Mast Cells Research Articles

Enhanced joint pain in diabetic patients with knee osteoarthritis is associated with increased synovitis, synovial immune cell infiltration, and erythrocyte extravasation.

Diabetes mellitus (DM) is an important risk factor for the development of osteoarthritis (OA), increasing OA progression and OA pain. To gain insight into the underlying mechanisms of how DM exacerbates OA processes and OA pain, this study analyzed histological differences of synovial tissues from non-DM and DM patients with OA and correlated these differences with knee pain severity. Synovial tissue was obtained from 12 non-DM and 10 DM patients with advanced knee OA who underwent total knee arthroplasty. Synovial inflammation was assessed using the Synovitis score developed by Krenn. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was used to assess knee pain intensity and disability in OA patients. The number of mast cells, macrophages, nerve fibers, capillaries, larger vessels and erythrocyte extravasation were analyzed microscopically in histological and immunostained synovial sections from non-DM and DM patients. Association analyses were performed to determine associations between OA knee pain and synovial changes affected by DM. Synovial tissue from OA patients with DM had a higher synovitis score, more erythrocyte extravasation, and contained higher numbers of mast cells and macrophages compared to non-DM patients. The number of capillaries and vessels in the lining/sublining layer of the synovial tissue was reduced in DM patients. OA patients with DM had more severe knee pain compared to non-DM patients. The KOOS pain score was associated with the synovitis score, the number of tissue macrophages, and the number of mast cells in the synovial tissue (adjusted for age, sex, and BMI). In addition, the erythrocyte extravasation score was associated with the KOOS pain score and with the synovitis score. The study suggests that increased OA progression and pain severity in patients with DM result from more pronounced synovitis and synovial vascular leakage and increased infiltration of macrophages and mast cells.

Integrated machine learning and Mendelian randomization reveal PALMD as a prognostic biomarker for nonspecific orbital inflammation

Background: Nonspecific Orbital Inflammation (NSOI) remains a perplexing enigma among proliferative inflammatory disorders. Its etiology is idiopathic, characterized by distinctive and polymorphous lymphoid infiltration within the orbital region. Preliminary investigations suggest that PALMD localizes within the cytosol, potentially playing a crucial role in cellular processes, including plasma membrane dynamics and myogenic differentiation. The potential of PALMD as a biomarker for NSOI warrants meticulous exploration. Methods: PALMD was identified through the intersection analysis of common DEGs from datasets GSE58331 and GSE105149 from the GEO database, alongside immune-related gene lists from the ImmPort database, using Lasso regression and SVM-RFE analysis. GSEA and GSVA were conducted with gene sets co-expressed with PALMD. To further investigate the correlation between PALMD and immune-related biological processes, the CIBERSORT algorithm and ESTIMATE method were employed to evaluate immune microenvironment characteristics of each sample. The expression levels of PALMD were subsequently validated using GSE105149. Results: Among the 314 DEGs identified, several showed significant differences. Lasso and SVM-RFE algorithms pinpointed 15 hub genes. Functional analysis of PALMD emphasized its involvement in cell-cell adhesion, leukocyte migration, and leukocyte-mediated immunity. Enrichment analysis revealed that gene sets positively correlated with PALMD were enriched in immune-related pathways. Immune infiltration analysis indicated that resting dendritic cells, resting mast cells, activated NK cells, and plasma cells positively associate with PALMD expression. Conversely, naive B cells, activated dendritic cells, M0 and M1 macrophages, activated mast cells, activated CD4 memory T cells, and naive CD4 T cells showed a negative correlation with PALMD expression. PALMD demonstrated significant diagnostic potential in differentiating NSOI. Conclusions: This study identifies PALMD as a potential biomarker linked to NSOI, providing insights into its pathogenesis and offering new avenues for tracking disease progression.

