TY - JOUR
T1 - Pronounced in vivo hemoglobin polymerization in red blood cells of Gulf toadfish
T2 - A general role for hemoglobin aggregation in vertebrate hemoparasite defense?
AU - Koldkjær, Pia
AU - McDonald, M. Danielle
AU - Prior, Ian
AU - Berenbrink, Michael
PY - 2013/11/15
Y1 - 2013/11/15
N2 - Two human hemoglobin (Hb) variants, Hb C and Hb S, are known to protect against Plasmodium falciparum malaria and have evolved repeatedly in malaria endemic areas. Both aggregate to insoluble crystals (Hb C) or polymers (Hb S) under certain physiological conditions, impair parasite growth, and may facilitate retention of infected red blood cells (RBCs) in the spleen. Given the profound effects of parasites on host evolution in general, and that RBC Hb concentration is often close to its solubility limit throughout vertebrates, similar mechanisms may operate in nonhuman vertebrates. Here we show exercise-induced, profound in vivo Hb polymerization in RBCs of the Gulf toadfish. Hb aggregation was closely associated with the extent of plasma acidosis, fully reversible, and without any signs of hemolysis or anemia. Our literature analysis suggests that aggregation prone Hbs may be relatively old, evolved multiple times in nonhuman vertebrates, show enhanced aggregation during hemoparasite infections, and can be uncovered in vivo by splenectomy. We discuss the working hypothesis that widespread Hb aggregation within several vertebrate groups may be the result of ongoing or past selection pressure against RBC parasites. Further comparative studies of these evolutionary old systems may provide valuable insights into hemoparasite susceptibility and reservoir potential of livestock and companion animals but also into human malaria and sickle cell disease.
AB - Two human hemoglobin (Hb) variants, Hb C and Hb S, are known to protect against Plasmodium falciparum malaria and have evolved repeatedly in malaria endemic areas. Both aggregate to insoluble crystals (Hb C) or polymers (Hb S) under certain physiological conditions, impair parasite growth, and may facilitate retention of infected red blood cells (RBCs) in the spleen. Given the profound effects of parasites on host evolution in general, and that RBC Hb concentration is often close to its solubility limit throughout vertebrates, similar mechanisms may operate in nonhuman vertebrates. Here we show exercise-induced, profound in vivo Hb polymerization in RBCs of the Gulf toadfish. Hb aggregation was closely associated with the extent of plasma acidosis, fully reversible, and without any signs of hemolysis or anemia. Our literature analysis suggests that aggregation prone Hbs may be relatively old, evolved multiple times in nonhuman vertebrates, show enhanced aggregation during hemoparasite infections, and can be uncovered in vivo by splenectomy. We discuss the working hypothesis that widespread Hb aggregation within several vertebrate groups may be the result of ongoing or past selection pressure against RBC parasites. Further comparative studies of these evolutionary old systems may provide valuable insights into hemoparasite susceptibility and reservoir potential of livestock and companion animals but also into human malaria and sickle cell disease.
KW - Malaria
KW - Opsanus beta
KW - Parasite
KW - Plasma acidosis
KW - Plasmodium falciparum
KW - Sickle cell
UR - http://www.scopus.com/inward/record.url?scp=84887600300&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84887600300&partnerID=8YFLogxK
U2 - 10.1152/ajpregu.00246.2013
DO - 10.1152/ajpregu.00246.2013
M3 - Article
C2 - 24026075
AN - SCOPUS:84887600300
VL - 305
SP - R1190-R1199
JO - American Journal of Physiology - Cell Physiology
JF - American Journal of Physiology - Cell Physiology
SN - 0363-6143
IS - 10
ER -