LncRNA OIP5-AS1-directed miR-7 degradation promotes MYMX production during human myogenesis

Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) modulate gene expression programs in physiology and disease. Here, we report a noncoding RNA regulatory network that modulates myoblast fusion into multinucleated myotubes, a process that occurs during muscle development and muscle regeneration after injury. In early stages of human myogenesis, the levels of lncRNA OIP5-AS1 increased, while the levels of miR-7 decreased. Moreover, OIP5-AS1 bound and induced miR-7 decay via target RNA-directed miRNA decay; accordingly, loss of OIP5-AS1 attenuated, while antagonizing miR-7 accelerated, myotube formation. We found that the OIP5-AS1-mediated miR-7 degradation promoted myoblast fusion, as it derepressed the miR-7 target MYMX mRNA, which encodes the fusogenic protein myomixer (MYMX). Remarkably, an oligonucleotide site blocker interfered with the OIP5-AS1-directed miR-7 degradation, allowing miR-7 to accumulate, lowering MYMX production and suppressing myotube formation. These results highlight a mechanism whereby lncRNA OIP5-AS1-mediated miR-7 decay promotes myotube formation by stimulating a myogenic fusion program.     

LncRNA OIP5-AS1 facilitates ox-LDL-induced endothelial cell injury through the miR-98-5p/HMGB1 axis

Cerebrovascular diseases have a high mortality and disability rate in developed countries. Endothelial cell injury is the main cause of atherosclerosis and cerebrovascular disease. Long non-coding RNA (lncRNA) has been proved to participate in the progression of endothelial cell. Our study aimed to develop the function of lncRNA opa-interacting protein 5 antisense RNA 1 (OIP5-AS1) in oxidative low-density lipoprotein (ox-LDL)-induced endothelial cell injury. The expression of OIP5-AS1, miR-98-5p and High-mobility group protein box-1 (HMGB1) was detected by quantitative real-time polymerase chain reaction (qRT-PCR). 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and flow cytometry were used to detect the cell proliferation and apoptosis. The levels of cyclinD1, Bcl-2 Associated X Protein (Bax), Cleaved-caspase-3, Toll like receptors 4 (TLR4), phosphorylation of p65 (p-P65), phosphorylation of nuclear factor-kappa B inhibitor α (p-IκB-α) and HMGB1 were measured by Western blot. The concentrations of Interleukin-6 (IL-6), Interleukin-1β (IL-1β) and Tumor necrosis factor-α (TNF-α) were detected by Enzyme-linked immunosorbent assay (ELISA). The production of Reactive oxygen species (ROS), Superoxide Dismutase (SOD) and malondialdehyde (MDA) was detected by the corresponding kit. The targets of OIP5-AS and miR-98-5p were predicted by starBase 3.0 and TargetScan and confirmed by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. The expression of OIP5-AS1 was upregulated, while miR-98-5p was downregulated in ox-LDL-induced human umbilical vein endothelial cells (HUVECs). Functionally, knockdown of OIP5-AS1 induced proliferation and inhibited apoptosis, inflammatory injury and oxidative stress injury in ox-LDL-induced HUVEC cells. Interestingly, miR-98-5p was a target of OIP5-AS1 and miR-98-5p inhibition abolished the effects of OIP5-AS1 downregulation on ox-LDL-induced HUVECs injury. More importantly, miR-98-5p directly targeted HMGB1, and OIP5-AS1 regulated the expression of HMGB1 by sponging miR-98-5p. Finally, OIP5-AS1 regulated the TLR4/nuclear factor-kappa B (NF-κB) signaling pathway through miR-98-5p/HMGB1 axis. LncRNA OIP5-AS1 accelerates ox-LDL-induced endothelial cell injury through regulating HMGB1 mediated by miR-98-5p via the TLR4/NF-κB signaling pathway.

