Nilotinib Effects on Safety, Tolerability, and Biomarkers in Alzheimer's Disease

TFEB agonist clomiphene citrate activates the autophagy-lysosomal pathway and ameliorates Alzheimer's disease symptoms in mice

Autophagy is a conserved eukaryotic cellular clearance and recycling process through the lysosome-mediated degradation of damaged organelles and protein aggregates to maintain homeostasis. Impairment of the autophagy-lysosomal pathway is implicated in the pathogenesis of Alzheimer's disease (AD). Transcription factor EB (TFEB) is a master regulator of autophagy and lysosomal biogenesis. Therefore, activating TFEB and autophagy provides a novel strategy for AD treatment. We previously described that clomiphene citrate (CC) promotes nuclear translocation of TFEB and increases autophagy and lysosomal biogenesis. In this study, 7 and 3-month-old APP/PS1 mice were treated with TFEB agonist CC and assessed. The behavioral tests were performed using Morris water maze and open field test. Additional changes in Aβ pathology, autophagy and inflammatory response were determined. We found that CC activated TFEB and the autophagy-lysosomal pathway in neuronal cells. Moreover, using mouse model of Alzheimer's disease, CC treatment promoted clearance of Aβ plaques and ameliorated cognitive function in both 7 and 3-month-old APP/PS1 mice. The CC-induced activation of TFEB occurs by promoting acetylation of TFEB for nuclear translocation. These findings provide a molecular mechanism for the TFEB-mediated activation of the autophagy-lysosome pathway by CC, which has the potential to be repurposed and applied in the treatment or prevention of AD.

c-KIT inhibitors reduce pathology and improve behavior in the Tg(SwDI) model of Alzheimer's disease

Treatments for Alzheimer's disease have primarily focused on removing brain amyloid plaques to improve cognitive outcomes in patients. We developed small compounds, known as BK40143 and BK40197, and we hypothesize that these drugs alleviate microglial-mediated neuroinflammation and induce autophagic clearance of neurotoxic proteins to improve behavior in models of neurodegeneration. Specificity binding assays of BK40143 and BK40197 showed primary binding to c-KIT/Platelet Derived Growth Factor Receptors (PDGFR)α/β, whereas BK40197 also differentially binds to FYVE finger-containing phosphoinositide kinase (PIKFYVE). Both compounds penetrate the CNS, and treatment with these drugs inhibited the maturation of peripheral mast cells in transgenic mice, correlating with cognitive improvements on measures of memory and anxiety. In the brain, microglial activation was profoundly attenuated and amyloid-beta and tau were reduced via autophagy. Multi-kinase inhibition, including c-KIT, exerts multifunctional effects to reduce neurodegenerative pathology via autophagy and microglial activity and may represent a potential therapeutic option for neurodegeneration.

Nilotinib as a Prospective Treatment for Alzheimer's Disease: Effect on Proteins Involved in Neurodegeneration and Neuronal Homeostasis

Nilotinib, a tyrosine kinase inhibitor that targets the Abelson tyrosine kinase (c-Abl) signaling pathway, is FDA-approved to treat chronic myeloid leukemia. Nilotinib has properties indicative of a possible utility in neuroprotection that have prompted exploration of repurposing the drug for the treatment of Alzheimer's disease (AD) and Parkinson's disease (PD). AD is a progressive age-related neurodegenerative disorder characterized by the deposition of extracellular amyloid-β plaques and intracellular neurofibrillary tangles. It is incurable and affects approximately 50 million patients worldwide. Nilotinib reduces c-Abl phosphorylation, amyloid-β levels, and dopaminergic neuron degeneration in preclinical AD models. This study explores the effects of nilotinib on amyloid processing and mitochondrial functioning in the SH-SY5Y human neuroblastoma cell line. SH-SY5Y cells were exposed to nilotinib (1, 5, and 10 µM). Real-time PCR and immunoblot analysis were performed to quantify the expression of genes pertaining to amyloid-β processing and neuronal health. Nilotinib did not significantly change APP, BACE1, or ADAM10 mRNA levels. However, BACE1 protein was significantly increased at 1 µM, and ADAM10 was increased at 10 µM nilotinib without affecting APP protein expression. Further, nilotinib treatment did not affect the expression of genes associated with neuronal health and mitochondrial functioning. Taken together, our findings do not support the efficacy of nilotinib treatment for neuroprotection.

Antineoplastics for treating Alzheimer's disease and dementia: Evidence from preclinical and observational studies

As the world population ages, there will be an increasing need for effective therapies for aging-associated neurodegenerative disorders, which remain untreatable. Dementia due to Alzheimer's disease (AD) is one of the leading neurological diseases in the aging population. Current therapeutic approaches to treat this disorder are solely symptomatic, making the need for new molecular entities acting on the causes of the disease extremely urgent. One of the potential solutions is to use compounds that are already in the market. The structures have known pharmacokinetics, pharmacodynamics, toxicity profiles, and patient data available in several countries. Several drugs have been used successfully to treat diseases different from their original purposes, such as autoimmunity and peripheral inflammation. Herein, we divulge the repurposing of drugs in the area of neurodegenerative diseases, focusing on the therapeutic potential of antineoplastics to treat dementia due to AD and dementia. We briefly touch upon the shared pathological mechanism between AD and cancer and drug repurposing strategies, with a focus on artificial intelligence. Next, we bring out the current status of research on the development of drugs, provide supporting evidence from retrospective, clinical, and preclinical studies on antineoplastic use, and bring in new areas, such as repurposing drugs for the prion-like spreading of pathologies in treating AD.

Alzheimer's disease approaches - Focusing on pathology, biomarkers and clinical trial candidates

The strategy for the development of new drugs for Alzheimer's disease (AD) recognizes that an effective therapy requires early therapeutic intervention and a multifactorial approach that considers the individual initiators of AD development. Current knowledge of AD includes the understanding of pathophysiology, risk factors, biomarkers, and the evolving patterns of biomarker abnormalities. This knowledge is essential in identifying potential molecular targets for new drug development. This review summarizes promising AD drug candidates, many of which are currently in phase 2 or 3 clinical trials. New agents are classified according to the Common Alzheimer's Disease Research Ontology (CADRO). The main targets of new drugs for AD are processes related to amyloid beta and tau neurotoxicity, neurotransmission, inflammation, metabolism and bioenergetics, synaptic plasticity, and oxidative stress. These interventions are aimed at preventing disease onset and slowing or eliminating disease progression. The efficacy of pharmacotherapy may be enhanced by combining these drugs with other treatments, antioxidants, and dietary supplements. Ongoing research into AD pathophysiology, risk factors, biomarkers, and the dynamics of biomarker abnormalities may contribute to the understanding of AD and offer hope for effective therapeutic strategies in the near future.

Tyrosine kinases: multifaceted receptors at the intersection of several neurodegenerative disease-associated processes

Tyrosine kinases (TKs) are catalytic enzymes activated by auto-phosphorylation that function by phosphorylating tyrosine residues on downstream substrates. Tyrosine kinase inhibitors (TKIs) have been heavily exploited as cancer therapeutics, primarily due to their role in autophagy, blood vessel remodeling and inflammation. This suggests tyrosine kinase inhibition as an appealing therapeutic target for exploiting convergent mechanisms across several neurodegenerative disease (NDD) pathologies. The overlapping mechanisms of action between neurodegeneration and cancer suggest that TKIs may play a pivotal role in attenuating neurodegenerative processes, including degradation of misfolded or toxic proteins, reduction of inflammation and prevention of fibrotic events of blood vessels in the brain. In this review, we will discuss the distinct roles that select TKs have been shown to play in various disease-associated processes, as well as identify TKs that have been explored as targets for therapeutic intervention and associated pharmacological agents being investigated as treatments for NDDs.

