Melatonin alleviates hyperoxia-induced lung injury through elevating MSC exosomal miR-18a-5p expression to repress PUM2 signaling.

Mesenchymal stem cells (MSC)-derived exosomes (Exo) are a possible option for hyperoxia-induced lung injury (HLI). We wanted to see if melatonin (MT)-pretreated MSC-derived exosomes (MT-Exo) were more effective against HLI, and we also tried to figure out the underlying mechanism. HLI models were established by hyperoxia exposure. HE staining was adopted to analyze lung pathological changes. MTT and flow cytometry were used to determine cell viability and apoptosis, respectively. The mitochondrial membrane potential (MMP) was analyzed using the JC-1 probe. LDH, ROS, SOD, and GSH-Px levels were examined by the corresponding kits. The interactions between miR-18a-5p, PUM2, and DUB3 were analyzed by molecular interaction experiments. MT-Exo could effectively inhibit hyperoxia-induced oxidative stress, inflammatory injury, and apoptosis in lung epithelial cells, while these effects of MT-Exo were weakened by miR-18a-5p knockdown in MSCs. miR-18a-5p reduced PUM2 expression in MLE-12 cells by directly targeting PUM2. In addition, PUM2 inactivated the Nrf2/HO-1 signaling pathway by promoting DUB3 mRNA decay post-transcriptionally. As expected, PUM2 overexpression or DUB3 knockdown abolished the protective effect of MT-Exo on hyperoxia-induced lung epithelial cell injury. MT-Exo carrying miR-18a-5p reduced hyperoxia-mediated lung injury in mice through activating Nrf2/HO-1 pathway. MT reduced PUM2 expression and subsequently activated the DUB3/Nrf2/HO-1 signal axis by increasing miR-18a-5p expression in MSC-derived exosomes to alleviate HLI.

miR-18a-5p promotes osteogenic differentiation of BMSC by inhibiting Notch2.

Postmenopausal osteoporosis (PMOP) is a metabolic disorder characterized by the loss of bone density, which increases the risk of developing complications such as fractures. A pivotal factor contributing to the onset of PMOP is the diminished osteogenic differentiation capacity of bone marrow mesenchymal stem cells (BMSCs). MicroRNAs (miRNAs) play a substantial role in this process; however, their specific impact on regulating BMSCs osteogenesis remains unclear. Studies have evidenced a reduced expression of miR-18a-5p in PMOP, and concomitantly, our observations indicate an augmented expression of miR-18a-5p during the osteogenic differentiation of BMSCs. This investigation seeks to elucidate the regulatory influence of miR-18a-5p on BMSC osteogenic differentiation and the underlying mechanisms. In vitro experiments demonstrated that the overexpression of miR-18a-5p facilitated the osteogenic differentiation of BMSCs, while the downregulation of miR-18a-5p yielded converse outcomes. Mechanistically, We employed bioinformatics techniques to screen out the target gene Notch2 of miR-18a-5p. Subsequently, dual-luciferase reporter gene assays and rescue experiments substantiated that miR-18a-5p promotes BMSC osteogenic differentiation by suppressing Notch2. Finally, miR-18a-5p was overexpressed via adenovirus injection into the femoral bone marrow cavity, with results demonstrating its capability to enhance osteogenic differentiation and alleviate PMOP symptoms. Our findings disclose that miR-18a-5p fosters osteogenic differentiation of BMSC by inhibiting Notch2, thereby offering novel targets and strategies for PMOP treatment.

MiR-18a affects hypoxia induced glucose metabolism transition in HT22 hippocampal neuronal cell line through the Hif1a gene.

Hypoxia can cause a variety of diseases, including ischemic stroke and neurodegenerative diseases. Within a certain range of partial pressure of oxygen, cells can respond to changes in oxygen. Changes in oxygen concentration beyond a threshold will cause damage or even necrosis of tissues and organs, especially for the central nervous system. Therefore, it is very important to find appropriate measures to alleviate damage. MiRNAs can participate in the regulation of hypoxic responses in various types of cells. MiRNAs are involved in regulating hypoxic responses in many types of tissues by activating the hypoxia-inducible factor (HIF) to affect angiogenesis, glycolysis and other biological processes. By analyzing differentially expressed miRNAs in hypoxia and hypoxia-related studies, as well as the HT22 neuronal cell line under hypoxic stress, we found that the expression of miR-18a was changed in these models. MiR-18a could regulate glucose metabolism in HT22 cells under hypoxic stress by directly regulating the 3'UTR of the Hif1a gene. As a small molecule, miRNAs are easy to be designed into small nucleic acid drugs, so this study can provide a theoretical basis for the research and treatment of nervous system diseases caused by hypoxia.

