Role of miR-155 in immune regulation and its relevance in oral lichen planus

The role of MicroRNAs in the diagnosis and treatment of oral premalignant disorders

Oral premalignant disorders (OPMDs) are a group of potentially malignant conditions that pose a significant health burden globally. MicroRNAs (miRNAs), small non-coding RNA molecules, have emerged as crucial regulators of gene expression and have been implicated in various biological processes, including carcinogenesis. This review synthesizes existing knowledge to provide a comprehensive understanding of the molecular mechanisms underlying OPMDs and to highlight the potential of miRNAs as promising biomarkers and therapeutic targets. Additionally, this review seeks to explore the potential of miRNA-based diagnostic biomarkers for early detection of OPMDs in the current literature on miRNAs in OPMDs, examining their involvement in disease pathogenesis, diagnostic potential, and therapeutic implications. Dysregulated miRNAs can target genes involved in critical cellular processes, such as cell cycle regulation, apoptosis, and DNA repair, leading to disease progression. Notably, miR-21, miR-31, miR-135b, and miR-486-5p have shown promise as potential biomarkers for early detection of oral premalignant lesions. Furthermore, the paper discusses the therapeutic implications of miRNAs in OPMDs. Preclinical studies have demonstrated the efficacy of miRNA-targeted therapies, such as miRNA mimics and inhibitors, in suppressing the growth of oral premalignant lesions. Early-phase clinical trials have shown promising results, indicating the potential for personalized treatment approaches. The findings underscore the importance of understanding the molecular mechanisms underlying these disorders and provide insights for the development of improved diagnostic and therapeutic strategies. However, they pose certain limitations given their intrinsic variability in expression profiles, the need for optimized isolation and detection methods, and potential hurdles in transitioning from preclinical success to clinical applications. Thus, future clinical studies are warranted to fully exploit the potential of miRNAs in the management of OPMDs.

MicroRNAs as novel biomarkers and potential therapeutic options for inflammatory cardiomyopathy

AIMS

Inflammation of the heart is a complex biological and pathophysiological response of the immune system to a variety of injuries leading to tissue damage and heart failure. MicroRNAs (miRNAs) emerge as pivotal players in the development of numerous diseases, suggesting their potential utility as biomarkers for inflammation and as viable candidates for therapeutic interventions. The primary aim of this investigation was to pinpoint and assess particular miRNAs in individuals afflicted by virus-negative inflammatory dilated cardiomyopathy (DCMi).

METHODS AND RESULTS

The study involved the analysis of 152 serum samples sourced from patients diagnosed with unexplained heart failure through endomyocardial biopsy. Among these samples, 38 belonged to DCMi patients, 24 to DCM patients, 44 to patients displaying inflammation alongside diverse viral infections, and 46 to patients solely affected by viral infections without concurrent inflammation. Additionally, serum samples from 10 healthy donors were included. The expression levels of 754 distinct miRNAs were evaluated using TaqMan OpenArray. MiR-1, miR-23, miR-142-5p, miR-155, miR-193, and miR-195 exhibited exclusive down-regulation solely in DCMi patients (P < 0.005). These miRNAs enabled effective differentiation between individuals with inflammation unlinked to viruses (DCMi) and all other participant groups (P < 0.005), boasting a specificity surpassing 86%.

CONCLUSIONS

The identification of specific miRNAs offers a novel diagnostic perspective for recognizing intramyocardial inflammation within virus-negative DCMi patients. Furthermore, these miRNAs hold promise as potential candidates for tailored therapeutic strategies in the context of virus-negative DCMi.

Salivary level of microRNA-146a and microRNA-155 biomarkers in patients with oral lichen planus versus oral squamous cell carcinoma

BACKGROUND

Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa, which has potential for malignant transformation. MicroRNAs play an important role in immunopathogenesis of OLP, and may be used for prediction of its malignant transformation. This study aimed to assess the salivary level of microRNA-146a and microRNA-155 biomarkers in patients with OLP and oral squamous cell carcinoma (OSCC).

