MicroRNA-10 regulates the angiogenic behavior of zebrafish and human endothelial cells by promoting vascular endothelial growth factor signaling

Sexual dimorphic miRNA-mediated response of bovine elongated embryos to the maternal microenvironment

A skewed male-to-female ratio in cattle is believed to be due to the biased embryo losses during pregnancy. The changes in biochemical secretion such as miRNAs by the embryo due to altered maternal environment could cause a sex biased selective implantation resulting in a skewed male to female ratio at birth. Nevertheless, it is still not clear whether the male and female embryos could modify their miRNA expression patterns differently in response to altered physiological developmental conditions. Therefore, this study was focused on identifying sex specific miRNA expression patterns induced in the embryo during the elongation period in response to the maternal environment. For this, in vitro produced day female and male embryos were transferred to Holsteins Frisian cows and heifers. The elongated female and male embryos were then recovered at day 13 of the gestation period. Total RNA including the miRNAs was isolated from each group of elongated embryo samples were subjected to the next generation miRNA sequencing. Sequence alignment, identification and quantification of miRNAs were done using the miRDeep2 software package and differential miRNA expression analyses were performed using the edgeR bioconductor package. The recovery rate of viable elongating embryos at day 13 of the gestation period was 26.6%. In cows, 2.8 more viable elongating male embryos were recovered than female embryos, while in heifers the sex ratio of the recovered elongating embryos was close to one (1.05). The miRNA analysis showed that 254 miRNAs were detected in both male and female elongated embryos developed either in cows or heifers, of which 14 miRNAs including bta-miR-10b, bta-miR-148a, bta-miR-26a, and bta-miR-30d were highly expressed. Moreover, the expression level of 32 miRNAs including bta-let-7c, bta-let-7b, bta-let-7g, bta-let-7d and bta-let-7e was significantly different between the male and female embryos developed in cows, but the expression level of only 4 miRNAs (bta-miR-10, bta-mR-100, bta-miR-155 and bta-miR-6119-5p) was different between the male and female embryos that were developed in heifers. Furthermore, 19 miRNAs including those involved in cellular energy homeostasis pathways were differentially expressed between the male embryos developed in cows and heifers, but no significantly differentially expressed miRNAs were detected between the female embryos of cows and heifers. Thus, this study revealed that the sex ratio skewed towards males in embryos developed in cows was accompanied by increased embryonic sexual dimorphic miRNA expression divergence in embryos developed in cows compared to those developed in heifers. Moreover, male embryos are more sensitive to respond to the maternal reproductive microenvironment by modulating their miRNA expression.

Engineering Extracellular Matrix-Bound Nanovesicles Secreted by Three-Dimensional Human Mesenchymal Stem Cells

Extracellular matrix (ECM) in the human tissue contains vesicles, which are defined as matrix-bound nanovesicles (MBVs). MBVs serve as one of the functional components in ECM, recapitulating part of the regulatory roles and in vivo microenvironment. In this study, extracellular vesicles from culture supernatants (SuEVs) and MBVs are isolated from the conditioned medium or ECM, respectively, of 3D human mesenchymal stem cells. Nanoparticle tracking analysis shows that MBVs are smaller than SuEVs (100-150 nm). Transmission electron microscopy captures the typical cup shape morphology for both SuEVs and MBVs. Western blot reveals that MBVs have low detection of some SuEV markers such as syntenin-1. miRNA analysis of MBVs shows that 3D microenvironment enhances the expression of miRNAs such as miR-19a and miR-21. In vitro functional analysis shows that MBVs can facilitate human pluripotent stem cell-derived forebrain organoid recovery after starvation and promote high passage fibroblast proliferation. In macrophage polarization, 2D MBVs tend to suppress the pro-inflammatory cytokine IL-12β, while 3D MBVs tend to enhance the anti-inflammatory cytokine IL-10. This study has the significance in advancing the understanding of the bio-interface of nanovesicles with human tissue and the design of cell-free therapy for treating neurological disorders such as ischemic stroke.

Exosomes in Cardiovascular Disease: From Mechanism to Therapeutic Target

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality globally. In recent decades, clinical research has made significant advances, resulting in improved survival and recovery rates for patients with CVD. Despite this progress, there is substantial residual CVD risk and an unmet need for better treatment. The complex and multifaceted pathophysiological mechanisms underlying the development of CVD pose a challenge for researchers seeking effective therapeutic interventions. Consequently, exosomes have emerged as a new focus for CVD research because their role as intercellular communicators gives them the potential to act as noninvasive diagnostic biomarkers and therapeutic nanocarriers. In the heart and vasculature, cell types such as cardiomyocytes, endothelial cells, vascular smooth muscle, cardiac fibroblasts, inflammatory cells, and resident stem cells are involved in cardiac homeostasis via the release of exosomes. Exosomes encapsulate cell-type specific miRNAs, and this miRNA content fluctuates in response to the pathophysiological setting of the heart, indicating that the pathways affected by these differentially expressed miRNAs may be targets for new treatments. This review discusses a number of miRNAs and the evidence that supports their clinical relevance in CVD. The latest technologies in applying exosomal vesicles as cargo delivery vehicles for gene therapy, tissue regeneration, and cell repair are described.

Upscaling human mesenchymal stromal cell production in a novel vertical-wheel bioreactor enhances extracellular vesicle secretion and cargo profile

Human mesenchymal stromal cells (hMSCs) are mechanically sensitive undergoing phenotypic alterations when subjected to shear stress, cell aggregation, and substrate changes encountered in 3D dynamic bioreactor cultures. However, little is known about how bioreactor microenvironment affects the secretion and cargo profiles of hMSC-derived extracellular vesicles (EVs) including the subset, "exosomes", which contain therapeutic proteins, nucleic acids, and lipids from the parent cells. In this study, bone marrow-derived hMSCs were expanded on 3D Synthemax II microcarriers in the PBS mini 0.1L Vertical-Wheel bioreactor system under variable shear stress levels at 25, 40, and 64 RPM (0.1-0.3 dyn/cm²). The bioreactor system promotes EV secretion from hMSCs by 2.5-fold and upregulates the expression of EV biogenesis markers and glycolysis genes compared to the static 2D culture. The microRNA cargo was also altered in the EVs from bioreactor culture including the upregulation of miR-10, 19a, 19b, 21, 132, and 377. EV protein cargo was characterized by proteomics analysis, showing upregulation of metabolic, autophagy and ROS-related proteins comparing with 2D cultured EVs. In addition, the scalability of the Vertical-Wheel bioreactor system was demonstrated in a 0.5L bioreactor, showing similar or better hMSC-EV secretion and cargo content compared to the 0.1L bioreactor. This study advances our understanding of bio-manufacturing of stem cell-derived EVs for applications in cell-free therapy towards treating neurological disorders such as ischemic stroke, Alzheimer's disease, and multiple sclerosis.