     

LncRNA OIP5-AS1 predicts poor prognosis and regulates cell proliferation and apoptosis in bladder cancer

Opa-interacting protein 5 antisense RNA 1 (OIP5-AS1) is a long intergenic noncoding RNA, which has been suggested to be dysregulated in human cancers and served as tumor suppressor or promoter depending on tumor types. However, the role of OIP5-AS1 in bladder cancer was still unknown. In our study, OIP5-AS1 was overexpressed in bladder cancer, and associated with clinical progression and short overall survival. The loss-of-function studies suggested downregulation of OIP5-AS1 expression decreased cell viability, induced cell-cycle arrest and promoted cell apoptosis in bladder cancer. There was a positive association between OIP5-AS1 expression and OIP5 expression in bladder cancer tissues. Moreover, downregulation of OIP5-AS1 expression reduced messenger RNA and protein levels of OIP5 in bladder cancer cell lines. In conclusion, OIP5-AS1 is a useful biomarker for predicting clinical progression and poor prognosis and promotes cell proliferation through modulating OIP5 expression.     

LncRNA OIP5-AS1 regulates radioresistance by targeting DYRK1A through miR-369-3p in colorectal cancer cells

Object

This study aimed to investigate the role of lncRNA OIP5-AS1 in regulating radioresistance of colorectal cancer (CRC) cells.

The role of lncRNA OIP5-AS1 in cancer development and progression

OIP5-AS1, a conserved lncRNA, has been reported to be involved in several biological and pathological processes, including oncogenesis. OIP5-AS1 exerts its oncogenic or antitumor functions via regulation of different miRNAs in various cancer types. In this review, we describe the dysregulation of OIP5-AS1 expression in a variety of human cancers. Moreover, we discuss the multiple functions of OIP5-AS1 in cancer, including in proliferation, apoptosis, autophagy, ferroptosis, cell cycle, migration, metastasis, invasion, epithelial to mesenchymal transition, angiogenesis, cancer stem cells and drug resistance. Furthermore, we provide a future perspective for OIP5-AS1 research. We conclude that targeting OIP5-AS1 might be a promising cancer therapy approach.

     

Transportin 2 regulates apoptosis through the RNA-binding protein HuR

In response to severe stress, apoptotic cell death is engaged. Apoptosis is a well orchestrated process that involves the activation and implication of many factors. In this study, we identified a role for the nuclear trafficking factor TRN2 (transportin 2) in cell death. TRN2 is normally responsible for the nuclear import of the RNA-binding protein HuR. During apoptosis, however, HuR accumulates in the cytoplasm. This is due to the caspase-mediated cleavage of the cytoplasmic fraction of HuR. One of the cleavage fragments generated by this processing of HuR interacts with TRN2 and thus blocks the re-import of HuR into the nucleus. This concentrates HuR in the cytoplasm, advancing apoptosis. Therefore, increasing or decreasing the levels of TRN2 has an inverse consequential effect on cell death, demonstrating for the first time the role of a nucleocytoplasmic transport factor in apoptosis.     

Integrative analysis of OIP5-AS1/HUR1 to discover new potential biomarkers and therapeutic targets in multiple sclerosis

Multiple sclerosis (MS) is a devastating autoimmune disease of the central nervous system associated with demyelination and axonal injury. This study was designed to find potential lncRNAs and their targets that are associated with the molecular basis of MS pathogenesis. In this study, peripheral blood samples were obtained from 50 relapsing-remitting MS (RR-MS) patients and 50 healthy controls. lncRNAs and their target were selected for validation using TaqMan Real-Time PCR. Interactions were studied based on approaches that used to investigation biological functions and signaling pathways affected by differentially expressed messenger RNAs (mRNAs). The results of this study indicate an increase in the expression of HUR1 (p = 0.0001), CPSF7 (p = 0.02), and reduction of CSTF2 expression (p = 0.04). Also, an increase in the expression of OIP5-AS1 (p = 0.01) was observed in men less than 30 years old. We performed a comparative analysis of the long noncoding RNAs (lncRNAs), and then we ranked them as candidate biomarkers according to a decreasing area under the receiver operating characteristic (ROC) curve (AUC) and plotted the results. Dysregulation of lncRNA expression has been linked to diseases. Further studies on the HUR1 gene can be used as diagnostic tools for the identification of high-risk individuals in families with a history of disease before, during, and even after treatment. Our data uncovered the expression profiles of lncRNAs and mRNAs in MS patients, which will help delineate the molecular mechanisms in MS pathogenesis. However, further studies need to determine the precise role of these genes in the pathological process in MS.     

