Insulin Receptor Expression and Activity in the Brains of Nondiabetic Sporadic Alzheimer’s Disease Cases
Figure 2
Total IRβ and [Tyr1162/1163]-phosphorylated IRβ contents in peripheral temporal muscle and in brain hippocampal formation specimens as a function of CDR. Total insulin IRβ contents in temporal muscle (a) and in the hippocampal formation (c) were assessed by western blot analysis using a commercial antibody that is selective for IRβ and is not cross-reactive with IGF-1Rβ. Contents of [Tyr1162/1163]-phosphorylated IRβ in temporal muscle (b) and in the hippocampal formation (d) were assessed by a commercial ELISA that is specific for [Tyr1162/1163]-phosphorylated IRβ, and is not cross-reactive with IGF-IRβ. In ((a) and (c)), total IRβ contents are expressed relative to β-actin levels assessed on the same Western blot using a specific β-actin antibody (Sigma, MO). Inset: representative western blot analysis of total IRβ and β-actin contents in muscle ((a), inset) and hippocampal formation ((c), inset) from CDR 0, 0.5, 1, 2, and 5 cases. In ((b) and (d)), [Tyr1162/1163]-phosphorylated IRβ is expressed relative to total protein contents. In ((a)–(d)), values represent group mean ± SEM values. ANOVA; and .478, respectively, for IRβ and [Tyr1162/1163]-phosphorylated IRβ in temporal muscle; and .425, respectively, for IRβ and [Tyr1162/1163]-phosphorylated IRβ in the hippocampal formation.
