SLC10A4 regulates IgE-mediated mast cell degranulation in vitro and mast cell-mediated reactions in vivo

Comparative analyses of various IgE-mediated and non-IgE-mediated inducers of mast cell degranulation for in vitro study

In vitro investigations of mast cell (MC) degranulation are essential for studying many diseases, particularly allergy and urticaria. Many MC-degranulation inducers are currently available. However, there is no previous systematic comparative analysis of these available inducers in term of their efficacies to induce MC degranulation. Herein, we performed systematic comparisons of efficacies of five well-known and commonly used MC-degranulation inducers. RBL-2H3 cells were sensitized with 50 ng/ml anti-DNP IgE or biotinylated IgE followed by stimulation with 100 ng/ml DNP-BSA or streptavidin, respectively. For non-IgE-mediated inducers, the cells were treated with 5 µg/ml substance P, compound 48/80, or A23187. At 15-, 30-, 45- and 60-min post-induction, several common MC-degranulation markers (including intracellular [Ca2+], β-hexosaminidase release, tryptase expression by immunofluorescence staining, cellular tryptase level by immunoblotting, secretory tryptase level by immunoblotting, CD63 expression by immunofluorescence staining, and CD63 expression by flow cytometry) were evaluated. The data showed that all these markers significantly increased after activation by all inducers. Among them, A23187 provided the greatest degrees of increases in intracellular [Ca2+] and β-hexosaminidase release at all time-points and upregulation of CD63 at one time-point. These data indicate that all these IgE-mediated (anti-DNP IgE/DNP-BSA and biotinylated IgE/streptavidin) and non-IgE-mediated (substance P, compound 48/80, and A23187) inducers effectively induce MC degranulation, while A23187 seems to be the most effective inducer for MC degranulation.

Exploring a novel seven-gene marker and mitochondrial gene TMEM38A for predicting cervical cancer radiotherapy sensitivity using machine learning algorithms

Background

Radiotherapy plays a crucial role in the management of Cervical cancer (CC), as the development of resistance by cancer cells to radiotherapeutic interventions is a significant factor contributing to treatment failure in patients. However, the specific mechanisms that contribute to this resistance remain unclear. Currently, molecular targeted therapy, including mitochondrial genes, has emerged as a new approach in treating different types of cancers, gaining significant attention as an area of research in addressing the challenge of radiotherapy resistance in cancer.

Methods

The present study employed a rigorous screening methodology within the TCGA database to identify a cohort of patients diagnosed with CC who had received radiotherapy treatment. The control group consisted of individuals who demonstrated disease stability or progression after undergoing radiotherapy. In contrast, the treatment group consisted of patients who experienced complete or partial remission following radiotherapy. Following this, we identified and examined the differentially expressed genes (DEGs) in the two cohorts. Subsequently, we conducted additional analyses to refine the set of excluded DEGs by employing the least absolute shrinkage and selection operator regression and random forest techniques. Additionally, a comprehensive analysis was conducted in order to evaluate the potential correlation between the expression of core genes and the extent of immune cell infiltration in patients diagnosed with CC. The mitochondrial-associated genes were obtained from the MITOCARTA 3.0. Finally, the verification of increased expression of the mitochondrial gene TMEM38A in individuals with CC exhibiting sensitivity to radiotherapy was conducted using reverse transcription quantitative polymerase chain reaction and immunohistochemistry assays.

Results

This process ultimately led to the identification of 7 crucial genes, viz., GJA3, TMEM38A, ID4, CDHR1, SLC10A4, KCNG1, and HMGCS2, which were strongly associated with radiotherapy sensitivity. The enrichment analysis has unveiled a significant association between these 7 crucial genes and prominent signaling pathways, such as the p53 signaling pathway, KRAS signaling pathway, and PI3K/AKT/MTOR pathway. By utilizing these 7 core genes, an unsupervised clustering analysis was conducted on patients with CC, resulting in the categorization of patients into three distinct molecular subtypes. In addition, a predictive model for the sensitivity of CC radiotherapy was developed using a neural network approach, utilizing the expression levels of these 7 core genes. Moreover, the CellMiner database was utilized to predict drugs that are closely linked to these 7 core genes, which could potentially act as crucial agents in overcoming radiotherapy resistance in CC.

Conclusion

To summarize, the genes GJA3, TMEM38A, ID4, CDHR1, SLC10A4, KCNG1, and HMGCS2 were found to be closely correlated with the sensitivity of CC to radiotherapy. Notably, TMEM38A, a mitochondrial gene, exhibited the highest degree of correlation, indicating its potential as a crucial biomarker for the modulation of radiotherapy sensitivity in CC.

