Project description:The paralogous genes Nppa and Nppb are organized in an evolutionary conserved cluster and are a valuable model to study coregulation and regulatory landscape organization during heart development and disease. Here, we analyzed the chromatin conformation, epigenetic status and enhancer potential of sequences of the Nppa-Nppb cluster in vivo. Our data indicate that the regulatory landscape of the cluster is present within a 60 kbp domain centered around Nppb. Both promoters and several potential regulatory elements interact with each other in a similar manner in different tissues and developmental stages. The distribution of H3K27ac and the association of Pol2 across the locus changed during cardiac hypertrophy, revealing their potential involvement in stress-mediated gene regulation. In summary, the developmental regulation and stress-response of the Nppa-Nppb cluster involve the concerted action of multiple enhancers and epigenetic changes distributed across a structurally rigid regulatory domain. We have used 4C-seq on several viewpoints around the Nppa-Nppb gene cluster in the heart and liver samples to investigate the role of chromatin conformation on regulation of Nppa and Nppb expression during heart development and disease.
Project description:Background: Right ventricular (RV) and left ventricular (LV) myocardium differ in their response to pressure-overload hypertrophy (POH). In this report we use microarray and proteomic analyses to identify pathways modulated by LV-, and RV-POH in the immature heart. Methods: Newborn New Zealand White rabbits underwent banding of the descending thoracic aorta (LV-POH; n=6). RV-POH was achieved by banding the pulmonary artery (n=6). Sham–control animals (SC; n=6 each) were sham-manipulated. Following 4 (LV-POH) and 6 weeks (RV-POH) recovery, the hearts were removed and matched sample RNA and proteins were isolated for microarray and proteomic analysis. Results: There was no difference in body weight in RV-, LV-POH vs. SC but there was a significant increase vs. SC in RV (3.2±0.8g vs. 1.2±0.3g; P<0.01) and LV weight (7.08±0.6g vs. 4.02±0.2g; P<0.01). Fractional area change (RV-POH) and shortening fraction (LV-POH) decreased significantly (23±6 vs. 47±6 and 21±4 vs.44±2, respectively, P<0.01). Microarray analysis demonstrated that LV-POH enriched pathways for oxidative phosphorylation, mitochondria energy pathways, actin, ILK, hypoxia, calcium and protein kinase-A signalling. RV-POH enriched pathways for cardiac oxidative phosphorylation. Proteomic analysis revealed 19 proteins were uniquely expressed in LV-POH vs. SC. Functional annotation clustering analysis indicated significant enrichment for the mitochondrion, cellular macromolecular complex assembly and oxidative phosphorylation. RV-POH had 15 uniquely expressed proteins vs. SC. Functional annotation clustering analysis indicated significant enrichment in structural constituents of muscle, cardiac muscle tissue development and calcium handling. Conclusion: Our results identify unique transcript and protein expression profiles in LV, RV-POH and provide new insight into the biological basis of ventricular specific hypertrophy. 3 different conditions: PAB-RV vs. Sham-control RV, PAB-RV [test] vs. PAB-LV [control], AOB-LV vs. Sham-control LV.
Project description:Itch is an unpleasant skin sensation which can be triggered by exposure to many chemicals including those released by mast cells. The Nppb-expressing class of sensory neurons when activated elicit scratching responses in mice, however, it is unclear which itch-inducing agents stimulate these cells and the receptors involved. Here, we identify receptors expressed by Nppb-neurons and demonstrate the functional importance of these receptors as sensors of endogenous pruritogens released by mast cells. Our search for receptors in Nppb-neurons revealed that they express leukotriene, serotonin, and sphingosine-1-phosphate receptors. Targeted cell ablation, calcium imaging of primary sensory neurons, and conditional receptor knockout studies demonstrate that these receptors induce itch by the direct stimulation of Nppb-neurons and neurotransmission through the canonical GRP-dependent spinal cord itch pathway. Together our results define a molecular and cellular pathway for mast cell-induced itch.
Project description:Background: Right ventricular (RV) and left ventricular (LV) myocardium differ in their response to pressure-overload hypertrophy (POH). In this report we use microarray and proteomic analyses to identify pathways modulated by LV-, and RV-POH in the immature heart. Methods: Newborn New Zealand White rabbits underwent banding of the descending thoracic aorta (LV-POH; n=6). RV-POH was achieved by banding the pulmonary artery (n=6). Sham–control animals (SC; n=6 each) were sham-manipulated. Following 4 (LV-POH) and 6 weeks (RV-POH) recovery, the hearts were removed and matched sample RNA and proteins were isolated for microarray and proteomic analysis. Results: There was no difference in body weight in RV-, LV-POH vs. SC but there was a significant increase vs. SC in RV (3.2±0.8g vs. 1.2±0.3g; P<0.01) and LV weight (7.08±0.6g vs. 4.02±0.2g; P<0.01). Fractional area change (RV-POH) and shortening fraction (LV-POH) decreased significantly (23±6 vs. 47±6 and 21±4 vs.44±2, respectively, P<0.01). Microarray analysis demonstrated that LV-POH enriched pathways for oxidative phosphorylation, mitochondria energy pathways, actin, ILK, hypoxia, calcium and protein kinase-A signalling. RV-POH enriched pathways for cardiac oxidative phosphorylation. Proteomic analysis revealed 19 proteins were uniquely expressed in LV-POH vs. SC. Functional annotation clustering analysis indicated significant enrichment for the mitochondrion, cellular macromolecular complex assembly and oxidative phosphorylation. RV-POH had 15 uniquely expressed proteins vs. SC. Functional annotation clustering analysis indicated significant enrichment in structural constituents of muscle, cardiac muscle tissue development and calcium handling. Conclusion: Our results identify unique transcript and protein expression profiles in LV, RV-POH and provide new insight into the biological basis of ventricular specific hypertrophy.
Project description:The goal of the study was to determine the effect of lentiviral- mediated overexpression of miR-495 (LV-miR-495) on the levels of gene expression in the nuclues accumbens of rats relative to control rats injected with the empty vector (LV-GFP). We used Rat Gene 2.0 ST Affymetrix expression arrays ( to identify genes whose expression levels were downregulated by overexpression of miR-495.
Project description:Analysis of gene expression changes in the LV of a rodent heart that occur with uncontrolled diabetes We used microarrays to detail the global changes that occur in gene expression in the LV of the heart as a result of STZ-induced diabetes. Keywords: single time point, comparison control animal v. diabetic animal
Project description:The paralogous genes Nppa and Nppb are organized in an evolutionary conserved cluster and are a valuable model to study coregulation and regulatory landscape organization during heart development and disease. Here, we analyzed the chromatin conformation, epigenetic status and enhancer potential of sequences of the Nppa-Nppb cluster in vivo. Our data indicate that the regulatory landscape of the cluster is present within a 60 kbp domain centered around Nppb. Both promoters and several potential regulatory elements interact with each other in a similar manner in different tissues and developmental stages. The distribution of H3K27ac and the association of Pol2 across the locus changed during cardiac hypertrophy, revealing their potential involvement in stress-mediated gene regulation. In summary, the developmental regulation and stress-response of the Nppa-Nppb cluster involve the concerted action of multiple enhancers and epigenetic changes distributed across a structurally rigid regulatory domain.