HIF1A promotes miR-210/miR-424 transcription to modulate the angiogenesis in HUVECs and HDMECs via sFLT1 under hypoxic stress

Angiogenesis is a critical process during human skin wound healing. However, hypoxia might lead to the dysfunction of the cellular interplay of endothelial cells and subcutaneous fibroblasts, resulting in the deregulation of angiogenesis. HIF1A is a key regulatory of the recovery of intracellular homeostasis under hypoxia. In the present study, the detailed role and mechanism of HIF1A in the angiogenesis under hypoxia were investigated. Via bioinformatic analyses on microarray profiles (GSE1041 and GSE17944), solube fms-related tyrosine kinase 1 (sFLT1, also known as sVEGFR1) and miR-210/miR-424 might be involved in HIF1A function on the angiogenesis under hypoxia in human umbilical vascular endothelium cells (HUVECs) and human dermal microvascular endothelial cells (HDMECs). In the present study, we identified sFLT1 as a downregulated gene in response to hypoxia and HIF1A overexpression in HUVECs and HDMECs. sFLT1 overexpression inhibited the capacity of migration and angiogenesis and significantly reversed the inducible effects of HIF1A on the migration and angiogenesis in both cell lines. miR-210 and miR-424 were upregulated by hypoxia and targeted sFLT1 3'-UTR to negatively modulate its expression. HIF1A modulated sFLT1 expression, VEGF signaling, and the migration and angiogenesis in HUVECs and HDMECs via miR-210/miR-424. Regarding the molecular mechanism, HIF1A bound the promoter region of miR-210 and miR-424 to activate their transcription, while miR-210/miR-424 bound sFLT1 3'-UTR to suppress its expression. In summary, HIF1A/miR-210/miR-424/sFLT1 axis modulates the angiogenesis in HUVECs and HDMECs upon hypoxic condition via VEGF signaling.

MicroRNAs: Important Players in Breast Cancer Angiogenesis and Therapeutic Targets

The high incidence of breast cancer (BC) is linked to metastasis, facilitated by tumor angiogenesis. MicroRNAs (miRNAs or miRs) are small non-coding RNA molecules that have an essential role in gene expression and are significantly linked to the tumor development and angiogenesis process in different types of cancer, including BC. There's increasing evidence showed that various miRNAs play a significant role in disease processes; specifically, they are observed and over-expressed in a wide range of diseases linked to the angiogenesis process. However, more studies are required to reach the best findings and identify the link among miRNA expression, angiogenic pathways, and immune response-related genes to find new therapeutic targets. Here, we summarized the recent updates on miRNA signatures and their cellular targets in the development of breast tumor angiogenetic and discussed the strategies associated with miRNA-based therapeutic targets as anti-angiogenic response.

Latest Advances in Endothelial Progenitor Cell-Derived Extracellular Vesicles Translation to the Clinic

Almost all nucleated cells secrete extracellular vesicles (EVs) that are heterogeneous spheroid patterned or round shape particles ranging from 30 to 200 nm in size. Recent preclinical and clinical studies have shown that endothelial progenitor cell-derived EVs (EPC-EVs) have a beneficial therapeutic effect in various diseases, including cardiovascular diseases and kidney, and lung disorders. Moreover, some animal studies have shown that EPC-EVs selectively accumulate at the injury site with a specific mechanism of binding along with angiogenic and restorative effects that are superior to those of their ancestors. This review article highlights current advances in the biogenesis, delivery route, and long-term storage methods of EPC-EVs and their favorable effects such as anti-inflammatory, angiogenic, and tissue protection in various diseases. Finally, we review the possibility of therapeutic application of EPC-EVs in the clinic.

The role of circulating blood microRNA-374 and microRNA-10 levels in the pathogenesis and therapeutic mechanisms of major depressive disorder

Compelling recent evidence suggests that microRNAs (miRNAs) regulate specific mRNA transcripts at the transcriptomic level and coordinately influence complex regulatory networks, which may play a crucial role in the pathogenesis of major depressive disorder (MDD) and the treatment effects of antidepressants. To evaluate the possible involvement of miRNAs in the pathophysiology and therapeutic response of MDD, we conducted a miRNA expression array analysis of the peripheral blood mononuclear cells (PBMCs) of 5 depressed patients and 5 healthy controls (HCs). Subsequently, we chose 2 miRNAs for validation with real-time PCR (RT-PCR) analysis pre- and post-treatment in another group of 25 MDD patients and 25 HCs. In the array, 5 miRNAs were differentially expressed in medication-naïve MDD patients compared to HCs, of which 2 miRNAs were upregulated and 3 were downregulated. Furthermore, in comparison with HCs, MDD patients showed significantly lower expression levels of miR-374b and miR-10a before treatment. After 8 weeks of antidepressant treatment, both miR-374b and the miR-10a expression levels in MDD patients were significantly elevated only in responders. In conclusion, these results indicate the involvement of miR-374b and miR-10a in the biological mechanisms and therapeutic response of MDD, and provide new insights for exploring miRNAs as potential biomarkers for MDD.

miR-7, miR-10a and miR-143 Expression May Predict Response to Bevacizumab Plus Chemotherapy in Patients with Metastatic Colorectal Cancer

Purpose

Bevacizumab is a monoclonal antibody that binds to vascular endothelial growth factor A. It is currently used in combination with chemotherapy to treat metastatic colorectal cancer. This therapy is not equally effective in every patient; in some, mechanisms of resistance arise that remain poorly understood. The aim of the present work was to determine whether the expression of 26 miRNAs could be associated with the effectiveness of bevacizumab plus chemotherapy, with progression-free survival (PFS), and with overall survival (OS) in metastatic colorectal cancer.

Patients and Methods

Paraffin-embedded biopsies from 76 patients with metastatic colorectal cancer were collected to isolate miRNAs. The expression of 26 miRNAs was analyzed by quantitative RT-PCR. For the purpose of analysis, patients were classified as either “responders” (PFS ≥6 months since beginning treatment) or “non-responders” (PFS <6 months). For the analysis of PFS and OS, patients were classified into two groups using the median gene expression value as the cut-off point (“high” [≥50% percentile] or “low” [<50% percentile]). Time-to-event data were analyzed using the Kaplan–Meier method and compared by the log rank test. Cox regression was used to estimate hazard ratios (HR) and their 95% confidence intervals.

Results

miR-7-5p and miR-10a-5p were more strongly expressed in non-responders than responders (p=0.049 and p=0.043, respectively), and OS was poorer in patients showing these higher expression levels (HR=2.54, 95% CI 1.42–4.55, p=0. 001, and HR=1.81, 95% CI 1.02–3.20, p=0.039, respectively). The overexpression of miR-143-3p, however, was associated with a better prognosis and significantly better PFS (HR=0.57; 95% CI: 0.33–0.96; p=0.033).

Conclusion

High expression values for miR-7-5p and miR-10a-5p might be considered markers of a poorer prognosis in patients with metastatic colorectal cancer treated with bevacizumab plus chemotherapy, while the same for miR-143-3p might be a marker of better outcomes.

Angioregulatory microRNAs in breast cancer: Molecular mechanistic basis and implications for therapeutic strategies

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Cancer-associated angiogenesis is a fundamental process in tumor growth and metastasis.

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Angioregulatory miRNA–target gene interaction is not only involved in sprouting vessels of breast tumors but also, trans-differentiation of breast cancer cells to endothelial cells in a process termed vasculogenic mimicry.

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Successful targeting of tumor angiogenesis is still a missing link in the treatment of Breast cancer (BC) due to the low effectiveness of anti-angiogenic therapies in this cancer.

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Response to anti-angiogenic therapeutics are controlled by a miRNAs, so the identification of interaction networks of miRNAs–targets can be applicable in determining anti-angiogeneic therapy and new biomarkers in BC.

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Angioregulatory miRNAs in breast cancer cells and their microenvironment have therapeutic potential in cancer treatment.

Background

Cancer-associated angiogenesis is a fundamental process in tumor growth and metastasis. A variety of signaling regulators and pathways contribute to establish neovascularization, among them as small endogenous non-coding RNAs, microRNAs (miRNAs) play prominent dual regulatory function in breast cancer (BC) angiogenesis.

Aim of Review

This review aims at describing the current state-of-the-art in BC angiogenesis-mediated by angioregulatory miRNAs, and an overview of miRNAs dysregulation association with the anti-angiogenic response in addition to potential clinical application of miRNAs-based therapeutics.

