Knockdown of MALAT1 expression inhibits HUVEC proliferation by upregulation of miR-320a and downregulation of FOXM1 expression

MicroRNA-320a enhances LRWD1 expression through the AGO2/FXR1-dependent pathway to affect cell behaviors and the oxidative stress response in human testicular embryonic carcinoma cells

BACKGROUND

Testicular cancer is fairly rare but can affect fertility in adult males. Leucine-rich repeats- and WD repeat domain-containing protein 1 (LRWD1) is a sperm-specific marker that mainly affects sperm motility in reproduction. Our previous study demonstrated the impact of LRWD1 on testicular cancer development; however, the underlying mechanisms remain unclear.

METHODS

In this study, various plasmids associated with LRWD1 and miR-320a manipulation were used to explore the roles and regulatory effects of these molecules in NT2D1 cellular processes. A Dual-Glo luciferin-luciferase system was used to investigate LRWD1 transcriptional activity, and qRT-PCR and western blotting were used to determine gene and protein expression.

RESULTS

The results suggested that miR-320a positively regulated LRWD1 and positively correlated with NT2D1 cell proliferation but negatively correlated with cell migration and invasion ability. In addition, the miRNA-ribonucleoprotein complex AGO2/FXR1 was shown to be essential in the mechanism by which miR-320a regulates LRWD1 mRNA expression. As miR-320a was required to regulate LRWD1 expression through the AGO2 and FXR1 complex, eEF2 and eLF4E were also found to be involved in miR-320a increasing LRWD1 expression. Furthermore, miR-320a and LRWD1 were responsive to oxidative stress, and NRF2 was affected by the presence of miR-320a in response to ROS stimulation.

CONCLUSIONS

This is the first study showing the role of miR-320a in upregulating the testicular cancer-specific regulator LRWD1 and the importance of the AGO2/FXR1 complex in miR-320a-mediated upregulation of LRWD1 during testicular cancer progression.

Exosomal miRNAs in the microenvironment of pancreatic cancer

Pancreatic cancer (PC) is highly aggressive having an extremely poor prognosis. The tumor microenvironment (TME) of PC is complex and heterogeneous. Various cellular components in the microenvironment are capable of secreting different active substances that are involved in promoting tumor development. Their release may occur via exosomes, the most abundant extracellular vesicles (EVs), that can carry numerous factors as well as act as a mean of intercellular communication. Emerging evidence suggests that miRNAs are involved in the regulation and control of many pathological and physiological processes. They can also be transported by exosomes from donor cells to recipient cells, thereby regulating the TME. Exosomal miRNAs show promise for use as future targets for PC diagnosis and prognosis, which may reveal new treatment strategies for PC. In this paper, we review the important role of exosomal miRNAs in mediating cellular communication in the TME of PC as well as their potential use in clinical applications.

Intermedin induces autophagy and attenuates hypoxia-induced injury in cardiomyocytes by regulation of MALAT1/ULK1

Myocardial infarction is a predominant cause of cardiovascular diseases with high incidence and death rate worldwide. Although growing evidence has suggested that IMD has significant protective influences on the cardiovascular system, the molecular regulatory mechanism of IMD in hypoxia-induced injury caused by myocardial infarction is urgent to be elucidated. In the present study, we found hypoxia led to a noteworthy enhancement in IMD expression and IMD alleviated hypoxia-induced myocardial injury of NRCMs. Furthermore, IMD was proved to inhibit hypoxia-induced injury by regulating MALAT1. Our findings suggested MALAT1 positively regulated the mRNA and protein expression level of ULK1 and hypoxia induced autophagy of NRCMs. MALAT1 stimulated autophagy to block hypoxia-induced cell injury in NRCMs via upregulation of ULK1 expression. Autophagy suppression abolished the protective capability of IMD overexpression against hypoxia-induced myocardial injury in NRCMs. In a word, our study shed light on the central mechanism of IMD in preventing hypoxia-induced injury caused by myocardial infarction. We confirmed IMD induced autophagy and attenuated hypoxia-induced injury in cardiomyocytes via MALAT1/ULK1, which may contribute to designing effective therapeutic approaches of myocardial infarction.

CD47 interactions with exportin-1 limit the targeting of m7G-modified RNAs to extracellular vesicles

CD47 is a marker of self and a signaling receptor for thrombospondin-1 that is also a component of extracellular vesicles (EVs) released by various cell types. Previous studies identified CD47-dependent functional effects of T cell EVs on target cells, mediated by delivery of their RNA contents, and enrichment of specific subsets of coding and noncoding RNAs in CD47+ EVs. Mass spectrometry was employed here to identify potential mechanisms by which CD47 regulates the trafficking of specific RNAs to EVs. Specific interactions of CD47 and its cytoplasmic adapter ubiquilin-1 with components of the exportin-1/Ran nuclear export complex were identified and confirmed by coimmunoprecipitation. Exportin-1 is known to regulate nuclear to cytoplasmic trafficking of 5'-7-methylguanosine (m7G)-modified microRNAs and mRNAs that interact with its cargo protein EIF4E. Interaction with CD47 was inhibited following alkylation of exportin-1 at Cys528 by its covalent inhibitor leptomycin B. Leptomycin B increased levels of m7G-modified RNAs, and their association with exportin-1 in EVs released from wild type but not CD47-deficient cells. In addition to perturbing nuclear to cytoplasmic transport, transcriptomic analyses of EVs released by wild type and CD47-deficient Jurkat T cells revealed a global CD47-dependent enrichment of m7G-modified microRNAs and mRNAs in EVs released by CD47-deficient cells. Correspondingly, decreasing CD47 expression in wild type cells or treatment with thrombospondin-1 enhanced levels of specific m7G-modified RNAs released in EVs, and re-expressing CD47 in CD47-deficient T cells decreased their levels. Therefore, CD47 signaling limits the trafficking of m7G-modified RNAs to EVs through physical interactions with the exportin-1/Ran transport complex.

