[Research progress on potential targets-mitochondrial dynamics-related proteins in treatment of myocardial ischemia-reperfusion injury].

Acute myocardial infarction(AMI) is still the leading cause of death worldwide. At present, the treatment of AMI is mainly to restore the cardiac blood supply through myocardial reperfusion. With the widespread use of coronary artery bypass grafting and percutaneous coronary intervention(PCI), myocardial reperfusion injury is a major clinical problem. Mitochondrial dysfunction is an important pathological basis for myocardial ischemic injury. Therefore, mitochondria can be used as an important target against myocardial damage. In this article, we would briefly review the physiological functions of mitochondrial dynamics-related proteins as well as their pathological mechanisms and pharmacological interventions in treatment of myocardial ischemia-reperfusion injury.

Research progress in targeting autophagy of traditional Chinese medicine and natural compounds to regulate atherosclerosis / 中国中药杂志

Atherosclerosis(AS) is the common pathological basis of many ischemic cardiovascular diseases, and its formation process involves various aspects such as vascular endothelial injury and platelet activation. Vascular endothelial injury is the initiating factor of AS plaque. Monocytes are recruited to differentiate into macrophages at the damaged endothelial cells, which absorb oxidized low-density lipoprotein(ox-LDL) and slowly transform into foam cells. Smooth muscle cells(SMCs) proliferate and migrate continuously. As the only cell producing interstitial collagen fibers in the fibrous cap, SMCs largely determine whether the plaque ruptured or not. The amplifying inflammatory response during the formation of AS recruits platelets to adhere to the damaged area of vascular endothelium and stimulates excessive platelet aggregation. Autophagy activity is associated with vascular lesions and abnormal platelet activation, and excessive autophagy is considered to be a negative factor for plaque stability. Therefore, precise regulation of different types of vascular autophagy and platelet autophagy to treat AS may provide a new therapeutic perspective for the prevention and treatment of atherosclerotic ischemic cardiovascular disease. Currently, treatment strategies for AS still focus on lowering lipid levels with high-intensity statins, which often cause significant side effects. Therefore, the development of safer and more effective drugs and treatment modes is the focus of current research. Traditional Chinese medicine and natural compounds have the potential to treat AS by targeted autophagy, and have been playing an increasingly important role in the prevention and treatment of cardiovascular diseases in China. This paper summarizes the experimental studies on different vascular cell types and platelet autophagy in AS, and sums up the published research results on targeted autophagy of traditional Chinese medicine and natural plant compounds to regulate AS, providing new ideas for further research.

LC-MS-Based Metabonomics Study of Yangxin Tongmaifang Against Coronary Heart Disease Differentiated into Blood Stasis Syndrome / 中国实验方剂学杂志

Objective:To observe the effect of Yangxin Tongmaifang （YXTM） on endogenous metabolites in the myocardial tissue of rats with coronary heart disease due to blood stasis based on the metabolomics approach， and to explore its mechanism in the treatment of heart blood stasis syndrome. Method:A rat model of chronic myocardial ischemia due to heart blood stasis was established via the high-fat diet combined with intragastric administration of vitamin D₃ and subcutaneous injection of isoproterenol （ISO）， followed by the intervention with YXTM. The metabolites in the myocardial tissues of rats in the normal group （<italic>n</italic>=8）， model group （<italic>n</italic>=8）， and YXTM group （<italic>n</italic>=8） were detected by ultra-high performance liquid chromatography coupled to high resolution mass spectrometry. The high-throughput metabolomics data were then subjected to multivariate statistical analysis using SIMCA 14.1， and the related metabolic pathways were analyzed with MetaboAnalyst. Result:The myocardial sample points of rats in the three groups were located in different areas of the elliptical confidence interval. The normal group and the model group were completely separated. There existed some crossovers and overlaps between the YXTM group and the normal group. The heart blood stasis syndrome model was proved successfully replicated from the perspective of metabolic profiling， and YXTM had the potential to promote the body to return to a normal state. After the intervention with YXTM， six differential metabolites changed significantly. Such metabolic pathways as valine， leucine， and isoleucine biosynthesis， pantothenate and coenzyme A （CoA） biosynthesis， valine， leucine， and isoleucine degradation， biosynthesis of aminoacyl-transfer RNA synthetases， and purine metabolism were involved. Conclusion:The therapeutic effect of YXTM on heart blood stasis syndrome in rats is related to the improved levels of myocardial endogenous metabolites， and its mechanism involves phospholipid metabolism， amino acid metabolism， energy metabolism， inflammatory response， and platelet activation and aggregation.

