RESUMO
Olfactory marker protein (OMP) may act as a modulator within the olfactory signal-transduction cascade. It has also been shown to have some importance in development of olfactory sensory organs. Here we used high resolution immunocytochemistry to localize OMP in the rat vomeronasal organ (VNO). Immunofluorescence for OMP was abundant in cilia and in apical dendrites of sensory cells, mostly associated with intraepithelial capillaries. Perikarya were stained to a lesser extent while intense OMP immunoreactivity was seen in axons of sensory neurons. Single cells within the non-sensory portion of the VNO exhibited intense OMP immunofluorescence in apical cilia and weak cytoplasmic staining. Some of the exocrine cells in the vomeronasal glands contained OMP positive secretory granules. Electron microscopy revealed that non-sensory ciliated cells had short rod like kinocilia as well as microvilli. These cells contained secretory vesicles. Their basal portion was in close apposition to nerve endings. Our findings suggest that the sensory part of the VNO contains OMP positive sensory neurons and that the non-sensory epithelium may contain secondary sensory cells. In addition OMP may be liberated from secretory glands into vomeronasal secretions.
Assuntos
Proteína de Marcador Olfatório/biossíntese , Órgão Vomeronasal/metabolismo , Animais , Capilares/citologia , Capilares/metabolismo , Capilares/ultraestrutura , Cílios/metabolismo , Cílios/ultraestrutura , Citoplasma/metabolismo , Citoplasma/ultraestrutura , Dendritos/metabolismo , Dendritos/ultraestrutura , Feminino , Imuno-Histoquímica , Masculino , Proteína de Marcador Olfatório/genética , Mucosa Olfatória/metabolismo , Mucosa Olfatória/ultraestrutura , Ratos , Ratos Wistar , Células Receptoras Sensoriais/metabolismo , Células Receptoras Sensoriais/ultraestrutura , Órgão Vomeronasal/ultraestruturaRESUMO
BACKGROUND: The olfactory neuroepithelium lines the upper nasal cavity and is in direct contact with the external environment and the olfactory bulbs. The ability to self-renew throughout life and the reproducible recovery after injury, make it a model tissue to study mechanisms underlying neurogenesis. In this study, X-rays were used to disrupt proliferating olfactory stem cell populations and to assess their role in the cellular and morphological changes involved in olfactory neurogenic processes. RESULTS: We have analysed the histological and functional effects of a sub-lethal dose of X-rays on the adult mouse olfactory neuroepithelium at 2 hours, 24 hours, 1 week, 2 weeks and 5 weeks. We have shown an immediate cessation of proliferating olfactory stem cells as shown by BrdU, Ki67 and pH3 expression. At 24 hours there was an increase in the neural transcription factors Mash1 and Pax6 expression, and a disruption of the basal lamina and increase in glandular cell marker expression at 1 week post-irradiation. Coincident with these changes was an impairment of the olfactory function in vivo. CONCLUSIONS: We have shown significant changes in basal cell proliferation as well as morphological changes in the olfactory neuroepithelium following X-ray irradiation. There is involvement of the basal lamina as well as a clear role for glandular and sustentacular cells.
Assuntos
Células Neuroepiteliais/citologia , Células Neuroepiteliais/efeitos da radiação , Neurogênese/efeitos da radiação , Bulbo Olfatório/efeitos da radiação , Neurônios Receptores Olfatórios/efeitos da radiação , Olfato/efeitos da radiação , Animais , Apoptose/efeitos da radiação , Fatores de Transcrição Hélice-Alça-Hélice Básicos/biossíntese , Movimento Celular/efeitos da radiação , Proliferação de Células/efeitos da radiação , Proteínas do Olho/biossíntese , Proteínas de Homeodomínio/biossíntese , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Bulbo Olfatório/citologia , Proteína de Marcador Olfatório/biossíntese , Neurônios Receptores Olfatórios/citologia , Fator de Transcrição PAX6 , Fatores de Transcrição Box Pareados/biossíntese , Proteínas Repressoras/biossíntese , Células-Tronco/efeitos da radiação , Fatores de TempoRESUMO
Consequent to the 2010 Deepwater Horizon oil spill in the Gulf of Mexico, there is an emergent concern about the short- and long-term adverse health effects of exposure to crude oil, weathered-oil products, and oil dispersants among the workforce employed to contain and clean up the spill. Oil dispersants typically comprise of a mixture of solvents and surfactants that break down floating oil to micrometer-sized droplets within the water column, thus preventing it from reaching the shorelines. As dispersants are generally sprayed from the air, workers are at risk for exposure primarily via inhalation. Such inhaled fractions might potentially permeate or translocate to the brain via olfactory or systemic circulation, producing central nervous system (CNS) abnormalities. To determine whether oil dispersants pose a neurological risk, male Sprague-Dawley rats were exposed by whole-body inhalation exposure to a model oil dispersant, COREXIT EC9500A (CE; approximately 27 mg/m(3) × 5 h/d × 1 d), and various molecular indices of neural dysfunction were evaluated in discrete brain areas, at 1 or 7 d postexposure. Exposure to CE produced partial loss of olfactory marker protein in the olfactory bulb. CE also reduced tyrosine hydroxylase protein content in the striatum. Further, CE altered the levels of various synaptic and neuronal intermediate filament proteins in specific brain areas. Reactive astrogliosis, as evidenced by increased expression of glial fibrillary acidic protein, was observed in the hippocampus and frontal cortex following exposure to CE. Collectively, these findings are suggestive of disruptions in olfactory signal transduction, axonal function, and synaptic vesicle fusion, events that potentially result in an imbalance in neurotransmitter signaling. Whether such acute molecular aberrations might persist and produce chronic neurological deficits remains to be ascertained.
