bluuebunny/crossref_metadata_2025 huggingface dataset:
Visualizing Tau Tangles in AD Retina with a BODIPY‐based Fluorescent Ligand
Authors: Mautone Lorenza , Gigante Ylenia , Barolo Lorenzo , Baiocco Paola , Boffi Alberto , Angelantonio Silvia Di
Published: December 2023

Background

Alzheimer’s disease (AD) is a neurodegenerative disease responsible for most cases of senile dementia. Despite numerous studies, there are no effective therapies or significant progress in symptom progression. To develop a therapeutic strategy, research has focused on accurate diagnostic methods. Coupled units of hyperphosphorylated protein (P‐Tau) and total‐Tau monomers (t‐Tau) are reliable biomarkers for AD. Early identification of neurofibrillary tangles (NFTs) in retinal tissue is a promising diagnostic tool. The development of highly specific Tau fluorophores has been achieved through the construction of a computational model of TAU oligomers.

Methods

The construction of the highly specific Tau fluorophore BT‐1 (Soloperto et al., 2021) consisting of a BODIPY‐based probe showed excellent photophysical properties and high selectivity allowing in vitro imaging of hyperphosphorylated tau protein filaments with minimal background noise. Delivery to living iPSC derived retinal cells was achieved by identifying a class of delivery cargoes among ferritin proteins, natural nanocages that can embed small molecules and enter human cells expressing the transferrin receptor.

Results

BT‐1 colocalizes with phosphorylated and oligomeric tau in AD retinal slices. Loading the ferritin nanocage with the fluorescent probe BT‐1 generated a unique formulation for the delivery of the fluorescent probe to retinal tissue.

Conclusion

The use of ferritin nanocages loaded with the fluorescent probe BT‐1 provides a promising method for the specific identification of NFTs in retinal tissue for the clinical diagnosis of AD. The encapsulation of other substrates in ferritin nanocages has potential applications in nanomedicine.
Transcriptomic analysis of astrocyte origin enriched plasma EVs in Alzheimer’s Disease
Authors: isik fatma busra
Published: December 2023

Background

Dementia is a neurodegenerative brain disorder characterized by cognitive decline. Accurate diagnosis of the various forms of dementia is as important as effective treatments as misdiagnosis can cause problems for individuals with symptoms of psychosis and Parkinsonism. Accurate subtyping is therefore essential for safe clinical management. Extracellular vesicles(EVs) are proposed as potential biomarkers for forms of dementia. EVscarry biologically active proteins, lipids and nucleic acids including micro‐RNA (miRNA)from their cells of origin. Because of their potential for transferring biological information, and their ability to act as carriers of biomarkers for specific diseases, EVs are currently a novel avenue to explore for the diagnosis or treatment of dementia.

Method

We isolated RNA from EVs from total plasma and astrocyte‐derived plasma EVs (GLAST) and neuronal‐derived EVs in individuals with Alzheimer’s disease and performed RNA‐sequencing. We identified differentially expressed genes (DEG) and performed functional enrichment analysis. We compared expression in EVs in total plasma EVsversus GLAST astrocyte‐derived and healthy controls (HC) and AD cases. We also used cryo‐TEM imaging for the characterisation of EV in human plasma samples.

Result

Enrichment analysis for AD vs HC total EV group, showed enrichment forGABAergic neuron activity. The AD vs HC GlastEV group showed 5 differentially expressed mitochondrial genes all of which were downregulated. AD Glast EVs and HC Glast EVs also were associated with mitochondria‐related functions. The AD and HC total EV vs Glast EV group showed enriched genes which are down‐regulated and relate to microtubule polymerization.

Conclusion

Mitochondrial dysfunction has been associated with Alzheimer’s disease previously and Aβ accumulation within the mitochondria has been observed within AD brain. Astrocytes convert excessive glutamate via TCA cycle of mitochondria to preserve the neural environment. Therefore, the mitochondria‐related functions associated with differentially expressed Glast EVs are biologically relevant and are a promising avenue in the development of biomarkers for dementias.
Phase 2 Study Design and New Data from the Phase 1 SAD/MAD Trial of LHP588, A Second‐Generation Gingipain Inhibitor for the Treatment of P. Gingivalis ‐ Positive Alzheimer Dementia
Authors: Detke Michael , Sabbagh Marwan , Holsinger Leslie J , Bolger Joanna , Wang Jianhong , Ryder Mark , Hendrix Suzanne B. , Dickson Samuel P. , Mallinckrodt Craig , Lynch Casey C , Dominy Stephen S
Published: December 2023

Background

Gingipains, toxic protease virulence factors from the bacterial pathogen P. gingivalis (Pg), were discovered in postmortem brains of patients with Alzheimer’s disease. Gingipain levels correlated with tau and ubiquitin pathology, and oral infection of wild‐type mice with Pg resulted in brain inflammation and neurodegeneration that was blocked by gingipain inhibitors.

LHP588 is a second‐generation orally bioavailable and brain‐penetrant lysine gingipain inhibitor that reduces the toxicity of Pg and the bacterial load. A first‐generation molecule (COR388/atuzaginstat) previously showed reduction of cognitive decline in prespecified cohorts defined by their infection load, but it was discontinued due to a hepatic safety signal. We will review new data from the LHP588 SAD/MAD, and the design of the Phase 2b study planned for initiation later this year.

Method

The Phase 1 study of LHP588 enrolled 32 individuals in the SAD component with 4 cohorts and concurrent placebo (25 mg, 50 mg, 100 mg, 200 mg) and 24 healthy subjects in the 10‐day MAD portion, with 3 cohorts and concurrent placebo (50, 100 mg, and 200 mg).

Result

In the study of atuzaginstat, significance was not observed in the full intent‐to‐treat population, however, prespecified subgroup analyses indicated efficacy in patients with Pg‐positive saliva (Pg+), slowing cognitive decline compared with placebo on the ADAS‐Cog11 by approximately 50% (p = 0.02). Changes in Pg DNA in saliva correlated significantly with changes on the ADAS‐Cog, CDR‐SB, and MMSE.

