The impact of Scn1a deficiency and ketogenic diet on the intestinal microbiome: a study in a genetic Dravet mouse model

ABSTRACT Background and Aims : Mouse and human data implicates the NOD1 and NOD2 sensors of the intestinal microbiome and the associated signal transduction via the RIPK2 kinase as a potentially key signaling node for the development of Inflammatory Bowel Disease (IBD) and an attractive target for pharmacologic intervention. The TRUC mouse model of IBD has been strongly indicated for evaluating the impact of RIPK2 antagonism on intestinal inflammation based on previous studies with NOD1, NOD2 and RIPK2 knockout mice. Methods. We identified and profiled the BI 706039 molecule as a potent and specific functional inhibitor of both human and mouse RIPK2 and with favorable pharmacokinetic properties. We dosed BI 706039 in the spontaneous TRUC mouse model from aged day 28 through aged day 56. Results : Oral, daily administration of BI 706039 caused dose-responsive and significant improvement in colonic histopathological inflammation, colon weight and terminal levels of protein normalized fecal lipocalin (all p< 0.001). These observations correlated with dose-responsively increasing systemic levels of the BI 706039 compound, splenic molecular target engagement of RIPK2 and modulation of inflammatory genes in the colon. Conclusions : A relatively low oral dose of a potent and selective RIPK2 inhibitor can block the signaling interface between the intestinal microbiome and the intestinal immune system and significantly improve disease associated intestinal inflammation.

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Ketogenic diet impairs Mycobacterium ulcerans growth and toxin production, enhancing hosts’ response to the infection in an experimental mouse model

The Journal of Infectious Diseases ◽

10.1093/infdis/jiab236 ◽

2021 ◽

Author(s):

Mélanie Foulon ◽

Marie Robbe-Saule ◽

Lucille Esnault ◽

Marine Malloci ◽

Anthony Mery ◽

...

Keyword(s):

Mouse Model ◽

Ketogenic Diet ◽

Buruli Ulcer ◽

Mycobacterium Ulcerans ◽

World Health ◽

Ketogenic Diets ◽

Experimental Mouse Model ◽

Experimental Mouse ◽

The Impact

Abstract Ketogenic diets have been used to treat diverse conditions, and there is growing evidence of their benefits for tissue repair and in inflammatory disease treatment. However, their role in infectious diseases has been little studied. Buruli ulcer (Mycobacterium ulcerans infection) is a chronic infectious disease characterized by large skin ulcerations caused by mycolactone, the major virulence factor of the bacillus. Here, we investigated the impact of ketogenic diet on this cutaneous disease in an experimental mouse model. This diet prevented ulceration, by modulating bacterial growth and host inflammatory response. β-hydroxybutyrate, the major ketone body produced during ketogenic diet and diffusing in tissues, impeded M. ulcerans growth and mycolactone production in vitro underlying its potential key role in infection. These results pave the way for the development of new patient management strategies involving shorter courses of treatment and improving wound healing, in line with the major objectives of the World Health Organization.

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1875-P: The Impact of Carbohydrate/Fat Intake Balance on Beta-Cell Dedifferentiation and Fatty Liver in Obese Mouse Model

Diabetes ◽

10.2337/db20-1875-p ◽

2020 ◽

Vol 69 (Supplement 1) ◽

pp. 1875-P ◽

Cited By ~ 2

Author(s):

EMI ISHIDA ◽

XIAO LEI ◽

EIJIRO YAMADA ◽

SHUICHI OKADA ◽

MASANOBU YAMADA

Keyword(s):

Mouse Model ◽

Beta Cell ◽

Fatty Liver ◽

Obese Mouse ◽

Fat Intake ◽

Cell Dedifferentiation ◽

The Impact

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Structural and functional brain-wide alterations in A350V Iqsec2 mutant mice displaying autistic-like behavior

Translational Psychiatry ◽

10.1038/s41398-021-01289-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Daniela Lichtman ◽

Eyal Bergmann ◽

Alexandra Kavushansky ◽

Nadav Cohen ◽

Nina S. Levy ◽

...