Dual-Action Kinase Inhibitors Influence p38α MAP Kinase Dephosphorylation

Reversible protein phosphorylation directs essential cellular processes including cell division, cell growth, cell death, inflammation, and differentiation. Because protein phosphorylation drives diverse diseases, kinases and phosphatases have been targets for drug discovery, with some achieving remarkable clinical success. Most protein kinases are activated by phosphorylation of their activation loops, which shifts the conformational equilibrium of the kinase towards the active state. To turn off the kinase, protein phosphatases dephosphorylate these sites, but how the conformation of the dynamic activation loop contributes to dephosphorylation was not known. To answer this, we modulated the activation loop conformational equilibrium of human p38α ΜΑP kinase with existing kinase inhibitors that bind and stabilize specific inactive activation loop conformations. From this, we discovered three inhibitors that increase the rate of dephosphorylation of the activation loop phospho-threonine by the PPM serine/threonine phosphatase WIP1. Hence, these compounds are "dual-action" inhibitors that simultaneously block the active site and stimulate p38α dephosphorylation. Our X-ray crystal structures of phosphorylated p38α bound to the dual-action inhibitors reveal a shared flipped conformation of the activation loop with a fully accessible phospho-threonine. In contrast, our X-ray crystal structure of phosphorylated apo human p38α reveals a different activation loop conformation with an inaccessible phospho-threonine, thereby explaining the increased rate of dephosphorylation upon inhibitor binding. These findings reveal a conformational preference of phosphatases for their targets and suggest a new approach to achieving improved potency and specificity for therapeutic kinase inhibitors.

Nilotinib treatment outcomes in autosomal dominant spinocerebellar ataxia over one year

We evaluated the efficacy and safety of 1-year treatment with nilotinib (Tasigna®) in patients with autosomal dominant spinocerebellar ataxia (ADSCA) and the factors associated with responsiveness. From an institutional cohort, patients with ADSCA who completed a 1-year treatment with nilotinib (150-300 mg/day) were included. Ataxia severity was assessed using the Scale for the Rating and Assessment of Ataxia (SARA), scores at baseline and 1, 3, 6, and 12 months. A subject was categorized 'responsive' when the SARA score reduction at 12 M was > 0. Pretreatment serum proteomic analysis included subjects with the highest (n = 5) and lowest (n = 5) SARA score change at 12 months and five non-ataxia controls. Thirty-two subjects (18 [56.2%] females, median age 42 [30-49.5] years) were included. Although SARA score at 12 M did not significantly improve in overall population, 20 (62.5%) subjects were categorized as responsive. Serum proteomic analysis identified 4 differentially expressed proteins, leucine-rich alpha-2-glycoprotein (LRG1), vitamin-D binding protein (DBP), and C4b-binding protein (C4BP) beta and alpha chain, which are involved in the autophagy process. This preliminary data suggests that nilotinib might improve ataxia severity in some patients with ADSCA. Serum protein markers might be a clue to predict the response to nilotinib.Trial Registration Information: Effect of Nilotinib in Cerebellar Ataxia Patients (NCT03932669, date of submission 01/05/2019).

Multi-target drugs for Alzheimer's disease

Alzheimer's disease (AD), a leading cause of dementia, increasingly challenges our healthcare systems and society. Traditional therapies aimed at single targets have fallen short owing to the complex, multifactorial nature of AD that necessitates simultaneous targeting of various disease mechanisms for clinical success. Therefore, targeting multiple pathologies at the same time could provide a synergistic therapeutic effect. The identification of new disease targets beyond the classical hallmarks of AD offers a fertile ground for the design of new multi-target drugs (MTDs), and building on existing compounds have the potential to yield in successful disease modifying therapies. This review discusses the evolving landscape of MTDs, focusing on their potential as AD therapeutics. Analysis of past and current trials of compounds with multi-target activity underscores the capacity of MTDs to offer synergistic therapeutic effects, and the flourishing genetic understanding of AD will inform and inspire the development of MTD-based AD therapies.

Overview of Psychiatric Medications in the Pipeline in Phase III Trials as of June 1, 2024: A Systematic Review

Objective

This systematic review provides an overview of psychiatric medications in the late stages of development (Phase III clinical trials) as of June 1, 2024. It details the mechanisms of action, efficacy, dosing, and adverse effects of these medications.

Methods

We searched the PubMed database for Phase III studies of psychiatric medications published until June 1, 2024, using the keywords "psychiatric" OR "psychopharm*" AND "medic*" OR "pharm*". Our review encompassed medications currently undergoing Phase III clinical trials and those that have completed Phase III but are awaiting approval from the United States Food and Drug Administration (FDA). We independently analyzed the identified studies and reached a consensus on the medications to be included in this systematic review.

Results

As of June 1, 2024, a total of 89 pipeline drug trials were identified, including nine for schizophrenia, five for bipolar disorders, 25 for depressive disorders, 11 for anxiety disorders, five for post-traumatic stress disorder (PTSD), one for obsessive compulsive disorder (OCD), two for eating disorders, two for sleep-wake disorders, three for sexual dysfunctions, one for substance-related and addictive disorders, 22 for neurocognitive disorders, and three for neurodevelopmental disorders, specifically attention deficit hyperactivity disorder (ADHD).

Conclusion

The psychiatric medications in the pipeline as of June 1, 2024, demonstrate significant promise in treating psychiatric disorders.

Role of Tau Protein in Neurodegenerative Diseases and Development of Its Targeted Drugs: A Literature Review

Tau protein is a microtubule-associated protein that is widely distributed in the central nervous system and maintains and regulates neuronal morphology and function. Tau protein aggregates abnormally and forms neurofibrillary tangles in neurodegenerative diseases, disrupting the structure and function of neurons and leading to neuronal death, which triggers the initiation and progression of neurological disorders. The aggregation of tau protein in neurodegenerative diseases is associated with post-translational modifications, which may affect the hydrophilicity, spatial conformation, and stability of tau protein, promoting tau protein aggregation and the formation of neurofibrillary tangles. Therefore, studying the role of tau protein in neurodegenerative diseases and the mechanism of aberrant aggregation is important for understanding the mechanism of neurodegenerative diseases and finding therapeutic approaches. This review describes the possible mechanisms by which tau protein promotes neurodegenerative diseases, the post-translational modifications of tau protein and associated influencing factors, and the current status of drug discovery and development related to tau protein, which may contribute to the development of new therapeutic approaches to alleviate or treat neurodegenerative diseases.

Developing theragnostics for Alzheimer's disease: Insights from cancer treatment

The prevalence of Alzheimer's disease (AD) and its associated economic and societal burdens are on the rise, but there are no curative treatments for AD. Interestingly, this neurodegenerative disease shares several biological and pathophysiological features with cancer, including cell-cycle dysregulation, angiogenesis, mitochondrial dysfunction, protein misfolding, and DNA damage. However, the genetic factors contributing to the overlap in biological processes between cancer and AD have not been actively studied. In this review, we discuss the shared biological features of cancer and AD, the molecular targets of anticancer drugs, and therapeutic approaches. First, we outline the common biological features of cancer and AD. Second, we describe several anticancer drugs, their molecular targets, and their effects on AD pathology. Finally, we discuss how protein-protein interactions (PPIs), receptor inhibition, immunotherapy, and gene therapy can be exploited for the cure and management of both cancer and AD. Collectively, this review provides insights for the development of AD theragnostics based on cancer drugs and molecular targets.

