Project description:NPY signalling via osteoblastic Y1 receptors has been shown to control bone mass but also contributes significantly to the control of whole-body insulin secretion and glucose homeostasis in mice through the release of novel factor(s) which are different from the previously implicated osteocalcin. We used microarrays to identify novel endocrine factors regulated by Y1 receptors and involved in the regulation of bone mass and whole-body homeostasis.
Project description:Neuropeptide Y (NPY) is an endogenous modulator of neuronal activity by regulating GABA and glutamate release. Previously, we found that estradiol modulates NPY expression in the hippocampal dentate gyrus. Here we investigated which estrogen receptor type activation is required for the NPY expression. Further, we determined effects of estrogen receptor activation on NPY release. Finally, we determined the contribution of estrogen-mediated remodeling of the GABAergic and glutamatergic network in relation to changes in coupling with NPY in ovariectomized rats. We found that activation of either estrogen receptor type increases NPY expression as well as NPY release in the dentate gyrus. We also found that compared to OVX rats, estrogen replacement increases the likeness of synergistic/antagonistic coupling between the NPY and GABAergic synapse genes while the glutamatergic synapse genes are less likely coupled with NPY. The data together suggest that estrogen plays a critical role in regulation of activity of the NPY system and its coupling to GABAergic and glutamatergic synapses in female rat dentate gyrus. Two-conditions (E = beta-estradiol replacement vs O = oil) experiment. Biological replicates: 4E, 4O.
Project description:Neuropeptide Y (NPY) is an endogenous modulator of neuronal activity by regulating GABA and glutamate release. Previously, we found that estradiol modulates NPY expression in the hippocampal dentate gyrus. Here we investigated which estrogen receptor type activation is required for the NPY expression. Further, we determined effects of estrogen receptor activation on NPY release. Finally, we determined the contribution of estrogen-mediated remodeling of the GABAergic and glutamatergic network in relation to changes in coupling with NPY in ovariectomized rats. We found that activation of either estrogen receptor type increases NPY expression as well as NPY release in the dentate gyrus. We also found that compared to OVX rats, estrogen replacement increases the likeness of synergistic/antagonistic coupling between the NPY and GABAergic synapse genes while the glutamatergic synapse genes are less likely coupled with NPY. The data together suggest that estrogen plays a critical role in regulation of activity of the NPY system and its coupling to GABAergic and glutamatergic synapses in female rat dentate gyrus.
Project description:In paravertebral sympathetic ganglia, 50 to 70% of the neurons selectively express neuropeptide Y (NPY). We sought to identify other genes that are differentially expressed by NPY-positive and NPY-negative neurons. This study used NPY reporter mice (B6.FVB-Tg(Npy-hrGFP)1Lowl/J) (Jackson Laboratory #006417) that were bred as hemizygotes with C57BL/6 mice.
Project description:The highly conserved MicroRNA-9 (miR-9) family consists of three members. We discovered that miR-9-1 deletion reduced mature miR-9 expression, causing 43% of the mice to display smaller size and postweaning lethality. MiR-9-1-deficient mice with growth defects experienced severe lymphopenia, but other blood cells were unaffected. The lymphopenia wasn’t due to defects in hematopoietic progenitors, as mutant bone marrow (BM) cells underwent normal lymphopoiesis after transplantation into wild-type recipients. Additionally, miR-9-1-deficient mice exhibited impaired osteoblastic bone formation, as mutant mesenchymal stem cells (MSCs) failed to differentiate into osteoblastic cells (OBs). RNA sequencing revealed reduced expression of master transcription factors for osteoblastic differentiation, Runt-related transcription factor 2 (Runx2) and Osterix (Osx), and genes related to collagen formation, extracellular matrix organization, and cell adhesion, in miR-9-1-deficient MSCs. Follistatin (Fst), an antagonist of bone morphogenetic proteins (BMPs), was found to be a direct target of miR-9-1. Its deficiency led to the up-regulation of Fst, inhibiting BMP signaling in MSCs, and reducing IL-7 and IGF-1. Thus, miR-9-1 controls osteoblastic regulation of lymphopoiesis by targeting the Fst/BMP/Smad signaling axis.
Project description:Our goal was to determine whether osteoblastic LuCaP 23.1 prostate cancer xenograft tumors can elicit an osteoblastic response at the gene expression level in human bone marrow stromal cells.
Project description:Our transcriptomic data shows that iron impact on human osteoblastic MG-63 cells by decreasing HHIPL-2 gene expression (2 fold ratio). This impact is corrected in presence of deferoxamine. Additional biological experiments in the manuscript suggest that the iron related modulation of HHIPL-2 gene expression could take place in the decrease of osteoblastic markers in the MG-63 cell line. Such mechanisms could participate to the development of osteoporosis in iron overloaded patients.