Abstract Body

Alzheimer’s disease(AD) is characterized by neuritic plaques, neurofibrillary tangles, neuroinflammation and synaptic dysfunction. Drugs currently used for AD only bring some degree of symptomatic relief, but no drug has been identified that effectively blocks or reverses the process of AD progression .

We first reported that dehydroevodiamine (DHED) purified from Evodia rutaecarpa Bentham, has anticholinesterase and antiamnesic activities and beneficial effects on neuronal death.

In addition, DHED has been reported to have various biological effects, such as antiinflammatory , Ca2+ and K+ channel blocking, cerebral blood flow and lipid metabolism enhancing , antithrombotic, antidepressant and antitumor effects.

Carboxy DHED( Cx-DHED) is highly soluble in water, indicating that its bioavailability and therapeutic effects are better than those of DHED.

Although many studies have demonstrated the effects of DHED on memory deficits and neuronal death

in dementia-related animal models, no studies have investigated the efficacy of DHED and Cx DHED in AD- Tg mice models.

In this study, we proposed that DHED and Cx-DHED might be effective for the memory impairment and AD-related neurochemical and pathological changes in ADTg mice.

We found that memory deficits and neurochemical and pathological changes significantly decreased but synaptic stabilization proteins greatly increased after treatment of Tg mice with them.

In conclusion,these results strongly suggest that Cx-DHED could block the progression of AD pathology and memory deficits in AD-Tg mice and might be a promising multitarget drug for AD.

Abstract Body

AIM: To assess the value of therapy using lithium microdoses in transgenic rats displaying Alzheimer’s disease (AD)-like brain pathology.

METHODS Transgenic AD-like rats and corresponding Wildtype littermates were treated-untreated with microdoses of lithium for 12 weeks ending either at pre-plaque or post plaque stages. Following behavioral assessments treated and untreated rats were investigated for their biochemical and morphological phenotype, with an emphasis on the status of AD-like pathology and cognitive outcomes.

RESULTS At Early AD-like pathology lithium microdose diminished the intraneuronal Aβ burden, inhibited GSK-3β reducing BACE1 activity and amyloid levels. We also observed a rescue of memory loss as well as improvement in CRTC1 promoter binding related to synaptic plasticity as well as preservation of hippocampal neurogenesis. In Late AD-like pathology we observed a diminution of plaque load, lower Aβ42 cortical levels, preservation of hippocampal cholinergic synapses, and of remote working memory as well a loss of key CNS inflammatory markers. In a separate study, we found a diminution of oxidative and nitrosative stress markers with diminished expression of Trem2 and reduction in microglia recruitment towards Aβ-burdened neurons.

CONCLUSIONS: The above observations are based in doses of lithium which were over 100 times lower than currently applied for mood disorders. The studies demonstrated that long term treatment with lithium microdoses should have significant beneficial outcomes in halting or slowing the AD amyloid pathology and disease-aggravating components, such as early inflammation and the formation of toxic free radical species; all under conditions that are most unlikely to provoke adverse effects.

Aims

Alzheimer’s disease is considered a serious global health problem with the increase of the elderly population and the absence of disease-modifying treatments. AD is neuropathologically characterized by the accumulation of β-amyloid in senile plaques and hyper-phosphorylated tau as neurofibrillary tangles, synaptic loss and neuroinflammation. Recently, stem cell therapy has provided great potential treating AD patients. However, there is an urgent need to replace the conventional intracerebral inoculation for a less invasive method to avoid some of the technical challenges but ensuring cells reach the brain. Our recently published results indicated that peripheral treatment with neural precursors (NPs) ameliorates clinical symptoms by reducing the disease-associated neuroinflammation in a mouse model of Parkinson’s disease. Therefore, we hypothesize that intravenous administration of NPs and their released neurotrophic factors can be used as a non-invasive therapy to ameliorate memory impairment in mouse models of AD.

Methods

In this pre-clinical study, NPs derived from mesenchymal stem cells (MSC-NPs) and induced pluripotent stem cells (iPSC-NPs) were intravenously injected into APP/PS1 and P301S mice at 3 or 6 months of age. Before treatment and at the age of 7 months old, experimental and control (PBS) animals were subjected to Barnes maze task and rotarod test.

Results

NPs treated mice displayed an amelioration in memory dysfunction compare to the PBS-injected animals. In addition, P301S mice injected with NPs showed improved motor function to rotarod coordination in comparison to the control group.

