Ocular-Component-Specific miRNA Expression in a Murine Model of Lens-Induced Myopia

Targeting MicroRNA in myopia: Current insights

Myopia, the most prevalent eye condition, has sparked notable interest regarding its origin and prevention. MicroRNAs (miRNAs) are short, non-coding RNA strands typically consisting of 18-24 nucleotides. They play a central role in post-transcriptional gene regulation and are closely associated with both normal and pathological processes in organisms. Recent advances in next-generation sequencing and bioinformatics have provided novel insights into miRNA expression and its regulatory role in myopia. This review discusses the distinct expression patterns, regulatory functions, and potential pathways of miRNAs involved in the onset and progression of myopia. The primary objective of this review was to provide valuable insights into molecular mechanisms underlying myopia and the contribution of miRNAs. These insights are expected to pave the way for further exploration of the molecular mechanisms, diagnosis, treatment, and clinical applications of myopia.

Crosstalk between heredity and environment in myopia: An overview

In recent years, the prevalence of myopia has gradually increased, and it has become a significant global public health problem in the 21st century, posing a serious challenge to human eye health. Currently, it is confirmed that the development of myopia is attributed to the combined action of genes and environmental factors. Thus, elucidating the risk factors and pathogenesis of myopia is of great significance for the prevention and control of myopia. To elucidate the impact of gene-environment interaction on myopia, we used the Pubmed database to search for literature related to myopia. Search terms are as follows: myopia, genes, environmental factors, gene-environment interaction, and treatment. This paper reviews the effects of gene and environmental interaction on myopia.

CircRNA expression profiles and regulatory networks in the vitreous humor of people with high myopia

Myopia is a global health and economic issue. Circular RNAs (circRNAs) have been shown to play an important role in the pathogenesis of many ocular diseases. We first evaluated the circRNA profiles and possible roles in vitreous humor samples of individuals with high myopia by a competitive endogenous RNA (ceRNA) array. Vitreous humor samples were collected from 15 high myopic (5 for ceRNA array, and 10 for qPCR) and 15 control eyes (5 for ceRNA array, and 10 for qPCR) with idiopathic epiretinal membrane (ERM) and macular hole (MH). 486 circRNAs (339 upregulated and 147 downregulated) and 264 mRNAs (202 upregulated and 62 downregulated) were differentially expressed between the high myopia and control groups. The expression of hsa_circ_0033079 (hsa-circDicer1), hsa_circ_0029989 (hsa-circNbea), hsa_circ_0019072 (hsa-circPank1) and hsa_circ_0089716 (hsa-circEhmt1) were validated by qPCR. Pearson analysis and multivariate regression analysis showed positive and significant correlations for axial length with hsa-circNbea and hsa-circPank1. KEGG analysis showed that the target genes of circRNAs were enriched in the mTOR, insulin, cAMP, and VEGF signaling pathways. GO analysis indicated that circRNAs mainly targeted transcription, cytoplasm, and protein binding. CircRNA-associated ceRNA network analysis and PPI network analysis identified several critical genes for myopia. The expression of circNbea, circPank1, miR-145-5p, miR-204-5p, Nras, Itpr1 were validated by qPCR in the sclera of form-deprivation myopia (FDM) mice model. CircPank1/miR-145-5p/NRAS and circNbea/miR-204-5p/ITPR1 were identified and may be important in the progression of myopia. Our findings suggest that circRNAs may contribute to the pathogenesis of myopia and may serve as potential biomarkers.

MiR-181a-5p may regulate cell proliferation and autophagy in myopia and the associated retinopathy

The mechanism of myopia and the associated retinopathy remains unclear, and dysregulated microRNAs (miRNAs) are implicated in this disease. In this research, we purposed to find out the regulatory function that miRNAs play in myopia and the associated retinopathy. We first performed miRNA microarray analysis in a lens-induced myopia mouse model and found that miR-9-5p, miR-96-5p, miR-182-5p, miR-183-5p, and miR-181a-5p were elevated in the myopic retina. Then, we examined the functions and regulatory mechanisms of miR-181a-5p utilizing the human retinal pigment epithelium (RPE) cell line ARPE-19 by overexpressing miR-181a-5p. RNA sequencing (RNA-Seq) and qRT-PCR analysis were employed to identify differentially expressed genes after transfection. The qRT‒PCR outcomes, immunoblotting, and immunofluorescence indicated that the SGSH expression was significantly hindered through miR-181a-5p overexpression. MiR-181a-5p overexpression has the ability to elevate RPE cell proliferation and induce autophagy by targeting SGSH. We validated the negative influence of miR-181a-5p on the SGSH expression through luciferase reporter assays, which demonstrated its ability to target the 3' untranslated region of SGSH. The reversal of implications of miR-181a-5p overexpression was achieved through SGSH upregulation. We provided novel perspectives into the miR-181a-5p function in regulating myopia development and may serve as a target for therapy and molecular biomarker for myopia.

