Abstract:Calcific aortic valve disease (CAVD) is the most common disease affecting the heart valves, characterized by thickening, fibrosis, and mineralization of the aortic valve leaflets. Currently, there is no effective pharmacological treatment. Aortic valve calcification is a complex and multifactorial process involving valve inflammation, fibrosis, calcification, valve thickening and outflow tract obstruction. The exact pathophysiological mechanisms of CAVD are not fully understood, but many studies have suggested that innate immune cells play a key role in the development of aortic valve calcification. This review focuses on the current role of innate immune cells in the development of CAVD.

Abstract:Aim To explore the effect of succinate/G protein coupled receptor 91 (GPR91) on mitochondria in vascular endothelial cells and its regulatory mechanisms. Methods Transmission electron microscopy, Western blot and fluorescence microscopy were used to observe the effects of succinate analogues diethyl succinate (DS), GPR91 agonist and inhibitor on the mitochondrial morphology, cristae, cristate homeostasis related proteins reactive oxygen species (ROS) content, Ca²＋ concentration, mitochondrial membrane potential, the expression of dihydroorotate dehydrogenase (DHODH) and oxidized coenzyme Q10 (CoQ10). Fluorescence probes were used to observe the effect of DHODH inhibitor and CoQ10 on ROS level and Ca²＋concentration of endothelial cells. Results After DS treatment, the mitochondria showed pyknosis and mitochondrial volume significantly decreased, electron density of the mitochondrial membrane increased, and the number of cristae decreased in endothelial cells; the expression of cristae homeostasis related proteins MIC60 decreased by 23%, while cellular ROS level and Ca²＋ concentration increased; mitochondrial membrane potential decreased (P＜0.05 or P＜0.01). After GPR91 agonist treatment, the expression of cristae homeostasis related proteins MIC60 decreased by 31%, meanwhile, cellular ROS level increased by 27% and Ca²＋ concentration increased by 36%; mitochondrial membrane potential decreased (P＜0.05 or P＜0.01). After GPR91 inhibitor treatment, the expression of cristae homeostasis related proteins MIC60 increased by 22% and ATP5I increased by 40%; the levels of ROS decreased by 41% and Ca²＋ concentration decreased by 67%; and the mitochondrial membrane potential was restored to normal (P＜0.05 or P＜0.01). After DS treatment, the expression of DHODH decreased by 43% and the level of oxidized CoQ10 increased by 120% (P＜0.05 or P＜0.01). After GPR91 agonist treatment, the expression of DHODH decreased by 22% and the level of oxidized CoQ10 increased by 36% (P＜0.05 or P＜0.01). After GPR91 inhibitor treatment, the expression of DHODH increased by 40% and the level of oxidized CoQ10 decreased by 39% (P＜0.01). After DHODH inhibitor treatment, the ROS level increased by 20% and Ca²＋ concentration increased by 28%, and mitochondrial membrane potential reduced at same time (P＜0.05 or P＜0.01). Exogenous oxidized CoQ10 inhibited ROS production by 30% and decreased Ca²＋ concentration by 20% (P＜0.05 or P＜0.01). Conclusion Succinate/GPR91 promotes mitochondrial damage in endothelial cells, and its mechanism may relate to down-regulating the expression of DHODH and inhibiting the reduction of CoQ10 by affecting the mitochondrial cristae homeostasis.

