miR-125b inhibits keratinocyte proliferation and promotes keratinocyte apoptosis in oral lichen planus by targeting MMP-2 expression through PI3K/Akt/mTOR pathway

Lessons learned from contamination with endotoxin originated from the supplement in the cell culture medium

Introduction

Endotoxin is a typical pyrogen derived from the outer membrane of Gram-negative bacteria. In fabricating cell-based medicinal products, it is necessary to control endotoxin in the process and the products. In the quality control tests of our clinical study, endotoxin concentration in the culture supernatant of autologous oral mucosal epithelial cell sheets exceeded the criterion value. Therefore, endotoxin measurements were conducted to clarify the cause of the endotoxin contamination.

Methods

The reagents used to prepare the culture medium, the unused culture medium, and the culture supernatants were diluted with pure water. Endotoxin concentrations in the diluted samples were measured.

Results

Endotoxin was detected in both the unused culture medium and the culture supernatant of the epithelial cell sheets at higher concentrations than the criterion value. Therefore, endotoxin concentrations in the reagents used to prepare the culture medium were measured and were found to be below the criterion value, except for cholera toxin. On the other hand, three lots of cholera toxin products were used for the measurement, and the endotoxin concentrations were higher than the criterion value. The results indicate that the endotoxin contamination is caused by the cholera toxin product.

Conclusions

To prevent endotoxin contamination in cell-based medicinal products, endotoxin concentrations in reagents used for the fabrication should be measured in the facility conducting clinical research or confirmed by an adequate certificate of analysis from the manufacturers of the reagents.

Fraxin alleviates oral lichen planus by suppressing OCT3-mediated activation of FGF2/NF-κB pathway

Oral lichen planus (OLP) is a carcinogenic chronic inflammatory oral disease, which lacks effective treatments. Fraxin is an active ingredient of the traditional Chinese medicine Qin Pi, which has an anti-inflammatory effect, but its effect on OLP is unclear. The aim of this study was to investigate the therapeutic effect of fraxin on OLP and the underlying mechanism. Human immortalized keratinocytes (HaCat) were incubated with fraxin (10, 20, or 40 µM) for 48 h and then treated with 10 µg/mL LPS for 24 h. Cell viability and apoptosis were detected. Next, the interaction between OCT3 and FGF2 was predicted by online database and verified by Co-IP analysis. Fraxin, Ad-OCT3, sh-OCT3, and sh-FGF2 were, respectively, applied to treat LPS-incubated HaCat cells, and cell viability, apoptosis, and secretion of inflammatory factors were detected with MTT, flow cytometry, and ELISA assays. Then, the involvement of OCT3 and FGF2 in the prevention of fraxin on HaCat cells from LPS-induced cell apoptosis and inflammation was investigated through multiple rescue experiments. In addition, OLP models were constructed in VDR-/- mice and NOD/SCID mice by injecting with human OLP pathological tissue homogenates to verify the therapeutic effect of fraxin on OLP. Fraxin treatment increased cell viability and reduced cell apoptosis and the secretion of IL-6 and TNF-α in a dose-dependent manner. OCT3 was significantly upregulated in oral mucosa tissues of OLP mice. OCT3 silencing inhibited LPS-induced cell apoptosis and secretion of inflammatory factors. Fraxin incubation reduced the expression of OCT3, and OCT3 interacted with FGF2 to upregulate FGF2 protein. FGF2 silencing reduced the expression of p-p65/NF-κB protein and improved LPS-induced cell apoptosis and secretion of inflammatory factors. OCT3 overexpression increased the expression of FGF2 and p-p65/NF-κB proteins, rh-FGF2 aggravated this effect, while FGF2-Neu-Ab reversed this effect. The results of in vivo experiments showed that fraxin alleviated cell apoptosis and inflammation in oral buccal mucosa tissues of OLP mice. Fraxin inhibited cell apoptosis and inflammation by suppressing OCT3-mediated activation of the FGF2/NF-κB pathway, alleviating the progression of OLP.

The disruption of NEAT1-miR-125b-5p-SLC1A5 cascade defines the oncogenicity and differential immune profile in head and neck squamous cell carcinoma

