Low expression of glucocorticoid receptor α in oral lichen planus correlates with activation of nuclear factor κB: a preliminary study

Dynamic changes of Th1/Th2/Th17 cytokines and hBD-2/3 in erosive oral lichen planus patients saliva before and after prednisone acetate treatment

Objective

This study aimed to investigate the expression of T helper 1 (Th1)/Th2/Th17- related cytokines and human beta defensins 2 and 3 (hBD-2 and -3) in the saliva of patients with erosive oral lichen planus (EOLP) and to explore their role in the pathogenesis of EOLP and the effects of glucocorticoids on EOLP.

Methods

A total of 30 patients with EOLP and 20 age- and sex-matched healthy individuals were included in this study. The patients were treated with prednisone at a dose of 0.4 mg/(kg·d) for 1 week and examined before and after treatment. Unstimulated whole saliva samples were collected to determine the levels of cytokines (interleukin 1 beta [IL-1β], tumour necrosis factor alpha [TNF]-α, interferon gamma [IFN-γ], IL-4, IL-6, IL-10 and IL-17) by cytometric bead array and those of hBD-2 and -3 b y enzyme-linked immunosorbent assay. In addition, oral rinse samples were collected to detect Candida load.

Results

The levels of salivary IL-1β, IL-6, hBD-2 and hBD-3 were higher and the IFN-γ/IL-4 and IL-1β/IL-6 ratios were lower in patients with EOLP than in healthy individuals. In patients with EOLP, hBD-2 levels were positively correlated with IFN-γ levels and negatively correlated with IL-17 levels, whereas hBD-3 levels were negatively correlated with IL-17 and IL-10 levels. In addition, the prevalence of EOLP was positively correlated with IL-6 levels and negatively correlated with the IFN-γ/IL-4 ratio. The levels of IL-1β, TNF-α, IFN-γ, IL-6, hBD-2 and hBD-3 and the IFN-γ/IL-4 ratio decreased after treatment with prednisone for 1 week. The levels of IL-6, hBD-2 and hBD-3 were significantly higher in EOLP patients than in healthy individuals; while TNF-α levels and the IFN-γ/IL-4 ratio were significantly lower in EOLP patients than in healthy individuals. Furthermore, the oral counts of Candida spp. (colony forming unit [CFU]) were negatively correlated with TNF-α levels. Numerical Rating Scale(NRS) and Sign scores decreased in EOLP patients after treatment. Approximately 80 % of patients were effectively treated. Salivary TNF-α levels were significantly higher in the treatment-ineffective group than in the treatment-effective group before treatment with prednisone, and differences in salivary IL-6 levels before and after treatment were significantly higher in the treatment-effective group than in the treatment-ineffective group.

Conclusions

High expression of IL-1β, IL-6, hBD-2 and Th1/Th2 imbalance in saliva may be associated with the pathogenesis of EOLP. IFN-γ/IL-4 balance may serve as a protective factor for EOLP. Glucocorticoids significantly alleviate the symptoms of EOLP and inhibit the expression of Th1/Th2 cytokines.

Probiotics as Potential Biological Immunomodulators in the Management of Oral Lichen Planus: What's New?

Oral lichen planus (OLP) is a T cell-mediated chronic inflammatory disorder with multifactorial aetiology and malignant transformation potential. Despite the treatments so far identified, new tailored and safe specific measures are needed. Recently, human microbiota imbalance has been linked to several immune-mediated diseases, opening new therapeutic perspectives for probiotics; besides their ability to directly interact with the host microbiota, they also display a strain-specific immune-modulatory effect. Thus, this non-systematic review aims to elucidate the molecular pathways underlying probiotic activity, mainly those of Lactobacilli and Bifidobacteria and their metabolites in OLP pathogenesis and malignant transformation, focusing on the most recent in vitro and in vivo research evidence. Findings related to their activity in other immune-mediated diseases are here included, suggesting a probiotic translational use in OLP. Probiotics show immune-modulatory and microbiota-balancing activities; they protect the host from pathogens, hamper an excessive effector T cell response, reduce nuclear factor-kappa B (NF-kB) signalling and basal keratinocytes abnormal apoptosis, shifting the mucosal response towards the production of anti-inflammatory cytokines, thus preventing uncontrolled damage. Therefore, probiotics could be a highly encouraging prevention and immunotherapeutic approach for a safer and more sustainable OLP management.

Clinical significance of miR-142-3p in oral lichen planus and its regulatory role in keratinocyte proliferation

OBJECTIVE

Accumulating microRNAs (miRNAs) have been identified as aberrantly expressed in patients with oral lichen planus (OLP). This study aimed to investigate the role and underlying mechanism of miR-142-3p in OLP.

