Relationship of blood levels of inflammatory and destructive biomarkers in coronary atherosclerosis with long-term results of surgical revascularization

Association of tumor necrosis factor-alpha and interleukin-10 levels with ultrasound characteristics of atherosclerotic plaques in patients with essential hypertension

Aim. To study the association  of ultrasound characteristics of carotid atherosclerotic  plaques  (ASPs) with the concentration  of tumor necrosis factor-alpha  (TNFα) and interleukin-10 (IL-10) in patients  with essential hypertension.

Material and methods. The study included 117 patients  (men, 75; women, 42) with essential hypertension aged 40 to 75 years (mean age, 55,8±7,5 years). All patients  underwent anthropometric  measurements (height, weight, body mass index, waist circumference),  assessment of blood pressure  and heart rate, blood tests (levels of glucose, creatinine with the calculation of glomerular filtration rate using CKD-EPI equation, lipid profile), duplex ultrasound of the carotid arteries.  Also, the blood concentration  of TNFα and IL-10 by the enzyme-linked immunosorbent assay using CYTOKIN-STIMUL-BEST (Novosibirsk,Russia) kit was determined.

Results.  According to the  results  of carotid  duplex ultrasound,  3 groups of patients  were identified. Group 1 included 48 patients  with homogeneous hyperechoic ASPs; group 2 — 56 patients with dominant hyperechoic  ASPs (>50% of areas);  group 3 — 13 patients  with anechoic, unstable,  low-density ASPs. TNFα concentration  in group 3 patients, amounting to 10,51±2.23 pg/ml, was significantly higher than in patients of group 1 (7,26±0,64 pg/ml (p<0,001)) and group 2 (8,93±0,98 pg/ml (p<0,001)).  Similar results were obtained for IL-10. The logistic regression  showed that the TNFα concentration  is an independent  factor associated with unstable  ASsP (relative risk, 2,72; 95% confidence interval 1,44-5,15  (p<0,02)). It was also revealed that TNFα >10 pg/ml increased the risk of ASP instability by ~8 times.

Conclusion.  An increase  in TNFα >10 pg/ml with a high specificity (95%) was associated with vulnerable unstable carotid ASPs.

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

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.