Project description:To explore the differences in the expression of circRNA in myocardial ischemia-reperfusion injury and the potential effects of these differences in circRNA. Methods 6 SPF male SD rats were randomly divided into two groups, including 3 in Myocardial ischemia reperfusion group and 3 threading without ligation in control group by ligating the left anteriors branch for 40 minutes and reperfusing for 2 hours to establish a model of myocardial ischemia reperfusion injury. The myocardial specimens from the infarct area were taken for high-throughput sequencing analysis to obtain differently expressed circRNA. After that, GO and KEGG analysis were performed to speculate on the biological functions and possible biological pathways involved. RT-qPCR was used to verify the sequencing results of differential circRNA, and bioinformatics analysis predicted that circRNA could combine with miRNA to construct a visual network diagram and their interaction. Results Analyzing of 13576 circRNAs detected in 6 rats from MIRI group and control group, A total of 132 circRNAs showed significant differential expression, of which 82 were up-regulated and 50 were down-regulated. The results of GO and KEGG analysis suggest that differential circRNA is closely related to myocardial ischemia reperfusion injury, and KEGG analysis suggests that differential circRNA is involved in calcium, AMPK, mTOR and adrenaline signal pathways. 4 circRNAs were extracted from the up-regulated circRNA for RT-qPCR verification, and the results of 2 were consistent with the high-throughput sequencing results. circRNA-miRNA interaction analysis shows that circRNA interacts with a variety of miRNAs. Conclusions The expression of circRNA in myocardial reperfusion injury rats is significantly different, which may be involved in the occurrence and development of myocardial ischemia-reperfusion injury through miRNA sponge action of circRNA.
Project description:CircRNAs have complex biological functions and are involved in the development of several cardiovascular diseases. The relationship between circRNAs and myocardial ischaemia-reperfusion injury (MIRI) is not yet clear. The aim of this study was to investigate the expression of circRNAs in rat plasma, to examine the differential expression profile of circRNAs in the plasma of MIRI rats, and to explore whether these circRNAs are potentially significant and have potential as novel markers for the diagnosis of MIRI and as therapeutic targets.
Project description:Mitochondrial Creatine Kinase 2 (Ckmt2) as a Plasma-Based Biomarker for Evaluating Reperfusion Injury in Acute Myocardial Infarction
Project description:This SuperSeries is composed of the following subset Series: GSE21405: MicroRNA Profiling In Ischemia-Reperfusion Injury Of The Gracilis Muscle In Rats GSE21406: Potential Target Genes of MicroRNA-21 In Ischemia-Reperfusion Injury Of The Gracilis Muscle In Rats Refer to individual Series
Project description:Background: Ischemic preconditioning (IPC), i.e., brief periods of ischemia, protect the heart from subsequent prolonged ischemic injury, and reduces infarction size. Myocardial stunning refers to transient loss of contractility in the heart after myocardial ischemia that recovers without causing permanent damage. The relationship between IPC and myocardial stunning remains incompletely understood. Purpose: The primary aim of this study was to examine the effects of IPC on the relationship between ischemia duration, stunning, and infarct size in an ischemia-reperfusion injury model. The secondary aim of the study was to examine to which extent the phosphoproteomic changes induced by IPC relate to myocardial contractile function. Methods: Rats were subjected to different durations of left anterior descending artery (LAD) occlusion, with or without preceding IPC. Echocardiograms were acquired at 4 and 48 hours to assess cardiac contraction in the affected myocardial segment. Reversible akinesia was defined as the presence of myocardial akinesia at 4 hours that resolved by 48 hours; and was considered to represent myocardial stunning. Infarction size was evaluated using triphenyl tetrazolium chloride staining. Phosphoproteomic analysis was performed in heart tissue from preconditioned and non-preconditioned animals using nano-liquid chromatography-mass spectrometry. Results: Reversible akinesia was observed in a majority of the rats that were subjected to IPC and subsequently exposed to ischemia of 13.5 or 15 minutes of ischemia (83.3% [n/N] and 66.6% [n/N] respectively). Among rats without IPC, who were exposed to either 10, 11, 12 or 13.5 minutes of ischemia, reversible akinesia was observed in 0% (n/N), 17% (2/12), 0% (n/N) and 0% (n/N) of rats (p<0.001). Phosphoproteomic analysis revealed significant differential regulation of 809 phosphopeptides between IPC and non-IPC groups, with significant associations with the sarcomere, Z-disc, and actin binding. Conclusion: Our study shows that IPC preferentially induces changes in phosphosites of proteins involved in myocardial contraction, and both increases the incidence of reversible post-ischemic myocardial stunning after ischemia-reperfusion injury and reduces infarction size.
Project description:Aims: Mesenchymal stem cells (MSCs) gradually become attractive candidates for cardiac inflammation modulation, yet understanding of the mechanism remains elusive. Strikingly, recent studies indicated that exosomes secreted by MSCs might be a novel mechanism for the beneficial effect of MSCs transplantation after myocardial infarction. We therefore explored the role of MSC-derived exosomes (MSC-Exo) in the immunomodulation of macrophages after myocardial ischemia-reperfusion and its implications in cardiac injury repair. Methods and Results: Exosomes were isolated from the supernatant of MSCs using a gradient centrifugation method. Administration of MSC-Exo through intramyocardial injection after myocardial ischemia reperfusion reduced infarct size and alleviated inflammation level in heart and serum. Systemic depletion of macrophages with clodronate liposomes abolished the curative effects of MSC-Exo. MSC-Exo modified the polarization of M1 macrophages to M2 macrophages both in vivo and in vitro. miRNA-sequencing of MSC-Exo and bioinformatics analysis implicated miR-182 as a potent candidate mediator of macrophage polarization and TLR4 as a downstream target. Diminishing miR-182 in MSC-Exo partially attenuated its modulation of macrophage polarization. Likewise, knock down of TLR4 also conferred cardioprotective efficacy and reduced inflammation level in a mouse model of myocardial ischemia/reperfusion. Conclusion: Our data indicates that MSC-Exo attenuates myocardial ischemia/reperfusion injury via shuttling miR-182 that modifies the polarization state of macrophages. This study sheds new light on the application of MSC-Exo a potential therapeutic tool for myocardial ischemia/reperfusion injury.
Project description:Stroke is a leading cause of mortality and long-term disability and ischemic stroke accounts for 87% of all strokes. Though timely recanalization of the occluded vessel is essential in the treatment of ischemic stroke, it is well known to cause ischemia-reperfusion (I/R) injury which result in neuronal cell death, brain tissue loss and severe neurological deficits. In this work, we employed a global proteomic approach to examine the changes of cerebral cortex proteins in rats undergoing acute and long-term I/R injury. In vivo middle cerebral artery occlusion (MCAO) model of focal cerebral I/R injury in rats was established. The animals were divided into three model groups with 2 h-MCAO followed with different reperfusion time, 1 day, 7 days and 14 days, respectively. For each model group a sham group was correspondingly set. Each group included four animals. For proteomic analysis, cerebral cortex proteins were extracted and analyzed by SDS-PAGE, whole-lane slicing, in-gel digestion and label-free quantitative LC-MS/MS. A total of 5621 proteins were identified and their quantities between the surgery and corresponding sham groups and across the three reperfusion time points were compared for mechanism investigation. This dataset includes all the raw files of the 840 LC-MS runs (6 groups x 4 animals x 35 gel squares/sample), as well as their identification and quantitation results at the levels of peptide fragments, peptides and proteins, respectively.