METTL14 promotes tumorigenesis by regulating lncRNA OIP5-AS1/miR-98/ADAMTS8 signaling in papillary thyroid cancer

BackgroundPapillary thyroid cancer (PTC) is the most common type of cancer of the endocrine system. Long noncoding RNAs (lncRNAs) are emerging as a novel class of gene expression regulators associated with tumorigenesis. Through preexisting databases available for differentially expressed lncRNAs in PTC, we uncovered that lncRNA OIP5-AS1 was significantly upregulated in PTC tissues. However, the function and the underlying mechanism of OIP5-AS1 in PTC are poorly understood.MethodsExpression of lncRNA OIP5-AS1 and miR-98 in PTC tissue and cells were measured by quantitative real-time PCR (qRT-PCR). And expression of METTL14 and ADAMTS8 in PTC tissue and cells were measured by qRT-PCR and western blot. The biological functions of METTL14, OIP5-AS1, and ADAMTS8 were examined using MTT, colony formation, transwell, and wound healing assays in PTC cells. The relationship between METTL14 and OIP5-AS1 were evaluated using RNA immunoprecipitation (RIP) and RNA pull down assay. And the relationship between miR-98 and ADAMTS8 were examined by luciferase reporter assay. For in vivo experiments, a xenograft model was used to investigate the effects of OIP5-AS1 and ADAMTS8 in PTC.ResultsFunctional validation revealed that OIP5-AS1 overexpression promotes PTC cell proliferation, migration/invasion in vitro and in vivo, while OIP5-AS1 knockdown shows an opposite effect. Mechanistically, OIP5-AS1 acts as a target of miR-98, which activates ADAMTS8. OIP5-AS1 promotes PTC cell progression through miR-98/ADAMTS8 and EGFR, MEK/ERK pathways. Furthermore, RIP and RNA pull down assays identified OIP5-AS1 as the downstream target of METTL14. Overexpression of METTL14 suppresses PTC cell proliferation and migration/invasion through inhibiting OIP5-AS1 expression and regulating EGFR, MEK/ERK pathways.ConclusionsCollectively, our findings demonstrate that OIP5-AS1 is a METTL14-regulated lncRNA that plays an important role in PTC progression and offers new insights into the regulatory mechanisms underlying PTC development.Subject terms: Tumour biomarkers, Oncogenes     

Impaired gametogenesis in mice that overexpress the RNA-binding protein HuR

A series of experiments, using cell culture models or in vitro assays, has shown that the RNA-binding protein HuR increases the half-life of some messenger RNAs that contain adenylate/uridylate-rich decay elements. However, its function in an integrated system has not yet been investigated. Here, using a mouse model, we report that misregulation of HuR, due to expression of an HuR transgene, prevents the production of fully functional gametes. This work provides the first evidence for a physiological function of HuR, and highlights its involvement in spermatogenesis.     

RNA-binding protein HuR interacts with thrombomodulin 5'untranslated region and represses internal ribosome entry site-mediated translation under IL-1 beta treatment

Reduction in host-activated protein C levels and resultant microvascular thrombosis highlight the important functional role of protein C anticoagulant system in the pathogenesis of sepsis and septic shock. Thrombomodulin (TM) is a critical factor to activate protein C in mediating the anticoagulation and anti-inflammation effects. However, TM protein content is decreased in inflammation and sepsis, and the mechanism is still not well defined. In this report, we identified that the TM 5′ untranslated region (UTR) bearing the internal ribosome entry site (IRES) element controls TM protein expression. Using RNA probe pulldown assay, HuR was demonstrated to interact with the TM 5′UTR. Overexpression of HuR protein inhibited the activity of TM IRES, whereas on the other hand, reducing the HuR protein level reversed this effect. When cells were treated with IL-1β, the IRES activity was suppressed and accompanied by an increased interaction between HuR and TM 5′UTR. In the animal model of sepsis, we found the TM protein expression level to be decreased while concurrently observing the increased interaction between HuR and TM mRNA in liver tissue. In summary, HuR plays an important role in suppression of TM protein synthesis in IL-1β treatment and sepsis.