Multiple circRNAs regulated by QKI5 conjointly spongemiR-214-3p to antagonize bisphenol A-inducedspermatocyte toxicity

Emerging regulatory roles of noncoding RNAs induced by bisphenol A (BPA) and its alternatives in human diseases

Bisphenols (BPs), including BPA, BPF, BPS, and BPAF, are synthetic phenolic organic compounds and endocrine-disrupting chemicals. These organics have been broadly utilized to produce epoxy resins, polycarbonate plastics, and other products. Mounting evidence has shown that BPs, especially BPA, may enter into the human body and participate in the development of human diseases mediated by nuclear hormone receptors. Moreover, BPA may negatively affect human health at the epigenetic level through processes such as DNA methylation and histone acetylation. Recent studies have demonstrated that, as part of epigenetics, noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), circular RNAs (circRNAs), and small nucleolar RNAs (snoRNAs), have vital impacts on BP-related diseases, such as reproductive system diseases, nervous system diseases, digestive system diseases, endocrine system diseases, and other diseases. Moreover, based on the bioinformatic analysis, changes in ncRNAs may be relevant to normal activities and functions and BP-induced diseases. Thus, we conducted a meta-analysis to identify more promising ncRNAs as biomarkers and therapeutic targets for BP exposure and relevant human diseases. In this review, we summarize the regulatory functions of ncRNAs induced by BPs in human diseases and latent molecular mechanisms, as well as identify prospective biomarkers and therapeutic targets for BP exposure and upper diseases.

CircDCBLD2 alleviates liver fibrosis by regulating ferroptosis via facilitating STUB1-mediated PARK7 ubiquitination degradation

BACKGROUND

Liver fibrosis can progress to cirrhosis and hepatic carcinoma without treatment. CircDCBLD2 was found to be downregulated in liver fibrosis. However, the precise underlying mechanism requires further investigation.

METHODS

qRT-PCR, Western blot, and immunohistochemistry assays were used to detect the related molecule levels. HE, Masson's trichrome, and Sirius Red staining were used to assess the pathological changes in mice's liver tissues. Flow cytometric analysis and commercial kit were used to assess the levels of lipid reactive oxygen species (ROS), malonaldehyde (MDA), glutathione (GSH), and iron. Cell viability was assessed by MTT. Immunoprecipitation was used to study the ubiquitination of PARK7. Mitophagy was determined by immunostaining and confocal imaging. RIP and Co-IP assays were used to assess the interactions of circDCBLD2/HuR, HuR/STUB1, and STUB1/PARK7. Fluorescence in situ hybridization and immunofluorescence staining were used to assess the co-localization of circDCBLD2 and HuR.

RESULTS

CircDCBLD2 was downregulated, whereas PARK7 was upregulated in liver fibrosis. Ferroptosis activators increased circDCBLD2 while decreasing PARK7 in hepatic stellate cells (HSCs) and mice with liver fibrosis. CircDCBLD2 overexpression reduced cell viability and GSH, PARK7, and GPX4 expression in erastin-treated HSCs while increasing MDA and iron levels, whereas circDCBLD2 knockdown had the opposite effect. CircDCBLD2 overexpression increased STUB1-mediated PARK7 ubiquitination by promoting HuR-STUB1 binding and thus increasing STUB1 mRNA stability. PARK7 overexpression or HuR knockdown reversed the effects of circDCBLD2 overexpression on HSC activation and ferroptosis. CircDCBLD2 reduced liver fibrosis in mice by inhibiting PARK7.

CONCLUSION

CircDCBLD2 overexpression increased PARK7 ubiquitination degradation by upregulating STUB1 through its interaction with HuR, inhibiting HSC activation and promoting HSC ferroptosis, ultimately enhancing liver fibrosis.

Circular RNAs with protein-coding ability in oncogenesis

As ubiquitously expressed transcripts in eukaryotes, circular RNAs (circRNAs) are covalently closed and lack a 5'-cap and 3'-polyadenylation (poly (A)) tail. Initially, circRNAs were considered non-coding RNA (ncRNA), and their roles as sponging molecules to adsorb microRNAs have been extensively reported. However, in recent years, accumulating evidence has demonstrated that circRNAs could encode functional polypeptides through the initiation of translation mediated by internal ribosomal entry sites (IRESs) or N6-methyladenosine (m6A). In this review, we collectively discuss the biogenesis, cognate mRNA products, regulatory mechanisms, aberrant expression and biological phenotypes or clinical relevance of all currently reported, cancer-relevant protein-coding circRNAs. Overall, we provide a comprehensive overview of circRNA-encoded proteins and their physiological and pathological functions.