RESUMEN
Signal transducer and activator of transcription 5 (STAT5) is well established as an essential regulator of tumor growth and angiogenesis. However, its specific role in retinal neovascularization (RNV) remains unclear. This research aims to elucidate the function of STAT5 in RNV progression and to identify the underlying molecular pathways. An oxygen-induced retinopathy (OIR) model was developed using C57BL/6 mice exposed to 75 ± 3 % O2 from postnatal day 7 (P7) to P12 and injected intravitreally with a STAT5 inhibitor (10 µM) at P12. Western blot and immunofluorescence were used to evaluate protein expression at P15 and P18. Neovascularization was quantified using a whole retinal flat-mount, and apoptosis was detected using Tunnel assay at P18. Human retinal microvascular endothelial cells (HRMVECs) were cultured for 12 h under normoxic (21 % O2) or hypoxic (1 % O2) conditions to assess the effects of the STAT5 inhibitor (2 µM) on cell proliferation, migration, and tube formation. STAT5 and phosphorylated STAT5 (p-STAT5) levels were elevated in the retinas of OIR mice, which exhibited colocalization in neovascular regions. The areas with RNV were significantly reduced by treatment with a STAT5 inhibitor, which also decreased STAT5 and p-STAT5 levels. Inhibiting STAT5 in the OIR mice elevated the expression of apoptotic markers, including PARP-1, Caspase-3/9, and Bax/Bcl-2. The STAT5 inhibitor significantly promoted apoptosis in the retinal neovascular regions. Furthermore, the proliferation, migration, invasion, and tube-forming capacities of HRMVECs were significantly suppressed following treatment with the STAT5 inhibitor. Our findings demonstrate that STAT5 signaling promotes RNV progression by enhancing endothelial cell survival and angiogenic functions.
Asunto(s)
Apoptosis , Células Endoteliales , Endotelio Vascular , Neovascularización Retiniana , Factor de Transcripción STAT5 , Animales , Neovascularización Retiniana/metabolismo , Neovascularización Retiniana/patología , Neovascularización Retiniana/prevención & control , Ratones Endogámicos C57BL , Factor de Transcripción STAT5/antagonistas & inhibidores , Factor de Transcripción STAT5/metabolismo , Ratones , Modelos Animales de Enfermedad , Células Cultivadas , Western Blotting , Humanos , Proliferación Celular , Células Endoteliales/metabolismo , Células Endoteliales/patología , Inyecciones Intravítreas , Movimiento Celular , Animales Recién Nacidos , Vasos Retinianos/patología , Endotelio Vascular/metabolismo , Endotelio Vascular/patologíaRESUMEN
Retinopathy of prematurity (ROP) is a vision-threatening disorder that leads to pathological growth of the retinal vasculature due to hypoxia. Here, we investigated the potential effects of alamandine, a novel heptapeptide in the renin-angiotensin system (RAS), on hypoxia-induced retinal neovascularization and its underlying mechanisms. In vivo, the C57BL/6J mice with oxygen-induced retinopathy (OIR) were injected intravitreally with alamandine (1.0 µmol/kg per eye). In vitro, human retinal microvascular endothelial cells (HRMECs) were utilized to investigate the effects of alamandine (10 µg/mL) on proliferation, apoptosis, migration, and tubular formation under vascular endothelial growth factor (VEGF) stimulation. Single-cell RNA sequencing (scRNA-seq) matrix data from the Gene Expression Omnibus (GEO) database and RAS-related genes from the Molecular Signatures Database (MSigDB) were sourced for subsequent analyses. By integrating scRNA-seq data across multiple species, we identified that RAS-associated endothelial cell populations were highly related to retinal neovascularization. The liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis revealed a significant decrease in alamandine levels in both the serum and retina of OIR mice compared to those in the control group. Next, alamandine ameliorated hypoxia-induced retinal pathological neovascularization and physiologic revascularization in OIR mice. In vitro, alamandine effectively mitigated VEGF-induced proliferation, scratch wound healing, and tube formation of HRMECs primarily by inhibiting the hypoxia-inducible factor-1α (HIF-1α)/VEGF pathway. Further, coincubation with D-Pro7 (Mas-related G protein-coupled receptor D (MrgD) antagonist) hindered the beneficial impacts of alamandine on hypoxia-induced pathological angiogenesis both in vivo and in vitro. Our findings suggested that alamandine could mitigate retinal neovascularization by targeting the MrgD-mediated HIF-1α/VEGF pathway, providing a potential therapeutic agent for OIR prevention and treatment.
Asunto(s)
Subunidad alfa del Factor 1 Inducible por Hipoxia , Oligopéptidos , Neovascularización Retiniana , Factor A de Crecimiento Endotelial Vascular , Animales , Neovascularización Retiniana/tratamiento farmacológico , Neovascularización Retiniana/prevención & control , Ratones Endogámicos C57BL , Factor A de Crecimiento Endotelial Vascular/metabolismo , Humanos , Ratones , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Oligopéptidos/farmacología , Oligopéptidos/uso terapéutico , Transducción de Señal/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Endoteliales/efectos de los fármacos , Retinopatía de la Prematuridad/tratamiento farmacológico , Apoptosis/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Sistema Renina-Angiotensina/efectos de los fármacos , Células CultivadasRESUMEN
Inhibitors of histone deacetylases (HDACs) suppress retinal angiogenesis by interrupting the vascular endothelial growth factor (VEGF)-mammalian target of rapamycin complex 1 (mTORC1) pathway in proliferating endothelial cells. To investigate the underlying mechanisms, we examined the effects of valproic acid (VPA) and vorinostat on the distribution of VEGF protein and phosphorylated S6 protein, an indicator of mTORC1 activity, in the neonatal mouse retina, an experimental model of retinal angiogenesis. Newborn mice were subcutaneously injected with VPA, vorinostat, or vehicle once daily from postnatal day (P) 0 to P3. Their eyes were collected at P4. Compared to vehicle-treated mice, retinal vascularization was delayed, and the number of proliferating vascular cells was reduced in front of the retinal vasculature in VPA- and vorinostat-treated mice. In P4 mice, a single injection of VPA or vorinostat reduced VEGF expression on the retinal surface at 2 and 6 h after injection. Both drugs reduced mTORC1 activity in proliferating endothelial cells. The proteasome inhibitor, MG132, suppressed the VPA- and vorinostat-induced reduction in VEGF expression on the retinal surface. These results suggest that HDAC inhibitors suppress retinal angiogenesis by preventing endothelial cell proliferation and accelerating VEGF protein degradation in a proteasome-dependent manner.