MicroRNA-18a prevents senescence of mesenchymal stem cells by targeting CTDSPL.

Stem cell therapy requires massive-scale homogeneous stem cells under strict qualification control. However, Prolonged ex vivo expansion impairs the biological functions and results in senescence of mesenchymal stem cells (MSCs). We investigated the function of CTDSPL in the premature senescence process of MSCs and clarified that miR-18a-5p played a prominent role in preventing senescence of long-term cultured MSCs and promoting the self-renewal ability of MSCs. Over-expression of CTDSPL resulted in an enlarged morphology, up-regulation of p16 and accumulation of SA-ß-gal of MSCs. The reduced phosphorylated RB suggested cell cycle arrest of MSCs. All these results implied that CTDSPL induced premature senescence of MSCs. We further demonstrated that miR-18a-5p was a putative regulator of CTDSPL by luciferase reporter assay. Inhibition of miR-18a-5p promoted the expression of CTDSPL and induced premature senescence of MSCs. Continuous overexpression of miR-18a-5p improved self-renewal of MSCs by reducing ROS level, increased expression of Oct4 and Nanog, and promoted growth rate and differentiation capability. We reported for the first time that the dynamic interaction of miR-18a-5p and CTDSPL is crucial for stem cell senescence.

Effect of circDCUN1D4 on proliferation,apoptosis and immune escape of lung cancer cells by regulating the miR-18a-5p/FBP1 axis / 局解手术学杂志

Objective To investigate the influences of circular RNA(circRNA)DCUN1D4 on the proliferation,apoptosis and immune escape of lung cancer cells by regulating the microRNA(miR)-18a-5p/fructose-1,6-bisphosphatase 1(FBP1)axis.Methods The human lung cancer cell lines H1975,H1650,A549 and SPCA-1 and human normal lung epidermal cells HPL-1 were selected,qRT-PCR was used to detect the expression levels of circDCUN1D4,miR-18a-5p and FBP1 mRNA in various cells.A549 cells in logarithmic growth phase were selected and divided into the blank group,circDCUN1D4 overexpression plasmid(circDCUN1D4)group,overexpression plasmid negative control(NC)group,circDCUN1D4+miR-18a-5p mimics negative control(circDCUN1D4+mimics NC)group,and circDCUN1D4+miR-18a-5p mimics group.The cell viability of each group was detected by CCK-8 method,the cell apoptosis was detected by flow cytometry,the expression levels of circDCUN1D4,miR-18a-5p and FBP1 mRNA of cells in each group were detected by qRT-PCR,the expression levels of FBP1,caspase-3,Ki67,proliferating cell nuclear antigen(PCNA)and programmed death ligand-1(PD-L1)were detected by Western blot,the targeting relationships of miR-18a-5p with circDCUN1D4 and FBP1 were verified by dual luciferase assay.Results Compared with HPL-1 cells,the mRNA expressions of circDCUN1D4 and FBP1 were significantly decreased(P<0.05),and the expression of miR-18a-5p was significantly increased(P<0.05).miR-18a-5p had targeting relationships with circDCUN1D4 and FBP1,respectively.Compared with the blank group and NC group,the OD values at 24 hours and 48 hours,and the expressions of Ki67,PCNA,miR-18a-5p and PD-L1 of cells in the circDCUN1D4 group were significantly decreased(P<0.05),and the apoptosis rate,and the expressions of circDCUN1D4,FBP1 and caspase-3 were significantly increased(P<0.05).Overexpression of miR-18a-5p reversed the inhibitory effect of circDCUN1D4 on the malignant behavior of lung cancer cells(P<0.05).Conclusion Overexpression of circDCUN1D4 can promote lung cancer cell apoptosis,inhibit lung cancer cell proliferation and immune escape,and its mechanism may be related to the regulation of miR-18a-5p/FBP1 axis.

CAFs-derived exosomes promote the development of cervical cancer by regulating miR-18a-5p-TMEM170B signaling axis.