Prophylactic treatment with the c-Abl inhibitor, neurotinib, diminishes neuronal damage and the convulsive state in pilocarpine-induced mice

The molecular mechanisms underlying seizure generation remain elusive, yet they are crucial for developing effective treatments for epilepsy. The current study shows that inhibiting c-Abl tyrosine kinase prevents apoptosis, reduces dendritic spine loss, and maintains N-methyl-d-aspartate (NMDA) receptor subunit 2B (NR2B) phosphorylated in in vitro models of excitotoxicity. Pilocarpine-induced status epilepticus (SE) in mice promotes c-Abl phosphorylation, and disrupting c-Abl activity leads to fewer seizures, increases latency toward SE, and improved animal survival. Currently, clinically used c-Abl inhibitors are non-selective and have poor brain penetration. The allosteric c-Abl inhibitor, neurotinib, used here has favorable potency, selectivity, pharmacokinetics, and vastly improved brain penetration. Neurotinib-administered mice have fewer seizures and improved survival following pilocarpine-SE induction. Our findings reveal c-Abl kinase activation as a key factor in ictogenesis and highlight the impact of its inhibition in preventing the insurgence of epileptic-like seizures in rodents and humans.

Disease-Modifying Treatments and Their Future in Alzheimer's Disease Management

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by memory impairment, a loss of cholinergic neurons, and cognitive decline that insidiously progresses to dementia. The pathoetiology of AD is complex, as genetic predisposition, age, inflammation, oxidative stress, and dysregulated proteostasis all contribute to its development and progression. The histological hallmarks of AD are the formation and accumulation of amyloid-β plaques and interfibrillar tau tangles within the central nervous system. These histological hallmarks trigger neuroinflammation and disrupt the physiological structure and functioning of neurons, leading to cognitive dysfunction. Most treatments currently available for AD focus only on symptomatic relief. Disease-modifying treatments (DMTs) that target the biology of the disease in hopes of slowing or reversing disease progression are desperately needed. This narrative review investigates novel DMTs and their therapeutic targets that are either in phase three of development or have been recently approved by the U.S. Food and Drug Administration (FDA). The target areas of some of these novel DMTs consist of combatting amyloid or tau accumulation, oxidative stress, neuroinflammation, and dysregulated proteostasis, metabolism, or circadian rhythm. Neuroprotection and neuroplasticity promotion were also key target areas. DMT therapeutic target diversity may permit improved therapeutic responses in certain subpopulations of AD, particularly if the therapeutic target of the DMT being administered aligns with the subpopulation's most prominent pathological findings. Clinicians should be cognizant of how these novel drugs differ in therapeutic targets, as this knowledge may potentially enhance the level of care they can provide to AD patients in the future.

Proteomics revealed an association between ribosome-associated proteins and amyloid beta deposition in Alzheimer's disease

Most scholars believe that amyloid-beta (Aβ) has the potential to induce apoptosis, stimulate an inflammatory cascade, promote oxidative stress and exacerbate the pathological progression of Alzheimer's disease (AD). Therefore, it is crucial to investigate the deposition of Aβ in AD. At approximately 6 months of age, APP/PS1 double transgenic mice gradually exhibit the development of plaques, as well as spatial and learning impairment. Notably, the hippocampus is specifically affected in the course of AD. Herein, 6-month-old APP/PS1 double transgenic mice were utilized, and the differentially expressed (DE) proteins in the hippocampus were identified and analyzed using 4D label-free quantitative proteomics technology and parallel reaction monitoring (PRM). Compared to wild-type mice, 29 proteins were upregulated and 25 proteins were downregulated in the AD group. Gene Ontology (GO) enrichment analysis of biological processes (BP) indicated that the DE proteins were mainly involved in 'ribosomal large subunit biogenesis'. Molecular function (MF) analysis results were primarily associated with '5.8S rRNA binding' and 'structural constituent of ribosome'. In terms of cellular components (CC), the DE proteins were mainly found in 'polysomal ribosome', 'cytosolic large ribosomal subunit', 'cytosolic ribosome', and 'large ribosomal subunit', among others. Furthermore, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis demonstrated that the results were mainly enriched in the 'Ribosome signaling pathway'. The key target proteins identified were ribosomal protein (Rp)l18, Rpl17, Rpl19, Rpl24, Rpl35, and Rpl6. The PRM verification results were consistent with the findings of the 4D label-free quantitative proteomics analysis. Overall, these findings suggest that Rpl18, Rpl17, Rpl19, Rpl24, Rpl35, and Rpl6 may have potential therapeutic value for the treatment of AD by targeting Aβ.

The identification of c-Abl inhibitors as potential agents for Parkinson's disease: a preliminary in silico approach

Parkinson's disease (PD) is the most common movement disorder worldwide. PD is primarily associated with the mutation, overexpression, and phosphorylation of α-synuclein. At the molecular level, the upstream protein c-Abl, a tyrosine kinase, has been shown to regulate α-synuclein activation and expression patterns. This study aimed to identify potential c-Abl inhibitors through in silico approaches. Molecular docking was performed using PyRx software, followed by Prime MM-GBSA studies. BBB permeability and toxicity were predicted using CBligand and ProTox-II, respectively. ADME was assessed using QikProp. Molecular dynamics were carried out using Desmond (Academic version). DFT calculations were performed using the Gaussian 16 suite program. The binding scores of the top hits, norimatinib, DB07326, and entinostat were - 11.8 kcal/mol, - 11.8 kcal/mol, and - 10.8 kcal/mol, respectively. These hits displayed drug-likeness with acceptable ADME properties, except for the standard, nilotinib, which violated Lipinski's rule of five. Similarly, the molecular dynamics showed that the top hits remained stable during the 100 ns simulation. DFT results indicate DB04739 as a potent reactive hit. While based on toxicity prediction, entinostat may be a potential candidate for preclinical and clinical testing in PD. Further studies are warranted to confirm the activity and efficacy of these ligands for PD.

Research Progress of Mitophagy in Alzheimer's Disease

The prevalence of Alzheimer's disease (AD) is increasing as the elderly population, which hurts elderly people's cognition and capacity for self-care. The process of mitophagy involves the selective clearance of ageing and impaired mitochondria, which is required to preserve intracellular homeostasis and energy metabolism. Currently, it has been discovered that mitophagy abnormalities are intimately linked to the beginning and progression of AD. This article discusses the mechanism of mitophagy, abnormal mitophagy, and therapeutic effects in AD. The purpose is to offer fresh perspectives on the causes and remedies of AD.

Cancer drugs with high repositioning potential for Alzheimer's disease

INTRODUCTION

Despite the recent full FDA approval of lecanemab, there is currently no disease modifying therapy (DMT) that can efficiently slow down the progression of Alzheimer's disease (AD) in the general population. This statement emphasizes the need to identify novel DMTs in the shortest time possible to prevent a global epidemic of AD cases as the world population experiences an increase in lifespan.

AREAS COVERED

Here, we review several classes of anti-cancer drugs that have been or are being investigated in Phase II/III clinical trials for AD, including immunomodulatory drugs, RXR agonists, sex hormone therapies, tyrosine kinase inhibitors, and monoclonal antibodies.

EXPERT OPINION

Given the overall course of brain pathologies during the progression of AD, we express a great enthusiasm for the repositioning of anti-cancer drugs as possible AD DMTs. We anticipate an increasing number of combinatorial therapy strategies to tackle AD symptoms and their underlying pathologies. However, we strongly encourage improvements in clinical trial study designs to better assess target engagement and possible efficacy over sufficient periods of drug exposure.

Recent advancement in therapeutic strategies for Alzheimer's disease: Insights from clinical trials

Alzheimer's disease (AD) is the most prevalent form of dementia, characterized by the presence of plaques of amyloid beta and Tau proteins. There is currently no permanent cure for AD; the only medications approved by the FDA for mild to moderate AD are cholinesterase inhibitors, NMDA receptor antagonists, and immunotherapies against core pathophysiology, that provide temporary relief only. Researchers worldwide have made significant attempts to find new targets and develop innovative therapeutic molecules to treat AD. The FDA-approved drugs are palliative and couldn't restore the damaged neuron cells of AD. Stem cells have self-differentiation properties, making them prospective therapeutics to treat AD. The promising results in pre-clinical studies of stem cell therapy for AD seek attention worldwide. Various stem cells, mainly mesenchymal stem cells, are currently in different phases of clinical trials and need more advancements to take this therapy to the translational level. Here, we review research from the past decade that has identified several hypotheses related to AD pathology. Moreover, this article also focuses on the recent advancement in therapeutic strategies for AD treatment including immunotherapy and stem cell therapy detailing the clinical trials that are currently undergoing development.

