With the development of high-throughput sequencing technology, circular RNAs (circRNAs) have gradually become a hotspot in the research on non-coding RNA. CircRNAs are produced by the covalent circularization of a downstream 3' splice donor and an upstream 5' splice acceptor through backsplicing, and they are pervasive in eukaryotic cells. CircRNAs used to be considered byproducts of false splicing, whereas an explosion of related studies in recent years has disproved this misconception. Compared with the rich studies of circRNAs in animals, the study of circRNAs in plants is still in its infancy. In this review, we introduced the discovery of plant circRNAs, the discovery of plant circRNAs, the circularization feature, expression specificity, conservation, and stability of plant circRNAs and expounded the identification tools, main types, and biogenesis mechanisms of circRNAs. Furthermore, we summarized the potential roles of plant circRNAs as microRNA (miRNA) sponges and translation templates and in response to biotic/abiotic stress, and briefed the degradation and localization of plant circRNAs. Finally, we discussed the challenges and proposed the future directions in the research on plant circRNAs.
Animals ; MicroRNAs/metabolism* ; Organelle Biogenesis ; Plants/metabolism* ; Protein Biosynthesis/physiology* ; RNA, Circular/metabolism* ; RNA, Plant/metabolism* ; Research/trends* ; Stress, Physiological/genetics*

Age-associated changes in immune cells have been linked to an increased risk for infection. However, a global and detailed characterization of the changes that human circulating immune cells undergo with age is lacking. Here, we combined scRNA-seq, mass cytometry and scATAC-seq to compare immune cell types in peripheral blood collected from young and old subjects and patients with COVID-19. We found that the immune cell landscape was reprogrammed with age and was characterized by T cell polarization from naive and memory cells to effector, cytotoxic, exhausted and regulatory cells, along with increased late natural killer cells, age-associated B cells, inflammatory monocytes and age-associated dendritic cells. In addition, the expression of genes, which were implicated in coronavirus susceptibility, was upregulated in a cell subtype-specific manner with age. Notably, COVID-19 promoted age-induced immune cell polarization and gene expression related to inflammation and cellular senescence. Therefore, these findings suggest that a dysregulated immune system and increased gene expression associated with SARS-CoV-2 susceptibility may at least partially account for COVID-19 vulnerability in the elderly.
Adult ; Aged ; Aged, 80 and over ; Aging ; genetics ; immunology ; Betacoronavirus ; CD4-Positive T-Lymphocytes ; metabolism ; Cell Lineage ; Chromatin Assembly and Disassembly ; Coronavirus Infections ; immunology ; Cytokine Release Syndrome ; etiology ; immunology ; Cytokines ; biosynthesis ; genetics ; Disease Susceptibility ; Flow Cytometry ; methods ; Gene Expression Profiling ; Gene Expression Regulation, Developmental ; Gene Rearrangement ; Humans ; Immune System ; cytology ; growth & development ; immunology ; Immunocompetence ; genetics ; Inflammation ; genetics ; immunology ; Mass Spectrometry ; methods ; Middle Aged ; Pandemics ; Pneumonia, Viral ; immunology ; Sequence Analysis, RNA ; Single-Cell Analysis ; Transcriptome ; Young Adult

Tanshinones are abietane-type norditerpenoid quinones that make up the main bioactive ingredients of traditional Chinese medicine Salvia miltiorrhiza. Cytochrome CYP450 plays an important role in the post-structural modification of tanshinone biosynthesis pathway. Long non-coding RNA( lncRNA) have been defined as transcripts longer than 200 nucleotides,which have been functionally characterized in regulating the growth and development,secondary metabolism and stress of medicinal plants. In this study,we perform a comprehensive identification of lncRNAs in response to tanshinone metabolism induced by yeast extract( YE) and Ag~+ S. miltiorrhiza hairy roots. Deep RNA sequencing was used to identify a set of different 8 942 lncRNAs,of which 6 755 were intergenic lncRNAs. We predicted a total of 1 115 814 lncRNA-coding gene pairs,including 122 lncRNA-coding gene as cis pairs. The correlation analysis between lncRNA and CYP450 related to tanshinone biosynthesis was carried out and a total of 16 249 lncRNA-CYP450 target gene pairs were identified. Further analysis with functional known CYP76 AH1,CYP76 AH3 and CYP76 AK1 involved in tanshinone biosynthesis,we also identified a set of 216 target genes. These candidate genes will be the important target in the downstream regulation mechanism analysis of the tanshinone biosynthesis pathway.
Cytochrome P-450 Enzyme System ; genetics ; Diterpenes, Abietane ; biosynthesis ; Gene Expression Regulation, Plant ; Plant Roots ; RNA, Long Noncoding ; genetics ; RNA, Plant ; genetics ; Salvia miltiorrhiza ; genetics

