Project description:Single Cell RNA-SEQ of Murine Kidney post Ischemia Reperfusion Injury demonstrates heterogeneous mesencymal cells post injury and recapitulates novel markers with transcipts
Project description:Ischemic preconditioning is effective in limiting subsequent ischemic acute kidney injury in experimental models. microRNAs are an important class of post-transcriptional regulator and show promise as biomarkers of kidney injury. An evaluation was performed of the time- and dose-dependent effects of ischemic preconditioning in a rat model of functional (bilateral) ischemia-reperfusion injury. A short, repetitive sequence of ischemic preconditioning resulted in optimal protection from subsequent ischemia-reperfusion injury. A detailed characterization of microRNA expression in ischemic preconditioning/ischemia-reperfusion injury was performed by small RNA-Seq.
Project description:Ischemic preconditioning is effective in limiting subsequent ischemic acute kidney injury in experimental models. microRNAs are an important class of post-transcriptional regulator and show promise as biomarkers of kidney injury. An evaluation was performed of the time- and dose-dependent effects of ischemic preconditioning in a rat model of functional (bilateral) ischemia-reperfusion injury. A short, repetitive sequence of ischemic preconditioning resulted in optimal protection from subsequent ischemia-reperfusion injury. A detailed characterization of microRNA expression in ischemic preconditioning/ischemia-reperfusion injury was performed by Exiqon miRCURY microRNA array.
Project description:Preconditioning strategies like caloric restriction (CR) and hypoxic preconditioning (HP) show remarkable protective effects in animal models of acute kidney injury (AKI). Since the underlying molecular effects are still not fully understood we performed an experiment directly comparing CR and HP in a murine model of ischemia-reperfusion injury (IRI) of the kidney. 8 to 12-week-old, male C57BL6/J mice were either put to 4 weeks of caloric restriction (70% of normal food intake) or placed in a hypoxic chamber (8%O2) for 3 consecutive days prior to IRI. Whole kidneys were used for transcriptional analysis (RNAseq) before and after ischemia-reperfusion injury to look for common effects of both modes of preconditioning.
Project description:Ischemia-reperfusion injury (IRI) is a well-known model for acute kidney injury (AKI).
We applied proteomic analysis to detect membrane proteins from IRI mouse kidneys. The analysis set are composed of negative control (sham operation), samples of 4-hour after IRI, and samples of 8-hour IRI.
Project description:Goal of the study was to compare single cell (sc) and single nucleus (sn) sequencing of murine kidney after mild (17min) and severe (27min) ischemia reperfusion injury
Project description:Heart disease remains the leading cause of death globally. Although reperfusion following myocardial ischemia can prevent death by restoring nutrient flow, ischemia/reperfusion injury can cause significant heart damage. The mechanisms that drive ischemia/reperfusion injury are not well understood; currently, few methods can predict the state of the cardiac muscle cell and its metabolic conditions during ischemia. Here, we explored the energetic sustainability of cardiomyocytes, using a model for cellular metabolism to predict the levels of ATP following hypoxia. We modeled glycolytic metabolism with a system of coupled ordinary differential equations describing the individual metabolic reactions within the cardiomyocyte over time. Reduced oxygen levels and ATP consumption rates were simulated to characterize metabolite responses to ischemia. By tracking biochemical species within the cell, our model enables prediction of the cell’s condition up to the moment of reperfusion. The simulations revealed a distinct transition between energetically sustainable and unsustainable ATP concentrations for various energetic demands. Our model illustrates how even low oxygen concentrations allow the cell to perform essential functions. We found that the oxygen level required for a sustainable level of ATP increases roughly linearly with the ATP consumption rate. An extracellular O2 concentration of ~0.007 mM could supply basic energy needs in non-beating cardiomyocytes, suggesting that increased collateral circulation may provide an important source of oxygen to sustain the cardiomyocyte during extended ischemia. Our model provides a time-dependent framework for studying various intervention strategies to change the outcome of reperfusion.
Project description:Acute kidney injury (AKI) is associated with an increased risk of chronic kidney disease (CKD). To extend our understanding of renal repair, and its limits, we performed a detailed molecular characterization of a murine ischemia reperfusion injury (IRI) model for 12 months post injury. RNA-seq analysis highlights a cascade of temporal specific gene expression patterns related to tubular injury/repair, fibrosis, innate and adaptive immunity.
Project description:Purpose: Acute kidney injury (AKI) is defined as a sudden event of kidney failure or kidney damage occurring within a short period. Ischemia-reperfusion injury (IRI) is a critical factor to induce severe AKI and end-stage kidney disease in the kidney. However, biological mechanisms of ischemia and reperfusion are not well elucidated due to its complex pathophysiological processes. We aim to investigate key biological pathways affected by ischemia and by reperfusion separately at the transcriptome level. Method: We analyzed steady-state gene expressions using RNA-seq transcriptome data for normal (pre-ischemia), ischemia and reperfusion conditions obtained from the human kidney tissue. A conventional differential expression analysis and self-organizing map (SOM) clustering analysis followed by pathway analysis were performed to identify the underlying biological mechanisms of ischemia and reperfusion. Results: Differential expression analysis showed that metabolism and gap junction-related pathways were dysregulated in ischemia, whereas hypertrophy and immune response-related pathways were dysregulated in reperfusion. In addition, SOM clustering analysis revealed that metabolism, apoptosis, and fibrosis-related pathways were significantly dysregulated by ischemia compared to pre-ischemia. On the other hand, cell growth, migration, and immune response-related pathways were highly dysregulated by reperfusion after ischemia. Pro-apoptotic genes and death receptors were down-regulated during ischemia, indicating a protective process against ischemic injury. Reperfusion induced alteration of genes associated with immune components such as B-cell, neutrophil, and interleukin-15. Additionally, genes related to cell growth and migration such as AKT, KRAS, and Rho signaling were down-regulated, which might imply injury responses during reperfusion. Semaphorin 4D and plexin B1 were also down-regulated. However, further investigations are needed to identify their roles. Conclusion: We showed that specific biological pathways were distinctively involved in ischemia and reperfusion during IRI, suggesting that condition-specific therapeutic strategies may be required to prevent severe kidney damage after IRI in clinical research.