MicroRNA-24 regulates the processing of latent TGFβ1 during cyclic mechanical stress in human trabecular meshwork cells through direct targeting of FURIN

MicroRNA signatures in the pathogenesis and therapy of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a persistent inflammatory illness of the gastrointestinal tract (GIT) triggered by an inappropriate immune response to environmental stimuli in genetically predisposed persons. Unfortunately, IBD patients' quality of life is negatively impacted by the symptoms associated with the disease. The exact etiology of IBD pathogenesis is not fully understood, but the emerging research indicated that the microRNA (miRNA) plays an important role. miRNAs have been documented to possess a significant role in regulating pro- and anti-inflammatory pathways, in addition to their roles in several physiological processes, including cell growth, proliferation, and apoptosis. Variations in the miRNA profiles might be a helpful prognostic indicator and a valuable tool in the differential diagnosis of IBD. Most interestingly, these miRNAs have a promising therapeutic target in several pre-clinical animal studies and phase 2 clinical studies to alleviate inflammation and improve patient's quality of life. This comprehensive review discusses the current knowledge about the significant physiological role of different miRNAs in the health of the intestinal immune system and addresses the role of the most relevant differentially expressed miRNAs in IBD, identify their potential targets, and emphasize their diagnostic and therapeutic potential for future research.

Identification of a circulating three-miRNA panel for the diagnosis of primary open angle glaucoma

PURPOSE

Conventional diagnosis of primary open angle glaucoma (POAG) needs a combination of ophthalmic examinations. An efficient assay is urgently needed for a timely POAG diagnosis. We aim to explore differential expressions of circulating microRNAs (miRNA) and provide novel miRNA biomarkers for POAG diagnosis.

METHODS

A total of 180 POAG patients and 210 age-related cataract (ARC) patients were enrolled. We collected aqueous humor (AH) and plasma samples from the recruited patients. The expressions of candidate miRNAs were measured using quantitative real time polymerase chain reaction. The diagnostic ability of candidate miRNAs was analyzed by receiver operating characteristic curve.

RESULTS

The expressions of miR-21-5p and miR-29b-3p were downregulated significantly in AH and plasma of POAG and miR-24-3p expression was significantly increased in AH and plasma of POAG, comparing with those of ARC. A three-miRNA panel was constructed by a binary logistic regression. And the panel could differentiate between POAG and ARC with an area under the curve of 0.8867 (sensitivity = 78.0%, specificity = 83.3%) in aqueous humor and 0.7547 (sensitivity = 73.8%, specificity = 81.2%) in plasma. Next, we verified the three-miRNA panel working as a potential diagnostic biomarker stable and reliable. At last, we identified related function and regulation pathways in vitro.

CONCLUSIONS

In conclusion, we built and identified a circulating three-miRNA panel as a potential diagnostic biomarker for POAG. It may be developed into an efficient assay and help improve the POAG diagnosis in the future.

Identification of biomarker candidates for exfoliative glaucoma from autoimmunity profiling

BACKGROUND

Exfoliative glaucoma (XFG) is a subtype of open-angle glaucoma characterized by distinctive extracellular fibrils and a yet unknown pathogenesis potentially involving immune-related factors. The aim of this exploratory study was to identify biomarkers for XFG using data from autoimmunity profiling performed on blood samples from a Scandinavian cohort of patients.

METHODS

Autoantibody screening was analyzed against 258 different protein fragments in blood samples taken from 30 patients diagnosed with XFG and 30 healthy donors. The 258 protein fragments were selected based on a preliminary study performed on 3072 randomly selected antigens and antigens associated with the eye. The "limma" package was used to perform moderated t-tests on the proteomic data to identify differentially expressed reactivity between the groups.

RESULTS

Multiple associated genes were highlighted as possible biomarker candidates including FUT2, CDH5, and the LOX family genes. Using seven variables, our binary logistic regression model was able to classify the cases from the controls with an AUC of 0.85, and our reduced model using only one variable corresponding to the FUT2 gene provided an AUC of 0.75, based on LOOCV. Furthermore, over-representation gene analysis was performed to identify pathways that were associated with antigens differentially bound to self-antibodies. This highlighted the enrichment of pathways related to collagen fibril formation and the regulatory molecules mir-3176 and mir-876-5p.

CONCLUSIONS

This study suggests several potential biomarkers that may be useful in developing further models of the pathology of XFG. In particular, CDH5, FUT2, and the LOX family seem to have a relationship which merits additional exploration.

Mechanical regulation of the Notch signaling pathway

The mechanical regulation of Notch signaling is an emerging area of interest in cell biology. Notch is essential in many physiological processes in which mechanical stress plays an important role. This review provides an overview of the mechanoregulation of Notch signaling in multiple steps of the pathway. First, we discuss the current knowledge on the direct mechanoregulation of Notch receptor maturation and localization to the membrane and the effect of mechanical stress on the Notch components. Next, we explore how ligand-receptor interactions and membrane dynamics are possible subjects to mechano-regulation, emphasizing the role of cytoskeletal interactions, membrane stiffness, and endocytic complex formation. We further delve into the necessity of tension generation for negative regulatory region (NRR) domain unfolding, facilitated by ligand endocytosis and other microforces. Additionally, we examine the indirect mechano-regulation of S2 and S3 cleavages. Finally, we discuss the mechanoregulation of the Notch intracellular domain (NICD) trafficking and nuclear entry and the impact of mechanical stress on heterochromatin dynamics and nuclear NICD interactions. This review aims to draw attention to the intricate interplay between mechanical cues and Notch signaling regulation, offering novel insights into the multifaceted nature of cellular mechanobiology.

Construction of miRNA-mRNA regulatory network indicates potential biomarkers for primary open-angle glaucoma

BACKGROUND

Trabecular meshwork (TM) dysfunction-induced elevation of intraocular pressure has been identified as the main risk factor of irreversible optic nerve injury in Primary open‑angle glaucoma (POAG). Increasing evidences suggest that microRNA (miRNA) plays a vital role in the pathogenesis of POAG. This study aims to construct a miRNA-mRNA regulatory network and identify biomarkers for POAG.

METHODS

miRNAs and mRNAs expression profiling of TM samples from controls and POAG patients were assessed through microarray analysis. Target genes of differentially expressed miRNAs (DEmiRNAs) were predicted by miEAA and miRNet. Then GO and KEGG pathway analysis of differentially expressed mRNAs (DEmRNAs) were performed. PPI of top 30 hub genes was identified and miRNA-mRNA network was established by STRING database and Cytoscape software. GSE27276 and GSE105269 datasets were used to verify the expression of hub genes and to predict potential biomarkers in TM and aqueous humor (AH) for POAG, respectively. Finally, GSEA analysis was conducted to estimate the main signaling pathway of POAG pathogenesis.

RESULTS

A total of 29 up-regulated and 7 down-regulated miRNAs, 923 up-regulated and 887 down-regulated mRNAs were identified in TM of POAG compared with controls. Target genes and DEmRNAs were mainly enriched in nitric oxide biosynthetic process, vasopressin-regulated water reabsorption, and so on. Through miRNA-mRNA network construction, top 30 hub genes were regulated by 24 DEmiRNAs. 8 genes were aberrantly expressed in dataset GSE27276. 3 genes (CREB1, CAPZA2, SLC2A3) and 2 miRNAs (miR-106b-5p, miR-15a-5p) were identified as potential biomarkers for POAG in TM and AH, respectively. GSEA analysis revealed that these 3 genes modulated POAG through different pathways.

CONCLUSION

In this study, construction of miRNA-mRNA network and identification of biomarkers provide a novel insight into the pathogenesis, early diagnosis and treatment for POAG.

Reduction-responsive polymeric micelles for trans-corneal targeted delivery of microRNA-21-5p and glaucoma-specific gene therapy

The therapeutic value of microRNA (miRNA) for the treatment of glaucoma has become a focus of attention. However, naked miRNA cannot cross the corneal barrier and reach the target tissue by itself. Thus, the precise transport of miRNA to the target sites is key to the success of gene therapy. Herein, we selected a miRNA, namely miR-21-5p, based on its unique intraocular pressure (IOP) mechano-sensing property. Moreover, a biocompatible polymeric poly(L-lysine) (PLL) micelle conjugated with collagenase and ABCA1 antibody was judiciously constructed to achieve the trans-corneal and target delivery of miR-21-5p to the trabecular meshwork (TM) and Schlemm's canal (SC) tissues inside the eye. The topically administrated PLL micelles as an eye drop successfully crossed the cornea with the help of collagenase and then preferentially accumulated in the target TM/SC tissues under the guidance of the ABCA1 antibody. When endocytosed by TM/SC cells, the PLL micelles could be decomposed in the reductive lysosomal environment to release miR-21-5p for successfully lowering the IOP by activating the miR-21-5p/eNOS/MMP9 signaling axis, which will open new prospects for glaucoma-specific gene therapy.

