Genome-wide profiling of cardiac H3K9me2 levels in response to ischemic preconditioning
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ABSTRACT: H3K9me2 ChIP-Seq of cardiac biopsies from the area at at risk and remote myocardium of mice subjected to ischemic preconditioning. Mice were subjected to ischemic preconditioning (IPC) through reversible ligation of the left coronary artery or a sham procedure. The procedure consisted of 5 minutes of ischemia followed by 5 minutes of reperfusion, repeated 4 times and then followed by a 30 minute reperfusion period. Biopsies were taken from the area at risk (AAR) and remote myocardium (RM) from six IPC mice
Project description:Microarray profiling of cardiac biopsies from the area at at risk and remote myocardium of mice subjected to ischemic preconditioning. Mice were subjected to ischemic preconditioning (IPC) through reversible ligation of the left coronary artery or a sham procedure. The procedure consisted of 4 minutes of ischemia followed by 4 minutes of reperfusion, repeated 4 times and then followed by a 30 minute reperfusion period. Biopsies were taken from the area at risk (AAR) and remote myocardium (RM) from two IPC mice and two sham control mice.
Project description:To investigate the mechanism by which ischemic preconditioning (IPC) produces tissue tolerance to renal ischemia reperfusion injury in a pig model 15 female Yorkshire pigs were divided into three groups: 1: no IPC and 90 minutes warm ischemia; 2: remote IPC with an early window followed by 90 min warm ischemia; 3: remote IPC with a late window followed by warm ischemia 24 hrs later. Kidney tissues were obtained after 72 hours.
Project description:Microarray profiling of cardiac biopsies from the area at at risk and remote myocardium of mice subjected to ischemic preconditioning.
Project description:To investigate the mechanism by which ischemic preconditioning (IPC) produces tissue tolerance to renal ischemia reperfusion injury in a pig model
Project description:Effects of Ischemic Preconditioning, Bevacizumab and Etanercept Ischemia and reperfusion injury provides an acute model of ischemic retinopathy that includes neurodegeneration and VEGF-dependent vascular permeability and is amenable to rapid drug testing. The distinct effects of ischemic preconditioning and bevacizumab demonstrate that the apoptotic and vascular responses to ischemia may be separated and that VEGF expression is not neuroprotective following ischemic-reperfusion. Using transient ischemia followed by reperfusion (IR) to model ischemic retinal disease, this study compares the effects of ischemic preconditioning (IPC) and therapies targeting vascular endothelial growth factor (VEGF) and tumor necrosis factor α (TNFα) on retinal apoptosis, vascular permeability and mRNA biomarker expression. Only the Ischemic Preconditioning (not Bevacizumab and Etanercept treated samples) were hybridized to arrays. Study contains 6 replicates of control and 6 IP treated retinal samples.
Project description:The clear benefits of ischemic preconditioning (IPC) in reducing ischemia reperfusion injury (IRI) remain indistinct in human liver transplantation. To further understand the mechanistic aspects of IPC in human deceased donor liver transplantation (DDLT), we performed microarray analyses to determine global gene expression profiles associated with IPC administration. Donor and recipient characteristics in both groups were comparable. Clinical data from our study subset and larger trial were similar. IPC increased expression of 10 transcripts at either time point with roles in: antioxidant defenses, immunological response, lipid biosynthesis, and xenobiotic metabolism. IPC decreased the expression of 1 cell development related transcript. Conclusions: 1) IPC in DDLT increased the expression of antioxidant transcripts similar to studies in animal IPC, anesthetic, and remote IPC. 2) IPC increased expression of lipogenic transcripts, which may be relevant to the clinically observed increased IRI in our IPC group. 3) Our microarray findings support our clinical observations and are compatible with the varied outcomes of hepatic IPC studies in human liver transplantation.
