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International Journal of Oncology Nov 2023T cell acute lymphoblastic leukemia (T‑ALL), a neoplasm derived from T cell lineage‑committed lymphoblasts, is characterized by genetic alterations that result in...
T cell acute lymphoblastic leukemia (T‑ALL), a neoplasm derived from T cell lineage‑committed lymphoblasts, is characterized by genetic alterations that result in activation of oncogenic transcription factors and the NOTCH1 pathway activation. The NOTCH is a transmembrane receptor protein activated by γ‑secretase. γ‑secretase inhibitors (GSIs) are a NOTCH‑targeted therapy for T‑ALL. However, their clinical application has not been successful due to adverse events (primarily gastrointestinal toxicity), limited efficacy, and drug resistance caused by several mechanisms, including activation of the AKT/mTOR pathway. Nelfinavir is an human immunodeficiency virus 1 aspartic protease inhibitor and has been repurposed as an anticancer drug. It acts by inducing endoplasmic reticulum (ER) stress and inhibiting the AKT/mTOR pathway. Thus, it was hypothesized that nelfinavir might inhibit the NOTCH pathway via γ‑secretase inhibition and blockade of aspartic protease presenilin, which would make nelfinavir effective against NOTCH‑associated T‑ALL. The present study assessed the efficacy of nelfinavir against T‑ALL cells and investigated mechanisms of action and in preclinical treatment studies using a transgenic mouse model. Nelfinavir blocks presenilin 1 processing and inhibits γ‑secretase activity as well as the NOTCH1 pathway, thus suppressing T‑ALL cell viability. Additionally, microarray analysis of nelfinavir‑treated T‑ALL cells showed that nelfinavir upregulated mRNA levels of (glutathione‑specific γ‑glutamylcyclotransferase 1, a negative regulator of NOTCH) and sestrin 2 (; a negative regulator of mTOR). As both factors are upregulated by ER stress, this confirmed that nelfinavir induced ER stress in T‑ALL cells. Moreover, nelfinavir suppressed mRNA expression in microarray analyses. These findings suggest that nelfinavir inhibited the NOTCH1 pathway by downregulating mRNA expression, upregulating and suppressing γ‑secretase via presenilin 1 inhibition and the mTOR pathway by upregulating via ER stress induction. Further, nelfinavir exhibited therapeutic efficacy against T‑ALL in an transgenic mouse model. Collectively, these findings highlight the potential of nelfinavir as a novel therapeutic candidate for treatment of patients with T‑ALL.
Topics: Humans; Mice; Animals; Nelfinavir; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma; Presenilin-1; Proto-Oncogene Proteins c-akt; Amyloid Precursor Protein Secretases; TOR Serine-Threonine Kinases; Enzyme Inhibitors; Transcription Factors; Mice, Transgenic; RNA, Messenger; Receptor, Notch1; Cell Line, Tumor; Sestrins
PubMed: 37800623
DOI: 10.3892/ijo.2023.5576 -
International Journal of Molecular... Mar 2023BG45 is a class Ⅰ histone deacetylase inhibitor (HDACI) with selectivity for HDAC3. Our previous study demonstrated that BG45 can upregulate the expression of synaptic...
BG45 is a class Ⅰ histone deacetylase inhibitor (HDACI) with selectivity for HDAC3. Our previous study demonstrated that BG45 can upregulate the expression of synaptic proteins and reduce the loss of neurons in the hippocampus of APPswe/PS1dE9 (APP/PS1) transgenic mice (Tg). The entorhinal cortex is a pivotal region that, along with the hippocampus, plays a critical role in memory in the Alzheimer's disease (AD) pathology process. In this study, we focused on the inflammatory changes in the entorhinal cortex of APP/PS1 mice and further explored the therapeutic effects of BG45 on the pathologies. The APP/PS1 mice were randomly divided into the transgenic group without BG45 (Tg group) and the BG45-treated groups. The BG45-treated groups were treated with BG45 at 2 months (2 m group), at 6 months (6 m group), or twice at 2 and 6 months (2 and 6 m group). The wild-type mice group (Wt group) served as the control. All mice were killed within 24 h after the last injection at 6 months. The results showed that amyloid-β (Aβ) deposition and IBA1-positive microglia and GFAP-positive astrocytes in the entorhinal cortex of the APP/PS1 mice progressively increased over time from 3 to 8 months of age. When the APP/PS1 mice were treated with BG45, the level of H3K9K14/H3 acetylation was improved and the expression of histonedeacetylase1, histonedeacetylase2, and histonedeacetylase3 was inhibited, especially in the 2 and 6 m group. BG45 alleviated Aβ deposition and reduced the phosphorylation level of tau protein. The number of IBA1-positive microglia and GFAP-positive astrocytes decreased with BG45 treatment, and the effect was more significant in the 2 and 6 m group. Meanwhile, the expression of synaptic proteins synaptophysin, postsynaptic density protein 95, and spinophilin was upregulated and the degeneration of neurons was alleviated. Moreover, BG45 reduced the gene expression of inflammatory cytokines interleukin-1β and tumor necrosis factor-α. Closely related to the CREB/BDNF/NF-kB pathway, the expression of p-CREB/CREB, BDNF, and TrkB was increased in all BG45 administered groups compared with the Tg group. However, the levels of p-NF-kB/NF-kB in the BG45 treatment groups were reduced. Therefore, we deduced that BG45 is a potential drug for AD by alleviating inflammation and regulating the CREB/BDNF/NF-kB pathway, and the early, repeated administration of BG45 can play a more effective role.
Topics: Animals; Mice; Alzheimer Disease; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Brain-Derived Neurotrophic Factor; Disease Models, Animal; Entorhinal Cortex; Hippocampus; Inflammation; Mice, Transgenic; Microglia; NF-kappa B; Presenilin-1; Histone Deacetylase Inhibitors
PubMed: 36902234
DOI: 10.3390/ijms24054805 -
International Journal of Molecular... Jan 2023In Alzheimer's disease (AD), the reduction in acetylcholinesterase (AChE) enzymatic activity is not paralleled with changes in its protein levels, suggesting the...
In Alzheimer's disease (AD), the reduction in acetylcholinesterase (AChE) enzymatic activity is not paralleled with changes in its protein levels, suggesting the presence of a considerable enzymatically inactive pool in the brain. In the present study, we validated previous findings, and, since inactive forms could result from post-translational modifications, we analyzed the glycosylation of AChE by lectin binding in brain samples from sporadic and familial AD (sAD and fAD). Most of the enzymatically active AChE was bound to lectins (Con A) and (LCA) that recognize terminal mannoses, whereas Western blot assays showed a very low percentage of AChE protein being recognized by the lectin. This indicates that active and inactive forms of AChE vary in their glycosylation pattern, particularly in the presence of terminal mannoses in active ones. Moreover, sAD subjects showed reduced binding to terminal mannoses compared to non-demented controls, while, for fAD patients that carry mutations in the PSEN1 gene, the binding was higher. The role of presenilin-1 (PS1) in modulating AChE glycosylation was then studied in a cellular model that overexpresses PS1 (CHO-PS1). In CHO-PS1 cells, binding to LCA indicates that AChE displays more terminal mannoses in oligosaccharides with a fucosylated core. Immunocytochemical assays also demonstrated increased presence of AChE in the trans-Golgi. Moreover, AChE enzymatic activity was higher in plasmatic membrane of CHO-PS1 cells. Thus, our results indicate that PS1 modulates trafficking and maturation of AChE in Golgi regions favoring the presence of active forms in the membrane.
Topics: Cricetinae; Animals; Humans; Acetylcholinesterase; Presenilin-1; Alzheimer Disease; Lectins; Brain; Cricetulus; Presenilin-2; Mutation
PubMed: 36674948
DOI: 10.3390/ijms24021437 -
Neurobiology of Disease May 2020Mutations in APP (amyloid precursor protein), PSEN1 (presenilin 1) or PSEN2 (presenilin 2) are the main cause of early-onset familial forms of Alzheimer's disease...
