Search

There is increasing evidence that circular RNAs (circRNAs) play significant roles in various biological processes, yet few reports have examined their roles and molecular mechanisms in ketamine-induced cystitis (KIC). This study examines the possible molecular mechanisms underlying the circRNA-microRNA-mRNA regulatory network in the development of KIC. Transcriptome data were collected, and bioinformatics analysis was conducted to create a circRNA-miRNA-mRNA regulatory network (ceRNA network) associated with the occurrence of KIC. Human bladder epithelial cells (SV-HUC-1) were used in in vitro cell assays. The binding affinity among circ-SFMBT2, miR-224-5p, and Metadherin (MTDH) was identified. To investigate the effects of circ-SFMBT2/miR-224-5p/MTDH on bladder function, KIC mouse models were induced by intraperitoneal injection of ketamine, and gain- or loss-of-function experiments were conducted. Our results demonstrate that MTDH may be a key gene involved in the occurrence of KIC. Both bioinformatics analysis and in vitro cell assays verified that circ-SFMBT2 can competitively bind to miR-224-5p, and miR-224-5p can target and inhibit MTDH. In the bladder tissues of KIC mice, circ-SFMBT2 and MTDH were up-regulated, while miR-224-5p was down-regulated. Animal experiments further confirmed that circ-SFMBT2 can up-regulate MTDH expression by sponging miR-224-5p, thereby exacerbating bladder dysfunction in KIC mice. This study proved that circ-SFMBT2 up-regulates MTDH by competitively binding to miR-224-5p, thereby exacerbating the bladder dysfunction of KIC. [ABSTRACT FROM AUTHOR]

Background: The proliferation of airway smooth muscle cells (ASMCs) contributes to the contractility and inflammation in the pathophysiology of asthma. This intrigued us to clarify the effect of microRNA (miR)-224-5p on biological characteristics of ASMCs in mice with asthma-like airway inflammation and responses through the FHL1-dependent MAPK pathway. Methods: An ovalbumin (OVA)-induced asthma mouse model was established, where ASMCs were isolated. The expression of FHL1 was determined in asthmatic mice. Artificial modulation of FHL1 expression was performed to explore its effect on airway inflammation of asthmatic mice and ASMC proliferation and apoptosis. Afterwards, we analyzed the interaction among miR-224-5p, FHL1 and the MAPK pathway, and explored their combined impacts on airway inflammation of asthmatic mice and ASMC proliferation and apoptosis. Results: FHL1 was highly expressed and miR-224-5p was poorly expressed in asthmatic mice. FHL1 was verified to be a target of miR-224-5p. Loss of FHL1 function reduced airway inflammation in asthmatic mice and proliferation of ASMCs while inducing their apoptosis. Besides, miR-224-5p inhibited the MAPK pathway by binding to FHL1. Overexpression of miR-224-5p relieved airway inflammation, inhibited ASMC proliferation, and increased apoptosis, which could be reversed by overexpression of FHL1. Conclusion: Altogether, miR-224-5p inhibited airway inflammation in asthmatic mice and ASMC proliferation through blocking the MAPK pathway by down-regulating FHL1. [ABSTRACT FROM AUTHOR]

The relevance of circular RNAs (circRNAs) has been indicated in the progression of various diseases. Nevertheless, the precise function of circRNAs in osteoarthritis (OA) remains to be established. Therefore, we aimed to investigate changes in the expression of a specific circRNA, hsa_circ_0134111 (circ_PDE1C) and predict its functions in OA. A rat model of OA was constructed to detect circ_PDE1C expression in knee joint tissues. Subsequently, CHON-001 chondrocytes were treated with IL-1β to mimic OA in vitro. circ_PDE1C was significantly overexpressed in knee cartilage tissues from OA patients relative to amputation patients. Knockdown of circ_PDE1C inhibited extracellular matrix (ECM) degradation and chondrocyte apoptosis. Furthermore, circ_PDE1C could target miR-224-5p, and miR-224-5p expressed poorly in knee cartilage tissues from OA patients. Overexpression of miR-224-5p inhibited ECM degradation and apoptosis in chondrocytes. miR-224-5p also targeted CCL2, which activated the JAK2/STAT signaling pathway, thereby promoting cartilage degradation and exacerbating the symptoms of OA patients. In conclusion, our findings underscore a novel role of circ_PDE1C in OA pathogenesis and suggest that targeting circ_PDE1C/miR-224-5p/CCL2 axis might provide an attractive approach for OA therapy. [ABSTRACT FROM AUTHOR]

