Project description:Ischemia/reperfusion injury (IRI) has a major impact on the long-term outcome of renal allografts. However, the mechanisms of IRI related to chronic allograft nephropathy (CAN) are still poorly understood. To address this issue, in a F344 to Lewis transplantation model of the rat, kidneys were either subjected to 20 min. or 24 hours of cold ischemia. A customized cDNA microarray representing 737 immune related genes was used for gene expression analysis after 12 hours and 6 months of engraftment. Thereby showing the 6-month graft function and histology were only moderately deteriorated following short cold ischemic time (20 min.), while prolonged ischemia (24 hrs) accelerated CAN development. Following prolonged cold ischemia already 12 hrs after engraftment about 30 genes were differentially expressed up to >20-fold. This included adhesion molecules, heat shock proteins, transcription factors and chemokines (CXCL10) associated with a strong CD68+ macrophage infiltration. Furthermore we observed a remarkable up-regulation of immunoproteasomes implying a re-organisation of the proteasome complex. This data might explain the higher incidence of alloreactivity following enhanced IRI. After 6 months, the prolonged cold ischemia of 24 hours revealed the significant induction of 4 genes: clusterin, C4, and the CCR7 ligands CCL19/21. This supported the observation of enhanced vasculopathy, humoral alloreactivity and increased tracking of MHC-II+ antigen presenting cells during CAN suggesting them as suitable novel targets for combating IRI. Keywords: transplantation, cold ischemia, inflammation, gene expression profiling Renal allografts from F344 donors were transplanted into unmodified LEW recipients. Before harvesting, grafts were perfused with University of Wisconsin solution at 4°C undergoing 20 min. (group A) or 24 hrs (group B) cold ischemia. Engrafted organs were either removed after 12 hrs (group I-A (n=3) and I-B (n=2)) or after 6 months (group II-A (n=3) and II-B (n=2)). Recipient animals of the group II received CyA treatment for 10 days at a dosage of 1.5 mg/kg. Untreated normal kidneys from F344 rats served as control. RNA from transplanted and untreated (control) rat kidneys were labeled by reverse transcription with Cy5 and Cy3 fluorescence, respectively.
Project description:Ischemia/reperfusion injury (IRI) has a major impact on the long-term outcome of renal allografts. However, the mechanisms of IRI related to chronic allograft nephropathy (CAN) are still poorly understood. To address this issue, in a F344 to Lewis transplantation model of the rat, kidneys were either subjected to 20 min. or 24 hours of cold ischemia. A customized cDNA microarray representing 737 immune related genes was used for gene expression analysis after 12 hours and 6 months of engraftment. Thereby showing the 6-month graft function and histology were only moderately deteriorated following short cold ischemic time (20 min.), while prolonged ischemia (24 hrs) accelerated CAN development. Following prolonged cold ischemia already 12 hrs after engraftment about 30 genes were differentially expressed up to >20-fold. This included adhesion molecules, heat shock proteins, transcription factors and chemokines (CXCL10) associated with a strong CD68+ macrophage infiltration. Furthermore we observed a remarkable up-regulation of immunoproteasomes implying a re-organisation of the proteasome complex. This data might explain the higher incidence of alloreactivity following enhanced IRI. After 6 months, the prolonged cold ischemia of 24 hours revealed the significant induction of 4 genes: clusterin, C4, and the CCR7 ligands CCL19/21. This supported the observation of enhanced vasculopathy, humoral alloreactivity and increased tracking of MHC-II+ antigen presenting cells during CAN suggesting them as suitable novel targets for combating IRI. Keywords: transplantation, cold ischemia, inflammation, gene expression profiling