Iron uptake and transport at the blood-brain barrier

Publikation: Konferencebidrag uden forlag/tidsskriftKonferenceabstrakt til konferenceForskningpeer review

Resumé

The mechanism by which iron is transported across the blood-brain barrier (BBB) remains controversial, and in this study we aimed to further clarify mechanisms by which iron is transported into the brain. We analyzed and compared the mRNA and protein expression of a variety of proteins involved in the transport of iron (transferrin receptor, divalent metal transporter I (DMT1), steap 2, steap 3, ceruloplasmin, hephaestin and ferroportin) in both primary rat brain capillary endothelial cells (BCEC) and immortalized rat brain capillary endothelial cell line (RBE4) grown in co-culture with defined polarity. The mRNA expression of the iron-related molecules was also investigated in isolated brain capillaries from iron deficiency, iron reversible and normal rats. We also performed iron transport studies to analyze the routes by which iron is transported through the brain capillary endothelial cells: i) We studied the transport of holo-transferrin that could indicate transcytotic transport of iron through the BBB, and ii) we studied the influence of iron export from brain endothelial cells in the presence of hepcidin known to inhibit the functioning of ferroportin, the rationale being that an influence of hepcidin on iron efflux would indicate that ferroportin plays a role for iron efflux of ferrous non-transferrin bound iron at the BBB. Collectively, our data indicate that both routes are significant for transport of iron through the BBB initiated by receptor-mediated uptake of holo-transferrin at the luminal side of brain capillaries and cellular entry in endosomes followed by: i) Transcytosis of holo-transferrin containing iron, and ii) Stepwise transport of iron through the endothelial cells from the endosomes via ferric reduction by Steap 2 and 3, transport of ferrous iron through the endosomal membrane to the cytosol mediated by DMT1, transport of ferrous iron through the abluminal endothelial cell membrane by ferroportin, and oxidation by the ferrooxidases ceruloplasmin and hephaestin. The two mechanisms for transport of iron at the BBB both explain how iron can enter the brain extracellular space on its non-toxic ferric form to become accessible for iron uptake by neurons and glia.
OriginalsprogDansk
Publikationsdato2014
StatusUdgivet - 2014
BegivenhedBarriers of the CNS -: Expanding the Understanding of CNS Barriers in Health and Disease - New London, NH, USA
Varighed: 15 jun. 201420 jun. 2014

Konference

KonferenceBarriers of the CNS -
LandUSA
ByNew London, NH
Periode15/06/201420/06/2014

Citer dette

Larsen, A. B., Thomsen, L. B., & Moos, T. (2014). Iron uptake and transport at the blood-brain barrier. Abstract fra Barriers of the CNS -, New London, NH, USA.
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abstract = "The mechanism by which iron is transported across the blood-brain barrier (BBB) remains controversial, and in this study we aimed to further clarify mechanisms by which iron is transported into the brain. We analyzed and compared the mRNA and protein expression of a variety of proteins involved in the transport of iron (transferrin receptor, divalent metal transporter I (DMT1), steap 2, steap 3, ceruloplasmin, hephaestin and ferroportin) in both primary rat brain capillary endothelial cells (BCEC) and immortalized rat brain capillary endothelial cell line (RBE4) grown in co-culture with defined polarity. The mRNA expression of the iron-related molecules was also investigated in isolated brain capillaries from iron deficiency, iron reversible and normal rats. We also performed iron transport studies to analyze the routes by which iron is transported through the brain capillary endothelial cells: i) We studied the transport of holo-transferrin that could indicate transcytotic transport of iron through the BBB, and ii) we studied the influence of iron export from brain endothelial cells in the presence of hepcidin known to inhibit the functioning of ferroportin, the rationale being that an influence of hepcidin on iron efflux would indicate that ferroportin plays a role for iron efflux of ferrous non-transferrin bound iron at the BBB. Collectively, our data indicate that both routes are significant for transport of iron through the BBB initiated by receptor-mediated uptake of holo-transferrin at the luminal side of brain capillaries and cellular entry in endosomes followed by: i) Transcytosis of holo-transferrin containing iron, and ii) Stepwise transport of iron through the endothelial cells from the endosomes via ferric reduction by Steap 2 and 3, transport of ferrous iron through the endosomal membrane to the cytosol mediated by DMT1, transport of ferrous iron through the abluminal endothelial cell membrane by ferroportin, and oxidation by the ferrooxidases ceruloplasmin and hephaestin. The two mechanisms for transport of iron at the BBB both explain how iron can enter the brain extracellular space on its non-toxic ferric form to become accessible for iron uptake by neurons and glia.",
author = "Larsen, {Annette Burkhart} and Thomsen, {Louiza Bohn} and Torben Moos",
year = "2014",
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Larsen, AB, Thomsen, LB & Moos, T 2014, 'Iron uptake and transport at the blood-brain barrier' Barriers of the CNS -, New London, NH, USA, 15/06/2014 - 20/06/2014, .

