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Transcriptomic analysis of Resp18mutant rat kidneys reveals up-regulation of Renin-Angiotensin system

ABSTRACT: Regulated 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.

ORGANISM(S): Rattus norvegicus

PROVIDER: GSE149006 | GEO | 2021/07/01

REPOSITORIES: GEO

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Project description:The etiology of trauma-hemorrhage shock-induced acute lung injury has been difficult to elucidate due, at least in part, to the inability of in vivo studies to separate the non-injurious pulmonary effects of trauma-hemorrhage from the tissue injurious ones. To circumvent this in vivo limitation, we utilized a model of trauma-hemorrhagic shock (T/HS) in which T/HS-lung injury was abrogated by dividing the mesenteric lymph duct. In this way, it was possible to separate the pulmonary injurious response from the non-injurious systemic response to T/HS by comparing the pulmonary molecular response of rats subjected to T/HS which did and did not develop lung injury as well as to non-shocked rats. Utilizing high-density oligonucleotide arrays and treatment group comparisons of whole lung tissue collected at 3 hours after the end of the shock or sham-shock period, 139 of the 8,799 assessed genes were differentially expressed. Experiment Overall Design: Four groups of rats (n=3) were studied in order to identify changes in pulmonary gene expression associated with T/HS, both in the presence and absence of lung injury. These included trauma-sham shock (T/SS) rats which had a laparotomy (trauma) but were not subjected to hemorrhagic shock. These rats had no lung injury and served as controls for rats which were subjected to T/HS (laparotomy plus 90 min of shock) and had lung injury. Differences in gene expression between these two groups would represent both the effects of hemorrhagic shock as well as lung injury. To distinguish the gene response of hemorrhagic shock from the gene response associated with lung injury, gene expression was also compared between T/HS rats (hemorrhage and lung injury) and rats subjected to T/HS plus lymph duct ligation (T/HS-LDL), since the T/HS-LDL rats experienced hemorrhagic shock but had no measurable lung injury. Lastly, to identify hemorrhagic shock- modified genes, the pulmonary gene response of T/HS-LDL (hemorrhage without lung injury) were compared to rats subjected to T/SS plus LDL (no hemorrhage or lung injury). Three hours after the end of the 90 min shock or sham-shock period (i.e. 4.5 hrs after the induction of T/HS), the rats were sacrificed and specimens harvested for genechip analysis and histology.

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Transcriptomic analysis of Resp18mutant rat kidneys reveals up-regulation of Renin-Angiotensin system

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