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

miR-708-3p targetedly regulates LSD1 to promote osteoblast differentiation of hPDLSCs in periodontitis

Periodontitis (PD) is a multifactorial inflammatory disease associated with periodontopathic bacteria. Lysine-specific demethylase 1 (LSD1), a type of histone demethylase, has been implicated in the modulation of the inflammatory response process in oral diseases by binding to miRNA targets. This study investigates the molecular mechanisms by which miRNA binds to LSD1 and its subsequent effect on osteogenic differentiation. First, human periodontal ligament stem cells (hPDLSCs) were isolated, cultured, and characterized. These cells were then subjected to lipopolysaccharide (LPS) treatment to induce inflammation, after which osteogenic differentiation was initiated. qPCR and western blot were employed to monitor changes in LSD1 expression. Subsequently, LSD1 was silenced in hPDLSCs to evaluate its impact on osteogenic differentiation. Through bioinformatics and dual luciferase reporter assay, miR-708-3p was predicted and confirmed as a target miRNA of LSD1. Subsequently, miR-708-3p expression was assessed, and its role in hPDLSCs in PD was evaluated through overexpression. Using chromatin immunoprecipitation (ChIP) and western blot assay, we explored the potential regulation of osterix (OSX) transcription by miR-708-3p and LSD1 via di-methylated H3K4 (H3K4me2). Finally, we investigated the role of OSX in hPDLSCs. Following LPS treatment of hPDLSCs, the expression of LSD1 increased, but this trend was reversed upon the induction of osteogenic differentiation. Silencing LSD1 strengthened the osteogenic differentiation of hPDLSCs. miR-708-3p was found to directly bind to and negatively regulate LSD1, leading to the repression of OSX transcription through demethylation of H3K4me2. Moreover, overexpression of miR-708-3p was found to promote hPDLSCs osteogenic differentiation in inflammatory microenvironment. However, the protective effect was partially attenuated by reduced expression of OSX. Our findings indicate that miR-708-3p targetedly regulates LSD1 to enhance OSX transcription via H3K4me2 methylation, ultimately promoting hPDLSCs osteogenic differentiation.

Porphyromonas gingivalis LPS-stimulated BMSC-derived exosome promotes osteoclastogenesis via miR-151-3p/PAFAH1B1

OBJECTIVES

Porphyromonas gingivalis-LPS regulated bone metabolism by triggering dysfunction of osteoblasts directly, and affecting activity of osteoclasts through intracellular communication. Exosome, as the mediator of intercellular communication, was important vesicle to regulate osteogenesis and osteoclastogenesis. This research was designed for investigating the mechanism of BMSCs-EXO in modulating osteoclastic activity under the P. gingivalis-LPS.

MATERIALS AND METHODS

The cytotoxicity and osteogenic effects of P. gingivalis-LPS on BMSCs was evaluated, and then osteoclastic activity of RAW264.7 co-cultured with exosomes was detected. Besides, Affymetrix miRNA array and luciferase reporter assay were used to identify the target exosomal miRNA signal pathway.

RESULTS

BMSCs' osteogenic differentiation and proliferation were decreased under 1 and 10 μg/mL P. gingivalis-LPS. Osteoclastic-related genes and proteins levels were promoted by P. gingivalis-LPS-stimulated BMSCs-EXO. Based on the miRNA microarray analysis, exosomal miR-151-3p was lessened in BMExo-LPS group, which facilitated osteoclastic differentiation through miR-151-3p/PAFAH1B1.

CONCLUSIONS

Porphyromonas gingivalis-LPS could regulated bone metabolism by inhibiting proliferation and osteogenesis of BMSCs directly. Also, P. gingivalis-LPS-stimulated BMSCs-EXO promoted osteoclastogenesis via activating miR-151-3p/PAFAH1B1 signal pathway.

PANoptosis is a compound death in periodontitis: A systematic review of ex vivo and in vivo studies

OBJECTIVE

The purpose of the systematic review is to verify the presence of PANoptosis in periodontitis based on the published literatures studying cell death in periodontitis.