Cross species systems biology discovers glial DDR2, STOM, and KANK2 as therapeutic targets in progressive supranuclear palsy

Progressive supranuclear palsy (PSP) is a neurodegenerative parkinsonian disorder characterized by cell-type-specific tau lesions in neurons and glia. Prior work uncovered transcriptome changes in human PSP brains, although their cell-specificity is unknown. Further, systematic data integration and experimental validation platforms to prioritize brain transcriptional perturbations as therapeutic targets in PSP are currently lacking. In this study, we combine bulk tissue (n = 408) and single nucleus RNAseq (n = 34) data from PSP and control brains with transcriptome data from a mouse tauopathy and experimental validations in Drosophila tau models for systematic discovery of high-confidence expression changes in PSP with therapeutic potential. We discover, replicate, and annotate thousands of differentially expressed genes in PSP, many of which reside in glia-enriched co-expression modules and cells. We prioritize DDR2, STOM, and KANK2 as promising therapeutic targets in PSP with striking cross-species validations. We share our findings and data via our interactive application tool PSP RNAseq Atlas ( https://rtools.mayo.edu/PSP_RNAseq_Atlas/ ). Our findings reveal robust glial transcriptome changes in PSP, provide a cross-species systems biology approach, and a tool for therapeutic target discoveries in PSP with potential application in other neurodegenerative diseases.

Clinical trials of new drugs for Alzheimer disease: a 2020-2023 update

Alzheimer's disease (AD) is the leading cause of dementia, presenting a significant unmet medical need worldwide. The pathogenesis of AD involves various pathophysiological events, including the accumulation of amyloid and tau, neuro-inflammation, and neuronal injury. Clinical trials focusing on new drugs for AD were documented in 2020, but subsequent developments have emerged since then. Notably, the US-FDA has approved Aducanumab and Lecanemab, both antibodies targeting amyloid, marking the end of a nearly two-decade period without new AD drugs. In this comprehensive report, we review all trials listed in clinicaltrials.gov, elucidating their underlying mechanisms and study designs. Ongoing clinical trials are investigating numerous promising new drugs for AD. The main trends in these trials involve pathophysiology-based, disease-modifying therapies and the recruitment of participants in earlier stages of the disease. These trends underscore the significance of conducting fundamental research on pathophysiology, prevention, and intervention prior to the occurrence of brain damage caused by AD.

Melanin: a unifying theory of disease as exemplified by Parkinson's, Alzheimer's, and Lewy body dementia

Melanin, a ubiquitous dark pigment, plays important roles in the immune system, including scavenging reactive oxygen species formed in response to ultraviolet radiation absorption, absorbing metals, thermal regulation, drug uptake, innate immune system functions, redox, and energy transduction. Many tissue types, including brain, heart, arteries, ovaries, and others, contain melanin. Almost all cells contain precursors to melanin. A growing number of diseases in which there is a loss of melanin and/or neuromelanin are increasingly thought to have infectious etiologies, for example, Alzheimer's disease (AD), Parkinson's disease (PD), Lewy Body Dementia (LBD), and vitiligo. AD, PD, LBD, and vitiligo have been linked with herpesvirus, which enters melanosomes and causes apoptosis, and with gut dysbiosis and inflammation. Herpesvirus is also linked with gut dysbiosis and inflammation. We theorize that under normal healthy states, melanin retains some of the energy it absorbs from electromagnetic radiation, which is then used to fuel cells, and energy from ATP is used to compliment that energy supply. We further theorize that loss of melanin reduces the energy supply of cells, which in the case of AD, PD, and LBD results in an inability to sustain immune system defenses and remove the plaques associated with the disease, which appear to be part of the immune system's attempt to eradicate the pathogens seen in these neurodegenerative diseases. In addition, in an attempt to explain why removing these plaques does not result in improvements in cognition and mood and why cognitions and moods in these individuals have ebbs and flows, we postulate that it is not the plaques that cause the cognitive symptoms but, rather, inflammation in the brain resulting from the immune system's response to pathogens. Our theory that energy retained in melanin fuels cells in an inverse relationship with ATP is supported by studies showing alterations in ATP production in relationship to melanin levels in melanomas, vitiligo, and healthy cells. Therefore, alteration of melanin levels may be at the core of many diseases. We propose regulating melanin levels may offer new avenues for treatment development.

Non-conducting functions of potassium channels in cancer and neurological disease

Cancer and neurodegenerative disease, albeit fundamental differences, share some common pathogenic mechanisms. Accordingly, both conditions are associated with aberrant cell proliferation and migration. Here, we review the causative role played by potassium (K+) channels, a fundamental class of proteins, in cancer and neurodegenerative disease. The concept that emerges from the review of the literature is that K+ channels can promote the development and progression of cancerous and neurodegenerative pathologies by dysregulating cell proliferation and migration. K+ channels appear to control these cellular functions in ways that not necessarily depend on their conducting properties and that involve the ability to directly or indirectly engage growth and survival signaling pathways. As cancer and neurodegenerative disease represent global health concerns, identifying commonalities may help understand the molecular basis for those devastating conditions and may facilitate the design of new drugs or the repurposing of existing drugs.

Treatment of Alzheimer's Disease: Beyond Symptomatic Therapies

In an ever-increasing aged world, Alzheimer's disease (AD) represents the first cause of dementia and one of the first chronic diseases in elderly people. With 55 million people affected, the WHO considers AD to be a disease with public priority. Unfortunately, there are no final cures for this pathology. Treatment strategies are aimed to mitigate symptoms, i.e., acetylcholinesterase inhibitors (AChEI) and the N-Methyl-D-aspartate (NMDA) antagonist Memantine. At present, the best approaches for managing the disease seem to combine pharmacological and non-pharmacological therapies to stimulate cognitive reserve. Over the last twenty years, a number of drugs have been discovered acting on the well-established biological hallmarks of AD, deposition of β-amyloid aggregates and accumulation of hyperphosphorylated tau protein in cells. Although previous efforts disappointed expectations, a new era in treating AD has been working its way recently. The Food and Drug Administration (FDA) gave conditional approval of the first disease-modifying therapy (DMT) for the treatment of AD, aducanumab, a monoclonal antibody (mAb) designed against Aβ plaques and oligomers in 2021, and in January 2023, the FDA granted accelerated approval for a second monoclonal antibody, Lecanemab. This review describes ongoing clinical trials with DMTs and non-pharmacological therapies. We will also present a future scenario based on new biomarkers that can detect AD in preclinical or prodromal stages, identify people at risk of developing AD, and allow an early and curative treatment.

Chloroquine Intervenes Nephrotoxicity of Nilotinib through Deubiquitinase USP13-Mediated Stabilization of Bcl-XL

Nephrotoxicity has become prominent due to the increase in the clinical use of nilotinib, a second-generation BCR-ABL1 inhibitor in the first-line treatment of Philadelphia chromosome-positive chronic myeloid leukemia. To date, the mechanism of nilotinib nephrotoxicity is still unknown, leading to a lack of clinical intervention strategies. Here, it is found that nilotinib could induce glomerular atrophy, renal tubular degeneration, and kidney fibrosis in an animal model. Mechanistically, nilotinib induces intrinsic apoptosis by specifically reducing the level of BCL2 like 1 (Bcl-XL) in both vascular endothelial cells and renal tubular epithelial cells, as well as in vivo. It is confirmed that chloroquine (CQ) intervenes with nilotinib-induced apoptosis and improves mitochondrial integrity, reactive oxygen species accumulation, and DNA damage by reversing the decreased Bcl-XL. The intervention effect is dependent on the alleviation of the nilotinib-induced reduction in ubiquitin specific peptidase 13 (USP13) and does not rely on autophagy inhibition. Additionally, it is found that USP13 abrogates cell apoptosis by preventing excessive ubiquitin-proteasome degradation of Bcl-XL. In conclusion, the research reveals the molecular mechanism of nilotinib's nephrotoxicity, highlighting USP13 as an important regulator of Bcl-XL stability in determining cell fate, and provides CQ analogs as a clinical intervention strategy for nilotinib's nephrotoxicity.

