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Background: Diabetic cardiomyopathy (DCM) is one of the serious complications of the accumulated cardiovascular system in the long course of diabetes. To date, there is no effective treatment available for DCM. Circular RNA (circRNA) is a novel r2egulatory RNA that participates in a variety of cardiac pathological processes. However, the regulatory role of circular RNA MAP3K5 (circMAP3K5) in DCM is largely unclear. Methods and Results: Microarray analysis of DCM rats' heart circular RNAs was performed and the highly species‐conserved circRNA mitogen‐activated protein kinase kinase kinase 5 (circMAP3K5) was identified, which participates in DCM processes. High glucose‐provoked cardiotoxicity leads to the up‐regulation of circMAP3K5, which mechanistically contributes to cardiomyocyte cell death. Also, in high glucose‐induced H9c2 cardiomyocytes, the level of apoptosis was significantly increased, as well as the expression of circMAP3K5. In contrast, the depletion of circMAP3K5 could reduce high glucose‐induced apoptosis in cardiomyocytes. In terms of mechanism, circMAP3K5 acts as a miR‐22‐3p sponge and miR‐22‐3p directly target death‐associated protein kinase 2 (DAPK2) in H9c2 cardiomyocytes, where in circMAP3K5 upregulates DAPK2 expression by targeting miR‐22‐3p. Moreover, we also found that miR‐22‐3p inhibitor and pcDNA DAPK2 could antagonize the protective effects brought by the depletion of circMAP3K5. Conclusion: CircMAP3K5 is a highly conserved noncoding RNA that is upregulated during DCM process. We concluded that circMAP3K5 promotes high glucose‐induced cardiomyocyte apoptosis by regulating the miR‐22‐3p/DAPK2 axis. The results of this study highlight a novel and translationally important circMAP3K5‐based therapeutic approach for DCM. [ABSTRACT FROM AUTHOR]

This document is a retraction note from the journal Cancer Cell International. The article titled "Circular RNA ITCH suppressed prostate cancer progression by increasing HOXB13 expression via spongy miR-17-5p" has been retracted at the request of the corresponding author. The retraction was prompted by concerns about image overlap in several figures of the article. The authors were unable to retrieve the data from a third-party biological company, leading to a loss of confidence in the presented data. The retraction was agreed upon by all authors. [Extracted from the article]

Intervertebral disc degeneration (IDD) is widely accepted as a cause of low back pain and related degenerative musculoskeletal disorders. Nucleus pulposus (NP) cell loss is closely related to IDD progression. Thus, investigating the specifically targeted therapeutic agents against NP cell loss depends on understanding the molecular mechanisms. In this study, human NP cells were treated with hydrogen peroxide (H2O2). Cell viability was assessed by using the Cell Counting Kit-8 (CCK-8) kit. The expression of circRNA arginine-glutamic acid dipeptide repeats (hsa_circ_RERE) and miR-299-5p was analyzed by real-time quantitative PCR. Western blot analysis was used to assess the protein expression levels. The autophagy levels in NP cells were detected by using an electronic microscope, LC3B protein immunofluorescence, and western blot. The apoptosis levels of NP cells were detected by flow cytometry and western blot. Dual-luciferase reporter assay analyzed the miR-299-5p bound to circ_RERE and galectin-3. Our results revealed that H2O2 significantly inhibited the viability of NP cells, promoted apoptosis and autophagy, and upregulated galectin-3 expression. miR-299-5p was reduced in IDD and H2O2-induced NP cells. The overexpression of miR-299-5p promoted cell viability and attenuated apoptosis and autophagy under H2O2 treatment. Besides, circ_RERE was upregulated in IDD and H2O2-induced NP cells. However, knockdown of circ_RERE reversed the effects of miR-299-5p overexpression on cell viability, apoptosis, and autophagy in NP cells. We propose that circ_RERE promotes the H2O2-induced apoptosis and autophagy of NP cells through the miR-299-5p/galectin-3 axis and may provide a new target for the clinical treatment of IDD. [ABSTRACT FROM AUTHOR]

