Person: Lledó Mayans, Victoria Eugenia
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First Name
Victoria Eugenia
Last Name
Lledó Mayans
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Bioquímica y Biología Molecular
Area
Identifiers
7 results
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Item Estudio del efecto protector de la melatonina en el cristalino, análisis de su acción hipotensora y modulación de su secreción usando un filtro amarillo(2022) Lledó Mayans, Victoria Eugenia; Guzmán Aránguez, Ana Isabel; Awad Alkozi, HananEl cristalino es una lente biconvexa, avascular y transparente situada en el polo anterior del ojo por detrás del iris. Su función principal es enfocar la luz a la retina. La opacificación o pérdida de transparencia del cristalino genera cataratas, la principal causa de ceguera reversible en el mundo, siendo el estrés oxidativo un mecanismo patológico clave en su desarrollo. La melatonina es una neurohormona secretada principalmente por la glándula pineal, también es producida a nivel ocular en estructuras como el cuerpo ciliar, la retina y el cristalino. La síntesis y liberación de melatonina sigue un ritmo circadiano, siendo suprimida su liberación mediante la luz por la activación del fotopigmento melanopsina. Recientes estudios han evidenciado la presencia de este fotopigmento en el cristalino y como su activación mediante luz azul disminuye la expresión de enzimas biosintéticas de la melatonina así como su producción, sugiriendo que la modificación de la luz, por ejemplo mediante el uso de filtros, podría regular la liberación de melatonina ocular. La melatonina actúa como agente antioxidante, adquiriendo así un potencial anticataratogénico. Se desconoce si los niveles de melatonina ocular presentan alguna alteración en la patología de cataratas, repercutiendo en la progresión de la enfermedad...Item Presence of melatonin in human tears(Journal of Optometry, 2016) Carracedo Rodríguez, Juan Gonzalo; Carpena Torres, Carlos; Concepción Cuevas, Eugenio Pablo; Díaz, Victor; García-García, Miguel; Jemnic, Nahla; Lledó Mayans, Victoria Eugenia; Martín, Marina; Pastrana Robles, Cristina; Pelissier, Raquel; Veselinova, Albena; Wang, Xiaoyu; Pintor Just, Jesús JerónimoItem PhDAY 2020 -FOO (Facultad de Óptica y Optometría)(2020) Pintor Just, Jesús Jerónimo; Carpena Torres, Carlos; Peral Cerda, María Asunción; Pérez de Lara, María Jesús; Toral, Fernando; Crooke Álvarez, Almudena; Pastrana Robles, Cristina; Carracedo Rodríguez, Juan Gonzalo; Cayuela López, Ana; Sorzano Sánchez, Óscar; Charbel, Carla; Garzón Jiménez, Nuria; Carballo Álvarez, Jesús; Diz Arias, Elena; Fernández Jiménez, Elena; Lledó Mayans, Victoria Eugenia; Gómez Pedrero, José Antonio; Durán Prieto, Elena; López Alonso, José Manuel; Fernández Torres, Miguel Ángel; Guzmán Aránguez, Ana Isabel; Gómez Manzanares, Ángela; Vázquez Molini, Daniel; Martínez Antón, Juan Carlos; Bernárdez Vilaboa, Ricardo; Mayorga Pinilla, Santiago; Álvarez Fernández-Balbuena, Antonio; Benítez, AntoJ.; Igalla El-Youssfi, Asmae; León Álvarez, Alejandro; Palomo Álvarez, Catalina; Awad Alkozi, Hanan; Sánchez Naves, Juan; Martínez Alberquilla, Irene; García Montero, María; Ruiz Alcocer, Javier; Madrid Costa, David; Martínez Florentín, Gema; Papas, Eric B.; Medrano Muñoz, Sandra Milena; Molina, Nancy; Jurado, Sandra; Oliveiros López, Juan; Platero Alvarado, Nadiuska Cristine; Garrido Mercado, Rafaela; Pérez Garmendia, Carlos; Antona Peñalba, Beatriz; Barrio De Santos, Ana Rosa; González Pérez, Mariano; Pérez Garmendia, Carlos; Serramito Blanco, María; Privado Aroco, Ana; Almalki, Wael; Bodas Romero, Julia; Ouzzani, Mohamed; Paune, Jaume; Calderón García, Raquel; Pitarch Velasco, Aída; Cebrián, José Luis; Sánchez Pérez, María Isabel; García Rojo, Marta María; Bonnin Arias, Cristina Natalia; Sánchez Ramos, Celia; Gutiérrez Jorrín, Sara Carmen; Rodríguez Alonso, Xabier; Laucirica Sáenz, Gorka; Arranz Márquez, Esther; Alonso Castellanos, Miriam; Teus Guezala, Miguel Ángel; Hernández Verdejo, José Luis; Mármol Errasti, Esther; Martín García, Beatriz; Arriola Villalobos, Pedro; Gómez De Liaño Sánchez, María Rosario; Mínguez Caro, N; Orduña Azcona, Javier; Navarro Gil, Francisco Javier; Huete Toral, Fernando; Rodríguez Pomar, Candela; Martínez Águila, Alejandro; Martín Gil, Alba; Tomé de la Torre, Miguel ÁngelPor cuarto año consecutivo los doctorandos de la Facultad de Óptica y Optometría de la Universidad Complutense de Madrid cuentan con un congreso propio organizado por y para ellos, el 4º