Korean J Med.  1999 May;56(5):598-605.

Effects of pertussis and cholera toxin on oxidized low density lipoprotein induced apoptosis in cultured bovine aortic endothelial cells

• Chang SA
• Choi YH
• Moon SD
• Ahn YB
• Son HS
• Yoon KH
• Kang MI
• Cha BY
• Lee KW
• Son HY
• Kang SK

Abstract

OBJECTIVES
Oxidized LDL is thought to play a key role in atherogenesis. Among their wide variety of biological properties, oxidized LDL injures the endothelium as an early event of atherogenesis. However, the mechanisms by which oxidized LDL injures endothelial cells are not definitely known. In order to evaluate the involvement of GTP-binding protein on the mechanism of apoptosis, we studied the effects of pertussis and cholera toxin on oxidized LDL-induced apoptosis in bovine aortic endothelial cells(BAECs).
METHODS
Oxidized LDL elicited apoptosis in cultured BAECs as shown by characteristic morphological and biochemical changes. Chromatin condensation and nucleus fragmentation were visualized by using fluorescence microscopy of intact cells staining by acridine orange/ ethidium bromide. DNA fragmentation was quantified by an ELISA with specific antibody for bromodeoxyuridine- labelled DNA fragments and confirmed with DNA ladder formation.
RESULTS
Studies using a combination of bacterial toxins which change the function of GTP-binding protein suggest that oxidized LDL-induced apoptosis was regulated by GTP-binding protein. Oxidized LDL-induced apoptosis was not changed by pretreatment of BAECs with pertussis toxin. In contrast, pretreatment with cholera toxin completely prevented the oxidized LDL- induced apoptosis.
CONCLUSION
These results show that oxidized LDL induces apoptosis of BAECs and suggest that cholera toxin-sensitive G-proteins are involved in signal transduction of oxidized LDL-induced apoptosis of BAEC.

Keyword

Endothelial cells; Apoptosis; GTP-binding protein; Pertussis toxin; Cholera toxin

MeSH Terms

Apoptosis*
Atherosclerosis
Bacterial Toxins
Cholera Toxin*
Cholera*
Chromatin
DNA
DNA Fragmentation
Endothelial Cells*
Endothelium
Enzyme-Linked Immunosorbent Assay
Ethidium
GTP-Binding Proteins
Lipoproteins*
Microscopy, Fluorescence
Pertussis Toxin
Signal Transduction
Whooping Cough*
Bacterial Toxins
Cholera Toxin
Chromatin
DNA
Ethidium
GTP-Binding Proteins
Lipoproteins
Pertussis Toxin