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International Journal of Molecular... May 2024Alzheimer's disease (AD) is a devastating disorder with a global prevalence estimated at 55 million people. In clinical studies administering certain anti-beta-amyloid...
Alzheimer's disease (AD) is a devastating disorder with a global prevalence estimated at 55 million people. In clinical studies administering certain anti-beta-amyloid (Aβ) antibodies, amyloid-related imaging abnormalities (ARIAs) have emerged as major adverse events. The frequency of these events is higher among apolipoprotein ε4 allele carriers () compared to non-carriers. To reflect patients most at risk for vascular complications of anti-Aβ immunotherapy, we selected an APPswe/PS1dE9 transgenic mouse model bearing the human gene (APPPS1:E4) and compared it with the same APP/PS1 mouse model bearing the human gene ( ε3 allele; APPPS1:E3). Using histological and biochemical analyses, we characterized mice at three ages: 8, 12, and 16 months. Female and male mice were assayed for general cerebral fibrillar and pyroglutamate (pGlu-3) Aβ deposition, cerebral amyloid angiopathy (CAA), microhemorrhages, apoE and cholesterol composition, astrocytes, microglia, inflammation, lysosomal dysfunction, and neuritic dystrophy. Amyloidosis, lipid deposition, and astrogliosis increased with age in APPPS1:E4 mice, while inflammation did not reveal significant changes with age. In general, carriers showed elevated Aβ, apoE, reactive astrocytes, pro-inflammatory cytokines, microglial response, and neuritic dystrophy compared to carriers at different ages. These results highlight the potential of the APPPS1:E4 mouse model as a valuable tool in investigating the vascular side effects associated with anti-amyloid immunotherapy.
Topics: Animals; Alzheimer Disease; Disease Models, Animal; Mice, Transgenic; Mice; Humans; Female; Male; Amyloid beta-Peptides; Apolipoprotein E4; Presenilin-1; Amyloid beta-Protein Precursor; Cerebral Amyloid Angiopathy; Brain
PubMed: 38891941
DOI: 10.3390/ijms25115754 -
Cell & Bioscience Jun 2024Neural progenitor cells (NPCs) can be cultivated from developing brains, reproducing many of the processes that occur during neural development. They can be isolated...
BACKGROUND
Neural progenitor cells (NPCs) can be cultivated from developing brains, reproducing many of the processes that occur during neural development. They can be isolated from a variety of animal models, such as transgenic mice carrying mutations in amyloid precursor protein (APP) and presenilin 1 and 2 (PSEN 1 and 2), characteristic of familial Alzheimer's disease (fAD). Modulating the development of these cells with inflammation-related peptides, such as bradykinin (BK) and its antagonist HOE-140, enables the understanding of the impact of such molecules in a relevant AD model.
RESULTS
We performed a global gene expression analysis on transgenic neurospheres treated with BK and HOE-140. To validate the microarray data, quantitative real-time reverse-transcription polymerase chain reaction (RT-PCR) was performed on 8 important genes related to the immune response in AD such as CCL12, CCL5, CCL3, C3, CX3CR1, TLR2 and TNF alpha and Iba-1. Furthermore, comparative analysis of the transcriptional profiles was performed between treatments, including gene ontology and reactome enrichment, construction and analysis of protein-protein interaction networks and, finally, comparison of our data with human dataset from AD patients. The treatments affected the expression levels of genes mainly related to microglia-mediated neuroinflammatory responses, with BK promoting an increase in the expression of genes that enrich processes, biological pathways, and cellular components related to immune dysfunction, neurodegeneration and cell cycle. B2 receptor inhibition by HOE-140 resulted in the reduction of AD-related anomalies caused in this system.
CONCLUSIONS
BK is an important immunomodulatory agent and enhances the immunological changes identified in transgenic neurospheres carrying the genetic load of AD. Bradykinin treatments modulate the expression rates of genes related to microglia-mediated neuroinflammation. Inhibiting bradykinin activity in Alzheimer's disease may slow disease progression.
