Mast Cell Membrane Research Articles

Molecular mechanism of IgE-mediated FcεRI activation.

Allergic diseases, affecting over a quarter of individuals in industrialized countries, have become significant public health concerns1,2. The high-affinity Fc receptor for IgE (FcεRI), mainly present on mast cells and basophils, plays a crucial role in allergic diseases3-5. Monomeric IgE binding to FcεRI regulates mast cell survival, differentiation, and maturation6-8. However, the underlying molecular mechanism remains unclear. Here we demonstrate that, prior to IgE binding, FcεRI mostly exists as a homo-dimer on human mast cell membrane. The structure of human FcεRI confirms the dimeric organization, with each promoter comprising one α subunit, one β subunit, and two γ subunits. The transmembrane helices of the α subunits form a layered arrangement with those of the γ and β subunits. The dimeric interface is mediated by a four-helix bundle of the α and γ subunits at the intracellular juxtamembrane region. Cholesterol-like molecules embedded within the transmembrane domain may stabilize the dimeric assembly. Upon IgE binding, the dimeric FcεRI dissociates into two protomers, each binding to an IgE molecule. Importantly, this process elicits transcriptional activation of Egr1/3 and Ccl2 in rat basophils, which can be attenuated by inhibiting the FcεRI dimer-to-monomer transition. Collectively, our study unveils the mechanism of antigen-independent, IgE-mediated FcεRI activation.

Effect of Polysaccharides Isolated from Saussurea salicifolia (L.) DC on Th2-Dependent Immune Response.

The effect of polysaccharides isolated from the aboveground parts of Saussurea salicifolia (L.) DC on Th2 type immune response reactions was studied. Administration of water-soluble polysaccharides presented by arabino-galacturonans (weight average molecular weight 158.49 kDa) to mice against the background of experimental Th2 immunity reduced the severity of anaphylactic and local immediate type hypersensitivity reactions. It also suppressed the production of ovalbumin-specific IgE and IgG1 and increased the stability of mast cell membranes. The studied polysaccharide complex increased IFNγ secretion and inhibited IL-4 synthesis. These findings suggest that these polysaccharides may be considered as potential anti-allergic agents that suppress the development of allergy in its early stages.

Camel Whey Protein and Baicalein Suppressed Mast Cell Degranulation in Mice Models of IgE- and Non-IgE-Mediated Anaphylaxes: Potential Mechanisms on Downstream Cell Signaling of Mast Cells

ABSTRACT Introduction Novel treatments are being researched to develop more safe and effective protective medications for anaphylaxis. Camel whey protein (CWP) and baicalein (BAC, one of the major flavones) have multiple beneficial properties including anti-inflammatory and antioxidant activities. Methods The current study investigated/compared the therapeutic protection of repeated intragastric administration of CWP (100 mg/kg body weight, as an animal extract) and BAC (10 mg/kg body weight, as a plant extract), before the challenge with ovalbumin (OVA) or receiving the compound 48/80 (C48/80), against mice models for IgE-independent and dependent anaphylaxes. Besides, their effects on mast cells (MCs) downstream cell signaling were explored. Results The results revealed that CWP and BAC reduced the mortality rate, as compared with a MCs stabilizer “sulfasalazine (SSZ, 100 mg/kg body weight, intraperitoneally),” in both mice models. Furthermore, they prevented the MCs degranulation and significantly reduced (p < .05) lung tissue levels of cell signaling (p-AKT, p-ERK, and p-IκBα). Additionally, they decreased histamine, tryptase, leukotriene C4, prostaglandin D2, interleukin (IL)-4, and IL-10 levels in broncho-alveolar and peritoneal lavages in systemic anaphylaxis mice models. They also restored the stabilization of peritoneal MCs membrane in inverted light microscopy results accompanied by amelioration of the lung histology. Discussion The present study provided evidence for the protective therapeutic effect of CWP and BAC against anaphylaxis. As a result, CWP and BAC may be used as preventative supplemented regimens for both non-vegetarian and vegetarian consumers to treat allergy through downregulation of MCs signal transduction pathways, and hence controlling the production of inflammatory mediators.

