Comprehensive Analysis of circRNA-Associated-ceRNA Networks in Human Corneal Endothelial Dysfunction.

PURPOSE: Circular RNAs (circRNAs) are a novel class of endogenous noncoding RNAs that regulate gene expression through the competitive endogenous RNA (ceRNA) mechanism. CircRNA-associated-ceRNA networks are closely related to oxidative stress-related diseases. Oxidative stress-induced dysfunction of the corneal endothelium (CE) is a major pathological feature in many corneal diseases. This study was aimed to analyze circRNA-associated-ceRNA networks in oxidative stress-induced CE dysfunction. METHODS: A CE dysfunction model was established using human corneal endothelial cells (HCECs) treated with H 2 O 2 at a concentration of 250 µM for 4 hours at 37°C. High-throughput sequencing was conducted to determine the expression profiles of circRNA, miRNA, and mRNA. Bioinformatic analyses, including Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes analysis, were conducted to identify the potential biological modules and pathologic pathways of dysregulated circRNAs. CircRNA-associated-ceRNA networks were established based on the data of sequencing and bioinformatic analyses. RESULTS: We obtained 108 differentially expressed circRNAs, including 77 upregulated and 31 downregulated circRNAs. GO analysis suggested that dysregulated circRNAs were mainly targeted to protein quality control for misfolded or incompletely synthesized proteins (biologic process), nuclear chromatin (cellular component), and ubiquitin protein ligase binding (molecular function). GO terms related to CE functions responding to oxidative stress were also identified. Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that dysregulated circRNAs were mostly enriched in the adherens junction pathway. Network analysis identified several potential therapeutic targets for CE dysfunction. CONCLUSIONS: CircRNAs are significantly dysregulated in HCECs under oxidative stress. The circRNA-associated-ceRNA networks are closely related to HCEC functions. Targeting these networks might provide novel therapies for CE dysfunction.

Comparative Analysis of Differentially Expressed Circular RNAs in Polarized Macrophages.

Macrophage polarization is a process that macrophages exert different functions according to surrounding micro-environment. Macrophages commonly exist in two distinct subsets: classically activated M1 macrophages and alternatively activated M2 macrophages. Circular RNAs (circRNAs) are a novel class of non-coding RNAs generated by back-splicing. Thousands of circRNAs were identified in different cells and tissues. Recent studies have revealed that circRNAs play a crucial role in regulating transcriptional and post-transcriptional gene expression. However, the effects and roles of circRNAs in macrophage polarization have not been well elucidated. Here, circRNAs expression profiles were determined in human THP-1 macrophages incubated in conditions causing activation toward M1 (interferon-γ + LPS) or M2 (interleukin-4) phenotypes. Overall, 9,720 circular RNA were detected from RNA sequencing data. Compared with M2 macrophages, a total of 140 circRNAs were aberrantly expressed in M1 macrophages, including 71 up-regulated circRNAs and 69 down-regulated circRNAs. Quantitative real-time PCR (qRT-PCR) results were generally consistent with the selected differentially expressed circRNAs. Gene Ontology (GO) and KEGG pathway analyses were used to predict biological functions and potential mechanisms of the host linear transcripts of these up-regulated and down-regulated circRNAs. Furthermore, we found that the expression level of circRNA-RNF19B (circRNF19B) in M1 macrophages was significantly higher than that in THP-1 macrophages and M2 macrophages. circRNF19B expression was increased when M2 converted to M1 whereas decreased when M1 converted to M2. Knockdown of circRNF19B following the activation of THP-1 cells using interferon-γ + LPS diminished the expression of M1 macrophages markers and elevated the expression of M2 macrophages markers. In conclusion, these data suggest the involvement of altered circRNAs expression patterns in macrophages exposure to different activating conditions. Circular RNAs may play important roles in regulating macrophage polarization.

RNA-seq identifies long non-coding RNAs as potential therapeutic targets for human corneal endothelial dysfunction under oxidative stress.

