Insulin Receptor Substrate 2 Expression and Involvement in Neuronal Insulin Resistance in Diabetic Neuropathy
Figure 3
pSer(731)IRS2 is elevated in DRG neurons from type 1 and type 2 diabetic mice. Protein was harvested from adult mouse DRG culture from diabetic ob/ob and nondiabetic mice (a), freshly isolated DRG from STZ-injected diabetic and nondiabetic C57Bl/6 mice (b), and from DRG neurons grown in hyperglycemic and control conditions (c). Western blots were performed using antibodies that recognized phosphorylated ser731 resides on IRS2, and levels of Ser(731)IRS2 were normalized to total IRS2. (a) Comparisons of pSer(731)IRS2 levels in nondiabetic and diabetic ob/ob mice revealed a significant increase in pSer(731)IRS2 levels in diabetic mice. *denotes versus nondiabetics. for nondiabetic mice and for diabetic mice. (b) Diabetes was induced in 8-week-old C57Bl/6 male mice with STZ, and diabetes was allowed to progress for 6 weeks. Similar to ob/ob diabetic mice, pSer(731)IRS2 levels were significantly elevated in STZ-injected diabetic mice. *denotes versus nondiabetics. for nondiabetic mice and for diabetic mice. (c) DRG neurons from nondiabetic animals were grown in 10 mM (control) and 25 mM (hyperglycemic) glucose concentrations. There was no significant change in IRS2 serine phosphorylation levels between groups. for 10 mM glucose and for 25 mM glucose.