Abstract:Aim Previous studies have indicated that H₂S can attenuate myocardial fibrosis. However, it is unclear whether mitochondria-targeted H₂S can attenuate myocardial fibrosis after myocardial infarction and whether its mechanism is associated with the regulation of mitochondrial fusion and fission. To investigate this relationship, this study was conducted. Methods Isoproterenol (ISO, 50 mg/(kg·d) was injected intraperitoneally to induce myocardial infarction in SD rats. Electrocardiograms were performed on each group of rats, and the rats were treated with AP39 (36 μg/(kg·d), intraperitoneal) for 4 weeks. Masson's staining was used to assess the extent of myocardial fibrosis. Western blot was used to measure the expression of relevant proteins. In vitro experiments were performed to induce hypoxic injury in H9c2 cardiomyocytes with CoCl₂ (800 μmol/L), H9c2 cells were treated with AP39 (100 nmol/L), and the endogenous hydrogen sulfide synthase cystathionine-γ-lyase(CSE) was inhibited using DL-propargylglycine (PAG, 2 mmol/L), and fluorescence probe was used to measure the level of reactive oxygen species(ROS) in myocardial cells. Results Myocardial fibrosis was evident in infarcted rat hearts, with a significant accumulation of collagen fibers. Additionally, the expression of CSE and mitofusin 2 (MFN2) proteins was downregulated, while dynamin-related protein 1(DRP1) protein expression was increased. Intervention with AP39 significantly improved the above changes, and the addition of CSE inhibitor PAG reversed the effects of AP39. In in vitro experiments, when H9c2 myocardial cells were subjected to hypoxic injury induced by CoCl₂, intracellular ROS levels increased, MFN2 expression was downregulated, and DRP1 expression was upregulated. AP39 upregulated MFN2 protein expression, inhibited DRP1 protein expression, and reduced ROS levels in myocardial cells. The addition of PAG reversed these changes. Conclusion The mitochondria-targeted H₂S donor, AP39, can improve myocardial fibrosis in rats with myocardial infarction and promote mitochondrial fusion and inhibit excessive mitochondrial division.

Abstract:Damage to organelles plays a significant role in myocardial ischemia/reperfusion injury, which results in the dysfunction of mitochondria and other related organelles. The communication between mitochondria and other organelles can also affect the development of myocardial ischemia/reperfusion injury. For instance, the mitochondria-associated endoplasmic reticulum membrane provides a “seamless connection” and regulates the exchange of organelles and metabolites (such as ions, lipids and proteins) between the mitochondria and the endoplasmic reticulum, which subsequently affects myocardial ischemia/reperfusion injury. However, there is a lack of studies regarding the interaction between mitochondria and related organelles, which is a critical component in triggering myocardial ischemia/reperfusion injury. Therefore, this article describes the role of mitochondrial crosstalk with endoplasmic reticulum, lysosomes and nuclei in myocardial ischemia/reperfusion injury, and aims to provide a theoretical basis for targeting mitochondrial crosstalk with other organelles in the treatment of myocardial ischemia/reperfusion injury.

Abstract:Mitochondria are the “power generators” in eukaryotic cells, therefore playing vital roles for basically all cellular activities. Not only supplying energy, mitochondria are also actively regulating important cellular processes, such as apoptosis, differentiation, and proliferation. But mitochondria are not “perpetual motion machines”. In fact, mitochondria are one of the most sensitive organelles to various pathological conditions. Dysfunction of mitochondria can cause many human diseases, such as Alzheimer's disease, diabetes, ischemic heart disease, etc. It is well known that changes in mitochondrial morphology affect the mitochondrial function, and vice versa. Under pathological conditions, mitochondria undergo various morphological changes. Research studies that characterized abnormal mitochondrial morphology have enabled us to understand the mitochondrial involvement in the pathogenesis of certain human diseases. This review mainly summarizes the research progress on mitochondrial morphological changes in human diseases, aiming to provide a theoretical overview.

