miR-20a represses endothelial cell migration by targeting MKK3 and inhibiting p38 MAP kinase activation in response to VEGF

Differential miRNA expression of hypoxic MCF7 and PANC-1 cells

Background

Hypoxia plays a critical role in the tumor microenvironment by affecting cellular proliferation, metabolism, apoptosis, DNA repair, and chemoresistance. Since hypoxia provokes a distinct shift of microRNA, it is important to illustrate the relative contribution of each hypoxamiR to cancer progression.

Aims

The present study aims to shed light on the hypoxamiRs that are involved in pancreatic and breast cancer progression to highlight novel targets for the development of new therapies.

Methods

For 20 cycles, MCF7 breast cancer cells and PANC-1 pancreatic cancer cells were subjected to chronic cyclic hypoxia, which consisted of 72 hours of hypoxia followed by 24 hours of reoxygenation. After 10 and 20 cycles of hypoxia, miRNA expression alterations were profiled using RT-PCR array and further analyzed using a visual analytics platform. The MTT cell proliferation assay was used to determine hypoxic cells' chemoresistance to doxorubicin.

Results

Under chronic cyclic hypoxia, hypoxic PANC-1 cells have a comparable doubling time with their normoxic counterparts, whereas hypoxic MCF7 cells show a massive increase in doubling time when compared to their normoxic counterparts. Both hypoxic cell lines developed EMT-like phenotypes as well as doxorubicin resistance. According to the findings of miRNet, 6 and 10 miRNAs were shown to play an important role in enriching six hallmarks of pancreatic cancer in the 10th and 20th cycles of hypoxia, respectively, while 7 and 11 miRNAs were shown to play an important role in enriching the four hallmarks of breast cancer in the 10th and 20th cycles of hypoxia, respectively.

Conclusions

miR-221, miR-21, miR-155, and miR-34 were found to be involved in the potentiation of hypoxic PANC-1 hallmarks at both the 10th and 20th cycles, while miR-93, miR-20a, miR-15, and miR-17 were found to be involved in the potentiation of hypoxic MCF7 hallmarks at both the 10th and 20th cycles. This variation in miRNA expression was also connected to the emergence of an EMT-like phenotype, alterations in proliferation rates, and doxorubicin resistance. The chemosensitivity results revealed that chronic cyclic hypoxia is critical in the formation of chemoresistant phenotypes in pancreatic and breast cancer cells. miR-181a and let-7e expression disparities in PANC1, as well as miR-93, miR-34, and miR-27 expression disparities in MCF7, may be associated with the formation of chemoresistant MCF7 and PANC-1 cells following 20 cycles of chronic cyclic hypoxia. Indeed, further research is needed since the particular mechanisms that govern these processes are unknown.

Clinical progress of anti-angiogenic targeted therapy and combination therapy for gastric cancer

The incidence of gastric cancer is increasing year by year. Most gastric cancers are already in the advanced stage with poor prognosis when diagnosed, which means the current treatment is not satisfactory. Angiogenesis is an important link in the occurrence and development of tumors, and there are multiple anti-angiogenesis targeted therapies. To comprehensively evaluate the efficacy and safety of anti-angiogenic targeted drugs alone and in combination against gastric cancer, we systematically searched and sorted out relevant literature. In this review, we summarized the efficacy and safety of Ramucirumab, Bevacizumab, Apatinib, Fruquintinib, Sorafenib, Sunitinib, Pazopanib on gastric cancer when used alone or in combination based on prospective clinical trials reported in the literature, and sorted response biomarkers. We also summarized the challenges faced by anti-angiogenesis therapy for gastric cancer and available solutions. Finally, the characteristics of the current clinical research are summarized and suggestions and prospects are raised. This review will serve as a good reference for the clinical research of anti-angiogenic targeted drugs in the treatment of gastric cancer.

Biochemical Functions and Clinical Characterizations of the Sirtuins in Diabetes-Induced Retinal Pathologies

Diabetic retinopathy (DR) is undoubtedly one of the most prominent causes of blindness worldwide. This pathology is the most frequent microvascular complication arising from diabetes, and its incidence is increasing at a constant pace. To date, the insurgence of DR is thought to be the consequence of the intricate complex of relations connecting inflammation, the generation of free oxygen species, and the consequent oxidative stress determined by protracted hyperglycemia. The sirtuin (SIRT) family comprises 7 histone and non-histone protein deacetylases and mono (ADP-ribosyl) transferases regulating different processes, including metabolism, senescence, DNA maintenance, and cell cycle regulation. These enzymes are involved in the development of various diseases such as neurodegeneration, cardiovascular pathologies, metabolic disorders, and cancer. SIRT1, 3, 5, and 6 are key enzymes in DR since they modulate glucose metabolism, insulin sensitivity, and inflammation. Currently, indirect and direct activators of SIRTs (such as antagomir, glycyrrhizin, and resveratrol) are being developed to modulate the inflammation response arising during DR. In this review, we aim to illustrate the most important inflammatory and metabolic pathways connecting SIRT activity to DR, and to describe the most relevant SIRT activators that might be proposed as new therapeutics to treat DR.

The Role of Epigenetic Modifications in Abdominal Aortic Aneurysm Pathogenesis

Abdominal aortic aneurysm (AAA) is a life-threatening disease associated with high morbidity and mortality in the setting of acute rupture. Recently, advances in surgical and endovascular repair of AAA have been achieved; however, pharmaceutical therapies to prevent AAA expansion and rupture remain lacking. This highlights an ongoing need to improve the understanding the pathological mechanisms that initiate formation, maintain growth, and promote rupture of AAA. Over the past decade, epigenetic modifications, such as DNA methylation, posttranslational histone modifications, and non-coding RNA, have emerged as important regulators of cellular function. Accumulating studies reveal the importance of epigenetic enzymes in the dynamic regulation of key signaling pathways that alter cellular phenotypes and have emerged as major intracellular players in a wide range of biological processes. In this review, we discuss the roles and implications of epigenetic modifications in AAA animal models and their relevance to human AAA pathology.

Predictive Biomarkers of Age-Related Macular Degeneration Response to Anti-VEGF Treatment

Age-related macular degeneration (AMD) is an incurable disease associated with aging that destroys sharp and central vision. Increasing evidence implicates both systemic and local inflammation in the pathogenesis of AMD. Intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents is currently the first-line therapy for choroidal neovascularization in AMD patients. However, a high number of patients do not show satisfactory responses to anti-VEGF treatment after three injections. Predictive treatment response models are one of the most powerful tools for personalized medicine. Therefore, the application of these models is very helpful to predict the optimal treatment for an early application on each patient. We analyzed the transcriptome of peripheral blood mononuclear cells (PBMCs) from AMD patients before treatment to identify biomarkers of response to ranibizumab. A classification model comprised of four mRNAs and one miRNA isolated from PBMCs was able to predict the response to ranibizumab with high accuracy (Area Under the Curve of the Receiver Operating Characteristic curve = 0.968), before treatment. We consider that our classification model, based on mRNA and miRNA from PBMCs allows a robust prediction of patients with insufficient response to anti-VEGF treatment. In addition, it could be used in combination with other methods, such as specific baseline characteristics, to identify patients with poor response to anti-VEGF treatment to establish patient-specific treatment plans at the first visit.

How Are Epigenetic Modifications Related to Cardiovascular Disease in Older Adults?

The rate of aging has increased globally during recent decades and has led to a rising burden of age-related diseases such as cardiovascular disease (CVD). At the molecular level, epigenetic modifications have been shown recently to alter gene expression during the life course and impair cellular function. In this regard, several CVD risk factors, such as lifestyle and environmental factors, have emerged as key factors in epigenetic modifications within the cardiovascular system. In this study, we attempted to summarized recent evidence related to epigenetic modification, inflammation response, and CVD in older adults as well as the effect of lifestyle modification as a preventive strategy in this age group. Recent evidence showed that lifestyle and environmental factors may affect epigenetic mechanisms, such as DNA methylation, histone acetylation, and miRNA expression. Several substances or nutrients such as selenium, magnesium, curcumin, and caffeine (present in coffee and some teas) could regulate epigenetics. Similarly, physical inactivity, alcohol consumption, air pollutants, psychological stress, and shift working are well-known modifiers of epigenetic patterns. Understanding the exact ways that lifestyle and environmental factors could affect the expression of genes could help to influence the time of incidence and severity of aging-associated diseases. This review highlighted that a healthy lifestyle throughout the life course, such as a healthy diet rich in fibers, vitamins, and essential elements, and specific fatty acids, adequate physical activity and sleep, smoking cessation, and stress control, could be useful tools in preventing epigenetic changes that lead to impaired cardiovascular function.