Asunto(s)
Proliferación Celular , Células Endoteliales , Inhibidores de Histona Desacetilasas , Neovascularización Retiniana , Ácido Valproico , Factor A de Crecimiento Endotelial Vascular , Animales , Proliferación Celular/efectos de los fármacos , Factor A de Crecimiento Endotelial Vascular/metabolismo , Inhibidores de Histona Desacetilasas/farmacología , Inhibidores de Histona Desacetilasas/uso terapéutico , Ácido Valproico/farmacología , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Células Endoteliales/citología , Vorinostat , Proteolisis/efectos de los fármacos , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Animales Recién Nacidos , Neovascularización Retiniana/patología , Neovascularización Retiniana/prevención & control , Neovascularización Retiniana/tratamiento farmacológico , Neovascularización Retiniana/metabolismo , Ratones Endogámicos C57BL , Ratones , Ácidos Hidroxámicos/farmacología , Retina/metabolismo , AngiogénesisRESUMEN
BACKGROUND: Angiogenesis is a dynamic process fine-tuned by transcription factors in endothelial cells. The KLF15 (Krüppel-like factor 15)-mediated transcriptional regulation mechanism is critical for cardiovascular diseases. However, the role of KLF15 in governing angiogenesis remains unknown. METHODS: KLF15 and VASN (vasorin) were deleted from endothelial cells using tamoxifen-inducible Cdh5 promoter-driven Cre recombinase in endothelial cell-KLF15 knockout (EC-KLF15 KO) and EC-VASN KO mice, respectively. EC-KLF15 KO, EC-VASN KO, and control mice were subjected to retinal angiogenesis or tumor cell transplantation. The RNA sequencing, assay for transposase-accessible chromatin using sequencing, and chromatin immunoprecipitation sequencing were conducted to identify VASN as a downstream effector of KLF15. Cell proliferation, wound healing, tube formation, and sprouting assays were performed to delineate endothelial cell function. RESULTS: In EC-KLF15 KO mice and adenovirus-mediated KLF15 overexpression mice, we showed that KLF15 negatively regulated retinal angiogenesis, as confirmed in cultured endothelial cells. KLF15 opened chromatin, bound to the promoters of GC-rich sequences, and transactivated the expression of VASN. Subsequently, VASN suppressed endothelial angiogenic function, which was essential for Dll4 (delta-like ligand 4)-induced Notch1 signaling activation. Moreover, increased expression of VASN in EC-KLF15 KO mice suppressed retinal angiogenesis, which was attenuated by γ-secretase inhibitor. EC-VASN KO mice recapitulated the promotion of retinal angiogenesis in EC-KLF15 KO mice. Finally, the EGF (epidermal growth factor)-like domain of VASN was essential for its interaction with Notch1, and VASN EGF-like domain-derived peptides activated Notch1 signaling and suppressed angiogenesis. CONCLUSIONS: The KLF15/VASN axis negatively regulates angiogenesis by activating Notch1 signaling. KLF15 and VASN might represent novel therapeutic targets for the treatment of impaired angiogenesis-related diseases and tumors.
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Células Endoteliales , Factores de Transcripción de Tipo Kruppel , Neovascularización Fisiológica , Receptor Notch1 , Neovascularización Retiniana , Factores de Transcripción , Animales , Transducción de Señal , Ratones Noqueados , Receptor Notch1/metabolismo , Receptor Notch1/genética , Factores de Transcripción de Tipo Kruppel/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Humanos , Ratones , Células Endoteliales/metabolismo , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Neovascularización Retiniana/metabolismo , Neovascularización Retiniana/genética , Neovascularización Retiniana/patología , Neovascularización Retiniana/prevención & control , Ratones Endogámicos C57BL , Células Cultivadas , Proliferación Celular , AngiogénesisRESUMEN
Purpose: To assess the efficacy of tetrahedral framework nucleic acids (tFNAs) as a delivery system for small interfering RNA (siRNA) targeting RUNX1 (siRUNX1) in inhibiting retinal neovascularization (RNV) and restoring vascular integrity via the Dll4/Notch1 signaling pathway. Methods: tFNAs and tFNAs-siRUNX1 were synthesized using annealing of single-stranded DNAs and characterized by PAGE and high-performance capillary electrophoresis. Human umbilical vein endothelial cells were treated under hypoxic conditions with tFNAs-siRUNX1, and cellular uptake was evaluated using fluorescence microscopy and flow cytometry. Angiogenesis was assessed through EdU proliferation, tube formation, and wound-healing assays. In vivo experiments used oxygen-induced retinopathy (OIR) and laser-induced choroidal neovascularization (CNV) models in mice, with subsequent imaging by optical coherence tomography (OCT) and fundus fluorescence angiography. Gene and protein expression were analyzed by RT-PCR and Western blotting, focusing on the Dll4/Notch1 pathway and apoptosis markers. Results: tFNAs-siRUNX1 effectively inhibited endothelial cell proliferation, migration, and tube formation in vitro. In OIR and CNV models, it reduced neovascularization, nonperfusion areas, and vascular leakage. The mechanism involved modulation of the Dll4/Notch1 pathway, with decreased Dll4, Notch1, and Hes1 and increased Nts expression. tFNAs-siRUNX1 also reduced endothelial cell apoptosis via the Bcl-2/Bax pathway. Conclusions: tFNAs-siRUNX1 is a promising delivery system for targeting RNV, inhibiting neovascularization, and restoring retinal vascular integrity, providing a potential therapeutic alternative to anti-VEGF treatments.