Abstract:Aim To study the effect of liraglutide on myocardial metabolites and related metabolic pathways in diabetic cardiomyopathy (DCM) rats. Methods Among 60 SPF male SD rats aged 3 weeks, 10 rats were randomly selected as normal control group (n＝10), and the remaining 50 rats were established by peritoneal injection of streptozotocin combined with high-sugar and high-fat diet for DCM rat model. A total of 36 rats were successfully modeled for DCM and randomly divided into DCM model group (DCM group, n＝12), low-dose liraglutide treatment group (LL group, n＝12) and high-dose liraglutide treatment group (HL group, n＝12). Rats in LL group (100 μg/kg) and HL group (200 μg/kg) were given intraperitoneal injection of liraglutide once a day. And after 12 weeks of intervention, the rats were killed under anesthesia after echocardiography to detect cardiac function, and the heart tissues were taken for metabolomics detection. The differential metabolites and related pathways that may be related to liraglutide improving myocardial metabolism in DCM rats were screened and enriched. Results Compared with normal control group, left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) in DCM group were significantly decreased, and the ratio of early to late diastolic mitralflow velocities (E/A) was significantly increased (P＜0.05). Compared with DCM group, LVEF and LVFS in LL group and HL group were significantly increased, and E/A ratio was significantly decreased (P＜0.05), suggesting that the impairment of left ventricular systolic and diastolic function in LL group and HL group was significantly alleviated. 395 metabolites were detected by metabolomics, among which 9,6 and 187 different metabolites and 3,6 and 20 metabolic pathways were enriched in DCM group and normal control group, LL group and DCM group, HL group and DCM group. In the above three groups, 29 key differential metabolites were identified related to 3 metabolic pathways including choline metabolic pathway, caffeine metabolic pathway and valine, leucine and isoleucine biosynthesis pathway, among which choline metabolic pathway had the most significant differences. Conclusion These results indicated that liraglutide can ameliorate cardiac dysfunction in DCM rats through improving myocardial metabolism in which choline metabolism pathway may play a key role.

Abstract:Aim To investigate how chili-derived exosome-like nanovesicle (CDELN) inhibited ox-LDL uptake and reduced ox-LDL-induced intracellular cholesterol accumulation. Methods CDELN were isolated and purified using tissue crushing, differential centrifugation, ultracentrifugation and sucrose density gradient centrifugation. Ox-LDL was used to stimulate THP-1-derived macrophages for 24 hours to establish a foam cell model in vitro, and the effect of CDELN on macrophage foam and its mechanism were further studied. Confocal laser microscopy was used to detect the uptake of CDELN and DiL-acetylated low density lipoprotein (DiL-ac-LDL) by THP-1 macrophages. Oil red O staining was used to detect intracellular cholesterol content and the positive area of oil red O staining in cells was analyzed to evaluate the effect of intracellular lipid accumulation. RT-qPCR and Western blot were used to detect mRNA and protein levels of scavenger receptor A (SRA) and cluster of differentiation 36 (CD36), lectin-like oxidized low density lipoprotein receptor-1 (LOX-1), ATP-binding cassette transporter A1/G1 (ABCA1/G1). The expression of mitogen-activated protein kinase (MAPK) pathway proteins including p-ERK, p-p38 MAPK and p-c-Jun, were also analyzed. Results CDELN were exosome-like nanovesicles with uniform size and double membrane, rich in protein and nucleic acids, which can be taken up by macrophages. The results of DiL-ac-LDL uptake showed that CDELN could inhibit cholesterol uptake of macrophages. Oil red O staining showed that CDELN could reduce ox-LDL-induced intracellular cholesterol accumulation. RT-qPCR and Western blot showed that CDELN could significantly reduce mRNA levels of matrix metalloprotein-9 (MMP-9), SRA, CD36 and LOX-1 and protein levels of p-ERK, SRA, CD36 and LOX-1 in ox-LDL-induced THP-1-derived macrophages. Treatment with the p-ERK agonist Yoda1 diminished the protective effect of CDELN. Conclusion CDELN can significantly inhibit macrophage foam cell formation, and this effect may be associated with the inhibition of phosphorylation levels of ERK1/2 in the MAPK pathway.