The second‐generation lysine gingipain inhibitor LHP588 was well‐tolerated in the SAD and 10‐day MAD study; adverse events in the active arms were mild and sporadic. PK with once‐daily dosing achieved target concentrations sufficient for reduction of systemic Pg infection at doses >25 mg of LHP588, and exposures equivalent or greater than those achieved with the high dose of atuzaginstat. LHP588 was also detected in the CSF.

Conclusion

LHP588 was well‐tolerated in healthy volunteers without evidence of hepatic safety signals to date, and its PK profile was supportive of once daily dosing. The Phase 2 trial of LHP588 proposed to start in late 2023 will be similar in design to the prior atuzaginstat study but will be restricted to subjects with Pg+ saliva.
New melatonin derivatives with donepezil fragment in Alzheimer’s disease as neuroprotectors
Authors: Stoyanov Boris Petrov
Published: December 2023

Background

Alzheimer’s disease is characterized by progressive, irreversible degeneration of acetylcholine‐producing neurons, cognitive impairment, and the accumulation of neurofibrillary tangles and amyloid plaques. The natural decline in melatonin levels with aging has been associated with insomnia and depression as well as the development of neurodegenerative disorders such as AD. Furthermore, the complexity of AD pathology has encouraged the design of molecules that are able to interact with two or more complementary targets, with the expectation that these multitarget ligands (MTL) may represent important advantages in the treatment of the disease. This study aimed to find new ChE inhibitors with improved toxicity.

Method

In vitro toxicity screening of the newly compounds on human neuroblastoma SH‐SY5Y, mouse neuroblastoma cell line Neuro‐2a and mouse fibroblast cells CCL‐1. The viability of the cells was assessed by MTT assay. The neuroprotective properties of the compounds were determined in a model of H2O2‐induced oxidative damage in SH‐SY5Y cells. For comparison, effects donepezil, melatonin and galanthamine were determined.

Result

Most of the compounds have IC50 values over 100 µM. Compound 3f possess statistically significant protective effects. It should be noted that the neuroprotective effects were more pronounced than those of donepezil and similar to melatonin and rasagiline.

Conclusion

The new series of melatonin derivatives with donepezil fragment exhibit low toxicity and a good in vitro safety profile. Further, in vitro protection study proved efficient prevention against oxidative stress in H2O2‐induced injury in SH‐SY5Ycells, especially by compound 3f and was proven as the most perspective for further investigations.

Acknowledgments: The financial support by the National Science Fund of Bulgaria (Grant KP‐06‐Н63/11 14.12.2022) is gratefully acknowledged.
Magnetic resonance image‐based brain age as a discriminator of dementia converter in patients with amyloid‐negative amnestic mild cognitive impairment
Authors: Kim Hye Weon , Kim Hyung‐Ji , Lee Hyunji , Yang Hyeonsik , Rieu ZunHyan , Kim Regina EY , Lee Minho , Kim Donghyeon , Lee Jae‐Hong
Published: December 2023

Background

Amyloid‐negative amnestic mild cognitive impairment (MCI) patients have a conversion rate to dementia of approximately 10% within 2 years. This study aimed to investigate whether brain age, calculated using quantitative data obtained from brain magnetic resonance imaging (MRI) artificial intelligence (AI) software can be an important factor in predicting the conversion of dementia in amyloid‐negative amnestic MCI patients.

Methods

We conducted a retrospective cohort study of patients with amyloid‐negative amnestic MCI who visited the memory clinic of Asan Medical Center. All participants underwent detailed neuropsychological testing, brain MRI, and [18F]‐florbetaben (FBB) positron emission tomography (PET) scan. Conversion to dementia was determined by a neurologist based on a clinical interview with a detailed neuropsychological test or a decline in the Korean version of the Mini‐Mental State Examination score of more than 4 points per year combined with impaired activities of daily living. Brain age was determined through volumetric assessment of 12 distinct brain regions using commercially available segmentation software, Neurophet AQUA.

Results

During the follow‐up period, 38% (35/91) of patients converted to dementia from amnestic MCI. 73% (66/91) of patients had a higher brain age than their actual chronological age. In the conversion group, all participants except three (91%, 32/35) had a brain age older than their chronological age. Conversely, the conversion rate to dementia was significantly lower in the group with a younger brain age than their actual age. The subjects were divided into eight groups based on sex, education level, and brain age. When defining the ‘survival’ as the non‐conversion of MCI to dementia, these groups significantly differed in survival probability with a p‐value of 0.036. The low‐educated female group with a higher brain age than their actual age had the lowest survival rate of all groups.

Conclusion

Our findings suggest that MRI‐based brain age used in this study can contribute to predicting conversion to dementia in patients with amyloid‐negative amnestic MCI.
TRAILBLAZER‐ALZ 4: Directly comparing donanemab to aducanumab on amyloid lowering in early, symptomatic Alzheimer’s disease ‐ Results from 12‐months
Authors: Pain Andrew , Ferguson Margaret B , Wang Hong , Salloway Stephen , Lee Elly , Papka Michelle , Hu Haoyan B , Lu Ming , Oru Ena B , Collins Emily C. , Brooks Dawn A. , Sims John R.
Published: December 2023

Background

TRAILBLAZER‐ALZ 4 demonstrated superiority of donanemab versus aducanumab at the 6‐month primary endpoint of the percentage of participants achieving amyloid plaque clearance (<24.1 Centiloids [CL]) in patients with early symptomatic AD (Salloway et al. CTAD 2022).

Methods

Participants (n = 148) were randomized 1:1 to receive donanemab (titration: 700mg IV Q4W [first 3 doses], then 1400mg IV Q4W [subsequent doses]) or aducanumab (titration per USPI: 1mg/kg IV Q4W [first 2 doses], 3mg/kg IV Q4W [next 2 doses], 6mg/kg IV Q4W [next 2 doses] and 10mg/kg IV Q4W [subsequent doses]). The study is ongoing with a total duration of 18 months.

