PLC, PTH and NF-κB increased during orthodontic bone remodeling in chronic stress rats

Abstract

This study was designed to investigate the potential effects of chronic stress on periodontal bone remodeling and its mechanism during orthodontic tooth movement in rats. Forty-eight male SD rats aged 8 weeks were randomly divided into control group and chronic stress group. Chronic unpredictable mild stress model (CUMS) was established in the stress group, which was validated by behavioral experiment as well as cortisol (CORT) and adrenocorticotropic hormone (ATCH) levels. Then, the two groups were further divided into three distinct groups, namely group with no orthodontic force, group with 30 g orthodontic force and group with 50 g orthodontic force respectively to construct orthodontic tooth movement model. The rats were sacrificed after 14 days and maxilla on the loading side was obtained to measure tooth movement distance. It was found that compared with the control group, the chronic stress group displayed increased parathyroid hormone (PTH), amino terminal peptide of type I procollagen (PINP) and c-terminal peptide of type I collagen branch (CTX) levels as measured by enzyme-linked immunosorbent assay (ELISA). Hematoxylin and Eosin (HE) and TRAP staining showed fewer osteoblasts and more number of osteoclasts. The results of western blot showed no significant change in expression of Adenylate cyclase (AC) but increased phospholipase C (PLC) levels were noted. In addition, increased NF-κB expression was observed by immunohistochemistry. Overall, chronic stress can affect bone remodeling during orthodontic tooth movement by increasing the content of PTH in the blood and increasing PLC and NF-κB.

Keywords:

• Chronic stress
• parathyroid hormone
• cortisol
• orthodontic tooth movement
• nuclear factor κB protein
• bone remodeling

Acknowledgments

We thank Heilongjiang Provincial Department of Education for supporting this project.

Disclosure statement

The authors report there are no competing interests to declare.

Additional information

Funding

This project entitled “Clinical research on the treatment of malocclusion in children with invisible braces” was funded by Heilongjiang Department of Education. The project number is 2019-KYYWF-1361.

Notes on contributors

Li Xiaotong

Li Xiaotong holds a master's degree in Stomatology from Jiamusi University. Her current research focuses on the relationship between chronic stress and orthodontic tooth movement.

Yu Jiazhi

Yu Jiazhi studied in Jiamusi University for a master's degree in Stomatology. At present, he mainly studies the relationship between chronic stress and orthodontic tooth movement and the role of MiRNA in orthodontic tooth movement.

Li Xiaoguang

Li Xiaoguang is an associate professor of stomatology at Jiamusi University. Her research interests include the relationship between chronic stress and orthodontic tooth movement as well as invisible orthodontic research.

Zhao Gang

Zhao Gang is a professor of stomatology at Jiamusi University. His research interests include the relationship between chronic stress and orthodontic tooth movement, drug therapy for oral squamous cell carcinoma, etc.