CircRNA circ-IQGAP1 Knockdown Alleviates Interleukin-1β-Induced Osteoarthritis Progression via Targeting miR-671-5p/TCF4

Hsa_circular RNA_0045474 Facilitates Osteoarthritis Via Modulating microRNA-485-3p and Augmenting Transcription Factor 4

Circular RNA (circRNA) influences on the pathological process of osteoarthritis (OA) and may be a potential marker for disease diagnosis. The study was to scrutinize the association of circ_0045474 with OA. Clinical samples of OA patients were collected, and 12 circRNAs derived from KPNA2 gene were examined. CHON-001 cells were stimulated with IL-1β to construct an OA chondrocyte model. miR-485-3p, transcription factor 4 (TCF4) and circ_0045474, type II procollagen (COL2A1), and human collagenase-3 (MMP13) were tested. Furthermore, cell activities were analyzed. The relationship between miR-485-3p, TCF4, and circ_0045474 was determined. The role of circ_0045474 in vivo was further confirmed by constructing an OA mouse model by anterior cruciate ligament transection. circ_0045474 expression was elevated in OA patients. Suppressing circ_0045474 restrained IL-1β-stimulated extracellular matrix degradation, inflammatory cytokine secretion, and chondrocyte apoptosis. Circ_0045474 competitively combined with miR-485-3p, while TCF4 was the target of miR-485-3p. Circ_0045474 modulated IL-1β-stimulated extracellular matrix degradation, inflammatory cytokine secretion, and chondrocyte apoptosis via miR-485-3p/TCF4 axis. Suppressing circ 0045474 was effective to alleviate OA in mice. Silenced circ_0045474 suppresses OA progression in vitro and vivo via miR-485-3p/TCF4 axis. In short, circ_0045474 can be considered a novel therapeutic target for OA.

Saikosaponin D alleviates inflammatory response of osteoarthritis and mediates autophagy via elevating microRNA-199-3p to target transcription Factor-4

OBJECTIVE

This study was to investigate the underlying mechanism by which Saikosaponin D (SSD) mitigates the inflammatory response associated with osteoarthritis (OA) and regulates autophagy through upregulation of microRNA (miR)-199-3p and downregulation of transcription Factor-4 (TCF4).

METHODS

A mouse OA model was established. Mice were intragastrically administered with SSD (0, 5, 10 μmol/L) or injected with miR-199-3p antagomir into the knee. Then, pathological changes in cartilage tissues were observed. Normal chondrocytes and OA chondrocytes were isolated and identified. Chondrocytes were treated with SSD and/or transfected with oligonucleotides or plasmid vectors targeting miR-199-3p and TCF4. Cell viability, apoptosis, inflammation, and autophagy were assessed. miR-199-3p and TCF4 expressions were measured, and their targeting relationship was analyzed.

RESULTS

In in vivo experiments, SSD ameliorated cartilage histopathological damage, decreased inflammatory factor content and promoted autophagy in OA mice. miR-199-3p expression was downregulated and TCF4 expression was upregulated in cartilage tissues of OA mice. miR-199-3p expression was upregulated and TCF4 expression was downregulated after SSD treatment. Downregulation of miR-199-3p attenuated the effect of SSD on OA mice. In in vitro experiments, SSD inhibited the inflammatory response and promoted autophagy in OA chondrocytes. Downregulation of miR-199-3p attenuated the effect of SSD on OA chondrocytes. In addition, upregulation of miR-199-3p alone inhibited inflammatory responses and promoted autophagy in OA chondrocytes. miR-199-3p targeted TCF4. Upregulation of TCF4 attenuated the effects of miR-199-3p upregulation on OA chondrocytes.

CONCLUSIONS

SSD alleviates inflammatory response and mediates autophagy in OA via elevating miR-199-3p to target TCF4.

Hsa_circ_0004662 Accelerates the Progression of Osteoarthritis via the microRNA-424-5p/VEGFA Axis

OBJECTIVE

Circular RNAs (circRNAs) have been extensively implicated in osteoarthritis (OA) progression. Therefore, this study explores the impact of hsa_circ_0004662 on OA progression and the related molecular mechanism.

