Effects of plasma from hibernating ground squirrels on monocyte-endothelial cell adhesive interactions.
Adhesion and subsequent penetration of leukocytes into central nervous system ischemic tissue proceeds via a coordinated inflammatory mechanism involving adhesion molecules at the blood-endothelium interface. Mammalian hibernation is a state of natural tolerance to severely reduced blood flow-oxygen delivery (i.e., ischemia). Hibernating thirteen-lined ground squirrels were investigated in an attempt to identify factors responsible for regulating this tolerance. Since leukocytopenia is closely associated with entrance into hibernation, the role of leukocyte adhesion to endothelium in this phenomenon was examined. Intercellular adhesion molecule-1 (ICAM-1) is expressed by endothelium and regulates interactions with circulating leukocytes that may result in margination or extravasation. ICAM-1 expression by rat cerebral microvascular endothelial cells (EC) cultured with plasma from hibernating (HP) or nonhibernating (NHP) thirteen-lined ground squirrels was dose dependently increased by HP and, to a lesser extent, by NHP. Treatment of EC with HP coincidentally induced significantly greater increases in monocyte adhesion to EC (37.2%) than were observed with NHP (23.9%). Study of the effects of HP and NHP on monocyte adhesion to EC may identify mechanisms responsible for ischemic tolerance in hibernators and could lead to the development of novel therapeutic approaches to the treatment of stroke.
Yasuma
Y
Y
Stroke Branch, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland 20892, USA.
McCarron
R M
RM
Spatz
M
M
Hallenbeck
J M
JM
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001143:Arousal; D018845:CD11 Antigens / Q000502:physiology; D018821:CD18 Antigens / Q000502:physiology; D002448:Cell Adhesion / Q000502:physiology*; D002478:Cells, Cultured; D002560:Cerebrovascular Circulation; D003470:Culture Media; D019040:E-Selectin / Q000096:biosynthesis; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D006605:Hibernation / Q000502:physiology*; D039041:Integrin alpha4beta1; D019012:Integrin beta1 / Q000502:physiology; D016023:Integrins / Q000502:physiology; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis* / Q000502:physiology; D008833:Microcirculation; D009000:Monocytes / Q000166:cytology / Q000502:physiology*; D051381:Rats; D011921:Rats, Inbred WKY; D016201:Receptors, Lymphocyte Homing / Q000502:physiology; D012589:Sciuridae / Q000097:blood*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D019010:Vascular Cell Adhesion Molecule-1 / Q000096:biosynthesis
D000911:Antibodies, Monoclonal; D018845:CD11 Antigens; D018821:CD18 Antigens; D003470:Culture Media; D019040:E-Selectin; D039041:Integrin alpha4beta1; D019012:Integrin beta1; D016023:Integrins; D016201:Receptors, Lymphocyte Homing; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1