Human corneal endothelial cells (CECs) have limited ability to regenerate in vivo. Oxidative stress has been proposed as one potential reason. Understanding the mechanism of oxidative stress-induced CEC dysfunction might provide novel targets for improving CEC regenerative capacity, and help develop non-surgical therapeutic strategies for CEC dysfunction. Long non-coding RNAs (lncRNAs) are non-coding transcripts with multiple biological functions. The roles of lncRNAs in ocular cells under oxidative stress have been widely studied, such as lens epithelial cells, trabecular meshwork cells, and retinal ganglion cells. In the current study, we established oxidative stress-induced CEC dysfunction model in vitro. By RNA sequencing technology, we identified 824 differentially expressed lncRNAs in CEC dysfunction group, including 667 upregulated lncRNAs and 157 downregulated lncRNAs. We finally demonstrated that CEC functions under oxidative stress, including cellular proliferation, apoptosis, and anti-oxidative stress ability, could be regulated by different lncRNAs, including lncRNA-Z93241.1, lncRNA-XLOC_000818, and lncRNA-AC007952.4. Targeting these lncRNAs might be useful to further elucidate the pathology of CEC dysfunction and develop novel therapeutic strategy.

LINC00852 is associated with poor prognosis in non-small cell lung cancer patients and its inhibition suppresses cancer cell proliferation and chemoresistance via the hsa-miR-145-5p/KLF4 axis.

BACKGROUND: Emerging evidence shows that long non-coding RNAs (lncRNAs) play important roles in human cancer. In the present study, we examined the expression, prognostic implications and functional roles of a lncRNA, LINC00852 in non-small cell lung cancer (NSCLC). METHODS: LINC00852 expression was examined by quantitative real-time PCR (qRT-PCR) in both NSCLC clinical samples and in vitro NSCLC cell lines. In patients with NSCLC, postoperative overall survival was estimated according to endogenous LINC00852 expression in their cancerous lung tissues. In NSCLC cell line SW900 and H441 cells, LINC00852 was down-regulated to examine its effects on cancer proliferation, cisplatin chemoresistance and cell-cycle transition in vitro, as well as tumorigenicity in vivo. The potential downstream target of LINC00852, the axis of human microRNA-145-5p (hsa-miR-145-5p) and Kruppel-like factor 4 (KLF4) gene, was investigated in NSCLC, by dual-luciferase assay, qRT-PCR and genetic knockdown functional assays. RESULTS: LINC00852 is up-regulated in both NSCLC tumors and NSCLC cell lines. High LINC00852 expression was significantly correlated with NSCLC patients' short overall survival. In NSCLC cell lines, LINC00852 down-regulation had anti-cancer effects by suppressing cancer cell proliferation, cisplatin chemoresistance and cell-cycle transition in vitro, as well as explant growth in vivo. Moreover, the hsa-miR-145-5p/KLF4 axis was demonstrated to be directly regulated by LINC00852 in NSCLC. Inhibiting hsa-miR-145-5p or overexpressing KLF4 could reverse the LINC00852-down-regulation-induced anti-cancer effects on NSCLC cancer cell proliferation and chemoresistance. CONCLUSIONS: LINC00852 may be a prognostic biomarker for NSCLC. The epigenetic signaling pathway of LINC00852/hsa-miR-145-5p/KLF4 may be considered as a novel molecular target for fighting NSCLC.

Circular RNA Expression Profiling Identifies Glaucoma-Related Circular RNAs in Various Chronic Ocular Hypertension Rat Models.

