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1.
Ophthalmol Sci ; 4(3): 100440, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38284098

RESUMEN

Purpose: Metformin use has been associated with a decreased risk of age-related macular degeneration (AMD) progression in observational studies. We aimed to evaluate the efficacy of oral metformin for slowing geographic atrophy (GA) progression. Design: Parallel-group, multicenter, randomized phase II clinical trial. Participants: Participants aged ≥ 55 years without diabetes who had GA from atrophic AMD in ≥ 1 eye. Methods: We enrolled participants across 12 clinical centers and randomized participants in a 1:1 ratio to receive oral metformin (2000 mg daily) or observation for 18 months. Fundus autofluorescence imaging was obtained at baseline and every 6 months. Main Outcome Measures: The primary efficacy endpoint was the annualized enlargement rate of the square root-transformed GA area. Secondary endpoints included best-corrected visual acuity (BCVA) and low luminance visual acuity (LLVA) at each visit. Results: Of 66 enrolled participants, 34 (57 eyes) were randomized to the observation group and 32 (53 eyes) were randomized to the treatment group. The median follow-up duration was 13.9 and 12.6 months in the observation and metformin groups, respectively. The mean ± standard error annualized enlargement rate of square root transformed GA area was 0.35 ± 0.04 mm/year in the observation group and 0.42 ± 0.04 mm/year in the treatment group (risk difference = 0.07 mm/year, 95% confidence interval = -0.05 to 0.18 mm/year; P = 0.26). The mean ± standard error decline in BCVA was 4.8 ± 1.7 letters/year in the observation group and 3.4 ± 1.1 letters/year in the treatment group (P = 0.56). The mean ± standard error decline in LLVA was 7.3 ± 2.5 letters/year in the observation group and 0.8 ± 2.2 letters/year in the treatment group (P = 0.06). Fourteen participants in the metformin group experienced nonserious adverse events related to metformin, with gastrointestinal side effects as the most common. No serious adverse events were attributed to metformin. Conclusions: The results of this trial as conducted do not support oral metformin having effects on reducing the progression of GA. Additional placebo-controlled trials are needed to explore the role of metformin for AMD, especially for earlier stages of the disease. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

2.
J Ophthalmol ; 2016: 9856736, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27429799

RESUMEN

Purpose. To identify retinal pigment epithelium (RPE)/choroid genes and their relevant expression pathways affected by intravitreal injections of dexamethasone and triamcinolone acetonide in mice at clinically relevant time points for patient care. Methods. Differential gene expression of over 34,000 well-characterized mouse genes in the RPE/choroid of 6-week-old C57BL/6J mice was analyzed after intravitreal steroid injections at 1 week and 1 month postinjection, using Affymetrix Mouse Genome 430 2.0 microarrays. The data were analyzed using GeneSpring GX 12.5 and Ingenuity Pathway Analysis (IPA) microarray analysis software for biologically relevant changes. Results. Both triamcinolone and dexamethasone caused differential activation of genes involved in "Circadian Rhythm Signaling" pathway at both time points tested. Triamcinolone (TAA) uniquely induced significant changes in gene expression in "Calcium Signaling" (1 week) and "Glutamate Receptor Signaling" pathways (1 month). In contrast, dexamethasone (Dex) affected the "GABA Receptor Signaling" (1 week) and "Serotonin Receptor Signaling" (1 month) pathways. Understanding how intraocular steroids affect the gene expression of RPE/choroid is clinically relevant. Conclusions. This in vivo study has elucidated several genes and pathways that are potentially altering the circadian rhythms and several other neurotransmitter pathways in RPE/choroid during intravitreal steroid injections, which likely has consequences in the dysregulation of RPE function and neurodegeneration of the retina.