Conclusions

Peripheral inoculation using NPs could be used as a treatment to reduce AD-related clinical signs.

Aims

Current therapies in Alzheimer's disease (AD), including Memantine, have proven to be only symptomatic but not curative nor disease-modifying. Fluoroethylnormemantine (FENM) is a structural analogue of Memantine, functionalized with a fluorine group that allowed its use as a positon emission tomography tracer. We here analyzed FENM

Methods

Swiss mice were treated intracerebroventricularly with aggregated Aβ_25-35 peptide and examined after one week in a battery of memory tests (spontaneous alternation; passive avoidance; object recognition; place learning in the water-maze; topographic memory in the Hamlet). Toxicity induced in the mouse hippocampus or cortex was analyzed biochemically or morphologically.

Results

Both Memantine and FENM showed symptomatic anti-amnesic effects in Aβ_25-35-treated mice. Interestingly, FENM was not amnesic when tested alone at 10 mg/kg, contrarily to Memantine. Drugs injected once-a-day prevented Aβ_25-35-induced memory deficits, oxidative stress (lipid peroxidation, cytochrome c release), inflammation (IL-6, TNFa increases; glial fibrillary acidic protein (GFAP) and Iba1 immunoreactivity in the hippocampus and cortex), and apoptosis and cell loss (Bax/Bcl-2 ratio; cell loss in the hippocampus CA1 area). However, FENM effects were more robust than observed with Memantine, with significant attenuations vs. the Aβ_25-35-treated group.

Conclusions

FENM therefore appeared as a potent neuroprotective drug in an AD model, with a superior efficacy as compared with Memantine, and an absence of direct amnesic effect at higher doses. These results open the possibility to use the compound at more relevant dosages than the ones actually proposed in Memantine treatment for AD.

Aims

The dopamine (DA) D1 receptor is important for cognition, wakefulness, motor activity and reward. Positive allosteric modulation of the D1 receptor (D1PAM) is a novel mechanism that could avoid problems associated with D1 agonists such as inverted U-shaped dose response and tolerance development. The objective was to evaluate this mechanism pre-clinically and in phase 1 human studies.

Methods

Selective D1PAMs (DETQ, DPTQ and LY3154207, mevidalen) were tested in vitro and in the humanized D1 (hD1) mouse and rhesus monkeys. Single and multiple ascending doses of LY3154207 were evaluated for safety/tolerability and pharmacokinetics in healthy volunteers and PD subjects. A biomarker study in healthy subjects assessed wakefulness using the Multiple Sleep Latency Test after 24 hours sleep deprivation

Results

The D1PAMs showed low nM potency in vitro in the cAMP assay. Increased locomotion was seen (3-240 mg/kg, PO) in the hD1 mouse without inverted U-shaped dose response or tolerance development. Neurochemical studies showed increased release of acetylcholine and histamine in cortical areas. In the rhesus monkey, DPTQ (0.1 -2.5 mg/kg, IM) showed sustained improvements in spatial working memory performance. Phase 1 clinical studies with LY3154207 demonstrated an acceptable safety and linear plasma PK profiles. CSF PK data showed relevant central exposures. LY3154207 improved wakefulness in sleep deprived subjects and showed a signal for efficacy on motor symptoms in PD subjects.

Conclusions

The current data provide support for the use of D1PAMs in the treatment of several neuropsychiatric disorders. The preclinical results suggest different profiles when compared to D1 agonists that could offer therapeutic advantages.

Aims

While the association between dysregulation of blood amylin (islet amyloid polypeptide; IAPP) and Alzheimer's disease (AD) pathology is not yet as widely studied as other aspects of AD biology, there has been accumulating evidence from multiple research teams describing amylin-amyloid β (Aβ) cross-seeding in brains of individuals with sporadic AD. This study assessed the interaction of circulating amylin with Aβ pathology in familial and sporadic forms of AD.

Methods

Immunochemical evidence of amylin-Aβ interaction was tested in brains of 31 familial AD mutation carriers and 20 cognitively unaffected individuals, and in cerebrospinal fluid (CSF) from 215 individuals who had measurements of CSF Aβ. In vivo amylin-Aβ interaction was further studied in APP/PS1 rats with genetically manipulated amylin secretion.