Promising anticancer activity of cromolyn in colon cancer: in vitro and in vivo analysis

PurposeColon cancer is a prevalent cancer globally, representing approximately 10% of all cancer cases and accounting for 10% of all cancer-related deaths. Therefore, finding new therapeutic methods with high efficiency will be very valuable. Cromolyn (C), a common anti-allergic and mast cell membrane stabilizing drug, has recently shown valuable anti-cancer effects in several studies. This study was designed to investigate the anti-cancer activity of cromolyn on colon cancer in vitro and in vivo and to determine values such as selectivity index and survival effect.MethodsHT-29 (colon cancer) and MCF-10 (normal epithelial) cell lines were treated with C and Doxorubicin (DOX; Positive control). IC50 values and the effects of C and DOX on apoptosis were explored using methyl thiazole diphenyl-tetrazolium bromide (MTT) assay and Annexin V/PI Apoptosis Assay Kit. To investigate in an animal study, colon cancer was subcutaneously induced by CT26 cells (mouse colon cancer) in bulb/c mice. Mice were treated with 0.05 LD50 intraperitoneal every other day for 35 days. After the death of mice, tumor volume, tumor weight, and survival rate were evaluated.ResultsC selectively and significantly suppressed the proliferation of cancer cells in a dose-dependent manner. The IC50 values for the MCF-10 and HT29 cell lines were 7.33 ± 0.78 μM and 2.33 ± 0.6 μM, respectively. Notably, the selective index (SI) highlighted that C displayed greater selectivity in inhibiting cancer cell growth compared to DOX, with SI values of 3.15 and 2.60, respectively. C exhibited higher effectiveness and selectivity in inducing apoptosis in cancer cells compared to DOX, with a significant p-value (61% vs. 52%, P-value ≤ 0.0001). Also, in mice bearing colon cancer, C reduced the tumor volume (6317 ± 1685mm3) and tumor weight (9.8 ± 1.6 g) compared to the negative control group (weight 12.45 ± 0.9 g; volume 7346 ± 1077) but these values were not statistically significant (P ≤ 0.05).ConclusionOur study showed that cromolyn is a selective and strong drug in inhibiting the proliferation of colon cancer cells. Based on our results, the efficacy of C in vitro analysis (MTT assays and apoptosis), as well as animal studies is competitive with the FDA-approved drug doxorubicin. C is very promising as a low-complication and good-efficacy drug for cancer drug repositioning. This requires clinical research study designs to comprehensively evaluate its anti-cancer effects.

Ultrastructural features of tumor-associated mast cells in parasympathetic paragangliomas (chemodectomas) of the neck.

The mechanisms of the pathogenesis of neck paraganglioma (PGL) and the possible role of mast cells (MCs) in its development and metastasis are still poorly understood. We analyzed MCs' morphologic characterization, activation, and the properties of their cytoplasmic/released granules in PGLs, using light and transmission electron microscopy. Paragangliomas showed a large tumor-associated MC population both in the connective tissue layers of the tumor and between the tumor cells. Notably, MCs were presented by a high expression of specific proteases, size variation, polymorphism, and variable ultrastructural phenotype of granules. A massive number of granules were released surrounding the degranulated MCs while the integrity of MC membrane was maintained. Granules were electron-dense with or without a membrane, ranging from 0.2 to 0.8 μm in diameter. MC plasmalemma was not found at the site of MC-collagen fibrils contact, whereas the secretome and fibrils were directly contacted. We observed direct and mediator-based interactions between MCs and paraganglioma cells. The latter preserved their membrane integrity when MC granules were not in proximity. The effects of the MC secretome on the paraganglioma microenvironment demonstrated its pathogenetic role in tumor progression and allow its application to new diagnostic criteria and the development of protocols for personalized therapy. RESEARCH HIGHLIGHTS: Ultrastructural analysis reveals novel regulatory effects of mast cells via diverse secretory pathways on the pathogenesis of parasympathetic paraganglioma, including fibrous extracellular matrix remodeling and mediator-based interactions between MCs and cells of the tumor microenvironment.

