Category: Cellular Technologies

1209-E - Nanoimaging of subcellular structures in activated mast cells using soft X-ray tomography

Wednesday, February 7, 2018
11:30 AM - 12:30 PM

During mast cells activation, they undergo degranulation, a process by which various kinds of mediators stored in the granules are released. Granule homeostasis in mast cells has mainly been studied by electron microscopy (EM), where the fine structures of subcellular organelles are partially destroyed during sample preparation. Migration and fusion of granules have not been studied in detail in three dimensions (3D) in unmodified samples. We have recently utilized soft X-ray tomography (SXT) coupled with fluorescence microscopy to study the detailed structures of intracellular organelles during cell activation. We observed granule fission, granule fusion to plasma membranes, and small vesicles budding from granules. We observed dramatic morphological changes of mitochondria in activated mast cells and 3D-reconstruction revealed the highly folded cristae inner membrane, features of functionally active mitochondria. These observation also showed a giant vesicles called granule-containing vesicles (GCVs). The presence of GCVs have been verified by EM in samples prepared by cryo-substitution and contain sub-cellular vesicles including  granules, mitochondria, and lipid droplets. Thus, our studies using SXT provide significant insights into mast cell activation at the organelle level.

Huan-Yuan Chen

Associate Research Scientist
Nankang, Taipei, Taiwan (Republic of China)

Our laboratory aims to promote research in inflammation and glycomedicine by 1) coordinating the Inflammation discussion, 2) providing reagents/services including those listed under “Service”. Our research is focused on 1) investigation of the functions of galectins in skin inflammation, such as atopic dermatitis, contact dermatitis, and psoriasis, and 2) investigation of the roles of galectin-3 in Alix-mediated functions, such as retrovirus budding and exosome secretion.