3.
Invest Ophthalmol Vis Sci ; 57(7): 3112-7, 2016 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-27294805

RESUMEN

PURPOSE: To determine the level of epithelial membrane protein-2 (EMP2) expression in preretinal membranes from surgical patients with proliferative vitreoretinopathy (PVR) or epiretinal membranes (ERMs). EMP2, an integrin regulator, is expressed in the retinal pigment epithelium and understanding EMP2 expression in human retinal disease may help determine whether EMP2 is a potential therapeutic target. METHODS: Preretinal membranes were collected during surgical vitrectomies after obtaining consents. The membranes were fixed, processed, sectioned, and protein expression of EMP2 was evaluated by immunohistochemistry. The staining intensity (SI) and percentage of positive cells (PP) in membranes were compared by masked observers. Membranes were categorized by their cause and type including inflammatory and traumatic. RESULTS: All of the membranes stained positive for EMP2. Proliferative vitreoretinopathy-induced membranes (all causes) showed greater expression of EMP2 than ERMs with higher SI (1.81 vs. 1.38; P = 0.07) and PP (2.08 vs. 1.54; P = 0.09). However all the PVR subgroups had similar levels of EMP2 expression without statistically significant differences by Kruskal-Wallis test. Inflammatory PVR had higher expression of EMP2 than ERMs (SI of 2.58 vs. 1.38); however, this was not statistically significant. No correlation was found between duration of PVR membrane and EMP2 expression. EMP2 was detected by RT-PCR in all samples (n = 6) tested. CONCLUSIONS: All studied ERMs and PVR membranes express EMP2. Levels of EMP2 trended higher in all PVR subgroups than in ERMs, especially in inflammatory and traumatic PVR. Future studies are needed to determine the role of EMP2 in the pathogenesis and treatment of various retinal conditions including PVR.


Asunto(s)
Membrana Epirretinal/genética , Regulación de la Expresión Génica , Glicoproteínas de Membrana/genética , ARN/genética , Epitelio Pigmentado de la Retina/metabolismo , Vitreorretinopatía Proliferativa/genética , Adulto , Anciano , Proliferación Celular , Membrana Epirretinal/metabolismo , Membrana Epirretinal/patología , Femenino , Humanos , Inmunohistoquímica , Masculino , Glicoproteínas de Membrana/biosíntesis , Persona de Mediana Edad , Reacción en Cadena en Tiempo Real de la Polimerasa , Epitelio Pigmentado de la Retina/patología , Vitreorretinopatía Proliferativa/metabolismo , Vitreorretinopatía Proliferativa/patología
4.
Curr Eye Res ; 41(3): 410-6, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-25897651

RESUMEN

PURPOSE: Previously, two cytosolic antioxidant enzymes, Glutathione S-transferase Mu 1 (GSTM1) and Mu 5 (GSTM5), were reduced in retinas with age-related macular degeneration (AMD). This study compared genomic copy number variations (gCNV) of these two antioxidant enzymes in AMD versus controls. METHODS: Genomic copy number (gCN) assays were performed using Taqman Gene Copy Number Assays (Applied Biosystems, Darmstadt, Germany) in technical quadruplicate for both GSTM1 and GSTM5. Peripheral leukocyte RNA levels were compared with controls in technical triplicates. Statistical comparisons were performed in SAS v9.2 (SAS Institute Inc., Cary, NC). RESULTS: A large percentage of patients in both AMD and age-matched control groups had no copies of GSTM1 (0/0). The mean gCN of GSTM1 was 1.40 (range 0-4) and 1.61 (range 0-5) for AMD and control, respectively (p = 0.29). A greater percentage of control patients had > 3 gCNs of GSTM1 compared with AMD, respectively (15.3% versus 3.0%, p = 0.004). The gCN of GSTM5 was 2 in all samples except one control sample. The relative quantification of GSTM1 and GSTM5 mRNA from peripheral blood leukocytes in patients showed significant differences in relative expression in AMD versus control (p < 0.05). Peripheral blood leukocyte mRNA and gCN were not significantly correlated (p = 0.27). CONCLUSION: Since high copy numbers of GSTM1 are found more frequently in controls than in AMD, it is possible that high copy number leads to increased retinal antioxidant defense. Genomic polymorphisms of GSTM1 and GSTM5 do not significantly affect the peripheral blood leukocyte mRNA levels.


