Institute of Translational Research, Ochsner Health System , New Orleans, Louisiana.
Neurological Cancer Research, Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center , New Orleans, Louisiana.
Am J Physiol Renal Physiol. 2018 Dec 1;315(6):F1833-F1842. doi: 10.1152/ajprenal.00608.2017. Epub 2018 Sep 12.
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.
p66ShcA 蛋白控制细胞对氧化应激、衰老和凋亡的反应。在这里，我们检验了这样一个假设，即与慢性肾脏病广泛范畴相关的衰老表型在糖尿病肾脏中加速，并与 p66ShcA 基因座相关。在器官水平上，组织干细胞通过替代衰老和功能失调的细胞来拮抗衰老表型。我们使用已建立的方法，从野生型（WT）和 p66 敲除（p66 KO）小鼠的肾脏中分离出高度纯化的干细胞抗原 1 阳性间充质干细胞（Sca-1 MSC）。细胞在含有正常葡萄糖（NG）或高葡萄糖（HG）的培养基中培养。在 HG 培养基中，WT 间充质干细胞中的活性氧（ROS）代谢显著增加，与细胞凋亡增加和衰老表型的获得有关。DNA 微阵列分析检测到 WT 和 p66 KO-MSCs 在 HG 培养基中的表达谱存在显著差异。出乎意料的是，p66 KO-MSCs 的分析显示，自我更新和分化相关的 Wnt 基因上调。为了测试在糖尿病肾脏中组成型表达 p66 的体内后果，我们将 Akita 糖尿病小鼠与 p66KO 小鼠杂交。p66 基因座的纯合突变延迟或防止了糖尿病肾病的肾脏中衰老表型（s）的发生，这些表型可能是糖尿病肾病的前兆。
