TY - JOUR
T1 - Gallium-inducible transferrin-independent iron acquisition is a property of many cell types
T2 - Possible role of alterations in the plasma membrane
AU - Olakanmi, Oyebode
AU - Stokes, John B.
AU - Britigan, Bradley E.
PY - 2005/4
Y1 - 2005/4
N2 - Background: We have previously shown that human myeloid cell types can acquire large amounts of iron (Fe)3+ from low-molecular-weight chelates by a process that is independent of adenosine triphosphate and dramatically increased by gallium (Ga) and other multivalent cationic metals. Methods: To provide further insight into the mechanism responsible and its relevance to other cellular systems, we investigated Fe acquisition from nitrilotriacetic acid (NTA) by several myeloid and nonmyeloid cell lines in the presence and absence of Ga. Results: Most nonmyeloid cells examined exhibited similar ability to acquire Fe from NTA. Ga increased the apparent maximum velocity (Vmax), with minimal changes in apparent Michaelis constant (Km), of all cell lines. Both erythrocytes and erythrocyte ghosts acquired Fe from NTA, which increased with Ga exposure, analogous to nucleated cells. However, liposomes made from phospholipids did not exhibit Ga-inducible Fe association. Enzymes that modify surface proteins and carbohydrates did not alter HL-60 cell Fe acquisition. Modifying HL-60 membrane fatty acid content had only a minimal effect. Ga exposure did not change membrane potential or fluidity. However, electron microscopy suggested that Ga alters plasma membrane physical properties. Conclusion: Multivalent cations appear to induce changes in cell membranes that may alter their interaction with Fe3+ and probably other multivalent cations.
AB - Background: We have previously shown that human myeloid cell types can acquire large amounts of iron (Fe)3+ from low-molecular-weight chelates by a process that is independent of adenosine triphosphate and dramatically increased by gallium (Ga) and other multivalent cationic metals. Methods: To provide further insight into the mechanism responsible and its relevance to other cellular systems, we investigated Fe acquisition from nitrilotriacetic acid (NTA) by several myeloid and nonmyeloid cell lines in the presence and absence of Ga. Results: Most nonmyeloid cells examined exhibited similar ability to acquire Fe from NTA. Ga increased the apparent maximum velocity (Vmax), with minimal changes in apparent Michaelis constant (Km), of all cell lines. Both erythrocytes and erythrocyte ghosts acquired Fe from NTA, which increased with Ga exposure, analogous to nucleated cells. However, liposomes made from phospholipids did not exhibit Ga-inducible Fe association. Enzymes that modify surface proteins and carbohydrates did not alter HL-60 cell Fe acquisition. Modifying HL-60 membrane fatty acid content had only a minimal effect. Ga exposure did not change membrane potential or fluidity. However, electron microscopy suggested that Ga alters plasma membrane physical properties. Conclusion: Multivalent cations appear to induce changes in cell membranes that may alter their interaction with Fe3+ and probably other multivalent cations.
KW - Gallium
KW - Iron
KW - Transport
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U2 - 10.2310/6650.2005.00310
DO - 10.2310/6650.2005.00310
M3 - Article
C2 - 15921034
AN - SCOPUS:18944394018
SN - 1708-8267
VL - 53
SP - 143
EP - 153
JO - Journal of Investigative Medicine
JF - Journal of Investigative Medicine
IS - 3
ER -