Project description:Mitogen-activated protein kinases (MAPKs) regulate cardiomyocyte growth and apoptosis in response to extracellular stimulation, but the downstream effectors that mediate their pathophysiological effects remain poorly understood. We determined the targets and role of p38 MAPK in the heart in vivo by using local adenovirus-mediated gene transfer of constitutively active upstream kinase mitogen-activated protein kinase kinase 3b (MKK3bE) and wild-type p38α in rats. DNA microarray analysis of animals with cardiac-specific overexpression of p38 MAPK revealed that 264 genes were upregulated more than 2-fold including multiple genes controlling cell division, cell signaling, inflammation, adhesion and transcription. Several previously unknown p38 target genes were found. Using gel mobility shift assays we identified several cardiac transcription factors that were directly activated by p38 MAPK. Finally, we determined the functional significance of the altered cardiac gene expression profile by histological analysis and echocardiographic measurements, which indicated that p38 MAPK overexpression induced gene expression results in cell proliferation, myocardial inflammation and fibrosis. In conclusion, we defined the novel target genes and transcription factors as well as the functional effects of p38 MAPK in the heart. Expression profiling of p38 MAPK overexpression identified cell cycle regulatory and inflammatory genes critical for pathological processes in the adult heart. Experiment Overall Design: Left ventricular gene expression profiles three days after MKK3bE + WT p38α gene transfer were compared with those of Lac Z âtreated animals by screening Affymetrix Rat Expression Set 230_2.0 Arrays (there are 5 samples in both group).
Project description:Mitogen-activated protein kinases (MAPKs) regulate cardiomyocyte growth and apoptosis in response to extracellular stimulation, but the downstream effectors that mediate their pathophysiological effects remain poorly understood. We determined the targets and role of p38 MAPK in the heart in vivo by using local adenovirus-mediated gene transfer of constitutively active upstream kinase mitogen-activated protein kinase kinase 3b (MKK3bE) and wild-type p38α in rats. DNA microarray analysis of animals with cardiac-specific overexpression of p38 MAPK revealed that 264 genes were upregulated more than 2-fold including multiple genes controlling cell division, cell signaling, inflammation, adhesion and transcription. Several previously unknown p38 target genes were found. Using gel mobility shift assays we identified several cardiac transcription factors that were directly activated by p38 MAPK. Finally, we determined the functional significance of the altered cardiac gene expression profile by histological analysis and echocardiographic measurements, which indicated that p38 MAPK overexpression induced gene expression results in cell proliferation, myocardial inflammation and fibrosis. In conclusion, we defined the novel target genes and transcription factors as well as the functional effects of p38 MAPK in the heart. Expression profiling of p38 MAPK overexpression identified cell cycle regulatory and inflammatory genes critical for pathological processes in the adult heart. Keywords: Gene transfer
Project description:Few studies have assessed the patterns of parasite populations of rodents over a longitudinal gradient in Chile. In this work, the gastrointestinal helminthic fauna of invasive rodents in Chile was examined to assess the association between their presence/absence and abundance with latitude, host sex, and host body condition, and to assess the coexistence and correlation of the abundance between parasite species. Rodents were obtained from 20 localities between 33 and 43°S. Helminths were extracted from the gastrointestinal tract and identified morphologically. Overall, 13 helminth taxa were obtained. The most frequently identified parasite species was Heterakis spumosa, and the most abundant was Syphacia muris, while Physaloptera sp. was the most widely distributed. No locality presented with a coexistence that was different from that expected by chance, while the abundance of five helminthic species correlated with the abundance of another in at least one locality, most likely due to co-infection rather than interaction. Host sex was associated with parasite presence or abundance, and female sex-biased parasitism was notably observed in all cases. Body condition and latitude presented either a positive or negative association with the presence or abundance of parasites depending on the species. It is notable that the likely native Physaloptera sp. is widely distributed among invasive rodents. Further, gravid females were found, suggesting spillback of this species to the native fauna. The low frequency and abundance of highly zoonotic hymenolepid species suggest that rodents are of low concern regarding gastrointestinal zoonotic helminths.