PubMed: 38890712
DOI: 10.1186/s13578-024-01251-3 -
Annals of Neurology Jun 2024The role of gamma-aminobutyric acid-ergic (GABAergic) neuron impairment in Alzheimer's disease (AD), and if and how transplantation of healthy GABAergic neurons can...
OBJECTIVE
The role of gamma-aminobutyric acid-ergic (GABAergic) neuron impairment in Alzheimer's disease (AD), and if and how transplantation of healthy GABAergic neurons can improve AD, remain unknown.
METHODS
Human-derived medial ganglionic eminence progenitors (hiMGEs) differentiated from programmed induced neural precursor cells (hiNPCs) were injected into the dentate gyrus region of the hippocampus (HIP).
RESULTS
We showed that grafts migrate to the whole brain and form functional synaptic connections in amyloid precursor protein gene/ presenilin-1 (APP/PS1) chimeric mice. Following transplantation of hiMGEs, behavioral deficits and AD-related pathology were alleviated and defective neurons were repaired. Notably, exosomes secreted from hiMGEs, which are rich in anti-inflammatory miRNA, inhibited astrocyte activation in vitro and in vivo, and the mechanism was related to regulation of CD4 Th1 cells mediated tumor necrosis factor (TNF) pathway.
INTERPRETATION
Taken together, these findings support the hypothesis that hiMGEs transplantation is an alternative treatment for neuronal loss in AD and demonstrate that exosomes with anti-inflammatory activity derived from hiMGEs are important factors for graft survival. ANN NEUROL 2024.
PubMed: 38860520
DOI: 10.1002/ana.27001 -
Journal of Molecular and Cellular... Jun 2024Mutations in ubiquitously expressed presenilin genes (PSENs) lead to early-onset familial Alzheimer's disease (FAD), but patients carrying the mutation also suffer from...
Mutations in ubiquitously expressed presenilin genes (PSENs) lead to early-onset familial Alzheimer's disease (FAD), but patients carrying the mutation also suffer from heart diseases. To elucidate the cardiac myocyte specific effects of PSEN ΔE9, we studied cardiomyocytes derived from induced pluripotent stem cells (iPSC-CMs) from patients carrying AD-causing PSEN1 exon 9 deletion (PSEN1 ΔE9). When compared with their isogenic controls, PSEN1 ΔE9 cardiomyocytes showed increased sarcoplasmic reticulum (SR) Ca leak that was resistant to blockage of ryanodine receptors (RyRs) by tetracaine or inositol-3-reseceptors (IPRs) by 2-ABP. The SR Ca leak did not affect electrophysiological properties of the hiPSC-CMs, but according to experiments and in silico simulations the leak induces a diastolic buildup of [Ca] near the perinuclear SR and reduces the releasable Ca during systole. This demonstrates that PSEN1 ΔE9 induced SR Ca leak has specific effects in iPSC-CMs, reflecting their unique structural and calcium signaling features. The results shed light on the physiological and pathological mechanisms of PSEN1 in cardiac myocytes and explain the intricacies of comorbidity associated with AD-causing mutations in PSEN1.
PubMed: 38851626
DOI: 10.1016/j.yjmcc.2024.06.003 -
Journal of Alzheimer's Disease : JAD 2024Chronic intake of extra virgin olive oil is beneficial for brain health and protects from age-related cognitive decline and dementia, whose most common clinical...
BACKGROUND
Chronic intake of extra virgin olive oil is beneficial for brain health and protects from age-related cognitive decline and dementia, whose most common clinical manifestation is Alzheimer's disease. Besides the classical pathologic deposits of amyloid beta peptides and phosphorylated tau proteins, another frequent feature of the Alzheimer's brain is neuroinflammation.
OBJECTIVE
In the current study, we assessed the effect that extra virgin olive oil has on neuroinflammation when administered to a mouse model of the disease.
METHODS
Triple transgenic mice were randomized to receive a diet enriched with extra virgin olive oil or regular diet for 8 weeks. At the end of this treatment period the expression level of several inflammatory biomarkers was assessed in the central nervous system.