Asunto(s)
Variaciones en el Número de Copia de ADN , Atrofia Geográfica/genética , Glutatión Transferasa/genética , Degeneración Macular Húmeda/genética , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Angiografía con Fluoresceína , Expresión Génica , Atrofia Geográfica/diagnóstico , Humanos , Masculino , Estudios Prospectivos , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Tomografía de Coherencia Óptica , Degeneración Macular Húmeda/diagnóstico
6.
Can J Ophthalmol ; 50 Suppl 1: S23-8, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26049886

RESUMEN

OBJECTIVE: To evaluate the patient's understanding of the importance and adherence to the various lifestyle and Age-Related Eye Disease Study (AREDS) supplement recommendations for age-related macular degeneration (AMD). DESIGN: Cross-sectional study. PARTICIPANTS: Patients with AMD treated at the vitreoretinal service clinic. METHODS: Telephone questionnaire survey was administered to assess knowledge and adherence to various recommendations made to patients with AMD about lifestyle and AREDS supplements in this single-institution study. RESULTS: Among 92 patients with AMD contacted, dietary modification, exercise and weight reduction, smoking cessation, and AREDS supplementation recommendations were recalled by 47 (51%), 21 (23%), 5 (5%), and 90 (98%) patients, respectively. The necessity of making these interventions was believed by 29 (62%), 16 (76%), 4 (80%), and 67 (74%) patients, respectively. Patient adherence to dietary modification was 81%, to exercise and weight reduction was 76%, to smoking cessation was 0%, and to AREDS supplementation was 88% (71% on correct dose). Financially, 29% of the patients noted a mean increase of $88 per month in expenditure because of making dietary modifications, but most reported such as justified; 61% noted a mean increase of $25 per month in expenditure from consumption of AREDS supplements, and most (96%) believed this was justified. CONCLUSIONS: Patients with AMD recalled recommendations for AREDS supplementation more often than other lifestyle changes but generally felt recommendations were necessary and affordable. Adherence to smoking cessation recommendation was poor (0%), but to other recommendations was good.

7.
J Cataract Refract Surg ; 40(4): 626-31, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24529660

RESUMEN

PURPOSE: To use ultra-high-resolution optical coherence tomography (OCT) subclinical anatomic alterations to explain suboptimum vision despite pseudophakic cystoid macula edema (CME) resolution. SETTING: University of California-Davis, Sacramento, California, USA. DESIGN: Case study. METHODS: This study comprised patients who had cataract phacoemulsification surgery. Cases of resolved postoperative CME (diagnosed postoperatively by 1 month and resolved by 1 year) were included. Exclusion criteria included any other cause for decreased vision or compounding factors. Patients with a history of resolved pseudophakic CME were imaged using a purpose-built ultra-high-resolution OCT system with 4.5 µm axial resolution and an acquisition speed of 9 frames/sec (1000 A-scans/frame). The corrected distance visual acuity (CDVA) was determined by Early Treatment Diabetic Retinopathy Study standards. Statistical analysis was by the unpaired t test. A P value less than 0.05 was considered significant. RESULTS: The review identified 56 patients with a pseudophakic CME diagnosis at least 1 month postoperatively. Fifteen eyes (26.8%) had less than 20/20 CDVA despite resolution of CME; 7 participated. Four patients with 20/20 CDVA after resolution of pseudophakic CME participated. Eyes with reduced CDVA after macula edema showed ultra-high-resolution OCT evidence of blurring of outer segments of photoreceptors, while controls showed normal outer retina morphology (P<.05). CONCLUSIONS: Persistent anatomic alteration of photoreceptors visualized by ultra-high-resolution OCT correlated with reduced CDVA in patients with pseudophakic CME compared with patients who had 20/20 CDVA after macula edema. This anatomic alteration in outer photoreceptor morphology is a plausible explanation for the reduced CDVA in this disease. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.


Asunto(s)
Edema Macular/diagnóstico , Facoemulsificación , Complicaciones Posoperatorias , Seudofaquia/diagnóstico , Segmento Externo de las Células Fotorreceptoras Retinianas/patología , Trastornos de la Visión/diagnóstico , Agudeza Visual/fisiología , Análisis de Fourier , Humanos , Implantación de Lentes Intraoculares , Edema Macular/etiología , Edema Macular/terapia , Seudofaquia/etiología , Seudofaquia/terapia , Estudios Retrospectivos , Tomografía de Coherencia Óptica , Trastornos de la Visión/fisiopatología
8.
Retina ; 34(7): 1384-90, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24368307