Key Scientific Concepts of Review

Angioregulatory miRNA–target gene interaction is not only involved in sprouting vessels of breast tumors but also, trans-differentiation of BC cells to endothelial cells (ECs) in a process termed vasculogenic mimicry. Using canonical and non-canonical angiogenesis pathways, the tumor cell employs the oncogenic characteristics such as miRNAs dysregulation to increase survival, proliferation, oxygen and nutrient supply, and treatment resistance. Angioregulatory miRNAs in BC cells and their microenvironment have therapeutic potential in cancer treatment. Although, miRNAs dysregulation can serve as tumor biomarker nevertheless, due to the association of miRNAs dysregulation with anti-angiogenic resistant phenotype, clinical benefits of anti-angiogenic therapy might be challenging in BC. Hence, unveiling the molecular mechanism underlying angioregulatory miRNAs sparked a booming interest in finding new treatment strategies such as miRNA-based therapies in BC.

Targeting the epigenome in in-stent restenosis: from mechanisms to therapy

Coronary artery disease (CAD) is one of the most common causes of death worldwide. The introduction of percutaneous revascularization has revolutionized the therapy of patients with CAD. Despite the advent of drug-eluting stents, restenosis remains the main challenge in treating patients with CAD. In-stent restenosis (ISR) indicates the reduction in lumen diameter after percutaneous coronary intervention, in which the vessel's lumen re-narrowing is attributed to the aberrant proliferation and migration of vascular smooth muscle cells (VSMCs) and dysregulation of endothelial cells (ECs). Increasing evidence has demonstrated that epigenetics is involved in the occurrence and progression of ISR. In this review, we provide the latest and comprehensive analysis of three separate but related epigenetic mechanisms regulating ISR, namely, DNA methylation, histone modification, and non-coding RNAs. Initially, we discuss the mechanism of restenosis. Furthermore, we discuss the biological mechanism underlying the diverse epigenetic modifications modulating gene expression and functions of VSMCs, as well as ECs in ISR. Finally, we discuss potential therapeutic targets of the small molecule inhibitors of cardiovascular epigenetic factors. A more detailed understanding of epigenetic regulation is essential for elucidating this complex biological process, which will assist in developing and improving ISR therapy.

MicroRNAs as diagnostic and prognostic biomarkers of age-related macular degeneration: advances and limitations

A main cause of vision loss in the elderly is age-related macular degeneration (AMD). Among the cellular, biochemical, and molecular changes linked to this disease, inflammation and angiogenesis appear as being crucial in AMD pathogenesis and progression. There are two forms of the disease: dry AMD, accounting for 80-90% of cases, and wet AMD. The disease usually begins as dry AMD associated with retinal pigment epithelium and photoreceptor degeneration, whereas wet AMD is associated with choroidal neovascularization resulting in severe vision impairment. The new vessels are largely malformed, leading to blood and fluid leakage within the disrupted tissue, which provokes inflammation and scar formation and results in retinal damage and detachment. MicroRNAs are dysregulated in AMD and may facilitate the early detection of the disease and monitoring disease progression. Two recent reviews of microRNAs in AMD had indicated weaknesses or limitations in four earlier investigations. Studies in the last three years have shown considerable progress in overcoming some of these concerns and identifying specific microRNAs as biomarkers for AMD. Further large-scale studies are warranted using appropriate statistical methods to take into account gender and age disparity in the study populations and confounding factors such as smoking status.

Why the hype - What are microRNAs and why do they provide unique investigative, diagnostic, and therapeutic opportunities in veterinary medicine?

MicroRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression by inhibiting translation or inducing transcript degradation. MiRNAs act as fine-tuning factors that affect the expression of up to 60% of all mammalian protein coding genes. In contrast to proteins, there is widespread conservation of miRNA sequences across species. This conservation strongly suggests that miRNAs appeared early in evolution and have retained their functional importance. Cross-species conservation provides advantages when compiling candidate markers for health and disease compared to protein-based discoveries. This broad utility is accompanied by the emergence of inexpensive sequencing protocols for the identification of all RNAs in a sample (including miRNAs). With the use of miRNA mimics and antagonists, unique research questions can be answered in biological systems with 'cause and effect' methodology. MiRNAs are readily detectable in blood making them attractive candidates as biomarkers for disease. Here, we review their utility as biomarkers and their potential as therapeutic agents or targets to combat disease.

Long intergenic non-protein coding RNA 324 prevents breast cancer progression by modulating miR-10b-5p

Mounting evidence suggests that long noncoding RNAs serve as specific biomarkers and potent modulators of multiple cancers. Long intergenic non-protein coding RNA 324 (LINC00324) is ubiquitously expressed in various tissues, including breast cancer. The biological function of LINC00324 in the development and progression of breast cancer remains unknown. Here, we fully elucidate the relation between LINC00324 expression and breast cancer, and suggest a potential mechanism of action. We found that decreased expression of LINC00324 was dramatically correlated with malignancy of breast cancer, both in breast cancer tissues and in cell lines. Overexpression of LINC00324 in MDA-MB-231 cells resulted in a decrease in cell proliferation, invasion, and migration, while increasing cells apoptosis. On the other hand, loss-of-function experiments indicated that deficiency of LINC00324 promoted malignant phenotypes in breast cancer cells. Mechanically, we found that LINC00324 is mainly distributed in the cytoplasm, fostering the expression of E-cadherin by sponging miR-10b-5p. Taken together, these findings suggest that LINC00324 plays a critical role in breast cancer progression by directly interacting with miR-10b-5p. LINC00324 can thus potentially act as an early diagnostic marker and a novel therapeutic agent for breast cancer.

Sevoflurane promotes the proliferation of HUVECs by activating VEGF signaling

The vascular endothelium plays an essential role in vascular disease and cardiovascular diseases. The effects and underlying mechanisms of sevoflurane on vascular endothelial growth factor (VEGF) in human endothelial cells have not been elucidated. The MTT colorimetric assay was used to determine HUVEC activity at different concentrations (1 and 3%, respectively) of sevoflurane for different time-points (12, 24 and 48 h, respectively). The regulation of sevoflurane on the mRNA levels of VEGFa, VEGFb, VEGFc and VEGFR1, 2, 3 was analyzed by real-time PCR. When VEGFR2 was inhibited by axitinib, VEGFR2 protein expression was determined by western blotting, and the cell viability was assessed by MTT analysis. The results revealed that sevoflurane increased cell viability in a dose- and time-dependent manner. Sevoflurane significantly upregulated VEGFA mRNA expression only. In addition, sevoflurane increased the expression of VEGFR2 at the mRNA and protein levels, whereas sevoflurane did not modulate the mRNA expression of VEGFR1 and VEGFR3. Furthermore, sevoflurane failed to increase the mRNA and protein expression of VEGFR2 when VEGFR2 was inhibited by axitinib, an inhibitor of VEGF receptors. In conclusion, sevoflurane may be a promising agent against endothelium dysfunction-caused vascular disease by activating the VEGF-A/VEGFR2 signaling pathway.