RESULTS
Among the 79 biomarkers measured, compared with the control group, mice receiving the extra virgin olive oil had a significant reduction in MIP-2, IL-17E, IL-23, and IL-12p70, but an increase in IL-5. To validate these results, specific ELISA kits were used for each of them. Confirmatory results were obtained for MIP-2, IL-17E, IL-23, and IL-12-p70. No significant differences between the two groups were observed for IL-5.
CONCLUSIONS
Our results demonstrate that chronic administration of extra virgin olive oil has a potent anti-neuroinflammatory action in a model of Alzheimer's disease. They provide additional pre-clinical support and novel mechanistic insights for the beneficial effect that this dietary intervention has on brain health and dementia.
Topics: Animals; Olive Oil; Alzheimer Disease; Mice, Transgenic; Mice; Disease Models, Animal; Neuroinflammatory Diseases; Amyloid beta-Protein Precursor; Humans; Brain; Biomarkers; Presenilin-1; Male; Cytokines
PubMed: 38848192
DOI: 10.3233/JAD-240374 -
Scientific Reports Jun 2024Calcium hydroxide (Ca(OH)NPs), calcium titanate (CaTiONPs) and yttrium oxide (YONPs) nanoparticles are prevalent in many industries, including food and medicine, but...
Yttrium oxide nanoparticles ameliorates calcium hydroxide and calcium titanate nanoparticles induced genomic DNA and mitochondrial damage, ROS generation and inflammation.
Calcium hydroxide (Ca(OH)NPs), calcium titanate (CaTiONPs) and yttrium oxide (YONPs) nanoparticles are prevalent in many industries, including food and medicine, but their small size raises concerns about potential cellular damage and genotoxic effects. However, there are very limited studies available on their genotoxic effects. Hence, this was done to investigate the effects of multiple administration of Ca(OH)NPs, CaTiONPs or/and YONPs on genomic DNA stability, mitochondrial membrane potential integrity and inflammation induction in mouse brain tissues. Mice were orally administered Ca(OH)NPs, CaTiONPs or/and YONPs at a dose level of 50 mg/kg b.w three times a week for 2 weeks. Genomic DNA integrity was studied using Comet assay and the level of reactive oxygen species (ROS) within brain cells was analyzed using 2,7 dichlorofluorescein diacetate dye. The expression level of Presenilin-1, tumor necrosis factor-alpha (TNF-α) and Interleukin-6 (IL-6) genes and the integrity of the mitochondrial membrane potential were also detected. Oral administration of Ca(OH)NPs caused the highest damage to genomic DNA and mitochondrial membrane potential, less genomic DNA and mitochondrial damage was induced by CaTiONPs administration while administration of YONPs did not cause any remarkable change in the integrity of genomic DNA and mitochondrial membrane potential. Highest ROS generation and upregulation of presenilin-1, TNF-α and IL-6 genes were also observed within the brain cells of mice administrated Ca(OH)NPs but YONPs administration almost caused no changes in ROS generation and genes expression compared to the negative control. Administration of CaTiONPs alone slightly increased ROS generation and the expression level of TNF-α and IL-6 genes. Moreover, no remarkable changes in the integrity of genomic DNA and mitochondrial DNA potential, ROS level and the expression level of presenilin-1, TNF-α and IL-6 genes were noticed after simultaneous coadministration of YONPs with Ca(OH)NPs and CaTiONPs. Coadministration of YONPs with Ca(OH)NPs and CaTiONPs mitigated Ca(OH)NPs and CaTiONPs induced ROS generation, genomic DNA damage and inflammation along with restoring the integrity of mitochondrial membrane potential through YONPs scavenging free radicals ability. Therefore, further studies are recommended to study the possibility of using YONPs to alleviate Ca(OH)NPs and CaTiONPs induced genotoxic effects.
Topics: Animals; Reactive Oxygen Species; Mice; DNA Damage; Calcium Hydroxide; Membrane Potential, Mitochondrial; Titanium; Inflammation; Yttrium; Nanoparticles; Mitochondria; Male; Brain; DNA, Mitochondrial
PubMed: 38844752
DOI: 10.1038/s41598-024-62877-4 -
Science (New York, N.Y.) Jun 2024Successive cleavages of amyloid precursor protein C-terminal fragment with 99 residues (APP-C99) by γ-secretase result in amyloid-β (Aβ) peptides of varying lengths....