Noncoding RNAs (ncRNAs) have played a critical role in cellular biological functions. Recently, some peptides or proteins originating from annotated ncRNAs were identified in organism development and various diseases. Here, we briefly review several novel peptides translated by annotated ncRNAs and related key functions. In addition, we summarize the potential mechanism of bifunctional ncRNAs and propose a specific "switch" triggering the transformation from the noncoding to the coding state under certain stimuli or cellular stress. The coding properties of ncRNAs and their peptide products may provide a novel horizon in proteomic research and can be regarded as a potential therapeutic target for the treatment of various diseases.
Animals ; Calcium/metabolism* ; Humans ; Open Reading Frames ; Protein Biosynthesis ; RNA, Messenger/genetics* ; RNA, Untranslated/physiology*

The secondary structures of hepatitis C virus (HCV) RNA and the cellular proteins that bind to them are important for modulating both translation and RNA replication. However, the sets of RNA-binding proteins involved in the regulation of HCV translation, replication and encapsidation remain unknown. Here, we identified RNA binding motif protein 24 (RBM24) as a host factor participated in HCV translation and replication. Knockdown of RBM24 reduced HCV propagation in Huh7.5.1 cells. An enhanced translation and delayed RNA synthesis during the early phase of infection was observed in RBM24 silencing cells. However, both overexpression of RBM24 and recombinant human RBM24 protein suppressed HCV IRES-mediated translation. Further analysis revealed that the assembly of the 80S ribosome on the HCV IRES was interrupted by RBM24 protein through binding to the 5'-UTR. RBM24 could also interact with HCV Core and enhance the interaction of Core and 5'-UTR, which suppresses the expression of HCV. Moreover, RBM24 enhanced the interaction between the 5'- and 3'-UTRs in the HCV genome, which probably explained its requirement in HCV genome replication. Therefore, RBM24 is a novel host factor involved in HCV replication and may function at the switch from translation to replication.
Cells, Cultured ; Hepacivirus ; genetics ; growth & development ; metabolism ; Humans ; Protein Biosynthesis ; RNA-Binding Proteins ; metabolism ; Virus Replication ; genetics

The present study was designed to elucidate whether the mechanism by which osthole decreases collagenI/III contents and their ratio is regulating the TGF-β/Smad signaling pathway in TGF-β1-overexpressed mouse cardiac fibroblasts (CFs). These CFs were cultured and treated with different concentrations of osthole. Our results showed that the TGF-β1 expression in the CFs transfected with that the recombinant expression plasmids pcDNA3.1(+)-TGF-β1 was significantly enhanced. After the CFs were treated with 1.25-5 μg·mL of osthole for 24 h, the mRNA and protein expression levels of collagensIand III were reduced. The collagen I/III ratio was also reduced. The mRNA and protein expression levels of TGF-β1, TβRI, Smad2/3, P-Smad2/3, Smad4, and α-SMA were decreased, whereas the expression level of Smad7 was increased. These effects suggested that osthole could inhibit collagen I and III expression and reduce their ratio via the TGF-β/Smad signaling pathway in TGF-β1 overexpressed CFs. These effects of osthole may play beneficial roles in the prevention and treatment of myocardial fibrosis.
Actins ; genetics ; Animals ; Cells, Cultured ; Collagen ; biosynthesis ; genetics ; Coumarins ; pharmacology ; Fibroblasts ; drug effects ; metabolism ; Gene Expression Regulation ; drug effects ; Mice ; Myocardium ; cytology ; Protein-Serine-Threonine Kinases ; genetics ; RNA, Messenger ; genetics ; Real-Time Polymerase Chain Reaction ; Receptor, Transforming Growth Factor-beta Type I ; Receptors, Transforming Growth Factor beta ; genetics ; Signal Transduction ; drug effects ; Smad Proteins ; genetics ; Transforming Growth Factor beta1 ; genetics

Lung cancer is the most commonly diagnosed cancer and the leading cause of cancer death in China. In recent years, therapies for oncogenedrivers and immune checkpoints have proved inspiring. Circular RNA (circRNA), which is a kind of RNA with covalent ring structure relating to stages and metastasis of cancer, has many special biological functions in physiological processes, diseases and so on. Thus, circRNA is expected to be a potential biomarker for cancer prediction and treatment in view of its high conservation and tissue-specific. However, function analysis and regulatory mechanism of circRNA in lung cancer come so far remains unclear and limited literatures are available. In this review, we highlight the research history, formation mechanism, biological function of circRNA and research progress in cancer, especially in lung cancer. We mean to provide theoretical evidences and new ideas for researches on circRNAs in lung cancer.
Animals ; Humans ; Lung Neoplasms ; genetics ; metabolism ; RNA ; biosynthesis ; genetics

