Aβ42 Expressing Drosophila melanogaster Model for Alzheimer's Disease: Quantitative Proteomics Identifies Altered Protein Dynamics of Relevance to Neurodegeneration

An update on mammalian and non-mammalian animal models for biomarker development in neurodegenerative disorders

Neurodegeneration is one of the leading factor for death globally, affecting millions of people. Developing animal models are critical to understand biological processes and comprehend pathological hallmarks of neurodegenerative diseases. For decades, many animal models have served as excellent tools to determine the disease progression, develop diagnostic methods and design novel therapies against distinct pathologies. Here, we provide a comprehensive overview of both, mammalian and non-mammalian animal models, with a focus on three most common and aggressive neurodegenerative disorders: Alzheimer's disease, Parkinson's disease and Spinocerebellar ataxia-1. We highlight various approaches including transgene, gene transfer, and chemically-induced methods used to develop disease models. In particular, we discuss applications of both non-mammalian and mammalian contributions in research on neurodegeneration. It is exciting to learn the roles of animal models in disease pathomechanisms, identifying biomarkers and hence devising novel interventions to treat neuropathological conditions.

Bacopa monnieri confers neuroprotection by influencing signaling pathways associated with interleukin 4, 13 and extracellular matrix organization in Alzheimer's disease: A proteomics-based perspective

Alzheimer's disease, a prevalent neurodegenerative disorder in the elderly, is characterized by the accumulation of senile plaques and neurofibrillary tangles, triggering oxidative stress, neuroinflammation, and neuronal apoptosis. Current therapies focus on symptomatic treatment rather than targeting the underlying disease-modifying molecular mechanisms and are often associated with significant side effects. Bacopa monnieri, a traditional Indian herb with nootropic properties, has shown promise in neurological disorder treatment from ancient times. However, its mechanisms of action in Alzheimer's disease remain elusive. In this study, a cellular model for Alzheimer's disease was created by treating differentiated IMR-32 cells with beta-amyloid, 1-42 peptide (Aβ42). Additionally, a recovery model was established through co-treatment with Bacopa monnieri to explore its protective mechanism. Co-treatment with Bacopa monnieri extract recovered Aβ42 induced damage as evidenced by the decreased apoptosis and reduced reactive oxygen species production. Mass spectrometry-based quantitative proteomic analysis identified 21,674 peptides, corresponding to 3626 proteins from the Alzheimer's disease model. The proteins dysregulated by Aβ42 were implicated in cellular functions, such as negative regulation of cell proliferation and microtubule cytoskeleton organization. The enriched pathways include extracellular matrix organization and interleukin-4 and interleukin-13 signaling. Bacopa monnieri co-treatment showed remarkable restoration of Aβ42 altered proteins, including FOSL1, and TDO2. The protein-protein interaction network analysis of Bacopa monnieri restored proteins identified the hub gene involved in Alzheimer's disease. The findings from this study may open up new avenues for creating innovative therapeutic approaches for Alzheimer's disease.

A comprehensive review on the progress and challenges of tetrahydroisoquinoline derivatives as a promising therapeutic agent to treat Alzheimer's disease

Alzheimer's disease (AD) is the most common and irreversible neurodegenerative disorder worldwide. While the precise mechanism behind this rapid progression and multifaceted disease remains unknown, the numerous drawbacks of the available therapies are prevalent, necessitating effective alternative treatment methods. In view of the rising demand for effective AD treatment, numerous reports have shown that tetrahydroisoquinoline (THIQ) is a valuable scaffold in various clinical medicinal molecules and has a promising potential as a therapeutic agent in treating AD due to its significant neuroprotective, anti-inflammatory, and antioxidative properties via several mechanisms that target the altered signaling pathways. Therefore, this review comprehensively outlines the potential application of THIQ derivatives in AD treatment and the challenges in imparting the action of these prospective therapeutic agents. The review emphasizes a number of THIQ derivatives, including Dauricine, jatrorrhizine, 1MeTIQ, and THICAPA, that have been incorporated in AD studies in recent years. Subsequently, a dedicated section of the review briefly discusses the emerging potential benefits of multi-target therapeutics, which lie in their ability to be integrated with alternative therapeutics. Eventually, this review elaborates on the rising challenges and future recommendations for the development of therapeutic drug agents to treat AD effectively. In essence, the valuable research insights of THIQ derivatives presented in this comprehensive review would serve as an integral reference for future studies to develop potent therapeutic drugs for AD research.

Lead optimization based design, synthesis, and pharmacological evaluation of quinazoline derivatives as multi-targeting agents for Alzheimer's disease treatment

The complexity and multifaceted nature of Alzheimer's disease (AD) have driven us to further explore quinazoline scaffolds as multi-targeting agents for AD treatment. The lead optimization strategy was utilized in designing of new series of derivatives (AK-1 to AK-14) followed by synthesis, characterization, and pharmacological evaluation against human cholinesterase's (hChE) and β-secretase (hBACE-1) enzymes. Amongst them, compounds AK-1, AK-2, and AK-3 showed good and significant inhibitory activity against both hAChE and hBACE-1 enzymes with favorable permeation across the blood-brain barrier. The most active compound AK-2 revealed significant propidium iodide (PI) displacement from the AChE-PAS region and was non-neurotoxic against SH-SY5Y cell lines. The lead molecule (AK-2) also showed Aβ aggregation inhibition in a self- and AChE-induced Aβ aggregation, Thioflavin-T assay. Further, compound AK-2 significantly ameliorated Aβ-induced cognitive deficits in the Aβ-induced Morris water maze rat model and demonstrated a significant rescue in eye phenotype in the Aꞵ-phenotypic drosophila model of AD. Ex-vivo immunohistochemistry (IHC) analysis on hippocampal rat brains showed reduced Aβ and BACE-1 protein levels. Compound AK-2 suggested good oral absorption via pharmacokinetic studies and displayed a good and stable ligand-protein interaction in in-silico molecular modeling analysis. Thus, the compound AK-2 can be regarded as a lead molecule and should be investigated further for the treatment of AD.

Anti-Aβ42 Aggregative Polyketides from the Antarctic Psychrophilic Fungus Pseudogymnoascus sp. OUCMDZ-3578

Seven new polyketides, diphenyl ketone (1), diphenyl ketone glycosides (2-4), diphenyl ketone-diphenyl ether dimer (6), and anthraquinone-diphenyl ketone dimers (7 and 8), together with compound 5, were isolated from the psychrophilic fungus Pseudogymnoascus sp. OUCMDZ-3578 fermented at 16 °C and identified by spectroscopic analysis. The absolute configurations of 2-4 were determined by acid hydrolysis and 1-phenyl-3-methyl-5-pyrazolone precolumn derivatization. The configuration of 5 was first determined by X-ray diffraction analysis. Compounds 6 and 8 showed the highest activity against amyloid beta (Aβ₄₂) aggregation with half-maximal inhibitory concentrations (IC₅₀) of 0.10 and 0.18 μM, respectively. They also showed strong abilities to chelate with metal ions, especially iron, were sensitive to Aβ₄₂ aggregation induced by metal ions, and displayed depolymerizing activity. Compounds 6 and 8 show potential as leads for the treatment of Alzheimer's disease to prevent Aβ₄₂ aggregation.