Prashant Bharadwaj

Background/Objectives: Effective disease-modifying therapies targeting pathogenic proteins associated with Alzheimer’s disease (AD) remain limited. This study investigated the therapeutic potential of the neuroprotective, cationic arginine-rich peptide R18D to mitigate the pathogenic effects of amyloid-beta (Aβ) and tau associated with AD. Methods: R18D was examined for its ability to inhibit Aβ aggregation in a cell-free assay, attenuate Aβ-induced cytotoxicity in MC65 cells, and suppress intracellular tau aggregation in two neural cell models. Intracellular tau aggregation was quantified using a homogeneous time-resolved fluorescence assay. Additionally, a pilot pharmacokinetic study of R18D was conducted in mice following oral gavage administration. Results: In the cell-free assay, R18D inhibited Aβ aggregation by up to 65%. In human MC65 cells induced to overexpress APP-C99 and accumulate Aβ, treatment with R18D inhibited cellular toxicity by as much as 100%. Preformed tau seeds were applied to human SH-SY5Y cells and rat primary cortical neurons to induce intracellular tau aggregation, and tau levels were quantified after 48 h. Exposure to tau seeds induced robust tau aggregation in both cellular models, which was significantly attenuated by R18D treatment, reducing aggregation by 34.8% in SH-SY5Y cells and 49.9% in cortical neurons. Pharmacokinetic studies demonstrated that R18D was detectable in plasma at 30 and 60 min following oral administration in mice. Conclusions: Together, these results demonstrate that R18D can modulate both Aβ and tau pathologies in vitro and is orally bioavailable, supporting its further evaluation as a therapeutic candidate for AD and other tau-associated neurodegenerative disorders.

Background/Objective: Accumulation of amyloid-beta (Aβ) senile plaques in the human brain is a major hallmark of Alzheimer’s disease (AD), which manifests as progressive decline in memory and cognitive functions and currently lacks effective disease-modifying therapies. Emerging evidence demonstrates that polyphenol-rich plant foods are potential complementary therapies for AD. Methods: In this study, we investigated crude polyphenol extracts (CPEs) and purified polyphenol extracts (PPEs) from three sorghum genotypes for their ability to inhibit Aβ₄₂-induced toxicity in MC-65 cells. Thioflavin T fluorescence, cell viability, mitochondrial function, oxidative stress assays, and Western blotting, along with RNA sequencing and computational analyses, were used to characterise both functional and transcriptomic responses of the cells to polyphenol treatments. Results: CPEs and PPEs inhibited Aβ₄₂ aggregation by 67–76% and significantly reduced Aβ oligomer species. The extracts increased cell viability against Aβ-induced toxicity by more than 70%, decreased intracellular oxidative stress, and enhanced mitochondrial activity by over 80%. Transcriptomic profiling revealed differential modulation of genes associated with ferroptosis and MAPK/NF- κB signalling pathways, indicating regulation of inflammatory and oxidative-stress responses are mechanisms underlying the observed neuroprotection. Conclusions: This study demonstrates that polyphenol extracts from black and red sorghum genotypes exert strong multitarget neuroprotection against Aβ₄₂ toxicity in MC-65 cells. These findings support further evaluation of sorghum-derived polyphenols as complementary therapeutic candidates for AD, with in vivo studies required to establish efficacy and translational potential.

Amyloidogenic proteins, such as amyloid‐β (Aβ), self‐assemble into cross‐β fibrils whose accumulation is central to Alzheimer's disease (AD). Measuring Aβ aggregation and clearance in living cells remains challenging using current cell‐based assays, which are often low‐throughput or not suited for real‐time monitoring. This study aimed to (1) develop a robust, quantitative, and scalable fluorescence‐based assay using Amytracker to monitor Aβ accumulation and clearance in an Aβ‐producing neuronal cell model, and (2) validate its utility for mechanistic studies and therapeutic screening. We established a plate‐based fluorescence assay using Amytracker in MC65 neuronal AD model expressing the Amyloid precursor protein C‐terminal fragment (APP‐C99) that generates Aβ. Accumulation and clearance of Aβ were quantified by measuring Amytracker fluorescence under basal conditions and after inducing Aβ clearance using a Tet‐suppressible system. We utilized this assay to evaluate cell death inhibitors ferrostatin‐1 and liproxstatin‐1 and proteasome activator IU1. Specificity of the assay for amyloidogenic proteins was assessed by treating wild‐type neuroblastoma cells with Aβ, human islet amyloid polypeptide (hIAPP), or non‐aggregating Aβ controls. Validation included Aβ immunoblotting and cell viability assays. In APP‐C99 expressing cells, elevated Amytracker fluorescence correlated with increased Aβ accumulation and reduced cell viability. Supplementation of ferrostatin‐1, liproxstatin‐1, and IU1, on these cells, markedly reduced Amytracker signal, indicating decreased Aβ burden. Furthermore, the Amytracker assay specifically detected amyloidogenic protein aggregation: wild‐type cells exposed to Aβ42 or hIAPP showed high fluorescence, whereas non‐aggregating Aβ16 peptide did not. The Amytracker assay provides a simple, non‐toxic, and high‐throughput platform for quantifying Aβ accumulation and clearance in live cell models. Its sensitivity, specificity, and compatibility with high‐throughput screening make it a valuable tool for studying Aβ dynamics, interrogating mechanisms of proteostasis, and identifying therapeutic candidates targeting Aβ. image

