Increased apoptosis of gingival epithelium is associated with impaired autophagic flux in medication-related osteonecrosis of the jaw

Xian Dong; Yang He; Jingang An; Linhai He; Yi Zheng; Xinyu Wang; Jie Wang; Shuo Chen; Yi Zhang

doi:10.1080/15548627.2023.2234228

Increased apoptosis of gingival epithelium is associated with impaired autophagic flux in medication-related osteonecrosis of the jaw

Autophagy. 2023 Nov;19(11):2899-2911. doi: 10.1080/15548627.2023.2234228. Epub 2023 Jul 21.

Authors

Xian Dong¹, Yang He¹, Jingang An¹, Linhai He^{1

2}, Yi Zheng¹, Xinyu Wang¹, Jie Wang¹, Shuo Chen¹, Yi Zhang¹

Affiliations

¹ Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology & National Center for Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing, China.
² First Clinical Division, Peking University School Hospital of Stomatology, Beijing, China.

PMID: 37477258
PMCID: PMC10549186 (available on 2024-07-21)
DOI: 10.1080/15548627.2023.2234228

Abstract

Macroautophagy/autophagy has both negative and positive aspects in the development of many diseases. Yet, its exact role and specific mechanism in the onset of medication-related osteonecrosis of the jaw (MRONJ) is still not fully understood. Retarded gingiva healing is the primary clinical manifestation in patients with MRONJ. In this study, we aimed to explore the relationship between autophagy and apoptosis in MRONJ gingival epithelium and search for a method to prevent this disease. First, we examined clinical samples from patients diagnosed with MRONJ and healthy controls, finding that autophagy-related markers MAP1LC3/LC3 and SQSTM1/p62 synchronously increased, thus suggesting that autophagic flux was suppressed in MRONJ. Moreover, mRNA sequencing analysis and TUNEL assay showed that the process of apoptosis was upregulated in patients and animals with MRONJ, indicating autophagy and apoptosis participate in the development of MRONJ. Furthermore, the level of autophagy and apoptosis in zoledronic acid (ZA)-treated human keratinocytes cell lines (HaCaT cells) was concentration dependent in vitro. In addition, we also found that RAB7 (RAB7, member RAS oncogene family) activator ML098 could rescue MRONJ gingival lesions in mice by activating the autophagic flux and downregulating apoptosis. To sum up, this study demonstrated that autophagic flux is impaired in the gingival epithelium during MRONJ, and the rescued autophagic flux could prevent the occurrence of MRONJ.Abbreviations: ACTB: actin beta; Baf-A1: bafilomycin A₁; CASP3: caspase 3; CASP8: caspase 8; CT: computed tomography; DMSO: dimethyl sulfoxide; GFP: green fluorescent protein; HaCaT cells: human keratinocytes cell lines; H&E: hematoxylin and eosin; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MRONJ: medication-related osteonecrosis of the jaw; PARP: poly(ADP-ribose) polymerase; RAB7: RAB7, member RAS oncogene family; RFP: red fluorescent protein; SQSTM1/p62: sequestosome 1; TEM: transmission electron microscopy; ZA: zoledronic acid.

Keywords: Apoptosis; autophagic flux; gingival epithelium; keratinocytes; medication-related osteonecrosis of the jaw; zoledronic acid.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Apoptosis* / genetics
Autophagy* / physiology
Epithelium / metabolism
Humans
Mice
Sequestosome-1 Protein / metabolism
Zoledronic Acid

Substances

Sequestosome-1 Protein
Zoledronic Acid

Grants and funding

The work was supported by the National Natural Science Foundation of China [82101041]; Beijing Natural Science Foundation [7202234]; Beijing Natural Science Foundation [7222223]; the Youth Found of Peking University School and Hospital of Stomatology [PKUSS20200110].