MATERIALS AND METHODS

We conducted a comprehensive review of literature studying the types of cell death in vitro cellular experiments, in vivo rodent studies and clinical studies from three major databases: PubMed, Scopus, and Web of Science. The present systematic review was recorded in the PROSPERO database, under registration number CRD42022383456.

RESULTS

In total, 51 articles were included in this study. Our analysis of in vitro cell models revealed that pyroptosis, necroptosis, and apoptosis could be induced by periodontal pathogens in macrophages, fibroblasts, stem cells, and periodontal ligament cells. Furthermore, three types of cell death were detected in in vivo rodent periodontitis models. Clinical studies on human periodontitis tissue specimens and gingival crevicular fluid (GCF) showed that some key proteins related to pyroptosis, necroptosis, and apoptosis were elevated in periodontitis.

CONCLUSIONS

Various studies have established similar in vivo and in vitro models with three modes of death detected under the same conditions, revealing complex interactions between different types of cell death pathways in periodontitis and the potential for PANoptosis to occur in periodontitis.

Role of transient receptor potential ankyrin 1 in idiopathic pulmonary fibrosis: modulation of M2 macrophage polarization

Idiopathic pulmonary fibrosis (IPF) poses significant challenges due to limited treatment options despite its complex pathogenesis involving cellular and molecular mechanisms. This study investigated the role of transient receptor potential ankyrin 1 (TRPA1) channels in regulating M2 macrophage polarization in IPF progression, potentially offering novel therapeutic targets. Using a bleomycin-induced pulmonary fibrosis model in C57BL/6J mice, we assessed the therapeutic potential of the TRPA1 inhibitor HC-030031. TRPA1 upregulation was observed in fibrotic lungs, correlating with worsened lung function and reduced survival. TRPA1 inhibition mitigated fibrosis severity, evidenced by decreased collagen deposition and restored lung tissue stiffness. Furthermore, TRPA1 blockade reversed aberrant M2 macrophage polarization induced by bleomycin, associated with reduced Smad2 phosphorylation in the TGF-β1-Smad2 pathway. In vitro studies with THP-1 cells treated with bleomycin and HC-030031 corroborated these findings, highlighting TRPA1's involvement in fibrotic modulation and macrophage polarization control. Overall, targeting TRPA1 channels presents promising therapeutic potential in managing pulmonary fibrosis by reducing pro-fibrotic marker expression, inhibiting M2 macrophage polarization, and diminishing collagen deposition. This study sheds light on a novel avenue for therapeutic intervention in IPF, addressing a critical need in the management of this challenging disease.

Identifying Oxidative Stress-Related Genes (OSRGs) as Potential Target for Treating Periodontitis Based on Bioinformatics Analysis

BACKGROUND

Periodontitis (PD) is a multifactorial inflammatory disease that is closely associated with periodontopathic bacteria. Numerous studies have demonstrated oxidative stress (OS) contributes to inflammation and is a prime factor in the development of PD. It is imperative to explore the function of newly discovered hub genes associated with OS in the advancement of PD, thereby identifying potential targets for therapeutic intervention.

OBJECTIVES

The goal of the current study was to identify the oxidative-stress-related genes (OSRGs) associated with periodontitis (PD) development using an integrated bioinformatics method.

METHODS

DEGs from GEO gene-expression data were identified using the "limma" package. We obtained OSRGs from GeneCards and utilized a Venn diagram to uncover differentially expressed OSRGs (DEOSRGs). After receiving the DEOSRGs, we employed Gene Ontology (GO), Kyoto Encyclopaedia of Genes and Genomes (KEGG), and protein-protein interaction (PPI) analytical tools to examine their possible functions and pathways in PD. Receiver operating characteristic (ROC) curves screened for hub genes of PD. RT-qPCR and western blot analysis were used to detect DEOSRG expression in mouse ligature-induced periodontitis gingival tissues.

