Intranasal deferoxamine reverses iron-induced memory deficits and inhibits amyloidogenic APP processing in a transgenic mouse model of Alzheimer's disease.

Increasing evidence indicates that a disturbance of normal iron homeostasis and an amyloid-β (Aβ)-iron interaction may contribute to the pathology of Alzheimer's disease (AD), whereas iron chelation could be an effective therapeutic intervention. In the present study, transgenic mice expressing amyloid precursor protein (APP) and presenilin 1 and watered with high-dose iron served as a model of AD. We evaluated the effects of intranasal administration of the high-affinity iron chelator deferoxamine (DFO) on Aβ neuropathology and spatial learning and memory deficits created in this AD model. The effects of Fe, DFO, and combined treatments were also evaluated in vitro using SHSY-5Y cells overexpressing the human APP Swedish mutation. In vivo, no significant differences in the brain concentrations of iron, copper, or zinc were found among the treatment groups. We found that high-dose iron (deionized water containing 10 mg/mL FeCl(3)) administered to transgenic mice increased protein expression and phosphorylation of APP695, enhanced amyloidogenic APP cleavage and Aβ deposition, and impaired spatial learning and memory. Chelation of iron via intranasal administration of DFO (200 mg/kg once every other day for 90 days) inhibited iron-induced amyloidogenic APP processing and reversed behavioral alterations. DFO treatment reduced the expression and phosphorylation of APP protein by shifting the processing of APP to the nonamyloidogenic pathway, and the reduction was accompanied by attenuating the Aβ burden, and then significantly promoted memory retention in APP/PS1 mice. The effects of DFO on iron-induced amyloidogenic APP cleavage were further confirmed in vitro. Collectively, the present data suggest that intranasal DFO treatment may be useful in AD, and amelioration of iron homeostasis is a potential strategy for prevention and treatment of this disease.

Guo C ，Wang T ，Zheng W ，Shan ZY ，Teng WP ，Wang ZY ... -  《-》

Intranasal deferoxamine engages multiple pathways to decrease memory loss in the APP/PS1 model of amyloid accumulation.

In addition to the hallmark accumulation of amyloid and hyper-phosphorylation of tau, brain changes in Alzheimer's disease are multifactorial including inflammation, oxidative stress, and metal dysregulation. Metal chelators have been explored as a less well known approach to treatment. One chelator currently being developed is deferoxamine (DFO), administered via the intranasal (IN) route. In the current study, APP/PS1 amyloid mice were treated with a chronic, low dose of IN DFO, subjected to a rigorous battery of behavior tests, and the mechanism of action was examined. Mice were treated 3x/week with 0.24 C IN DFO for 18 weeks from 36 to 54 weeks of age, 4 weeks of behavior tests were performed that included both working and reference memory, anxiolytic and motor behaviors, and finally brain tissues were analyzed for amyloid, protein oxidation, and other proteins affected by DFO. We found that IN DFO treatment significantly decreased loss of both reference and working memory in the Morris and radial arm water mazes (p < 0.05), and also decreased soluble Aβ40 and Aβ42 in cortex and hippocampus (p < 0.05). Further, IN DFO decreased activity of GSK3β, and led to decreases in oxidative stress (p < 0.05). These data demonstrate that low doses of IN DFO can modify several targets along the multiple pathways implicated in the neuropathology of Alzheimer's, making it an attractive candidate for the treatment of this heterogeneous disease.

Fine JM ，Renner DB ，Forsberg AC ，Cameron RA ，Galick BT ，Le C ，Conway PM ，Stroebel BM ，Frey WH 2nd ，Hanson LR ... -  《-》

Deferoxamine inhibits iron induced hippocampal tau phosphorylation in the Alzheimer transgenic mouse brain.

