# Function of cementocytes in cellular cementum formation and resorption

> **NIH NIH R03** · OHIO STATE UNIVERSITY · 2020 · $148,304

## Abstract

PROJECT SUMMARY/ABSTRACT
Tooth root cementum plays an essential role in tooth attachment as part of the periodontal complex. Cementum
and bone feature comparable extracellular matrix composition and mineral content, however cementum is non-
innervated, avascular, and exhibits little or no physiological remodeling, growing by apposition throughout life.
Cementum can be compromised by genetic conditions, periodontal diseases, or root resorption, however
therapies for periodontal diseases are currently unpredictable, while those for root resorption are non-existent.
Critical gaps in knowledge about cementum biology present obstacles to more effectively preventing, abrogating,
and reversing periodontal diseases such as apical root resorption. Cementocytes residing in the mineralized
extracellular matrix of the cellular cementum exhibit many similarities to osteocytes, mechanoresponsive cells
found in bone that direct local bone remodeling based on mechanical loading. It has been speculated that
cementocytes may play a regulatory role in cellular cementum formation and/or resorption as osteocytes do in
bone, however, at present this question remains uninvestigated and these hypotheses have not been directly
tested. Evidence for cementocyte functions in cementum formation or resorption include: 1) Cementocytes
present an in vivo and in vitro expression profile parallel to osteocytes; 2) Genetic inactivation causing abnormal
osteocytes and defective bone mineralization show parallel changes in cementocytes and cellular cementum; 3)
Knockout of Sost in mice promotes increased bone from altered osteocyte-osteoblast signaling, and similarly
expanded cellular cementum formation suggests common molecular regulation between cementocytes and
cementoblasts; 4) In a model of experimentally induced apposition (EIA) in mice used to promote rapid, new
cellular cementum deposition, cementocytes exhibited cellular changes and signs of activation, and proteomic
analysis of cellular cementum after EIA identified increased intracellular and cell membrane proteins, evidence
of cementocyte activation; and 5) Cementocytes express osteoclast signal RANKL in vitro and in vivo its
expression is linked to cellular cementum resorption. We hypothesize that cementocytes function in cementum
formation and resorption, and this will be tested by two specific aims: 1) Define the requirement for cementocytes
in cellular cementum apposition using novel transgenic mice in a model of EIA, combined with proteomic
analysis; and 2) Determine the function of cementocytes in cellular cementum resorption using transgenic mice
and a mode of orthodontics -induced apical root resorption and by mechanically loading a cementocyte line in
vitro for gene analysis. Future Research Plans: Experiments will provide the first definitive data on roles of
cementocytes in cementum biology and begin to define molecular signaling pathways involved in cementum
apposition and resorption, providing fundamental and...

## Key facts

- **NIH application ID:** 9890917
- **Project number:** 5R03DE028632-02
- **Recipient organization:** OHIO STATE UNIVERSITY
- **Principal Investigator:** Brian Lee Foster
- **Activity code:** R03 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $148,304
- **Award type:** 5
- **Project period:** 2019-04-01 → 2022-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9890917

## Citation

> US National Institutes of Health, RePORTER application 9890917, Function of cementocytes in cellular cementum formation and resorption (5R03DE028632-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9890917. Licensed CC0.

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