PMCID
string
Title
string
Sentences
string
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
Serum samples from three patients with previously reported Satoyoshi syndrome were analyzed in this study .
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
A brief summary of the three cases follows.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
The first case was a 28-year-oldwoman from Albacete (Spain), who developed alopecia at 10 years of age.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
Two years later, she began experiencing progressive, painful muscle spasms, followed by diarrhea with carbohydrate malabsorption, iron-deficiency anemia, weight loss, skeletal abnormalities, and amenorrhea.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
A definitive Satoyoshi syndrome diagnosis was not reached until the patient was 18 years old.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
Treatment with prednisone (30 mg/day) and methotrexate (7.5 mg/week) was initiated, with dramatic improvement of muscle spasms, resolution of diarrhea, weight gain of 20 kg, and recovery of menstruation.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
The second case was a 17-year-old girl from the Canary Islands (Spain), with a history of asthma and allergic rhinitis, presenting with alopecia universalis at 5 years of age.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
At 11 years of age, she exhibited painful, intermittent muscle spasms, significant growth retardation, diarrhea, and abdominal pain.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
Her self-limiting muscle spasms, localized to the acral areas of her limbs, increased with physical activity and typically lasted several minutes.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
The patient was diagnosed with Satoyoshi syndrome, and treatment with carbamazepine and otilonium bromide led to the disappearance of her muscle spasms and diarrhea.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
The third case was a 38-year-old woman from Kiel (Germany).
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
At 13 years of age, she began presenting muscle spasms, with jaw cramps being the most uncomfortable.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
She was treated with carbamazepine, prednisolone, and sexsteroids.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
After introducing low doses of methotrexate to the therapy, the patient recovered from muscle spasms, alopecia, and diarrhea.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
At 18 years of age, methotrexate and corticosteroid medication were tapered off, without relapse.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
Initiation of sexsteroid treatment resulted in pubertal development and regular menstrual cycles.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
She has thus far experienced three pregnancies, all terminating in spontaneous abortions.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
Two control groups were included as follows: (a) one consisting of 30 blood donors provided by the Albacete General University Hospital Blood Bank, and (b) a second group of patients with other neurological pathologies.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
The patients included in this second category were a 58-year-old female with radiculopathy, a 41-year-old male with acute disseminated encephalomyelitis, a 55-year-old female with secondary progressive multiple sclerosis, a 73-year-old male with Parkinson’s disease, a 34-year-old female with encephalitis caused by human herpes virus type 6, and a 53-year-old male with demyelinating polyneuropathy.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
Samples from these patients were provided by the Albacete General University Hospital Biobank.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
The present study was compliant with the Declaration of Helsinki, and ethical approval was obtained prior to data and sample collection by the local Medicine Research Ethics Committee of the Albacete General University Hospital (Acta 04/2016 and Acta 10/2021).
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
All participants provided written informed consent for this study.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
For the identification of autoantibodies in patient serum, we used whole brain homogenate (Biochain, Newark, CA, USA), lysates from SH-SY5Y (ATCC, Manassas, VA, USA) cells, and differentiated SH-SY5Y cells.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
The brain homogenate was reconstituted according to the manufacturer’s instructions.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
SH-SY5Y cells were cultured in Dulbecco’s Modified Eagle Medium/Ham’s Nutrient Mixture F-12 (DMEM F-12) supplemented with 2 mM L-glutamine (Gibco, Grand Island, NY, USA), 100 U/mL penicillin and 100 U/mL streptomycin (penicillin–streptomycin; Gibco, Grand Island, NY, USA), and 10% (v/v) heat-inactivated fetal bovine serum (FBS; Gibco, Gaithersburg, MD, USA).
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
Cultures were grown in a humidified incubator at 37 °C under a 5% CO2 atmosphere.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
To induce differentiation, the SH-SY5Y cells were treated with 0.1% retinoic acid (Sigma-Aldrich, Saint Louis, MO, USA) for 5 days, with the medium changed every 2 days.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
The culture medium of the SH-SY5Y cells was removed, and the cells were washed with ice-cold phosphate-buffered saline (PBS, 0.1 M phosphate, 0.15 M sodium chloride, pH 7.2) and lysed for 5 min in 300 μL of ice-cold lysis buffer (Pierce IP, Thermo Fisher Scientific, Rockford, IL, USA).