Results

Baseline demographics and characteristics were well‐balanced across treatment arms (donanemab [N = 71], aducanumab [N = 69]). Twenty‐seven donanemab‐treated and 28 aducanumab‐treated participants had low/medium (intermediate) tau levels based on screening tau PET scans. In all participants at 12 months, 70.2%±6.3% (least square [LS] mean ± standard error [SE]) donanemab‐treated vs. 21.9%±5.9% aducanumab‐treated participants achieved amyloid plaque clearance (p<0.001) assessed by florbetapir F18 PET scans. In the low/medium tau subpopulation, 80.0%±9.9% donanemab‐treated vs. 9.6%±5.4% aducanumab‐treated participants achieved amyloid clearance (p<0.001). The percent change (LS mean ± SE) in brain amyloid levels were ‐82.8%±3.1% (baseline [LS mean ± standard deviation]: 97.59±28.20 CL) and ‐57.0%±3.1% (baseline: 102.71±35.30 CL) in donanemab and aducanumab arms, respectively (p<0.001). In the low/medium tau subpopulation, percent change in brain amyloid levels were ‐82.7%±4.6% (baseline: 104.97±25.68 CL) and ‐57.0%±4.5% (baseline: 102.99±27.87 CL) in donanemab and aducanumab arms, respectively (p<0.001). Adverse events occurred in 78.9% of donanemab‐treated and 82.6% of aducanumab‐treated participants, respectively. Amyloid‐related imaging abnormalities occurred in 29.6% (1.4% serious [n = 1]) and 40.6% (2.9% serious [n = 2]) of participants in the donanemab and aducanumab arms, respectively, with higher rates in ApoE4 carriers.

Conclusions

TRAILBLAZER‐ALZ 4 provides the first active comparator data on amyloid plaque clearance in patients with early symptomatic AD and demonstrates the higher brain amyloid reduction of donanemab vs. aducanumab at 12 months when drug titration has been completed and the treatment regime has stabilized.
Three‐objects‐three‐places test as a screening test for prodromal and mild dementia: validation in a memory clinic population
Authors: Krug Sophie , Ribaldi Federica , Altomare Daniele , Garibotto Valentina , Chicherio Christian , Frisoni Giovanni B
Published: December 2023

Background

The Three‐Objects‐Three‐Places (3O3P) test has been developed as a quick screen for episodic memory impairment due to Alzheimer’s Disease (AD). The examiner shows the patient three objects and hides them in three separate places. The patient is later asked what the objects and hiding places were, and which object was hidden where, producing a score out of 9. The aim of this study was to investigate the convergent, discriminant, and diagnostic validity of the test.

Method

1685 unselected patients from the Geneva Memory Center cohort who underwent the 3O3P test as a screen test in the context of routine assessment were included. The convergent and discriminant validity of the 3O3P test was assessed using an exploratory factor analysis. The known‐group validity was assessed in Cognitively Unimpaired (CU) vs Mild Cognitive Impairment (MCI) and demented using the Area Under the Curve (AUC) and comparing AUCs of the 3O3P test with those of other widely used cognitive tests (MMSE and Delayed recall ‐ DTR). The known‐group validity of the 3O3P was tested also in patients with AD biomarkers.

Results

Mean age was 72 years (SD 11.5), 53% were female, mean years of education was 13 (SD 4.4), and mean MMSE was 28.5 (SD 1.5, N = 436) for CU, 25.6 (3.0, N = 767) for MCI and 19.5 (SD 5.2, N = 481). The 3O3P and DTR tests loaded strongly on the same (“memory”) factor, with a saturation of ‐0.89 and ‐0.88 respectively, and weakly on other (“non‐memory”) factors. The 3O3P test can discriminate CU versus MCI with an AUC of 0.71 and versus dementia with an AUC of 0.91. However, MMSE (AUC = 0.83 CU vs MCI; 0.97 CU vs dementia) and DTR (AUC = 0.78 CU vs MCI; 0.93 CU vs dementia) performed significantly better (p<0.001). Patients who were amyloid positive, tau positive, and with significant neurodegeneration achieved lower 3O3P scores.

Conclusion

The 3O3P test has demonstrated good convergent and discriminant validity supporting the notion that the test assesses the construct of episodic memory. Although the MMSE and DTR tests generally distinguished between diagnostic groups more effectively, the 3O3P test carries several advantages over these tests, such as its short duration, easy administration, culture‐ and language‐ free nature.
Predicting cognitive decline in amyloid‐positive patients with mild cognitive impairment or mild dementia
Authors: van der Veere Pieter J. , Hoogland Jeroen , Visser Leonie N.C. , van Harten Argonde C. , Meester Hanneke F.M. Rhodius‐ , Barkhof Frederik , Teunissen Charlotte E. , van de Giessen Elsmarieke , Berkhof Johannes , van der Flier Wiesje M.
Published: December 2023

Background

Cognitive decline rates in Alzheimer’s disease (AD) vary greatly. Disease‐modifying treatments (DMT) may alter cognitive decline trajectories, rendering their prediction increasingly relevant. We aimed to construct clinically applicable prediction models of cognitive decline in amyloid‐positive patients with mild cognitive impairment (MCI) or mild dementia.

Methods

From the Amsterdam Dementia Cohort, we selected amyloid‐positive participants with MCI (n = 317, 66±7yrs, 45%Female, baseline MMSE 26±2) or mild dementia (n = 666, 65±7yrs, 49%Female, MMSE 22±4) and ≥2 annual MMSEs. Follow‐up was 3±2yrs with 4±2 MMSEs. Amyloid positivity was based on cerebrospinal fluid (CSF) AD biomarker concentrations or amyloid PET. We used linear mixed modelling to predict MMSE over time. First, decline trajectories were described with cubic time curves (S‐shaped). Then, we backwards selected predictors from baseline MMSE, age, sex, APOE ε4 dose, magnetic resonance imaging (MRI; visual scores: medial temporal lobe [MTA], global atrophy), CSF concentrations (phosphorylated tau [pTau], Aβ1‐42), and their interactions with linear time. MCI and mild dementia were modelled separately as stratification increased log‐likelihood.