MALAT1/miR-320a in bone marrow mesenchymal stem cells function may shed light on mechanisms underlying osteoporosis

INTRODUCTION

Growing evidence supports the involvement of long noncoding RNAs (lncRNAs) in bone metabolism and diseases. This study aims to investigate the involvement of the lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in the pathological process of osteoporosis and the effects of MALAT1 on regulation of BMSC differentiation through competitive endogenous RNA (ceRNA) mechanisms.

MATERIAL AND METHODS

The expression of MALAT1 and miR-320a was determined using RT-PCR in bone tissue derived from female SD (Sprague Dawley) rats with osteoporosis. Immunohistochemical (IHC) staining was used to evaluate the expression of neuropilin-1 (NRP-1) and β-catenin. Bone marrow mesenchymal stem cells (BMSCs) were divided into 4 groups: control, NC (negative control), MALAT1 siRNA, and miR-320a mimics. Forty-eight hours later, the effect of MALAT1 on the miR-320a expression, proliferation and osteogenic differentiation of BMSCs was investigated. Two weeks later, the cell activity, alkaline phosphatase (ALP) activity, and mRNA expression of Osterix and Runx2 were evaluated. Three weeks later, alizarin red staining of calcified nodules and Western blot analysis of the expression of β-catenin, NRP-1, osteocalcin (OCN), and osteopontin (OPN) were performed.

RESULTS

Downregulated MALAT1or upregulated miR-320a expression inhibited the activity and osteogenic differentiation of BMSCs, resulting in low ALP activity and NRP-1 expression, fewer calcified nodules, decreased mRNA levels of Osterix and Runx2, and inhibited expression of NRP-1, OCN, and OPN. MALAT1 silencing did not decrease the protein level of β-catenin in the cytoplasm but suppressed that in the nucleus.

CONCLUSIONS

Downregulated MALAT1 and upregulated miR-320a expression play an important role in the pathological process of osteoporosis, via inhibition of the osteogenic differentiation of BMSCs.

Roles of MicroRNAs in Peripheral Artery In-Stent Restenosis after Endovascular Treatment

Endovascular repair including percutaneous transluminal angioplasty (PTA) and stent implantation has become the standard approach for the treatment of peripheral arterial disease; however, restenosis is still the main limited complication for the long-term success of the endovascular repair. Endothelial denudation and regeneration, inflammatory response, and neointimal hyperplasia are major pathological processes occurring during in-stent restenosis (ISR). MicroRNAs exhibit great potential in regulating several vascular biological events in different cell types and have been identified as novel therapeutic targets as well as biomarkers for ISR prevention. This review summarized recent experimental and clinical studies on the role of miRNAs in ISR modification, with the aim of unraveling the underlying mechanism and potential therapeutic strategy of ISR.

lncRNA MALAT1/miR‑26a/26b/ST8SIA4 axis mediates cell invasion and migration in breast cancer cell lines

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a long non-coding RNA that is overexpressed in various human cancers, including breast cancer. Evidence has associated the function of the α-2,8-sialyltransferase (ST8SIA) family with breast cancer. The present study aimed to investigate the potential roles of MALAT1 in breast cancer development and progression using analyses of both breast cancer tissues and cell lines. The mRNA levels of MALAT1, microRNA (miR)-26a/26b and ST8SIA4 were detected by reverse transcription-quantitative PCR (RT-qPCR) and the protein level of ST8SIA4 was assessed by western blot analysis. Cell proliferation, invasion and migration were detected by CCK-8, wound healing and Transwell assays, respectively. Interactions between MALAT1 and miR-26a/26b were assessed using fluorescence in situ hybridization, RNA immunoprecipitation and luciferase reporter assays. Herein, different levels of MALAT1 were primarily observed in human breast cancer samples and cells. Upregulated MALAT1 was a crucial predictor of poor breast cancer prognosis. Altered MALAT1 modulated cell progression in breast cancer. Moreover, miR-26a/26b was confirmed as a direct regulator of MALAT1, and ST8SIA4 was predicted as a target of miR-26a/26b. Functional analysis in human breast cancer cell lines demonstrated that MALAT1 modulated breast cancer cell tumorigenicity by acting as a competing endogenous lncRNA (ceRNA) to regulate ST8SIA4 levels by sponging miR-26a/26b. The identification of the MALAT1/miR-26a/26b/ST8SIA4 axis which contributes to breast cancer progression may constitute a potential new therapeutic target.

Exercise Improves Endothelial Function via the lncRNA MALAT1/miR-320a Axis in Obese Children and Adolescents

Background

Endothelial dysfunction commonly occurs in obese children and adolescents, leading to an increased risk of cardiovascular diseases. Exercise has significant protective effects against endothelial dysfunction through regulating some noncoding RNAs. This study aimed to investigate the relationship of long noncoding RNA MALAT1 and microRNA-320a (miR-320a) with the exercise-induced improvement of endothelial dysfunction in obese children and adolescents.

Methods

Sixty obese children and adolescents were included in this study, including 40 cases that received 12-week exercise training and 20 cases that received only diet control. The anthropometric and blood indices before and after exercise were recorded and compared, and the endothelial dysfunction was evaluated by examining the levels of markers, including VCAM-1, ICAM-1, and E-selectin, using an ELISA assay. The expression levels of noncoding RNAs were assessed using real-time quantitative PCR, and their correlation with patients' recorded indices and endothelial dysfunction markers was analyzed.

Results

The 12-week exercise training significantly decreased the levels of VCAM-1, ICAM-1, and E-selectin and could inhibit MALAT1 but promote miR-320a expression in obese children and adolescents. The expression of MALAT1 and miR-320a was correlated with the changes in the anthropometric and blood indices of obese children and adolescents, and their correlations with endothelial dysfunction markers were obtained.

