Non-Nitrogen-Containing Bisphosphonates Prevent Pyrophosphorylation of Exocytosis Proteins.

Background: Clodronate, a non-nitrogen-containing bisphosphonate (non-NBP), is intracellularly converted into non-hydrolyzable ATP analogs. Clodronate and its analogs impair normal cell functions, including the exocytosis process. However, how this occurs in mast cells is still not well characterized.

Inhibition of Histamine Release from RBL-2H3 Cells by Zoledronate Did Not Affect Rab27a/Doc2a Interaction.

Mast cell (MC) exocytosis is organized by prenylated protein, including Rab families. Among Rab proteins, Rab3a, Rab27a, and Rab11 are responsible for exocytosis arrangement. Rab3a and Rab27a are contributed to exocytosis by interacting with other exocytosis proteins.

Radioactive gold nanocluster (198-AuNCs) showed inhibitory effects on cancer cells lines.

Cancer is a global epidemic disease responsible for over ten millions death worldwide. The early diagnosis and the precise treatment with reduced adverse reactions are the main goal worldwide. In this study, we produced, characterized and evaluated ( in three different cancer cell lines (protaste, breast and melanoma) a radioactive gold nanocluster (R-AuNC) (Au25(Capt)18).

Mast cell activation markers for in vitro study.

Mast cells (MCs) are well known for their role in allergic conditions. This cell can be activated by various types of secretagogues, ranging from a small chemical to a huge protein. Mast cell activation by secretagogues triggers the increase in intracellular calcium (iCa) concentration, granule trafficking, and exocytosis.

Tachykinin-1 receptor antagonism suppresses substance-P- and compound 48/80-induced mast cell activation from rat mast cells expressing functional mas-related GPCR B3.

Objective: Mice and rats are important animal models for mast cell (MC) study. However, rat Mas-related-GPCR-B3 receptor (MRGPRB3) has been less studied than its mouse counterpart. Therefore, we aimed to characterize rat MRGPRB3.

Morphological and functional analysis of beige (Chèdiak-Higashi syndrome) mouse mast cells with giant granules.

Chèdiak-Higashi syndrome is a rare autosomal recessive disease that causes hypopigmentation, recurrent infections, mild coagulation defects and neurological problems. Beige mice carry a mutation in the lysosome trafficking regulator (LYST) gene and display some of the key characteristics of human Chèdiak-Higashi syndrome, in particular, a high susceptibility to infection due to aberrant natural killer (NK) cell and polymorphonuclear leucocyte function. Morphological analysis of beige mice reveals the presence of enlarged lysosomes in a variety of cell types, including leucocytes, hepatocytes, fibroblasts and renal tubule cells.

Histamine uptake mediated by plasma membrane monoamine transporter and organic cation transporters in rat mast cell lines.

The resources of released histamine from activated mast cells, as initial effectors of allergic disease, include not only endogenous prepackaged histamine and newly synthesized histamine, but also histamine that is obtained through the de novo reuptake pathway. To investigate the de novo histamine production pathway, a mast cell line, RBL-2H3 Sc98 in which endogenous histamine production is lacking and only the de novo histamine release pathway via transporters is maintained, was used to dissect histamine reuptake in the present study. Histamine content measurements indicated that RBL-2H3 Sc98 cells took up extracellular histamine for storage in granules and subsequent release after stimulation by an antigen.

High-throughput screening system for dynamic monitoring of exocytotic vesicle trafficking in mast cells.

Mast cells, in addition to endocrine cells and neurons, are typical secretory cells. Their function in allergic inflammation is to secrete inflammatory mediators from secretory vesicles. Intracellular synthesized inflammatory mediators are transported by vesicular monoamine transporters (VMATs) to vesicles where they are stored.

Zoledronate modulates intracellular vesicle trafficking in mast cells via disturbing the interaction of myosinVa/Rab3a and sytaxin4/VAMP7.

Nitrogen-containing bisphosphonates (NBPs) have been widely used as bone anti-resorptive drugs for the treatment of osteoclast-dependent bone disorders. Zoledronate is currently the most potent NBP, and has potential as an inhibitor of farnesyl pyrophosphate synthase. The present study was undertaken to elucidate the possible effects of zoledronate on FcεRI-dependent mast cell activity in vitro, which is essential for in maintaining homeostasis of the gastrointestinal mucosa.

Inhibition of the mevalonate pathway by simvastatin interferes with mast cell degranulation by disrupting the interaction between Rab27a and double C2 alpha proteins.

Statins are well-known inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, which block the mevalonate pathway. The activity of statins not only decreases cholesterol levels but also ameliorates inflammation and modulates the immune system. In this study, we investigated the effects of simvastatin on histamine release using rat basophilic leukaemia (RBL-2H3) cells, and examined its interaction with proteins involved in the exocytosis process.

CRACM3 regulates the stability of non-excitable exocytotic vesicle fusion pores in a Ca(2+)-independent manner via molecular interaction with syntaxin4.

Ca(2+) release-activated calcium channel 3 (CRACM3) is a unique member of the CRAC family of Ca(2+)-selective channels. In a non-excitable exocytosis model, we found that the extracellular L3 domain and the cytoplasmic C-terminus of CRACM3 interacted in an activity-dependent manner with the N-peptide of syntaxin4, a soluble N-ethylmaleimide-sensitive factor attachment receptor protein. Our biochemical, electrophysiological and single-vesicle studies showed that knockdown of CRACM3 suppressed functional exocytosis by decreasing the open time of the vesicle fusion pore without affecting Ca(2+) influx, the activity-dependent membrane capacitance (Cm) change, and the total number of fusion events.