MMP-8, TRAP-5, and OPG Levels in GCF Diagnostic Potential to Discriminate between Healthy Patients', Mild and Severe Periodontitis Sites

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.

Lipopolysaccharide induces inflammatory microglial activation through CD147-mediated matrix metalloproteinase expression

Microglia-mediated neuroinflammation plays a vital role in the pathophysiological processes of multiple neurodegenerative diseases. Lipopolysaccharide (LPS) is an environmental poison that can induce inflammatory microglial activation. Matrix metalloproteinases (MMPs) are vital factors regulating microglial activation, and CD147 is a key MMP inducer, which can induce inflammation by inducing MMPs. However, whether it is involved in the regulation of microglial activation has not been reported. In this study, the role of CD147 in LPS-induced microglial inflammatory activation was investigated by establishing in vivo and in vitro models. The results suggested that LPS-induced microglial activation was accompanied by the induction of CD147 expression while the inhibition of CD147 expression could inhibit LPS-induced microglial inflammatory activation. In addition, the results also indicated that the role of CD147 in LPS-induced pro-inflammatory activation of microglia was related to its downstream MMP-3, MMP-8, and autophagy. Furthermore, the inhibition of MMP-3, MMP-8, and autophagy attenuated LPS-induced inflammatory activation of microglia. At the same time, there was a certain interaction between MMPs and autophagy, which is shown that inhibiting the expression of MMPs could inhibit autophagy, whereas inhibiting autophagy could inhibit the expression of MMPs. Taken together, we provided the first evidence that CD147/MMPs can be involved in LPS-induced inflammatory activation of microglia through an autophagy-dependent manner.

Effect of Low-Level Laser Therapy on Early Wound Healing and Levels of Inflammatory Mediators in Gingival Crevicular Fluid Following Open Flap Debridement

Introduction Low-level laser therapy (LLLT) has a beneficial effect on pain relief and wound healing. This study aims at a clinical evaluation of early wound healing and a biochemical evaluation of inflammatory mediators in gingival crevicular fluid (GCF) following LLLT with an open flap debridement (OFD) in periodontal therapy. Material and methods This randomized controlled trial included 40 chronic periodontitis patients with bilateral attachment loss, pocket depths of 5 mm affecting at least two quadrants, and radiographic evidence of horizontal bone loss. 120 control sites were randomly selected to receive OFD, and contralateral 120 test sites received bio-stimulation with a diode laser (890 nm) after OFD. The wound healing index was recorded at the 1st and 2nd weeks, and clinical parameters such as the plaque index, gingival index, pocket probing depth, clinical attachment level, and GCF inflammatory mediators were evaluated at baseline, 3, and 6 months. Results From the start of the study to 6 months later, there was a statistically significant drop in plaque index, gingival index, probing pocket depth, and gain clinical attachment levels in both groups. However, when the two groups were compared, there were no significant differences at any time intervals. GCF inflammatory mediators tumor necrosis factor (TNF) alpha and matrix metalloproteinases (MMP-8) decrease, and osteoprotegerin (OPG) levels increase in both the test group and control group from baseline to 3 months and 6 months. In intergroup comparisons, there was a statistically significant reduction in the test group as compared to the control group at 6 months. There was a decline in gingival crevicular fluid - interleukin-6 (GCF IL-6) levels from baseline to 3 months and 6 months in both the groups but when analysed statistically, the results were not significant on intergroup and intragroup comparison at any time interval. The Landry Wound Healing Index values in the 1st and 2nd weeks were showing statistically significant improved healing in the test group as compared to the control group. There was significantly better wound healing at sites where a diode laser was used. Conclusion LLLT increases early wound healing after periodontal surgical procedures.

Ability of matrix metalloproteinase-8 biosensor, IFMA, and ELISA immunoassays to differentiate between periodontal health, gingivitis, and periodontitis

Objective

The aim of this study was to determine the diagnostic utility of an MMP‐8 biosensor assay in differentiating periodontal health from gingivitis and periodontitis and compare it with an established time‐resolved immunofluorescence assay (IFMA) and enzyme‐linked immunosorbent assay (ELISA).

Background

Currently available antibody‐based assays display a wide variability in their ability to accurately measure matrix metalloproteinase‐8 (MMP‐8) levels in saliva.

Methods

Salivary MMP‐8 levels were analyzed in 189 systemically healthy participants using an antibody‐based biosensor prototype that operates using a surface acoustic wave technology and compared with IFMA and ELISA antibody assays. Participants were categorized into 3 groups: periodontal health (59), gingivitis (63), and periodontitis (67). A sub‐population of participants (n = 20) with periodontitis received periodontal treatment and were monitored for 6 months.

Results

All the assays demonstrated significantly higher salivary MMP‐8 concentrations in participants with periodontitis versus gingivitis, periodontitis versus health, and gingivitis versus health (all p < .05). The biosensor data demonstrated significant correlations with IFMA (r = .354, p < .001) and ELISA (r = .681, p < .001). Significant reductions in salivary MMP‐8 concentrations were detected by the biosensor (p = .030) and IFMA (p = .002) in participants with periodontitis 6 months after non‐surgical periodontal treatment. IFMA had the best sensitivity (89.2%) for detecting periodontitis and gingivitis versus health and 96.6% for detecting periodontitis versus health and gingivitis. The biosensor had an AUC value of 0.81 and diagnostic accuracy of 74.2% for differentiating periodontitis and gingivitis from health; an AUC value of 0.86 and diagnostic accuracy of 82.8% for periodontitis versus health and gingivitis.