Mounting studies have showed that tumor microenvironment (TME) is crucial for cervical cancer (CC), and cancer-related fibroblasts (CAFs) play a major role in it. Recently, exosomal miRNAs secreted by CAFs have been found to be potential targets for cancer diagnosis and therapy. In this paper, we aimed to investigate the function of CAFs-mediated exosome miR-18a-5p (CAFs-exo-miR-18a-5p) in CC. First, in combination with bioinformatic data analysis of the GEO database (GSE86100) and RT-qPCR of CC clinical tissue samples and cell lines, miR-18a-5p was discovered to be markedly up-regulated in CC. Next, CAFs-secreted exosomes were isolated and it was found that miR-18a-5p expression was dramatically promoted in CC cell lines when treated with CAFs-exos. The CAFs-exo-miR-18a-5p was then elucidated to stimulate the proliferation and migration and inhibit the apoptosis of CC cells. In order to clarify the underlying mechanism, we further screened the target genes of miR-18a-5p. TMEM170B was selected by bioinformatic data analysis of online databases combined with RT-qPCR of CC clinical tissues and cells. Luciferase reporter gene analysis combined with molecular biology experiments further elucidated that miR-18a-5p suppressed TMEM170B expression in CC. Finally, both cell and animal experiments demonstrated that TMEM170B over-expression attenuated the oncogenic effect of CAFs-exo-miR-18a-5p. In conclusion, our study indicates that CAFs-mediated exosome miR-18a-5p promotes the initiation and development of CC by suppressing TMEM170B signaling axis, which provides a possible direction for the diagnosis and therapy of CC.

Prognostic significance of serum miR-18a-5p in severe COVID-19 Egyptian patients.

BACKGROUND: The identification of miRNAs as well as characterization of miRNA-mRNA interactions in SARS-CoV-2 infection is important to understand their role in disease pathogenesis. Therefore the aim of the present study was to measure the expression levels of hsa-mir-18a-5p in the sera of severe COVID-19 Egyptian patients admitted to ICU to investigate its roles in the pathogenesis and severity of COVID-19 disease. METHODS: A total of 180 unvaccinated severe COVID-19 patients were enrolled in our study. Besides the routine laboratory work, the expression level of hsa-mir-18a-5p was done using reverse transcription quantitative real-time PCR (RTqPCR) technique. Also, target genes of hsa-mir-18a-5p were explored by using online bioinformatics databases. RESULTS: The expression level of hsa-mir-18a-5p decreased in nonsurvival severe COVID-19 patients (0.38 ± 0.26) when compared to the survival ones (0.84 ± 0.23). While as a prognostic tool for the prediction of bad prognosis and mortality among severe COVID-19 patients, our results showed that the serum hsa-mir-18a-5p expression level is a good sensitive and specific marker. By using bioinformatics tools, our results revealed that the decreased hsa-mir-18a-5p expression level may have a crucial role in COVID-19 pathogenesis and severity through decreased immunological responses (interpreted as lymphopenia) or increased inflammation (interpreted as increased serum levels of IL-6, CRP, LDH). CONCLUSION: Taken together, the decreased expression level of hsa-mir-18a-5p could be a bad prognostic marker and therapeutic overexpression of hsa-mir-18a-5p could be a novel approach in the treatment of COVID-19 disease.

Effect of miR-18a-5p, miR-19a-3p, and miR-20a-5p on In Vitro Cardiomyocyte Differentiation of Human Endometrium Tissue-Derived Stem Cells Through Regulation of Smad4 Expression.

Background: Smad4 regulates the expression of the genes required for heart homeostasis. Regarding the central role of microRNAs in cardiac biology, we investigated the expression of the three Smad4-targeting miRNAs, namely miR-18a-5p, miR-19a-3p, and miR-20a-5p, as well as Smad4 during differentiation of human endometrium-derived mesenchymal stem cells (hEMSCs) into cardiomyocytes (CMs). Methods: To evaluate mesenchymal phenotype and multi-lineage differentiation ability of hEMSCs, immunophenotyping by flow cytometry and differentiation into osteoblasts and adipocytes were performed, respectively. For transdifferentiation into CMs, hEMSCs were exposed to a cardiomyogenic medium composed of 5-aza and bFGF for 30 days. The comparison between transcriptional expression levels of Nkx2-5, GATA4, Smad4, TNNT2, TBX5, miR-18a-5p, miR-19a-3p, and miR-20a-5p by qRT-PCR, as well as protein levels of Nkx2-5, Smad4, and cTnT by immunofluorescence staining, was conducted in every 6 days. Results: In vitro, the mesenchymal stem cell phenotype of hEMSCs and their potency for differentiation into other MSCs were confirmed. Differentiated hEMSCs had morphological characteristics of CMs. The percentage of positive cells for Nkx2-5, Smad4, and cTnT proteins was increased following induction and culminated on the 24th day. Also, mRNA levels of Nkx2-5, GATA4, Smad4, TNNT2, and TBX5 exhibited the same trend. The expression of investigated miRNAs was significantly decreased sequentially. A significant negative correlation between expressions of Smad4 and investigated miRNAs was observed. Conclusion: Our results indicate that miR-18a-5p, miR-19a-3p, and miR-20a-5p are involved in the cardiac differentiation propensity of hEMSCs potentially by regulation of Smad levels. Although, more mechanistic experiments are required to confirm this idea.

