Long non-coding RNAs: new players in ocular neovascularization

The role of long noncoding RNAs in ocular angiogenesis and vascular oculopathy

BACKGROUND

Long noncoding RNAs (lncRNAs) are RNA transcripts over 200 nucleotides in length that do not code for proteins. Initially considered a genomic mystery, an increasing number of lncRNAs have been shown to have vital roles in physiological and pathological conditions by regulating gene expression through diverse mechanisms depending on their subcellular localization. Dysregulated angiogenesis is responsible for various vascular oculopathies, including diabetic retinopathy, retinopathy of prematurity, age-related macular degeneration, and corneal neovascularization. While anti-VEGF treatment is available, it is not curative, and long-term outcomes are suboptimal, and some patients are unresponsive. To better understand these diseases, researchers have investigated the role of lncRNAs in regulating angiogenesis and models of vascular oculopathies. This review summarizes recent research on lncRNAs in ocular angiogenesis, including the pro-angiogenic lncRNAs ANRIL, HOTAIR, HOTTIP, H19, IPW, MALAT1, MIAT, NEAT1, and TUG1, the anti-angiogenic lncRNAs MEG3 and PKNY, and the human/primate specific lncRNAs lncEGFL7OS, discussing their functions and mechanisms of action in vascular oculopathies.

Roles and mechanisms of long non-coding RNAs in age-related macular degeneration

Worldwide, age-related macular degeneration (AMD) is a multifactorial progressive fundus disorder that can cause vision impairment and severe central blindness in older adults. Currently, there are no approved prevention or treatment strategies for non-exudative AMD. While targeting VEGF is the main therapeutic approach to delay the degeneration process in exudative AMD, a significant number of patients show insensitivity or ineffectiveness to anti-VEGF therapy. Despite years of research, the exact mechanism underlying drusen formation and macular atrophy in AMD remains unknown. In the pathogenesis of AMD, lncRNAs play crucial roles, as discussed in this paper. This review focuses on the function of dysregulated lncRNAs and the mechanisms by which specific molecules target these lncRNAs in AMD. The analysis reveals that lncRNAs primarily regulate the progression of AMD by mediating apoptosis, epithelial-mesenchymal transition (EMT), dedifferentiation, and oxidative stress in choroidal vascular endothelial cells, retinal pigment epithelium (RPE) cells, and photoreceptors. Consequently, the regulation of apoptosis, dedifferentiation, EMT, and other processes by lncRNAs has emerged as a crucial focus in AMD research.These findings contribute to our understanding of the role of lncRNAs in AMD and their potential as valuable biomarkers. Furthermore, they highlight the need for further basic and clinical studies to explore the value of lncRNAs as biomarkers and potential therapeutic targets for AMD.

Long Non-Coding RNAs and Proliferative Retinal Diseases

Retinopathy refers to disorders that affect the retina of the eye, which are frequently caused by damage to the retina's vascular system. This causes leakage, proliferation, or overgrowth of blood vessels through the retina, which can lead to retinal detachment or breakdown, resulting in vision loss and, in rare cases, blindness. In recent years, high-throughput sequencing has significantly hastened the discovery of new long non-coding RNAs (lncRNAs) and their biological functions. LncRNAs are rapidly becoming recognized as critical regulators of several key biological processes. Current breakthroughs in bioinformatics have resulted in the identification of several lncRNAs that may have a role in retinal disorders. Nevertheless, mechanistic investigations have yet to reveal the relevance of these lncRNAs in retinal disorders. Using lncRNA transcripts for diagnostic and/or therapeutic purposes may aid in the development of appropriate treatment regimens and long-term benefits for patients, as traditional medicines and antibody therapy only provide temporary benefits that must be repeated. In contrast, gene-based therapies can provide tailored, long-term treatment solutions. Here, we will discuss how different lncRNAs affect different retinopathies, including age-related macular degeneration (AMD), diabetic retinopathy (DR), central retinal vein occlusion (CRVO), proliferative vitreoretinopathy (PVR), and retinopathy of prematurity (ROP), which can cause visual impairment and blindness, and how these retinopathies can be identified and treated using lncRNAs.

The impact of non-coding RNAs in the pathobiology of eye disorders

Eye disorders are common disorders with significant effects on personal, economic, and social aspects of life. These disorders have a genetic background and are associated with dysregulation of non-coding RNAs. Three classes of these transcripts, namely long non-coding RNAs (lncRNAs), circular RNAs (circRNAs) and microRNAs (miRNAs) have established roles in the regulation of gene expression and pathoetiology of ocular disorders. H19, MEG3, BANCR, UCA1, HOTAIR, ANRIL, XIST and MIAT are among important lncRNAs in ocular disorders. CircRNAs from ZBTB44, HIPK3, circ-PSEN1, COL1A2, ZNF532 and FAM158A loci have also been found to affect pathoetiology of ocular disorders. Both lncRNAs and circRNAs can serve as molecular sponges for miRNAs. In this review, we searched PubMed and Google Scholar databases to find the research articles summarizing the impact of non-coding RNAs in ocular disorders. The results of these studies would help in identification of suitable targets for treatment of ocular disorders.

Metabolomics and Biomarkers in Retinal and Choroidal Vascular Diseases

The retina is one of the most important structures in the eye, and the vascular health of the retina and choroid is critical to visual function. Metabolomics provides an analytical approach to endogenous small molecule metabolites in organisms, summarizes the results of “gene-environment interactions”, and is an ideal analytical tool to obtain “biomarkers” related to disease information. This study discusses the metabolic changes in neovascular diseases involving the retina and discusses the progress of the study from the perspective of metabolomics design and analysis. This study advocates a comparative strategy based on existing studies, which encompasses optimization of the performance of newly identified biomarkers and the consideration of the basis of existing studies, which facilitates quality control of newly discovered biomarkers and is recommended as an additional reference strategy for new biomarker discovery. Finally, by describing the metabolic mechanisms of retinal and choroidal neovascularization, based on the results of existing studies, this study provides potential opportunities to find new therapeutic approaches.