Conclusions

The biosensor, IFMA, and ELISA assays differentiated between periodontal health, gingivitis, and periodontitis based on salivary MMP‐8 levels. Only the biosensor and, particularly, IFMA identified an effect of periodontal treatment in the participants with periodontitis. Our findings support the potential utility of salivary oral fluid aMMP‐8‐based point‐of‐care technology in the future of periodontal diagnostics.

Evaluation of Gingival Crevicular Fluid and Serum Tartrate-resistant Acid Phosphatase Levels in Subjects with Clinically Healthy Periodontium and Chronic Periodontitis - A Clinico-biochemical Study

BACKGROUND

Periodontitis is a chronic inflammatory disease with conglomerate etiology making it difficult to diagnose at the early stages. Potential biomarkers in gingival crevicular fluid (GCF) would determine the presence of the current disease activity, predict sites vulnerable for future breakdown, and assess the response to periodontal interventions. Merely elevated levels of inflammatory soft-tissue markers do not indicate bone destruction. Since there is no single ideal biomarker established, bone-related biomarkers such as telopeptide of type I collagen, osteocalcin, calprotectin, osteopontin, and tartrate-resistant acid phosphatase (TRAP) seem to hold great promise as predictive markers to determine bone destruction and active phases in the disease progression. The present study is intended to explore the biologic plausibility of the levels of TRAP in health and chronic periodontitis.

MATERIALS AND METHODS

The present cross-sectional clinico-biochemical study comprised 30 systemically healthy subjects with 15 periodontally healthy and 15 chronic periodontitis subjects who were age and gender matched. GCF and blood samples were collected from all the patients. TRAP estimation was done in both the samples using an enzyme-linked immunosorbent assay kit. The data were analyzed using independent t-test and Pearson correlation test.

RESULTS

Serum and GCF TRAP levels in chronic periodontitis subjects were significantly higher when compared to the periodontally healthy group. There were no significant correlations found among serum and GCF TRAP levels with increasing age and gender in both the groups. An increase in disease severity, i.e., increase in probing pocket depth and clinical attachment level, did not show correlation with the GCF and serum TRAP levels in the chronic periodontitis group.

CONCLUSION

Based on the findings of the present study, increased GCF TRAP levels in chronic periodontitis seem to be a potential marker for identifying ongoing periodontal destruction.

AdipoRon Promotes the Osseointegration of Dental Implants in Mice With Type 2 Diabetes Mellitus

AdipoRon is an oral active synthetic small molecule with biological functions similar to adiponectin (APN). It is an APN receptor agonist that can improve insulin resistance and glucose intolerance. However, the role of AdipoRon in bone metabolism and related molecular mechanisms remains to be investigated. To explore the effect of AdipoRon on bone absorption and bone integration of type 2 diabetes mellitus (T2DM) mice with implants, we established surgery-induced model of osseointegration of dental implantation in T2DM mice of C57BL/6 db/db and normal mice homologous to diabetic mice. Micro-CT was used to analyze the femurs with the implant in the mice to detect the bone mass, H&E, and tartrate-resistant acid phosphatase (TRAP), and Safranin O-fast green staining was performed to analyze the bone formation and bone resorption. Bone integration-related markers as Rankl, bone morphogenetic protein 2 (BMP2), osteoprotegerin (OPG), osteopontin (OPN), and runt-related transcription factor 2 (Runx2) were also measured using immunohistochemistry. Our results indicated that diabetic mice showed a lower bone mass and decreased the osteoblast differentiation. AdipoRon attenuated diabetes-impaired bone volume (BV)/total volume (TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular separation (Tb.Sp), and bone integration-related markers variation and promoted bone hyperplasia as well as repressed the osteoclast formation, especially in diabetic mice. AdipoRon may improve the osseointegration of dental implants in mice with T2DM by promoting osteogenesis and inhibiting bone resorption, and AdipoRon may serve as a promising oral strategy to improve the osseointegration ability of patients with diabetes.

Active MMP-8 Quantitative Test as an Adjunctive Tool for Early Diagnosis of Periodontitis

Periodontitis is a host-mediated bacterial disease that affects the tooth attachment apparatus. Metalloproteinase-8 (MMP-8), a validated biomarker, could aid in clinical diagnosis. This study aimed to evaluate the diagnostic performance of active (a) MMP-8 immunotest versus total (t) MMP-8 ELISA for quantitative real-time diagnosis and assessment of periodontitis severity at the site level. Gingival crevicular fluid (GCF) was sampled from 30 healthy, 42 mild, and 59 severe periodontitis sites from thirty-one volunteers. MMP-8 concentrations were determined by time-resolved immunofluorometric assay (IFMA) and enzyme-linked immunosorbent assay (ELISA). Statistical analysis was performed using the STATA package. Both active and total MMP-8-based methods discriminated among sites according to periodontal diagnosis and severity, with a positive correlation between the two tests (p < 0.001). (a) MMP-8 models showed the best performance in receiver operating characteristic (ROC) curves to discriminate between healthy and periodontitis sites (area under the curve [AUC] = 0.89), while (t) MMP-8 demonstrated a high diagnostic precision in the detection of mild from severe periodontitis sites (AUC ≥ 0.80). The use of (a) MMP-8 and (t) MMP-8 could represent a useful adjunctive tool for periodontitis diagnosis and severity. These results support the applicability of new point-of-care methods in the monitoring of high-risk periodontal patients.