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The incidence of the autoimmune disease type 1 diabetes is increasing, likely caused by environmental factors. A gluten-free diet has previously been shown to ameliorate autoimmune diabetes in non-obese diabetic (NOD) mice and humans. Although the exact mechanisms are not understood, interventions influencing the intestinal microbiota early in life affect the risk of type 1 diabetes. Here, we characterize how NOD mice that are fed a gluten-free (GF) diet differ from NOD mice that are fed a gluten-containing standard (STD) diet in terms of their microbiota composition by 16S rRNA gene amplicon sequencing and pancreatic immune environment by real-time quantitative PCR at the prediabetic stage at 6 and 13 weeks of age. Gut microbiota analysis revealed highly distinct microbiota compositions in both the cecum and the colon of GF-fed mice compared with STD-fed mice. The microbiotas of the GF-fed mice were characterized by an increased Firmicutes/Bacteroidetes ratio, an increased abundance of short chain fatty acid (particularly butyrate)-producing bacteria, and a reduced abundance of Lactobacilli compared with STD mice. We found that the insulitis score in the GF mice was significantly reduced compared with the STD mice and that the markers for regulatory T cells and T helper 2 cells were upregulated in the pancreas of the GF mice. In conclusion, a GF diet during pre- and early post-natal life induces shifts in the cecal and colonic microbiota compatible with a less inflammatory environment, providing a likely mechanism for the protective effect of a GF diet in humans.

Sulfide develops during transport of sewage in pumping mains. Dosing of ferrous and ferric iron to the sewage, is a commonly used strategy for abatement of sulfide. How addition of these chemicals alter the microbial population in the biofilm, over the longitudinal section of a pumping main, is presented.

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Symposium : Cellular Signalling; International audience

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Corticosteroids are a group of steroid hormones derived from cholesterol, which are used as endocrine signaling molecules in all classes of vertebrates. In fish, the main corticosteroid hormones are the glucocorticoid hormone, cortisol, and the mineralocorticoid hormone, 11-deoxycorticosterone. These hormones bind specifically to corticosteroid receptors to regulate target-gene transcription. Teleost fish possess two glucocorticoid receptors, GR1 and GR2, which bind cortisol, and one mineralocorticoid receptor, MR, which binds cortisol and 11-deoxycorticosterone (DOC). The physiological significance of DOC is still largely unknown, unlike cortisol which is involved in the regulation of physiological processes, such as metabolism, growth, immune function, reproduction, and hydromineral homeostasis, and is an essential part of the stress response.

Corticosteroids are a group of steroid hormones derived from cholesterol, which are used as endocrine signaling molecules in all classes of vertebrates. In fish, the main corticosteroid hormones are the glucocorticoid hormone, cortisol, and the mineralocorticoid hormone, 11-deoxycorticosterone. These hormones bind specifically to corticosteroid receptors to regulate target-gene transcription. Teleost fish possess two glucocorticoid receptors, GR1 and GR2, which bind cortisol, and one mineralocorticoid receptor, MR, which binds cortisol and 11-deoxycorticosterone (DOC). The physiological significance of DOC is still largely unknown, unlike cortisol which is involved in the regulation of physiological processes, such as metabolism, growth, immune function, reproduction, and hydromineral homeostasis, and is an essential part of the stress response.

Corticosteroids are a group of steroid hormones derived from cholesterol, which are used as endocrine signaling molecules in all classes of vertebrates. In fish, the main corticosteroid hormones are the glucocorticoid hormone, cortisol, and the mineralocorticoid hormone, 11-deoxycorticosterone. These hormones bind specifically to corticosteroid receptors to regulate target-gene transcription. Teleost fish possess two glucocorticoid receptors, GR1 and GR2, which bind cortisol, and one mineralocorticoid receptor, MR, which binds cortisol and 11-deoxycorticosterone (DOC). The physiological significance of DOC is still largely unknown, unlike cortisol which is involved in the regulation of physiological processes, such as metabolism, growth, immune function, reproduction, and hydromineral homeostasis, and is an essential part of the stress response.