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
The cell lysates were centrifuged at 13,000× g for 10 min.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
The supernatants were kept for Western blot analysis, and the pellets discarded.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
Protein concentrations were determined spectrophotometrically using the Micro BCA Protein Reagent Kit (Thermo Fisher Scientific, Rockford, IL, USA).
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
A total of 25 µg of protein from brain homogenate, SH-SY5Y lysate, and differentiated SH-SY5Y lysate were separated by electrophoresis on 8% SDS-PAGE gels for 30 min at 60V and 1.5–2 h at 100V.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
Following electrophoresis, the proteins were transferred to nitrocellulose membranes (Immobilon; Millipore Corporation, Billerica, MA, USA) previously activated with transfer buffer [3 g of Base Trizma (Sigma-Aldrich, Saint Louis, MO, USA), 14.4 g of glycine (Sigma-Aldrich, Saint Louis, MO, USA), 200 mL of methanol, and 800 mL of milliQ water], in a Trans-Blot SD Semi-Dry Transfer Cell (Bio-Rad, Hercules, CA, USA) at a constant amperage of 20 mA for 1.5 h. Nonspecific protein binding was blocked using a blocking buffer, 10% w/v skimmed milk, and 0.1% Tween 20 (Sigma-Aldrich, Saint Louis, MO, USA) in PBS for 1 h at room temperature (RT).
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
The membranes were incubated overnight at 4 °C with patient serum samples or control serum samples, diluted 1:50 in a blocking buffer.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
After washing with PBS containing 0.1% v/v Tween 20, 5 times for 5 min, the membranes were incubated with an anti-human IgG secondary antibody (anti-human IgG (Fc specific)−peroxidase antibody produced in goat; Sigma-Aldrich, Saint Louis, MO, USA), diluted 1:1000 in blocking buffer at RT and washed again with PBS containing 0.1% v/v Tween 20, 5 times for 5 min.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
Antibodies were detected using an enhanced chemiluminescence detection kit (GE Healthcare, Little Chalfont, Buckinghamshire, UK).
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
The images were acquired using atransilluminator (Luminescent Image Analyzer LAS-4000 mini, Fujifilm, Tokyo, Japan) with the image capture software LAS-4000 Image Reader (Fujifilm, Tokyo, Japan).
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
In our first experiment, we assessed the autoimmune immunoreactivity of the serum from the Satoyoshi patients in brain homogenate and SH-SY5Y cell lysates.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
We observed a pattern of three bands between 70 and 100 kDa in both the brain homogenate and SH-SY5Y lysate samples.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
A higher intensity and definition of the bands was observed for the SH-SY5Y lysate (Figure 1a).
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
An additional Western blot was performed to compare the SH-SY5Y lysate and the differentiated SH-SY5Y lysate.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
The same band pattern was found for both lysates, with no differences in band intensity or definition (Figure 1b).
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
In the second experiment using only SH-SY5Y lysate samples, we observed a common band pattern between 70 kDa and 100 kDa for the serum samples of the three Satoyoshi syndrome patients (Figure 2, E = case 1, F = case 2, G = case 3).
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
This band pattern was absent in the blood donors (Figure 2A–D) and the patients with other neurological conditions (Figure 2H–M), suggesting that this band pattern is specific to Satoyoshi syndrome.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
No other specific band pattern was found in the blood donors or the other neurological conditions group.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
We were able to identify a characteristic band pattern in our three patients with Satoyoshi syndrome, which was more visible using the SH-SY5Y cell lysate than the brain homogenate.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
No differences in band intensity or definition were found between the SH-SY5Y and differentiated SH-SY5Y cell lysates.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
This immunoreactive band pattern was absent in the serum of blood donors or patients with other neurological conditions.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
No specific band pattern was expected in either the donor group or in the patients with other neurological diseases.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
Healthy individuals may present variations in their serum circulating antibodies, and the neurological patients presented different diseases from each other; therefore, a similar pattern among them could not be presumed.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
The band pattern found in our study for our three Satoyoshi patients, between 70 and 100 kDa, is within the range of the bands described by Endo et al. (85 kDa) and Matsuura et al. (90 kDa), who employed a similar Western blot technique .
