RESUMO
The p66ShcA protein controls cellular responses to oxidative stress, senescence, and apoptosis. Here, we test the hypothesis that aging phenotype(s) commonly associated with the broad category of chronic kidney disease are accelerated in diabetic kidneys and linked to the p66ShcA locus. At the organ level, tissue stem cells antagonize senescent phenotypes by replacing old dysfunctional cells. Using established methods, we isolated a highly purified population of stem cell antigen-1-positive mesenchymal stem cells (Sca-1+ MSCs) from kidneys of wild-type (WT) and p66 knockout (p66 KO) mice. Cells were plated in culture medium containing normal glucose (NG) or high glucose (HG). Reactive oxygen species (ROS) metabolism was substantially increased in WT MSCs in HG medium in association with increased cell death by apoptosis and acquisition of the senescent phenotype. DNA microarray analysis detected striking differences in the expression profiles of WT and p66 KO-MSCs in HG medium. Unexpectedly, the analysis for p66 KO-MSCs revealed upregulation of Wnt genes implicated in self-renewal and differentiation. To test the in vivo consequences of constitutive p66 expression in diabetic kidneys, we crossed the Akita diabetic mouse with the p66KO mouse. Homozygous mutation at the p66 locus delays or prevents aging phenotype(s) in the kidney that may be precursors to diabetic nephropathy.
Assuntos
Envelhecimento/metabolismo , Nefropatias Diabéticas/metabolismo , Rim/metabolismo , Células-Tronco Mesenquimais/metabolismo , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src/metabolismo , Fatores Etários , Envelhecimento/genética , Envelhecimento/patologia , Animais , Apoptose , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Senescência Celular , Nefropatias Diabéticas/genética , Nefropatias Diabéticas/patologia , Modelos Animais de Doenças , Glucose/metabolismo , Rim/patologia , Células-Tronco Mesenquimais/patologia , Camundongos Knockout , Fenótipo , Espécies Reativas de Oxigênio/metabolismo , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src/deficiência , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src/genética , Nicho de Células-Tronco , Via de Sinalização WntRESUMO
By using experimentally infected rabbits as a model for early syphilis, the applicability of in vitro DNA amplification was explored for detection of Treponema pallidum. It was determined that whole blood in heparin or EDTA (but not serum), lesion exudate, and punch biopsy as well as swabs of lesions are useful specimens for examination by the polymerase chain reaction. Swabs do not require special diluents, and the specimens, whether kept at room temperature or frozen, are well suited for use in the polymerase chain reaction.