Corticosteroids are a group of steroid hormones derived from cholesterol, which are used as endocrine signaling molecules in all classes of vertebrates. In fish, the main corticosteroid hormones are the glucocorticoid hormone, cortisol, and the mineralocorticoid hormone, 11-deoxycorticosterone. These hormones bind specifically to corticosteroid receptors to regulate target-gene transcription. Teleost fish possess two glucocorticoid receptors, GR1 and GR2, which bind cortisol, and one mineralocorticoid receptor, MR, which binds cortisol and 11-deoxycorticosterone (DOC). The physiological significance of DOC is still largely unknown, unlike cortisol which is involved in the regulation of physiological processes, such as metabolism, growth, immune function, reproduction, and hydromineral homeostasis, and is an essential part of the stress response.

Corticosteroids are a group of steroid hormones derived from cholesterol, which are used as endocrine signaling molecules in all classes of vertebrates. In fish, the main corticosteroid hormones are the glucocorticoid hormone, cortisol, and the mineralocorticoid hormone, 11-deoxycorticosterone. These hormones bind specifically to corticosteroid receptors to regulate target-gene transcription. Teleost fish possess two glucocorticoid receptors, GR1 and GR2, which bind cortisol, and one mineralocorticoid receptor, MR, which binds cortisol and 11-deoxycorticosterone (DOC). The physiological significance of DOC is still largely unknown, unlike cortisol which is involved in the regulation of physiological processes, such as metabolism, growth, immune function, reproduction, and hydromineral homeostasis, and is an essential part of the stress response.

Corticosteroids are a group of steroid hormones derived from cholesterol, which are used as endocrine signaling molecules in all classes of vertebrates. In fish, the main corticosteroid hormones are the glucocorticoid hormone, cortisol, and the mineralocorticoid hormone, 11-deoxycorticosterone. These hormones bind specifically to corticosteroid receptors to regulate target-gene transcription. Teleost fish possess two glucocorticoid receptors, GR1 and GR2, which bind cortisol, and one mineralocorticoid receptor, MR, which binds cortisol and 11-deoxycorticosterone (DOC). The physiological significance of DOC is still largely unknown, unlike cortisol which is involved in the regulation of physiological processes, such as metabolism, growth, immune function, reproduction, and hydromineral homeostasis, and is an essential part of the stress response.

International audience

The ability to reverse the net direction of gill ion transport in response to a salinity change is critical for euryhaline teleosts and involves a complex cellular and molecular remodelling of the gill epithelium. The present study aimed to clarify the cellular localisation and exact quantitative inter-relationship of Na+,K+-ATPase - and -subunit transcripts in Atlantic salmon gill during salinity change. The combined expression level of all -isoforms in the gill increased by 100% after freshwater (FW) to seawater (SW) transfer. The 1a and 1b isoforms were both in the range 1-6amol20ng-1 total RNA; 1a decreased and 1b increased after SW-transfer, their ratio changing from 5:1 in FW to 0.26:1 in SW. The 1c and 3 levels were 10- and 100-fold lower, respectively. The 1-subunit mRNA level was 0.1-0.3amol20ng-1 total RNA, thus much lower than the sum of -subunits. Even though increasing 3-fold after SW-transfer, -subunit availability may still limit functional pump synthesis. The mRNAs of the predominant 1a and 1b isoforms were localised by in situ hybridisation in specific gill cells of both FW and SW salmon. Labelling occurred mainly in presumed chloride cells and cells deep in the filament but occasionally also on lamellae. Overall, the salinity-induced variation in labelling pattern and intensity matched the quantification data. In conclusion, the predominant switching of Na+,K+-ATPase -subunit isoform mRNA during salinity acclimation reflects a marked remodelling of mitochondrion-rich cells (MRCs) in the gill and probably tuning of the pump performance to accomplish a net reversal of gill ion transport in hypo- and hypertonic environments.