Identification of circulating lncRNA in chronic kidney disease based on bioinformatics analysis

Chronic kidney disease (CKD) is a high mortality disease and generally remains asymptomatic in the early stages. Long non-coding RNA (lncRNA) is defined as a non-protein-coding transcript more than 200 nucleotides which participate in numerous biological processes and have been identified as novel diagnostic markers for many diseases. Detection of circulating lncRNAs is a rapidly evolving, new area of molecular diagnosis. The purpose of our research was to identify circulating lncRNA expression profiles and possible molecular mechanisms involved in CKD. Blood samples were obtained from patients with CKD and healthy volunteers, and high-throughput sequencing was performed to identify differentially expressed (DE) lncRNAs and mRNAs. DE lncRNAs and mRNAs in peripheral blood mononuclear cells (PBMCs) were confirmed by quantitative reverse transcription polymerase chain reaction (qRT-PCR) to ensure the reliability and validity of RNA-seq data. Bioinformatics analysis was used to obtain biological functions and key pathways related to the pathogenesis of CKD. The interaction and co-expression functional networks for DE lncRNAs and mRNAs were also constructed. Our data showed that of the 425 DE lncRNAs detected, 196 lncRNAs were upregulated, while that of 229 lncRNAs were downregulated. A total of 433 DE mRNAs were identified in patients with CKD compared to healthy individuals. GO analysis revealed that DE lncRNAs were highly correlated with binding and pathway regulation. KEGG analysis suggested that DE lncRNAs were obviously enriched in regulatory pathways, such as antigen processing and presentation. We successfully constructed a potential DE lncRNA-mRNA co-expression network and analyzed the target genes of DE lncRNAs to predict cis- and trans-regulation in CKD. 100 lncRNAs that corresponded to 14 transcription factors (TFs) were identified in the TF-lncRNA binary network. Our findings on the lncRNA expression profiles and functional networks may help to interpret the possible molecular mechanisms implied in the pathogenesis of CKD; the results demonstrated that lncRNAs could potentially to be used as diagnostic biomarkers in CKD.

Exploring the lncRNA localization landscape within the retinal pigment epithelium under normal and stress conditions

Background

Long noncoding RNAs (lncRNAs) are emerging as a class of genes whose importance has yet to be fully realized. It is becoming clear that the primary function of lncRNAs is to regulate gene expression, and they do so through a variety of mechanisms that are critically tied to their subcellular localization. Although most lncRNAs are poorly understood, mapping lncRNA subcellular localization can provide a foundation for understanding these mechanisms.

Results

Here, we present an initial step toward uncovering the localization landscape of lncRNAs in the human retinal pigment epithelium (RPE) using high throughput RNA-Sequencing (RNA-Seq). To do this, we differentiated human induced pluripotent stem cells (iPSCs) into RPE, isolated RNA from nuclear and cytoplasmic fractions, and performed RNA-Seq on both. Furthermore, we investigated lncRNA localization changes that occur in response to oxidative stress. We discovered that, under normal conditions, most lncRNAs are seen in both the nucleus and the cytoplasm to a similar degree, but of the transcripts that are highly enriched in one compartment, far more are nuclear than cytoplasmic. Interestingly, under oxidative stress conditions, we observed an increase in lncRNA localization in both nuclear and cytoplasmic fractions. In addition, we found that nuclear localization was partially attributable to the presence of previously described nuclear retention motifs, while adenosine to inosine (A-to-I) RNA editing appeared to play a very minimal role.

Conclusions

Our findings map lncRNA localization in the RPE and provide two avenues for future research: 1) how lncRNAs function in the RPE, and 2) how one environmental factor, in isolation, may potentially play a role in retinal disease pathogenesis through altered lncRNA localization.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08777-1.

Screening of single nucleotide polymorphisms among fuchs’ endothelial corneal dystrophy subjects in Malaysia

Background

The pathophysiology underlying Fuchs' Endothelial Corneal Dystrophy (FECD), especially in older individuals, remains unclear, with a genetic predisposition being reported as the single best predictor of the disease. Genetic studies have shown that several genes in various loci such as COL8A2, SLC4A11, TCF8/ZEB1 and TCF4 are associated with FECD in different populations and ethnicities. A case–control study was conducted to determine the association between genetic variants and FECD in a tertiary care setting in Malaysia. A total number of 12 patients with clinically diagnosed FECD and 12 age, gender and race matched control subjects were recruited. Extracted genomic DNA were genotyped using Infinium Global Screening Array (GSA)-24 version 1.0 BeadChip with iScan high-throughput system. Illumina GenomeStudio 2.0 Data Analysis and PLINK version 1.9 software were used to perform association tests and determine the distribution of obtained variants among the cases and controls.

Results

A significant novel genetic variant, rs11626651, a variant of the LOC105370676 gene or known as the LINC02320 gene, located at chromosome 14, has been identified as a suggestive association with FECD (p < 5 × 10−6). Further analysis in this study suggested that candidate genes such as COL8A2, ZEB1/TCF8, TCF4 and SLC4A11 had no significant associations with FECD.

Conclusions

The discovery of a novel variant may influence the underlying pathogenic basis of FECD in Malaysia. The current study is the first genetic study on FECD to use Infinium GSA. It is the first comprehensive report in Malaysia to provide genetic information of potential relevance to FECD, which may pave the way for new therapeutic strategies in the future. A detailed analysis with a larger sample size is recommended for further evaluation.

Retina stem cells, hopes and obstacles

Retinal degeneration is a major contributor to visual dysfunction worldwide. Although it comprises several eye diseases, loss of retinal pigment epithelial (RPE) and photoreceptor cells are the major contributors to their pathogenesis. Early therapies included diverse treatments, such as provision of anti-vascular endothelial growth factor and many survival and trophic factors that, in some cases, slow down the progression of the degeneration, but do not effectively prevent it. The finding of stem cells (SC) in the eye has led to the proposal of cell replacement strategies for retina degeneration. Therapies using different types of SC, such as retinal progenitor cells (RPCs), embryonic SC, pluripotent SCs (PSCs), induced PSCs (iPSCs), and mesenchymal stromal cells, capable of self-renewal and of differentiating into multiple cell types, have gained ample support. Numerous preclinical studies have assessed transplantation of SC in animal models, with encouraging results. The aim of this work is to revise the different preclinical and clinical approaches, analyzing the SC type used, their efficacy, safety, cell attachment and integration, absence of tumor formation and immunorejection, in order to establish which were the most relevant and successful. In addition, we examine the questions and concerns still open in the field. The data demonstrate the existence of two main approaches, aimed at replacing either RPE cells or photoreceptors. Emerging evidence suggests that RPCs and iPSC are the best candidates, presenting no ethical concerns and a low risk of immunorejection. Clinical trials have already supported the safety and efficacy of SC treatments. Serious concerns are pending, such as the risk of tumor formation, lack of attachment or integration of transplanted cells into host retinas, immunorejection, cell death, and also ethical. However, the amazing progress in the field in the last few years makes it possible to envisage safe and effective treatments to restore vision loss in a near future.

