Role of ferroptosis in periodontitis: An animal study in rats

Iron Status and Risk of Periodontitis and Dental Caries: A Mendelian Randomization Study

BACKGROUND

Previous studies have indicated a potential relationship between iron status and oral health outcomes, specifically periodontitis and dental caries. This study employed Mendelian randomization (MR) to investigate the causal effects of iron status on these oral health conditions. The focus of this study was on key iron biomarkers, namely serum iron, ferritin, transferrin saturation (TSAT), and total iron-binding capacity (TIBC).

METHODS

This two-sample MR analysis employed genome-wide association study (GWAS) data. The instrumental variables (IVs) were selected based on their genome-wide significance and independence from confounders. The statistical analyses employed the inverse variance weighted (IVW) method, MR-Egger regression, weighted median, and weighted mode. Additionally, sensitivity analyses were conducted to verify the reliability of the causal association results.

RESULTS

The MR analysis indicated a suggestive negative causal relationship between TIBC and periodontitis, with an odds ratios of 0.875 and a 95% CI of 0.766-0.998, with a P-value of .047. No significant other associations were found. The results of sensitivity analyses demonstrated the robustness of these findings.

CONCLUSION

This MR study suggested a potential negative association between TIBC and periodontitis, highlighting the importance of considering iron status in the clinical management of chronic periodontitis. However, more standardized, multi-population studies are needed to confirm this causality.

Crosstalk between neuroinflammation and ferroptosis: Implications for Parkinson's disease progression

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by the degeneration of dopaminergic neurons and the aggregation of α-synuclein. Neuroinflammation is triggered by the activation of microglia and astrocytes, which release pro-inflammatory factors that exacerbate neuronal damage. This inflammatory state also disrupts iron homeostasis, leading to the occurrence of ferroptosis. Ferroptosis is characterized by lipid peroxidation of cell membranes and iron overload. Abnormal accumulation of iron in the brain increases oxidative stress and lipid peroxidation, further aggravating neuroinflammation and damage to dopaminergic neurons. Natural products have garnered attention for their antioxidant, anti-inflammatory, and neuroprotective properties, with many plant extracts showing promising therapeutic potential in PD research. This study further investigates the potential therapeutic roles of various natural products in regulating neuroinflammation and ferroptosis. The results suggest that natural products have significant therapeutic potential in modulating the interaction between neuroinflammation and ferroptosis, making them potential treatments for PD. Future research should further validate the safety and efficacy of these natural compounds in clinical applications to develop novel therapeutic strategies for PD.

Identification of ferroptosis-related genes in periodontitis through bioinformatics analysis and experimental validation

BACKGROUND

Periodontitis is a multifactorial chronic inflammatory disease of periodontal tissues. Ferroptosis is a form of regulated cell death, which is characterized by iron-dependent lipid peroxidation and involved in various inflammatory diseases. This study aims to identify ferroptosis-related genes associated with periodontitis and further validate their relevance through in vitro experiments.

METHODS

Iron accumulation and localization were detected using Prussian blue staining. Differentially expressed genes in periodontitis were identified from GSE16134 and GSE10334, and intersected with ferroptosis genes to obtain differentially expressed ferroptosis genes (FerDEGs). Functional enrichment analyses of FerDEGs were performed by GO and KEGG. Hub genes were screened through PPI network analysis. The expression of these hub genes in gingival tissues and in lipopolysaccharide (LPS)-stimulated human gingival fibroblasts (HGFs) with/without ferrostatin-1 (Fer-1) detected by qRT-PCR and Western Blot.

RESULTS

Ferroptosis was observed in gingival tissues affected by periodontitis. A total of 24 FerDEGs involved in periodontitis were identified. GO analysis and KEGG analysis highlighted the intrinsic apoptotic signaling pathway and ferroptosis as the top enriched pathways. PPI network analysis identified five hub genes. The mRNA expression levels of hub genes were significantly higher in inflammatory gingival tissues and HGFs stimulated with LPS (P < 0.05). The upregulated expression of PTGS2 and IL6 in HGFs were reversed by Fer-1 (P < 0.05).

CONCLUSION

This study highlights five ferroptosis-related genes as potential targets for future research into the pathogenesis of periodontitis.

Programmed Cell Death Tunes Periodontitis

OBJECTIVE

To review current knowledge of the various processes of programmed cell death and their roles in immunoregulation in periodontitis.

METHODS

Relevant literature in the PubMed, Medline, and Scopus databases was searched, and a narrative review was performed. Programmed cell death and the regulation of its various pathways implicated in periodontal infection were reviewed.

RESULTS

Multicellular organisms dispose of unnecessary or damaged cells via programmed cell death. Programmed cell death lies at the core of the balance of cell death and survival in pathological progress and infection. Periodontitis is a complex infectious disease involving virulence factors of periodontal pathogens and tightly regulated immune responses of the host. Different types of programmed cell death can play opposite roles in periodontitis or exert their action combinatorially.

CONCLUSION

The coordinated system of various programmed cell death pathways and the extensive crosstalk among them play a fundamental role in the pathophysiology of periodontitis. Illuminating the precise roles and mechanisms of programmed cell death in periodontitis could open up novel therapeutic approaches.