Optimizing Siglec-8-Directed Immunotherapy for Eosinophilic and Mast Cell Disorders

Background/Objective: Current treatments for eosinophilic and mast cell disorders are often ineffective. One promising target to improve outcomes is sialic acid-binding immunoglobulin-like lectin-8 (Siglec-8). As limitations, there are few Siglec-8 monoclonal antibodies (mAbs) available to date, and Siglec-8-directed treatments have so far primarily focused on unconjugated mAbs, which may be inadequate, especially against mast cells. Methods: Here, we used transgenic mice to raise a diverse panel of fully human mAbs that either recognize the V-set domain, membrane-distal C2-set domain, or membrane-proximal C2-set domain of full-length Siglec-8 as a basis for novel therapeutics. Results: All mAbs were efficiently internalized into Siglec-8-expressing cells, suggesting their potential to deliver cytotoxic payloads. Tool T cell-engaging bispecific antibodies (BiAbs) and chimeric antigen receptor (CAR)-modified natural killer (NK) cells using single-chain variable fragments from Siglec-8 mAbs showed highly potent cytolytic activity against Siglec-8-positive cells even in cases of very low target antigen abundance, whereas they elicited no cytolytic activity against Siglec-8-negative target cells. Siglec-8V-set-directed T cell-engaging BiAbs and Siglec-8V-set-directed CAR-modified NK cells induced substantially greater cytotoxicity against cells expressing an artificial smaller Siglec-8 variant containing only the V-set domain than cells expressing full-length Siglec-8, consistent with the notion that targeting membrane-proximal epitopes enhances effector functions of Siglec-8 antibody-based therapeutics. Indeed, unconjugated Siglec-8C2-set mAbs, Siglec-8C2-set-directed T cell-engaging BiAbs, and Siglec-8C2-set-directed CAR-modified NK cells showed high antigen-specific cytolytic activity against Siglec-8-positive human cell lines and primary patient eosinophils. Conclusions: Together, these data demonstrate Siglec-8-directed immunotherapies can be highly potent, supporting their further development for eosinophilic and mast cell disorders.

Short-term influence of Immufen™ on mild allergic rhinitis: a randomized, double-blind, placebo-controlled study.

Allergic rhinitis (AR) is an IgE-mediated reaction to inhaled allergens, and is a prominent health concern affecting approximately 400 million people worldwide. A comprehensive understanding of AR's pathophysiology is imperative for developing novel therapies, especially considering its frequent co-morbidity with asthma and conjunctivitis. The escalating prevalence of AR is correlated with increased urbanization and environmental pollutants, recognized as prominent contributing factors. Dysregulation in immune networks, Th1/Th2 cytokine imbalance, activation of mast cells and eosinophils are implicated in AR progression. Classic AR symptoms include nasal congestion, nasal itching, rhinorrhea, and sneezing which significantly impact the quality of life, social interactions, and workplace productivity. This randomized, double-blind, placebo-controlled, three-arm, three-sequence study was aimed to assess the efficacy of supplementation of a co-delivery form of turmeric extract with ashwagandha extract (CQAB) in comparison with a bioavailable curcumin (CGM) and placebo in alleviating AR symptoms and enhancing the quality of life in individuals with mild AR. Participants received either placebo, CGM, or CQAB twice/day for 28 days, and subjective measures were recorded at the baseline and at the end of study. CQAB supplementation demonstrated a significant (P < 0.05) improvement in Total Nasal Symptom Score (TNSS) compared to placebo and CGM. Furthermore, CQAB administration resulted in enhanced sleep quality (P < 0.05) as evaluated by the BIS questionnaire, heightened energy levels, and decreased fatigue and overall mood disturbance (POMS-SF) compared to both placebo and CGM. The results suggests that CQAB has the potential to be used as a dietary supplement in alleviating AR discomforts. https://ctri.nic.in/Clinicaltrials/login.php; Identifier CTRI/2021/01/030355.

Identification of novel biomarkers for atherosclerosis using single-cell RNA sequencing and machine learning.