Circ_0007535 upregulates TGFBR1 to promote pulmonary fibrosis in TGF-ß1-treated lung fibroblasts via sequestering miR-18a-5p.

Circular RNAs (circRNAs) are functional molecules in all kinds of fibrosis diseases. The current study was performed for the exploration of circ_0007535 in pulmonary fibrosis. RNA levels for circ_0007535, miR-18a-5p, and transforming growth factor-ß receptor 1 (TGFBR1) were assayed via a reverse transcription-quantitative polymerase chain reaction. Cell growth was determined by cell counting kit-8 assay for viability and ethynyl-2'-deoxyuridine assay for proliferation. Cell invasion and migration were examined by transwell assay and scratch assay. Western blot was performed for the detection of different proteins. Enzyme-linked immunosorbent assay was used to assess inflammatory response. The interaction analysis was conducted using dual-luciferase reporter assay, RNA immunoprecipitation assay, and biotin-coupled pull-down assay. Circ_0007535 was significantly upregulated by TGF-ß1 in HFL1 cells. TGF-ß1-induced proliferation, motility, ECM accumulation, and inflammatory reaction in HFL1 cells were alleviated by circ_0007535 knockdown. Circ_0007535 exhibited interaction with miR-18a-5p, and miR-18a-5p inhibition reversed all influences of circ_0007535 downregulation in TGF-ß1-treated HFL1 cells. Circ_0007535 acted as a miR-18a-5p sponge to regulate the expression of downstream target TGFBR1. MiR-18a-5p induced TGFBR1 level inhibition to attenuate TGF-ß1-mediated cell injury in HFL1 cells. This study evidenced that circ_0007535 facilitated TGF-ß1-induced pulmonary fibrosis by depending on the absorption of miR-18a-5p to upregulate TGFBR1.

Propofol synergizes with circAPBB2 to protect against hypoxia/reoxygenation-induced oxidative stress, inflammation, and apoptosis of human cardiomyocytes.

BACKGROUND: Myocardial injury is the main manifestation of cardiovascular diseases, and previous studies have shown that propofol (PPF) regulates myocardial injury. However, the mechanism of PPF in regulating myocardial injury remains to be further explored. This work aims to analyze the effects of PPF on human cardiomyocyte injury and the underlying mechanism. METHODS: The regulatory and functional role of PPF and circAPBB2 in human cardiomyocyte injury were analyzed using an in vitro hypoxia/reoxygenation (H/R) cell model, which was established by treating human cardiomyocytes (AC16 cells) with H/R. The study evaluated AC16 cell injury by analyzing cytotoxicity, oxidative stress, inflammation and apoptosis of H/R-induced AC16 cells. Quantitative real-time polymerase chain reaction was performed to detect circAPBB2, miR-18a-5p and dual specificity phosphatase 14 (DUSP14) expression. Protein expression was analyzed by Western blot analysis assay. Dual-luciferase reporter assay, RNA pull-down assay and RNA immunoprecipitation assay were performed to identify the associations among circAPBB2, miR-18a-5p and DUSP14. Cytotoxicity was investigated by cell counting kit-8 assay and lactate dehydrogenase activity detection kit. Oxidative stress was evaluated by cellular reactive oxygen species assay kit and superoxide dismutase activity assay kit. The production of tumor necrosis factor-α and interleukin-1ß was evaluated by enzyme-linked immunosorbent assays. RESULTS: The expression of circAPBB2 and DUSP14 was significantly decreased, while miR-18a-5p was increased in H/R-induced AC16 cells when compared with controls. H/R treatment-induced cytotoxicity, oxidative stress, inflammation and cell apoptosis were attenuated after circAPBB2 overexpression or PPF treatment, whereas these effects were restored by increasing miR-18a-5p expression. PPF treatment improved the inhibitory effect of ectopic circAPBB2 expression on H/R-induced cell injury. MiR-18a-5p silencing ameliorated H/R-induced AC16 damage by interacting with DUSP14. Mechanically, circAPBB2 acted as a miR-18a-5p sponge, and miR-18a-5p targeted DUSP14 in AC16 cells. CONCLUSION: PPF synergized with circAPBB2 to protect AC16 cells against H/R-induced oxidative stress, inflammation and apoptosis through the miR-18a-5p/DUSP14 pathway.