Potential of Long Non-Coding RNAs in Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is the leading cause of visual impairment in the aging population with poorly known pathogenesis and lack of effective treatment. Age and family history are the strongest AMD risk factors, and several loci were identified to contribute to AMD. Recently, also the epigenetic profile was associated with AMD, and some long non-coding RNAs (lncRNAs) were shown to involve in AMD pathogenesis. The Vax2os1/2 (ventral anterior homeobox 2 opposite strand isoform 1) lncRNAs may modulate the balance between pro- and anti-angiogenic factors in the eye contributing to wet AMD. The stress-induced dedifferentiation of retinal pigment epithelium cells can be inhibited by the ZNF503-AS1 (zinc finger protein 503 antisense RNA 2) and LINC00167 lncRNAs. Overexpression of the PWRN2 (Prader-Willi region non-protein-coding RNA 2) lncRNA aggravated RPE cells apoptosis and mitochondrial impairment induced by oxidative stress. Several other lncRNAs were reported to exert protective or detrimental effects in AMD. However, many studies are limited to an association between lncRNA and AMD in patients or model systems with bioinformatics. Therefore, further works on lncRNAs in AMD are rational, and they should be enriched with mechanistic and clinical studies to validate conclusions obtained in high-throughput in vitro research.

lncRNA-SUMO3 and lncRNA-HDMO13 modulate the inflammatory response by binding miR-21 and miR-142a-3p in grass carp

Septicemia is a systemic inflammatory response to bacterial infection in grass carp (Ctenopharyngodon idella). It could lead to lethality. There is increasing evidence that long noncoding RNAs are involved in the regulation of inflammatory response. In the present study, we firstly confirmed that lncRNA-SUMO3 and lncRNA-HDMO13 could involve in the inflammatory response following infection with Aeromonas hydrophila. Dual-luciferase reporter assays and lncRNA expression profiling confirmed that lncRNA-SUMO3 and lncRNA-HDMO13 contains a functional miR-21 and miR-142a-3p binding site. Meanwhile, transfection with lncRNAs mimics and inhibitors affected the expression of miRNAs and its target genes, including jnk, ccr7, glut3 and tnfaip2. Moreover, the downstream proinflammatory factors of miR-21 and miR-142a-3p were also regulated by lncRNA-SUMO3 and lncRNA-HDMO13. Our results provide a theoretical basis for exploring the molecular mechanism of grass carp lncRNAs regulating inflammation.

The roles of long non-coding RNAs in ocular diseases

In recent years, lncRNAs have been shown to regulate gene expression at the epigenetic, transcriptional and translational level, thus exerting various functions in biological and pathological processes involving cell proliferation, apoptosis, cell cycle and immune response. An increasing number of researches have unveiled that lncRNAs are dysregulated in pathogenesis and the development of different ocular diseases, such as glaucoma, cataract, retinal disease and ocular tumors. Also, it has been reported that lncRNAs may exert significant roles in various ocular diseases. Here, we summarized the functions of lncRNAs on relevant ocular diseases and further clarified their mechanisms. Here, several previous studies with detailed information of lncRNAs which have been proved to be the diagnostic or prognostic biomarkers and potential therapeutic targets were included. Also, it is our hope to provide a thorough knowledge of the functions of lncRNAs in eye diseases and the methods by which lncRNAs can influence ocular diseases.

Effects of long non-coding RNA myocardial infarction-associated transcript on retinal neovascularization in a newborn mouse model of oxygen-induced retinopathy

Whether long non-coding RNA myocardial infarction-associated transcript is involved in oxygen-induced retinopathy remains poorly understood. To validate this hypothesis, we established a newborn mouse model of oxygen-induced retinopathy by feeding in an oxygen concentration of 75 ± 2% from postnatal day 8 to postnatal day 12, followed by in normal air. On postnatal day 11, the mice were injected with the myocardial infarction-associated transcript siRNA plasmid via the vitreous cavity to knockdown long non-coding RNA myocardial infarction-associated transcript. Myocardial infarction-associated transcript siRNA transcription significantly inhibited myocardial infarction-associated transcript mRNA expression, reduced the phosphatidylinosital-3-kinase, phosphorylated Akt and vascular endothelial growth factor immunopositivities, protein and mRNA expression, and alleviated the pathological damage to the retina of oxygen-induced retinopathy mouse models. These findings suggest that myocardial infarction-associated transcript is likely involved in the retinal neovascularization in retinopathy of prematurity and that inhibition of myocardial infarction-associated transcript can downregulate phosphatidylinosital-3-kinase, phosphorylated Akt and vascular endothelial growth factor expression levels and inhibit neovascularization. This study was approved by the Animal Ethics Committee of Shengjing Hospital of China Medical University, China (approval No. 2016PS074K) on February 25, 2016.

LncRNA NEAT1 Sponges MiRNA-148a-3p to Suppress Choroidal Neovascularization and M2 macrophage polarization

PURPOSE

Long noncoding RNAs (lncRNAs) have emerged as essential regulators in many biological processes; however, little is known about the role of lncRNAs in choroidal neovascularization (CNV). The aim of this study was to investigate the role of lncRNA NEAT1 in CNV formation, and assessed whether inhibition of lncRNA NEAT1 could suppress M2-type macrophage polarization and CNV.

METHODS

The expression profiles of lncRNAs in a CNV mice model were accessed via microarray analysis. The role of lncRNA NEAT1 on macrophage polarization was assessed both in vitro and vivo. The interaction between lncRNA NEAT1, miR-148a-3p, and PTEN was assessed using a dual-luciferase reporter assay and RNA immunoprecipitation assay. Additionally, to evaluate the role of lncRNA NEAT1 on CNV development, eyes of mice in the mice CNV model were examined by Fluorescein Angiography (FA) and choroidal flatmounts on days 3 and 7 after intravitreal injection.

RESULTS

The results revealed that 128 lncRNAs were significantly altered in the RPE-choroid-sclera complexes of CNV mice (P < 0.05, fold change > 2.0). Additionally, lncRNA NEAT1 increased in CNV formation and M2 macrophage polarization. LncRNA NEAT1 sponging miRNA-148a-3p targeting PTEN can modulate M2 macrophage polarization in mice CNV models as well as in bone marrow-derived macrophages cultured in vitro. Inhibition of lncRNA NEAT1 can suppress M2 macrophage both in vitro and vivo. Moreover, the intravitreal injection of a lncRNA NEAT1 Smart Silencer can inhibit CNV leakage and neovascularization.

CONCLUSION

LncRNA NEAT1 via miRNA-148a-3p targeting PTEN plays a significant role in M2 macrophage polarization, while the inhibition of lncRNA NEAT1 can suppress choroidal neovascularization by inhibiting M2 macrophage polarization.

Effect and mechanism of the long noncoding RNA MALAT1 on retinal neovascularization in retinopathy of prematurity

AIMS

The most typical pathological manifestation of retinopathy of prematurity (ROP) is Retinal neovascularization (RNV). Long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been reported to mediate angiogenesis. Our experiment aimed to research the effect and mechanism of the MALAT1 on RNV in ROP.

MAIN METHODS

C57 mice was used to establish oxygen-introduced retinopathy (OIR), and divided into control, hyperoxia, hyperoxia control siRNA, and hyperoxia MALAT1 siRNA groups.

KEY FINDINGS

It was shown that MALAT1 mRNA was high expressed in the retinas of OIR mice. Further studies revealed that after intravitreal injection of MALAT1 siRNA, the degree of retinopathy was significantly reduced compared with OIR group. In addition, the protein and mRNA expression levels of CCN1, AKT and VEGF were significantly decreased. This was accompanied by a decrease in inflammatory genes including IL-1β, IL-6, and TNF-α compared with the hyperoxia control siRNA mice.

SIGNIFICANCE

The result suggested that MALAT1 may be involved in the process of RNV in ROP and MALAT1 siRNA may be a promising agent for the treatment of ROP by inhibiting RNV.

