Strong iron demand during hypoxia-induced erythropoiesis is associated with down-regulation of iron-related proteins and myoglobin in human skeletal muscle

[EN] Iron is essential for oxygen transport because it is incorporated in the heme of the oxygen-binding proteins hemoglobin and myoglobin. An interaction between iron homeostasis and oxygen regulation is further suggested during hypoxia, in which hemoglobin and myoglobin syntheses have been reported to increase. This study gives new insights into the changes in iron content and iron-oxygen interactions during enhanced erythropoiesis by simultaneously analyzing blood and muscle samples in humans exposed to 7 to 9 days of high altitude hypoxia (HA). HA up-regulates iron acquisition by erythroid cells, mobilizes body iron, and increases hemoglobin concentration. However, contrary to our hypothesis that muscle iron proteins and myoglobin would also be up-regulated during HA, this study shows that HA lowers myoglobin expression by 35% and down-regulates iron-related proteins in skeletal muscle, as evidenced by decreases in L-ferritin (43%), transferrin receptor (TfR; 50%), and total iron content (37%). This parallel decrease in L-ferritin and TfR in HA occurs independently of increased hypoxia-inducible factor 1 (HIF-1) mRNA levels and unchanged binding activity of iron regulatory proteins, but concurrently with increased ferroportin mRNA levels, suggesting enhanced iron export. Thus, in HA, the elevated iron requirement associated with enhanced erythropoiesis presumably elicits iron mobilization and myoglobin down-modulation, suggesting an altered muscle oxygen homeostasis.

Sostenibilidad y gestión ambiental de la acuicultura marina: ciclo de conferencias

[ES]Contiene: Ceremonia de inauguración/ José Miguel Álamo Mendoza, Fernando Tuya Cortés, Juan Manuel Afonso López -- Presentación del proyecto MACAROMOD/ Óscar Pérez --- Mesa redonda: Acuicultura sostenible/ Fernando Tuya; Ioannis Karakassis; Ricardo Haroun; Pablo Ávila; Gerence Courois --- Mesa redonda: Efectos sobre hábitats y comunidades/ Óscar Monterroso Hoyos; Daniel Montero; Pablo Sánchez Jerez; Paolo Tomassetti; Rodrigo Riera --- Mesa redonda: Control medioambiental de la acuicultura en jaulas/Pablo Sánchez Jerez; Óscar Monterroso; Paolo Tomassetti; Ioannis Karakassis; Cayetano Collado --- Mesa redonda: Ordenación espacila de la acuicultura/ Alejandro Báez; Monstserrat Gimeno; Pablo Sánchez Jerez; José Carlos Macías; Enrique Haro --- Mesa redonda final/ Fernando Tuya

Curso de dragados y rellenos en zonas marítimas

Organizado por la Universidad de Las Palmas de Gran Canaria, RALEY (Estudios costeros) ; colaboran, Ministerio de Fomento, Puertos del Estado, Fundación Puertos de Las Palmas, en la Sala de Grado de la Facultad de Ciencias del Mar de la Universidad de Las Palmas de Gran Canaria, los días 24 al 30 de mayo de 2013