Therapeutic Target For Neurodegenerative Diseases Research Articles

Neurodegenerative diseases associated with the disruption of proteostasis and their therapeutic strategies using chemical chaperones.

Aberrant proteostasis is thought to be involved in the pathogenesis of neurodegenerative diseases. Some proteostasis abnormalities are ameliorated by chaperones. Chaperones are divided into three groups: molecular, pharmacological, and chemical. Chemical chaperones intended to alleviate stress in organelles, such as the endoplasmic reticulum (ER), are now being administered clinically. Of the chemical chaperones, 4-phenylbutyrate (4-PBA) has been used as a research reagent, and its mechanism of action includes chaperone effects and the inhibition of histone deacetylase. Moreover, it also binds to the B-site of SEC24 and regulates COPII-mediated transport from the ER. Although its therapeutic effect may not be strong, elucidating the mechanism of action of 4-PBA may contribute to the identification of novel therapeutic targets for neurodegenerative diseases.

Discovery of a novel DYRK1A inhibitor with neuroprotective activity by virtual screening and in vitro biological evaluation.

Dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) is implicated in accumulation of amyloid β-protein (Aβ) and phosphorylation of Tau proteins, and thus represents an important therapeutic target for neurodegenerative diseases. Though many DYRK1A inhibitors have been discovered, there is still no marketed drug targeting DYRK1A. This is partly due to the lack of effective and safe chemotypes. Therefore, it is still necessary to identify new classes of DYRK1A inhibitors. By performing virtual screening with the workflow mainly composed of pharmacophore modeling and molecular docking as well as the following DYRK1A inhibition assay, we identified compound L9, ((Z)-1-(((5-phenyl-1H-pyrazol-4-yl)methylene)-amino)-1H-tetrazol-5-amine), as a moderately active DYRK1A inhibitor (IC50: 1.67μM). This compound was structurally different from the known DYRK1A inhibitors, showed a unique binding mode to DYRK1A. Furthermore, compound L9 showed neuroprotective activity against okadaic acid (OA)-induced injury in the human neuroblastoma cell line SH-SY5Y by regulating the expression of Aβ and phosphorylation of Tau protein. This compound was neither toxic to the SH-SY5Y cells nor to the human normal liver cell line HL-7702 (IC50: >100μM). In conclusion, we have identified a novel DYRK1A inhibitor with neuroprotective activity through virtual screening and in vitro biological evaluation, which holds the promise for further study.

Roles of microglial calcium channels in neurodegenerative diseases

Microglia are crucial for neurodevelopment, and the maintenance of central nervous system functions. Calcium signals in microglia regulate the neuronal plasticity critical for learning, memory, and neuron survival. Growing evidence highlights the pivotal function of calcium channels in microglia, along with their cognate proteins, in modulating oxidative stress, neuroinflammation, and multiple neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. In this review, we summarized the important role and regulatory mechanism of these critical calcium channels and their associated proteins, highlighting their potential as novel therapeutic targets for neurodegenerative diseases.

Gangliosides as Therapeutic Targets for Neurodegenerative Diseases.

Gangliosides, sialic acid-containing glycosphingolipids, are abundant in cell membranes and primarily involved in controlling cell signaling and cell communication. The altered ganglioside pattern has been demonstrated in several neurodegenerative diseases, characterized during early-onset or infancy, emphasizing the significance of gangliosides in the brain. Enzymes required for the biosynthesis of gangliosides are linked to several devastating neurological disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS), hereditary spastic paraplegia (HSP). In this review, we summarized not only the critical roles of biosynthetic enzymes and their inhibitors in ganglioside metabolism but also the efficacy of treatment strategies of ganglioside to address their significance in those diseases.

Novel insights into RAGE signaling pathways during the progression of amyotrophic lateral sclerosis in RAGE-deficient SOD1 G93A mice.

Amyotrophic lateral sclerosis (ALS) is neurodegenerative disease characterized by a progressive loss of motor neurons resulting in paralysis and muscle atrophy. One of the most prospective hypothesis on the ALS pathogenesis suggests that excessive inflammation and advanced glycation end-products (AGEs) accumulation play a crucial role in the development of ALS in patients and SOD1 G93A mice. Hence, we may speculate that RAGE, receptor for advanced glycation end-products and its proinflammatory ligands such as: HMGB1, S100B and CML contribute to ALS pathogenesis. The aim of our studies was to decipher the role of RAGE as well as provide insight into RAGE signaling pathways during the progression of ALS in SOD1 G93A and RAGE-deficient SOD1 G93A mice. In our study, we observed alternations in molecular pattern of proinflammatory RAGE ligands during progression of disease in RAGE KO SOD1 G93A mice compared to SOD1 G93A mice. Moreover, we observed that the amount of beta actin (ACTB) as well as Glial fibrillary acidic protein (GFAP) was elevated in SOD1 G93A mice when compared to mice with deletion of RAGE. These data contributes to our understanding of implications of RAGE and its ligands in pathogenesis of ALS and highlight potential targeted therapeutic interventions at the early stage of this devastating disease. Moreover, inhibition of the molecular cross-talk between RAGE and its proinflammatory ligands may abolish neuroinflammation, gliosis and motor neuron damage in SOD1 G93A mice. Hence, we hypothesize that attenuated interaction of RAGE with its proinflammatory ligands may improve well-being and health status during ALS in SOD1 G93A mice. Therefore, we emphasize that the inhibition of RAGE signaling pathway may be a therapeutic target for neurodegenerative diseases.

