The cellular mechanisms of body iron homeostasis
Biol. Res
; 33(2): 133-142, 2000. ilus, graf
Article
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| LILACS
| ID: lil-443669
Biblioteca responsable:
BR1.1
ABSTRACT
Cells tightly regulate iron levels through the activity of iron regulatory proteins (IRPs) that bind to RNA motifs called iron responsive elements (IREs). When cells become iron-depleted, IRPs bind to IREs present in the mRNAs of ferritin and the transferrin receptor, resulting in diminished translation of the ferritin mRNA and increased translation of the transferrin receptor mRNA. Similarly, body iron homeostasis is maintained through the control of intestinal iron absorption. Intestinal epithelia cells sense body iron through the basolateral endocytosis of plasma transferrin. Transferrin endocytosis results in enterocytes whose iron content will depend on the iron saturation of plasma transferrin. Cell iron levels, in turn, inversely correlate with intestinal iron absorption. In this study, we examined the relationship between the regulation of intestinal iron absorption and the regulation of intracellular iron levels by Caco-2 cells. We asserted that IRP activity closely correlates with apical iron uptake and transepithelial iron transport. Moreover, overexpression of IRE resulted in a very low labile or reactive iron pool and increased apical to basolateral iron flux. These results show that iron absorption is primarily regulated by the size of the labile iron pool, which in turn is regulated by the IRE/IRP system.
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LILACS
Asunto principal:
Receptores de Transferrina
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Proteínas Reguladoras del Hierro
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Ferritinas
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Absorción Intestinal
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Hierro
Límite:
Humans
Idioma:
En
Revista:
Biol. Res
Asunto de la revista:
BIOLOGIA
Año:
2000
Tipo del documento:
Article
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Project document