An Integrative Study of Aortic mRNA/miRNA Longitudinal Changes in Long-Term LVAD Support

Studying the long-term impact of continuous-flow left ventricular assist device (CF-LVAD) offers an opportunity for a complex understanding of the pathophysiology of vascular changes in aortic tissue in response to a nonphysiological blood flow pattern. Our study aimed to analyze aortic mRNA/miRNA expression changes in response to long-term LVAD support. Paired aortic samples obtained at the time of LVAD implantation and at the time of heart transplantation were examined for mRNA/miRNA profiling. The number of differentially expressed genes (Pcorr < 0.05) shared between samples before and after LVAD support was 277. The whole miRNome profile revealed 69 differentially expressed miRNAs (Pcorr < 0.05). Gene ontology (GO) analysis identified that LVAD predominantly influenced genes involved in the extracellular matrix and collagen fibril organization. Integrated mRNA/miRNA analysis revealed that potential targets of miRNAs dysregulated in explanted samples are mainly involved in GO biological process terms related to dendritic spine organization, neuron projection organization, and cell junction assembly and organization. We found differentially expressed genes participating in vascular tissue engineering as a consequence of LVAD duration. Changes in aortic miRNA levels demonstrated an effect on molecular processes involved in angiogenesis.

Mesenchymal stromal cell-derived exosomes in cardiac regeneration and repair

Mesenchymal stromal cell (MSC)-derived exosomes play a promising role in regenerative medicine. Their trophic and immunomodulatory potential has made them a promising candidate for cardiac regeneration and repair. Numerous studies have demonstrated that MSC-derived exosomes can replicate the anti-inflammatory, anti-apoptotic, and pro-angiogenic and anti-fibrotic effects of their parent cells and are considered a substitute for cell-based therapies. In addition, their lower tumorigenic risk, superior immune tolerance, and superior stability compared with their parent stem cells make them an attractive option in regenerative medicine. The therapeutic effects of MSC-derived exosomes have consequently been evaluated for application in cardiac regeneration and repair. In this review, we summarize the potential mechanisms and therapeutic effects of MSC-derived exosomes in cardiac regeneration and repair and provide evidence to support their clinical application.

Hydrogel-mediated delivery of microRNA-92a inhibitor polyplex nanoparticles induces localized angiogenesis

Localized stimulation of angiogenesis is an attractive strategy to improve the repair of ischemic or injured tissues. Several microRNAs (miRNAs) such as miRNA-92a (miR-92a) have been reported to negatively regulate angiogenesis in ischemic disease. To exploit the clinical potential of miR-92a inhibitors, safe and efficient delivery needs to be established. Here, we used deoxycholic acid-modified polyethylenimine polymeric conjugates (PEI-DA) to deliver a locked nucleic acid (LNA)-based miR-92a inhibitor (LNA-92a) in vitro and in vivo. The positively charged PEI-DA conjugates condense the negatively charged inhibitors into nano-sized polyplexes (135 ± 7.2 nm) with a positive net charge (34.2 ± 10.6 mV). Similar to the 25 kDa-branched PEI (bPEI₂₅) and Lipofectamine RNAiMAX, human umbilical vein endothelial cells (HUVECs) significantly internalized PEI-DA/LNA-92a polyplexes without any obvious cytotoxicity. Down-regulation of miR-92a following the polyplex-mediated delivery of LNA-92a led to a substantial increase in the integrin subunit alpha 5 (ITGA5), the sirtuin-1 (SIRT1) and Krüppel-like factors (KLF) KLF2/4 expression, formation of capillary-like structures by HUVECs, and migration rate of HUVECs in vitro. Furthermore, PEI-DA/LNA-92a resulted in significantly enhanced capillary density in a chicken chorioallantoic membrane (CAM) model. Localized angiogenesis was substantially induced in the subcutaneous tissues of mice by sustained release of PEI-DA/LNA-92a polyplexes from an in situ forming, biodegradable hydrogel based on clickable poly(ethylene glycol) (PEG) macromers. Our results indicate that PEI-DA conjugates efficiently deliver LNA-92a to improve angiogenesis. Localized delivery of RNA interference (RNAi)-based therapeutics via hydrogel-laden PEI-DA polyplex nanoparticles appears to be a safe and effective approach for different therapeutic targets.

Gene-activated matrix harboring a miR20a-expressing plasmid promotes rat cranial bone augmentation

Gene-activated matrix (GAM) has a potential usefulness in bone engineering as an alternate strategy for the lasting release of osteogenic proteins but efficient methods to generate non-viral GAM remain to be established. In this study, we investigated whether an atelocollagen-based GAM containing naked-plasmid (p) DNAs encoding microRNA (miR) 20a, which may promote osteogenesis in vivo via multiple pathways associated with the osteogenic differentiation of mesenchymal stem/progenitor cells (MSCs), facilitates rat cranial bone augmentation. First, we confirmed the osteoblastic differentiation functions of generated pDNA encoding miR20a (pmiR20a) in vitro, and its transfection regulated the expression of several of target genes, such as Bambi1 and PPARγ, in rat bone marrow MSCs and induced the increased expression of BMP4. Then, when GAMs fabricated by mixing 100 μl of 2% bovine atelocollagen, 20 mg β-TCP granules and 0.5 mg (3.3 μg/μl) AcGFP plasmid-vectors encoding miR20a were transplanted to rat cranial bone surface, the promoted vertical bone augmentation was clearly recognized up to 8 weeks after transplantation, as were upregulation of VEGFs and BMP4 expressions at the early stages of transplantation. Thus, GAM-based miR delivery may provide an alternative non-viral approach by improving transgene efficacy via a small sequence that can regulate the multiple pathways.

Mechanisms of action of metformin and its regulatory effect on microRNAs related to angiogenesis

Angiogenesis is rapidly initiated in response to pathological conditions and is a key target for pharmaceutical intervention in various malignancies. Anti-angiogenic therapy has emerged as a potential and effective therapeutic strategy for treating cancer and cardiovascular-related diseases. Metformin, a first-line oral antidiabetic agent for type 2 diabetes mellitus (T2DM), not only reduces blood glucose levels and improves insulin sensitivity and exerts cardioprotective effects but also shows benefits against cancers, cardiovascular diseases, and other diverse diseases and regulates angiogenesis. MicroRNAs (miRNAs) are endogenous noncoding RNA molecules with a length of approximately 19-25 bases that are widely involved in controlling various human biological processes. A large number of miRNAs are involved in the regulation of cardiovascular cell function and angiogenesis, of which miR-21 not only regulates vascular cell proliferation, migration and apoptosis but also plays an important role in angiogenesis. The relationship between metformin and abnormal miRNA expression has gradually been revealed in the context of numerous diseases and has received increasing attention. This paper reviews the drug-target interactions and drug repositioning events of metformin that influences vascular cells and has benefits on angiogenesis-mediated effects. Furthermore, we use miR-21 as an example to explain the specific molecular mechanism underlying metformin-mediated regulation of the miRNA signaling pathway controlling angiogenesis and vascular protective effects. These findings may provide a new therapeutic target and theoretical basis for the clinical prevention and treatment of cardiovascular diseases.