Asunto(s)
Péptidos y Proteínas de Señalización Intracelular , ARN Interferente Pequeño , Receptor Notch1 , Neovascularización Retiniana , Neovascularización Retiniana/metabolismo , Neovascularización Retiniana/genética , Neovascularización Retiniana/prevención & control , Animales , Receptor Notch1/metabolismo , Receptor Notch1/genética , Humanos , Ratones , Transducción de Señal , Modelos Animales de Enfermedad , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/administración & dosificación , Células Endoteliales de la Vena Umbilical Humana , Angiografía con Fluoresceína , Proliferación Celular , Ratones Endogámicos C57BL , Western Blotting , Proteínas de Unión al Calcio , Células Cultivadas , Tomografía de Coherencia Óptica , Proteínas Adaptadoras Transductoras de Señales , Citometría de Flujo , Apoptosis , Vasos Retinianos , Neovascularización Coroidal/metabolismo , Movimiento Celular , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Masculino , Subunidad alfa 2 del Factor de Unión al Sitio PrincipalRESUMEN
Retinopathy of prematurity is characterised by abnormal retinal neovascularization in response to hypoxia stress. Prolyl 4-hydroxylase domain protein 3 (PHD3) is a well-known molecular oxygen sensor. However, the role that PHD3 plays in retinopathy of prematurity remains unclear. In this work, a mouse model of oxygen-induced retinopathy (OIR) was used for in vivo studies. Compared with the mice in room air, OIR mice showed sprouting of retinal neovascularization and increased level of PHD3. It was further found that PHD3 overexpression weakened OIR-induced retinal neovascularization and promoted cell apoptosis in the retina, indicating a mitigative effect on retinopathy. More importantly, OIR-induced upregulation of hypoxia inducible factor-1 alpha (HIF-1α) and vascular endothelial growth factor (VEGFA) was offset by PHD3 overexpression. In in vitro experiments, mouse retinal microvascular endothelial cells (MRMECs) were cultured under hypoxic conditions. The functions of endothelial cells including cell proliferation, cell migration, and tube formation ability were suppressed by PHD3, suggesting an anti-angiogenesis effect of PHD3. In line with in vivo experiments, the expression of HIF-1α and VEGFA levels declined in endothelial cells when PHD3 was overexpressed. Taken together, PHD3 alleviates retinopathy of prematurity through anti-angiogenesis, and the core mechanism may involve cell apoptosis of retina endothelial cell and HIF-1α-VEGFA axis. These findings provide exciting new insights into the pathogenesis of retinopathy of prematurity, and could offer new treatment directions.
Asunto(s)
Prolina Dioxigenasas del Factor Inducible por Hipoxia , Procolágeno-Prolina Dioxigenasa , Neovascularización Retiniana , Retinopatía de la Prematuridad , Animales , Retinopatía de la Prematuridad/patología , Retinopatía de la Prematuridad/metabolismo , Retinopatía de la Prematuridad/genética , Neovascularización Retiniana/patología , Neovascularización Retiniana/metabolismo , Neovascularización Retiniana/genética , Neovascularización Retiniana/prevención & control , Ratones , Prolina Dioxigenasas del Factor Inducible por Hipoxia/metabolismo , Prolina Dioxigenasas del Factor Inducible por Hipoxia/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Ratones Endogámicos C57BL , Apoptosis , Proliferación Celular , Células Endoteliales/metabolismo , Células Endoteliales/patología , Humanos , Movimiento Celular , Retina/patología , Retina/metabolismo , Modelos Animales de Enfermedad , Animales Recién Nacidos , Procolágeno-Prolina Dioxigenasa/metabolismoRESUMEN
Purpose: To investigate the therapeutic efficacy of BEZ235, a dual PI3K/mTOR inhibitor, in suppressing pathological neovascularization in an oxygen-induced retinopathy (OIR) mouse model and explore the role of cyclin D1 in endothelial cell cycle regulation. Methods: Single-cell RNA sequencing was performed to analyze gene expression and cell-cycle alterations in retinal endothelial cells under normoxic and OIR conditions. The effects of BEZ235 on human umbilical vein endothelial cells (HUVECs) and human retinal microvascular endothelial cells (HRMECs) were evaluated by assessing cell viability, cell-cycle progression, proliferation, migration, and tube formation. In the OIR mouse model, retinal neovascularization was evaluated by retinal flatmount immunofluorescence staining, hematoxylin and eosin (H&E) staining, quantitative reverse-transcription polymerase chain reaction (RT-qPCR), and western blot analyses. The in vivo toxicity of BEZ235 was evaluated by electroretinography (ERG) and histological examination of the heart, liver, spleen, lungs, and kidneys. Results: In vitro, BEZ235 significantly inhibited cell cycle progression by downregulating cyclin D1 at both mRNA and protein levels, inducing G0/G1 phase arrest. This led to significant reductions in cell viability, proliferation, migration, and tube formation. In the OIR model, BEZ235 substantially decreased neovascularization and improved vascular organization. BEZ235 mediates its effects by inhibiting the PI3K/Akt/mTOR pathway, reducing Akt and 4E-binding protein 1 (4EBP1) phosphorylation levels, thus downregulating cyclin D1 expression. ERG and histological examination suggested that BEZ235 did not induce evident retinal or systemic toxicity at the dosage used to inhibit retinal neovascularization. Conclusions: BEZ235 effectively inhibits retinal neovascularization by downregulating cyclin D1 via 4EBP1 phosphorylation inhibition, highlighting its potential as a promising therapeutic agent for retinal neovascularization diseases.