Analysis and validation of potential ICD-related biomarkers in development of myopia using machine learning

PURPOSE

We aimed to identify and verify potential biomarkers in the development of myopia associated with immunogenic cell death (ICD).

METHODS

We download high myopia (HM) dataset GSE136701 from Gene Expression Omnibus. Differentially expressed genes in HM were identified to overlapped with ICD-related genes. Least absolute shrinkage and selection operator were used to select the Hub genes. Furthermore, the correlation between the hub genes and immune infiltration, immune response activities, and hub genes Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis was investigated using Spearman's rank correlation. Prediction of the miRNAs upstream of the Hub genes was based on the TargetScan database. We used guinea pig lens-induced myopia model's scleral tissues performed quantitative real-time polymerase chain reaction.

RESULTS

We identified overlapped with ICD-related genes (LY96, IL1A, IL33, and AGER) and two genes (LY96 and AGER) as hub genes. Single sample gene set enrichment analysis and Spearman's rank correlation revealed that hub gene expression levels in HM were significantly correlated with the infiltration percentages of CD56dim natural killer cells, macrophages, immature B cells, and the immune response activities of APC co-stimulation and Kyoto Encyclopedia of Genes and Genomes pathways, such as terpenoid backbone biosynthesis, aminoacyl-trna biosynthesis, Huntington's disease, oxidative phosphorylation; there were a few additional signaling pathways compared to normal samples. Additionally, several miRNA were predicted as upstream regulators of LY96 and AGER. LY96 was identified as a significantly differentially expressed biomarker in myopia guinea pig's scleral tissues, as verified by qPCR.

CONCLUSION

LY96 was identified and verified as a ICD-related potential myopia biomarker. Molecular mechanisms or pathways involved in myopia development by LY96 requires further research.

Identification of miR-671-5p and Its Related Pathways as General Mechanisms of Both Form-Deprivation and Lens-Induced Myopia in Mice

Animal models have been indispensable in shaping the understanding of myopia mechanisms, with form-deprivation myopia (FDM) and lens-induced myopia (LIM) being the most utilized. Similar pathological outcomes suggest that these two models are under the control of shared mechanisms. miRNAs play an important role in pathological development. Herein, based on two miRNA datasets (GSE131831 and GSE84220), we aimed to reveal the general miRNA changes involved in myopia development. After a comparison of the differentially expressed miRNAs, miR-671-5p was identified as the common downregulated miRNA in the retina. miR-671-5p is highly conserved and related to 40.78% of the target genes of all downregulated miRNAs. Moreover, 584 target genes of miR-671-5p are related to myopia, from which we further identified 8 hub genes. Pathway analysis showed that these hub genes are enriched in visual learning and extra-nuclear estrogen signaling. Furthermore, two of the hub genes are also targeted by atropine, which strongly supports a key role of miR-671-5p in myopic development. Finally, Tead1 was identified as a possible upstream regulator of miR-671-5p in myopia development. Overall, our study identified the general regulatory role of miR-671-5p in myopia as well as its upstream and downstream mechanisms and provided novel treatment targets, which might inspire future studies.

Characteristic tetraspanin expression patterns mark various tissues during early Xenopus development

The tetraspanins (Tspans) constitute a family of cell surface proteins with four transmembrane domains. Tspans have been found on the plasma membrane and on exosomes of various organelles. Reports on the function of Tspans during the early development of Xenopus have mainly focused on the expression of uroplakins in gametes. Although the roles of extracellular vesicles (EVs) including exosomes have been actively analyzed in cancer research, the contribution of EVs to early development is not well understood. This is because the diffusivity of EVs is not compatible with a very strict developmental process. In this study, we analyzed members of the Tspan family in early development of Xenopus. Expression was prominent in specific organs such as the notochord, eye, cranial neural crest cells (CNCs), trunk neural crest cells, placodes, and somites. We overexpressed several combinations of Tspans in CNCs in vitro and in vivo. Changing the partner changed the distribution of fluorescent-labeled Tspans. Therefore, it is suggested that expression of multiple Tspans in a particular tissue might produce heterogeneity of intercellular communication, which has not yet been recognized.

