Nutr Res Pract.  2008 Jun;2(2):74-79.

Zinc deficiency decreased cell viability both in endothelial EA.hy926 cells and mouse aortic culture ex vivo and its implication for anti-atherosclerosis

• Cho YE
• Choi JE
• Alam MJ
• Lee MH
• Sohn HY
• Beattie JH
• Kwun IS

Abstract

Zinc plays a protective role in anti-atherosclerosis but the clear mechanism has not been proposed yet. In the present study, we evaluated whether zinc modulates atherosclerotic markers, VACM-1 and ICAM-1 and cell viability both in endothelial cells in vitro and mouse aortic cell viability ex vivo. In study 1, as in vitro model, endothelial EA.hy926 cells were treated with TNFalpha for 5 hours for inducing oxidative stress, and then treated with Zn-adequacy (15 micrometer Zn) or Zn-deficiency (0 micrometer Zn) for 6 hours. Pro-atherosclerosis factors, VCAM-1 and ICAM-1 mRNA expression and cell viability was measured. In study 2, as ex vivo model, mouse aorta ring was used. Mourse aorta was removed and cut in ring then, cultured in a 96-well plate. Aortic ring was treated with various TNFalpha (0-30 mg/ml) and intracellular zinc chelator, N, N, N', N', -tetrakis (2-pyridylmethyl) ethylenediamine (TPEN, 0-30 microM) for cellular zinc depletion for 2 days and then cell viability was measured. The results showed that in in vitro study, Zn-adequate group induced more VCAM-1 & ICAM-1 mRNA expression than Zn-deficient group during 6-hour zinc treatment post-5 hour TNF-alpha treatment, unexpectedly. These results might be cautiously interpreted that zinc would biologically induce the early expression of anti-oxidative stress through the increased adhesion molecule expression for reducing atherosclerotic action, particularly under the present 6-hour zinc treatment. In ex vivo, mouse aortic ring cell viability was decreased as TNF-alpha and TPEN levels increased, which suggests that mouse aortic blood vessel cell viability was decreased, when oxidative stress increases and cellular zinc level decreases. Taken together, it can be suggested that zinc may have a protective role in anti-atherosclerosis by cell viability in endothelial cells and aorta tissue. Further study is needed to clarify how pro-atherosclerosis molecule expression is modulated by zinc.

Keyword

Zn-deficiency; endothelial cells; EA.hy926 cell; mouse aorta; atherosclerosis

MeSH Terms

Animals
Aorta
Atherosclerosis
Blood Vessels
Cell Survival
Endothelial Cells
Ethylenediamines
Glycosaminoglycans
Intercellular Adhesion Molecule-1
Mice
Oxidative Stress
RNA, Messenger
Tumor Necrosis Factor-alpha
Vascular Cell Adhesion Molecule-1
Zinc
Ethylenediamines
Glycosaminoglycans
Intercellular Adhesion Molecule-1
RNA, Messenger
Tumor Necrosis Factor-alpha
Vascular Cell Adhesion Molecule-1
Zinc

Figure

• 

  Fig. 1 The endothelial EA.hy926 cell morphology by Zn treatment at 6 hours. The cells were exposed to TNFα (10 ng/ml) for 5 hours and after then, the cells were treated with TPEN (5 or 10 µM) and either Zn-deficient (0 µM Zn as ZnCl2, Zn-) or Zn adequate (15 µM Zn as ZnCl2, Zn+) medium for 6 hours. ZnCl2 was used for making 10 mM Zn stock solution. A: Zn chelator 10 µM TPEN with Zn- (0 µM) or Zn+ (15 µM). B: Zn chelator 5 µM TPEN with Zn- (0 µM) or Zn+ (15 µM).

• 

  Fig. 2 (A) Confirmation of von Willebrand factor gene expression in EA.hy926 cells. Zero day means when the cells were at confluence. (B) Representative gene expression image of VCAM-1 and ICAM-1 of 6 hour zinc treatment in EA.hy 926 cells. The cells were exposed to TNFα (10 ng/ml) for 5 hours and after then, the cells were treated with TPEN (5 or 10 µM) and either Zn- (0 µM) or Zn+ (15 µM) for 6 hours. The experiment was done in triplicate.

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