High-glucose--triggered apoptosis in cultured endothelial cells.
High ambient glucose concentration, linked to vascular complications in diabetes in vivo, modulates mRNA expression of fibronectin, collagen, tissue-type plasminogen activator, and plasminogen activator inhibitor and induces delayed replication and excess cell death in cultured vascular endothelial cells. To determine the role of high ambient glucose (30 mmol/l) in apoptosis, paired cultures of individual isolates of human umbilical vein endothelial cells (HUVECs) were exposed to both high (30 mmol/l) and low (5 mmol/l) concentrations of glucose for short-term (24, 48, and 72 h) and long-term (13 +/- 1 days) experiments. Incubation of HUVECs with high glucose for > 48 h increased DNA fragmentation (13.7 +/- 6.5% of total DNA, mean +/- SD) versus cultures kept in 5 mmol/l glucose (10.9 +/- 5.6%, P < 0.005), as measured by [3H]thymidine assays. Data were confirmed by apoptosis-specific fluorescence-activated cell sorter analysis of confluent HUVEC cultures, which displayed after long-term exposure to 30 mmol/l glucose a 1.5-fold higher prevalence of apoptosis than control cultures exposed to 5 mmol/l glucose (P < 0.005). In contrast, no increase in DNA fragmentation in response to 30 mmol/l glucose was seen for standardized cell lines (K 562, P 815, YT) and fibroblasts. Expression of clusterin mRNA, originally reported to be a molecular marker of apoptosis, was only slightly affected by short-term (24-h) high-glucose exposure but was significantly reduced after long-term incubation in 30 mmol/l glucose (82.2 +/- 13.8% of control) versus 5 mmol/l glucose, which questions the role of clusterin gene expression as a marker of apoptosis.(ABSTRACT TRUNCATED AT 250 WORDS)
Baumgartner-Parzer
S M
SM
Department of Internal Medicine III, University of Vienna, Austria.
Wagner
L
L
Pettermann
M
M
Grillari
J
J
Gessl
A
A
Waldhäusl
W
W
D017209:Apoptosis / Q000187:drug effects*; D015152:Blotting, Northern; D002478:Cells, Cultured; D051152:Clusterin; D004247:DNA / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004587:Electrophoresis, Agar Gel; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D005434:Flow Cytometry; D015870:Gene Expression / Q000187:drug effects; D005947:Glucose / Q000494:pharmacology*; D006023:Glycoproteins / Q000096:biosynthesis; D006801:Humans; D007700:Kinetics; D018832:Molecular Chaperones; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D013936:Thymidine / Q000378:metabolism; D014471:Umbilical Veins
C495242:CLU protein, human; D051152:Clusterin; D006023:Glycoproteins; D018832:Molecular Chaperones; D012333:RNA, Messenger; D004247:DNA; D005947:Glucose; D013936:Thymidine