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Proteínas Adaptadoras Transductoras de Señales , Ciclina D1 , Imidazoles , Proteínas Proto-Oncogénicas c-akt , Quinolinas , Neovascularización Retiniana , Animales , Ciclina D1/metabolismo , Ciclina D1/genética , Ratones , Neovascularización Retiniana/metabolismo , Neovascularización Retiniana/tratamiento farmacológico , Neovascularización Retiniana/patología , Neovascularización Retiniana/prevención & control , Humanos , Quinolinas/farmacología , Quinolinas/uso terapéutico , Modelos Animales de Enfermedad , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Imidazoles/farmacología , Imidazoles/uso terapéutico , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proliferación Celular/efectos de los fármacos , Proteínas de Ciclo Celular/metabolismo , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Ratones Endogámicos C57BL , Transducción de Señal/efectos de los fármacos , Western Blotting , Células Cultivadas , Movimiento Celular , Supervivencia CelularRESUMEN
Purpose: Retinopathy of prematurity (ROP) results from postnatal hyperoxia exposure in premature infants and is characterized by aberrant neovascularization of retinal blood vessels. Epithelial membrane protein-2 (EMP2) regulates hypoxia-inducible factor (HIF)-induced vascular endothelial growth factor (VEGF) production in the ARPE-19 cell line and genetic knock-out of Emp2 in a murine oxygen-induced retinopathy (OIR) model attenuates neovascularization. We hypothesize that EMP2 blockade via intravitreal injection protects against neovascularization. Methods: Ex vivo choroid sprouting assay was performed, comparing media and human IgG controls versus anti-EMP2 antibody (Ab) treatment. In vivo, eyes from wild-type (WT) mice exposed to hyperoxia from postnatal (P) days 7 to 12 were treated with P12 intravitreal injections of control IgG or anti-EMP2 Abs. Neovascularization was assessed at P17 by flat mount imaging. Local and systemic effects of anti-EMP2 Ab treatment were assessed. Results: Choroid sprouts treated with 30 µg/mL of anti-EMP2 Ab demonstrated a 48% reduction in vessel growth compared to control IgG-treated sprouts. Compared to IgG-treated controls, WT OIR mice treated with 4 µg/g of intravitreal anti-EMP2 Ab demonstrated a 42% reduction in neovascularization. They demonstrated down-regulation of retinal gene expression in pathways related to vasculature development and up-regulation in genes related to fatty acid oxidation and tricarboxylic acid cycle respiratory electron transport, compared to controls. Anti-EMP2 Ab-treated OIR mice did not exhibit gross retinal histologic abnormalities, vision transduction abnormalities, or weight loss. Conclusions: Our results suggest that EMP2 blockade could be a local and specific treatment modality for retinal neovascularization in oxygen-induced retinopathies, without systemic adverse effects.
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Oxígeno , Neovascularización Retiniana , Retinopatía de la Prematuridad , Animales , Humanos , Ratones , Animales Recién Nacidos , Modelos Animales de Enfermedad , Hiperoxia/complicaciones , Inyecciones Intravítreas , Glicoproteínas de Membrana/antagonistas & inhibidores , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/genética , Ratones Endogámicos C57BL , Oxígeno/toxicidad , Neovascularización Retiniana/metabolismo , Neovascularización Retiniana/prevención & control , Neovascularización Retiniana/patología , Retinopatía de la Prematuridad/tratamiento farmacológico , Retinopatía de la Prematuridad/metabolismo , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Pathological retinal angiogenesis is not only the hallmark of retinopathies, but also a major cause of blindness. Guanylate binding protein 2 (GBP2) has been reported to be associated with retinal diseases such as diabetic retinopathy and hypoxic retinopathy. However, GBP2-mediated pathological retinal angiogenesis remains largely unknown. The present study aimed to investigate the role of GBP2 in pathological retinal angiogenesis and its underlying molecular mechanism. In this study, we established oxygen-induced retinopathy (OIR) mice model for in vivo study and hypoxia-induced angiogenesis in ARPE-19 cells for in vitro study. We demonstrated that GBP2 expression was markedly downregulated in the retina of mice with OIR and ARPE-19 cells treated with hypoxia, which was associated with pathological retinal angiogenesis. The regulatory mechanism of GBP2 in ARPE-19 cells was studied by GBP2 silencing and overexpression. The regulatory mechanism of GBP2 in the retina was investigated by overexpressing GBP2 in the retina of OIR mice. Mechanistically, GBP2 downregulated the expression and secretion of vascular endothelial growth factor (VEGFA) in ARPE-19 cells and retina of OIR mice. Interestingly, overexpression of GBP2 significantly inhibited neovascularization in OIR mice, conditioned medium of GBP2 overexpressing ARPE-19 cells inhibited angiogenesis in human umbilical vein endothelial cells (HUVECs). Furthermore, we confirmed that GBP2 downregulated VEGFA expression and angiogenesis by inhibiting the AKT/mTOR signaling pathway. Taken together, we concluded that GBP2 inhibited pathological retinal angiogenesis via the AKT/mTOR/VEGFA axis, thereby suggesting that GBP2 may be a therapeutic target for pathological retinal angiogenesis.
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Modelos Animales de Enfermedad , Proteínas de Unión al GTP , Ratones Endogámicos C57BL , Proteínas Proto-Oncogénicas c-akt , Neovascularización Retiniana , Vasos Retinianos , Transducción de Señal , Serina-Treonina Quinasas TOR , Factor A de Crecimiento Endotelial Vascular , Animales , Humanos , Ratones , Hipoxia de la Célula , Línea Celular , Proteínas de Unión al GTP/metabolismo , Proteínas de Unión al GTP/genética , Oxígeno/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Neovascularización Retiniana/metabolismo , Neovascularización Retiniana/patología , Neovascularización Retiniana/genética , Neovascularización Retiniana/prevención & control , Epitelio Pigmentado de la Retina/metabolismo , Epitelio Pigmentado de la Retina/patología , Vasos Retinianos/metabolismo , Vasos Retinianos/patología , Serina-Treonina Quinasas TOR/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Factor A de Crecimiento Endotelial Vascular/genéticaRESUMEN
PURPOSE: Metformin, a biguanide antihyperglycemic drug, can exert various beneficial effects in addition to its glucose-lowering effect. The effects of metformin are mainly mediated by AMP-activated protein kinase (AMPK)-dependent pathway. AMPK activation interferes with the action of the mammalian target of rapamycin complex 1 (mTORC1), and blockade of mTORC1 pathway suppresses pathological retinal angiogenesis. Therefore, in this study, we examined the effects of metformin on pathological angiogenesis and mTORC1 activity in the retinas of mice with oxygen-induced retinopathy (OIR). METHODS: OIR was induced by exposing the mice to 80% oxygen from postnatal day (P) 7 to P10. The OIR mice were treated with metformin, rapamycin (an inhibitor of mTORC1), or the vehicle from P10 to P12 or P14. The formation of neovascular tufts, revascularization in the central avascular areas, expression of vascular endothelial growth factor (VEGF) and VEGF receptor (VEGFR) 2, and phosphorylated ribosomal protein S6 (pS6), a downstream indicator of mTORC1 activity, were evaluated at P10, P13, or P15. RESULTS: Neovascular tufts and vascular growth in the central avascular areas were observed in the retinas of P15 OIR mice. The formation of neovascular tufts, but not the revascularization in the central avascular areas, was attenuated by metformin administration from P10 to P14. Metformin had no significant inhibitory effect on the expression of VEGF and VEGFR2, but it reduced the pS6 immunoreactivity in vascular cells at the sites of angiogenesis. Rapamycin completely blocked the phosphorylation of ribosomal protein S6 and markedly reduced the formation of neovascular tufts. CONCLUSIONS: These results suggest that metformin partially suppresses the formation of neovascular tufts on the retinal surface by blocking the mTORC1 signaling pathway. Metformin may exert beneficial effects against the progression of ocular diseases in which abnormal angiogenesis is associated with the pathogenesis.