Analysis of Long Noncoding RNAs in Choroid Neovascularization

Purpose: Choroidal neovascularization (CNV) is the major pathological features of wet age-related macular degeneration (AMD). Long noncoding RNAs play great roles in numerous biological processes. The purpose of the study was to investigate the expression profile and possible functions of the lncRNAs in CNV. Methods: In this study, the mice CNV model were conducted by laser photocoagulation. The expression profiles of lncRNAs were accessed by microarray analysis. Selected altered lncRNAs of mice CNV and wet AMD patients were validated by RT-PCR. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and lncRNA-mRNA coexpression network were conducted to reveal the biological functions. Results: The results revealed that 128 lncRNAs were significantly altered in RPE-choroid-sclera complexes of CNV mice (P < .05, fold change > 2.0). GO analysis revealed that the altered target genes of the selected lncRNAs most enriched in angiogenesis. KEGG pathway analysis demonstrated that altered target genes of lncRNAs most enriched in focal adhesion signaling pathway. H19 was significantly increased in the aqueous humor of wet AMD patients. Moreover, Inhibition of lncRNA H19 could suppresses M2 macrophage gene expression of laser-induced CNV mice. Conclusions: Our study identified differential expressions of lncRNAs in CNV, and lncRNA H19 might be novel potential target for the prevention and treatment of CNV.

Anti-VEGF Treatment and Response in Age-related Macular Degeneration: Disease's Susceptibility, Pharmacogenetics and Pharmacokinetics

The current review is focussing different factors that contribute and directly correlate to the onset and progression of Age-related Macular Degeneration (AMD). In particular, the susceptibility to AMD due to genetic and non-genetic factors and the establishment of risk scores, based on the analysis of different genes to measure the risk of developing the disease. A correlation with the actual therapeutic landscape to treat AMD patients from the point of view of pharmacokinetics and pharmacogenetics is also exposed. Treatments commonly used, as well as different regimes of administration, will be especially important in trying to classify individuals as "responders" and "non-responders". Analysis of different genes correlated with drug response and also the emerging field of microRNAs (miRNAs) as possible biomarkers for early AMD detection and response will be also reviewed. This article aims to provide the reader a review of different publications correlated with AMD from the molecular and kinetic point of view as well as its commonly used treatments, major pitfalls and future directions that, to our knowledge, could be interesting to assess and follow in order to develop a personalized medicine model for AMD.

WDR7 up-regulation upon knocking down of neighboring non-coding RNA using siRNAs encapsulated in polyamidoamine dendrimers

Objective(s):

Breast cancer is the second leading cause of cancer death in females. Understanding molecular mechanisms in cancer cells compared with normal cells is crucial for diagnostic and therapeutic strategies. Long intergenic non-protein coding RNA, a regulator of reprogramming (lincRNA-RoR) is a noncoding RNA which initially was detected in induced pluripotent stem cells, and it has an important role in cell reprogramming and highly expressed in breast cancer cells. A key point in successful gene silencing is the usage of siRNA delivery system that is safe and efficient.

Materials and Methods:

In this study, the fifth-generation of PAMAM dendrimer is used as a nanocarrier for entering siRNA molecules for gene silencing of lincRNA-RoR. WDR7 is the gene encoding adjacent of lincRNA-RoR, which has an important role in apoptosis and cell cycle. Gel retardation assay was used to find the best Negative/Positive (N/P) molar charge ratio of siRNA- PAMAM transfected into MDA-MB 231 cells. MTT assay was performed 24 hr after transfection revealed the IC50 value (half maximal inhibitory concentrations) about 100 nanomolar for lincRNA-ROR siRNA.

Results:

The lincRNA-RoR and WDR7 gene expression changes were evaluated by real-time PCR after siRNA treatment and showed an increase in the gene expression of WDR7.

Conclusion:

This study showed that PAMAM dendrimer G5/ siRNA could be a useful system delivery for future gene therapy approaches.

Altered Long Non-coding RNAs Involved in Immunological Regulation and Associated with Choroidal Neovascularization in Mice

Choroidal neovascularization (CNV) is a severe complication of the wet form of age-related macular degeneration (AMD). Long non-coding RNAs (lncRNAs) have been implicated in the pathogenesis of different ocular neovascular diseases. To identify the function and therapeutic potential of lncRNAs in CNV, we assessed lncRNAs and mRNA expression profile in a mouse model of laser-induced CNV by microarray analysis. The results of altered lncRNAs were validated by qRT-PCR. Bioinformatics analyses, including Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, were performed to clarify the potential biological functions and signaling pathways with which altered genes are most closely related. Moreover, to identify the interaction of lncRNAs and mRNAs, we constructed a coding-non-coding gene co-expression (CNC) network. By microarray analysis, we identified 716 altered lncRNAs and 821 altered mRNAs in CNV mice compared to controls. A CNC network profile based on 7 validated altered lncRNAs (uc009ewo.1, AK148935, uc029sdr.1, ENSMUST00000132340, AK030988, uc007mds.1, ENSMUST00000180519) as well as 282 interacted and altered mRNAs, and were connected by 713 edges. GO and KEGG analyses suggested that altered mRNAs, as well as those lncRNA-interacted mRNAs were enriched in immune system process and chemokine signaling pathway. Thus, lncRNAs are significantly altered in this mouse model of CNV and are involved in immunological regulation, suggesting that lncRNAs may play a critical role in the pathogenesis of CNV. Thus, dysregulated lncRNAs and their target genes might be promising therapeutic targets to suppress CNV in AMD.

Expression profiles of long noncoding RNAs in retinopathy of prematurity

Long noncoding RNA (lncRNA) regulates the proliferation and migration of human retinal endothelial cells, as well as retinal neovascularization in diabetic retinopathy. Based on similarities between the pathogenesis of retinopathy of prematurity (ROP) and diabetic retinopathy, lncRNA may also play a role in ROP. Seven-day-old mice were administered 75 ± 2% oxygen for 5 days and normoxic air for another 5 days to establish a ROP model. Expression of lncRNA and mRNA in the retinal tissue of mice was detected by high-throughput sequencing technology, and biological functions of the resulted differentially expressed RNAs were evaluated by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. The results showed that compared with the control group, 57 lncRNAs were differentially expressed, including 43 upregulated and 14 downregulated, in the retinal tissue of ROP mice. Compared with control mice, 42 mRNAs were differentially expressed in the retinal tissue of ROP mice, including 24 upregulated and 18 downregulated mRNAs. Differentially expressed genes were involved in ocular development and related metabolic pathways. The differentially expressed lncRNAs may regulate ROP in mice via microRNAs and multiple signaling pathways. Our results revealed that these differentially expressed lncRNAs may be therapeutic targets for ROP treatment. This study was approved by the Medical Ethics Committee of Shengjing Hospital of China Medical University on February 25, 2016 (approval No. 2016PS074K).

