Role of iron in inducing oxidative stress in thalassemia: Can it be prevented by inhibition of absorption and by antioxidants?
The pathophysiology of thalassemia is, to a certain extent, associated with the generation of labile iron in the pathological red blood cell (RBC). The appearance of such forms of iron at the inner and outer cell surfaces exposes the cell to conditions whereby the labile metal promotes the formation of reactive oxygen species (ROS) leading to cumulative cell damage. Another source of iron accumulation results from increased absorption due to decreased expression of hepcidin. The presence of labile plasma iron (LPI) was carried out using fluorescent probes in the FACS. RNA expression of hepcidin was measured in two models of thalassemic mice. Hepcidin expression was also measured in human hepatoma HepG2 cells following incubation with thalassemic sera. LPI was identified and could be quantitatively measured and correlated with other parameters of iron overload. Hepcidin expression was downregulated in the livers of thalassemic mice, in major more than in intermedia. Thalassemic sera down regulated hepcidin expression in HepG2 liver cells. A possible way to decrease iron absorption could be by modulating hepcidin expression pharmacologically, by gene therapy or by its administration. Treatment with combination of antioxidants such as N-acetylcysteine for proteins and vitamin E for lipids in addition to iron chelators could neutralize the deleterious effects of ROS and monitored by quantitation of LPI.
Rachmilewitz
Eliezer A
EA
Department of Hematology, The Edith Wolfson Medical Center, P.O. Box 5, 58100 Holon, Israel. rachmilewitz@wolfson.health.gov.il
Weizer-Stern
Orly
O
Adamsky
Konstantin
K
Amariglio
Ninette
N
Rechavi
Gideon
G
Breda
Laura
L
Rivella
Stefano
S
Cabantchik
Z Ioav
ZI
D000111:Acetylcysteine / Q000008:administration & dosage / Q000627:therapeutic use; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000096:biosynthesis / Q000235:genetics; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D001853:Bone Marrow / Q000378:metabolism; D006528:Carcinoma, Hepatocellular / Q000473:pathology; D045744:Cell Line, Tumor; D004195:Disease Models, Animal; D004359:Drug Therapy, Combination; D004912:Erythrocytes / Q000737:chemistry; D005786:Gene Expression Regulation; D015316:Genetic Therapy; D064451:Hepcidins; D006801:Humans; D007408:Intestinal Absorption / Q000502:physiology; D007501:Iron / Q000009:adverse effects / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics / Q000502:physiology*; D007502:Iron Chelating Agents / Q000008:administration & dosage / Q000627:therapeutic use; D019266:Iron, Dietary / Q000493:pharmacokinetics; D008113:Liver Neoplasms / Q000473:pathology; D051379:Mice; D016877:Oxidants / Q000737:chemistry / Q000493:pharmacokinetics; D018384:Oxidative Stress; D013789:Thalassemia / Q000188:drug therapy / Q000378:metabolism* / Q000503:physiopathology; D014810:Vitamin E / Q000008:administration & dosage / Q000627:therapeutic use
D023181:Antimicrobial Cationic Peptides; D000975:Antioxidants; C578702:HAMP protein, human; C579599:Hamp protein, mouse; D064451:Hepcidins; D007502:Iron Chelating Agents; D019266:Iron, Dietary; D016877:Oxidants; D014810:Vitamin E; D007501:Iron; D000111:Acetylcysteine