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Metformina , Enfermedades de la Retina , Neovascularización Retiniana , Animales , Ratones , Factor A de Crecimiento Endotelial Vascular/metabolismo , Proteína S6 Ribosómica , Metformina/efectos adversos , Proteínas Quinasas Activadas por AMP/metabolismo , Angiogénesis , Neovascularización Patológica , Enfermedades de la Retina/complicaciones , Transducción de Señal , Oxígeno , Sirolimus/farmacología , Sirolimus/uso terapéutico , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Neovascularización Retiniana/tratamiento farmacológico , Neovascularización Retiniana/prevención & control , Ratones Endogámicos C57BL , Modelos Animales de Enfermedad , Mamíferos/metabolismoRESUMEN
Diabetic retinopathy (DR) is one of the serious complications of diabetes, which has become the fourth leading cause of vision loss worldwide. Current treatment of DR relies on intravitreal injections of antiangiogenic agents, which has made considerable achievements in reducing visual impairment. However, long-term invasive injections require advanced technology and can lead to poor patient compliance as well as the incidence of ocular complications including bleeding, endophthalmitis, retinal detachment and others. Hence, we developed non-invasive liposomes (EA-Hb/TAT&isoDGR-Lipo) for efficiency co-delivery of ellagic acid and oxygen, which can be administered intravenously or by eye drops. Among that, ellagic acid (EA), as an aldose reductase inhibitor, could remove excessive reactive oxygen species (ROS) induced by high glucose for preventing retinal cell apoptosis, as well as reduce retinal angiogenesis through the blockage of VEGFR2 signaling pathway; carried oxygen could ameliorate DR hypoxia, and further enhanced the anti-neovascularization efficacy. Our results showed that EA-Hb/TAT&isoDGR-Lipo not only effectively protected retinal cells from high glucose-induced damage, but also inhibited VEGF-induced vascular endothelial cells migration, invasion, and tube formation in vitro. In addition, in a hypoxic cell model, EA-Hb/TAT&isoDGR-Lipo could reverse retinal cell hypoxia, thereby reducing the expression of VEGF. Significantly, after being administered as an injection or eye drops, EA-Hb/TAT&isoDGR-Lipo obviously ameliorated the structure (central retinal thickness and retinal vascular network) of retina by eliminating ROS and down-regulating the expression of GFAP, HIF-1α, VEGF and p-VEGFR2 in a DR mouse model. In summary, EA-Hb/TAT&isoDGR-Lipo holds great potentials in improvement of DR, which provides a novel approach for the treatment of DR.
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Diabetes Mellitus , Retinopatía Diabética , Neovascularización Retiniana , Ratones , Animales , Retinopatía Diabética/tratamiento farmacológico , Retinopatía Diabética/metabolismo , Retinopatía Diabética/prevención & control , Neovascularización Retiniana/tratamiento farmacológico , Neovascularización Retiniana/metabolismo , Neovascularización Retiniana/prevención & control , Liposomas/farmacología , Ácido Elágico/metabolismo , Ácido Elágico/farmacología , Ácido Elágico/uso terapéutico , Factor A de Crecimiento Endotelial Vascular/metabolismo , Oxígeno/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Células Endoteliales/metabolismo , Retina/metabolismo , Hipoxia , Glucosa/farmacología , Soluciones Oftálmicas/farmacologíaRESUMEN
BACKGROUND: We have investigated the efficacy of a new strategy to limit pathological retinal neovascularization (RNV) during ischemic retinopathy by targeting the cholesterol metabolizing enzyme acyl-coenzyme A: cholesterol transferase 1 (ACAT1). Dyslipidemia and cholesterol accumulation have been strongly implicated in promoting subretinal NV. However, little is known about the role of cholesterol metabolism in RNV. Here, we tested the effects of inhibiting ACAT1 on pathological RNV in the mouse model of oxygen-induced retinopathy (OIR). METHODS: In vivo studies used knockout mice that lack the receptor for LDL cholesterol (LDLR-/-) and wild-type mice. The wild-type mice were treated with a specific inhibitor of ACAT1, K604 (10 mg/kg, i.p) or vehicle (PBS) during OIR. In vitro studies used human microglia exposed to oxygen-glucose deprivation (OGD) and treated with the ACAT1 inhibitor (1 µM) or PBS. RESULTS: Analysis of OIR retinas showed that increased expression of inflammatory mediators and pathological RNV were associated with significant increases in expression of the LDLR, increased accumulation of neutral lipids, and formation of toxic levels of cholesterol ester (CE). Deletion of the LDLR completely blocked OIR-induced RNV and significantly reduced the AVA. The OIR-induced increase in CE formation was accompanied by significant increases in expression of ACAT1, VEGF and inflammatory factors (TREM1 and MCSF) (p < 0.05). ACAT1 was co-localized with TREM1, MCSF, and macrophage/microglia makers (F4/80 and Iba1) in areas of RNV. Treatment with K604 prevented retinal accumulation of neutral lipids and CE formation, inhibited RNV, and decreased the AVA as compared to controls (p < 0.05). The treatment also blocked upregulation of LDLR, ACAT1, TREM1, MCSF, and inflammatory cytokines but did not alter VEGF expression. K604 treatment of microglia cells also blocked the effects of OGD in increasing expression of ACAT1, TREM1, and MCSF without altering VEGF expression. CONCLUSIONS: OIR-induced RNV is closely associated with increases in lipid accumulation and CE formation along with increased expression of LDLR, ACAT1, TREM1, and MCSF. Inhibiting ACAT1 blocked these effects and limited RNV independently of alterations in VEGF expression. This pathway offers a novel strategy to limit vascular injury during ischemic retinopathy.