Abstract:Aim To explore the feasibility of using machine learning algorithms combined with coronary computed tomography (CT) derived perivascular fat attenuation index (FAI) and plaque information to evaluate myocardial ischemia in stable coronary heart disease patients. Methods A retrospective analysis was conducted on the clinical and imaging data of patients who underwent preoperative coronary CT angiography (CCTA), invasive coronary angiography (ICA), and flow reserve fraction (FFR) measurements at Zhongshan Hospital Affiliated to Fudan University from April 2019 to October 2021. 206 patients with stable coronary heart disease were selected. The semi-automatic plaque analysis software was used for quantification of plaque and lumen parameters and perivascular FAI measurement, with manual delineation of a 40 mm segment of the coronary artery starting 10 mm from the ostium for perivascular FAI measurement. Differences in plaque characteristics, perivascular FAI, and coronary perivascular FAI between stable coronary heart disease patients with FFR≤0.8 and FFR＞0.8 were compared. The diagnostic performance of combining perivascular FAI, coronary perivascular FAI, and plaque features using machine learning algorithms for myocardial ischemia in stable coronary heart disease patients was evaluated through ROC curves. Results 206 stable coronary heart disease patients were divided into FFR≤0.8 group (50 cases) and FFR＞0.8 group (156 cases). The mean periplaque FAI of patients with FFR≤0.8 was －69.28±5.65 HU, significantly higher than that of patients with FFR＞0.8 at －80.10±7.75 HU (P＜0.001). Further analysis was conducted using machine learning models, including XGBoost, random forest, and Logistic regression models, all of which had an accuracy rate of over 0.8 in diagnosing myocardial ischemia. Among them, the XGBoost model performed the best with an accuracy of 0.903, an F1 value of 0.774, and an AUC of 0.931, indicating its high effectiveness in diagnosing myocardial ischemia. Conclusion The combination of FAI and machine learning algorithm XGBoost model is a new method for diagnosing myocardial ischemia, which has better diagnostic value in evaluating myocardial ischemia in stable coronary heart disease patients.

Abstract:Aim To investigate the relationship between serum 8-hydroxydeoxyguanosine (8-OHdG), chemokine C-X3-C ligand 1 (CX3CL1) and cognitive dysfunction in patients with cerebral small vessel disease (CSVD). Methods 128 patients with CSVD admitted to our hospital from May 2021 to May 2022 were selected and divided into cognitive impairment group and non-cognitive impairment group based on the Montreal cognitive assessment scale (MoCA) scores. The relationship between serum 8-OHdG, CX3CL1 levels and the MoCA scores of CSVD patients was investigated by Pearson correlation analysis, Logistic regression analysis was used to analyze the influencing factors of cognitive impairment in patients with CSVD, and ROC curves were drawn to study the predictive efficacy of serum 8-OHdG and CX3CL1 on cognitive impairment in CSVD patients. Results The serum 8-OHdG and CX3CL1 levels of patients with cognitive impairment were higher than those of non-cognitive impairment group. However, their MoCA scores were lower than those of non-cognitive impairment group (P＜0.05). Serum 8-OHdG and CX3CL1 levels were negatively correlated with MoCA scores (r＝－0.715 and －0.413, P＜0.05). Serum 8-OHdG level was higher in severe cognitive impairment group than that of moderate cognitive impairment group and mild cognitive impairment group (P＜0.05), and it was higher in moderate cognitive impairment group than that of mild cognitive impairment group (P＜0.05). Serum of CX3CL1 level was higher in severe cognitive impairment group than that in moderate cognitive impairment group and mild cognitive impairment group (P＜0.05), and it was higher in moderate cognitive impairment group than that in mild cognitive impairment group (P＜0.05). The area under the ROC curve (AUC) of 8-OHdG for the diagnosis of cognitive impairment in CSVD patients was 0.866, with sensitivity and specificity of 76.53% and 80.00%, respectively (P＜0.05); The AUC of CX3CL1 for the diagnosis of cognitive impairment in CSVD patients was 0.868, with sensitivity and specificity of 86.73% and 80.00%, respectively (P＜0.05); The AUC of the combination of 8-OHdG and CX3CL1 for the diagnosis of cognitive impairment in CSVD patients was 0.922, with sensitivity and specificity of 88.78% and 86.67%, respectively (P＜0.05). Serum 8-OHdG＞2.69 μg/L and CX3CL1＞179.18 pg/L were both influencing factors for cognitive impairment in CSVD patients (P＜0.05).Conclusion The levels of serum 8-OHdG and CX3CL1 are positively correlated with cognitive impairment in CSVD patients, and both can serve as auxiliary indicators for predicting cognitive impairment in CSVD patients.

