title: Allopregnanolone promotes regeneration and reduces β-amyloid burden in a preclinical model of Alzheimer's disease.
abstract: Previously, we demonstrated that allopregnanolone (APα) promoted proliferation of rodent and human neural progenitor cells in vitro. Further, we demonstrated that APα promoted neurogenesis in the hippocampal subgranular zone (SGZ) and reversed learning and memory deficits in the male triple transgenic mouse model of Alzheimer's (3xTgAD). In the current study, we determined the efficacy of APα to promote the survival of newly generated neural cells while simultaneously reducing Alzheimer's disease (AD) pathology in the 3xTgAD male mouse model. Comparative analyses between three different APα treatment regimens indicated that APα administered 1/week for 6 months was maximally efficacious for simultaneous promotion of neurogenesis and survival of newly generated cells and reduction of AD pathology. We further investigated the efficacy of APα to impact Aβ burden. Treatment was initiated either prior to or post intraneuronal Aβ accumulation. Results indicated that APα administered 1/week for 6 months significantly increased survival of newly generated neurons and simultaneously reduced Aβ pathology with greatest efficacy in the pre-pathology treatment group. APα significantly reduced Aβ generation in hippocampus, cortex, and amygdala, which was paralleled by decreased expression of Aβ-binding-alcohol-dehydrogenase. In addition, APα significantly reduced microglia activation as indicated by reduced expression of OX42 while increasing CNPase, an oligodendrocyte myelin marker. Mechanistic analyses indicated that pre-pathology treatment with APα increased expression of liver-X-receptor, pregnane-X-receptor, and 3-hydroxy-3-methyl-glutaryl-CoA-reductase (HMG-CoA-R), three proteins that regulate cholesterol homeostasis and clearance from brain. Together these findings provide preclinical evidence for the optimal treatment regimen of APα to achieve efficacy as a disease modifying therapeutic to promote regeneration while simultaneously decreasing the pathology associated with Alzheimer's disease.
authors.affiliation: Department of Pharmacology and Pharmaceutical Science, School of Pharmacy, University of Southern California, Los Angeles, California, United States of America.
authors.forename: Shuhua
authors.initials: S
authors.lastname: Chen
authors.forename: Jun Ming
authors.initials: JM
authors.lastname: Wang
authors.forename: Ronald W
authors.initials: RW
authors.lastname: Irwin
authors.forename: Jia
authors.initials: J
authors.lastname: Yao
authors.forename: Lifei
authors.initials: L
authors.lastname: Liu
authors.forename: Roberta Diaz
authors.initials: RD
authors.lastname: Brinton
mesh_terms: D015087:2',3'-Cyclic-Nucleotide Phosphodiesterases / Q000235:genetics / Q000378:metabolism; D000544:Alzheimer Disease / Q000188:drug therapy* / Q000378:metabolism*; D000682:Amyloid; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000818:Animals; D005434:Flow Cytometry; D006801:Humans; D006903:Hydroxymethylglutaryl CoA Reductases / Q000235:genetics / Q000378:metabolism; D015151:Immunoblotting; D008297:Male; D051379:Mice; D017628:Microglia / Q000187:drug effects / Q000378:metabolism; D011280:Pregnanolone / Q000627:therapeutic use*
chemical_list: D000682:Amyloid; D016229:Amyloid beta-Peptides; D011280:Pregnanolone; D006903:Hydroxymethylglutaryl CoA Reductases; D015087:2',3'-Cyclic-Nucleotide Phosphodiesterases