Effect of docosahexaenoic acid plus insulin on atherosclerotic human endothelial cells

Aysan Eslami Abriz,Alireza Nourazarian,Morteza Heidarzadeh,Reza Rahbarghazi,Maryam Rahnema,Atefeh Araghi,Çıgır Biray Avci,Soltan Ali Mahboob

doi:10.1186/s12950-021-00277-5

Abstract

BackgroundAtherosclerosis is touted as one of the most critical consequences of diabetes mellitus indicated by local inflammation of endothelial cells. The Effect of Omega 3 fatty acids, mainly docosahexaenoic acid (DHA), has been investigated in cells after exposure to high doses of lipids. The current experiment aimed to address the modulatory effects of docosahexaenoic acid and insulin in palmitic-treated human endothelial cells.MethodsHuman umbilical vein endothelial cells were treated with 1 mM palmitic acid, 50 μM insulin, 50 μM docosahexaenoic acid, and their combination for 48 h. Cell survival rate and apoptosis were measured using MTT and flow cytometry assays. The Griess assay detected NO levels. Protein levels of TNF-α, IL-6, and NF-κB were studied using ELISA and immunofluorescence imaging. The expression of genes participating in atherosclerosis was monitored using PCR array analysis.ResultsOil Red O staining showed the inhibitory effect of DHA and insulin to reduce the intracellular accumulation of palmitic acid. Both DHA and Insulin blunted palmitic acid detrimental effects on HUVECs indicated by an increased survival rate (p < 0.05). The percent of apoptotic cells was decreased in palmitic-treated cells received insulin and DHA compared to palmitic-treated group (p < 0.05). Based on our data, DHA and Insulin diminished the production of all inflammatory cytokines, TNF-α, IL-6, and NF-κB, in palmitic-treated cells (p < 0.05). Similar to these data, NO production was also decreased in all groups treated with insulin and DHA compared to the palmitic-treated cells (p < 0.05). PCR array analysis revealed the modulatory effect of DHA and insulin on the expression of atherosclerosis-related genes pre-treated with palmitic acid compared to the control group (p < 0.05).ConclusionDHA and Insulin could alter the dynamic growth and dysfunctional activity of human endothelial cells after treatment with palmitic acid. Taken together, Omega 3 fatty acids, along with insulin, could dictate specific cell behavior in endothelial cells in vitro.

Highlights

Atherosclerosis is touted as a leading cause of cardiovascular diseases, leading to a high rate of mortality [1, 2]
docosahexaenoic acid (DHA) decreased intracellular pal accumulation revealed by oil red O staining To confirm atherosclerotic changes in human umbilical vein endothelial cells (HUVECs) after being-incubated with 1 mM Pal, we performed Oil red O staining (Fig. 1a)
The treatment of HUVECs with 50 μM insulin did not yield statistically significant differences in viability rate compared to the control cells (p > 0.05)

Summary

Introduction

Atherosclerosis is touted as a leading cause of cardiovascular diseases, leading to a high rate of mortality [1, 2]. The emergence of chronic metabolic disorders, such as type 2 diabetes mellitus (T2DM), was shown to increase the risk of atherosclerotic plaques development [6]. It is thought that the increased insulin occurs in response to insulin receptors’ sensitivity after the onset of T2DM In response to these conditions, endothelial cells adopted themselves to decrease the membrane distribution of insulin receptors [9]. Along with these changes, the downstream insulin signaling pathway is ceased, contributing to a decrease of Akt phosphorylation, and inactivation of endothelial nitric oxide (eNOS) coincided with increased palmitoylation rate [10].

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