Assuntos
Encéfalo/efeitos dos fármacos , Emulsificantes/toxicidade , Recuperação e Remediação Ambiental/efeitos adversos , Exposição por Inalação/efeitos adversos , Lipídeos/toxicidade , Animais , Encéfalo/metabolismo , Proteína Glial Fibrilar Ácida/biossíntese , Masculino , Modelos Animais , Proteína de Marcador Olfatório/biossíntese , Poluição por Petróleo , Ratos , Ratos Sprague-Dawley , Testes de Toxicidade Aguda , Tirosina 3-Mono-Oxigenase/biossínteseRESUMO
Knowledge of the vomeronasal neuroepithelium (VNNE) microanatomy is disproportionately based on rodents. To broaden our knowledge, we examined olfactory marker protein (OMP) expression in a sample of twenty-three non-human primates. The density of OMP (+) vomeronasal sensory neurons (VSNs) in the VNNE was measured. Here we compared OMP (+) VSN density in five species of Saguinus (a genus of New World monkey) of different ages to a comparative primate sample that included representatives of every superfamily in which a VNO is postnatally present. In Saguinus spp., the VNNE at birth is thin, usually comprising one or two nuclear rows. At all ages studied, few VNNE cells are OMP reactive as view in coronal sections. In the comparative sample, the OMP (+) VSNs appear to be far more numerous in the spider monkey (another New World monkey) and the bushbaby (a distant relative). Other species (e.g., owl monkey) had a similar low density of OMP (+) VSNs as in Saguinus. These results expand our earlier finding that few VSNs are OMP (+) in Saguinus geoffroyi to other species of the genus. Our sample indicates that the number of OMP (+) VSNs in primates varies from ubiquitous to few with New World monkeys varying the most. The scarcity of OMP (+) cells in some primate VNOs reflects a lower number of terminally differentiated VSNs compared to a diverse range of mammals. If primates with relatively few OMP (+) VSNs have a functional vomeronasal system, OMP is not critical for stimulus detection.
Assuntos
Epitélio/metabolismo , Proteína de Marcador Olfatório/biossíntese , Saguinus/fisiologia , Órgão Vomeronasal/metabolismo , Envelhecimento/metabolismo , Animais , Aotidae , Atelinae , Contagem de Células , Células Epiteliais , Feminino , Imuno-Histoquímica , Lemur , Masculino , Saimiri , Especificidade da Espécie , Tarsiidae , Órgão Vomeronasal/crescimento & desenvolvimento , Órgão Vomeronasal/inervaçãoRESUMO
OBJECTIVE: It is not known how many olfactory receptor neurons should be intact to maintain olfaction in mouse models treated with 3-methylindole. The aim of this study is to investigate the relationship between a simple olfactory test outcome and the olfactory neuronal population. STUDY DESIGN: Mouse model. SETTING: Animal laboratory of the Seoul National University Bundang Hospital. SUBJECTS AND METHODS: Olfactory dysfunction was induced by intraperitoneal injection of 3-methylindole in 38 six-week-old female C57BL6 mice. Olfactory function was evaluated by a food-finding test following 72-hour starvation. The olfactory neuronal population was quantified by olfactory marker protein (OMP) expression. RESULTS: The average time for finding food was 8.1 seconds in control mice. It was 13.4, 84.4, 90.1, and 111.4 seconds for mice injected with 100, 200, 300, and 400 µg/g of 3-methylindole, respectively. Harvesting the whole olfactory neuroepithelium, densitometric analysis showed significant decrease of OMP in the 300- and 400-µg/g groups as compared with controls (18.8% and 17.5% of relative density, respectively). In the olfactory bulb, there was a significant decrease of OMP in the 200-, 300-, and 400-µg/g groups (44.5%, 37.0%, and 9.0% of relative density, respectively). The food-finding time had a significant reverse correlation with the relative density of OMP both in the olfactory bulb and in the olfactory neuroepithelium. CONCLUSION: Our study showed that olfactory impairment was correlated with olfactory neuronal population in mice treated with 3-methylindole. The food-finding test would be a useful tool that could be easily performed without special training in the 3-methylindole-treated C57BL6 anosmic mouse model.