A multi-platform analysis of human gingival crevicular fluid reveals ferroptosis as a relevant regulated cell death mechanism during the clinical progression of periodontitis

Ferroptosis is implicated in the pathogenesis of numerous chronic-inflammatory diseases, yet its association with progressive periodontitis remains unexplored. To investigate the involvement and significance of ferroptosis in periodontitis progression, we assessed sixteen periodontitis-diagnosed patients. Disease progression was clinically monitored over twelve weeks via weekly clinical evaluations and gingival crevicular fluid (GCF) collection was performed for further analyses. Clinical metrics, proteomic data, in silico methods, and bioinformatics tools were combined to identify protein profiles linked to periodontitis progression and to explore their potential connection with ferroptosis. Subsequent western blot analyses validated key findings. Finally, a single-cell RNA sequencing (scRNA-seq) dataset (GSE164241) for gingival tissues was analyzed to elucidate cellular dynamics during periodontitis progression. Periodontitis progression was identified as occurring at a faster rate than traditionally thought. GCF samples from progressing and non-progressing periodontal sites showed quantitative and qualitatively distinct proteomic profiles. In addition, specific biological processes and molecular functions during progressive periodontitis were revealed and a set of hub proteins, including SNCA, CA1, HBB, SLC4A1, and ANK1 was strongly associated with the clinical progression status of periodontitis. Moreover, we found specific proteins - drivers or suppressors - associated with ferroptosis (SNCA, FTH1, HSPB1, CD44, and GCLC), revealing the co-occurrence of this specific type of regulated cell death during the clinical progression of periodontitis. Additionally, the integration of quantitative proteomic data with scRNA-seq analysis suggested the susceptibility of fibroblasts to ferroptosis. Our analyses reveal proteins and processes linked to ferroptosis for the first time in periodontal patients, which offer new insights into the molecular mechanisms of progressive periodontal disease. These findings may lead to novel diagnostic and therapeutic strategies.

Effects of the ferroptosis inducer erastin on osteogenic differentiation and biological pathways of primary osteoblasts

BACKGROUND

Periodontitis is a chronic destructive inflammatory disease exacerbated by osteoblast dysfunction. Ferroptosis has emerged as a significant factor that could contribute to the pathological changes observed in periodontitis. However, the impact of ferroptosis on osteogenic differentiation and gene expression patterns of primary osteoblasts remain elusive.

METHODS

In this study, osteoblasts were osteogenically induced for specific durations with and without the ferroptosis inducer erastin. Subsequently, cell proliferation, ferroptosis-related molecules, and osteogenic differentiation capacity were assessed. Furthermore, the differences in transcriptome expression following erastin treatment were analyzed by RNA sequencing.

RESULTS

The results demonstrated that erastin treatment induced ferroptosis, resulting in suppressed cell proliferation and impaired osteogenic differentiation. Transcriptomic analysis revealed significant alterations in processes such as hydrogen peroxide catabolism, response to lipid peroxidation, and metal iron binding, as well as BMP receptor activity and collagen type XI trimer.

CONCLUSION

The ferroptosis inducer erastin inhibited osteoblast proliferation and differentiation. Our study provides novel insights into the effect of ferroptosis on osteogenesis, suggesting that targeting ferroptosis may present a promising approach in the treatment of periodontitis.

Unraveling ferroptosis in osteogenic lineages: implications for dysregulated bone remodeling during periodontitis progression

Periodontitis is a highly prevalent disease characterized by inflammation and destruction of tooth-supporting tissues that leads to tooth loss in extreme situations. Elucidating the underlying mechanisms of periodontitis pathogenesis and progression will establish the groundwork for developing effective treatment strategies. Recently, evidence concerning the role of ferroptosis in periodontitis progression has emerged. Osteogenic lineage cells are key regulators of bone remodeling. Osteogenic cell death, as observed in experimental periodontitis models, disrupts the balance between bone resorption and bone formation. However, whether the osteogenic lineage undergoes ferroptosis during periodontitis and the corresponding effect on periodontitis progression remain elusive. Here, we investigated cell-specific ferroptosis within the alveolar bone in a murine periodontitis model. Through immunofluorescence double staining and immunohistochemistry, we identified ferroptotic osteocytes and osteoblasts in inflammatory alveolar bone. Next, in vivo administration of erastin or liproxstatin-1 was conducted to either induce or inhibit ferroptosis, respectively. Severe bone resorption and inflammation, accompanied by increased osteoclast formation and impaired osteogenic potential were detected following ferroptosis activation. Subsequently, we carried out in vitro experiments on osteocytes and further verified that ferroptosis enhanced the osteocytic expression of RANKL and IL-6. These findings suggest that ferroptosis occurring within the osteogenic lineage acts as a catalyst in the progression of periodontitis by stimulating osteoclastogenesis through the secretion of inflammatory cytokines and inhibiting osteoblastic function, providing insights into ferroptosis-induced alterations in microenvironment-based intercellular communication. Ferroptosis is a promising target for controlling inflammation and preventing bone resorption in periodontitis.