The Application of MicroRNAs in Glaucoma Research: A Bibliometric and Visualized Analysis

Glaucoma is similar to a neurodegenerative disorder and leads to global irreversible loss of vision. Despite extensive research, the pathophysiological mechanisms of glaucoma remain unclear, and no complete cure has yet been identified for glaucoma. Recent studies have shown that microRNAs can serve as diagnostic biomarkers or therapeutic targets for glaucoma; however, there are few bibliometric studies that focus on using microRNAs in glaucoma research. Here, we have adopted a bibliometric analysis in the field of microRNAs in glaucoma research to manifest the current tendencies and research hotspots and to present a visual map of the past and emerging tendencies in this field. In this study, we retrieved publications in the Web of Science database that centered on this field between 2007 and 2022. Next, we used VOSviewer, CiteSpace, Scimago Graphica, and Microsoft Excel to present visual representations of a co-occurrence analysis, co-citation analysis, tendencies, hotspots, and the contributions of authors, institutions, journals, and countries/regions. The United States was the main contributor. Investigative Ophthalmology and Visual Science has published the most articles in this field. Over the past 15 years, there has been exponential growth in the number of publications and citations in this field across various countries, organizations, and authors. Thus, this study illustrates the current trends, hotspots, and emerging frontiers and provides new insight and guidance for searching for new diagnostic biomarkers and clinical trials for glaucoma in the future. Furthermore, international collaborations can also be used to broaden and deepen the field of microRNAs in glaucoma research.

Glaucoma: Novel antifibrotic therapeutics for the trabecular meshwork

Glaucoma is a chronic and progressive neurodegenerative disease characterized by the loss of retinal ganglion cells and visual field defects, and currently affects around 1% of the world's population. Elevated intraocular pressure (IOP) is the best-known modifiable risk factor and a key therapeutic target in hypertensive glaucoma. The trabecular meshwork (TM) is the main site of aqueous humor outflow resistance and therefore a critical regulator of IOP. Fibrosis, a reparative process characterized by the excessive deposition of extracellular matrix components and contractile myofibroblasts, can impair TM function and contribute to the pathogenesis of primary open-angle glaucoma (POAG) as well as the failure of minimally invasive glaucoma surgery (MIGS) devices. This paper provides a detailed overview of the current anti-fibrotic therapeutics targeting the TM in glaucoma, along with their anti-fibrotic mechanisms, efficacy as well as the current research progress from pre-clinical to clinical studies.

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.

Advances in targeting the extracellular matrix for glaucoma therapy: current updates

INTRODUCTION

Elevated intraocular pressure (IOP) is a well-recognized risk factor for development of primary open angle glaucoma (POAG), a leading cause of irreversible blindness. Ocular hypertension is associated with excessive extracellular matrix (ECM) deposition in trabecular meshwork (TM) resulting in increased aqueous outflow resistance and elevated IOP. Hence, therapeutic options targeting ECM remodeling in TM to lower IOP in glaucomatous eyes are of considerable importance.

AREAS COVERED

This paper discusses the complex process of ECM regulation in TM and explores promising therapeutic targets. The role of Transforming Growth Factor-β as a central player in ECM deposition in TM is discussed. We elaborate the key regulatory processes involved in its activation, release, signaling, and cross talk with other signaling pathways including Rho GTPase, Wnt, integrin, cytokines, and renin-angiotensin-aldosterone. Further, we summarize the therapeutic agents that have been explored to target ECM dysregulation in TM.

EXPERT OPINION

Targeting molecular pathways to reduce ECM deposition and/or enhance its degradation are of considerable significance for IOP lowering. Challenges lie in pinpointing specific targets and designing drug delivery systems to precisely interact with pathologically active/inactive signaling. Recent advances in monoclonal antibodies, fusion molecules, and vectored nanotechnology offer potential solutions.

Augmentation of natriuretic peptide (NP) receptor A and B (NPR-A and NPR-B) and cyclic guanosine monophosphate (cGMP) signalling as a therapeutic strategy in heart failure

INTRODUCTION

Heart failure is a complex, debilitating condition and despite advances in treatment, it remains a significant cause of morbidity and mortality worldwide. Therefore, the need for alternative treatment strategies is essential. In this review, we explore the therapeutic strategies of augmenting natriuretic peptide receptors (NPR-A and NPR-B) and cyclic guanosine monophosphate (cGMP) in heart failure.

AREAS COVERED

We aim to provide an overview of the evidence of preclinical and clinical studies on novel heart failure treatment strategies. Papers collected in this review have been filtered and screened following PubMed searches. This includes epigenetics, modulating enzyme activity in natriuretic peptide (NP) synthesis, gene therapy, modulation of downstream signaling by augmenting soluble guanylate cyclase (sGC) and phosphodiesterase (PDE) inhibition, nitrates, c-GMP-dependent protein kinase, synthetic and designer NP and RNA therapy.

EXPERT OPINION

The novel treatment strategies mentioned above have shown great potential, however, large randomized controlled trials are still lacking. The biggest challenge is translating the results seen in preclinical trials into clinical trials. We recommend a multi-disciplinary team approach with cardiologists, geneticist, pharmacologists, bioengineers, researchers, regulators, and patients to improve heart failure outcomes. Future management can involve telemedicine, remote monitoring, and artificial intelligence to optimize patient care.

MicroRNA-210-3p mediates trabecular meshwork extracellular matrix accumulation and ocular hypertension - Implication for novel glaucoma therapy

Elevation of intraocular pressure (IOP) is a major, controllable risk factor of primary open-angle glaucoma (POAG). Transforming growth factor-β2 (TGF-β2)-induced excessive accumulation of extracellular matrix (ECM) in the trabecular meshwork (TM) has been demonstrated to contribute significantly to the development of high IOP. We previously showed that treatment with salidroside (Sal), a plant-derived glucoside, can ameliorate the TGF-β2-induced ECM expression in cultured human TM cells and reduce TGF-β2-induced ocular hypertension in mice. In the current study, its underlying molecular mechanism associated with microRNA-210-3p (miR-210-3p) was characterized. We discovered that, in TM tissues of POAG patients, there was an increase in miR-210-3p. And miR-210-3p mediated a portion of the pathological effects of TGF-β2 in vitro (excessive accumulation of ECM in cultured human TM cells) and in vivo (mouse ocular hypertension and ECM accumulation in the TM). Most interestingly, miR-210-3p was down-regulated by Sal, which appeared to mediate a significant portion of its IOP-lowering effect. Thus, these results shed light on the probable molecular mechanisms of TGF-β2 and Sal and indicate that manipulation of miR-210-3p level/activity represents a potential new therapeutic strategy for POAG.

Lentiviral Vectors for Ocular Gene Therapy

This review offers the basics of lentiviral vector technologies, their advantages and pitfalls, and an overview of their use in the field of ophthalmology. First, the description of the global challenges encountered to develop safe and efficient lentiviral recombinant vectors for clinical application is provided. The risks and the measures taken to minimize secondary effects as well as new strategies using these vectors are also discussed. This review then focuses on lentiviral vectors specifically designed for ocular therapy and goes over preclinical and clinical studies describing their safety and efficacy. A therapeutic approach using lentiviral vector-mediated gene therapy is currently being developed for many ocular diseases, e.g., aged-related macular degeneration, retinopathy of prematurity, inherited retinal dystrophies (Leber congenital amaurosis type 2, Stargardt disease, Usher syndrome), glaucoma, and corneal fibrosis or engraftment rejection. In summary, this review shows how lentiviral vectors offer an interesting alternative for gene therapy in all ocular compartments.

Differentially Expressed miRNAs in Ulcerative Colitis and Crohn’s Disease

Differential microRNA (miRNA or miR) regulation is linked to the development and progress of many diseases, including inflammatory bowel disease (IBD). It is well-established that miRNAs are involved in the differentiation, maturation, and functional control of immune cells. miRNAs modulate inflammatory cascades and affect the extracellular matrix, tight junctions, cellular hemostasis, and microbiota. This review summarizes current knowledge of differentially expressed miRNAs in mucosal tissues and peripheral blood of patients with ulcerative colitis and Crohn’s disease. We combined comprehensive literature curation with computational meta-analysis of publicly available high-throughput datasets to obtain a consensus set of miRNAs consistently differentially expressed in mucosal tissues. We further describe the role of the most relevant differentially expressed miRNAs in IBD, extract their potential targets involved in IBD, and highlight their diagnostic and therapeutic potential for future investigations.