An Emerging Role for isomiRs and the microRNA Epitranscriptome in Neovascularization

Therapeutic neovascularization can facilitate blood flow recovery in patients with ischemic cardiovascular disease, the leading cause of death worldwide. Neovascularization encompasses both angiogenesis, the sprouting of new capillaries from existing vessels, and arteriogenesis, the maturation of preexisting collateral arterioles into fully functional arteries. Both angiogenesis and arteriogenesis are highly multifactorial processes that require a multifactorial regulator to be stimulated simultaneously. MicroRNAs can regulate both angiogenesis and arteriogenesis due to their ability to modulate expression of many genes simultaneously. Recent studies have revealed that many microRNAs have variants with altered terminal sequences, known as isomiRs. Additionally, endogenous microRNAs have been identified that carry biochemically modified nucleotides, revealing a dynamic microRNA epitranscriptome. Both types of microRNA alterations were shown to be dynamically regulated in response to ischemia and are able to influence neovascularization by affecting the microRNA’s biogenesis, or even its silencing activity. Therefore, these novel regulatory layers influence microRNA functioning and could provide new opportunities to stimulate neovascularization. In this review we will highlight the formation and function of isomiRs and various forms of microRNA modifications, and discuss recent findings that demonstrate that both isomiRs and microRNA modifications directly affect neovascularization and vascular remodeling.

miR-10a-5p and miR-29b-3p as Extracellular Vesicle-Associated Prostate Cancer Detection Markers

Extracellular vesicles (EVs) are shed by many different cell types. Their nucleic acids content offers new opportunities for biomarker research in different solid tumors. The role of EV RNA in prostate cancer (PCa) is still largely unknown. EVs were isolated from different benign and malignant prostate cell lines and blood plasma from patients with PCa (n = 18) and controls with benign prostatic hyperplasia (BPH) (n = 7). Nanoparticle tracking analysis (NTA), Western blot, electron microscopy, and flow cytometry analysis were used for the characterization of EVs. Non-coding RNA expression profiling of PC3 metastatic PCa cells and their EVs was performed by next generation sequencing (NGS). miRNAs differentially expressed in PC3 EVs were validated with qRT-PCR in EVs derived from additional cell lines and patient plasma and from matched tissue samples. 92 miRNAs were enriched and 48 miRNAs were depleted in PC3 EVs compared to PC3 cells, which could be confirmed by qRT-PCR. miR-99b-5p was significantly higher expressed in malignant compared to benign EVs. Furthermore, expression profiling showed miR-10a-5p (p = 0.018) and miR-29b-3p (p = 0.002), but not miR-99b-5p, to be overexpressed in plasma-derived EVs from patients with PCa compared with controls. In the corresponding tissue samples, no significant differences in the miRNA expression could be observed. We thus propose that EV-associated miR-10a-5p and miR-29b-3p could serve as potential new PCa detection markers.

MircroRNA-10b Promotes Human Embryonic Stem Cell-Derived Cardiomyocyte Proliferation via Novel Target Gene LATS1

Adult mammalian cardiomyocytes (CMs) retain a limited proliferative ability, which is insufficient for the repair of CM loss in ischemic cardiac injury. Regulation of the Hippo signaling pathway to promote endogenous CM proliferation has emerged as a promising strategy for heart regeneration. Previous studies have shown that the microRNA cluster miR302-367 negatively regulates the Hippo pathway, promoting CM proliferation. In this study, we identified another microRNA, miR-10b, that regulates the Hippo pathway and promotes cell proliferation in human embryonic stem cell-derived CMs (hESC-CMs). We observed that miR-10b expression was enriched in the early stage of CMs, but its expression was reduced over time. Overexpression of miR-10b promoted CM proliferation, while knockdown of miR-10b suppressed CM proliferation. Moreover, miR-10b protected CMs against apoptosis. miR-10b functions, in part, by directly targeting LATS1, which is a major component of the Hippo pathway. Our study suggests that miR-10b has promising potential for heart regeneration.

ETV2/ER71 regulates the generation of FLK1+ cells from mouse embryonic stem cells through miR-126-MAPK signaling

Previous studies including ours have demonstrated a critical function of the transcription factor ETV2 (ets variant 2; also known as ER71) in determining the fate of cardiovascular lineage development. However, the underlying mechanisms of ETV2 function remain largely unknown. In this study, we demonstrated the novel function of the miR (micro RNA)-126-MAPK (mitogen-activated protein kinase) pathway in ETV2-mediated FLK1 (fetal liver kinase 1; also known as VEGFR2)⁺ cell generation from the mouse embryonic stem cells (mESCs). By performing a series of experiments including miRNA sequencing and ChIP (chromatin immunoprecipitation)-PCR, we found that miR-126 is directly induced by ETV2. Further, we identified that miR-126 can positively regulate the generation of FLK1⁺ cells by activating the MAPK pathway through targeting SPRED1 (sprouty-related EVH1 domain containing 1). Further, we showed evidence that JUN/FOS activate the enhancer region of FLK1 through AP1 (activator protein 1) binding sequences. Our findings provide insight into the novel molecular mechanisms of ETV2 function in regulating cardiovascular lineage development from mESCs.

Endothelial progenitor cell transplantation attenuates lipopolysaccharide-induced acute lung injury via regulating miR-10a/b-5p

Background

Bone marrow-derived endothelial progenitor cells (EPCs) are shown to attenuate lipopolysaccharide- (LPS-) induced acute lung injury (ALI) in animal models. However, the molecular mechanism is largely unknown.

Materials and methods

The animal model of ALI was induced by intratracheal instillation of purified LPS with 2.5 mg/ml/kg. The expression of microRNAs and ADAM15 in lung tissues and LPS-induced mouse pulmonary microvascular endothelial cells (MPMVECs) was determined by quantitative real-time PCR and western blot analysis. The target relationship between miR-10a/b-5p and ADAM15 was confirmed by luciferase reporter assay and RNA interference. The effect of EPCs on MPMVEC proliferation was detected by MTT assay.

Results

EPCs increased the expression of miR-10a/b-5p and reduced ADAM15 protein level in LPS-induced ALI lung tissues and MPMVECs (p < 0.05), and promoted LPS-induced MPMVEC proliferation (p < 0.05). ADAM15 was confirmed to be a downstream target of miR-10a/b-5p. Additionally, EPCs promoted LPS-induced MPMVEC proliferation and exerted the therapeutic effect of ALI via regulating miR-10a/b-5p/ADAM15 axis.

Conclusion

EPC transplantation exerted its therapeutic effect of ALI via increasing miR-10a/b-5p and reducing ADAM15, thus providing a novel insight into the molecular mechanism of EPC transplantation in treating ALI.

Electronic supplementary material

The online version of this article (10.1186/s12944-019-1079-3) contains supplementary material, which is available to authorized users.

Extracellular Nanovesicles Secreted by Human Osteosarcoma Cells Promote Angiogenesis

Angiogenesis involves a number of different players among which extracellular nanovesicles (EVs) have recently been proposed as an efficient cargo of pro-angiogenic mediators. Angiogenesis plays a key role in osteosarcoma (OS) development and progression. Acidity is a hallmark of malignancy in a variety of cancers, including sarcomas, as a result of an increased energetic metabolism. The aim of this study was to investigate the role of EVs derived from osteosarcoma cells on angiogenesis and whether extracellular acidity, generated by tumor metabolism, could influence EVs activity. For this purpose, we purified and characterized EVs from OS cells maintained at either acidic or neutral pH. The ability of EVs to induce angiogenesis was assessed in vitro by endothelial cell tube formation and in vivo using chicken chorioallantoic membrane. Our findings demonstrated that EVs derived from osteosarcoma cells maintained either in acidic or neutral conditions induced angiogenesis. The results showed that miRNA and protein content of EVs cargo are correlated with pro-angiogenic activity and this activity is increased by the acidity of tumor microenvironment. This study provides evidence that EVs released by human osteosarcoma cells act as carriers of active angiogenic stimuli that are able to promote endothelial cell functions relevant to angiogenesis.

The microRNApolymorphisms inmiR-150 and miR-1179 are associated with risk of idiopathic recurrent pregnancy loss

RESEARCH QUESTION

Are single nucleotide polymorphisms of microRNAs (miRNAs) and risk of idiopathic recurrent pregnancy loss (RPL) associated?

