Inhibition Of miR-21 Research Articles

MiR-155 protects against sepsis-induced cardiomyocyte apoptosis via activation of NO/cGMP signaling pathway by eNOS

Purpose: To examine the impact of miR-155 on sepsis-induced myocardial apoptosis and heart failure, and to explore its molecular mechanism.
 Methods: Mice were divided into four groups and septic myocardial dysfunction was induced by intraperitoneal injection of lipopolysaccharide (LPS, 5 mg/kg). The LPS stimulation expression of miR-155 levels was determined by real time-polymerase chain reaction (RT-PCR). In vivo, echocardiography and TUNEL staining were used to investigate the effects of miR-155 in inhibiting cardiac function and myocardial apoptosis. Changes in the expression of eNOS when miR-155 was overexpressed or inhibited were determined by RT-PCR, while double luciferase gene assay assessed the relationship between eNOS and miR-155, eNOS, expression of iNOS, SGC alpha 1, and PKG protein.
 Results: MiR-155 was significantly increased after LPS stimulation (p < 0.01). In vitro, the inhibition of miR-155 by antagomiR significantly down-regulated the apoptosis of cardiomyocytes (p < 0.05), while overexpression of miR-155 by agomiR significantly up-regulated the apoptosis of cardiomyocytes (p < 0.05). In vivo, ejection fraction, fractional shortening and heart weight were significantly increased (p < 0.05), while apoptosis was significantly decreased (p < 0.05). MiR-155 negatively regulated the expression of eNOS (p < 0.01), and targeted the expression of eNOS mRNA (p < 0.001). In addition, the expression of eNOS, sGCα1 and PKA were significantly up-regulated (p < 0.05), while the expression of iNOS was significantly down-regulated (p < 0.05) after the inhibition of miR-155 in LPS mouse model.
 Conclusion: MiR-155 regulates sepsis-induced cardiomyocyte apoptosis and heart failure through eNOS /NO/cGMP signaling pathway. Thus, these findings can potentially facilitate the development of an effective strategy for management of heart failure.

Palmitic acid inhibits vascular smooth muscle cell switch to synthetic phenotype via upregulation of miR-22 expression.

Synthetic phenotype switch of vascular smooth muscle cells (VSMCs) has been shown to play key roles in vascular diseases. Mounting evidence has shown that fatty acid metabolism is highly associated with vascular diseases. However, how fatty acids regulate VSMC phenotype is poorly understood. Hence, the effects of palmitic acid (PA) on VSMC phenotype were determined in this study. The effect of the PA on VSMCs was measured by live/dead and EdU assays, as well as flow cytometry. Migration ability of VSMCs was evaluated using transwell assay. The underlying targets of miR-22 were predicted using bioinformatics online tools, and confirmed by luciferase reporter assay. The RNA and protein expression of certain gene was detected by qRT-PCR or western blot. PA inhibited VSMC switch to synthetic phenotype, as manifested by inhibiting VSMC proliferation, migration, and synthesis. PA upregulated miR-22 in VSMCs, and miR-22 mimics exerted similar effects as PA treatment, inhibiting VSMC switch to synthetic phenotype. Inhibition of miR-22 using miR-22 inhibitor blocked the impacts of PA on VSMC phenotype modulation, suggesting that PA modulated VSMC phenotype through upregulation of miR-22 expression. We found that ecotropic virus integration site 1 protein homolog (EVI1) was the target of miR-22 in regulation of VSMC phenotype. Overexpression of miR-22 or/and PA treatment attenuated the inhibition of EVI1 on switch of VSMCs. These findings suggested that PA inhibits VSMC switch to synthetic phenotype through upregulation of miR-22 thereby inhibiting EVI1, and correcting the dysregulation of miR-22/EVI1 or PA metabolism is a potential treatment to vascular diseases.