LncRNAs in ocular neovascularizations

The prevalence of eye diseases worldwide is dramatically increasing and represents a major concern in underdeveloped and developed regions. Ocular diseases, previously associated with a higher depression risk, also impose a substantial economic burden on affected families, thus early detection and/or accurate treatment in order to avoid and prevent blindness should be emphasized. Ocular neovascularization (NV), the leading cause of blindness in a variety of eye diseases, is a pathologic process characterized by the formation, proliferation and infiltration of anomalous, tiny and leaky fragile blood vessels within the eye. Genetics have been suspected to play an important role in the occurrence of eye diseases, with the detection of a numbers of specific gene mutations. Long non-coding RNA (lncRNAs) are novel class of regulatory molecules previously associated with various biological processes and diseases, however the nature of the relation and pathways by which they might contribute to the development of corneal, choroidal and retinal NV have not yet been completely elucidated. In this review, we focus on the regulation and characteristics of lncRNAs, summarize results from ocular NV-related studies and discuss the implication of lncRNAs in ocular NV development.

Microarray Analysis of Long Non-Coding RNAs and Messenger RNAs in a Mouse Model of Oxygen-Induced Retinopathy

Objective: Retinal neovascularization is a severe complication of many ocular diseases. To clarify the possible functions and therapeutic potential of long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) in retinal neovascularization, we assessed their expression profile in a mouse model of oxygen-induced retinopathy (OIR). Methods: Microarray analysis was performed to identify altered lncRNA and mRNA expressions between OIR and control mice. The microarray results were validated by qRT-PCR. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were conducted to determine biological functions and signaling pathways of the altered or interacted mRNAs. A coding-non-coding gene co-expression (CNC) network was constructed to identify the interaction of lncRNAs and mRNAs. Results: We identified 198 up-regulated and 175 down-regulated lncRNAs (fold change≥2.0, P<0.05), respectively in OIR mice compared to control mice. We also identified 412 up-regulated and 127 down-regulated mRNAs (fold change≥2.0, P<0.05), respectively in OIR mice compared to control mice. GO and KEGG analyses suggested that altered mRNAs were enriched in immune system process, exopeptidase activity, ECM-receptor interaction and protein digestion and absorption. Four validated lncRNAs (ENSMUST00000165968, ENSMUST00000153785, ENSMUST00000134409, and ENSMUST00000154285) and the nearby coding gene pairs were analyzed. A CNC network profile based on those validated altered lncRNAs as well as 410 interacted mRNAs was composed of 509 connections. Moreover, the GO and KEGG analyses demonstrated that these interacted mRNAs mainly enriched in blood vessel development, angiogenesis, cell adhesion molecules and leukocyte transendothelial migration pathways. Conclusion: Our data highlight the utility of altered lncRNA and mRNA profiling in understanding the pathogenesis of ischemia-induced retinal neovascularization and further suggest that therapeutic potential of altered lncRNA for retinal neovascularization.

New Therapies of Neovascular AMD-Beyond Anti-VEGFs

Neovascular age-related macular degeneration (nAMD) is one of the leading causes of blindness among the aging population. The current treatment options for nAMD include intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF). However, standardized frequent administration of anti-VEGF injections only improves vision in approximately 30–40% of nAMD patients. Current therapies targeting nAMD pose a significant risk of retinal fibrosis and geographic atrophy (GA) development in nAMD patients. A need exists to develop new therapies to treat nAMD with effective and long-term anti-angiogenic effects. Recent research on nAMD has identified novel therapeutic targets and angiogenic signaling mechanisms involved in its pathogenesis. For example, tissue factor, human intravenous immune globulin, interferon-β signaling, cyclooxygenase-2 (COX-2) and cytochrome P450 monooxygenase lipid metabolites have been identified as key players in the development of angiogenesis in AMD disease models. Furthermore, novel therapies such as NACHT, LRR and PYD domains containing protein 3 (NLRP3) inflammasome inhibition, inhibitors of integrins and tissue factor are currently being tested at the level of clinical trials to treat nAMD. The aim of this review is to discuss the scope for alternative therapies proposed as anti-VEGFs for the treatment of nAMD.

Angio-LncRs: LncRNAs that regulate angiogenesis and vascular disease

Long noncoding RNAs (lncRNAs) represent a large subgroup of RNAs that are longer than 200 nucleotides and have no apparent protein coding potential. They have diverse functions in different biological processes by regulating chromatin remodeling or protein translation. This review summarizes the recent progress of lncRNAs in angiogenesis and vascular diseases. A general overview of lncRNA functional mechanisms will be introduced. A list of lncRNAs, which are termed "Angio-LncRs", including MALAT1, MANTIS, PUNISHER, MEG3, MIAT, SENCR and GATA6-AS, will be discussed regarding their expression, regulation, function and mechanism of action in angiogenesis. Implications of lncRNAs in vascular diseases, such as atherosclerosis, hypertension, vascular retinopathies and tumor angiogenesis will also be discussed.

Identification of lncRNAs involved in biological regulation in early age-related macular degeneration

Background

Age-related macular degeneration (AMD) is one of the most common causes of adult blindness in developed countries. However, the role of long noncoding RNAs (lncRNAs) in the development and progression of early AMD is unclear.

Methods

We established the lncRNA profile of early AMD by reannotation of microarrays from the gene expression omnibus database. Quantitative real-time polymerase chain reaction was used to determine the expression of selected lncRNAs.

Results

The expression profiles of 9 cases of AMD and 7 controls were studied. A total of 266 differentially expressed genes (DEGs) were detected (94 upregulated and 172 downregulated). Among all the DEGs, 64 were lncRNAs. Advanced bioinformatics analyses demonstrated that differentially expressed lncRNAs could play significant roles in visual perception, sensory perception of light stimulus, and cognition. The pathway analyses showed that the two most significantly influenced Kyoto Encyclopedia of Genes and Genomes pathways were those of phototransduction and purine metabolism. By the analyses of the key lncRNAs, it was found that RP11-234O6.2 was downregulated in the aging retinal pigment epithelium (RPE) cellular model. Exogenous RP11-234O6.2 treatment led to increased cell viability and improved apoptosis but it did not affect the cell migration ability of aging RPE cells.

Conclusion

This study indicated that lncRNAs are differentially expressed in early AMD and may produce important regulative effects. An lncRNA, RP11-234O6.2, might be involved in the biological regulation of early AMD and have therapeutic potential.

