Project description:Interleukin (IL)-18 is recognized as a multifunctional mediator in inflammation and immune responses. In addition, the production of IL-18 is stimulated by physiological and/or psychological stress implicated in several behavioral disorders. However, it still remains unclear about the role of IL-18 on the central nervous system. In this study, we analyzed gene expression of 6 brain regions; the olfactory bulb, prefrontal cortex, striatum, amygdala, hypothalamus, and hippocampus. Microarray analysis indicated the regional differences of expression in IL-18-/- mice. In particular, the most profound change was observed in the amygdala, in which 1,237 genes were differentially expressed.
Project description:Interleukin (IL)-18 is recognized as a multifunctional mediator in inflammation and immune responses. In addition, the production of IL-18 is stimulated by physiological and/or psychological stress implicated in several behavioral disorders. However, it still remains unclear about the role of IL-18 on the central nervous system. In this study, we analyzed gene expression of 6 brain regions; the olfactory bulb, prefrontal cortex, striatum, amygdala, hypothalamus, and hippocampus. Microarray analysis indicated the regional differences of expression in IL-18-/- mice. In particular, the most profound change was observed in the amygdala, in which 1,237 genes were differentially expressed. We purchased IL-18-/- mice and C57BL/6 mice from Charles River Japan . To produce F1 generation mice, three male IL-18-/- mice were mated with six female C57BL/6J mice. We mated F1 mice and created their F2 littermates. Six week-old F2 mice littermates were weaned. At 12 weeks, mice were sacrificed at 14:00 under general anesthesia with diethyl ether. After the systemic perfusion with cold phosphate-buffered saline through the heart using a syringe attached to a 21-G needle, the whole mouse brains were removed. Coronal brain sections (1 mm thick) were prepared on ice using a brain slicer . The olfactory bulb was sliced between 3.5 and 4.5 anterior to bregma. The prefrontal cortex was sliced between 2.5 and 3.5 mm anterior to bregma. The striatum was sliced between -0.5 and 0.5 mm posterior to bregma. The hypothalamus, the amygdala, and the hippocampus were sliced between 1.5 and 2.5 mm posterior to bregma. Total RNA was immediately prepared from these samples using TRIzol and purified by RNeasy kit.
Project description:Importin α4, which is encoded by the Kpna4 gene, is a well characterized nuclear-cytoplasmic transport factor known to mediate transport of transcription factors including NF-κB. Here, we report that Kpna4 knock-out (KO) mice exhibit psychiatric disorder-related behavioral abnormalities such as anxiety-related behaviors, deceased social interaction and sensorimotor gating deficits. Contrary to a previous study predicting attenuated NF-κB activity as a result of Kpna4 deficiency, we observed a significant increase in expression levels of NF-κB genes and pro-inflammatory cytokines such as TNFα, Il1β or Il-6 in the Prefrontal Cortex or Basolateral Amygdala of the KO mice. Moreover, examination of inflammatory responses in primary cells revealed that Kpna4 deficient cells have an increased inflammatory response, which was rescued by addition of not only full-length, but also a nuclear transport deficient truncation mutant of importin α4, suggesting contribution of its non-transport functions. Furthermore, RNAseq of sorted adult Microglia and Astrocytes and subsequent transcription factor analysis suggested increases in Polycomb repressor complex 2 (PRC2) activity in Kpna4 KO cells. Taken together, importin α4 deficiency induces psychiatric disorder-related behavioral deficits in mice, along with an increased inflammatory response and possible alteration of PRC2 activity in glial cells.
Project description:Fear extinction is an adaptive behavioral process critical for organism’s survival, but deficiency in extinction may lead to PTSD. While the amygdala and its neural circuits are critical for fear extinction, the molecular identity and organizational logic of cell types that lie at the core of these circuits remain unclear. Here we report that mice deficient for amygdala-enriched gastrin-releasing peptide gene (Grp-/-) exhibit enhanced neuronal activity in the basolateral amygdala (BLA) and stronger fear conditioning, as well as deficient extinction in stress-enhanced fear learning (SEFL). rAAV2-retro-based tracing combined with visualization of the GFP knocked in the Grp gene showed that BLA receives several GRPergic conditioned stimulus projections: from the indirect auditory thalamus-to-auditory cortex pathway, medial prefrontal cortex, ventral hippocampus and ventral tegmental area. Transcription of dopamine-related genes was decreased in BLA of Grp-/- mice following SEFL extinction recall, suggesting that the GRP may mediate fear extinction regulation by dopamine.
