A high-resolution, double-labeling method for the study of in vivo red blood cell aging.
BACKGROUND
Red blood cell (RBC) senescence is a process that has received considerable study, yet remains poorly understood. This has been primarily due to the difficulty in isolating a RBC cohort of narrowly distributed, well-defined age. Biotin labeling has previously been used to produce an identifiable cell cohort of known mean age; however, the variability of RBC age within the cohort is relatively large for most of its existence. Treatments typically employed on animal subjects to reduce this variability can perturb erythropoiesis and result in abnormal RBC aging.


METHODS
The objective of this study was to improve on the traditional in vivo biotinylation method by introducing a chemically distinct, second labeling step. In this case, digoxigenin was used to label cells 1 to 2 days before the injection of biotin.


RESULTS
It was shown, in the rat, that two identifiable subpopulations of labeled RBCs can be followed over time: a broad, double-labeled cohort and a narrow, single-labeled cohort, the latter consisting of only those cells created between the first and second labeling steps. The utility of this technique was demonstrated by observing the age-dependent exposure of phosphatidylserine in the single-labeled RBCs.


CONCLUSIONS
Its capacity to generate a cohort of narrowly distributed age, without the adverse effects associated with animal treatment, should make this a useful method for the study of RBC senescence.
Visual & Circulatory Biophysics Laboratory, Department of Biomedical Engineering, Boston University, MA 02215, USA.
Sean C
SC
Gifford
Tatsuro
T
Yoshida
Sergey S
SS
Shevkoplyas
Mark W
MW
Bitensky
D000818:Animals; D019921:Biotinylation; D004076:Digoxigenin / Q000097:blood; D004905:Erythrocyte Aging; D004912:Erythrocytes / Q000502:physiology*; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D051381:Rats; D011916:Rats, Inbred F344; D012680:Sensitivity and Specificity
D004076:Digoxigenin