Atherosclerosis (AS) is a predominant etiological factor in numerous cardiovascular diseases, with its associated complications such as myocardial infarction and stroke serving as major contributors to worldwide mortality rates. Here, we devised dependable AS-related biomarkers through the utilization of single-cell RNA sequencing, weighted co-expression network (WGCNA), and differential expression analysis. Furthermore, we employed various machine learning techniques (LASSO and SVM-RFE) to enhance the identification of AS biomarkers, subsequently validating them using the GEO dataset. Following this, CIBERSORT was employed to investigate the correlation between biomarkers and infiltrating immune cells. Consequently, 256 differentially expressed genes (DEGs) were selected in samples of AS and normal. GO and KEGG analyses indicated that these DEGs may be related to the negative regulation of leukocyte-mediated immunity, leukocyte cell-cell adhesion, and immune system processes. Notably, C1QC and COL1A1 were pinpointed as potential diagnostic markers for AS, a finding that was further validated in the GSE21545 dataset. Moreover, the area under the curve (AUC) values for these markers exceeded 0.8, underscoring their diagnostic utility. Analysis of immune cell infiltration revealed that the expression of C1QC was correlated with M0 macrophages, gamma delta T cells, activated mast cells and memory B cells. Similarly, COL1A1 expression was linked to M0 macrophages, memory B cells, activated mast cells, gamma delta T cells, and CD4 native T cells. Finally, these results were validated using mice and human samples through immunofluorescence, immunohistochemistry, and ELISA analysis. Overall, C1QC and COL1A1 would be potential biomarkers for AS diagnosis, and that would provides novel perspectives on the diagnosis and treatment of AS.

The Role of Mast Cells in the Remodeling Effects of Molecular Hydrogen on the Lung Local Tissue Microenvironment under Simulated Pulmonary Hypertension

Molecular hydrogen (H2) has antioxidant, anti-inflammatory, and anti-fibrotic effects. In a rat model simulating pulmonary fibrotic changes induced by monocrotaline-induced pulmonary hypertension (MPH), we had previously explored the impact of inhaled H2 on lung inflammation and blood pressure. In this study, we further focused the biological effects of H2 on mast cells (MCs) and the parameters of the fibrotic phenotype of the local tissue microenvironment. MPH resulted in a significantly increased number of MCs in both the pneumatic and respiratory parts of the lungs, an increased number of tryptase-positive MCs with increased expression of TGF-β, activated interaction with immunocompetent cells (macrophages and plasma cells) and fibroblasts, and increased MC colocalization with a fibrous component of the extracellular matrix of connective tissue. The alteration in the properties of the MC population occurred together with intensified collagen fibrillogenesis and an increase in the integral volume of collagen and elastic fibers of the extracellular matrix of the pulmonary connective tissue. The exposure of H2 together with monocrotaline (MCT), despite individual differences between animals, tended to decrease the intrapulmonary MC population and the severity of the fibrotic phenotype of the local tissue microenvironment compared to changes in animals exposed to the MCT effect alone. In addition, the activity of collagen fibrillogenesis associated with MCs and the expression of TGF-β and tryptase in MCs decreased, accompanied by a reduction in the absolute and relative content of reticular and elastic fibers in the lung stroma. Thus, with MCT exposure, inhaled H2 has antifibrotic effects involving MCs in the lungs of rats. This reveals the unknown development mechanisms of the biological effects of H2 on the remodeling features of the extracellular matrix under inflammatory background conditions of the tissue microenvironment.

Evolutionary engineering of methylotrophic E. coli enables fast growth on methanol

As methanol can be derived from either CO2 or methane, methanol economy can play an important role in combating climate change. In this scenario, rapid utilization of methanol by an industrial microorganism is the first and crucial step for efficient utilization of the C1 feedstock chemical. Here, we report the development of a methylotrophic E. coli strain with a doubling time of 3.5 hours under optimal conditions, comparable or faster than native model methylotrophs Methylorubrum extorquens AM1 (Td~4hr) and Bacillus methanolicus at 37°C (Td~5hr). To accomplish this, we develop a bacterial artificial chromosome (BAC) with dynamic copy number variation (CNV) to facilitate overcoming the formaldehyde-induced DNA-protein cross-linking (DPC) problem in the evolution process. We track the genome variations of 75 cultures along the evolution process by next-generation sequencing, and identified the features of the fast-growing strain. After stabilization, the final strain (SM8) grows to 20 g/L of cell mass within 77 hrs in a bioreactor. This study illustrates the potential of dynamic CNV as an evolution tool and synthetic methylotrophs as a platform for sustainable biotechnological applications.

CREB Is Critically Implicated in Skin Mast Cell Degranulation Elicited via FcεRI and MRGPRX2.