Ozone causes depressive-like response through PI3K/Akt/GSK3β pathway modulating synaptic plasticity in young rats

Ozone pollution has been associated with several adverse effects, including memory impairment, intellectual retardation, emotional disturbances. However, the potential mechanisms remain uncertain. The present study aimed to investigate whether ozone (O3) regulates synaptic plasticity through PI3K/Akt/GSK3β signaling pathway and induces neurobehavioral modifications among the young rats. In vivo, the newborn rats were used to construct the animal model of early postnatal O3 treatment. In vitro, this study measured the effect of different concentrations of serum from O3 treated rats on the viability of the PC12 cells, and investigated the modifications of synaptic plasticity and PI3K/Akt/GSK3β signaling pathway in the hippocampus and PC12 cells after O3 treated. The results revealed significant depression-like behavior and increased hippocampal histopathological damage in the young rats after O3 treated. Compared with the control group, the expression levels of synaptic related proteins including Drebrin, PSD95, Synaptophysin and PIK3R1, p-Akt, and p-GSK3β were decreased in the O3 treated group. In vitro assays, a significant reduction in Drebrin, PSD95, Synaptophysin, PIK3R1, p-Akt, and p-GSK3β was found in PC12 cells after O3 serum treated. While 740Y-P (a specific PI3K activator) administered, the expression levels of Drebrin, PSD95, Synaptophysin, PIK3R1, p-Akt, and p-GSK3β in the 740Y-P + O3 group were significantly elevated in vivo and vitro compared with the O3-only group. In addition, miRNAs modulating PIK3R1 were screened on bioinformatics website, the study found aberrant expression of miR-221–3p in the hippocampus and serum of O3 treated group. Inhibition of miR-221–3p expression effectively reversed the reduction of Drebrin, PSD95, Synaptophysin, PIK3R1, p-Akt, and p-GSK3β in PC12 cells induced by O3 treatment. Altogether, these studies indicate that O3 restrained the expression of PI3K/Akt/GSK3β signaling pathway and impaired synaptic plasticity that resulted in depressive-like behavior in young rats. Moreover, miR-221–3p plays an important role in this procedure by regulating PIK3R1.

Long non-coding RNA FABP5P3/miR-22 axis improves TGFβ1-induced fatty acid oxidation deregulation and fibrotic changes in proximal tubular epithelial cells of renal fibrosis

ABSTRACT Severe hydronephrosis increases the risk of urinary tract infection and irretrievable renal fibrosis. While TGFβ1-mediated fibrotic changes in proximal tubular epithelial cells and fatty acid oxidation (FAO) deregulation contribute to renal fibrosis and hydronephrosis. Firstly, a few elements were analyzed in this paper, including differentially-expressed long non-coding RNAs (lncRNAs), and miRNAs correlated to CPT1A, RXRA, and NCOA1. This paper investigated TGFβ1 effects on lncRNA FABP5P3, CPT1A, RXRA, and NCOA1 expression and fibrotic changes in HK-2 cells and FABP5P3 overexpression effects on TGFβ1-induced changes. Moreover, this paper predicted and proved that miR-22 binding to lncRNA FABP5P3, 3’UTR of CPT1A, RXRA, and NCOA1 was validated. The dynamic effects of the FABP5P3/miR-22 axis on TGFβ1-induced changes were investigated. A Renal fibrosis model was established in unilateral ureteral obstruction (UUO) mice, and FABP5P3 effects were investigated. Eventually, this paper concluded that TGFβ1 inhibited lncRNA FABP5P3, CPT1A, RXRA, and NCOA1 expression, induced fibrotic changes in HK-2 cells, and induced metabolic reprogramming within HK-2 cells, especially lower FAO. FABP5P3 overexpression partially reversed TGFβ1-induced changes. miR-22 targeted lncRNA FABP5P3, CPT1A, RXRA, and NCOA1. LncRNA FABP5P3 counteracted miR-22 inhibition of CPT1A, NCOA1, and RXRA through competitive binding. TGFβ1 stimulation induced the activation of TGFβ/SMAD and JAG/Notch signaling pathways; Nocth2 knockdown reversed TGFβ1 suppression on lncRNA FABP5P3. FABP5P3 overexpression attenuated renal fibrosis in unilateral ureteral obstruction mice. The LncRNA FABP5P3/miR-22 axis might be a potent target for improving the FAO deregulation and fibrotic changes in proximal TECs under TGFβ1 stimulation.

