Uday Parom
Research Mentor: Yuji Mishina
Mentor Department: Biological and Material Sciences, Dentistry
Author(s): Uday Parom, Mylene Martins, Yuji Mishina
Session: Session 5 (2:00 PM – 2:50 PM)
Presentation Type: Poster 39
Abstract
The coordinated activity between osteoblasts, bone forming cells, and osteoclasts, bone-resorbing cells, is essential for maintaining bone homeostasis. Previous studies have revealed how osteoblasts communicate to osteoclasts through the RANKL/RANK pathway, where osteoblasts produce RANKL to activate osteoclasts via their RANK receptor. The communication pathway from osteoclasts to osteoblasts has also been discovered, such as Ephrin-Eph signaling, Semaphorins, and BMP signaling, which regulate osteoblast differentiation. Despite significant progress in characterizing these communication pathways, quantifiable data on the specific pathways that drive postnatal bone development remains limited. To address this, this study aims to quantitatively analyze the ratio and spatial distribution of osteoblasts and osteoclasts in the subchondral bone of the distal femur at two postnatal developmental stages, early juvenile (P23) and early adulthood (2 months), establishing baseline cellular ratios and distribution patterns in mice under physiological conditions. A comprehensive quantitative and spatial characterization of osteoblast and osteoclast populations would allow us to hypothesize intercellular communication at distinct developmental stages, forming a basis for future studies. Moreover, such data would contextualize the design of age-appropriate therapeutic interventions, including the optimization of dosage parameters and anatomical targeted drug delivery systems. For analysis, Col1a1-GFP; Rosa26-tdTomato reporter mice were dissected under physiological conditions. Samples were fixed in paraformaldehyde (PFA), decalcified using EDTA, cryoprotected, embedded in optimal cutting temperature (OCT) compound, and rapidly frozen at -75 °C prior to cryosectioning at 10 µm. Sections were stained with DAPI and imaged using confocal microscopy to quantify total cell number and spatial organization. Preliminary results suggest increased Osteoblast activity, and a longer epiphyseal growth plate at P23 compared to 2 months old mice.
