Phosphoproteomic and proteomic profiling in post-infarction chronic heart failure.

Background: Post-infarction chronic heart failure is the most common type of heart failure. Patients with chronic heart failure show elevated morbidity and mortality with limited evidence-based therapies. Phosphoproteomic and proteomic analysis can provide insights regarding molecular mechanisms underlying post-infarction chronic heart failure and explore new therapeutic approaches. Methods and results: Global quantitative phosphoproteomic and proteomic analysis of left ventricular tissues from post-infarction chronic heart failure rats were performed. A total of 33 differentially expressed phosphorylated proteins (DPPs) and 129 differentially expressed proteins were identified. Bioinformatic analysis indicated that DPPs were enriched mostly in nucleocytoplasmic transport and mRNA surveillance pathway. Bclaf1 Ser658 was identified after construction of Protein-Protein Interaction Network and intersection with Thanatos Apoptosis Database. Predicted Upstream Kinases of DPPs based on kinase-substrate enrichment analysis (KSEA) app showed 13 kinases enhanced in heart failure. Proteomic analysis showed marked changes in protein expression related to cardiac contractility and metabolism. Conclusion: The present study marked phosphoproteomics and proteomics changes in post-infarction chronic heart failure. Bclaf1 Ser658 might play a critical role in apoptosis in heart failure. PRKAA1, PRKACA, and PAK1 might serve as potential therapeutic targets for post-infarction chronic heart failure.

Physiological ischemic training improves cardiac function through the attenuation of cardiomyocyte apoptosis and the activation of the vagus nerve in chronic heart failure.

Purpose: This study investigated the functional outcomes of patients with chronic heart failure (CHF) after physiological ischemic training (PIT), identified the optimal PIT protocol, evaluated its cardioprotective effects and explored the underlying neural mechanisms. Methods: Patients with CHF were randomly divided into experimental group (n = 25, PIT intervention + regular treatment) and control group (n = 25, regular treatment). The outcomes included the left ventricular ejection fraction (LVEF), brain natriuretic peptide (BNP) and cardiopulmonary parameters. LVEF and cardiac biomarkers in CHF rats after various PIT treatments (different in intensity, frequency, and course of treatment) were measured to identify the optimal PIT protocol. The effect of PIT on cardiomyocyte programmed cell death was investigated by western blot, flow cytometry and fluorescent staining. The neural mechanism involved in PIT-induced cardioprotective effect was assessed by stimulation of the vagus nerve and muscarinic M2 receptor in CHF rats. Results: LVEF and VO2max increased while BNP decreased in patients subjected to PIT. The optimal PIT protocol in CHF rats was composed of five cycles of 5 min ischemia followed by 5 min reperfusion on remote limbs for 8 weeks. LVEF and cardiac biomarker levels were significantly improved, and cardiomyocyte apoptosis was inhibited. However, these cardioprotective effects disappeared after subjecting CHF rats to vagotomy or muscarinic M2 receptor inhibition. Conclusion: PIT improved functional outcomes in CHF patients. The optimal PIT protocol required appropriate intensity, reasonable frequency, and adequate treatment course. Under these conditions, improvement of cardiac function in CHF was confirmed through cardiomyocyte apoptosis reduction and vagus nerve activation.

Novel lncRNA-miRNA-mRNA Competing Endogenous RNA Triple Networks Associated Programmed Cell Death in Heart Failure.

Objective: Increasing evidence has uncovered the roles of lncRNA-miRNA-mRNA regulatory networks in cardiovascular diseases. However, the crosstalk between ceRNA networks and development of heart failure (HF) remains unclear. This study was to investigate the role of lncRNA-mediated ceRNA networks in the pathophysiological process of HF and its potential regulatory functions on programmed cell death. Methods: We firstly screened the GSE77399, GSE52601 and GSE57338 datasets in the NCBI GEO database for screening differentially expressed lncRNAs, miRNAs and mRNAs. lncRNA-miRNA-mRNA regulatory networks based on the ceRNA theory were subsequently constructed. GO and KEGG enrichment analysis was conducted to predict potential biological functions of mRNAs in ceRNA networks. Differentially expressed mRNAs were then interacted with programmed cell death related genes. lncRNA-mediated ceRNA regulatory pathways on programmed cell death were validated with qRT-PCR testing. Results: Based on our bioinformatic analysis, two lncRNAs, eight miRNAs and 65 mRNAs were extracted to construct two lncRNAs-mediated ceRNA networks in HF. Biological processes and pathways were enriched in extracellular matrix. Seven lncRNA-mediated ceRNA regulatory pathways on programmed cell death, GAS5/miR-345-5p/ADAMTS4, GAS5/miR-18b-5p/AQP3, GAS5/miR-18b-5p/SHISA3, GAS5/miR-18b-5p/C1orf105, GAS5/miR-18b-5p/PLIN2, GAS5/miR-185-5p/LPCAT3, and GAS5/miR-29b-3p/STAT3, were finally validated. Conclusions: Two novel ceRNA regulatory networks in HF were discovered based on our bioinformatic analysis. Based on the interaction and validation analysis, seven lncRNA GAS5-mediated ceRNA regulatory pathways were hypothesized to impact programmed cell death including seven for apoptosis, three for ferroptosis, and one for pyroptosis. Upon which, we provided novel insights and potential research plots for bridging ceRNA regulatory networks and programmed cell death in HF.