Влияние кромогликата натрия и интрамуральных ганглиев на экспрессию гена TNFR1 в бронхах крыс с овальбумин-индуцированной бронхиальной астмой

The purpose of this article was to study TNFR1 gene expression in the bronchi of rats with ovalbumininduced bronchial asthma, taking into account intramural metasympathetic ganglia and the stabilization of mast cell membranes with sodium cromoglycate. In this paper, gene expression refers to the accumulation of mRNA in bronchial tissues. Expression of the TNFR1 gene and receptor plays an important role in the development of allergic asthma. For this reason, the TNFR1 gene was chosen for the analysis. Materials and methods. Bronchial samples from Wistar rats were studied using real-time polymerase chain reaction. For experiments, bronchi with ganglia (in the bifurcation area) and bronchi without ganglia (straight sections) were taken. The material was collected from 7 groups of rats: with ovalbumin-induced bronchial asthma (6 groups) and control animals (1 group). Mast cell stabilizer sodium cromoglycate was used to treat 3 groups of rats with simulated asthma. Results. It was found that the expression of mRNA encoding TNFR1 increases in rats developing bronchial asthma. In bronchial samples with ganglia, TNFR1 gene expression was higher than in bronchial preparations without ganglia. Under the influence of sodium cromoglycate, TNFR1 gene expression decreased. Based on the results obtained, it was suggested that mast cells and neurons of the intramural ganglion have a rather pronounced effect on TNFR1 gene expression.

Synovial microenvironment-influenced mast cells promote the progression of rheumatoid arthritis

Mast cells are phenotypically and functionally heterogeneous, and their state is possibly controlled by local microenvironment. Therefore, specific analyses are needed to understand whether mast cells function as powerful participants or dispensable bystanders in specific diseases. Here, we show that degranulation of mast cells in inflammatory synovial tissues of patients with rheumatoid arthritis (RA) is induced via MAS-related G protein-coupled receptor X2 (MRGPRX2), and the expression of MHC class II and costimulatory molecules on mast cells are upregulated. Collagen-induced arthritis mice treated with a combination of anti-IL-17A and cromolyn sodium, a mast cell membrane stabilizer, show significantly reduced clinical severity and decreased bone erosion. The findings of the present study suggest that synovial microenvironment-influenced mast cells contribute to disease progression and may provide a further mast cell-targeting therapy for RA.

Biomarkers of Autoimmune Chronic Spontaneous Urticaria.

Chronic spontaneous urticaria and chronic inducible urticaria (CSU/CindU) are caused by mast cell and basophil activation leading to degranulation and the release of histamine and several other mediators. Three kinds of factors can trigger mast cells in CSU: (1) activation of stimulating receptor(s) on the mast cell membrane, (2) upregulation of certain receptor(s), and (3) intracellular dysregulation in signaling with overexpression of the spleen tyrosine kinase (SYK) or reduced activation of the inhibitory Src homology 2 (SH2)-containing inositol phosphatases (SHIP)-related pathways. In CSU, two major endotypes exist based on the primary receptor activating mechanism: type I hypersensitivity (IgE-mediated, directed against auto-allergens) and type IIb (autoimmune, via IgG autoantibodies directed against IgE or the IgE-receptor). Their treatment responses vary. We discuss in vitro and in vivo biomarkers. Patients with auto-allergic CSU have clinical characteristics that can distinguish them partly from those with autoimmune CSU. Most importantly, their disease generally presents a less aggressive course, a better response to second generation (up-dosed) antihistamines and a good response to omalizumab, if necessary. Meanwhile, autoimmune CSU/CindU patients fare less well and often need immunosuppressive drugs. Biomarkers that might help endotype CSU/CindU patients and select the most appropriate treatment, dose, and duration, e.g., for autoallergic CSU, high total IgE and IgE against auto-allergens; for autoimmune CSU, low IgE, basopenia, and IgG against autoantigens like thyroid peroxidase and a positive autologous serum skin test (but sometimes also positive in autoallergy). Some biomarkers are easily accessible but of low specificity; others are highly specific but more futuristic.

