Long non-coding RNA nuclear paraspeckle assembly transcript 1 inhibits the apoptosis of retina Müller cells after diabetic retinopathy through regulating miR-497/brain-derived neurotrophic factor axis

Mechanistic and therapeutic perspectives of non-coding RNA-modulated apoptotic signaling in diabetic retinopathy

Diabetic retinopathy (DR), a significant and vision-endangering complication associated with diabetes mellitus, constitutes a substantial portion of acquired instances of preventable blindness. The progression of DR appears to prominently feature the loss of retinal cells, encompassing neural retinal cells, pericytes, and endothelial cells. Therefore, mitigating the apoptosis of retinal cells in DR could potentially enhance the therapeutic approach for managing the condition by suppressing retinal vascular leakage. Recent advancements have highlighted the crucial regulatory roles played by non-coding RNAs (ncRNAs) in diverse biological processes. Recent advancements have highlighted that non-coding RNAs (ncRNAs), including microRNAs (miRNAs), circular RNAs (circRNAs), and long non-coding RNAs (lncRNAs), act as central regulators in a wide array of biogenesis and biological functions, exerting control over gene expression associated with histogenesis and cellular differentiation within ocular tissues. Abnormal expression and activity of ncRNAs has been linked to the regulation of diverse cellular functions such as apoptosis, and proliferation. This implies a potential involvement of ncRNAs in the development of DR. Notably, ncRNAs and apoptosis exhibit reciprocal regulatory interactions, jointly influencing the destiny of retinal cells. Consequently, a thorough investigation into the complex relationship between apoptosis and ncRNAs is crucial for developing effective therapeutic and preventative strategies for DR. This review provides a fundamental comprehension of the apoptotic signaling pathways associated with DR. It then delves into the mutual relationship between apoptosis and ncRNAs in the context of DR pathogenesis. This study advances our understanding of the pathophysiology of DR and paves the way for the development of novel therapeutic strategies.

BDNF Modulation by microRNAs: An Update on the Experimental Evidence

MicroRNAs can interfere with protein function by suppressing their messenger RNA translation or the synthesis of its related factors. The function of brain-derived neurotrophic factor (BDNF) is essential to the proper formation and function of the nervous system and is seen to be regulated by many microRNAs. However, understanding how microRNAs influence BDNF actions within cells requires a wider comprehension of their integrative regulatory mechanisms. Aim: In this literature review, we have synthesized the evidence of microRNA regulation on BDNF in cells and tissues, and provided an analytical discussion about direct and indirect mechanisms that appeared to be involved in BDNF regulation by microRNAs. Methods: Searches were conducted on PubMed.gov using the terms "BDNF" AND "MicroRNA" and "brain-derived neurotrophic factor" AND "MicroRNA", updated on 1 September 2023. Papers without open access were requested from the authors. One hundred and seventy-one papers were included for review and discussion. Results and Discussion: The local regulation of BDNF by microRNAs involves a complex interaction between a series of microRNAs with target proteins that can either inhibit or enhance BDNF expression, at the core of cell metabolism. Therefore, understanding this homeostatic balance provides resources for the future development of vector-delivery-based therapies for the neuroprotective effects of BDNF.

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.

New insights on the role of microRNAs in retinal Müller glial cell function

MicroRNAs belong to the family of non-coding RNAs that participate in cell proliferation, cell death and development. The Müller glial cells are the inherent and specific neuroglia cells in the retinal organisation and play significant roles in retinal neuroprotection, organisational maintenance, inflammation and immunity, regeneration, and the occurrence and development of retinal diseases. However, only a few studies report the underlying mechanism of how miRNAs drive the function of Müller glial cells in the development of retinal diseases. This review aims to summarise the roles of miRNAs in retinal Müller glial cell function, including gliogenesis, inflammation and immunity, regeneration, the development of retinal diseases, and retinal development. This review may point out a novel miRNA-based insight into retinal repair and regeneration. MiRNAs in Müller glial cells may be considered a diagnostic and therapeutic target in the process of retinal repair and regeneration.