The role of microRNAs in glaucoma

In this review, we aim to provide a comprehensive summary of the various microRNAs (miRNAs) shown to be involved in glaucoma and intraocular pressure regulation. miRNAs are short, single-stranded, and noncoding RNAs that regulate gene expression in a number of physiological conditions and human diseases, including glaucoma. Numerous miRNAs display differential expression in glaucoma-affected tissues, such as aqueous humor, tears, trabecular meshwork, and retina analyzed from patients and animal models, suggesting their potential involvement in glaucoma pathogenesis. Several studies summarized here have also investigated the challenge of delivering intact miRNAs to target tissues in order to develop miRNA-based glaucoma therapies. We extend these reports by conducting an additional layer of analysis that integrates the interaction between glaucoma-related miRNAs and glaucoma-associated genes. We conclude with a comprehensive discussion of the therapeutic potential of miRNAs, the cellular pathways that link these miRNAs together, and the most promising miRNAs for future glaucoma research.

Versatile role of miR-24/24-1*/24-2* expression in cancer and other human diseases

MiRNAs (miRs) have been proven to be well-validated therapeutic targets. Emerging evidence has demonstrated that intricate, intrinsic and paradoxical functions of miRs are context-dependent because of their multiple upstream regulators, broad spectrum of downstream molecular targets and distinct expression in various tissues, organs and disease states. Targeted therapy has become an emerging field of research. One key for the development of successful miR-based/targeted therapy is to acquire integrated knowledge of its regulatory network and its association with disease phenotypes to identify critical nodes of the underlying pathogenesis. Herein, we systematically summarized the comprehensive role of miR-24-3p (miR-24), along with its passenger strands miR-24-1-5p* (miR-24-1) and miR-24-2-5p* (miR-24-2), emphasizing their microenvironment, intracellular targets, and associated gene networks and regulatory phenotypes in 18 different cancer types and 13 types of other disorders. MiR-24 targets and regulates numerous genes in various cancer types and enhances the expression of several oncogenes (e.g., cMyc, BCL2 and HIF1), which are challenging in terms of druggability. In contrast, several tumor suppressor proteins (p21 and p53) have been reported to be downregulated by miR-24. MiR-24 also regulates the cell cycle and is associated with numerous cancer hallmarks such as apoptosis, proliferation, metastasis, invasion, angiogenesis, autophagy, drug resistance and other diseases pathogenesis. Overall, miR-24 plays an emerging role in the diagnosis, prognosis and pathobiology of various diseases. MiR-24 is a potential target for targeted therapy in the era of precision medicine, which expands the landscape of targetable macromolecules, including undruggable proteins.

Toward a New Paradigm for Targeted Natriuretic Peptide Enhancement in Heart Failure

The natriuretic peptide system (NPS) plays a fundamental role in maintaining cardiorenal homeostasis, and its potent filling pressure-regulated diuretic and vasodilatory effects constitute a beneficial compensatory mechanism in heart failure (HF). Leveraging the NPS for therapeutic benefit in HF has been the subject of intense investigation during the last three decades and has ultimately reached widespread clinical use in the form of angiotensin receptor-neprilysin inhibition (ARNi). NPS enhancement via ARNi confers beneficial effects on mortality and hospitalization in HF, but inhibition of neprilysin leads to the accumulation of a number of other vasoactive peptides in the circulation, often resulting in hypotension and raising potential concerns over long-term adverse effects. Moreover, ARNi is less effective in the large group of HF patients with preserved ejection fraction. Alternative approaches for therapeutic augmentation of the NPS with increased specificity and efficacy are therefore warranted, and are now becoming feasible particularly with recent development of RNA therapeutics. In this review, the current state-of-the-art in terms of experimental and clinical strategies for NPS augmentation and their implementation will be reviewed and discussed.

Fundamental Biomaterial Considerations in the Development of a 3D Model Representative of Primary Open Angle Glaucoma

Glaucoma is a leading cause of irreversible blindness globally, with primary open angle glaucoma (POAG) being the most common subset. Raised intraocular pressure is an important risk factor for POAG and is caused by a reduction in aqueous humour (AqH) outflow due to dysfunctional cellular and matrix dynamics in the eye’s main drainage site, the trabecular meshwork (TM) and Schlemm’s canal (SC). The TM/SC are highly specialised tissues that regulate AqH outflow; however, their exact mechanisms of AqH outflow control are still not fully understood. Emulating physiologically relevant 3D TM/S in vitro models poses challenges to accurately mimic the complex biophysical and biochemical cues that take place in healthy and glaucomatous TM/SC in vivo. With development of such models still in its infancy, there is a clear need for more well-defined approaches that will accurately contrast the two central regions that become dysfunctional in POAG; the juxtacanalicular tissue (JCT) region of the TM and inner wall endothelia of the Schlemm’s canal (eSC). This review will discuss the unique biological and biomechanical characteristics that are thought to influence AqH outflow and POAG progression. Further consideration into fundamental biomaterial attributes for the formation of a biomimetic POAG/AqH outflow model will also be explored for future success in pre-clinical drug discovery and disease translation.

The Future of Stem Cells and Their Derivates in the Treatment of Glaucoma. A Critical Point of View

This review focuses on the clinical translation of preclinical studies, especially those that have used stem cells in the treatment of glaucoma, with an emphasis on optic nerve regeneration. The studies referred to in the review aim to treat optic nerve atrophy, while cell therapies targeting other sites in the eye, such as the trabecular meshwork, have not been addressed. Such complex and varied pathophysiological mechanisms that lead to glaucoma may explain the fact that although stem cells have a high capacity of neuronal regeneration, the treatments performed did not have the expected results and the promise offered by animal studies was not achieved. By analyzing the facts associated with failure, important lessons are to be learned: the type of stem cells that are used, the route of administration, the selection of patients eligible for these treatments, additional therapies that support stem cells transplantation and their mode of action, methods of avoiding the host’s immune response. Many of these problems could be solved using exosomes (EV), but also miRNA, which allows more targeted approaches with minimal side effects.

Long-Term Decrease of Intraocular Pressure in Rats by Viral Delivery of miR-146a

Purpose

To evaluate the effects of miR-146a in trabecular meshwork (TM) cells and on intraocular pressure (IOP) in vivo via viral delivery of miR-146a to the anterior chamber of rat eyes.

Methods

Human TM cells were transfected with miR-146 mimic or inhibitor. Some cells from each group were then subjected to cyclic mechanical stress (CMS). Other cells from each group had no force applied. Gene expression was then analyzed by quantitative polymerase chain reaction (qPCR). Replication-deficient adenovirus and lentivirus expressing miR-146a were inoculated into the anterior segment of Brown Norway rat eyes. IOP was monitored by rebound tonometry, visual acuity was evaluated by optokinetic tracking (OKT), and inflammation markers in the anterior segment were examined by slit-lamp, qPCR, and semi-thin sections.

Results

miR-146 affected the expression of genes potentially involved in outflow homeostasis at basal levels and under CMS. Both lentiviral and adenoviral vectors expressing miR-146a resulted in sustained decreases in IOP ranging from 2.6 to 4.4 mmHg. Long term follow-up of rats injected with lentiviral vectors showed a sustained effect on IOP of 4.4 ± 2.9 mmHg that lasted until rats were sacrificed more than 8 months later. Eyes showed no signs of inflammation, loss of visual acuity, or other visible abnormalities.

Conclusions

Intracameral delivery of miR-146a can provide a long-term decrease of IOP in rats without signs of inflammation or other visible adverse effects.

Transitional Relevance

The IOP-lowering effects of miR-146 observed in rats provides a necessary step toward the development of an effective gene therapy for glaucoma in humans.

Xeno- and Feeder-Free Differentiation of Human iPSCs to Trabecular Meshwork-Like Cells by Recombinant Cytokines

Purpose

Stem cell-based therapy has the potential to become one approach to regenerate the damaged trabecular meshwork (TM) in glaucoma. Co-culture of induced pluripotent stem cells (iPSCs) with human TM cells has been a successful approach to generate autologous TM resembling cells. However, the differentiated cells generated using this approach are still problematic for clinical usage. This study aimed to develop a clinically applicable strategy for generating TM-like cells from iPSCs.

Methods

Highly expressed receptors during iPSC differentiation were identified by AutoSOME, Gene Ontology, and reverse transcription polymerase chain reaction (RT-PCR) analysis. The recombinant cytokines that bind to these receptors were used to generate a new differentiation protocol. The resultant TM-like cells were characterized morphologically, immunohistochemically, and transcriptionally.