Circular RNAs are characterized as a class of covalently closed circular RNA transcripts and are associated with a variety of cellular processes and neurological diseases by sponging microRNAs. Expression profiling of circular RNAs in glaucoma, which is a form of optic neuropathy, has not been performed to date. The most common characteristic of all forms of glaucoma is the loss of retinal ganglion cells. While the pathogenesis of glaucoma is not fully understood, intraocular pressure is unquestionably the only proven modifiable factor which makes chronic ocular hypertension (COH) animals the classical glaucoma models. Based on these findings, we completed the first in-depth study of rat retinal circular RNA expression profiling to identify probable biomarkers for the diagnosis of glaucoma. Two ocular hypertension models were induced by episcleral vein ligation (EVL) and microbead injection in rats. Overall, 15,819 circular RNA were detected. Furthermore, 3,502 differentially expressed circular RNAs verified in both COH rats were identified, of which 691 were upregulated and 2,811 were downregulated. Seven significantly downregulated (both log2FoldChange < -2.5 and adjusted P < 0.001) and seven significantly upregulated (both log2FoldChange > 2.5 and adjusted P < 0.001) circular RNAs were shown. Six target microRNAs aligned with the top 14 circular RNAs were identified. According to the construction of the circular RNA-microRNA network and circBase information, only RNO_CIRCpedia_1775 had the homologous hsa_circ_0023826 in the human genome. The hsa_circ_0023826 and mRNA of the host gene TENM4 (teneurin transmembrane protein 4) were validated in aqueous humor samples of five glaucoma patients and five cataract control patients. The expression of hsa_circ_0023826 showed a significant decrease in glaucoma patients, while TENM4 mRNA showed no significant difference compared to cataract patients (P = 0.024 and P = 0.294, respectively). The results of this study comprehensively characterized the expression profiles of circular RNA in glaucoma-affected eyes, as verified by two different ocular hypertension rat models. Together with the target microRNAs underlying the top differentially expressed circular RNAs, a new target of hsa_circ_0023826 and its host gene TENM4 were identified and further verified in the aqueous humor of glaucoma patients, indicating a promising biomarker for the disease.

FTO regulates ocular angiogenesis via m6A-YTHDF2-dependent mechanism.

Pathological ocular angiogenesis commonly results in visual impairment or even blindness. Unveiling the mechanisms of pathological angiogenesis is critical to identify the regulators and develop effective targeted therapies. Here, we used corneal neovascularization (CNV) model to investigate the mechanism of pathological ocular angiogenesis. We show that N6-methyladenosine (m6A) mRNA demethylation mediated by fat mass- and obesity-associated protein (FTO) could regulate endothelial cell (EC) function and pathological angiogenesis during CNV. FTO levels are increased in neovascularized corneas and ECs under pathological conditions. In vitro silencing of FTO in ECs results in reduced cellular proliferation, migration, and tube formation under both basal and pathological conditions. Furthermore, FTO silencing attenuates suture-induced CNV in vivo. Mechanically, FTO silencing in ECs could increase m6A methylation levels in critical pro-angiogenic genes, such as FAK, leading to decreased RNA stability and increased RNA decay through m6A reader YTHDF2. Our study demonstrates that FTO regulates pathological ocular angiogenesis by controlling EC function in an m6A-YTHDF2-dependent manner.

Differentially expressed circular RNAs in orbital adipose/connective tissue from patients with thyroid-associated ophthalmopathy.

Our study aimed to investigate the differentially expressed circRNAs and their potential roles in orbital adipose/connective tissue from patients with thyroid-associated ophthalmopathy (TAO). The orbital adipose/connective tissue samples from three TAO patients and three control individuals were collected for RNA sequencing after depletion of ribosomal RNA. Differentially expressed mRNAs and up-regulated circRNAs were used for co-expression analysis. Functional and pathway enrichment analysis were conducted for the up- and down-regulated mRNAs in the circRNA-mRNA co-expression network. Meanwhile, circRNA-miRNA interaction network was established by miRanda software. The expression levels of mRNAs and circRNAs in control and TAO samples were determined by qRT-PCR. Among all the 16,329 circRNAs predicted from RNA sequencing data, 163 circRNAs (95 down-regulated and 68 up-regulated) were differentially expressed in TAO samples. Besides, 607 differentially expressed mRNAs were identified. The co-expression analysis showed circRNA_14940 was correlated with CCND1 and TNXB, while circRNA_10135 was correlated with PTGFR, and circRNA_14936 was correlated with TNFRSF19. The up-regulated CCND1 participated in Wnt signaling pathway. The down-regulated TNXB was involved in the ECM-receptor interaction, focal adhesion, and PI3K-Akt signaling pathway. PTGFR participated in neuroactive ligand-receptor interaction and calcium signaling pathway. TNFRSF19 was involved in cytokine-cytokine receptor interaction. In the interaction network, circRNA_14936 could interact with hsa-miR-10392-3p, and circRNA_12367 could interact with hsa-miR-1228-3p. Moreover, the expression changes of MMP2, TNXB, PTGFR, CCND1, and TNFRSF19, as well as circRNA_14936, circRNA_14940, and circRNA_12367 were validated by qRT-PCR. In conclusion, the differentially expressed circRNAs might participate in pathogenesis of TAO, and we speculated that circRNA_14940-CCND1-Wnt signaling pathway might be an important regulatory axis.

