Project description:To quantify gene expression differences in olfactory epithelium between the mouse (Mus musculus) and the Nile rat (Arvicanthis niloticus), paired-end RNA sequencing (RNA-seq) was used to profile olfactory epithelium transcriptomes of six Nile rats and six mice (C57BL/6J) (one male and one female at the age of 8, 12, and 16 weeks for each species).
Project description:The olfactory epithelium contains two basal stem cell populations that facilitate the normally life-long ability for neuronal regeneration that is required for maintaining our sense of smell over the long term. Horizontal basal cells (HBCs) are generally quiescent and only become active after direct injury to the epithelium that kills more than just the olfactory sensory neurons (OSNs). Globose basal cells (GBCs) lie apical to HBCs and are solely responsible for the ongoing generation of olfactory neurons in the undamaged epithelium. Understanding how these two neurogenic stem cell populations are regulated as OSNs are replenished is hampered by a lack of robust culture models. Here, we report the development of a 3-dimensional organoid model that recapitulates the neurogenic cascade while maintaining both HBCs and GBCs in culture. We use this model to demonstrate that despite their relative quiescence, HBCs form a critical niche for the emergence and composition of the organoid.
Project description:A reduced sense of smell has been reported in people with cystic fibrosis (CF). These olfactory defects have largely been attributed to secondary manifestations of the disease, such as inflammation of the nasal mucosa. Here we show that CFTR, the gene responsible for CF, is expressed in proliferating olfactory human cells and that newborn CFTR null pigs display ultrastructural abnormalities in the olfactory epithelium and olfactory bulbs. In the absence of CFTR, olfactory sensory neurons still produce odor-evoked activity, but mutant animals display defective odor-guided suckling behavior after birth. Consistent with epithelial changes, we found a reduced expression of genes implicated in cell cycle and development in globose basal cells (GBCs), the neurogenic progenitor cells in the olfactory epithelium. Targeted sequencing revealed enhanced CFTR expression in the subpopulation of GBCs that is actively proliferating. Furthermore, CFTR loss caused a global reduction in the number of sensory neurons and altered olfactory receptors expression. Our findings highlight a previously unknown role of CFTR in olfactory system function by regulating progenitor cell proliferation in the olfactory epithelium.
Project description:A reduced sense of smell has been reported in people with cystic fibrosis (CF). These olfactory defects have largely been attributed to secondary manifestations of the disease, such as inflammation of the nasal mucosa. Here we show that CFTR, the gene responsible for CF, is expressed in proliferating olfactory human cells and that newborn CFTR null pigs display ultrastructural abnormalities in the olfactory epithelium and olfactory bulbs. In the absence of CFTR, olfactory sensory neurons still produce odor-evoked activity, but mutant animals display defective odor-guided suckling behavior after birth. Consistent with epithelial changes, we found a reduced expression of genes implicated in cell cycle and development in globose basal cells (GBCs), the neurogenic progenitor cells in the olfactory epithelium. Targeted sequencing revealed enhanced CFTR expression in the subpopulation of GBCs that is actively proliferating. Furthermore, CFTR loss caused a global reduction in the number of sensory neurons and altered olfactory receptors expression. Our findings highlight a previously unknown role of CFTR in olfactory system function by regulating progenitor cell proliferation in the olfactory epithelium.
Project description:Expression profiling of mRNA abundance in the adult mouse olfactory epithelium during replacement of OSNs forced by the bilateral ablation of the olfactory bulbs. The experiment was done on 6 week old male C57Bl/6 mice. Olfactory epithelium tissue samples were collected on days 1, 5, and 7 after bulbectomy. The cellular processes activated by bulbectomy include apoptosis of mature olfactory sensory neurons, infiltration of macrophages and dendritic cells, stimulation of proliferation of basal cell progenitors, and differentation of new sensory neurons.
