PROJECT SUMMARY / ABSTRACT
The goal of the current proposal is to develop a brain penetrating erythropoietin (EPO) analogue with negligible
hematopoietic side effects, for AD. EPO is a unique therapeutic candidate for AD since it targets a spectrum of
process that are involved in the pathophysiology and disease progression of AD, and importantly, promotes
neurogenesis and improves cognition. This is clearly distinct from the numerous anti-Aß agents that are
currently under development for AD since anti-Aß agents do not reverse the existing neuronal damage or
cognitive decline. EPO on the other hand has both neuroprotective and neuroregenerative properties. This
provides the scientific rationale to develop EPO for AD. Two major obstacles to the development of EPO for
AD are: a) limited blood-brain barrier (BBB) penetration necessitating transcranial administration or use of high
doses, and b) high doses of EPO result in undesired hematopoietic effects. To achieve our goal, a fusion
protein of EPO with a monoclonal antibody (MAb) against the mouse transferrin receptor (TfR) has been
engineered and is designated as cTfRMAb-EPO. The cTfRMAb-EPO fusion protein offers dual advantages: a)
it rapidly enters the brain via the BBB TfR and b) it is rapidly cleared from the systemic circulation via the
peripheral TfR, resulting in negligible hematopoietic effects. Our central hypothesis is that chronic systemic
administration of the cTfRMAb-EPO fusion protein modifies multiple targets of AD pathophysiology and
disease progression (Aß-pathology (¿), neuroinflammation (¿), synaptic loss (¿), neurogenesis (¿), cognitive
function (¿), and is thus therapeutic in AD with negligible hematopoietic effects. In the proposed studies,
APPswe, PSEN1dE9 (APP/PS1) mice will be treated with either the cTfRMAb-EPO fusion protein, recombinant
human EPO (rhuEPO) or vehicle, and the following specific aims will be addressed: Aim 1: Determine the
cytoprotective effects of the cTfRMAb-EPO fusion protein in the APP/PS1 mice. Specifically, microglial
activation (CD11b), neuroinflammation (brain cytokine levels), neurodegeneration (FluoroJade C), synaptic
loss (synaptophysin) and neurogenesis (5-bromo-2'-deoxyuridine immunostaining) will be studied. Additionally,
we will also study the effect of the brain-penetrating EPO on hematocrit, serum chemistry and histological
effects on major organs following chronic dosing; Aim 2: Characterize the effects of the cTfRMAb-EPO fusion
protein on cognitive deficits in the APP/PS1 mice. In particular, recognition memory and exploration will be
assessed using the novel object recognition and open-field activity tests; Aim 3: Determine the effects of the
cTfRMAb-EPO fusion protein on Aß-pathology in the APP/PS1 mice. Specifically, the effect of the cTfRMAb-
EPO fusion protein on Aß plaque burden will be studied. The proposal will underscore the need for a
neuroprotective-neuroregenerative approach for AD and provide a drug-delivery strategy to deliver EPO to the
brain with negligible hematopoietic side effects.