Metabolic reprogramming sustains malignant head and neck squamous cell carcinoma (HNSCC) to overcome stressful microenvironments, and increased glutamine uptake is a common metabolic hallmark in cancers. Since metabolic reprogramming has been recognized as a new therapeutic target for tumor cells, understanding the regulatory axis of glutamine uptake in HNSCC and its potential downstream effects in its pathogenesis of HNSCC would be incredibly beneficial. Bioinformatic analysis of the Cancer Genome Atlas (TCGA)-HNSCC dataset and RNAseq analysis performed on HNSCC indicated that SLC1A5 was the most dysregulated transporter among the seven homologous glutamate or neutral amino acid transporters in the SLC1A family. To further clarify the role of SLC1A5 in HNSCC, we knocked down SLC1A5 expression. This knockdown decelerated cell growth, induced G0/G1 arrest, diminished tumorigenicity, and increased cleavage caspase3, LC3B, and intracellular Fe2+. Inhibitors against apoptosis, autophagy, or ferroptosis rescued the cell viability repressed by SLC1A5 knockdown. SLC1A5 knockdown also suppressed glutamine uptake, enhanced oxidative stress, and increased sensitivity to cisplatin. CRISPR/dCas9-mediated SLC1A5 induction conferred cisplatin resistance and reduced apoptosis, autophagy, and ferroptosis. Reporter assays and western blot data demonstrated that miR-125b-5p targets and attenuates SLC1A5, while the si-NEAT1 increases miR-125b-5p expression. Analysis of the TCGA-HNSCC databases showed concordant upregulation of NEAT1 and downregulation of miR-125b-5p, along with SLC1A5 upregulation in tumors. Analysis of transcriptomic data revealed that tumors harboring higher SLC1A5 expression had significantly lower immune scores in CD8+, monocytes, and dendritic cells, and higher scores in M0 and M1 macrophages. Disruptions in immune modulation, metabolism, and oxidative stress components were associated with SLC1A5 aberrations in HNSCC. This study concludes that the NEAT1/miR-125b-5p/SLC1A5 cascade modulates diverse activities in oncogenicity, treatment efficacy, and immune cell profiles in head and neck/oral carcinoma.

Upregulation of IL-37 in epithelial cells: A potential new mechanism of T cell inhibition induced by tacrolimus

Oral lichen planus (OLP) is a chronic T cell-mediated mucocutaneous disease characterized by T cell infiltration at the connective tissue-epithelium interface. Traditionally, topical corticosteroids are used as the first-line drugs to treat OLP. However, long-term use of corticosteroids may lead to drug tolerance, secondary candidiasis, and autoimmune adrenal insufficiency. Although topical tacrolimus has often been recommended for short-term use in corticosteroid-refractory OLP, the precise role of tacrolimus in epithelial cells remains elusive. This study showed that tacrolimus could directly upregulate the expression of IL-37 in human gingival epithelial cells by promoting the TGF-βRI/Smad3 pathway independently of calcineurin inhibition and MAPKs. In contrast, dexamethasone, one of the corticosteroids, did not have the same effect. Moreover, IL-37 could inhibit the proliferation of activated T cells and the secretion of effector cytokines and alleviate epithelial cell apoptosis and death caused by activated T cells ina co-culturesystem. Furthermore, compared with healthy controls, IL-37 and p-Smad3 levels significantly increased in the oral mucosa affected by OLP, especially in the epithelium. IL-37 might have mediated a negative feedback mechanism to curb excessive inflammation in OLP. However, the expression of IL-37 was not associated with the infiltration of CD8+ T cells and Tregs in OLP, implying that IL-37 might mostly affect T cell activation rather than T cell differentiation and migration. Overall, this study discovered a potential novel mechanism by which tacrolimus might indirectly inhibit T cell-mediated immune damage by upregulating IL-37 in human gingival epithelial cells.

The PI3K-Akt-mTOR and Associated Signaling Pathways as Molecular Drivers of Immune-Mediated Inflammatory Skin Diseases: Update on Therapeutic Strategy Using Natural and Synthetic Compounds

The dysregulated phosphatidylinositol-3-kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) signaling pathway has been implicated in various immune-mediated inflammatory and hyperproliferative dermatoses such as acne, atopic dermatitis, alopecia, psoriasis, wounds, and vitiligo, and is associated with poor treatment outcomes. Improved comprehension of the consequences of the dysregulated PI3K/Akt/mTOR pathway in patients with inflammatory dermatoses has resulted in the development of novel therapeutic approaches. Nonetheless, more studies are necessary to validate the regulatory role of this pathway and to create more effective preventive and treatment methods for a wide range of inflammatory skin diseases. Several studies have revealed that certain natural products and synthetic compounds can obstruct the expression/activity of PI3K/Akt/mTOR, underscoring their potential in managing common and persistent skin inflammatory disorders. This review summarizes recent advances in understanding the role of the activated PI3K/Akt/mTOR pathway and associated components in immune-mediated inflammatory dermatoses and discusses the potential of bioactive natural products, synthetic scaffolds, and biologic agents in their prevention and treatment. However, further research is necessary to validate the regulatory role of this pathway and develop more effective therapies for inflammatory skin disorders.

SPTLC2 ameliorates chondrocyte dysfunction and extracellular matrix metabolism disturbance in vitro and in vivo in osteoarthritis