Project description:Myocardial ischemic preconditioning (IPC) enhances myocardial resilience to ischemic injury. Myocardial stunning is a transient, reversible dysfunction, while necrosis involves irreversible cell death. The relationship between IPC, stunning, and necrosis is not well understood, requiring further molecular investigation. This study aimed to investigate the proteomic changes associated with IPC, focusing on its relationship with myocardial stunning and necrosis. A novel 13.5-minute ischemia-reperfusion (I/R) rat model was specifically chosen to induce myocardial stunning, providing a unique approach to assess IPC effects in this context. Rats underwent either IPC with two 5-minute ischemia/reperfusion cycles followed by a 13.5-minute ischemic period or the procedure without IPC (no ischemic preconditioning, NIPC). Myocardial samples were collected at early (T1) and 4-hour post-reperfusion (T2) time points for proteomic analysis. Protein levels were quantified by differential labeling using TMTpro reagents, and subsequent liquid chromatography-mass spectrometry. IPC induced upregulation of proteins involved in endocytosis and Fc gamma R-mediated phagocytosis pathways at T1, while downregulating proteins related to tissue remodeling, immune response, and coagulation at T2. Conversely, NIPC exhibited upregulation of proteins associated with tissue damage and inflammation. IPC rats demonstrated enhanced leukocyte migration, complement activation, and immune response between T1 and T2. Consistent proteomic changes were observed between T1 and T2 in IPC vs. NIPC groups, and common alterations between IPC T2 vs. T1 and NIPC T2 vs. T1 comparisons underline shared pathways in cardiac complement and coagulation cascades. Our study reveals distinct proteomic changes induced by IPC in the context of myocardial stunning and necrosis. IPC activates early protective pathways, attenuates tissue damage and inflammation, and preserves myocardial function. These findings underscore IPC's reparative potential and identify myocardial stunning as an important, transient adaptation, which may have implications for supportive clinical management in I/R.
Project description:The clear benefits of ischemic preconditioning (IPC) in reducing ischemia reperfusion injury (IRI) remain indistinct in human liver transplantation. To further understand the mechanistic aspects of IPC in human deceased donor liver transplantation (DDLT), we performed microarray analyses to determine global gene expression profiles associated with IPC administration. Donor and recipient characteristics in both groups were comparable. Clinical data from our study subset and larger trial were similar. IPC increased expression of 10 transcripts at either time point with roles in: antioxidant defenses, immunological response, lipid biosynthesis, and xenobiotic metabolism. IPC decreased the expression of 1 cell development related transcript. Conclusions: 1) IPC in DDLT increased the expression of antioxidant transcripts similar to studies in animal IPC, anesthetic, and remote IPC. 2) IPC increased expression of lipogenic transcripts, which may be relevant to the clinically observed increased IRI in our IPC group. 3) Our microarray findings support our clinical observations and are compatible with the varied outcomes of hepatic IPC studies in human liver transplantation. We conducted a nested sub-study in 12/101 subjects enrolled in a prospective randomized trial of 10 min IPC in DDLT during 2003-2006. Liver biopsies were performed at the end of cold storage and at 90 minutes after allograft reperfusion. Six biopsy pairs from both IPC and No IPC (STD) groups within a narrow donor risk index range were selected. Total RNA was extracted and hybridized with Affymetrix GeneChip Human Gene 1.0 ST Array. IPC effects were examined by comparing IPC vs. STD at both time points. Transcripts whose expression changed 2-fold with p<0.05 were considered significant.
Project description:Similar to remote ischemic preconditioning bouts of exercise may possess immediate protective effects against ischemia-reperfusion injury. However, underlying mechanisms are largely unknown. This study compared the impact of single and repeated handgrip exercise versus remote ischemic preconditioning on inflammatory biomarkers in patients with cerebral small vessel disease (cSVD). In this crossover study, 14 patients with cSVD were included. All participants performed 4-days of handgrip exercise (4x5-minutes at 30% of maximal handgrip strength) and remote ischemic preconditioning (rIPC; 4x5-minutes cuff occlusion around the upper arm) twice daily. Patients were randomized to start with either handgrip exercise or rIPC and the two interventions were separated by >9 days. Venous blood was drawn before and after one intervention, and after 4-days of repeated exposure. We performed a targeted proteomics on inflammation markers in all blood samples.