Background: Proteostasis dysfunction plays a central role in Alzheimer's disease (AD), where aberrant accumulation of amyloid precursor protein (APP)-derived peptides, including APP-C99 and amyloid-β (Aβ), contributes to neurotoxicity. Previous work with an APP-C99 neuronal cell model revealed impaired proteasome activity, lysosomal dysfunction, and increased autophagic markers LC3 and p62. Objective: To identify small molecule modulators of proteostasis that reduce Aβ-mediated toxicity and to evaluate their mechanism of action in both cellular and C. elegans models of AD. Methods: We screened a library of small molecule proteostasis modulators in the APP-C99 cell model to identify compounds that reduce Aβ-mediated cell death. Hits were further analyzed for their effects on APP-C99/Aβ clearance, autophagy, and proteasomal function. Neuroprotective effects were validated in an AD C. elegans model. Results: The USP14 deubiquitinase inhibitor IU1 increased cell survival by 40%, reduced APP-C99 and Aβ accumulation, restored proteasomal activity, LC3 and p62 levels to control. IU1 also decreased neuronal loss and improved survival and behavior in AD worms. Notably, autophagy activators, including mTOR inhibitors rapamycin, everolimus, and temsirolimus, worsened Aβ toxicity. Conversely, autophagy inhibitors such as Bafilomycin A and chloroquine reduced APP-C99/Aβ accumulation, enhanced proteasomal activity, decreased cell death, and improved neurodegeneration and behavior in the worm model. Conclusions: This study reveals that, under Aβ-mediated proteostasis dysfunction, autophagy activation exacerbates toxicity, whereas proteasome activation via allosteric inhibition of USP14 using IU1 was neuroprotective. These findings provide evidence to suggest that targeting proteasome stimulation via pharmacological inhibition of USP14 offers a promising therapeutic strategy for AD.

Alzheimer's disease (AD) is a progressive, age‐related, neurodegenerative disorder marked by cognitive decline, memory loss, and accumulation of amyloid beta (Aβ) plaques and tau tangles. A key feature of AD is impaired protein homeostasis, often driven by autophagy dysfunction. Autophagy, a cellular degradation and recycling process, plays a vital role in maintaining neuronal health and is increasingly recognized as a therapeutic target in AD. Lifestyle factors such as diet, physical activity, and sleep can positively influence autophagy and support cognitive function. Intermittent fasting (IF) and calorie restriction (CR) activate autophagy and promote longevity; physical activity enhances cerebral blood flow and neurotrophic signaling; and adequate sleep supports autophagic processes, while sleep deprivation disrupts them. However, excessive autophagy may be detrimental. Understanding how lifestyle modulates autophagy is essential for developing non‐pharmacological strategies to delay or prevent AD. This review explores the mechanistic links between autophagy and lifestyle interventions to support brain health in aging.