Disturbances in chondrocyte extracellular matrix (ECM) metabolism in osteoarthritis (OA) are a major cause of OA and potentially lead to personal disability, placing a huge burden on society. Chondrocyte apoptosis and ECM catabolism have a major role in the OA process. Firstly, bioinformatics analysis was performed to screen differentially expressed genes (DEGs) in OA, and serine palmitoyltransferase subunit 2 (SPTLC2) was chosen, which had high-level expression in the OA cartilage tissues and OA chondrocytes. Overexpression and knockdown of SPTLC2 were achieved in OA chondrocytes and normal chondrocytes respectively to study the effect of SPTLC2 upon ECM metabolism of chondrocytes. Cell viability and apoptosis were measured using MTT and flow cytometry analyses; SPTLC2 overexpression enhanced the OA chondrocyte viability and decreased apoptotic rate. In addition, Western blot detection of ECM-related factors (Collagen I, Collage II, MMP-1, MMP-3, and MMP-13) revealed that SPTLC2 overexpression promoted the expression of collagens (Collagen I and Collage II) and suppressed matrix metalloproteinase (MMP-1, MMP-3, and MMP-13) level. In contrast, SPTLC2 knockdown in normal chondrocytes showed opposite effects on cell viability, apoptosis, and ECM degeneration. The articular cartilage of OA rats was transfected with lentivirus overexpressing SPTLC2; HE and Safranin-O fast green demonstrated that SPTLC2 overexpression could alleviate chondrocyte injuries and slow down the development of OA. In conclusion, SPTLC2 plays a role in OA and may be a potential target gene for the treatment of OA.

Network Pharmacology and Molecular Docking Analysis Explores the Mechanisms of Cordyceps sinensis in the Treatment of Oral Lichen Planus

Objective

Oral lichen planus (OLP) is the most common potentially malignant disorder of the oral cavity. This study aimed to investigate the mechanism of action of Cordyceps sinensis in the treatment of OLP and provides a theoretical support for improving current treatment regimens for OLP.

Methods

The active components and therapeutic targets of Cordyceps sinensis were predicted and screened using the TCMSP, SymMap, PubMed, HIT 2.0, and PharmMapper databases, while the relevant OLP targets were predicted and screened using the DisGeNET and GeneCards databases. Protein-protein interactions (PPI) were examined using the String database, and Cytoscape was used to combine and illustrate the findings. GO and KEGG pathway enrichment analyses were carried out using RStudio, and AutoDock Vina and Pymol were used for molecular docking and visualization, respectively.

Results

A total of 404 potential target genes were discovered after evaluating 21 active compounds from Cordyceps sinensis. Potential therapeutic targets included 67 targets that matched and overlapped with OLP, including TNF, IL-6, CD4, EGFR, and IL1B. Key targets were predominantly engaged in the PI3K-Akt signaling pathway and the MAPK signaling pathway, according to the GO and KEGG analyses. These targets have a connection to biological processes including apoptosis signaling pathway regulation, T cell activation, and oxidative stress response. The molecular docking results showed that TNF, IL-6, CD4, EGFR, and IL1B could bind to their corresponding active components.

Conclusions

Cordyceps sinensis contains multiple components and acts on multiple targets and multiple pathways. Particularly, Cordyceps sinensis targets TNF, IL-6, CD4, EGFR, and IL1B, regulates PI3K-Akt and MAPK signaling pathways, as well as takes part in biological processes including apoptosis, T cell activation, and oxidative stress. Cordyceps sinensis could be a crucial choice in the therapy of OLP.

The Functional Mechanism of MicroRNA in Oral Lichen Planus

Non-coding RNAs (ncRNAs) are transcribed from the genomes of mammals and other complex organisms, and many of them are alternately spliced and processed into smaller products. Types of ncRNAs include microRNAs (miRNAs), circular RNAs, and long ncRNAs. miRNAs are about 21 nucleotides long and form a broad class of post-transcriptional regulators of gene expression that affect numerous developmental and physiological processes in eukaryotes. They usually act as negative regulators of mRNA expression through complementary binding sequences in the 3’-UTR of the target mRNA, leading to translation inhibition and target degradation. In recent years, the importance of ncRNA in oral lichen planus (OLP), particularly miRNA, has attracted extensive attention. However, the biological functions of miRNAs and their mechanisms in OLP are still unclear. In this review, we discuss the role and function of miRNAs in OLP, and we also describe their potential functional roles as biomarkers for the diagnosis of OLP. MiRNAs are promising new therapeutic targets, but more work is needed to understand their biological functions.

The expression of salivary microRNAs in oral lichen planus: Searching for a prognostic biomarker

Oral lichen planus (OLP) is a premalignant disease with unknown etiology. It has been demonstrated that inflammation and immune activation play a central role in the pathogenesis of OLP. Various cellular and molecular mechanisms are involved in the pathogenesis of OLP. Studies have shown that 2-7% of OLP patients develop oral squamous cell carcinoma (OSCC). As a result, determining the prognosis of the disease will be promising in preventing oral carcinoma. MicroRNAs are involved in the regulation of cytokine expression and cytokines have a central role in the pathogenesis of OLP. As a result, their evaluation in body fluids may be helpful in assessing the disease's status and progression, and facilitating the treatment process. In this regard, much attention has been paid to the saliva of OLP patients as the sampling is cost-effective and non-invasive. Here, we discuss the potential of miRNAs in predicting the disease severity and progression.

Ropivacaine inhibits wound healing by suppressing the proliferation and migration of keratinocytes via the PI3K/AKT/mTOR Pathway

Background

After surgery, millions of people suffer from delayed healing or wound dehiscence with subsequent severe complications, even death. Previous studies have reported that ropivacaine exhibits anti-proliferative and anti-migratory activities on numerous cells. Whether ropivacaine is able to influence the proliferation and migration of keratinocytes is still unclear. This study aimed to investigate the effect of ropivacaine on keratinocytes and its underlying molecular mechanism.

