Plasma Protein Profiling to Discern Indolent from Advanced Systemic Mastocytosis.

Mastocytosis is a heterogeneous disorder characterized by abnormal mast cell accumulation, in which the clinical severity may be explained by distinct molecular mechanisms. This study aimed to explore plasma protein biomarkers associated with systemic mastocytosis subtypes, as well as the cellular origin of the identified proteins. Plasma samples from patients with mastocytosis, including cutaneous mastocytosis (CM), indolent systemic mastocytosis (ISM), and advanced systemic mastocytosis (AdvSM), and a reference group of patients with polycythemia vera, were analyzed by Proximity Extension Assay technology targeting 275 proteins.

Back to the future: re-establishing guinea pig in vivo asthma models.

Research using animal models of asthma is currently dominated by mouse models. This has been driven by the comprehensive knowledge on inflammatory and immune reactions in mice, as well as tools to produce genetically modified mice. Many of the identified therapeutic targets influencing airway hyper-responsiveness and inflammation in mouse models, have however been disappointing when tested clinically in asthma.

Changing the threshold-Signals and mechanisms of mast cell priming.

Mast cells play a key role in allergy and other inflammatory diseases involving engagement of multivalent antigen with IgE bound to high-affinity IgE receptors (FcεRIs). Aggregation of FcεRIs on mast cells initiates a cascade of signaling events that eventually lead to degranulation, secretion of leukotrienes and prostaglandins, and cytokine and chemokine production contributing to the inflammatory response. Exposure to pro-inflammatory cytokines, chemokines, bacterial and viral products, as well as some other biological products and drugs, induces mast cell transition from the basal state into a primed one, which leads to enhanced response to IgE-antigen complexes.

Knockdown of the antiapoptotic Bcl-2 family member A1/Bfl-1 protects mice from anaphylaxis.

Many forms of hypersensitivity reactions and allergic responses depend on deregulated mast cell activity. Several reports suggested that the antiapoptotic Bcl-2 family protein Bcl2a1/Bfl-1/A1 plays a critical role in mast cell survival upon activation. However, its in vivo relevance is poorly understood because of quadruplication of the Bcl2a1 gene locus in mice, hindering conventional knockout studies.

Mast cell mediators cause early allergic bronchoconstriction in guinea-pigs in vivo: a model of relevance to asthma.

One feature of allergic asthma, the EAR (early allergic reaction), is not present in the commonly used mouse models. We therefore investigated the mediators involved in EAR in a guinea-pig in vivo model of allergic airway inflammation. Animals were sensitized using a single OVA (ovalbumin)/alum injection and challenged with aerosolized OVA on day 14.

Insights into mast cell functions in asthma using mouse models.

Therapeutics targeting specific mechanisms of asthma have shown promising results in mouse models of asthma. However, these successes have not transferred well to the clinic or to the treatment of asthma sufferers. We suggest a reason for this incongruity is that mast cell-dependent responses, which may play an important role in the pathogenesis of both atopic and non-atopic asthma, are not a key component in most of the current asthma mouse models.

Mast cell engraftment of the peripheral lung enhances airway hyperresponsiveness in a mouse asthma model.

Allergic asthma is a chronic inflammatory disease, characterized by airway hyperresponsiveness (AHR), inflammation, and tissue remodeling, in which mast cells play a central role. In the present study, we analyzed how mast cell numbers and localization influence the AHR in a chronic murine model of asthma. C57BL/6 (wild-type) and mast cell-deficient B6.

FcεR1-mediated mast cell reactivity is amplified through prolonged Toll-like receptor-ligand treatment.

Background: Mast cell-derived mediators mediate several of the pathological features of asthma. Microbial infections induce asthma exacerbations in which the contribution of mast cells remains incomprehensible.

Principal Findings: In this study we have investigated the characteristic expression pattern of Toll-like receptors (TLRs) 1-9 and the effect of TLR ligand treatment on IgE-receptor mediated mast cell reactivity.

Distinct platelet packaging, release, and surface expression of proangiogenic and antiangiogenic factors on different platelet stimuli.

The present study characterized platelet secretion and surface expression of proangiogenic stromal cell-derived factor-1α (SDF-1α) and vascular endothelial growth factor (VEGF) and antiangiogenic PF4 and endostatin on activation. The angiogenic factors presented in randomly distributed granules in resting platelets, which were peripherized on activation. Confocal and immunogold electron microscopy demonstrated that SDF-1α/CXCL12 and PF4/CXCL4 mostly present in different granules.