Validated Impacts of N6-Methyladenosine Methylated mRNAs on Apoptosis and Angiogenesis in Myocardial Infarction Based on MeRIP-Seq Analysis.

Objectives: N6-methyladenosine (m6A) is hypothesized to play a role in the regulation of pathogenesis of myocardial infarction (MI). This study was designed to compare m6A-tagged transcript profiles to identify mRNA-specific changes on pathophysiological variations after MI. Methods: N6-methyladenosine methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA sequencing (RNA-seq) were interacted to select m6A-modified mRNAs with samples collected from sham operated and MI rat models. m6A methylation regulated mRNAs were interacted with apoptosis/angiogenesis related genes in GeneCards. Afterwards, MeRIP-quantitative real-time PCR (MeRIP-qRT-PCR) was performed to measure m6A methylation level of hub mRNAs. m6A methylation variation was tested under different oxygen concentration or hypoxic duration in H9c2 cells and HUVECs. In addition, Western blot and qRT-PCR were employed to detect expression of hub mRNAs and relevant protein level. Flow cytometry and Tunel assay were conducted to assess apoptotic level. CCK-8, EdU, and tube formation assay were performed to measure cell proliferation and tube formation ability. Results: Upregulation of Mettl3 was firstly observed in vivo and in vitro, followed by upregulation of m6A methylation level. A total of 567 significantly changed m6A methylation peaks were identified, including 276 upregulated and 291 downregulated peaks. A total of 576 mRNAs were upregulated and 78 were downregulated. According to combined analysis of MeRIP-seq and RNA-seq, we identified 26 significantly hypermethylated and downregulated mRNAs. Based on qRT-PCR and interactive analysis, Hadh, Kcnn1, and Tet1 were preliminarily identified as hub mRNAs associated with apoptosis/angiogenesis. MeRIP-qRT-PCR assay confirmed the results from MeRIP-seq. With the inhibition of Mettl3 in H9c2 cells and HUVECs, downregulated m6A methylation level of total RNA and upregulated expression of hub mRNAs were observed. Increased m6A level was verified in the gradient context in terms of prolonged hypoxic duration and decreased oxygen concentration. Under simulated hypoxia, roles of Kcnn1 and Tet1 in angiogenesis and Hadh, Tet1, and Kcnn1 in apoptosis were further confirmed with our validation experiments. Conclusion: Roles of m6A-modified mRNA transcripts in the context of MI were preliminarily verified. In the context of m6A methylation, three hub mRNAs were validated to impact the process of apoptosis/angiogenesis. Our study provided theoretical basis and innovative targets for treatment of MI and paved the way for future investigations aiming at exploring upstream epigenetic mechanisms of pathogenesis after MI.

Can Cardiopulmonary Rehabilitation Facilitate Weaning of Extracorporeal Membrane Oxygenation (CaRe-ECMO)? Study Protocol for a Prospective Multidisciplinary Randomized Controlled Trial.

Background: Mortality of patients suffering from critical illness has been dramatically improved with advanced technological development of extracorporeal membrane oxygenation (ECMO) therapy. However, the majority of ECMO-supported patients failed to wean from ECMO therapy. As one of several options, cardiopulmonary rehabilitation serves as effective intervention in the improvement of cardiovascular and respiratory function in various major critical illness. Nonetheless, its role in facilitating ECMO weaning has not yet been explored. The purpose of this study is to investigate the effectiveness of cardiopulmonary rehabilitation on rate of ready for ECMO weaning in ECMO-supported patients (CaRe-ECMO). Methods: The CaRe-ECMO trial is a randomized controlled, parallel group, clinical trial. This trial will be performed in a minimum number of 366 ECMO-supported eligible patients. Patients will be randomly assigned to either: (1) the CaRe-ECMO group, which will be treated with usual care including pharmacotherapy, non-pharmacotherapy, and specific nursing for ECMO therapy and the CaRe-ECMO program; or (2) the control group, which will receive usual care only. The CaRe-ECMO program consists of protocolized positioning, passive range of motion (PROM) training, neuromuscular electrical stimulation (NMES), surface electrical phrenic nerve stimulation (SEPNS), and pulmonary rehabilitation. The primary outcome of the CaRe-ECMO trial is the rate of ready for ECMO weaning at CaRe-ECMO day 7 (refers to 7 days after the CaRe-ECMO program initiation). Secondary outcomes include rate of ECMO and mechanical ventilation weaning, total length in day of ready for ECMO weaning, ECMO weaning and mechanical ventilation, all-cause mortality, rate of major post-ECMO complications, ECMO unit length of stay (LOS) and hospital LOS, total cost for hospitalization, cerebral performance category (CPC), activities of daily living (ADL), and health-related quality of life (HRQoL). Discussion: The CaRe-ECMO is designed to answer the question "whether cardiopulmonary rehabilitation can facilitate weaning of ECMO (CaRe-ECMO)." Should the implementation of the CaRe-ECMO program result in superior primary and secondary outcomes as compared to the controls, specifically the add-on effects of cardiopulmonary rehabilitation to the routine ECMO practice for facilitating successful weaning, the CaRe-ECMO trial will offer an innovative treatment option for ECMO-supported patients and meaningfully impact on the standard care in ECMO therapy. Clinical Trial Registration: ClinicalTrials.gov, identifier: NCT05035797.