A new animal model in pancreatology- Pancreatic ductal fluid and bicarbonate secretion in wild type ferrets

ABSTRACT Studying vitamin E [α-tocopherol (α-T)] metabolism and function in the brain and other tissues requires an animal model with low α-T status, such as the transgenic α-T transfer protein (Ttpa)–null (Ttpa−/−) mouse model. Ttpa+/− dams can be used to produce Ttpa−/− and Ttpa+/+mice for these studies. However, the α-T content in Ttpa+/− dams’ diet requires optimization; diets must provide sufficient α-T for reproduction, while minimizing the transfer of α-T to the offspring destined for future studies that require low baseline α-T status. The goal of this work was to assess the effectiveness and feasibility of 2 breeding diet strategies on reproduction outcomes and offspring brain α-T concentrations. These findings will help standardize the breeding methodology used to generate the Ttpa−/− mice for neurological studies.

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A32 EMPAGLIFOZIN IMPROVES GASTROINTESTINAL INFLAMMATION IN A MOUSE MODEL OF COLITIS

Journal of the Canadian Association of Gastroenterology ◽

10.1093/jcag/gwab002.031 ◽

2021 ◽

Vol 4 (Supplement_1) ◽

pp. 213-215

Author(s):

K Madsen ◽

H Dang ◽

N Hotte ◽

V Mocanu ◽

M Ferdaoussi ◽

...

Keyword(s):

Animal Model ◽

Sglt2 Inhibitor ◽

Direct Effects ◽

Lipocalin 2 ◽

Wild Type ◽

Gut Inflammation ◽

Beneficial Effects ◽

Histological Score ◽

Cytokine Levels ◽

Gastrointestinal Inflammation

Abstract Background Empagliflozin (EMPA) is a highly selective sodium glucose cotransporter-2 (SGLT2) inhibitor and is increasingly being utilized as an antihyperglycemic agent in the management of type 2 diabetes. Interestingly, it has been demonstrated in human trials that EMPA treatment exerts potent cardioprotective effects by reducing cardiac inflammation independently of glycemic control. Further, EMPA has also been shown to suppress LPS-induced renal and systemic inflammation in an animal model. Based on these findings, we hypothesized that EMPA treatment may also be effective in reducing gut inflammation. Aims The aim of this study was to examine the effects of treatment with EMPA on gastrointestinal inflammation in an animal model of inflammatory bowel disease and to determine mechanistic insights regarding its direct effects on gut cytokine secretion. Methods Adult male and female IL-10-/- mice with established colitis were treated with a daily gavage of EMPA (10mg/kg; n=10) or vehicle (n=10) for 14 days. Disease activity was assessed by measurement of mouse weight, colonic weight and length, histological score, cytokine levels in colonic homogenate and lipocalin-2 levels in stool. To examine for possible direct effects of EMPA, colonic explants from wild-type (n=8) and IL-10-/- (n=8) mice were incubated with increasing doses of EMPA (0.1–5 µM) ± LPS (10µg/ml) for 2 hours and tissue levels of IL-1β and TNFα protein measured by ELISA. Results After 14 days EMPA treated IL-10-/- mice had a significant improvement in colonic inflammation as evidenced by decreased colonic weight to length ratio (p=0.019), decreased fecal lipocalin-2 (p=0.03), as well as decreased enterocyte injury (p=0.01), decreased lamina propria neutrophils (p=0.01) and decreased total histological score (p=0.006). EMPA treated mice also maintained their weight over the 14 days while untreated mice continued to lose weight (p=0.04). There were no significant differences in colonic homogenate levels of TNFα, IL-1β, or IL-6 or in blood glucose levels between EMPA-treated mice and controls. In addition, EMPA did not suppress levels of basal or LPS-induced TNFα and IL-1β in colonic explants from either wild-type or IL-10-/- mice suggesting that the beneficial effects in IL-10-/- mice were not due to direct effects of EMPA on colonic TNFα or IL-1β cytokine levels. Conclusions EMPA treatment dramatically improved histologic and fecal inflammatory markers and maintained body weight in adult IL-10-/- mice with established colitis. These findings suggest further investigations into the effects of EMPA in treating gut inflammation are warranted. Funding Agencies CAG, CIHR

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Characterizing a Murine Model for Astrovirus Using Viral Isolates from Persistently Infected Immunocompromised Mice

Journal of Virology ◽

10.1128/jvi.00223-19 ◽

2019 ◽

Vol 93 (13) ◽

Cited By ~ 4

Author(s):

Valerie Cortez ◽

Bridgett Sharp ◽

Jiangwei Yao ◽

Brandi Livingston ◽

Peter Vogel ◽

...

