Dominance hierarchies are ubiquitous in invertebrates and vertebrates, but little is known on how genes influence dominance rank. Our gaps in knowledge are specifically significant concerning female hierarchies and in insects. To start filling these gaps we studied the social bumble bee Bombus terrestris, in which social hierarchies among females are common and functionally significant. Dominance rank in this bee is influenced by multiple factors, including juvenile hormone (JH) that is a major gonadotropin in this species. We tested the hypothesis that the JH responsive transcription factor Krüppel homologue 1 (Kr-h1) mediates hormonal influence on dominance behavior in the bumble bee. We first developed and validated a perfluorocarbon nanoparticles-based RNA interference protocol for knocking down Kr-h1 expression. We then used this procedure to show that Kr-h1 mediates the influence of JH not only on oogenesis and wax production, but also on aggression and dominance rank. To the best of our knowledge, this is the first study causally linking a gene to dominance rank in social insects, and one of only a few such studies in insects or in female hierarchies. These findings are important for determining whether there are general molecular principles governing dominance rank across gender and taxa.

Expression of Krüppel–like factor 15 (KLF15), a stress induced transcription factor, is induced during bovine herpesvirus 1 (BoHV-1) reactivation from latency, and KLF15 stimulates BoHV-1 replication. Transient transfection studies revealed KLF15 and glucocorticoid receptor (GR) cooperatively transactivate the BoHV-1 immediate early transcription unit 1 (IEtu1), herpes sim-plex virus type 1 (HSV-1) infected cell protein 0 (ICP0), and ICP4 promoter. The IEtu1 promoter drives expression of bICP0 and bICP4, two key BoHV-1 transcriptional regulatory proteins. Based on these studies, we hypothesized infection is a stressful stimulus that increases KLF15 ex-pression and enhances productive infection. New studies demonstrated that silencing KLF15 impaired HSV-1 productive infection and KLF15 steady state protein levels were increased at late stages of productive infection. KLF15 was primarily localized to the nucleus following in-fection of cultured cells with HSV-1, but not BoHV-1. When cells were transfected with a KLF15 promoter construct and then infected with HSV-1, promoter activity was significantly increased. The ICP0 gene and to a lesser extent bICP0 transactivated the KLF15 promoter in the absence of other viral proteins. In contrast, BoHV-1 or HSV-1 encoded VP16 had no effect on KLF15 pro-moter activity. Collectively, these studies revealed HSV-1 and BoHV-1 productive infection in-creased KLF15 steady state protein levels, which correlated with increased virus production.

KLFs seem to associate with congenital heart disease-linked syndromes, malformations because of autosomal diseases, mutations that relate to protein instability, and/or loss functions such as atheroprotective activities. Ischemic damage also relates to KLF dysregulation because of differentiation of cardiac myofibroblasts or a modified fatty acid oxidation, related to the formation of a dilated cardiomyopathy; myocardial infarctions, left ventricular hypertrophy and diabetic cardiomyopathies. MicroRNA have been involved in certain regulatory loops of KLFs as they may function as critical modulators of vascular smooth muscle cells in atherosclerosis, in heart failure and as markers of endothelial damage in acute myocardial infarction.

Cardiac hypertrophy typically follows myocardial damage, a process known to involve members of the Krüppel-Like Factors (KLFs) which have pro-hypertrophic and anti-hypertrophic roles. Our study delved into the molecular mechanisms underlying KLFs-cardiac hypertrophy interplay post myocardial infraction. We induced myocardial dam-age in rats using isoproterenol. Total RNA was extracted from the left ventricle and Quantitative Real Time RT-PCR was conducted to assess the expression of KLFs, cardiac commitment genes, inflammatory markers, and certain conduction-related genes. We devel-oped a computational approach to construct a proteomic network centered on KLFs. Initial results revealed early expression (2-3 days post-induction) of KLF3, KLF4 and KLF6, followed by the subsequent expression of KLF11 and KLF15 (5-8 days after induction). In the maturation stage, KLF12 and KLF13 regulators were found upregulated. IL-6 was gradually found to be upregulated through. Interaction analysis revealed KLF3, KLF8 and KLF12 interacted with cardiac electrical functions. RT-PCR confirmed up-regulation in cardiac genes linked to electrical function and scar maturation. Our findings underscore the central role of KLFs during the modulation of the cardiac hypertrophic response. Dysregulation of KLF expression resulted in damaged myocardium, participating in the progression of abnormal hypertrophy, highlighting their potential as therapeutic targets for heart diseases.