METHODS

In this case-control study, unstimulated saliva samples were collected from 60 patients, including 15 patients with dysplastic OLP, 15 OLP patients without dysplasia, 15 patients with OSCC, and 15 healthy controls according to the Navazesh technique. After RNA extraction, the expression of microRNA-146a and microRNA-155 was quantified by real-time quantitative polymerase chain reaction (RT-qPCR). The data were analyzed by the Kruskal-Wallis and Dunn-Bonferroni tests.

RESULTS

The difference in expression of microRNA-146a and microRNA-155 among the four groups was significant (P < 0.05). Pairwise comparisons of the groups showed significantly higher expression of microRNA-146a in OLP (P = 0.004) and dysplastic OLP (P = 0.046) patients compared with the control group. Up-regulation of this biomarker in OSCC patients was not significant compared with the control group (P = 0.076). Up-regulation of micro-RNA-155 was only significant in OLP group, compared with the control group (P = 0.009). No other significant differences were found (P > 0.05).

CONCLUSION

Considering the altered expression of MicroRNA-146a and microRNA-155 in dysplastic OLP and OSCC, their altered expression may serve as an alarming sign of malignancy. However, further investigations are still required.

Roles of the miR-155 in Neuroinflammation and Neurological Disorders: A Potent Biological and Therapeutic Target

Neuroinflammation plays a crucial role in the development and progression of neurological disorders. MicroRNA-155 (miR-155), a miR is known to play in inflammatory responses, is associated with susceptibility to inflammatory neurological disorders and neurodegeneration, including Alzheimer's disease, Parkinson's disease, multiple sclerosis, and amyotrophic lateral sclerosis as well as epilepsy, stroke, and brain malignancies. MiR-155 damages the central nervous system (CNS) by enhancing the expression of pro-inflammatory cytokines, like IL-1β, IL-6, TNF-α, and IRF3. It also disturbs the blood-brain barrier by decreasing junctional complex molecules such as claudin-1, annexin-2, syntenin-1, and dedicator of cytokinesis 1 (DOCK-1), a hallmark of many neurological disorders. This review discusses the molecular pathways which involve miR-155 as a critical component in the progression of neurological disorders, representing miR-155 as a viable therapeutic target.

MiR-155-5p modulates inflammatory phenotype of activated oral lichen-planus-associated-fibroblasts by targeting SOCS1

BACKGROUND

Oral lichen planus (OLP) is a chronic inflammatory oral mucosal disease. Cytokines are closely associated with OLP development. In addition to immune cells, fibroblasts have been reported to induce regional inflammation. MicroRNA(miR)-155-5p is reportedly increased significantly in OLP and is known to regulate inflammation. This study aimed to investigate the role of miR-155-5p in fibroblasts of OLP lesions.

METHODS AND RESULTS

Normal mucosal fibroblasts (NFs) and OLP associated-fibroblasts (OLP AFs) were isolated from the oral mucosa of 15 healthy controls and 30 OLP patients. We detected the expression of miR-155-5p and fibroblast activation protein alpha (FAP-α) using quantitative RT-PCR and analyzed their correlation. Interleukin (IL)-6 and IL-8 levels were determined using ELISA. Expression of suppressor of cytokine signaling (SOCS) 1 was analyzed by western blotting. A dual-luciferase reporter assay was performed to investigate the interaction between miR-155-5p and SOCS1. MiR-155-5p and FAP-α were significantly increased and positively correlated in OLP AFs. Overexpression of miR-155-5p in OLP AFs augmented IL-6 and IL-8 release and decreased SOCS1 expression, whereas knockdown of miR-155-5p in OLP AFs decreased IL-6 and IL-8 release. The expression of SOCS1 was downregulated in OLP AFs, and SOCS1 silencing augmented IL-6 and IL-8 production in OLP AFs. Furthermore, miR-155-5p inhibited SOCS1 expression by directly targeting its 3'-UTR in OLP AFs.

CONCLUSIONS

MiR-155-5p regulates the secretion of IL-6 and IL-8 by downregulating the expression of SOCS1 in activated OLP AFs. Our results provide novel insights into the pathogenesis of OLP and identify a potential new target for OLP therapy.