Dysregulation of the deubiquitinating enzyme Ubiquitin-specific peptidase 14 (USP14) is implicated in several neurodegenerative diseases, and IU1, an allosteric inhibitor, has shown neuroprotective effects by reducing protein aggregate toxicity. This study aimed to develop new IU1 analogues and evaluate their ability to mitigate amyloid-β (Aβ) accumulation and toxicity in Alzheimer’s disease (AD) cell and Caenorhabditis elegans worm models. IU1 and 71 newly designed analogues identified using the AtomNet^® virtual screening platform were assessed in an amyloid precursor protein-C terminal fragment/amyloid-β (APP-C99/Aβ)-producing AD cell model using a high-throughput toxicity assay. Lead compounds were further evaluated for their effects on neurodegeneration, behaviour, and survival. IU1 reduced Aβ-mediated toxicity and neurodegeneration in cell and worm models. Of the 71 analogues predicted to bind ubiquitin-specific peptidase 14 (USP14), two compounds, AA10 and AA51, showed >50% rescue of Aβ-induced toxicity and robust enhancement of autophagy and proteasome activity. In Caenorhabditis elegans, both compounds alleviated glutamatergic neuron loss and rescued behavioural impairments. IU1 and analogues exhibit protective effects against Aβ toxicity in AD models. Analogues AA10 and AA51 showed greater potency than IU1 and effectively enhanced proteostasis pathways. These findings support USP14 as a promising therapeutic target and provide a basis for the development of improved IU1-derived compounds for AD and related disorders.

Alzheimer’s disease (AD), a complex neurodegenerative disorder characterised by progressive cognitive decline, affects millions globally. With no current cure, treatment focuses on symptom management and slowing disease progression. Early identification is therefore crucial. Fecal microRNA (miRNA) analysis is emerging as a promising non-invasive diagnostic tool. Evidence suggests that miRNAs present in fecal samples may regulate gene expression linked to AD pathology, impacting cellular functions and disease progression. Dietary factors critically influence gut microbiota composition and diversity, affecting brain health via the gut brain axis. Macronutrients such as carbohydrates, proteins, and fats modulate miRNA expression and gut microbiota, influencing AD risk. High-fat diets can increase inflammation and contribute to AD. This review aims to provide a comprehensive overview of how diet-modulated fecal miRNAs and gut microbiota interplay may serve as novel, non-invasive indicators for early detection and intervention strategies in AD.

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder marked by amyloid-β plaque accumulation, tau tangles, and extensive neuroinflammation. Neuroinflammation, driven by glial cells like microglia and astrocytes, plays a critical role in AD progression. Initially, these cells provide protective functions, such as debris clearance and neurotrophic support. However, as AD progresses, chronic activation of these cells exacerbates inflammation, contributing to synaptic dysfunction, neuronal loss, and cognitive decline. Microglia release pro-inflammatory cytokines and reactive oxygen species (ROS), while astrocytes undergo reactive astrogliosis, further impairing neuronal health. This maladaptive response from glial cells significantly accelerates disease pathology. Current AD treatments primarily aim at symptomatic relief, with limited success in disease modification. While amyloid-targeting therapies like Aducanumab and Lecanemab show some promise, their efficacy remains limited. In this context, natural compounds have gained attention for their potential to modulate neuroinflammation and promote neuroprotection. Among these, butyrate and lauric acid are particularly notable. Butyrate, produced by a healthy gut microbiome, acts as a histone deacetylase (HDAC) inhibitor, reducing pro-inflammatory cytokines and supporting neuronal health. Lauric acid, on the other hand, enhances mitochondrial function, reduces oxidative stress, and modulates inflammatory pathways, thereby supporting glial and neuronal health. Both compounds have been shown to decrease amyloid-β deposition, reduce neuroinflammation, and promote neuroprotection in AD models. This review explores the mechanisms through which butyrate and lauric acid modulate glial and neuronal activity, highlighting their potential as therapeutic agents for mitigating neuroinflammation and slowing AD progression.

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and most common cause of dementia among older people. The main pathological hallmarks of AD are formation of insoluble amyloid beta senile plaques and paired helical filaments of neurofibrillary tangles. AD features gradual memory decline, mild to severe cognitive impairment, eventually total dependence of patients on caregivers. Currently available drugs have not been able to modify AD pathology. This has drawn increasing attention to plant food materials with high nutritional and bioactive constituents as potential complementary therapy for AD. Sorghum bicolor is a widely available cost-effective source of proteins, fats, crude fibres, biopeptides and polyphenols which are vital for human wellbeing. This review discussed the major mechanisms underlying AD pathology. The nutritional and bioactive constituents of Sorghum bicolor grains were extensively described. There is limited report on anti-AD activities of sorghum grains. Therefore, the pharmacological mechanisms of action including scavenging of reactive oxygen species, inhibition of oxidative stress, anti-acetylcholinesterase activity and modulation of mitophagy were only speculated. This comprehensive update suggests more robust innovative studies that will provide critical theoretical details necessary to promote utilization of sorghum grains as functional food or source of bioactive molecules for AD therapy.