Methods

Adult male Sprague–Dawley rats were allocated to establish wound healing models with or without 0.75% ropivacaine treatment and assessed the epidermal thickness by HE staining. HaCaT cells were cultured to evaluate the effect of ropivacaine on wound healing. The cell proliferation, apoptosis status and migration were detected in vitro. Moreover, western blotting was used to examine expression to with PI3K/AKT/mTOR signaling pathways for molecular studies and the changes in inflammatory factors (IL-6, IL-10, TNF-α) were detected by ELISA.

Results

In the present study, we found that ropivacaine delayed wound closure in vivo. In vitro experiments, it was demonstrated that ropivacaine significantly inhibited the proliferation and migration of HaCaT cells via the suppression of PI3K/AKT/mTOR signaling pathway. Activation of PI3K/AKT/mTOR signaling pathway reversed the effects of ropivacaine on the proliferation and migration of HaCaT cells. Furthermore, ropivacaine contributed to the release of pro-inflammatory cytokines (IL-6 and TNF-α) and inhibited the secretion of anti-inflammatory cytokines of keratinocytes (IL-10).

Conclusions

Our research demonstrated that ropivacaine treatment showed a more decreased wound closure rate. Mechanistically, we found that ropivacaine suppressed the proliferation and migration of keratinocytes and altered the expression of cytokines by inhibiting PI3K/AKT/mTOR pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01646-0.

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.

Inflammatory and immune-related factor Caspase 1 contributes to the development of oral lichen planus

OBJECTIVE

In this study, we aimed at underlying the potential regulatory mechanism and overall biological functions of caspase 1 (CASP1) in oral lichen planus (OLP).

DESIGN

Buccal mucosa tissue samples were gained from healthy subjects or patients diagnosed with OLP. Immunochemical staining was applied to detect CASP1 in OLP tissues. Lipopolysaccharide (LPS) was used to construct OLP in vitro models. Cell counting kit-8 (CCK-8) and flow cytometry assay were applied to detecte cell viability and apoptosis.

RESULTS

The upregulation of CASP1 in OLP has been identified through comprehensive bioinformatics analysis and verified in clinical samples. In OLP tissues, inflammation-related factors, including tumor necrosis factor alpha (TNF-α), interleukin (IL)-1β, IL-6, and IL-18, were elevated and positively correlated with CASP1. In HaCaT cells, LPS stimulation induced CASP1 upregulation, suppressed cell viability, facilitated cell apoptosis, and elevated the levels of TNF-α, IL-1β, IL-6, and IL-18; silencing of CASP1 attenuated LPS-induced damages to HaCaT cells. Pearson's correlation analysis identified that 45 immune-related genes were positively correlated with CASP1; these 45 genes were enriched in the immune system process, associated with combined immunodeficiency, and spleen-specific and CD56 + NK cell-specific. PPI network among CASP1 and correlated immune-related factors was constructed, and CASP1 was positively correlated with RAC2, CYBB, and ARHGDIB. In HaCaT cells, LPS stimulation induced RAC2, CYBB, and ARHGDIB expression, whereas knocking down CASP1 attenuated LPS-induced increases in RAC2, CYBB, and ARHGDIB.

CONCLUSION

CASP1 is upregulated in OLP tissues. Knockdown of CASP1 in HaCaT cells could protect HaCaT cells from LPS-induced inflammatory injury. Comprehensive bioinformatics indicates that the interaction of CASP1 with RAC2, CYBB, and ARHGDIB, might be the potential molecular mechanism.

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.

Exosomal miR-125b Exerts Anti-Metastatic Properties and Predicts Early Metastasis of Hepatocellular Carcinoma

BACKGROUND & AIMS

Cancer metastasis is responsible for the majority of cancer-related deaths. Exosomal miRNAs have emerged as promising biomarkers for cancer, serving as signaling molecules that can regulate tumor growth and metastasis. This study examined circulating exosomal miRNAs that could predict hepatocellular carcinoma (HCC) metastasis.

METHODS

Exosomal miRNA was measured by quantitative real-time PCR (qRT-PCR) in a large set of patients (n = 284). To investigate the role of exosomal miRNA in HCC, we performed a series of in vitro tests, such as exosome labeling, qRT-PCR, reverse transcription PCR, wound healing assay, transwell assay, and Western blot assay.

RESULTS

Exosomal miR-125b was drastically downregulated in HCC patients with metastasis than in those without metastasis. In vitro, we observed the uptake of miR-125b by exosome in recipient cells. Exosome-mediated miR-125b significantly inhibited migration and invasion abilities and downregulated the mRNA expressions of MMP-2, MMP-9, and MMP-14 in recipient cells via intercellular communication. Further investigation revealed that miR-125b suppressed SMAD2 protein expression in recipient cells by binding to its 3' untranslated regions. Exosome-mediated miR-125b transfer also disrupted TGF-β1-induced epithelial-mesenchymal transition and TGF-β1/SMAD signaling pathway in recipient cells by leading to a decrease of SMAD2 protein expression. Moreover, exosomal miR-125b was downregulated after metastasis compared with that at baseline in patients with serial measurements before and after metastasis.