A genome-wide association study identified a novel genetic loci STON1-GTF2A1L/LHCGR/FSHR for bilaterality of neovascular age-related macular degeneration

Bilateral neovascular age-related macular degeneration (AMD) causes much more handicaps for patients than unilateral neovascular AMD. Although several AMD-susceptibility genes have been evaluated for their associations to bilaterality, genome-wide association study (GWAS) on bilaterality has been rarely reported. In the present study, we performed GWAS using neovascular AMD cases in East Asian. The discovery stage compared 581,252 single nucleotide polymorphisms (SNPs) between 803 unilateral and 321 bilateral Japanese cases but no SNP showed genome-wide significance, while SNPs at six regions showed P-value < 1.0 × 10⁻⁵, STON1-GTF2A1L/LHCGR/FSHR, PLXNA1, CTNNA3, ARMS2/HTRA1, LHFP, and FLJ38725. The first replication study for these six regions comparing 36 bilateral and 132 unilateral Japanese cases confirmed significant associations of rs4482537 (STON1-GTF2A1L/LHCGR/FSHR), rs2284665 (ARMS2/HTRA1), and rs8002574 (LHFP) to bilaterality. In the second replication study comparing 24 bilateral and 78 unilateral cases from Singapore, rs4482537 (STON1-GTF2A1L/LHCGR/FSHR) only showed significant association. Meta-analysis of discovery and replication studies confirmed genome-wide level significant association (P = 2.61 × 10⁻⁹) of rs4482537 (STON1-GTF2A1L/LHCGR/FSHR) and strong associations (P = 5.76 × 10⁻⁷ and 9.73 × 10⁻⁷, respectively) of rs2284665 (ARMS2/HTRA1) and rs8002574 (LHFP). Our GWAS for neovascular AMD bilaterality found new genetic loci STON1-GTF2A1L/LHCGR/FSHR and confirmed the previously reported association of ARMS2/HTRA1.

Decoding Noncoding RNAs: Role of MicroRNAs and Long Noncoding RNAs in Ocular Neovascularization

Ocular neovascularization is a pathological sequel of multiple eye diseases. Based on the anatomical site into which the abnormal neovessels grow, ocular neovascularization can be categorized into corneal neovascularization, choroidal neovascularization, and retinal neovascularization. Each category is intractable, and may lead to blindness if not appropriately treated. However, the current therapeutic modalities, including laser photocoagulation, vitrectomy surgery, and anti-VEGF drugs, raise concerns due to limited efficacy, damage on retinal parenchyma and vasculature, and the patients' unresponsiveness to the treatments. Therefore, the in-depth study on pathogenesis of and the search for novel therapeutic targets to the ocular neovascularization are needed. During the last 10 years or so, a large number of literatures have emerged indicating a critical role of noncoding RNAs, particularly microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), in the pathogenesis and regulation of the ocular neovascularization. This review summarizes the current understanding of the biosynthesis and functions of the miRNAs and lncRNAs, the regulation of the miRNAs and lncRNAs in neovascular eye diseases, as well as the roles of these noncoding RNAs in the disease models of ocular neovascularization, in the hope that it could provide clues for the pathogenesis of and molecular targets to the ocular neovascularization.

Precise long non-coding RNA modulation in visual maintenance and impairment

Long non-coding RNAs (lncRNAs) are remarkably powerful, flexible and pervasive cellular regulators. With the help of cheaper RNA-seq, high-throughput screening of lncRNAs has become widely applied and has identified large numbers of specific lncRNAs in various physiological or pathological processes. Vision is known to be a complex and vital perception that comprises 80% of the sensory information we receive. A consensus has been reached that normal visual maintenance and impairment are primarily driven by gene regulation. Recently, it has become understood that lncRNAs are key regulators in most biological processes, including cell proliferation, apoptosis, differentiation, immune responses, oxidative stress and inflammation. Our review is intended to provide insight towards a comprehensive view of the precise modulation of lncRNAs in visual maintenance and impairment. We also highlight the challenges and future directions in conducting lncRNA studies, particularly in patients whose lncRNAs may hold expanded promise for diagnostic, prognostic and therapeutic applications.

The Role of HOTAIR/miR-148b-3p/USF1 on Regulating the Permeability of BTB

Homeobox transcript antisense intergenic RNA (HOTAIR), as a long non-coding RNA (lncRNA), has been considered to play critical roles in the biological properties of various tumors. The purposes of this study were to investigate the role and possible molecular mechanisms of HOTAIR in regulating the permeability of blood tumor barrier (BTB) in vitro. Our present study elucidated that the expressions of HOTAIR and upstream stimulatory factor 1 (USF1) was up-regulated, but miR-148b-3p was down-regulated in glioma microvascular endothelial cells (GECs). Knockdown of HOTAIR could increase the permeability of BTB as well as down-regulated the expressions of tight junction related proteins ZO-1, occludin, claudin-5, but up-regulated miR-148b-3p expressions in GECs. Meanwhile, dual-luciferase reporter assays demonstrated that HOTAIR was a target RNA of miR-148b-3p. Furthermore, overexpression of miR-148b-3p increased the permeability of BTB by down-regulating the expressions of tight junction related proteins and USF1 in GECs, and vice versa. And further result revealed USF1 was a target of miR-148b-3p. Silence of USF1 increased the permeability of BTB duo to their interaction with the promoters of ZO-1, occludin, and claudin-5 in GECs. Taken together, our finding indicated that knockdown of HOTAIR increased BTB permeability via binding to miR-148b-3p, which further reducing tight junction related proteins in GECs by targeting USF1. Thus, HOTAIR will attract more attention since it can serve as a potential target of drug delivery across BTB and may provide novel strategies for glioma treatment.

Variable Levels of Long Noncoding RNA Expression in DNA Mismatch Repair-Proficient Early-Stage Colon Cancer

BACKGROUND

Long noncoding RNAs (lncRNAs) have been suggested to be biomarkers for diagnosis and prognosis of sporadic colorectal cancer.

AIMS

This study aimed to characterize the expression profile of lncRNAs in DNA mismatch repair-proficient (pMMR) early-stage colon cancer (CC).

METHODS

The microsatellite instability (MSI) status was examined by a multiplex PCR. The expression of lncRNA and mRNA was analyzed by microarrays. The differentially expressed lncRNAs and mRNAs were determined by bioinformatic analyses and validated in 44 CC samples and 32 non-tumor colonic specimens by quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

We found that 16 out of 67 CC had MSI-L CC and 7 with MSI-H. In comparison with that in five non-tumor colonic samples, microarray indicated that 1492 lncRNAs and 1639 mRNAs were upregulated while 1804 lncRNAs and 1073 mRNAs downregulated in four pMMR early-stage CC. Bioinformatic analyses revealed that the differentially expressed mRNAs were involved in the process of cell division, angiogenesis, apoptotic, differentiation, the PI3K-Akt/p53/TNF pathways and others. The co-expression lncRNA and mRNA networks indicated five hot spots with significantly high co-expression degrees. Further quantitative RT-PCR revealed that 4 out of 6 lncRNAs were significantly upregulated while the other 2 lncRNAs were downregulated in the CC. Stratification analysis demonstrated that 5 out of 6 lncRNAs were significantly associated with TNM stage and/or distant metastasis in this population.

CONCLUSION

Differentially expressed lncRNAs were significantly associated with clinical features of patients with pMMR CC and may participate in the tumorigenesis of pMMR CC.