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
SH-SY5Y cells express a large number of proteins with molecular weights between 70 and 100 kDa, including those related to neurotransmission, neuronal growth, cell proliferation, cell adhesion, the cytoskeleton, and stress response, among others .
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
Further analysis using additional techniques will be required to confirm the results and determine which specific proteins are targeted by the autoantibodies produced by patients with Satoyoshi syndrome.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
The serum samples in this study were obtained at least 5 years after the onset of the disease, when the patients had already received treatment and no longer showed symptoms.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
The persistence of these characteristic autoantibodies after treatment may allow a retrospective diagnosis.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
The symptomatology of Satoyoshi syndrome takes years to fully develop, and the appearance of the different symptoms is heterogeneous across patients.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
Up to now, diagnosis has been based on a typical clinical pattern.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
A future Western blot test could provide an early diagnosis when patients only present with alopecia or muscle spasms, for example.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
Satoyoshi syndrome is a very rare disease; therefore, patients are very few and dispersed across the world, making it very difficult to obtain samples.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
However, samples from more patients are needed to prove the validity of the test.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
We hope that this preliminary evidence will encourage other professionals to contribute new samples and collaborate with our research.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
Additionally, efforts should be made to identify the autoantibodies responsible for the immunoreactivity we found, as well as the target protein or proteins.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
In summary, we present a first preliminary approach suggesting that the Western blot technique could be used as a laboratory test to assist in Satoyoshi syndrome diagnosis.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
SH-SY5Y lysate is a suitable antigen alternative to human brain homogenate when using this technique.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
The advantages of SH-SY5Y lysate include improved band visualization, better reproducibility, and lower cost.
PMC12610766
Preliminary Evidence for a Western Blot Diagnosis of Satoyoshi Syndrome Using SH-SY5Y Neuroblastoma Cell Lysate as the Antigen Source
Additional studies involving more Satoyoshi syndrome patients are needed to validate our results.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Background/Objectives: Tau protein, a central player in Alzheimer’s disease (AD) pathology, is classically known for its role in microtubule stabilisation.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
However, accumulating evidence indicates that tau also localises to the neuronal nucleus, particularly the nucleolus, where it may regulate chromatin organisation and transcription.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
In this study, we investigated whether different phosphorylation states of nuclear tau display age- and disease-dependent patterns, with a specific focus on the AT8 epitope (phospho-Ser202/Thr205).
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Methods: We analysed nuclear tau epitopes (Tau-1, AT8, PHF1, T181, and S262) by indirect immunofluorescence in SK-N-BE neuroblastoma cells under proliferative and retinoic acid-induced differentiated conditions and in post-mortem hippocampal CA1 neurons from foetal, young, aged, and AD brains.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Other functional markers (UBTF, Ki67, fibrillarin and acetylated histone H4) were used to assess nuclear organisation and function.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Results: Compared with the other epitopes, AT8 was unique in showing dynamic nuclear localisation: absent in proliferating cells but present after differentiation, abundant in young neurons, and significantly reduced in aged and AD samples.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Nuclear AT8 co-localised with Ki67, and its decline was associated with neuronal cell cycle re-entry and nucleolar disorganisation.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Conclusions: Among multiple nuclear tau epitopes, AT8 was the only one displaying age- and disease-related changes, and its reduction during ageing and AD correlates with nuclear stress, aberrant cell cycle activity, and neuronal vulnerability.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Loss of nuclear AT8 may therefore represent an early marker of dysfunction in ageing and AD brains.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Neurodegenerative disorders represent a heterogeneous group of chronic and progressive conditions affecting the central nervous system (CNS), in which specific neuronal populations gradually lose their function and viability.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Among them, Alzheimer’s disease (AD) is the most prevalent and a major cause of dementia worldwide.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
A central pathological feature of AD is the abnormal accumulation of misfolded proteins, including β-amyloid (Aβ) and hyperphosphorylated tau, which contribute to synaptic dysfunction and neuronal loss.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Despite decades of research, the molecular mechanisms that initiate and sustain these processes remain incompletely understood .