CONCLUSIONS

The results imply that exosome-mediated miR-125b exerts anti-metastatic properties in HCC. These findings highlight that circulating exosomal miR-125b might represent a reliable biomarker with diagnostic and therapeutic implications for extrahepatic metastasis from HCC.

Mesenchymal stem cell-derived exosomes protect trabecular meshwork from oxidative stress

This study aims to investigate the beneficial effects of exosomes derived from bone marrow mesenchymal stem cells (BMSCs) on trabecular meshwork cells under oxidative stress and predict candidate genes associated with this process. Trabecular meshwork cells were pretreated with BMSC-derived exosomes for 24 h, and exposed to 0.1 mM H2O2 for 6 h. Survival rate of trabecular meshwork cells was measured with CCK-8 assay. Production of intracellular reactive oxygen species (iROS) was measured using a flow cytometer. RT-PCR and ELISA were used to detect mRNA and protein levels of inflammatory cytokines and matrix metalloproteinases (MMPs). Sequencing of RNA and miRNA for trabecular meshwork cells from Exo and control groups was performed on BGISEQ500 platform. Phenotypically, pretreatment of BMSC-derived exosomes improves survival rate of trabecular meshwork cells exposed to H2O2, reduces production of iROS, and inhibits expression of inflammatory cytokines, whereas increases expression of MMPs. There were 23 miRNAs, 307 lncRNAs, and 367 mRNAs differentially expressed between Exo and control groups. Exosomes derived from BMSCs may protect trabecular meshwork cells from oxidative stress. Candidate genes responsible for beneficial effects, such as DIO2 and HMOX1, were predicted.

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.

miR-383 reduces keratinocyte proliferation and induces the apoptosis in psoriasis via disruption of LCN2-dependent JAK/STAT pathway activation

Psoriasis is a chronic and relapsing disorder with considerable negative effects on patients' quality of life. The finer details associated with the molecular mechanism of psoriasis and its pathogenesis remain somewhat elusive. Extensive studies have highlighted the crucial role of microRNAs (miRNAs) in the development of psoriasis. Hence, the current study aimed to investigate the effect of miR-383 on a psoriasis rat model and elucidate the underlying molecular mechanism. The rat psoriasis model was established via imiquimod (IMQ) induction followed by verification of miR-383 and LCN2 expression in the skin tissues of the models. ELISA was conducted to determine the secretion of inflammatory factors. Keratinocyte proliferation and apoptosis was evaluated by MTT assay and flow cytometric analysis. Down-regulation of miR-383 and up-regulation of LCN2 were detected in the psoriasis rat model. Our data indicated that miR-383 targeted LCN2 by binding to its 3'UTR and inhibited JAK/STAT pathway activation. Notably, miR-383 overexpression or LCN2 knockdown attenuated psoriasis-like symptoms, suppressed inflammatory response, reduced the expression of JAK3 and STAT3, ceased keratinocyte proliferation, and promoted the apoptosis. The findings of our study suggest that miR-383 may inhibit LCN2 and inactivate the JAK/STAT pathway, suppressing the progression of psoriasis in a rat model. This study provided novel insights into the pathogenesis of psoriasis and offered potential targets for psoriasis treatment.

Noncoding RNAs in oral premalignant disorders and oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) has the highest mortality rate among all head and neck cancers and a relatively low five-year survival rate. Generally, the development of an oral mucosal malignancy represents a multistep process beginning with normal oral mucosa epithelium and culminating in OSCC after transitioning through intermediary oral premalignant disorders (OPMDs), during which dysplasia is often observed. Noncoding RNAs (ncRNAs) are RNAs that are not translated into proteins, but still can participate in regulating neoplastic cell behavior. Recently, data have emerged on the role of ncRNAs in the progression of oral mucosal malignant diseases, but the exact mechanisms through which ncRNAs are involved remain to be elucidated.

CONCLUSIONS

Knowledge on ncRNAs has added an extra layer of complexity to our understanding of the malignant progression of oral mucosal diseases. The identification of ncRNAs in multiple body fluids as biomarkers may provide new diagnostic options that can be used for the diagnosis and prognosis of OPMDs and OSCC, respectively. Despite overall advances that have been made in cancer treatment, the treatment options for OPMDs and OSCC are still limited. Several studies have shown that ncRNA-based treatment regimens may hold promise as alternative methods for treating OPMDs and OSCC. The use of ncRNAs as therapeutic agents, including miR-155, miR-34 and lncRNA HOTAIR, appear promising.

Quercetin protects human oral keratinocytes from lipopolysaccharide-induced injury by downregulating microRNA-22

BACKGROUND

Quercetin exerts anti-inflammatory effects, but whether it can benefit patients with the chronic inflammatory disease of oral lichen planus (OLP), which is a common chronic mucocutaneous disorder with an immune-mediated pathogenesis, is unclear. The present research examined the impacts of quercetin in a cell-based OLP model in which human oral keratinocytes (HOKs) were treated with lipopolysaccharide (LPS).

