Inhibition of myocardial remodeling through miR-150/TET3 axis after AMI.

BACKGROUND: Current studies have suggested that miRNA is beneficial in inhibiting myocardial remodeling after myocardial infarction (AMI), however, its underlying mechanism is unclear. OBJECTIVES: We aimed to investigate whether miR-150 can inhibit myocardial remodeling after myocardial infarction and whether this process is regulated by the miR-150/TET3 pathway. METHODS: On the first day, C57BL/6 AMI mice(n = 15) were administrated with miR-150, and another 15 AMI mice were administrated with the same volume of control Agomir. Left ventricular ejection fraction (LVEF%) and myocardial remodeling were compared after one week; TET3 (ten-eleven translocation 3) and VEGF-α (vascular endothelial growth factor-α) were also determined in the infracted heart simultaneously. The neovascularization in the infarcted area at day 21 was compared through CD31 using fluorescence microscopy; Activated monocytes stimulated with LPS were transfected with miR-150. Laser scanning confocal microscopy was used to detect the intracytoplasmic imaging of miR-150 in Ly6Chigh monocytes. Expression of the miR-150 in the monocytes was measured using Q-PCR. After 48 h, the proportion of Ly6Chigh/low monocytes was determined using flow cytometry. Expression of TET3 in Ly6Chigh/low monocytes was measured using Q-PCR and Western blot. After the downregulation of TET3 specifically, the levels of Ly6Chigh/low monocytes were further determined. RESULTS: We first observed an increased trend of mice survival rate in the miR-150 injection group, but it didn't reach a statistical difference (66.7% vs. 40.0%, p = 0.272). However, AMI mice administrated with miR-150 displayed better LVEF% (51.78%±2.90% vs. 40.28%±4.20%, p<0.001) and decreased infarct size% (25.47 ± 7.75 vs. 50.39 ± 16.91, p = 0.002). After miR-150 was transfected into monocytes, the percentage of Ly6Clow monocytes increased significantly after 48 h (48.5%±10.1% vs. 42.5%±8.3%, p < 0.001). Finally, Western blot analysis (0.56 ± 0.10/ß-actin vs. 0.99 ± 0.12/ß-actin, p < 0.001) and real-time PCR (1.09 ± 0.09/GAPDH vs. 2.53 ± 0.15/GAPDH, p < 0.001, p < 0.001) both confirmed decreased expression of TET3 in monocytes after transfection with miR-150. After the downregulation of TET3 specifically, Ly6Clow monocytes showed a significant increase (16.73%±6.45% vs. 6.94%±2.99%, p<0.001, p < 0.001). CONCLUSIONS: miR-150 alleviated myocardial remodeling after AMI. Possible mechanisms are ascribed to the regulating of TET3 and VEGF-α in inflammatory monocytes.

Widely targeted metabolomic profiling combined with transcriptome analysis sheds light on flavonoid biosynthesis in sweet orange 'Newhall' (C. sinensis) under magnesium stress.

Sweet orange 'Newhall' peels (SOPs) are abundant in flavonoids, making them increasingly popular in the realms of nutrition, food, and medicine. However, there is still much unknown about flavonoid components in SOPs and the molecular mechanism of flavonoid biosynthesis when subjected to magnesium stress. The previous experiment conducted by the research group found that the total flavonoid content of Magnesium deficiency (MD) was higher than Magnesium sufficiency (MS) in SOPs. In order to study the metabolic pathway of flavonoids under magnesium stress, an integrative analysis of the metabolome and transcriptome was performed in SOPs at different developmental stages, comparing MS and MD. A comprehensive analysis revealed the identification of 1,533 secondary metabolites in SOPs. Among them, 740 flavonoids were classified into eight categories, with flavones identified as the dominant flavonoid component. The influence of magnesium stress on flavonoid composition was evaluated using a combination of heat map and volcanic map, which indicated significant variations between MS and MD varieties at different growth stages. The transcriptome detected 17,897 differential genes that were significantly enriched in flavonoid pathways. Further analysis was performed using Weighted gene correlation network analysis (WGCNA) in conjunction with flavonoid metabolism profiling and transcriptome analysis to identify six hub structural genes and ten hub transcription factor genes that play a crucial role in regulating flavonoid biosynthesis from yellow and blue modules. The correlation heatmap and Canonical Correspondence Analysis (CCA) results showed that CitCHS had a significant impact on the synthesis of flavones and other flavonoids in SOPs, as it was the backbone gene in the flavonoid biosynthesis pathway. The qPCR results further validated the accuracy of transcriptome data and the reliability of candidate genes. Overall, these results shed light on the composition of flavonoid compounds in SOPs and highlight the changes in flavonoid metabolism that occur under magnesium stress. This research provides valuable insights for improving the cultivation of high-flavonoid plants and enhancing our understanding of the molecular mechanisms underlying flavonoid biosynthesis.