RESUMEN

PURPOSE: To evaluate the effect of intravitreal ciliary neurotrophic factor (CNTF) implant on mean macular thickness (MMT) in eyes with retinitis pigmentosa using high-resolution Fourier domain optical coherence tomography imaging. METHODS: A cohort of 8 patients (CNTF-3: n = 5; CNTF-4: n = 3) enrolled in Neurotech sponsored Phase 2 clinical trial underwent Fourier domain optical coherence tomography imaging. A ≥3% change in MMT from baseline or fellow eye was considered as a measurable change. RESULTS: Two patients enrolled in the CNTF-3 study received low-dose implant. At 18 months, a change in MMT from -4.47 µm to 6 µm from baseline was noted. Six patients received high-dose implant (CNTF-3: n = 3; CNTF-4: n = 3). In CNTF-3 group, 1 eye showed an increase in MMT by 19.25 µm (+7.6%) from baseline at 18 months. In CNTF-4 group, 1 eye had an increase in MMT of 27.08 µm (+11%) from baseline at 30 months; second eye had increase in MMT of 31.36 µm (+12%) from contralateral eye. Amongst these 3 responsive high-dose implant eyes, overall thickening of the retina could not be attributed to any specific retinal layer. CONCLUSION: A heterogeneous dose-dependent response on MMT was noted in eyes treated using intravitreal CNTF implant for retinitis pigmentosa. We recommend corroboration of our findings with Neurotech sponsored clinical trial results.


Asunto(s)
Factor Neurotrófico Ciliar/administración & dosificación , Retina/patología , Retinitis Pigmentosa/tratamiento farmacológico , Tomografía de Coherencia Óptica , Adulto , Anciano , Relación Dosis-Respuesta a Droga , Implantes de Medicamentos , Femenino , Análisis de Fourier , Humanos , Imagenología Tridimensional , Masculino , Persona de Mediana Edad , Tamaño de los Órganos , Estudios Prospectivos , Retinitis Pigmentosa/diagnóstico , Cuerpo Vítreo , Adulto Joven
9.
Ophthalmic Genet ; 35(2): 112-6, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23521024

RESUMEN

BACKGROUND: Familial exudative vitreoretinopathy (FEVR) is a genetic disease caused by abnormal retinal vascular development. New additional genetic loci for FEVR have recently been identified. Microduplication of 22q11.2 has been reported with a heterogeneous phenotype and microdeletion of 22q11.2 has been associated with FEVR. We describe a case of a girl with microduplication of 22q11.2 and falciform macular folds. MATERIALS AND METHODS: The infant and first-degree relatives were examined. A dilated fundus examination was performed. Genetic screening was done by chromosomal microarray analysis and confirmed by fluorescent in situ hybridization (FISH). RESULTS: Bilateral macular folds were found with temporal fibrosis in the proband. A chromosomal microarray revealed a 2.21 Mb microduplication of the 22q11.2 region. CONCLUSION: This is the first report to associate microduplication of 22q11.2 with macular folds, supporting the potential for a FEVR locus on chromosome 22q11.2. We encourage full ophthalmological examination for patients with microduplication of 22q11.2 to identify ocular associations.


Asunto(s)
Anomalías Múltiples/genética , Duplicación Cromosómica/genética , Síndrome de DiGeorge/genética , Enfermedades Genéticas Ligadas al Cromosoma X/genética , Enfermedades de la Retina/genética , Vitreorretinopatía Proliferativa/genética , Anomalías Múltiples/diagnóstico , Cromosomas Humanos Par 22/genética , Síndrome de DiGeorge/diagnóstico , Exudados y Transudados , Vitreorretinopatías Exudativas Familiares , Femenino , Enfermedades Genéticas Ligadas al Cromosoma X/diagnóstico , Humanos , Lactante , Análisis por Micromatrices , Microcefalia/diagnóstico , Microcefalia/genética , Enfermedades de la Retina/diagnóstico , Vitreorretinopatía Proliferativa/diagnóstico
10.
Clin Ophthalmol ; 7: 2085-9, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24204111

RESUMEN

The development of spectral-domain optical coherence tomography (OCT) allows for the highest commercially available resolution of in vivo retinal anatomic details to date. The ability to see the macula with ever increasing detail is dramatically improving our understanding of the pathogenesis of retinal disease. However, the only prospective study that partially evaluated spectral-domain OCT versus time-domain OCT failed to show any clinical benefit of increased OCT resolution. Clinical outcomes, eg, best-corrected visual acuity, central macular thickness and number of injections, with "newer" OCT technologies remain an unproven advantage.