Conclusion

All the data revealed that exercise has significantly protective effects against endothelial dysfunction and can regulate the expression of the MALAT1/miR-320a axis. MALAT1 and miR-320a were correlated with endothelial dysfunction markers, indicating that the MALAT1/miR-320a axis may be related with the alleviating effects of exercise on endothelial function in obese children and adolescents.

LncRNA MALAT1/miR-320a axis is associated with exercise-induced improvement of endothelial dysfunction in obese children

BACKGROUND

Endothelial dysfunction commonly occurs in obese children, leading to increased risk of cardiovascular diseases. Exercise has protective effects against endothelial dysfunction through regulating some noncoding RNAs. This study aimed to investigate the relationship of long noncoding RNA MALAT1 and microRNA-320a (miR-320a) with the exercise-induced improvement of endothelial dysfunction in obese children.

METHODS

Sixty obese children were included in this study, and 40 cases received a 12-week exercise training. The morphological and blood indices before and after exercise were recorded and compared, and the endothelial dysfunction was evaluated by examining the levels of VCAM-1, ICAM-1, E-selectin, IL-6 and TNF-α using ELISA kits. The expression of noncoding RNAs was assessed using Real-Time quantitative PCR. Endothelial cells were used to explore the effects of MALAT1 and miR-320a on endothelial function.

RESULTS

The 12-well exercise training decreased the levels of VCAM-1, ICAM-1 and E-selectin, and inhibited MALAT1 but promoted miR-320a expression in obese children. The expression of MALAT1 and miR-320a was correlated with the changes of morphological and blood indices in obese children, and their correlations with endothelial dysfunction markers were obtained. Additionally, MALAT1 overexpression or miR-320a reduction led to inhibited proliferation and increased inflammation in HUVECs.

CONCLUSION

All the data revealed that exercise has significantly protective effects against endothelial dysfunction, and can regulate the expression of the MALAT1/miR-320a axis. MALAT1 and miR-320a were correlated with endothelial dysfunction, indicating that the MALAT1/miR-320a axis may be related with the alleviating effects of exercise on endothelial function in obese children.

FOXM1 and Cancer: Faulty Cellular Signaling Derails Homeostasis

Forkhead box transcription factor, FOXM1 is implicated in several cellular processes such as proliferation, cell cycle progression, cell differentiation, DNA damage repair, tissue homeostasis, angiogenesis, apoptosis, and redox signaling. In addition to being a boon for the normal functioning of a cell, FOXM1 turns out to be a bane by manifesting in several disease scenarios including cancer. It has been given an oncogenic status based on several evidences indicating its role in tumor development and progression. FOXM1 is highly expressed in several cancers and has also been implicated in poor prognosis. A comprehensive understanding of various aspects of this molecule has revealed its role in angiogenesis, invasion, migration, self- renewal and drug resistance. In this review, we attempt to understand various mechanisms underlying FOXM1 gene and protein regulation in cancer including the different signaling pathways, post-transcriptional and post-translational modifications. Identifying crucial molecules associated with these processes can aid in the development of potential pharmacological approaches to curb FOXM1 mediated tumorigenesis.

Increase in MEG3, MALAT1, NEAT1 significantly predicts the clinical parameters in patients with rheumatoid arthritis

Aim: This study investigated deregulation of lncRNAs MEG3, MALAT1, NEAT1 and their associations with clinical parameters in rheumatoid arthritis (RA). Materials & methods: LncRNAs MALAT1, MEG3, NEAT1 were quantified from peripheral blood mono-nuclear cells (PBMCs) and plasma of 82 RA patients with 15 matched controls and from knee fluid of 24 RA patients with ten osteoarthritis controls. Multivariate analyses were performed among lncRNAs and clinical parameters of RA. Results: MALAT1, MEG3, NEAT1 were increased in PBMCs, plasma, synovial fluid (p < 0.05) of RA patients. Significant correlations were observed for MEG3 with TJC (r = 0.29), NEAT1 with TJC (r = 0.49), swollen joint count (r = 0.20), DAS28-CRP (r = 0.29). Multivariate analysis revealed that 48.5% of TJC and 31.5% of swollen joint count could be predicted by lncRNAs. Conclusion: The findings suggested that the lncRNAs might be explored as probable markers in monitoring disease activity.

lncRNA NEAT1 regulates the proliferation and migration of hepatocellular carcinoma cells by acting as a miR‑320a molecular sponge and targeting L antigen family member 3

Long non‑coding RNAs (lncRNAs) serve a pivotal role in hepatocellular carcinoma (HCC) progression and have been confirmed to participate in the carcinogenesis and development of HCC. Certain studies have focused on lncRNA nuclear enriched abundant transcript 1 (NEAT1) in HCC. However, the relationship between lncRNA NEAT1 and HCC remains unclear. The present study found that NEAT1 was significantly overexpressed in HCC cell lines compared with LX‑2 hepatic stellate cells. NEAT1 expression in Huh7 and MHCC‑97H cells was increased following transfection with lentivirus (LV)‑NEAT1 but inhibited by LV‑short hairpin NEAT1. Knockdown of NEAT1 significantly repressed HCC cell viability, increased cell apoptosis, and inhibited cell migration and invasion capacity. By contrast, upregulation of NEAT1 demonstrated the reverse effects. Furthermore, microRNA‑320a (miR‑230a) was predicted to be a direct target of NEAT1 and was significantly reduced in HCC cells. Additionally, a luciferase activity reporter assay and RNA immunoprecipitation assay were performed to confirm the interaction between miR‑320a and NEAT1. Using a dual‑luciferase activity assay, L antigen family member 3 (LAGE3) was found to be a target of miR‑320a. Finally, in vivo nude mouse models were established, and the results indicated that NEAT1 suppressed HCC progression by targeting miR‑320a. In conclusion, the present findings revealed that the NEAT1/miR‑320a/LAGE3 axis participates in HCC development and that NEAT1 could be used as a biomarker for HCC.

