title: Defining a longitudinal survival model to examine forced treadmill running as a countermeasure for diet-induced weight gain.
abstract: Diet-induced weight gain increases disease risk via disruption of the innate immune system. Flow cytometry is commonly used to assess the immune system; however, in mice such measurements traditionally require terminal procedures and tissue collection to generate sufficient sample. The present study refined an existing flow cytometry method to reduce the number of mice needed to longitudinally measure monocytes. CD-1 male mice were randomly assigned to one of the three groups: DS (diet-induced weight gain + sedentary), DE (diet-induced weight gain + forced treadmill running [total distance 35,755 ± 1832 m]) or NS (normal weight gain + sedentary). DS and DE consumed a 60% fat diet and NS consumed a 10% fat diet ad libitum. Saphenous vein blood samples were collected weekly for a period of six weeks and three-colour flow cytometry was used to measure changes in monocyte (CD11b(+)/14(+)) concentration and cell-surface toll-like receptor 4 (TLR4) expression. DS (18%) and DE (17%) gained more weight than NS (P < 0.001). On a group basis, DS expressed 17% more TLR4 than DE and NS (P = 0.005). The present study demonstrates that a longitudinal survival model can be used to reduce the number of animals needed to complete flow cytometry experiments. Exercise during diet-induced weight prevented some (decreased monocyte TLR4 expression) but not all aspects of innate immune system function.
authors.affiliation: National Institute for Athletic Health & Performance, 1210 W 18th Street, Suite 204, Sioux Falls, SD 57104, USA.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Esposito
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Simpson
authors.forename: Kelley
authors.initials: K
authors.lastname: Strohacker
authors.forename: Katie C
authors.initials: KC
authors.lastname: Carpenter
authors.forename: Brian K
authors.initials: BK
authors.lastname: McFarlin
mesh_terms: D000821:Animal Feed / Q000009:adverse effects*; D023401:Animal Use Alternatives; D000818:Animals; D001835:Body Weight; D005080:Exercise Test / Q000187:drug effects*; D005434:Flow Cytometry; D007113:Immunity, Innate / Q000187:drug effects* / Q000276:immunology; D008136:Longevity / Q000187:drug effects*; D008137:Longitudinal Studies; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D015233:Models, Statistical; D009000:Monocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D009043:Motor Activity / Q000187:drug effects*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051197:Toll-Like Receptor 4 / Q000378:metabolism; D015430:Weight Gain / Q000187:drug effects
chemical_list: C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4