Assuntos
Noxas/efeitos adversos , Transtornos do Olfato/induzido quimicamente , Neurônios Receptores Olfatórios/efeitos dos fármacos , Escatol/efeitos adversos , Olfato/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Feminino , Injeções Intraperitoneais , Camundongos , Camundongos Endogâmicos C57BL , Noxas/administração & dosagem , Proteína de Marcador Olfatório/biossíntese , Escatol/administração & dosagemRESUMO
ApoE, a protein component of lipoproteins, is extensively expressed in the primary olfactory pathway. Because apoE has been shown to play a vital role in nerve repair and remodeling, we hypothesized that apoE expression will increase in the injured olfactory epithelium (OE), and that apoE deficiency in apoE knockout (KO) mice will lead to delayed/incomplete reconstitution of the OE following injury. To directly test this hypothesis, we compared OE regeneration in wild-type (WT) and KO mice following injury induced by intranasal irrigation of Triton X-100. OE was collected at 0, 3, 7, 21, 42, and 56 days post lesion. The amount and distribution of apoE in the regenerating OE was measured by immunoblotting and immunohistochemistry. Rate of OE reconstitution in WT and KO mice was assessed by using three independent measures: (1) OE thickness was measured in cresyl-violet stained sections, (2) basal cell proliferation was determined by using bromodeoxyuridine (BrdU) staining, and (3) differentiation and maturation of olfactory sensory neurons were measured by immunoblotting and immunohistochemical analysis of growth associated protein (GAP) 43 and olfactory marker protein (OMP). The results revealed that apoE expression in the OE is highly regulated during the entire course of OE reconstitution post injury, and that apoE deficiency in apoE KO mice leads to delayed recovery of mature OMP(+) cells in the reconstituting OE. The data suggest that apoE production increases in the injured OE to facilitate maturation of olfactory sensory neurons.
Assuntos
Apolipoproteínas E/genética , Apolipoproteínas E/fisiologia , Mucosa Olfatória/lesões , Mucosa Olfatória/fisiologia , Actinas/biossíntese , Animais , Antimetabólitos , Western Blotting , Bromodesoxiuridina , Contagem de Células , Proliferação de Células , Células Epiteliais/fisiologia , Proteína GAP-43/biossíntese , Proteína GAP-43/genética , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Bulbo Olfatório/metabolismo , Proteína de Marcador Olfatório/biossíntese , Proteína de Marcador Olfatório/genética , Mucosa Olfatória/citologia , Recuperação de Função Fisiológica/genética , Recuperação de Função Fisiológica/fisiologiaRESUMO
Age-related changes were examined in the distribution and severity of spontaneous lesions in the neuroepithelium and Bowman's glands in mouse olfactory mucosa. The olfactory mucosa of female ICR mice at postnatal ages from 10 days to 16 months were investigated histologically by hematoxylin and eosin staining, high-iron diamine-Alcian blue (HID-AB) staining, and immunohistochemistry for olfactory marker protein (OMP), betaIII tubulin (betaIIIT), and Ki67. The lesions in the neuroepithelium and Bowman's glands were quantitatively assessed by morphometric analyses of sections stained with anti-OMP antibody or HID-AB. The first appearance of neuroepithelial abnormality was observed in the dorsomedial portion of the olfactory mucosa in 5-month-old mice. The distribution and severity of lesions progressed with increasing age. In mildly affected epithelium in which OMP-positive olfactory receptor neurons (ORNs) were present but in smaller amounts, the numbers of betaIIIT-positive and Ki67-positive neuroepithelial cells tended to be increased, indicating that neurogenesis was upregulated in these areas. In contrast, severely affected epithelium in which OMP-positive ORNs were virtually absent showed high variability in the numbers of betaIIIT- and Ki67-positive cells among the areas examined, probably reflecting differences in the capacity of the basal cells remaining in the affected area to generate new neuronal cells. Histological analysis with HID-AB revealed that spontaneous lesions in Bowman's glands also occurred in aged mouse olfactory mucosa. Lesions in the neuroepithelium and underlying Bowman's glands tended to be spatially co-localized, suggesting a close association between pathogeneses in these two structures. Moreover, lesions in Bowman's glands were associated with changes in the biochemical composition of mucus on the olfactory mucosa. This information should prove useful in improving the understanding of the pathogenetic mechanisms underlying age-related changes in the peripheral olfactory system.