MiR-18a-5p attenuates HER2-positive breast cancer development by regulating PI3K/AKT pathway.

OBJECTIVE: Human epidermal growth factor receptor 2 positive (HER2+) breast cancer (BC) is associated with poor prognosis. This study aimed to elucidate the role of miR-18a-5p in regulation of HER2+-BC progression along with its mechanism of action. METHODS: The expression of miR-18a-5p and HER2 in BC cells and tissues was analyzed using quantitative real-time PCR while protein level expression of AKT Serine/Threonine Kinase 1 (AKT), phosphorylated AKT (p-AKT), Phosphatidylinositol 3-kinase (PI3K), phosphorylated-PI3K (p-PI3K), and HER2 were assessed by western blotting. Cell Counting Kit-8, wound healing, and cell adhesion assays were used for in vitro analysis along with xenograft tumor model construction for in vivo analysis. Pearson correlation analysis and dual-luciferase reporter (DLR) assays were used to ascertain the targeting association between miR-18a-5p and HER2. RESULTS: There was a downregulation of miR-18a-5p expression in the BC tissues and cells. Functionally, overexpression of miR-18a-5p prevented BC cells from proliferation, adherence, migration, and activation of the P-PI3K/P-AKT pathway. In vivo experiment revealed that tumor growth was suppressed when miR-18a-5p was overexpressed. In BC, HER2 overexpression increased cell proliferation, cell-cell adhesion, migration, and P-PI3K/P-AKT signaling, but overexpression of miR-18a-5p reversed this effect because of the target relationship between miR-18a-5p and HER2. CONCLUSION: miR-18a-5p inhibits HER2+ BC progression by targeting HER2 to inhibit PI3K/AKT pathway activation. A theoretical foundation for the identification of new therapeutic targets for HER2+ BC may be provided by the miR-18a-5p - HER2 axis.

Antagonizing exosomal miR-18a-5p derived from prostate cancer cells ameliorates metastasis-induced osteoblastic lesions by targeting Hist1h2bc and activating Wnt/ß-catenin pathway.

More than 50% of prostate cancer (PCa) patients have bone metastasis with osteoblastic lesions. MiR-18a-5p is associated with the development and metastasis of PCa, but it remains unclear whether it is involved in osteoblastic lesions. We first found that miR-18a-5p was highly expressed in the bone microenvironment of patients with PCa bone metastases. To address how miR-18a-5p affects PCa osteoblastic lesions, antagonizing miR-18a-5p in PCa cells or pre-osteoblasts inhibited osteoblast differentiation in vitro. Moreover, injection of PCa cells with miR-18a-5p inhibition improved bone biomechanical properties and bone mineral mass in vivo. Furthermore, miR-18a-5p was transferred to osteoblasts by exosomes derived from PCa cells and targeted the Hist1h2bc gene, resulting in Ctnnb1 up-regulation in the Wnt/ß-catenin signaling pathway. Translationally, antagomir-18a-5p significantly improved bone biomechanical properties and alleviated sclerotic lesions from osteoblastic metastases in BALB/c nude mice. These data suggest that inhibition of exosome-delivered miR-18a-5p ameliorates PCa-induced osteoblastic lesions.

miR-18a expression correlates with ATM and p53 levels and poor prognosis in lymphomas.

microRNAs (miRNAs) are non-coding, endogenous, small-molecule RNAs. They are involved in cell proliferation, differentiation, apoptosis, and metabolism. Additionally, they play an essential role in the development and progression of various malignancies. Recent research has revealed that miR-18a plays an important role in cancer development. However, its role in lymphoma is not yet fully understood. In this study, we investigated the clinicopathological characteristics and potential functional roles of miR-18a in lymphomas. First, we predicted the potential downstream genes of miR-18a using miRTarBase software and subjected these downstream genes to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses to determine the potential mechanisms of action of these genes. We found that these target genes were closely related to cellular senescence, the p53 signaling pathway, and other signaling pathways. From the predicted downstream target genes, ATM and p53 were selected as the target genes; their deletion in patients with lymphoma was detected using the fluorescence in situ hybridization technique. The results showed that some patients with lymphoma have a deletion of the ATM and p53 genes. In addition, the deletion rates of ATM and p53 were positively correlated with the expression of miR-18a. Next, the expression levels of miR-18a and the deletion rates of ATM and p53 were used for correlation and prognostic analyses with patient clinical information. The findings revealed a significant difference in disease-free survival (DFS) between patients with lymphoma with ATM deletion and those with a normal ATM gene expression (p < 0.001). Moreover, a significant difference in overall survival (OS) and DFS between patients with p53 deletion and those with normal p53 expression was observed (p < 0.001). The results indicate that the deletion of ATM and p53 downstream of miR-18a is closely associated with the development of lymphoma. Thus, these biomarkers may serve as key prognostic biomarkers for lymphomas.

