SNHG16 promotes the progression of osteoarthritis through activating microRNA-93-5p/CCND1 axis

Establishment of Ferroptosis-Related Key Gene Signature and Its Validation in Compression-Induced Intervertebral Disc Degeneration Rats

Cell death and functional loss of nucleus pulposus cell play essential roles in intervertebral disc degeneration (IDD). Ferroptosis is a newly identified cell death type, and its role in IDD is still under investigation. Identifying the key genes of ferroptosis in IDD helps to identify the therapeutic targets of IDD. In this study, we downloaded the human IDD mRNA microarray data from the Gene Expression Omnibus and ferroptosis genes from FerrDb, then performed a series of analyses using strict bioinformatics algorithms. In general, we obtained 40 ferroptosis-related differential expression genes (FerrDEGs) and identified six ferroptosis key gene signatures, namely, ATF3, EIF2S1, AR, NQO1, TXNIP, and AKR1C3. In addition, enrichment analysis of the FerrDEGs was conducted, the protein-protein interaction network was constructed, the correlations between ferroptosis key genes and immune infiltrating cells were analyzed, and the lncRNA-miRNA-mRNA ceRNA network was constructed. In particular, ATF3 and EIF2S1 showed the strongest correlation with immune cell function, which might lead to the development of IDD. Finally, the expressions of ferroptosis key genes were verified in the rat compression-induced IDD. In conclusion, this preliminary study analyzed and verified the mechanism of ferroptosis in IDD, laid a foundation for the follow-up study of the mechanism of ferroptosis in IDD, and provided new targets for preventing and delaying IDD.

Multi-omics molecular biomarkers and database of osteoarthritis

Osteoarthritis (OA) is the most common form of arthritis in the adult population and is a leading cause of disability. OA-related genetic loci may play an important role in clinical diagnosis and disease progression. With the rapid development of diverse technologies and omics methods, many OA-related public data sets have been accumulated. Here, we retrieved a diverse set of omics experimental results from 159 publications, including genome-wide association study, differentially expressed genes and differential methylation regions, and 2405 classified OA-related gene markers. Meanwhile, based on recent single-cell RNA-seq data from different joints, 5459 cell-type gene markers of joints were collected. The information has been integrated into an online database named OAomics and molecular biomarkers (OAOB). The database (http://ibi.zju.edu.cn/oaobdb/) provides a web server for OA marker genes, omics features and so on. To our knowledge, this is the first database of molecular biomarkers for OA.

Circular RNA RHOT1 Regulates miR-142-5p/CCND1 to Participate in Chondrocyte Autophagy and Proliferation in Osteoarthritis

Background

Osteoarthritis (OA) serves as one of the most prevalent types of joint disorders and is a leading cause of symptoms of stiffness, swelling, and arthralgia. Circular RNAs (circRNAs) have been reported to participate in various cellular processes by competing with microRNAs. Meanwhile, cyclinD1 (CCND1) is a key cell cycle regulatory protein and plays a crucial role in OA progression. Nevertheless, the function of circRHOT1 in the modulation of OA progression is still obscure. Here, we explored the effect of circRHOT1 on autophagy and extracellular matrix (ECM) in OA.

Methods

The expression of circRHOT1 and autophagy markers was detected in OA samples. The effect of circRHOT1 on OA was analyzed in the OA rat model. The function of circRHOT1 in the regulation of OA was assessed by CCK-8, colony formation, flow cytometry analysis, quantitative real-time PCR, Western blot analysis, and luciferase reporter gene assay in chondrocytes.

