ACE-inhibition induces a cardioprotective transcriptional response in the metabolic syndrome heart.

The goal of the current study was to characterize the cardiac transcriptional signature of the metabolic syndrome (MetS) murine model relative to the healthy, control heart and the differential changes induced by ACE-inhibition, a frequent intervention in MetS subjects, at the transcriptomic level in control and MetS hearts. Methods - LDLR-/-;ob/ob (DKO, MetS model) and C57Bl6/J (WT) mice were injected with ACE-inhibitor captopril (10 mg/kg/day) between 12 and 24 weeks of age, or NaCl 0,9% as controls. Transcriptome analysis (RNA-seq) from the whole heart RNA samples was performed. Differential gene expression was analysed with Cufdiff. Ingenuity Pathway Analysis (IPA) was used to determine functional enrichment, and analyse pathways, networks, and upstream regulators. Transcription factor motif enrichment analysis was performed with i-cisTarget. Results – 288 genes implicating 72 pathways were differentially expressed between DKO and WT hearts. The hallmarks of MetS in the heart were an increase in activity of the following pathways: ILK, Rho, dendritic cell maturation, production of nitric oxide and reactive oxygen species in macrophages, atherosclerosis, LXR-RXR, cardiac hypertrophy, and acute phase response. ACE-inhibition resulted in a limited transcriptional effect in WT hearts and in a decrease in activity of Rho-associated signalling pathways. In contrast, a more prominent transcriptional effect was observed in DKO hearts. Similar to WT, Rho-associated pathways were affected, but ACE-inhibition further displayed a counteracting effect on the pathways affected by MetS in the heart Conclusion –MetS and control mouse hearts have unique transcriptional profiles, with characteristic baseline gene expression landscapes prior to ACE-inhibition, and a partially specific transcriptional response to ACE-inhibition. The Rho-associated signalling pathways and Rho, Rock, Myl, and Fos genes represent potential therapeutic targets. Experimental animal models: DKO; LDLR-/- and ob/ob)18. C57BL/6 (WT); RNA Extraction and Sequencing; RNA-Seq Data Analysis; Pathway and Regulatory Network Analysis; Ethical committee approval.