RESULTS

The investigation identified 273 OSRGs. Based on PPI analysis, we recognized 20 OSRGs as hub genes. GO and KEGG enrichment analysis indicated that these hub genes were predominantly enriched in leukocyte migration, lymphocyte proliferation, and humoral immune response, and associated with leukocyte trans-endothelial migration, cytokine-cytokine receptor interaction, and NF-κB signaling pathway. Following ROC analysis, VCAM1, ITGAM, FCGR3A, IL1A, PECAM1, and VCAM1were identified as PD prognostic gene. RT-qPCR and western blot analyses confirmed that the expression ITGAM, FCGR3A, and PECAM1 were significantly elevated in the gingival tissues obtained from mice.

CONCLUSION

This investigation revealed that ITGAM, FCGR3A, and PECAM1 may have a crucial function in the advancement of PD.

Acetylshikonin induces apoptosis through the endoplasmic reticulum stress-activated PERK/eIF2α /CHOP axis in oesophageal squamous cell carcinoma

Acetylshikonin (AS) is an active component of Lithospermum erythrorhizon Sieb. et Zucc that exhibits activity against various cancers; however, the underlying mechanisms of AS against oesophageal squamous carcinoma (ESCC) need to be elusive. The research explores the anti-cancer role and potential mechanism of AS on ESCC in vitro and in vivo, providing evidences for AS treatment against ESCC. In this study, we firstly demonstrated that AS treatment effectively inhibits cell viability and proliferation of ESCC cells. In addition, AS significantly induces G1/S phage arrest and promotes apoptosis in ESCC cell lines. Further studies reveal that AS induces ER stress, as observed by dose- and time-dependently increased expression of BIP, PDI, PERK, phosphorylation of eIF2α , CHOP and splicing of XBP1. CHOP knockdown or PERK inhibition markedly rescue cell apoptosis induced by AS. Moreover, AS treatment significantly inhibits ESCC xenograft growth in nude mice. Elevated expression of BIP and CHOP is also observed in xenograft tumours. Taken together, AS inhibits proliferation and induces apoptosis through ER stress-activated PERK/eIF2α /CHOP pathway in ESCC, which indicates AS represents a promising candidate for ESCC treatment.

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

Melanocytes stimulated by ultraviolet radiation (UVR) produce melanin and melanosomes, which causes skin pigmentation and acts as an important physiological defence process for photoprotection. Neutral luminal pH of melanosomes is critical for providing optimal conditions for the rate-limiting, pH-sensitive melanin synthesizing enzyme tyrosinase (TYR). As a major component of extraocular phototransduction pathway, transient receptor potential ankyrin1 (TRPA1) can be activated by ultraviolet B (UVB) and reported to be expressed in melanocytes. However, whether TRPA1 is involved in the regulation of melanogenesis remains unclear. Melanogenic activity of TRPA1 was evaluated in primary normal human epidermal melanocytes (HEMs) and murine B16-F10 cell cultures, and the effects of topical applications of TRPA1 specific agonist and antagonist on UVB-induced skin pigmentation were confirmed on in vivo guinea pig models. Calcium (Ca²⁺ ) imaging and pH imaging were performed to analyse the effects of TRPA1 on intracellular Ca²⁺ concentration ([Ca²⁺ ]_ic ) and melanosome luminal pH. TRPA1 regulated melanin synthesis, UVB-induced Ca²⁺ influx and melanosome luminal pH in HEMs and B16-F10 cells. Topical treatment of TRPA1 specific agonist JT010 increased UVB-induced skin pigmentation in guinea pigs, while topical using of TRPA1 selective antagonist HC-030031 mitigated such pigmentation. Our results indicated that TRPA1 activated by UVB enhanced the skin pigmentation, most likely by regulating the [Ca²⁺ ]_ic and the melanosomal pH, consequently influencing the enzymatic activity of TYR. Therefore, the results suggest TRPA1 as a potential therapeutic target in the treatment of skin pigmented disorders that are at high risk under UVB irradiation.