MicroRNA-210 Plays a Critical Role in the Angiogenic Effect of Isoprenaline on Human Umbilical Vein Endothelial Cells via Regulation of Noncoding RNAs

Background:

β-adrenoceptors play a crucial regulatory role in blood vessel endothelial cells. Isoprenaline (ISO, a β-adrenergic agonist) has been reported to promote angiogenesis through upregulation of vascular endothelial growth factor (VEGF) expression; however, the underlying mechanism remains to be investigated. It is widely accepted that certain noncoding RNAs, including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), can regulate endothelial cell behavior, including their involvement in angiogenesis. Therefore, we aimed to investigate whether noncoding RNAs participate in ISO-mediated angiogenesis using human umbilical vein endothelial cells (HUVECs).

Methods:

We evaluated VEGF-A messenger RNA (mRNA) and protein levels in ISO-treated HUVECs by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. To establish whether noncoding RNAs are associated with ISO-mediated angiogenesis, we measured expression of the miRNAs miR-210, miR-21, and miR-1, as well as that of the lncRNAs growth arrest-specific transcript 5 (GAS5), maternally expressed 3 (MEG3), and metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in HUVECs exposed to ISO. Furthermore, to ascertain its importance in ISO-mediated angiogenesis, we constructed the HUVECs with overexpressing miR-210 and detected the subsequent expression of VEGF-A and noncoding RNAs. All statistical analyses were performed using SPSS 16.0 software. Intergroup comparisons were carried out by one-way analysis of variance.

Results:

VEGF-A mRNA levels were elevated in the ISO group (1.57 ± 0.09) compared to those in the control group (P < 0.01). Moreover, concentrations of VEGF-A in culture supernatants significantly differed between the control (113.00 ± 19.21 pg/ml) and ISO groups (287.00 ± 20.27 pg/ml; P < 0.01). Expression of miR-1, miR-21, and miR-210 was higher (3.89 ± 0.44, 2.87 ± 087, and 3.33 ± 1.31, respectively) in ISO-treated cells than that in controls (P < 0.01), whereas that of GAS5 and MEG3 (0.22 ± 0.10 and 0.58 ± 0.16, respectively) was lower as a result of ISO administration (P < 0.05). There was no significant difference in the expression of MALAT1 between the groups. Interestingly, miR-210 overexpression heightened the levels of VEGF-A and miR-21 (5.87 ± 1.24 and 2.74 ± 1.15, respectively; P < 0.01) and reduced those of GAS5 and MEG3 (0.19 ± 0.01 and 0.09 ± 0.05, respectively; P < 0.01).

Conclusions:

ISO-mediated angiogenesis was associated with altered expression of miR-210, miR-21, and the lncRNAs GAS5 and MEG3. The effects of miR-210 on the expression of VEGF-A and noncoding RNAs were similar to those of ISO, indicating that it might play an important role in ISO-mediated angiogenesis.

Tristetraprolin regulates the decay of the hypoxia-induced vascular endothelial growth factor mRNA in ARPE-19 cells

The aim of the present study was to investigate the effects of tristetraprolin (TTP) on the vascular endothelial growth factor (VEGF) mRNA and protein expression levels in retinal pigment epithelial cells under hypoxic conditions, and to consider the possibility of using TTP as a novel treatment tool for neovascular age‑related macular degeneration (AMD). Overexpression of TTP reduced the expression and secretion levels of VEGF in ARPE‑19 cells under hypoxic conditions. TTP destabilized the VEGF mRNA by binding to adenosine and uridine‑rich elements regions in its 3'‑untranslated region. Furthermore, conditioned medium (CM) from TTP‑overexpressing ARPE‑19 cells suppressed the tube formation in human umbilical vein endothelial cells compared with hypoxic CM. These findings indicate that regulation of TTP expression may be a promising therapeutic tool for neovascular AMD, however, further research is required.

Long Non-coding RNA TUSC7, a Target of miR-23b, Plays Tumor-Suppressing Roles in Human Gliomas

Tumour suppressor candidate 7 (TUSC7) is a novel tumor suppressor gene generating long non-coding RNA (lncRNAs) in several types of human cancers. The expression and function of TUSC7 in human brain glioma has yet to be elucidated. In this study, TUSC7 was poorly expressed in tissues and cell lines of glioma, and the lower expression was correlated with glioma of the worse histological grade. Moreover, TUSC7 is a prognostic biomarker of glioma patients. Up-regulation of TUSC7 suppressed cellular proliferation and invasion of glioma cells, and accelerated cellular apoptosis. Bioinformatics analysis showed that TUSC7 specifically binds to miR-23b. MiR-23b was up-regulated in glioma and negatively correlated with the expression of TUSC7. The miR-23b expression was inhibited remarkably by the upregulation of TUSC7 and the reciprocal inhibition was determined between TUSC7 and miR-23b.RNA pull-down and luciferase reporter assays were used to validate the sequence-specific correlation between miR-23b and TUSC7. TUSC7 inhibited the proliferation, migration and invasion of glioma cells and promoted cellular apoptosis largely bypassing miR-23b. We conclude that the lncRNA TUSC7 acted as a tumor suppressor gene negatively regulated by miR-23b, suggesting a novel therapeutic strategy against gliomas.

Novel Insights into the Role of Long Noncoding RNA in Ocular Diseases

Recent advances have suggested that long noncoding RNAs (lncRNAs) are differentially expressed in ocular tissues and play a critical role in the pathogenesis of different types of eye diseases. Here, we summarize the functions and mechanisms of known aberrantly-expressed lncRNAs and present a brief overview of relevant reports about lncRNAs in such ocular diseases as glaucoma, proliferative vitreoretinopathy (PVR), diabeticretinopathy (DR), and ocular tumors. We intend to highlight comprehensive studies that provide detailed data about the mechanisms of lncRNAs, their applications as diagnostic or prognostic biomarkers, and their potential therapeutic targets. Although our understanding of lncRNAs is still in its infancy, these examples may provide helpful insights into the methods by which lncRNAs interfere with ocular diseases.

Role of long non-coding RNA MIAT in proliferation, apoptosis and migration of lens epithelial cells: a clinical and in vitro study

Age‐related cataract is among the most common chronic disorders of ageing and is the world's leading blinding disorder. Long non‐coding RNAs play important roles in several biological processes and complicated diseases. However, the role of lncRNAs in the setting of cataract is still unknown. Here, we extracted total RNAs from the transparent and age‐matched cataractous human lenses, and determined lncRNA expression profiles using microarray analysis. We found that 38 lncRNAs were differentially expressed between transparent and cataractous lenses. 17 of 20 differentially expressed lncRNAs were further verified by quantitative RT‐PCRs. One top abundant lncRNA, MIAT, was specifically up‐regulated both in the plasma fraction of whole blood and aqueous humor of cataract patients. MIAT knockdown could affect the proliferation, apoptosis and migration of Human lens epithelial cells (HLECs) upon oxidative stress. Posterior capsule opacification (PCO) is a common complication of cataract surgery, which is associated with abnormal production of inflammatory factors. MIAT knockdown could repress tumour necrosis factor‐α‐induced abnormal proliferation and migration of HLECs, suggesting a potential role of MIAT in PCO‐related pathological process. Moreover, we found that MIAT acted as a ceRNA, and formed a feedback loop with Akt and miR‐150‐5p to regulate HLEC function. Collectively, this study provides a novel insight into the pathogenesis of age‐related cataract.

