Cardiac Contractility Modulation Attenuates Chronic Heart Failure in a Rabbit Model via the PI3K/AKT Pathway

miR-455-5p promotes pathological cardiac remodeling via suppression of PRMT1-mediated Notch signaling pathway

Pathological cardiac remodeling plays an essential role in the progression of cardiovascular diseases, and numerous microRNAs have been reported to participate in pathological cardiac remodeling. However, the potential role of microRNA-455-5p (miR-455-5p) in this process remains to be elucidated. In the present study, we focused on clarifying the function and searching the direct target of miR-455-5p, as well as exploring its underlying mechanisms in pathological cardiac remodeling. We found that overexpression of miR-455-5p by transfection of miR-455-5p mimic in vitro or tail vain injection of miR-455-5p agomir in vivo provoked cardiac remodeling, whereas genetic knockdown of miR-455-5p attenuated the isoprenaline-induced cardiac remodeling. Besides, miR-455-5p directly targeted to 3'-untranslated region of protein arginine methyltransferase 1 (PRMT1) and subsequently downregulated PRMT1 level. Furthermore, we found that PRMT1 protected against cardiac hypertrophy and fibrosis in vitro. Mechanistically, miR-455-5p induced cardiac remodeling by downregulating PRMT1-induced asymmetric di-methylation on R1748, R1750, R1751 and R1752 of Notch1, resulting in suppression of recruitment of Presenilin, Notch1 cleavage, NICD releasing and Notch signaling pathway. Finally, circulating miR-455-5p was positively correlated with parameters of left ventricular wall thickening. Taken together, miR-455-5p plays a provocative role in cardiac remodeling via inactivation of the PRMT1-mediated Notch signaling pathway, suggesting miR-455-5p/PRMT1/Notch1 signaling axis as potential therapeutic targets for pathological cardiac remodeling.

The regulatory role of PI3K in ageing-related diseases

Ageing is a physiological/pathological process accompanied by the progressive damage of cell function, triggering various ageing-related disorders. Phosphatidylinositol 3-kinase (PI3K), which serves as one of the central regulators of ageing, is closely associated with cellular characteristics or molecular features, such as genome instability, telomere erosion, epigenetic alterations, and mitochondrial dysfunction. In this review, the PI3K signalling pathway was firstly thoroughly explained. The link between ageing pathogenesis and the PI3K signalling pathway was then summarized. Finally, the key regulatory roles of PI3K in ageing-related illnesses were investigated and stressed. In summary, we revealed that drug development and clinical application targeting PI3K is one of the focal points for delaying ageing and treating ageing-related diseases in the future.

Upregulation of miR-144-3p alleviates Doxorubicin-induced heart failure and cardiomyocytes apoptosis via SOCS2/PI3K/AKT axis

MicroRNAs (miRs) are implicated in heart failure (HF). Thereby, we aim to uncover the role of miR-144-3p in HF. Doxorubicin (Dox)-induced HF model was constructed in rats and cardiomyocytes H9C2, and the cardiac function was determined using ultrasound cardiogram. Morphology of cardiac tissue was observed using hematoxylin-eosin (H&E) staining. The viability and apoptosis of Dox-treated and transfected cardiomyocytes were determined using Cell Counting Kit-8 (CCK-8) assay and flow cytometry. Relative expressions of the HF-associated miRs (including miR-144-3p), suppressor of cytokine signaling 2 (SOCS2), apoptosis- and phosphoinositide 3-kinase (PI3K)/AKT pathway-related factors (B-cell lymphoma 2, Bcl-2; Bcl-2 associated X protein, Bax; cleaved [C] capsase-3; phosphoinositide 3-kinase, PI3K; phosphorylated-PI3K, p-PI3K; p-AKT; AKT) were measured with quantitative real-time polymerase chain reaction or Western blot. Target gene of miR-144-3p was predicted by Starbase and TargetScan and confirmed with dual-luciferase reporter assay. Dox caused rat cardiac dysfunction, aggravated cardiac injury, decreased cardiomyocytes viability, and the expression of miR-144-3p, Bcl-2, and phosphorylation of both PI3K and AKT yet the upregulated those of Bax and C caspase-3, which was reversed by upregulating miR-144-3p, whereas downregulating miR-144-3p did oppositely. SOCS2 was the target gene of miR-144-3p, Dox promoted SOCS2 expression, which was reversed by upregulating miR-144-3p, while downregulating miR-144-3p did conversely. In addition, silencing SOCS2 reversed the effects of miR-144-3p downregulation in Dox-treated cardiomyocytes. Upregulating miR-144-3p alleviated Dox-induced cardiac dysfunction and cell apoptosis via targeting SOCS2, providing a novel evidence of miR-144-3p in HF.