Successive cleavages of amyloid precursor protein C-terminal fragment with 99 residues (APP-C99) by γ-secretase result in amyloid-β (Aβ) peptides of varying lengths. Most cleavages have a step size of three residues. To elucidate the underlying mechanism, we determined the atomic structures of human γ-secretase bound individually to APP-C99, Aβ49, Aβ46, and Aβ43. In all cases, the substrate displays the same structural features: a transmembrane α-helix, a three-residue linker, and a β-strand that forms a hybrid β-sheet with presenilin 1 (PS1). Proteolytic cleavage occurs just ahead of the substrate β-strand. Each cleavage is followed by unwinding and translocation of the substrate α-helix by one turn and the formation of a new β-strand. This mechanism is consistent with existing biochemical data and may explain the cleavages of other substrates by γ-secretase.
Topics: Humans; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Amyloid Precursor Protein Secretases; Crystallography, X-Ray; Models, Molecular; Peptide Fragments; Presenilin-1; Protein Conformation, alpha-Helical; Protein Conformation, beta-Strand; Proteolysis; Substrate Specificity
PubMed: 38843321
DOI: 10.1126/science.adn5820 -
Neurotoxicity Research Jun 2024Parkinson's disease with dementia (PDD) is a neurological disorder that clinically and neuropathologically overlaps with Parkinson's disease (PD) and Alzheimer's disease...
Parkinson's disease with dementia (PDD) is a neurological disorder that clinically and neuropathologically overlaps with Parkinson's disease (PD) and Alzheimer's disease (AD). Although it is assumed that alpha-synuclein ( -Syn), amyloid beta (A ), and the protein Tau might synergistically induce cholinergic neuronal degeneration, presently the pathological mechanism of PDD remains unclear. Therefore, it is essential to delve into the cellular and molecular aspects of this neurological entity to identify potential targets for prevention and treatment strategies. Cholinergic-like neurons (ChLNs) were exposed to rotenone (ROT, 10 M) for 24 h. ROT provokes loss of , generation of reactive oxygen species (ROS), phosphorylation of leucine-rich repeated kinase 2 (LRRK2 at Ser) concomitantly with phosphorylation of -synuclein ( -Syn, Ser), induces accumulation of intracellular A (iA ), oxidized DJ-1 (Cys), as well as phosphorylation of TAU (Ser/Thr), increases the phosphorylation of c-JUN (Ser/Ser), and increases expression of proapoptotic proteins TP53, PUMA, and cleaved caspase 3 (CC3) in ChLNs. These neuropathological features resemble those reproduced in presenilin 1 (PSEN1) E280A ChLNs. Interestingly, anti-oxidant and anti-amyloid cannabidiol (CBD), JNK inhibitor SP600125 (SP), TP53 inhibitor pifithrin- (PFT), and LRRK2 kinase inhibitor PF-06447475 (PF475) significantly diminish ROT-induced oxidative stress (OS), proteinaceous, and cell death markers in ChLNs compared to naïve ChLNs. In conclusion, ROT induces p- -Syn, iA , p-Tau, and cell death in ChLNs, recapitulating the neuropathology findings in PDD. Our report provides an excellent in vitro model to test for potential therapeutic strategies against PDD. Our data suggest that ROT induces a neuropathologic phenotype in ChLNs similar to that caused by the mutation PSEN1 E280A.
Topics: Rotenone; Cholinergic Neurons; Animals; Parkinson Disease; alpha-Synuclein; Dementia; Phenotype; Reactive Oxygen Species; Humans; Cells, Cultured
PubMed: 38842585
DOI: 10.1007/s12640-024-00705-3 -
International Journal of Nanomedicine 2024Exosomes are membrane vesicles secreted by various cells and play a crucial role in intercellular communication. They can be excellent delivery vehicles for...
Engineered Exosomes Containing microRNA-29b-2 and Targeting the Somatostatin Receptor Reduce Presenilin 1 Expression and Decrease the β-Amyloid Accumulation in the Brains of Mice with Alzheimer's Disease.