From Answers to Insights: Unveiling the Strengths and Limitations of ChatGPT and Biomedical Knowledge Graphs

Purpose

Large Language Models (LLMs) have shown exceptional performance in various natural language processing tasks, benefiting from their language generation capabilities and ability to acquire knowledge from unstructured text. However, in the biomedical domain, LLMs face limitations that lead to inaccurate and inconsistent answers. Knowledge Graphs (KGs) have emerged as valuable resources for organizing structured information. Biomedical Knowledge Graphs (BKGs) have gained significant attention for managing diverse and large-scale biomedical knowledge. The objective of this study is to assess and compare the capabilities of ChatGPT and existing BKGs in question-answering, biomedical knowledge discovery, and reasoning tasks within the biomedical domain.

Methods

We conducted a series of experiments to assess the performance of ChatGPT and the BKGs in various aspects of querying existing biomedical knowledge, knowledge discovery, and knowledge reasoning. Firstly, we tasked ChatGPT with answering questions sourced from the "Alternative Medicine" sub-category of Yahoo! Answers and recorded the responses. Additionally, we queried BKG to retrieve the relevant knowledge records corresponding to the questions and assessed them manually. In another experiment, we formulated a prediction scenario to assess ChatGPT's ability to suggest potential drug/dietary supplement repurposing candidates. Simultaneously, we utilized BKG to perform link prediction for the same task. The outcomes of ChatGPT and BKG were compared and analyzed. Furthermore, we evaluated ChatGPT and BKG's capabilities in establishing associations between pairs of proposed entities. This evaluation aimed to assess their reasoning abilities and the extent to which they can infer connections within the knowledge domain.

Results

The results indicate that ChatGPT with GPT-4.0 outperforms both GPT-3.5 and BKGs in providing existing information. However, BKGs demonstrate higher reliability in terms of information accuracy. ChatGPT exhibits limitations in performing novel discoveries and reasoning, particularly in establishing structured links between entities compared to BKGs.

Conclusions

To address the limitations observed, future research should focus on integrating LLMs and BKGs to leverage the strengths of both approaches. Such integration would optimize task performance and mitigate potential risks, leading to advancements in knowledge within the biomedical field and contributing to the overall well-being of individuals.

Tau and neuroinflammation in Alzheimer's disease: interplay mechanisms and clinical translation

Alzheimer's Disease (AD) contributes to most cases of dementia. Its prominent neuropathological features are the extracellular neuritic plaques and intercellular neurofibrillary tangles composed of aggregated β-amyloid (Aβ) and hyperphosphorylated tau protein, respectively. In the past few decades, disease-modifying therapy targeting Aβ has been the focus of AD drug development. Even though it is encouraging that two of these drugs have recently received accelerated US Food and Drug Administration approval for AD treatment, their efficacy or long-term safety is controversial. Tau has received increasing attention as a potential therapeutic target, since evidence indicates that tau pathology is more associated with cognitive dysfunction. Moreover, inflammation, especially neuroinflammation, accompanies AD pathological processes and is also linked to cognitive deficits. Accumulating evidence indicates that inflammation has a complex and tight interplay with tau pathology. Here, we review recent evidence on the interaction between tau pathology, focusing on tau post-translational modification and dissemination, and neuroinflammatory responses, including glial cell activation and inflammatory signaling pathways. Then, we summarize the latest clinical trials targeting tau and neuroinflammation. Sustained and increased inflammatory responses in glial cells and neurons are pivotal cellular drivers and regulators of the exacerbation of tau pathology, which further contributes to its worsening by aggravating inflammatory responses. Unraveling the precise mechanisms underlying the relationship between tau pathology and neuroinflammation will provide new insights into the discovery and clinical translation of therapeutic targets for AD and other tau-related diseases (tauopathies). Targeting multiple pathologies and precision therapy strategies will be the crucial direction for developing drugs for AD and other tauopathies.

From Answers to Insights: Unveiling the Strengths and Limitations of ChatGPT and Biomedical Knowledge Graphs

Large Language Models (LLMs) have demonstrated exceptional performance in various natural language processing tasks, utilizing their language generation capabilities and knowledge acquisition potential from unstructured text. However, when applied to the biomedical domain, LLMs encounter limitations, resulting in erroneous and inconsistent answers. Knowledge Graphs (KGs) have emerged as valuable resources for structured information representation and organization. Specifically, Biomedical Knowledge Graphs (BKGs) have attracted significant interest in managing large-scale and heterogeneous biomedical knowledge. This study evaluates the capabilities of ChatGPT and existing BKGs in question answering, knowledge discovery, and reasoning. Results indicate that while ChatGPT with GPT-4.0 surpasses both GPT-3.5 and BKGs in providing existing information, BKGs demonstrate superior information reliability. Additionally, ChatGPT exhibits limitations in performing novel discoveries and reasoning, particularly in establishing structured links between entities compared to BKGs. To overcome these limitations, future research should focus on integrating LLMs and BKGs to leverage their respective strengths. Such an integrated approach would optimize task performance and mitigate potential risks, thereby advancing knowledge in the biomedical field and contributing to overall well-being.

c-Abl tyrosine kinase down-regulation as target for memory improvement in Alzheimer's disease

Background

Growing evidence suggests that the non-receptor tyrosine kinase, c-Abl, plays a significant role in the pathogenesis of Alzheimer's disease (AD). Here, we analyzed the effect of c-Abl on the cognitive performance decline of APPSwe/PSEN1ΔE9 (APP/PS1) mouse model for AD.

Methods

We used the conditional genetic ablation of c-Abl in the brain (c-Abl-KO) and pharmacological treatment with neurotinib, a novel allosteric c-Abl inhibitor with high brain penetrance, imbued in rodent's chow.

Results

We found that APP/PS1/c-Abl-KO mice and APP/PS1 neurotinib-fed mice had improved performance in hippocampus-dependent tasks. In the object location and Barnes-maze tests, they recognized the displaced object and learned the location of the escape hole faster than APP/PS1 mice. Also, APP/PS1 neurotinib-fed mice required fewer trials to reach the learning criterion in the memory flexibility test. Accordingly, c-Abl absence and inhibition caused fewer amyloid plaques, reduced astrogliosis, and preserved neurons in the hippocampus.

Discussion

Our results further validate c-Abl as a target for AD, and the neurotinib, a novel c-Abl inhibitor, as a suitable preclinical candidate for AD therapies.

Protein aggregation: Consequences, mechanism, characterization and inhibitory strategies

Proteins play a major role in the regulation of various cellular functions including the synthesis of structural components. But proteins are stable under physiological conditions only. A slight variation in environmental conditions can cost them huge in terms of conformational stability ultimately leading to aggregation. Under normal conditions, aggregated proteins are degraded or removed from the cell by a quality control system including ubiquitin-proteasomal machinery and autophagy. But they are burdened under diseased conditions or are impaired by the aggregated proteins leading to the generation of toxicity. The misfolding and aggregation of protein such as amyloid-β, α-synuclein, human lysozyme etc., are responsible for certain diseases including Alzheimer, Parkinson, and non- neuropathic systemic amyloidosis respectively. Extensive research has been done to find the therapeutics for such diseases but till now we have got only symptomatic treatment that will reduce the disease severity but will not target the initial formation of nucleus responsible for disease progression and propagation. Hence there is an urgent need to develop the drugs targeting the cause of the disease. For this, a wide knowledge related to misfolding and aggregation under the same heading is required as described in this review alongwith the strategies hypothesized and implemented till now. This will contribute a lot to the work of researchers in the field of neuroscience.