Friedreich's ataxia (FRDA) is a genetic neurodegenerative disease that is caused by guanine-adenine-adenine (GAA) nucleotide repeat expansions in the first intron of the frataxin (FXN) gene. Although present in the intron, this mutation leads to a substantial decrease in protein expression. Currently, no effective treatment is available for FRDA, and, in addition to FXN, other targets with therapeutic potential are continuously sought. As miRNAs can regulate the expression of a broad spectrum of genes, are used as biomarkers, and can serve as therapeutic tools, we decided to identify and characterize differentially expressed miRNAs and their targets in FRDA cells compared to unaffected control (CTRL) cells. In this study, we performed an integrated miRNAseq and RNAseq analysis using the same cohort of primary FRDA and CTRL cells. The results of the transcriptome studies were supported by bioinformatic analyses and validated by qRT-PCR. miRNA interactions with target genes were assessed by luciferase assays, qRT-PCR, and immunoblotting. In silico analysis identified the FXN transcript as a target of five miRNAs upregulated in FRDA cells. Further studies confirmed that miRNA-224-5p indeed targets FXN, resulting in decreases in mRNA and protein levels. We also validated the ability of miRNA-10a-5p to bind and regulate the levels of brain-derived neurotrophic factor (BDNF), an important modulator of neuronal growth. We observed a significant decrease in the levels of miRNA-10a-5p and increase in the levels of BDNF upon correction of FRDA cells via zinc-finger nuclease (ZFN)-mediated excision of expanded GAA repeats. Our comprehensive transcriptome analyses identified miRNA-224-5p and miRNA-10a-5p as negative regulators of the FXN and BDNF expression, respectively. These results emphasize not only the importance of miRNAs in the pathogenesis of FRDA but also their potential as therapeutic targets for this disease. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the potential role and regulatory mechanism of long non-coding RNA ferritin heavy polypeptide 1 pseudogene 3 (FTH1P3) in glioma development. The expression of FTH1P3 in low- and high-grade glioma tissues was investigated using reverse transcription-quantitative polymerase chain reaction. FTH1P3 expression was overexpressed or suppressed in U251 glioma cells to examine the involvement of FTH1P3 in glioma cell proliferation and apoptosis using MTT assay and flow cytometry respectively. In addition, the regulatory association between FTH1P3, microRNA (miR)-224-5p and tumor protein (TP) D52 was investigated to elucidate the potential underlying mechanisms of FTH1P3 in glioma by luciferase reporter assay. The results revealed that FTH1P3 was up-regulated in glioma tissues, and FTH1P3 expression in high-grade glioma tissues was significantly higher compared with that in low-grade glioma tissues. Upregulation of FTH1P3 promoted glioma cell proliferation and inhibited apoptosis. Furthermore, FTH1P3 inhibited miR-224-5p expression, which in turn negatively regulated TPD52 expression. Overexpression of miR-224-5p significantly inhibited U251 cell proliferation and induced cellular apoptosis; this effect was clearly reversed following co-transfection of miR-224-5p and TPD52. These data revealed that upregulation of FTH1P3 may have promoted glioma cell proliferation and inhibited apoptosis. Thus, the miR-224-5p/TPD52 axis may be a downstream mechanism of FTH1P3 in glioma progression. The findings of the present study may provide a theoretical basis for the study of the treatment of glioma in the future. [ABSTRACT FROM AUTHOR]