Skin mast cells (MCs) mediate acute allergic reactions in the cutaneous environment and contribute to chronic dermatoses, including urticaria, and atopic or contact dermatitis. The cAMP response element binding protein (CREB), an evolutionarily well conserved transcription factor (TF) with over 4,000 binding sites in the genome, was recently found to form a feedforward loop with KIT, maintaining MC survival. The most selective MC function is degranulation with its acute release of prestored mediators. Herein, we asked whether CREB contributes to the expression and function of the degranulation-competent receptors FcεRI and MRGPRX2. Interference with CREB by pharmacological inhibition (CREBi, 666-15) or RNA interference only slightly affected the expression of these receptors, while KIT was strongly attenuated. Interestingly, MRGPRX2 surface expression moderately increased following CREB-knockdown, whereas MRGPRX2-dependent exocytosis simultaneously decreased. FcεRI expression and function were regulated consistently, although the effect was stronger at the functional level. Preformed MC mediators (tryptase, histamine, β-hexosaminidase) remained comparable following CREB attenuation, suggesting that granule synthesis did not rely on CREB function. Collectively, in contrast to KIT, FcεRI and MRGPRX2 moderately depend on unperturbed CREB function. Nevertheless, CREB is required to maintain MC releasability irrespective of stimulus, insinuating that CREB may operate by safeguarding the degranulation machinery. To our knowledge, CREB is the first factor identified to regulate MRGPRX2 expression and function in opposite direction. Overall, the ancient TF is an indispensable component of skin MCs, orchestrating not only survival and proliferation but also their secretory competence.

On the pathogenesis of COVID-19: the role of transforming growth factor beta

Proteins of the transforming growth factor beta (TGF-β) family regulate numerous cellular processes that are essential in the pathogenesis of acute respiratory distress syndrome (ARDS), contributing to increased alveolar epithelial permeability, activation of fibroblasts, and extracellular matrix remodeling. TGF-β is involved in the pathogenesis of inflammatory respiratory diseases during the development of COVID-19. SARS-CoV-2 leads to complex immune responses that include the release of inflammatory cytokines, increased activity of mast cells, and the release of mast cell secretome, in particular profibrotic enzymes and cytokines, including TGF-β.Tryptaseand chymase-positive mast cells play a major role in pulmonary fibrosis and embolism in COVID-19. Mast cell chymase is angiotensin-converting enzyme 2-independent due to extracellular formation of angiotensin II in the interstitium; it also activates TGF-β and other molecules, thereby playing a role in tissue remodeling. Mast cell β-tryptase increases the secretion of TGF-β1 by airway smooth muscle tissue and the expression of α-smooth muscle actin (α-SMA). TGF-β also induces the generation of mitochondrial reactive oxygen species (ROS), which enhances the production of ROS in lung fibroblasts. TGF-β is crucial for induing the synthesis of extracellular matrix components by fibroblasts.The review is devoted to the structure of TGF-β, the sources of its secretion and functions, the mechanism of its involvement in the pathogenesis of COVID-19, and the possibility of its use as a prognostic marker of COVID-19 severity.

Mitochondrial regulation in the tumor microenvironment: targeting mitochondria for immunotherapy

Mitochondrial regulation plays a crucial role in cancer immunity in the tumor microenvironment (TME). Infiltrating immune cells, including T cells, natural killer (NK) cells, and macrophages, undergo mitochondrial metabolic reprogramming to survive the harsh conditions of the TME and enhance their antitumor activity. On the other hand, immunosuppressive cells like myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs), mast cells, and tumor-associated macrophages (TAMs) rely on mitochondrial regulation to maintain their function as well. Additionally, mitochondrial regulation of cancer cells facilitates immune evasion and even hijacks mitochondria from immune cells to enhance their function. Recent studies suggest that targeting mitochondria can synergistically reduce cancer progression, especially when combined with traditional cancer therapies and immune checkpoint inhibitors. Many mitochondrial-targeting drugs are currently in clinical trials and have the potential to enhance the efficacy of immunotherapy. This mini review highlights the critical role of mitochondrial regulation in cancer immunity and provides lists of mitochondrial targeting drugs that have potential to enhance the efficacy of cancer immunotherapy.