Results

For MCI and mild dementia, rates of cognitive decline increased over time. In MCI, average MMSE declined from 26.4(95%CI:26.2‐26.7) to 25.8(25.5‐26.1) after 18 months, to 24.2(23.7‐24.6) after three years, and to 21.0(20.1‐21.7) after five years. In mild dementia, MMSE declined from 22.4(95%CI:22.0‐22.6) to 19.8(19.4‐20.2), 15.3(14.6‐15.9), and 7.8(6.7‐8.9). For MCI, selected predictors of future MMSE were baseline MMSE, and interactions of time with age, MTA and pTau (table 1). For mild dementia, additional selected interactions with time were baseline MMSE, Aβ1‐42, and APOE ε4. Figure 1 shows the predicted decline distribution. As an example; predicted MMSE after three years for a 65yrs female MCI patient with baseline MMSE 27, would be 26.3 with MTA 0 and pTau 20pg/ml, compared to 23.8 with MTA 1 and pTau 40pg/ml (figure 2a;2b). In the latter case, 27% slower decline would lengthen follow‐up to a predicted MMSE of twenty by fourteen months.

Conclusion

We constructed models for MCI and mild dementia that predict MMSE over time. These models could inform patients about their potential cognitive trajectory and aid in conversations about DMT initiation and the evaluation of their potential effect.
Performance of Alzheimer’s disease plasma biomarkers in primary care: results from the AgeCoDe study
Authors: Martino‐Adami Pamela , Chatterjee Madhurima , Kleineidam Luca , Pentzek Michael , Weyerer Siegfried , Bickel Horst , Wiese Birgitt , Riedel‐Heller Steffi G. , Scherer Martin , Blennow Kaj , Zetterberg Henrik , Wagner Michael , Schneider Anja , Ramirez Alfredo
Published: December 2023

Background

Blood‐based biomarkers offer a major benefit to Alzheimer’s disease screening because they are less invasive and costly than cerebrospinal fluid or imaging biomarkers, but they have been mainly studied in individuals from memory clinics often exhibiting only mild comorbidities. Therefore, it is necessary to validate plasma biomarkers in more heterogeneous population‐based studies to transfer these results to the general population.

Method

Plasma levels of Aβ42/Aβ40, P‐tau181, NfL, and GFAP were measured using Single molecule array (Simoa) technology in samples from 1007 non‐demented participants from the longitudinal population‐based German Study on Ageing, Cognition and Dementia in Primary Care Patients (AgeCoDe). Participants had a median age of 83 years old and were followed for up to 8 years. We evaluated the association of plasma biomarkers with risk of progression to dementia of the Alzheimer’s type (DAT) and cognitive decline using Cox regressions and linear mixed‐effects models, and their capacity to discriminate between non‐converters and DAT‐converters with logistic regressions.

Result

Cox regressions adjusted for age and sex in non‐demented participants indicated that higher levels of P‐tau181 (HR = 1.32, p = 2.14×10−5), NfL (HR = 1.15, p = 0.03), and GFAP (HR = 1.33, p = 2.55×10−7), and a lower Aβ42/Aβ40 ratio (HR = 0.83, p = 0.02) were associated with a higher risk of progression to DAT. In addition, higher plasma levels of P‐tau181 (p = 3.05×10−4), NfL (p = 0.04), and GFAP (p = 2.78×10−7) were associated with faster cognitive decline, but no association was found with plasma Aβ42/Aβ40 ratio (p = 0.24). When evaluated separately, plasma biomarkers displayed a rather low AUC at different time points (2, 4, 6, 8 years from baseline; AUC < 0.7) to discriminate between non‐converters and DAT‐converters. However, when combined into a single prediction model, plasma biomarkers substantially improved the discrimination capacity beyond demographics and APOE genotype within a 6‐year period (AUC base model = 0.66, AUC biomarkers model = 0.72, DeLong’s test: p = 0.01).

Conclusion

Plasma biomarkers are associated with progression to DAT in non‐demented participants. Assessing multiple plasma biomarkers will considerably improve risk assessment for progressing to DAT in primary care.
Not all regions are created equal: identifying regions and cell types associated with cognitive resilience in the AD‐BXD model population
Authors: Gurdon Brianna , Hadad Niran , Telpoukhovskaia Maria , Murdy Thomas J , Yates Sharon , Puchades Maja Amedjkouh , Bjaalie Jan , Kaczorowski Catherine C.
Published: December 2023

Background

The relationship between regional cell composition, brain pathology, and memory impairment in Alzheimer’s disease (AD) remains incompletely understood. The specific brain regions and tracts (and their interactions) that explain the heterogeneity of cognitive decline with AD are not clear. By integrating brain‐wide immunohistochemistry and cognitive outcomes we can achieve unbiased detection of regions of interest (ROIs) and identify cellular correlates of cognitive resilience for causal testing.

Method

Immunohistochemistry(IHC) was completed to evaluate neurodegeneration (NeuN), gliosis (Iba1&GFAP), amyloid beta(Aβ) pathology(AB1‐42), and cell bodies(Thionine) in adult (6 months(m)) and middle‐aged (14m) mice of the AD‐BXD genetic reference panel (n = 227). Using the QUINT workflow, hemibrain slices were systematically segmented and registered to the Allen Brain Atlas to gain a global perspective of percent cell and pathology coverage. IHC traits were correlated with contextual fear conditioning outcomes to identify regions whose stain composition is associated with memory performance.

Results

Contrary to our prior work using ELISA‐based Aβ measurement, we find that Aβ quantified via IHC at the presymptomatic time point (6m) is strongly correlated with differences in short‐ and long‐term memory in 14m female 5XFAD carriers. Furthermore, the degree of astrogliosis at 6m in cortical, striatal, and thalamic regions acts as a predictor of cognitive outcomes at 14m. While age‐related decreases in NeuN load were not observed, wide variation in neurodegeneration levels could be attributed to strain differences and 14m NeuN load was positively correlated with 14m long‐term memory among this female 5XFAD population. Highlighting the importance of genetic background on AD progression, we were able to categorize strains as resilient or susceptible to pathological and cognitive decline and evaluate the overlap of these traits. Strains that exhibit the unique identity of being pathologically susceptible but cognitively resilient offer a novel opportunity to investigate the underlying mechanisms of protection from cognitive decline with AD.