Overexpression of histone deacetylase SIRT1 exerts an antiangiogenic role in diabetic retinopathy via miR-20a elevation and YAP/HIF1α/VEGFA depletion

As a basic member of the Class III histone deacetylases, SIRT1 has been implicated in the occurrence and progression of diabetic retinopathy (DR). The current study aimed to investigate the roles of SIRT1/miR-20a/Yse-associated protein (YAP)/hypoxia-inducible factor 1 α (HIF1α)/vascular endothelial growth factor A (VEGFA) in DR. The expression of SIRT1 was initially determined through quantitative RT-PCR and Western blot analysis following the successful establishment of a DR mouse model, followed by detection of SIRT1 catalytic activity. Retinal microvascular endothelial cells (RMECs) were cultured in media supplemented with normal glucose (NG) or high glucose (HG). Thereafter, SIRT1 was either silenced or overexpressed in RMECs, after which EdU staining and Matrigel-based tube formation assay were performed to assess cell proliferation and tube formation. The binding relationship between YAP, HIF1α, and VEGFA was further illustrated using dual-luciferase reporter assay. Preretinal neovascular cell number was tallied with the IB4-positive vascular endothelial cells, as determined by immunofluorescence. SIRT1 was poorly expressed in mice with DR and HG-treated RMECs with low catalytic activity. The proliferation and tube formation capabilities of RMECs were elevated under HG conditions, which could be reversed following overexpression of SIRT1. SIRT1 was identified as positively regulating the expression of miR-20a with YAP detected as the key target gene of miR-20a. Our data suggested that YAP could upregulate VEGFA via induction of HIF1α. Moreover, SIRT1 overexpression strongly repressed RMEC proliferation and angiogenesis, which could be reversed via restoration of YAP/HIF1α/VEGFA expression. Taken together, the key findings of our study suggest that upregulation of SIRT1 inhibits the development of DR via miR-20a-induced downregulation of YAP/HIF1α/VEGFA.

MicroRNAs and obesity-induced endothelial dysfunction: key paradigms in molecular therapy

The endothelium plays a pivotal role in maintaining vascular health. Obesity is a global epidemic that has seen dramatic increases in both adult and pediatric populations. Obesity perturbs the integrity of normal endothelium, leading to endothelial dysfunction which predisposes the patient to cardiovascular diseases. MicroRNAs (miRNAs) are short, single-stranded, non-coding RNA molecules that play important roles in a variety of cellular processes such as differentiation, proliferation, apoptosis, and stress response; their alteration contributes to the development of many pathologies including obesity. Mediators of obesity-induced endothelial dysfunction include altered endothelial nitric oxide synthase (eNOS), Sirtuin 1 (SIRT1), oxidative stress, autophagy machinery and endoplasmic reticulum (ER) stress. All of these factors have been shown to be either directly or indirectly caused by gene regulatory mechanisms of miRNAs. In this review, we aim to provide a comprehensive description of the therapeutic potential of miRNAs to treat obesity-induced endothelial dysfunction. This may lead to the identification of new targets for interventions that may prevent or delay the development of obesity-related cardiovascular disease.

The Effect of MicroRNA-101 on Angiogenesis of Human Umbilical Vein Endothelial Cells during Hypoxia and in Mice with Myocardial Infarction

Background

Previous studies showed that recanalization and angiogenesis within the infarct region are of vital importance to the survival of myocardial cells during the treatment of acute myocardial infarction (AMI).

Methods

In this study, EdU cell proliferation assay, Transwell assay, scratch wound assay, and tube formation assay were used. Twelve bioinformatics analysis packages were used to predict the target genes of miR-101. Target genes were verified by luciferase reporter generation and assay, fluorescent quantitative PCR, and western blotting. Animal model and treatments were detected by M-mode echocardiography and immunofluorescent staining of CD31, Ki67, and α-SMA.

Results

AgomiR-101 significantly enhanced HUVEC proliferation, migration, and tube formation. A double-luciferase reporter assay revealed that the hsa-miR-101 mimic attenuated the activity of the EIF4E3′-UTR-wt type plasmid by 36%. The expression levels of HIF-1α and VEGF-A in the scrambled RNA group were significantly lower than those in the EIF4E3 siRNA and agomiR-101 groups. The left ventricular ejection fraction of the AMI+Adv-miR-101 group was significantly higher than that of the AMI+Adv-null and Sham+Adv-null groups. The proliferation of vessel cells in the peripheral infarcted myocardium was higher in the AMI+Adv-miR-101 group than that in the AMI+Adv-null and Sham+Adv-null groups.

Conclusion

MiR-101 can promote angiogenesis in the region surrounding the myocardial infarction.

Identification of key miRNAs and genes for mouse retinal development using a linear model

MicroRNAs (miRNAs) are upstream regulators of gene expression and are involved in several biological processes. The purpose of the present study was to obtain a detailed spatiotemporal miRNA expression profile in mouse retina, to identify one or more miRNAs that are key to mouse retinal development and to investigate the roles and mechanisms of these miRNAs. The miRNA expression pattern of the developing mouse retina was acquired from Locked Nucleic Acid microarrays. Data were processed to identify differentially expressed miRNAs (DE‑miRNAs) using the linear model in Python 3.6. Following bioinformatics analysis and reverse transcription‑quantitative polymerase chain reaction validation, 8 miRNAs (miR‑9‑5p, miR‑130a‑3p, miR‑92a‑3p, miR‑20a‑5p, miR‑93‑5p, miR‑9‑3p, miR‑709 and miR‑124) were identified as key DE‑miRNAs with low variability during mouse retinal development. Gene Ontology analysis revealed that the target genes of the DE‑miRNAs were enriched in cellular metabolic processes. Kyoto Encyclopedia of Genes and Genomes analysis demonstrated that the target genes of the DE‑miRNAs were significantly enriched in PI3K/AKT/mTOR, class O of forkhead box transcription factors, mitogen‑activated protein kinase (MAPK), neurotrophin and transforming growth factor (TGF)‑β signaling, as well as focal adhesion and the axon guidance pathway. PI3K, AKT, PTEN, MAPK1, Son of Sevenless, sphingosine‑1‑phosphate receptor 1, BCL‑2L11, TGF‑β receptor type 1/2 and integrin α (ITGA)/ITGAB, which are key components of the aforementioned pathways and were revealed to be target genes of several of the DE‑miRNAs. The present study used a linear model to identify several DE‑miRNAs, as well as their target genes and associated pathways, which may serve crucial roles in mouse retinal development. Therefore, the results obtained in the present study may provide the groundwork for further experiments.

Micro-RNAs in the aqueous humour of patients with diabetic macular oedema

IMPORTANCE

Micro-RNAs (miRNAs) have been studied as new biomarkers or mediators in various diseases, but the value of aqueous humour (AH) miRNAs in diabetic macular oedema (DMO) is still not known.

BACKGROUND

To compare AH miRNAs and related cytokine expression in DMO patients and healthy controls.

DESIGN

Prospective cross-sectional study.

PARTICIPANTS

Twenty naïve DMO patients and 13 control subjects, who were scheduled for intravitreal injection and cataract surgery, respectively.

METHODS

AH samples were collected at the beginning of each procedure and analysed using a miRNA polymerase chain reaction (PCR) array composed of 84 miRNAs, reverse transcripase-quantitative PCR (qPCR) for verifying selected differentially expressed miRNAs, and a cytokine assay, the results of which were compared with bioinformatics conducted to find out genes associated with DMO-related miRNAs.

MAIN OUTCOMES MEASURES

AH expression of miRNAs and cytokines and the bioinformatics results.

RESULTS

Five miRNAs (hsa-miR-185-5p, hsa-miR-17-5p, hsa-miR-20a-5p, hsa-miR-15b-5p and hsa-miR-15a-5p) showing a fold change greater than -50 in log2 values in the miRNA PCR array were selected, all significantly down-regulated in the DMO group compared to the control group (P < .05), and showed a direct relationship with tumour necrosis factor, nuclear factor kappa B subunit 1 and interleukin-6 (IL-6) in bioinformatics analysis, all of which were related to vascular endothelial growth factor (VEGF). In the cytokine assay, the aqueous concentrations of VEGF, placental growth factor, IL-6 and IL-8 were significantly higher in the DMO group compared to the control group.

CONCLUSIONS AND RELEVANCE

This study is the first to perform miRNA profiling of the AH of DMO patients. We identified differentially expressed miRNAs in DMO AH, which may be used as potential biomarkers or novel therapeutic targets for DMO.

A Strong Decrease in TIMP3 Expression Mediated by the Presence of miR-17 and 20a Enables Extracellular Matrix Remodeling in the NSCLC Lesion Surroundings

Background: Lung cancer is one of the most common causes of death worldwide with a relatively high fatality rate and a mean 5-years survival of about 18%. One of the hallmarks of cancer is the extracellular matrix (ECM) remodeling, which is crucial for metastasis. This process may be regulated by miRs targeting metalloproteinases (MMPs) associated with the ECM breakdown and metastatic process or blocking the action of tissue inhibitors of metalloproteinases (TIMPs). Search for early biomarkers is essential in detecting non-small cell lung cancer (NSCLC) and distinguishing its subtypes: Adenocarcinoma (AC) from Squamous Cell Carcinoma (SCC), enabling targeted chemotherapy.