Results

We observed that autophagy markers, including LC3 and beclin1, were repressed in clinical OA samples. The expression of circRHOT1 and CCND1 was induced but the miR-142-5p expression was reduced in clinical OA samples. The miR-142-5p expression was negatively correlated with circRHOT1 and CCND1, and the circRHOT1 expression was positively associated with CCND1 in clinical OA samples. Meanwhile, the apoptosis was induced in OA rats but the depletion of circRHOT1 could block the phenotype in the rats. The articular cartilage degeneration was promoted in OA rats, while the knockdown of circRHOT1 repressed the degeneration. The serum levels of CTX-II and COMP were increased in OA rats, and the silencing of circRHOT1 downregulated levels of these proteins. In addition, the expression of collagen II and aggrecan was promoted by the depletion of circRHOT1 in the OA rats. Significantly, the expression of LC3 and beclin1 was suppressed in OA rats, in which the knockdown of circRHOT1 could reverse the effect. Moreover, the depletion of circRHOT1 repressed the cell viability and proliferation but induced apoptosis of chondrocytes. The expression levels of LC3, beclin1, collagen II, and aggrecan were induced by circRHOT1 knockdown. Mechanically, circRHOT1 was able to enhance the CCND1 expression by sponging miR-142-5p in chondrocytes. The overexpression of CCND1 or the inhibition of miR-142-5p reversed circRHOT1 depletion-mediated chondrocyte phenotypes.

Conclusions

Circular RNA RHOT1 enhances the CCND1 expression by sponging miR-142-5p to inhibit chondrocyte autophagy and promote chondrocyte proliferation in osteoarthritis. Our findings provided a promising therapeutic target for OA.

Bioinformatics-Based Research on Key Genes and Pathways of Intervertebral Disc Degeneration

OBJECTIVE

To find out the pathways and key genes and to reveal disc degeneration pathogenesis based on bioinformatic analyses.

DESIGN

The GSE70362 dataset was downloaded from the GEO (Gene Expression Omnibus) database. Differentially expressed genes (DEGs) between the patients having disc degeneration and healthy controls were screened by Limma package in R language. Critical genes were identified by adopting gene ontologies (GOs), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and protein-protein interaction (PPI) networks.

RESULTS

We identified 112 DEGs, including 60 genes which were upregulated and 52 that were downregulated. Analyses, such as GO and KEGG demonstrated that the DEGs got enriched in 4 biological processes and 2 signaling pathways, mainly related to disc degeneration. The PPI network analyses identified 5 key proteins, CCND1 (cyclin D1), GATA3, TNFSF11, LEF1, and DKK1 (Dickkopf related protein 1).

CONCLUSION

In this study, the DEGs and pathways determined promoted us understand the disc degeneration mechanisms. Also, the study may contribute novel biomarkers for the diagnosis and prevention of disc degeneration, and seek new treatment methods to repair and even regenerate degenerative intervertebral disc.

hsa‑miR‑15a‑5p inhibits colon cell carcinoma via targeting CCND1

Colon carcinoma is one of the most common cancers worldwide. Epidemiological studies have revealed that colon cancer is the third leading cause of cancer-related deaths, which is due to the increased incidence and mortality rates. However, the treatment strategies for colon cancer remain unsatisfactory for patients, especially for those with advanced or recurrent colon cancer. Dysregulated microRNAs (miRNAs) are considered to influence tumor development and metastasis. However, the molecular mechanism through which miRNAs affect cancer progression is not yet completely understood. The aim of the present study was to investigate the expression levels of has-miR-15a-5p and its molecular mechanism in colon cell carcinoma. In the present study, the expression levels of hsa-miR-15a-5p were found to be decreased in colon tumor tissues and cancer cell lines. Hsa-miR-15a-5p overexpression inhibited colon cell proliferation and migration. Mechanistically, the G1/S-specific cyclin-D1 (CCND1) gene was predicted as a target of hsa-miR-15a-5p, as evidenced by bioinformatics and dual-luciferase reporter assay analyses. CCND1 overexpression significantly increased the progression of colon cancer. Furthermore, CCND1 was demonstrated to mediate the effects of hsa-miR-15a-5p on colon cancer cells. The present study demonstrated that hsa-miR-15a-5p alleviated the proliferation, migration and invasion of colon cancer by targeting the CCND1 gene, which represents a potential molecular target for the diagnosis and treatment of colon cancer.

