Paeonol protects rat vascular endothelial cells from ox-LDL-induced injury in vitro via downregulating microRNA-21 expression and TNF-α release.

Abstract

AIM:

Paeonol (2'-hydroxy-4'-methoxyacetophenone) from Cortex moutan root is a potential therapeutic agent for atherosclerosis. This study sought to investigate the mechanisms underlying anti-inflammatory effects of paeonol in rat vascular endothelial cells (VECs) in vitro.

METHODS:

VECs were isolated from rat thoracic aortas. The cells were pretreated with paeonol for 24 h, and then stimulated with ox-LDL for another 24 h. The expression of microRNA-21 (miR-21) and PTEN in VECs was analyzed using qRT-PCR. The expression of PTEN protein was detected by Western blotting. TNF-α release by VECs was measured by ELISA.

RESULTS:

Ox-LDL treatment inhibited VEC growth in dose- and time-dependent manners (the value of IC50 was about 20 mg/L at 24 h). Furthermore, ox-LDL (20 mg/L) significantly increased miR-21 expression and inhibited the expression of PTEN, one of downstream target genes of miR-21 in VECs. In addition, ox-LDL (20 mg/L) significantly increased the release of TNF-α from VECs. Pretreatment with paeonol increased the survival rate of ox-LDL-treated VECs in dose- and time-dependent manners. Moreover, paeonol (120 μmol/L) prevented ox-LDL-induced increases in miR-21 expression and TNF-α release, and ox-LDL-induced inhibition in PTEN expression. A dual-luciferase reporter assay showed that miR-21 bound directly to PTEN's 3'-UTR, thus inhibiting PTEN expression. In ox-LDL treated VECs, transfection with a miR-21 mimic significantly increased miR-21 expression and inhibited PTEN expression, and attenuated the protective effects of paeonol pretreatment, whereas transfection with an miR-21 inhibitor significantly decreased miR-21 expression and increased PTEN expression, thus enhanced the protective effects of paeonol pretreatment.

CONCLUSION:

miR-21 is an important target of paeonol for its protective effects against ox-LDL-induced VEC injury, which may play critical roles in development of atherosclerosis.

• Authors: Ya-rong Liu, Jun-jun Chen, Min Dai
• Journal: Acta pharmacologica Sinica (Acta Pharmacol Sin) Vol. 35 Issue 4 Pg. 483-8 (Apr 2014) ISSN: 1745-7254 [Electronic] United States
• PMID: 24562307 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• 3' Untranslated Regions
• Acetophenones
• Anti-Inflammatory Agents
• Inflammation Mediators
• Lipoproteins, LDL
• MicroRNAs
• Tumor Necrosis Factor-alpha
• mirn21 microRNA, rat
• oxidized low density lipoprotein
• paeonol
• PTEN Phosphohydrolase
• Pten protein, rat

Topics

• 3' Untranslated Regions
• Acetophenones (pharmacology)
• Animals
• Anti-Inflammatory Agents (pharmacology)
• Aorta, Thoracic (drug effects, immunology, metabolism, pathology)
• Binding Sites
• Cell Survival (drug effects)
• Cells, Cultured
• Cytoprotection
• Dose-Response Relationship, Drug
• Down-Regulation
• Endothelial Cells (drug effects, immunology, metabolism, pathology)
• Gene Expression Regulation, Enzymologic
• Genes, Reporter
• Inflammation Mediators (metabolism)
• Inhibitory Concentration 50
• Lipoproteins, LDL (toxicity)
• Male
• MicroRNAs (genetics, metabolism)
• PTEN Phosphohydrolase (genetics, metabolism)
• Rats, Sprague-Dawley
• Time Factors
• Transfection
• Tumor Necrosis Factor-alpha (metabolism)