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Neovascularización Retiniana , Retinopatía de la Prematuridad , Recién Nacido , Animales , Humanos , Ratones , Neovascularización Retiniana/metabolismo , Neovascularización Retiniana/patología , Neovascularización Retiniana/prevención & control , Retinopatía de la Prematuridad/metabolismo , Receptor Activador Expresado en Células Mieloides 1 , Factor A de Crecimiento Endotelial Vascular/metabolismo , Oxígeno/metabolismo , Colesterol , Transferasas , Coenzima A/efectos adversos , Lípidos/efectos adversos , Ratones Endogámicos C57BL , Modelos Animales de Enfermedad , Acetil-CoA C-AcetiltransferasaRESUMEN
This study aimed to explore the effect and the molecular mechanism of tetrahedral framework nucleic acids (tFNAs), a novel self-assembled nanomaterial with excellent biocompatibility and superior endocytosis ability, in inhibition of pathological retinal neovascularization (RNV) and more importantly, in amelioration of vaso-obliteration (VO) in ischaemic retinopathy. tFNAs were synthesized from four single-stranded DNAs (ssDNAs). Cell proliferation, wound healing and tube formation assays were performed to explore cellular angiogenic functions in vitro. The effects of tFNAs on reducing angiogenesis and inhibiting VO were explored by oxygen-induced retinopathy (OIR) model in vivo. In vitro, tFNAs were capable to enter endothelial cells (ECs), inhibit cell proliferation, tube formation and migration under hypoxic conditions. In vivo, tFNAs successfully reduce RNV and inhibit VO in OIR model via the PI3K/AKT/mTOR/S6K pathway, while vascular endothelial growth factor fusion protein, Aflibercept, could reduce RNV but not inhibit VO. This study provides a theoretical basis for the further understanding of RNV and suggests that tFNAs might be a novel promising candidate for the treatment of blind-causing RNV.
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Ácidos Nucleicos , Neovascularización Retiniana , Transducción de Señal , Ácidos Nucleicos/química , Ácidos Nucleicos/farmacología , Neovascularización Retiniana/prevención & control , Animales , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Receptores de Factores de Crecimiento Endotelial Vascular , Proteínas Recombinantes de Fusión/farmacología , Células Endoteliales de la Vena Umbilical Humana , Humanos , Ratones , Ratones Endogámicos C57BL , Movimiento CelularRESUMEN
Diabetic retinopathy (DR) is a key reason for legal blindness worldwide. Currently, it is urgently necessary to determine the etiology and pathological molecular mechanism of DR to search for resultful therapies. Dickkopf-1 (DKK1) is inhibitive for canonical Wnt signaling via negative feedback, and has been reported as a biomarker for DR. However, the related mechanisms are still unclear. In this work, our data showed that DKK1 was decreased in the vitreous tissues at an early stage of diabetes triggered by streptozotocin (STZ) injection in rats. We subsequently found that DKK1 intravitreal injection significantly ameliorated the physiological function of retina in STZ-challenged rats, accompanied by improved retinal structure. Surprisingly, our results indicated that DKK1 injection remarkably suppressed PANoptosis in retinal tissues of STZ-challenged rats with DR, as proved by ameliorated pyroptosis, apoptosis and necroptosis, which were mainly through the blockage of cleaved Gasdermin-D (GSDMD), Caspase-3 and receptor-interacting protein kinase-3 (RIPK3). Additionally, Wnt signaling including the expression of Wnt, ß-catenin and LDL receptor-related protein 5/6 (LRP5/6) was also highly prohibited in retina of DKK1-injected rats with DR. Furthermore, retinal neovascularization and acellular vessel in DR rats were also considerably abolished after DKK1 injection, accompanied by reduced expression levels of retinal vascular endothelial growth factor (VEGF), matrix metalloproteinase-2 (MMP2) and matrix metalloproteinase-9 (MMP9). More in vitro experiments showed that DKK1 treatment markedly repressed the proliferative and migratory ability of endothelial cells via inhibiting angiogenesis-related molecules. Together, all our results broaden the knowledge of the correlation between DKK1 and DR, and then provide a novel therapeutic strategy for the suppression of management of DR.
