Mast cells have gained increased recognition as immunomodulators playing a role in a variety of physiological and pathological processes. They were first described in 1879, but their origin remained controversial for almost a century. Today, it is known that mast cells are present in the bone marrow as committed mast cell precursors. They leave the bone marrow as progenitors and complete their ...

1. In this study mast cells were found to comprise 2.1% of total cells recovered by enzymatic digestion of human lung tissue. 2. This mast cell population consisted of 79% formalin-sensitive, Alcian Blue-positive mast cells and 21% formalin-insensitive, Alcian Blue-positive mast cells. 3. By the use of centrifugal elutriation and subsequent Percoll gradient centrifugation, separate mixed cell p...

Mast cell degranulation is a highly regulated, calcium-dependent process, which is important for the acute release of inflammatory mediators during the course of many pathological conditions. We previously found that Synaptotagmin-2, a calcium sensor in neuronal exocytosis, was expressed in a mast cell line. We postulated that this protein may be involved in the control of mast cell-regulated e...

Rationale: Lymphangioleiomyomatosis (LAM) is a multisystem disease that causes lung cysts and respiratory failure. Loss of TSC (tuberous sclerosis complex) gene function results in clone “LAM cells” with dysregulated mTOR (mechanistic target rapamycin) activity. LAM cells fibroblasts form nodules also contain mast cells, although their significance unknown. Objectives: To understand the mechani...

Mast cells have been implicated in the pathogenesis of fibrosis because of their increased number in chronic inflammatory reactions. In a previous study, we had shown that human mast cells readily attach and form heterotypic cell-cell contacts when seeded on top of fibroblast monolayers. Here, we report that human mast cells stimulate fibroblast proliferation after cell-cell contact. Proliferat...

Zarnegar, B. 2016. Mechanisms triggering the recruitment of mast cell progenitors to the lung and regulation of mast cell degranulation. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine 1274. 51 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-554-9746-0. Mast cells stem from the bone marrow and migrate via the blood as mast cell progenitors. Upon ar...

Aim: Mast cells are versatile innate immune cells and are reported to promote vascular inflammation and neointimal lesion formation, thereby contributing to the development of vascular stenosis and atherosclerosis. However, it is not clear whether mast cells also regulate vascular matrix remodelling in established neointima. This study addressed the hypothesis that perivascular mast cells regul...

The UV radiation in sunlight is the primary cause of skin cancer. UV is also immunosuppressive and numerous studies have shown that UV-induced immune suppression is a major risk factor for skin cancer induction. Previous studies demonstrated that dermal mast cells play a critical role in the induction of immune suppression. Mast cell-deficient mice are resistant to the immunosuppressive effects...

Mast cell activation is associated with atopic and inflammatory diseases, but the natural controls of mast cell homeostasis are poorly understood. We hypothesized that CD4(+)CD25(+) regulatory T cells (Treg) could function in mast cell homeostasis. In this study, we demonstrate that mast cells can recruit both Treg and conventional CD4(+) T cells (Tconv). Furthermore, Treg, but not Tconv, suppr...

Mast cells are known to have a detrimental impact on a variety of pathological conditions. There is therefore an urgent need of developing strategies that limit their harmful effects. The aim of this study was to accomplish this by developing a means of inducing mast cell apoptosis. The strategy was to identify novel compounds that induce mast cell apoptosis by permeabilization of their secreto...