Methods:MiR-17 and miR-20a targeting MMP2 and TIMP3 were selected by TCGA data analysis with further validation using miRTarBase and literature. The study group comprised 47 patients with primary NSCLC (AC and SCC subtypes). RNA was isolated from the tumor and normal-looking neighboring tissue (NLNT) free of cancer cells. MiRs from peripheral blood exosomes were extracted on admission and 5–7 days after surgery. Gene and miRs expression were assessed in qPCR using TaqMan probes.

Results: The MMP2 has been expressed on a similar level in NLNT, as in cancer. While, TIMP3 expression was decreased both in cancer tissue and NLNT, with significantly lower expression in cancer. TIMP3 downregulation in NLNT and in SCC subtype correlated negatively with miR-20a. The preoperative miR-17 expression was significantly higher among patients with SCC compared to AC. Receiver operating characteristic (ROC) analysis of miR-17 as AC subtype classifier revealed 90% specificity and 48% sensitivity in optimal cut-off point with area under ROC curve (AUC): 0.71 (95%CI: 0.55–0.87). Within NSCLC subtypes: a strong negative correlation between pack-years (PY) and TIMP3 expression was observed for NLNT in the SCC group.

Conclusion: The TIMP3 silencing observed in the NLNT and its negative correlation with presurgical expression of miR-20a (from serum exosomes), suggest that miRs can influence ECM remodeling at a distance from the center of the lesion. The miRs expression pattern in serum obtained before surgery significantly differs between AC and SCC subtypes. Moreover, decreased TIMP3 expression in NLNT (in SCC group) negatively correlates with the amount of tobacco smoked in a lifetime in PY.

The protective role of microRNA-21 against coxsackievirus B3 infection through targeting the MAP2K3/P38 MAPK signaling pathway

Background

The P38 mitogen-activated protein kinase (MAPK) pathway plays an essential role in CVB3-induced diseases. We previously demonstrated microRNA-21 has potential inhibitory effect on the MAP2K3 which locates upstream of P38 MAPK and was upregulated in mouse hearts upon CVB3 infection. However, the effect and underlying mechanism of miRNA-21 on CVB3 infection remain unclear.

Methods

We detected continuous changes of cellular miRNA-21 and P38 MAPK proteins expression profiling post CVB3 infection in vitro within 12 h. P38 MAPK signaling was inhibited by the specific inhibitor, small interfering RNA and miRNA-21 mimic in vitro, CVB3 replication, cell apoptosis rate and proliferation were detected. Viral load in the mice heart, cardiomyocyte apoptosis rate and histological of the heart were also detected in the mice model of viral myocarditis pretreated with miRNA-21-lentivirus.

Results

We observed significant upregulation of miRNA-21 expression followed by suppression of the MAP2K3/P38 MAPK signaling in CVB3-infected Hela cells. The inactivation of the MAP2K3/P38 MAPK signaling by P38 MAPK specific inhibitor, small interfering RNA against MAP2K3, or miRNA-21 overexpression significantly inhibited viral progeny release from CVB3-infected cells. Mechanistically, when compared with control miRNA, miRNA-21 showed no effect on capsid protein VP1 expression and viral load within host cells, while significantly reversing CVB3-induced caspase-3 activation and cell apoptosis rate, further promoting proliferation of infected cells, which indicates the inhibitory effect of miRNA-21 on CVB3 progeny release. In the in vivo study, when compared with control miRNA, miRNA-21 pretreatment remarkably inactivated the MAP2K3/P38 MAPK signaling in mice and protected them against CVB3 infection as evidenced by significantly alleviated cell apoptosis rate, reduced viral titers, necrosis in the heart as well as by remarkably prolonged survival time.

Conclusions

miRNA-21 were reverse correlated with P38 MAPK activation post CVB3 infection, miRNA-21 overexpression significantly inhibited viral progeny release and decreased myocytes apoptosis rate in vitro and in vivo, suggesting that miRNA-21 may serve as a potential therapeutic agent against CVB3 infection through targeting the MAP2K3/P38 MAPK signaling.

Differences in placental capillary shear stress in fetal growth restriction may affect endothelial cell function and vascular network formation

Fetal growth restriction (FGR) affects 5-10% of pregnancies, leading to clinically significant fetal morbidity and mortality. FGR placentae frequently exhibit poor vascular branching, but the mechanisms driving this are poorly understood. We hypothesize that vascular structural malformation at the organ level alters microvascular shear stress, impairing angiogenesis. A computational model of placental vasculature predicted elevated placental micro-vascular shear stress in FGR placentae (0.2 Pa in severe FGR vs 0.05 Pa in normal placentae). Endothelial cells cultured under predicted FGR shear stresses migrated significantly slower and with greater persistence than in shear stresses predicted in normal placentae. These cell behaviors suggest a dominance of vessel elongation over branching. Taken together, these results suggest (1) poor vascular development increases vessel shear stress, (2) increased shear stress induces cell behaviors that impair capillary branching angiogenesis, and (3) impaired branching angiogenesis continues to drive elevated shear stress, jeopardizing further vascular formation. Inadequate vascular branching early in gestation could kick off this cyclic loop and continue to negatively impact placental angiogenesis throughout gestation.

Evaluation of Serum microRNAs in Patients with Diabetic Kidney Disease: A Nested Case-Controlled Study and Bioinformatics Analysis

BACKGROUND Diabetic kidney disease (DKD) can result in end-stage kidney disease and renal failure. This study aimed to examine the expression of serum microRNAs (miRNAs), miR-20a, miR-99b, miR-122-5p, and miR-486-5p, and to use bioinformatics data to investigate the pathways involved in DKD. MATERIAL AND METHODS Serum miRNAs were obtained from 25 healthy volunteers, 50 patients with non-complicated type 2 diabetes mellitus (T2DM), and 42 patients with T2DM and DKD. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of serum miRNAs. Specificity and sensitivity of the association between serum miRNAs in DKD were evaluated by analysis of the receiver operating characteristic (ROC) area under the curve (AUC). Serum miRNAs and clinical parameters of the patients were compared. Bioinformatics data analysis accessed the miRNA targets involved in the pathways related to the pathogenesis of DKD. RESULTS Serum levels of miR-99b and miR-122 significantly increased, and mir-20a and miR-486 decreased in the DKD group compared with healthy controls. Serum levels of miR-20a, miR-99b, miR-486-5p, and miR-122-5p were significantly correlated with albuminuria, estimated glomerular filtration rate (eGFR), blood glucose and lipid profiles. ROC curve analysis showed that diagnostic accuracy of serum levels of miR-99b for DKD was superior to miR-486-5p, miR-122-5p, and miR-20a, resulting in AUCs of 0.895, 0.853, 0.80, and 0.697, respectively. These four miRNAs regulate several genes affecting oxidative stress, inflammation, and apoptosis. CONCLUSIONS Serum miR-99b, miR-486-5p, miR-122-5p, and miR-20a were differentially expressed in patients with T2DM and DKD and should be evaluated further as potential biomarkers for DKD.

Transcoronary gradients of HDL-associated MicroRNAs in unstable coronary artery disease

AIMS

MicroRNAs (miRNAs) are transported on high-density lipoproteins (HDLs) and HDL-associated miRNAs are involved in intercellular communication. We explored HDL-associated miRNAs concentration gradients across the coronary circulation in stable and unstable coronary artery disease patients and whether changes in the transcoronary gradient were associated with changes in HDL composition and size.

METHODS

Acute coronary syndrome (ACS, n=17) patients, those with stable coronary artery disease (stable CAD, n=19) and control subjects without CAD (n=6) were studied. HDLs were isolated from plasma obtained from the coronary sinus (CS), aortic root (arterial blood) and right atrium (venous blood). HDL-associated miRNAs (miR-16, miR-20a, miR-92a, miR-126, miR-222 and miR-223) were quantified by TaqMan miRNA assays. HDL particle sizes were determined by non-denaturing polyacrylamide gradient gel electrophoresis. HDL composition was measured immunoturbidometrically or enzymatically.

