Alpha-linolenic acid attenuates high glucose-induced apoptosis in cultured human umbilical vein endothelial cells via PI3K/Akt/eNOS pathway.
OBJECTIVE
High glucose-induced apoptosis in vascular endothelial cells contributes to the acceleration of atherosclerosis associated with diabetes. We hypothesized that alpha-linolenic acid (ALA) might attenuate high glucose-induced apoptosis in cultured human umbilical vein endothelial cells (HUVECs).


METHODS
HUVECs were cultured at 5.5 and 33 mmol/L for 72 h. ALA with different concentrations was added with defatted bovine serum albumin as a carrier for 18 h before incubation with high glucose.


RESULTS
Exposure of HUVECs to high glucose media for 72 h significantly increased the number of apoptotic cells compared with normal glucose control, as evaluated by flow cytometry and terminal deoxyuridine triphosphate nick end labeling assay. Pretreatment with low concentrations of ALA (10, 50, and 100 micromol/L) significantly attenuated high glucose-induced apoptosis of HUVECs, but increasing ALA to 200 micromol/L exerted the opposite effect. Furthermore, high glucose reduced phosphorylation of Akt and endothelial nitric oxide synthase (eNOS) with subsequent nitric oxide production, whereas ALA treatment attenuated the reduction caused by high glucose. Pretreatment with phosphatidylinositol 3' -kinase kinase inhibitor LY294002 and eNOS inhibitor N(G)-nitro-arginine methyl ester eliminated ALA' antiapoptotic effect.


CONCLUSIONS
ALA exerts an antiapoptotic effect by the phosphatidylinositol 3'-kinase/Akt/eNOS pathway in HUVECs exposed to high glucose and thus may represent a candidate therapeutic agent for diabetic cardiovascular complications.
Zhang
Wei
W
Department of Cardiology, Tangdu hospital, Fourth Military Medical University, Xi'an, People's Republic of China. zhangwei@fmmu.edu.cn
Wang
Rui
R
Han
Shu-fang
SF
Bu
Lun
L
Wang
Si-wang
SW
Ma
Heng
H
Jia
Guo-liang
GL
D017209:Apoptosis / Q000187:drug effects*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D005434:Flow Cytometry; D005947:Glucose / Q000009:adverse effects*; D006801:Humans; D020287:In Situ Nick-End Labeling; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D051058:Oncogene Protein v-akt / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D014471:Umbilical Veins / Q000166:cytology; D017962:alpha-Linolenic Acid / Q000494:pharmacology*
D017962:alpha-Linolenic Acid; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III; D019869:Phosphatidylinositol 3-Kinases; D051058:Oncogene Protein v-akt; D005947:Glucose