Curcumin is a natural polyphenol with powerful antioxidant and anti-inflammatory properties. The present study evaluated the protective effect of curcumin on myocardial injury in rats as well as the mechanisms underlying these effects, and examined the expression of nuclear factor-κB (NF-κB), peroxisome proliferator-activated receptor-γ (PPAR-γ) and B-cell leukemia/lymphoma-2 (Bcl-2) following myocardial infarction. A rat model of myocardial infarction was successfully established. Hematoxylin and eosin staining showed cellular atrophy and hyperchromatic cytoplasm in the myocardial infarction area. The myocardial cells displayed lysis and breakage of cardiac muscle fibers, karyopyknosis and karyorrhexis associated with infiltration of inflammatory cells and proliferation of fibrous tissue. Curcumin treatment at a dosage of 150 mg/kg/body weight resulted in an increase in surviving cells, fewer apoptotic cells, decreased proliferation of fibrous tissue and reduced infiltration of inflammatory cells, though necrosis was still present compared with the rats without curcumin treatment. The immunohistochemical assay demonstrated that curcumin treatment inhibited the expression of NF-κB, but increased the expression of PPAR-γ. The results of the reverse transcription-polymerase chain reaction indicated that curcumin treatment significantly increased the mRNA expression levels of Bcl-2 (P<0.01). Therefore, curcumin antagonizes cardiomyocyte apoptosis and inhibits inflammatory cell infiltration following myocardial infarction, which may be associated with its inhibitory effects on the expression of NF-κB, and activating effects on the expression of PPAR-γ and Bcl-2 in myocardial cells. Curcumin may be useful in clinical practice for saving more living heart muscle in the area of myocardial infarction and improving cardiac function following the elective opening of obstructed coronary arteries.

The dipeptidyl peptidase 4 inhibitor vildagliptin (VLD), a widely used anti‐diabetic drug, exerts favourable effects on vascular endothelium in diabetes. We determined for the first time the improving effects of VLD on mitochondrial dysfunction in diabetic mice and human umbilical vein endothelial cells (HUVECs) cultured under hyperglycaemic conditions, and further explored the mechanism behind the anti‐diabetic activity. Mitochondrial ROS (mtROS) production was detected by fluorescent microscope and flow cytometry. Mitochondrial DNA damage and ATP synthesis were analysed by real time PCR and ATPlite assay, respectively. Mitochondrial network stained with MitoTracker Red to identify mitochondrial fragmentation was visualized under confocal microscopy. The expression levels of dynamin‐related proteins (Drp1 and Fis1) were determined by immunoblotting. We found that VLD significantly reduced mtROS production and mitochondrial DNA damage, but enhanced ATP synthesis in endothelium under diabetic conditions. Moreover, VLD reduced the expression of Drp1 and Fis1, blocked Drp1 translocation into mitochondria, and blunted mitochondrial fragmentation induced by hyperglycaemia. As a result, mitochondrial dysfunction was alleviated and mitochondrial morphology was restored by VLD. Additionally, VLD promoted the phosphorylation of AMPK and its target acetyl‐CoA carboxylase in the setting of high glucose, and AMPK activation led to a decreased expression and activation of Drp1. In conclusion, VLD improves endothelial mitochondrial dysfunction in diabetes, possibly through inhibiting Drp1‐mediated mitochondrial fission in an AMPK‐dependent manner.

Coronary heart disease (CHD) is a major cause of morbidity and mortality and an important public health problem globally, but the mechanism of CHD is still complex and unclear. The purpose of the current study was to explore the mechanism underlying CHD using high-throughput technology. The study participants were patients with coronary angiography (CAG)-proven severity of coronary artery stenosis. Patients were divided into control and test group based on specific inclusion criteria, and data were collected regarding the results of routine inspection and the Gensini score (GS). We explored the mechanism underlying CHD with high-throughput integration of circular RNA (circRNA)-microRNA (miRNA) data. Through the expression of circRNA-miRNA, we discovered a total of 110 circRNAs to be differentially expressed in the two groups. Of these, 73 were upregulated and 37 downregulated in the CHD (fold ≥2.0 and P<0.05). Among 18 miRNAs, 13 were upregulated and 5 were downregulated in the CHD group (fold ≥2.0 and P<0.05). Enrichment analysis showed that circRNAs participate in a variety of disease development processes, biological processes, molecular functions, cellular components, and pathways (P<0.05). The mechanism underlying CHD may be closely related to up- or downregulated circRNA and miRNA and co-expression of circRNA-miRNA specifically involved regulate multiple pathways and multiple cellular and molecular biological processes.