PURPOSE
Exosomes are membrane vesicles secreted by various cells and play a crucial role in intercellular communication. They can be excellent delivery vehicles for oligonucleotide drugs, such as microRNAs, due to their high biocompatibility. MicroRNAs have been shown to be more stable when incorporated into exosomes; however, the lack of targeting and immune evasion is still the obstacle to the use of these microRNA-containing nanocarriers in clinical settings. Our goal was to produce functional exosomes loaded with target ligands, immune evasion ligand, and oligonucleotide drug through genetic engineering in order to achieve more precise medical effects.
METHODS
To address the problem, we designed engineered exosomes with exogenous cholecystokinin (CCK) or somatostatin (SST) as the targeting ligand to direct the exosomes to the brain, as well as transduced CD47 proteins to reduce the elimination or phagocytosis of the targeted exosomes. MicroRNA-29b-2 was the tested oligonucleotide drug for delivery because our previous research showed that this type of microRNA was capable of reducing presenilin 1 (PSEN1) gene expression and decreasing the β-amyloid accumulation for Alzheimer's disease (AD) in vitro and in vivo.
RESULTS
The engineered exosomes, containing miR29b-2 and expressing SST and CD47, were produced by gene-modified dendritic cells and used in the subsequent experiments. In comparison with CD47-CCK exosomes, CD47-SST exosomes showed a more significant increase in delivery efficiency. In addition, CD47-SST exosomes led to a higher delivery level of exosomes to the brains of nude mice when administered intravenously. Moreover, it was found that the miR29b-2-loaded CD47-SST exosomes could effectively reduce PSEN1 in translational levels, which resulted in an inhibition of beta-amyloid oligomers production both in the cell model and in the 3xTg-AD animal model.
CONCLUSION
Our results demonstrated the feasibility of the designed engineered exosomes. The application of this exosomal nanocarrier platform can be extended to the delivery of other oligonucleotide drugs to specific tissues for the treatment of diseases while evading the immune system.
Topics: Animals; Exosomes; Alzheimer Disease; MicroRNAs; Presenilin-1; Brain; Receptors, Somatostatin; Amyloid beta-Peptides; Mice; CD47 Antigen; Somatostatin; Humans; Disease Models, Animal
PubMed: 38828204
DOI: 10.2147/IJN.S442876 -
Alzheimer's & Dementia : the Journal of... Jun 2024Familial Alzheimer's disease (fAD) is heterogeneous in terms of age at onset and clinical presentation. A greater understanding of the pathogenicity of fAD variants and...
INTRODUCTION
Familial Alzheimer's disease (fAD) is heterogeneous in terms of age at onset and clinical presentation. A greater understanding of the pathogenicity of fAD variants and how these contribute to heterogeneity will enhance our understanding of the mechanisms of AD more widely.
METHODS
To determine the pathogenicity of the unclassified PSEN1 P436S mutation, we studied an expanded kindred of eight affected individuals, with magnetic resonance imaging (MRI) (two individuals), patient-derived induced pluripotent stem cell (iPSC) models (two donors), and post-mortem histology (one donor).
RESULTS
An autosomal dominant pattern of inheritance of fAD was seen, with an average age at symptom onset of 46 years and atypical features. iPSC models and post-mortem tissue supported high production of amyloid beta 43 (Aβ43). PSEN1 peptide maturation was unimpaired.
DISCUSSION
We confirm that the P436S mutation in PSEN1 causes atypical fAD. The location of the mutation in the critical PSEN1 proline-alanine-leucine-proline (PALP) motif may explain the early age at onset despite appropriate protein maturation.
HIGHLIGHTS
PSEN1 P436S mutations cause familial Alzheimer's disease. This mutation is associated with atypical clinical presentation. Induced pluripotent stem cells (iPSCs) and post-mortem studies support increased amyloid beta (Aβ43) production. Early age at onset highlights the importance of the PALP motif in PSEN1 function.
PubMed: 38824433
DOI: 10.1002/alz.13904