Iron-independent neuronal expression of transferrin receptor mRNA in the rat.
Neuronal transferrin receptor protein expression is highly upregulated widely in CNS following iron deficiency. Using the medial habenular nucleus as a model of neuronal transferrin receptor mRNA expression, the present study examined 17-day-old rats subjected to variations in dietary iron. Changing the iron availability resulted in alterations in plasma and cerebrospinal fluid (CSF) levels of transferrin and iron. The iron-binding capacity of transferrin in CSF was exceeded in normal and iron-overloaded rats. In spite of a lowering of the concentration of brain iron by approximately 22% in iron-deficient rats, neuronal transferrin receptor mRNA was not affected when measured by quantitative densitometry. Brain iron and neuronal transferrin receptor mRNA expression was unaltered in iron overloaded rats. The absence of a rise in transferrin receptor mRNA during iron deficiency suggests that neuronal transferrin receptor mRNA expression is regulated by another mechanism than the post-transcriptional regulation mechanism, which has been attributed to cells of non-neural tissue.
Moos
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Department of Medical Anatomy, Section C, The Panum Institute, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark. t.moos@mai.ku.dk
Oates
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Morgan
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D000818:Animals; D005315:Fetal Diseases / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D019262:Habenula / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006418:Heme / Q000378:metabolism; D007501:Iron / Q000097:blood / Q000134:cerebrospinal fluid / Q000494:pharmacology*; D000090463:Iron Deficiencies; D019190:Iron Overload / Q000235:genetics / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics*; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D009569:Nitric Oxide / Q000502:physiology; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D051381:Rats; D011990:Receptors, Transferrin / Q000096:biosynthesis / Q000235:genetics*; D014168:Transferrin / Q000032:analysis / Q000134:cerebrospinal fluid
D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D011990:Receptors, Transferrin; D014168:Transferrin; D009569:Nitric Oxide; D006418:Heme; D007501:Iron