Differential methylation of microRNA encoding genes may contribute to high myopia

Introduction: High myopia (HM), an eye disorder with a refractive error ≤-6.0 diopters, has multifactorial etiology with environmental and genetic factors involved. Recent studies confirm the impact of alterations in DNA methylation and microRNAs (miRNAs) on myopia. Here, we studied the combined aspects evaluating to the role of methylation of miRNA encoding genes in HM. Materials and Methods: From the genome-wide DNA methylation data of 18 Polish children with HM and 18 matched controls, we retrieved differentially methylated CG dinucleotides localized in miRNA encoding genes. Putative target genes of the highest-ranked miRNAs were obtained from the miRDB and included in overrepresentation analyses in the ConsensusPathDB. Expression of target genes was assessed using the RNA sequencing data of retinal ARPE-19 cell line. Results: We identified differential methylation of CG dinucleotides in promoter regions of MIR3621, MIR34C, MIR423 (increased methylation level), and MIR1178, MIRLET7A2, MIR885, MIR548I3, MIR6854, MIR675, MIRLET7C, MIR99A (decreased methylation level) genes. Several targets of these miRNAs, e.g. GNAS, TRAM1, CTNNB1, EIF4B, TENM3 and RUNX were previously associated with myopia/HM/refractive error in Europeans in genome-wide association studies. Overrepresentation analyses of miRNAs' targets revealed enrichment in pathways/processes related to eye structure/function, such as axon guidance, transcription, focal adhesion, and signaling pathways of TGF-β, insulin, MAPK and EGF-EGFR. Conclusion: Differential methylation of indicated miRNA encoding genes might influence their expression and contribute to HM pathogenesis via disrupted regulation of transcription of miRNAs' target genes. Methylation of genes encoding miRNAs may be a new direction in research on both the mechanisms determining HM and non-invasive indicators in diagnostics.

The Connection between High Myopia Patients and MiR-708a or MiR-148 Expression Levels in Aqueous Studies of Visual Acuity

Myopia goes far beyond the inconvenience it brings. It is a prevailing and vision-threatening eye disease, especially in Asia. Aberrantly expressed miR-708a and miR-148 are critical for accurate diagnosis, good prognosis, and precise response prediction of myopia. In this paper, we aim to examine the potential contributions of miR-708a, miR-148a, and PAX6 to high myopia (HM). First, aqueous samples were taken from 25 exclusively HM eyes and 25 exclusively cataract eyes. For next-generation sequencing and bioinformatics analysis, RNA from sample 30one was used. Twenty more samples were used for RT-qPCR. 341 miRNAs in total were found in HM eyes; 249 mature miRNAs and 17 new miRNAs showed differential expression. The expression of hsa-miR-127-3p, hsa-let-7i-5p, and hsa-miR-98-5p was identified using RT-qPCR. MiR-708a and miR-148, which may be linked to the development of myopia and serve as possible biomarkers, are notably highly expressed in atrial tissues of HM patients. Our findings may help deepen the understanding of the mechanisms behind the high expression of miR-708a and miR-148 in atrial tissues of patients with HM.

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.

MicroRNA-376b-3p ameliorates nonalcoholic fatty liver disease by targeting FGFR1 and regulating lipid oxidation in hepatocytes

AIMS

Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease whose molecular mechanisms remain unclear. This study aimed to explore the role and mechanisms of microRNA-376b-3p in NAFLD.

MATERIALS AND METHODS

We used a microarray to reveal hepatic microRNA expression profiles and validated their expression in cellular and mouse models via qRT-PCR. In vitro, the expression of microRNA-376b-3p was increased by a microRNA-376b-3p mimic and decreased by a microRNA-376b-3p inhibitor. The role and potential mechanisms of microRNA-376b-3p in NAFLD were investigated in mice injected with lentiviral vectors before high-fat diet (HFD) feeding, and the direct target gene was explored using a dual-luciferase reporter gene assay and confirmed by Western blotting.