Medical therapy for conjunctivitis. Literature review

Conjunctivitis, according to various studies, is the most common reason for going to the initial outpatient appointment and can be caused by several factors at the same time. Treatment is carried out comprehensively, depending on the clinical picture, somatic status and anamnesis data. In accordance with the clinical guidelines developed by the Russian Association of Ophthalmologists, the following groups of drugs are recommended for use: antibacterial, antiseptic, antihistamine, nonsteroidal anti-inflammatory drugs.Purpose: to analyze the use of the above groups of drugs in the treatment of conjunctivitis in order to recommend a reasonable prescription of the necessary therapy.Materials and methods. The literature data on the study of the features of the action of the above pharmacological groups in the treatment of conjunctivitis, obtained on the resources of PubMed, eLibrary, Crossref Metadata, mainly over the past 20 years, are presented.Results. The presence of signs of an allergic reaction involves the appointment of antiallergic drugs with multiple pharmacological effects – blockade of histamine receptors, stabilization of mast cell membranes and suppression of eosinophil filtration. Given the different mechanisms of action within this group of drugs, it is necessary to select them individually. When prescribing tablet forms of antihistamines, it must be remembered that with prolonged use, they can cause patients to feel dry in their eyes. In cases where the above antiallergic drugs do not adequately control the allergic inflammatory process, anti-inflammatory drugs are used. Nonsteroidal and steroid anti-inflammatory drugs are used as anti-inflammatory drugs. Usually nonsteroidal anti-inflammatory drugs are recommended for use in chronic conjunctivitis and patients with a history of systemic diseases. Steroid drugs are indicated for severe forms of manifestation of the allergic process on the eyes, as well as the appointment of steroid anti-inflammatory drugs is recommended for use in short courses (up to 2 weeks), and with their longer use, control of intraocular pressure is necessary. Literature data indicate the lack of efficacy of antiviral drugs such as acyclovir and others from this group in the treatment of conjunctivitis of adenoviral etiology. Drugs with an immunomodulatory effect based on interferon or inducers of interferon synthesis are widely used. The prescription of antibiotics should be justified, since in recent years the level of resistance to them has significantly increased. Antiseptics that have a wide spectrum of action (bacteria, viruses, fungi and protozoa) are an alternative to antibiotics, but it must be remembered that this group of drugs often causes allergic reactions.Conclusion. The treatment of conjunctivitis must be approached carefully, taking into account not only the etiology of the disease, but also the somatic and immune status of the patient. To avoid the negative effects of the use of antibiotics, replace them with alternative drugs and do not use them in the treatment of conjunctivitis of a non-bacterial nature.

Thymic stromal lymphopoietin (TSLP) is a substrate for tryptase in patients with mastocytosis

Mastocytosis is a heterogeneous disease associated to uncontrolled proliferation and increased density of mast cells in different organs. This clonal disorder is related to gain-of-function pathogenic variants of the c-kit gene that encodes for KIT (CD117) expressed on mast cell membrane. Thymic stromal lymphopoietin (TSLP) is a pleiotropic cytokine, which plays a key role in allergic disorders and several cancers. TSLP is a survival and activating factor for human mast cells through the engagement of the TSLP receptor. Activated human mast cells release several preformed mediators, including tryptase. Increased mast cell-derived tryptase is a diagnostic biomarker of mastocytosis. In this study, we found that in these patients serum concentrations of TSLP were lower than healthy donors. There was an inverse correlation between TSLP and tryptase concentrations in mastocytosis. Incubation of human recombinant TSLP with sera from patients with mastocytosis, containing increasing concentrations of tryptase, concentration-dependently decreased TSLP immunoreactivity. Similarly, recombinant β-tryptase reduced the immunoreactivity of recombinant TSLP, inducing the formation of a cleavage product of approximately 10 kDa. Collectively, these results indicate that TSLP is a substrate for human mast cell tryptase and highlight a novel loop involving these mediators in mastocytosis.

