Identification of a regulatory domain controlling the Nppa-Nppb gene cluster during heart development and stress
Ontology highlight
ABSTRACT: 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.
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: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.