Identification of neutrophil extracellular traps genes as potential biomarkers in psoriasis based on bioinformatics analysis

The epidermal infiltration of neutrophils is a hallmark of psoriasis (PSO) and its activation leads to the release of neutrophil extracellular traps (NETs). However, the molecular mechanism of NETs-related genes (NETRGs) has not been extensively studied in PSO. To define NETs-related-biomarkers for PSO. The GSE13355 and GSE78097 datasets, and NETRGs gene set were included in this study. The datasets used in this study were all microarray data. The weighted gene co-expression network analysis (WGCNA) and machine learning algorithms were used to mine key genes. Later on, single-gene gene set enrichment analysis (GSEA) and immune infiltration analysis were implemented. Finally, the expression of key genes was verified using quantitative real-time fluorescence PCR (qRT-PCR). A total of 3 key genes (S100A9, CLEC7A, and CXCR4) were derived, and they all had excellent diagnostic performance. The single-gene GSEA enrichment results indicated that the key genes were mainly enriched in the chemokine signaling pathway and humoral immune response in the high-expression group, while focal adhesion was enriched in the low-expression group. The correlation analysis indicated that all key genes were strongly negatively correlated with resting mast cells and TGF-β family member receptor, while they were strongly positively correlated with activated CD4 memory T cells and antigen processing and presentation. Lastly, the experimental results showed that the expression trends of key genes were consistent with public database. In this study, we successfully screened three potential PSO diagnostic genes (S100A9, CLEC7A and CXCR4) that were closely related to NETs, and these findings not only provided new molecular marker candidates for the precise diagnosis of PSO patients, but also revealed possible future therapeutic targets. However, further in-depth research and validation were necessary.

Evidence of IL-17-secreting mast cells in scalp lesions of folliculitis decalvans points to new therapeutic targets in recalcitrant lesions.

Folliculitis decalvans (FD) is a chronic neutrophilic scarring alopecia which exact pathogenesis remains unknown. The recent report on the successful use of a novel anti-IL17 biologic agent in FD and the presence of IL-17-secreting mast cells in other types of scarring alopecias point to a distinct pathogenic mechanism in this disease. Our aim was to study and correlate the expression of IL-17 and mast cells in lesional and non-lesional FD scalp, using immunohistochemical techniques. Increased expression in IL-17 and mast cells was found in lesional scalp compared to non-lesional scalp areas (p<.05). A significant positive correlation between IL-17 and Mast cell Tryptase immunolabeling in non-lesional scalp (r=.64) highlights the role of IL-17-secreting mast cells in "normal-appearing" sites of FD. These findings suggest that targeting both IL-17 and mast cells may be potentially beneficial to better control the chronic inflammatory status of the disease specially in recalcitrant cases of FD.

Ursolic acid attenuates pseudo-allergic reactions via reducing MRGPRX2-mediated mast cell degranulation

Mas-related G protein–coupled receptor X2 (MRGPRX2) is a newly identified receptor on mast cells that contribute to IgE-independent pseudo-allergy. Ursolic acid (UA), a pentacyclic triterpenoid, has been reported for its anti-allergy effects. However, the protective mechanism against pseudo-allergic reactions remains unclear. This study aims to investigate the effects of UA on pseudo-allergic reactions both in vivo and in vitro, focusing on the therapeutical mechanism underlying its effect on mast cells. In present study, UA reduced degranulation and chemokines production induced by MRGPRX2 agonists, including compound 48/80 (C48/80) and substance P (SP), in LAD2 cells in vitro. UA also alleviated C48/80 and SP-induced systemic anaphylaxis and passive cutaneous anaphylaxis (PCA) in vivo. Furthermore, UA demonstrated strong binding affinity to the MRGPRX2 protein, leading to a decrease in calcium influx in both LAD2 cells and MRGPRX2-HEK293 cells stimulated with C48/80 and SP. Moreover, UA effectively suppressed phosphorylation levels within phospholipase C-γ (PLCγ) pathway and nuclear factor kappa-B (NF-κB) pathway of MRGPRX2 downstream proteins. Our findings indicated that UA exerts an attenuating effect in pseudo-allergic reactions by suppressing MRGPRX2-mediated mast cell activation, targeting PLCγ pathway and NF-κB pathway. These results suggest that UA may serve as a promising therapeutic agent for MRGPRX2-dependent pseudo-allergic reactions.

Investigation of the Theragnostic Role of KIT Expression for the Treatment of Canine Mast Cell Tumors with Tyrosine Kinase Inhibitors.