Accumulation of Renal Fibrosis in Hyperuricemia Rats Is Attributed to the Recruitment of Mast Cells, Activation of the TGF-β1/Smad2/3 Pathway, and Aggravation of Oxidative Stress

Renal fibrosis is relentlessly progressive and irreversible, and a life-threatening risk. With the continuous intake of a high-purine diet, hyperuricemia has become a health risk factor in addition to hyperglycemia, hypertension, and hyperlipidemia. Hyperuricemia is also an independent risk factor for renal interstitial fibrosis. Numerous studies have reported that increased mast cells (MCs) are closely associated with kidney injury induced by different triggering factors. This study investigated the effect of MCs on renal injury in rats caused by hyperuricemia and the relationship between MCs and renal fibrosis. Our results reveal that hyperuricemia contributes to renal injury, with a significant increase in renal MCs, leading to renal fibrosis, mitochondrial structural disorders, and oxidative stress damage. The administration of the MCs membrane stabilizer, sodium cromoglycate (SCG), decreased the expression of SCF/c-kit, reduced the expression of α-SMA, MMP2, and inhibited the TGF-β1/Smad2/3 pathway, thereby alleviating renal fibrosis. Additionally, SCG reduced renal oxidative stress and mitigated mitochondrial structural damage by inhibiting Ang II production and increasing renal GSH, GSH-Px, and GR levels. Collectively, the recruitment of MCs, activation of the TGF-β1/Smad2/3 pathway, and Ang II production drive renal oxidative stress, ultimately promoting the progression of renal fibrosis in hyperuricemic rats.

Guiding Clinical Prescription of Topical Extemporaneous Formulations of Sodium Cromoglycate Based on Pharmaceutical Performance.

Cromoglycate (SCG) is widely used for allergy processes, and inflammatory states acting as a mast cell membrane stabilizer that inhibits the histamine and mediator release. Currently, SCG topical extemporaneous compounding formulations are prepared in hospitals and community pharmacies, as no industrial fabricated medicines are available in Spain. The stability of these formulations is unknown. Additionally, there are no clear guidelines on which concentration and vehicle are more suitable to enhance permeation across the skin. In this work, the stability of commonly prescribed topical SCG formulations in clinical practice was evaluated. Different vehicles commonly employed by pharmacists daily for formulating topical SCG were investigated (Eucerinum, Acofar Creamgel, and Beeler's base) at different concentrations, ranging from 0.2 to 2%. The stability of topical extemporaneous compounded SCG formulations can be extended for up to three months at room temperature (25 °C). Creamgel 2% formulations significantly improved the topical permeation of SCG across the skin, being 4.5-fold higher than formulations prepared with Beeler's base. The reason attributed to this performance can be related to the lower droplet size formed upon dilution in aqueous media combined with a lower viscosity, which facilitates its application and extensibility on the skin. The higher the SCG concentration in Creamgel formulations, the higher the permeability across both synthetic membranes and pig skin (p-value < 0.05). These preliminary results can be used as a guide to prompt a rational prescription of topical SCG formulations.

Contributions of Diet and Age to Ulcerative Dermatitis in Female C57BL/6J Mice.

C57BL/6J (B6) mice are commonly affected by ulcerative dermatitis (UD), a disease of unknown etiology with poor response to treatment. To study the possible role of diet in UD, we compared skin changes in B6 female mice fed a high-fat diet with those of mice fed a control diet. In addition, skin samples from mice with no, mild, moderate, and severe clinical signs of UD were examined by light and transmission electron microscopy (TEM). Mice fed a high-fat diet for 2 mo had more skin mast cell degranulation than did mice fed the control diet for the same period. Regardless of diet, older mice had more skin mast cells and more of these cells were degranulating as compared with younger mice. Microscopic changes in very early lesions were characterized by an increase in dermal mast cells and degranulation with focal areas of epidermal hyperplasia with or without hyperkeratosis. As the condition progressed, a mixed but predominantly neutrophilic inflammatory cell infiltrate appeared in the dermis, with or without epidermal erosion and scab formation. TEM showed that dermal mast cell membranes had disrupted and released of large number of electron dense granules, whereas degranulated mast cells were filled with isolated and coalescing empty spaces due to fusion of granule membranes. Ulceration appeared to occur very quickly, probably as result of intense scratching due to the pruritogenic properties of the histamine released from mast cell granules. This study showed a direct correlation between dietary fat and skin mast cell degranulation in female B6 mice. In addition, the number of skin mast cells and degranulation rates was higher in older mice. Treatments directed at preventing mast cell degranulation may result in better outcomes when applied early in UD cases. As noted previously in studies using caloric restriction, lower fat content in rodent diets may help prevent UD.