Non-coding RNA profiling of the developing murine lens

Non-coding RNAs (ncRNAs) are emerging as an important player in the regulation of genome integrity and gene expression, and they have been implicated in the pathogenesis of many diseases. The aim of the present study is to identify the repertoire of ncRNAs expressed in the developing mouse lens. We previously reported the mouse lens transcriptome, including mRNA and microRNA (miRNA) profiling at two embryonic (E15 and E18) and four postnatal (P0, P3, P6, and P9) time points. We analyzed the data from small RNA-Seq and mRNA-Seq libraries to investigate the ncRNA profile. Our analysis revealed expression of 12 different classes of ncRNA in the murine lens at six developmental time points. Annotation of small RNA data showed expression of 1,756 antisense ncRNA (asncRNA) in the mouse lens transcriptome. Likewise, we identified 82 P-element-induced wimpy testis (PIWI)-interacting RNA (piRNA), 345 transfer RNA (tRNA), 12 small nuclear RNA (snRNA), 167 small nucleolar RNA (snoRNA), 19 small Cajal body-specific RNA (scaRNA), six ribosomal RNA (rRNA), 18 tRNA-like structures, one MALAT1-associated small cytoplasmic RNA (mascRNA), one Vault RNA (vtRNA), and one Y RNA expressed in the developing mouse lens. In parallel, bioinformatic investigation of mRNA-Seq data identified expression of 1,952 long intergenic ncRNA (lincRNA) in the developing mouse lens. In conclusion, we report a comprehensive ncRNA profile in the murine lens at six developmental time points. To the best of our knowledge, this is first report investigating different classes of ncRNAs in the developing mouse lens and will be monumental in elucidating processes essential for the development of the ocular lens and the maintenance of its transparency.

The long noncoding RNA TUG1 regulates blood-tumor barrier permeability by targeting miR-144

Blood-tumor barrier (BTB) limits the delivery of chemotherapeutic agent to brain tumor tissues. Long non-coding RNAs (lncRNAs) have been shown to play critical regulatory roles in various biologic processes of tumors. However, the role of lncRNAs in BTB permeability is unclear. LncRNA TUG1 (taurine upregulated gene 1) was highly expressed in glioma vascular endothelial cells from glioma tissues. It also upregulated in glioma co-cultured endothelial cells (GEC) from BTB model in vitro. Knockdown of TUG1 increased BTB permeability, and meanwhile down-regulated the expression of the tight junction proteins ZO-1, occludin, and claudin-5. Both bioinformatics and luciferase reporter assays demonstrated that TUG1 influenced BTB permeability via binding to miR-144. Furthermore, Knockdown of TUG1 also down-regulated Heat shock transcription factor 2 (HSF2), a transcription factor of the heat shock transcription factor family, which was defined as a direct and functional downstream target of miR-144. HSF2 up-regulated the promoter activities and interacted with the promoters of ZO-1, occludin, and claudin-5 in GECs. In conclusion, our results indicate that knockdown of TUG1 increased BTB permeability via binding to miR-144 and then reducing EC tight junction protein expression by targeting HSF2. Thus, TUG1 may represent a useful future therapeutic target for enhancing BTB permeability.

Identification and characterization of proliferative retinopathy-related long noncoding RNAs

Proliferative vitreoretinopathy (PVR) is a serious complication of retinal detachment and vitreoretinal surgery, which can lead to severe vision reduction. Long non-coding RNAs (lncRNAs) play critical roles in many biological processes and disease development. We attempted to determine the role of lncRNAs in the setting of PVR. Microarray analysis revealed that 78 lncRNAs were abnormally expressed in the epiretinal membranes (ERMs) of PVR patients, including 48 up-regulated and 30 down-regulated lncRNA transcripts. We subsequently focus on one lncRNA, MALAT1, and investigated its expression pattern in the biofluid of PVR patients. MALAT1 was significantly up-regulated in the cellular and plasma fraction of peripheral blood in PVR patients. MALAT1 expression was obviously reduced after PVR operation. In vitro experiments revealed the role of MALAT1 in regulating RPE proliferation and migration, which is critical for ERMs formation. This study suggests that lncRNAs are the potential regulators of PVR pathology. MALAT1 is a potential prognostic indicator and a target for the diagnosis and gene therapy for PVR diseases.

Pathogenic role of lncRNA-MALAT1 in endothelial cell dysfunction in diabetes mellitus

Long noncoding RNAs (lncRNAs) have important roles in diverse biological processes. Our previous study has revealed that lncRNA-MALAT1 deregulation is implicated in the pathogenesis of diabetes-related microvascular disease, diabetic retinopathy (DR). However, the role of MALAT1 in retinal vasculature remodeling still remains elusive. Here we show that MALAT1 expression is significantly upregulated in the retinas of STZ-induced diabetic rats and db/db mice. MALAT1 knockdown could obviously ameliorate DR in vivo, as shown by pericyte loss, capillary degeneration, microvascular leakage, and retinal inflammation. Moreover, MALAT1 knockdown could regulate retinal endothelial cell proliferation, migration, and tube formation in vitro. The crosstalk between MALAT1 and p38 MAPK signaling pathway is involved in the regulation of endothelial cell function. MALAT1 upregulation represents a critical pathogenic mechanism for diabetes-induced microvascular dysfunction. Inhibition of MALAT1 may serve as a potential target for anti-angiogenic therapy for diabetes-related microvascular complications.

miRNA-dependent cross-talk between VEGF and Ang-2 in hypoxia-induced microvascular dysfunction

Ocular neovascularization is a vision-threatening complication of ischemic retinopathy that develops in various ocular disorders, such as retinopathy of prematurity (ROP) and diabetic retinopathy. Both Ang-2 and VEGF are implicated in this pathogenesis. However, their inter-regulation still remains elusive. Competitive endogenous RNAs (ceRNAs) are messenger RNA (mRNA) molecules that affect each other expression through the competition for the shared miRNA. Herein, we assessed whether the expression of Ang-2 and VEGF is interdependent through the sequestration of common miRNAs. Bioinformatics prediction and 3'-UTR luciferase assay revealed that Ang-2 and VEGF is commonly targeted by miR-351. Silencing either Ang-2 or VEGF increases the availabilities of shared miR-351, therefore reduces the activity of Luc-Ang-2 3'-UTR. The interdependence of VEGF and Ang-2 is miRNA- and 3'-UTR dependent, as silencing Dicer abolishes the interdependence. We also found that miR-351 dependency of VEGF-Ang-2 crosstalk occurs in retinal endothelial cells and rat retinas. miR-351 over-expression significantly reduces the level of VEGF and Ang-2 expression in vivo and in vitro. Overall, miRNA-dependent crosstalk between Ang-2 and VEGF plays a role in hypoxia-induced microvascular response. miRNA-based therapy can affect the expression of Ang-2 and VEGF, which represents a therapeutic potential for the treatment of vascular disease.