Mutations in APP (amyloid precursor protein), PSEN1 (presenilin 1) or PSEN2 (presenilin 2) are the main cause of early-onset familial forms of Alzheimer's disease (autosomal dominant AD or ADAD). These genes affect γ-secretase-dependent generation of Amyloid β (Aβ) peptides, the main constituent of amyloid plaques and one of the pathological hallmarks of AD. Evaluation of patients with ADAD includes assessment of family history, clinical presentation, biomarkers, neuropathology when available and DNA sequencing data. These analyses frequently uncover novel variants of unknown significance in ADAD genes. This presents a barrier to recruitment of such individuals into clinical trials, unless a biochemical test can demonstrate that a novel mutation results in altered APP processing in a manner consistent with pathogenicity. Here we describe generation and characterization of a novel presenilin 1 and 2 double knock-out in N2A mouse neuroblastoma cells using CRISPR/Cas9, which results in complete ablation of Aβ production, decreased Pen-2 expression and Nicastrin glycosylation. Because of the absence of background Aβ secretion from endogenous γ-secretases, these cells can be used for validation of PSEN1 and PSEN2 variant effects on production of Aβ or other γ-secretase substrates and for biochemical studies of γ-secretase function using novel variants. We examined several PSEN1 and PSEN2 mutations of known and unknown pathogenicity. Known mutants increased Aβ42/Aβ40 ratio with varying effect on Aβ40, Aβ42, total Aβ levels and Pen-2 expression, which aligns with previous work on these mutants. Our data on novel PSEN1 V142F, G206V and G206D mutations suggest that these mutations underlie the reported clinical observations in ADAD patients. We believe our novel cell line will be valuable for the scientific community for reliable validation of presenilin mutations and helpful in defining their pathogenicity to improve and facilitate evaluation of ADAD patients, particularly in the context of enrollment in clinical trials.
Topics: Alzheimer Disease; Amyloid Precursor Protein Secretases; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Animals; Cell Line; Mice; Mutation; Patient Selection; Peptide Fragments; Plaque, Amyloid; Presenilin-1; Presenilin-2
PubMed: 32032730
DOI: 10.1016/j.nbd.2020.104785 -
Alzheimer's Research & Therapy Jan 2024Alzheimer's disease (AD) is a degenerative neurological disorder. Recent studies have indicated that histone deacetylases (HDACs) are among the most prominent epigenetic...
Histone deacetylase inhibitors VPA and WT161 ameliorate the pathological features and cognitive impairments of the APP/PS1 Alzheimer's disease mouse model by regulating the expression of APP secretases.
BACKGROUND
Alzheimer's disease (AD) is a degenerative neurological disorder. Recent studies have indicated that histone deacetylases (HDACs) are among the most prominent epigenetic therapy targets and that HDAC inhibitors have therapeutic effects on AD. Here, we identified sodium valproate (VPA), a pan-HDAC inhibitor, and WT161, a novel HDAC6 selective inhibitor, as potential therapeutic agents for AD. Underlying molecular mechanisms were investigated.
METHODS
A cellular model, N2a-APPswe, was established via lentiviral infection, and the APPswe/PSEN1dE9 transgenic mouse model was employed in the study. LC-MS/MS was applied to quantify the concentration of WT161 in the mouse brain. Western blotting, immunohistochemical staining, thioflavin-S staining and ELISA were applied to detect protein expression in cells, tissues, or serum. RNA interference was utilized to knockdown the expression of specific genes in cells. The cognitive function of mice was assessed via the nest-building test, novel object recognition test and Morris water maze test.