KEY FINDINGS

Microarray analysis and subsequent validation showed that the expression of microRNA-376b-3p was downregulated by nearly 90 % in the livers of HFD-fed mice and by >50 % in free fatty acid-stimulated hepatocytes. Overexpression of microRNA-376b-3p markedly ameliorated hepatic lipid accumulation, which was attributable to an increase in fatty acid oxidation. Conversely, inhibition of miR-376b-3p exhibited the opposite effects. The luciferase reporter assay indicated that Fgfr1 is a direct target gene of miR-376b-3p. Fgfr1 intervention eliminated the effect of miR-376b-3p on the lipid oxidation pathway and hepatocyte steatosis, which suggests that miR-376b-3p regulates fatty acid oxidation by targeting Fgfr1 to influence NAFLD development.

SIGNIFICANCE

miR-376b-3p was downregulated in NAFLD and has a novel regulatory role in lipid oxidation through a miR-376b-3p-Fgfr1-dependent mechanism. Thus, miR-376b-3p may serve as a potential diagnostic marker or therapeutic target for NAFLD.

Molecular and endocrine mechanisms involved in preterm birth

Preterm birth is a worldwide social problem. Incidence rates may vary from 5 to 18% of all deliveries, with important differences observed between developed and developing countries. Preterm birth has a negative impact on newborns and neonatal mortality and morbidity are high. Despite improvements in modern neonatal care, we know little of the mechanisms that determine the onset and development of preterm birth. Infections seem to be one the most important triggers, determining the activation of protective mechanisms aimed at ending the pregnancy and safeguarding the health of the woman. However, threatened preterm birth often occurs even in women who do not have any ongoing infectious process. Of these, which are the majority, the causes and the activation mechanisms remain unknown or unclear; however, there are several molecular and endocrine mechanisms that finally lead to preterm birth. In this review, we seek to shed light and summarize the molecular and endocrine mechanisms underlying the development of preterm birth. Their understanding could help us to understand the dynamics of premature birth but, above all, to allow an early diagnosis and primary prevention of the problem.

Hsa-miR-142-3p reduces collagen I in human scleral fibroblasts by targeting TGF-β1 in high myopia

High myopia has been continually increasing globally until now and often results in visual impairment. Scleral extracellular matrix (ECM) remodeling is considered a common factor contributing to progression of myopia. However, the role of microRNAs (miRNAs) in regulating scleral ECM organization is not well understood. We aimed to explore the effect and regulatory mechanism of hsa-miR-142-3p on collagen I in human scleral fibroblasts in high myopia. First, next-generation sequencing was conducted to identify 37 miRNAs differentially expressed in the aqueous humor of high myopia samples and control samples. Furthermore, hsa-miR-142-3p in the aqueous humor was found to positively relate to the ocular axial length. Besides, the results of immunofluorescence and Western blot assay indicated that hsa-miR-142-3p overexpression decreased collagen I expression in the human fetal scleral fibroblasts (HFSFs); while hsa-miR-142-3p downregulation increased collagen I. Moreover, hsa-miR-142-3p targets TGFβ-1 gene expression. Quantitative polymerase chain reaction (qPCR) and Western blot analysis showed that miRNA 142-3p reduced TGFβ-1 expression while an inhibitor had an opposite effect. Therefore, there is an inverse relationship between changes in miR-142-3p expression levels and those of collagen1a1 in human scleral fibroblasts. Such a dependence suggests that miR-142-3p may be a target to improve therapeutic management of this condition.

Advances in biomedical study of the myopia-related signaling pathways and mechanisms

Myopia has become one of the most critical health problems in the world with the increasing time spent indoors and increasing close work. Pathological myopia may have multiple complications, such as myopic macular degeneration, retinal detachment, cataracts, open-angle glaucoma, and severe cases that can cause blindness. Mounting evidence suggests that the cause of myopia can be attributed to the complex interaction of environmental exposure and genetic susceptibility. An increasing number of researchers have focused on the genetic pathogenesis of myopia in recent years. Scleral remodeling and excessive axial elongating induced retina thinning and even retinal detachment are myopia's most important pathological manifestations. The related signaling pathways are indispensable in myopia occurrence and development, such as dopamine, nitric oxide, TGF-β, HIF-1α, etc. We review the current major and recent progress of biomedicine on myopia-related signaling pathways and mechanisms.

MicroRNA-29a May Influence Myopia Development by Regulating Collagen I

PURPOSE

The aim of this study was to characterize the regulatory role of microRNA-29a (miR-29a) in myopia, providing support for potential biomarkers and new therapeutic targets of myopia in humans.