Several reports have indicated that canine MCTs express a mutated form of a tyrosine kinase receptor, namely KIT, that is involved in abnormal mast cell growth and differentiation. Currently, the post-surgical prognosis for MCTs is related to three different KIT immunohistochemical expression patterns. However, to our knowledge, there are few studies specifically exploring the efficacy of treatment with tyrosine kinase inhibitors related to KIT staining pattern. The purpose of this study was to investigate the potential theragnostic role of KIT expression patterns by studying their correlation to the overall survival and progression-free survival in dogs treated with only tyrosine kinase inhibitors immediately after surgery. We selected 66 cases of canine cutaneous MCTs with complete clinical background. A statistical analysis was performed to assess the overall survival status. Our data suggest an important role of KIT in the etiopathogenesis of canine MCTs and indicate that the anomalous cytoplasmatic distribution of KIT is potentially related to a lower efficacy of tyrosine kinase inhibitors, thus providing a significant prognostic information about the treatment outcome.

Detection of KIT Mutations in Systemic Mastocytosis: How, When, and Why.

More than 90% of patients affected by mastocytosis are characterized by a somatic point mutation of KIT, which induces ligand-independent activation of the receptor and downstream signal triggering, ultimately leading to mast cell accumulation and survival. The most frequent mutation is KIT p.D816V, but other rarer mutations can also be found. These mutations often have a very low variant allele frequency (VAF), well below the sensitivity of common next-generation sequencing (NGS) methods used in routine diagnostic panels. Highly sensitive methods are developing for detecting mutations. This review summarizes the current indications on the recommended methods and on how to manage and interpret molecular data for the diagnosis and follow-up of patients with mastocytosis.

Unveiling ficolins: diagnostic and prognostic biomarkers linked to the Tumor Microenvironment in Lung Cancer

BackgroundFicolins (FCNs) are a family of proteins, comprising FCN1, FCN2 and FCN3, and integral to the immune system which have been implicated in the onset and progression of tumors. Despite their recognized roles, a comprehensive analysis of FCNs in lung cancer remains elusive.MethodsWe employed a variety of bioinformatics tools, including UCSC, SangerBox, Ualcan, cBioPortal, String, Metascape, GeneMANIA, TIDE, CTD, and CAMP databases to investigate the differential expression, diagnostic and prognostic significance, genetic alterations, functional enrichment, immune infiltration, and potential immunotherapeutic implications of FCN1, FCN2, and FCN3 in lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD). Additionally, RT-qPCR and immunohistochemistry were utilized to validate the expressions of FCNs at the mRNA and protein levels in LUSC and LUAD.ResultsOur comprehensive bioinformatic analysis, supported by RT-qPCR and immunohistochemistry, revealed that the expressions of FCN1, FCN2 and FCN3 were consistently downregulated in both LUSC and LUAD tumor tissues. FCNs demonstrated significant diagnostic potential for LUSC and LUAD, with the area under the receiver operating characteristic curve (AUC) for FCN1 and FCN3 exceeding 0.90. Furthermore, FCN2 and FCN3 showed a strong negative correlation with overall survival (OS) in LUSC, whereas FCN1 and FCN2 were positively correlated with OS in LUAD, suggesting their prognostic value in lung cancer. Gene enrichment analysis indicated that FCNs were predominantly associated with the complement system and complement activation pathways. Immune infiltration analysis further revealed a significant positive correlation between FCNs and the presence of neutrophils and resting mast cells. Our analysis of immunotherapy outcomes revealed a significant disparity in the immunophenoscore (IPS) among lung cancer patients treated with immune checkpoint inhibitors (ICIs), distinguishing those with high FCN expression from those with low FCN expression. Additionally, we identified small molecule compounds related to FCNs and drugs pertinent to LUSC and LUAD.ConclusionFCNs held promise as diagnostic and prognostic biomarkers for LUSC and LUAD. This study also elucidated the relationship of FCNs with the tumor microenvironment, offering novel insights into the immunotherapeutic landscape for LUSC and LUAD.