DESIGN

A total 375 patients with idiopathic RPL (age, mean ± standard deviation [SD] 33.02 ± 4.24 years; body mass index [BMI], mean ± SD, 21.57 ± 3.70 kg/m²) and 276 control participants (age, mean ± SD, 33.01 ± 5.27 years; BMI, mean ± SD, 21.58 ± 3.20) were recruited. Pregnancy loss was diagnosed using human chorionic gonadotrophin concentrations, ultrasonography and/or physical examination prior to 20 weeks of gestation. The genotype of the participants was determined by polymerase chain reaction restriction fragment length polymorphism analysis. Statistical analysis was performed to investigate the differences in frequencies between the control and RPL genotypes RESULTS: The miR-150G>A heterozygous genotype was significantly associated with increased risk of RPL (adjusted odds ratio 2.502, 95% confidence interval 1.555-4.025; P = 0.0002). The miR-1179A>T heterozygous genotype was significantly associated with decreased risk of RPL (adjusted odds ratio 0.633, 95% confidence interval 0.454-0.884; P = 0.007). Some allele combinations that included miR-150A or miRNA-1179T resulted in an increase or decrease in risk of RPL, respectively.

CONCLUSIONS

The miR-150G>A and miR-1179A>T polymorphisms were more frequently associated with RPL compared with controls.

Micrornas at the Interface between Osteogenesis and Angiogenesis as Targets for Bone Regeneration

Bone formation and regeneration is a multistep complex process crucially determined by the formation of blood vessels in the growth plate region. This is preceded by the expression of growth factors, notably the vascular endothelial growth factor (VEGF), secreted by osteogenic cells, as well as the corresponding response of endothelial cells, although the exact mechanisms remain to be clarified. Thereby, coordinated coupling between osteogenesis and angiogenesis is initiated and sustained. The precise interplay of these two fundamental processes is crucial during times of rapid bone growth or fracture repair in adults. Deviations in this balance might lead to pathologic conditions such as osteoarthritis and ectopic bone formation. Besides VEGF, the recently discovered important regulatory and modifying functions of microRNAs also support this key mechanism. These comprise two principal categories of microRNAs that were identified with specific functions in bone formation (osteomiRs) and/or angiogenesis (angiomiRs). However, as hypoxia is a major driving force behind bone angiogenesis, a third group involved in this process is represented by hypoxia-inducible microRNAs (hypoxamiRs). This review was focused on the identification of microRNAs that were found to have an active role in osteogenesis as well as angiogenesis to date that were termed "CouplingmiRs (CPLGmiRs)". Outlined representatives therefore represent microRNAs that already have been associated with an active role in osteogenic-angiogenic coupling or are presumed to have its potential. Elucidation of the molecular mechanisms governing bone angiogenesis are of great relevance for improving therapeutic options in bone regeneration, tissue-engineering, and the treatment of bone-related diseases.

A ribosomal DNA-hosted microRNA regulates zebrafish embryonic angiogenesis

MicroRNAs (miRNAs) are single-stranded small non-coding RNAs, generally 18-25 nucleotides in length, that act as repressors of gene expression. miRNAs are encoded by independent genes or processed from a variety of different RNA species. So far, there is no evidence showing that the ribosomal DNA-hosted microRNA is implicated in vertebrate development. Currently, we found a highly expressed small RNA hosted in ribosomal DNA was predicted as a novel miRNA, named miR-ntu1, in zebrafish endothelial cells by deep sequencing analysis. The miRNA was validated by custom-designed Taqman PCR, Northern Blot, and in silico analysis. Furthermore, we demonstrated that miR-ntu1 played a crucial role in zebrafish angiogenesis via modulation of Notch signaling. Our findings provide a notable case that a miRNA hosted in ribosomal DNA is involved in vertebrate development.

Early Detection of Preeclampsia Using Circulating Small non-coding RNA

Preeclampsia is one of the most dangerous pregnancy complications, and the leading cause of maternal and perinatal mortality and morbidity. Although the clinical symptoms appear late, its origin is early, and hence detection is feasible already at the first trimester. In the current study, we investigated the abundance of circulating small non-coding RNAs in the plasma of pregnant women in their first trimester, seeking transcripts that best separate the preeclampsia samples from those of healthy pregnant women. To this end, we performed small non-coding RNAs sequencing of 75 preeclampsia and control samples, and identified 25 transcripts that were differentially expressed between preeclampsia and the control groups. Furthermore, we utilized those transcripts and created a pipeline for a supervised classification of preeclampsia. Our pipeline generates a logistic regression model using a 5-fold cross validation on numerous random partitions into training and blind test sets. Using this classification procedure, we achieved an average AUC value of 0.86. These findings suggest the predictive value of circulating small non-coding RNA in the first trimester, warranting further examination, and lay the foundation for producing a novel early non-invasive diagnostic tool for preeclampsia, which could reduce the life-threatening risk for both the mother and fetus.

Transcriptome Profiling of Neovascularized Corneas Reveals miR-204 as a Multi-target Biotherapy Deliverable by rAAVs

Corneal neovascularization (NV) is the major sight-threatening pathology caused by angiogenic stimuli. Current drugs that directly target pro-angiogenic factors to inhibit or reverse the disease require multiple rounds of administration and have limited efficacies. Here, we identify potential anti-angiogenic corneal microRNAs (miRNAs) and demonstrate a framework that employs discovered miRNAs as biotherapies deliverable by recombinant adeno-associated viruses (rAAVs). By querying differentially expressed miRNAs in neovascularized mouse corneas induced by alkali burn, we have revealed 39 miRNAs that are predicted to target more than 5,500 differentially expressed corneal mRNAs. Among these, we selected miR-204 and assessed its efficacy and therapeutic benefit for treating injured corneas. Our results show that delivery of miR-204 by rAAV normalizes multiple novel target genes and biological pathways to attenuate vascularization of injured mouse cornea. Importantly, this gene therapy treatment alternative is efficacious and safe for mitigating corneal NV. Overall, our work demonstrates the discovery of potential therapeutic miRNAs in corneal disorders and their translation into viable treatment alternatives.

MicroRNA-133b Negatively Regulates Zebrafish Single Mauthner-Cell Axon Regeneration through Targeting tppp3 in Vivo

Axon regeneration, fundamental to nerve repair, and functional recovery, relies on rapid changes in gene expression attributable to microRNA (miRNA) regulation. MiR-133b has been proved to play an important role in different organ regeneration in zebrafish, but its role in regulating axon regeneration in vivo is still controversial. Here, combining single-cell electroporation with a vector-based miRNA-expression system, we have modulated the expression of miR-133b in Mauthner-cells (M-cells) at the single-cell level in zebrafish. Through in vivo imaging, we show that overexpression of miR-133b inhibits axon regeneration, whereas down-regulation of miR-133b, promotes axon outgrowth. We further show that miR-133b regulates axon regeneration by directly targeting a novel regeneration-associated gene, tppp3, which belongs to Tubulin polymerization-promoting protein family. Gain or loss-of-function of tppp3 experiments indicated that tppp3 was a novel gene that could promote axon regeneration. In addition, we observed a reduction of mitochondrial motility, which have been identified to have a positive correlation with axon regeneration, in miR-133b overexpressed M-cells. Taken together, our work provides a novel way to study the role of miRNAs in individual cell and establishes a critical cell autonomous role of miR-133b in zebrafish M-cell axon regeneration. We propose that up-regulation of the newly founded regeneration-associated gene tppp3 may enhance axonal regeneration.

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.