Effects of Lactobacillus fermentation on Eucheuma spinosum polysaccharides: Characterization and mast cell membrane stabilizing activity

Eucheuma polysaccharides have varieties of biological activities. However, it is accompanied by problems like large molecular weight, high viscosity, and low utilization. Here, we first prepared fermented Eucheuma spinosum polysaccharides (F-ESP) by Lactobacillus fermentation, compared with low-temperature freeze-thaw ESP (L-ESP) prepared by the freeze-thaw method, explored the composition and structural characteristics of F-ESP and L-ESP, and evaluation of the ability of different samples to inhibit mast cell degranulation using classical mast cell model. Then, the activity of L-ESP and F-ESP in vivo was preliminarily evaluated using a passive cutaneous anaphylaxis model. Two kinds of F-ESP named F1-ESP-3 and F2-ESP-3 were obtained by fermentation of Eucheuma spinosum with the selected strains of Lactobacillus.sakei subsp.sakei and Lactobacillus.rhamnosus. Compared with the purified component L-ESP-3, the monosaccharide composition of F1-ESP-3 contains more glucuronic acid, the molecular weight reduced from >600 kDa (L-ESP-3) to 28.30 kDa (F1-ESP-3) and 33.58 kDa (F2-ESP-3), F1-ESP-3 has higher solubility and lower apparent viscosity. Fermentation did not destroy the functional groups and structure of ESP. Moreover, F1-ESP-3 significantly inhibited RBL-2H3 cell degranulation by reducing depolymerization of F-actin and Ca2+ influx. F1-ESP-3 reduced the symptoms of mast cell-mediated passive cutaneous anaphylaxis, indicating that F1-ESP-3 may have better anti-allergic activity in vivo.

Uric acid accumulation in the kidney triggers mast cell degranulation and aggravates renal oxidative stress

The accumulation of uric acid (UA) in the body can lead to the occurrence of hyperuricemia or uric acid nephropathy. Mast cells (MCs) increase oxidative stress and release renin to promote the production of Ang II. The aim of this study was to investigate the effect of UA on MCs in rat kidneys and the association between MCs and renal injury. Our results show that UA accumulation in the kidney stimulated the degranulation of MCs and the release of renin to promote Ang II production, resulting in renal oxidative stress, mitochondrial structural damage, and microvascular system damage. The expression of urate-related transporters was regulated by the UA level and serum urinary toxins levels were substantially elevated in hyperuricemia. Administration of the MCs membrane stabilizer sodium cromoglycate (SCG) or the angiotensin receptor antagonist Valsartan decreased the production of renin and Ang II and relieved renal oxidative stress, mitigated mitochondrial structural damage and microvascular system damage, and promoted the excretion of UA and urinary toxins by increasing the expression of urate-related transporters. These results demonstrate that the accumulation of UA in the kidney can trigger the degranulation of MCs and promote the development of renal oxidative stress. Administration of SCG and Valsartan ameliorated UA-induced renal injury by inhibiting MCs degranulation and reducing renal oxidative stress by inhibiting renin and Ang II production and accelerating renal clearance of UA and uremic toxins.

