- IACUC). Targeted elimination of CX3CR1+ cells. CX3CR1-DTR mice were treated with diphtheria toxin (DT, List Biological Lab Inc., Campbell, CA) three times over seven days using a dose of 200ng/20g mouse. Preliminary
The following compounds were used in the reported studies: CL 316,241 (in saline; from Tocris); C75 (RPMI medium 1640; from Tocris);67,68 capsaicin (3.3% Tween-80 in saline; from Sigma)14, CNO (in saline; from Enzo Life Science)14, and diphtheria toxin (in saline; List Biological, cat. no. 150).
The type of nutrient utilized by the organism at any given time-substrate utilization-is a critical component of energy metabolism. The neuronal mechanisms involved in the regulation of substrate utilization in mammals are largely unknown. Here, we found that activation of hypothalamic Agrp neurons rapidly altered whole-body substrate utilization, increasing carbohydrate utilization, while decreasing fat utilization. These metabolic changes occurred even in the absence of caloric ingestion and were coupled to increased lipogenesis. Accordingly, inhibition of fatty acid synthase-a key enzyme that mediates lipogenesis-blunted the effects of Agrp neuron activation on substrate utilization. In pair-fed conditions during positive energy balance, activation of Agrp neurons improved metabolic efficiency, and increased weight gain and adiposity. Conversely, ablation of Agrp neurons impaired fat mass accumulation. These results suggest Agrp neurons regulate substrate utilization, contributing to lipogenesis and fat mass accumulation during positive energy balance.
Activation of Mevalonate Pathway Via LKB1 is Essential for Stability of Treg Cells
- All mice were intragastrically (ig) sensitized to the cow's milk protein whey (DMV International, Veghel, the Netherlands) dissolved in PBS (20 mg whey in 0.5 ml PBS, Lonza, Verviers, Belgium) with cholera toxin (CT, 15 μg CT in 0.5 ml, List Biological Laboratories Inc Cached
Background. In previous studies, we showed that a fructo-oligosaccharide- (FOS-) supplemented diet enhanced oral immunotherapy (OIT) efficacy in a mouse model for cow’s milk allergy. Fermentation of FOS by intestinal bacteria leads to production of short-chain fatty acids (SCFA) including butyrate. Aim. To investigate the contribution of butyrate in the enhanced efficacy of OIT + FOS. Methods. C3H/HeOuJ mice were sensitized and received OIT with or without FOS or butyrate supplementation. After treatment, whole blood was collected to conduct a basophil activation test (BAT) and allergen challenges were performed to measure acute allergic symptoms. CD4 + CD25 + regulatory T cells (Tregs) were isolated from treated mice or differentiated in vitro and used in a bone marrow-derived mast cell (BMMC) suppression assay. Cecum content was collected to analyze SCFA concentrations. Results. Allergen-induced basophil activation was reduced in OIT + butyrate samples compared to OIT. Accordingly, the acute allergic skin response and mast cell degranulation upon challenge were reduced in OIT + butyrate and OIT + FOS mice compared to sensitized controls. Butyrate was increased in the cecum content of OIT + FOS mice compared to OIT mice and sensitized controls. Treg-mediated BMMC suppression was enhanced after in vivo butyrate and FOS exposure in combination with OIT but with a more pronounced effect for butyrate. Conclusion. Butyrate supplementation enhanced OIT-induced desensitization of basophils and mast cells and Treg functionality. Only OIT + FOS treatment induced potential microbial alterations, shown by increased butyrate levels in cecum content. Both butyrate and FOS are promising candidates to improve OIT efficacy in human studies to treat food allergies.
Chi3l3 induces oligodendrogenesis in an experimental model of autoimmune neuroinflammation
... ptide, Gardner, MA) peptide that was emulsified in complete Freund’s adjuvant (CFA; Sigma-Aldrich) containing 200 μg Mycobacterium tuberculosis (Difco), followed by 200 ng pertussis toxin (PT; List Biological Laboratories) in 0.2 ml PBS by intraperitoneal (i.p.) injections at the time of immunization and 48 h later. Control mice were immunized with CFA, followed by PT injection. Mice we ... ptide, Gardner, MA) peptide that was emulsified in complete Freund’s adjuvant (CFA; Sigma-Aldrich) containing 200 μg Mycobacterium tuberculosis (Difco), followed by 200 ng pertussis toxin (PT; List Biological Laboratories) in 0.2 ml PBS by intraperitoneal (i.p.) injections at the time of immunization and 48 h later. Control mice were immunized with CFA, followed by PT injection. Mice we
In demyelinating diseases including multiple sclerosis (MS), neural stem cells (NSCs) can replace damaged oligodendrocytes if the local microenvironment supports the required differentiation process. Although chitinase-like proteins (CLPs) form part of this microenvironment, their function in this differentiation process is unknown. Here, we demonstrate that murine Chitinase 3-like-3 (Chi3l3/Ym1), human Chi3L1 and Chit1 induce oligodendrogenesis. In mice, Chi3l3 is highly expressed in the subventricular zone, a stem cell niche of the adult brain, and in inflammatory brain lesions during experimental autoimmune encephalomyelitis (EAE). We find that silencing Chi3l3 increases severity of EAE. We present evidence that in NSCs Chi3l3 activates the epidermal growth factor receptor (EGFR), thereby inducing Pyk2-and Erk1/2- dependent expression of a pro-oligodendrogenic transcription factor signature. Our results implicate CLP-EGFR-Pyk2-MEK-ERK as a key intrinsic pathway controlling oligodendrogenesis.