Does modulation of tau hyperphosphorylation represent a reasonable therapeutic strategy for Alzheimer's disease? From preclinical studies to the clinical trials

Protein kinases (PKs) have emerged as one of the most intensively investigated drug targets in current pharmacological research, with indications ranging from oncology to neurodegeneration. Tau protein hyperphosphorylation was the first pathological post-translational modification of tau protein described in Alzheimer's disease (AD), highlighting the role of PKs in neurodegeneration. The therapeutic potential of protein kinase inhibitors (PKIs)) and protein phosphatase 2 A (PP2A) activators in AD has recently been explored in several preclinical and clinical studies with variable outcomes. Where a number of preclinical studies demonstrate a visible reduction in the levels of phospho-tau in transgenic tauopathy models, no reduction in neurofibrillary lesions is observed. Amongst the few PKIs and PP2A activators that progressed to clinical trials, most failed on the efficacy front, with only a few still unconfirmed and potential positive trends. This suggests that robust preclinical and clinical data is needed to unequivocally evaluate their efficacy. To this end, we take a systematic look at the results of preclinical and clinical studies of PKIs and PP2A activators, and the evidence they provide regarding the utility of this approach to evaluate the potential of targeting tau hyperphosphorylation as a disease modifying therapy.

Functional variants identify sex-specific genes and pathways in Alzheimer's Disease

The incidence of Alzheimer's Disease in females is almost double that of males. To search for sex-specific gene associations, we build a machine learning approach focused on functionally impactful coding variants. This method can detect differences between sequenced cases and controls in small cohorts. In the Alzheimer's Disease Sequencing Project with mixed sexes, this approach identified genes enriched for immune response pathways. After sex-separation, genes become specifically enriched for stress-response pathways in male and cell-cycle pathways in female. These genes improve disease risk prediction in silico and modulate Drosophila neurodegeneration in vivo. Thus, a general approach for machine learning on functionally impactful variants can uncover sex-specific candidates towards diagnostic biomarkers and therapeutic targets.

Regulation of beta-amyloid for the treatment of Alzheimer's disease: Research progress of therapeutic strategies and bioactive compounds

Alzheimer's disease (AD) is a progressive neurodegenerative disease that is difficult to treat. Extracellular amyloid is the principal pathological criterion for the diagnosis of AD. Amyloid β (Aβ) interacts with various receptor molecules on the plasma membrane and mediates a series of signaling pathways that play a vital role in the occurrence and development of AD. Research on receptors that interact with Aβ is currently ongoing. Overall, there are no effective medications to treat AD. In this review, we first discuss the importance of Aβ in the pathogenesis of AD, then summarize the latest progress of Aβ-related targets and compounds. Finally, we put forward the challenges and opportunities in the development of effective AD therapies.

Tau, tau kinases, and tauopathies: An updated overview

Tau is a macrotubule-associated protein primarily involved in the stabilization of the cytoskeleton. Under normal conditions, phosphorylation reduces the affinity of tau for tubulin, allowing the protein to detach from microtubules and ensuring the system dynamics in neuronal cells. However, hyperphosphorylated tau aggregates into paired helical filaments, the main constituents of neurofibrillary tangles found in the brains of patients with Alzheimer's disease and other tauopathies. In this review, we provide an overview of the structure of tau and the pathophysiological roles of tau phosphorylation. We also evaluate the major protein kinases involved and discuss the progress made in the development of drug therapies aimed at inhibiting tau kinases.

Therapeutic Monitoring of Orally Administered, Small-Molecule Anticancer Medications with Tumor-Specific Cellular Protein Targets in Peripheral Fluid Spaces-A Review

Orally administered, small-molecule anticancer drugs with tumor-specific cellular protein targets (OACD) have revolutionized oncological pharmacotherapy. Nevertheless, the differences in exposure to these drugs in the systemic circulation and extravascular fluid compartments have led to several cases of therapeutic failure, in addition to posing unknown risks of toxicity. The therapeutic drug monitoring (TDM) of OACDs in therapeutically relevant peripheral fluid compartments is therefore essential. In this work, the available knowledge regarding exposure to OACD concentrations in these fluid spaces is summarized. A review of the literature was conducted by searching Embase, PubMed, and Web of Science for clinical research articles and case reports published between 10 May 2001 and 31 August 2022. Results show that, to date, penetration into cerebrospinal fluid has been studied especially intensively, in addition to breast milk, leukocytes, peripheral blood mononuclear cells, peritoneal fluid, pleural fluid, saliva and semen. The typical clinical indications of peripheral fluid TDM of OACDs were (1) primary malignancy, (2) secondary malignancy, (3) mental disorder, and (4) the assessment of toxicity. Liquid chromatography-tandem mass spectrometry was most commonly applied for analysis. The TDM of OACDs in therapeutically relevant peripheral fluid spaces is often indispensable for efficient and safe treatments.

Maiden voyage: induced pluripotent stem cell-based drug screening for amyotrophic lateral sclerosis

Using patient-derived induced pluripotent stem cells, neurodegenerative disease phenotypes have been recapitulated and their pathogenesis analysed leading to significant progress in drug screening. In amyotrophic lateral sclerosis, high-throughput screening using induced pluripotent stem cells-derived motor neurons has identified candidate drugs. Owing to induced pluripotent stem cell-based drug evaluation/screening, three compounds, retigabine, ropinirole and bosutinib, have progressed to clinical trials. Retigabine blocks hyperexcitability and improves survival in amyotrophic lateral sclerosis patient-derived motor neurons. In a randomized clinical trial (n = 65), treatment with retigabine reduced neuronal excitability after 8 weeks. Ropinirole, identified in a high-throughput screening, attenuates pathological phenotypes in patient-derived motor neurons. In a trial limited by a small sample size (n = 20), ropinirole was tolerable and had clinical benefits on function and survival. A phase 1 study of bosutinib has reported safety and tolerability for 12 weeks. Thus, these clinical trials show safety and positive effects and confirm the reliability of stem cell-based drug discovery. This novel strategy leads to reduced costs and time when compared to animal testing and opens new avenues for therapy in intractable diseases.

c-Abl kinase at the crossroads of healthy synaptic remodeling and synaptic dysfunction in neurodegenerative diseases

Our ability to learn and remember depends on the active formation, remodeling, and elimination of synapses. Thus, the development and growth of synapses as well as their weakening and elimination are essential for neuronal rewiring. The structural reorganization of synaptic complexes, changes in actin cytoskeleton and organelle dynamics, as well as modulation of gene expression, determine synaptic plasticity. It has been proposed that dysregulation of these key synaptic homeostatic processes underlies the synaptic dysfunction observed in many neurodegenerative diseases. Much is known about downstream signaling of activated N-methyl-D-aspartate and α-amino-3-hydroxy-5-methyl-4-isoazolepropionate receptors; however, other signaling pathways can also contribute to synaptic plasticity and long-lasting changes in learning and memory. The non-receptor tyrosine kinase c-Abl (ABL1) is a key signal transducer of intra and extracellular signals, and it shuttles between the cytoplasm and the nucleus. This review focuses on c-Abl and its synaptic and neuronal functions. Here, we discuss the evidence showing that the activation of c-Abl can be detrimental to neurons, promoting the development of neurodegenerative diseases. Nevertheless, c-Abl activity seems to be in a pivotal balance between healthy synaptic plasticity, regulating dendritic spines remodeling and gene expression after cognitive training, and synaptic dysfunction and loss in neurodegenerative diseases. Thus, c-Abl genetic ablation not only improves learning and memory and modulates the brain genetic program of trained mice, but its absence provides dendritic spines resiliency against damage. Therefore, the present review has been designed to elucidate the common links between c-Abl regulation of structural changes that involve the actin cytoskeleton and organelles dynamics, and the transcriptional program activated during synaptic plasticity. By summarizing the recent discoveries on c-Abl functions, we aim to provide an overview of how its inhibition could be a potentially fruitful treatment to improve degenerative outcomes and delay memory loss.