Сучасні погляди на етіопатогенетичні механізми гострої кропив’янки в дітей

The purpose - to analyze modern approaches to understanding the mechanisms of occurrence and etiological factors of acute urticaria in children. Acute urticaria remains a common pathology in the structure of emergency conditions. That is why there is a need for a unified approach to understanding the mechanisms of its occurrence, as well as the management of such patients. The results of modern research on the interpretation of the causes of the appearance of acute urticaria in childhood are given. Identification of an etiological factor is not always successful; triggers or risk factors can be confirmed only in 21-55% of cases. However, this fact does not diminish the interest in the problem. Taking into account the fact that the mechanisms of urticaria can be immune or non-immune, their clinical features are given, detailing possible etiological factors. Considerable attention is paid to the mechanisms of mast cell degranulation, which can be caused by immune effects (IgE, activation of the complement system, immune complexes); direct influence of certain chemical or physical factors on fat cells without the development of a hypersensitivity reaction (histamine release); or instability of mast cell membranes (congenital defects). The authors highlight good reasons among medicines and food products that have a pronounced histamine-releasing ability, which helps the practicing doctor in understanding the mechanisms of urticaria. Given the children’s age, many researchers are interested in the role of infectious agents in the pathogenesis of urticaria. It is generally known about the high prevalence of acute infectious pathology in children, as well as the higher infectious index especially in children of the first years of life. According to the results of numerous publications, an obvious connection with viral and bacterial infections has been established in more than 80% of children with acute urticaria. It is often difficult for the clinician that acute viral infections can cause rashes on the skin, which must be differentiated from urticaria. It is appropriate to recall that clinically, urticaria can be manifested by a large number of diseases: somatic, oncological, autoimmune, which requires careful differentiation. No conflict of interests was declared by the authors.

PD-1+ mast cell enhanced by PD-1 blocking therapy associated with resistance to immunotherapy

BackgroundProgrammed cell death protein 1 (PD-1) antibody has been approved for a variety of tumors, but its effective rate is unsatisfactory. New evidence suggests that mast cells are an important component of the tumor microenvironment and are associated with resistance to immunotherapy, but the underlying mechanism is not clear.MethodsBioinformatics analysis of patients with melanoma in TCGA-SKCM and GSE91061 was used to determine the prognostic value of mast cells and their association with anti-PD-1 immunotherapy. HMC-1 cells (mast cell line) and bone marrow-derived mast cells (BMMCs) were used to verify the effect of PD-1 antibody and cromolyn sodium in vitro. The mouse subcutaneous melanoma model was used to verify the effect of the PD-1 antibody on mast cells in vivo.ResultsBioinformatics analysis showed that mast cells were a poor prognostic factor associated with resistance to anti-PD-1 immunotherapy. PD-1 was expressed on the mast cell membrane. The PD-1 antibody promoted the release of histamine and cytokines from mast cells via the PI3K/AKT pathway and calcium signaling pathway. The activation of mast cells induced by PD-1 antibody could be partially inhibited by cromolyn sodium. In vivo, cromolyn sodium increased the efficacy of PD-1 antibody and decreased the infiltration of mast cells and the density of microvessels.ConclusionPD-1+ mast cell activated by PD-1 antibody plays a negative role in the tumor microenvironment via the enhanced function of releasing histamine and cytokines. Inhibition of mast cell may provide a new solution to solve the low response rate of anti-PD-1 immunotherapy.

Prevention of omalizumab for seasonal allergic rhinoconjunctivitis: a retrospective cohort study.

BackgroundAllergic rhinoconjunctivitis (ARC) is an allergic disease that is characterized by conjunctival and nasal symptoms such as edema and congestion of conjunctiva, rhinorrhea, sneezing, and blocked nose. Seasonal ARC (SARC) is usually induced by seasonal allergens and often occurs at specific times during the year. Traditional treatments of SARC include nasal corticosteroids, antihistamines, and mast cell membrane stabilizers. Biological agents such as omalizumab have also been proved effective in the treatment of SARC.ObjectivesWe aim to certify the preventative efficacy of omalizumab for SARC and explore its influence factors.MethodsMedical records of 64 SARC patients were retrospectively analyzed, and generalized linear models were used to analyze influence factors of efficacy of omalizumab.ResultsCompared with forepassed pollen season without omalizumab treatment, the combined symptom and medication score (CSMS) of ARC with pre-seasonal omalizumab was significantly lower (with omalizumab: 0.67[0.00,1.83], without omalizumab: 4.00[2.83,4.96], p<0.001, max score=6). Subgroup analysis was conducted to explore the influence factor of preventative efficacy of omalizumab. The CSMS with omalizumab treatment were not significantly different among different age, gender, dosage, number of injections, and injection date subgroups (p>0.05).ConclusionPre-seasonal omalizumab treatment could significantly relieve SARC related symptoms and reduce medication use. This preventative efficacy would not be influenced by the dosage and number of injections of omalizumab. A single dose of 150mg omalizumab could achieve a satisfactory outcome.