Clinical Values of miR-23a-3p in Oral Lichen Planus and Its Role in Keratinocyte Proliferation and Inflammatory Response

Purpose

Oral lichen planus (OLP) is a chronic inflammatory disease occurring in the oral cavity, and several miRNAs have been identified to be involved in the disease progression and malignant transformation. This study investigated the expression changes of miR-23a-3p in OLP patients, and further explored its functional role in keratinocyte cell proliferation and inflammatory response.

Patients and Methods

Fifty buccal mucosal tissue samples were collected from OLP patients. HaCaT cells were cultured with lipopolysaccharides (LPS) to mimic the condition of OLP in vitro. RNA extraction and quantitative real-time PCR (qRT-PCR) were used for the measurement of miR-23a-3p levels. The cell viability and inflammation were detected by using cell counting kit-8 (CCK-8) and enzyme-linked immunosorbent assay (ELISA). The target gene of miR-23a-3p was verified by using luciferase reporter assay.

Results

Compared with the control group, miR-23a-3p was significantly downregulated in the buccal mucosal tissues of OLP patients, and a remarkably decreased level of miR-23a-3p was detected in patients with erosive OLP. ROC curve demonstrated the diagnostic value of miR-23a-3p for OLP with the AUC of 0.908, it can also distinguish erosive OLP from the non-erosive ones. MiR-23a-3p level was negatively associated with RAE (reticular, atrophic, erosive) score in OLP patients (r = -0.790, P < 0.001). The in vitro experiments indicated that overexpression of miR-23a-3p reversed the promotive effect of LPS on HaCaT cell proliferation and reduced the protein levels of TNF-α and IL-6. The cyclin D1 (CCND1) was a direct target gene of miR-23a-3p, it was overexpressed in OLP cell models.

Conclusion

MiR-23a-3p was at the low expression in OLP patients and showed close association with the disease severity. Overexpression of miR-23a-3p might inhibit keratinocyte proliferation and inflammatory response via targeting CCND1.

Association of MAPK and its regulatory miRNAs (603, 4301, 8485, and 4731) with the malignant transformation of oral lichen planus

Oral lichen planus (OLP) is a potentially malignant oral lesion that may transform into oral squamous cell carcinoma (OSCC). The purpose of this study was to assess the level of expression of MAPK/ERK1/2 gene, and microRNA (miR)-603, 4301, 8485, and 4731 in the MAPK signaling pathway in OLP and OSCC lesions. This case-control study evaluated 26 OSCC, 20 OLP and 20 healthy control tissue specimens. After RNA extraction, the respective miRNA and MAPK/ERK1/2 mRNA levels were assessed by quantitative reverse transcription polymerase chain reaction (RT-PCR). Significant upregulation of MAPK/ERK1/2 gene was noted in the OLP and OSCC specimens compared with healthy controls (p < 0.001). The expression level of miR-4731 was significantly lower in the OLP and OSCC specimens than in the healthy specimens (p < 0.001). The expression of MiR-603 was the lowest in OLP, followed by OSCC and then the control group (p < 0.001). No significant difference was found in miR-4801 levels between OSCC and OLP specimens compared with healthy controls (p = 0.43 and p = 0.86, respectively). In addition, a non-significant decrease in miR-8485 levels was noted in the OSCC and OLP specimens compared with healthy controls (p = 0.98 and p = 0.61, respectively). A significant decrease in level of miR-603 was noted in OLP compared with OSCC group (p < 0.001). The miR-4801 and miR-8485 expression levels were directly correlated with MAPK/ERK1/2 mRNA expression (p = 0.01). Higher expression level of MAPK/ERK1/2, miR-603, miR-4801, and miR-4731, and lower expression level of miR-8485 were correlated with significantly lower overall survival rate in OSCC patients. The increased expression of MAPK/ERK1/2 and decreased expression of miR-603 and miR-4731 are associated with greater risk of OLP malignant transformation and poor histopathological characteristics of OSCC.