Person: Crooke Álvarez, Almudena
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First Name
Almudena
Last Name
Crooke Álvarez
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Bioquímica y Biología Molecular
Area
Bioquímica y Biología Molecular
Identifiers
9 results
Search Results
Now showing 1 - 9 of 9
Item Signs and Symptoms of Dry Eye in Keratoconus Patients: A Pilot Study(Current Eye Research, 2015) Carracedo Rodríguez, Juan Gonzalo; Recchioni, Alberto; Alejandre Alba, Nicolás; Martín Gil, Alba; Crooke Álvarez, Almudena; Jiménez Alfaro-Morote, Ignacio; Pintor Just, Jesús JerónimoPurpose: To compare signs and symptoms of dry eye in keratoconus (KC) patients versus healthy subjects. Methods: A total of 15 KC patients (KC group, n = 15 eyes) and 16 healthy subjects (control group, 16 eyes) were enrolled in this study. The Schirmer I test with no anesthetic, tear break-up time (TBUT), corneal staining characteristics, and ocular surface disease index (OSDI) scores were evaluated for both groups. Impression cytology, combined with/scanning laser confocal microscopy (LCM), was performed to evaluate goblet cell density, mucin cloud height (MCH), and goblet cell layer thickness (CLT). Finally, tear concentrations of di-adenosine tetraphosphate (Ap4A) were assessed. Results were statistically analyzed using Shapiro–Wilk and non-parametric Wilcoxon rank sum tests. Statistical significance was set at p < 0.05. Results: KC patients had lower tear volumes and greater corneal staining than did healthy subjects (p < 0.05). OSDI scores were 44.96 ± 8.65 and 17.78 ± 6.50 for the KC and control groups, respectively (p < 0.05). We found no statistically significant differences in TBUT between groups. Impression cytology revealed lower goblet cell densities in KC group patients versus control group subjects (84.88 ± 32.98 and 128.88 ± 50.60 cells/mm,2 respectively, p < 0.05). There was a statistically significant reduction in MCH and CLT in KC group patients compared with control group subjects. Ap4A tear concentrations were higher in KC group patients than in control group subjects (2.56 ± 1.10 and 0.15 ± 0.12 µM, respectively, p < 0.05). Conclusions: The parameters evaluated in this study indicate that KC patients suffer greater symptoms of dry eye and greater tear instability, primarily due to the decreased mucin production in their tears, than do healthy patients with no KC.Item Therapeutic potential of topical administration of siRNAs against HIF-1α for corneal neovascularization(Experimental Eye Research, 2022) Peral Cerda, María Asunción; Mateo Ibáñez, Jesús; Domínguez Godínez, Carmen Olalla; Carracedo Rodríguez, Juan Gonzalo; Gómez Pedrero, José Antonio; Crooke Álvarez, Almudena; Pintor Just, Jesús JerónimoGiven the implications of the problem of neovascularization on ocular health, as well as the growth in the number of cases, the purpose of the present study has been testing the efficacy of siRNAs (small interfering RNA) designed to silence Hypoxia Inducible Factor -1α (HIF-1α) and to demonstrate that their use stops neovascularization in a model of corneal burn. Corneal wounds in the limbic zone were made in the eyes of New Zealand white rabbits. Topical applications of siRNAs were done the next day to the wound for four consecutive days and eyes were examined with a slit lamp. Evaluation of neovascularization progress was done by analyzing images by ImageJTM and to determine the neovascular area in Matlab ® was used. At the same time, a rabbit corneal cell line was used for in vitro study of hypoxia exposure and Western blot analysis of the cell's extracts were done. Under normal cell culture oxygenation, the expression of HIF-1α was lower than that observed under hypoxic conditions. After 2 h of hypoxia, there was a significant increase in the HIF-1α expression, effect that was maintained up to 6 h. The increased in HIF-1α was mimicked by a cell permeable prolyl-4-hydroxylase inhibitor. Cobalt chloride showed no capacity