Differential MRGPRX2-dependent activation of human mast cells by polymyxins and octapeptins

The emergence of multi-drug resistant Gram-negative bacteria has led to renewed interest in the antimicrobial activity of polymyxins and novel polymyxin analogues (e.g. nonapeptides and octapeptin). In some individuals, clinically used polymyxins can cause acute hypersensitivity reactions through mast cell activation, with a recent study attributing this effect to activation of the MAS-related G protein-coupled receptor X2 (MRGPRX2). In the present study, HEK293 cells expressing human MRGPRX2 and the human mast cell line LAD2 were used to characterize the activity of the broader family of polymyxins. Octapeptin C4, polymyxin B and colistin produced concentration-dependent calcium mobilization, degranulation, and CCL-2 (MCP-1) release in LAD2 mast cells, with the former being highly potent. CRISPR-Cas9 knockdown of MRGPRX2 in LAD2 cells and a MRGPRX2 inverse agonist caused a significant reduction in calcium mobilization, degranulation, and CCL-2 release, demonstrating dependency on MRGPRX2 expression. In contrast, polymyxin nonapeptides were far less potent calcium mobilisers and failed to induce functional degranulation in LAD2 cells. Our results confirm that activation of mast cells induced by polymyxin-related antibiotics is MRGPRX2-dependent and reveal that octapeptin C4 might be more liable, whilst nonapeptides are less liable, to trigger immediate hypersensitivity reactions clinically. The mechanism underpinning the difference in MRGPRX2 activation between polymyxin-related antibiotics is important to better understand as it may help design new, safer polymyxins and guide the optimal clinical use of existing polymyxin drugs.

Investigation of local stimulation effects of embedding PGLA at Zusanli (ST36) acupoint in rats based on TRPV2 and TRPV4 ion channels.

Acupoint Catgut Embedding (ACE) is an extended and developed form of traditional acupuncture that serves as a composite stimulation therapy for various diseases. However, its local stimulation effects on acupoints remain unclear. Acupuncture can activate mechanically sensitive calcium ion channels, TRPV2 and TRPV4, located on various cell membranes, promoting Ca2+ influx in acupoint tissues to exert effects. Whether ACE can form mechanical physical stimulation to regulate these channels and the related linkage effect requires validation. This study investigates the influence of TRPV2 and TRPV4 ion channels on the local stimulation effects of ACE by embedding PGLA suture at the Zusanli (ST36) acupoint in rats and using TRPV2 and TRPV4 inhibitors. Flow cytometry, immunofluorescence, Western blot, and Real-time quantitative PCR were employed to detect intracellular Ca2+ fluorescence intensity, the expression of macrophage (Mac) CD68 and mast cell (MC) tryptase, as well as the protein and mRNA expression of TRPV2 and TRPV4 in acupoint tissues after PGLA embedding. The results indicate that ACE using PGLA suture significantly increases the mRNA and protein expression of TRPV2 and TRPV4, Ca2+ fluorescence intensity, and the expression of Mac CD68 and MC tryptase in acupoint tissues, with these effects diminishing over time. The increasing trends are reduced after using inhibitors, particularly when both inhibitors are used simultaneously. Furthermore, correlation analysis shows that embedding PGLA suture at the ST36 acupoint regulates Mac and MC functions through Ca2+ signaling involving not only TRPV2 and TRPV4 but multiple pathways. These results suggest that embedding PGLA suture at the ST36 acupoint generates mechanical physical stimulation and regulates TRPV2 and TRPV4 ion channels, which couple with Ca2+ signaling to form a linkage effect that gradually weakens over time. This provides new reference data for further studies on the stimulation effects and clinical promotion of ACE.

Beyond Cancer Cells: How the Tumor Microenvironment Drives Cancer Progression.

Liver cancer represents a substantial global health challenge, contributing significantly to worldwide morbidity and mortality. It has long been understood that tumors are not composed solely of cancerous cells, but also include a variety of normal cells within their structure. These tumor-associated normal cells encompass vascular endothelial cells, fibroblasts, and various inflammatory cells, including neutrophils, monocytes, macrophages, mast cells, eosinophils, and lymphocytes. Additionally, tumor cells engage in complex interactions with stromal cells and elements of the extracellular matrix (ECM). Initially, the components of what is now known as the tumor microenvironment (TME) were thought to be passive bystanders in the processes of tumor proliferation and local invasion. However, recent research has significantly advanced our understanding of the TME's active role in tumor growth and metastasis. Tumor progression is now known to be driven by an intricate imbalance of positive and negative regulatory signals, primarily influenced by specific growth factors produced by both inflammatory and neoplastic cells. This review article explores the latest developments and future directions in understanding how the TME modulates liver cancer, with the aim of informing the design of novel therapies that target critical components of the TME.