11.
Cornea ; 32(10): 1315-20, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23928948

RESUMEN

PURPOSE: To determine the penetration of orally administered trimethoprim (TMP)-sulfamethoxazole (SMX) into the aqueous and vitreous cavity of noninflamed human eyes. METHODS: Nine adult patients undergoing cataract surgery and 10 adult patients undergoing pars plana vitrectomy were given 3 doses of oral TMP-SMX every 12 hours before the surgery. Aqueous and blood samples were collected from patients undergoing cataract surgery; vitreous and blood samples were collected from patients undergoing vitrectomy. The levels of TMP and SMX were analyzed using high-performance liquid chromatography and were compared with the mean minimum inhibitory concentrations (MIC) of potential ocular pathogens. RESULTS: TMP-SMX was present in all samples. Among eyes undergoing cataract surgery, the mean concentrations of TMP in aqueous and blood were 0.341 ± 0.141 µg/mL (mean ± SD) and 1.501 ± 0.433 µg/mL and of SMX were 5.259 ± 0.929 µg/mL and 11.835 ± 2.100 µg/mL, respectively. Among eyes undergoing vitrectomy, the mean concentrations of TMP in vitreous and blood were 1.864 ± 0.807 µg/mL and 4.591 ± 2.979 µg/mL and of SMX were 5.910 ± 2.705 µg/mL and 39.289 ± 15.469 µg/mL, respectively. MIC levels were achieved against many bacterial pathogens, including methicillin-resistant Staphylococcus aureus. CONCLUSIONS: TMP-SMX penetrates both the aqueous and vitreous cavities when given orally. The components reach therapeutic inhibitory concentrations in the ocular cavity against many potential pathogens.


Asunto(s)
Antibacterianos/farmacocinética , Humor Acuoso/metabolismo , Combinación Trimetoprim y Sulfametoxazol/farmacocinética , Cuerpo Vítreo/metabolismo , Administración Oral , Anciano , Anciano de 80 o más Años , Bacterias/efectos de los fármacos , Disponibilidad Biológica , Extracción de Catarata , Cromatografía Líquida de Alta Presión , Humanos , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Distribución Tisular , Vitrectomía
12.
Can J Ophthalmol ; 48(3): 204-9, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23769783

RESUMEN

OBJECTIVE: To evaluate the patient's understanding of the importance and adherence to the various lifestyle and Age-Related Eye Disease Study (AREDS) supplement recommendations for age-related macular degeneration (AMD). DESIGN: Cross-sectional study. PARTICIPANTS: Patients with AMD treated at the vitreoretinal service clinic. METHODS: Telephone questionnaire survey was administered to assess knowledge and adherence to various recommendations made to patients with AMD about lifestyle and AREDS supplements in this single-institution study. RESULTS: Among 92 patients with AMD contacted, dietary modification, exercise and weight reduction, smoking cessation, and AREDS supplementation recommendations were recalled by 47 (51%), 21 (23%), 5 (5%), and 90 (98%) patients, respectively. The necessity of making these interventions was believed by 29 (62%), 16 (76%), 4 (80%), and 67 (74%) patients, respectively. Patient adherence to dietary modification was 81%, to exercise and weight reduction was 76%, to smoking cessation was 0%, and to AREDS supplementation was 88% (71% on correct dose). Financially, 29% of the patients noted a mean increase of $88 per month in expenditure because of making dietary modifications, but most reported such as justified; 61% noted a mean increase of $25 per month in expenditure from consumption of AREDS supplements, and most (96%) believed this was justified. CONCLUSIONS: Patients with AMD recalled recommendations for AREDS supplementation more often than other lifestyle changes but generally felt recommendations were necessary and affordable. Adherence to smoking cessation recommendation was poor (0%), but to other recommendations was good.


