Gene Expression Analysis Reveals the Cell Cycle and Kinetochore Genes Participating in Ischemia Reperfusion Injury and Early Development in Kidney

The molecular mechanisms that mediate the ischemia-reperfusion (I/R) injury in kidney are not completely understood. It is also largely unknown whether such mechanisms overlap with those governing the early development of kidney.We performed gene expression analysis to investigate the transcriptome changes during regeneration after I/R injury in the rat (0 hr, 6 hr, 24 hr, and 120 hr after reperfusion) and early development of mouse kidney (embryonic day 16 p.c. and postnatal 1 and 7 day). Pathway analysis revealed a wide spectrum of molecular functions that may participate in the regeneration and developmental processes of kidney as well as the functional association between them. While the genes associated with cell cycle, immunity, inflammation, and apoptosis were globally activated during the regeneration after I/R injury, the genes encoding various transporters and metabolic enzymes were down-regulated. We also observed that these injury-associated molecular functions largely overlap with those of early kidney development. In particular, the up-regulation of kinases and kinesins with roles in cell division was common during regeneration and early developmental kidney as validated by real-time PCR and immunohistochemistry.In addition to the candidate genes whose up-regulation constitutes an overlapping expression signature between kidney regeneration and development, this study lays a foundation for studying the functional relationship between two biological processes

Sulfenic Acid Modification of ET- B Receptor is Responsible for the Benefit of a Nonsteroidal MR Antagonist in Renal Ischemia

International audienceAKI is associated with high mortality rates and the development of CKD. Ischemia/reperfusion (IR) is an important cause of AKI. Unfortunately, there is no available pharmacologic approach to prevent or limit renal IR injury in common clinical practice. Renal IR is characterized by diminished nitric oxide bioavailability and reduced renal blood flow; however, the mechanisms leading to these alterations are poorly understood. In a rat model of renal IR, we investigated whether the administration of the novel nonsteroidal mineralocorticoid receptor (MR) antagonist BR-4628 can prevent or treat the renal dysfunction and tubular injury induced by IR. Renal injury induced by ischemia was associated with increased oxidant damage, which led to a cysteine sulfenic acid modification in endothelin B receptor and consequently decreased endothelial nitric oxide synthase activation. These modifications were efficiently prevented by nonsteroidal MR antagonism. Furthermore, we demonstrated that the protective effect of BR-4628 against IR was lost when a selective endothelin B receptor antagonist was coadministered. These data describe a new mechanism for reduced endothelial nitric oxide synthase activation during renal IR that can be blocked by MR antagonism with BR-4628