Commutative regulation between endothelial NO synthase and insulin receptor substrate 2 by microRNAs

Endothelial NO synthase (eNOS) expression is regulated by a number of transcriptional and post-transcriptional mechanisms, but the effects of competing endogenous RNAs (ceRNAs) on eNOS mRNA and the underlying mechanisms are still unknown. Our bioinformatic analysis revealed three highly expressed eNOS-targeting miRNAs (miR-15b, miR-16, and miR-30b) in human endothelial cells (ECs). Among the 1103 mRNA targets of these three miRNAs, 15 mRNAs share a common disease association with eNOS. Gene expression and correlation analysis in patients with cardiovascular diseases identified insulin receptor substrate 2 (IRS2) as the most correlated eNOS-ceRNA. The expression levels of eNOS and IRS2 were coincidentally increased by application of laminar shear but reduced with eNOS or IRS2 siRNA transfection in human ECs, which was impeded by Dicer siRNA treatment. Moreover, luciferase reporter assay showed that these three miRNAs directly target the 3'UTR of eNOS and IRS2. Overexpression of these three miRNAs decreased, whereas inhibition of them increased, both mRNA and protein levels of eNOS and IRS2. Functionally, silencing eNOS suppressed the Akt signal pathway, while IRS2 knockdown reduced NO production in ECs. Thus, we identified eNOS and IRS2 as ceRNAs and revealed a novel mechanism explaining the coincidence of metabolic and cardiovascular diseases.

Emerging Roles of Long non-coding RNAs in The Tumor Microenvironment

Long non-coding RNAs (lncRNAs) are a diverse class of longer than 200 nucleotides RNA transcripts that have limited protein coding capacity. LncRNAs display diverse cellular functions and widely participate in both physiological and pathophysiological processes. Aberrant expressions of lncRNAs are correlated with tumor progression, providing sound rationale for their targeting as attractive anti-tumor therapeutic strategies. Emerging evidences support that lncRNAs participate in tumor-stroma crosstalk and stimulate a distinctive and suitable tumor microenvironment (TME). The TME comprises several stromal cells such as cancer stem cells (CSCs), cancer-associated endothelial cells (CAEs), cancer-associated fibroblasts (CAFs) and infiltrated immune cells, all of which are involved in the complicated crosstalk with tumor cells to affect tumor progression. In this review, we summarize the essential properties and functional roles of known lncRNAs in related to the TME to validate lncRNAs as potential biomarkers and promising anti-cancer targets.

Long Non-Coding RNA Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1) Promotes Hypertension by Modulating the Hsa-miR-124-3p/Nuclear Receptor Subfamily 3, Group C, Member 2 (NR3C2) and Hsa-miR-135a-5p/NR3C2 Axis

Background

This study was designed to investigate the role of long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in the proliferation as well as apoptosis of human umbilical vein endothelial cells (HUVECs), to offer a basis for therapy of hypertension.

Material/Methods

The lncRNA MALAT1 expression, hsa-miR-124-3p, hsa-miR-135a-5p, hsa-miR-135b-5p, and hsa-miR-455-5p in plasma were measured from 230 patients with hypertension and 230 non-hypertensive controls. The mechanism for lncRNA MALAT1 modulating the proliferation and apoptosis of HUVECs was explored by cell transfection, Cell Counting Kit-8 (CCK-8), quantitative real-time polymerase chain reaction (qRT-PCR), western blot, and dual-luciferase reporter assays.

Results

The expression of hsa-miR-124-3p and hsa-miR-135a-5p was reduced and the expression of lncRNA MALAT1 was increased in the plasma of hypertensive patients. Moreover, the plasma levels of hsa-miR-124-3p and hsa-miR-135a-5p of hypertensive patients were negatively correlated with lncRNA MALAT1 (r=−0.64, −0.72; P<0.01, P<0.01, respectively). The level of nuclear receptor subfamily 3, group C, member 2 (NR3C2) protein was negatively correlated with hsa-miR-124-3p and hsa-miR-135a-5p (r=−0.74, −0.84; P<0.01, P<0.01, respectively). The proliferation of HUVECs was inhibited after the inhibition of MALAT. Additionally, after knocking down MALAT, the levels of hsa-miR-124-3p and hsa-miR-135a-5p in HUVECs were markedly increased, while the expression level of NR3C2 protein was decreased. The apoptotic rate of HUVECs after the transfection of MALAT1 small interfering RNA (si-MALAT1) (3.64±0.21%) was significantly reduced compared to that of transfected si-MALAT1 no template control (NC) (3.76±0.19%) and the control group (10.51±1.24%).

Conclusions

LncRNA MALAT1 regulates proliferation and apoptosis of HUVECs through the hsa-miR-124-3p/NR3C2 and/or hsa-miR-135a-5p/NR3C2 axis.

Unveiling ncRNA regulatory axes in atherosclerosis progression

Completion of the human genome sequencing project highlighted the richness of the cellular RNA world, and opened the door to the discovery of a plethora of short and long non-coding RNAs (the dark transcriptome) with regulatory or structural potential, which shifted the balance of pathological gene alterations from coding to non-coding RNAs. Thus, disease risk assessment currently has to also evaluate the expression of new RNAs such as small micro RNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), competing endogenous RNAs (ceRNAs), retrogressed elements, 3'UTRs of mRNAs, etc. We are interested in the pathogenic mechanisms of atherosclerosis (ATH) progression in patients suffering Chronic Kidney Disease, and in this review, we will focus in the role of the dark transcriptome (non-coding RNAs) in ATH progression. We will focus in miRNAs and in the formation of regulatory axes or networks with their mRNA targets and with the lncRNAs that function as miRNA sponges or competitive inhibitors of miRNA activity. In this sense, we will pay special attention to retrogressed genomic elements, such as processed pseudogenes and Alu repeated elements, that have been recently seen to also function as miRNA sponges, as well as to the use or miRNA derivatives in gene silencing, anti-ATH therapies. Along the review, we will discuss technical developments associated to research in lncRNAs, from sequencing technologies to databases, repositories and algorithms to predict miRNA targets, as well as new approaches to miRNA function, such as integrative or enrichment analysis and their potential to unveil RNA regulatory networks.

