sPLA2-IIA Augments Oxidized LDL-Induced MCP-1 Expression in Vitro Through Activation of Akt.

Abstract

BACKGROUND/AIMS:

Group IIA secretory phospholipase A2 (sPLA2-IIA) has an important role in atherosclerosis. In this study, we explored whether sPLA2-IIA overexpression could promote atherosclerosis in normal environment alone or with other inflammatory factors.

METHODS:

Human aortic smooth muscle cells (HASMCs) were transduced with Lv-GFP-sPLA2-IIA, a plasmid containing sPLA2-IIA coupled with green fluorescent protein (GFP). Cells were incubated in the presence or absence of oxidized low-density lipoprotein (LDL), sPLA2 inhibitor LY315920 or PI3K/Akt inhibitor LY294002. The mRNA expression and protein secretion of monocyte chemoattractant protein-1 (MCP-1) were assessed by quantitative real-time polymerase chain reaction (QRT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Phosphorylation of Akt was examined by western blotting.

RESULTS:

Lv-GFP-sPLA2-IIA-transduced HASMCs remained fluorescent during 72 h of the study period with infection ratio of around 80%. The mRNA expression and protein secretion of MCP-1 was not altered in groups of HASMCs, Lv-GFP transduced and Lv-GFP-sPLA2-IIA-transduced HASMCs (p>0.05), but was significantly increased in the presence of oxidized LDL especially in Lv-GFP-sPLA2-IIA transduction group (p<0.01). However, with the addition of LY315920, this enhancement was notably decreased (p<0.05). This enhancement was also markedly abolished by co-incubation with LY294002, paralleled with suppressed Akt phosphorylation.

CONCLUSIONS:

Overexpression of sPLA2-IIA does not alter MCP-1 level at baseline, but could enhance the atherogenic effect of oxidized LDL in HASMCs, at least partly due to activation of Akt. These findings may provide a strategy for treatment of inflammatory cardiovascular diseases.

• Authors: Yongjun Guo, Bo Li, Xuejing Xu, Rong Wu, Weihua Li
• Journal: Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology (Cell Physiol Biochem) Vol. 37 Issue 4 Pg. 1345-54 ( 2015) ISSN: 1421-9778 [Electronic] Germany
• PMID: 26488172 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2015 S. Karger AG, Basel.

Chemical References

• Acetates
• CCL2 protein, human
• Chemokine CCL2
• Chromones
• Indoles
• Keto Acids
• Lipoproteins, LDL
• Morpholines
• Phosphoinositide-3 Kinase Inhibitors
• RNA, Messenger
• oxidized low density lipoprotein
• varespladib methyl
• 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one
• Proto-Oncogene Proteins c-akt
• Group II Phospholipases A2

Topics

• Acetates (pharmacology)
• Cell Line
• Chemokine CCL2 (metabolism)
• Chromones (pharmacology)
• Enzyme-Linked Immunosorbent Assay
• Gene Expression (drug effects)
• Genes, Reporter
• Group II Phospholipases A2 (antagonists & inhibitors, genetics, metabolism)
• HEK293 Cells
• Humans
• Indoles (pharmacology)
• Keto Acids
• Lipoproteins, LDL (toxicity)
• Morpholines (pharmacology)
• Myocytes, Smooth Muscle (cytology, metabolism)
• Phosphatidylinositol 3-Kinases (metabolism)
• Phosphoinositide-3 Kinase Inhibitors
• Phosphorylation
• Proto-Oncogene Proteins c-akt (antagonists & inhibitors, metabolism)
• RNA, Messenger (metabolism)