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Circular RNA (circRNA) is a subclass of non-coding RNAs that enables the circular transcripts resistant to the exonuclease digestion. Iron homeostasis is essential for the body to maintain normal physiological functions. At present, the relationship among circRNA, iron metabolism and heart failure remains largely unknown. This study aimed to explore the regulatory mechanism of circRNA and iron metabolism in heart failure. We obtained circRNA, miRNA and mRNA data from public databases and built a ceRNA network. The prediction results were verified in the myocardial tissues of pressure overload-induced heart failure mice through the use of histopathological staining methods, iron and malondialdehyde (MDA) measurement tests, quantitative real-time PCR (qRT-PCR), Western blot analysis and luciferase reporter assay. A total of 4 genes related to iron metabolism and oxidative stress were identified, and a ceRNA network involving 7 circRNAs, 7 miRNAs, and 4 mRNAs was constructed using bioinformatics tools. The results of qRT-PCR and Western blot analyses indicated that the expression level of FTH1 was similar with that predicted by bioinformatics analysis. Echocardiographic measurement showed that heart failure mice have lower fractional shortening and ejection fraction. Moreover, the myocardium of heart failure mice displayed obvious fibrosis as well as increased levels of iron and MDA compared to control mice. Besides, circSnx12 could act as an endogenous sponge to bind with miR-224-5p, and the 3'UTR region of FTH1 also had miRNA binding sites. A circRNA-miRNA-mRNA regulatory network was successfully constructed by identifying differentially expressed genes related to iron metabolism. This new approach reveals potential circRNA targets for the treatment of heart failure., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Zheng, Shi, Tong, Liu and Hou.)

MICA and MICB genes encode ligands that interact with the natural killer (NK) cell activating receptor, NKG2D. These ligands display a highly polymorphic allelic repertoire, although the true functional significance of this polymorphism remains elusive. We previously reported additional polymorphism in the 5' untranslated region (UTR) proximal promoter region of these genes by sequencing international histocompatibility workshop (IHW) cell line DNA promoter and coding regions. The present study extends this analysis by further characterising the 3'UTR region of the same IHW reference panel to achieve a more complete understanding of MICA and MICB haplotype diversity and possible functional relevance. We found 17 extended MICA haplotypes encompassing the coding region and 3'UTR, including four novel haplotypes identified in IHW cell line DNA. This increased to 21 when also considering the 5'UTR proximal promoter region. Analysis of the MICB 3'UTR revealed two novel sequences in cell lines KLO and WIN designated MICB-UTR8 and UTR9, respectively. A total of 11 MICB haplotypes were identified in this study and five were unique. The present study, characterising MICA/B 3'UTR polymorphism utilising IHW reference cell lines, could be useful for future studies investigating the role of microRNA in post-transcriptional repression of gene expression and for immunotherapy strategies to combat cancer progression., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: The present study aims to investigate the distinct expression pattern of circular RNAs (circRNAs) in periodontal ligament stem cells (PDLSCs) during osteogenesis., Methods: PDLSCs were isolated and cultured in osteogenic medium. Total RNA was extracted from cells at day 0 (D0), day 3 (D3), day 7 (D7), and day 14 (D14) and submitted to RNA-sequencing to detect expression profiles of circRNAs, messenger RNAs (mRNAs), and microRNAs (miRNAs). Real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was performed to validate expression of circRNAs and miRNAs. Differential expression analysis and gene ontology analysis were performed. A circRNA-miRNA-mRNA network was constructed to reveal the potential regulatory role of circRNAs., Results: A total of 12,693 circRNA transcripts were detected, and circRNAs displayed stage-specific expression. Expression of four well-known circRNAs was validated by qRT-PCR. In total, 118 circRNAs were differentially expressed at D3, 128 circRNAs were differentially expressed at D7, and 139 circRNAs were differentially expressed at D14 compared with D0. Host genes of differentially expressed circRNAs were enriched in cytoplasmic or membrane-bound vesicles and extracellular matrix, indicating their potential roles in modulating biogenesis of extracellular vesicles. Moreover, mRNAs that were potentially regulated by circRNAs were enriched in bone-formation-associated processes, including extracellular matrix organization, cell differentiation, and bone morphogenetic protein signaling pathway., Conclusion: Expression profiles of circRNAs were significantly altered during osteogenic differentiation of PDLSCs, providing a clue for future studies on the role of circRNAs in osteoblast differentiation.

Objective and Method: We developed and evaluated five novel real-time RT-PCR assays targeting conserved regions in the 5'-untranslated region (5'-UTR), envelope (E'), non-structural protein 2A (NS2A), NS5 and 3'-UTR of the ZIKV genome., Results: The ZIKV-5'-UTR assay exhibited the lowest in vitro limit of detection (5-10 RNA copies/reaction and 3.0 × 10 -1 plaque-forming units/ml). Compared to the modified version of a widely adopted RT-PCR assay targeting the ZIKV-E gene, the ZIKV-5'-UTR assay showed better sensitivity in human clinical specimens, and representative mouse specimens, including many organs which are known to be involved in human ZIKV infection but difficult to obtain in clinical settings. The ZIKV-5'-UTR assay detected ZIKV RNA in 84/84 (100.0%) ZIKV-E'-positive and an additional 30/296 (10.1%, P < 0.01) ZIKV-E'-negative mouse specimens. The higher sensitivity of the ZIKV-5'-UTR assay was most significant in kidney and testis/epididymis specimens (P < 0.01). No in vitro or in vivo cross-reactivity was found between the ZIKV-5'-UTR assay and dengue virus, yellow fever virus, Japanese encephalitis virus, West Nile virus, hepatitis C virus and Chikungunya virus., Conclusions: The highly sensitive and specific ZIKV-5'-UTR assay may help to improve the laboratory diagnosis of ZIKV infection., (© 2017 John Wiley & Sons Ltd.)