Suppression of Hepatocellular Carcinoma Progression through FOXM1 and EMT Inhibition via Hydroxygenkwanin-Induced miR-320a Expression

Daphne genkwa, a Chinese medicinal herb, is used frequently in Southeast Asian countries to treat diseases; the flavonoid hydroxygenkwanin (HGK) is extracted from its flower buds. The bioactivity of HGK, particularly as an anti-liver cancer agent, has not been explored. In this study, human hepatocellular carcinoma (HCC) cell lines and an animal xenograft model were employed to investigate both the activity of HGK against liver cancer and its cellular signaling mechanisms. HCC cells treated with HGK were subjected to cell function assays. Whole transcriptome sequencing was used to identify genes whose expression was influenced by HGK, and the flavonoid’s cancer suppression mechanisms were further investigated through gain- and loss-of-function assays. Finally, in vitro findings were tested in a mouse xenograft model. The data showed that HGK induced the expression of the microRNA miR-320a, which in turn inhibited the expression of the transcription factor ‘forkhead box protein M1’ (FOXM1) and downstream FOXM1-regulated proteins related to epithelial–mesenchymal transition, thereby leading to the suppression of liver cancer cell growth and invasion. Significant inhibition of tumor growth was also observed in HGK-treated mice. Hence, the present study demonstrated the activity of HGK against liver cancer and validated its potential use as a therapeutic agent.

The role of lncRNA MALAT1 in cardiovascular disease

Cardiovascular disease (CVD) is the first leading cause of death worldwide. Understanding the molecular mechanism of signaling pathways involved in pathology of CVD is benefit for targeted therapeutics. Recently, long non-coding RNAs (lncRNAs) are found and involved in regulation of pathology of CVD at different levels. Among them, MALAT1 attracted more attention as it was profoundly expressed in endothelial cells or cardiomyocytes in response to the risk factors of CVD, such as hypoxia, high glucose, cytokine, and oxidative stress. In this review, we summarize recent progresses in research on the molecular mechanism of MALAT1 on regulating the pathophysiological processes of CVD as well as its potential therapeutic applications.

A Brief Overview of lncRNAs in Endothelial Dysfunction-Associated Diseases: From Discovery to Characterization

Long non-coding RNAs (lncRNAs) are a novel class of regulatory RNA molecules and they are involved in many biological processes and disease developments. Several unique features of lncRNAs have been identified, such as tissue-and/or cell-specific expression pattern, which suggest that they could be potential candidates for therapeutic and diagnostic applications. More recently, the scope of lncRNA studies has been extended to endothelial biology research. Many of lncRNAs were found to be critically involved in the regulation of endothelial function and its associated disease progression. An improved understanding of endothelial biology can thus facilitate the discovery of novel biomarkers and therapeutic targets for endothelial dysfunction-associated diseases, such as abnormal angiogenesis, hypertension, diabetes, and atherosclerosis. Nevertheless, the underlying mechanism of lncRNA remains undefined in previous published studies. Therefore, in this review, we aimed to discuss the current methodologies for discovering and investigating the functions of lncRNAs and, in particular, to address the functions of selected lncRNAs in endothelial dysfunction-associated diseases.

Vitamin B1 and B12 mitigates neuron apoptosis in cerebral palsy by augmenting BDNF expression through MALAT1/miR-1 axis

Through the roles of vitamin B1 and B12 in neuroprotection and in improving cerebral palsy symptoms have been previously noticed, the action mechanism is still unclear. This study aims to investigate the protective effect of vitamin B1 and B12 on neuron injury in cerebral palsy and to clarify the mechanism of vitamin B1 and B12 inhibiting neurons apoptosis, and to focus on the role of lncRNA MALAT1 in this process. In order to investigate the effect of vitamin B1 and B12 on neurons injury in vivo and on neuron apoptosis in vitro, we, respectively, introduced vitamin B1 and B12 into cerebral palsy rat and in apoptosis-induced N2A neurons by Oxygen Glucose Deprivation/reoxygenation (OGD/R). Our results demonstrated that vitamin B1 and B12 treatment improved the motor and memory functions and ameliorated the neurons injury in cerebral palsy rats. OGD/R treatment repressed the expression of MALAT1 and BDNF and the phosphorylation of PI3K and Akt, and enhanced the miR-1 expression, which were all reversed by vitamin B1 and B12 treatment in N2A neurons. Vitamin B1 and B12 inhibited miR-1 expression through MALAT1, promoted BDNF expression and activated PI3K/Akt signaling through the MALAT1/miR-1 axis. Vitamin B1 and B12 suppressed neuron apoptosis by up-regulating BDNF via MALAT1/miR-1 pathway. MALAT1 interference abolished the neuroprotective effect of vitamin B1 and B12 in cerebral palsy rats. Collectively, vitamin B1 and B12 up-regulates BDNF and its downstream PI3K/Akt signaling through MALAT1/miR-1 axis, thus suppressing neuron apoptosis and mitigating nerve injury in cerebral palsy rats.

Crosstalk Between Long Non-coding RNAs, Micro-RNAs and mRNAs: Deciphering Molecular Mechanisms of Master Regulators in Cancer

Cancer is a complex disease, and its study requires deep understanding of several biological processes and their regulation. It is an accepted fact that non-coding RNAs are vital components of the regulation and cross-talk among cancer-related signaling pathways that favor tumor aggressiveness and metastasis, such as neovascularization, angiogenesis, and vasculogenic mimicry. Both long non-coding RNAs (lncRNAs) and micro-RNAs (miRNAs) have been described as master regulators of cancer on their own; yet there is accumulating evidence that, besides regulating mRNA expression through independent mechanisms, these classes of non-coding RNAs interact with each other directly, fine-tuning the effects of their regulation. While still relatively scant, research on the lncRNA-miRNA-mRNA axis regulation is growing at a fast rate, it is only in the last 5 years, that lncRNA-miRNA interactions have been identified in tumor-related vascular processes. In this review, we summarize the current progress of research on the cross-talk between lncRNAs and miRNAs in the regulation of neovascularization, angiogenesis and vasculogenic mimicry.