Results

We first determined two stages of iPSC differentiation and identified highly expressed receptors associated with the differentiation at each stage. The expression of these receptors was further confirmed by RT-PCR analysis. Exposure to the recombinant cytokines that bind to these receptors, including transforming growth factor beta 1, nerve growth factor beta, erythropoietin, prostaglandin F2 alpha, and epidermal growth factor, can efficiently differentiate iPSCs into TM-like cells, which express TM biomarkers and can form dexamethasone-inducible CLANs.

Conclusions

We successfully generated a xeno- and feeder-free differentiation protocol with recombinant cytokines to generate the TM progenitor and TM-like cells from human iPSCs.

Translational Relevance

The new approach minimizes the risks from contamination and also improves the differentiation efficiency and consistency, which are particularly crucial for clinical use of stem cells in glaucoma treatment.

Identifying Circulating MicroRNA in Kawasaki Disease by Next-Generation Sequencing Approach

Kawasaki disease (KD) typically occurs in children aged under 5 years and can cause coronary artery lesions (CALs). Early diagnosis and treatment with intravenous immunoglobulin can reduce the occurrence of CALs; therefore, identifying a good biomarker for diagnosing KD is essential. Here, using next-generation sequencing in patients with recurrent KD, those with viral infection, and healthy controls, we identified dysregulated circulating microRNAs as diagnostic biomarkers for KD. Pathway enrichment analysis illustrated the putative role of these miRNAs in KD progression. Their expression levels were validated using real-time polymerase chain reaction (qPCR). Fifteen dysregulated circulating miRNAs (fold changes >2 and <0.5) were differentially expressed in the recurrent KD group compared with the viral infection and control groups. These miRNAs were significantly involved in the transforming growth factor-β, epithelial-mesenchymal transition, and cell apoptosis signaling pathways. Notably, their expression levels were frequently restored after intravenous immunoglobulin treatment. Among the candidates, miR-24-3p expression level was significantly higher in patients with recurrent KD compared with healthy controls or viral infection controls (p < 0.001). Receiver operating characteristic analysis revealed that high miR-24-3p expression levels may be a potential biomarker for KD diagnosis. In conclusion, we identified miR-24-3p significantly higher in KD patients, which may be a potential diagnostic biomarker for KD.

Mirna Expression in Glaucomatous and TGFβ2 Treated Lamina Cribrosa Cells

Glaucoma is a group of optic neuropathies that leads to irreversible vision loss. The optic nerve head (ONH) is the site of initial optic nerve damage in glaucoma. ONH-derived lamina cribrosa (LC) cells synthesize extracellular matrix (ECM) proteins; however, these cells are adversely affected in glaucoma and cause detrimental changes to the ONH. LC cells respond to mechanical strain by increasing the profibrotic cytokine transforming growth factor-beta 2 (TGFβ2) and ECM proteins. Moreover, microRNAs (miRNAs or miR) regulate ECM gene expression in different fibrotic diseases, including glaucoma. A delicate homeostatic balance between profibrotic and anti-fibrotic miRNAs may contribute to the remodeling of ONH. This study aimed to determine whether modulation of miRNAs alters the expression of ECM in human LC cells. Primary human normal and glaucoma LC cells were grown to confluency and treated with or without TGFβ2 for 24 h. Differences in expression of miRNAs were analyzed using miRNA qPCR arrays. miRNA PCR arrays showed that the miR-29 family was significantly decreased in glaucomatous LC cell strains compared to age-matched controls. TGFβ2 treatment downregulated the expression of multiple miRNAs, including miR-29c-3p, compared to controls in LC cells. LC cells transfected with miR-29c-3p mimics or inhibitors modulated collagen expression.

Pathogenesis and prospects for therapeutic clinical application of noncoding RNAs in glaucoma: Systematic perspectives

Noncoding ribonucleic acids (ncRNAs) are an increasingly studied class of RNA molecules with extensive biological activities, including important roles in human development, health, and disease. Glaucoma is a neurodegenerative disease of the retina, and one of the leading causes of blindness worldwide. However, the specific roles of ncRNAs in the development and progression of glaucoma are unclear, and related reports are fragmented. An in‐depth understanding of ncRNAs participating in the pathogenesis and progression of glaucoma would be helpful for opening up new avenues to facilitate the early diagnosis and clinical treatment. Therefore, in this review, we aimed to discuss the current research progress, the potentialfuture clinical applications and the research limitations of three critical classes of ncRNAs in glaucoma, namely microRNAs, long noncoding RNAs, and circular RNAs.

The micro-RNA content of unsorted cryopreserved bovine sperm and its relation to the fertility of sperm after sex-sorting

BACKGROUND

The use of sex-sorted sperm in cattle assisted reproduction is constantly increasing. However, sperm fertility can substantially differ between unsorted (conventional) and sex-sorted semen batches of the same sire. Sperm microRNAs (miRNA) have been suggested as promising biomarkers of bull fertility the last years. In this study, we hypothesized that the miRNA profile of cryopreserved conventional sperm is related to bull fertility after artificial insemination with X-bearing sperm. For this purpose, we analyzed the miRNA profile of 18 conventional sperm samples obtained from nine high- (HF) and nine low-fertility (LF) bulls that were contemporaneously used to produce conventional and sex-sorted semen batches. The annual 56-day non-return rate for each semen type (NRRconv and NRRss, respectively) was recorded for each bull.

RESULTS

In total, 85 miRNAs were detected. MiR-34b-3p and miR-100-5p were the two most highly expressed miRNAs with their relative abundance reaching 30% in total. MiR-10a-5p and miR-9-5p were differentially expressed in LF and HF samples (false discovery rate < 10%). The expression levels of miR-9-5p, miR-34c, miR-423-5p, miR-449a, miR-5193-5p, miR-1246, miR-2483-5p, miR-92a, miR-21-5p were significantly correlated to NRRss but not to NRRconv. Based on robust regression analysis, miR-34c, miR-7859 and miR-342 showed the highest contribution to the prediction of NRRss.

CONCLUSIONS

A set of miRNAs detected in conventionally produced semen batches were linked to the fertilizing potential of bovine sperm after sex-sorting. These miRNAs should be further evaluated as potential biomarkers of a sire's suitability for the production of sex-sorted sperm.

An update: mechanisms of microRNA in primary open-angle glaucoma

Glaucoma is a disease with characteristic optic neuropathy and loss of vision, leading to blindness, and primary open-angle glaucoma (POAG) is the most common glaucoma type throughout the world. Genetic susceptibility is the main factor in POAG, and most susceptibility genes cause changes in microRNA expression and function, thereby leading to POAG occurrence and development. Increasing evidence indicates that many microRNAs are involved in the regulation of intraocular pressure (IOP) and play an important role in the increase in IOP in POAG. Additionally, microRNA is closely related to optic nerve damage factors (mechanical stress, hypoxia and inflammation). This review discusses the effect of single-nucleotide polymorphisms in POAG-related genes on microRNA and the value of microRNA in the diagnosis and treatment of POAG.

Regulation of microRNA-221, -222, -21 and -27 in articular cartilage subjected to abnormal compressive forces

Key points

microRNAs (miRs) are small non‐coding molecules that regulate post‐transcriptional target gene expression.

miRs are involved in regulating cellular activities in response to mechanical loading in all physiological systems, although it is largely unknown whether this response differs with increasing magnitudes of load.

miR‐221, miR‐222, miR‐21‐5p and miR‐27a‐5p were significantly increased in ex vivo cartilage explants subjected to increasing load magnitude and in in vivo joint cartilage exposed to abnormal loading.

TIMP3 and CPEB3 are putative miR targets in chondrocytes

Identification of mechanically regulated miRs that have potential to impact on tissue homeostasis provides a mechanism by which load‐induced tissue behaviour is regulated, in both health and pathology, in all physiological systems.