Keyword(s):

Animal Model ◽

Small Animal ◽

Enteric Viruses ◽

Mouse Strains ◽

Wild Type ◽

Small Animal Model ◽

Human Astroviruses ◽

Duration Of Infection ◽

Human Astrovirus ◽

Immunocompromised Mice

ABSTRACT Human astroviruses are single-stranded RNA enteric viruses that cause a spectrum of disease ranging from asymptomatic infection to systemic extragastrointestinal spread; however, they are among the least-characterized enteric viruses, and there is a lack of a well-characterized small animal model. Finding that immunocompromised mice were resistant to human astrovirus infection via multiple routes of inoculation, our studies aimed to determine whether murine astrovirus (MuAstV) could be used to model human astrovirus disease. We experimentally infected wild-type mice with MuAstV isolated from immunocompromised mice and found that the virus was detected throughout the gastrointestinal tract, including the stomach, but was not associated with diarrhea. The virus was also detected in the lung. Although virus levels were higher in recently weaned mice, the levels were similar in male and female adult mice. Using two distinct viruses isolated from different immunocompromised mouse strains, we observed virus strain-specific differences in the duration of infection (3 versus 10 weeks) in wild-type mice, indicating that the within-host immune pressure from donor mice shaped the virus kinetics in immunocompetent recipient hosts. Both virus strains elicited minimal pathology and a lack of sustained immunity. In summary, MuAstV represents a useful model for studying asymptomatic human infection and gaining insight into the astrovirus pathogenesis and immunity. IMPORTANCE Astroviruses are widespread in both birds and mammals; however, little is known about the pathogenesis and the immune response to the virus due to the lack of a well-characterized small-animal model. Here we describe two distinct strains of murine astrovirus that cause infections in immunocompetent mice that mirror aspects of asymptomatic human infections, including minimal pathology and short-lived immunity. However, we noted that the duration of infection differed greatly between the strains, highlighting an important facet of these viruses that was not previously appreciated. The ubiquitous nature and diversity of murine astroviruses coupled with the continuous likelihood of reinfection raise the possibility of viral interference with other mouse models of disease.

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Elicitation of Neutralizing Antibodies Targeting the V2 Apex of the HIV Envelope Trimer in a Wild-Type Animal Model

Cell Reports ◽

10.1016/j.celrep.2017.09.024 ◽

2017 ◽

Vol 21 (1) ◽

pp. 222-235 ◽

Cited By ~ 31

Author(s):

James E. Voss ◽

Raiees Andrabi ◽

Laura E. McCoy ◽

Natalia de Val ◽

Roberta P. Fuller ◽

...

Keyword(s):

Animal Model ◽

Neutralizing Antibodies ◽

Wild Type ◽

Wild Type Animal ◽

Hiv Envelope

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Effect of Slc26a6 deletion on apical Cl−/HCO3− exchanger activity and cAMP-stimulated bicarbonate secretion in pancreatic duct

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00286.2006 ◽

2007 ◽

Vol 292 (1) ◽

pp. G447-G455 ◽

Cited By ~ 41

Author(s):

Hiroshi Ishiguro ◽

Wan Namkung ◽

Akiko Yamamoto ◽

Zhaohui Wang ◽

Roger T. Worrell ◽

...

Keyword(s):

Pancreatic Duct ◽

Apical Membrane ◽

Pancreatic Ducts ◽

Bicarbonate Secretion ◽

Wild Type ◽

Rt Pcr ◽

Secretory Rate ◽

Transport Fluid ◽

Exchange Activity

The role of Slc26a6 (PAT1) on apical Cl−/HCO3− exchange and bicarbonate secretion in pancreatic duct cells was investigated using Slc26a6 null and wild-type (WT) mice. Apical Cl−/HCO3− exchange activity was measured with the pH-sensitive dye BCECF in microperfused interlobular ducts. The HCO3−-influx mode of apical [Cl−]i/[HCO3−]o exchange (where brackets denote concentration and subscripts i and o denote intra- and extracellular, respectively) was dramatically upregulated in Slc26a6 null mice ( P < 0.01 vs. WT), whereas the HCO3−-efflux mode of apical [Cl−]o/[HCO3−]i exchange was decreased in Slc26a6 null mice ( P < 0.05 vs. WT), suggesting the unidirectionality of the Slc26a6-mediated HCO3− transport. Fluid secretory rate in interlobular ducts were comparable in WT and Slc26a6 null mice ( P > 0.05). In addition, when pancreatic juice was collected from whole animal in basal and secretin-stimulated conditions, neither juice volume nor its pH showed differences between WT and Slc26a6 null mice. Semiquantitative RT-PCR demonstrated more than fivefold upregulation in Slc26a3 (DRA) expression in Slc26a6 knockout pancreas. In conclusion, these results point to the role of Slc26a6 in HCO3− efflux at the apical membrane and also suggest the presence of a robust Slc26a3 compensatory upregulation, which can replace the function of Slc26a6 in pancreatic ducts.

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A Mouse Model for Human Norovirus

mBio ◽

10.1128/mbio.00450-13 ◽

2013 ◽

Vol 4 (4) ◽

Cited By ~ 122

Author(s):

Stefan Taube ◽

Abimbola O. Kolawole ◽

Marina Höhne ◽

John E. Wilkinson ◽

Scott A. Handley ◽

...