Exosomal miR-423-5p mediates the proangiogenic activity of human adipose-derived stem cells by targeting Sufu

Background

Human adipose-derived stem cells (hADSCs) are an important source of cells for regenerative medicine. Evidence of extensive interactions with the surrounding microenvironment has led researchers to focus more on hADSCs as activating agents of regenerative pathways, rather than simply replacing damaged cells. Several studies have found that functional miRNAs can be packaged into exosomes and transferred from donor cells into recipient cells, indicating that transported miRNAs may be a new class of cell-to-cell regulatory species. The aim of the present study was to evaluate whether the exosome-derived miRNAs secreted by hADSCs are capable of influencing angiogenesis, a key step in tissue regeneration.

Methods

Exosomes were purified from hADSCs followed by the characterization of their phenotype and angiogenic potential in vitro. RNA sequencing was performed to detect the miRNAs that were enriched in the hADSC-derived exosomes. A miRNA-mimic experiment was used to detect the key miRNAs in the proangiogenic activity of hADSC-derived exosomes.

Results

Exosomes isolated from hADSCs were characterized as round membrane vesicles with a size of approximately 100 nm and were positive for CD9 and flotillin. The exosomes were internalized by primary human umbilical vein endothelial cells (HUVECs) and stimulated HUVEC proliferation and migration. Remarkably, the exosomes promoted vessel-like formation by HUVECs in a dose-dependent manner, and their maximum activity (10 μg/mL) was comparable with that of 5% FBS. The RNA-seq bioinformatics analysis predicted 1119 gene targets of the top 30 exosomal miRNAs in Gene Ontology (GO) analysis and Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis, and the pathway involved in the angiogenesis was among the top KEGG pathways. Moreover, intact miR-423-5p was further demonstrated to be transferred into HUVECs via exosomes and to exert its angiogenic function by targeting Sufu.

Conclusions

Exosomal miR-423-5p mediated the proangiogenic activity of hADSCs by targeting Sufu, which may contribute to the exploitation of exosomes from hADSCs as a therapeutic tool for regenerative medicine.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1196-y) contains supplementary material, which is available to authorized users.

Long noncoding RNAs in cancer cells

Long noncoding RNA (lncRNA) has recently been investigated as key modulators that regulate many biological processes in human cancers via diverse mechanisms. LncRNAs can interact with macromolecules such as DNA, RNA, or protein to exert cellular effects and to act as either tumor promoters or tumor suppressors in various malignancies. Moreover, the aberrant expression of lncRNAs may be detected in multiple cancer phenotypes by employing the rapidly developing modern gene chip technology and bioinformatics analysis. Herein, we highlight the mechanisms of action of lncRNAs, their functional cellular roles and their involvement in cancer progression. Finally, we provide an overview of recent progress in the lncRNA field and future potential for lncRNAs as cancer diagnostic markers and therapeutics.

MALAT1: a potential biomarker in cancer

Purpose

The research of long non-coding RNAs (lncRNAs) has become a new passion with the discovery of abundant new lncRNAs and extensive investigation of their roles in various diseases, especially in cancers. Metastasis associated in lung adenocarcinoma transcript 1 (MALAT1) emerges as a hotspot, which has been reported to be involved in dysregulation of cell signaling and closely correlated with cancer development, progression, and response to therapy. This review is a brief update of the current knowledge related to the role of MALAT1 in cancer-associated molecular pathways and pathophysiology and possible determinants for MALAT1 to function as a biomarker, aiming to stimulate the basic investigation of lncRNA MALAT1 as well as its translation to clinical applications.

Methods

We have selected vast literature from electronic databases including studies associated with its clinical significance and the pivotal functions in cancer processes such as cell proliferation, apoptosis, metastasis, immunity, angiogenesis, and drug resistance.

Results

Studies have shown that aberrant expression of MALAT1 is related to cancer pathophysiology with the potential to be translated clinically and MALAT1 can regulate cancer processes by interacting with molecules, such as proteins, RNAs and DNAs, and further altering different signal pathways.

Conclusion

MALAT1 lncRNA promises to be a potential biomarker for cancer diagnosis as well as prognosis. Additionally, it might be a therapeutic target for human cancers.

Hyperbaric oxygen boosts long noncoding RNA MALAT1 exosome secretion to suppress microRNA-92a expression in therapeutic angiogenesis

BACKGROUND

Hyperbaric oxygen (HBO) could improve wound healing by enhancement of angiogenesis. The effect of HBO on metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a proangiogenic long noncoding RNA, and on endothelial cell-derived exosome is unknown. We aim to investigate both whether MALAT1 is altered in human coronary artery endothelial cells (HCAECs)-derived exosomes in response to HBO as well as the molecular regulatory mechanisms of MALAT1 in HCAECs under HBO treatment.

METHODS AND RESULTS

HCAECs were cultured and HBO was applied at 2.5 atmosphere absolute (ATA) in a hyperbaric chamber. Exosomes were extracted from culture media. A rat model of hind-limb ischemia was performed by ligation of the right femoral artery. HBO at 2.5 ATA significantly increased MALAT1 expression in HCAECs and HCAECs-derived exosomes. MALAT1 suppressed miR-92a expression in HCAEC-derived exosomes under HBO. Silencing MALAT1 by MALAT1 siRNA significantly inhibited KLF2 mRNA expression induced by HBO, as did MiR-92a. MiR-92a significantly decreased KLF2 luciferase activity in HCAECs under HBO. HBO and HBO-induced exosomes significantly increased cell proliferation and the capillary-like network formation of HCAECs. MALAT1 siRNA and miR-92a overexpression significantly attenuated the cell proliferation and tube formation caused by HBO-induced exosome. HBO and HBO-induced exosomes significantly improved neovascularization in a rat model of hind-limb ischemia.

