The odorant metabolizing enzyme UGT2A1: Immunolocalization and impact of the modulation of its activity on the olfactory response

International audienceOdorant metabolizing enzymes (OMEs) are expressed in the olfactory epithelium (OE) where they play a significant role in the peripheral olfactory process by catalyzing the fast biotransformation of odorants leading either to their elimination or to the synthesis of new odorant stimuli. The large family of OMEs gathers different classes which interact with a myriad of odorants alike and complementary to olfactory receptors. Thus, it is necessary to increase our knowledge on OMEs to better understand their function in the physiological process of olfaction. This study focused on a major olfactory UDP-glucuronosyltransferase (UGT): UGT2A1. Immunohistochemistry and immunogold electronic microscopy allowed to localize its expression in the apical part of the sustentacular cells and originally at the plasma membrane of the olfactory cilia of the olfactory sensory neurons, both locations in close vicinity with olfactory receptors. Moreover, using electroolfactogram, we showed that a treatment of the OE with beta-glucuronidase, an enzyme which counterbalance the UGTs activity, increased the response to eugenol which is a strong odorant UGT substrate. Altogether, the results supported the function of the olfactory UGTs in the vertebrate olfactory perireceptor process

7-ketocholesterol- and 7β-hydroxycholesterol-induced peroxisomal disorders in glial, microglial and neuronal cells: Potential role in neurodegeneration

International audiencePeroxisomopathies are qualitative or quantitative deficiencies in peroxisomes which lead to increases in the level of very-long-chain fatty acids (VLCFA) and can be associated with more or less pronounced dysfunction of central nervous system cells: glial and microglial cells. Currently, in frequent neurodegenerative diseases, Alzheimer’s disease (AD) and multiple sclerosis (MS), peroxisomal dysfunction is also suspected due to an increase in VLCFA, which can be associated with a decrease of plasmalogens, in these patients. Moreover, in patients suffering from peroxisomopathies, such as X-linked adrenoleukodystrophy (X-ALD), AD, or MS, the increase in oxidative stress observed leads to the formation of cytotoxic oxysterols: 7-ketocholesterol (7KC) and 7β-hydroxycholesterol (7β-OHC). These observations led to the demonstration that 7KC and 7β-OHC alter the biogenesis and activity of peroxisomes in glial and microglial cells. In X-ALD, AD, and MS, it is suggested that 7KC and 7β-OHC affecting the peroxisome, and which also induce mitochondrial dysfunctions, oxidative stress, and inflammation, could promote neurodegeneration. Consequently, the study of oxisome in peroxisomopathies, AD and MS, could help to better understand the pathophysiology of these diseases to identify therapeutic targets for effective treatments

Correction: The odorant metabolizing enzyme UGT2A1: Immunolocalization and impact of the modulation of its activity on the olfactory response.

[This corrects the article DOI: 10.1371/journal.pone.0249029.]

Continuous exposure to low-dose of bisphenol A alone or in mixture alters adipogenesis.

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Odorant metabolism in olfactory mucus: characterization and impact on olfactory perception.

Published Abstrac

Modification des préférences gustatives et de la plasticité structurale des glandes salivaires par une exposition chronique au bisphenol A chez le rat male adulte

Modification des préférences gustatives et de la plasticité structurale des glandes salivaires par une exposition chronique au bisphenol A chez le rat male adulte. colloque de la SFOR

Submandibular salivary glands as an endocrine disruptor target: impact of the period of gensitein/vinclozolin exposure in the Rat

Submandibular salivary glands as an endocrine disruptor target: impact of the period of gensitein/vinclozolin exposure in the Rat. Colloque PNR-PE <National endocrine disruptor research program

Persistence of fermented food bacteria in the oral cavity of rats after one week of consumption