Role of Lnc-RNAs in the Pathogenesis and Development of Diabetic Retinopathy

Important advances in diabetic retinopathy (DR) research and management have occurred in the last few years. Neurodegenerative changes before the onset of microvascular alterations have been well established. So, new strategies are required for earlier and more effective treatment of DR, which still is the first cause of blindness in working age. We describe herein gene regulation through Lnc-RNAs as an interesting subject related to DR. Long non-coding RNAs (Lnc-RNAs) are non-protein-coding transcripts larger than 200 nucleotides. Lnc-RNAs regulate gene expression and protein formation at the epigenetic, transcriptional, and translational levels and can impact cell proliferation, apoptosis, immune response, and oxidative stress. These changes are known to take part in the mechanism of DR. Recent investigations pointed out that Lnc-RNAs might play a role in retinopathy development as Metastasis-Associated Lung Adenocarcinoma Transcript (Lnc-MALAT1), Maternally expressed gene 3 (Lnc-MEG3), myocardial-infarction-associated transcript (Lnc-MIAT), Lnc-RNA H19, Lnc-RNA HOTAIR, Lnc-RNA ANRIL B-Raf proto-oncogene (Lnc-RNA BANCR), small nucleolar RNA host gene 16 (Lnc-RNA SNHG16) and others. Several molecular pathways are impacted. Some of them play a role in DR pathophysiology, including the PI3K-Akt signaling axis, NAD-dependent deacetylase sirtuin-1 (Sirti1), p38 mitogen-activated protein kinase (P38/mapk), transforming growth factor beta signaling (TGF-β) and nuclear factor erythroid 2-related factor 2 (Nrf2). The way Lnc-RNAs affect diabetic retinopathy is a question of great relevance. Performing a more in-depth analysis seems to be crucial for researchers if they want to target Lnc-RNAs. New knowledge on gene regulation and biomarkers will enable investigators to develop more specialized therapies for diabetic retinopathy, particularly in the current growing context of precision medicine.

Roles of non-coding RNAs in eye development and diseases

The prevalence of ocular disorders is dramatically increasing worldwide, especially those that cause visual impairment and permanent loss of vision, including cataract, glaucoma, age-related macular degeneration, and diabetic retinopathy. Extensive evidence has shown that ncRNAs are key regulators in various biogenesis and biological functions, controlling gene expression related to histogenesis and cell differentiation in ocular tissues. Aberrant expression and function of ncRNA can lead to dysfunction of visual system and mediate progression of eye disorders. Here, we mainly offer an overview of the role of precise modulation of ncRNAs in eye development and function in patients with eye diseases. We also highlight the challenges and future perspectives in conducting ncRNA studies, focusing specifically on the role of ncRNAs that may hold expanded promise for their diagnostic and therapeutic applications in various eye diseases. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs RNA in Disease and Development > RNA in Disease RNA in Disease and Development > RNA in Development.

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.

Noncoding RNAs Are Promising Therapeutic Targets for Diabetic Retinopathy: An Updated Review (2017-2022)

Diabetic retinopathy (DR) is the most common complication of diabetes. It is also the main cause of blindness caused by multicellular damage involving retinal endothelial cells, ganglial cells, and pigment epithelial cells in adults worldwide. Currently available drugs for DR do not meet the clinical needs; thus, new therapeutic targets are warranted. Noncoding RNAs (ncRNAs), a new type of biomarkers, have attracted increased attention in recent years owing to their crucial role in the occurrence and development of DR. NcRNAs mainly include microRNAs, long noncoding RNAs, and circular RNAs, all of which regulate gene and protein expression, as well as multiple biological processes in DR. NcRNAs, can regulate the damage caused by various retinal cells; abnormal changes in the aqueous humor, exosomes, blood, tears, and the formation of new blood vessels. This study reviews the different sources of the three ncRNAs-microRNAs, long noncoding RNAs, and circular RNAs-involved in the pathogenesis of DR and the related drug development progress. Overall, this review improves our understanding of the role of ncRNAs in various retinal cells and offers therapeutic directions and targets for DR treatment.