CONCLUSIONS

HBO upregulates MALAT1 to suppress miR-92a expression and counteracts the inhibitory effect of miR-92a on KLF2 expression in HCAECs to enhance neovascularization. HBO-induced derivation of exosomes from HCAECs enhances angiogenesis. Exosomes containing MALAT1 might serve as a valuable therapeutic tool for neovascularization by HBO.

Forkhead box M1 inhibits endothelial cell apoptosis and cell-cycle arrest through ROS generation

BACKGROUND

Hyperglycemia, a characteristic feature of diabetes, induces vascular complications by accelerating endothelial cell (EC) apoptosis and limiting their proliferation. The potential role of Forkhead box M1 (FoxM1) in high glucose (HG)-induced EC injury remains largely unknown. We aimed to investigate the role and underlying mechanism of FoxM1 in regulating EC injury.

MATERIAL AND METHODS

Human umbilical vein endothelial cells (HUVECs) were treated with various concentrations of glucose (5.5, 15, 30 and 50 mM). The expression of FoxM1 was determined via qPCR and western blotting. Overexpression of FoxM1 was achieved by transfection with FoxM1 overexpression plasmid. Reactive oxygen species (ROS) production, cell apoptotic rates, and cell cycle analysis were detected by flow cytometry, and cell proliferation was measured by CCK8 assay.

RESULTS

The expression level of FoxM1 was downregulated in HUVECs under HG condition when compared to cells with normal glucose. HG treatment induced overproduction of ROS and subsequent apoptosis. However, FoxM1 overexpression of FoxM1 reduced the levels of ROS and inhibited apoptosis. In addition, HG induced impairment of cell proliferation and caused cell cycle arrest in the G0/G1 phrase. Contrarily, FoxM1 overexpression promoted cell proliferation and alleviated G0/G1 cell cycle arrest caused by HG stimulation. Moreover, treatment with HG reduced phosphorylation of the Akt and ERK signaling pathways, and this was remarkably reversed by FoxM1 overexpression.

CONCLUSION

FoxM1 protects ECs from HG-induced growth arrest and cell apoptosis by suppressing ROS caused by the regulation of Akt and ERK pathways, which can aid in developing new therapeutic strategies for the treatment of EC dysfunction.

Angiogenic lncRNAs: A potential therapeutic target for ischaemic heart disease

Long noncoding RNAs (LncRNAs) are involved in biological processes and the pathology of diseases and represent an important biomarker or therapeutic target for disease. Emerging evidence has suggested that lncRNAs modulate angiogenesis by regulating the angiogenic cell process-including vascular endothelial cells (VECs); stem cells, particularly bone marrow-derived stem cells, endothelial progenitor cells (EPCs) and mesenchymal stem cells (MSCs); and vascular smooth muscle cells (VSMCs)-and participating in ischaemic heart disease (IHD). Therapeutic angiogenesis as an alternative therapy to promote coronary collateral circulation has been demonstrated to significantly improve the prognosis and quality of life of patients with IHD in past decades. Therefore, lncRNAs are likely to represent a novel therapeutic target for IHD through regulation of the angiogenesis process. This review summarizes the classification and functions of lncRNAs and their roles in regulating angiogenesis and in IHD, in the context of an overview of therapeutic angiogenesis in clinical trials.

Reduced expression of microRNA-199a-3p is associated with vascular endothelial cell injury induced by type 2 diabetes mellitus

The aim of the present study was to investigate the function and mechanism of action of microRNA (miRNA or miR)-199a-3p in vascular endothelial cell injury induced by type 2 diabetes mellitus (T2DM). A total of 36 patients with T2DM (26 males and 10 females; mean age, 52.5±7.0 years) and 20 healthy subjects (10 males and 10 females; mean age, 55.6±4.5 years) were included in the present study. Peripheral blood samples were obtained from all participants and total RNA was extracted Reverse transcription-quantitative polymerase chain reaction was performed to determine the expression of miR-199a-3p. Following the transfection of human umbilical vein endothelial cells (HUVECs) with a negative control (NC) miRNA or miR-199a-3p mimics, cell proliferation was assessed using a Cell Counting kit-8 assay. Cell migration was investigated using Transwell assays and flow cytometry was performed to detect the apoptosis of HUVECs. HUVECs were infected with Ad-GFP-LC3B and laser-scanning confocal microscopy was performed to observe autophagosomes in HUVECs. Western blotting was used to measure the expression of proteins associated with autophagy and the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/nuclear factor (NF)-κB signaling pathway. MiR-199a-3p was downregulated in peripheral blood from patients with T2DM compared with healthy subjects. Transfection with miR-199a-3p mimics promoted the proliferation and migration of HUVECs. However, miR-199a-3p overexpression inhibited the apoptosis of HUVECs. MiR-199a-3p facilitated HUVEC autophagy by affecting autophagy-associated signaling pathways. Furthermore, miR-199a-3p regulated the biological functions of HUVECs via the PI3K/AKT/NF-κB signaling pathway. The results of the present study suggest that miR-199a-3p expression was reduced in patients with T2DM compared with healthy subjects and may be associated with vascular endothelial cell injury. In addition, miR-199a-3p promoted the proliferation, migration and autophagy of HUVECs, potentially by regulating the PI3K/AKT/NF-κB signaling pathway. Therefore, miR-199a-3p may function as protector of vascular endothelia.

