Vascular interstitial cells in retinal arteriolar annuli are altered during hypertension

The authors thank Veronica Melgarejo, Lorena Noya, and Angel Vazquez for technical assistance. Supported by grants from Instituto de Salud Carlos III (PI12/00605, PI16/00719, SAF2014-59945-R, and Red de Investigación Renal REDinREN 12/0021/0013), Spain; Fundação para a Ciência e a Tecnologia (SFRH/BPD/102573/2014, SFRH/BD/95330/2013), Ministerio da Educação e Ciência, Portugal; and Fondo Europeo de Desarrollo Regional (FEDER).Supported by grants from Instituto de Salud Carlos III (PI12/00605, PI16/00719, SAF2014-59945-R, and Red de Investigacion Renal REDinREN 12/0021/0013), Spain; Fundacao para a Ciencia e a Tecnologia (SFRH/BPD/102573/2014, SFRH/BD/95330/2013), Ministerio da Educacao e Ciencia, Portugal; and Fondo Europeo de Desarrollo Regional (FEDER).PURPOSE. It has been suggested that arteriolar annuli localized in retinal arterioles regulate retinal blood flow acting as sphincters. Here, the morphology and protein expression profile of arteriolar annuli have been analyzed under physiologic conditions in the retina of wildtype, β-actin-Egfp, and Nestin-gfp transgenic mice. Additionally, to study the effect of hypertension, the KAP transgenic mouse has been used. METHODS. Cellular architecture has been studied using digested whole mount retinas and transmission electron microscopy. The profile of protein expression has been analyzed on paraffin sections and whole mount retinas by immunofluorescence and histochemistry. RESULTS. The ultrastructural analysis of arteriolar annuli showed a different cell population found between endothelial and muscle cells that matched most of the morphologic criteria established to define interstitial Cajal cells. The profile of protein expression of these vascular interstitial cells (VICs) was similar to that of interstitial Cajal cells and different from the endothelial and smooth muscle cells, because they expressed b-actin, nestin, and CD44, but they did not express CD31 and a-SMA or scarcely express F-actin. Furthermore, VICs share with pericytes the expression of NG2 and platelet-derived growth factor receptor beta (PDGFR-β). The high expression of Ano1 and high activity of nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase observed in VICs was diminished during hypertensive retinopathy suggesting that these cells might play a role on the motility of arteriolar annuli and that this function is altered during hypertension. CONCLUSIONS. A novel type of VICs has been described in the arteriolar annuli of mouse retina. Remarkably, these cells undergo important molecular modifications during hypertensive retinopathy and might thus be a therapeutic target against this disease

Elaboració d'un atles fotogràfic per a l'autoaprenentatge de l'anatomia del ratolí

La versemblança del genoma del ratolí i de l'home, com també el desenvolupament de les tècniques de mutagènesi, han convertit el ratolí en l'eina bàsica de recerca preclínica destinada a la comprensió de la fisiopatologia i el tractament de les malalties humanes. L'objectiu principal d'aquest projecte consisteix en la producció d'un atles fotogràfic de gran qualitat sobre l'anatomia del ratolí, atès que no hi ha un llibre d'aquestes característiques en el mercat mundial. L'eina docent que estem fent ha de permetre l'autoaprenentatge dels estudiants de grau i de postgrau dedicats a les ciències de la salut i la biomedicina i millorar-ne la formació i el rendiment. Aquest atles també ha de permetre comprendre les modificacions anatòmiques existents en els ratolins modificats genèticament.La verosimilitud del genoma del ratón y del hombre, como también el desarrollo delas técnicas de mutagénesis, han convertido el ratón en la herramienta básica de investigación preclínica destinada a la comprensión de la fisiopatología y el tratamiento de las enfermedades humanas. El objetivo principal de este proyecto consiste en la producción de un atlas fotográfico de gran calidad sobre la anatomía del ratón, dado que no hay un libro de estas características en el mercado mundial. La herramienta docente que estamos haciendo tiene que permitir el autoaprendizaje de los estudiantes de grado y de postgrado dedicados a las ciencias de la salud y la biomedicina y mejorar la formación y el rendimiento. Este atlas también tiene que permitir comprender las modificaciones anatómicas existentes en los ratones modificados genéticamente.The resemblance between the genomes of the mouse and the human being and the development of mutagenic techniques, have made the mouse the basic pre-clinical researchtool for understanding the physiopathology and treatment of human diseases. The main objective of this project is to produce a high quality photographic atlas of the anatomy of the mouse, as there is no book of this type available on the international market. The teaching tool we are producing must enable independent learning by graduate and postgraduate students in the health and biomedical sciences and improve their education and achievement. This atlas must also enable the anatomical changes in genetically modified mice to be included

L-Ferritin Binding to Scara5 : A New Iron Traffic Pathway Potentially Implicated in Retinopathy