Mechanism of Epimedium intervention in heart failure based on network pharmacology and molecular docking technology

To analyze the pharmacological mechanism of Epimedium in regulating heart failure (HF) based on the network pharmacology method, and to provide a reference for the clinical application of Epimedium in treating HF. Obtaining the main active ingredients and their targets of Epimedium through TCMSP (Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform) database. Access to major HF targets through Genecards, OMIM, PharmGKB, Therapeutic Target Database, Drug Bank database. Protein interaction analysis using String platform and construction of PPI network. Subsequently, Cytoscape software was used to construct the "Epimedium active ingredient-heart failure target" network. Finally, the molecular docking is verified through the Systems Dock Web Site. The core active ingredients of Epimedium to regulate HF are quercetin, luteolin, kaempferol, etc. The core targets are JUN, MYC, TP53, HIF1A, ESR1, RELA, MAPK1, etc. Molecular docking validation showed better binding activity of the major targets of HF to the core components of Epimedium. The biological pathways that Epimedium regulates HF mainly act on lipid and atherosclerotic pathways, PI3K-Akt signaling pathway, and chemoattractant-receptor activation. And its molecular functions are mainly DNA-binding transcription factor binding, RNA polymerase II-specific DNA-binding transcription factor binding, and neurotransmitter receptor activity. This study reveals the multi-component, multi-target and multi-pathway mechanism of action of Epimedium in regulating mental failure, and provides a basis for the clinical development and utilization of Epimedium to intervene in HF.

Gentianella acuta improves TAC-induced cardiac remodelling by regulating the Notch and PI3K/Akt/FOXO1/3 pathways

Cardiac remodelling mainly manifests as excessive myocardial hypertrophy and fibrosis, which are associated with heart failure. Gentianella acuta (G. acuta) is reportedly effective in cardiac protection; however, the mechanism by which it protects against cardiac remodelling is not fully understood. Here, we discuss the effects and mechanisms of G. acuta in transverse aortic constriction (TAC)-induced cardiac remodelling in rats. Cardiac function was analysed using echocardiography and electrocardiography. Haematoxylin and eosin, Masson's trichrome, and wheat germ agglutinin staining were used to observe pathophysiological changes. Additionally, real-time quantitative reverse transcription polymerase chain reaction and western blotting were used to measure protein levels and mRNA levels of genes related to myocardial hypertrophy and fibrosis. Immunofluorescence double staining was used to investigate the co-expression of endothelial and interstitial markers. Western blotting was used to estimate the expression and phosphorylation levels of the regulatory proteins involved in autophagy and endothelial-mesenchymal transition (EndMT). The results showed that G. acuta alleviated cardiac dysfunction and remodelling. The elevated levels of myocardial hypertrophy and fibrosis markers, induced by TAC, decreased significantly after G. acuta intervention. G. acuta decreased the expression of LC3 II and Beclin1, and increased p62 expression. G. acuta upregulated the expression of CD31 and vascular endothelial-cadherin, and prevented the expression of α-smooth muscle actin and vimentin. Furthermore, G. acuta inhibited the PI3K/Akt/FOXO1/3a pathway and activated the Notch signalling. These findings demonstrated that G. acuta has cardioprotective effects, such as alleviating myocardial fibrosis, inhibiting hypertrophy, reducing autophagy, and blocking EndMT by regulating the PI3K/Akt/FOXO1/3a and Notch signalling pathways.