The Improvement of Porcine In Vitro Embryo Development through Regulating Autophagy by miRNA-143 Inhibition.

Simple SummaryThe improvement of in vitro embryo development is an important factor for the advancement of reproductive technology. Recently, studying microRNA related to early embryos is a strategic approach. This research applies miR-143 (mimics and inhibitors) to the porcine parthenogenetically activated embryos. Interesting results are revealed in this study: the miR-143 inhibitor improves the embryo development to the blastocyst. In addition, our research reveals the enhancement of autophagy and ER-phagy associated markers with higher levels of gene expression.In vitro embryo research is an important stage for the advancement of many reproductive technologies in research and agriculture. For this reason, the improvement of in vitro embryo development is a strategic field worthy of investigation. Relatively little is known about miR-143 and its effects on autophagy associated with embryo development and in vitro embryo culture. In this study, we examined the effect of miR-143 (via mimics and inhibitors) on embryonic development threatened by microinjection after parthenogenetic activation. We evaluated rates of cleavage, blastocyst, and total cell number of blastocyst; additionally, we performed LC3 immunofluorescence analysis and mRNA expression analyses of genes associated with autophagy, endoplasmic reticulum (ER)-phagy, ER stress, embryo quality, and apoptosis. The inhibition of miR-143 positively influenced embryo development by increasing the activity of autophagy and ER-phagy and the expression of embryo quality-related genes, while reducing apoptosis. In contrast, treatment with miR-143 mimics increased ER stress-related gene expression and apoptosis, and reduced embryo development. Together, our findings indicate that miR-143 plays a role in the interplay between autophagy, ER-phagy, and embryo quality during early porcine embryo development.

Perspectives on Drug Development in Early ADPKD.

Perspectives on Drug Development in Early ADPKD.

MiR-21 regulates epithelial-mesenchymal transition in intestinal fibrosis of Crohn's disease by targeting PTEN/mTOR.

Previous studies suggested miR-21 regulated epithelial-mesenchymal transition (EMT) and fibrosis in organs. The aim of this study was to explore the role and mechanism of miR-21 in EMT process of CD(Crohn's disease)-associated intestinal fibrosis. Tissue biopsies from fibrotic and nonfibrotic intestine of CD patients, and non-CD patients were obtained; chronic intestinal fibrosis model established by TNBS was treated with antagonist of miR-21; human intestinal epithelial cell, NCM460, were transfected with miR-21 mimics or inhibitor. The expressions of PTEN and mTOR, EMT-related markers and severity of colitis and fibrosis were examined. Compared to the controls, miR-21 was significantly upregulated in the intestinal tissues from CD patients with fibro stenosis, followed by decreased PTEN expression, increased EMT markers, and mTOR expression, and imbalanced ratio of MMP9(matrix metalloproteinase 9)/TIMP1(tissue inhibitor of metalloproteinase 1). MiR-21 downregulated the expression of PTEN and upregulated mTOR signal in NCM460 cell. Also, knocking miR-21 down reduced EMT in vitro. Inhibiting miR-21 with antagonists reversed TNBS-induced intestinal fibrosis in vivo, through suppressing EMT and balancing MMPs/TIMPs. We identified the involvement of miR-21 in EMT during intestinal fibrosis via targeting PTEN and mTOR, and miR-21 inhibition relieved intestinal fibrosis by regulating extracellular matrix (ECM) remodeling . Our results indicated miR-21 as a potential new target for the treatment of fibrosis complication in CD.

