Preclinical Assessment of Young Blood Plasma for Alzheimer Disease.
OBJECTIVE
Alzheimer disease (AD) pathology starts long before clinical symptoms manifest, and there is no therapy to treat, delay, or prevent the disease. A shared blood circulation between 2 mice (aka parabiosis) or repeated injections of young blood plasma (plasma from 2- to 3-month-old mice) into old mice has revealed benefits of young plasma on synaptic function and behavior. However, to our knowledge, the potential benefit of young blood has not been tested in preclinical models of neurodegeneration or AD.


OBJECTIVE
To determine whether young blood plasma ameliorates pathology and cognition in a mouse model for AD and could be a possible future treatment for the disease.


METHODS
In this preclinical study, mice that harbor a human mutant APP gene, which causes familial AD, were aged to develop AD-like disease including accumulation of amyloid plaques, loss of synaptic and neuronal proteins, and behavioral deficits. The initial parabiosis studies were done in 2010, and the final studies were conducted in 2014. Alzheimer disease model mice were then treated either by surgically connecting them with a young healthy mouse, thus providing a shared blood circulation through parabiosis, or through repeated injections of plasma from young mice.


METHODS
Neuropathological parameters and changes in hippocampal gene expression in response to the treatment were assessed. In addition, cognition was tested in AD model mice intravenously injected with young blood plasma.


RESULTS
Aged mutant amyloid precursor protein mice with established disease showed a near complete restoration in levels of synaptic and neuronal proteins after exposure to young blood in parabiosis (synaptophysin P = .02; calbindin P = .02) or following intravenous plasma administration (synaptophysin P < .001; calbindin P = .14). Amyloid plaques were not affected, but the beneficial effects in neurons in the hippocampus were accompanied by a reversal of abnormal extracellular receptor kinase signaling (P = .05), a kinase implicated in AD. Moreover, young plasma administration was associated with improved working memory (P = .01) and associative memory (P = .02) in amyloid precursor protein mice.


CONCLUSIONS
Factors in young blood have the potential to ameliorate disease in a model of AD.
Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California.
Jinte
J
Middeldorp
Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California.
Benoit
B
Lehallier
Department of Anatomy, University of California, San Francisco3The Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, San Francisco, California.
Saul A
SA
Villeda
Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California.
Suzanne S M
SS
Miedema
Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California.
Emily
E
Evans
Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California.
Eva
E
Czirr
Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California.
Hui
H
Zhang
Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California.
Jian
J
Luo
Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California.
Trisha
T
Stan
Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California.
Kira I
KI
Mosher
Department of Neurosciences, University of California San Diego, La Jolla5Department of Pathology, University of California San Diego, La Jolla.
Eliezer
E
Masliah
Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California6Center for Tissue Regeneration, Repair and Restoration, Veterans Affairs Palo Alto Health Care System, Palo Alto, California.
Tony
T
Wyss-Coray
D000367:Age Factors; D000544:Alzheimer Disease / Q000378:metabolism* / Q000628:therapy*; D016564:Amyloid beta-Protein Precursor; D000818:Animals; D016913:Blood Component Transfusion / Q000379:methods*; D003427:Cross Circulation / Q000379:methods*; D004195:Disease Models, Animal; D006624:Hippocampus / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic
C545487:APP protein, human; D016564:Amyloid beta-Protein Precursor