METHODS

Human articular chondrocyte injury was induced by IL-1β to construct the OA model in vitro. Hsa_circ_0004662 and microRNA (miR)-424-5p expression in chondrocytes was evaluated with qRT-PCR. Vascular endothelial growth factors A (VEGFA) expression was examined with qRT-PCR and western blot after hsa_circ_0004662 knockdown or miR-424-5p overexpression in chondrocytes. Subsequent to loss- and gain-of-function assays in IL-1β-induced chondrocytes, the proliferation and apoptosis of chondrocytes were assessed with CCK-8 assay and flow cytometry, respectively. The expression of MMP13, Aggrecan, and apoptosis-related proteins Bax and Bcl-2 was measured with western blot. The binding of miR-424-5p to hsa_circ_0004662 and VEGFA was assessed with a dual-luciferase reporter gene assay.

RESULTS

Hsa_circ_0004662 was up-regulated, but miR-424-5p was down-regulated in IL-1β-induced chondrocytes. Mechanistically, both hsa_circ_0004662 and VEGFA bound to miR-424-5p, and hsa_circ_0004662 enhanced VEGFA expression by downregulating miR-424-5p. Hsa_circ_0004662 knockdown elevated cell proliferation, decreased apoptosis and MMP13 and Bax expression, and increased Aggrecan and Bcl- 2 expression in IL-1β-induced chondrocytes, which was counteracted by further miR- 424-5p down-regulation or VEGFA overexpression.

CONCLUSION

Hsa_circ_0004662 facilitates OA progression via the miR-424-5p/ VEGFA axis.

Exosomal circ-AHCY promotes glioblastoma cell growth via Wnt/β-catenin signaling pathway

BACKGROUND

Glioblastoma (GBM) is the most aggressive brain tumor. Reportedly, circular RNAs (circRNAs) participate in regulation of the development and progression of diverse cancers, including GBM.

METHODS

Dysregulated circRNAs in GBM tissues were screened out from GEO database. The expression of candidate circRNAs in GBM cells was measured by qRT-PCR. Loss-of function assays, including colony formation assay, EdU assay, TUNEL assay, and flow cytometry analysis were conducted to determine the effects of circ-AHCY knockdown on GBM cell proliferation and apoptosis. Animal study was further used to prove the inhibitory effect of circ-AHCY silencing on GMB cell growth. Mechanistic experiments like luciferase reporter, RNA pull-down and RNA-binding protein immunoprecipitation (RIP) assays were performed to unveil the downstream molecular mechanism of circ-AHCY. Nanosight Nanoparticle Tracking Analysis (NTA) and PKH67 staining were applied to identify the existence of exosomes.

RESULTS

Circ-AHCY was confirmed to be highly expressed in GBM cells. Circ-AHCY silencing suppressed GBM cell proliferation both in vitro and in vivo. Mechanistically, circ-AHCY activates Wnt/β-catenin signaling pathway by sequestering miR-1294 to up-regulate MYC which activated CTNNB1 transcription. It was also found that circ-AHCY recruited EIF4A3 to stabilize TCF4 mRNA. Enhanced levels of TCF4 and β-catenin contributed to the stability of TCF4/β-catenin complex. In turn, TCF4/β-catenin complex strengthened the transcriptional activity of circ-AHCY. Exosomal circ-AHCY derived from GBM cells induced abnormal proliferation of normal human astrocytes (NHAs).

CONCLUSION

Exosomal circ-AHCY forms a positive feedback loop with Wnt/β-catenin signaling pathway to promote GBM cell growth.