LINC00240/miR-155 axis regulates function of trophoblasts and M2 macrophage polarization via modulating oxidative stress-induced pyroptosis in preeclampsia

BackgroundThis study aimed to investigate the effects of LINC00240/miR-155/Nrf2 axis on trophoblast function and macrophage polarization in the pathogenesis of preeclampsia.MethodsBindings between LINC00240, miR-155 and Nrf2 were validated by dual luciferase reporter assay or RNA-immunoprecipitation. Cell proliferation, migration, invasion, and pyroptosis were detected by CCK-8, clone formation, wound healing, Transwell system, and flow cytometry, respectively. Macrophage polarization was tested by flow cytometry. The expression levels of LINC00240, miR-155, Nrf2, and oxidative stress and pyroptosis-related markers in in vitro and in vivo preeclampsia models were analyzed by qPCR, western blot, or ELISA assays. Blood pressure, urine protein levels, liver and kidney damages, and trophoblast markers in placenta tissues were further studied in vivo.ResultsPlacenta tissues from preeclampsia patients and animals showed decreased LINC00240 and Nrf2 and increased miR-155 expression levels, and the decreased M2 macrophage polarization. LINC00240 directly bound and inhibited expression of miR-155, which then inhibited oxidative stress-induced pyroptosis, promoting proliferation, migration and invasion abilities of trophoblasts, and M2 macrophage polarization. Inhibition of miR-155 led to increased Nrf2 expression and similar changes as LINC00240 overexpression in trophoblast function and macrophage polarization. Overexpression of LINC00240 in in vivo preeclampsia model decreased blood pressure, urine protein, liver and kidney damages, increased fetal weight and length, and induced trophoblast function and M2 macrophage polarization.ConclusionLINC00240 inhibited symptoms of preeclampsia through regulation on miR-155/Nrf2 axis, which suppressed oxidative stress-induced pyroptosis to improve trophoblast function and M2 macrophage polarization. LINC00240 could be a potential therapeutic target for preeclampsia.

MiR204 potentially promotes non-alcoholic fatty liver disease by inhibition of cpt1a in mouse hepatocytes

Non-alcoholic fatty liver disease (NAFLD) is associated with hepatic metabolism dysfunction. However, the mechanistic role of miR204 in the development of NAFLD is unknown. We investigate the functional significance of miR204 in the evolution of NAFLD. IDH2 KO mice feed a normal diet (ND) or HFD increased body weight, epididymal fat-pad weight, lipid droplet in liver, blood parameter and inflammation compared to WT mice fed a ND or HFD. Moreover, the expression of miR204 is increased in mice with IDH2 deficiency. Increased miR204 by IDH2 deficiency regulates carnitine palmitoyltransferase 1a (cpt1a) synthesis, which inhibits fatty acid β-oxidation. Inhibition of miR204 prevents the disassembly of two fatty acid-related genes by activating CPT1a expression, which decreases lipid droplet in liver, inflammatory cytokines, epididymal fat pad weight, blood parameters. Increased miR204 by IDH2 deficiency promotes the pathogenesis of HFD-induced NAFLD by regulating hepatic fatty acid metabolism and inflammation.

Role of miR-214 in biomaterial transplantation therapy for osteonecrosis.

The effectiveness and availability of conservative therapies for osteonecrosis of the femoral head (ONFH) are limited. Transplantation of bone marrow mesenchymal stem cells (BMSCs) combined with Bio-Oss, which is a good bone scaffold biomaterial for cell proliferation and differentiation, is a new potential therapy. Of note, the expression of miRNAs was significantly modified in cells cultured with Bio-Oss, and MiR-214 was correlated positively with osteonecrosis. Furthermore, miR-214 was upregulated in cells exposed to Bio-Oss. To investigate whether targeting miR-214 further improves the transplantation effect. We treated BMSCs with agomiR-214 (a miR-214 agonist), antagomiR-214 (a miR-214 inhibitor), or vehicle, followed by their transplantation into ONFH model rats. Histological and histomorphometric data showed that bone formation was significantly increased in the experimental groups (Bio-Oss and BMSCs treated with antagomiR-214) compared with other groups. miR-214 participates in the inhibition of osteoblastic bone formation, and the inhibition of miR-214 to bone formation during transplantation therapy with Bio-Oss combined with BMSCs for ONFH.