RNA-sequencing analysis reveals the long noncoding RNA profile in the mouse myopic retina

Aim: Myopia is a prevalent public health problem. The long noncoding RNA (lncRNA) mechanisms for dysregulated retinal signaling in the myopic eye have remained elusive. The aim of this study was to analyze the expression profiles and possible pathogenic roles of lncRNAs in mouse form-deprived myopia (FDM) retinas. Methods: A mouse FDM model was induced and retinas from the FDM right eyes and the contralateral eyes were collected for RNA sequencing. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, and lncRNA-mRNA coexpression network analyses were conducted to explore the biological functions of the differentially expressed lncRNAs. In addition, the levels of differentially expressed lncRNAs in the myopic retinas were validated by quantitative real-time PCR (qRT-PCR). Fluorescence in situ hybridization (FISH) was used to detect the localization of lncRNAs in mouse retinas. Results: FDM eyes exhibited reduced refraction and increased ocular axial length compared to control fellow eyes. RNA sequencing revealed that there were 655 differentially expressed lncRNAs between the FDM and control retinas. Functional enrichment analysis indicated that the differentially expressed RNAs were mostly enriched in cellular processes, cytokine-cytokine receptor interactions, retinol metabolism, and rhythmic processes. Differentially expressed lncRNAs were validated by qRT-PCR. Additionally, RNA FISH showed that XR_384718.4 (Gm35369) localized in the ganglion cell (GCL) and inner nuclear layers (INL). Conclusion: This study identified the differential expression profiles of lncRNAs in myopic mouse retinas. Our results provide scientific evidence for investigations of myopia and the development of putative interventions in the future.

Long Non-coding RNAs: Pivotal Epigenetic Regulators in Diabetic Retinopathy

Diabetic retinopathy (DR) is a severe complication of diabetes; however, its mechanism is not fully understood. Evidence has recently revealed that long non-coding RNAs (lncRNAs) are abnormally expressed in DR, and lncRNAs may function as pivotal regulators. LncRNAs are able to modulate gene expression at the epigenetic level by acting as scaffolds of histone modification complexes and sponges of binding with microRNAs (miRNAs). LncRNAs are believed to be important epigenetic regulators, which may become beneficial in the diagnosis and therapy of DR. However, the mechanisms of lncRNAs in DR are still unclear. In this review, we summarize the possible functions and mechanisms of lncRNAs in epigenetic regulation to target genes in the progression of DR.

LncRNA XIST restrains the activation of Müller cells and inflammation in diabetic retinopathy via stabilizing SIRT1

BACKGROUND

Recent studies have provided strong evidence that lncRNAs play a functional regulatory role in diabetic retinopathy (DR). The purpose of this study was to investigate the effect of long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) in DR.

METHODS

A DR mouse model was established by intraperitoneal injection of streptozotocin (STZ), and then the mouse retinal Müller cells (mMCs) were isolated from retina tissues of mice. Human retinal Müller cell line (HMCs) and mMCs and were treated with high glucose (HG) to simulate an in vitro DR model. XIST expression was detected by qRT-PCR. Next, XIST overexpression was performed in mMCs and HMCs to examine its effect on the activation of Müller cells and production of pro-inflammatory cytokines. Subsequently, the interaction between XIST and SIRT1 was verified, and the ubiquitination level of SIRT1 as well as the stability of SIRT1 protein were assessed.

RESULTS

XIST was down-regulated in retinal tissues of DR mice and HG-induced HMCs. Overexpression of XIST inhibited HG-induced activation of mMCs and HMCs, and reduced the production of pro-inflammatory cytokines. XIST promoted SIRT1 expression via interacting with SIRT1 and inhibiting the ubiquitination of SIRT1. Furthermore, SIRT1 silencing partly abrogated the effect of XIST overexpression on the activation of mMCs and HMCs as well as the production of pro-inflammatory cytokines induced by HG.

CONCLUSION

We concluded that XIST restrained the activation of Müller cells and the production of pro-inflammatory cytokines via stabilizing SIRT1.

miRNA, lncRNA and circRNA: Targeted Molecules Full of Therapeutic Prospects in the Development of Diabetic Retinopathy

Diabetic retinopathy (DR) is a common diabetic complication and the main cause of blindness worldwide, which seriously affects the quality of life of patients. Studies have shown that noncoding RNA (ncRNA) has distinct differentiated expression in DR and plays an important role in the occurrence and development of DR. ncRNAs represented by microRNAs (miRNAs), lncRNAs (lncRNAs), and circRNAs (circRNAs) have been shown to be widely involved in the regulation of gene expression and affect multiple biological processes of retinopathy. This article will review three RNAs related to the occurrence and development of DR on the basis of previous studies (especially their effects on retinal microangiopathy, retinal pigment epithelial cells, and retinal nerve cells) and discuss their underlying mechanisms and connections. Overall, this review will help us better understand the role of ncRNAs in the occurrence and development of DR and provide ideas for exploring potential therapeutic directions and targets.

