Person: Kastanenka, Ksenia
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Kastanenka
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Ksenia
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Kastanenka, Ksenia
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Publication Optogenetic Restoration of Disrupted Slow Oscillations Halts Amyloid Deposition and Restores Calcium Homeostasis in an Animal Model of Alzheimer’s Disease(Public Library of Science, 2017) Kastanenka, Ksenia; Hou, Steven; Shakerdge, Naomi; Logan, Robert; Feng, Danielle; Wegmann, Susanne; Chopra, Vanita; Hawkes, Jonathan M.; Chen, Xiqun; Bacskai, BrianSlow oscillations are important for consolidation of memory during sleep, and Alzheimer’s disease (AD) patients experience memory disturbances. Thus, we examined slow oscillation activity in an animal model of AD. APP mice exhibit aberrant slow oscillation activity. Aberrant inhibitory activity within the cortical circuit was responsible for slow oscillation dysfunction, since topical application of GABA restored slow oscillations in APP mice. In addition, light activation of channelrhodopsin-2 (ChR2) expressed in excitatory cortical neurons restored slow oscillations by synchronizing neuronal activity. Driving slow oscillation activity with ChR2 halted amyloid plaque deposition and prevented calcium overload associated with this pathology. Thus, targeting slow oscillatory activity in AD patients might prevent neurodegenerative phenotypes and slow disease progression.Publication CRISPR/Cas9 Mediated Disruption of the Swedish APP Allele as a Therapeutic Approach for Early-Onset Alzheimer’s Disease(American Society of Gene & Cell Therapy, 2018) György, Bence; Loov, Camilla; Zaborowski, Mikołaj P.; Takeda, Shuko; Kleinstiver, Benjamin; Commins, Caitlin; Kastanenka, Ksenia; Mu, Dakai; Volak, Adrienn; Giedraitis, Vilmantas; Lannfelt, Lars; Maguire, Casey; Joung, J. Keith; Hyman, Bradley; Breakefield, Xandra; Ingelsson, MartinThe APPswe (Swedish) mutation in the amyloid precursor protein (APP) gene causes dominantly inherited Alzheimer’s disease (AD) as a result of increased β-secretase cleavage of the amyloid-β (Aβ) precursor protein. This leads to abnormally high Aβ levels, not only in brain but also in peripheral tissues of mutation carriers. Here, we selectively disrupted the human mutant APPSW allele using CRISPR. By applying CRISPR/Cas9 from Streptococcus pyogenes, we generated allele-specific deletions of either APPSW or APPWT. As measured by ELISA, conditioned media of targeted patient-derived fibroblasts displayed an approximate 60% reduction in secreted Aβ. Next, coding sequences for the APPSW-specific guide RNA (gRNA) and Cas9 were packaged into separate adeno-associated viral (AAV) vectors. Site-specific indel formation was achieved both in primary neurons isolated from APPSW transgenic mouse embryos (Tg2576) and after co-injection of these vectors into hippocampus of adult mice. Taken together, we here present proof-of-concept data that CRISPR/Cas9 can selectively disrupt the APPSW allele both ex vivo and in vivo—and thereby decrease pathogenic Aβ. Hence, this system may have the potential to be developed as a tool for gene therapy against AD caused by APPswe and other point mutations associated with increased Aβ.Publication An acute functional screen identifies an effective antibody targeting amyloid-β oligomers based on calcium imaging(Nature Publishing Group UK, 2018) Wang, Xueying; Kastanenka, Ksenia; Arbel-Ornath, Michal; Commins, Caitlin; Kuzuya, Akira; Lariviere, Amanda J.; Krafft, Grant A.; Hefti, Franz; Jerecic, Jasna; Bacskai, BrianSoluble amyloid β oligomers (AβOs) are widely recognized neurotoxins that trigger aberrant signaling in specific subsets of neurons, leading to accumulated neuronal damage and memory disorders in Alzheimer’s disease (AD). One of the profound downstream consequences of AβO-triggered events is dysregulation of cytosolic calcium concentration ([Ca2+]i), which has been implicated in synaptic failure, cytoskeletal abnormalities, and eventually neuronal death. We have developed an in vitro/in vivo drug screening assay to evaluate putative AβO-blocking candidates by measuring AβO-induced real-time changes in [Ca2+]i. Our screening assay demonstrated that the anti-AβO monoclonal antibody ACU3B3 exhibits potent blocking capability against a broad size range of AβOs. We showed that picomolar concentrations of AβOs were capable of increasing [Ca2+]i in primary neuronal cultures, an effect prevented by ACU3B3. Topical application of 5 nM AβOs onto exposed cortical surfaces also elicited significant calcium elevations in vivo, which was completely abolished by pre-treatment of the brain with 1 ng/mL (6.67 pM) ACU3B3. Our results provide strong support for the utility of this functional screening assay in identifying and confirming the efficacy of AβO-blocking drug candidates such as the human homolog of ACU3B3, which may emerge as the first experimental AD therapeutic to validate the amyloid oligomer hypothesis.Publication Novel botanical drug DA-9803 prevents deficits in Alzheimer’s mouse models(BioMed Central, 2018) Pagnier, Guillaume