MicroRNA-375 repression of Kruppel-like factor 5 improves angiogenesis in diabetic critical limb ischemia.

Peripheral artery disease (PAD) is an occlusive disease of limb arteries. Critical limb ischemia (CLI) is an advanced form of PAD that is prognostically worse in subjects with diabetes and can result in limb loss, gangrene, and death, although the underlying signaling mechanisms that contribute to its development remain poorly understood. By comparing plasma samples from diabetic humans with PAD and mouse models of PAD, we identified miR-375 to be significantly downregulated in humans and mice during progression to CLI. Overexpression of miR-375 was pro-angiogenic in endothelial cells in vitro and induced endothelial migration, proliferation, sprouting, and vascular network formation, whereas miR-375 inhibition conferred anti-angiogenic effects. Intramuscular delivery of miR-375 improved blood flow recovery to diabetic mouse hindlimbs following femoral artery ligation (FAL) and improved neovessel growth and arteriogenesis in muscle tissues. Using RNA-sequencing and prediction algorithms, Kruppel-like factor 5 (KLF5) was identified as a direct target of miR-375 and siRNA knockdown of KLF5 phenocopied the effects of miR-375 overexpression in vitro and in vivo through regulatory changes in NF-kB signaling. Together, a miR-375-KLF5-NF-kB signaling axis figures prominently as a potential therapeutic pathway in the development CLI in diabetes.

LincRNA RMRP Regulates Phenylephrine-induced Cardiomyocyte Hypertrophy by Means of Targeting miR-1.

Cardiac hypertrophy is a feature of hypertrophic cardiomyopathy (HCM), which could lead to heart failure and other cardiovascular diseases. Cardiomyocyte hypertrophy (CH) is the primary characteristic of cardiac hypertrophy. Long noncoding RNA (lncRNA, lincRNA) plays an important role in CH. In this study, the expression of linc-RMRP and its correlation with cardiac hypertrophy were analyzed in cardiac tissues of patients with HCM. Real-time qPCR and western blotting measured the expressions of lincf-RMRP, miR-1, and hypertrophic marker genes. RNA pulldown and luciferase reporter gene assays were performed to validate the combination between linc-RMRP and miR-1. We confirmed that Linc-RMRP was upregulated in both cardiac hypertrophy tissues and phenylephrine (PE)-induced CH cells, and the cells presented hypertrophic features, enlarged cell surface area and volume, elevated total protein contents, and increased expressions of ANP, BNP, β-MHC, and activated p70S6K and 4EBP1. Bioinformatic analysis found that linc-RMRP directly bonds to miR-1. RNA pulldown, mutation, and luciferase reporter gene assays verified this combination. Silencing linc-RMRP significantly attenuated hypertrophic responses induced by PE while the expression of miR-1 was released. However, the transfection of miR-1 inhibitor reversed the effects of linc-RMRP knockdown exerted on PE-treated cardiomyocytes. In summary, our study identified the modulatory role linc-RMRP played in regulating PE-induced CH by means of binding miR-1, and this might provide a new target for cardiac hypertrophy therapy.

Effect of miR-195 inhibition on human skeletal muscle-derived stem/progenitor cells.