Abstract:Aim To investigate the levels of krüppel-like factor 2 (KLF2) and endothelial nitric oxide synthase 3 (NOS3) in the serum of patients with acute cerebral infarction (ACI) of large-artery atherosclerosis (LAA) type, and to analyze their value in the diagnosis and disease assessment of LAA type ACI. Methods A total of 150 patients with LAA type ACI were divided into mild group (n＝36), moderate group (n＝48), and severe group (n＝66) based on their condition. Additionally, a control group (n＝150) was selected from health exminers during the same period. The levels of serum KLF2 and NOS3 in each group were compared; receiver operator characteristic(ROC) curve was applied to analyze the diagnostic value of serum KLF2 and NOS3 levels for LAA type ACI and the predictive value for the occurrence of severe LAA type ACI, respectively. Results The serum KLF2 and NOS3 levels were significantly lower in LAA type ACI group than those in control group (P＜0.05). The serum KLF2 and NOS3 levels in the mild, moderate and severe groups were significantly decreased in turn(P＜0.05). The area under the curve (AUC) of the combined diagnosis of serum KLF2 and NOS3 for LAA type ACI was 0.858, with a sensitivity of 73.33% and a specificity of 86.00%, which was superior to the individual diagnosis of KLF2 and NOS3 (Z_combined detection-KLF2＝3.796, Z_combined detection-NOS3＝4.689, all P＜0.001). The AUC of combined prediction of serum KLF2 and NOS3 for the occurrence of severe LAA type ACI was 0.878, with a sensitivity of 77.27% and a specificity of 90.48%, which was superior to the independent prediction of KLF2 and NOS3 (Z_combined detection-KLF2＝2.401, P＝0.016; Z_combined detection-NOS3＝3.070, P＝0.002). Conclusions The serum levels of KLF2 and NOS3 in patients with LAA type ACI were significantly reduced and negatively correlated with the severity of the disease. The combination of the two has high evaluation efficacy in the diagnosis and disease prediction of LAA type ACI.

Abstract:Myocardial ischemia/reperfusion injury (MIRI) occurs after cardiopulmonary bypass open heart surgery, cardiovascular intervention and thrombolytic therapy, which is the most important cause of cardiac insufficiency, heart failure, and even death in patients after treatment. In recent years, studies have found that the release of endogenous active peptides can alleviate the production of MIRI, and regulating the function and action of endogenous peptides may be one of the most effective ways to treat MIRI. Dipeptidyl peptidase 4 (DPP4) is an important serine protease in mammals, with enzymatic activity to hydrolyze endogenous peptides. Its primary physiological function is to metabolize short peptides, including growth factors, hormones, etc. This review aims to better understand and search for effective therapeutic targets by elucidating the impact of DPP4 on the hydrolysis of endogenous peptides in MIRI, and ultimately provide new ideas for the therapeutic effects of MIRI.

Abstract:Myocardial infarction is myocardial necrosis caused by acute and persistent ischemia and hypoxia of coronary artery, with high incidence rate and mortality. Although the recovery of blood supply through coronary intervention or thrombolytic drugs can improve the survival rate of patients, it is difficult to rescue the lost cardiomyocytes in the infarcted area, and the limited self repair ability of the adult mammalian heart is the main factor that causes myocardial fibrosis and eventually progresses to heart failure. For a long time, the existing treatment methods are difficult to reverse the process of heart failure after myocardial infarction. Cell transplantation is a promising therapeutic method to promote the repair and regeneration of infarcts. Due to the ischemia and hypoxia microenvironment, the limited survival and retention of stem cells after transplantation are not ideal. And acellular biomaterials promoting angiogenesis and reducing fibrosis show the potential of preclinical treatment. This paper summarizes the advantages and disadvantages of various acellular biomaterials, epicardial infarct repair and intramyocardial injection in a minimally invasive manner to promote cardiac regeneration and improve cardiac function, and to promote myocardial regeneration by combining acellular biomaterials with optimized drugs in the future for reference.

Abstract:Cerebral small vessel disease (CSVD) refers to a series of clinical imaging pathological syndromes caused by various etiologies affecting cerebral small vessels, which have the characteristics of insidious onset, high incidence and easy recurrence. Insulin resistance (IR) is a decrease in the body's sensitivity to insulin. In recent years, more and more studies have confirmed that IR is associated with the occurrence and development of imaging features of CSVD, but the mechanism is still unclear. This article reviews the relationship between IR and cerebral small vessel disease and its possible mechanism, in order to provide reference for the prevention and treatment of cerebral small vessel disease.