International audienceFermented foods constitute a wide source of exogenous lactic acid bacteria (LAB) which could modify the endogenous microbiota of the consumer's digestive tract. This assumption depends on the ability of LAB to persist, at least transiently, in the oral cavity. The aim of this study was to evaluate the persistence of 3 LAB species, Streptococcus thermophilus, Lactococcus lactis, and Lacticaseibacillus paracasei in the oral cavity of rats by feeding them with a daily portion of model cheese containing the three bacteria for one week. Saliva samples were collected 16 h and one week after the last daily cheese intake. Their cheese bacteria contents were quantified by qPCR. When 16 h after cheese consumption, cheese bacteria were detected in the oral cavity of about ⅓ of the rats ranging from 10−3% to 10−1% of the total bacteria. One week after the last cheese intake, 1/8 LAB remains in the oral cavity. This study is a proof of concept showing that LAB can remain in the oral cavity several days after fermented food consumption with variability depending on individuals

Effect of a Chronic Cholesterol-rich Diet on Vascular Structure and Oxidative Stress in LDLR^-/- Mice

International audienceAims: There is conflicting evidence regarding the relationship between hypercholesterolemia and oxidative stress in vessels. To test the potential relationship, a mouse model of hypercholesterolemia was used.Methods: Low density lipoprotein receptor-deficient (LDLR(-/-)) and control (C57Bl/6) mice were fed a normal or (1.25%) high-cholesterol (HC) diet for 8 weeks, and the incidence of this chronic diet was evaluated on the degree of vascular oxidative stress and vascular structure (collagen content and lipid infiltration expressed in arbitrary units: AU=%/mm(2)).Results: Animals treated with the HC diet presented an increase in lipid infiltration (0.35±0.13 vs. 1.7±0.18 control and 1.04±0.16 vs. 1.84±0.23 LDLR(-/-), AU p<0.05) associated with higher collagen content (control: 2.13±0.40 vs. 3.46±0.36 and LDLR(-/-): 2.37±0.36 vs. 3.79±0.60; AU p<0.05 red Sirius staining). Interestingly, ROS production in the aorta was only increased in the LDLR(-/-) +cholesterol group (0.17±0.04 and 0.16±0.05 in the control groups, 0.14±0.02 vs. 0.34±0.06 in the LDLR(-/-) groups, p<0.05). C57Bl/6 and LDLR(-/-) mice presented altered vascular structure associated with the rich cholesterol diet, which was not necessarily associated with increased oxidative stress.Conclusion: These findings highlight the complex interrelation between oxidative stress and lipid metabolism in the circulatory tract

Protein expression in submandibular glands of young rats is modified by a high-fat/high-sugar maternal diet

International audienceOBJECTIVE: Maternal diet has consequences on many organs of the offspring, but salivary glands have received little attention despite the importance of the saliva secretory function in oral health and control of food intake. The objective of this work was therefore to document in rats the impact of maternal high-fat/high-sugar diet (Western Diet) on submandibular glands of the progeny. DESIGN: Sprague-Dawley rat dams were fed either a Western diet or control diet during gestation and lactation and their pups were sacrificed 25 days after birth. The pups' submandibular gland protein content was characterized by means of 2D-electrophoresis followed by LC-MS/MS. Data were further analyzed by Gene Ontology enrichment analysis and protein-protein interactions mapping. The expression of two specific proteins was also evaluated using immunohistochemistry. RESULTS: Combining both male and female pups (n = 18), proteome analysis revealed that proteins involved in protein quality control (e.g. heat shock proteins, proteasome sub-units) and microtubule proteins were over-expressed in Western diet conditions, which may translate intense metabolic activity. A cluster of proteins controlling oxidative stress (e.g. Glutathione peroxidases, peroxiredoxin) and enhancement of the antioxidant activity molecular function were also characteristic of maternal Western diet as well as under-expression of annexin A5. The down-regulating effect of maternal Western diet on Annexin A5 expression was significant only for males (p < 0.05). CONCLUSIONS: A maternal Western diet modifies the protein composition of the offspring's salivary glands, which may have consequences on the salivary function