Long-term pioglitazone improves learning and attenuates pathological markers in a mouse model of AD

ABSTRACT: Thiazolidinediones (TZDs) are agonists at peroxisome proliferator-activated gamma-type (PPAR-y) receptors and are used clinically for the treatment of type 2 diabetes where they have been shown to reestablish insulin sensitivity, improve lipids profile, and reduce inflammation. Recent work also suggests that TZDs may be beneficial in Alzheimer's disease (AD), ameliorating cognitive decline early in the disease process. However, there have been only a few studies identifying mechanisms through which cognitive benefits may be exerted. Starting at 10 months of age, the triple transgenic mouse model of AD (3xTg-AD) with accelerated amyloid-B (AB) deposition and tau pathology was treated with the TZD pioglitazone (PIO- Actos) at 18 mg/Kg body weight/day. After four months, PIO-treated animals showed multiple beneficial effects, including improved learning on the active avoidance task, reduced serum cholesterol, decreased hippocampal AB deposits, and enhanced short- and long-term plasticity. Baseline electrophysiological membrane properties and blood glucose levels were unchanged by PIO treatment. Gene microarray analyses of hippocampal tissue identified predicted transcriptional responses following TZD treatment as well as potentially novel targets of TZDs, including facilitation of estrogenic processes, and decreases in glutamatergic and ketone metabolic/ cholesterol dependent processes. Taken together, these results confirm prior animal studies showing that TZDs can ameliorate cognitive deficits associated with AD-related pathology, but also extend these findings by pointing to novel molecular targets in the brain. Keywords : Hippocampus; LTP; Microarray analysis; Avoidance learning; Aging; PPAR; Synaptic hyperpolarization; T2DM We used the 3xTg-AD mouse model of Alzheimer's disease and monitored the effects of pioglitazone (PIO-Actos a TZD) on behavioral, electrophysiological, and molecular variables. Emphasis was placed on identifying hippocampal PIO-sensitive genes that were also associated with learning and memory processes. Starting at 10 months of age, female mice were treated for approximately 14 weeks with either a control diet or a PIO-containing diet. PIO was incorporated into the diet to yield a final dose of approximately 18 mg/kg body weight/day.

ORGANISM(S): Mus musculus

SUBMITTER: Eric Blalock 

PROVIDER: E-GEOD-32536 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress