title: Effect of IP3R3 and NPY on age-related declines in olfactory stem cell proliferation.
abstract: Losing the sense of smell because of aging compromises health and quality of life. In the mouse olfactory epithelium, aging reduces the capacity for tissue homeostasis and regeneration. The microvillous cell subtype that expresses both inositol trisphosphate receptor type 3 (IP3R3) and the neuroproliferative factor neuropeptide Y (NPY) is critical for regulation of homeostasis, yet its role in aging is undefined. We hypothesized that an age-related decline in IP3R3 expression and NPY signaling underlie age-related homeostatic changes and olfactory dysfunction. We found a decrease in IP3R3(+) and NPY(+) microvillous cell numbers and NPY protein and a reduced sensitivity to NPY-mediated proliferation over 24 months. However, in IP3R3-deficient mice, there was no further age-related reduction in cell numbers, proliferation, or olfactory function compared with wild type. The proliferative response was impaired in aged IP3R3-deficient mice when injury was caused by satratoxin G, which induces IP3R3-mediated NPY release, but not by bulbectomy, which does not evoke NPY release. These data identify IP3R3 and NPY signaling as targets for improving recovery following olfactotoxicant exposure.
authors.affiliation: Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA.
authors.forename: Cuihong
authors.initials: C
authors.lastname: Jia
authors.affiliation: Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA. Electronic address: hegg@msu.edu.
authors.forename: Colleen C
authors.initials: CC
authors.lastname: Hegg
mesh_terms: D000375:Aging / Q000235:genetics* / Q000473:pathology*; D000818:Animals; D049109:Cell Proliferation / Q000235:genetics*; D005260:Female; D006706:Homeostasis / Q000235:genetics; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000502:physiology*; D008297:Male; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009478:Neuropeptide Y / Q000378:metabolism / Q000502:physiology*; D000857:Olfaction Disorders / Q000235:genetics / Q000473:pathology; D009830:Olfactory Bulb / Q000166:cytology*; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D013234:Stem Cells / Q000166:cytology*; D014255:Trichothecenes / Q000633:toxicity
chemical_list: D053496:Inositol 1,4,5-Trisphosphate Receptors; C581220:Itpr3 protein, rat; D009478:Neuropeptide Y; D014255:Trichothecenes; C028268:satratoxin G
keywords: Injury; Olfactory sensory neurons; Olfactory stem cells; Olfactory-mediated behavior; Proliferation