Iron uptake and transport at the blood-brain barrier. / Larsen, Annette Burkhart; Thomsen, Louiza Bohn; Moos, Torben.

2014. Abstract fra Barriers of the CNS -, New London, NH, USA.

Publikation: Konferencebidrag uden forlag/tidsskriftKonferenceabstrakt til konferenceForskningpeer review

TY - ABST

T1 - Iron uptake and transport at the blood-brain barrier

AU - Larsen, Annette Burkhart

AU - Thomsen, Louiza Bohn

AU - Moos, Torben

PY - 2014

Y1 - 2014

N2 - The mechanism by which iron is transported across the blood-brain barrier (BBB) remains controversial, and in this study we aimed to further clarify mechanisms by which iron is transported into the brain. We analyzed and compared the mRNA and protein expression of a variety of proteins involved in the transport of iron (transferrin receptor, divalent metal transporter I (DMT1), steap 2, steap 3, ceruloplasmin, hephaestin and ferroportin) in both primary rat brain capillary endothelial cells (BCEC) and immortalized rat brain capillary endothelial cell line (RBE4) grown in co-culture with defined polarity. The mRNA expression of the iron-related molecules was also investigated in isolated brain capillaries from iron deficiency, iron reversible and normal rats. We also performed iron transport studies to analyze the routes by which iron is transported through the brain capillary endothelial cells: i) We studied the transport of holo-transferrin that could indicate transcytotic transport of iron through the BBB, and ii) we studied the influence of iron export from brain endothelial cells in the presence of hepcidin known to inhibit the functioning of ferroportin, the rationale being that an influence of hepcidin on iron efflux would indicate that ferroportin plays a role for iron efflux of ferrous non-transferrin bound iron at the BBB. Collectively, our data indicate that both routes are significant for transport of iron through the BBB initiated by receptor-mediated uptake of holo-transferrin at the luminal side of brain capillaries and cellular entry in endosomes followed by: i) Transcytosis of holo-transferrin containing iron, and ii) Stepwise transport of iron through the endothelial cells from the endosomes via ferric reduction by Steap 2 and 3, transport of ferrous iron through the endosomal membrane to the cytosol mediated by DMT1, transport of ferrous iron through the abluminal endothelial cell membrane by ferroportin, and oxidation by the ferrooxidases ceruloplasmin and hephaestin. The two mechanisms for transport of iron at the BBB both explain how iron can enter the brain extracellular space on its non-toxic ferric form to become accessible for iron uptake by neurons and glia.

AB - The mechanism by which iron is transported across the blood-brain barrier (BBB) remains controversial, and in this study we aimed to further clarify mechanisms by which iron is transported into the brain. We analyzed and compared the mRNA and protein expression of a variety of proteins involved in the transport of iron (transferrin receptor, divalent metal transporter I (DMT1), steap 2, steap 3, ceruloplasmin, hephaestin and ferroportin) in both primary rat brain capillary endothelial cells (BCEC) and immortalized rat brain capillary endothelial cell line (RBE4) grown in co-culture with defined polarity. The mRNA expression of the iron-related molecules was also investigated in isolated brain capillaries from iron deficiency, iron reversible and normal rats. We also performed iron transport studies to analyze the routes by which iron is transported through the brain capillary endothelial cells: i) We studied the transport of holo-transferrin that could indicate transcytotic transport of iron through the BBB, and ii) we studied the influence of iron export from brain endothelial cells in the presence of hepcidin known to inhibit the functioning of ferroportin, the rationale being that an influence of hepcidin on iron efflux would indicate that ferroportin plays a role for iron efflux of ferrous non-transferrin bound iron at the BBB. Collectively, our data indicate that both routes are significant for transport of iron through the BBB initiated by receptor-mediated uptake of holo-transferrin at the luminal side of brain capillaries and cellular entry in endosomes followed by: i) Transcytosis of holo-transferrin containing iron, and ii) Stepwise transport of iron through the endothelial cells from the endosomes via ferric reduction by Steap 2 and 3, transport of ferrous iron through the endosomal membrane to the cytosol mediated by DMT1, transport of ferrous iron through the abluminal endothelial cell membrane by ferroportin, and oxidation by the ferrooxidases ceruloplasmin and hephaestin. The two mechanisms for transport of iron at the BBB both explain how iron can enter the brain extracellular space on its non-toxic ferric form to become accessible for iron uptake by neurons and glia.

UR - https://www.grc.org/programs.aspx?id=12832

M3 - Konferenceabstrakt til konference

ER -

Larsen AB, Thomsen LB, Moos T. Iron uptake and transport at the blood-brain barrier. 2014. Abstract fra Barriers of the CNS -, New London, NH, USA.