RESULTS

A concentration gradient across the coronary circulation was observed for all the HDL-associated miRNAs. In ACS patients, there was a significant inverse transcoronary gradient for HDL-associated miR-16, miR-92a and miR-223 (p<0.05) compared to patients with stable CAD. Changes in HDL-miRNA transcoronary gradients were not associated with changes in HDL composition or size.

CONCLUSION

HDLs are depleted of miR-16, miR-92a and miR-223 during the transcoronary passage in patients with ACS compared to patients with stable CAD.

Circulating ectosomes: Determination of angiogenic microRNAs in type 2 diabetes

Ectosomes (Ects) are a subpopulation of extracellular vesicles formed by the process of plasma membrane shedding. In the present study, we profiled ectosome-specific microRNAs (miRNAs) in patients with type 2 diabetes mellitus (T2DM) and analyzed their pro- and anti-angiogenic potential. Methods: We used different approaches for detecting and enumerating Ects, including atomic force microscopy, cryogenic transmission electron microscopy, and nanoparticle tracking analysis. Furthermore, we used bioinformatics tools to analyze functional data obtained from specific miRNA enrichment signatures during angiogenesis and vasculature development. Results: Levels of miR-193b-3p, miR-199a-3p, miR-20a-3p, miR-26b-5p, miR-30b-5p, miR-30c-5p, miR-374a-5p, miR-409-3p, and miR-95-3p were significantly different between Ects obtained from patients with T2DM and those obtained from healthy controls. Conclusion: Our results showed differences in the abundance of pro- and anti-angiogenic miRNAs in Ects of patients with T2DM, and are suggestive of mechanisms underlying the development of vascular complications due to impaired angiogenesis in such patients.

MicroRNA-20a protects human aortic endothelial cells from Ox-LDL-induced inflammation through targeting TLR4 and TXNIP signaling

MiR-20a has been previously reported to participate in the development of various human diseases. However, the role of miR-20a in the pathology of atherosclerosis remains elusive. The present study aimed to reveal the relationship between miR-20a expression and atherosclerosis using in vitro cell model. The expression level of miR-20a was detected in human aortic endothelial cells (HAECs) under Ox-LDL exposure. Meanwhile, the regulatory effects of miR-20a on predicted targets (TLR4 and TXNIP) were also determined. Moreover, the levels of key proteins and inflammatory mediators in TLR4 and NLRP3 signaling were detected to further confirm the regulatory effects of miR-20a. We found that miR-20a expression was repressed under Ox-LDL condition, and both TLR4 and TXNIP acted as regulatory targets of miR-20a. Overexpressed miR-20a reduced ROS generation under Ox-LDL treatment, and this effect was restored by forced expression of TLR4. Moreover, key molecules (including MyD88, TRIF, phosphorylated NF-κB (p65), NLRP3, ASC, cleaved caspase-1, ICAM-1 and IL-1β) in TLR4 and NLRP3 signaling were significantly repressed under miR-20a overexpression. In conclusion, miR-20a could negatively regulate TLR4 and NLRP3 signaling to protect HAECs from inflammatory injuries, which provides a new insight into the inhibition of atherosclerotic development.

The potential inhibitory effects of miR‑19b on vulnerable plaque formation via the suppression of STAT3 transcriptional activity

Atherosclerotic plaque growth requires angiogenesis, and acute coronary syndrome (ACS) is usually triggered by the rupture of unstable atherosclerotic plaques. Previous studies have identified typically circulating microRNA (miRNA/miR) profiles in patients with ACS. miRNAs serve important roles in the pathophysiology of atherosclerotic plaque progression. The present study aimed to investigate the potential role and mechanism of miR‑19b in plaque stability. miRNA array data indicated that 28 miRNAs were differentially expressed in the plasma of patients with unstable angina (UA; n=12) compared with in control individuals (n=12), and miR‑19b exhibited the most marked upregulation. Circulating miR‑19b levels were further validated in another independent cohort, which consisted of 34 patients with UA and 24 controls, by quantitative polymerase chain reaction. Gene Ontology annotations of the predicted target genes of miR‑19b suggested that miR‑19b may be involved in endothelial cell (EC) proliferation, migration and angiogenesis, which was confirmed by Cell Counting kit‑8, wound healing and tube formation assays in the present study. Finally, the present study indicated that miR‑19b may suppress signal transducer and activator of transcription 3 (STAT3) tyrosine phosphorylation and transcriptional activity in ECs, as determined by western blot analysis and luciferase reporter assay. In conclusion, the present study revealed that increased miR‑19b expression may delay unstable plaque progression in patients with UA by inhibiting EC proliferation, migration and angiogenesis via the suppression of STAT3 transcriptional activity.

MicroRNA-30b controls endothelial cell capillary morphogenesis through regulation of transforming growth factor beta 2

The importance of microRNA (miRNA) to vascular biology is becoming increasingly evident; however, the function of a significant number of miRNA remains to be determined. In particular, the effect of growth factor regulation of miRNAs on endothelial cell morphogenesis is incomplete. Thus, we aimed to identify miRNAs regulated by pro-angiogenic vascular endothelial growth factor (VEGF) and determine the effects of VEGF-regulated miRNAs and their targets on processes important for angiogenesis. Human umbilical vein endothelial cells (HUVECs) were thus stimulated with VEGF and miRNA levels assessed using microarrays. We found that VEGF altered expression of many miRNA, and for this study focused on one of the most significantly down-regulated miRNA in HUVECs following VEGF treatment, miR-30b. Using specific miRNA mimics, we found that overexpression of miR-30b inhibited capillary morphogenesis in vitro, while depletion of endogenous miR-30b resulted in increased capillary morphogenesis indicating the potential significance of down-regulation of miR-30b as a pro-angiogenic response to VEGF stimulation. MiR-30b overexpression in HUVEC regulated transforming growth factor beta 2 (TGFβ2) production, which led to increased phosphorylation of Smad2, indicating activation of an autocrine TGFβ signaling pathway. Up-regulation of TGFβ2 by miR-30b overexpression was found to be dependent on ATF2 activation, a transcription factor known to regulate TGFβ2 expression, as miR-30b overexpressing cells exhibited increased levels of phosphorylated ATF2 and depletion of ATF2 inhibited miR-30b-induced TGFβ2 expression. However, miR-30b effects on ATF2 were indirect and found to be via targeting of the known ATF2 repressor protein JDP2 whose mRNA levels were indirectly correlated with miR-30b levels. Increased secretion of TGFβ2 from HUVEC was shown to mediate the inhibitory effects of miR-30b on capillary morphogenesis as treatment with a neutralizing antibody to TGFβ2 restored capillary morphogenesis to normal levels in miR-30b overexpressing cells. These results support that the regulation of miR-30b by VEGF in HUVEC is important for capillary morphogenesis, as increased miR-30b expression inhibits capillary morphogenesis through enhanced expression of TGFβ2.

Angiogenesis regulation by nanocarriers bearing RNA interference

Since the approval of bevacizumab as anti-angiogenic therapy in 2004 by the FDA, an array of angiogenesis inhibitors have been developed and approved. However, results were disappointing with regard to their therapeutic efficacy. RNA interference approaches offer the possibility of rational design with high specificity, lacking in many current drug treatments for various diseases including cancer. However, in vivo delivery issues still represent a significant obstacle for widespread clinical applications. In the current review, we summarize the advances in the last decade in the field of angiogenesis-targeted RNA interference approaches, with special emphasis on oncology applications. We present pro-angiogenic and anti-angiogenic factors as potential targets, experimental evidence and clinical trials data on angiogenesis regulation by RNA interference. Consequent challenges and opportunities are discussed.

MicroRNA as Therapeutic Targets for Chronic Wound Healing

Wound healing is a highly complex biological process composed of three overlapping phases: inflammation, proliferation, and remodeling. Impairments at any one or more of these stages can lead to compromised healing. MicroRNAs (miRs) are non-coding RNAs that act as post-transcriptional regulators of multiple proteins and associated pathways. Thus, identification of the appropriate miR involved in the different phases of wound healing could reveal an effective third-generation genetic therapy in chronic wound care. Several miRs have been shown to be upregulated or downregulated during the wound healing process. This article examines the biological processes involved in wound healing, the miR involved at each stage, and how expression levels are modulated in the chronic wound environment. Key miRs are highlighted as possible therapeutic targets, either through underexpression or overexpression, and the healing benefits are interrogated. These are prime miR candidates that could be considered as a gene therapy option for patients suffering from chronic wounds. The success of miR as a gene therapy, however, is reliant on the development of an appropriate delivery system that must be designed to overcome both extracellular and intracellular barriers.