Project description:Highly pathogenic avian influenza viruses (HPAIV) induce severe inflammation in poultry and men. There is still an ongoing threat that these viruses may acquire the capability to freely spread as novel pandemic virus strains that may cause major morbidity and mortality. One characteristic of HPAIV infections is the induction of a cytokine burst that strongly contributes to viral pathogenicity. It has been suggested, that this cytokine overexpression is an intrinsic feature of infected cells and involves hyperinduction of p38 mitogen activated protein kinase (MAPK). Here we investigate the role of MAPK p38 signaling in the antiviral response against HPAIV in mice as well as in endothelial cells, the latter a primary source for cytokines during systemic infections. Global gene expression profiling of HPAIV infected endothelial cells in the presence of the MAP kinase p38-specific inhibitor SB202190 revealed, that inhibition of MAPK p38 leads to reduced expression of interferon (IFN) and other cytokines after A/Thailand/1(KAN-1)/2004 (H5N1) and A/FPV/Bratislava/79 (H7N7) infection. Furthermore, the expression of interferon stimulated genes (ISGs) after treatment with IFN or conditioned media from HPAIV infected cells was decreased when the target cells were preincubated with SB202190. Finally, promoter analysis confirmed a direct impact of p38 MAPK on the IFN-enhanceosome and ISG-promoter activity. In vivo inhibition of MAP kinase p38 greatly diminishes virus induced cytokine expression concomitant with reduced viral titers, thereby protecting mice from lethal infection. These observations show, that MAPK p38 acts on two levels of the antiviral IFN response: Initially the kinase regulates IFN induction and at a later stage MAPK p38 controls IFN signaling and thereby expression of IFN-stimulated genes. Thus, inhibition of MAP kinase p38 may be an antiviral strategy that significantly protects mice from lethal influenza via suppression of overshooting cytokine expression. HUVEC were infected with FPV in the presence or absence of a p38 MAP kinase inhibitor
Project description:A recombinant SARS-CoV lacking the envelope (E) protein is attenuated in vivo. Here we report that E protein PDZ-binding motif (PBM), a domain involved in protein-protein interactions, is a major virulence determinant in vivo. Elimination of SARS-CoV E protein PBM by using reverse genetics led to attenuated viruses (SARS-CoV-mutPBM) and to a reduction in the deleterious exacerbate immune response triggered during infection with the parental virus (SARS-CoV-wt). Cellular protein syntenin bound E protein PBM during SARS-CoV infection. Syntenin activates p38 MAPK leading to overexpression of inflammatory cytokines, and we have shown that active p38 MAPK was reduced in lungs of mice infected with SARS-CoVs lacking E protein PBM (SARS-CoV-mutPBM) as compared with the parental virus (SARS-CoV-wt), leading to a decreased expression of inflammatory cytokines and to viral attenuation. Therefore, E protein PBM is a virulence factor that activates pathogenic immune response most likely by using syntenin as a mediator of p38 MAPK induced inflammation. Three biological replicates were independently hybridized (one channel per slide) for each sample type (SARS-CoV-wt, SARS-CoV-mutPBM, Mock). Slides were Sure Print G3 Agilent 8x60K Mouse (G4852A-028005)
Project description:The mitogen-activated protein kinase (MAPK) p38 signaling pathway is essential for normal heart function. However, p38 also contributes to heart failure pathogenesis by affecting heart contractility and cardiomyocyte survival. To unravel the complex cardiac role of p38, we report the interactome of p38α and p38γ, the two well expressed isoforms in the heart, obtained via an APEX proximity assay performed in cultured neonatal rat ventricular myocytes. The p38α and p38γ have distinct interactomes in cardiomyocytes for both studied states; basal and activated by an osmotic stress. Interestingly, the activated p38α interactome contains many spliceosome implicated RNA-binding proteins. The serine/arginine-rich splicing factor 3 (SRSF3) is of particular interest and its interaction with p38α was validated by co-immunoprecipitation. p38 is sufficient to partially relocate nuclear SRSF3 to cytoplasm. The alternative splicing function of SRSF3 is also modulated by the p38 pathway. Our findings reveal a novel set of proteins to investigate in order to decipher cardiac functions of the MAPK p38, as well as a specific regulation mechanism of SRSF3 by p38 in cardiomyocytes.