show Abstracthide AbstractRegulated endocrine specific protein 18 (Resp18), expression has been specifically located in a series of tissues and cell types however the exact cellular function is unknown. In previous studies we have showed that a targeted disruption of Resp18 in Dahl SS rats (Resp18mutant) resulted in higher blood pressure (BP), increased renal fibrosis, and decreased survival rate on a long term (6-week) 2% high salt (HS) diet treatment compared with wild type SS rats. In the current study we studied whether a short term (1 week) exposure to HS diet shows a similar effect in Resp18mutant rats. Furthermore, previously we have shown that in addition to BP phenotype Resp18mutant rats have demonstrated deteriorative kidney phenotype evident through renal fibrosis, protein urea and protein cast formation. Based on this background we conducted BP study and performed transcriptomic profiling of the kidney after one-week exposure to HS diet treatment. Through radio-telemetry procedure, we found that the systolic BP was increased in the Resp18mutant rats compared with SS rats even with short term HS diet exposure. Therefore, we sought out to investigate if there was any alteration in the transcriptomic response by HS diet treatment in the Resp18mutant rat kidneys. Using RNA sequencing approach, we found that Resp18mutant rats showed a differential expression of 25 genes of which one was an upregulation of Ren. We confirmed the upregulation of Ren and other differentially expressed genes via qRT-PCR analysis. Upon KEGG pathway enrichment we found that the Resp18mutant rat showed upregulation in the renin angiotensin system (RAAS), and renin secretion pathway. Furthermore, the renin activity is found to be higher in Resp18mutant rats serum compared with SS rats. Therefore, these observations demonstrate that upon disruption of Resp18 gene in SS rats associated with the increase in renin secretion and thus increase BP. Overall design: RNA sequencing of Kidneys from control and Resp18 mutant rat RNA samples in triplicate, using Illumina.