J.; Kastanenka, Ksenia; Sohn, Miwon; Choi, Sangzin; Choi, Song-hyen; Soh, HyeYeon; Bacskai, BrianBackground: Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by deposition of amyloid plaques and disruption of neural circuitry, leading to cognitive decline. Animal models of AD deposit senile plaques and exhibit structural and functional deficits in neurons and neural networks. An effective treatment would prevent or restore these deficits, including calcium dyshomeostasis observed with in-vivo imaging. Methods: We examined the effects of DA-9803, a multimodal botanical drug, in 5XFAD and APP/PS1 transgenic mice which underwent daily oral treatment with 30 or 100 mg/kg DA-9803 or vehicle alone. Behavioral testing and longitudinal imaging of amyloid deposits and intracellular calcium in neurons with multiphoton microscopy was performed. Results: Chronic administration of DA-9803 restored behavioral deficits in 5XFAD mice and reduced amyloid-β levels. DA-9803 also prevented progressive amyloid plaque deposition in APP/PS1 mice. Elevated calcium, detected in a subset of neurons before the treatment, was restored and served as a functional indicator of treatment efficacy in addition to the behavioral readout. In contrast, mice treated with vehicle alone continued to progressively accumulate amyloid plaques and calcium overload. Conclusions: In summary, treatment with DA-9803 prevented structural and functional outcome measures in mouse models of AD. Thus, DA-9803 shows promise as a novel therapeutic approach for Alzheimer’s disease. Electronic supplementary material The online version of this article (10.1186/s13195-018-0338-2) contains supplementary material, which is available to authorized users.Publication Pathogenic PS1 phosphorylation at Ser367(eLife Sciences Publications, Ltd, 2017) Maesako, Masato; Horlacher, Jana; Zoltowska, Katarzyna; Kastanenka, Ksenia; Kara, Eleanna; Svirsky, Sarah; Keller, Laura J; Li, Xuejing; Hyman, Bradley; Bacskai, Brian; Berezovska, OksanaThe high levels of serine (S) and threonine (T) residues within the Presenilin 1 (PS1) N-terminus and in the large hydrophilic loop region suggest that the enzymatic function of PS1/γ-secretase can be modulated by its ‘phosphorylated’ and ‘dephosphorylated’ states. However, the functional outcome of PS1 phosphorylation and its significance for Alzheimer’s disease (AD) pathogenesis is poorly understood. Here, comprehensive analysis using FRET-based imaging reveals that activity-driven and Protein Kinase A-mediated PS1 phosphorylation at three domains (domain 1: T74, domain 2: S310 and S313, domain 3: S365, S366, and S367), with S367 being critical, is responsible for the PS1 pathogenic ‘closed’ conformation, and resulting increase in the Aβ42/40 ratio. Moreover, we have established novel imaging assays for monitoring PS1 conformation in vivo, and report that PS1 phosphorylation induces the pathogenic conformational shift in the living mouse brain. These phosphorylation sites represent potential new targets for AD treatment. DOI: http://dx.doi.org/10.7554/eLife.19720.001Publication Cerebrospinal fluid amyloid-β 42/40 ratio in clinical setting of memory centers: a multicentric study(BioMed Central, 2015) Dumurgier, Julien; Schraen, Susanna; Gabelle, Audrey; Vercruysse, Olivier; Bombois, Stéphanie; Laplanche, Jean-Louis; Peoc’h, Katell; Sablonnière, Bernard; Kastanenka, Ksenia; Delaby, Constance; Pasquier, Florence; Touchon, Jacques; Hugon, Jacques; Paquet, Claire; Lehmann, SylvainIntroduction: The cerebrospinal fluid (CSF) biomarkers amyloid-β (Aβ), tau and phosphorylated tau (p-tau181) are now used for the diagnosis of Alzheimer’s disease (AD). Aβ40 is the most abundant Aβ peptide isoform in the CSF, and the Aβ 42/40 ratio has been proposed to better reflect brain amyloid production. However, its additional value in the clinical setting remains uncertain. Methods: A total of 367 subjects with cognitive disorders who underwent a lumbar puncture were prospectively included at three French memory centers (Paris-North, Lille and Montpellier; the PLM Study). The frequency of positive, negative and indeterminate CSF profiles were assessed by various methods, and their adequacies with the diagnosis of clinicians were tested using net reclassification improvement (NRI) analyses. Results: On the basis of local optimum cutoffs for Aβ42 and p-tau181, 22% of the explored patients had indeterminate CSF profiles. The systematic use of Aβ 42/40 ratio instead of Aβ42 levels alone decreased the number of indeterminate profiles (17%; P = 0.03), but it failed to improve the classification of subjects (NRI = −2.1%; P = 0.64). In contrast, the use of Aβ 42/40 ratio instead of Aβ42 levels alone in patients with a discrepancy between p-tau181 and Aβ42 led to a reduction by half of the number of indeterminate profiles (10%; P < 0.001) and was further in agreement with clinician diagnosis (NRI = 10.5%; P = 0.003). Conclusions: In patients with a discrepancy between CSF p-tau181 and CSF Aβ42, the assessment of Aβ 42/40 ratio led to a reliable biological conclusion in over 50% of cases that agreed with a clinician’s diagnosis. Electronic supplementary material The online version of this article (doi:10.1186/s13195-015-0114-5) contains supplementary material, which is available to authorized users.