Calycosin as a Novel PI3K Activator Reduces Inflammation and Fibrosis in Heart Failure Through AKT-IKK/STAT3 Axis

Aim: Inflammation and fibrosis have been shown to be critical factors in heart failure (HF) progression. Calycosin (Cal) is the major active component of Astragalus mongholicus Bunge and has been reported to have therapeutic effects on the cardiac dysfunction after myocardial infarction. However, whether Cal could ameliorate myocardial infarction (MI)-induced inflammation and fibrosis and precise mechanisms remain uncertain. The aim of this study is to explore the role of Cal in HF and to clarify the underlying mechanisms.

Methods: For in vivo experiments, rats underwent left anterior descending artery ligation for heart failure model, and the cardioprotective effects of Cal were measured by echocardiographic assessment and histological examination. RNA-seq approach was applied to explore potential differential genes and pathways. For further mechanistic study, proinflammatory-conditioned media (conditioned media)-induced H9C2 cell injury model and TGFβ-stimulated cardiac fibroblast model were applied to determine the regulatory mechanisms of Cal.

Results: In the in vivo experiments, echocardiography results showed that Cal significantly improved heart function. GO and reactome enrichment revealed that inflammation and fibrosis pathways are involved in the Cal-treated group. KEGG enrichment indicated that the PI3K–AKT pathway is enriched in the Cal-treated group. Further experiments proved that Cal alleviated cardiomyocyte inflammatory responses evidenced by downregulating the expressions of phosphorylated IκB kinase α/β (p-IKKα/β), phosphorylated nuclear factor kapa B (p-NFκB), and tumor necrosis factor α (TNFα). Besides, Cal effectively attenuated cardiac fibrosis through the inhibitions of expressions and depositions of collagen I and collagen III. In the in vitro experiments, the phosphatidylinositol three kinase (PI3K) inhibitor LY294002 could abrogate the anti-inflammation and antifibrosis therapeutic effects of Cal, demonstrating that the cardioprotective effects of Cal were mediated through upregulations of PI3K and serine/threonine kinase (AKT).

Conclusion: Cal inhibited inflammation and fibrosis via activation of the PI3K–AKT pathway in H9C2 cells, fibroblasts, and heart failure in postacute myocardial infarction rats.

Identification of vital modules and genes associated with heart failure based on weighted gene coexpression network analysis

Aims

Heart failure (HF) is a chronic heart disease with a high incidence and mortality. Due to the regulatory complexity of gene coexpression networks, the underlying hub genes regulation in HF remain incompletely appreciated. We aimed to explore potential key modules and genes for HF using weighted gene coexpression network analysis (WGCNA).

Methods and results

The expression profiles by high throughput sequencing of heart tissues samples from HF and non‐HF samples were obtained from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) between HF and non‐HF samples were firstly identified. Then, a coexpression network was constructed to identify key modules and potential hub genes. The biological functions of potential hub genes were analysed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses. Finally, a protein–protein interaction (PPI) network was constructed using the STRING online tool. A total of 135 DEGs (133 up‐regulated and 2 down‐regulated DEGs) between HF and non‐HF samples were identified in the GSE135055 and GSE123976 datasets. Moreover, a total of 38 modules were screened based on WGCNA in the GSE135055 dataset, and six potential hub genes (UCK2, ASB1, CCNI, CUX1, IRX6, and STX16) were screened from the key module by setting the gene significance over 0.2 and the module membership over 0.8. Furthermore, 78 potential hub genes were obtained by taking the intersection of the 135 DEGs and all genes in the key module, and enrichment analysis revealed that they were mainly involved in the MAPK and PI3K‐AKT signalling pathways. Finally, in a PPI network constructed with the 78 potential hub genes, CUX1 and ASB1 were identified as hub genes in HF because they were also identified as potential hub genes in the WGCNA.