Rosa davurica Inhibited Allergic Mediators by Regulating Calcium and Histamine Signaling Pathways

Rosa davurica Pall. exhibits antioxidant, antiviral, and anti-inflammatory properties; however, its pharmacological mechanism in allergy is yet to be understood. This study confirmed the effects of R. davurica Pall. leaf extract (RLE) on allergy as a new promising material. To evaluate the therapeutic potential of RLE against allergy, we investigated the effects of RLE on the regulatory β-hexosaminidase, histamine, histidine decarboxylase (HDC), Ca²⁺ influx, nitric oxide (NO), and cytokines induced by lipopolysaccharide (LPS) and DNP-IgE/BSA in Raw 264.7 and RBL-2H3 cells. Furthermore, we examined the effects of RLE on the signaling pathways of mitogen-activated protein kinase (MAPK) and Ca²⁺ pathways. After stimulating Raw 264.7 cells with LPS, RLE reduced the release of inflammatory mediators, such as NO, cyclooxygenase (COX)-2, inducible nitric oxygen synthase (iNOS), interleukin (IL)-1β, -6, and tumor necrosis factor (TNF)-α. Also, RLE reduced the β-hexosaminidase, histamine, HDC, Ca²⁺ influx, Ca²⁺ pathways, and phosphorylation of MAPK in DNP-IgE/BSA-stimulated RBL-2H3 cells. Our studies indicated that RLE is a valuable ingredient for treating allergic diseases by regulating cytokine release from macrophages and mast cell degranulation. Consequently, these results suggested that RLE may serve as a possible alternative promising material for treating allergies.

The Multifaceted Roles of Mast Cells in Immune Homeostasis, Infections and Cancers

Mast cells (MCs) play important roles in normal immune responses and pathological states. The location of MCs on the boundaries between tissues and the external environment, including gut mucosal surfaces, lungs, skin, and around blood vessels, suggests a multitude of immunological functions. Thus, MCs are pivotal for host defense against different antigens, including allergens and microbial pathogens. MCs can produce and respond to physiological mediators and chemokines to modulate inflammation. As long-lived, tissue-resident cells, MCs indeed mediate acute inflammatory responses such as those evident in allergic reactions. Furthermore, MCs participate in innate and adaptive immune responses to bacteria, viruses, fungi, and parasites. The control of MC activation or stabilization is a powerful tool in regulating tissue homeostasis and pathogen clearance. Moreover, MCs contribute to maintaining the homeostatic equilibrium between host and resident microbiota, and they engage in crosstalk between the resident and recruited hematopoietic cells. In this review, we provide a comprehensive overview of the functions of MCs in health and disease. Further, we discuss how mouse models of MC deficiency have become useful tools for establishing MCs as a potential cellular target for treating inflammatory disorders.

Nasal irrigation with Glycyrrhiza glabra extract for treatment of allergic rhinitis - A study of in vitro, in vivo and clinical trial

ETHNOPHARMACOLOGICAL RELEVANCE

Glycyrrhiza glabra, a family of licorice and a traditional Chinese medicine with sweet taste and favorable smell, has anti-inflammatory, anti-allergic and immunomodulatory functions.

AIM OF THE STUDY

We developed a licorice extract (LE) by using glycyrrhiza glabra and administered it through nasal irrigation to treat allergic rhinitis (AR).

MATERIALS AND METHODS

LE was prepared into extract powder, and the anti-inflammatory effect of the LE was evaluated by calcium ionophore-induced activated mast cell model (in vitro). Then, local passive anaphylaxis assays were applied to investigate the anti-IgE-mediated allergic reaction of the LE in mice (in vivo). A developed LE was administered through nasal irrigation to treat AR in clinic settings. A total of 60 participants diagnosed with AR were included in this clinical trial; they were randomly assigned to three interventions: licorice nasal irrigation (LNI), corticosteroid nasal irrigation (CNI), and saline nasal irrigation (SNI). They performed nasal irrigation once a day for 1 month. Both subjective questionnaires (22-item Sino-Nasal Outcome Test [SNOT-22] and visual analog scale [VAS]) and objective examinations (acoustic rhinometry and nasal endoscopy) were used for effectiveness assessments.