Conclusion

Integrating brain‐wide IHC and behavioral data, we were able to identify regional and cellular correlates that may predict downstream cognitive outcomes. Detection of these biomarkers may prove a valuable resource to disseminate the insidious prodromal stages of AD in which biochemical changes precede apparent clinical symptoms.
The AppNLGF mouse model of amyloid pathology: age‐related behavioural characterisation
Authors: Boxall Ffion A , Good Mark A
Published: December 2023

Background

2nd generation knock‐in models of amyloid pathology have been generated to overcome the non‐specific effects of the overexpression of human APP mutation in mice (Saito et al., 2014). AppNLGF
mice are a relatively new model that expresses human mutant APP at endogenous levels without cellular artefacts noted in transgenic mice (Sasaguri et al., 2022). The key question of how this more restricted expression of human APP mutations influences behaviour in mice has yet to be fully understood. The aim of this study was to establish the profile of memory and anxiety processes in AppNLGF
mice with age.

Methods

To monitor the effect of progressive Aβ deposition, AppNLGF
mice underwent testing at 4‐6, 8‐10, 12‐14, and 22‐23 months old. Behavioural tests were selected to interrogate key neuronal networks affected in AD. Spatial recognition memory was assessed using the Object Location Test (OLT). Spatial working memory was tested using Spontaneous Alternation (SA) testing. Anxiety‐like behaviours were observed with Open Field (OF) and Elevated Plus Maze (EPM) tests.

Results

During OLT, AppNLGF
mice showed no significant difference in object discrimination compared to control animals at all ages tested. However, at 8‐10 and 22‐23m/o, AppNLGFs
were unable to discriminate the object in the novel location. Furthermore, AppNLGFs
showed intact alternation in SA testing until 22‐23m/o. Interestingly, AppNLGFs
exhibited decreased inner zone exploration in OF testing at 22‐23m/o, but consistently showed substantial preference for open arms in the EPM test from as early as 4m/o.

Conclusion

The AppNLGF
model shows subtle cognitive deficits that are most apparent at an advanced age. The severity of the deficits is relatively mild compared to transgenic models assessed on similar tasks. This is probably related to the absence of overexpression‐related artefacts and may speak to the more subtle effects of amyloid on synaptic plasticity. These mice also lack key cellular AD hallmarks such as tau hyperphosphorylation and cell loss. Nevertheless, AppNLGFs
robustly display substantial early anxiolytic‐like behaviour in the EPM test, and anxiogenic‐like behaviour in the OF test at an advanced age, suggesting that amyloid pathology may contribute to behavioural and neuropsychiatric changes.
Cerebral amyloid angiopathy (CAA) in dementia cohort‐ biomarkers
Authors: Rothenberg Kasia Gustaw
Published: December 2023

Background

Cerebral amyloid angiopathy (CAA) defined as deposition of amyloid β‐protein (Aβ) in brain vessels, leads to hemorrhagic phenomena and cognitive impairment. As a disease with Aβ deposition, CAA is commonly compared to Alzheimer’s disease (AD). Imaging‐based Boston criteria allow a diagnosis of probable CAA in vivo, but cannot predict the development of CAA thus development of reliable biomarkers is necessary.

Recognizing the potential risks of CAA in patients with dementia is of great importance in the context of emerging accessibility of anti‐Aβ immunotherapy. Clinicians will be balancing the risks and benefits of such therapy for their Patients with Alzheimer’s disease on daily basis. This situation calls for developing better biomarkers of cerebral amyloid angiopathy.

Method

Presented here a retrospective cohort study of 463 bio‐banked patients with cognitive disorders. De‐identified parameters like sex, age, MOCA, APOE; CSF levels: Aβ 1‐40, Aβ 1‐42, p and t Tau were correlated with the signs of CAA (as assessed by MRI).

Results

CAA was present in 53 out of 463 (11.5%) of the examined population with different types of dementia. 33% of those with CAA were diagnosed with Alzheimer’s disease; 38% with Vascular dementia;23% with MCI‐amnestic; 4% with MCI‐non‐amnestic; 2% with Lewy Body Dementia. Age and level of Amyloid beta 1‐40 were significantly associated with the occurrence of CAA, . An increase in age will increase the odds of developing CAA. From all the other parameters analyzed, the odds of CAA were linked to the low CSF level of Amyloid beta 1‐40.

Conclusion

Low CSF level of Amyloid beta 1‐40 may be considered a biomarker of CAA in dementia.
Utilizing low‐volume PBMC samples from Alzheimer’s disease clinical research cohorts for immune cell RNA‐sequencing
Authors: Viera Andrea M Román , Bellier Jean‐Pierre , Runnels Alexi , Touil Hanane , Fitzpatrick Colleen D , Tuncali Idil , Greco Graziella , Liu Lei , Chhatwal Jasmeer P. , Johnson Keith A. , Scherzer Clemens , Selkoe Dennis J , De Jager Philip L , Sperling Reisa A. , Yang Hyun‐Sik
Published: December 2023

Background

Studies using peripheral blood mononuclear cells (PBMCs) from individuals with Alzheimer’s disease (AD) biomarker information has the potential to clarify the role of peripheral immune systems in AD. However, PBMC collection often requires immediate labor‐intensive processing and large‐volume collection, making it difficult to implement in clinical AD research. Here, we present our optimized protocol to collect, cryopreserve, and process PBMC samples for monocyte and lymphocyte RNA‐sequencing (RNA‐Seq) studies in large clinical AD research programs.