Assuntos
Células Neuroepiteliais/patologia , Mucosa Olfatória/patologia , Neurônios Receptores Olfatórios/patologia , Fatores Etários , Animais , Progressão da Doença , Feminino , Imuno-Histoquímica , Antígeno Ki-67/biossíntese , Camundongos , Camundongos Endogâmicos ICR , Cavidade Nasal/metabolismo , Cavidade Nasal/patologia , Células Neuroepiteliais/metabolismo , Proteína de Marcador Olfatório/biossíntese , Mucosa Olfatória/metabolismo , Neurônios Receptores Olfatórios/metabolismo , Tubulina (Proteína)/biossínteseRESUMO
AdipoR1 and AdipoR2 are receptors for the adipocyte-derived hormone adiponectin, which is an important regulator of glucose and lipid metabolism, and which has also been implicated in the control of food intake and energy homeostasis. In the present study, we have demonstrated that AdipoR1 is expressed in mature sensory neurons of the olfactory mucosa of mice, in a pattern reminiscent of the olfactory marker protein. AdipoR1 expression levels in the olfactory mucosa have been observed to increase gradually during late embryogenesis until adulthood. No local expression of adiponectin has been detected in nasal tissues, indicating that serum adiponectin is the ligand for AdipoR1 in olfactory sensory neurons. As the serum adiponectin concentration is regulated depending on adipose tissue mass, with a reduction of adiponectin levels being seen in obesity, AdipoR1 function in the olfactory epithelium seems to be directly linked to the nutritional status of the body, suggesting a potential modulatory role for AdipoR1 in the adjustment of the olfactory system to energy balance requirements.
Assuntos
Adiponectina/metabolismo , Mucosa Olfatória/metabolismo , Receptores de Adiponectina/biossíntese , Animais , Camundongos , Camundongos Endogâmicos C57BL , Proteína de Marcador Olfatório/biossíntese , Proteína de Marcador Olfatório/genética , Mucosa Olfatória/citologia , Condutos Olfatórios/citologia , Condutos Olfatórios/metabolismo , Receptores de Adiponectina/genéticaRESUMO
BACKGROUND: Olfactory loss is a challenging disease. Although glucocorticoid is sometimes used for the treatment of anosmia, it has been reported that it potentiated neural damage in the early phase of treatment. This study is designed to identify the effect of ginkgo biloba, an antioxidant that acts as a free radical scavenger, in the treatment of olfactory injury aggravated by dexamethasone. METHODS: Anosmia mouse model was induced by i.p. injection of 3-methylindole (3-MI). Twenty-five mice were divided into one control group without anosmia and four anosmia treatment groups (given treatments of dexamethasone and/or ginkgo biloba). The effects of treatment were evaluated by behavioral test, Western blot, and immunohistochemistry 2 weeks after 3-MI injection. RESULTS: Induction of anosmia was confirmed by behavioral tests. The thickness and cell number of olfactory neuroepithelium were decreased more significantly in the dexamethasone treatment group than in the combination treatment group. The expression of olfactory marker protein (OMP) in olfactory epithelium was more decreased also in the dexamethasone treatment group than in the combination treatment group. The expression of OMP was decreased significantly in the olfactory bulbs of anosmia groups but there were no differences between the anosmia treatment groups. CONCLUSION: Dexamethasone treatment was associated with further deterioration of olfactory injury by 3-MI and it was recovered by combination treatment of dexamethasone and ginkgo biloba. The antioxidant effect of ginkgo biloba might play a role in restoration of olfactory loss and it was effective only when oxidative stress is maximized by dexamethasone.