Abstract

MicroRNAs (miRs) are small non‐coding molecules that regulate post‐transcriptional target gene expression and are involved in mechano‐regulation of cellular activities in all physiological systems. It is unknown whether such epigenetic mechanisms are regulated in response to increasing magnitudes of load. The present study investigated mechano‐regulation of miRs in articular cartilage subjected to ‘physiological’ and ‘non‐physiological’ compressive loads in vitro as a model system and validated findings in an in vivo model of abnormal joint loading. Bovine full‐depth articular cartilage explants were loaded to 2.5 MPa (physiological) or 7 MPa (non‐physiological) (1 Hz, 15 min) and mechanically‐regulated miRs identified using next generation sequencing and verified using a quantitative PCR. Downstream targets were verified using miR‐specific mimics or inhibitors in conjunction with 3′‐UTR luciferase activity assays. A subset of miRs were mechanically‐regulated in ex vivo cartilage explants and in vivo joint cartilage. miR‐221, miR‐222, miR‐21‐5p and miR‐27a‐5p were increased and miR‐483 levels decreased with increasing load magnitude. Tissue inhibitor of metalloproteinase 3 (TIMP3) and cytoplasmic polyadenylation element binding protein 3 (CPEB3) were identified as putative downstream targets. Our data confirm miR‐221 and ‐222 mechano‐regulation and demonstrates novel mechano‐regulation of miR‐21‐5p and miR‐27a‐5p in ex vivo and in vivo cartilage loading models. TIMP3 and CPEB3 are putative miR targets in chondrocytes. Identification of specific miRs that are regulated by increasing load magnitude, as well as their potential to impact on tissue homeostasis, has direct relevance to other mechano‐sensitive physiological systems and provides a mechanism by which load‐induced tissue behaviour is regulated, in both health and pathology.

microRNAs (miRs) are small non‐coding molecules that regulate post‐transcriptional target gene expression.

miRs are involved in regulating cellular activities in response to mechanical loading in all physiological systems, although it is largely unknown whether this response differs with increasing magnitudes of load.

miR‐221, miR‐222, miR‐21‐5p and miR‐27a‐5p were significantly increased in ex vivo cartilage explants subjected to increasing load magnitude and in in vivo joint cartilage exposed to abnormal loading.

TIMP3 and CPEB3 are putative miR targets in chondrocytes

Identification of mechanically regulated miRs that have potential to impact on tissue homeostasis provides a mechanism by which load‐induced tissue behaviour is regulated, in both health and pathology, in all physiological systems.

Expression of mRNAs, miRNAs, and lncRNAs in Human Trabecular Meshwork Cells Upon Mechanical Stretch

Purpose

Intraocular pressure (IOP), the primary risk factor for primary open-angle glaucoma, is determined by resistance to aqueous outflow through the trabecular meshwork (TM). IOP homeostasis relies on TM responses to mechanical stretch. To model the effects of elevated IOP on the TM, this study sought to identify coding and non-coding RNAs differentially expressed in response to mechanical stretch.

Methods

Monolayers of TM cells from non-glaucomatous donors (n = 5) were cultured in the presence or absence of 15% mechanical stretch, 1 cycle/second, for 24 hours using a computer-controlled Flexcell unit. We profiled mRNAs and lncRNAs with stranded total RNA sequencing and microRNA (miRNA) expression with NanoString-based miRNA assays. We used two-tailed paired t-tests for mRNAs and long non-coding RNAs (lncRNAs) and the Bioconductor limma package for miRNAs. Gene ontology and pathway analyses were performed with WebGestalt. miRNA–mRNA interactions were identified using Ingenuity Pathway Analysis Integrative miRNA Target Finder software. Validation of differential expression was conducted using droplet digital PCR.

Results

We identified 219 mRNAs, 42 miRNAs, and 387 lncRNAs with differential expression in TM cells upon cyclic mechanical stretch. Pathway analysis indicated significant enrichment of genes involved in steroid biosynthesis, glycerolipid metabolism, and extracellular matrix–receptor interaction. We also identified several miRNA master regulators (miR-125a-5p, miR-30a-5p, and miR-1275) that regulate several mechanoresponsive genes.

Conclusions

To our knowledge, this is the first demonstration of the differential expression of coding and non-coding RNAs in a single set of cells subjected to cyclic mechanical stretch. Our results validate previously identified, as well as novel, genes and pathways.

miR-21-5p: A viable therapeutic strategy for regulating intraocular pressure

Lowering intraocular pressure (IOP) is the most effective treatment of glaucoma, however most of the current available glaucoma drugs target a single molecule. MicroRNAs (miRNAs) are noncoding RNAs that target a network of molecules. This study aims to investigate the role of miR-21-5p in regulating IOP and the mechanism of function. miR-21-5p mimics was topically applied to C57/BL6 mouse eyes, which significantly increased miR-21-5p expression in the conventional outflow tissue and reduced IOP by a maximum of 17.77% at 24 h after treatment. The conventional outflow facility measured by ex vivo moue eye perfusion of miR-21-5p was significantly increased by 60.14%. Moreover, miR-21-5p overexpression significantly reduced the transendothelial electrical resistance in porcine angular aqueous plexus cells. Transcriptome analysis and further quantification by Western blot and PCR revealed that SMAD7 and FGF18 might be the downstream target of miR-21-5p in regulating aqueous humor outflow. The predicted functional pathways PTEN/eNOS, RhoB/pMLC and TIMP3/MMP9 were significantly altered after miR-21-5p transfection. Dual luciferase assay verified the direct targets of miR-21-5p. In conclusion, miR-21-5p seems to regulate IOP by modulating multiple genes that are associated with aqueous humor outflow, including genes those regulating cell adhesion, cytoskeletal dynamics and extracellular matrix turnover. Thus, miR-21-5p represents a new therapeutic strategy for glaucoma and a viable alternative to existing multidrug regimens.

Developmental nicotine exposure engenders intergenerational downregulation and aberrant posttranslational modification of cardinal epigenetic factors in the frontal cortices, striata, and hippocampi of adolescent mice

BACKGROUND

Maternal smoking of traditional or electronic cigarettes during pregnancy, which constitutes developmental nicotine exposure (DNE), heightens the risk of neurodevelopmental disorders including ADHD, autism, and schizophrenia in children. Modeling the intergenerationally transmissible impacts of smoking during pregnancy, we previously demonstrated that both the first- and second-generation adolescent offspring of nicotine-exposed female mice exhibit enhanced nicotine preference, hyperactivity and risk-taking behaviors, aberrant rhythmicity of home cage activity, nicotinic acetylcholine receptor and dopamine transporter dysfunction, impaired furin-mediated proBDNF proteolysis, hypocorticosteronemia-related glucocorticoid receptor hypoactivity, and global DNA hypomethylation in the frontal cortices and striata. This ensemble of multigenerational DNE-induced behavioral, neuropharmacological, neurotrophic, neuroendocrine, and DNA methylomic anomalies recapitulates the pathosymptomatology of neurodevelopmental disorders such as ADHD, autism, and schizophrenia. Further probing the epigenetic bases of DNE-induced multigenerational phenotypic aberrations, the present study examined the expression and phosphorylation of key epigenetic factors via an array of immunoblot experiments.

RESULTS

Data indicate that DNE confers intergenerational deficits in corticostriatal DNA methyltransferase 3A (DNMT3A) expression accompanied by downregulation of methyl-CpG-binding protein 2 (MeCP2) and histone deacetylase 2 (HDAC2) in the frontal cortices and hippocampi, while the expression of ten-eleven translocase methylcytosine dioxygenase 2 (TET2) is unaltered. Moreover, DNE evokes multigenerational abnormalities in HDAC2 (Ser394) but not MeCP2 (Ser421) phosphorylation in the frontal cortices, striata, and hippocampi.

CONCLUSIONS

In light of the extensive gene regulatory roles of DNMT3A, MeCP2, and HDAC2, the findings of this study that DNE elicits downregulation and aberrant posttranslational modification of these factors in both first- and second-generation DNE mice suggest that epigenetic perturbations may constitute a mechanistic hub for the intergenerational transmission of DNE-induced neurodevelopmental disorder-like phenotypes.

Integrative analysis of an lncRNA‑associated competing endogenous RNA network in human trabecular meshwork cells under oxidative stress

Long non‑coding RNAs (lncRNAs) are a group of non‑coding transcripts of >200 nucleotides. They can act as competing endogenous RNAs (ceRNAs) and suppress microRNA (miRNA) function by preventing them from binding to and interacting with target mRNAs. However, the specific role of the lncRNA‑associated ceRNA network in the pathogenesis of glaucoma has not yet been elucidated. To study this, data were downloaded from the Gene Expression Omnibus database (GSE126170), which contained three human trabecular meshwork cell (HTMC) samples treated with 300 µm hydrogen peroxide and three control samples treated with vehicle. Differentially expressed lncRNAs and mRNAs of HTMCs were obtained using the R package limma. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses of differentially expressed mRNAs were performed using the R package clusterProfiler. Finally, the ceRNA network was constructed using the mircode, miRDB, miRTarBase and TargetScan databases, and visualized using Cytoscape v3.6.1. The results showed that 70 lncRNAs and 558 mRNAs were identified to be significantly dysregulated (|log2FoldChange| >1 and adjusted P<0.05) in HTMCs under oxidative stress compared to those in HTMCs under control conditions. Moreover, 24 lncRNAs, 24 miRNAs and 40 mRNAs were closely connected, and were part of the ceRNA network. Among these, the expression levels of 19 lncRNAs were upregulated, and those of 5 lncRNAs were downregulated. To conclude, using bioinformatics analysis, the differential expression profiles of lncRNAs were reported and a lncRNA‑associated ceRNA network in HTMCs under oxidative stress was constructed. These results may bring to light a new pathological mechanism or a potential therapeutic target for glaucoma.

miR-223 induces retinal ganglion cells apoptosis and inflammation via decreasing HSP-70 in vitro and in vivo

PURPOSE

Glaucoma is an eye disease characterized by the loss of peripheral vision, high pressure in the eye, optic nerve damage, and the loss of peripheral vision due to loss of retinal ganglion cells (RGCs). A number of miRNA have been detected in the pathogenesis of glaucoma. The paper was to focus on the miR-223 in RGCs apoptosis and inflammation, and investigated the possible mechanisms in vitro and in vivo.