New Aspects of Mortellaro’s Disease: A Literature Review

Introduction. All over the word, hoof diseases, and Mortellaro’s disease in particular, are being among the most widespread and difficult to treat diseases in dairy cattle husbandry. They cause irreparable economic damage to the dairy industry by reducing the cattle reproductive ability indicators, feed conversion ratio, which compels to spend considerable amounts on treatment, prevention and culling of animals. Mortellaro’s disease is especially widespread in Europe and Western countries, but the current rate of national economy growth leads to the necessity to purchase the cattle abroad, which results in the increase of the Mortellaro’s disease incidence in Russia: at the farms where cattle has been imported, the percentage of the disease is 14.17±5.15% of the total number of hoof diseases in the herd. The aim of this review is to summarise the results of scientific research on the Mortellaro’s disease pathogenesis over the past 20 years.Materials and Methods. To achieve the stated objective, the criteria of inclusion into the search were defined. It was decided to include in the review the studies/reports presenting the results on: 1) the disease etiology and factors affecting the course of Mortellaro’s disease; 2) symptoms of Mortellaro’s disease manifestation in different species of farm animals; 3) the methods of Mortellaro’s disease treatment. The materials published in Elsevier, ASM Journal, Irish Veterinary Journal, Thieme, American Dairy Science Association, Epidemics, Schweiz Arch Tierheilkd, Journal of Clinical Microbiology, eLIBRARY.RU, Google Scholar have been investigated in the frame of the literature search. The search by the following keywords was done: interdigital dermatitis, Mortellaro’s disease, hoof diseases of cattle, contagious interdigital dermatitis. The time range of sources – those published within the period from 2003 to 2023.Results. In total, 44 articles have been analysed, 33 of which have been included in the present review. According to the studied materials, one of the prerequisites underlying the spread of Mortellaro’s disease in the Russian Federation is the import of the infected cattle, since the measures undertaken during the temporary housing and quarantine periods do not give the desired result. The animals get infected with the bacteria of the genus Treponema, which are localized deep in the hoof tissues, therefore, after the disease is endured, it turns into its chronic form. The specific symptoms of Mortellaro’s disease course in various cattle breeds have been established: in beef cows and buffaloes the interdigital dermatitis is characterised by a low level of pain symptom severity; in sheep – by the ulcerative lesions of the сoronary band, which progress and lead to the destruction of the abaxial hoof wall and loss of the hoof horn. The areas with the erosion are very painful, but the intercellular adhesive junctions are not lost, which allows for positive prognosis of the disease. The main indicators of productivity and fertility are reduced due to the disease, as is the immunity in general, and there is an estrous cycle delay. In the samples of patients sick with the digital dermatitis, an increase of the number of intact and degranulated mast cells is observed, compared to the healthy ones, which indicates that mast cells can play an important role in the pathogenesis of digital dermatitis. Nowadays, the Mortellaro’s disease treatment abroad and in Russia is based on the elimination of symptoms, and not the pathogen itself. The local treatment is mainly represented by the antiseptic baths, surgical treatment, local application of antibiotics to the wound. The experiments on antibiotic susceptibility of Treponema, which are the important step in the search for the specific treatment of Mortellaro’s disease, have been performed. The antibiotic susceptibility tests gave positive results (all isolates of Treponema were sensitive to tiamulin, valnemulin, tylosin, aivlosin, lincomycin, doxyclin), however, the difficulty lies in the method of drug administration into the source of Treponema localization, since the conventional ways of administration of antibiotics entail restrictions on the sale of milk and meat.Conclusion. The presented review of the scientific publications on Mortellaro’s disease made it possible to summarise the currently known results and identify the areas for further research. For example, it should be still investigated why the interdigital dermatitis requires the presence of many Treponema species rather than one? What role do representatives of the Mycoplasma, Porphyromonas and other bacteria play in the pathogenesis of the studied disease? And of course, there is a serious scientific gap in finding treatment of Mortellaro’s disease capable of eliminating the pathogen itself, rather than its symptoms. It should be mentioned that not all Treponema species can be cultivated, which also slows down the scientific process and makes the problem of Mortellaro’s disease treatment relevant worldwide.