Local administration of anti-hepatocyte growth factor-neutralizing antibody reverts naturally occurring periodontitis

LIGHT protein: A novel gingival crevicular fluid biomarker associated with increased probing depth after periodontal surgery

AIM

To evaluate the protein profiles in gingival crevicular fluid (GCF) in relation to clinical outcomes after periodontal surgery and examine if any selected proteins affect the mRNA expression of pro-inflammatory cytokines in human gingival fibroblasts.

MATERIALS AND METHODS

This exploratory study included 21 consecutive patients with periodontitis. GCF was collected, and the protein pattern (n = 92) and clinical parameters were evaluated prior to surgery and 3, 6 and 12 months after surgery. Fibroblastic gene expression was analysed by real-time quantitative polymerase chain reaction.

RESULTS

Surgical treatment reduced periodontal pocket depth (PPD) and changed the GCF protein pattern. Twelve months after surgery, 17% of the pockets showed an increase in PPD. Levels of a number of proteins in the GCF decreased after surgical treatment but increased with early signs of tissue destruction, with LIGHT being one of the proteins that showed the strongest association. Furthermore, LIGHT up-regulated the mRNA expression of pro-inflammatory cytokines interleukin (IL)-6, IL-8 and MMP9 in human gingival fibroblasts.

CONCLUSIONS

LIGHT can potentially detect subjects at high risk of periodontitis recurrence after surgical treatment. Moreover, LIGHT induces the expression of inflammatory cytokines and tissue-degrading enzymes in gingival fibroblasts.

Hepatocyte growth factor is protective in early stage but bone-destructive in late stage of experimental periodontitis

BACKGROUND AND OBJECTIVE

Clinical studies found high levels of hepatocyte growth factor (HGF) expression in patients with periodontitis. Studies suggest that HGF plays an important role in periodontitis, is involved in inflammation, and modulates alveolar bone integrity in periodontitis. This study aims to investigate the effects and mechanisms of HGF in the progression of experimental periodontitis.

METHODS

We used silk thread ligation to induce periodontitis in HGF-overexpressing transgenic (HGF-Tg) and wild-type C57BL/6J mice. The effects of HGF overexpression on alveolar bone destruction were assessed by microcomputed tomography imaging at baseline and on days 7, 14, 21, and 28. We analyzed the cytokines (IL-6 and TNF-α) and lymphocytes in periodontitis tissues by enzyme-linked immunosorbent assay and flow cytometry. The effects of HGF on alveolar bone destruction were further tested by quantifying the systemic bone metabolism markers CTXI and PINP and by RNA sequencing for the signaling pathways involved in bone destruction. Western blotting and immunohistochemistry were performed to further elucidate the involved signaling pathways.

RESULTS

We found that experimental periodontitis increased HGF production in periodontitis tissues; however, the effects of HGF overexpression were inconsistent with disease progression. In the early stage of periodontitis, periodontal inflammation and alveolar bone destruction were significantly lower in HGF-Tg mice than in wild-type mice. In the late stage, HGF-Tg mice showed higher inflammatory responses and progressively aggravated bone destruction with continued stimulation of inflammation. We identified the IL-17/RANKL/TRAF6 pathway as a signaling pathway involved in the HGF effects on the progression of periodontitis.

CONCLUSION

HGF plays divergent effects in the progression of experimental periodontitis and accelerates osteoclastic activity and bone destruction in the late stage of inflammation.