[Application of traditional Chinese medicine theory in modern traditional Chinese medicine nano-preparation: taking tumor treatment as an example].

With Zang-Fu organs, meridians, Qi and blood, and body fluid as the physiological and pathological basis, traditional Chinese medicine(TCM) theory is guided by the holistic concept and characterized by syndrome differentiation. It has made significant contributions to human health maintenance and disease prevention. Modern TCM preparation is developed on the basis of inheriting and developing TCM preparations using modern science and technology under the guidance of TCM theory. At present, the incidence and mortality of common tumors are increasing. TCM has rich clinical experience in the treatment of tumors. However, in the current stage, some TCM preparations have a tendency to deviate from the guidance of TCM theory. With the modernization of TCM, it is worth considering how TCM theory guides modern TCM preparations. Taking tumor treatment as an example, this paper introduced the development of TCM nano-preparation under the influence of modern nanotechnology, summarized the research on the development of modern TCM nano-preparation from the aspects of TCM holistic concept, TCM treatment principles, and TCM theory application, and discussed the application prospect of TCM nano-preparation in overall therapy, drug pairing, carrier selection, and targeted substance selection under the guidance of TCM theory. This paper provides new references for further developing the combination of tradition and modernization of TCM nano-preparation.

Machine Learning Revealed Ferroptosis Features and a Novel Ferroptosis-Based Classification for Diagnosis in Acute Myocardial Infarction.

Acute myocardial infarction (AMI) is a leading cause of death and disability worldwide. Early diagnosis of AMI and interventional treatment can significantly reduce myocardial damage. However, owing to limitations in sensitivity and specificity, existing myocardial markers are not efficient for early identification of AMI. Transcriptome-wide association studies (TWASs) have shown excellent performance in identifying significant gene-trait associations and several cardiovascular diseases (CVDs). Furthermore, ferroptosis is a major driver of ischaemic injury in the heart. However, its specific regulatory mechanisms remain unclear. In this study, we screened three Gene Expression Omnibus (GEO) datasets of peripheral blood samples to assess the efficiency of ferroptosis-related genes (FRGs) for early diagnosis of AMI. To the best of our knowledge, for the first time, TWAS and mRNA expression data were integrated in this study to identify 11 FRGs specifically expressed in the peripheral blood of patients with AMI. Subsequently, using multiple machine learning algorithms, an optimal prediction model for AMI was constructed, which demonstrated satisfactory diagnostic efficiency in the training cohort (area under the curve (AUC) = 0.794) and two external validation cohorts (AUC = 0.745 and 0.711). Our study suggests that FRGs are involved in the progression of AMI, thus providing a new direction for early diagnosis, and offers potential molecular targets for optimal treatment of AMI.

Exosomal miR-17-3p Alleviates Programmed Necrosis in Cardiac Ischemia/Reperfusion Injury by Regulating TIMP3 Expression.

OBJECTIVE: Myocardial ischemia/reperfusion (I/R) injury can aggravate myocardial injury. Programmed necrosis plays a crucial role in this injury. However, the role of exosomal miRNAs in myocardial I/R injury remains unclear. Therefore, this study is aimed at exploring the function and mechanism of exosomal miR-17-3p in myocardial I/R injury. METHODS: The myocardial I/R injury animal model was established in C57BL/6 mice. Exosomes were identified using transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blotting. Programmed necrosis was detected by PI staining. Heart function and myocardial infarct size were evaluated using echocardiography and triphenyl tetrazolium chloride (TTC) staining, respectively. Histopathological changes were visualized by hematoxylin and eosin (H&E) and Masson staining. The regulation of TIMP3 expression by miR-17-3p was verified using a dual-luciferase reporter assay. Lactate dehydrogenase (LDH) and tumor necrosis factor-α (TNF-α) levels were measured by enzyme-linked immunosorbent assays (ELISA). TIMP3 expression was measured by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting. RESULTS: We demonstrated that miR-17-3p was significantly downregulated in peripheral blood exosomes after cardiac I/R injury. Further analysis indicated that exosomal miR-17-3p attenuated H2O2-induced programmed necrosis in cardiomyocytes in vitro. Moreover, TIMP3 was a target for miR-17-3p. TIMP3 affected H2O2-induced programmed necrosis in cardiomyocytes. This effect was modulated by miR-17-3p in vitro. Furthermore, exosomal miR-17-3p greatly alleviated cardiac I/R injury in vivo. CONCLUSIONS: The present study demonstrated that exosomal miR-17-3p alleviated the programmed necrosis associated with cardiac I/R injury by regulating TIMP3 expression. These findings could represent a potential treatment for I/R injury.