CircRNAs in osteoarthritis: research status and prospect

Osteoarthritis (OA) is the most common joint disease globally, and its progression is irreversible. The mechanism of osteoarthritis is not fully understood. Research on the molecular biological mechanism of OA is deepening, among which epigenetics, especially noncoding RNA, is an emerging hotspot. CircRNA is a unique circular noncoding RNA not degraded by RNase R, so it is a possible clinical target and biomarker. Many studies have found that circRNAs play an essential role in the progression of OA, including extracellular matrix metabolism, autophagy, apoptosis, the proliferation of chondrocytes, inflammation, oxidative stress, cartilage development, and chondrogenic differentiation. Differential expression of circRNAs was also observed in the synovium and subchondral bone in the OA joint. In terms of mechanism, existing studies have mainly found that circRNA adsorbs miRNA through the ceRNA mechanism, and a few studies have found that circRNA can serve as a scaffold for protein reactions. In terms of clinical transformation, circRNAs are considered promising biomarkers, but no large cohort has tested their diagnostic value. Meanwhile, some studies have used circRNAs loaded in extracellular vesicles for OA precision medicine. However, there are still many problems to be solved in the research, such as the role of circRNA in different OA stages or OA subtypes, the construction of animal models of circRNA knockout, and more research on the mechanism of circRNA. In general, circRNAs have a regulatory role in OA and have particular clinical potential, but further studies are needed in the future.

CircRNA-mediated ceRNA mechanism in Osteoarthritis: special emphasis on circRNAs in exosomes and the crosstalk of circRNAs and RNA methylation

Osteoarthritis (OA) is an age-related joint disease with chronic inflammation, progressive articular cartilage destruction and subchondral bone sclerosis. CircRNAs (circRNAs) are a class of non-coding RNA with a circular structure that participate in a series of important pathophysiological processes of OA, especially its ceRNA mechanisms, and play an important role in OA. CircRNAs may be potential biomarkers for the diagnosis and prognosis of OA. Additionally, differentially expressed circRNAs were found in patients with OA, indicating that circRNAs are involved in the pathogenesis of OA. Experiments have shown that the intra-articular injection of modified circRNAs can effectively relieve OA. Exosomal circRNAs and methylated circRNAs also provide new ideas for the treatment of OA. Clarifying the important roles of circRNAs in OA will deepen people's understanding of the pathogenesis of OA. CircRNAs may be developed as new biomarkers or drug targets for the diagnosis of OA and provide new methods for the treatment of OA.

Circ_0002715 promotes the development of osteoarthritis through regulating LXN by sponging miR-127-5p

BACKGROUND

Our study aims to investigate the role and mechanism of circular RNA_0002715 (circ_0002715) in osteoarthritis (OA) progression.

METHODS

IL-1β-induced CHON-001 cells were used to mimic OA cell model. Circ_0002715, microRNA (miR)-127-5p and Latexin (LXN) expression was detected by quantitative real-time PCR. Cell functions were determined by MTT assay, flow cytometry and ELISA assay. Protein expression was examined by western blot.

RESULTS

Circ_0002715 was highly expressed in OA cartilage tissues. Circ_0002715 silencing inhibited inflammation, apoptosis, and ECM degradation in IL-1β-interfered CHON-001 cells. Circ_0002715 could sponge miR-127-5p, and miR-127-5p could target LXN. The effect of circ_0002715 down-regulation on chondrocyte injury was partially restored by miR-127-5p inhibitor. MiR-127-5p could suppress chondrocyte injury by inhibiting LXN expression.

CONCLUSION

Circ_0002715 might be a new therapeutic target for OA, which regulated miR-127-5p/LXN axis to promote IL-1β-induced chondrocyte injury.