MicroRNA (miR)-224-5p has been reported to be associated with multiple types of cancer. However, its biological role and underlying mechanism in hepatocellular carcinoma (HCC) has yet to be fully elucidated. The aim of the present study was to investigate whether miR-224-5p mRNA expression level was increased in hepatocellular carcinoma and whether it was associated with poor prognosis. Decreased mRNA expression level of miR-224-5p was shown to suppress liver cancer cell migration, invasion and epithelial-mesenchymal transition (EMT). Mechanistically, E2F1 was found to regulate miR-224-5p expression by binding to its promoter region. Melanoregulin (MREG) was identified as the direct target of miR-224-5p by searching the TargetScan, miRDB and StarBase databases. Overexpression of MREG could attenuate liver cancer cell migration, invasion and EMT. Rescue experiments further confirmed that MREG was associated with the regulation of miR-224-5p in liver cancer. In addition, the E2F1/miR-224-5p axis was shown to promote liver cancer cell migration, invasion and EMT by regulating MREG expression. These results suggested that E2F1-induced upregulation of miR-224-5p may serve an important role in MREG-induced liver cancer cell migration, invasion and EMT, and highlights the regulatory function of miR-224-5p in liver cancer. Therefore, the E2F1/miR-224-5p/MREG axis may provide a theoretical basis for the clinical treatment of hepatocellular carcinoma. [ABSTRACT FROM AUTHOR]

Pancreatic mucinous cystadenocarcinoma (MCC) is a rare malignant tumor, with a limited number of studies. The present study aimed to investigate the function and mechanism of microRNA (miR)-224-5p on proliferation, migration and invasion of MCC of the pancreas. Reverse transcription-quantitative PCR was used to explorethe expression of miR-224-5p and the PTEN gene. MTT, wound healing, Transwell and tumorigenesis assays were conducted to investigate the proliferation, migration and invasion of MCC1 cells in vitro and in vivo. Western blot analysis was employed to test the protein expression of PTEN. The target gene of miR-224-5p was assessed and verified by luciferase assay. miR-224-5p expression was notably higher, while PTEN expression was lower, in MCC1 cells compared with normal tissues and cells. Overexpression of miR-224-5p promoted the proliferation, migration and invasion of MCC and knockdown of miR-224-5p inhibited these functions. Bioinformatics analysis and luciferase assay indicated that PTEN was the direct target gene of miR-224-5p. The negative correlation between miR-224-5p and PTEN was confirmed both in vitro and in vivo. PTEN reversed the effects of miR-224-5p on proliferation, migration and invasion of MCC1 cells. The present study revealed for the first time, to the best of the authors' knowledge, that miR-224-5p was highly expressed and served an oncogenic role in MCC. miR-224-5p not only regulated the proliferation, migration and invasion of pancreatic MCC but may also be a potential therapeutic target for MCC. [ABSTRACT FROM AUTHOR]

The prognosis of invasive pancreatic mucinous cystadenocarcinoma (MCC) is poor, and the molecular mechanism underlying its development remains unclear. The present study aimed to explore the potential role of autophagy in pancreatic MCC. The results demonstrated an increase in autophagy signaling in pancreatic MCC tissues and the MCC1 cell line compared with adjacent tissues and normal human pancreatic ductal epithelium (HPDE) cells. In addition, abnormal autophagy activation facilitated the migration and invasion of MCC1 cells. MicroRNA (miR)-224-5p expression levels were significantly higher in MCC1 cells compared with those in HPDE cells. Treatment with rapamycin further demonstrated that high levels of autophagy elevated miR-224-5p expression in MCC1 cells in a time-dependent manner. BCL2 was identified as a downstream target gene of miR-224-5p, which binds to the 3′-untranslated region of BCL2. In addition, the results of the present study demonstrated that BCL2 knockdown reversed the inhibition of autophagy mediated by the miR-224-5p inhibitor. To the best of our knowledge, this is the first study to evaluate the role of autophagy in pancreatic MCC. Thus, these results suggested that autophagy may be hyperactivated in pancreatic MCC. In addition, the present study identified a positive feedback loop between autophagy signaling and miR-224-5p, which may promote the aggressive migration and invasion of MCC1. These results may provide a new insight into the relationship between autophagy and tumor metastasis in pancreatic MCC. [ABSTRACT FROM AUTHOR]