Keyword(s):

Animal Model ◽

Mouse Model ◽

Small Animal ◽

Morbidity And Mortality ◽

Significant Morbidity ◽

Wild Type ◽

Small Animal Model ◽

Human Norovirus ◽

Human Noroviruses ◽

Deficient Mice

ABSTRACT Human noroviruses (HuNoVs) cause significant morbidity and mortality worldwide. However, despite substantial efforts, a small-animal model for HuNoV has not been described to date. Since “humanized” mice have been successfully used to study human-tropic pathogens in the past, we challenged BALB/c mice deficient in recombination activation gene (Rag) 1 or 2 and common gamma chain (γc) (Rag-γc) engrafted with human CD34+ hematopoietic stem cells, nonengrafted siblings, and immunocompetent wild-type controls with pooled stool isolates from patients positive for HuNoV. Surprisingly, both humanized and nonhumanized BALB/c Rag-γc-deficient mice supported replication of a GII.4 strain of HuNoV, as indicated by increased viral loads over input. In contrast, immunocompetent wild-type BALB/c mice were not infected. An intraperitoneal route of infection and the BALB/c genetic background were important for facilitating a subclinical HuNoV infection of Rag-γc-deficient mice. Expression of structural and nonstructural proteins was detected in cells with macrophage-like morphology in the spleens and livers of BALB/c Rag-γc-deficient mice, confirming the ability of HuNoV to replicate in a mouse model. In summary, HuNoV replication in BALB/c Rag-γc-deficient mice is dependent on the immune-deficient status of the host but not on the presence of human immune cells and provides the first genetically manipulable small-animal model for studying HuNoV infection. IMPORTANCE Human noroviruses are a significant cause of viral gastroenteritis worldwide, resulting in significant morbidity and mortality. Antivirals and vaccines are currently not available, in part due to the inability to study these viruses in a genetically manipulable, small-animal model. Herein, we report the first mouse model for human noroviruses. This model will accelerate our understanding of human norovirus biology and provide a useful resource for evaluating antiviral therapies.

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Investigation of pancreatic ductal fluid and HCO3-secretion in NHERF1 knockout and wild-type mice

Zeitschrift für Gastroenterologie ◽

10.1055/s-0032-1312412 ◽

2012 ◽

Vol 50 (05) ◽

Author(s):

P Pallagi ◽

A Kumar Singh ◽

P Hegyi ◽

V Venglovecz ◽

R Engelhardt ◽

...

Keyword(s):

Wild Type ◽

Ductal Fluid

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Mutations in the lspA1 and lspA2 Genes of Haemophilus ducreyi Affect the Virulence of This Pathogen in an Animal Model System

Infection and Immunity ◽

10.1128/iai.71.5.2478-2486.2003 ◽

2003 ◽

Vol 71 (5) ◽

pp. 2478-2486 ◽

Cited By ~ 18

Author(s):

Christine K. Ward ◽

Jo L. Latimer ◽

Joseph Nika ◽

Merja Vakevainen ◽

Jason R. Mock ◽

...

Keyword(s):

Animal Model ◽

Parent Strain ◽

Type Strain ◽

Double Mutant ◽

Wild Type Strain ◽

Culture Supernatant ◽

Haemophilus Ducreyi ◽

Supernatant Fluid ◽

Wild Type ◽

Wild Type Parent

ABSTRACT Haemophilus ducreyi 35000HP contains two genes, lspA1 and lspA2, whose predicted protein products have molecular weights of 456,000 and 543,000, respectively (C. K. Ward, S. R. Lumbley, J. L. Latimer, L. D. Cope, and E. J. Hansen, J. Bacteriol. 180:6013-6022, 1998). We have constructed three H. ducreyi 35000HP mutants containing antibiotic resistance cartridges in one or both of the lspA1 and lspA2 open reading frames. Western blot analysis using LspA1- and LspA2-specific monoclonal antibodies indicated that the wild-type parent strain 35000HP expressed LspA1 protein that was readily detectable in culture supernatant fluid together with a barely detectable amount of LspA2 protein. The lspA2 mutant 35000HP.2 expressed LspA1 protein that was detectable in culture supernatant fluid and no LspA2 protein. In contrast, the H. ducreyi lspA1 mutant 35000HP.1, which did not express the LspA1 protein, expressed a greater quantity of the LspA2 protein than did the wild-type parent strain. The lspA1 lspA2 double mutant 35000HP.12 expressed neither LspA1 nor LspA2. The three mutant strains adhered to human foreskin fibroblasts and to a human keratinocyte cell line in vitro at a level that was not significantly different from that of the wild-type strain 35000HP. Lack of expression of the LspA1 protein by both the lspA1 mutant and the lspA1 lspA2 double mutant was associated with an increased tendency to autoagglutinate. When evaluated in the temperature-dependent rabbit model for chancroid, the lspA1 lspA2 double mutant was substantially less virulent than the wild-type strain 35000HP. The results of these studies indicated that H. ducreyi requires both the LspA1 and LspA2 proteins to be fully virulent in this animal model for experimental chancroid.

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