Exosomal miR-18a-5p promotes EMT and metastasis of NPC cells via targeting BTG3 and activating the Wnt/ß-catenin signaling pathway.

This study investigated the underlying mechanism of miR-18a-5p regulating the proliferation, invasion, and metastasis of nasopharyngeal carcinoma (NPC) cells in vitro and in vivo to indicate the pathogenesis of NPC. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) was utilized to determine miR-18a-5p expression level in NPC tissues and cell lines. Besides, 2,5-diphenyl-2 H-tetrazolium bromide (MTT) and colony formation assays were employed to detect the effect of miR-18a-5p expression level on NPC cell proliferation. Wound healing and Transwell assays were utilized to detect the effect of miR-18a-5p on NPC cell invasion and migration. The expression levels of epithelial-mesenchymal transition (EMT)-related proteins (Vimentin, N-cadherin, and E-cadherin) were identified by Western blot assay. After collecting exosomes from CNE-2 cells, it was found that exosomal miR-18a-5p secreted from NPC cells promoted NPC cell proliferation, migration, invasion, and EMT, whereas inhibition of miR-18a-5p expression level led to the opposite results. The dual-luciferase reporter assay showed that BTG anti-proliferation factor 3 (BTG3) was the target gene of miR-18a-5p, and BTG3 could overturn the effect of miR-18a-5p on NPC cells. Xenograft mouse model of NPC nude mice showed that miR-18a-5p promoted NPC growth and metastasis in vivo. This study revealed that exosomal miR-18a-5p derived from NPC cells promoted angiogenesis via targeting BTG3 and activating the Wnt/ß-catenin signaling pathway.

Loss of lncRNA UCA1 ameliorates the injury managed by cerebral ischemia-reperfusion by sponging miR-18a-5p.

INTRODUCTION: Acute ischemic stroke (AIS) is a disease with high morbidity and mortality in the clinic. The current experiments aimed to study the effects of UCA1 interfering miR-18a-5p on cerebral ischemia-reperfusion (CI/R). MATERIAL AND METHODS: For rat models undergoing middle cerebral artery infarction (MCAO) surgery, the expression of UCA1 and miR-18a-5p was evaluated by qRT-PCR, and underlying function was identified by detecting infarct size, neurological scores, and inflammation. Luciferase report was applied to verify the relationship between UCA1 and miR-18a-5p. In the cell models, the impacts of UCA1 and miR-18a-5p were validated by CCK-8 assay, flow cytometry analysis, and ELISA. In patients with AIS, Pearson correlation was carried out to unveil the association between UCA1 and miR-18a-5p. RESULTS: The expression of UCA1 was at high levels and miR-18a-5p was at low levels in AIS patients. UCA1 knockdown showed a protective role in infarct size, neurofunction, and inflammation via binding miR-18a-5p. MiR-18a-5p participated in the regulation of UCA1 on cell viability, cell apoptosis, lactate dehydrogenase (LDH) levels, and inflammation. In patients with AIS, overexpression of UCA1 and underexpression of miR-18a-5p had a reverse correlation. CONCLUSIONS: Elimination of UCA1 was favourable to the recovery of the rat model and cells from CI/R damage by efficaciously sponging miR-18a-5p.

Epigenetics in Canine Mammary Tumors: Upregulation of miR-18a and miR-18b Oncogenes Is Associated with Decreased ERS1 Target mRNA Expression and ERα Immunoexpression in Highly Proliferating Carcinomas.