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Among the various hypotheses proposed in the literature regarding the etiopathogenesis of neurodegenerative disorders, substantial evidence accumulated over the last two decades has supported the “cell cycle hypothesis,” which suggests that aberrant re-entry of post-mitotic neurons into the cell cycle represents an early and critical event in AD.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
This dysregulation is closely linked to tau phosphorylation and nuclear tau depletion, leading to chromatin disorganisation and nucleolar dysfunction .
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
In AD, cell cycle alterations in vulnerable neurons appear to contribute to the accumulation of hyperphosphorylated tau, leading to the formation of neurofibrillary tangles (NFTs) and the simultaneous expression of cell cycle markers.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Specifically, tau phosphorylated at the AT8 epitope (Ser202/Thr205) localises to nuclear compartments such as the nucleolus and pericentromeric heterochromatin, where it may influence chromatin structure and transcriptional regulation .
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
In vitro and in vivo studies indicate that nuclear tau phosphorylation at epitopes including AT8, Tau-1, T181, and PHF1 correlates with neuronal differentiation states and nucleolar activity, suggesting a regulatory role in rDNA transcription and chromatin maintenance .
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Dysregulation of this phosphorylation pattern has been associated with aberrant cell cycle re-entry and neuronal vulnerability in AD .
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Several studies have specifically demonstrated the presence of Ki67 and cyclins in post-mitotic neurons of aged and AD brains , supporting the aberrant cell cycle re-entry hypothesis in neurodegeneration.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Neuronal cell cycle re-entry can be either “abortive,” where neurons die at the G1/S checkpoint, or “non-abortive,” in which post-mitotic neurons undergo DNA synthesis in the S phase but fail to complete mitosis, ultimately dying before the G2/M transition .
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
It has been proposed that nuclear tau depletion is associated with chromatin instability at the nuclear lamina and nucleolus, along with dysfunctional nucleocytoplasmic reorganisation .
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Intracellular NFTs and extracellular amyloid-β (Aβ) plaques are the main histopathological markers of AD, but their link to cognitive decline remains debated.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
While senile plaques are weakly correlated with cognitive symptoms, hyperphosphorylated tau is more strongly associated with synaptic dysfunction and disease progression .
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
The hippocampus, particularly CA1 neurons, is highly susceptible to tau pathology and neurodegeneration, making it a critical region for studying nuclear tau dynamics across ageing and disease progression .
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
However, the precise mechanisms by which nuclear tau phosphorylation contributes to neuronal stability, nucleolar homeostasis, and cell cycle control remain poorly defined.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
While cytoplasmic NFTs are well-established hallmarks of AD and are closely associated with disease progression, recent findings indicate that nuclear tau localisation plays a critical role in the early stages of AD.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Specifically, nuclear tau has been detected in two primary locations: the nucleolus and pericentromeric heterochromatin .
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
In vitro studies have identified specific nuclear tau epitopes, such as Tau-1 (Pro189/Gly207) and AT8 (pSer202/Thr205), which may interact directly with DNA and/or RNA.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
These epitopes appear to be involved in early AD events, potentially linking nuclear tau to neuronal differentiation.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Notably, AT8 is considered a marker of neuronal differentiation, and its nucleolar localisation suggests an association with rDNA transcriptional repression .
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
In the present study, we focus on the nuclear functions of tau and its phosphorylation states, analysing neuroblastoma cells and human hippocampal neurons across different ages and AD stages.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Our aim is to elucidate how tau phosphorylation at specific nuclear epitopes correlates with nucleolar integrity, cell cycle re-entry, and neurodegenerative processes.
PMC12650037
Loss of AT8 Nuclear Tau as a Marker of Neuronal Ageing and Alzheimer’s Disease Progression
Understanding these nuclear tau dynamics could provide novel insights into early AD pathogenesis and highlight potential therapeutic targets.