Method

We used 8 mL Cell Preparation Tubes (CPT) to collect blood samples, and each CPT was processed and cryopreserved into two aliquots per the manufacturer’s protocol. Later, one PBMC vial ( = 4 mL blood) was thawed and washed in RPMI (+10% FBS, +1% PS). After recording cell numbers and viability, 2.0×106 cells from each sample were stained with anti‐CD4, CD8, CD14, CD20 antibodies, and Sytox blue (viability) in PBS (+2% FBS). The cells were washed and resuspended in 500 uL PBS (+2% FBS; target concentration 4.0×106/mL) for flow cytometry. We sorted and collected CD4+ T cells, CD8+ T cells, CD14+ monocytes, and CD20+ B cells into RNA lysis‐buffer (TCL + 1% BME), aiming for 5,000 or 10,000 cells/cell type/donor. We used the RNeasy micro kit for RNA extraction and Fragment Analyzer for quality control.

Result

We collected and cryopreserved PBMC samples from 436 Memory and Aging Cohort (MAC) participants. We used 28 samples for this pilot study (mean age = 68.2 ± 8.1, 21 females). From one cryopreserved aliquot ( = 4 mL of blood), we recovered an average of 3.40×106 ± 1.43×106 viable cells (mean viability 90.4% ± 5.8). Average quantity of RNA was 12.2 ± 4.95 ng/104 cells. The RNA integrity (RIN) score was 8.89 ± 1.7, consistent with excellent RNA quality (Fig. 1).

Conclusion

Our low‐volume protocol (4 mL of blood per participant) deployed in a large clinical AD study yielded excellent‐quality RNA for cell‐type‐specific bulk RNA‐Seq (using SMART‐Seq2 library). This protocol can be readily adapted for cell‐type‐specific proteomics or single‐cell multiome projects and is a promising approach to deeply phenotype the peripheral immune system in the context of aging and AD.
Baseline characteristics of INTERCEPT‐AD: A phase 1 trial with ACU193 targeting soluble amyloid beta oligomers for the treatment of early Alzheimer’s disease
Authors: Feaster Todd , Ziemba Shane , Sundell Karen L , Skljarevski Vladimir , Sethuraman Gopalan , Siemers Eric R
Published: December 2023

Background

Alzheimer’s disease (AD) is a neurodegenerative disorder affecting approximately 40 million people worldwide. There are few treatments available that affect the underlying degenerative process, making AD one of the largest unmet medical needs. ACU193 is a humanized, IgG2 subclass monoclonal antibody that targets soluble amyloid beta oligomers (sAβOs). Evidence supports the view that sAβOs are one of the primary instigators of AD neurodegeneration. Thus, blocking the toxicity of sAβOs with ACU193 may be a promising approach for the treatment of AD.

Method

INTERCEPT‐AD is a phase 1 randomized, placebo‐controlled, single‐ and multiple‐dose study investigating the safety, tolerability, and pharmacokinetics of intravenous ACU193 in mild cognitive impairment or mild dementia due to AD. The SAD portion includes four cohorts with 2 mg/kg, 10 mg/kg, 25 mg/kg, and 60 mg/kg ACU193 or placebo. The MAD portion includes three cohorts receiving three doses of ACU193 or placebo: 10 mg/kg once every four weeks (Q4W), 60 mg/kg Q4W and 25 mg/kg once every 2 weeks (Q2W). Key inclusion criteria are 55‐90 years of age, PET scan positive for brain amyloid, MMSE 18‐30 and CDR‐Global score 0.5 or 1.0. The INTERCEPT‐AD trial is fully enrolled.

Result

At 17 sites in the U.S., 260 participants were screened, 65 were randomized, and 62 received at least one dose of ACU193 or placebo, including 33 females (53%) and 29 males (47%). Negative PET (61%) was the most common reason for screen failure. Baseline age was 72.1 ± 7.8 years (mean ± SD), CDR Sum of Boxes score was 3.5 ± 1.8, ADAS‐Cog‐13 was 24.2 ± 9.0 and screening MMSE was 24.2 ± 3.6. ApoE e4 homozygotes accounted for 13% of the study population and ApoE e4 heterozygotes for 46.7%. Traditionally underrepresented ethnoracial populations comprised 23% of the study (5% Black/African American, 16% Hispanic/Latino, 2% Other). Additional baseline measures including demographics, clinical characteristics, AD medication, and imaging data will be presented.

Conclusion

We describe key baseline demographic, clinical, and cognitive characteristics of participants in the INTERCEPT‐AD trial. Data generated from this trial will guide further development of ACU193 for the treatment of early AD.
APOE loss‐of‐function variants: Compatible with longevity and associated with resistance to Alzheimer’s Disease pathology
Authors: Guen Yann Le , Chemparathy Augustine , Chen Sunny , Leong Lesley , Gorzynski John John , Xue Guangxue , Belloy Michael E , Kasireddy Nandita , Tauber Andres Peña , Williams Kennedy , Wingo Thomas S. , Lah James J. , Jayadev Suman , Hales Chadwick M , Peskind Elaine R , Child Daniel D , Keene C Dirk , Le Cong , Ashley Euan , Yu Chang‐En , Greicius Michael D
Published: December 2023

Background

The ε4 variant of APOE is the strongest genetic risk factor for late‐onset Alzheimer’s disease (AD). It remains unclear if the ε4 protein increases AD risk through a gain of abnormal function, or whether it functions less well than the ε3 protein. Framed bluntly: Would knocking down ε4 in an ε4 carrier increase or decrease AD risk?

Method

We searched whole‐exomes and whole‐genomes from ∼47,000 older controls and AD cases in the Alzheimer’s Disease Sequencing Project (ADSP) looking for early loss‐of‐function variants on APOE. Five of 26,605 older controls carried a loss‐of‐function variant while only one of 20,856 AD cases did (Figure.1A/B). We reasoned that if ε4 does not function as well as ε3, then loss‐of‐function of either ε3 or ε4 should have an ε4‐like impact on risk. However, if ε4 is inherently detrimental, loss‐of‐function of ε4, specifically, should have a protective effect.