Asunto(s)
Antioxidantes/administración & dosificación , Suplementos Dietéticos , Conocimientos, Actitudes y Práctica en Salud , Degeneración Macular/epidemiología , Cooperación del Paciente/estadística & datos numéricos , Anciano , Anciano de 80 o más Años , Ácido Ascórbico/administración & dosificación , California/epidemiología , Estudios Transversales , Conducta Alimentaria , Femenino , Adhesión a Directriz , Encuestas Epidemiológicas , Humanos , Estilo de Vida , Degeneración Macular/prevención & control , Masculino , Persona de Mediana Edad , Calidad de Vida , Encuestas y Cuestionarios , Vitamina E/administración & dosificación , Vitaminas/administración & dosificación , Compuestos de Zinc/administración & dosificación , beta Caroteno/administración & dosificación
13.
Invest Ophthalmol Vis Sci ; 54(3): 2216-24, 2013 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-23439599

RESUMEN

PURPOSE: Therapeutic retinal laser photocoagulation can damage the neurosensory retina and cause iatrogenic visual impairment. Subthreshold micropulse photocoagulation may decrease this risk by selective tissue treatment. The aim of this study was to compare subthreshold 810-nm diode micropulse laser and subthreshold 532-nm micropulse laser on the retina by histologic examination and differential protein expression. METHODS: Fourteen Dutch-belted rabbits received subthreshold 810-nm diode micropulse laser photocoagulation in their right eye and subthreshold 532-nm micropulse laser photocoagulation in their left eye. Histology and immunohistochemical detection of stromal cell-derived factor-1 (SDF-1), ß-actin, vascular endothelial growth factor (VEGF), glial fibrillary acidic protein (GFAP), and insulin-like growth factor 1 (IGF-1) were analyzed 12 hours, 3 days, 14 days, and 28 days post-laser photocoagulation. RESULTS: Histologically, all time points produced a similar degree of retinal disruption in both wavelengths. Immunohistochemically, SDF-1 expression was greatest at the 12-hour time point and decreased thereafter. SDF-1, VEGF, and ß-actin up-regulation was detected at early time points in both the 810- and 532-nm micropulse laser-treated animals. CONCLUSIONS: Subthreshold micropulse retinal laser photocoagulation caused equivalent histologic changes from both 532- and 810-nm diode lasers. Differential protein expression was not evident between the different laser conditions.


Asunto(s)
Coagulación con Láser/efectos adversos , Retina/efectos de la radiación , Animales , Biomarcadores/metabolismo , Proteínas del Ojo/metabolismo , Inmunohistoquímica , Coagulación con Láser/métodos , Conejos , Retina/metabolismo , Retina/patología
14.
Invest Ophthalmol Vis Sci ; 54(3): 2367-72, 2013 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-23439602

RESUMEN

PURPOSE: VEGF production by RPE cells has been shown to be important in regulating aberrant angiogenesis in the retina, which is responsible for multiple types of ocular pathology. EMP2 is highly expressed in the RPE and has been shown to regulate FAK activation, which is implicated in VEGF expression in other cell lines. The purpose of this study was to determine whether EMP2 regulates VEGF expression in the RPE cell line, ARPE-19. METHODS: ARPE-19 cells were engineered to overexpress EMP2. EMP2 siRNA was used to decrease EMP2 expression. The small molecule inhibitor PP2 was used to inhibit FAK activation. VEGF levels were measured by Western blot and ELISA. Functional differences in secreted VEGF were assayed using HUVEC migration. RESULTS: VEGF expression levels correlated with levels of EMP2. An increase of VEGF by 150% was observed in EMP2 overexpressing cells as compared with ARPE-19 cells. Concordantly, EMP2 knockdown resulted in a 57% decrease in VEGF expression. HUVEC migration (P = 0.01) and vessel tube formation (P < 0.01) were significantly increased when exposed to cell culture supernatants from EMP2 overexpressing cells. CONCLUSIONS: This study establishes a novel connection between EMP2 and VEGF and may reflect either a direct effect through the tetraspan web or an indirect change through FAK activation. This connection is functionally significant. In addition to the direct use of anti-VEGF antibodies, modulation of EMP2 with impact on VEGF is potentially a distinct therapeutic target for the treatment of neovascularization associated with retinal diseases that involve pathologic angiogenesis.