MATERIALS AND METHODS

After miR-223 inhibitor and mimics transfected into RGCs, the expression of miR-223 was detected by QRT-PCR, cell proliferation were performed by CCK-8 and EdU assays, cell apoptosis were measured by flow cytometer and TUNEL assays, apoptosis and inflammation -related proteins were detected by western blot, and whether miR-223 target to HSP-70 was detected by Luciferease reporter assay. Moreover, the effects si-HSP-70 on RGCs or RGCs transfected with miR-223 inhibitor were detected. In vivo study. New Zealand White rabbits (20 females) were used to detect the effect of miR-223 on the rabbit glaucoma model induced by injection of carbomer.

RESULTS

CCK-8 and EdU assays demonstrated that miR-223 mimics decreased RGCs proliferation. FITC-Annexin V/PI Apoptosis and TUNEL assays showed that miR-223 mimics induced RGCs apoptosis. Western blot revealed that miR-223 mimics enhanced the expression of relative apoptosis and inflammation factors. Further, we demonstrated that miR-223 could inhibit cell proliferation, induce cell apoptosis as well as inflammation by targeting HSP-70 in RGCs. Moreover, the results were confirmed in rabbit glaucoma model.

CONCLUSIONS

In summary, miR-223 plays a vital role in RGCs by regulating HSP-70 expression, and the new therapeutic strategy might potentially contribute to benefit glaucoma treatment.

Oxidative stress and antioxidants in the trabecular meshwork

Glaucoma is an age-dependent disease closely related to oxidative stress and is regarded as the second leading cause of irreversible blindness worldwide. In recent years, many studies have shown that morphological and functional abnormalities of the trabecular meshwork (TM) are closely related to glaucoma, especially with respect to oxidative stress. In this review, the mechanisms of oxidative stress in the TM and treatment strategies for this condition, including strategies involving antioxidants, noncoding RNAs and exogenous compounds, are discussed. Although many questions remain to be answered, the reviewed findings provide insights for further research on oxidative stress alleviation in glaucoma and suggest new targets for glaucoma prevention.

Developmental nicotine exposure elicits multigenerational disequilibria in proBDNF proteolysis and glucocorticoid signaling in the frontal cortices, striata, and hippocampi of adolescent mice

Maternal smoking of conventional or vapor cigarettes during pregnancy, a form of developmental nicotine exposure (DNE), enhances the risk of neurodevelopmental disorders such as ADHD, autism, and schizophrenia in children. Modeling the multigenerational effects of smoking during pregnancy and nursing in the first- (F1) and second- (F2) generation adolescent offspring of oral nicotine-treated female C57BL/6J mice, we have previously reported that DNE precipitates intergenerational transmission of nicotine preference, hyperactivity and impulsivity-like behaviors, altered rhythmicity of home cage activity, corticostriatal nicotinic acetylcholine receptor and dopamine transporter dysfunction, and corticostriatal global DNA methylome deficits. In aggregate, these DNE-evoked behavioral, neuropharmacological, and epigenomic anomalies mirror fundamental etiological aspects of neurodevelopmental disorders including ADHD, autism, and schizophrenia. Expanding this line of research, the current study profiled the multigenerational neurotrophic and neuroendocrine consequences of DNE. Results reveal impaired proBDNF proteolysis as indicated by proBDNF-BDNF imbalance, downregulation of the proBDNF processing enzyme furin, atypical glucocorticoid receptor (GR) activity as implied by decreased relative nuclear GR localization, and deficient basal plasma corticosterone (CORT) levels in adolescent DNE offspring and grandoffspring. Collectively, these data recapitulate the BDNF deficits and HPA axis dysregulation characteristic of neurodevelopmental disorders such as ADHD, autism, and schizophrenia as well as the children of maternal smokers. Notably, as BDNF is a quintessential mediator of neurodevelopment, our prior findings of multigenerational DNE-induced behavioral and neuropharmacological abnormalities may stem from neurodevelopmental insults conferred by the proBDNF-BDNF imbalance detected in DNE mice. Similarly, our findings of multigenerational GR hypoactivity may contribute to the increased risk-taking behaviors and aberrant circadian rhythmicity of home cage activity that we previously documented in first- and second-generation DNE mice.

Identification of Candidate miRNA Biomarkers for Glaucoma

Purpose

Glaucoma, a leading cause of blindness worldwide, often remains undetected until irreversible vision loss has occurred. Treatments focus on lowering intraocular pressure (IOP), the only modifiable and readily measurable risk factor. However, IOP can vary and does not always predict disease progression. MicroRNAs (miRNAs) are promising biomarkers. They are abundant and stable in biological fluids, including plasma and aqueous humor (AqH). We aimed to identify differentially expressed miRNAs in AqH and plasma from glaucoma, exfoliation syndrome (XFS), and control subjects.

Methods

Plasma and AqH from two ethnic cohorts were harvested from glaucoma or XFS (often associated with glaucoma, n = 33) and control (n = 31) patients undergoing elective surgery. A custom miRNA array measured 372 miRNAs. Molecular target prediction and pathway analysis were performed with Ingenuity Pathway Analysis (IPA) and DIANA bioinformatical tools.

Results

Levels of miRNAs in plasma, a readily accessible biomarker source, correlated with miRNA levels in AqH. Twenty circulating miRNAs were at least 1.5-fold higher in glaucoma or XFS patients than in controls across two ethnic cohorts: miR-4667-5p (P = 4.1 × 10⁻⁵), miR-99b-3p (P = 4.8 × 10⁻⁵), miR-637 (P = 5.1 × 10⁻⁵), miR-4490 (P = 5.7 × 10⁻⁵), miR-1253 (P = 6.0 × 10⁻⁵), miR-3190-3p (P = 3.1 × 10⁻⁴), miR-3173-3p (P = 0.001), miR-608 (P = 0.001), miR-4725-3p (P = 0.002), miR-4448 (P = 0.002), and miR-323b-5p (P = 0.002), miR-4538 (P = 0.003), miR-3913-3p (P = 0.003), miR-3159 (P = 0.003), miR-4663 (P = 0.003), miR-4767 (P = 0.003), miR-4724-5p (P = 0.003), miR-1306-5p (P = 0.003), miR-181b-3p (P = 0.004), and miR-433-3p (P = 0.004). miR-637, miR-1306-5p, and miR-3159, in combination, allowed discrimination between glaucoma patients and control subjects (AUC = 0.91 ± 0.008, sensitivity 85.0%, specificity 87.5%).

Conclusions

These results identify specific miRNAs as potential biomarkers and provide insight into the molecular processes underlying glaucoma.

miR‑17‑5p regulates the proliferation and apoptosis of human trabecular meshwork cells by targeting phosphatase and tensin homolog

Glaucoma is one of the leading causes of blindness. Previous studies have indicated that the oxidative stress-induced apoptosis of trabecular meshwork cells (TMCs) may serve a key role in the pathogenesis of glaucoma, and that micro RNA(miR)-17-5p may be involved in this process. However, the specific mechanisms require further investigation. The aim of the present study was to investigate the effects of miR-17-5p on the proliferation and apoptosis of human TMCs (HTMCs) in response to oxidative stress. It was observed that exposure to H₂O₂ induced a significant decrease in the proliferation and a marked increase in the apoptosis of HTMCs. H₂O₂ exposure also suppressed the expression of miR-17-5p and promoted the expression of phosphatase and tensin homolog (PTEN). Furthermore, transient overexpression of miR-17-5p induced a significant increase in the proliferation and a significant decrease in the apoptosis of HTMCs by affecting the expression of PTEN, and the apoptosis-related proteins B-cell lymphoma-associated X protein (Bax), B-cell lymphoma-extra large (Bcl-xL) and B-cell lymphoma-2 (Bcl-2). However, knockdown of miR-17-5p demonstrated the opposite results. The results of a dual luciferase reporter assay demonstrated that PTEN may be a direct target of miR-17-5p. In conclusion, miR-17-5p was downregulated in HTMCs under oxidative conditions, and miR-17-5p may regulate the apoptosis of HTMCs by targeting PTEN. These results provide a novel theoretical basis and potential therapeutic target for the treatment of glaucoma.

