Changes in human endothelial cell energy metabolic capacities during in vitro cultivation. The role of "aerobic glycolysis" and proliferation.
BACKGROUND
In this study the influence of cultivation and proliferation on energy metabolic characteristics of human umbilical vein endothelial cells (HUVEC) has been examined. The energy metabolic capacities of human endothelial cells freshly isolated from the umbilical vein were compared with those after cultivation for three passages and as subconfluent and confluent cultures.


METHODS
Expression of cell type-specific differentiation markers and proliferative activity were studied in dependency on cultivation characteristics. Furthermore, the energy metabolic characteristics of HUVEC were analyzed by measurement of the maximum catalytic activities of marker enzymes of various metabolic pathways.


RESULTS
Examination of a typical marker of proliferation, Ki67, confirmed that HUVEC changed in culture from a non-proliferative to a proliferative state. Compared to other cell types, the enzyme pattern of HUVEC showed a high glycolytic and a high NADPH regenerating capacity. These capacities increased by cultivation nearly to the same degree as marker enzymes of other metabolic pathways (e.g. citric acid cycle).


CONCLUSIONS
Our data support the theory that metabolism of EC is primarily by "aerobic glycolysis", i.e. the conversion of glucose to lactate in the presence of oxygen. These characteristics were independent of whether the cells are freshly isolated/non-proliferating or cell culture-adapted/proliferating.
Peters
Kirsten
K
Department of Cell Biology, University of Rostock, Germany. kirsten.peters@med.uni-rostock.de
Kamp
Gunter
G
Berz
Ansgar
A
Unger
Ronald E
RE
Barth
Susanne
S
Salamon
Achim
A
Rychly
Joachim
J
Kirkpatrick
C James
CJ
D049109:Cell Proliferation; D002478:Cells, Cultured; D002952:Citric Acid Cycle; D042783:Endothelial Cells / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D004734:Energy Metabolism / Q000502:physiology*; D005947:Glucose / Q000378:metabolism; D006019:Glycolysis / Q000502:physiology*; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism
D019394:Ki-67 Antigen; D019344:Lactic Acid; D009249:NADP; D010088:Oxidoreductases; D005947:Glucose