Circular RNA-ZBTB44 regulates the development of choroidal neovascularization.

Rationale: Choroidal neovascularization (CNV) is a major cause of severe vision loss and occurs in many ocular diseases, especially neovascular age-related macular degeneration (nAMD). Circular RNAs (circRNAs) are emerging as a new class of endogenous noncoding RNAs, which have been implicated in the regulation of endothelial cell dysfunction in diabetes mellitus and cancer. In this study, we aimed to determine the role of circRNA-ZBTB44 (cZBTB44) in the pathogenesis of CNV. Methods: Quantitative polymerase chain reaction was conducted to detect cZBTB44 expression pattern during CNV development. Isolectin B4 staining, hematoxylin and eosin (HE) staining, and choroidal sprouting assay ex vivo were conducted to evaluate the role of cZBTB44 in the development of CNV. Endothelial cell proliferation, migration and tube formation assays were conducted to determine the role of cZBTB44 in angiogenic effect in vitro. Bioinformatics analysis, RNA immunoprecipitation assay, luciferase assay, and in vitro studies were conducted to investigate the mechanism of cZBTB44-mediated CNV development. Results: cZBTB44 expression was significantly up-regulated in a laser-induced CNV mouse model in vivo and in endothelial cells upon hypoxia stress in vitro. cZBTB44 silencing retarded CNV development, while overexpression of cZBTB44 showed the opposite effects. The role of cZBTB44 in CNV development was confirmed in choroidal sprouting assay ex vivo. cZBTB44 silencing reduced endothelial cell viability, proliferation, migration and tube formation in vitro. cZBTB44 acted as miR-578 sponge to sequester and inhibit miR-578 activity, which led to increased expression of vascular endothelial growth factor A (VEGFA) and vascular cell adhesion molecule-1 (VCAM1). Overexpression of miR-578 mimicked cZBTB44 silencing-mediated anti-angiogenic effects in vivo and in vitro. Furthermore, dysregulated cZBTB44 expression was detected in the clinical samples of nAMD patients. Conclusions: This study provided novel insights into the molecular pathogenesis of CNV. The cZBTB44-miR-578-VEGFA/VCAM1 axis might be a potential source of novel therapeutic targets for neovascularization-related diseases.

Targeting pericyte-endothelial cell crosstalk by circular RNA-cPWWP2A inhibition aggravates diabetes-induced microvascular dysfunction.

The crosstalk between vascular pericytes and endothelial cells (ECs) is critical for microvascular stabilization and remodeling; however, the crosstalk is often disrupted by diabetes, leading to severe and even lethal vascular damage. Circular RNAs are a class of endogenous RNAs that regulate several important physiological and pathological processes. Here we show that diabetes-related stress up-regulates cPWWP2A expression in pericytes but not in ECs. In vitro studies show that cPWWP2A directly regulates pericyte biology but indirectly regulates EC biology via exosomes carrying cPWWP2A. cPWWP2A acts as an endogenous miR-579 sponge to sequester and inhibit miR-579 activity, leading to increased expression of angiopoietin 1, occludin, and SIRT1. In vivo studies show that cPWWP2A overexpression or miR-579 inhibition alleviates diabetes mellitus-induced retinal vascular dysfunction. By contrast, inhibition of cPWWP2A-mediated signaling by silencing cPWWP2A or overexpressing miR-579 aggravates retinal vascular dysfunction. Collectively, this study unveils a mechanism by which pericytes and ECs communicate. Intervention of cPWWP2A or miR-579 expression may offer opportunities for treating diabetic microvascular complications.

Comprehensive circular RNA profiling of proliferative vitreoretinopathy and its clinical significance.

