Publications by authors named "Haapasalo A"

Article Synopsis
  • In Alzheimer's disease, amyloid beta (Aβ) triggers the cleavage of the TrkB-FL receptor, disrupting essential BDNF signaling that is crucial for neuron health and function.
  • Researchers found that TrkB-FL cleavage occurs early in the disease and worsens with increased pathology, using human samples and cerebrospinal fluid for their studies.
  • They developed a TAT-TrkB peptide that successfully prevents TrkB-FL cleavage, showing potential in improving cognitive function and synaptic issues in a mouse model of Alzheimer's, indicating it could be a safe and effective treatment option.
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Article Synopsis
  • - The study examines the incidence and prevalence of early-onset dementia (EOD) in two areas of Finland from 2010 to 2021, finding that the crude incidence rate was 12.3 cases per 100,000 persons per year with specific age groups showing higher rates.
  • - Out of the 794 new EOD cases identified, Alzheimer’s disease (AD) was the most common subtype, making up 48.2% of cases, followed by behavioral variant frontotemporal dementia at 12.7%.
  • - The findings indicate that the incidence rates for EOD are higher than previous reports, with a notable increase in early-onset AD cases over time, while other EOD subtypes remained
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We investigated the effects of daily ultraviolet A1 (UV-A1, 340-400 nm) exposures on mood states (#R19055, approval on 21 October 2020). Based on our earlier findings of the influence of diurnal preference on mood, we investigated further whether diurnal preference plays a role in the influence of UV-A1 on mood states. Forty-one healthy participants aged 19-55 years were randomized to receive either UV-A1 (n = 21) or control (n = 20) exposures (violet light, 390-440 nm).

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Autoantibodies directed against the GluA3 subunit (anti-GluA3 hIgGs) of AMPA receptors have been identified in 20%-25% of patients with frontotemporal lobar degeneration (FTLD). Data from patients and in vitro/ex vivo pre-clinical studies indicate that anti-GluA3 hIgGs negatively affect glutamatergic neurotransmission. However, whether and how the chronic presence of anti-GluA3 hIgGs triggers synaptic dysfunctions and the appearance of FTLD-related neuropathological and behavioural signature has not been clarified yet.

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Background: Amyotrophic lateral sclerosis (ALS) is a progressive disease for which no curative treatment is currently available.

Objective: This study aimed to investigate whether cortico-spinal transcranial direct current stimulation (tDCS) could mitigate symptoms in ALS patients via a randomized, double-blind, sham-controlled trial, followed by an open-label phase.

Methods: Thirty-one participants were randomized into two groups for the initial controlled phase.

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Charcot-Marie-Tooth disease (CMT) is a heterogeneous set of hereditary neuropathies whose genetic causes are not fully understood. Here, we characterize three previously unknown variants in PMP22 and assess their effect on the recently described potential CMT biomarkers' growth differentiation factor 15 (GDF15) and neurofilament light (NFL): first, a heterozygous PMP22 c.178G > A (p.

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Background: Due to the significant presence of neuropsychiatric symptoms in patients with frontotemporal dementia (FTD) spectrum disorders, psychiatric misdiagnoses, diagnostic delay, and use of psychiatric treatments are common prior to the FTD diagnosis. Furthermore, treatment of diagnosed FTD patients mainly relies on off-label psychopharmacological approaches. Currently, limited real-world data are available regarding the actual use of psychopharmacological medications in FTD.

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Organotypic slice culture models surpass conventional in vitro methods in many aspects. They retain all tissue-resident cell types and tissue hierarchy. For studying multifactorial neurodegenerative diseases such as tauopathies, it is crucial to maintain cellular crosstalk in an accessible model system.

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Article Synopsis
  • * Researchers utilized mass spectrometry to analyze cerebrospinal fluid and plasma from both A673T carriers and non-carriers, revealing significant decreases in soluble APPβ and amyloid beta levels in carriers.
  • * In cell culture studies, the A673T variant showed the potential to lower harmful proteins associated with Alzheimer's, suggesting its important role in mitigating AD-related pathology.
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Frontotemporal dementia (FTD) can manifest as diverse clinical phenotypes and is frequently caused by mutations in different genes, complicating differential diagnosis. This underlines the urgent need for valid biomarkers. Altered lysosomal and immune functions proposedly contribute to FTD pathogenesis.

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Background: Currently, there are few studies considering possible modifiable risk factors of frontotemporal dementia (FTD).

Objective: In this retrospective case-control study, we evaluated whether a history of traumatic brain injury (TBI) associates with a diagnosis of FTD or modulates the clinical phenotype or onset age in FTD patients.

Methods: We compared the prevalence of prior TBI between individuals with FTD (N = 218) and age and sex-matched AD patients (N = 214) or healthy controls (HC; N = 100).

