Inhibition of TRPA1 Ameliorates Periodontitis by Reducing Periodontal Ligament Cell Oxidative Stress and Apoptosis via PERK/eIF2α/ATF-4/CHOP Signal Pathway

Abstract

Objective. In periodontitis, excessive oxidative stress combined with subsequent apoptosis and cell death further exacerbated periodontium destruction. TRPA1, an important transient receptor potential (TRP) cation channel, may participate in the process. This study is aimed at exploring the role and the novel therapeutic function of TRPA1 in periodontitis. Methods. Periodontal ligament cells or tissues derived from healthy and periodontitis (PDLCs/Ts and P-PDLCs/Ts) were used to analyze the oxidative and apoptotic levels and TRPA1 expression. TRPA1 inhibitor (HC030031) was administrated in inflammation induced by P. gingivalis lipopolysaccharide (P.g.LPS) to investigate the oxidative and apoptotic levels of PDLCs. The morphology of the endoplasmic reticulum (ER) and mitochondria was identified by transmission electron microscope, and the PERK/eIF2α/ATF-4/CHOP signal pathways were detected. Finally, HC030031 was administered to periodontitis mice to evaluate its effect on apoptotic and oxidative levels in the periodontium and the relieving of periodontitis. Results. The oxidative, apoptotic levels and TRPA1 expression were higher in P-PDLC/Ts from periodontitis patients and in P.g.LPS-induced inflammatory PDLCs. TRPA1 inhibitor significantly decreased the intracellular calcium, oxidative stress, and apoptosis of inflammatory PDLCs and decreased ER stress by downregulating PERK/eIF2α/ATF-4/CHOP pathways. Meanwhile, the overall calcium ion decrease induced by EGTA also exerted similar antiapoptosis and antioxidative stress functions. In vivo, HC030031 significantly reduced oxidative stress and apoptosis in the gingiva and periodontal ligament, and less periodontium destruction was observed. Conclusion. TRPA1 was highly related to periodontitis, and TRPA1 inhibitor significantly reduced oxidative and apoptotic levels in inflammatory PDLCs via inhibiting ER stress by downregulating PERK/eIF2α/ATF-4/CHOP pathways. It also reduced the oxidative stress and apoptosis in periodontitis mice thus ameliorating the development of periodontitis.

Identification of Key Genes and Pathways Associated with Oxidative Stress in Periodontitis

“…In recent years, increasing evidence has shown that oxidative stress plays an important role in the pathogenesis of various types of chronic inflammation, including periodontitis [ 13 ]. It has been demonstrated previously that protecting periodontal tissues or cells from oxidative stress by blocking OS-gene activation in inflammation can reduce periodontal tissue loss [ 12 ]. Although many publications have reported on oxidative stress biomarker levels in patients with periodontitis, very few studies evaluate the OS-genes in the pathogenesis of periodontitis [ 8 ].…”

“…Oxidative stress is generally regulated by differentially expressed oxidative stress-related genes (OS-genes) that are responsible, both directly and indirectly, for the pathogenesis of diseases [ 10 , 11 ]. Up to now, only a small fraction of OS-genes has been studied intensively and is known to play an essential role in periodontitis progression [ 12 ]. Hence, identifying more key OS-genes may help validate the underlying mechanisms of periodontitis and offer therapeutic strategies for these patients.…”

Near-Infrared-Enhanced Dual Enzyme-Mimicking Ag–TiO2–x@Alginate Microspheres with Antibactericidal and Oxygeneration Abilities to Treat Periodontitis

“…After obtaining informed consent, periodontal ligament stem cells (PDLSCs) were obtained from the orthodontic teeth extracted from patients aged 15–45 years as described in the previous literature …”

“…After obtaining informed consent, periodontal ligament stem cells (PDLSCs) were obtained from the orthodontic teeth extracted from patients aged 15− 45 years as described in the previous literature. 38 The cytotoxicity of ATA was evaluated by the CCK8 assay and live/ dead staining, in which pure alginate (A) microspheres were used as a negative control. In detail, PDLSCs were first seeded in a 24-well Transwell plate (2 × 10 4 cells per well) for 12 h to ensure cell adhesion.…”

TRPA1 promotes UVB‐induced skin pigmentation by regulating melanosome luminal pH

“…B16-F10 cells were seeded in a 6-well plate at a density of 1.5 × 10 5 cells/well. After 24 h of incubation, cells were treated with HA-TRPA1 plasmid transfection, or TRPA1-shRNA adenovirus infection for 48 h, JT010 (1 μM) 27 or HC-030031(10 μM) 28,29 for 30 min, or 25 mJ/cm 2 UVB irradiation. 20 The UVB irradiation in vitro was performed using a UVB lamp (290-320 nm, SS-01, Sigma) with 5 mW/ cm 2 for 5 s. The UVB intensity was measured and calibrated by a UV meter (Sigma).…”