Asunto(s)
Glicoproteínas de Membrana/fisiología , Epitelio Pigmentado de la Retina/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Western Blotting , Células Cultivadas , Ensayo de Inmunoadsorción Enzimática , Proteína-Tirosina Quinasas de Adhesión Focal/antagonistas & inhibidores , Regulación de la Expresión Génica/fisiología , Humanos , Glicoproteínas de Membrana/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Epitelio Pigmentado de la Retina/citología
15.
Exp Eye Res ; 102: 10-6, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22728127

RESUMEN

Epithelial membrane protein 2 (EMP2) regulates collagen gel contraction by the retinal pigment epithelium cell line ARPE-19 by modulating FAK activation. Collagen gel contraction is one in vitro model for an aberrant wound healing response, proliferative vitreoretinopathy (PVR), which occurs as a complication of severe ocular trauma. The purpose of this study is to investigate whether EMP2 specific recombinant diabody decreases activation of FAK and collagen gel contraction in ARPE-19. Anti-EMP2 diabody was recombinantly constructed from a human phage library-derived clone selected for reactivity against an extracellular domain of human EMP2. ARPE-19 cells were exposed to an anti-EMP2 or control diabody, and toxicity, adhesion, and migration were assessed respectively through toluidine blue exclusion, binding to collagen type 1, and a migration assay. Collagen gel contraction was assessed using an in vitro assay. FAK activation was evaluated using Western blot. Exposure to anti-EMP2 diabody, resulted in a 75% reduction in EMP2 protein levels at 4 h. No significant toxicity was observed with anti-EMP2 diabody at levels that maximally reduced EMP2. Anti-EMP2 diabody, but not control diabody, significantly reduced collagen gel contraction (p < 0.001), without changes in adhesion or migration. Concordantly, anti-EMP2 diabody as compared to a control diabody reduced collagen stimulated FAK activation (p = 0.01). Anti-EMP2 diabody decreases EMP2 protein levels, FAK activation, and collagen gel contraction by ARPE-19 cells without an adverse effect on cell survival. Modulation of EMP2 using anti-EMP2 diabody could be a new approach for targeting EMP2 and pathologic consequences associated with EMP2.


Asunto(s)
Anticuerpos Bloqueadores/fisiología , Colágeno Tipo I/metabolismo , Quinasa 1 de Adhesión Focal/metabolismo , Glicoproteínas de Membrana/inmunología , Epitelio Pigmentado de la Retina/metabolismo , Reacciones Antígeno-Anticuerpo , Apoptosis/efectos de los fármacos , Western Blotting , Camptotecina/toxicidad , Línea Celular , Movimiento Celular , Técnica del Anticuerpo Fluorescente Indirecta , Humanos , Fragmentos de Inmunoglobulinas , Microscopía Confocal , Biblioteca de Péptidos , Epitelio Pigmentado de la Retina/citología , Epitelio Pigmentado de la Retina/efectos de los fármacos , Anticuerpos de Cadena Única
16.
Invest Ophthalmol Vis Sci ; 53(2): 986-94, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22247454

RESUMEN

PURPOSE: To determine long-term safety of intravitreal administration of good manufacturing practice (GMP)-grade human bone-marrow-derived CD34(+) cells in NOD-SCID (nonobese diabetic-severe combined immunodeficiency) mice with acute retinal ischemia-reperfusion injury, a model for retinal vasculopathy. METHOD: Acute ischemia-reperfusion injury was induced in the right eye of adult NOD-SCID mice (n = 23) by transient elevation of intraocular pressure. Seven days later, 12 injured eyes and 5 normal contralateral eyes were injected each intravitreally with 5 × 10(4) CD34(+) cells isolated under GMP conditions from a healthy human donor bone marrow using an immunomagnetic cell isolation system. The remaining 11 injured eyes were not treated and served as controls. Mice were euthanized 1 day, 4 months, and 8 months later. Both eyes were enucleated and examined by immunohistochemical analysis and hematoxylin and eosin staining. Among mice followed for 8 months, electroretinography (ERG) was performed on both eyes before euthanization. All major organs were examined grossly and histologically after serial sectioning. RESULTS: Immunohistochemical staining 4 months after injection showed detectable CD34(+) cells in the retinal vasculature. ERG at 8 months after CD34(+) cell injection showed signals that were similar in untreated eyes. Histology of the enucleated eyes injected with CD34(+) cells showed no intraocular tumor or abnormal tissue growth after 8 months. Histologic analysis of all major organs showed no abnormal proliferation of human cells. CONCLUSIONS: Intravitreal administration of GMP-grade human bone-marrow-derived CD34(+) cells appears to be well tolerated long-term in eyes with acute retinal ischemic injury. A clinical trial will start to further explore this therapy.