Down-regulated miR-187 promotes oxidative stress-induced retinal cell apoptosis through P2X7 receptor

Several microRNAs (miRNAs) expressed in the retina were confirmed to involve in retinal cell apoptosis, which was closely linked with the development of retinal diseases. Our previous studies have confirmed a vital role of miR-187 in retinal cells apoptosis. The aim of this study was to further elucidate the precise role of miR-187 and its probable mechanisms in RGC-5 cells apoptosis. The cellular oxidative stress status was assessed by reactive oxygen species (ROS) production and malondialdehyde (MDA) level. Our results showed that the elevated pressure, glutamate and H₂O₂-induced oxidative stress in RGC-5 cells was accompanied by a decrease in miR-187 expression and an increase in P2X7R expression. However, overexpression of miR-187 reversed this activation of oxidative stress in RGC-5 cells. Moreover, we also revealed that miR-187 inhibited the oxidative stress-induced apoptosis of RGC-5 cells through negative regulating P2X7R, probably through interacting with the 3'UTR of P2X7R. Finally, we confirmed that the forced miR-187 expression alleviated oxidative stress injury in retina tissues of rat models with chronic ocular hypertension. Our data demonstrated that miR-187/P2X7R signaling was involved in retinal cell apoptosis, at least in part, through activating oxidative stress.

Bone remodeling induced by mechanical forces is regulated by miRNAs

The relationship between mechanical force and alveolar bone remodeling is an important issue in orthodontics because tooth movement is dependent on the response of bone tissue to the mechanical force induced by the appliances used. Mechanical cyclical stretch (MCS), fluid shear stress (FSS), compression, and microgravity play different roles in the cell differentiation and proliferation involved in bone remodeling. However, the underlying mechanisms are unclear, particularly the molecular pathways regulated by non-coding RNAs (ncRNAs) that play essential roles in bone remodeling. Amongst the various ncRNAs, miRNAs act as post-transcriptional regulators that inhibit the expression of their target genes. miRNAs are considered key regulators of many biologic processes including bone remodeling. Here, we review the role of miRNAs in mechanical force-induced bone metabolism.

Micro RNA-1298 opposes the effects of chronic oxidative stress on human trabecular meshwork cells via targeting on EIF4E3

OBJECTIVE

This study aimed to investigate the effect and potential mechanism of miR-1298 in the progression of human trabecular meshwork (HTM) cells.

MATERIAL AND METHODS

Expression of miR-1298 was assessed by quantitative real time PCR (qRT-PCR), as well as in HTM-1 and HTM-2 cells. Mature miR-1298 mimic, miR-1298 inhibitor, and si-EIF4E3 and their corresponding controls were transfected into HTM-1 and HTM-2 to obtain stable HTM cells. Luciferase reporter assay was used to verify regulation between miR-1298 and EIF4E3. Cytotoxicity and Oxidative damage were assessed using commercial kits, and apoptosis was determined using flow cytometry. ECM and apoptosis related factors were determined using qRT-PCR and western blotting, as well as the pathway related factors.

RESULTS

The expression of miR-1298 was significantly decreased both in glaucoma and HTM cells. MiR-1298 mimic could significantly inhibit the increase of cytotoxicity, apoptosis, accumulation of carbonylated proteins and ECM induced by COS, but miR-1298 inhibitor could obviously promote the increase effects caused by COS in HTM cells. EIF4E3 was a downstream target of miR-1298. Sliced EIF4E3 could significantly inhibit the increase effects induced miR-1298 inhibitor in HTM cells under COS. The expression levels of TGF-β2 and Smad4 were significantly increased, and Wnt3a and β-cantenin were obviously decreased under COS, and miR-1298 inhibitor could markedly promote this increase effect, while sliced EIF4E3 could reverse the effect of miR-1298 under COS.

CONCLUSIONS

miR-1298 could protect HTM cells to against damage caused by COS via inhibiting TGF-β2/Smad4 pathway and activating canonical Wnt pathway.

Molecular Pathogenesis of Chlamydia Disease Complications: Epithelial-Mesenchymal Transition and Fibrosis

The reproductive system complications of genital chlamydial infection include fallopian tube fibrosis and tubal factor infertility. However, the molecular pathogenesis of these complications remains poorly understood. The induction of pathogenic epithelial-mesenchymal transition (EMT) through microRNA (miRNA) dysregulation was recently proposed as the pathogenic basis of chlamydial complications. Focusing on fibrogenesis, we investigated the hypothesis that chlamydia-induced fibrosis is caused by EMT-driven generation of myofibroblasts, the effector cells of fibrosis that produce excessive extracellular matrix (ECM) proteins. The results revealed that the targets of a major category of altered miRNAs during chlamydial infection are key components of the pathophysiological process of fibrogenesis; these target molecules include collagen types I, III, and IV, transforming growth factor β (TGF-β), TGF-β receptor 1 (TGF-βR1), connective tissue growth factor (CTGF), E-cadherin, SRY-box 7 (SOX7), and NFAT (nuclear factor of activated T cells) kinase dual-specificity tyrosine (Y) phosphorylation-regulated kinase 1a (Dyrk1a). Chlamydial induction of EMT resulted in the generation of α-smooth muscle actin (α-SMA)-positive myofibroblasts that produced ECM proteins, including collagen types I and III and fibronectin. Furthermore, the inhibition of EMT prevented the generation of myofibroblasts and production of ECM proteins during chlamydial infection. These findings may provide useful avenues for targeting EMT or specific components of the EMT pathways as a therapeutic intervention strategy to prevent chlamydia-related complications.

Stem Cell-Derived Exosomes, Autophagy, Extracellular Matrix Turnover, and miRNAs in Cardiac Regeneration during Stem Cell Therapy

Stem cell therapy (SCT) raises the hope for cardiac regeneration in ischemic hearts. However, underlying molecular mechanisms for repair of dead myocardium by SCT in the ischemic heart is poorly understood. Growing evidences suggest that cardiac matrix stiffness and differential expressions of miRNAs play a crucial role in stem cell survival and differentiation. However, their roles on transplanted stem cells, for myocardial repair of the ischemic heart, remain unclear. Transplanted stem cells may act in an autocrine and/or paracrine manner to regenerate the dead myocardium. Paracrine mediators such as stem cell-derived exosomes are emerging as a novel therapeutic strategy to overcome some of the limitations of SCT. These exosomes carry microRNAs (miRNAs) that may regulate stem cell differentiation into a specific lineage. MicroRNAs may also contribute to stiffness of surrounding matrix by regulating extracellular matrix (ECM) turnover. The survival of transplanted stem cell depends on its autophagic process that maintains cellular homeostasis. Therefore, exosomes, miRNAs, extracellular matrix turnover, and autophagy may have an integral role in improving the efficacy of SCT. This review elaborates the specific roles of these regulatory components on cardiac regeneration in the ischemic heart during SCT.

Targeting Transforming Growth Factor-β Signaling in Primary Open-Angle Glaucoma

Transforming growth factor-β (TGF-β) may play a role in the pathogenesis of primary open-angle glaucoma (POAG). Elevated levels of TGF-β are found in the aqueous humor and in reactive optic nerve astrocytes in patients with glaucoma. In POAG, aqueous humor outflow resistance at the trabecular meshwork (TM) leads to increased intraocular pressure and retinal ganglion cell death. It is hypothesized that TGF-β increases outflow resistance by altering extracellular matrix homeostasis and cell contractility in the TM through interactions with other proteins and signaling molecules. TGF-β may also be involved in damage to the optic nerve head. Current available therapies for POAG focus exclusively on lowering intraocular pressure without addressing extracellular matrix homeostasis processes in the TM. The purpose of this review is to discuss possible therapeutic strategies targeting TGF-β in the treatment of POAG. Herein, we describe the current understanding of the role of TGF-β in POAG pathophysiology, and examine ways TGF-β may be targeted at the levels of production, activation, downstream signaling, and homeostatic regulation.

Inhibition of microRNA-24 increases liver fibrosis by enhanced menin expression in Mdr2-/- mice

BACKGROUND

Liver transplantation remains the primary treatment for primary sclerosing cholangitis (PSC). Mdr2-/- mice provide a reliable in vivo model of PSC and develop characteristic biliary inflammation and fibrosis. We tested the hypothesis that the tumor suppressor protein menin is implicated in the progression of liver fibrosis and that menin expression can be regulated in the liver via microRNA-24 (miR-24).