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Diabetes Mellitus Experimental , Retinopatía Diabética , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Neovascularización Retiniana , Animales , Diabetes Mellitus Experimental/metabolismo , Retinopatía Diabética/metabolismo , Células Endoteliales/metabolismo , Metaloproteinasa 2 de la Matriz/metabolismo , Ratas , Retina/metabolismo , Neovascularización Retiniana/metabolismo , Neovascularización Retiniana/prevención & control , Estreptozocina , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Purpose: KC7F2 is a novel molecule compound that can inhibit the translation of hypoxia-inducible factor 1α (HIF1α). It has been reported to exhibit potential antiangiogenic effect. We hypothesized that KC7F2 could inhibit oxygen-induced retinal neovascularization (RNV). The purpose of this study was to investigate this assumption. Methods: Oxygen-induced retinopathy (OIR) models in C57BL/6J mice and Sprague-Dawley rats were used for in vivo study. After intraperitoneal injections of KC7F2, RNV was detected by immunofluorescence and hematoxylin and eosin staining. Retinal inflammation was explored by immunofluorescence. EdU incorporation assay, cell counting kit-8 assay, scratch test, transwell assay, and Matrigel assay were used to evaluate the effect of KC7F2 on the proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVEC) induced by vascular endothelial growth factor (VEGF) in vitro. Protein expression was examined by Western blot. Results: KC7F2 treatment (10 mg/kg/d) in OIR mice significantly attenuated pathological neovascularization and decreased the number of preretinal neovascular cell nuclei, without changing the avascular area, which showed the same trends in OIR rats. Consistently, after the KC7F2 intervention (10 µM), cell proliferation was inhibited in VEGF-induced HUVEC, which was in agreement with the trend observed in the retinas of OIR mice. Meanwhile, KC7F2 suppressed VEGF-induced HUVEC migration and tube formation, and decreased the density of leukocytes and microglia colocalizing neovascular areas in the retinas. Moreover, the HIF1α-VEGF pathway activated in retinas of OIR mice and hypoxia-induced HUVEC, was suppressed by KC7F2 treatment. Conclusions: The current study revealed that KC7F2 was able to inhibit RNV effectively via HIF1α-VEGF pathway, suggesting that it might be an effective drug for RNV treatment.
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Disulfuros/farmacología , Subunidad alfa del Factor 1 Inducible por Hipoxia/antagonistas & inhibidores , Neovascularización Retiniana , Retinopatía de la Prematuridad , Sulfonamidas/farmacología , Animales , Animales Recién Nacidos , Modelos Animales de Enfermedad , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Hipoxia , Recién Nacido , Ratones , Ratones Endogámicos C57BL , Neovascularización Patológica , Oxígeno/metabolismo , Oxígeno/toxicidad , Ratas , Ratas Sprague-Dawley , Neovascularización Retiniana/tratamiento farmacológico , Neovascularización Retiniana/metabolismo , Neovascularización Retiniana/prevención & control , Retinopatía de la Prematuridad/tratamiento farmacológico , Retinopatía de la Prematuridad/metabolismo , Retinopatía de la Prematuridad/prevención & control , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
PURPOSE: To investigate the expression of CD146 and its role in proliferative diabetic retinopathy (PDR). METHODS: Enzyme linked immunosorbent assay was performed to analyse the expression and relationship of sCD146, vascular endothelial growth factor (VEGF), sVEGFR1 and sVEGFR2 in vitreous specimens from PDR and idiopathic epiretinal membranes (IERM) or idiopathic macular hole patients. The location of CD146 in ERMs was detected by immunofluorescence. The oxygen-induced retinopathy (OIR) mice model was established and the adeno-associated virus expressing a shRNA of CD146 (AAV1-shCD146-GFP) was administered via intravitreal injection. The effect of AAV1-shCD146-GFP was explored by immunofluorescence, Western blot and quantitative real-time PCR. RESULTS: The levels of sCD146 in vitreous specimens from PDR patients and CD146 in retinas from OIR mice were significantly increased. Immunofluorescence showed that CD146 was co-located with CD31, VEGF, VEGFR1 and VEGFR2, respectively. Intravitreal injection of AAV1-shCD146-GFP could dramatically reduce the formation of neovascularization and non-perfusion area by inhibiting VEGFR2 phosphorylation. CONCLUSION: Our results indicated that CD146 was involved in the development of retinal neovascularization via VEGFR2 pathway. Anti-CD146 may be an innovative or adjuvant therapy, which provides a new direction for the treatment of PDR and other ocular neovascular diseases.
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Diabetes Mellitus , Retinopatía Diabética , Neovascularización Retiniana , Animales , Antígeno CD146/metabolismo , Diabetes Mellitus/metabolismo , Retinopatía Diabética/metabolismo , Ensayo de Inmunoadsorción Enzimática , Humanos , Ratones , Neovascularización Retiniana/metabolismo , Neovascularización Retiniana/prevención & control , Factor A de Crecimiento Endotelial Vascular/metabolismo , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismo , Cuerpo Vítreo/metabolismoRESUMEN
Pathological angiogenesis (PA) contributes to various ocular diseases, including age-related macular degeneration, diabetic retinopathy, and retinopathy of prematurity, which are major causes of blindness over the world. Current treatments focus on anti-vascular endothelial growth factor (VEGF) therapy, but persistent avascular retina, recurrent intravitreal neovascularization, and general adverse effects are reported. We have previously found that recombinant thrombomodulin domain 1 (rTMD1) can suppress vascular inflammation. However, the function of rTMD1 in VEGF-induced PA remains unknown. In this study, we found that rTMD1 inhibited VEGF-induced angiogenesis in vitro. In an oxygen induced retinopathy (OIR) animal model, rTMD1 treatment significantly decreased retinal neovascularization but spared normal physiological vessel growth. Furthermore, loss of TMD1 significantly promoted PA in OIR. Meanwhile, hypoxia-inducible factor-1α, the transcription factor that upregulates VEGF, was suppressed after rTMD1 treatment. The levels of interleukin-6, and intercellular adhesion molecule-1 were also significantly suppressed. In conclusion, our results indicate that rTMD1 not only has dual effects to suppress PA and inflammation in OIR, but also can be a potential HIF-1α inhibitor for clinical use. These data bring forth the possibility of rTMD1 as a novel therapeutic agent for PA.