METHODS

The miR-29a expression level was detected in the aqueous humor and peripheral blood plasma of 21 high myopic patients and eight cataract control patients using quantitative polymerase chain reaction. iTRAQ analysis of proteomes was conducted to show the regulatory effect of miR-29a on human scleral fibroblasts (SFs) cultured in vitro. We also assessed proliferation, migration, and collagen I synthesis in SF cells, mediated by miR-29a.

RESULTS

MiR-29a expression was significantly higher in the aqueous humor of highly myopic patients than in the cataract control patients (fold change: 4.861, p = 0.001). miR-29a inhibited the synthesis of type I collagen in human SF cells and enhanced cell migration, but had no significant effect on cell proliferation.

CONCLUSION

MiR-29a was highly expressed in aqueous humor of myopia patients and inhibited the synthesis of type I collagen in human SF cells in vivo, thereby it may play an important role in myopia development.

Association of hsa-mir-328-3p Expression in Whole Blood With Optical Density of Retinal Pigment Epithelial Cells

AIM

To investigate the association of the pair box 6 gene (PAX6) and hsa-miR-328-3p with optical density of macular pigment.

MATERIALS AND METHODS

We evaluated 112 individuals (34 with moderate myopia, eight with high-degree myopia, and 70 healthy individuals). The optical density of macular pigment was measured using single-wavelength reflectometry. DNA and RNA were extracted from whole blood samples. Expression of hsa-miR-328-3p and genotyping of single-nucleotide polymorphism of PAX6 (rs662702) were performed using Applied Biosystems 7900HT real-time polymerase chain reaction system. Optical density of retinal pigment epithelial cells was evaluated using Fundus plus camera.

RESULTS

In the group with myopia, with increasing ∆Ct hsa-miR-328-3p, the median optical density of the retinal pigment epithelium decreased statistically significantly (p<0.032). No statistically significant association was found between SNP rs662702 genotype variant of the PAX6 gene and the optical density of the retinal pigment epithelium.

CONCLUSION

The increased expression of hsa-miR-328-3p in the blood indicates a decrease in the optical density of the retinal pigment epithelium in those with myopia.

IMI 2021 Yearly Digest

Purpose

The International Myopia Institute (IMI) Yearly Digest highlights new research considered to be of importance since the publication of the first series of IMI white papers.

Methods

A literature search was conducted for articles on myopia between 2019 and mid-2020 to inform definitions and classifications, experimental models, genetics, interventions, clinical trials, and clinical management. Conference abstracts from key meetings in the same period were also considered.

Results

One thousand articles on myopia have been published between 2019 and mid-2020. Key advances include the use of the definition of premyopia in studies currently under way to test interventions in myopia, new definitions in the field of pathologic myopia, the role of new pharmacologic treatments in experimental models such as intraocular pressure-lowering latanoprost, a large meta-analysis of refractive error identifying 336 new genetic loci, new clinical interventions such as the defocus incorporated multisegment spectacles and combination therapy with low-dose atropine and orthokeratology (OK), normative standards in refractive error, the ethical dilemma of a placebo control group when myopia control treatments are established, reporting the physical metric of myopia reduction versus a percentage reduction, comparison of the risk of pediatric OK wear with risk of vision impairment in myopia, the justification of preventing myopic and axial length increase versus quality of life, and future vision loss.

Conclusions

Large amounts of research in myopia have been published since the IMI 2019 white papers were released. The yearly digest serves to highlight the latest research and advances in myopia.

Ambient Light Regulates Retinal Dopamine Signaling and Myopia Susceptibility

Purpose

Exposure to high-intensity or outdoor lighting has been shown to decrease the severity of myopia in both human epidemiological studies and animal models. Currently, it is not fully understood how light interacts with visual signaling to impact myopia. Previous work performed in the mouse retina has demonstrated that functional rod photoreceptors are needed to develop experimentally-induced myopia, alluding to an essential role for rod signaling in refractive development.

Methods

To determine whether dim rod-dominated illuminance levels influence myopia susceptibility, we housed male C57BL/6J mice under 12:12 light/dark cycles with scotopic (1.6 × 10⁻³ candela/m²), mesopic (1.6 × 10¹ cd/m²), or photopic (4.7 × 10³ cd/m²) lighting from post-natal day 23 (P23) to P38. Half the mice received monocular exposure to −10 diopter (D) lens defocus from P28–38. Molecular assays to measure expression and content of DA-related genes and protein were conducted to determine how illuminance and lens defocus alter dopamine (DA) synthesis, storage, uptake, and degradation and affect myopia susceptibility in mice.

