Figure 2.

BCAA metabolism is impaired in transgenic APP_Swe mice. 8-month-old WT or APP_Swe AD mice were sacrificed after overnight fasting. (A) Fasting plasma BCAA levels measured by spectrophotometric assay. (B) Western blots showing liver protein abundance of BCKDH, the rate-limiting enzyme in BCAA breakdown; phosphorylated, inactive state of BCKDH (pBCKDH); BCKDH kinase, an enzyme that phosphorylates BCKDH; and BCAT, an enzyme involved in the reversible first step in BCAA degradation. (C) Analysis of BCKDH, pBCKDH, and the inactivity index (pBCKDH/BCKDH ratio). (D) Analysis of BCKDH kinase and BCAT in liver. (E) mRNA expression analysis of BCKDH, BCKDH phosphatase, and BCKDH kinase via RT-qPCR in liver normalized to GAPDH. n = 7–13 males/group; Analyzed by student’s t-test. * p < 0.05. Phosphatase—BCKDH phosphatase; Kinase—BCKDH kinase.