Keyword(s):

Social Behavior ◽

Functional Connectivity ◽

Mouse Model ◽

Ampa Receptor ◽

Social Preference ◽

Autism Spectrum ◽

Receptor Trafficking ◽

Anterior Cingulate ◽

The Impact ◽

Ampa Receptor Trafficking

AbstractIQSEC2 is an X-linked gene that is associated with autism spectrum disorder (ASD), intellectual disability, and epilepsy. IQSEC2 is a postsynaptic density protein, localized on excitatory synapses as part of the NMDA receptor complex and is suggested to play a role in AMPA receptor trafficking and mediation of long-term depression. Here, we present brain-wide structural volumetric and functional connectivity characterization in a novel mouse model with a missense mutation in the IQ domain of IQSEC2 (A350V). Using high-resolution structural and functional MRI, we show that animals with the A350V mutation display increased whole-brain volume which was further found to be specific to the cerebral cortex and hippocampus. Moreover, using a data-driven approach we identify putative alterations in structure–function relations of the frontal, auditory, and visual networks in A350V mice. Examination of these alterations revealed an increase in functional connectivity between the anterior cingulate cortex and the dorsomedial striatum. We also show that corticostriatal functional connectivity is correlated with individual variability in social behavior only in A350V mice, as assessed using the three-chamber social preference test. Our results at the systems-level bridge the impact of previously reported changes in AMPA receptor trafficking to network-level disruption and impaired social behavior. Further, the A350V mouse model recapitulates similarly reported brain-wide changes in other ASD mouse models, with substantially different cellular-level pathologies that nonetheless result in similar brain-wide alterations, suggesting that novel therapeutic approaches in ASD that result in systems-level rescue will be relevant to IQSEC2 mutations.

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DIPG-25. KETOGENIC DIET IN DIFFUSE INTRINSIC PONTINE GLIOMA IN CHILDREN: A RETROSPECTIVE STUDY INVESTIGATING THE FEASIBILITY

Neuro-Oncology ◽

10.1093/neuonc/noaa222.074 ◽

2020 ◽

Vol 22 (Supplement_3) ◽

pp. iii291-iii292

Author(s):

Alexandre Perez ◽

Janak Nathan ◽

Moatasem El-Ayadi ◽

Christian Korff ◽

Marc Ansari ◽

...

Keyword(s):

Ketogenic Diet ◽

Controlled Trial ◽

Diffuse Intrinsic Pontine Glioma ◽

Inclusion Criteria ◽

Pontine Glioma ◽

Randomized Controlled ◽

Small Patient Population ◽

Small Patient ◽

The Impact ◽

Aggressive Clinical Behavior

Abstract PURPOSE Diffuse Intrinsic Pontine Glioma (DIPG) is one of the most devastating diseases amongst children with cancer, thus novel strategies are urgently needed. We aimed to retrospectively evaluate the feasibility of the carbohydrate restricted ketogenic diet (KD) in DIPG patients. METHODS Searches of MEDLINE and Embase identified four publications meeting the inclusion criteria (diagnosis of DIPG and exposition to a KD ≥ 3 months). One additional case was identified by contact with experts. The minimal feasibility criteria were defined as the ability to use the KD for ≥ 3 months. Individual patient data were extracted from the publications or obtained from investigators. RESULTS Five patients (males, n=3; median age 4.4 years; range, 2.5–17 years) met the inclusion criteria (one patient – identified and not included - was on KD < 3 months due to disease progression). Further feasibility analyses showed a duration of the KD of ≥ 3 months and less than 7 months (n=2), > 7 months and less than 1 year (n= 2), and two years (n=1), respectively. CONCLUSION These results – based on a small patient population – suggest that the KD appears to be a feasible treatment option for children with DIPG. The potential duration of the KD is limited by the aggressive clinical behavior of DIPG. The safety analysis is currently being retrospectively assessed. These data should encourage further studies on a larger scale; ideally assessing the impact of the KD in DIPG patients in a randomized controlled trial.

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Indirect cholinergic activation slows down pancreatic cancer growth and tumor-associated inflammation

Journal of Experimental & Clinical Cancer Research ◽

10.1186/s13046-020-01796-4 ◽

2020 ◽

Vol 39 (1) ◽

Author(s):

Paulo L. Pfitzinger ◽

Laura Fangmann ◽

Kun Wang ◽

Elke Demir ◽

Engin Gürlevik ◽

...