RESULTS
Previous studies have focused mainly on the impact of HDAC inhibitors on histone deacetylase activity. Our study discovered that VPA and WT161 can downregulate the expression of multiple HDACs, such as HDAC1 and HDAC6, in both AD cell and mouse models. Moreover, they also affect the expression of APP and APP secretases (BACE1, PSEN1, ADAM10). RNA interference and subsequent vitamin C induction further confirmed that the expression of APP and APP secretases is indeed regulated by HDAC1 and HDAC6, with the JNK pathway being the intermediate link in this regulatory process. Through the above pathways, VPA and WT161 effectively reduced Aβ deposition in both AD cell and mouse models and significantly improved cognitive function in AD mice.
CONCLUSIONS
In general, we have discovered that the HDAC6-JNK-APP secretases cascade is an important pathway for VPA and WT161 to exert their therapeutic effects on AD. Investigations into the safety and efficacy of VPA and WT161 were also conducted, providing essential preclinical evidence for assessing these two epigenetic drugs for the treatment of AD.
Topics: Mice; Animals; Alzheimer Disease; Histone Deacetylase Inhibitors; Amyloid Precursor Protein Secretases; Amyloid beta-Peptides; Chromatography, Liquid; Aspartic Acid Endopeptidases; Tandem Mass Spectrometry; Mice, Transgenic; Cognitive Dysfunction; Disease Models, Animal; Amyloid beta-Protein Precursor; Presenilin-1; Hydroxamic Acids; Terphenyl Compounds
PubMed: 38245771
DOI: 10.1186/s13195-024-01384-0 -
Scientific Reports Aug 2023Familial Alzheimer's disease (FAD) is a complex neurodegenerative disorder for which there are no therapeutics to date. Several mutations in presenilin 1 (PSEN 1), which...
Familial Alzheimer's disease (FAD) is a complex neurodegenerative disorder for which there are no therapeutics to date. Several mutations in presenilin 1 (PSEN 1), which is the catalytic component of γ-secretase complex, are causal of FAD. Recently, the p.Ile416Thr (I416T) PSEN 1 mutation has been reported in large kindred in Colombia. However, cell and molecular information from I416T mutation is scarce. Here, we demonstrate that menstrual stromal cells (MenSCs)-derived planar (2D) PSEN 1 I416T cholinergic-like cells (ChLNS) and (3D) cerebral spheroids (CSs) reproduce the typical neuropathological markers of FAD in 4 post-transdifferentiating or 11 days of transdifferentiating, respectively. The models produce intracellular aggregation of APPβ fragments (at day 4 and 11) and phosphorylated protein TAU at residue Ser/Thr (at day 11) suggesting that iAPPβ fragments precede p-TAU. Mutant ChLNs and CSs displayed DJ-1 Cys-SO (sulfonic acid), failure of mitochondria membrane potential (ΔΨ), and activation of transcription factor c-JUN and p53, expression of pro-apoptotic protein PUMA, and activation of executer protein caspase 3 (CASP3), all markers of cell death by apoptosis. Moreover, we found that both mutant ChLNs and CSs produced high amounts of extracellular eAβ. The I416T ChLNs and CSs were irresponsive to acetylcholine induced Ca influx compared to WT. The I416T PSEN 1 mutation might work as dominant-negative PSEN1 mutation. These findings might help to understanding the recurring failures of clinical trials of anti-eAβ, and support the view that FAD is triggered by the accumulation of other intracellular AβPP metabolites, rather than eAβ42.
