Genome-wide analysis of renal gene expression during hyperoxaluria development. Rattus norvegicus

Previous studies have proposed that production of reactive oxygen species (ROS) is an important contributor to renal injury and inflammation following exposure to oxalate or calcium-oxalate crystals. The present study was conducted to determine, utilizing global transcriptome analyses, if the NADPH oxidase system is activated in kidneys of rats fed a diet leading to hyperoxaluria and crystal deposition. HLP was used to induce hyperoxaluria. Hyperoxaluria will lead to crystallization and up regulation of various NADPH oxidase subunits followed by increased expression of different specific genes. It is our hypothesis that crystallization induces inflammation of the kidneys via the activation of renin-angiotensin system (RAS) and production of reactive oxygen species (ROS) through NADPH oxidase complex. Apocynin was used to block hyperoxaluria and production of reactive oxygen species (ROS) with the inhibition of NADPH oxidase system as Apocynin inhibits membrane translocation of p47 subunit of NADPH oxidase. Overall design: The present study was designed based on NADPH oxidase system and rats were divided into 4 groups (n= 6/group). Group 1 was fed regular rat chow diet, Group 2 received regular rat chow diet supplemented with 5% (Hydroxy-L-Proline) HLP, Group 3 received rat chow diet with 4 mmol Apocynin to drink, and Group 4 received regular rat chow diet with 5% HLP and 4 mmol Apocynin. After 28 days each rat was euthanized, their kidneys freshly explanted and dissected to obtain both cortex and medulla tissues. So the 4 groups were divided into cortex and medulla forming 8 groups. RNA was isolated from all the 8 specimens