Mitochondrial Dynamics Mediates Myocardial Energy Metabolism in Coronary Heart Disease due to Blood Stasis / 中国实验方剂学杂志

Objective:To explore the mechanism of energy changes in the three stages of the formation of coronary heart disease due to blood stasis in rat model from the perspective of mitochondrial fusion-fission dynamic changes. Method:Thirty healthy male rats were divided into the blank control group （<italic>n</italic>=6） and model group （<italic>n</italic>=24） using SPSS 21.0 simple random sampling method. The rats in the blank control group were fed an ordinary diet， while those in the model group a high-fat diet. After seven days of adaptive feeding， the rats were treated with intragastric administration of vitamin D₃ （VitD₃） at 300 000 U·kg^-1 and then at 200 000 U·kg^-1 14 d later. The high-fat diet continued for 21 d， and six rats were randomly selected as samples for the pre-stage blood stasis syndrome group， followed by model verification and sampling. The remaining rats continued to receive the high-fat diet for 30 d， and six were randomly selected and categorized into the sub-stage blood stasis syndrome group， followed by model verification and sampling. The rest of rats were classified into the heart blood stasis syndrome group. While continuing the high-fat diet， they were also treated with multipoint subcutaneous injection of isoproterenol （ISO，5 mg·kg^-1） for three consecutive days. One week later， the electrocardiogram （ECG） was recorded for determining whether the modeling was successful and the samples were taken at the same time. The changes in mitochondrial morphology and quantity were observed under a transmission electron microscope. The expression of mitochondrial dynamics-related proteins was measured by Western blot and the cellular localization of related proteins by immunofluorescence assay. Result:The levels of total cholesterol and low-density lipoprotein cholesterol in the pre-stage and sub-stage blood stasis syndrome groups were significantly increased as compared with those in the blank control group （<italic>P</italic><0.05）. The blood rheology index in the pre-stage blood stasis syndrome group was significantly elevated in contrast to that in the blank control group （<italic>P</italic><0.05）. The three-layered membrane of the aorta in the blank group was intact. However， the tunica media of the pre-stage blood stasis syndrome group began to show obvious calcification， with a small number of inflammatory cells adhering to the intima. The subintima and media smooth muscles in the sub-stage blood stasis syndrome group exhibited cavity structures. The three-layered structure of the arterial wall in the heart blood stasis syndrome group was severely damaged. The ECG of the blank control group revealed the regular appearance of P wave，regular QRS waveform （no broadening or deformity）， and no obvious ST-segment depression or elevation. The ECG of the pre-stage blood stasis syndrome group showed no obvious abnormalities as compared with that of the blank control group. In the sub-stage blood stasis syndrome group， the ECG showed an upward trend of the J point and slight ST-segment elevation， with the elevation≤0.1 mV. The ECG in the heart blood stasis syndrome group displayed significant ST-segment depression （>0.1 mV） and J point depression >0.1 mV. The mitochondria in the blank control group were normal in size and morphology， with clear and dense cristae， whereas those in the pre-stage blood stasis syndrome group were fusiform with sparse cristae. Some mitochondria in the sub-stage blood stasis syndrome group were significantly elongated， and even vacuole-like changes were present. In the heart blood stasis syndrome group， the mitochondria were ruptured. As demonstrated by comparison with the blank control group， the expression levels of mitofusin 2 （Mfn2）， dynamin-related protein 1 （Drp1）， and fission protein 1 （Fis1） in the model group were significantly up-regulated （<italic>P</italic><0.05，<italic>P</italic><0.01）. Compared with the pre-stage blood stasis syndrome group， the heart blood stasis syndrome group exhibited down-regulated Mfn2 （<italic>P<</italic>0.05）. Compared with the blank control group and the pre-stage blood stasis syndrome group， the sub-stage blood stasis syndrome group and the heart blood stasis syndrome group displayed down-regulated optic atrophy 1（OPA1） （<italic>P</italic><0.05，<italic>P</italic><0.01）. The Drp1 and Fis1 protein expression declined significantly in the sub-stage blood stasis syndrome group in comparison with that in the pre-stage blood stasis syndrome group （<italic>P</italic><0.05，<italic>P</italic><0.01）. The expression levels of Mfn2 and Drp1 in the heart blood stasis syndrome group were lower than those in the sub-stage blood stasis syndrome group （<italic>P<</italic>0.01）. The comparison with the blank control group showed that Mfn2 and OPA1 were extensively accumulated in mitochondria of both the pre-stage and sub-stage blood stasis syndrome groups， while the red-stained Mfn2 was significantly reduced in the heart blood stasis syndrome group. The Drp1/Fis1 fluorescence was weak in the blank group and the pre-stage blood stasis syndrome group but strong in the sub-stage blood stasis syndrome group and heart blood stasis syndrome group. Conclusion:The cardiomyocyte mitochondria dynamics changes with the change in energy demand of cardiomyocytes. Mfn2 is dominated by fusion effect in the early stage of the formation of coronary heart disease due to blood stasis. With the gradual development of this disease， Mfn2 begins to mediate mitochondrial autophagy. OPA1 plays a role in intimal fusion and cristae integrity. The decreased OPA1 expression is closely related to the accelerated progression of coronary heart disease differentiated into blood stasis syndrome. The process by which Drp1 and Fis1 separate damaged mitochondria to prepare for mitochondrial autophagy contributes to alleviating the imbalance between the energy demand and supply of human body.