Keyword(s):

Pancreatic Cancer ◽

Mouse Model ◽

Tumor Stage ◽

Ache Inhibitors ◽

Impact On Survival ◽

The Impact ◽

Ache Expression ◽

Cholinergic Activation

Abstract Background Nerve-cancer interactions are increasingly recognized to be of paramount importance for the emergence and progression of pancreatic cancer (PCa). Here, we investigated the role of indirect cholinergic activation on PCa progression through inhibition of acetylcholinesterase (AChE) via clinically available AChE-inhibitors, i.e. physostigmine and pyridostigmine. Methods We applied immunohistochemistry, immunoblotting, MTT-viability, invasion, flow-cytometric-cell-cycle-assays, phospho-kinase arrays, multiplex ELISA and xenografted mice to assess the impact of AChE inhibition on PCa cell growth and invasiveness, and tumor-associated inflammation. Survival analyses were performed in a novel genetically-induced, surgically-resectable mouse model of PCa under adjuvant treatment with gemcitabine+/−physostigmine/pyridostigmine (n = 30 mice). Human PCa specimens (n = 39) were analyzed for the impact of cancer AChE expression on tumor stage and survival. Results We discovered a strong expression of AChE in cancer cells of human PCa specimens. Inhibition of this cancer-cell-intrinsic AChE via pyridostigmine and physostigmine, or administration of acetylcholine (ACh), diminished PCa cell viability and invasion in vitro and in vivo via suppression of pERK signaling, and reduced tumor-associated macrophage (TAM) infiltration and serum pro-inflammatory cytokine levels. In the novel genetically-induced, surgically-resectable PCa mouse model, adjuvant co-therapy with AChE blockers had no impact on survival. Accordingly, survival of resected PCa patients did not differ based on tumor AChE expression levels. Patients with higher-stage PCa also exhibited loss of the ACh-synthesizing enzyme, choline-acetyltransferase (ChAT), in their nerves. Conclusion For future clinical trials of PCa, direct cholinergic stimulation of the muscarinic signaling, rather than indirect activation via AChE blockade, may be a more effective strategy.

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Gastric Enzyme Supplementation Inhibits Food Allergy in a BALB/c Mouse Model

Nutrients ◽

10.3390/nu13030738 ◽

2021 ◽

Vol 13 (3) ◽

pp. 738

Author(s):

Nazanin Samadi ◽

Denise Heiden ◽

Martina Klems ◽

Martina Salzmann ◽

Johanna Rohrhofer ◽

...

Keyword(s):

Food Allergy ◽

Mouse Model ◽

Gastric Acid ◽

Clinical Symptoms ◽

Acid Suppression ◽

Gastric Digestion ◽

Enzyme Solution ◽

Allergic Symptoms ◽

Gastric Acid Suppression ◽

The Impact

Impaired gastric digestion due to suppressed gastric acidity enhances the risk for food allergy development. In the current study, we aimed to evaluate the impact of a supported gastric digestion via application of a pharmaceutical gastric enzyme solution (GES) on food allergy development and allergic reactions in a BALB/c mouse model. The ability of the GES to restore hypoacidic conditions was tested in mice treated with gastric acid suppression medication. To evaluate the impact on allergic symptoms, mice were orally sensitized with ovalbumin (OVA) under gastric acid suppression and subjected to oral challenges with or without GES. The immune response was evaluated by measurement of antibody titers, cytokine levels, mucosal allergy effector cell influx and regulatory T-cell counts. Clinical response was objectified by core body temperature measurements after oral OVA challenge. Supplementation of GES transiently restored physiological pH levels in the stomach after pharmaceutical gastric acid suppression. During oral sensitization, supplementation of gastric enzymes significantly reduced systemic IgE, IgG1 and IgG2a levels and allergic symptoms. In food allergic mice, clinical symptoms were reduced by co-administration of the gastric enzyme solution. Support of gastric digestion efficiently prevents food allergy induction and alleviates clinical symptoms in our food allergy model.

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Corticosteroids alter alveolar macrophage control of Lichtheimia corymbifera spores in an ex vivo mouse model

Medical Mycology ◽

10.1093/mmy/myaa104 ◽

2020 ◽

Author(s):

Kévin Brunet ◽

François Arrivé ◽

Jean-Philippe Martellosio ◽

Isabelle Lamarche ◽

Sandrine Marchand ◽

...