Proliferative vitreoretinopathy (PVR) is one of the major challenges in retinal surgery, which occurs in the patient with complex retinal surgery or penetrating eye injury. Circular RNAs (circRNAs) have emerged as important regulators in many biological processes and disease development. However, the characterization and function of circRNAs in PVR remains elusive. In this study, we identified 91 dysregulated circRNAs in the epiretinal membranes (ERMs) of PVR patients. We further investigated the expression pattern of circ_0043144. circ_0043144 was significantly up-regulated in the vitreous samples and the corresponding serum samples of the patients with PVR. circ_0043144 expression was significantly down-regulated after PVR operation. In vitro studies revealed that circ_0043144 was involved in the regulation of the proliferation, migration and secretion ability of ARPE-19 cells, which is critical for ERM formation. Collectively, this study indicates that circRNAs are potential regulators of the pathogenesis of PVR. circ_0043144 is a promising prognostic and diagnostic indicator for PVR diseases.

Microarray expression profile and functional analysis of circular RNAs in choroidal neovascularization.

Choroidal neovascularization (CNV) is a leading cause of visual loss in age-related macular degeneration (AMD). However, the molecular mechanism for CNV progression is still unclear. This study aimed to identify CNV-related circular RNAs (circRNAs), a novel class of non-coding RNAs with diverse functions. A total of 117 circRNAs were differentially expressed in the murine CNV model by microarrays. Gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed to identify the functions of selected circRNAs. The host genes of these circRNAs were predicted to be targeted to neurogenesis (ontology: biological process), proteinaceous extracellular matrix (ECM) (ontology: cellular component), and binding (ontology: molecular function). Differentially expressed circRNAs-mediated regulatory networks were enriched in ECM receptor interaction. Most of the dysregulated circRNAs could potentially bind to five different miRNAs by TargetScan and miRanda. Specifically, circ_15752 was identified in this circRNAs pool which may facilitate vascular endothelial cell proliferation, migration, and tube formation, suggesting a critical role in endothelial angiogenesis. Our work suggests that dysregulated circRNAs may be involved in CNV pathogenesis and serve as potential biomarkers for CNV.

Insights into catalytic roles of noble-metal-free catalysts CoxSy for reduction of 4-nitrophenol.

To develop noble-metal-free catalysts, three CoxSy samples, i.e. Co9S8, CoS and CoS2, have been prepared and investigated for the reduction of 4-nitrophenol. Co9S8 has the best surface electron immigration efficiency and the highest H2-adsorption capability, which make it the most promising catalyst. On the other hand, CoS has higher electron transfer efficiency than CoS2, leading to stronger H absorption capability. As a result, the catalytic activity of the three catalysts shows the following trend: Co9S8 > CoS > CoS2 under the same reaction conditions. Finally, a plausible catalytic mechanism has also been proposed, which is helpful in acquiring an in-depth insight into the catalytic role of CoxSy.

Circular RNA-ZNF609 regulates retinal neurodegeneration by acting as miR-615 sponge.

Glaucoma is a major cause of visual impairment characterized by progressive retinal neurodegeneration. Circular RNAs are a class of endogenous noncoding RNAs that regulate gene expression in eukaryotes. In this study, we investigated the role of cZNF609 in retinal neurodegeneration induced by glaucoma. Methods: qRT-PCR and Sanger sequencing were conducted to detect cZNF609 expression pattern during retinal neurodegeneration. Immunofluorescence staining was conducted to detect the effect of cZNF609 silencing on retinal neurodegeneration in vivo. MTT assay, Ki67 staining, and PI staining were conducted to detect the effect of cZNF609 silencing on retinal glial cells and RGC function in vitro. Bioinformatics analysis, RNA pull-down assays, and in vitro studies were conducted to reveal the mechanism of cZNF609-mediated retinal neurodegeneration. Results: cZNF609 expression was significantly up-regulated during retinal neurodegeneration. cZNF609 silencing reduced retinal reactive gliosis and glial cell activation, and facilitated RGC survival in vivo. cZNF609 silencing directly regulated Müller cell function but indirectly regulated RGC function in vitro. cZNF609 acted as an endogenous miR-615 sponge to sequester and inhibit miR-615 activity, which led to increased METRN. METRN overexpression could partially rescue cZNF609 silencing-mediated inhibitory effects on retinal glial cell proliferation. Conclusion: Intervention of cZNF609 expression is a promising therapeutic strategy for retinal neurodegeneration.

