Hippocampal transcriptional dysregulation after renal ischemia and reperfusion

Neurological complications contribute largely to the morbidity and mortality in patients with acute renal failure. In order to study pathophysiological complications of renal failure, a murine model of renal ischemia/reperfusion-induced acute kidney injury (AKI) was generated by 60 min bilateral ischemia, and followed by 2 h or 24 h reperfusion (B-60'IRI). Compared to the sham-operated mice, B-60'IRI mice exhibited a significant inflammatory injury to remote brain. We found that serum and brain levels of KC, G-CSF and MCP-1 were significantly increased in B-60'IRI mice after 2 h and 24 h reperfusion when compared with sham-operated mice. Moreover, B-60'IRI mice exhibited increased numbers of activated microglial cells in the brain, and severe blood-brain barrier (BBB) permeability when compared with the control sham mice. The technology of cDNA microarray and quantitated RT-PCR are used to identify hippocampal genes whose expression is altered in response to AKI in B-60' IRI mice. The initiation of transcriptional abnormality was indicated by the finding that B-60' IRI mice exhibited upregulated mRNA levels of genes involved in inflammation, cell signaling, extracellular matrix and cell-cycle regulation and downregulated mRNA levels of genes involved in transporters, G protein-coupled receptor signaling, cell survival and chaperone. Our data suggest that renal IR contributes to a complicated hippocampal gene irregulation in inflammation and physiological homeostasis.