MATERIALS AND METHODS

Menin expression was measured in human PSC and Mdr2-/- mice. Twelve-week-old FVB/NJ wild-type (WT) and Mdr2-/- mice were treated with miR-24 Vivo-Morpholino to knockdown miR-24 expression levels. Liver fibrosis was evaluated by Sirius Red staining and quantitative polymerase chain reaction (qPCR) for genes associated with liver fibrosis, such as fibronectin 1, collagen type 1 alpha 1, transforming growth factor-β1 (TGF-β1), and α-smooth muscle actin. Studies were also performed in vitro using immortalized murine cholangiocyte lines treated with miR-24 hairpin inhibitor and mimic.

RESULTS

Menin gene expression was increased in Mdr2-/- mice and late-stage human PSC samples. Treatment of FVB/NJ WT and Mdr2-/- mice with miR-24 Vivo-Morpholino increased menin expression, which correlated with increased expression of fibrosis genes. In vitro, inhibition of miR-24 also significantly increased the expression of fibrosis genes.

CONCLUSIONS

Inhibition of miR-24 increases menin and TGF-β1 expression, subsequently increasing hepatic fibrosis in FVB/NJ WT and Mdr2-/- mice. Modulation of the menin/miR-24 axis may provide novel targeted therapies to slow the progression of hepatic fibrosis into cirrhosis in PSC patients by altering TGF-β1 expression.

Epigenetic regulation of TGF-β1 signalling in dilative aortopathy of the thoracic ascending aorta

The term 'epigenetics' refers to heritable, reversible DNA or histone modifications that affect gene expression without modifying the DNA sequence. Epigenetic modulation of gene expression also includes the RNA interference mechanism. Epigenetic regulation of gene expression is fundamental during development and throughout life, also playing a central role in disease progression. The transforming growth factor β1 (TGF-β1) and its downstream effectors are key players in tissue repair and fibrosis, extracellular matrix remodelling, inflammation, cell proliferation and migration. TGF-β1 can also induce cell switch in epithelial-to-mesenchymal transition, leading to myofibroblast transdifferentiation. Cellular pathways triggered by TGF-β1 in thoracic ascending aorta dilatation have relevant roles to play in remodelling of the vascular wall by virtue of their association with monogenic syndromes that implicate an aortic aneurysm, including Loeys-Dietz and Marfan's syndromes. Several studies and reviews have focused on the progression of aneurysms in the abdominal aorta, but research efforts are now increasingly being focused on pathogenic mechanisms of thoracic ascending aorta dilatation. The present review summarizes the most recent findings concerning the epigenetic regulation of effectors of TGF-β1 pathways, triggered by sporadic dilative aortopathy of the thoracic ascending aorta in the presence of a tricuspid or bicuspid aortic valve, a congenital malformation occurring in 0.5-2% of the general population. A more in-depth comprehension of the epigenetic alterations associated with TGF-β1 canonical and non-canonical pathways in dilatation of the ascending aorta could be helpful to clarify its pathogenesis, identify early potential biomarkers of disease, and, possibly, develop preventive and therapeutic strategies.

Survival Improvement in Human Retinal Pigment Epithelial Cells via Fas Receptor Targeting by miR-374a

Oxidative conditions of the eye could contribute to retinal cells loss through activating the Fas-L/Fas pathway. This phenomenon is one of the leading causes of some ocular diseases like age-related macular degeneration (AMD). By targeting proteins at their mRNA level, microRNAs (miRNAs) can regulate gene expression and cell function. The aim of the present study is to investigate Fas targeting by miR-374a and find whether it can inhibit Fas-mediated apoptosis in primary human retinal pigment epithelial (RPE) cells under oxidative stress. So, the primary human RPE cells were transfected with pre-miR-374a pLEX construct using polymeric carrier and were exposed to H₂ O₂ (200 μM) as an oxidant agent for induction of Fas expression. Fas expression at mRNA and protein level was evaluated by quantitative real-time PCR and Western blot analysis, respectively. These results revealed that miR-374a could prevent Fas upregulation under oxidative conditions. Moreover, Luciferase activity assay confirmed that Fas could be a direct target of miR-374a. The cell viability studies demonstrated that caspase-3 activity was negligible in miR-374a treated cells compared to the controls. Our data suggest miR-374a is a negative regulator of Fas death receptor which is able to enhance the cell survival and protect RPE cells against oxidative conditions. J. Cell. Biochem. 118: 4854-4861, 2017. © 2017 Wiley Periodicals, Inc.

Autophagy and mechanotransduction in outflow pathway cells

Because of elevations in IOP and other forces, cells in the trabecular meshwork (TM) are constantly subjected to mechanical strain. In order to preserve cellular function and regain homeostasis, cells must sense and adapt to these morphological changes. We and others have already shown that mechanical stress can trigger a broad range of responses in TM cells; however, very little is known about the strategies that TM cells use to respond to this stress, so they can adapt and survive. Autophagy, a lysosomal degradation pathway, has emerged as an important cellular homeostatic mechanism promoting cell survival and adaptation to a number of cytotoxic stresses. Our laboratory has reported the activation of autophagy in TM cells in response to static biaxial strain and high pressure. Moreover, our newest data also suggest the activation of chaperon-assisted selective autophagy, a recently identified tension-induced autophagy essential for mechanotransduction, in TM cells under cyclic mechanical stress. In this review manuscript we will discuss autophagy as part of an integrated response triggered in TM cells in response to strain, exerting a dual role in repair and mechanotransduction, and the potential effects of dysregulated in outflow pathway pathophysiology.

Regulation of intraocular pressure by microRNA cluster miR-143/145

Glaucoma is a major cause of irreversible blindness worldwide. Elevated intraocular pressure (IOP), which causes optic nerve damage and retinal ganglion cell death, is the primary risk factor for blindness in glaucoma patients. IOP is controlled by the balance between aqueous humor secretion from the ciliary body (CB) and its drainage through the trabecular meshwork (TM). How microRNAs (miRs) regulate IOP and glaucoma in vivo is largely unknown. Here we show that miR-143 and miR-145 expression is enriched in the smooth muscle and trabecular meshwork in the eye. Targeted deletion of miR-143/145 in mice results in significantly reduced IOP, consistent with an ~2-fold increase in outflow facilities. However, aqueous humor production in the same mice appears to be normal based on a microbeads-induced glaucoma model. Mechanistically, we found that miR-143/145 regulates actin dynamics and the contractility of TM cells, consistent with its regulation of actin-related protein complex (ARPC) subunit 2, 3, and 5, as well as myosin light chain kinase (MLCK) in these cells. Our data establish miR-143/145 as important regulators of IOP, which may have important therapeutic implications in glaucoma.

A Common Variant in MIR182 Is Associated With Primary Open-Angle Glaucoma in the NEIGHBORHOOD Consortium

PURPOSE

Noncoding microRNAs (miRNAs) have been implicated in the pathogenesis of glaucoma. We aimed to identify common variants in miRNA coding genes (MIR) associated with primary open-angle glaucoma (POAG).

METHODS

Using the NEIGHBORHOOD data set (3853 cases/33,480 controls with European ancestry), we first assessed the relation between 85 variants in 76 MIR genes and overall POAG. Subtype-specific analyses were performed in high-tension glaucoma (HTG) and normal-tension glaucoma subsets. Second, we examined the expression of miR-182, which was associated with POAG, in postmortem human ocular tissues (ciliary body, cornea, retina, and trabecular meshwork [TM]), using miRNA sequencing (miRNA-Seq) and droplet digital PCR (ddPCR). Third, miR-182 expression was also examined in human aqueous humor (AH) by using miRNA-Seq. Fourth, exosomes secreted from primary human TM cells were examined for miR-182 expression by using miRNA-Seq. Fifth, using ddPCR we compared miR-182 expression in AH between five HTG cases and five controls.

RESULTS

Only rs76481776 in MIR182 gene was associated with POAG after adjustment for multiple comparisons (odds ratio [OR] = 1.23, 95% confidence interval [CI]: 1.11-1.42, P = 0.0002). Subtype analysis indicated that the association was primarily in the HTG subset (OR = 1.26, 95% CI: 1.08-1.47, P = 0.004). The risk allele T has been associated with elevated miR-182 expression in vitro. Data from ddPCR and miRNA-Seq confirmed miR-182 expression in all examined ocular tissues and TM-derived exosomes. Interestingly, miR-182 expression in AH was 2-fold higher in HTG patients than nonglaucoma controls (P = 0.03) without controlling for medication treatment.

CONCLUSIONS

Our integrative study is the first to associate rs76481776 with POAG via elevated miR-182 expression.