The application of a circulating miR-195 inhibitor could be a helping factor in the in vitro model of human skeletal muscle-derived stem/progenitor cells (SkMDS/PCs). Previously, microRNA-195 (miR-195) expression has been reported to be a negative factor for myogenesis. The study aimed to obtain anti-apoptotic and anti-aging effects in in vitro cultured myoblasts and to improve their ability to form myotubes by suppressing miR-195 expression. Human wild-type (WT) SkMDS/PC cells incubated with control (nonspecific) miRNA inhibitor and miR-195-inhibited SkMDS/PCs were studied. Functional assays (myotube formation and cell aging), antioxidant, and myogenic gene expression analyses were performed at two time points, at the seventh and eleventh cell passages. Myotube formation was found to be almost 2-fold higher in the miR-195-inhibited SkMDS/PCs population (P < 0.05) compared to WT cells. miR-195 inhibition did not appear to affect cell aging or rejuvenate human SkMDS/PCs. Antioxidant (SOD3 and FOXO) gene expression was augmented in the miR-195-inhibited SkMDS/PCs population, but no positive effect on the remaining antioxidant genes (SOD1, SOD2, and catalase) was observed. A significant increase in MyoD gene expression with a concomitant decrease in MyoG (P < 0.05) was further documented in miR-195- -inhibited SkMDS/PCs compared to WT cells (the eleventh cell passage). The performed studies may lead to the preconditioning of myogenic stem cells to extend their potential for pro-regenerative activity. The miR-195 inhibitor may serve as a conditioning factor augmenting selective antioxidant gene expression and proliferative potential of SkMDS/PCs, but it does not have an impact on cell aging and/ or apoptosis.

Decreased cell proliferation and induced apoptosis in human B-chronic lymphocytic leukemia following miR-221 inhibition through modulation of p27 expression

BackgroundThis study aimed to investigate the effects of the miR-221 inhibition on the human B-chronic lymphocytic leukemia (B-CLL) cell viability and the p27 gene expression, to introduce a new treatment approach for this type of cancer. In this context, the cyclin-dependent kinase (Cdk) inhibitor 1B (p27Kip1) is considered as an enzyme inhibitor that encodes a protein belonging to the Cip/Kip family of the Cdk inhibitor proteins.MethodsThe affected miR-221 inhibition in the B-CLL cell viability was initially assessed. The inhibition of miR-221 in the B-CLL cell line (183-E95) was thus performed using locked nucleic acid (LNA) as an antagomir. After the LNA-anti-miR-221 transfection, the miR-221 quantification, cell viability, and apoptosis assays were evaluated at different intervals by the reverse transcription-quantitative polymerase chain reaction (RT-qPCR), the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, and flow cytometry (FC), respectively. The qRT-PCR was also completed for the p27 gene. The data were subsequently analyzed by independent-samples t-test and one-way analysis of variance (ANOVA).ResultsA gradual reduction was observed in the B-CLL cell viability, and consequently the transfected LNA-anti-miR cell viability reached below 55% of the untreated cells after 72 h of transfection. A statistically significant difference was found in the cell viability between the LNA-anti-miR-treated and control groups (p-value ≤ 0.043). The downregulation of miR-221 in the B-CLL (183-E95) cells was further conducted by LNA-anti-miR-221.ConclusionThe miR-221 inhibition significantly decreases cell viability through augmenting the p27 gene expression and inducing apoptosis. Moreover, the findings demonstrated that the inhibition of miR-221 might be a new treatment approach for B-CLL, although more confirmation is needed by investigating appropriate animal models.

LncRNA 1700020I14Rik promotes AKR1B10 expression and activates Erk pathway to induce hepatocyte damage in alcoholic hepatitis