Accuracy of triggering receptor expressed on myeloid cells 1 in diagnosis and prognosis of acute myocardial infarction: a prospective cohort study.

BACKGROUND: Acute myocardial infarction (AMI) is one of the fatal cardiac emergencies. The detection of triggering receptor expressed on myeloid cells 1 (TREM1), a cell surface immunoglobulin that amplifies pro-inflammatory responses, screened by bioinformatics was shown to be significant in diagnosing and predicting the prognosis of AMI. METHODS: GSE66360, GSE61144 and GSE60993 were downloaded from the Gene Expression Omnibus (GEO) database to explore the differentially expressed genes (DEGs) between AMI and control groups using R software. A total of 147 patients in total were prospectively enrolled from October 2018 to June 2019 and divided into two groups, the normal group (n = 35) and the AMI group (n = 112). Plasma was collected from each patient at admission and all patients received 6-month follow-up care. RESULTS: According to bioinformatic analysis, TREM1 was an important DEG in patients with AMI. Compared with the normal group, TREM1 expression was markedly increased in the AMI group (p < 0.001). TREM1 expression was positively correlated with fasting plasma glucose (FPG), glycosylated hemoglobin (HbAC), and the number of lesion vessels, although it had no correlation with Gensini score. TREM1 expression in the triple-vessels group was significantly higher than that of the single-vessel group (p < 0.05). Multiple linear regression showed that UA and HbAC were two factors influencing TREM1 expression. The ROC curve showed that TREM1 had a diagnostic significance in AMI (p < 0.001), especially in AMI patients without diabetes. Cox regression showed increased TREM1 expression was closely associated with 6-month major adverse cardiac events (MACEs) (p < 0.001). CONCLUSIONS: TREM1 is a potentially significant biomarker for the diagnosis of AMI and may be closely associated with the severity of coronary lesions and diabetes. TREM1 may also be helpful in predicting the 6-month MACEs after AMI.

Serum Exosomes Attenuate H2O2-Induced Apoptosis in Rat H9C2 Cardiomyocytes via ERK1/2.

Exosomes are small-sized vesicles that can be released from cells into the serum. Exosomes play important roles in regulating many biological processes including cell proliferation, apoptosis, cell cycle, and metabolism. However, the roles and mechanisms of plasma exosomes in the apoptosis of rat H9C2 cardiomyocytes are largely unknown. In this study, we isolated plasma exosomes as confirmed by the marker protein CD63. Using flow cytometry and western blot analysis, we found that exosomes attenuated hydrogen peroxide (H2O2)-induced apoptosis and improved survival of rat H9C2 cardiomyocytes. Furthermore, the anti-apoptosis effects of serum exosomes in rat H9C2 cardiomyocytes were mediated by the activation of ERK1/2 signaling pathway. These data indicated that plasma exosomes had the protective effects against cardiomyocyte apoptosis and might be a novel therapy strategy for myocardial injury.

Serum Extracellular Vesicles Retard H9C2 Cell Senescence by Suppressing miR-34a Expression.

Extracellular vesicles (EVs) are small-sized membrane-surrounded structures released from cells into the blood, which play important roles in regulating various biological processes. However, the role of EVs in Doxorubicin (DOX)-induced cardiomyocytes senescence remains elusive. In this study, we found that human serum EVs inhibited DOX-induced senescence in H9C2 cells, which was abolished by miR-34a mimic. Our study also proved that miR-34a mediated DOX-induced H9C2 cell senescence by targeting phosphatase 1 nuclear targeting subunit (PNUTS). In addition to the downregulation of miR-34a, EVs could upregulate the expression of PNUTS. Moreover, the inhibitory effect of serum EVs on DOX-induced H9C2 cell senescence was also impeded by PNUTS siRNA. In conclusion, our study suggests that serum EVs retard H9C2 cell senescence through the miR-34a/PNUTS pathway, providing a potential therapy for cardiac aging.

Circular RNAs in Organ Fibrosis.

Fibrosis refers to a process involving the accumulation of extracellular matrix components. It could happen in chronic organ injury or during the recovery of acute organ injury. The severity of fibrosis interferes with the function of the organ involved. Numerous studies have been carried out to explore the mechanism of fibrosis, including parenchyma injury, fibrillar ECM accumulation, fibroblast activation, microvasculature rarefaction, and a mononuclear infiltrate. Unfortunately, its underlying mechanism is at largely unknown. The studying of noncoding RNAs has provided novel insight for circRNA-miRNA-mRNA in learning disease progress. Emerging evidence has shown that circRNA is related to fibrosis activity and could potentially be a monitoring factor for fibrosis or, more excitingly, could be a target for treatment. In this chapter, we will first present the basic mechanism of organ fibrosis. Then we will focus on the recent studies about how circRNA dysregulation contributes to organ fibrosis. Finally, the advantages and potential challenges of circRNA-based therapeutics for the treatment of fibroproliferative diseases will be discussed.