Emerging evidence indicates that aldosterone and mineralocorticoid receptors (MRs) are associated with the pathogenesis of erectile dysfunction. However, the molecular mechanisms remain largely unknown. In this study, freshly isolated penile corpus cavernosum tissue from rats was treated with aldosterone, with or without MRs inhibitors. Nuclear factor (NF)-kappa B (NF-κB) activity was evaluated by real-time quantitative PCR, luciferase assay, and immunoblot. The results demonstrated that mRNA levels of the NF-κB target genes, including inhibitor of NF-κB alpha (IκB-α), NF-κB1, tumor necrosis factor-alpha (TNF-α), and interleukin 6 (IL-6), were higher after aldosterone treatment. Accordingly, phosphorylation of p65/RelA, IκB-α, and inhibitor of NF-κB kinase-β was markedly increased by aldosterone. Furthermore, knockdown of MRs prevented activation of the NF-κB canonical pathway by aldosterone. Consistent with this finding, ectopic overexpression of MRs enhanced the transcriptional activation of NF-κB by aldosterone. More importantly, the MRs antagonist, spironolactone blocked aldosterone-mediated activation of the canonical NF-κB pathway. In conclusion, aldosterone has an inflammatory effect in the corpus cavernosum penis, inducing NF-κB activation via an MRs-dependent pathway, which may be prevented by selective MRs antagonists. These data reveal the possible role of aldosterone in erectile dysfunction as well as its potential as a novel pharmacologic target for treatment.
Aldosterone/pharmacology* ; Animals ; Cytokines/biosynthesis* ; Gene Knockdown Techniques ; I-kappa B Kinase/antagonists & inhibitors* ; Interleukin-6/genetics* ; Male ; Mineralocorticoid Receptor Antagonists/pharmacology* ; NF-kappa B/genetics* ; Penis/metabolism* ; Protein Serine-Threonine Kinases/antagonists & inhibitors* ; RNA, Messenger/biosynthesis* ; Rats ; Rats, Inbred WKY ; Receptors, Mineralocorticoid/genetics* ; Signal Transduction/drug effects* ; Spironolactone/pharmacology* ; Transcriptional Activation ; Tumor Necrosis Factor-alpha/biosynthesis* ; NF-kappaB-Inducing Kinase

Objective To investigate effect of let-7a gene over-expression on apoptosis of gastric cancer cell lines SGC-7901.Methods The stable let-7a gene over-expressing SGC-7901 cells, SGC-7901/let-7a cells, were established using shRNA lentiviral vector methods. Real-time RT-PCR analysis was used to evaluate the expression level of let-7a mRNA. Cells apoptosis was assessed by flow cytometry.Results RT-PCR analysis revealed let-7a expression in SGC-7901/let-7a cells was significantly increased. Cellular apoptosis assay showed that over-expression of let-7a could increase apoptosis of SGC-7901 cells (P=0.002).Conclusion Up-regulating let-7a expression promoted apoptosis in SGC-7901 cells.
Apoptosis ; Cell Line, Tumor ; Gene Expression Regulation, Neoplastic ; Humans ; MicroRNAs ; biosynthesis ; genetics ; RNA, Neoplasm ; biosynthesis ; genetics ; Stomach Neoplasms ; genetics ; metabolism ; pathology ; Up-Regulation

Mitochondrial tRNAgene mutation is closely related to acoustic nerve deafness. Some mutations can affect the structure and transcriptional processing of tRNA, for instance m.7444G>A mutation in tRNAprecursor 3' side, m.7472 insC as well as m.7511T>C mutations in the stem and ring of tRNA, may influence tRNAstability, thus affect the synthesis of mitochondrial peptides, reduce the production of ATP and cause deafness. This article focuses on mitochondrial tRNAgene mutations as well as the mechanism underlying hearing loss.
Amino Acid Sequence ; Base Sequence ; Genetic Predisposition to Disease ; genetics ; Hearing Loss ; genetics ; Humans ; Mitochondrial Proteins ; biosynthesis ; genetics ; Mutation ; Nucleic Acid Conformation ; RNA ; chemistry ; genetics ; RNA, Transfer, Ser ; chemistry ; genetics