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Epigenetic alterations occur in many physiological and pathological processes. N6-methyladenosine (m6A) modification is the most prevalent modification in eukaryotic mRNAs. However, the role of m6A modification in pathological angiogenesis remains elusive. In this study, we showed that the level of m6A modification was significantly upregulated in endothelial cells and mouse retinas following hypoxic stress, which was caused by increased METTL3 levels. METTL3 silencing or METTL3 overexpression altered endothelial cell viability, proliferation, migration, and tube formation in vitro. METTL3 knockout in vivo decreased avascular area and pathological neovascular tufts in an oxygen-induced retinopathy model and inhibited alkali burn-induced corneal neovascularization. Mechanistically, METTL3 exerted its angiogenic role by regulating Wnt signaling through the m6A modification of target genes (e.g., LRP6 and dishevelled 1 [DVL1]). METTL3 enhanced the translation of LRP6 and DVL1 in an YTH m6A RNA-binding protein 1 (YTHDF1)-dependent manner. Collectively, this study suggests that METTL3-mediated m6A modification is an important hypoxic stress-response mechanism. The targeting of m6A through its writer enzyme METTL3 is a promising strategy for the treatment of angiogenic diseases.

Antibody-based therapy is an effective strategy for treating ocular angiogenesis. However, short-acting efficacy and poor treatment compliance usually occurs in clinical practices. Thus, it is required to develop a drug delivery system to improve the bioavailability and decrease the toxicity of anti-angiogenic antibody. Bevacizumab is a recombinant humanized monoclonal antibody against vascular endothelial growth factor (VEGF). In this study, bevacizumab was encapsulated into poly (lactide-co-glycolide) (PLGA) nanoparticles. PLGA encapsulation could prolong the residency of bevacizumab in the vitreous and aqueous humor and produce long-lasting drug concentrations. Bevacizumab-encapsulated PLGA had no significant cytotoxicity and tissue toxicity effect in vitro and in vivo. In vitro studies showed that bevacizumab-encapsulated PLGA was more effective than bevacizumab in inhibiting VEGF-mediated endothelial cell proliferation, migration and tube formation. In vivo studies showed that bevacizumab-encapsulated PLGA enhanced the anti-angiogenic efficiency of bevacizumab for treating corneal neovascularization and retinal neovascularization. Thus, bevacizumab-encapsulated PLGA could increase the bioavailability and decrease the toxicity of bevacizumab during ocular angiogenesis therapy.

Excessive light exposure leads to retinal degeneration and accelerates the progression and severity of several ocular diseases, such as age-related macular degeneration (AMD) and retinitis pigmentosa. Long non-coding RNAs (LncRNAs) have emerged as important regulators of photoreceptor development and ocular diseases. In this study, we investigated the role of lncRNA-MEG3 in light-induced retinal degeneration. MEG3 expression was significantly up-regulated after light insult in vivo and in vitro. MEG3 silencing protected against light-induced retinal degeneration in vivo and light-induced photoreceptor cell apoptosis in vitro. Mechanistically, MEG3 regulated retinal photoreceptor cell function by acting as p53 decoy. MEG3 silencing decreased caspase 3/7 activity, up-regulated anti-apoptotic protein (Bcl-2) expression, and down-regulated pro-apoptotic protein (Bax) expression. Taken together, this study provides a promising method of MEG3 silencing for treating light-induced retinal degeneration.

Background/Aims: Pterygium is a common ocular surface disease with an unknown etiology and threatens vision as it invades into the cornea. Circular RNAs (circRNAs) are a novel class of RNA transcripts that participate in several physiological and pathological processes. However, the role of circRNAs in pathogenesis of pterygium remains largely unknown. Methods: Genome-wide circRNA expression profiling was performed to identify pterygium -related circRNAs. GO analysis, pathway analysis, and miRNA response elements analysis was performed to predict the function of differentially expressed circRNAs in pterygium. MTT assays, Ki67 staining, Transwell assay, Hoechst 33342 staining, and Calcein-AM/PI staining were performed to determine the effect of circRNA silencing on pterygium fibroblast and epithelial cell function. Results: Approximately 669 circRNAs were identified to be abnormally expressed in pterygium tissues. GO analysis demonstrated that the host genes of differentially expressed circRNAs were targeted to extracellular matrix organization (ontology: biological process), cytoplasm (ontology: cellular component), and protein binding (ontology: molecular function). Pathway analysis showed that dysregulated circRNAs-mediated regulatory networks were mostly enriched in focal adhesion signaling pathway. Notably, circ_0085020 (circ-LAPTM4B) was shown as a potential biomarker for pterygium. circ_0085020 (circ-LAPTM4B) silencing affected the viability, proliferation, migration, and apoptosis of pterygium fibroblast and epithelial cells in vitro. Conclusions: This study provides evidence that circRNAs are involved in the pathogenesis of pterygium and might constitute promising targets for the therapeutic intervention of pterygium.

Epigenetic alterations occur in many physiological and pathological processes. N

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.

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.