Project description:Chronic pain is one of the most significant and costly medical problems throughout the world. Recent evidence has confirmed the hippocampus as an active modulator of pain chronicity but the underlying mechanisms remain poorly defined. By means of in vivo electrophysiology together with chemogenetic and optogenetic manipulations in freely behaving mice, we identified a neural ensemble in the ventral hippocampal CA1 (vCA1) that showed inhibitory responses to noxious external stimuli, but not to innocuous stimuli. Following peripheral inflammation, this neuronal ensemble became responsive to innocuous stimuli and causally contributed to sensory hypersensitivity in inflammatory animals. Mimicking this inhibition of vCA1 neurons using chemogenetics in naïve mice induced chronic pain-like behavioral changes, whereas activating these vCA1 neurons in mice with chronic peripheral inflammation resulted in a striking reduction of pain-related behaviors. Pathway-specific manipulation of vCA1 projections to the basolateral amygdala (BLA) and infralimbic cortex (IL) showed that these pathways were differentially involved in pain modulation at different temporal stages of chronic inflammatory pain. These results confirm a crucial role of the ventral hippocampus and its circuits in modulating the development of chronic pain in mice.
Project description:We report that murine MPP8 and MORC2A are highly expressed in the brain and exclusively found in neurons. We show that genetic inactivation of Mphosph8 (coding for MPP8) or Morc2a in the nervous system of mice leads to alterations in brain architecture, behavioral impairments and reduction of life span. By doing RNA-seq and ChIP-seq experiments, we found that MPP8 and MORC2A suppress the repetitive-like protocadherin gene cluster on mouse chromosome 18 in a H3K9me3-dependent manner.
Project description:We report that murine MPP8 and MORC2A are highly expressed in the brain and exclusively found in neurons. We show that genetic inactivation of Mphosph8 (coding for MPP8) or Morc2a in the nervous system of mice leads to alterations in brain architecture, behavioral impairments and reduction of life span. By doing RNA-seq and ChIP-seq experiments, we found that MPP8 and MORC2A suppress the repetitive-like protocadherin gene cluster on mouse chromosome 18 in a H3K9me3-dependent manner.
Project description:We report that murine MPP8 and MORC2A are highly expressed in the brain and exclusively found in neurons. We show that genetic inactivation of Mphosph8 (coding for MPP8) or Morc2a in the nervous system of mice leads to alterations in brain architecture, behavioral impairments and reduction of life span. By doing RNA-seq and ChIP-seq experiments, we found that MPP8 and MORC2A suppress the repetitive-like protocadherin gene cluster on mouse chromosome 18 in a H3K9me3-dependent manner.
Project description:Deletion of the GC receptor (GR) in macrophages in mice, aggravates obesity-related insulin resistance, by reducing anti-inflammatory macrophages, and enhancing adipose tissue inflammation. Consequently, the reduction of anti-inflammatory macrophages leads to exaggerated adipose tissue lipolysis and severe hepatic steatosis. Mechanistically, macrophages deficient for GR show a diminished response to IL-4 driven anti-inflammatory polarization, due to disruption of an epigenetic crosstalk between GC and IL-4 signaling involving synergistic loading of GR and STAT6. Our results demonstrate that GR plays an important role in macrophage polarization during obesity by limiting adipose tissue inflammation and lipolysis to promote insulin sensitivity
Project description:Few families of signaling factors have been implicated in the control of development. Here we identify the neuropeptides nociceptin and somatostatin, a neurotransmitter and neuroendocrine hormone, as a class of developmental signals in chick and zebrafish. We show that signals from the anterior mesendoderm are required for the formation of anterior placode progenitors with one of the signals being somatostatin. Somatostatin controls ectodermal expression of nociceptin and both peptides regulate Pax6 in lens and olfactory progenitors. Consequently, loss of somatostatin and nociceptin signaling leads to severe reduction of lens formation. Our findings not only uncover these neuropeptides as developmental signals, but also identify a long-sought-after mechanism that initiates Pax6 in placode progenitors and may explain the ancient evolutionary origin of neuropeptides, pre-dating a complex nervous system. We used progenitors for anterior and posterior sensory placodes dissected from chick embryos HH5-7; these were either processed immediately or cultured for 5 hrs to hybridise to Affymetrix chick array. We aimed to identify genes that are co regualted with Pax6, a key regulator of lens and olfactory progenitor cells. Pax6 is normally present in anterior, but not posterior placode precursors, but upregulated in both after 5 hrs culture.