Result

Loss of ε3 was seen in two cognitively healthy ε3 homozygotes, last assessed at ages 82 and 88. This suggests that the ε3/null effective genotype is not a strong driver of AD risk. Subject 6‐nominally ε3/ε4 but effectively ε4/null ‐developed symptoms at 75 and died at 87 with autopsy‐confirmed AD, with an age‐at‐onset similar to typical ε3/ε4 (μ = 73.5y), but later typical than ε4/ε4 (μ = 69.7y). This suggests that the loss of ε3 does not result in an ε4‐like phenotype, as seen with Subjects 3 and 5. The most illustrative phenotypes are seen in Subjects 1 and 2 who are nominally ε3/ε4 but effectively ε3/null. Subject 2 was cognitively healthy at 79, with normal levels of amyloid and tau in cerebrospinal fluid at 76, while 2/3rds of ε3/ε4 are amyloid‐positive by 75. Subject 1 was assessed as cognitively normal at 90, died the same year, and had no amyloid pathology, and no amyloid deposits in the cerebral blood vessels, making him a prominent outlier compared to 1700 ε3/ε4 individuals in NACC (Figure.1C).

Conclusion

Taken together, these results provide the strongest human genetics evidence yet available to support the hypothesis that ε4 drives AD risk through a gain of abnormal function and that reducing ε4 should be expected to reduce AD risk.
Studying TLR9 loss‐of‐function in iPSC of patients with deleterious mutation
Authors: Cacace Rita , Frydas Alexandros , van Broeckhoven Christine
Published: December 2023

Background

Toll‐like Receptor 9 (TLR9) is an essential innate and adaptive immune component. In human it is predominantly expressed in B cells and in plasmacytoid dendritic cells (pDC). We have previously identified a novel heterozygous variant in TLR9 (p.E317D), located in the CpG‐DNA binding pocket, co‐segregating with Alzheimer’s disease (AD) in an early‐onset (EO) Flanders‐Belgian family. We showed that p.E317D decreases the TLR9 CpG‐induced signaling efficiency in HEK293 cells, suggesting loss‐of‐function (LoF). Cytokine profiling of human wild‐type peripheral blood mononuclear cells (PBMCs), upon TLR9 activation, revealed a predominantly anti‐inflammatory response. The cytokines released suppressed inflammation and promoted phagocytosis of Aβ42 oligomers in human induced pluripotent stem cells (iPSC)‐derived microglia. In this study, we aim to investigate the mutation effect in patients derived bio‐samples with the hypothesis that failure of the innate immune system to clear Aβ, rather than an overproduction of the Aβ peptides, is likely the disease mechanism in TLR9 LoF mutation.

Method

IPSc were generated from two p.E317D mutation carriers from the Flanders‐Belgian family. Isogenic and knock‐out (KO) TLR9 iPSC lines were obtained by CRISPR‐based genome editing. Optimization of the derived‐pDC differentiation protocol in a feeder‐free culture methods and derived‐pDC characterization were performed.

Result

Differentiation of pDC was optimized in an iPSC control line. The formation of embryoid bodies (EB) was followed by induction of hematopoietic progenitor cells (HPCs) using timed addition of specific factors. HPCs were matured into pDCs through the addition of master regulators of cell faith (FLT3L, SCF and GM‐CSF). Derived‐pDC expressed specific cell surface markers, CD123, CD304, ILT3, DR6 and HLA‐DR and showed high expression levels of TLR9.

Conclusion

The generation of derived‐pDC will allow us to test TLR9 response to its ligand in mutation carriers compared to isogenic cell lines. Furthermore, we will be able to test the effect of the complete loss of TLR9 in KO cell lines form the same patients. These cells, upon treatment with TLR9 ligands will produce specific conditioned media that will be used in additional investigations, among others, to treat iPSC‐derived microglia in presence of Aβ42 oligomers, to better understand the effect of LoF p.E317D mutation.
VIVIAD, A Phase 2b Study Investigating Varoglutamstat in Patients with MCI or Mild AD: Analysis of Baseline Cognition Data
Authors: Wenzkowski Christine , Schaeffer Michael , Fuchs Katharina , Weber Frank , Li Yanqi , Miller Claire Prener , Bihlet Asger Reinstrup , Alexandersen Peter , Axelsen Tobias Melton , Harrison John E , Vijverberg Everard G.B.
Published: December 2023

Background

Varoglutamstat (PQ912) is an oral, small molecule inhibitor of glutaminyl cyclase, preventing the formation of neurotoxic N3pE amyloid. A Phase 2a study (NCT02389413, Scheltens et al., 2018) reported encouraging first evidence of varoglutamstat’s disease‐modifying activity, most importantly with statistically significant changes from baseline in working memory after only 12 weeks of treatment.

Method

VIVIAD (NCT04498650, Vijverberg et al., 2021) is an informed multicenter, randomized, placebo‐controlled, double‐blind, parallel group dose‐finding Phase 2b study in 250 patients with Mild Cognitive Impairment (MCI) and early Alzheimer´s disease (AD). Treatment duration varies between 48 and 96 weeks depending on the time of inclusion, with participants receiving 300mg or 600mg varoglutamstat, or placebo, twice‐daily (BID). The participants’ disease status at time of inclusion was confirmed by Abeta1‐42 and phospho‐tau CSF biomarker profiles, various cognition tests including MMSE, DSST/WAIS‐IV Coding test (WAIS‐IV), and A‐IADL‐Q. Primary outcome is a composite score of the cognitive domains attention and working memory using the Cogstate Neuropsychological Test Battery (Cogstate NTB).

Result

Enrollment has been completed, with a total of N = 259 patients randomized. The 300mg BID varoglutamstat arm was switched to 600mg BID based on positive independent Data Safety Monitoring Board review in June 2022. As of April 14, 2023, 23 patients had completed 96 weeks of treatment. The study will continue until the last patient has completed 48 weeks of treatment with the corresponding follow‐up visit. While most AD trials focus on cognitive tests assessing memory deficits rather than working memory and attention, VIVIAD uses WAIS‐IV to select patients with rescuable cognitive deficits in the target domains. In contrast to MMSE, WAIS‐IV performance shows a reasonably good correlation with the primary outcome measures. Comparing baseline data of male and female participants showed no significant gender differences except for Abeta1‐42 levels.