to increase HIF-1α in vitro. The effect of three different siRNA on HIF-1α was tested after 4 h of hypoxia. siRNA#1 was able to silence 80% of HIF-1α expression, siRNA#2 and siRNA#3 reduce the expression in 45% and 40% respectively. In addition, the three siRNA were tested in a corneal model of neovascularization. scrambledsiRNA#2 was the most effective inhibitor of blood vessel production, followed by siRNA#3 and siRNA#1. Compared to the scrambled siRNA (100% of blood vessel generation), siRNA#2 blocked the presence of blood vessels by 83 ± 2%, siRNA#3 inhibited 45 ± 7% and siRNA#1 only inhibited 18 ± 5%. The necessary time to observe the 50% of effect showed values of NV50 of 10.2 ± 2.4 days for the scrambled siRNA, 9.1 ± 1.4 for siRNA#1, 6.5 ± 1.85 for siRNA#2 and 4.8 ± 1.8 days for siRNA#3. In conclusion, the topical application of siRNA towards HIF-1α seems to be an effective and reliable method to stop neovascularization.Item Dual-Mode Gold Nanoparticle-Based Method for Early Detection of Acanthamoeba(International Journal of Molecular Sciences, 2022) Pastrana Robles, Cristina; Guerreiro, Joana Rafaela L.; Elumalai, Monisha; Carpena Torres, Carlos; Crooke Álvarez, Almudena; Carracedo Rodríguez, Juan Gonzalo; Prado, Marta; Huete Toral, FernandoAcanthamoeba keratitis is an aggressive and rapidly progressing ocular pathology whose main risk factor is the use of contact lenses. An early and differential diagnosis is considered the main factor to prevent the progression and improve the prognosis of the pathology. However, current diagnosis techniques require time, complex and costly materials making an early diagnosis challenging. Thus, there is a need for fast, accessible, and accurate methods for Acanthamoeba detection by practitioners for timely and suitable treatment and even for contact lens user as preventive diagnosis. Here, we developed a dual-mode colorimetric-based method for fast, visual, and accurate detection of Acanthamoeba using gold nanoparticles (AuNPs). For this strategy, AuNPs were functionalized with thiolated probes and the presence of target Acanthamoeba genomic sequences, produce a colorimetric change from red to purple. This approach allows the detection of 0.02 and 0.009 μM of the unamplified Acanthamoeba genome by the naked eye in less than 20 min and by color analysis using a smartphone. Additionally, real samples were successfully analyzed showing the potential of the technology considering the lack of point-of-care tools that are mostly needed.Item The role of dinucleoside polyphosphates on the ocular surface and other eye structures(Progress in Retinal and Eye Research, 2016) Carracedo Rodríguez, Juan Gonzalo; Crooke Álvarez, Almudena; Guzmán Aránguez, Ana Isabel; Pintor Just, Jesús JerónimoDinucleoside polyphosphates comprises a group of dinucleotides formed by two nucleosides linked by a variable number of phosphates, abbreviated NpnN (where n represents the number of phosphates). These compounds are naturally occurring substances present in tears, aqueous humour and in the retina. As the consequence of their presence, these dinucleotides contribute to many ocular physiological processes. On the ocular surface, dinucleoside polyphosphates can stimulate tear secretion, mucin release from goblet cells and they help epithelial wound healing by accelerating cell migration rate. These dinucleotides can also stimulate the presence of proteins known to protect the ocular surface against microorganisms, such as lysozyme and lactoferrin. One of the latest discoveries is the ability of some dinucleotides to facilitate the paracellular way on the cornea, therefore allowing the delivery of compounds, such as antiglaucomatous ones, more easily within the eye. The compound Ap4A has been described being abnormally elevated in patient's tears suffering of dry eye, Sjogren syndrome, congenital aniridia, or after refractive surgery, suggesting this molecule as biomarker for dry eye condition. At the intraocular