Results

We found that mice exposed to either scotopic or photopic lighting developed significantly less severe myopic refractive shifts (lens treated eye minus contralateral eye; –1.62 ± 0.37D and −1.74 ± 0.44D, respectively) than mice exposed to mesopic lighting (–3.61 ± 0.50D; P < 0.005). The 3,4-dihydroxyphenylacetic acid /DA ratio, indicating DA activity, was highest under photopic light regardless of lens defocus treatment (controls: 0.09 ± 0.011 pg/mg, lens defocus: 0.08 ± 0.008 pg/mg).

Conclusions

Lens defocus interacted with ambient conditions to differentially alter myopia susceptibility and DA-related genes and proteins. Collectively, these results show that scotopic and photopic lighting protect against lens-induced myopia, potentially indicating that a broad range of light levels are important in refractive development.

microRNA profiling in the aqueous humor of highly myopic eyes using next generation sequencing

PURPOSE

To characterize microRNAs (miRNAs) and their possible roles in high myopia by using next generation sequencing.

METHODS

Aqueous humor samples were obtained from 25 highly myopic eyes and 25 cataract eyes at the onset of surgery. miRNA next generation sequencing and bioinformatics analyses were performed using RNA extracted from 30 samples. The remaining 20 samples were used for quantitative polymerase chain reaction validation of sequencing results.

RESULTS

A total of 341 microRNAs were detected in the aqueous humor samples of highly myopic eyes; 201 miRNAs were detected in the aqueous humor samples of cataractous control eyes. A total of 249 mature miRNAs and 17 novel miRNAs were differentially expressed during myopia. Possible pathways regulated by these aberrantly expressed miRNAs included the TNF, MAPK, PI3K-Akt, and HIF-1 signaling pathways. The relative expression patterns of hsa-let-7i-5p, hsa-miR-127-3p, and hsa-miR-98-5p were confirmed by quantitative polymerase chain reaction.

CONCLUSIONS

The current study provided an overall view of miRNA profiling in the aqueous humor of highly myopic eyes. These profiles may be associated with myopia pathogenesis, and are potential biomarkers.

RNA sequencing analysis of long non-coding RNA expression in ocular posterior poles of guinea pig myopia models

Purpose

To detect the differential expression of long non-coding RNAs (lncRNAs) in the ocular posterior poles of two guinea pig myopia models and explore the pathogenic role of lncRNAs in myopia.

Methods

Form-deprived myopia (FDM) and lens-induced myopia (LIM) models were induced in guinea pig right eyes by wearing a translucent latex balloon head mask and a -10.00 diopter (D) lens, respectively. Ocular biometric parameters were measured biweekly. At 6 weeks after the induction of myopia, the guinea pig eyeballs were processed for hematoxylin and eosin staining to examine the ocular morphology. The ocular posterior poles from the normal control, FDM, and LIM groups were collected to analyze the differential expression of lncRNAs between the groups with high-throughput RNA sequencing (RNA-seq). Further, the lncRNA-mRNA colocation network was delineated to predict the functions of the differentially expressed lncRNAs. Last, Gene Ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed on the colocated mRNAs of the differentially expressed lncRNAs. Additionally, the expression of the most differentially expressed lncRNAs in the myopia-induced eyes and the contralateral eyes was validated with quantitative real-time PCR (qPCR).

Results

Compared with the normal controls and the contralateral eyes, the myopia-induced eyes in the FDM and LIM groups exhibited decreased scleral and choroidal thicknesses, reduced refraction, and increased ocular axial length but without changes in the corneal curvature radius at 6 weeks after myopia was induced. RNA-seq showed that 372 and 247 lncRNAs were differentially expressed in the FDM and LIM groups, respectively, in comparison to the normal counterparts. There were 380 differentially expressed lncRNAs in the LIM group compared to the FDM group. The GO and KEGG analyses showed that the colocated mRNAs of the differentially expressed lncRNAs were enriched in cellular components such as the extracellular matrix (ECM) structural constituent; in molecular functions such as kinase activity, metabolism, and growth; as well as in pathways including ECM-receptor interaction, glycosaminoglycan degradation, and mucin type O-Glycan biosynthesis. The expression patterns of the selected lncRNAs were verified with qPCR.

Conclusions

High-throughput RNA-seq revealed previously undescribed lncRNA expression profiling in guinea pig FDM and LIM models. These results may shed light on the molecular pathogenesis of myopia and provide clues for interventional targets for this highly prevalent visual disorder.