Aims

We have previously identified a mouse antibody (TAP01), which bound to non-plaque forms of Aβ and showed therapeutic potential in mouse models of Alzheimer’s disease (AD). Here, we report the development of novel humanized antibodies, the crystal structure of the binding pocket and the discovery of a novel epitope representing a vaccine for active immunization. The therapeutic effects of these new therapeutic approaches were evaluated using two transgenic Alzheimer mouse models on the level of synaptic activity, plaque load, memory and neuron loss.

Methods

Transgenic mice (5XFAD, Tg4-42), Morris water maze, neuron count, ¹⁸F-Florbetaben-PET/MRI imaging, ¹⁸F-FDG-PET/MRI imaging, immunostaining, in vivo amyloid imaging, in vivo glucose uptake

Results

Crystal structures of N-truncated Abeta revealed that bound N-terminal region of Aβ adopted a novel structure, not related to any fibrillar or amyloid associated conformations reported and accounts for the non-plaque specificity of TAP01. The crystal structures enabled the design of a novel Abeta peptide epitope used as a vaccine. Active immunization of the AD mouse model 5XFAD resulted in a striking reduction in amyloid-plaque load in brain tissue by both immunostaining and in vivo ¹⁸F-Florbetaben-PET retention analysis. Moreover, using in vivo glucose imaging, we could show a rescue of glucose metabolism after active immunization. In addition, active immunization of the AD mouse model Tg4-42 rescued learning and memory deficits, and rescued loss of neurons in the hippocampus. Comparable positive therapeutic indications were also seen after TAP01 antibody passive immunization in both animal models.

Conclusions

Active immunization with the novel epitope has therapeutic effects in vivo.

Aims

Alzheimer’s disease (AD) is a devastating pathology with no effective treatment or appropriate diagnostic criteria. An accumulating body of evidence have highlighted the necessity of a diagnosis in the very early stages, as early intervention would presumably be the most effective. Indeed, there is need to define rigorous criteria that selectively identify patients to be enrolled in clinical trials, thereby excluding non-AD dementias patients who cannot benefit from an AD-specific treatment and make the outcomes of clinical trial unpredictable and often confounding. We propose to target the Tyr682 residue of APP to design a personalized pharmacologic approach using Fyn Tyrosine kinase inhibitors (TKI) in AD patients showing increased APP Tyr682 phosphorylation levels.

Methods

My group has been working for nearly a decade on the comprehensive role of APP Tyr682 residue in AD onset and progression, demonstrating that the aberrant phosphorylation of APP Tyr682 residue leads to Aβ production and neuronal degeneration in human neurons as well as in AD mimicking mice and mini-pig models.

Results

We reported increased phosphorylation levels of APP Tyr682 residue in neurons, fibroblasts and recently from blood samples of patients with a diagnosis of sporadic as well as familiar AD when compared to heathy controls. We demonstrated that, when FynTK selectively triggers APP Tyr682 phosphorylation and increases APP processing to generate Aβ and APP intracellular peptides in AD neurons.

Conclusions

A therapy using Fyn TKI in subsets of patients with increased phosphorylation of APP Tyr682 residue would result in more targeted effects, plausibly yielding more specific and effective therapeutic outcomes.

Aims

Methods

Results

Conclusions

Aims

To evaluate the neuroprotective effect of artemisinin on AD and try to find its possible mechanism, which may provide essential evidence for finding new therapeutic candidate for the treatment of Alzheimer's disease.

Methods

In this experiment we used Aβ to establish cell injury model. Hoechst staining, MTT, Flow cytometry, caspase3 and lactate dehydrogenase kit to detect cell apoptosis; JC-1 and ROS to detect mitochondrial function changes; IHC /IF/ ICC / Western blot was used to detect changes in pathway protein levels. Stereotactic brain injection was used to establish animal model and intraperitoneal injection was used to give drugs.