Background: As one of the most common chronic diseases in the world, osteoporosis occurs especially in postmenopausal women. Circular RNAs (circRNAs) are emerging as major drivers in human disease. The aim of the present study was to analyse circRNA expression profiles in osteoporosis and to explore the clinical significance and the regulatory molecular mechanism of hsa_circ_0006859 during osteoporosis. Methods: Exosomes were isolated from clinically collected serum samples. A circRNA microarray was performed to screen differentially expressed circRNAs. Quantitative real-time PCR (qRT-PCR) and western blot were performed to analyse target gene mRNA expression and protein expression. Alizarin red staining (ARS) was performed to evaluate the mineralization ability of human bone marrow mesenchymal stem cells (hBMSCs). Oil Red O staining was performed to evaluate the lipid droplet formation ability of hBMSCs. Bioinformatics analysis and the luciferase reporter assay were performed to investigate the interaction between two genes. Results: Hsa_circ_0006859 was identified as one of the most upregulated circRNAs in the microarray analysis. Hsa_circ_0006859 in exosomes was upregulated in osteoporosis patients compared to healthy controls. Hsa_circ_0006859 differentiated osteopenia or osteoporosis patients from healthy controls with high sensitivity and specificity. Hsa_circ_0006859 suppressed osteoblastic differentiation and promoted adipogenic differentiation of hBMSCs. Hsa_circ_0006859 directly bound to miR-431-5p, and ROCK1 was identified as a novel target gene of miR-431-5p. Hsa_circ_0006859 is a competing endogenous RNA (ceRNA) of miR-431-5p that promotes ROCK1 expression. Hsa_circ_0006859 suppressed osteogenesis and promoted adipogenesis by sponging miR-431-5p to upregulate ROCK1. Conclusions: Exosomal hsa_circ_0006859 is a potential biomarker for postmenopausal osteoporosis and controls the balance between osteogenesis and adipogenesis in hBMSCs by sponging miR-431-5p. [ABSTRACT FROM AUTHOR]

Background: Circular RNA Itchy E3 ubiquitin protein ligase (Circ-ITCH) is significantly down-regulated in various kinds of tumors, however, the mechanisms of action and functions of circITCH gene in prostate cancer (PC) are still under investigation. The mail goal of this research was to study the functional role of Circ-ITCH gene in prostate cancer and to illuminate the function role of circ-ITCH gene in prostate cancer by targeting miR-17-5p/HOXB13. Methods: RT-qPCR was applied to measure the expression level of circ-ITCH and miR-17-5p in PC cell lines and tissues. CCK-8, colony formation, Brdu incorporation labeling and flow cytometry assays were applied to detect the effects of circ-ITCH and miR-17-5p on proliferation and cell apoptosis. Target gene prediction and screening, luciferase reporter gene assays were utilized to assess downstream target genes of miR-17-5p and Circ-ITCH. The protein and expression of HOXB13 gene were measured by Western blotting and RT-qPCR. Results: CircITCH was significantly reduced in PC cell lines and tissues. Low circITCH expression level was highly related with preoperative PSA, tumor stage and Gleason score. Overexpression of circITCH can inhibit the malignant phenotype of prostate cancer. There was a high negative relationship between the expression level of microRNA-17-5p and circITCH in PC tissues, however, there existed a positive relationship between the expression of HOXB13 and circITCH. CircITCH acted as a sponge of miR-17-5p to increase HOXB13 gene expression. In addition, miR-17-5p overexpression or HOXB13 silencing can reduce the carcinogenic effects of circICCH in prostate cancer. Conclusion: CircITCH promoted prostate cancer progression by regulating the HOXB13/miR-17-5p axis, and circITCH have a potential usage as therapeutic target for PC tumors. [ABSTRACT FROM AUTHOR]

Noncoding RNAs (ncRNAs) do not participate in protein-coding. Ferroptosis is a newly discovered form of cell death mediated by reactive oxygen species and lipid peroxidation. Recent studies have shown that ncRNAs such as microRNAs, long noncoding RNAs, circular RNAs, and ferroptosis are involved in the occurrence and development of osteosarcoma (OS). Studies have confirmed that ncRNAs participate in the development of OS by regulating the ferroptosis. However, systematic summary on this topic are still lacking. This review summarises the potential role of ncRNAs in the diagnosis, treatment, drug resistance, and prognosis of OS and the basis for diagnosing, preventing, and treating clinical OS and developing effective drugs. This review summarises the latest research progress on ncRNAs that regulate ferroptosis in OS, attempts to clarify the molecular mechanisms by which ncRNAs regulate ferroptosis in the pathogenesis of OS, and elaborates on the involvement of ferroptosis in OS from the perspective of ncRNAs. [Display omitted] • NcRNAs play an important role in the treatment, diagnosis, prognosis, and drug resistance of osteosarcoma. • Ferroptosis involving ncRNAs provides a new direction for the pathogenesis of osteosarcoma. • NcRNAs may act as a hub for regulating the ferroptosis of osteosarcoma with other forms of cell metabolism and death. • The expression of ncRNAs related with ferroptosis is correlated with immune checkpoint, which can be explored as a new idea of immunotherapy for osteosarcoma. [ABSTRACT FROM AUTHOR]