Circular RNA SLTM as a miR-421-competing endogenous RNA to mediate HMGB2 expression stimulates apoptosis and inflammation in arthritic chondrocytes

Osteoarthritis (OA) is the most common age-related joint disease characterized by chronic inflammation, progressive articular cartilage destruction, and subchondral sclerosis. Accumulating evidence suggests that circular RNAs (circRNAs) play key roles in OA, but the function of circSLTM in OA remains greatly unknown. Therefore, this study focused on interleukin-1β (IL-1β)-treated primary human chondrocytes as well as a rat model to investigate the expression pattern and functional role of circSLTM in OA in vitro and in vivo. CircSLTM and high mobility group protein B2 (HMGB2) were upregulated in IL-1β-induced chondrocytes, whereas miR-421 was downregulated. Knockdown of circSLTM or overexpression of miR-421 ameliorated IL-1β-induced chondrocyte apoptosis and inflammation. The regulatory relationship between circSLTM and miR-421, as well as that between miR-421 and HMGB2, was predicted by bioinformatics and then verified by the RNA immunoprecipitation experiment and dual-luciferase reporter gene assay. Furthermore, silencing of circSLTM increased cartilage destruction and decreased cartilage tissue apoptosis rate and inflammation in a rat model of OA. Taken together, our findings demonstrate the fundamental role of circSLTM in OA progression and provide a potential molecular target for OA therapy.

CircAGK regulates high dihydrotestosterone-induced apoptosis in DPCs through the miR-3180-5p/BAX axis

The incidence of androgen alopecia (AGA), also known as seborrheic alopecia, has surged in recent years, and onset is occurring at younger ages. Dermal papilla cells (DPCs) are key to maintaining hair cycling, and apoptosis-driven processes in DPCs are closely related to hair follicle regeneration. Circular RNAs (circRNAs) are widely present in the human body and are closely related to the occurrence and development of many diseases. Currently, the biological functions of circRNAs in AGA are largely unknown. Whole-transcriptome sequencing was used to screen differential circRNA expression profiles between AGA patients and non-AGA patients. We found that hsa_circ_0002980 (circAGK) was significantly highly expressed in the AGA group. CircAGK promoted DPC apoptosis in the presence of high dihydrotestosterone (DHT) (15 nmol/L). By regulating the miR-3180-5p/BAX axis, circAGK promotes DPC apoptosis in a high DHT environment in vitro and inhibits hair growth in AGA mice in vivo, indicating that circAGK is a potential target for the clinical treatment of AGA.

Research progress on the role and mechanism of miR-671 in bone metabolism and bone-related diseases

Bone metabolism consists of bone formation and resorption and maintains a dynamic balance in vivo. When bone homeostasis is broken, it can manifest as osteoarthritis (OA), rheumatoid arthritis (RA), osteosarcoma (OS), etc. MiR-671, an important class of non-coding nucleotide sequences in vivo, is regulated by lncRNA and regulates bone metabolism balance by regulating downstream target proteins and activating various signaling pathways. Based on the structure and primary function of miR-671, this paper summarizes the effect and mechanism of miR-671 in bone-related inflammation and cancer diseases, and prospects the application possibility of miR-671, providing reference information for targeted therapy of bone-related disorders.

A review on the role of miR-671 in human disorders

miR-671 is encoded by a gene on 7q36.1 and contributes to the pathogenesis of a variety of disorders, including diverse types of cancers, atherosclerosis, ischemic stroke, liver fibrosis, osteoarthritis, Parkinson's disease, rheumatoid arthritis, acute myocardial infarction and Crohn's disease. In the context of cancer, different studies have revealed opposite roles for this miRNA. In brief, it has been shown to be down-regulated in pancreatic ductal carcinoma, ovarian cancer, gastric cancer, osteosarcoma, esophageal squamous cell carcinoma and myelodysplastic syndromes. Yet, miR-671 has been up-regulated in glioma, colorectal cancer, prostate cancer and hepatocellular carcinoma. Studies in breast, lung and renal cell carcinoma have reported inconsistent results. The current review aims at summarization of the role of miR-671 in these disorders focusing on its target mRNA in each context and dysregulated signaling pathways. We also provide a summary of the role of this miRNA as a prognostic factor in malignancies.

