LAUSR

Patients suffering from acute lung injury (ALI) are at a high risk of developing cardiac arrhythmias. Our recent study demonstrated that bleomycin (Bleo)-induced ALI in rats exhibited significantly more spontaneous premature ventricular contractions (PVCs) from one to three weeks post induction. Although spontaneous PVCs disappeared at 4 weeks post ALI, PVCs were evoked again by electrical stimulation of the decentralized stellate ganglia in Bleo-exposed rats but not in normal rats. In the current study, we aimed to utilize non-biased RNA-Seq analysis to identify potential gene candidates in cardiac tissues, which may be associated with cardiac arrhythmia during the recovery from ALI. We created an ALI rat model using a single tracheal instillation of bleomycin (2.5 mg/kg), with saline as a vehicle (Veh) control. Blood troponin level was measured between Veh- and Bleo-treated rats at Week 1 (W1) post Veh/Bleo. Cardiac tissues were harvested at W4 post Veh/Bleo for RNA-seq analysis and following PCR validation. At W1 post ALI, cardiac troponin level was significantly increased in Bleo-treated rats whereas it was undetectable in Veh-treated (Control) rats. RNA-seq analysis indicated 11 downregulated (AABR07045427, Habp2, AC130862, Per2, Coch, Phactr3, Angptl7, LOC103690108, Mthfd2, Sorcs1, U6) and 13 upregulated (Calhm5, Metazoa_SRP, Tgm1, Pcare, Drd4, Selplg, AABR07027722; Rn5-8s, 5_8S_rRNA) genes in cardiac tissues at 4 weeks post ALI vs Veh. PCR validated that the gene expressions of Habp2, Coch, Phactr3, LOC103690108, Mthfd2 were significantly downregulated and the gene expressions of Pcare, Drd4 were significantly upregulated in the hearts of Bleo-treated rats at W4 post ALI. Our study demonstrated that multiple gene changes in cardiac tissues are associated with cardiac injury and arrhythmogenesis in bleomycin-induced ALI in male rats. Future studies will further determine the cause-effect relationship between these altered genes and cardiac arrhythmia post ALI. This study was supported by NIH grant R01 HL-152160 and in part, by NIH grants R01 HL126796. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.