Photoinduced in Situ Deposition of Uniform and Well-Dispersed PtO2 Nanoparticles on ZnO Nanorods for Efficient Catalytic Reduction of 4-Nitrophenol.

Based on the photochemical property of semiconductors, a light irradiation-assisted strategy has been designed using one-dimensional ZnO nanorods as carriers to synthesize the rod-type PtO2/ZnO catalyst with a well-defined structure. The high crystallinity and uniform crystal structure of the ZnO matrix conduct the in situ deposition of PtO2 nanoparticles with 1.1-2.1 nm, which are evenly and densely anchored on the surface. Those small-sized and well-dispersed PtO2 nanoparticles endow the PtO2/ZnO catalyst a superior catalytic performance for the reduction of 4-nitrophenol to 4-aminophenol, which can convert all the substrates within 6.25 min. It is demonstrated that the catalytic activity of the PtO2/ZnO catalyst is 2.3 times as high as that of the sample obtained by traditional wet-oxidation method under the same reaction conditions. Moreover, the light-irradiation time has been found to greatly affect the structure and activity of PtO2/ZnO catalysts, and the product with 30 min exhibits the best catalytic performance in this work, as well as the good stability for ten runs. In terms of the photoexcited process of ZnO and reactive species-trapped experiments, the formation mechanism of PtO2/ZnO catalysts has been explored in detail, which will probably stimulate the design and study of other metal-supported catalysts.

Targeting circular RNA-ZRANB1 for therapeutic intervention in retinal neurodegeneration.

Glaucoma is a neurodegenerative disease characterized by retinal ganglion cell (RGC) loss, optic disc excavation, and progressive visual field loss. Direct or indirect ameliorating retinal neurodegeneration is a promising therapeutic therapy for glaucoma. Circular RNAs (circRNAs) are a class of covalently closed circular RNA transcripts and have emerged as potential regulators in several neurodegenerative diseases. In this study, we show that cZRANB1 expression is significantly upregulated in retinal neurodegeneration induced by glaucoma. cZRANB1 knockdown decreases retinal reactive gliosis, glial cell activation, and facilitates RGC survival in vivo. cZRANB1 knockdown directly regulates Müller cell function and indirectly regulates RGC function in vitro. cZRANB1 acts as miRNA sponge to regulate Müller cell function through cZRANB1/miR-217/RUNX2 network. Intervention of cZRANB1 expression would become an effective strategy for treating retinal neurodegeneration.

Class A1 scavenger receptor modulates glioma progression by regulating M2-like tumor-associated macrophage polarization.

Macrophages enhance glioma development and progression by shaping the tumor microenvironment. Class A1 scavenger receptor (SR-A1), a pattern recognition receptor primarily expressed in macrophages, is up-regulated in many human solid tumors. We found that SR-A1 expression in 136 human gliomas was positively correlated with tumor grade (P<0.01), but not prognosis or tumor recurrence. SR-A1-expressing macrophages originated primarily from circulating monocytes attracted to tumor tissue, and were almost twice as numerous as resident microglia in glioma tissues (P<0.001). The effects of SR-A1 on glioma proliferation and invasion were assessed in vivo using an SR-A1-deficient murine orthotopic glioma model. SR-A1 deletion promoted M2-like tumor-associated macrophage (TAM) polarization in mice by activating STAT3 and STAT6, which resulted in robust orthotopic glioma proliferation and angiogenesis. Finally, we found that HSP70 might be an endogenous ligand that activates SR-A1-dependent anti-tumorigenic pathways in gliomas, although its expression does not appear informative for diagnostic purposes. Our findings demonstrate a relationship between TAMs, SR-A1 expression and glioma growth and provide new insights into the pathogenic role of TAMs in glioma.