A Novel Method for Treating Bronchial Asthma with Newly Designed Histaglobulin Therapy

Asthma, a chronic inflammatory disease of the airways is considered as an incurable disease and extensive research is going on in developing novel treatment. The objective of the study is to establish that the antihistamine antibody has low serum histamine binding capacity (SHBC) in allergic patients as compared to normal persons and that it can be raised with our novel method of Histaglobulin treatment thereby effecting a ‘cure’ in bronchial asthma. About 67 normal and 135 allergic persons, were identified based on serum level of total immunoglobulin E (IgE) estimated by ELISA. Antihistamine antibody was separated from serum by affinity chromatography. Presence of antihistamine antibody in the elute was confirmed by SDS-PAGE test. The antihistamine antibody was IgG, confirmed by MALDI-TOF analysis. The SHBC of the antihistamine antibody was estimated based on standard curve, plotted with different concentrations of serum antihistamine antibody by histamine ELISA test. Total Immunoglobulin E and SHBC were estimated in 135 allergic patients. In normal and allergic persons, the total IgE level was &lt;100 IU/ml and 200 IU/ml respectively. The average SHBC of normal persons was 116 µg/ml, which was 39% more as compared to allergic patients whose average SHBC before treatment was 83.6 µg/ml. 135 allergic patients were first subjected to antihistamine, mast cell-membrane stabilizers, anti-inflammatory and bronchodilator drugs followed by histaglobulin injection. The SHBC level was raised in 122 (90.4%) patients to an average of 111.6 µg/ml. Overall, 132 (97.8%) allergic patients responded well to our treatment and were free from allergic manifestation throughout the follow-up period of about 5 years. Hence, this novel treatment with histaglobulin which has scientific basis, effective and well tolerated can be adopted across the world for effecting a cure from bronchial asthma and allergic rhinitis.

Mechanism of ketotifen fumarate inhibiting renal calcium oxalate stone formation in SD rats

ObjectivesTo investigate the inhibitory effect of ketotifen fumarate (KFA), a mast cell membrane stabilizer, on renal calcium oxalate stone (CaOx) formation and its possible molecular mechanism. MethodsWe used the Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database for functional and pathway enrichment analyses of osteopontin (OPN), CD44 and fibronectin (FN). Blood biochemistry, reactive oxygen species ratio (ROS), mast cells, proteins (CD44, OPN and FN) and OPN receptor integrin family genes were detected by ELISA, flow cytometry, immunohistochemistry and RT-QPCR, respectively. ResultsThe crystal area of CaOx in the KFA and Control group was significantly smaller than that in the Model group. The number of activated mast cells, the expression levels of OPN and CD44 in the Control and KFA groups were significantly lower than those in the Model group, and the percentage of ROS in the KFA group was also significantly lower than that in the Model group. The mRNA expression levels of ITGB1, ITGA9, ITGAV and ITGA4 genes in the prominent OPN receptor integrin family increased significantly in the Model group. ConclusionsKetotifen can effectively inhibit the crystal formation of CaOx and reduce the inflammatory response of tissue in SD rats. The mechanism may be to reduce the infiltration and activation of mast cells in renal tissue and down-regulate the expression of OPN, CD44 and FN in renal tubules and renal interstitium. And affect the synthesis of integrins (ITGA9, ITGA4, ITGAV, ITGB1, ITGB3 and ITGB5) and ROS.