Alteration of Autophagy and Glial Activity in Nilotinib-Treated Huntington's Disease Patients

Nilotinib is a tyrosine kinase inhibitor that is safe and tolerated in neurodegeneration, it achieves CSF concentration that is adequate to inhibit discoidin domain receptor (DDR)-1. Nilotinib significantly affects dopamine metabolites, including Homovanillic acid (HVA), resulting in an increase in brain dopamine. HD is a hereditary disease caused by mutations in the Huntingtin's (HTT) gene and characterized by neurodegeneration and motor and behavioral symptoms that are associated with activation of dopamine receptors. We explored the effects of a low dose of nilotinib (150 mg) on behavioral changes and motor symptoms in manifest HD patients and examined the effects of nilotinib on several brain mechanisms, including dopamine transmission and gene expression via cerebrospinal fluid (CSF) miRNA sequencing. Nilotinib, 150 mg, did not result in any behavioral changes, although it significantly attenuated HVA levels, suggesting reduction of dopamine catabolism. There was no significant change in HTT, phosphorylated neuro-filament and inflammatory markers in the CSF and plasma via immunoassays. Whole miRNA genome sequencing of the CSF revealed significant longitudinal changes in miRNAs that control specific genes associated with autophagy, inflammation, microglial activity and basal ganglia neurotransmitters, including dopamine and serotonin.

RENEWAL: REpurposing study to find NEW compounds with Activity for Lewy body dementia-an international Delphi consensus

Drug repositioning and repurposing has proved useful in identifying new treatments for many diseases, which can then rapidly be brought into clinical practice. Currently, there are few effective pharmacological treatments for Lewy body dementia (which includes both dementia with Lewy bodies and Parkinson's disease dementia) apart from cholinesterase inhibitors. We reviewed several promising compounds that might potentially be disease-modifying agents for Lewy body dementia and then undertook an International Delphi consensus study to prioritise compounds. We identified ambroxol as the top ranked agent for repurposing and identified a further six agents from the classes of tyrosine kinase inhibitors, GLP-1 receptor agonists, and angiotensin receptor blockers that were rated by the majority of our expert panel as justifying a clinical trial. It would now be timely to take forward all these compounds to Phase II or III clinical trials in Lewy body dementia.

Science disconnected: the translational gap between basic science, clinical trials, and patient care in Alzheimer's disease

Both research and clinical practice have traditionally centred on the dementia syndrome of Alzheimer's disease rather than its preclinical and prodromal stages. However, there is a strong scientific and ethical impetus to shift focus to earlier disease stages to improve brain health outcomes and help to keep affected individuals symptom-free (dementia-free) for as long as possible. We provide an overview of recent advancements in early detection, drug development, and trial methodology that should be utilised in the development of new therapies for use in brain health clinics. We propose a triad approach to Alzheimer's disease clinical trials, encompassing (1) experimental medicine studies to gather greater knowledge of disease mechanisms, (2) a more comprehensive platform of phase 2 learning trials to inform phase 3 confirmatory trials, and (3) precision medicine involving smaller subgroups of patients with shared characteristics. This triad would ensure that treatment targets are identified accurately, trial methodology focuses on at-risk populations, and sensitive outcome measures capture potential treatment effects. Clinical services around the world must embrace the brain health clinic model so that neurodegenerative diseases can be detected in their earliest phase to quicken drug development pipelines and potentially improve prognosis.

Effectiveness and safety of anti-tau drugs for Alzheimer's disease: Systematic review and meta-analysis

OBJECTIVE

To assess the cognitive effectiveness and safety of tau-targeting drugs for Alzheimer's disease (AD) METHODS: The MEDLINE, Embase, Cochrane Library, PsycINFO, ClinicalTrials.gov, and WHO International Clinical Trials Registry Platform databases were searched from inception to 22 November 2021. A systematic review and meta-analysis of randomized controlled trials were performed RESULTS: Thirty-four randomized controlled trials comprising 5549 participants, of which fifteen (51.7%) had a low risk of bias, were included. The meta-analysis showed no differences in the cognitive subscale of the AD: Assessment Scale (ADAS-Cog) between anti-tau drugs and placebo (mean difference [MD]: -0.77, 95% CI: -1.64 to 0.10; minimal important difference 3.1-3.8 points, moderate certainty evidence). For ADAS-Cog, the results subgroup analysis suggested a statistical effect of tau posttranslational modifications on drug inhibition (MD: -0.80, 95% CI: -1.43 to -0.17), which was not seen with tau aggregation inhibitors or immunotherapy (interaction p = 0.24). A total of 11.0%, 5.2%, and 4.8% of drugs inhibiting tau aggregation, immunotherapy, and drugs targeting posttranslational modifications, respectively, had a reduced risk of dropouts due to adverse events (AEs).

DISCUSSION

Current evidence suggests that anti-tau drugs are unlikely to have an important impact on slowing cognitive impairment. Although the subgroup analysis suggested that inhibition of tau posttranslational modifications is statistically effective and generally safer because of reduced dropouts due to AEs, the analysis has limited credibility. Additional large-scale and well-designed randomized and placebo-controlled trials will be necessary to explore the benefit of a certain type of anti-tau drug for AD.

Identification of risk genes for Alzheimer's disease by gene embedding

Most disease-gene association methods do not account for gene-gene interactions, even though these play a crucial role in complex, polygenic diseases like Alzheimer's disease (AD). To discover new genes whose interactions may contribute to pathology, we introduce GeneEMBED. This approach compares the functional perturbations induced in gene interaction network neighborhoods by coding variants from disease versus healthy subjects. In two independent AD cohorts of 5,169 exomes and 969 genomes, GeneEMBED identified novel candidates. These genes were differentially expressed in post mortem AD brains and modulated neurological phenotypes in mice. Four that were differentially overexpressed and modified neurodegeneration in vivo are PLEC, UTRN, TP53, and POLD1. Notably, TP53 and POLD1 are involved in DNA break repair and inhibited by approved drugs. While these data show proof of concept in AD, GeneEMBED is a general approach that should be broadly applicable to identify genes relevant to risk mechanisms and therapy of other complex diseases.

Nilotinib modulates LPS-induced cognitive impairment and neuroinflammatory responses by regulating P38/STAT3 signaling

BACKGROUND

In chronic myelogenous leukemia, reciprocal translocation between chromosome 9 and chromosome 22 generates a chimeric protein, Bcr-Abl, that leads to hyperactivity of tyrosine kinase-linked signaling transduction. The therapeutic agent nilotinib inhibits Bcr-Abl/DDR1 and can cross the blood-brain barrier, but its potential impact on neuroinflammatory responses and cognitive function has not been studied in detail.

METHODS

The effects of nilotinib in vitro and in vivo were assessed by a combination of RT-PCR, real-time PCR, western blotting, ELISA, immunostaining, and/or subcellular fractionation. In the in vitro experiments, the effects of 200 ng/mL LPS or PBS on BV2 microglial cells, primary microglia or primary astrocytes pre- or post-treated with 5 µM nilotinib or vehicle were evaluated. The in vivo experiments involved wild-type mice administered a 7-day course of daily injections with 20 mg/kg nilotinib (i.p.) or vehicle before injection with 10 mg/kg LPS (i.p.) or PBS.