Alcoholic hepatitis (AH), a kind of alcoholic liver disease, shows poor prognosis. Long noncoding RNAs (lncRNAs) exert critical role in liver diseases. Here, we intended to investigate the possible molecular mechanism that 1700020I14Rik-based regulation of microRNA (miR)-137/Aldo-keto reductase family 1 member B10 (AKR1B10) affecting the inflammatory response and hepatocyte damage in AH. AH-related genes and the down-stream regulatory pathway were screnned by bioinformatics. Mouse normal hepatocyte cell line AML12 was selected to construct an ethanol-induced hepatocyte injury model for in vitro mechanistic validation, while we also established an AH mouse model using the ethanol with gradually increased concentration of 2–4% (v/v) for in vivo study. Specific role of 1700020I14Rik/miR-137/AKR1B10 in AML12 cell viability, proliferation and apoptotic capacity as well as inflammation and liver damage in mice were analyzed following ectopic and depletion approaches. We found elevated AKR1B10 and 1700020I14Rik but reduced miR-137 in AH. 1700020I14Rik was able to elevated miR-137-mediated AKR1B10. In vitro cell experiments and in vivo animal experiments validated that 1700020I14Rik reduced ethanol-induced hepatocyte damage and inflammation in AH mice through regulation of miR-137–mediated AKR1B10/Erk axis. The current study underlied that 1700020I14Rik could activate AKR1B10/Erk signaling through inhibition of miR-137, thereby promoting the hepatocyte damage in AH mice.

Nicotine exacerbates endothelial dysfunction and drives atherosclerosis via extracellular vesicle-miRNA.

Nicotine, a major component of tobacco, is an important factor contributing to atherosclerosis. However, the molecular mechanisms underlying the link between nicotine and atherosclerosis are unclear. As extracellular vesicles (EVs) are involved in intercellular communication in atherosclerosis, we investigated whether their influence on arterial pathophysiology under nicotine stimulation. EVs from the serum of smokers (smoker-EVs) were significantly increased and exacerbated endothelial inflammation, as well as apoptosis according to functional studies. Meanwhile, inhibition of EVs blunted the nicotine-induced atherosclerosis progression, and injection of nicotine-induced EVs promoted atherosclerosis progression in ApoE-/- mice. Furthermore, quantitative reverse transcription-polymerase chain reaction analysis revealed a remarkable increase in miR-155 levels in smoker-EVs, which was correlated with carotid plaque formation in patients measured by ultrasound imaging. Moreover, CD14 levels were significantly increased in EVs from smokers (representing EVs derived from monocytes), indicating that monocytes are an important source of smoker-EVs. DNA methylation and the transcription factor HIF1α may contribute to increased miR-155 levels in monocytes, as assessed with bisulfite conversion sequencing and chromatin immunoprecipitation. Mechanistically, EVs encapsulated miR-155 induced endothelial cell dysfunction by directedly targeting BCL2, MCL1, TIMP3, BCL6, and activating NF-κB pathway, as verified in a series of molecular and biological experiments. Injecting EVs from nicotine-stimulated monocytes promoted plaque formation and triggered vascular endothelial injury in ApoE-/- mice, whereas inhibition of miR-155 weakened this effect. Our findings revealed an EV-dependent mechanism of nicotine-aggravated atherosclerosis. Accordingly, we propose an EV-based intervention strategy for atherosclerosis management.

Retraction: MiR-22 inhibition alleviates cardiac dysfunction in doxorubicin-induced cardiomyopathy by targeting the sirt1/PGC-1α pathway.

[This retracts the article DOI: 10.3389/fphys.2021.646903.].

Prognostic impact of MUC1 and potential regulatory miR-145 and miR-21 expression in salivary mucoepidermoid carcinoma.