PhDAY- FOO. Se trata de un congreso gratuito abierto en la que estos jóvenes científicos podrán presentar sus investigaciones al resto de sus compañeros predoctorales y a toda la comunidad universitaria que quiera disfrutar de este evento. Apunta en tu agenda: el 15 de octubre de 2020. En esta ocasión será un Congreso On-line para evitar que la incertidumbre asociada a la pandemia Covid-19 pudiera condicionar su celebración.Item Melatonin counteracts oxidative damage in lens by regulation of Nrf2 and NLRP3 inflammasome activity(Experimental Eye Research, 2021) Lledó Mayans, Victoria Eugenia; Alkozi, Hanan Awad; Sánchez Naves, Juan; Fernández Torres, Miguel Ángel; Guzmán Aránguez, Ana IsabelOxidative stress, generated because of an imbalance between reactive oxygen species (ROS) generation and elimination, is associated with lens damage and cataract progression. ROS generation is known to activate NLRP3(nucleotide-binding oligomerization domain-like receptor family, pyrin domain-cointaining 3) inflammasome, and is believed to be an important link between oxidative stress and inflammation, that is also related to cataract development. Potential oxidative hazard to the lens by white light-emitting diode (LED) light, a source of illu-mination commonly used nowadays, has been suggested, although available information is limited. In this work,we evaluated the cytotoxicity induced by hydrogen peroxide (an oxidative stressor agent) and white LED light in lens epithelial cells as well as melatonin ability to counteract the effects induced by them. Melatonin is a neurohormone secreted by different ocular structures that could be useful to alleviate oxidative damage induced by different oxidative stressors in lens. Particularly, the modulation of Nrf2 (nuclear erythroid 2-related factor)/Keap 1 (Kelch-like ECH-associated protein 1), an essential oxidative stress regulator, and NLRP3 activity by melatonin was evaluated in lens epithelial cells. ROS levels rose after white LED light exposure and cell viability was reduced after challenge with oxidative stressor agents. Melatonin prevented cell death triggered by hydrogen peroxide and white LED light, precluded ROS generation induced by white LED light and promoted antioxidant lens capacity through upregulation of Nrf2 protein levels and SOD activity. NLRP3, caspase-1 and IL1-β expression significantly increased in human lens cells exposed to H2O2 or irradiated with white LED light. Activation of NLRP3 inflammasome triggered by oxidative stressors was also abrogated by melatonin. Attenuation of inflammatory and cytotoxic effects induced by oxidative stressors provided by melatonin in lens indicate the interest of this molecule as a potential therapeutic agent for cataract prevention/managementItem Effects of hyperosmolarity on annexin A1 on ocular surface epithelium in vitro(Experimental Eye Research, 2022) Fernández Torres, Miguel Ángel; Lledó Mayans, Victoria Eugenia; Pérez de Lara, María Jesús; Guzmán Aránguez, Ana IsabelOsmotic stress is an important challenge to cell function. Dry eye pathology is characterized by elevated tear film osmolarity as consequence of decreased tear secretion and/or increased evaporation. Dry eye pathogenesis is not completely clarified. However, it is known that tear hyperosmolarity induces NLRP3 (nucleotide-binding oligomerization domain-like receptor family, pyrin domain-cointaining 3) inflammasome activation and inflammatory mediators release that leads to ocular surface damage. Annexin A1 is a protein involved in anti-inflammatory or pro-resolution actions in different tissues while its presence and biological role on ocular surface has been scarcely examined. In this study, potential changes in annexin A1 protein expression and secretion on the ocular surface after exposure to hyperosmolar conditions were evaluated. In addition, considering the significant role of inflammation in dry eye pathology, the potential anti-inflammatory activity of Ac2-26, an annexin A1 peptide mimicking its N-terminus, was assessed. Cytosolic and membrane staining was detected for annexin A1 in corneal and conjunctival epithelial cells. A native form of annexin A1 together with a truncated form were detected by western blot analysis. Under hyperosmotic conditions increased protein levels of intracellular and secreted annexin A1 as well as higher expression of its receptor Fpr2 (formyl peptide receptor type 2) were found. Treatment with mimetic peptide Ac2-26 ameliorated NLRP3 activation and interleukin 1β (IL-1β) release triggered by elevated osmolarity in corneal and conjunctival epithelial cells. These findings suggest a potential role of annexin A1 and its mimetic peptide modulating key inflammatory events associated to dry eye.Item Yellow Filter Effect on Melatonin Secretion in the Eye: Role in IOP Regulation(Current Eye Research, 2019) Lledó Mayans, Victoria Eugenia; Alkozi, Hanan Awad; Pintor Just, Jesús JerónimoPurpose: Melatonin is a neurohormone mainly synthesized in the pineal gland; however, it is also present in the aqueous humor. One of melatonins’ functions in the eye is the regulation of intraocular pressure (IOP). Melatonin is known to be sensitive to light. Recently, the photopigment which controls melatonin synthesis, melanopsin, was found in the crystalline lens. Therefore, light conditions are an interesting possible way of regulating melatonin levels in the aqueous humor. The current study used yellow filters, since melanopsin is activated by short wavelength (blue light). Methods: New Zealand white rabbits were used, divided in two groups, one under controlled 12 h light/dark cycles, while the rest had their cages encased with a yellow filter (λ 465–480). IOP measurements were taken every week at the same time before they were anesthetized for aqueous humor extraction. Results: Keeping the rabbits under the yellow filter resulted in a decrease in IOP up to 43.8 ± 7.8% after 3 weeks. This effect was reversed after the topical application of selective and nonselective melatonin receptors antagonists, 4PPDOT and luzindole. Also, blocking melanopsin by its antagonist AA92593 under white light condition decreased IOP. Finally, melatonin levels were found significantly higher in the aqueous humor of rabbits developed under yellow filter compared to controls (37.4 ± 4.2 and 15.3 ± 3.1 ng/ml, respectively). Conclusion: Yellow filters modulate melatonin levels in the aqueous humor due to deactivating melanopsin activity. This effect leads to a decrease in IOP mediated by melatonin receptors.Item Modulation of aqueous humor melatonin levels by yellow-filter and its protective effect on lens(Journal of Photochemistry and Photobiology B: Biology, 2021) Lledó Mayans, Victoria Eugenia; Alkozi, Hanan Awad; Sánchez Naves, Juan; Fernández Torres, Miguel Ángel; Guzmán Aránguez, Ana IsabelMelatonin is mainly secreted by the pineal gland, and it is also produced by various ocular structures such as the lens. It has been recently demonstrated that melatonin ocular synthesis can be induced by blocking the blue component of white light by means of filters. Melatonin exhibits antioxidant properties that can be useful to face light-induced oxidative stress as well as oxidative events associated to ocular pathologies like cataracts. Moreover, as oxidative stress is a main event in cataract development, changes in melatonin levels could happen and be relevant in the progression of this pathology, a subject that remains uncertain. The goal of this work was to analyze the ability of a short wavelength light blocking (yellow) filter to modulate endogenous melatonin concentration and the antioxidant and cytoprotective actions induced by yellow filter’s use in lens. Furthermore, we evaluated the potential changes in aqueous humor melatonin concentration from patients with cataracts. In human lens epitheli cells, white light-emitting diode (LED) light challenge reduced melatonin secretion, protein levels of the enzymes involved in melatonin synthesis (hydroxyindole-O-methyltransferase and unphosphorylated and phosphorylated forms of arylalkylamine N-acetyltransferase) and cell viability whereas increased reactive oxygen species production. Yellow filter exposure precluded melatonin secretion reduction and protected cells from oxidative damage. Consistent with cataract patient’s results, significantly lower levels of melatonin were observed in aqueous humor of alloxan-induced diabetic cataract rabbits as compared to those of control rabbits. In contrast, aqueous humor melatonin levels of diabetic cataract animals maintaining in cages covered with a yellow filter resembled control values. This recovery seems to be mediated by the induction of melatonin biosynthetic enzymes protein expression. Yellow filter also preserved Nrf2 lens protein expression and superoxide dismutase protein levels and activity in diabetic animals. Modulation of endogenous ocular melatonin concentration using blocking filters might be a promising approach to prevent premature lens opacification.