The expression of miRNAs is one of the main epigenetic mechanisms responsible for the regulation of gene expression in mammals, and in cancer, miRNAs participate by regulating the expression of protein-coding cancer-associated genes. In canine mammary tumors (CMTs), the ESR1 gene encodes for ERα, and represents a major target gene for miR-18a and miR-18b, previously found to be overexpressed in mammary carcinomas. A loss in ERα expression in CMTs is commonly associated with poor prognosis, and it is noteworthy that the downregulation of the ESR1 would appear to be more epigenetic than genetic in nature. In this study, the expression of ESR1 mRNA in formalin-fixed, paraffin-embedded (FFPE) canine mammary tumors (CMTs) was evaluated and compared with the expression levels of miR18a and miR18b, both assessed via RT-qPCR. Furthermore, the possible correlation between the miRNA expression data and the immunohistochemical prognostic factors (ERα immunoexpression; Ki67 proliferative index) was explored. A total of twenty-six FFPE mammary samples were used, including 22 CMTs (7 benign; 15 malignant) and four control samples (three normal mammary glands and one case of lobular hyperplasia). The obtained results demonstrate that miR-18a and miR-18b are upregulated in malignant CMTs, negatively correlating with the expression of target ESR1 mRNA. Of note, the upregulation of miRNAs strictly reflects the progressive loss of ERα immunoexpression and increased tumor cell proliferation as measured using the Ki67 index. The results suggest a central role of miR-18a and miR-18b in the pathophysiology of canine mammary tumors as potential epigenetic mechanisms involved in ERα downregulation. Moreover, as miRNA expression reflects ERα protein status and a high proliferative index, miR-18a and miR-18b may represent promising biomarkers with prognostic value. More detailed investigations on a larger number of cases are needed to better understand the influence of these miRNAs in canine mammary tumors.

MiR-18a-5p aggravates homocysteine-induced myocardial injury via autophagy. / MiR-18a-5pé€šè¿‡ä»‹å¯¼è‡ªå™¬åŠ é‡åŒåž‹åŠèƒ±æ°¨é ¸è¯±å¯¼çš„å¿ƒè‚ŒæŸä¼¤.

OBJECTIVES: Hyperhomocysteinaemia (Hcy) is an independent risk factor for cardiovascular and cerebrovascular diseases. MicroRNA (miR)-18a-5p is closely related to cardiovascular diseases. This study aims to investigate the effects of miR-18a-5p on homocysteine (Hcy)-induced myocardial cells injury. METHODS: H9c2 cells were transfected with miR-18a-5p mimic/miR-18a-5p mimic negative control (NC) or combined with Hcy for intervention, and untreated cells were set as a control group. The transfection efficiency was verified by real-time RT-PCR, and cell counting kit-8 (CCK-8) assay was used to determine cell viability. Flow cytometry was used to detect apoptosis and reactive oxygen species (ROS) levels. Western blotting was performed to measure the protein levels of microtubule-associated protein 1 light chain 3 (LC3)-I, LC3-II, Beclin1, p62, Bax, Bcl-2, and Notch2. Dual luciferase reporter assay was used to detect the interaction of miR-18a-5p with Notch2. RESULTS: Compared with the control, treatment with Hcy or transfection with miR-18a-5p mimic alone, or combined treatment with Hcy and miR-18a-5p mimic/miR-18a-5p mimic NC significantly reduced the H9c2 cell viability, promoted apoptosis and ROS production, up-regulated the expressions of Bax and Beclin, down-regulated the expressions of Bcl-2, p62, and Notch2, and increased the ratio of LC3-II/LC3-I (all P<0.05). Compared with the combined intervention of miR-18a-5p mimic NC and Hcy group, the above indexes were more significantly changed in the combined intervention of miR-18a-5p mimic and Hcy group, and the difference between the 2 groups was statistically significant (all P<0.05). There is a targeted binding between Notch2 and miR-18a-5p. CONCLUSIONS: MiR-18a-5p could induce autophagy and apoptosis via increasing ROS production in cardiomyocytes, and aggravate Hcy-induced myocardial injury. Notch2 is a target of miR-18a-5p.

Circ_0000566 contributes oxygen-glucose deprivation and reoxygenation (OGD/R)-induced human brain microvascular endothelial cell injury via regulating miR-18a-5p/ACVR2B axis.

Circular RNAs (circRNAs) exert regulatory roles in cerebrovascular disease. Human brain microvascular endothelial cells (HBMECs) participated in brain vascular dysfunction in ischemic stroke. Herein, the functions of circ_0000566 in oxygen-glucose deprivation and reoxygenation (OGD/R)-induced HBMECs were investigated. The expression of circ_0000566, miR-18a-5p, and Activin receptor type 2B (ACVR2B) was measured via quantitative real-time PCR (qRT-PCR). Cell Counting Kit-8 (CCK-8) and flow cytometry assays were utilized to detect cell viability and cell apoptosis. Western blot assay was employed to measure the levels of apoptotic-related proteins and ACVR2B. The secretion of IL-1ß, IL-6, and TNF-α was detected via corresponding kits. The relationship between miR-18a-5p and circ_0000566 or ACVR2B was examined via dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Circ_0000566 and ACVR2B were highly expressed, while miR-18a-5p was down-regulated in OGD/R-treated HBMECs. OGD/R treatment promoted HBMECs apoptosis and inflammation and suppressed cell viability, which could be attenuated by silencing of circ_0000566. Circ_0000566 acted as a miR-18a-5p sponge to contribute to OGD/R-induced HBMECs injury. ACVR2B served as a direct target of miR-18a-5p, and ACVR2B overexpression might abolish the inhibitory role of miR-18a-5p on OGD/R-treated HBMEC injury. Circ_0000566 sponged miR-18a-5p to regulate OGD/R-induced HBMECs injury via regulating ACVR2B expression.