Long non-coding RNA-MIAT promotes neurovascular remodeling in the eye and brain.

Although nervous and vascular systems are functionally different, they usually share similar mechanisms for function maintenance. Neurovascular dysfunction has became the pathogenesis of several vascular and nervous disorders. Here we show that long non-coding RNA-MIAT is aberrantly expressed under neurovascular dysfunction condition. MIAT is shown as a regulator of vascular dysfunction, including retinal angiogenesis, corneal angiogenesis, and vascular permeability. MIAT is also shown as a regulator of retinal neurodegeneration under diabetic condition. Mechanistically, MIAT regulates neural and vascular cell function via MIAT/miR-150-5p/VEGF network. The eye is a valuable model to study central nervous system (CNS) disorders. We show that MIAT knockdown leads to cerebral microvascular degeneration, progressive neuronal loss and neurodegeneration, and behavioral deficits in a CNS neurovascular disorder, Alzheimer's disease. MIAT may represent a pharmacological target for treating neurovascular-related disorders.

Piezo2 protein: A novel regulator of tumor angiogenesis and hyperpermeability.

Angiogenesis is important for invasive tumor growth and metastasis. Its inhibition is a promising tactic for limiting tumor progression. Here, we showed that Piezo2 knockdown led to decreased glioma angiogenesis and reduced vascular hyperpermeability. Piezo2 was highly expressed in tumor endothelial cells, and its knockdown suppressed vascular leakage and tumor angiogenesis. In a retinal vasculature development assay, corneal angiogenesis assay and a modified Miles assay, Piezo2 knockdown obviously decreased angiogenesis and vascular hyperpermeability. In vitro assays revealed that Piezo2 knockdown inhibited endothelial cell proliferation, migration, and tube formation. Moreover, In vitro co-culture system assay showed that Piezo2 knockdown in endothelial cells suppressed cell proliferation, migration, and invasion of glioma tumor cells. Piezo2 could regulate glioma angiogenesis via Ca2+/Wnt11/ß-catenin signaling in endothelial cells. Taken together, these studies provide the evidence for Piezo2 as a critical regulator of tumor angiogenesis and vascular permeability.

Nmnat 1: a Security Guard of Retinal Ganglion Cells (RGCs) in Response to High Glucose Stress.

BACKGROUND/AIMS: Retinal neurodegeneration is an early event in the pathological process of diabetic retinopathy (DR). Retinal ganglion cell (RGC) injury is an important pathological feature during neurodegenerative process. Protecting RGCs from high glucose-induced injury is a promising strategy for delaying or hindering diabetes mellitus-related retinal neuropathy. This study aims to investigate the role of Nmnat1, an enzyme which catalyzes a key step in the biosynthesis of nicotinamide adenine dinucleotide (NAD), in high glucose-induced RGC injury. METHODS: Western blot and immunofluorescence analysis was conducted to detect Nmnat1 expression pattern in the retina and RGC-5 cell. MTT assay, Hoechst staining, trypan blue staining, and calcein-AM/ propidium iodide (PI) staining was conducted to determine the effect of Nmnat1 knockdown on RGC-5 cell function. Microarray and bioinformatics analysis was conducted to identify potential signaling pathways affected by Nmnat1 knockdown. Pharmacological intervention, molecular intervention, and in vitro experiments were conducted to reveal molecular mechanism of Nmnat1-mediated protective effect on RGC-5 cell function. RESULTS: Nmnat1 is constitutively expressed in retina and RGC-5 cells. Nmnat1 knockdown aggravates RGC injury, and accelerates the development of RGC-5 cell apoptosis upon high glucose stress. MAPK signaling is the primary signaling pathway affected by Nmnat1 knockdown. Under high glucose stress, Nmnat1 knockdown leads to p38-MAPK signaling inactivation. p38-MAPK pathway inhibitor strongly blocks Nmnat1-mediated protective effect on RGC-5 cell function. CONCLUSION: Nmnat1 protects RGC against high glucose-induced injury via p38-MAPK signaling pathway. Nmnat1 may serve as a neuroprotective target for diabetes mellitus-related retinal neuropathy.

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

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