RESULTS

In BV2 microglial cells, pre- and post-treatment with nilotinib altered LPS-induced proinflammatory/anti-inflammatory cytokine mRNA levels by suppressing AKT/P38/SOD2 signaling. Nilotinib treatment also significantly downregulated LPS-stimulated proinflammatory cytokine levels in primary microglia and primary astrocytes by altering P38/STAT3 signaling. Experiments in wild-type mice showed that nilotinib administration affected LPS-mediated microglial/astroglial activation in a brain region-specific manner in vivo. In addition, nilotinib significantly reduced proinflammatory cytokine IL-1β, IL-6 and COX-2 levels and P38/STAT3 signaling in the brain in LPS-treated wild-type mice. Importantly, nilotinib treatment rescued LPS-mediated spatial working memory impairment and cortical dendritic spine number in wild-type mice.

CONCLUSIONS

Our results indicate that nilotinib can modulate neuroinflammatory responses and cognitive function in LPS-stimulated wild-type mice.

Foresee novel targets for Alzheimer's disease by investigating repurposed drugs

BACKGROUND

Alzheimer's Disease (AD) is the most rampant neurodegenerative disorder which has caused havoc worldwide. More than a century has passed since the first case of AD was reported, but still no stable treatment is known to mankind. The available medications only provide temporary relief and are not a cure for the disease. The hunt for advanced techniques in drug development has paved the way for drug repurposing, i.e., repositioning or reutilizing drugs as an innovative approach.

METHODOLOGY

Several drugs which were repurposed for AD were collected by following PRISMA 2020 systemic review. Databases like PubMed, ScienceDirect, JSTOR, and SciELO were used for data extraction. Further, Drugbank database was used to download all the identified drugs. Later, the Swiss Target Prediction tool was used to identify protein receptors for these drugs and the biological pathway followed by them.

RESULTS

Drugs like Zileuton, Salbutamol, Baricitinib, Carmustine, Paclitaxel, and Nilotinib were observed to be involved in regulation of neurotransmitters. Similarly, Metformin, Liraglutide, UDCA, and Bexarotene are involved in protein kinase cascades which also is one of the prime processes in metabolic disorders like AD. Furthermore, drugs like Rosiglitazone, Pioglitazone, and Lonafarnib are involved in interleukin-3 biosynthetic processes, which is again one of the most important processes studied in AD treatment.

CONCLUSION

The study concluded that the reviewed drugs that follow similar biological and molecular processes can be repurposed for AD if chosen judiciously with current medications and thus drug repurposing is a promising approach that can be utilized to find a cure for AD within a brief time and fewer resources compared to de novo drug synthesis. Although certain loopholes still need to be worked upon, the technique has great prospects. Furthermore, in silico methods can be utilized to justify the findings and identify the best drug candidate.

Current Therapies and Drug Development Pipeline in Lewy Body Dementia: An Update

The term Lewy body dementia refers to either of two related diagnoses: dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD). Clinical management of Lewy body dementia is challenging. The current treatment options focus on relieving symptoms; no disease-modifying therapies are available. There are currently no US Food and Drug Administration (FDA) approved drugs for the treatment of DLB, and there are only a few for PDD. Cholinesterase inhibitors are shown to be beneficial in improving cognitive symptoms in Lewy body dementia. Rivastigmine was approved by the FDA to treat PDD. Donepezil was approved in Japan as a treatment for DLB. Levodopa may provide modest benefit in treating motor symptoms and zonisamide in adjunct to low-dose levodopa helps with parkinsonism. Treatment of autonomic symptoms are based on symptomatic treatment with off-label agents. Our main objective in this article is to present an overview of the current pharmacological options available to treat the clinical features of DLB and PDD. When evaluating the existing management options for Lewy body dementia, it is difficult to fully separate PDD from DLB. However, we have attempted to identify whether the cited studies include patients with PDD and/or DLB. Moreover, we have provided an overview of the current drug pipeline in Lewy body dementia. All currently active trials are in phase I or II and most are focused on disease modification rather than symptomatic treatment. Phase II trial results for neflamapimod show promising results. Due to heterogeneity of symptoms and underlying pathophysiology, there is a need for new biomarker strategies and improved definitions of outcome measures for Lewy body dementia drug trials.

Can We Treat Neurodegenerative Proteinopathies by Enhancing Protein Degradation?

Neurodegenerative proteinopathies are defined as a class of neurodegenerative disorders, with either genetic or sporadic age-related onset, characterized by the pathological accumulation of aggregated protein deposits. These mainly include Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD) as well as frontotemporal lobar degeneration (FTLD). The deposition of abnormal protein aggregates in the brain of patients affected by these disorders is thought to play a causative role in neuronal loss and disease progression. On that account, the idea of improving the clearance of pathological protein aggregates has taken hold as a potential therapeutic strategy. Among the possible approaches to pursue for reducing disease protein accumulation, there is the stimulation of the main protein degradation machineries of eukaryotic cells: the ubiquitin proteasomal system (UPS) and autophagy lysosomal pathway (ALP). Of note, several clinical trials testing the efficacy of either UPS- or ALP-active compounds are currently ongoing. Here, we discuss the main gaps and controversies emerging from experimental studies and clinical trials assessing the therapeutic efficacy of modulators of either the UPS or ALP in neurodegenerative proteinopathies, to gather whether they may constitute a real gateway from these disorders. © 2022 International Parkinson and Movement Disorder Society.

Therapeutic strategies for tauopathies and drug repurposing as a potential approach

Tauopathies are neurodegenerative diseases characterized by the deposition of abnormal tau in the brain. To date, there are no disease-modifying therapies approved by the U.S. Food and Drug Administration (US FDA) for the treatment of tauopathies. In the past decades, extensive efforts have been provided to develop disease-modifying therapies to treat tauopathies. Specifically, exploring existing drugs with the intent of repurposing for the treatment of tauopathies affords a reasonable alternative to discover potent drugs for treating these formidable diseases. Drug repurposing will not only reduce formulation and development stage effort and cost but will also take a key advantage of the established toxicological studies, which is one of the main causes of clinical trial failure of new molecules. In this review, we provide an overview of the current treatment strategies for tauopathies and the recent progress in drug repurposing as an alternative approach to treat tauopathies.

c-Abl Activation Linked to Autophagy-Lysosomal Dysfunction Contributes to Neurological Impairment in Niemann-Pick Type A Disease

Niemann-Pick type A (NPA) disease is a fatal lysosomal neurodegenerative disorder caused by the deficiency in acid sphingomyelinase (ASM) activity. NPA patients present severe and progressive neurodegeneration starting at an early age. Currently, there is no effective treatment for this disease and NPA patients die between 2 and 3 years of age. NPA is characterized by an accumulation of sphingomyelin in lysosomes and dysfunction in the autophagy-lysosomal pathway. Recent studies show that c-Abl tyrosine kinase activity downregulates autophagy and the lysosomal pathway. Interestingly, this kinase is also activated in other lysosomal neurodegenerative disorders. Here, we describe that c-Abl activation contributes to the mechanisms of neuronal damage and death in NPA disease. Our data demonstrate that: 1) c-Abl is activated in-vitro as well as in-vivo NPA models; 2) imatinib, a clinical c-Abl inhibitor, reduces autophagy-lysosomal pathway alterations, restores autophagy flux, and lowers sphingomyelin accumulation in NPA patient fibroblasts and NPA neuronal models and 3) chronic treatment with nilotinib and neurotinib, two c-Abl inhibitors with differences in blood-brain barrier penetrance and target binding mode, show further benefits. While nilotinib treatment reduces neuronal death in the cerebellum and improves locomotor functions, neurotinib decreases glial activation, neuronal disorganization, and loss in hippocampus and cortex, as well as the cognitive decline of NPA mice. Our results support the participation of c-Abl signaling in NPA neurodegeneration and autophagy-lysosomal alterations, supporting the potential use of c-Abl inhibitors for the clinical treatment of NPA patients.