Cancer Hallmarks and MicroRNAs: The Therapeutic Connection

Human cancers are characterized by a number of hallmarks, including sustained proliferative signaling, evasion of growth suppressors, activated invasion and metastasis, replicative immortality, angiogenesis, resistance to cell death, and evasion of immune destruction. As microRNAs (miRNAs) are deregulated in virtually all human cancers, they show involvement in each of the cancer hallmarks as well. In this chapter, we describe the involvement of miRNAs in cancer from a cancer hallmarks and targeted therapeutics point of view. As no miRNA-based cancer therapeutics are available to date, and the only clinical trial on miRNA-based cancer therapeutics (MRX34) was terminated prematurely due to serious adverse events, we are focusing on protein-coding miRNA targets for which targeted therapeutics in oncology are already approved by the FDA. For each of the cancer hallmarks, we selected major protein-coding players and describe the miRNAs that target them.

miRNAs in vascular integrity

Endothelial cells (ECs) are confirmed as important regulators of vascular integrity, particularly in relation to angiogenesis, wound repair post-injury, and during embryogenesis. Futher, miRNAs have been implicated in EC function and proliferation. Moreover, knockdown of these miRNAs resulted in altered expressions of several important regulators of endothelial biology and angiogenesis including vascular endothelial growth factor receptor 2, endothelial nitric oxide synthase and tubule formation capacity. Several miRNAs have been identified to play a role in the regulation of function, proliferation and growth of vascular ECs. These miRNAs may be important therapeutic targets in the treatment of a range of ischemic diseases, as well as in the regulation of angiogenesis during cancer and tumour progression. The present review discuss some of the important miRNAs having confirmed regulatory role in EC in connection espically with cardiovascular disease.

Cellular microRNA miR-10a-5p inhibits replication of porcine reproductive and respiratory syndrome virus by targeting the host factor signal recognition particle 14

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most economically important viruses affecting the swine industry worldwide. MicroRNAs have recently been demonstrated to play vital roles in virus-host interactions. Our previous research on small RNA deep sequencing showed that the expression level of miR-10a increased during the viral life cycle. The present study sought to determine the function of miR-10a and its molecular mechanism during PRRSV infection. In the current study, the result of PRRSV infection inducing miR-10a expression was validated by quantitative reverse transcriptase PCR. Overexpression of miR-10a-5p using its mimics markedly reduced the expression level of intracellular PRRSV ORF7 mRNA and N protein. Simultaneously, overexpression of miR-10a-5p also significantly decreased the expression level of extracellular viral RNA and virus titres in the supernatants. These results demonstrated that miR-10a-5p could suppress the replication of PRRSV. A direct interaction between miR-10a-5p and signal recognition particle 14 (SRP14) was confirmed using bioinformatic prediction and experimental verification. miR-10a-5p could directly target the 3'UTR of pig SRP14 mRNA in a sequence-specific manner and decrease SRP14 expression through translational repression but not mRNA degradation. Further, knockdown of SRP14 by small interfering RNA also inhibits the replication of PRRSV. Collectively, these results suggested that miR-10a-5p inhibits PRRSV replication through suppression of SRP14 expression, which not only provides new insights into virus-host interactions during PRRSV infection but also suggests potential new antiviral strategies against PRRSV infection.

MicroRNAs: Impaired vasculogenesis in metal induced teratogenicity

Certain metals have been known for their toxic effects on embryos and fetal development. The vasculature in early pregnancy is extremely dynamic and plays an important role in organogenesis. Nascent blood vessels in early embryonic life are considered to be a primary and delicate target for many teratogens since the nascent blood islands follow a tightly controlled program to form vascular plexus around and inside the embryo for resourcing optimal ingredients for its development. The state of the distribution of toxic metals, their transport mechanisms and the molecular events by which they notch extra-embryonic and embryonic vasculatures are illustrated. In addition, pharmacological aspects of toxic metal induced teratogenicity have also been portrayed. The work reviewed state of the current knowledge of specific role of microRNAs (miRNAs) that are differentially expressed in response to toxic metals, and how they interfere with the vasculogenesis that manifests into embryonic anomalies.

microRNA-10a Targets T-box 5 to Inhibit the Development of Cardiac Hypertrophy

The mechanism of cardiac hypertrophy involving microRNAs (miRNAs) is attracting increasing attention. Our study aimed to investigate the role of miR-10a in cardiac hypertrophy development and the underlying regulatory mechanism.Transverse abdominal aortic constriction (TAAC) surgery was performed to establish a cardiac hypertrophy rat model, and angiotensin II (AngII) was used to induce cardiac hypertrophy in cultured neonatal rat cardiomyocytes. Expression of T-box 5 (TBX5) and miR-10a was altered by cell transfection of siRNA or miRNA mimic/inhibitor. Leucine incorporation assay, histological and cytological examination, quantitative real-time PCR (qRT-PCR), and Western blot were performed to detect the effects of miR-10a and TBX5 on cardiac hypertrophy. Dual-luciferase reporter assay was conducted to verify the regulation of TBX5 by miR-10a.miR-10a was down-regulated, and TBX5 was up-regulated in the rat model and AngII-stimulated cardiomyocytes. miR-10a inhibited TBX5 expression by directly targeting the binding site in Tbx5 3'UTR. Overexpression of miR-10a in AngII-treated cardiomyocytes decreased relative cell area, and significantly reduced the mRNA levels of natriuretic peptide A (Nppa), myosin heavy chain 7 cardiac muscle beta (Myh7), and leucine incorporation (P < 0.01 or P < 0.001). Knockdown of Tbx5 had similar effects on AngII-induced cardiomyocytes.Our findings indicate that miR-10a may inhibit cardiac hypertrophy via targeting Tbx5. Thus, miR-10a provides promising therapeutic strategies for the treatment of cardiac hypertrophy.

miR-19b Regulates Ventricular Action Potential Duration in Zebrafish

Sudden cardiac death due to ventricular arrhythmias often caused by action potential duration (APD) prolongation is a common mode of death in heart failure (HF). microRNAs, noncoding RNAs that fine tune gene expression, are frequently dysregulated during HF, suggesting a potential involvement in the electrical remodeling process accompanying HF progression. Here, we identified miR-19b as an important regulator of heart function. Zebrafish lacking miR-19b developed severe bradycardia and reduced cardiac contractility. miR-19b deficient fish displayed increased sensitivity to AV-block, a characteristic feature of long QT syndrome in zebrafish. Patch clamp experiments from whole hearts showed that miR-19b deficient zebrafish exhibit significantly prolonged ventricular APD caused by impaired repolarization. We found that miR-19b directly and indirectly regulates the expression of crucial modulatory subunits of cardiac ion channels, and thereby modulates AP duration and shape. Interestingly, miR-19b knockdown mediated APD prolongation can rescue a genetically induced short QT phenotype. Thus, miR-19b might represent a crucial modifier of the cardiac electrical activity, and our work establishes miR-19b as a potential candidate for human long QT syndrome.

Embryological Origin of Human Smooth Muscle Cells Influences Their Ability to Support Endothelial Network Formation

Vascular smooth muscle cells (SMCs) from distinct anatomic locations derive from different embryonic origins. Here we investigated the respective potential of different embryonic origin-specific SMCs derived from human embryonic stem cells (hESCs) to support endothelial network formation in vitro. SMCs of three distinct embryological origins were derived from an mStrawberry-expressing hESC line and were cocultured with green fluorescent protein-expressing human umbilical vein endothelial cells (HUVECs) to investigate the effects of distinct SMC subtypes on endothelial network formation. Quantitative analysis demonstrated that lateral mesoderm (LM)-derived SMCs best supported HUVEC network complexity and survival in three-dimensional coculture in Matrigel. The effects of the LM-derived SMCs on HUVECs were at least in part paracrine in nature. A TaqMan array was performed to identify the possible mediators responsible for the differential effects of the SMC lineages, and a microarray was used to determine lineage-specific angiogenesis gene signatures. Midkine (MDK) was identified as one important mediator for the enhanced vasculogenic potency of LM-derived SMCs. The functional effects of MDK on endothelial network formation were then determined by small interfering RNA-mediated knockdown in SMCs, which resulted in impaired network complexity and survival of LM-derived SMC cocultures. The present study is the first to show that SMCs from distinct embryonic origins differ in their ability to support HUVEC network formation. LM-derived SMCs best supported endothelial cell network complexity and survival in vitro, in part through increased expression of MDK. A lineage-specific approach might be beneficial for vascular tissue engineering and therapeutic revascularization.