Salivary gland mucoepidermoid carcinoma (MEC) poses a considerable risk of locoregional and distant metastasis after conventional treatments. There is an evident need for specifying prognostic biomarkers to identify patients who are in need of more intensive and prolonged follow-ups. This study aimed to assess the mucin 1 (MUC1) expression level and its potential regulatory microRNAs in salivary gland MEC and their prognostic potentials. The expression of MUC1 in salivary gland MEC tissues was assessed in 47 samples using immunohistochemistry. Related microRNA (miR-145 and miR-21) were evaluated using quantitative Reverse Transcription PCR. The associations between MUC1 and microRNAs expressions and clinicopathological parameters were investigated. MUC1 expression levels positively correlated with histologic grade (p < 0.001), clinical stage (p = 0.04), risk of nodal metastasis (p = 0.02), as well as the likelihood of opting for radical treatment (p = 0.01). Increased expression of miR-21 (p < 0.001) and decreased expression of miR-145 (p < 0.001) were observed in MECs compared to normal salivary gland tissue. MiR-145 negatively (p = 0.01) and miR-21 positively (p = 0.01) correlated with MUC1 overexpression. Based on the univariate cox proportional hazard model, histologic grade and MUC1 expression level were significantly associated with disease-free, cancer-specific, and overall survival. However, the multivariable cox proportional hazard model indicated tumor grade as the only prognostic factor associated with disease-free survival. Our results support the tumor suppressor role of miR-145 and the oncogenic role of miR-21 in salivary gland MEC. Also, MUC1 and miR-145 overexpression, as well as miR-21 suppression, show promising association with histologic tumor grade and clinical stage.

MiR-375 mitigates retinal angiogenesis by depressing the JAK2/STAT3 pathway.

Aberrant neovascularization in the retina is an important threat to vision and closely related to several retinal diseases, such as wet form of age-related macular degeneration, diabetic retinopathy, and retinopathy of prematurity. However, the pathogenesis remains largely unknown. MicroRNAs (miRNAs) have been demonstrated to play critical regulatory roles in angiogenesis. Therefore, we aimed to identify the key miRNAs that regulate retinal neovascularization and elucidate the potential underlying mechanisms. In the present study, we performed RNA sequencing of microRNAs in the retina and found that miR-375 was significantly downregulated in the retina of oxygen-induced retinopathy mice. In retinal microvascular endothelial cells (RMECs), overexpression of miR-375 inhibited cell proliferation and angiogenesis. Conversely, inhibition of miR-375 had the opposite effects. Moreover, our results showed that miR-375 negatively regulated the protein expression of JAK2 by inhibiting its translation. The promoting effects of anti-miR-375 on cell proliferation and angiogenesis were attenuated by an inhibitor of STAT3. These results indicate that miR-375 mitigates cell proliferation and angiogenesis, at least in part, through the JAK2/STAT3 pathway in RMECs, which implies an important underlying mechanism of retinal angiogenesis and provides potential therapeutic targets for retinal microangiopathy.

MiR-182 Inhibition Protects Against Experimental Stroke in vivo and Mitigates Astrocyte Injury and Inflammation in vitro via Modulation of Cortactin Activity.

Ischemic stroke remains a devastating cerebrovascular disease that accounts for a high proportion of mortality and disability worldwide. MicroRNAs (miRNAs) are a class of small non-coding RNAs that are responsible for regulation of post-transcriptional gene expression, and growing evidence supports a role for miRNAs in stroke injury and recovery. The current study examined the role of miR-182 in experimental stroke using both in vitro and in vivo models of ischemic injury. Brain levels of miR-182 significantly increased after transient middle cerebral artery occlusion (MCAO) in mice and in primary astrocyte cultures subjected to combined oxygen-glucose deprivation/reperfusion (OGD/R) injury. In vivo, stroke volume and neurological score were significantly improved by pre-treatment with miR-182 antagomir. Astrocyte cultures stressed with OGD/R resulted in mitochondrial fragmentation and downregulation of cortactin, an actin-binding protein. Inhibition of miR-182 significantly preserved cortactin expression, reduced mitochondrial fragmentation and improved astrocyte survival after OGD/R. In parallel, lipopolysaccharide (LPS)-induced nitric-oxide release in astrocyte cultures was significantly reduced by miR-182 inhibition, translating to reduced injury in primary neuronal cultures subjected to conditioned medium from LPS-treated astrocytes. These findings identify miR-182 and/or cortactin as potential clinical targets to preserve mitochondrial structure and mitigate neuroinflammation and cell death after ischemic stroke.