Long non‑coding RNA SENCR alleviates the inhibitory effects of rapamycin on human umbilical vein endothelial cells

Rapamycin (RPM) is frequently used as the drug coating in drug‑eluting stents (DESs) as it can inhibit the growth of smooth muscle cells. However, RPM also inhibits the proliferation and migration of vascular endothelial cells, and impairs reendothelialization in DES implantation. Therefore, the development of a strategy to protect vascular endothelial cells after DES implantation is of great importance. Long non‑coding RNAs (lncRNAs) metastasis‑associated lung adenocarcinoma transcript 1 (MALAT1) and smooth muscle and endothelial cell‑enriched migration/differentiation‑associated lncRNA (SENCR) are able to enhance the proliferation, migration and angiogenesis of endothelial cells, which suggests that they may have potential as antagonists of the adverse effects of RPM in DES. However, the relationship between RPM and lncRNAs in endothelial cells during the intervention is not fully understood at present. The current study investigated the role and potential mechanism of the lncRNA SENCR on the activity of human umbilical vein endothelial cells (HUVECs) after RPM treatment. The proliferation, migration, angiogenic capacity and cell cycle progression of lncRNA SENCR‑overexpressing HUVECs following RPM treatment was examined. The proliferation‑related proteins of lncRNA SENCR‑modified HUVECs were evaluated to understand the mechanism of action. LncRNA SENCR significantly alleviated the inhibition of proliferation, migration, angiogenesis and cell cycle progression of HUVECs caused by RPM by activating extracellular signal‑regulated kinase 1/2 and mammalian target of RPM. The lncRNA SENCR could alleviate the inhibitory effects of RPM on HUVECs and may be useful as a new combinative agent to avoid the disadvantages of RPM in DES implantation.

Long Non-coding RNAs in Endothelial Biology

In recent years, the role of RNA has expanded to the extent that protein-coding RNAs are now the minority with a variety of non-coding RNAs (ncRNAs) now comprising the majority of RNAs in higher organisms. A major contributor to this shift in understanding is RNA sequencing (RNA-seq), which allows a largely unconstrained method for monitoring the status of RNA from whole organisms down to a single cell. This observational power presents both challenges and new opportunities, which require specialized bioinformatics tools to extract knowledge from the data and the ability to reuse data for multiple studies. In this review, we summarize the current status of long non-coding RNA (lncRNA) research in endothelial biology. Then, we will cover computational methods for identifying, annotating, and characterizing lncRNAs in the heart, especially endothelial cells.

Long non-coding RNAs within the tumour microenvironment and their role in tumour-stroma cross-talk

Long non-coding RNAs (lncRNAs) are a diverse class of RNA transcripts which have limited protein coding potential. They perform a variety of cellular functions in health, but have also been implicated during malignant transformation. A further theme in recent years is the critical role of the tumour microenvironment and the dynamic interactions between cancer and stromal cells in promoting invasion and disease progression. Whereas the contribution of deregulated lncRNAs within cancer cells has received considerable attention, their significance within the tumour microenvironment is less well understood. The tumour microenvironment consists of cancer-associated stromal cells and structural extracellular components which interact with one another and with the transformed epithelium via complex extracellular signalling pathways. LncRNAs are directly and indirectly involved in tumour/stroma cross-talk and help stimulate a permissive tumour microenvironment which is more conducive for invasive tumour growth. Furthermore, lncRNAs play key roles in determining the phenotype of cancer associated stromal cells and contribute to angiogenesis and immune evasion pathways, extracellular-matrix (ECM) turnover and the response to hypoxic stress. Here we explore the multifaceted roles of lncRNAs within the tumour microenvironment and their putative pathophysiological effects.

Tumor-derived extracellular vesicles in angiogenesis

Angiogenesis is crucial for tumor growth and metastasis. Recent studies revealed that tumor cells promote angiogenesis by secreting extracellular vesicles, which can be captured by endothelial cells. These tumor-derived extracellular vesicles carry microRNAs, long non-coding RNAs, and proteins, which activate pro-angiogenic signaling in endothelial cells. In this review, we will summarize the roles of tumor-derived extracellular vesicles in angiogenesis and the underlying molecular mechanisms.

Understanding the role of non-coding RNA (ncRNA) in stent restenosis

Coronary heart disease (CHD) is one of the leading disorders with the highest mortality rate. Percutaneous angioplasty and stent implantation are the currently available standard methods for the treatment of obstructive coronary artery disease. However, the stent being an exogenous substance causes several complications by promoting the proliferation of vascular smooth muscle cells, immune responses and neointima formation after implantation, leading to post-stent restenosis (ISR) and late thrombosis. The prevention of these adverse vascular events is important to achieve long-term proper functioning of the heart after stent implantation. Non-coding ribonucleic acids (ncRNAs) are RNA molecules not translated into proteins, theyhave a great potential in regulating endothelial cell and vascular smooth muscle function as well as inflammatory reactions. In this review, we outline the regulatory functions of different classes of ncRNA in cardiovascular disease and propose ncRNAs as new targets for stent restonosis treatment.

Targeting the long noncoding RNA MALAT1 blocks the pro-angiogenic effects of osteosarcoma and suppresses tumour growth

Osteosarcoma (OS), the commonest primary malignant tumour originating from bone, affects a substantial number of people, mostly during adolescent growth, and leads to a very poor prognosis as a result of the high rate of early metastases. Consequently, there is urgent demand for a novel treatment for this disease. There are growing concerns focused on OS-induced pro-angiogenic effects, but to date, the mechanism of OS-induced pro-angiogenesis is still insufficiently well-understood. Long noncoding RNAs (lncRNAs) have attracted increasing interest due to their strong correlation with a variety of diseases and their powerful capacity for epigenetic regulation. Recently, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a lncRNA, has been discovered to be closely related to OS progression and hypoxia responses which are associated with angiogenesis. In this study, we confirm that MALAT1 induces pro-angiogenic effects, and demonstrate that the underlying mechanism involves a MALAT1/mechanistic target of rapamycin (mTOR)/hypoxia inducible factor-1α (HIF-1α) loop. With the help of chemically-modified small interfering RNAs targeting MALAT1 (siMALAT1), we confirm that siMALAT could provide a potential strategy to block the abnormally active OS-induced pro-angiogenic effect, and ultimately successfully suppress progression of OS tumours.