The Importance of Non-Coding RNAs in Neurodegenerative Processes of Diabetes-Related Molecular Pathways

Diabetes mellitus (DM) is a complex condition and serious health problem, with growing occurrence of DM-associated complications occurring globally. Persistent hyperglycemia is confirmed as promoting neurovascular dysfunction leading to irreversible endothelial cell dysfunction, increased neuronal cell apoptosis, oxidative stress and inflammation. These collaboratively and individually result in micro- and macroangiopathy as well as neuropathy demonstrated by progressive neuronal loss. Recently, major efforts have been pursued to select not only useful diagnostic and prognostic biomarkers, but also novel therapeutic approaches. Both microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) belong to a class of non-coding RNAs identified in most of the body fluids i.e., peripheral blood, cerebrospinal fluid, brain tissue and neurons. Numerous miRNAs, lncRNAs and their target genes are able to modulate signaling pathways known to play a role in the pathophysiology of progressive neuronal dysfunction. Therefore, they pose as promising biomarkers and treatment for the vast majority of neurodegenerative disorders. This review provides an overall assessment of both miRNAs' and lncRNAs' utility in decelerating progressive nervous system impairment, including neurodegeneration in diabetic pathways.

LncRNA LINC00641 Sponges miR-497-5p to Ameliorate Neural Injury Induced by Anesthesia via Up-Regulating BDNF

Introduction

Ketamine, which is widely used in anesthesia, can induce cortical neurotoxicity in patients. This study aims to investigate the effects of long non-coding RNA LINC00641 on the ketamine-induced neural injury.

Materials and Methods

In this study, rat pheochromocytoma cells (PC12 cells) were used as a cell model and Sprague–Dawley postnatal day 7 rats were used for experiments in vivo. Ketamine-induced aberrant expression levels of LINC00641, miR-497-5p and brain-derived neurotrophic factor (BDNF) were examined by qRT-PCR. The effects of LINC00641 and miR-497-5p on ketamine-induced neural injury were then examined by MTT assays and TUNEL analysis. In addition, the activity of ROS and caspase-3 was measured. The regulatory relationships between LINC00641 and miR-497-5p, miR-497-5p and BDNF were detected by dual-luciferase reporter assay, respectively.

Results

Ketamine induced the apoptosis of PC12 cells, accompanied by down-regulation of LINC00641 and BDNF, and up-regulation of miR-497-5p. LINC00641 overexpression enhanced the resistance to the apoptosis of PC12 cells, while transfection of miR-497-5p had opposite effects. Furthermore, LINC00641 could bind to miR-497-5p and reduce its expression, but indirectly increase the BDNF expression, which was considered as a protective factor in neural injury and activated TrkB/PI3K/Akt pathway.

Conclusion

Collectively, LINC00641/miR-497-5p/BDNF axis was validated to be an important signaling pathway in modulating ketamine-induced neural injury.

Transcriptome Analyses of lncRNAs in A2E-Stressed Retinal Epithelial Cells Unveil Advanced Links between Metabolic Impairments Related to Oxidative Stress and Retinitis Pigmentosa