METHODS

Effects of quercetin on viability, proliferation, and apoptosis of HOKs were assessed using the Cell Counting Kit-8 assay, Western blotting, and flow cytometry, respectively. Effects of treatment on levels of microRNA-22 (miR-22) were measured using stem-loop reverse transcription polymerase chain reaction, while levels of proteins and phosphorylation in the PI3K/AKT and JAK1/STAT3 cascades were analyzed by Western blot.

RESULTS

Quercetin mitigated LPS-induced reduction in HOK viability and elevation of apoptosis. It also weakened LPS-induced upregulation of miR-22. Quercetin treatment led to significantly higher levels of p-PI3K, p-AKT, p-JAK1, and p-STAT3. These effects of quercetin were enhanced when miR-22 was knocked down and partly reversed when miR-22 was overexpressed.

CONCLUSION

Quercetin can mitigate LPS-induced injury in HOKs by downregulating miR-22, thereby activating PI3K/AKT and JAK1/STAT3 cascades.

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.

Possible treatment for cutaneous lichen planus: An in vitro anti-inflammatory role of Angelica polysaccharide in human keratinocytes HaCaT

Cutaneous lichen planus (CLP) is an autoimmune disease. Angelica polysaccharide (AP) has been found to exert immunomodulation activity. In this study, we explored the roles of AP in lipopolysaccharide (LPS)-induced inflammatory injury of human keratinocytes (HaCaT cells), as well as the underlying mechanisms. LPS-induced cell injury was evaluated by alterations of cell viability, apoptosis, and expressions of proteins associated with apoptosis and inflammatory cytokines. Then, the protective effects of AP on LPS-induced cell injury were assessed. The protein expressions of sirtuin 1 (SIRT1) and key kinases in the Nrf2/HO-1 and nuclear factor κB (NF-κB) pathways were measured using western blotting. SIRT1 knockdown and overexpression were used to analyze whether AP affected HaCaT cells through regulating SIRT1. Finally, the possible inhibitory effects of AP on cell injury after LPS treatment were also evaluated. We found that LPS reduced HaCaT cell viability, enhanced apoptosis, and induced release of inflammatory cytokines. AP alleviated LPS-induced HaCaT cell inflammatory injury. The expression of SIRT1 was enhanced after AP treatment. AP activated Nrf2/HO-1 pathway while inhibited NF-κB pathway in HaCaT cells. The protective effects of AP on LPS-induced HaCaT cell injury were reversed by SIRT1 knockdown. Dysregulation of SIRT1 altered the activation of Nrf2/HO-1 and NF-κB pathways in LPS-treated HaCaT cells. Furthermore, AP also exerted inhibitory effects on HaCaT cell injury after LPS stimulation. In conclusion, AP could alleviate LPS-induced inflammatory injury of HaCaT cells through upregulating SIRT1 expression and then activating Nrf2/HO-1 pathway but inactivating NF-κB pathway. This study provided a possible therapeutic strategy for clinical CLP treatments.

MicroRNA-125b-5p regulates IL-1β induced inflammatory genes via targeting TRAF6-mediated MAPKs and NF-κB signaling in human osteoarthritic chondrocytes

Abnormal post-transcriptional modulations in inflammatory genes by microRNAs (miRNAs) play a crucial role in human disorders including arthritis. In this study, we determined the effect of hsa-miR-125b-5p on interleukin (IL)-1β induced inflammatory genes in human osteoarthritic (OA) chondrocytes. Bioinformatics algorithms showed 3′untranslated region (3′UTR) of TRAF6 mRNA (NM_004620.3) has perfectly matched ‘seed-sequence’ for hsa-miR-125b-5p. Treatment of cells with IL-1β up-regulates TRAF6 mRNA and down-regulates hsa-miR-125b-5p expression. This negative correlation between TRAF6 and hsa-miR-125b-5p was verified by transfection with miR-125b mimic (pre-miR-125b). Moreover, transfection with miR-125b mimic caused marked inhibition of IL-1β-induced phosphorylation of p38-MAPK, JNK-MAPKs and ERK-MAPKs and also suppressed the nuclear levels of NF-κBp50, NF-κBp65 and inhibited the activation of IκBα. Furthermore, transfected chondrocytes with miR-125b mimic in the presence of IL-1β also showed marked inhibition in the secretion of several proinflammatory cytokines, chemokines and growth factors including IL-6, IL-8, INF-γ, TGF-β1, IGFBP-1 and PGDF-BB. Importantly, this transfection also significantly inhibited IL-1β- induced MMP-13 expression/production. In short, this study concludes that hsa-miR-125b-5p acts as a negative co-regulator of inflammatory genes including MMP-13 via targeting TRAF6/MAPKs/NF-κB pathway in human OA chondrocytes.

