Myocardial infarction (MI) is the leading cause of cardiovascular disease-related death worldwide. Nonetheless, existing therapeutic approaches for MI are hampered by issues such as reliance on pharmacological agents and suboptimal patient adherence. Caffeic acid (CA) is a bioactive polyphenolic compound with important anti-inflammatory, anti-bacterial and anti-oxidant functions. Still, its specific role and mechanism in treating cardiovascular disease remain to be further studied. In recent years, a large number of studies have shown that the kelch-like ECH-associated protein 1/nuclear factor erythroid 2 related factor 2 (Keap1/Nrf2) pathway is a key factor in the occurrence and development of cardiovascular diseases. In this study, H₂O₂-induced oxidative stress model of H9c2 cells and left anterior descending branch (LAD) conjunctival induced acute myocardial infarction reperfusion (AMI/R) model were used to evaluate the protective effect of CA on the heart. The interaction between CA and Keap1 was analyzed by CA-labeled fluorescence probe, target fishing, isothermal titration calorimetry (ITC), protein crystallography and surface plasmon resonance (SPR). Our results suggested that CA binds Keap1 and degrades Keap1 in a p62-dependent manner, further promoting nuclear transcription of Nrf2 and thus effectively reducing oxidative stress. In addition, based on the three-dimensional eutectic structure, it was confirmed that CA directly targets Keap1 protein by interacting with residues M550 and N532, inducing conformation changes in Keap1 protein. We also found that the CA analog chlorogenic acid (GCA) can bind Keap1. In conclusion, this study elucidates a novel molecular mechanism and structural basis for the protective effects of CA against oxidative damage via the Keap1-Nrf2 pathway.

Background The correlation between depression and sleep quality is well established in adults, but similar evidence is lacking in adolescents. Objective To study the sleep quality, the positive rate of depressive symptoms, and their correlation among middle school students in Shanghai, so as to provide a basis for providing mental health and sleep management to this group of students. Methods From September to November 2020, using multi-stage stratified cluster random sampling method, a total of 7796 students from 32 middle schools in 16 districts of Shanghai were selected to conduct a questionnaire survey. The questionnaire for middle school students of the 2020 Shanghai Students’ Common Diseases and Health Influencing Factors Surveillance was used to collect students' demographic information, history of smoking, history of drinking, and history of chronic diseases; the Pittsburgh Sleep Quality Index was used to assess sleep quality; and the Center for Epidemiological Studies Depression Scale was used to evaluate depressive symptoms. χ² test was used to compare qualitative data between groups. Binary logistic regression was used to analyze the correlation between sleep quality and depressive symptoms among middle school students in Shanghai. Results After excluding incomplete questionnaires, a total of 7160 valid questionnaires were collected. The average sleep time of middle school students in Shanghai was (7.54±1.15) h. Among them, 84.8% reported insufficient sleep time < 9 h, and only 15.2% reported sleep time ≥9 h. In addition, 9.2% of the students had poor sleep quality (Pittsburgh Sleep Quality Index ≥8 points). The sleep quality of urban students was worse than that of suburban students. The sleep quality of girls was worse than that of boys. The sleep quality of students in the third grade of middle school was worse than that of students in the first and second grades of middle school. Students with smoking history, drinking history, and chronic disease history had worse sleep quality than those without (P<0.05). The positive rate of depressive symptoms among middle school students in Shanghai was 22.2%, among which 7.0% reported possible depressive symptoms and 15.2% reported definite depressive symptoms. The positive rate of depressive symptoms in female students (26.1%) was higher than that in male students (18.5%); among different grades of middle school, the positive rate of depressive symptoms of the third grade middle school students was the highest (24.1%); the positive rates of depressive symptoms in students with smoking history, drinking history, and chronic disease history were higher than those without; the positive rate of depressive symptoms was higher in students with poor sleep quality (P<0.05). The results of logistic regression analysis indicated that the students with poor sleep quality showed higher risks of reporting depressive symptoms, and the OR (95%CI) was 17.064 (14.024-20.764). Conclusion The positive rates of poor sleep quality and depressive symptoms of middle school students in Shanghai are high, and there is a significant correlation between these two indicators. For students’ mental health and sleep management, more attention should be paid to the quality in addition to the quantity of sleep.

Objective:To evaluate the effect of 2-aminoethoxydiphenyl-borate (2-APB) on cardiac dysfunction in arsenic poisoning rats by stratified strain technique.Methods:Thirty-two 12-week-old SD rats were randomly divided into control group ( n=8) and arsenic exposure group ( n=24). After 12 weeks of arsenic exposure, arsenic exposure group was divided into three groups: natural recovery group ( n=8), low-dose intervention group (n=8) and high-dose intervention group ( n=8). The rats were treated with 2-APB for 21 days. After the last administration, the routine parameters and the layered strain parameters were measured by ultrasonic instrument. Then the rats were killed and their blood and myocardial samples were obtained. The levels of serum creatine kinase isoenzyme (CK-MB) and lactate dehydrogenase (LDH) were tested, and the morphological changes of cardiomyocytes were observed by HE staining. Results:Left ventricular ejection fraction (LVEF), left ventricular short axis shortening (LVFS), global circumferential strain of subendocardial myocardium (GCS-endo), global circumferential strain of middle myocardium (GCS-mid), global circumferential strain of subepicardial myocardium (GCS-epi) and circumferential strain rate of left ventricular segments (SrC) in the natural recovery group were lower than those in the control group ( P<0.05), while serum CK-MB and LDH were higher than those in the control group ( P<0.05). Some ultrasonic parameters and biochemical indexes in the low and high dose intervention groups were improved in varying degrees compared with the natural recovery group ( P<0.05). The correlation between GCS-endo and CK-MB was the highest ( r=-0.931, P<0.05). Myocardial HE staining showed that the degree of myocardial cell swelling and necrosis were reduced, and erythrocyte exudation was reduced in the low and high dose intervention groups compared with the natural recovery group. Conclusions:The stratified strain technique can be used to evaluate the protective effect of 2-APB on cardiac dysfunction in arsenic poisoning rats, and GCS-endo may be one of its sensitive indexes.

Objective To compare the 2 methods of the flow cytometry and the microcolumn gel agglutination assay for testing anti-ABO Ig G antibody.Methods The flow cytometry and the microcolumn gel agglutination assay were adopted to detect the an-ti-ABO IgG antibody in the O blood type pregnant women(experimental group)and the A/B blood type pregnant women (control group).The difference in the positive rates between the experimental and control groups and the correlation between these two methods were analysed.The different titers of samples were selected for detection on different days to compare their reproducibili-ty.Results 300 samples from the experimental goup and 300 samples from the control group were collected.The detection results of 2 methods showed that the positive rates of the experimental group was significantly higher than that of the control group with statistical difference(P <0.05).The correlation coefficients(rs )between these two methods were 0.694.The coefficient of variation in the flow cytometry was smaller than that in the microcolumn gel agglutination assay(P <0.05).Conclusion ABO blood type in-compatibility is more common in O type pregnant women.The flow cytometry and the microcolumn gel agglutination assay possess good correlation.The reproducibility of the flow cytometry is better than that of microcolumn gel agglutination assay.