RESULTS

All three interventions could improve SNOT-22 scores, but the effects of LNI and CNI were more significant. According to VAS scores for nasal blockage, rhinorrhea, sneezing, nasal pruritus, postnasal discharge, and olfactory disturbance, the effect of LNI was superior to those of CNI and SNI. The results of rhinometry revealed that LNI significantly improved nasal resistance. Endoscopic analysis showed that both LNI and CNI, but not SNI, could significantly improve turbinate hypertrophy. Moreover, the best procedural comfort was found for LNI, which had no side effects or complications during the trial.

CONCLUSIONS

LNI is a natural, safe, and innovative therapy that can effectively treat AR. Its effect is superior to those of CNI and SNI, and it has greatly improved procedural comfort.

Extracellular ATP: A Feasible Target for Cancer Therapy

Adenosine triphosphate (ATP) is one of the main biochemical components of the tumor microenvironment (TME), where it can promote tumor progression or tumor suppression depending on its concentration and on the specific ecto-nucleotidases and receptors expressed by immune and cancer cells. ATP can be released from cells via both specific and nonspecific pathways. A non-regulated release occurs from dying and damaged cells, whereas active release involves exocytotic granules, plasma membrane-derived microvesicles, specific ATP-binding cassette (ABC) transporters and membrane channels (connexin hemichannels, pannexin 1 (PANX1), calcium homeostasis modulator 1 (CALHM1), volume-regulated anion channels (VRACs) and maxi-anion channels (MACs)). Extracellular ATP acts at P2 purinergic receptors, among which P2X7R is a key mediator of the final ATP-dependent biological effects. Over the years, P2 receptor- or ecto-nucleotidase-targeting for cancer therapy has been proposed and actively investigated, while comparatively fewer studies have explored the suitability of TME ATP as a target. In this review, we briefly summarize the available evidence suggesting that TME ATP has a central role in determining tumor fate and is, therefore, a suitable target for cancer therapy.

Extracellular ATP and P2 purinergic signalling in the tumour microenvironment

Modulation of the biochemical composition of the tumour microenvironment is a new frontier of cancer therapy. Several immunosuppressive mechanisms operate in the milieu of most tumours, a condition that makes antitumour immunity ineffective. One of the most potent immunosuppressive factors is adenosine, which is generated in the tumour microenvironment owing to degradation of extracellular ATP. Accruing evidence over the past few years shows that ATP is one of the major biochemical constituents of the tumour microenvironment, where it acts at P2 purinergic receptors expressed on both tumour and host cells. Stimulation of P2 receptors has different effects depending on the extracellular ATP concentration, the P2 receptor subtype engaged and the target cell type. Among P2 receptors, the P2X purinergic receptor 7 (P2X7R) subtype appears to be a main player in host-tumour cell interactions. Preclinical studies in several tumour models have shown that P2X7R targeting is potentially a very effective anticancer treatment, and many pharmaceutical companies have now developed potent and selective small molecule inhibitors of P2X7R. In this Review, we report on the multiple mechanisms by which extracellular ATP shapes the tumour microenvironment and how its stimulation of host and tumour cell P2 receptors contributes to determining tumour fate.

Elaeocarpusin Inhibits Mast Cell-Mediated Allergic Inflammation

Mast cells are major effector cells for allergic responses that act by releasing inflammatory mediators, such as histamine and pro-inflammatory cytokines. Accordingly, different strategies have been pursued to develop anti-allergic and anti-inflammatory candidates by regulating the function of mast cells. The purpose of this study was to determine the effectiveness of elaeocarpusin (EL) on mast cell-mediated allergic inflammation. We isolated EL from Elaeocarpus sylvestris L. (Elaeocarpaceae), which is known to possess anti-inflammatory properties. For this study, various sources of mast cells and mouse anaphylaxis models were used. EL suppressed the induction of markers for mast cell degranulation, such as histamine and β-hexosaminidase, by reducing intracellular calcium levels. Expression of pro-inflammatory cytokines, such as tumor necrosis factor-α and IL-4, was significantly decreased in activated mast cells by EL. This inhibitory effect was related to inhibition of the phosphorylation of Fyn, Lyn, Syk, and Akt, and the nuclear translocation of nuclear factor-κB. To confirm the effect of EL in vivo, immunoglobulin E-mediated passive cutaneous anaphylaxis (PCA) and ovalbumin-induced active systemic anaphylaxis (ASA) models were induced. EL reduced the PCA reaction in a dose dependent manner. In addition, EL attenuated ASA reactions such as hypothemia, histamine release, and IgE production. Our results suggest that EL is a potential therapeutic candidate for allergic inflammatory diseases that acts via the inhibition of mast cell degranulation and expression of proinflammatory cytokines.