Tumor Cell-Derived Exosomal miR-770 Inhibits M2 Macrophage Polarization via Targeting MAP3K1 to Inhibit the Invasion of Non-small Cell Lung Cancer Cells

Background

Non-small cell lung carcinoma (NSCLC) is a type lung cancer with high malignant behaviors. MicroRNAs (miRNAs) are known to be involved in progression of NSCLC. In order to explore potential targets for the treatment of NSCLC, bioinformatics tool was used to analyze differential expressed miRNAs between NSCLC and adjacent normal tissues.

Methods

Bioinformatics tool was used to find potential targets for NSCLC. Cell proliferation was investigated by Ki67 staining. Cell apoptosis was measured by flow cytometry. mRNA and protein expression in NSCLC cells were detected by RT-qPCR and Western-blot, respectively. Transwell assay was performed to test the cell migration and invasion. In order to investigate the function of exosomal miRNA in NSCLC, in vivo model of NSCLC was constructed.

Results

MiR-770 was identified to be downregulated in NSCLC, and miR-770 agomir could significantly inhibit NSCLC cell proliferation through inducing the apoptosis. Additionally, the metastasis of NSCLC cells was decreased by miR-770 agomir. MAP3K1 was identified to be the target mRNA of miR-770. Meanwhile, tumor cell-derived exosomal miR-770 inhibited M2 macrophage polarization via downregulation of MAP3K1, which in turn suppressed NSCLC cell invasion. Besides, tumor cell-derived exosomal miR-770 markedly decreased NSCLC tumor growth in vivo through suppressing M2 macrophage polarization.

Conclusion

Tumor cell-derived exosomal miR-770 inhibits M2 macrophage polarization to inhibit the invasion of NSCLC cells via targeting MAP3K1. Thus, this study provided a new strategy for the treatment of NSCLC.

lncRNA SNHG16 promotes the occurrence of osteoarthritis by sponging miR‑373‑3p

Osteoarthritis (OA) is a common age‑related joint disorder, for which no effective disease‑modifying drugs are currently available. Long non‑coding RNAs (lncRNAs) are involved in the occurrence of OA. lncRNA small nucleolar RNA host gene 16 (SNHG16) has been reported to regulate inflammation; however, the exact biological function of SNHG16 in OA and its underlying mechanism of action remain unclear. In this study, gene and protein expression levels were detected using reverse transcription‑quantitative PCR and western blotting, respectively. Cell apoptosis was analyzed using flow cytometry and ELISA was performed to detect TNF‑α levels. The interactions between lncRNA SNHG16 and microRNA (miR)‑373‑3p were examined using the dual‑luciferase reporter assay. lncRNA SNHG16 was upregulated in OA tissue compared with normal joint tissue. The expression levels of collagen II were significantly reduced in OA tissue compared with normal tissue. Similarly, aggrecan expression levels were significantly reduced in IL‑1β‑treated CHON‑001 cells compared with the controls. In addition, the protein expression levels of MMP13 were significantly increased in OA tissues and IL‑1β‑treated CHON‑001 cells compared with the controls. SNHG16 knockdown significantly increased the expression levels of aggrecan, and decreased the expression levels of MMP13, cleaved caspase‑3 and p21 in IL‑1β‑treated CHON‑001 cells. In addition, IL‑1β induced CHON‑001 cell apoptosis, while SNHG16 knockdown decreased IL‑1β‑induced apoptosis. Furthermore, the luciferase activity assay suggested that SNHG16 negatively regulated miR‑373‑3p in OA. Finally, the results suggested that the proinflammatory effect of IL‑1β on CHON‑001 cells was significantly reduced by SNHG16 knockdown. In conclusion, lncRNA SNHG16 knockdown significantly limited the progression of OA by sponging miR‑373‑3p in vitro, which suggested that SNHG16 may serve as a potential therapeutic target for OA.