SIGNIFICANCE

Mural cells are essential for the stabilization and maturation of new endothelial cell networks. However, relatively little is known of the effect of the developmental origins of mural cells on their signaling to endothelial cells and how this affects vessel development. The present study demonstrated that human smooth muscle cells (SMCs) from distinct embryonic origins differ in their ability to support endothelial network formation. Lateral mesoderm-derived SMCs best support endothelial cell network complexity and survival in vitro, in part through increased expression of midkine. A lineage-specific approach might be beneficial for vascular tissue engineering and therapeutic revascularization.

Antiangiogenic Eye Gene Therapy

The idea of treating disease in humans with genetic material was conceived over two decades ago and with that a promising journey involving development and efficacy studies in cells and animals of a large number of novel therapeutic reagents unfolded. In the footsteps of this process, successful gene therapy treatment of genetic conditions in humans has shown clear signs of efficacy. Notably, significant advancements using gene supplementation and silencing strategies have been made in the field of ocular gene therapy, thereby pinpointing ocular gene therapy as one of the compelling "actors" bringing gene therapy to the clinic. Most of all, this success has been facilitated because of (1) the fact that the eye is an effortlessly accessible, exceedingly compartmentalized, and immune-privileged organ offering a unique advantage as a gene therapy target, and (2) significant progress toward efficient, sustained transduction of cells within the retina having been achieved using nonintegrating vectors based on recombinant adeno-associated virus and nonintegrating lentivirus vectors. The results from in vivo experiments and trials suggest that treatment of inherited retinal dystrophies, ocular angiogenesis, and inflammation with gene therapy can be both safe and effective. Here, the progress of ocular gene therapy is examined with special emphasis on the potential use of RNAi- and protein-based antiangiogenic gene therapy to treat exudative age-related macular degeneration.

Embryonic atrazine exposure alters zebrafish and human miRNAs associated with angiogenesis, cancer, and neurodevelopment

MicroRNAs (miRNAs) are short, single-stranded RNA that regulate post-transcriptional control of mRNA translation. Knowledge on the role of these critical regulators in toxicological responses in increasing, but is still limited. Atrazine is a herbicide used throughout the Midwestern US that is reported to frequently contaminate potable water supplies above the maximum contaminant level of 3 parts per billion. Atrazine is a suspected endocrine disrupting chemical and studies have begun to investigate the genetic mechanisms of toxicity; however, studies investigating epigenetic mechanisms are limited. In this study both zebrafish and human miRNAs were significantly altered in response to an embryonic atrazine exposure of 0.3, 3, or 30 ppb in zebrafish. Altered miRNAs are known to play a role in angiogenesis, cancer, or neuronal development, differentiation, and maturation. Targeted analysis of altered human miRNAs with genes previously identified to be altered by atrazine exposure revealed several targets linked to cell cycle and cell signaling. Further analysis of hsa-miRNA-126-3p, which had altered expression in all three atrazine treatments at 72 hpf, revealed alterations also occurred at 60 hpf in the 30 ppb treatment group. Results from this study indicate miRNA deregulation in zebrafish and human miRNAs following an embryonic atrazine exposure in zebrafish.

MicroRNA-195a-3p inhibits angiogenesis by targeting Mmp2 in murine mesenchymal stem cells

MicroRNAs (miRNAs) modulate complex physiological and pathological processes, including the regulation of angiogenesis. Our previous study reported that bone marrow-derived mesenchymal stem cells (MSCs) are recruited into choroidal neovascularization lesions. miRNA-195 is highly expressed in MSCs, but its function remains unknown. In the present study, miR-195a-3p abundance was significantly decreased in hypoxia-treated murine MSCs; on the other hand, its overexpression reduced MSC proliferation and migration while increasing the activation of anti-angiogenic factor pigment epithelium-derived factor (PEDF). We further discovered that matrix metalloproteinase 2 (Mmp2) transcript is a target of miR-195a-3p, and that silencing Mmp2 phenocopied the reduced proliferation and migration of MSCs. The therapeutic potential of miR-195a-3p as an angiogenesis inhibitor was also demonstrated in a laser-induced choroidal neovascularization mouse model. These findings collectively indicate that miR-195a-3p is a negative modulator of angiogenesis, and could be used as an angiogenesis inhibitor. Mol. Reprod. Dev. 83: 413-423, 2016. © 2016 Wiley Periodicals, Inc.

High-Throughput Sequencing Identifies MicroRNAs from Posterior Intestine of Loach (Misgurnus anguillicaudatus) and Their Response to Intestinal Air-Breathing Inhibition

MicroRNAs (miRNAs) exert important roles in animal growth, immunity, and development, and regulate gene expression at the post-transcriptional level. Knowledges about the diversities of miRNAs and their roles in accessory air-breathing organs (ABOs) of fish remain unknown. In this work, we used high-throughput sequencing to identify known and novel miRNAs from the posterior intestine, an important ABO, in loach (Misgurnus anguillicaudatus) under normal and intestinal air-breathing inhibited conditions. A total of 204 known and 84 novel miRNAs were identified, while 47 miRNAs were differentially expressed between the two small RNA libraries (i.e. between the normal and intestinal air-breathing inhibited group). Potential miRNA target genes were predicted by combining our transcriptome data of the posterior intestine of the loach under the same conditions, and then annotated using COG, GO, KEGG, Swissprot and Nr databases. The regulatory networks of miRNAs and their target genes were analyzed. The abundances of nine known miRNAs were validated by qRT-PCR. The relative expression profiles of six known miRNAs and their eight corresponding target genes, and two novel potential miRNAs were also detected. Histological characteristics of the posterior intestines in both normal and air-breathing inhibited group were further analyzed. This study contributes to our understanding on the functions and molecular regulatory mechanisms of miRNAs in accessory air-breathing organs of fish.

MicroRNA-10a/10b represses a novel target gene mib1 to regulate angiogenesis

AIMS

MicroRNA-10 (miR-10) was originally shown to regulate angiogenesis by directly modulating the levels of membrane-bound fms-related tyrosine kinase 1 (mflt1) and its soluble splice isoform sflt1 post-transcriptionally in zebrafish. Given that flt1 knockdown incompletely rescues the angiogenic phenotypes in miR-10 morphants, flt1 is unlikely to be the only important target of miR-10 in endothelial cells (ECs). It will be interesting to investigate new mechanism responsible for angiogenic defect induced by miR-10 knockdown.

METHODS AND RESULTS

Firstly, we demonstrated that miR-10a and miR-10b (miR-10a/10b) were highly enriched in embryonic zebrafish ECs using deep sequencing, Taqman polymerase chain reaction, and in situ hybridisation. Subsequently, we proved that loss of miR-10a/10b impaired blood vessel outgrowth through regulating tip cell behaviours. Mib1 was identified as a potential direct target of miR-10a/10b through in silicon analysis and in vitro luciferase sensor assay. In vivo reporter assay in zebrafish embryos confirmed the binding of miR-10 with 3'-UTR of zebrafish mib1. Furthermore, inhibition of mib1 and Notch signaling rescued the angiogenic defects in miR-10-deficient zebrafish embryos. In addition, we provided evidences that miR-10 regulates human ECs behaviour through targeting Mib1 as well.