level, some diadenosine polyphosphates are abnormally elevated in glaucoma patients, and this can be related to the stimulation of a P2Y2 receptor that increases the chloride efflux and water movement in the ciliary epithelium. In the retina, the dinucleotide dCp4U, has been proven to be useful to help in the recovery of retinal detachments. Altogether, dinucleoside polyphosphates are a group of compounds which present relevant physiological actions but which also can perform promising therapeutic benefits.Item Contact Lenses Loaded with Melatonin Analogs: A Promising Therapeutic Tool against Dry Eye Disease(Journal of Clinical Medicine, 2022) Navarro Gil, Francisco Javier; Huete Toral, Fernando; Domínguez Godínez, Carmen Olalla; Carracedo Rodríguez, Juan Gonzalo; Crooke Álvarez, Almudena; Versura, Piera; Dogru, MuratMelatonin analogs topically administered evoke a potent tear secretagogue effect in rabbits. This route of drug administration requires high drug concentration and frequent dosing due to its reduced ocular surface retention. Therefore, contact lenses (CLs) have emerged as an alternative drug- delivery system that prolongs drug retention in the cornea, improving its therapeutic performance. This study explores the in vitro ability of five commercially available hydrogel CLs to act as a delivery system for melatonin analogs and the in vivo secretagogue effect of melatonin analog-loaded CLs. We soaked CLs with melatonin or melatonin analog solutions (1 mM) for 12 h. Spectroscopic assays showed that IIK7-loaded CLs led to the inadequate delivery of this compound. Conventional hydrogel lenses loaded with agomelatine released more agomelatine than silicone ones (16–33% more). In contrast, the CLs of silicone materials are more effective as a delivery system of 5-MCA-NAT than CLs of conventional materials (24–29%). The adaptation of CLs loaded with agomelatine or 5-MCA-NAT in rabbits triggered a higher tear secretion than the corresponding eye drops (78% and 59% more, respectively). These data suggest that CLs preloaded with melatonin analogs could be an adequate strategy to combat aqueous tear deficient dry eye disease.Item Effect of Melatonin and Analogues on Corneal Wound Healing: Involvement of Mt2 Melatonin Receptor(Current Eye Research, 2015) Crooke Álvarez, Almudena; Guzmán Aránguez, Ana Isabel; Mediero Muñoz, Aránzazu; Alarma Estrany, Pilar; Carracedo Rodríguez, Juan Gonzalo; Peláez García, María Teresa; Peral Cerda, María Asunción; Pintor Just, Jesús JerónimoPurpose: We have investigated the effect of melatonin and its analogues on rabbit corneal epithelial wound healing. Methods: New Zealand rabbits were anaesthetised and wounds were made by placing Whatman paper discs soaked in n-heptanol on the cornea. Melatonin and analogues (all 10 nmol) were instilled. Wound diameter was measured every 2 hours by means of fluorescein application with a Topcon SL-8Z slit lamp. Melatonin antagonists (all 10 nmol) were applied 2 hours before the application of the n-heptanol-soaked disc and then every 6 hours together with melatonin. To confirm the presence of MT2 receptors in corneal epithelial cells immunohistochemistry, Western blot and RT-PCR assays in native tissue and in rabbit corneal epithelial cells were performed. The tear components were extracted then processed by HPLC to quantify melatonin in tears. Results: Migration assays revealed that melatonin and particularly the treatment with the MT2 agonist IIK7, accelerated the rate of healing (p < 0.001). The application of the non-selective melatonin receptor antagonist luzindole and the MT2 antagonist DH97 (but not prazosin), prevented the effect of melatonin on wound healing (both p < 0.001). Immunohistochemistry, Western blot and RT-PCR assays showed the presence of MT2 melatonin receptor in corneal epithelial cells. In addition, we have identified melatonin in tears and determined its daily variations. Conclusions: These data suggest that MT2 receptors are