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Background: Frontotemporal dementia (FTD) covers a spectrum of neurodegenerative disorders with various clinical and neuropathological subtypes. The two major pathological proteins accumulating in the brains of FTD patients, depending on their genetic background, are TDP-43 and tau. We aimed to evaluate whether total TDP-43 levels measured from the serum associate with the genotype or clinical phenotype of the FTD patients and whether serum TDP-43 provides prognostic or diagnostic value in the FTD spectrum disorders.

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Article Synopsis
  • Amyloid-beta 42 (Aβ42) and phosphorylated tau (pTau) levels in cerebrospinal fluid (CSF) offer better insight into Alzheimer's disease (AD) than just clinical diagnosis.
  • The European Alzheimer & Dementia Biobank (EADB) analyzed data from 31 cohorts with over 13,000 individuals, identifying new genetic associations such as CR1 for Aβ42 and BIN1 for pTau, alongside novel associations with GMNC and C16orf95.
  • Analysis of all AD risk loci revealed four biological categories linked to Aβ42 and pTau, suggesting multiple pathways in AD's development, with further studies indicating GMNC and C16orf95 also relate to brain ventricular volume.
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Objective: Only a few studies have evaluated modifiable risk factors for frontotemporal dementia (FTD). Here, we evaluated several modifiable factors and their association with disease phenotype, genotype, and prognosis in a large study population including Finnish and Italian patients with FTD and control groups.

Methods: In this case-control study, we compared the presence of several cardiovascular and other lifestyle-related diseases and education between Finnish and Italian patients with familial (n = 376) and sporadic (n = 654) FTD, between different phenotypes of FTD, and between a subgroup of Finnish FTD patients (n = 221) and matched Finnish patients with Alzheimer's disease (AD) (n = 214) and cognitively healthy controls (HC) (n = 100).

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Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis.

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  • Extrapyramidal symptoms (EP symptoms) frequently appear in patients with behavioral variant frontotemporal dementia (bvFTD), complicating the diagnosis of this and similar disorders such as progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD).
  • A study screened 2751 patients for diagnoses and EP symptoms, ultimately analyzing neuroimaging data from 139 patients, revealing that EP+ patients had significantly lower gray matter volumes in key brain regions like the putamen and brain stem.
  • The findings indicate a link between EP symptoms and brainstem atrophy in both bvFTD patients and the larger cohort, suggesting that the source of these symptoms may differ from those in Parkinson's disease.
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Neurofilament light (NFL) is one of the proteins forming multimeric neuron-specific intermediate filaments, neurofilaments, which fill the axonal cytoplasm, establish caliber growth, and provide structural support. Dominant missense mutations and recessive nonsense mutations in the neurofilament light gene () are among the causes of Charcot-Marie-Tooth (CMT) neuropathy, which affects the peripheral nerves with the longest axons. We previously demonstrated that a neuropathy-causing homozygous nonsense mutation in led to the absence of NFL in patient-specific neurons.

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Alzheimer's disease (AD) is the most common form of dementia, which is neuropathologically characterized by extracellular senile plaques containing amyloid-β and intracellular neurofibrillary tangles composed of hyperphosphorylated tau protein. Previous studies have suggested a role for septin (SEPTIN) protein family members in AD-associated cellular processes. Here, we elucidated the potential role of presynaptic SEPTIN5 protein and its post-translational modifications in the molecular pathogenesis of AD.

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Frontotemporal lobar degeneration (FTLD) comprises a heterogenous group of progressive neurodegenerative syndromes. To date, no validated biomarkers or effective disease-modifying therapies exist for the different clinical or genetic subtypes of FTLD. The most common genetic cause underlying FTLD and amyotrophic lateral sclerosis (ALS) is a hexanucleotide repeat expansion in the C9orf72 gene (C9-HRE).

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Frontotemporal lobar degeneration (FTLD) comprises a heterogenous group of fatal neurodegenerative diseases and, to date, no validated diagnostic or prognostic biomarkers or effective disease-modifying therapies exist for the different clinical or genetic subtypes of FTLD. Current treatment strategies rely on the off-label use of medications for symptomatic treatment. Changes in several neurotransmitter systems including the glutamatergic, GABAergic, dopaminergic, and serotonergic systems have been reported in FTLD spectrum disease patients.

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Article Synopsis
  • Mutations in the mitochondrial DNA subunit MT-ATP6 can lead to various neurological conditions, including peripheral neuropathy and ataxia, due to disruptions in ATP synthase function and mitochondrial structure.
  • The specific mutation m.9154C>T was analyzed using patient-derived stem cells, revealing that its impact on cellular behavior varies based on the level of mutation present—affecting neurogenesis and metabolism of motor neurons.
  • Additionally, the study found that Notch signaling was hyperactivated in motor neuron differentiation related to the mutation, suggesting changes in mitochondrial morphology might play a key role in the development of peripheral motor neuropathies.
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