Regulación de la expresión gónica por la lisil oxidasa (LOX): modulación de la α 2-macroglobulina en células endoteliales / Regulation of gene expression by lysyl oxidase (LOX): α 2-macroglobulin modulation in endothelial cells

RESUMEN

Introducción La lisil oxidasa (LOX), enzima implicada en la maduración de la matriz extracelular, juega un papel clave en el mantenimiento de la homeostasis del endotelio. Sin embargo, se desconoce el mecanismo a través del cual la LOX regula la función de la célula endotelial. Nuestro objetivo ha sido caracterizar los procesos celulares controlados por la LOX en células endoteliales. Métodos La LOX se sobreexpresó en células endoteliales humanas de vena de cordón umbilical (HUVEC) utilizando un sistema lentiviral. Las consecuencias de la sobreexpresión de LOX sobre el patrón de expresión se determinaron mediante microarrays. La expresión de LOX y de la (..) (AU)

ABSTRACT

Abstract Introduction: Lysyl oxidase (LOX) is an enzyme involved in extracellular matrix maturation that plays a crucial role in the maintenance of endothelial homeostasis. However, the specific mechanisms underlying the ability of LOX to regulate endothelial function are currently unknown. Our objective was to characterize the cellular processes controlled by LOX in endothelial cells. Methods: LOX was over expressed in human umbilical vein endothelial cells (HUVEC) when a lentiviral system was used. The consequences of LOX over expression were analyzed by microarray.LOX and 2-macroglobulin (A2 M) expression was assessed by real-time polymerase chain reaction and/or Western-Blot. Results: The lentiviral expression system significantly increased LOX expression in HUVEC (more than 20-fold). In agreement with this result, Western-Blot analysis revealed a marked enhancement of LOX protein levels in the cell extract for both the mature and catalytically active form and for the pro-enzyme. This approach also increased the level of LOX secreted into the culture medium. By microarray analysis we demonstrated that LOX over expression strongly alters the endothelial expression pattern and regulates genes mainly involved in the control of cell signaling, communication and adhesion. A2 M, a pan protease inhibitor with multiple biological activities, was one of the genes most strongly inhibited in LOX overexpressing cells. Conclusion: LOX overexpression strongly affects the expression profile of endothelial cells and significantly reduces A2M expression, an effect that could have a substantial impact on endothelial cell function (AU)