Serum-Derived Extracellular Vesicles Protect Against Acute Myocardial Infarction by Regulating miR-21/PDCD4 Signaling Pathway.

Acute myocardial infarction (AMI) represents a leading cause of morbidity and mortality worldwide. Extracellular vesicles (EVs) are being recognized as a promising therapeutic approach in protecting against MI. Serum is a rich source of EVs, which transports various microRNAs (miRNAs, miRs). EVs from serum have been shown beneficial for protecting against ischemia-reperfusion injury; however, their roles in AMI are unclear. In addition, whether a miRNA might be responsible for the effects of serum EVs on protecting against AMI is undetermined. Here, we demonstrated that serum EVs significantly reduced cardiomyocytes apoptosis in both cellular and mouse models of AMI, and dramatically attenuated the infarct size in mouse hearts after AMI. Inhibition of miR-21 was shown to reduce the protective effects of serum EVs in inhibiting cardiomyocytes apoptosis. miR-21 was decreased in mouse hearts after AMI, while serum EVs increased that. In addition, the programmed cell death 4 (PDCD4) expression was identified as a target gene of miR-21. Therefore, our study showed the protective effects of serum EVs on AMI, and provided a novel strategy for AMI therapy.

Serum extracellular vesicles promote proliferation of H9C2 cardiomyocytes by increasing miR-17-3p.

Emerging evidence showed that cardiac proliferation played a significant role in the cardiac rehabilitation and repair. Extracellular vesicles (EVs) are known to regulate multiple cell functions, whereas the role of EVs in cardiac proliferation still remains unclear. In this study, we found that serum EVs promoted cell proliferation in rat heart myoblastic H9C2 cells with significantly increased expression level of miR-17-3p. Inhibition of miR-17-3p could decrease H9C2 cells proliferation induced by serum EVs. Additionally, we found that TIMP3 was a target of miR-17-3p in H9C2 cells proliferation and the expression of TIMP3 was downregulated by serum EVs. Meanwhile, inhibition of TIMP3 increased cardiac proliferation. In conclusion, results of our study indicated that serum EVs could promote the proliferation of H9C2 cells via regulating miR-17-3p/TIMP3, which may be a potential therapeutic target for treatment of cardiac injury.

Exercise Exerts Its Beneficial Effects on Acute Coronary Syndrome: Clinical Evidence.

Acute coronary syndrome (ACS) is characterized with high morbidity, high mortality, long hospitalization and frequent revisits. It has been the most serious coronary artery diseases in the world. A large body of clinical evidence demonstrates that exercise is associated with reduced cardiovascular disease risk. In addition, different types of exercise have become the central to most cardiac rehabilitation/risk reduction programs. However, the detailed effects of exercise in ACS is still unclear and there is still lack of evidence on which exercise regimen may be ideal for ACS. This chapter presents a brief review of the pathophysiology of ACS and the relationship between exercise and the cardiovascular system. Besides that, this chapter also provide an updated discussion of the most relevant discoveries regarding to exercise and its role in managing ACS in clinical studies.

Peripartum Cardiomyopathy: Do Exosomes Play a Role?

Peripartum cardiomyopathy (PPCM) refers to irreversible cardiomyocyte damage that occurs during the last month of pregnancy, or within 5 months after giving birth. It is characterized by systolic heart failure. This life-threatening condition is relatively uncommon, but the incidence has been climbing up. Because of its high mortality, it is crucial for physicians to have high suspicious for the disease. Studies have been done to search into specific lab test and treatment for PPCM. Therapies like anti-viral, anti-inflammatory and immunosuppression regimen have been explored. New regimen like exosomes has also been explored and revealed promising effects.

Roles of miR-17-92 Cluster in Cardiovascular Development and Common Diseases.

MicroRNAs (miRNAs and miRs) are a large class of noncoding, single-stranded, small RNA molecules. The precise control of their expression is essential for keeping tissue homeostasis and normal development of organisms. Thus, unbalanced expression of miRNAs is a hallmark of many diseases. Two to dozens of miRNAs can form into a miRNA cluster, and the miR-17-92 cluster is one of them. Although firstly described as an oncogenic miRNA cluster, the miR-17-92 cluster has also been found to play critical role in normal cardiac development and cardiovascular disease. This review focuses on the characteristics and functions of miR-17-92 cluster in heart.