Integrated Analysis of lncRNA-miRNA-mRNA ceRNA Network in Mixed Dry Eye Disease

In order to investigate the relationship between inflammation and lncRNA in mixed dry eye disease (DED), this study establishes competitive endogenous RNA (ceRNA) network in mixed DED. Microarray analysis of cornea from mixed DED mice is performed to screen for differences in lncRNA and target genes, and miRNA bioinformatics were predicted based on the ceRNA hypothesis. The ceRNA network, which consists of 96 relationship pairs, is constructed using the top 10 upregulated lncRNAs and all upregulated mRNAs and two pairs of lncRNA-miRNA-mRNA pairs (NONMMUT047964.2-miR-671-5p-Egr-1andNONMMUT054540.2-miR-1934-5p-Grm2) are selected for RT-qRCR verification in mouse corneal epithelial cells under high osmotic pressure and the samples for microarray. Meanwhile, mouse corneal epithelial cell lines (MCECs), transfected siRNA of NONMMUT047964.2 under high osmotic pressure, shows a decrease in apoptosis rate and a decrease in expression of IL-1β and IL-6. The experimental results show that the NONMMUT047964.2-miR-671-5p-Egr-1 axis may regulate the inflammation and promote the apoptosis of corneal epithelial cells under hypertonic condition.

Engineering Closed-Loop, Autoregulatory Gene Circuits for Osteoarthritis Cell-Based Therapies

PURPOSE OF REVIEW

Genetic engineering offers the possibility to simultaneously target multiple cellular pathways in the joints affected by osteoarthritis (OA). The purpose of this review is to summarize the ongoing efforts to develop disease-modifying osteoarthritis drugs (DMOADs) using genetic engineering, including targeting approaches, genome editing techniques, and delivery methods.

RECENT FINDINGS

Several gene circuits have been developed that reprogram cells to autonomously target inflammation, and their efficacy has been demonstrated in chondrocytes and stem cells. Gene circuits developed for metabolic disorders, such as those targeting insulin resistance and obesity, also have the potential to mitigate the impact of these conditions on OA onset and/or progression. Despite the strides made in characterizing the inflammatory environment of the OA joint, our incomplete understanding of how the multiple regulators interact to control signal transduction, gene transcription, and translation to protein limits the development of targeted disease-modifying therapeutics. Continuous advances in targeted genome editing, combined with online toolkits that simplify the design and production of gene circuits, have the potential to accelerate the discovery and clinical application of multi-target gene circuits with disease-modifying properties for the treatment of OA.

Identification of microRNA-mRNA-TF regulatory networks in periodontitis by bioinformatics analysis

BACKGROUND

Periodontitis is a complex infectious disease with various causes and contributing factors. The aim of this study was to identify key genes, microRNAs (miRNAs) and transcription factors (TFs) and construct a miRNA-mRNA-TF regulatory networks to investigate the underlying molecular mechanism in periodontitis.

METHODS

The GSE54710 miRNA microarray dataset and the gene expression microarray dataset GSE16134 were downloaded from the Gene Expression Omnibus database. The differentially expressed miRNAs (DEMis) and mRNAs (DEMs) were screened using the "limma" package in R. The intersection of the target genes of candidate DEMis and DEMs were considered significant DEMs in the regulatory network. Next, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted. Subsequently, DEMs were uploaded to the STRING database, a protein-protein interaction (PPI) network was established, and the cytoHubba and MCODE plugins were used to screen out key hub mRNAs and significant modules. Ultimately, to investigate the regulatory network underlying periodontitis, a global triple network including miRNAs, mRNAs, and TFs was constructed using Cytoscape software.

RESULTS

8 DEMis and 121 DEMs were found between the periodontal and control groups. GO analysis showed that mRNAs were most significantly enriched in positive regulation of the cell cycle, and KEGG pathway analysis showed that mRNAs in the regulatory network were mainly involved in the IL-17 signalling pathway. A PPI network was constructed including 81 nodes and 414 edges. Furthermore, 12 hub genes ranked by the top 10% genes with high degree connectivity and five TFs, including SRF, CNOT4, SIX6, SRRM3, NELFA, and ONECUT3, were identified and might play crucial roles in the molecular pathogenesis of periodontitis. Additionally, a miRNA-mRNA-TF coregulatory network was established.