Results

In this study, we found that artemisinin improved the cognitive deficit and other AD-type pathologies in 3xTg-AD mouse. Artemisinin dose-dependently reduced cell injury and decreased amyloid-beta deposit and hyperphosphorylation of tau protein . Artemisinin also inhibited glia cell activation and inflammation . Western blot assay showed that artemisinin stimulated the activation of CREB/BDNF pathway. Consistent with this hypothesis, artemisinin promoted the survival of SH-SY5Y cell line against toxicity of Aβ1-42 induced apoptosis. Artemisinin also stimulated the phosphorylation of CREB in SH-SY5Y cells. Inhibition of CREB/BDNF pathway attenuated the protective effect of artemisinin.

Conclusions

These data put together suggested that artemisinin has the potential to protect neuronal cells in vitro as well as in vivo animal model 3xTg-AD mouse via, at least in part, the activation of the CREB/BDNF pathway. Our findings also strongly support the potential of artemisinin as a new multi-target drug that can be used for preventing and treating the Alzheimer’s disease.

Aims

The identification of an effective medication for patients with Alzheimer’s disease (AD) given after disease onset remains one of the most challenging topics in neuroscience research. In this study, we investigated whether the FDA approved drug fingolimod (FTY720) can rescue AD-associated synaptic and memory impairments in an AD mouse model when treatment starts after onset of symptoms.

Methods

Male APP/PS1 mice were intraperitoneally injected every second day with FTY720 for 1-2 months starting at the age of 5-6 months. We conducted Golgi-Cox staining combined with fluorescent labeling of amyloid plaques and long-term potentiation (LTP) recordings for performing structural and synaptic analysis respectively in treated and untreated animals. Furthermore, we tested spatial memory performance through the Morris water maze task and investigated the levels of neuroinflammation and amyloid beta accumulation in AD mice observed in response to FTY720 treatment.

Results

FTY720 rescued spine and LTP deficits in hippocampal CA1 pyramidal neurons and ameliorated hippocampus-dependent memory dysfunctions observed in untreated APP/PS1 animals at the age of 6-7 months. We also found that our FTY720 treatment regime strongly down-regulated neuroinflammation in hippocampus and neocortex, accompanied by a moderate reduction of amyloid beta deposition in the same brain areas.

Conclusions

Our results demonstrate a beneficial effect of FTY720, when applied after onset of disease symptoms in APP/PS1 mice, and suggest that our treatment regime rescues synaptic and memory deficits observed in untreated AD mice through anti-neuroinflammatory actions of the drug on brain immune cells.

Aims

Evaluating the impact of disease-modifying investigational Aβ and tau targeting monoclonal antibodies using a quantitative systems pharmacology model representing the disease pathology of Alzheimer’s Disease (AD).

Methods

The model includes the mechanisms of Aβ and tau pathologies in AD. The model tracks the production, aggregation, transport, and clearance of biomarkers associated with Aβ and tau pathways in the brain, CSF, and plasma, as well as the pharmacokinetics–pharmacodynamics of investigational treatments (solanezumab, crenezumab, aducanumab, gantenerumab, and semorinemab) on these processes. SimBiology, a MATLAB^® based application was used for the implementation of the model.

Results

The model scope enables scientific hypothesis assessments of: biomarker target engagement in brain/CSF, biomarker transport dynamics, and therapy-benchmarking. It is calibrated to pharmacokinetic and pharmacodynamic/biomarker data in plasma and CSF from published and in-house clinical studies. Simulations allow quantitative assessment of target engagement in brain and CSF enabling a comparison between therapies intervening the Aβ and tau pathways and study effect of different doses, durations, and dosing regimens (flat/titration doses). The model is able to predict available imaging-based Aβ PET SUVR data of plaque targeting antibodies directly assessing disease burden. The model is positioned for simulation-based analysis of tau targeting antibodies and their effect on biomarker engagement and dynamics in brain, CSF, and plasma.