The p38 pathway, a major pleiotropic cascade that transduces stress and metastatic signals in endothelial cells

By gating the traffic of molecules and cells across the vessel wall, endothelial cells play a central role in regulating cardiovascular functions and systemic homeostasis and in modulating pathophysiological processes such as inflammation and immunity. Accordingly, the loss of endothelial cell integrity is associated with pathological disorders that include atherosclerosis and cancer. The p38 mitogen-activated protein kinase (MAPK) cascades are major signaling pathways that regulate several functions of endothelial cells in response to exogenous and endogenous stimuli including growth factors, stress and cytokines. The p38 MAPK family contains four isoforms p38α, p38β, p38γ and p38δ that are encoded by four different genes. They are all widely expressed although to different levels in almost all human tissues. p38α/MAPK14, that is ubiquitously expressed is the prototype member of the family and is referred here as p38. It regulates the production of inflammatory mediators, and controls cell proliferation, differentiation, migration and survival. Its activation in endothelial cells leads to actin remodeling, angiogenesis, DNA damage response and thereby has major impact on cardiovascular homeostasis, and on cancer progression. In this manuscript, we review the biology of p38 in regulating endothelial functions especially in response to oxidative stress and during the metastatic process.

Dynamic regulation of VEGF-inducible genes by an ERK/ERG/p300 transcriptional network

The transcriptional pathways activated downstream of vascular endothelial growth factor (VEGF) signaling during angiogenesis remain incompletely characterized. By assessing the signals responsible for induction of the Notch ligand delta-like 4 (DLL4) in endothelial cells, we find that activation of the MAPK/ERK pathway mirrors the rapid and dynamic induction of DLL4 transcription and that this pathway is required for DLL4 expression. Furthermore, VEGF/ERK signaling induces phosphorylation and activation of the ETS transcription factor ERG, a prerequisite for DLL4 induction. Transcription of DLL4 coincides with dynamic ERG-dependent recruitment of the transcriptional co-activator p300. Genome-wide gene expression profiling identified a network of VEGF-responsive and ERG-dependent genes, and ERG chromatin immunoprecipitation (ChIP)-seq revealed the presence of conserved ERG-bound putative enhancer elements near these target genes. Functional experiments performed in vitro and in vivo confirm that this network of genes requires ERK, ERG and p300 activity. Finally, genome-editing and transgenic approaches demonstrate that a highly conserved ERG-bound enhancer located upstream of HLX (which encodes a transcription factor implicated in sprouting angiogenesis) is required for its VEGF-mediated induction. Collectively, these findings elucidate a novel transcriptional pathway contributing to VEGF-dependent angiogenesis.

Exosome-based immunomodulation during aging: A nano-perspective on inflamm-aging

Exosomes are nanovesicles formed by inward budding of endosomal membranes. They exert complex immunomodulatory effects on target cells, acting both as antigen-presenting vesicles and as shuttles for packets of information such as proteins, coding and non-coding RNA, and nuclear and mitochondrial DNA fragments. Albeit different, all such functions seem to be encompassed in the adaptive mechanism mediating the complex interactions of the organism with a variety of stressors, providing both for defense and for the evolution of symbiotic relationships with others organisms (gut microbiota, bacteria, and viruses). Intriguingly, the newly deciphered human virome and exosome biogenesis seem to share some physical-chemical characteristics and molecular mechanisms. Exosomes are involved in immune system recognition of self from non-self throughout life: they are therefore ideal candidate to modulate inflamm-aging, the chronic, systemic, age-related pro-inflammatory status, which influence the development/progression of the most common age-related diseases (ARDs). Not surprisingly, recent evidence has documented exosomal alteration during aging and in association with ARDs, even though data in this field are still limited. Here, we review current knowledge on exosome-based trafficking between immune cells and self/non-self cells (i.e. the virome), sketching a nano-perspective on inflamm-aging and on the mechanisms involved in health maintenance throughout life.

Function, Role, and Clinical Application of MicroRNAs in Vascular Aging

Vascular aging, a specific type of organic aging, is related to age-dependent changes in the vasculature, including atherosclerotic plaques, arterial stiffness, fibrosis, and increased intimal thickening. Vascular aging could influence the threshold, process, and severity of various cardiovascular diseases, thus making it one of the most important risk factors in the high mortality of cardiovascular diseases. As endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) are the main cell biological basis of these pathology changes of the vasculature, the structure and function of ECs and VSMCs play a key role in vascular aging. MicroRNAs (miRNAs), small noncoding RNAs, have been shown to regulate the expression of multiple messenger RNAs (mRNAs) posttranscriptionally, contributing to many crucial aspects of cell biology. Recently, miRNAs with functions associated with aging or aging-related diseases have been studied. In this review, we will summarize the reported role of miRNAs in the process of vascular aging with special emphasis on EC and VSMC functions. In addition, the potential application of miRNAs to clinical practice for the diagnosis and treatment of cardiovascular diseases will also be discussed.

Serum miR-92a-3p as a New Potential Biomarker for Diagnosis of Kawasaki Disease with Coronary Artery Lesions

Recent studies have suggested that serum microRNAs (miRNAs) are novel biomarkers for many cardiovascular diseases, but their role in Kawasaki disease (KD) is still unclear. We demonstrated that serum miR-92a-3p levels were significantly higher in children with KD compared with children with fever and controls (both P < 0.05). When the disease recovered, miR-92a-3p levels returned to those of controls. Clinical and pathological data showed that high levels of miR-92a-3p were significantly associated with coronary artery lesions (CALs). Analysis of the receiver operating characteristic (ROC) curve showed that serum miR-92a-3p had a sensitivity of 81.8% and a specificity of 66.7% for distinguishing KD with CALs from KD without CALs. The area under the curve was 0.816 (P < 0.05, 95% CI 0.669-0.962). Therefore, the miRNA miR-92a-3p may be used as a potential biomarker for diagnosis of KD and KD with coronary artery lesions.

Suppression of Bim by microRNA-19a may protect cardiomyocytes against hypoxia-induced cell death via autophagy activation

Microvascular obstruction (MO), one of unfavorable complications of percutaneous coronary intervention (PCI), is responsible for the lost benefit of reperfusion therapy. Determination of microRNA-19a, a member of the miR-17-92 cluster, using quantitative real-time polymerase chain reaction (PCR) revealed notably down-regulated microRNA-19a, in myocardium with MO. Nonetheless, the role of miR-19a in MO and the underlying mechanism remains to be elucidated. To this end, an in vitro microembolization model in cardiomyocytes was used. Our data revealed that hypoxic exposure prompted cardiomyocyte apoptosis in a time-dependent manner accompanied by reduced miR-19a. miR-19a overexpression clearly ameliorated hypoxia-induced cell death (necrosis and apoptosis), at least in part, through switching on autophagy. Further dual-luciferase reporter assay and immunoblotting studies demonstrated that miR-19a-induced cytoprotection might be achieved in part through modulation of the specific target Bcl-2 interacting mediator of cell death, Bim, an apoptotic activator. Bim sufficiently interfered with miR-19a-induced LC3 conversion and increased cardiomyocyte apoptosis under hypoxia. Moreover, cardiomyocytes pretreated with 3-methyladenine conferred resistance to the cytoprotective effect of miR-19a and displayed notably increased TUNEL staining and caspase-3 activity. In conclusion, miR-19a protected cardiomyocytes against hypoxia-induced lethality at least in part via Bim suppression and subsequently autophagy activation.