Results

Amylin accumulated in Aβ plaques and intraneuronal deposits. High CSF amylin levels were associated with decreased CSF Aβ₄₂ concentrations. Suppression of amylin secretion protected APP/PS1 rats against AD effects. In contrast, hypersecretion or intravenous injection of human amylin in APP/PS1 rats exacerbated AD-like pathology through disruption of CSF-brain Aβ exchange and cerebral amylin-Aβ cross-seeding.

Conclusions

These findings strengthened the hypothesis of amylin-Aβ cross-seeding in AD and suggest that modulation of circulating amylin levels may alter Aβ-related pathology/symptoms. Our results constitute a basis for additional research to help understanding: 1, what triggers amylin-Aβ interaction and whether reducing amylin dyshomeostasis could slow the progression of AD; 2, the impact of peripheral amylin dyshomeostasis on Aβ clearance across the blood-brain barrier; and 3, effects of circulating amylin levels on CSF-brain Aβ exchange in human AD.

Aims

To assess safety, tolerability and pharmacokinetics of allopregnanolone following a single-dose administration and after chronic exposure over a 12-week period of once-per-week dosing in persons with early Alzheimer’s disease (AD).

Methods

Randomized, double-blinded, placebo-controlled, single and multiple ascending dose study (ClinicalTrials.gov-NCT02221622). Intravenous allopregnanolone or placebo was administered once-per-week for 12 weeks with a 1-month follow-up. Participants with early AD (MCI due to AD or mild AD), a Mini-Mental State Examination score of 20-26 and age ≥55 years were randomized. Primary endpoint was safety and tolerability. Secondary endpoints included pharmacokinetic (PK) parameters and maximally tolerated dose (MTD). Exploratory endpoints included cognitive and imaging biomarkers.

Results

Twenty-four participants completed the trial. Allopregnanolone was safe and well-tolerated. No

differences between treatment arms in the occurrence and severity of adverse events (AE). Most

common AEs were mild to moderate in severity and included rash [n=4 (22%)] and fatigue [n=3 (17%)].

A single non-serious AE, dizziness, was attributable to treatment. Pharmacokinetics indicated

predictable linear dose-response in plasma allopregnanolone following 30-minute infusion. The

maximum plasma concentrations for the 2mg, 4mg, 6mg and 10mg dosages were 14.53ng/ml

(+/-7.31), 42.05ng/ml (+/-14.55), 60.07ng/ml (+/-12.8), and 137.48ng/ml (+/-38.69), respectively.

MTD was established based on evidence of allopregnanolone-induced mild sedation at the highest

doses (males10mg; females 14mg). No adverse outcomes on cognition or MRI-based imaging outcomes

were evident. Exploratory imaging analyses were indicative of responders and non-responders on

outcomes relevant to regeneration.

Conclusions

Allopregnanolone was well-tolerated and safe across all doses in this cohort. Safety, MTD and PK profiles support advancement to a phase 2 efficacy trial.

Aims

The plasma fraction GRF6021 reverses age-related changes in the mouse brain, including impaired memory, reduced synaptic density, and neuroinflammation. In this trial, we evaluated the safety and tolerability of GRF6021 in subjects with Parkinson’s Disease (PD) and cognitive impairment.

Methods

In this 24-week trial, subjects aged 40-85 with a diagnosis of PD with mild cognitive impairment or dementia were randomized in a 2:1 ratio to receive 250 mL GRF6021 or placebo IV daily for 5 consecutive days during weeks 1 and 13. Study drug allocation was blinded to subjects, raters, and investigators. The primary endpoint was safety and tolerability. Secondary endpoints included the Montreal Cognitive Assessment (MoCA), the Cognitive Drug Research system, the Delis-Kaplan Executive Function System verbal fluency, the Movement Disorders Society Unified PD Rating Scale (MDS-UPDRS), the PD Questionnaire 39, and the DCTclock digital clock drawing.

Results

79 subjects (26 women, 53 men) with a mean age of 67, an MDS-UPDRS Total score of 65 (range 20-123) and a MoCA score of 22 (range 14-25) received GRF6021 (n=53) or placebo (n=26). GRF6021 was safe and well tolerated compared to placebo. The trial was not statistically powered to detect differences in secondary efficacy endpoints; however, numerical superiority of GRF6021 over placebo was observed on multiple cognitive endpoints.

Conclusions

This trial met its primary endpoint by demonstrating that daily infusions of GRF6021 for 5 consecutive days at 3-month intervals were safe and well tolerated. Secondary endpoints indicated that GRF6021 may have cognitive benefits and future development in PD with cognitive impairment is planned.

Aims

Methods

Results

Conclusions