Prior work has shown that iron interacts with hyperphosphorylated tau, which contributes to the formation of neurofibrillary tangles (NFTs) in Alzheimer's disease (AD), whereas iron chelator desferrioxamine (DFO) slows down the clinical progression of the cognitive decline associated with this disease. However, the effects of DFO on tau phosphorylation in the presence or absence of iron have yet to be determined. Using amyloid precursor protein (APP) and presenilin 1 (PS1) double transgenic mouse brain as a model system, we investigated the effects and potential mechanisms of intranasal administration of DFO on iron induced abnormal tau phosphorylation. High-dose iron treatment markedly increased the levels of tau phosphorylation at the sites of Thr205, Thr231 and Ser396, whereas highly induced tau phosphorylation was abolished by intranasal administration of DFO in APP/PS1 transgenic mice. Moreover, DFO intranasal administration also decreases Fe-induced the activities of cyclin-dependent kinase 5 (CDK5) and glycogen synthase kinase 3β (GSK3β), which in turn suppressing tau phosphorylation. Cumulatively, our data show that intranasal DFO treatment exerts its suppressive effects on iron induced tau phosphorylation via CDK5 and GSK3β pathways. More importantly, elucidation of DFO mechanism in suppressing tau phosphorylation may provide insights for developing therapeutic strategies to combat AD.

Guo C ，Wang P ，Zhong ML ，Wang T ，Huang XS ，Li JY ，Wang ZY ... -  《-》

A modified formulation of Chinese traditional medicine improves memory impairment and reduces Aβ level in the Tg-APPswe/PS1dE9 mouse model of Alzheimer's disease.

SuHeXiang Wan (SHXW), a Chinese traditional medicine has been used orally for the treatment of seizures, infantile convulsion, stroke and so forth. Previously, we reported the effects of modified SHXW essential oil mixture of the fragrance containing herbs on the sedative effect, anticonvulsant property and antioxidative activity after fragrance inhalation. This study was undertaken to evaluate beneficial effects of a modified recipe of SHXW (termed as KSOP1009) consisting of a ethanol extract of 8 herbs including resin of Liquidambar orientalis Miller, seed of Myristica fragrans Houtt., rhizome of Cnidium officinale Makino, lumber of Santalum album L., fructus of Piper longum L., flower buds of Eugenia caryophyllata Merrill et Perry, pollen of Typha orientalis Presl., and root of Salvia miltiorrhiza Bunge in the neurodegenerative diseases such as Alzheimer's disease (AD). The transgenic mice of AD, Tg-APPswe/PS1dE9, were fed KSOP1009 or as a positive control, donepezil for 3 months from 4.5 months of age. Behavioral, immunological and ELISA analyses were used to assess memory impairment, Aβ accumulation and plaque deposition in the brain. Other in vitro works were performed to examine whether KSOP1009 inhibits the Aβ(1-42)-induced neurotoxicity in human neuroblastoma cell line, SH-SY5Y cells. Intake of KSOP1009 improved the Aβ-induced memory impairment and suppressed Aβ levels and plaque deposition in the brain of Tg-APPswe/PS1dE9 mice as much as that of donepezil treatment. KSOP1009 prevented the down-regulation of phospho-CREB and increased AKT phosphorylation in the AD-like brains. Moreover, KSOP1009 suppresses Aβ-induced apoptosis and ROS production in SH-SY5Y cells. The present study suggests that KSOP1009 may develop as a therapeutic drug for treatment of AD patients.

Jeon S ，Bose S ，Hur J ，Jun K ，Kim YK ，Cho KS ，Koo BS ... -  《-》

Gintonin, a ginseng-derived lysophosphatidic acid receptor ligand, attenuates Alzheimer's disease-related neuropathies: involvement of non-amyloidogenic processing.

Hwang SH ，Shin EJ ，Shin TJ ，Lee BH ，Choi SH ，Kang J ，Kim HJ ，Kwon SH ，Jang CG ，Lee JH ，Kim HC ，Nah SY ... -  《-》