# Spatial correlation of osteocyte gene response to local mechanical strain in bone tissue

> **NIH NIH R21** · UNIVERSITY OF NOTRE DAME · 2021 · $164,851

## Abstract

Project Summary
There were more than 2 million osteoporotic fractures in the U.S. in 2005, which exceeded the incidence of
heart attack, stroke, and breast cancer combined. Osteoporotic fractures are associated with a high level of
mortality and morbidity; more than one in five patients who suffer a hip fracture will die within one year due to
causes related to their injury. The annual medical costs exceeded $17 billion in 2005 and are expected to
increase to $25 billion by 2025.
Bone physiology and adaptation are regulated by mechanical loading, which alters gene and protein
expression in bone cells. Mechanical loads on bone are sensed by osteocytes embedded in the bone that
signal to progenitor cells on the bone surface and in the marrow. Experiments have identified threshold levels
of bone strain and cell shear stress that trigger osteocyte signaling, but are generally aggregated over many
cells or larger regions of bone. These measures provide limited information about the stochastic or variable
nature of cell responses to load.
In the near future, computational power will allow models of bone adaptation incorporating response to
individual cell signaling molecules to be employed to explore bone physiology and predict the response of
bone to new treatments. Such models will provide better insight into experimental and clinical data related to
bone diseases. In anticipation of these models, the goal of this project is to measure the probability of
expression of key signaling genes in osteocytes based on the local mechanical environment. The aims are to
measure gene expression in bone subsequent to controlled loading in a bioreactor system, calculate the stress
field using high-fidelity computational models, and perform spatial correlations to determine the likelihood of
altered gene expression for a given mechanical environment.

## Key facts

- **NIH application ID:** 10129902
- **Project number:** 5R21AR075937-02
- **Recipient organization:** UNIVERSITY OF NOTRE DAME
- **Principal Investigator:** GLEN L NIEBUR
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $164,851
- **Award type:** 5
- **Project period:** 2020-04-01 → 2023-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10129902

## Citation

> US National Institutes of Health, RePORTER application 10129902, Spatial correlation of osteocyte gene response to local mechanical strain in bone tissue (5R21AR075937-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10129902. Licensed CC0.

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