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

The effective treatment for periodontitis is to completely and sustainedly eradicate the bacterial pathogens from the complex periodontal pockets. Local sustained-release antibiotics as a complementary treatment after scaling and root planning can sustainedly combat bacterial pathogens in the periodontal pockets to help treat the disease, but the increasing concern of bacterial resistance limits its future use. Here, we reported a local antibacterial system based on microsized multifunctional Ag-TiO_2-x encapsulated in alginate (ATA) microspheres. We confirmed that ATA displayed strong photothermally enhanced dual enzyme-mimicking (peroxidase-like and catalase-like) activities and weak photocatalytic activity under 808 nm near-infrared (NIR) irradiation, which could boost the generation of reactive oxygen species (ROS) and O₂ in the presence of low-level H₂O₂. As a result, the ATA/H₂O₂/NIR system exhibited efficient antibacterial activity against Porphyromonas gingivalis and Streptococcus gordonii in both planktonic and biofilm forms. With the help of ROS, ATA could release Ag⁺ in concentrations sufficient to inhibit periodontal pathogens as well. Moreover, the in situ-generated oxygen was supposed to alleviate the local hypoxic environment and would help downregulate the lipopolysaccharide-mediated inflammatory response of periodontal stem cells. The in vivo rat periodontitis treatment results demonstrated that the ATA/H₂O₂/NIR system reduced the bacterial load, relieved inflammation, and improved tissue healing. Our work developed a new local prolonged bactericidal and oxygenation system for enhanced periodontitis. Avoiding the usage of antibiotics and nanomaterials, this strategy showed great promise in adjunctive periodontitis treatment and also in other biomedical applications.

Inflammation-the role of TRPA1 channel

Recently, increasing numbers of studies have demonstrated that transient receptor potential ankyrin 1 (TRPA1) can be used as a potential target for the treatment of inflammatory diseases. TRPA1 is expressed in both neuronal and non-neuronal cells and is involved in diverse physiological activities, such as stabilizing of cell membrane potential, maintaining cellular humoral balance, and regulating intercellular signal transduction. TRPA1 is a multi-modal cell membrane receptor that can sense different stimuli, and generate action potential signals after activation via osmotic pressure, temperature, and inflammatory factors. In this study, we introduced the latest research progress on TRPA1 in inflammatory diseases from three different aspects. First, the inflammatory factors released after inflammation interacts with TRPA1 to promote inflammatory response; second, TRPA1 regulates the function of immune cells such as macrophages and T cells, In addition, it has anti-inflammatory and antioxidant effects in some inflammatory diseases. Third, we have summarized the application of antagonists and agonists targeting TRPA1 in the treatment of some inflammatory diseases.

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

Background and Objective. Oxidative stress has been associated with the progression of periodontitis. However, oxidative stress-related genes (OS-genes) have not been used as disease-specific biomarkers that correlate with periodontitis progression. This study is aimed at screening the key OS-genes and pathways in periodontitis by bioinformatics methods. Methods. The differentially expressed genes (DEGs) were identified using periodontitis-related microarray from the GEO database, and OS-genes were extracted from GeneCards database. The intersection of the OS-genes and the DEGs was considered as oxidative stress-related DEGs (OS-DEGs) in periodontitis. The Pearson correlation and protein-protein interaction analyses were used to screen key OS-genes. Gene set enrichment, functional enrichment, and pathway enrichment analyses were performed in OS-genes. Based on key OS-genes, a risk score model was constructed through logistic regression, receiver operating characteristic curve, and stratified analyses. Results. In total, 74 OS-DEGs were found in periodontitis, including 65 upregulated genes and 9 downregulated genes. Six of them were identified as key OS-genes (CXCR4, SELL, FCGR3B, FCGR2B, PECAM1, and ITGAL) in periodontitis. All the key OS-genes were significantly upregulated and associated with the increased risk of periodontitis. Functional enrichment analysis showed that these genes were mainly associated with leukocyte cell-cell adhesion, phagocytosis, and cellular extravasation. Pathway analysis revealed that these genes were involved in several signaling pathways, such as leukocyte transendothelial migration and osteoclast differentiation. Conclusion. In this study, we screened six key OS-genes that were screened as risk factors of periodontitis. We also identified multiple signaling pathways that might play crucial roles in regulating oxidative stress damage in periodontitis. In the future, more experiments need to be carried out to validate our current findings.