Diabetic retinopathy (DR) is the leading cause of blindness in working-age adults. Vascular pericyte degeneration is the predominant clinical manifestation of DR, yet the mechanism governing pericyte degeneration is poorly understood. Circular RNAs (circRNAs) play important roles in multiple biological processes and disease progression. Here, we investigated the role of circRNA in pericyte biology and diabetes-induced retinal vascular dysfunction. cZNF532 expression was upregulated in pericytes under diabetic stress, in the retinal vessels of a diabetic murine model, and in the vitreous humor of diabetic patients. cZNF532 silencing reduced the viability, proliferation, and differentiation of pericytes and suppressed the recruitment of pericytes toward endothelial cells in vitro. cZNF532 regulated pericyte biology by acting as a miR-29a-3p sponge and inducing increased expression of NG2, LOXL2, and CDK2. Knockdown of cZNF532 or overexpression of miR-29a-3p aggravated streptozotocin-induced retinal pericyte degeneration and vascular dysfunction. By contrast, overexpression of cZNF532 or inhibition of miR-29a-3p ameliorated human diabetic vitreous-induced retinal pericyte degeneration and vascular dysfunction. Collectively, these data identify a circRNA-mediated mechanism that coordinates pericyte biology and vascular homeostasis in DR. Induction of cZNF532 or antagonism of miR-29a-3p is an exploitable therapeutic approach for the treatment of DR.

VEGF-induced neovascularization plays a pivotal role in corneal neovascularization (CoNV). The current study investigated the potential effect of ginsenoside Rh2 (GRh2) on neovascularization. In HUVECs, pretreatment with GRh2 largely attenuated VEGF-induced cell proliferation, migration, and vessel-like tube formation in vitro. At the molecular level, GRh2 disrupted VEGF-induced VEGF receptor 2 (VEGFR2)-Grb-2-associated binder 1 (Gab1) association in HUVECs, causing inactivation of downstream AKT and ERK signaling. Gab1 knockdown (by targeted short hairpin RNA) similarly inhibited HUVEC proliferation and migration. Notably, GRh2 was ineffective against VEGF in Gab1-silenced HUVECs. In a mouse cornea alkali burn model, GRh2 eyedrops inhibited alkali-induced neovascularization and inflammatory cell infiltrations in the cornea. Furthermore, alkali-induced corneal expression of mRNAs/long noncoding RNAs in cornea were largely attenuated by GRh2. Overall, GRh2 inhibits VEGF-induced angiogenic effect via inhibiting VEGFR2-Gab1 signaling in vitro. It also alleviates angiogenic and inflammatory responses in alkali burn-treated mouse corneas.-Zhang, X.-P., Li, K.-R., Yu, Q., Yao, M.-D., Ge, H.-M., Li, X.-M., Jiang, Q., Yao, J., Cao, C. Ginsenoside Rh2 inhibits vascular endothelial growth factor-induced corneal neovascularization.

Numerical calculations with time dependant one-dimensional fluid model are performed at various conditions in argon atmospheric pressure to calculate electrical characteristics and plasma parameters including charged and metastable molecules densities. The simulation results show after steady discharge are formed, the voltage of discharge gap nearly remain constant and the phase is 0.36π advance of the applied voltage; The current density are in the same period as the applied voltage, the phase is 0.58π ahead of the applied voltage; The steady state Ar are in high number density in the whole discharge gap; The Ar* number density appear peak at the middle of the discharge gap; The Ar+ number density appear peak in the negative bright area.

Because of increased resistance to apoptosis in tumor cells, inhibition of specific anti-apoptotic factors may provide a rational approach for the development of novel therapeutic strategies. Livin, a novel inhibitor of apoptosis protein family, has been found to be expressed in various malignancies and is suggested to have poorly prognostic significance. However, no data are available concerning the significance of livin in gastric cancer. In this study, we detected the expression of livin in human gastric carcinoma and investigated the apoptotic susceptibility of SGC - 7901 cell by shRNA-mediated silencing of the livin gene.The mRNA and protein expression of livin were analyzed by RT-PCR and western blot assay. The relationship between livin expression and clinical pathologic parameters was investigated. The small interfering RNA eukaryotic expression vector specific to livin was constructed by gene recombination, and the nucleic acid was sequenced. Then it was transfected into SGC-7901 cells by Lipofectamin 2000. RT-PCR and Western blot assay were used to validate gene-silencing efficiency of livin in SGC-7901 cells. Stable clones were obtained by G418 screening. The cell apoptosis was assessed by flow cytometry (FCM). Cell growth state and 50 % inhibition concentration (IC50) of 5-FU and cisplatin was determined by MTT method.The expression of livin mRNA and protein were detected in 19 of 40 gastric carcinoma cases (47.5%) and SGC-7901 cells. No expression of livin was detected in tumor adjacent tissues and benign gastric lesion. The positive correlation was found between livin expression and poor differentiation of tumors as well as lymph node metastases (P0.05). Four small interfering RNA eukaryotic expression vector specific to livin were constructed by gene recombination. And one of them can efficiently decrease the expression of livin, the inhibition of the gene was not less than 70% (P0.01). The recombinated plasmids were extracted and transfected gastric cancer cells. The stable clones were obtained by G418 screening, and were amplified and cultured. When livin gene was silenced, the reproductive activity of the gastric cancer cells was significantly lower than the control groups(P0.05). The study also showed that IC50 of 5-Fu and cisplatin on gastric cancer cells treated by shRNA was decreased and the cells were more susceptible to proapoptotic stimuli (5-Fu and cisplatin) (P0.01).Livin is overexpressed in gastric carcinoma with a relationship to tumor differentiation and lymph node metastases, which is suggested to be one of the molecular prognostic factors for some cases of gastric cancer. ShRNA can inhibit livin expression in SGC-7901 cells and induce cell apoptosis. Livin may serve as a new target for apoptosis-inducing therapy of gastric cancer.