Poster 1: Cell and Tissue Studies

Rosa Guerra, Megan Coffin, Shannon Modla, Velia Fowler, Liyun Wang

University of Delaware

Osteocytes are the master orchestrator of bone remodeling, and their dendrites enable them to communicate with other cells. With aging, osteocyte dendrites deteriorate leading to declined bone quality. Similar to epithelial microvilli and inner ear stereocilia, osteocyte dendrite integrity is thought to depend on tightly packed cross-linked F-actin bundles. However, the dendrite cytoskeleton details remain unclear due to technical challenges. In this study, we screened three RNA sequencing databases and identified four candidate F-actin cross-linkers. Our approach is to detect if they are present in osteocytes using immunohistochemistry and then dissect their role in dendrite structure via gene deletion. The protocols of cell culture, immunohistology, confocal and high-resolution STED imaging, and transmission electron microscopy (TEM) are being optimized. The objectives are to form long dendrites, preserve F-actin filaments and cross-linkers, and image F-actin and cross-linkers in normal and gene-deleted osteocytes. Our pilot data demonstrated multiple F-actin filaments within the dendrite and fimbrin (a known F-actin cross-linker) expressed in both cytoplasm and dendrites. Our long-term goal is to uncover the molecular mechanisms underlying the osteocyte dendrite formation, maintenance, and eventual decline with aging.

Research Area: Bone