Meta-signature guided investigation of miRNA candidates as potential biomarkers of oral cancer.

OBJECTIVES: This study aimed to experimentally validate dysregulated expression of miRNA candidates selected through updated meta-analysis of most commonly deregulated miRNAs in oral cancer and to explore their diagnostic and prognostic potential. MATERIALS AND METHODS: Five miRNAs (miR-31-3p, miR-135b-5p, miR-18a-5p, miR-30a-5p and miR-139-5p) from updated meta-signature were selected for validation by qRT-PCR method in 35 oral cancer clinical specimens and adjacent non-cancerous tissue. RESULTS: Updated meta-analysis has identified 13 most commonly deregulated miRNAs in oral cancer. Seven miRNAs were consistently up-regulated (miR-21-5p, miR-31-3p, miR-135b-5p, miR-31-5p, miR-424-5p, miR-18a-5p and miR-21-3p), while five were down-regulated (miR-139-5p, miR-30a-3p, miR-375-3p, miR-376c-3p and miR-30a-5p). Increased expression of miR-31-3p and miR-135b-5p, and decreased expression of miR-139-5p and miR-30a-5p were confirmed in oral cancer compared to adjacent non-cancerous tissue. A three miRNAs combination (miR-31-3p, miR-139-5p and miR-30a-5p) gave the most promising diagnostic potential for discriminating oral cancer from non-cancerous tissue (AUC: 0.780 [95% CI: 0.673-0.886], p < 0.0005, sensitivity 94.3%, specificity 51.4%). High expression of miR-135b-5p, miR-18a-5p and miR-30a-5p was associated with poor survival (p = 0.003, p = 0.048, p = 0.016 respectively). CONCLUSION: miR-31-3p, miR-139-5p and miR-30a-5p panel was confirmed as a potential diagnostic biomarker when distinguishing oral cancer from non-cancerous tissue. miR-135b-5p, miR-18a-5p and miR-30a-5p might serve as potential biomarkers of poor survival of oral cancer patients.

MiR -18a -5p aggravates homocysteine -induced myocardial injury via autophagy / 中南大学学报(医学版)

OBJECTIVES@#Hyperhomocysteinaemia (Hcy) is an independent risk factor for cardiovascular and cerebrovascular diseases. MicroRNA (miR)-18a-5p is closely related to cardiovascular diseases. This study aims to investigate the effects of miR-18a-5p on homocysteine (Hcy)-induced myocardial cells injury.@*METHODS@#H9c2 cells were transfected with miR-18a-5p mimic/miR-18a-5p mimic negative control (NC) or combined with Hcy for intervention, and untreated cells were set as a control group. The transfection efficiency was verified by real-time RT-PCR, and cell counting kit-8 (CCK-8) assay was used to determine cell viability. Flow cytometry was used to detect apoptosis and reactive oxygen species (ROS) levels. Western blotting was performed to measure the protein levels of microtubule-associated protein 1 light chain 3 (LC3)-I, LC3-II, Beclin1, p62, Bax, Bcl-2, and Notch2. Dual luciferase reporter assay was used to detect the interaction of miR-18a-5p with Notch2.@*RESULTS@#Compared with the control, treatment with Hcy or transfection with miR-18a-5p mimic alone, or combined treatment with Hcy and miR-18a-5p mimic/miR-18a-5p mimic NC significantly reduced the H9c2 cell viability, promoted apoptosis and ROS production, up-regulated the expressions of Bax and Beclin, down-regulated the expressions of Bcl-2, p62, and Notch2, and increased the ratio of LC3-II/LC3-I (all P<0.05). Compared with the combined intervention of miR-18a-5p mimic NC and Hcy group, the above indexes were more significantly changed in the combined intervention of miR-18a-5p mimic and Hcy group, and the difference between the 2 groups was statistically significant (all P<0.05). There is a targeted binding between Notch2 and miR-18a-5p.@*CONCLUSIONS@#MiR-18a-5p could induce autophagy and apoptosis via increasing ROS production in cardiomyocytes, and aggravate Hcy-induced myocardial injury. Notch2 is a target of miR-18a-5p.