Down-regulation of miRNA-27b-3p suppresses keratinocytes apoptosis in oral lichen planus

Oral lichen planus (OLP) is considered a precancerous lesion with no known cure. Recent studies reported that abnormal regulation of apoptosis was involved in the pathogenesis of OLP. Next generation sequencing was used to screen the candidate microRNAs and genes in biopsies from patients with OLP and healthy mucosa. Human oral keratinocytes were transfected into the related oligonucleotides of miR‐27b‐3p/cyclophilin D and their control groups. Apoptosis was detected by TdT‐mediated dUTP nick end labelling and flow cytometry. The levels of mRNA and protein were detected by quantitative PCR, Western blots, and enzyme‐linked immunosorbent assays, respectively. Luciferase assays were performed to detect the luciferase activities of miR‐27b‐3p and cyclophilin D. Here, we showed that basal epithelium apoptosis was reduced and the miR‐27b‐3p levels were decreased in clinical OLP samples. We also found that down‐regulation of miR‐27b‐3p inhibited epithelial keratinocyte apoptosis by up‐regulating cyclophilin D expression. Moreover, cyclophilin D increased the protein stability of Bcl2 through direct binding, and Bcl2 suppressed caspase9/3 activation and cytochrome C release. Taken together, these data showed that miR‐27b‐3p regulated keratinocyte apoptosis through cyclophilin D/Bcl2 signalling, suggesting the miR‐27b‐3p regulated the pathogenesis of OLP.

miR‑122 and miR‑199 synergistically promote autophagy in oral lichen planus by targeting the Akt/mTOR pathway

The aim of the present study was to characterize the roles of two microRNAs (miRNAs), miR-122 and miR-199, in oral lichen planus (OLP). miRNA microarray analysis was performed to detect potential miRNAs involved in OLP, while in-silicon analysis, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blot and immunohistochemistry (IHC) analyses were utilized to explore the molecular mechanisms underlying the roles of miR-199 and miR-122 in OLP. The results from the microarray and RT-qPCR analyses demonstrated that the expression levels of miR-122 and miR-199 were significantly decreased in the peripheral blood mononuclear cells (PBMCs) collected from the OLP group compared with the control group. In addition, miR-122 and miR-199 directly targeted AKT serine/threonine kinase 1 (AKT1) and mammalian target of rapamycin (mTOR), respectively, by binding to their 3′ UTRs. AKT1 and mTOR were highly expressed in PBMCs derived from OLP patients. In fact, a negative regulatory relationship was observed between miR-122 and AKT1, and between miR-199 and mTOR, with negative correlation coefficients of −0.41 and −0.51, respectively. Furthermore, the protein levels of AKT1, mTOR and microtubule associated protein 1 light chain 3β (LC3B) were upregulated in the OLP group compared with the control group. Finally, overexpression of miR-122 inhibited the expression of AKT1 and LC3B, while overexpression of miR-199 reduced the levels of mTOR and LC3B. In conclusion, the present study demonstrated that miR-199 and miR-122 are implicated in the pathogenesis of OLP by regulating the expression of mTOR and AKT1.

Forkhead box p3 controls progression of oral lichen planus by regulating microRNA-146a

Oral lichen planus (OLP) is a severe T cell-mediated disorder of the mucosa, which causes chronic inflammation. Forkhead box P3 (Foxp3) regulates the immune response and plays an important role in immunological diseases. The current study aimed to determine the role of Foxp3 and microRNA (miR)-146a in OLP. Western blot analysis and a quantitative real-time polymerase chain reaction assay showed that the expression of Foxp3 and miR-146a was upregulated in OLP tissues and in lipopolysaccharide (LPS)-incubated HaCaT cells, compared with controls. Foxp3 inhibition significantly decreased miR-146a expression, ameliorated LPS stimulation by decreased cell proliferation, and apoptosis in LPS-incubated HaCaT cells as compared with the LPS group. Cotransfection of Foxp3 small interfering RNA and miR-146a mimics elevated cell proliferation and apoptosis compared with the Foxp3 small interfering RNA group. In addition, miR-146a overexpression upregulated, whereas miR-146a inhibition downregulated, the proliferation and apoptosis of LPS-incubated HaCaT cells. The target gene of miR--146a, tumor necrosis factor receptor-associated factor 6 (TRAF6), was predicted by bioinformatics software and identified by the luciferase reporter assay. Furthermore, Foxp3/miR-146a elevated T regulatory cells and regulated TRAF6 expression in CD4+ T cells that were isolated from peripheral blood of patients with OLP. In conclusion, our study suggests that Foxp3 and miR-146a regulate the progression of OLP by negatively regulating TRAF6, which may provide a promising therapeutic target for OLP treatment.

