Activation of human aortic endothelial cells by LDL from Type 1 diabetic patients: an in vitro study.
An altered interaction between circulating LDL and endothelial cells might be at the basis of the increased prevalence of atherosclerosis in diabetes mellitus. The aim of the present work was to investigate the effect of a short incubation period with LDL from Type 1 diabetic patients in good metabolic control on endothelial cells derived from human aorta (HAEC). Cultured HAEC were incubated for 3 h with culture medium alone (control HAEC), with native LDL from healthy subjects (control LDL), or with native LDL from Type 1 diabetic patients (Type 1 LDL). After the incubation the following parameters were evaluated: endothelial cell nitric oxide synthase (NOS) activity, nitric oxide (NO) and peroxynitrite production, Na(+)/K(+)-ATPase and Ca(2+)-ATPase activities, intracellular Ca(2+) concentration and fluidity of the superficial part of the plasma membrane studied by 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH). Moreover, we studied the cellular activation, evaluated by the fluid phase endocytosis of TMA-DPH, and the microetherogeneity of the membrane surface, evaluated by dynamic fluorescence. HAEC incubated with control LDL showed compared with control HAEC: increased anisotropy and exponential lifetime of TMA-DPH, and enhanced TMA-DPH internalization. HAEC incubated with Type 1 LDL showed compared with both control HAEC and HAEC incubated with control LDL: (i) increased Na(+)/K(+)-ATPase and Ca(2+)-ATPase activities, and intracellular Ca(2+) concentration; (ii) increased NOS activity, NO and peroxynitrite production; (iii) increased anisotropy of TMA-DPH; (iv) enhanced internalization of the probe. The exponential lifetime and the width of distribution of TMA-DPH were significantly increased by Type 1 LDL only in comparison with control HAEC. The results suggest that a short-term interaction with LDL from Type 1 diabetic patients causes alterations of the plasma membrane surface and of cellular functions in endothelial cells in a possibly atherogenic way.
Department of Diabetology, Italian National Research Center on Aging, Ancona, Italy.
Rosa A
RA
Rabini
Arianna
A
Vignini
Eleonora
E
Salvolini
Roberto
R
Staffolani
Daniela
D
Martarelli
Natalia
N
Moretti
Laura
L
Mazzanti
D001013:Aorta, Thoracic / Q000166:cytology; D000252:Calcium-Transporting ATPases / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology; D003925:Diabetic Angiopathies / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects*; D005454:Fluorescence Polarization; D006801:Humans; D066298:In Vitro Techniques; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000187:drug effects / Q000378:metabolism*; D011336:Probability; D012016:Reference Values; D012680:Sensitivity and Specificity; D000254:Sodium-Potassium-Exchanging ATPase / Q000187:drug effects / Q000378:metabolism
D008077:Lipoproteins, LDL; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D000252:Calcium-Transporting ATPases; D000254:Sodium-Potassium-Exchanging ATPase