Inhibitory effects of fenofibrate on apoptosis and cell proliferation in human endothelial cells in high glucose.
Fenofibrate has beneficial effects on the progression and clinical emergence of atherosclerosis in normoglycemic and in diabetic patients. Given the involvement of endothelium in these processes, we speculated that fenofibrate may influence endothelial cell apoptosis and proliferation, regulators of endothelium integrity. Fenofibrate effects on apoptosis and proliferation were studied in human umbilical vein endothelial cells under normal (5.5 mmol/l, NG) and high (22 mmol/l, HG) glucose with or without fenofibrate (50 micromol/l). Apoptosis was evaluated by annexin V, by poly(ADP-ribose) polymerase protein cleavage, and cyclooxygenase-2 (COX-2), Bax/Bcl-2, and p53 protein levels; proliferation was assessed by determining cell cycle phase distribution and the amounts of the cell cycle regulators E2F1, cyclin D1, E1, and A and the levels of the hyper-phosphorylated form of the retinoblastoma protein (ppRb). HG resulted in increased (p<0.05) apoptosis rate associated with COX-2 protein overexpression, without modification of Bax/Bcl2 ratio and p53 levels. Fenofibrate decreased apoptosis and normalized increased COX-2 expression in HG (p<0.05). Both in HG and NG, fenofibrate dramatically reduced cell proliferation (p<0.05) through a G1/G0 block mediated by the reduction in ppRb and the decrease in E2F1, cyclin E1, A, and D1 protein expression, with a mechanism that, for cyclin E1, occurred at the posttranscriptional level. In conclusion, our data show that fenofibrate reduces apoptosis caused by HG but severely interferes with endothelial cell proliferation both in NG and HG. The resulting effect may influence endothelium integrity in vivo and may impact the outcome of acute complications of atherosclerosis in diabetes.
Zanetti
Michela
M
UCO Clinica Medica-DSCMT, Ospedale di Cattinara, Strada di Fiume 447, 34100, Trieste, Italy. zanetti@units.it
Stocca
Alessia
A
Dapas
Barbara
B
Farra
Rossella
R
Uxa
Laura
L
Bosutti
Alessandra
A
Barazzoni
Rocco
R
Bossi
Fleur
F
Giansante
Carlo
C
Tedesco
Francesco
F
Cattin
Luigi
L
Guarnieri
Gianfranco
G
Grassi
Gabriele
G
D017209:Apoptosis / Q000187:drug effects*; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D019925:Cyclin A / Q000378:metabolism; D056741:Cyclin D; D019927:Cyclin E / Q000378:metabolism; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D050760:Cyclin-Dependent Kinase Inhibitor p27; D016213:Cyclins / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D050687:E2F1 Transcription Factor / Q000378:metabolism; D042783:Endothelial Cells / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D011345:Fenofibrate / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D000960:Hypolipidemic Agents / Q000494:pharmacology*; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D015513:Oncogene Proteins / Q000378:metabolism; D047493:PPAR alpha / Q000819:agonists* / Q000378:metabolism; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D016160:Retinoblastoma Protein / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000378:metabolism
C494826:BAX protein, human; C475820:CCNE1 protein, human; C493956:CDKN1A protein, human; C436291:CDKN1B protein, human; D019925:Cyclin A; D056741:Cyclin D; D019927:Cyclin E; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D050687:E2F1 Transcription Factor; C493753:E2F1 protein, human; D000960:Hypolipidemic Agents; D047908:Intracellular Signaling Peptides and Proteins; D015513:Oncogene Proteins; D047493:PPAR alpha; D019253:Proto-Oncogene Proteins c-bcl-2; D016160:Retinoblastoma Protein; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; D013481:Superoxides; D050760:Cyclin-Dependent Kinase Inhibitor p27; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D005947:Glucose; D011345:Fenofibrate