B cells. VISTA+ Bregs displayed high metabolic demand and were able to produce different cytokines, including interleukin (IL)-10, transforming growth factor (TGF)-β, IL-6, tumor necrosis factor (TNF), and granulocyte–macrophage colony-stimulating factor (GM-CSF). Spatial analysis showed colocalization of B cells with CD4+/CD8+ T lymphocytes in TME. The computational analysis of intercellular communications that links ligands to target genes, performed by NicheNet, predicted B-T interactions via VISTA-PSGL-1 axis. Colocalization analyses revealed that PSGL-1 T cells and VISTA+ B cells are adjacent in the TME. Notably, tumor infiltrating CD8+ T cells expressing PSGL-1 exhibited enhanced metabolism and cytotoxicity. In NSCLC patients, prediction analysis performed by PENCIL revealed the presence of an association between PSGL-1+CD8+ T cells and VISTA+ Bregs with lung recurrence. Our findings suggest a potential interaction between Bregs and T cells through the VISTA-PSGL-1 axis, that could influence NSCLC recurrence.