BACKGROUND/AIMS: Deficiency of the divalent metal transporter 1 (DMT1) leads to 
hypochromic microcytic anemia. We have previously shown that DMT1 deficiency 
impairs erythroid differentiation and induces apoptosis of erythroid cells. Here 
we analyzed metabolic processes and survival of mature erythrocytes in order to 
address potential involvement of erythrocyte defect in the pathophysiology of 
the disease.
METHODS: FACS analysis was used to determine the half-life of erythrocytes (CFSE 
fluorescence), phosphatidylserine exposure (Annexin V binding), cytosolic Ca(2+) 
(Fluo3/AM fluorescence) and reactive oxygen species (ROS; DCF fluorescence). 
Enzyme activities were determined by standard biochemical methods. The 
concentration of ATP and ADP was measured on HPLC-MS/MS.
RESULTS: We observed an accelerated clearance of CFSE-labeled DMT1-mutant 
erythrocytes from circulating blood when compared to wild-type erythrocytes. In 
vitro, DMT1-mutant erythrocytes showed significantly increased Annexin V binding 
after exposure to hyperosmotic shock and glucose depletion. Despite exaggerated 
anti-oxidative defense, higher ROS levels were present in DMT1-mutant 
erythrocytes. Accelerated anaerobic glycolysis and reduced ATP/ADP ratio 
detected in DMT1-mutant erythrocytes indicate enhanced demand for ATP.
CONCLUSIONS: We propose that DMT1 deficiency negatively affects metabolism and 
life span of mature erythrocytes; two other aspects of defective erythropoiesis 
which contribute to the pathophysiology of the disease.