Iron is essential in the retina because the heme-containing enzyme guanylate cyclase modulates phototransduction in rods and cones. Transferrin endocytosis is the classical pathway for obtaining iron from the blood circulation in the retina. However, the iron storage protein ferritin has been also recently proposed as an iron carrier. In this study, the presence of Scara5 and its binding to L-ferritin was investigated in the retina. Our results showed that Scara5, the specific receptor for L-ferritin, was expressed in mouse and human retinas in many cell types, including endothelial cells. Furthermore, we showed that intravenously injected ferritin crossed the blood retinal barrier through L-ferritin binding to Scara5 in endothelial cells. Thus, suggesting the existence of a new pathway for iron delivery and trafficking in the retina. In a murine model of photoreceptor degeneration, Scara5 was downregulated, pointing out this receptor as a potential player implicated in retinopathy and also as a possible therapeutic target

miniBELEN: a modular neutron counter for (a, n) reactions

miniBELEN is a modular and transportable neutron moderated counter with a nearly flat neutron detection efficiency up to 10 MeV. Modularity implies that the moderator can be reassembled in different ways in order to obtain different types of response. The detector has been developed in the context of the Measurement of Alpha Neutron Yields (MANY) collaboration, which is a scientific effort aiming to carry out measurements of (a, n) production yields, reaction cross-sections and neutron energy spectra. In this work we present and discuss several configurations of the miniBELEN detector. The experimental validation of the efficiency calculations using 252Cf sources and the measurement of the 27Al(a, n) 30P reaction is also presented.This work has been supported by the Spanish Ministerio de Economía y Competitividad under grants FPA2017-83946- C2-1 & C2-2 and PID2019-104714GB-C21 & C22, the Generalitat Valenciana Grant PROMETEO/2019/007, both cofounded by FEDER (EU), and the SANDA project funded under H2020-EURATOM-1.1 Grant No. 847552. The authors acknowledge the support from Centro de Microanálisis de Materiales (CMAM) - Universidad Autónoma de Madrid, for the beam time proposal (Comissioning of neutron detector systems for (a,݊n) reaction measurements) with code P01156, and its technical staff for their contribution to the operation of the accelerator.Article signat per 41 autors/es: N. Mont-Geli, A. Tarifeño-Saldivia, L.M. Fraile, S. Viñals, A. Perea, M. Pallàs, G. Cortés, E. Nácher, J.L. Tain, V. Alcayne, A. Algora, J. Balibrea-Correa, J. Benito, M.J.G. Borge, J.A. Briz, F. Calviño, D. Cano-Ott, A. De Blas, C. Domingo-Pardo, B. Fernández, R. Garcia, G. García, J. Gómez-Camacho, E.M. González-Romero, C. Guerrero, J. Lerendegui-Marco, M. Llanos, T. Martínez, E. Mendoza, J.R. Murias, S.E.A. Orrigo, A. Pérez de Rada, V. Pesudo, J. Plaza, J.M. Quesada, A. Sánchez, V. Sánchez-Tembleque, R. Santorelli, O. Tengblad, J.M. Udías and D. Villamarín.Postprint (published version

Ferritin But Not Iron Increases in Retina Upon Systemic Iron Overload in Diabetic and Iron-Dextran Injected Mice

Iron overload causes oxidative damage in the retina, and it has been involved in the pathogeny of diabetic retinopathy, which is one of the leading causes of blindness in the adult population worldwide. However, how systemic iron enters the retina during diabetes and the role of blood retinal barrier (BRB) in this process remains unclear. The db/db mouse, a well-known model of type 2 diabetes, and a model of systemic iron overload induced by iron dextran intraperitoneal injection, were used. Perls staining and mass spectrophotometry were used to study iron content. Western blot and immunohistochemistry of iron handling proteins were performed to study systemic and retinal iron metabolism. BRB function was assessed by analyzing vascular leakage in fundus angiographies, whole retinas, and retinal sections and by studying the status of tight junctions using transmission electron microscopy and Western blot analysis. Twenty-week-old db/db mice with systemic iron overload presented ferritin overexpression without iron increase in the retina and did not show any sign of BRB breakdown. These findings were also observed in iron dextran-injected mice. In those animals, after BRB breakdown induced by cryopexy, iron entered massively in the retina. Our results suggested that BRB protects the retina from excessive iron entry in early stages of diabetic retinopathy. Furthermore, ferritin overexpression before iron increase may prepare the retina for a potential BRB breakdown and iron entry from the systemic circulation

L-Ferritin Binding to Scara5 : A New Iron Traffic Pathway Potentially Implicated in Retinopathy

Iron is essential in the retina because the heme-containing enzyme guanylate cyclase modulates phototransduction in rods and cones. Transferrin endocytosis is the classical pathway for obtaining iron from the blood circulation in the retina. However, the iron storage protein ferritin has been also recently proposed as an iron carrier. In this study, the presence of Scara5 and its binding to L-ferritin was investigated in the retina. Our results showed that Scara5, the specific receptor for L-ferritin, was expressed in mouse and human retinas in many cell types, including endothelial cells. Furthermore, we showed that intravenously injected ferritin crossed the blood retinal barrier through L-ferritin binding to Scara5 in endothelial cells. Thus, suggesting the existence of a new pathway for iron delivery and trafficking in the retina. In a murine model of photoreceptor degeneration, Scara5 was downregulated, pointing out this receptor as a potential player implicated in retinopathy and also as a possible therapeutic target