CONCLUSION

In this study, we performed an integrated analysis based on public databases to identify specific TFs, miRNAs, and mRNAs that may play a pivotal role in periodontitis. On this basis, a TF-miRNA-mRNA network was established to provide a comprehensive perspective of the regulatory mechanism networks of periodontitis.

Circ_0005526 contributes to interleukin-1β-induced chondrocyte injury in osteoarthritis via upregulating transcription factor 4 by interacting with miR-142-5p

Circular RNAs (circRNAs) can regulate the progression of osteoarthritis (OA) via serving as competing endogenous RNAs (ceRNAs). This work was performed for functional research of circ_0005526 in Interleukin-1β (IL-1β)-induced OA injury. Circ_0005526, microRNA-142-5p (miR-142-5p) or transcription factor 4 (TCF4) expression was measured via reverse transcription-quantitative polymerase chain reaction assay. Cell analysis was performed by Cell Counting Kit-8 assay for cell viability, EdU assay for cell proliferation and flow cytometry for cell apoptosis. The protein level detection was conducted using western blot. Target analysis was carried out via dual-luciferase reporter assay and RNA pull-down assay. Circ_0005526 was upregulated in OA cartilage tissues and IL-1β-exposed chondrocyte cells. IL-1β inhibited cell viability and proliferation but enhanced cell apoptosis and inflammation, then these damages were attenuated after downregulation of circ_0005526. Circ_0005526 interacted with miR-142-5p, and circ_0005526 knockdown suppressed IL-1β-induced OA progression through upregulating miR-142-5p. TCF4 was regulated by circ_0005526 via targeting miR-142-5p. The function of circ_0005526 was also achieved by upregulation of TCF4. These results unraveled that circ_0005526 promoted IL-1β-induced chondrocyte injury in OA via suppressing miR-142-5p binding to TCF4.

Circ_0043947 contributes to interleukin 1β-induced injury in chondrocytes by sponging miR-671-5p to up-regulate RTN3 expression in osteoarthritis pathology

Objective

Osteoarthritis (OA) is a chronic joint disease featured by articular cartilage degeneration and damage. Accumulating evidence have demonstrated the pivotal regulatory roles of circular RNAs in OA pathology. However, the role of circ_0043947 in OA progression and its associated mechanism remain largely unknown.

Methods

The expression of RNA and protein was determined by reverse transcription-quantitative polymerase chain reaction and Western blot assay. Cell viability was assessed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell proliferation was analyzed by 5-Ethynyl-2′-deoxyuridine (EdU) assay and flow cytometry. Cell apoptosis was assessed by flow cytometry. Enzyme linked immunosorbent assay was conducted to analyze the release of pro-inflammatory cytokines. Dual-luciferase reporter assay and RNA immunoprecipitation assay were performed to confirm the target interaction between microRNA-671-5p (miR-671-5p) and circ_0043947 or reticulon 3 (RTN3).

Results

Interleukin 1β (IL-1β) stimulation up-regulated the expression of circ_0043947 in chondrocytes. IL-1β treatment restrained the viability and proliferation and induced the apoptosis, extracellular matrix degradation and inflammatory response of chondrocytes partly by up-regulating circ_0043947. Circ_0043947 interacted with miR-671-5p, and miR-671-5p silencing largely reversed circ_0043947 knockdown-mediated protective effects in IL-1β-induced chondrocytes. miR-671-5p interacted with the 3′ untranslated region (3′UTR) of RTN3. miR-671-5p overexpression attenuated IL-1β-induced injury in chondrocytes, and these protective effects were largely overturned by the overexpression of RTN3. Circ_0043947 acted as a molecular sponge for miR-671-5p to up-regulate RTN3 level in chondrocytes.

Conclusion

Circ_0043947 silencing alleviated IL-1β-induced injury in chondrocytes by targeting miR-671-5p/RTN3 axis.

