Applicability of [ 11 C]PIB micro-PET imaging for in vivo follow-up of anti-amyloid treatment effects in APP23 mouse model.

In this study, we evaluated the anti-amyloid effect of functionalized nanoliposomes (mApoE-PA-LIP) in a mouse model of Alzheimer's disease with use of positron emission tomography and β-amyloid (Aβ)-targeted tracer [ ¹¹ C]Pittsburgh compound B ([ ¹¹ C]PIB). APP23 mice were injected with mApoE-PA-LIP or saline (3 times per week for 3 weeks) and [ ¹¹ C]PIB imaging was performed at baseline, after the treatment and after 3 months follow-up period, accompanied by Aβ immunohistochemistry and ELISA. After the treatment, [ ¹¹ C]PIB binding ratios between mApoE-PA-LIP and saline groups were equivalent in all analyzed brain regions; however, in the saline group, binding ratios increased from the baseline, whereas no increase was detected in the mApoE-PA-LIP group. During the additional follow-up, [ ¹¹ C]PIB binding increased significantly from baseline in both groups, and binding ratios correlated with the immunohistochemically defined Aβ load. This study further supports the use of [ ¹¹ C]PIB positron emission tomography imaging as a biomarker of Aβ deposition in APP23 mice and highlights the benefits of noninvasive follow-up, that is, using baseline data for animal stratification and normalization of treatment effects to baseline values, for future anti-amyloid treatment studies.
(Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)