implicated in the effect of melatonin on corneal wound healing regulating migration rate. This suggests the potential use of melatonin and its analogues to enhance epithelial wound healing in ocular surface disease.Item Effect of Melatonin and Its Analogs on Tear Secretion(The Journal of pharmacology and experimental therapeutics, 2019) Navarro Gil, Francisco Javier; Huete Toral, Fernando; Crooke Álvarez, Almudena; Domínguez Godínez, Carmen Olalla; Carracedo Rodríguez, Juan Gonzalo; Pintor Just, Jesús JerónimoMelatonin has been shown to enhance tear secretion associated with dinucleotide diadenosine tetraphosphate. This study investigated the isolated action of melatonin and its analogs, agomelatine, N-butanoyl-2-(2-methoxy-6H-isoindolo[2,1-a]indol-11-yl) ethanamine (IIK7), and 5-methoxycarbonylamino-N-cetyltryptamine (5-MCA-NAT) (10 µl at 100 µM), on tear secretion when applied topically in the rabbit cornea and its relationship with the melatonin MT1, MT2, and MT3/quinone reductase QR2 receptors. The results showed a significant increase in tear secretion, with a maximal effect at 60 minutes for the agonists (138.9% ± 6.5%, 128.9% ± 6.4%, and 120.0% ± 5.2%, respectively; P < 0.05; 100% control) but not for melatonin (101.6% ± 7.9%; P > 0.05). Agonist action was tested combined with the antagonists DH97 (MT2 selective), prazosin (MT3/QR2 inhibitor), and luzindole (nonselective MT membrane receptor) (10 µl at 100 µM). DH97 reversed the effect of agomelatine, IIK7, and 5-MCA-NAT up to 30.85% ± 7.6%,108% ± 7.2%, and 87.01% ± 7.6%, respectively (P < 0.05; 100% control). Luzindole antagonized agomelatine and 5-MCA-NAT up to 67.35% ± 7.6% and 92.12% ± 8%, respectively (P < 0.05). Prazosin only reversed 5-MCA-NAT action up to 84.2% ± 7.7% (P < 0.05). These results suggest different pathways for the agonists to act through MT membrane receptors. Therefore, agomelatine, IIK7, and 5-MCA-NAT act through MT membrane receptors as secretagogues of tear secretion, and these analogs could be considered excellent therapeutic candidates for dry eye treatment.Item Optimization of a Rabbit Dry Eye Model Induced by Topical Instillation of Benzalkonium Chloride(Journal of Ophthalmology, 2020) Carpena Torres, Carlos; Pintor Just, Jesús Jerónimo; Pérez de Lara, María Jesús; Huete Toral, Fernando; Crooke Álvarez, Almudena; Pastrana Robles, Cristina; Carracedo Rodríguez, Juan GonzaloPurpose. To optimize a rabbit dry eye model induced by topical instillation of benzalkonium chloride (BAC), reduce the days of instillation of the original model by increasing the concentration of BAC from 0.1% to 0.2%. Materials and Methods. An experimental, prospective, and randomized study was performed on 10 male New Zealand white rabbits, divided into two groups, considering both eyes: 5 rabbits as control (n = 10) and 5 rabbits with 0.2% BAC treatment (n = 10). Saline solution (control) and 0.2% BAC were instilled for 5 consecutive days, twice daily. Tear secretion with and without anesthesia, tear breakup time, tear osmolarity, corneal staining, conjunctival hyperemia, density of goblet cells, height of mucin cloud, and transcript levels of IL-6 were measured before and after the treatment. Results. After the instillation of 0.2% BAC for 5 consecutive days, there was a significant increase in tear secretion without anesthesia (P < 0.001), corneal staining (P < 0.001), conjunctival hyperemia (P < 0.001), and levels of IL-6 mRNA (P = 0.005) compared to the control group. Conversely, there was a decrease in tear secretion with anesthesia (P < 0.001), tear breakup time (P = 0.007), tear osmolarity (P < 0.001), density of goblet cells (P < 0.001), and height of mucin cloud (P < 0.001). Conclusions. )e topical instillation of 0.2% BAC for 5 consecutive days, twice daily, was a proper procedure to induce a rabbit dry eye model, reducing the number of days of instillation compared to the original model (14 days).Item 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.