Asunto(s)
Antígenos CD34 , Células de la Médula Ósea/inmunología , Células Madre Hematopoyéticas/inmunología , Daño por Reperfusión/tratamiento farmacológico , Enfermedades de la Retina/tratamiento farmacológico , Trasplante de Células Madre/métodos , Enfermedad Aguda , Animales , Células de la Médula Ósea/citología , Electrorretinografía , Estudios de Seguimiento , Supervivencia de Injerto , Humanos , Inyecciones Intravítreas , Ratones , Ratones Endogámicos NOD , Ratones SCID , Daño por Reperfusión/patología , Daño por Reperfusión/fisiopatología , Enfermedades de la Retina/patología , Enfermedades de la Retina/fisiopatología , Factores de Tiempo , Trasplante Heterólogo
17.
Invest Ophthalmol Vis Sci ; 52(12): 8965-78, 2011 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-21873667

RESUMEN

PURPOSE: To identify retinal genes and their relevant expression pathways affected by intravitreal injections of dexamethasone (Dex) and triamcinolone acetonide (TAA) in mice at clinically relevant time points for patient care. METHODS: Differential gene expressions of over 34,000 well-characterized mouse genes, in the retinas of 6-week-old C57BL/6J mice, were analyzed after intravitreal steroid injections at 1 week and 1 month time points, using mouse genome microarrays. The data were analyzed using commercial microarray analysis software for biologically relevant changes in gene expression pathways. RESULTS: A common gene pathway, with differentially activated genes for both steroids and time points, was "Semaphorin Signaling in Neurons," a member of the "Axonal Guidance Signaling System." At 1 week postinjection a common theme was activation of genes expressed in retinal glial cells, tumor necrosis factor-α, and transforming growth factor-ß signaling pathways and upregulation of stress response proteins (Serpina3n, Cebpd), as well as neuropeptide signaling somatostatin receptor (Sstr2). Unique for Dex was the upregulation of acute phase proteins (Gfap, Cp, Edn2) as well as Plexna2, a semaphorin signaling receptor, whereas EphrinB receptor ephexin 1 (Argef15) was downregulated. Folate signaling appears to be unique for TAA at 1 week (Folh1, Cubn), whereas aryl-hydrocarbon receptor signaling might be important for both steroids at 1 month postinjection. CONCLUSIONS: Understanding the molecular and genetic effects of intraocular steroid treatments is of clinical relevance. This in vivo study has elucidated several genes and pathways that are potentially altering the neuroprotective/neurodegenerative balance between glial and retinal ganglion cells during intravitreal steroid treatment.


Asunto(s)
Dexametasona/farmacología , Perfilación de la Expresión Génica , Glucocorticoides/farmacología , Degeneración Nerviosa/inducido químicamente , Degeneración Nerviosa/genética , Triamcinolona/farmacología , Animales , Regulación de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica/fisiología , Genómica , Humanos , Inyecciones Intravítreas , Masculino , Ratones , Ratones Endogámicos C57BL , Fármacos Neuroprotectores/farmacología , Reacción en Cadena en Tiempo Real de la Polimerasa , Retina/efectos de los fármacos , Retina/fisiología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Factores de Tiempo
19.
Semin Ophthalmol ; 26(3): 192-7, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21609232

RESUMEN

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly. The cause of AMD is complex and many risk factors have been implicated including age, family history (genetics), diet, smoking, and other environmental risk factors. Over the past decade, studies has found that inflammation play a large role in the pathogenesis of age-related macular degeneration (AMD). In fact, the main genetic changes (polymorphism) associated with AMD were found to be genes that regulate inflammation, most notably complement Factor H. This review ties together many studies done over the past decade to give us new insight into the role inflammation plays in the development of AMD.


Asunto(s)
Inflamación/complicaciones , Degeneración Macular/etiología , Retinitis/complicaciones , Factor H de Complemento/genética , Humanos , Sistema Inmunológico/fisiología , Factores de Riesgo
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