Conclusion

The use of MMSE and DSST/WAIS‐IV together with CSF biomarkers is a valuable tool in identifying and recruiting patients with MCI or mild AD. The strategy of recruiting individuals with evidence of baseline deficits on the WAIS‐IV Coding test has successfully enriched the study cohort with respect to deficits in attention and working memory, enabling reliable assessment of potential cognitive improvement after treatment.
BCAT proteins: A metabolic link between Type II Diabetes and Alzheimer’s Disease
Authors: Lush Marie , Moraes Marcela Usmari , Conway Myra
Published: December 2023

Background

Aberrant energy pathways compounded by dysregulated cellular redox plays a pivotal role in the pathogenesis of Alzheimer’s disease (AD) but the underlying mechanisms are not clear. Clinical and epidemiological data show that those with Type II Diabetes Mellitus (T2DM) have a 65% increased risk of developing AD (Arvanitakis et al., 2004). Our group and others have shown that serum branched chain amino acids and the branched chain aminotransferase proteins (BCAT) are increased in subjects with AD and T2DM, which has been linked with dysregulated autophagy and metabolic reprogramming. Here, we explore how changes in cellular redox regulate and influence metabolic‐related pathology changes associated with AD.

Methods

SHSY‐5Y cells were used as a neuronal model to observe the effects of BCATc dysregulation in neuronal metabolism. Cells were transfected with our BCATc overexpression constructs and metabolite load assessed using LC‐MS/MS. Activity of glycolytic enzymes GAPDH and enolase were assessed, and overall glycolytic rate characterised using a Seahorse XF analyser. Oxidative stress was measured using the HyPer‐7 molecular probe (Bousolov et al, 2004) and cells were visualised using confocal microscopy. Finally, Western blot analysis was performed to assess levels of BCATc in the presence of increasing glucose (+/‐ 100 nM insulin) and hydrogen peroxide treatments and to demonstrate changes in levels of β‐amyloid and hyperphosphorylated tau.

Results

Here we show that BCATc overexpression increases the level of glucose and fructose, whilst decreasing GAPDH, enolase activity and glycolytic rate (p < 0.05). There was an observable increase in hydrogen peroxide generation (p<0.001), while levels of amyloid precursor protein (P<0.01), β‐amyloid (p>0.05) and hyperphosphorylated tau (p<0.05) were significantly increased. In addition, levels of BCATc increased dose‐dependently following hydrogen peroxide treatments (p < 0.001) and decreased in the presence of excess glucose (+ 100 nM insulin) (p<0.05).

Conclusion

Our results demonstrate that the reprogramming of BCAT as a result of hallmarks of T2DM such as excess dietary‐derived nutrient signals and a concurrent increase in oxidative stress, are associated with aberrant processing and aggregation of β‐amyloid and tau protein and are likely to contribute to the pathophysiology of AD.
Interim phase 1 part A results for ALN‐APP, the first investigational RNAi therapeutic in development for Alzheimer’s disease
Authors: Cohen Sharon , Ducharme Simon , Brosch Jared R. , Vijverberg Everard G.B. , Apostolova Liana G. , Sostelly Alexandre , Goteti Sasikiran , Makarova Nune , Avbersek Andreja , Guo Weinong , Bostwick Bret , Mummery Catherine J.
Published: December 2023

Background

Genetic‐driven deregulation of the amyloid pathway and overproduction of downstream amyloid‐β are known to cause early‐onset Alzheimer’s disease (EOAD)1. ALN‐APP is an investigational intrathecally (IT) administered RNAi therapeutic designed to reduce upstream intracellular and extracellular amyloid precursor protein (APP) levels by lowering APP mRNA. As a result, we hypothesize that ALN‐APP may alter the cascade of events that result in neurodegeneration, potentially slowing, halting, or reversing Alzheimer’s disease progression.

Method

ALN‐APP‐001 (NCT05231785) Part A is an ongoing randomized, double‐blind, placebo‐controlled, Phase 1 single‐ascending dose study in patients with EOAD. Patients are required to have disease onset at age <65 years, Clinical Dementia Rating® global score of 0.5 or 1.0, and Mini Mental State Examination score >20. Patients are being evaluated over 6 months, with further follow‐up of up to 6 months as needed. The primary endpoint is the safety and tolerability of ALN‐APP. Secondary objectives include the evaluation of pharmacokinetics and pharmacodynamic effects of ALN‐APP.

Result

12 patients were enrolled and randomized 2:1 to receive ALN‐APP or placebo in 25mg and 75mg dose cohorts. Baseline characteristics are shown in Table 1. Mean (SD) duration on study was 6.7 (1.7) months for cohort 1 (25mg) and 2.0 (1.0) months for cohort 2 (75mg). Dose‐dependent reductions of soluble APPα and APPβ (sAPPα and sAPPβ) levels in cerebrospinal fluid (CSF) at day 15 were observed following a single dose of ALN‐APP, with mean reductions from baseline of 55% (sAPPα) and 69% (sAPPβ), and maximum reductions of 71% (sAPPα) and 83% (sAPPβ) in the 75mg cohort (n = 4) (Table 2). All adverse events (AEs) by data cut‐off on 01/17/2023 were mild or moderate (Table 3), with no AEs deemed related to study drug by the investigators. Additional cohort data will be presented at the meeting.

Conclusion

This first clinical study of a CNS‐administered RNAi therapeutic demonstrates target engagement of APP, with reductions in CSF sAPPα and sAPPβ. To date, ALN‐APP remains generally well tolerated with all reported AEs mild or moderate. These interim results support further evaluation of ALN‐APP in patients with EOAD.

Reference:

1. Hampel H et al. Molecular Psychiatry (2021). 26:5481‐5503.