Resting and actively degranulating mast cells are found on the brain side of the blood-brain barrier. In the periphery, exocytosis of mast cell granules results in the release of soluble mediators and insoluble granule remnants. These mast cell constituents are found in a variety of nearby cell types, acquired by fusion of granule and cellular membranes or by cellular capture of mast cell granu...

We previously reported that mast cells express renin, the rate-limiting enzyme in the renin-angiotensin cascade. We have now assessed whether mast cell renin release triggers angiotensin formation in the airway. In isolated rat bronchial rings, mast cell degranulation released enzyme with angiotensin I-forming activity blocked by the selective renin inhibitor BILA2157. Local generation of angio...

Primate alpha-chymases are mast cell neutral proteases that are involved in regulating several regulatory peptides including angiotensin II. Because of significant substrate specificity differences among the chymase group of enzymes, animal models that overexpress primate chymases are crucial for delineating the in vivo function of these enzymes. Activation of alpha-prochymase requires processi...

Introduction: Positive effects of topical application of honey on open skin wounds have been observed, Mast cell are playing role in normal wound healing and its disturbances but the role of mast cells in wound healing in existence of honey is uncertain. Objective: The aim of this investigation was to study the effects of two times per day topical application of honey on the number of mas...

Primary cutaneous lymphomas (PCLs) are clonal Tor B-cell neoplasms, which originate in the skin. In recent years, mast cells were described as regulators of the tumor microenvironment in different human malignancies. Here, we investigated the role of mast cells in the tumor microenvironment of PCL. We found significantly increased numbers of mast cells in skin biopsies from patients with cutane...

Mast cells are well positioned in host tissue for detecting environmental signals, including allergens, leading to activation of the high-affinity IgE receptor FcεRI, and initiating a signaling cascade that perpetuates the production of biologically potent mediators, including chemokines. We have identified a novel target of mast cell FcεRI activity in the transcription factor early growth resp...

Angiogenesis is in part related to mast cells. However, the biological significance of mast cells within lung carcinoma remains unclear. Immunohistochemistry was used to stain for tryptase, CD34 and vascular endothelial growth factor (VEGF) in 85 cases of stage I nonsmall cell lung carcinoma. VEGF was found in 33 of 53 adenocarcinomas and 14 of 32 squamous cell carcinomas. Cases of adenocarcino...

Two different types of cells in the peritoneal cavity of mice produce mast cell colonies in methylcellulose. "Large" mast cell colonies are produced by bone marrow-derived precursors resembling lymphoid cells by light microscopy (L-CFU-Mast), whereas "medium" and "small" mast cell colonies are produced by morphologically identifiable mast cells (M-CFU-Mast and S-CFU-Mast, respectively). In the ...

Increased mast cell burden is observed in the inflamed tissues and affected organs and tissues of patients with mast cell proliferative disorders. However, normal mast cells participate in host defense, so approaches to preferentially target clonally expanding mast cells are needed. We found that mammalian target of rapamycin complex 1 (mTORC1) and 2 (mTORC2) are up-regulated in neoplastic and ...

Background: Spermatogenesis is under the control of variety of factors, which include mast cells. Any changes in testicular mast cells’ number and distribution resulting in deterioration of comlex regulation and fine-turning of spermatogenesis. Increased number of mast cells and their abnormal spread pattern have been described in the testis with fertility disturbances. Mast cells’ tryptase enz...