The analysis of differential gene expression after remote ischemic preconditioning of renal ischemia reperfusion injury
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ABSTRACT: 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: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
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: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:The initial factor in the occurrence, development, and prognosis of cerebral ischemia is vascular dysfunction in the brain, and vascular remodeling of the brain is the key therapeutic target and strategy for ischemic tissue repair. Limb remote ischemic preconditioning exhibits potential pleiotropic protective effects in many brain-related diseases, including stroke.Whether limb remote ischemic preconditioning has other effects such as vascular protective effects and the detailed mechanism by which limb remote ischemic preconditioning improves pathology and angiogenesis in cerebral ischemia remains to be further elucidated. The present study was designed to investigate whether limb remote ischemic preconditioning protects vascular structure and promotes angiogenesis in cerebral ischemic rats.
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:Despite advances in surgery support there are unmet needs for cardiopulmonary bypass (CPB) patients being at risk of perioperative ischemia. Remote ischemic preconditioning (RIPC) is considered as adjuvant therapy, but its effects are still underexplored. Thus, we monitored transcriptomic responses from the RIPC procedure during and after cardiac surgery in a pilot study, comprising 34 samples and 10 for validation from patients. We systematically compared the response between CTRL and RIPC including individual effects and dynamics. We gratefully acknowledge the support from the study participants as part of the clinical trial (ClinicalTrials.gov ID: NCT01067703). Different individual and time-resolved patterns were found for preconditioned patients (RIPC) comprising alternated cytokine, ribosomal and stress related genes. This was confirmed by a tailored method for ranking candidates by integrating variance and expression changes at once.
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.