STUDY DESIGN

Fifty-six patients with OLP and 44 control participants without OLP were recruited, and real-time quantitative reverse transcription polymerase chain reaction was used for the measurement of miR-142-3p. A receiver operating characteristic (ROC) was counted to assess the diagnostic value. Cell Counting Kit‑8 was used to assess cell proliferation. The luciferase reporter assay was performed to confirm the target gene.

RESULTS

Compared with the control group, an elevated expression of miR-142-3p was detected in the serum, saliva, and tissues samples from patients with OLP. ROC curve analysis suggested that miR-142-3p could distinguish patients with OLP from those in the control group, and the expression of miR-142-3p was closely associated with the disease severity. Downregulation of miR-142-3p inhibited keratinocyte proliferation. Glucocorticoid receptor α (GRα) was a target gene of miR-142-3p.

CONCLUSIONS

MiR-142-3p might be a candidate diagnostic biomarker for OLP. Downregulation of miR-142-3p inhibits keratinocyte proliferation, and GRα might be involved in its regulatory role.

Aberrant expression of interleukin-22 and its targeting microRNAs in oral lichen planus: a preliminary study

BACKGROUND

Oral lichen planus (OLP) is a T cell-mediated autoimmune disease involving oral mucosa. Interleukin-22 (IL-22) as the signature cytokine of T helper 22 cells is increasingly recognized as a key regulator in various autoimmune diseases. Our previous study reported that IL-22 immunoexpression in OLP was significantly increased compared with the normal controls.

METHODS

The objective of this preliminary study was to compare the IL-22 expression levels in oral biopsies from patients with OLP (n = 50) against normal oral mucosa (n = 19) using RT-qPCR and Western blot, identify the potential targeting miRNAs of IL-22, and examine the miRNA expression levels in OLP.

RESULTS

Interleukin-22 expression level in OLP was significantly increased compared with the normal controls. The Dual-Luciferase reporter assay system in human embryonic kidney 293 (HEK293) cells demonstrated that miR-562 and miR-203 were the target miRNAs of IL-22, which was consistent with predictions from bioinformatics software analyses. Interestingly, miR-562 expression in OLP was significantly decreased, but miR-203 expression in OLP was significantly increased compared with the normal controls.

CONCLUSION

This preliminary study for the first time reported that aberrant expression levels of miR-562 and miR-203 were associated with high expression of IL-22 and demonstrated the target relationship between miRNAs and IL-22 in HEK293 cells. Our data indicated that IL-22 and its targeting miRNAs contribute to the pathogenesis of OLP. Further studies are required to investigate the regulatory pathways of IL-22 and miR-562 and miR-203 in OLP.

Chronic stress accelerates ligature-induced periodontitis by suppressing glucocorticoid receptor-α signaling

Periodontitis is a common chronic inflammatory disease. Recent studies have shown that chronic stress (CS) might modulate periodontal disease, but there are few models of CS-induced periodontitis, and the underlying mechanisms are unclear. The present study established a rat model of periodontitis associated with CS induced by nylon thread ligatures. The severity of periodontitis was evaluated in this model by radiographic and pathological examination. The inflammatory reaction indicated by the elevated serum levels of interleukin (IL)-1β, IL-6 and IL-8 was assessed by enzyme-linked immunosorbent assay. Toll-like receptor-4 (TLR4) and glucocorticoid receptor-α (GR-α) expressions were detected by reverse transcriptase-PCR and western blotting. Open-field tests and serum corticosterone were used to evaluate CS. The results showed that CS induced behavioral changes and increased corticosterone levels of the animals with periodontitis. CS stimulation markedly increased alveolar bone loss, periodontal pocket depth and the number of plaques. It also enhanced the inflammatory reaction. These results suggest that CS accelerated the ligature-induced pathological changes associated with periodontitis. Further analysis of the mechanisms involved showed that GR-α expression was significantly downregulated in periodontal tissues of the animals undergoing CS. Blocking GR-α signaling in lipopolysaccharide and corticosteroid-treated human periodontal ligament fibroblast cells in vitro significantly upregulated the expression of p-Akt (protein kinase B) and TLR4, promoted nuclear factor-κB activity and increased levels of IL-1β, IL-6 and IL-8. This research suggests that CS might accelerate the pathological progression of periodontitis by a GR-α signaling-mediated inflammatory response and that this may be a potential therapeutic target for the treatment of periodontal disease, particularly in patients with CS.