Improving stem cell therapy in cardiovascular diseases: the potential role of microRNA

The initial promising prospect of autologous bone marrow-derived stem cell therapy in the setting of cardiovascular diseases has been overshadowed by functional shortcomings of the stem cell product. As powerful epigenetic regulators of (stem) cell function, microRNAs are valuable targets for novel therapeutic strategies. Indeed, modulation of specific miRNA expression could contribute to improved therapeutic efficacy of stem cell therapy. First, this review elaborates on the functional relevance of miRNA dysregulation in bone marrow-derived progenitor cells in different cardiovascular diseases. Next, we provide a comprehensive overview of the current evidence on the effect of specific miRNA modulation in several types of progenitor cells on cardiac and/or vascular regeneration. By elaborating on the cardioprotective regulation of progenitor cells on cardiac miRNAs, more insight in the underlying mechanisms of stem cell therapy is provided. Finally, some considerations are made regarding the potential of circulating miRNAs as regulators of the miRNA signature of progenitor cells in cardiovascular diseases.

miR-17 and -20a Target the Neuron-Derived Orphan Receptor-1 (NOR-1) in Vascular Endothelial Cells

Neuron-derived orphan receptor-1 (NOR-1) plays a major role in vascular biology by controlling fibroproliferative and inflammatory responses. Because microRNAs (miRNAs) have recently emerged as key players in the regulation of gene expression in the vasculature, here we have investigated the regulation of NOR-1 by miRNAs in endothelial cells. Computational algorithms suggest that NOR-1 could be targeted by members of the miR-17 family. Accordingly, ectopic over-expression of miR-17 or miR-20a in endothelial cells using synthetic premiRNAs attenuated the up-regulation of NOR-1 expression induced by VEGF (as evidenced by real time PCR, Western blot and immunocitochemistry). Conversely, the antagonism of these miRNAs by specific antagomirs prevented the down-regulation of NOR-1 promoted by miR-17 or miR-20a in VEGF-stimulated cells. Disruption of the miRNA-NOR-1 mRNA interaction using a custom designed target protector evidenced the selectivity of these responses. Further, luciferase reporter assays and seed-sequence mutagenesis confirmed that miR-17 and -20a bind to NOR-1 3’-UTR. Finally, miR-17 and -20a ameliorated the up-regulation of VCAM-1 mediated by NOR-1 in VEGF-stimulated cells. Therefore, miR-17 and -20a target NOR-1 thereby regulating NOR-1-dependent gene expression.

New insights into microRNAs in skin wound healing

Chronic wounds are a major burden to overall healthcare cost and patient morbidity. Chronic wounds affect a large portion of the US, and billions of healthcare dollars are spent in their treatment and management. microRNAs (miRNAs) are small, noncoding double-stranded RNAs that post-transcriptionally downregulate the expression of protein-coding genes. Studies have identified miRNAs involved in all three phases of wound healing including inflammation, proliferation, and remodeling. Some miRNAs have been demonstrated in vitro with primary keratinocyte wound healing model and in vivo with mouse wound healing model through regulation of miRNA expression to affect the wound healing process. This review updates the current miRNAs involved in wound healing and discusses the future therapeutic implications and research directions.

Effects of the Pinggan Qianyang Recipe on MicroRNA Gene Expression in the Aortic Tissue of Spontaneously Hypertensive Rats

The present study aimed to investigate the relationship between miRNAs and in spontaneously hypertensive rats (SHR) vascular remodeling and analyze the impact of the Pinggan Qianyang recipe (PQR) on miRNAs. Mammalian miRNA microarrays containing 509 miRNA genes were employed to analyze the differentially expressed miRNAs in the three groups. MiRNAs were considered to be up- or downregulated when the fluorescent intensity ratio between the two groups was over 4-fold. Validation of those miRNAs changed in SHR after PQR treatment was used by real-time quantitative RT-PCR (qRT-PCR). Compared with the normal group, a total of 32 miRNAs were differentially expressed by more than twofold; among these, 18 were upregulated and 14 were downregulated in the model group. Compared with the normal group, there were a number of 17 miRNAs which were significantly expressed by more than twofold in the different expressions of 32 miRNAs; among these, 10 were downregulated and 7 were upregulated in the PQR group. qRT-PCR verified that miR-20a, miR-145, miR-30, and miR-98 were significantly expressed in the three groups. These data show that PQR could exert its antihypertensive effect through deterioration of the vascular remodeling process. The mechanism might be associated with regulating differentially expressed miRNAs in aorta tissue.

The role of miR-205 in the VEGF-mediated promotion of human ovarian cancer cell invasion

OBJECTIVE

Our objective was to investigate a miRNA pathway that acts downstream of VEGF-induced invasion of ovarian cancer cells.

METHOD

We used two paired high and low metastatic serous ovarian cancer cells to demonstrate the role of miR-205 in VEGF-induced invasion of ovarian cancer cells and to investigate the gene targets of miR-205.

RESULTS

Our previous comparative proteomics studies showed that VEGF decreased the expression of Ezrin and Lamin A/C, and this result was validated in the present study using qPCR and Western blotting. Then we found that VEGF enhanced the invasiveness of and inhibited apoptosis in ovarian cancer cells as assessed by transwell invasion assays and Annexin V-FITC immunostaining, respectively. VEGFR was also expressed in ovarian cancer cells, as assessed by immunocytochemical staining. Furthermore, using the dual-luciferase report assay system, we demonstrated that miR-205 targeted Ezrin and Lamin A/C. MiR-205 was up-regulated in ovarian cancer cells exposed to VEGF, as determined by miRNA microarray analysis and verified by qPCR. MiR-205 promoted the invasion and proliferation of ovarian cancer cells.

CONCLUSION

Our data reveal a new potential pathway in which VEGF promotes the invasion of ovarian cancer cells, partially via the down-regulation of Ezrin and Lamin A/C caused by increased expression of miR-205.

Nestin-mediated cytoskeletal remodeling in endothelial cells: novel mechanistic insight into VEGF-induced cell migration in angiogenesis

Nestin is highly expressed in poorly differentiated and newly formed proliferating endothelial cells (ECs); however, the role of this protein in angiogenesis remains unknown. Additionally, the cytoskeleton and associated cytoskeleton-binding proteins mediate the migration of vascular ECs. Therefore, the aim of the present study was to determine whether VEGF regulates the cytoskeleton, as well as other associated proteins, to promote the migration of vascular ECs. The coexpression of nestin and CD31 during angiogenesis in alkali-burned rat corneas was examined via immunohistochemical analysis. Western blot analyses revealed that the exposure of human umbilical vein endothelial cells (HUVECs) to hypoxia promoted nestin expression in vitro. Additionally, nestin silencing via siRNA significantly inhibited many of the process associated with VEGF-induced angiogenesis, including tube formation and the migration and proliferation of HUVECs. Moreover, FITC-phalloidin labeling revealed that F-actin filaments were successfully organized into microfilaments in VEGF-treated cells, suggesting a network rearrangement accomplished via F-actin that contrasted with the uniform and loose actin filament network observed in the siRNA-nestin cells. The results of the present study highlight the key role played by nestin in activated HUVECs during angiogenesis. The inhibition of the ERK pathway suppressed the nestin expression induced by VEGF in the HUVECs. Therefore, our study provides the first evidence that nestin-mediated cytoskeleton remodeling in ECs occurs via filopodia formation along the cell edge, facilitating both filopodia localization and cell polarization and ultimately promoting HUVEC migration via VEGF induction, which may be associated with ERK pathway activation.

Post-transcriptional gene regulation by RNA-binding proteins in vascular endothelial dysfunction

Endothelial cell dysfunction is a term which implies the dysregulation of normal endothelial cell functions, including impairment of the barrier functions, control of vascular tone, disturbance of proliferative and migratory capacity of endothelial cells, as well as control of leukocyte trafficking. Endothelial dysfunction is an early step in vascular inflammatory diseases such as atherosclerosis, diabetic vascular complications, sepsis-induced or severe virus infection-induced organ injuries. The expressions of inflammatory cytokines and vascular adhesion molecules induced by various stimuli, such as modified lipids, smoking, advanced glycation end products and bacteria toxin, significantly contribute to the development of endothelial dysfunction. The transcriptional regulation of inflammatory cytokines and vascular adhesion molecules has been well-studied. However, the regulation of those gene expressions at post-transcriptional level is emerging. RNA-binding proteins have emerged as critical regulators of gene expression acting predominantly at the post-transcriptional level in microRNA-dependent or independent manners. This review summarizes the latest insights into the roles of RNA-binding proteins in controlling vascular endothelial cell functions and their contribution to the pathogenesis of vascular inflammatory diseases.

