Cardiac transcriptome analysis of RKIP-transgenic and GRK2-transgenic mice by NGS

The RAF kinase inhibitor protein, RKIP, is a dual inhibitor of the RAF1 kinase and the G-protein-coupled receptor kinase 2 (GRK2). By inhibition of the proto-oncogenic and pro-survival RAF1-MAPK pathway, the RAF kinase inhibitor protein, RKIP, acts as a tumor suppressor, which enhances cardiomyocyte death and promotes the development of symptoms of heart failure. To elucidate pathomechanisms of heart failure induced by RKIP, the study determined the cardiac transcriptomes of eight-month-old, male, transgenic mice with cardiac-specific expression of RKIP (PEBP1) under control of the myocardium-specific, alpha-MHC promoter. In addition, the study determined the cardiac transcriptomes of GRK2-transgenic mice. Tg-GRK2 mice have a slightly increased transgenic expression of GRK2. According to NGS data, cardiac GRK2-Grk2 transcript levels of Tg-GRK2 mice are 1.59±0.10-fold higher than those of non-transgenic FVB hearts. In Tg-GRK2 mice, transgenic GRK2 is expressed under control of the ubiquitous CMV immediate-early promoter/enhancer. The non-transgenic control group are age-matched, male, nontransgenic FVB/N mice. NGS data of this study document transcriptome changes underlying the heart failure phenotype induced by transgenic RKIP expression and cardiac degeneration induced by GRK2 expression. Cardiac transcriptomes were determined by NGS of hearts isolated from three male RKIP-transgenic (Tg-RKIP) mice and three male GRK2-transgenic (Tg-GRK2) mice at an age of 8 months. Tg-RKIP mice and Tg-GRK2 mice have an FVB/N background. The non-transgenic control group are three, age-matched, non-transgenic, male FVB/N mice. Hearts were isolated from male mice at the end of the observation period at an age of 8 months. The group size was n=3 male mice at an age of 8 months per group. Tg-RKIP mice showed symptoms of heart failure. NGS data of the cardiac transcriptome confirmed the heart heart failure phenotype induced by an increased cardiac RKIP (PEBP1) transcript level. NGS data also showed altered transcript levels of selected heart failure-promoting genes in hearts of Tg-GRK2 mice with slightly (1.59-fold) increased cardiac GRK2 levels. All mice of the study were weaned at an age of 3 to 4 weeks, housed in groups of 2-5 mice in individually ventilated cages under SPF conditions with a 12h dark cycle, and had free access to food and water until the end of the observation period at an age of 8 months.