Conclusions

To the best of our knowledge, our study is the first to employ WGCNA to identify the key module and hub genes for HF. Our study identified a module and two genes that might play important roles in HF, which may provide potential biomarkers for the diagnosis of HF and improve our knowledge of the molecular mechanisms underlying HF.

miR-124 promotes apoptosis and inhibits the proliferation of vessel endothelial cells through P38/MAPK and PI3K/AKT pathways, making it a potential mechanism of vessel endothelial injury in acute myocardial infarction

Due to its rapid onset and high rates of fatality, acute myocardial infarction (AMI) has long been one of the most fatal diseases among all types of heart diseases. Therefore, intensive research efforts have been focused on understanding AMI's potential pathogenesis to seek effective treatment options. In the present study, 20 peripheral blood samples were collected from patients with AMI, after which reverse transcription-quantitative PCR analysis revealed that microRNA (miR)-124 levels in the peripheral blood of patients with AMI was significantly elevated compared with that in the control group. In vitro, a model using pcDNA3.1-miR-124 transfected human umbilical vein endothelial cells (HUVECs) indicated that overexpression of miR-124 could significantly promote the apoptosis and suppress the proliferation of HUVECs using flow cytometry, TUNEL assay and Cell Counting Kit-8 assays. Based on the present findings, RNA samples of HUVECs overexpressing miR-124 was extracted and sequenced to explore the gene expression profile after miR-124 overexpression. Gene Set Enrichment Analysis (GSEA) analysis revealed that the downregulated genes were mainly enriched in signaling pathways, such as PI3K-AKT, whilst the upregulated genes were mainly enriched in metabolism-related signaling pathways, such as the metabolism of xenobiotics by cytochrome P450 pathway. Additionally, Rideogram software was used to determine the chromosomal localization of the differentially expressed genes. The results demonstrated that they were distributed on all chromosomes except for chromosome Y. In addition, characteristic profiles of the differentially expressed genes caused by miR-124 overexpression were analyzed using Connectivity Map. In total, two medicines, anisomycin and sanguinarine, which function as p38/MAPK signaling agonists that can inhibit angiogenesis, presented with the highest enrichment scores. Together with the GSEA results, which indicated that the differentially expressed genes were mainly enriched in the angiogenesis-inhibiting PI3K/AKT signaling pathway, the present study reported that high expression of miR-124 was negatively associated with patients with AMI, promoting the apoptosis and suppressing the proliferation of vessel endothelial cells.

Guidelines for animal exercise and training protocols for cardiovascular studies

Whole body exercise tolerance is the consummate example of integrative physiological function among the metabolic, neuromuscular, cardiovascular, and respiratory systems. Depending on the animal selected, the energetic demands and flux through the oxygen transport system can increase two orders of magnitude from rest to maximal exercise. Thus, animal models in health and disease present the scientist with flexible, powerful, and, in some instances, purpose-built tools to explore the mechanistic bases for physiological function and help unveil the causes for pathological or age-related exercise intolerance. Elegant experimental designs and analyses of kinetic parameters and steady-state responses permit acute and chronic exercise paradigms to identify therapeutic targets for drug development in disease and also present the opportunity to test the efficacy of pharmacological and behavioral countermeasures during aging, for example. However, for this promise to be fully realized, the correct or optimal animal model must be selected in conjunction with reproducible tests of physiological function (e.g., exercise capacity and maximal oxygen uptake) that can be compared equitably across laboratories, clinics, and other proving grounds. Rigorously controlled animal exercise and training studies constitute the foundation of translational research. This review presents the most commonly selected animal models with guidelines for their use and obtaining reproducible results and, crucially, translates state-of-the-art techniques and procedures developed on humans to those animal models.