Apomorphine Therapy for Neuronal Insulin Resistance in a Mouse Model of Alzheimer's Disease

作者：Nakamura Norimichi; Ohyagi Yasumasa^*; Imamura Tomohiro; Yanagihara Yuki T; Iinuma Kyoko M; Soejima Naoko; Murai Hiroyuki; Yamasaki Ryo; Kira Jun Ichi

来源：Journal of Alzheimer's Disease, 2017, 58(4): 1151-1161.

DOI：10.3233/JAD-160344

• 3xTg-AD
• apomorphine
• insulin-degrading enzyme
• insulin receptor substrate-1
• insulin resistance
• memory

Apomorphine (APO) promotes intraneuronal amyloid-beta (A beta) degradation and improves memory function in an Alzheimer's disease (AD) model, 3xTg-AD mice. Since insulin resistance is increased in AD neurons, we investigated the effects of APO on brain insulin resistance in 3xTg-AD mice at early and late stages. After 1-month subcutaneous injection of Apokyn (R) to 3xTg-AD mice at 6 or 12 months of age, memory function was significantly improved in both age groups. Protein levels of insulin-degrading enzyme (IDE), which is linked to insulin signaling and degrades A beta, significantly increased in the 3xTg-AD mice brain compared with non-transgenic mice, and were further increased by APO. Protein levels of two types of serine-phosphorylated insulin receptor substrate-1 (IRS-1), pS(616) and pS(636/639), significantly decreased following APO treatment in the 13-month-old 3xTg-AD mice brain, suggesting improved brain insulin resistance. Immunostaining of the IDE, pS(616) and pS(636/639) IRS-1 demonstrated similar changes due to APO treatment. Thus, brain insulin resistance is considered an important therapeutic target in AD, and APO may provide improved neuronal insulin resistance.

• 出版日期2017