Topics: Humans; Alzheimer Disease; Amyloid beta-Peptides; Presenilin-1; Neurons; Cholinergic Agents; Mutation
PubMed: 37553376
DOI: 10.1038/s41598-023-39630-4 -
Aging Cell Aug 2023Although pathogenic variants in PSEN1 leading to autosomal-dominant Alzheimer disease (ADAD) are highly penetrant, substantial interindividual variability in the rates... (Observational Study)
Observational Study
Although pathogenic variants in PSEN1 leading to autosomal-dominant Alzheimer disease (ADAD) are highly penetrant, substantial interindividual variability in the rates of cognitive decline and biomarker change are observed in ADAD. We hypothesized that this interindividual variability may be associated with the location of the pathogenic variant within PSEN1. PSEN1 pathogenic variant carriers participating in the Dominantly Inherited Alzheimer Network (DIAN) observational study were grouped based on whether the underlying variant affects a transmembrane (TM) or cytoplasmic (CY) protein domain within PSEN1. CY and TM carriers and variant non-carriers (NC) who completed clinical evaluation, multimodal neuroimaging, and lumbar puncture for collection of cerebrospinal fluid (CSF) as part of their participation in DIAN were included in this study. Linear mixed effects models were used to determine differences in clinical, cognitive, and biomarker measures between the NC, TM, and CY groups. While both the CY and TM groups were found to have similarly elevated Aβ compared to NC, TM carriers had greater cognitive impairment, smaller hippocampal volume, and elevated phosphorylated tau levels across the spectrum of pre-symptomatic and symptomatic phases of disease as compared to CY, using both cross-sectional and longitudinal data. As distinct portions of PSEN1 are differentially involved in APP processing by γ-secretase and the generation of toxic β-amyloid species, these results have important implications for understanding the pathobiology of ADAD and accounting for a substantial portion of the interindividual heterogeneity in ongoing ADAD clinical trials.
Topics: Humans; Male; Female; Adult; Brain; Positron-Emission Tomography; Magnetic Resonance Imaging; Presenilin-1; Mutation; Alzheimer Disease; Cognition; Amyloid beta-Peptides; tau Proteins; Longitudinal Studies; Cross-Sectional Studies; Biomarkers
PubMed: 37291760
DOI: 10.1111/acel.13871 -
Neurochemical Research Aug 2021Early-onset Alzheimer's disease (AD) is associated with variants in amyloid precursor protein (APP) and presenilin (PSEN) 1 and 2. It is increasingly recognized... (Review)
Review
Early-onset Alzheimer's disease (AD) is associated with variants in amyloid precursor protein (APP) and presenilin (PSEN) 1 and 2. It is increasingly recognized that patients with AD experience undiagnosed focal seizures. These AD patients with reported seizures may have worsened disease trajectory. Seizures in epilepsy can also lead to cognitive deficits, neuroinflammation, and neurodegeneration. Epilepsy is roughly three times more common in individuals aged 65 and older. Due to the numerous available antiseizure drugs (ASDs), treatment of seizures has been proposed to reduce the burden of AD. More work is needed to establish the functional impact of seizures in AD to determine whether ASDs could be a rational therapeutic strategy. The efficacy of ASDs in aged animals is not routinely studied, despite the fact that the elderly represents the fastest growing demographic with epilepsy. This leaves a particular gap in understanding the discrete pathophysiological overlap between hyperexcitability and aging, and AD more specifically. Most of our preclinical knowledge of hyperexcitability in AD has come from mouse models that overexpress APP. While these studies have been invaluable, other drivers underlie AD, e.g. PSEN2. A diversity of animal models should be more frequently integrated into the study of hyperexcitability in AD, which could be particularly beneficial to identify novel therapies. Specifically, AD-associated risk genes, in particular PSENs, altogether represent underexplored contributors to hyperexcitability. This review assesses the available studies of ASDs administration in clinical AD populations and preclinical studies with AD-associated models and offers a perspective on the opportunities for further therapeutic innovation.
Topics: Aging; Alzheimer Disease; Animals; Anticonvulsants; Comorbidity; Epilepsy; Humans; Mutation; Presenilin-1; Presenilin-2; Seizures
PubMed: 33929683
DOI: 10.1007/s11064-021-03332-y -
International Journal of Molecular... Apr 2022Presenilin-1 (PS-1), a component of the gamma (γ)-secretase catalytic complex, has been implicated in Alzheimer's disease (AD) and in tumorigenesis. Interestingly, AD...