: Long non-coding RNAs (lncRNAs) are untranslated transcripts which regulate many biological processes. Changes in lncRNA expression pattern are well-known related to various human disorders, such as ocular diseases. Among them, retinitis pigmentosa, one of the most heterogeneous inherited disorder, is strictly related to oxidative stress. However, little is known about regulative aspects able to link oxidative stress to etiopathogenesis of retinitis. Thus, we realized a total RNA-Seq experiment, analyzing human retinal pigment epithelium cells treated by the oxidant agent N-retinylidene-N-retinylethanolamine (A2E), considering three independent experimental groups (untreated control cells, cells treated for 3 h and cells treated for 6 h). Differentially expressed lncRNAs were filtered out, explored with specific tools and databases, and finally subjected to pathway analysis. We detected 3,3'-overlapping ncRNAs, 107 antisense, 24 sense-intronic, four sense-overlapping and 227 lincRNAs very differentially expressed throughout all considered time points. Analyzed lncRNAs could be involved in several biochemical pathways related to compromised response to oxidative stress, carbohydrate and lipid metabolism impairment, melanin biosynthetic process alteration, deficiency in cellular response to amino acid starvation, unbalanced regulation of cofactor metabolic process, all leading to retinal cell death. The explored lncRNAs could play a relevant role in retinitis pigmentosa etiopathogenesis, and seem to be the ideal candidate for novel molecular markers and therapeutic strategies.

Long non-coding RNA DLX6-AS1 regulates neuroblastoma progression by targeting YAP1 via miR-497-5p

AIMS

The lncRNA distal-less homeobox 6 antisense 1 (DLX6-AS1) has been reported to be an oncogenic lncRNA in diverse malignant cancers; however, whether it has oncogenic role in neuroblastoma(NB) remain largely unknown. This study explored the expression status, function and potential mechanism of DLX6-AS1 in NB.

MAIN METHOD

In the current study, a total of 70 human NB tissues and matched adjacent non-tumor tissues were collected. Quantitative PCR (qPCR) was performed to study the expression differences of DLX6-AS1 in tissues and NB cell lines. Proliferation, migration, invasion and EMT status of transfected NB cells were evaluated by WST-1 assay, colony formation unit assay, Transwell assay and qPCR, respectively. The interaction between DLX6-AS1 and its potential targets was confirmed by luciferase reporter assay. Xenograft models were established to evaluate tumor proliferation in vivo.

KEY FINDING

We found that the expression of DLX6-AS1 was significantly increased in both NB tissues and cell lines, and elevated DLX6AS1 expression was positively correlated with advanced stage and poor survival. Proliferation rate, migration and invasion ability, as well as EMT process of NB cells was inhibited after DLX6-AS1 knockdown, meanwhile, the tumor growth in vivo was impaired after DLX6-AS1 inhibition. Further analysis showed that DLX6-AS1 regulates the expression of YAP1 by sponging miR-497-5p. DLX6-AS1 directly interacts with miR-497-5p and reduces the binding of miR-497-5p to YAP1 3'UTR, thus inhibiting the degradation of YAP1 by miR-497-5p.

SIGNIFICANCE

This work demonstrates that DLX6-AS1 partially enhances the proliferation, migration and invasion abilities of NB cells through the miR-497-5p/YAP1 pathway, DLX6-AS1 might act as a promising therapeutic target for NB.

Comparison of expression profiling of circular RNAs in vitreous humour between diabetic retinopathy and non-diabetes mellitus patients

AIMS

To compare circular (circRNA) expression levels in the vitreous humour between PDR (proliferative diabetic retinopathy) and the control groups.

METHODS

The present study collected vitreous humour samples of both the PDR group and the control group (composed of rhegmatogenous retinal detachment, idiopathic macular hole and idiopathic macular epiretinal membrane). All the samples were subjected to circRNA and mRNA sequencing as well as bioinformatic analysis.

RESULTS

The vitreous humour of the PDR and control groups was collected during PPV surgery. Compared to the control group, 122 upregulated and 9 downregulated circRNAs, and 818 upregulated mRNAs and 864 downregulated mRNAs were identified. We further selected 12 circRNAs to validate the RNA expression level by qPCR; results showed that with the exception of 2 downregulated circRNAs the remaining were significantly upregulated in the PDR group, which was consistent with RNA sequencing results. Bioinformatic analysis was conducted to predict possible miRNAs absorbed by circRNAs. Each circRNA could interact with at least five miRNAs. We randomly chose three miRNAs to test the expression level in the vitreous humour by qPCR and found these miRNAs were significantly downregulated in the PDR group.

CONCLUSIONS

The changed profiling of circRNAs in the vitreous humour was reliable and may become a promising biomarker of DR and the circRNA-miRNA-mRNA network. It may also play an important role in the progression of DR.