MicroRNAs, immune cells and pregnancy

MicroRNAs (miRNAs) are a recently discovered class of non-coding RNAs that are expressed in many cell types, where they regulate the expression of complementary RNAs, thus modulating the stability and translation of mRNAs. miRNAs are predicted to regulate the expression of ∼50% of all protein coding genes in mammals. Therefore, they participate in virtually all cellular processes investigated so far. Altered miRNAs expressions are associated with both physiological (pregnancy) and pathological processes (cancer). As the dynamic maternal-fetal interface plays a critical role in the maintenance of successful pregnancy, it is not surprising that the miRNAs that are unique to reproductive tissues are abundantly expressed. Research in this field has demonstrated the presence and dysregulation of a distinct set of pregnancy-associated miRNAs; however, most studies have centered on localizing various miRNAs in reproductive microdomains associated with normal or complicated pregnancies. Although several independent miRNA regulatory mechanisms associated with endometrial receptivity, immune cells, angiogenesis and placental development have been studied, miRNA-mediated regulation of pregnancy remains poorly understood. This review provides a summary of the current data on miRNA regulation as well as functional profiles of miRNAs that are found in the uterus, in immune cells associated with maternal tolerance to the fetus, and those involved in angiogenesis and placental development.

Histamine synergistically promotes bFGF-induced angiogenesis by enhancing VEGF production via H1 receptor

Histamine, a major mediator present in mast cells that is released into the extracellular milieu upon degranulation, is well known to possess a wide range of biological activities in several classic physiological and pathological processes. However, whether and how it participates in angiogenesis remains obscure. In the present study, we observed its direct and synergistic action with basic fibroblast growth factor (bFGF), an important inducer of angiogenesis, on in vitro angiogenesis models of endothelial cells. Data showed that histamine (0.1, 1, 10 µM) itself was absent of direct effects on the processes of angiogenesis, including the proliferation, migration, and tube formation of endothelial cells. Nevertheless, it could concentration-dependently enhance bFGF-induced angiogenesis as well as production of vascular endothelial growth factor (VEGF) from endothelial cells. The synergistic effect of histamine on VEGF production could be reversed by pretreatments with diphenhydramine (H1-receptor antagonist), SB203580 (selective p38 mitogen-activated protein kinase (MAPK) inhibitor) and L-NAME (nitric oxide synthase (NOS) inhibitor), but not with cimetidine (H2-receptor antagonist) and indomethacin (cyclooxygenase (COX) inhibitor). Moreover, histamine could augment bFGF-incuced phosphorylation and degradation of IκBα, a key factor accounting for the activation and translocation of nuclear factor κB (NF-κB) in endothelial cells. These findings indicated that histamine was able to synergistically augment bFGF-induced angiogenesis, and this action was linked to VEGF production through H1-receptor and the activation of endothelial nitric oxide synthase (eNOS), p38 MAPK, and IκBα in endothelial cells.

Identification of microRNA-mRNA functional interactions in UVB-induced senescence of human diploid fibroblasts

BACKGROUND

Cellular senescence can be induced by a variety of extrinsic stimuli, and sustained exposure to sunlight is a key factor in photoaging of the skin. Accordingly, irradiation of skin fibroblasts by UVB light triggers cellular senescence, which is thought to contribute to extrinsic skin aging, although molecular mechanisms are incompletely understood. Here, we addressed molecular mechanisms underlying UVB induced senescence of human diploid fibroblasts.

RESULTS

We observed a parallel activation of the p53/p21(WAF1) and p16(INK4a)/pRb pathways. Using genome-wide transcriptome analysis, we identified a transcriptional signature of UVB-induced senescence that was conserved in three independent strains of human diploid fibroblasts (HDF) from skin. In parallel, a comprehensive screen for microRNAs regulated during UVB-induced senescence was performed which identified five microRNAs that are significantly regulated during the process. Bioinformatic analysis of miRNA-mRNA networks was performed to identify new functional mRNA targets with high confidence for miR-15a, miR-20a, miR-20b, miR-93, and miR-101. Already known targets of these miRNAs were identified in each case, validating the approach. Several new targets were identified for all of these miRNAs, with the potential to provide new insight in the process of UVB-induced senescence at a genome-wide level. Subsequent analysis was focused on miR-101 and its putative target gene Ezh2. We confirmed that Ezh2 is regulated by miR-101 in human fibroblasts, and found that both overexpression of miR-101 and downregulation of Ezh2 independently induce senescence in the absence of UVB irradiation. However, the downregulation of miR-101 was not sufficient to block the phenotype of UVB-induced senescence, suggesting that other UVB-induced processes induce the senescence response in a pathway redundant with upregulation of miR-101.

CONCLUSION

We performed a comprehensive screen for UVB-regulated microRNAs in human diploid fibroblasts, and identified a network of miRNA-mRNA interactions mediating UVB-induced senescence. In addition, miR-101 and Ezh2 were identified as key players in UVB-induced senescence of HDF.

Regulation of endothelial permeability and transendothelial migration of cancer cells by tropomyosin-1 phosphorylation

BACKGROUND

Loss of endothelial cell integrity and selective permeability barrier is an early event in the sequence of oxidant-mediated injury and may result in atherosclerosis, hypertension and facilitation of transendothelial migration of cancer cells during metastasis. We already reported that endothelial cell integrity is tightly regulated by the balanced co-activation of p38 and ERK pathways. In particular, we showed that phosphorylation of tropomyosin-1 (tropomyosin alpha-1 chain = Tm1) at Ser283 by DAP kinase, downstream of the ERK pathway might be a key event required to maintain the integrity and normal functions of the endothelium in response to oxidative stress.

METHODS

Endothelial permeability was assayed by monitoring the passage of Dextran-FITC through a tight monolayer of HUVECs grown to confluence in Boyden chambers. Actin and Tm1 dynamics and distribution were evaluated by immunofluorescence. We modulated the expression of Tm1 by siRNA and lentiviral-mediated expression of wild type and mutated forms of Tm1 insensitive to the siRNA. Transendothelial migration of HT-29 colon cancer cells was monitored in Boyden chambers similarly as for permeability.

RESULTS

We provide evidence indicating that Tm1 phosphorylation at Ser283 is essential to regulate endothelial permeability under oxidative stress by modulating actin dynamics. Moreover, the transendothelial migration of colon cancer cells is also regulated by the phosphorylation of Tm1 at Ser283.

CONCLUSION

Our finding strongly support the role for the phosphorylation of endothelial Tm1 at Ser283 to prevent endothelial barrier dysfunction associated with oxidative stress injury.

Annexin-1-mediated endothelial cell migration and angiogenesis are regulated by vascular endothelial growth factor (VEGF)-induced inhibition of miR-196a expression

Endothelial cell migration induced in response to vascular endothelial growth factor (VEGF) is an essential step of angiogenesis. It depends in part on the activation of the p38/MAPKAP kinase-2/LIMK1/annexin-A1 (ANXA1) signaling axis. In the present study, we obtained evidence indicating that miR-196a specifically binds to the 3'-UTR region of ANXA1 mRNA to repress its expression. In accordance with the role of ANXA1 in cell migration and angiogenesis, the ectopic expression of miR-196a is associated with decreased cell migration in wound closure assays, and the inhibitory effect of miR-196a is rescued by overexpressing ANXA1. This finding highlights the fact that ANXA1 is a required mediator of VEGF-induced cell migration. miR-196a also reduces the formation of lamellipodia in response to VEGF suggesting that ANXA1 regulates cell migration by securing the formation of lamellipodia at the leading edge of the cell. Additionally, in line with the fact that cell migration is an essential step of angiogenesis, the ectopic expression of miR-196a impairs the formation of capillary-like structures in a tissue-engineered model of angiogenesis. Here again, the effect of miR-196a is rescued by overexpressing ANXA1. Moreover, the presence of miR-196a impairs the VEGF-induced in vivo neo-vascularization in the Matrigel Plug assay. Interestingly, VEGF reduces the expression of miR-196a, which is associated with an increased level of ANXA1. Similarly, the inhibition of miR-196a with an antagomir results in an increased level of ANXA1. We conclude that the VEGF-induced decrease of miR-196a expression may participate to the angiogenic switch by maintaining the expression of ANXA1 to levels required to enable p38-ANXA1-dependent endothelial cell migration and angiogenesis in response to VEGF.