Vitamin D/VDR signaling suppresses microRNA-802-induced apoptosis of keratinocytes in oral lichen planus

Vitamin D is known to play a protective role in inflammatory diseases. Although the suppressive effect of vitamin D/vitamin D receptor (VDR) signaling has been shown in the context of oral lichen planus (OLP), the molecular basis of its regulatory function remains poorly understood. Herein, we reported that miR-802 overexpression in OLP could aggravate apoptosis of oral keratinocytes by targeting B-cell lymphoma 2 mRNA. In addition, vitamin D/VDR signaling was able to suppress miR-802 expression in LPS-treated or activated CD4⁺ T cell-stimulated human oral keratinocytes by blocking NF-κB pathways, thereby inhibiting OLP apoptosis. Consistent with the results in vitro, we showed that miR-802 expression was enhanced in oral keratinocytes from VDR^-/- mice, and an inverse correlation between VDR and miR-802 was found in human biopsy specimens of OLP. Collectively, our data suggest that vitamin D/VDR signaling suppresses oral keratinocyte apoptosis by targeting miR-802.-Zhao, B., Xu, N., Li, R., Yu, F., Zhang, F., Yang, F., Ge, X., Li, Y. C., Du, J. Vitamin D/VDR signaling suppresses microRNA-802-induced apoptosis of keratinocytes in oral lichen planus.

Schisandrin B inhibits the proliferation and invasion of glioma cells by regulating the HOTAIR-micoRNA-125a-mTOR pathway

Glioma is one of the most common malignant central nervous system tumors in humans. Schisandrin B (Sch B) has been confirmed to cause the proliferation and invasion of glioma cells. In the present study, the potential mechanism underlying the antitumor effect of Sch B on glioma cells was investigated. The glioma cell lines, U251 and U87, were exposed to Sch B, and the cell viability, apoptosis, migration, and invasion were determined using the MTT assay, flow cytometry, and transwell assay, respectively. Then, the effects of HOTAIR and miR-125a on tumor biology and the mammalian target of rapamycin (mTOR) protein expression in cell lines exposed to Sch B were investigated. The results showed that Sch B decreased HOTAIR expression and increased miR-125a-5p expression. HOTAIR overexpression decreased miR-125a expression and increased mTOR expression in cells with the treatment of Sch B. The miR-125a inhibitor reversed the effects of HOTAIR downregulation on cell proliferation and migration. On co-incubation with rapamycin, a specific mTOR inhibitor, the cell viability, migration, and invasion were decreased and cell apoptosis was increased in two cell lines exposed to Sch B after the treatment of pcDNA-HOTAIR. In conclusion, Sch B played an inhibitory role in the proliferation and invasion of glioma cells by regulating the HOTAIR-micoRNA-125a-mTOR pathway.

Assessing miRNAs profile expression as a risk stratification biomarker in oral potentially malignant disorders: A systematic review

OBJECTIVES

This paper aims to systematically review current findings on altered expression of miRNAs in OPMDs and whether they can be used as risk stratification biomarkers.

METHODS

Studies were collated after searching three different electronic databases: PubMed, Embase, Medline. Additional searches were carried out through cross checking the bibliographies of selected articles. After a thorough selection process made by two of the authors, 40 articles met the inclusion criteria and were included in the review. Studies were assessed and analysed in terms of how the candidate miRNA biomarkers were differentially expressed and validated.

RESULTS

The included studies examined the expression of miRNAs from human specimens (blood serum/plasma, saliva, tissue) as diagnostic or prognostic biomarkers in patients with OPMDs, some of which have been utilised as risk stratification biomarkers for malignant transformation and have showed promising findings.

CONCLUSION

The current evidence to support or refute the prognostic utility of miRNAs in predicting cancer progression in OPMDs is equivocal. Further longitudinal prospective studies with solid study design are warranted.

MicroRNA-20a-5p suppresses IL-17 production by targeting OSM and CCL1 in patients with Vogt-Koyanagi-Harada disease

Aim

To elucidate the role of microRNA-20a-5p (miR-20a-5p) in the pathogenesis of Vogt-Koyanagi-Harada (VKH) disease.

Methods

Quantitative real-time PCR was used to quantify miR-20a-5p expression in CD4+ T cells from patients with active VKH and normal controls. The promoter methylation status of miR-20a-5p was detected by bisulfite sequencing PCR. Targets were evaluated by a luciferase reporter assay. The functional effects of miR-20a-5p on CD4+ T cells from patients with active VKH were assessed by upregulation or downregulation of its expression using liposomes.

Results

The miR-20a-5p level was significantly decreased in CD4+ T cells from patients with active VKH as compared with normal controls. The two genes, oncostatin M (OSM) and C-C motif chemokine ligand 1 (CCL1), were identified as targets of miR-20a-5p. The upregulation of miR-20a-5p significantly suppressed interleukin 17 (IL-17) production in CD4+ T cells from patients with active VKH, whereas downregulation of miR-20a-5p exhibited an inverse effect. In addition, overexpression of OSM and CCL1 could rescue the effect of the upregulation of miR-20a-5p. Moreover, the level of miR-20a-5p was reduced in response to hypermethylation of the promoter. Further study showed that miR-20a-5p suppressed the activity of the phosphoinositide 3-kinase-AKT pathway.

Conclusions

Our findings indicate that downregulation of miR-20a-5p is caused by promoter hypermethylation. MiR-20a-5p could also suppress the production of IL-17 by targeting OSM and CCL1 production in CD4+ T cells in patients with active VKH.