Crosstalk Among circRNA/lncRNA, miRNA, and mRNA in Osteoarthritis

Osteoarthritis (OA) is a joint disease that is pervasive in life, and the incidence and mortality of OA are increasing, causing many adverse effects on people's life. Therefore, it is very vital to identify new biomarkers and therapeutic targets in the clinical diagnosis and treatment of OA. ncRNA is a nonprotein-coding RNA that does not translate into proteins but participates in protein translation. At the RNA level, it can perform biological functions. Many studies have found that miRNA, lncRNA, and circRNA are closely related to the course of OA and play important regulatory roles in transcription, post-transcription, and post-translation, which can be used as biological targets for the prevention, diagnosis, and treatment of OA. In this review, we summarized and described the various roles of different types of miRNA, lncRNA, and circRNA in OA, the roles of different lncRNA/circRNA-miRNA-mRNA axis in OA, and the possible prospects of these ncRNAs in clinical application.

Non-coding RNA-based regulation of inflammation

Inflammation is a multifactorial process and various biological mechanisms and pathways participate in its development. The presence of inflammation is involved in pathogenesis of different diseases such as diabetes mellitus, cardiovascular diseases and even, cancer. Non-coding RNAs (ncRNAs) comprise large part of transcribed genome and their critical function in physiological and pathological conditions has been confirmed. The present review focuses on miRNAs, lncRNAs and circRNAs as ncRNAs and their potential functions in inflammation regulation and resolution. Pro-inflammatory and anti-inflammatory factors are regulated by miRNAs via binding to 3'-UTR or indirectly via affecting other pathways such as SIRT1 and NF-κB. LncRNAs display a similar function and they can also affect miRNAs via sponging in regulating levels of cytokines. CircRNAs mainly affect miRNAs and reduce their expression in regulating cytokine levels. Notably, exosomal ncRNAs have shown capacity in inflammation resolution. In addition to pre-clinical studies, clinical trials have examined role of ncRNAs in inflammation-mediated disease pathogenesis and cytokine regulation. The therapeutic targeting of ncRNAs using drugs and nucleic acids have been analyzed to reduce inflammation in disease therapy. Therefore, ncRNAs can serve as diagnostic, prognostic and therapeutic targets in inflammation-related diseases in pre-clinical and clinical backgrounds.

The potential role of hsa_circ_0001079 in androgenetic alopecia via sponging hsa-miR-136-5p

Background

Androgenetic alopecia (AGA) is an androgen‐dependent polygenic hereditary disease.

Methods

Diseased hair follicles from 5 AGA patients and normal hair follicles from 5 healthy individuals were selected as specimens to carry out whole transcriptome sequencing. Multiple high‐expression circular RNAs (circRNAs) were screened from the diseased group. We further verified the presence of the circRNAs in the clinical specimens by real‐time fluorescence quantitative PCR (qRT‐PCR).

Results

In total, 100 circRNAs were significantly upregulated, and 184 circRNAs were significantly downregulated. The top 10 upregulated circRNAs were hsa_circ_0101041, hsa_circ_0001578, hsa_circ_0135062, hsa_circ_0002980, hsa_circ_0005062, hsa_circ_0072688, hsa_circ_0133954, hsa_circ_0001079, hsa_circ_0005974, hsa_circ_0000489. The top 10 downregulated circRNAs were hsa_circ_0001278, hsa_circ_0031482, hsa_circ_0008285, hsa_circ_0003784, hsa_circ_0077096, hsa_circ_0001148, hsa_circ_0006886, hsa_circ_0000638, hsa_circ_0084521, and hsa_circ_0101074. Among top 10 upregulated circRNAs, hsa_circ_0001079 showed significantly high expression via large‐sample verification and clinical application potential. Based on a database comparison and base pairing analysis, we found that has‐miR‐136‐5p bound to hsa_circ_0001079 and that hsa‐miR‐136‐5p had potential binding sites with Wnt5A.

Conclusion

In summary, through high‐throughput sequencing and bioinformatic analysis, a potential diagnostic marker for alopecia and a key circRNA that might adsorb microRNA (miRNA) through a sponging mechanism, thus mediating alopecia, were discovered in this study.