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Regulación de la Expresión Génica , Subunidad alfa del Factor 1 Inducible por Hipoxia/antagonistas & inhibidores , Neovascularización Patológica/prevención & control , Neovascularización Retiniana/prevención & control , Trombomodulina/metabolismo , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Animales , Apoptosis , Movimiento Celular , Proliferación Celular , Células Cultivadas , Femenino , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Neovascularización Patológica/genética , Neovascularización Patológica/metabolismo , Neovascularización Patológica/patología , Neovascularización Retiniana/genética , Neovascularización Retiniana/metabolismo , Neovascularización Retiniana/patología , Trombomodulina/genética , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo , RatonesRESUMEN
Genistein, a natural tyrosine kinase inhibitor, may act as an intraocular antiangiogenic agent. Its therapeutical use, however, is limited by its nonlinear pharmacokinetics. We aimed to determine genistein's kinetics and retinal tissue distributions in normal and diabetic rats. We developed an isocratic, reverse-phase C18 HPLC system to measure genistein concentration in blood and retinas of streptozotocin (65 mg/kg IV)-diabetic and non-diabetic rats receiving two types of genistein-rich diet (150 and 300 mg/kg) for ten days. Genistein's decay exhibited a two-compartmental open model. Half-lives of distribution and elimination were 2.09 and 71.79 min, with no difference between groups. Genistein steady-state concentration in blood for 150 and 300 mg/kg diet did not differ between diabetic (0.259 ± 0.07 and 0.26 ± 0.06 µg/ml) and non-diabetic rats (0.192 ± 0.05 and 0.183 ± 0.09 µg/ml). In retina, genistein concentration was significantly higher in diabetic rats (1.05 ± 0.47 and 0.997 ± 0.47 µg/gm wt. vs. 0.087 ± 0.11 and 0.314 ± 0.18 µg/gm wt., p < 0.05). The study determined that increasing genistein dose did not change its bioavailability, perhaps due to the poor aqueous solubility. The retina's increased genistein could be due to increased permeability of blood-retinal barrier that occurs early in diabetes.
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Genisteína , Retina , Distribución Tisular , Inhibidores de la Angiogénesis/análisis , Inhibidores de la Angiogénesis/metabolismo , Inhibidores de la Angiogénesis/farmacocinética , Animales , Disponibilidad Biológica , Barrera Hematorretinal , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/fisiopatología , Relación Dosis-Respuesta a Droga , Genisteína/análisis , Genisteína/metabolismo , Genisteína/farmacocinética , Inhibidores de Proteínas Quinasas/análisis , Inhibidores de Proteínas Quinasas/metabolismo , Inhibidores de Proteínas Quinasas/farmacocinética , Ratas , Retina/efectos de los fármacos , Retina/metabolismo , Retina/patología , Neovascularización Retiniana/etiología , Neovascularización Retiniana/metabolismo , Neovascularización Retiniana/prevención & control , SolubilidadRESUMEN
Purpose: Nattokinase (NK), an active ingredient extracted from traditional food Natto, has been studied for prevention and treatment of cardiovascular diseases due to various vasoprotective effects, including fibrinolytic, antihypertensive, anti-atherosclerotic, antiplatelet, and anti-inflammatory activities. Here, we reported an antineovascular effect of NK against experimental retinal neovascularization. Methods: The inhibitory effect of NK against retinal neovascularization was evaluated using an oxygen-induced retinopathy murine model. Expressions of Nrf2/HO-1 signaling and glial activation in the NK-treated retinae were measured. We also investigated cell proliferation and migration of human umbilical vein endothelial cells (HUVECs) after NK administration. Results: NK treatment significantly attenuated retinal neovascularization in the OIR retinae. Consistently, NK suppressed VEGF-induced cell proliferation and migration in a concentration-dependent manner in cultured vascular endothelial cells. NK ameliorated ischemic retinopathy partially via activating Nrf2/HO-1. In addition, NK orchestrated reactive gliosis and promoted microglial activation toward a reparative phenotype in ischemic retina. Treatment of NK exhibited no cell toxicity or anti-angiogenic effects in the normal retina. Conclusions: Our results revealed the anti-angiogenic effect of NK against retinal neovascularization via modulating Nrf2/HO-1, glial activation and neuroinflammation, suggesting a promising alternative treatment strategy for retinal neovascularization.
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Inhibidores de la Angiogénesis/uso terapéutico , Gliosis/tratamiento farmacológico , Hemo-Oxigenasa 1/metabolismo , Proteínas de la Membrana/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Neuroglía/efectos de los fármacos , Neovascularización Retiniana/prevención & control , Subtilisinas/uso terapéutico , Animales , Animales Recién Nacidos , Western Blotting , Movimiento Celular/fisiología , Proliferación Celular/fisiología , Dextranos/administración & dosificación , Modelos Animales de Enfermedad , Fluoresceína-5-Isotiocianato/administración & dosificación , Fluoresceína-5-Isotiocianato/análogos & derivados , Gliosis/metabolismo , Células Endoteliales de la Vena Umbilical Humana , Humanos , Etiquetado Corte-Fin in Situ , Ratones , Ratones Endogámicos C57BL , Neuroglía/metabolismo , Órbita/efectos de los fármacos , Neovascularización Retiniana/metabolismo , Neovascularización Retiniana/patología , Alimentos de Soja , TransfecciónRESUMEN
Diabetic retinopathy (DR), characterized by intraretinal vessel formation, is a major complication in diabetes. Neovascularization is an important characteristic of DR, but its formation mechanism remains unclear. In this research, Malat1, miR-205-5p, and VEGF-A levels in high glucose (HG) treat-human retinal microvascular endothelial cells (hRMECs) was detected with qRT-PCR. CCK-8 assay, transwell assay, and tube formation assay was applied to access hRMEC viability, migration, and angiogenesis. Expression level of endothelial-mesenchymal transition (EndMT) markers (VE-cadherin, FSP1, and α-SMA) was detected by western blotting assay. Interaction among Malat1, miR-205-5p, and VEGF-A was confirmed by dual-luciferase reporter assay. Furthermore, in vivo DR mouse model was induced, and the effect of Malat1 on DR and EndMT markers was confirmed through hematoxylin-eosin (HE) staining and western blotting. As a result, Malat1 and VEGF-A was upregulated while miR-205-5p was suppressed under HG conditions. Malat1 could sponge miR-205-5p to regulate VEGF-A expression. Malat1 knockdown inhibited hRMEC proliferation, migration, and tube formation by targeting miR-205-5p under HG conditions. Furthermore, inhibition of Malat1 prevented the HG-induced EndMT process. In summary, Malat1 knockdown diminished hRMEC dysfunctions by regulating miR-205-5p/VEGF-A, providing a useful insight for exploring new therapeutic target for DR.