Keyword(s):

Mouse Model ◽

Alveolar Macrophage ◽

Oxidative Burst ◽

Ex Vivo ◽

Fungal Growth ◽

Invasive Infection ◽

Ex Vivo Model ◽

Lichtheimia Corymbifera ◽

The Impact

Abstract Alveolar macrophages (AM) are the first-line lung defense against Mucorales in pulmonary mucormycosis. Since corticosteroid use is a known risk factor for mucormycosis, the aim of this study was to describe the role of corticosteroids on AM capacities to control Lichtheimia corymbifera spore growth using a new ex vivo model. An in vivo mouse model was developed to determine the acetate cortisone dose able to trigger pulmonary invasive infection. Then, in the ex vivo model, male BALB/c mice were pretreated with the corticosteroid regimen triggering invasive infection, before AM collection through bronchoalveolar lavage. AMs from corticosteroid-treated mice and untreated control AMs were then exposed to L. corymbifera spores in vitro (ratio 1:5). AM control of fungal growth, adherence/phagocytosis, and oxidative burst were assessed using optical densities by spectrophotometer, flow cytometry, and 2', 7'-dichlorofluoresceine diacetate fluorescence, respectively. Cortisone acetate at 500 mg/kg, at D-3 and at D0, led to pulmonary invasive infection at D3. Co-incubated spores and AMs from corticosteroid-treated mice had significantly higher absorbance (fungal growth) than co-incubated spores and control AMs, at 24 h (P = .025), 36 h (P = .004), and 48 h (P = .001). Colocalization of spores with AMs from corticosteroid-treated mice was significantly lower than for control AMs (7.6 ± 1.9% vs 22.3 ± 5.8%; P = .003), reflecting spore adherence and phagocytosis inhibition. Finally, oxidative burst was significantly increased when control AMs were incubated with spores (P = 0.029), while corticosteroids hampered oxidative burst from treated AMs (P = 0.321). Corticosteroids enhanced fungal growth of L. corymbifera through AM phagocytosis inhibition and burst oxidative decrease in our ex vivo model. Lay Summary The aim of this study was to describe the impact of corticosteroids on alveolar macrophage (AM) capacities to control Mucorales growth in a new murine ex vivo model. Corticosteroids enhanced fungal growth of L. corymbifera through AM phagocytosis inhibition and burst oxidative decrease.

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Abstract 16485: The Nitroxyl Donor 1-Nitrosocyclohexyl Acetate Limits Cardiac Superoxide Upregulation and Diastolic Dysfunction in a Mouse Model of Diabetic Cardiomyopathy

Circulation ◽

10.1161/circ.130.suppl_2.16485 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Rebecca H Ritchie ◽

Nga Cao ◽

Yung George Wong ◽

Sarah Rosli ◽

Helen Kiriazis ◽

...

Keyword(s):

Heart Failure ◽

Mouse Model ◽

Diastolic Dysfunction ◽

Diabetic Cardiomyopathy ◽

Ex Vivo ◽

Systolic Function ◽

Left Ventricular ◽

Cardiomyocyte Hypertrophy ◽

Lv Diastolic Dysfunction ◽

The Impact

Nitroxyl (HNO), a redox congener of NO•, is a novel regulator of cardiovascular function combining vasodilator and positive inotropic properties. Our previous studies have demonstrated these properties occur concomitantly in the intact heart; HNO moreover also exhibits antihypertrophic and superoxide-suppressing actions. HNO donors may thus offer favorable actions in heart failure. The impact of chronic HNO donor administration has however yet to be reported in this context. We tested the hypothesis that the HNO donor 1-nitrosocyclohexyl acetate (1-NCA) limits cardiomyocyte hypertrophy and left ventricular (LV) diastolic dysfunction in a mouse model of diabetic cardiomyopathy in vivo. Male 6 week-old FVB/N mice received either streptozotocin (55 mg/kg/day i.p. for 5 days, n=17), to induce type 1 diabetes, or citrate vehicle (n=16). After 4 weeks of hyperglycemia, mice were allocated to 1-NCA therapy (83mg/kg/day i.p.) or vehicle, and followed for a further 4 weeks. As shown in the table, blood glucose was unaffected by 1-NCA. LV diastolic dysfunction was evident in diabetic mice, measured as echocardiography-derived A wave velocity, deceleration time and E:A ratio; LV systolic function was preserved. Diabetes-induced diastolic dysfunction was accompanied by increased LV cardiomyocyte size, hypertrophic and pro-fibrotic gene expression, and upregulation of LV superoxide. These characteristics of diabetic cardiomyopathy were largely prevented by 1-NCA treatment. Selectivity of 1-NCA as a donor of HNO versus NO• was demonstrated by the sensitivity of the coronary vasodilation response of 1-NCA to the HNO scavenger L-cysteine (4mM), but not to the NO• scavenger hydroxocobalamin (50μM), in the normal rat heart ex vivo (n=3-7). Collectively, our studies provide the first evidence that HNO donors may represent a promising new strategy for the treatment of diabetic cardiomyopathy, and implies their therapeutic efficacy in settings of chronic heart failure.

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