Conclusions

The model serves as a tool for simulation-based quantitative assessment of target engagement and biomarker dynamics by disease-modifying therapies in the brain and CSF. The model provides a comprehensive platform to test scientific hypothesis related to target and biomarker dynamics.

Aims

Inflammatory cytokines, increased reactive oxidative species (ROS), and decreased brain blood flow accelerates the progression of both vascular contributions to cognitive impairment and dementia (VCID) and Alzheimer's disease related dementia (ADRD).

Our novel synthetic glycosylated Angiotensin-(1-7) derivative (PNA5), optimized for better blood-brain-barrier penetration and enhanced half-life, reverses cognitive deficits, inhibits brain ROS production, and limits VCID induced microglial activation in our preclinical VCID model.

We hypothesized that 1) neural inflammatory cytokines and phosphorylated Tau protein (pTau) concentrations are increased in our preclinical VCID model and 2) PNA5 treatment mitigates both brain and systemic inflammation.

Methods

Adult male C57BL/6J mice (10-15/group) were subjected to heart failure (HF) 5 weeks prior to treatment with either 1) Saline 2) 50 μg/kg/day PNA5, or 3) 500 μg/kg/day PNA5 for 21 days. Control-saline mice underwent sham surgery. Cognitive function is measured by novel-object recognition (NOR) and represented as a DRatio. Data expressed as mean and SE were analyzed by one-way ANOVA or T-test.

Results

VCID-saline mice displayed cognitive impairment (DRatio -0.02+/-0.07) compared to control-saline (DRatio 0.57+/-0.1) and PNA5 treatment rescued cognitive function at all doses (DRatio 50μg/kg/day 0.61+/-0.09). VCID-saline demonstrated increased circulating TNF-α (3.12+/-1.9E-¹⁶ vs 3.49+/-0.15 pg/ml, p=0.017), decreased brain anti-inflammatory cytokines, IL-13,IP-10, IL-2, IL-10 and increased brain pTau compared to control-saline (p=0.04). Treatment with PNA5 at all doses decreased circulating TNF-a (50μg/kg/day 3.1+/-0.02 pg/ml) and reversed VCID induced changes in brain cytokines.

Conclusions

These data suggest that PNA5 protects against VCID cognitive impairment by inhibiting VCID induced changes in systemic and brain cytokines.

(Supported by NIA).

Aims

Agitation and aggression are major psychiatric symptoms which significantly contribute to patient and caregiver burden in Alzheimer’s Disease (AD), usually managed with antipsychotics and sedatives. Finding a safe alternative will bring significant relief to the AD community

Methods

PGI3814 was identified as a lead compound following medicinal chemistry efforts on analogs identified by phenotypic screening using our proprietary in vivo murine SmartCube© Platform. PGI3814 activates brain regions in mice associated with fear and aggression. To test its potential as a non-sedative tranquilizer it was tested in models of aggression and agitation of relevance to AD.

In the feral rat assay a male intruder rat was introduced to a home cage of a territorial male rat. After several training sessions, the territorial male was treated with PGI3814 using a Latin Square design. Latency to attach, number of attacks, and other behaviors were quantified.

Male APP/PS1 mice were prescreened for aggressive behavior against male C57BL/6J mice intruders and rescreened after treatment with PGI3814 or risperidone. Latency to attach and number of attacks were quantified. Locomotor activity was assessed in the same mice.

Results

Both territorial aggression assays showed clear anti-aggressive effects of PGI3814, with reduction in the number of attacks and lengthening of the attack latency.

APP/PS1 mice hyperactivity, in a locomotor assay, returned to normal WT levels with PGI3814 (3-10 mg/kg). Risperidone (0.03 mg/kg) decreased activity beyond that of WT, suggesting a more sedative effect.

Conclusions

PGI3814 shows a promising and safe profile as novel treatment for agitation and aggression in Alzheimer's Disease.