Presenilin-1 (PS-1), a component of the gamma (γ)-secretase catalytic complex, has been implicated in Alzheimer's disease (AD) and in tumorigenesis. Interestingly, AD risk is inversely related to melanoma, suggesting that AD-related factors, such as PS-1, may affect melanomagenesis. PS-1 has been shown to reduce Wnt activity by promoting degradation of beta-catenin (β-catenin), an important Wnt signaling partner. Since Wnt is known to enhance progression of different cancers, including melanoma, we hypothesized that PS-1 could affect Wnt-associated melanoma aggressiveness. Western blot results showed that aggressive melanoma cells expressed significantly lower levels of both PS-1 and phosphorylated-β-catenin (P-β-catenin) than nonaggressive melanoma cells. Immunohistochemistry of human melanoma samples showed significantly reduced staining for PS-1 in advanced stage melanoma compared with early stage melanoma. Furthermore, γ-secretase inhibitor (GSI) treatment of aggressive melanoma cells was followed by significant increases in PS-1 and P-β-catenin levels, suggesting impaired Wnt signaling activity as PS-1 expression increased. Finally, a significant reduction in cell migration was associated with the higher levels of PS-1 and P-β-catenin in the GSI-treated aggressive melanoma cells. We demonstrate for the first time that PS-1 levels can be used to assess melanoma aggressiveness and suggest that by enhancing PS-1 expression, Wnt-dependent melanoma progression may be reduced.
Topics: Alzheimer Disease; Amyloid Precursor Protein Secretases; Humans; Melanoma; Presenilin-1; Wnt Signaling Pathway; beta Catenin
PubMed: 35563300
DOI: 10.3390/ijms23094904 -
BMC Neuroscience Dec 2023It has been suggested that exercise training and postbiotic supplement could decelerate the progress of functional and biochemical deterioration in double transgenic...
BACKGROUND
It has been suggested that exercise training and postbiotic supplement could decelerate the progress of functional and biochemical deterioration in double transgenic mice overexpresses mutated forms of the genes for human amyloid precursor protein (APP) and presenilin 1 (m146L) (APP/PS1). Our earlier published data indicated that the mice performed better than controls on the Morris Maze Test parallel with decreased occurrence of amyloid-β plaques in the hippocampus. We investigated the neuroprotective and therapeutic effects of high-intensity training and postbiotic supplementation.
METHODS
Thirty-two adult APP/PS1 mice were randomly divided into four groups: (1) control, (2) high-intensity training (3) postbiotic, (4) combined (training and postbiotic) treatment for 20 weeks. In this study, the whole hemibrain without hippocampus was used to find molecular traits explaining improved brain function. We applied qualitative RT-PCR for gene expression, Western blot for protein level, and Zymography for LONP1 activity. Disaggregation analysis of Aβ-40 was performed in the presence of Lactobacillus acidophilus and Bifidobacterium longum lysate.
RESULTS
We found that exercise training decreased Alzheimer's Disease (AD)-related gene expression (NF-kB) that was not affected by postbiotic treatment. The preparation used for postbiotic treatment is composed of tyndallized Bifidobacterium longum and Lactobacillus acidophilus. Both of the postbiotics effectively disaggregated amyloid-β/Aβ-40 aggregates by chelating Zn and Cu ions. The postbiotic treatment decreased endogenous human APP protein expression and mouse APP gene expression in the hemibrains. In addition, the postbiotic treatment elevated mitochondrial LONP1 activity as well.
CONCLUSION
Our findings revealed distinct mechanisms behind improved memory performance in the whole brain: while exercise training modulates NF-kB signaling pathway regulating immune response until postbiotic diminishes APP gene expression, disaggregates pre-existing amyloid-β plaques and activates mitochondrial protein quality control in the region of brain out of hippocampus. Using the above treatments complements and efficiently slows down the development of AD.
Topics: Mice; Male; Humans; Animals; Alzheimer Disease; Mice, Transgenic; NF-kappa B; Amyloid beta-Protein Precursor; Amyloid beta-Peptides; Brain; Hippocampus; Plaque, Amyloid; Disease Models, Animal; Presenilin-1; Mitochondrial Proteins; ATP-Dependent Proteases
PubMed: 38110905
DOI: 10.1186/s12868-023-00836-x