CONCLUSION

Taken together, these results indicate that miR-10 regulates the angiogenic behaviour in a Notch-dependent manner by directly targeting mib1.

The short and long of noncoding sequences in the control of vascular cell phenotypes

The two principal cell types of importance for normal vessel wall physiology are smooth muscle cells and endothelial cells. Much progress has been made over the past 20 years in the discovery and function of transcription factors that coordinate proper differentiation of these cells and the maintenance of vascular homeostasis. More recently, the converging fields of bioinformatics, genomics, and next generation sequencing have accelerated discoveries in a number of classes of noncoding sequences, including transcription factor binding sites (TFBS), microRNA genes, and long noncoding RNA genes, each of which mediates vascular cell differentiation through a variety of mechanisms. Alterations in the nucleotide sequence of key TFBS or deviations in transcription of noncoding RNA genes likely have adverse effects on normal vascular cell phenotype and function. Here, the subject of noncoding sequences that influence smooth muscle cell or endothelial cell phenotype will be summarized as will future directions to further advance our understanding of the increasingly complex molecular circuitry governing normal vascular cell differentiation and how such information might be harnessed to combat vascular diseases.

Multigenic lentiviral vectors for combined and tissue-specific expression of miRNA- and protein-based antiangiogenic factors

Lentivirus-based gene delivery vectors carrying multiple gene cassettes are powerful tools in gene transfer studies and gene therapy, allowing coexpression of multiple therapeutic factors and, if desired, fluorescent reporters. Current strategies to express transgenes and microRNA (miRNA) clusters from a single vector have certain limitations that affect transgene expression levels and/or vector titers. In this study, we describe a novel vector design that facilitates combined expression of therapeutic RNA- and protein-based antiangiogenic factors as well as a fluorescent reporter from back-to-back RNApolII-driven expression cassettes. This configuration allows effective production of intron-embedded miRNAs that are released upon transduction of target cells. Exploiting such multigenic lentiviral vectors, we demonstrate robust miRNA-directed downregulation of vascular endothelial growth factor (VEGF) expression, leading to reduced angiogenesis, and parallel impairment of angiogenic pathways by codelivering the gene encoding pigment epithelium-derived factor (PEDF). Notably, subretinal injections of lentiviral vectors reveal efficient retinal pigment epithelium-specific gene expression driven by the VMD2 promoter, verifying that multigenic lentiviral vectors can be produced with high titers sufficient for in vivo applications. Altogether, our results suggest the potential applicability of combined miRNA- and protein-encoding lentiviral vectors in antiangiogenic gene therapy, including new combination therapies for amelioration of age-related macular degeneration.

Hypoxia-responsive microRNA-101 promotes angiogenesis via heme oxygenase-1/vascular endothelial growth factor axis by targeting cullin 3

AIMS

Hypoxia induces expression of various genes and microRNAs (miRs) that regulate angiogenesis and vascular function. In this study, we investigated a new functional role of new hypoxia-responsive miR-101 in angiogenesis and its underlying mechanism for regulating heme oxygenase-1 (HO-1) and vascular endothelial growth factor (VEGF) expression.

RESULTS

We found that hypoxia induced miR-101, which binds to the 3'untranslated region of cullin 3 (Cul3) and stabilizes nuclear factor erythroid-derived 2-related factor 2 (Nrf2) via inhibition of the proteasomal degradation pathway. miR-101 overexpression promoted Nrf2 nuclear accumulation, which was accompanied with increases in HO-1 induction, VEGF expression, and endothelial nitric oxide synthase (eNOS)-derived nitric oxide (NO) production. The elevated NO-induced S-nitrosylation of Kelch-like ECH-associated protein 1 and subsequent induction of Nrf2-dependent HO-1 lead to further elevation of VEGF production via a positive feedback loop between the Nrf2/HO-1 and VEGF/eNOS axes. Moreover, miR-101 promoted angiogenic signals and angiogenesis both in vitro and in vivo, and these events were attenuated by inhibiting the biological activity of HO-1, VEGF, or eNOS. Moreover, these effects were also observed in aortic rings from HO-1(+/-) and eNOS(-/-) mice. Local overexpression of miR-101 improved therapeutic angiogenesis and perfusion recovery in the ischemic mouse hindlimb, whereas antagomiR-101 diminished regional blood flow.

INNOVATION

Hypoxia-responsive miR-101 stimulates angiogenesis by activating the HO-1/VEGF/eNOS axis via Cul3 targeting. Thus, miR-101 is a novel angiomir.

CONCLUSION

Our results provide new mechanistic insights into a functional role of miR-101 as a potential therapeutic target in angiogenesis and vascular remodeling.

MicroRNA-377 regulates mesenchymal stem cell-induced angiogenesis in ischemic hearts by targeting VEGF

MicroRNAs have been appreciated in various cellular functions, including the regulation of angiogenesis. Mesenchymal-stem-cells (MSCs) transplanted to the MI heart improve cardiac function through paracrine-mediated angiogenesis. However, whether microRNAs regulate MSC induced angiogenesis remains to be clarified. Using microRNA microarray analysis, we identified a microRNA expression profile in hypoxia-treated MSCs and observed that among all dysregulated microRNAs, microRNA-377 was decreased the most significantly. We also validated that vascular endothelial growth factor (VEGF) is a target of microRNA-377 using dual-luciferase reporter assay and Western-blotting. Knockdown of endogenous microRNA-377 promoted tube formation in human umbilical vein endothelial cells. We then engineered rat MSCs with lentiviral vectors to either overexpress microRNA-377 (MSC miR-377) or knockdown microRNA-377 (MSC Anti-377) to investigate whether microRNA-377 regulated MSC-induced myocardial angiogenesis, using MSCs infected with lentiviral empty vector to serve as controls (MSC Null). Four weeks after implantation of the microRNA-engineered MSCs into the infarcted rat hearts, the vessel density was significantly increased in MSC Anti-377-hearts, and this was accompanied by reduced fibrosis and improved myocardial function as compared to controls. Adverse effects were observed in MSC miR-377-treated hearts, including reduced vessel density, impaired myocardial function, and increased fibrosis in comparison with MSC Null-group. These findings indicate that hypoxia-responsive microRNA-377 directly targets VEGF in MSCs, and knockdown of endogenous microRNA-377 promotes MSC-induced angiogenesis in the infarcted myocardium. Thus, microRNA-377 may serve as a novel therapeutic target for stem cell-based treatment of ischemic heart disease.

The myriad essential roles of microRNAs in cardiovascular homeostasis and disease

According to the World Health Organization, cardiovascular disease accounts for approximately 30% of all deaths in the United States, and is the worldwide leading cause of morbidity and mortality. Over the last several years, microRNAs have emerged as critical regulators of physiological homeostasis in multiple organ systems, including the cardiovascular system. The focus of this review is to provide an overview of the current state of knowledge of the molecular mechanisms contributing to the multiple causes of cardiovascular disease with respect to regulation by microRNAs. A major challenge in understanding the roles of microRNAs in the pathophysiology of cardiovascular disease is that cardiovascular disease may arise from perturbations in intracellular signaling in multiple cell types including vascular smooth muscle and endothelial cells, cardiac myocytes and fibroblasts, as well as hepatocytes, pancreatic β-cells, and others. Additionally, perturbations in intracellular signaling cascades may also have profound effects on heterocellular communication via secreted cytokines and growth factors. There has been much progress in recent years to identify the microRNAs that are both dysregulated under pathological conditions, as well as the signaling pathway(s) regulated by an individual microRNA. The goal of this review is to summarize what is currently known about the mechanisms whereby microRNAs maintain cardiovascular homeostasis and to attempt to identify some key unresolved questions that require further study.