OmicSynth: An open multi-omic community resource for identifying druggable targets across neurodegenerative diseases

Treatments for neurodegenerative disorders remain rare, but recent FDA approvals, such as lecanemab and aducanumab for Alzheimer disease (MIM: 607822), highlight the importance of the underlying biological mechanisms in driving discovery and creating disease modifying therapies. The global population is aging, driving an urgent need for therapeutics that stop disease progression and eliminate symptoms. In this study, we create an open framework and resource for evidence-based identification of therapeutic targets for neurodegenerative disease. We use summary-data-based Mendelian randomization to identify genetic targets for drug discovery and repurposing. In parallel, we provide mechanistic insights into disease processes and potential network-level consequences of gene-based therapeutics. We identify 116 Alzheimer disease, 3 amyotrophic lateral sclerosis (MIM: 105400), 5 Lewy body dementia (MIM: 127750), 46 Parkinson disease (MIM: 605909), and 9 progressive supranuclear palsy (MIM: 601104) target genes passing multiple test corrections (pSMR_multi<2.95×10-6 and pHEIDI>0.01). We created a therapeutic scheme to classify our identified target genes into strata based on druggability and approved therapeutics, classifying 41 novel targets, 3 known targets, and 115 difficult targets (of these, 69.8% are expressed in the disease-relevant cell type from single-nucleus experiments). Our novel class of genes provides a springboard for new opportunities in drug discovery, development, and repurposing in the pre-competitive space. In addition, looking at drug-gene interaction networks, we identify previous trials that may require further follow-up such as riluzole in Alzheimer disease. We also provide a user-friendly web platform to help users explore potential therapeutic targets for neurodegenerative diseases, decreasing activation energy for the community.

SIRT2 as a potential new therapeutic target for Alzheimer's disease.

Alzheimer's disease is the most common cause of dementia globally with an increasing incidence over the years, bringing a heavy burden to individuals and society due to the lack of an effective treatment. In this context, sirtuin 2, the sirtuin with the highest expression in the brain, has emerged as a potential therapeutic target for neurodegenerative diseases. This review summarizes and discusses the complex roles of sirtuin 2 in different molecular mechanisms involved in Alzheimer's disease such as amyloid and tau pathology, microtubule stability, neuroinflammation, myelin formation, autophagy, and oxidative stress. The role of sirtuin 2 in all these processes highlights its potential implication in the etiology and development of Alzheimer's disease. However, its presence in different cell types and its enormous variety of substrates leads to apparently contradictory conclusions when it comes to understanding its specific functions. Further studies in sirtuin 2 research with selective sirtuin 2 modulators targeting specific sirtuin 2 substrates are necessary to clarify its specific functions under different conditions and to validate it as a novel pharmacological target. This will contribute to the development of new treatment strategies, not only for Alzheimer's disease but also for other neurodegenerative diseases.

NADPH oxidase 4 (NOX4) as a biomarker and therapeutic target in neurodegenerative diseases.

Diseases like Alzheimer's and Parkinson's diseases are defined by inflammation and the damage neurons undergo due to oxidative stress. A primary reactive oxygen species contributor in the central nervous system, NADPH oxidase 4, is viewed as a potential therapeutic touchstone and indicative marker for these ailments. This in-depth review brings to light distinct features of NADPH oxidase 4, responsible for generating superoxide and hydrogen peroxide, emphasizing its pivotal role in activating glial cells, inciting inflammation, and disturbing neuronal functions. Significantly, malfunctioning astrocytes, forming the majority in the central nervous system, play a part in advancing neurodegenerative diseases, due to their reactive oxygen species and inflammatory factor secretion. Our study reveals that aiming at NADPH oxidase 4 within astrocytes could be a viable treatment pathway to reduce oxidative damage and halt neurodegenerative processes. Adjusting NADPH oxidase 4 activity might influence the neuroinflammatory cytokine levels, including myeloperoxidase and osteopontin, offering better prospects for conditions like Alzheimer's disease and Parkinson's disease. This review sheds light on the role of NADPH oxidase 4 in neural degeneration, emphasizing its drug target potential, and paving the path for novel treatment approaches to combat these severe conditions.

Thermal proteome profiling unveils protein targets of deoxycholic acid in living neuronal cells

Bile acids, synthesized in the liver and modified by the gut microbiota, play vital roles in various physiological processes. The dysregulation of bile acids has been extensively documented in patients with neurodegenerative diseases. However, limited attention has been given to the protein targets associated with microbiota-derived bile acids in neurological diseases. To address this knowledge gap, we conducted comprehensive thermal proteomic analyses to elucidate and comprehend the protein targets affected by microbiota-derived bile acids. Our investigation identified sixty-five unique proteins in SH-SY5Y neuronal cells as potential targets of deoxycholic acid (DCA), a primary component of the bile acid pool originating from the gut microbiota. Notably, Nicastrin and Casein kinase 1 epsilon stood out among these proteins. We found that DCA, through its interaction with the Nicastrin subunit of γ-secretase, significantly contributed to the formation of amyloid beta, a key hallmark in the pathology of neurodegenerative diseases. In summary, our findings provide crucial insights into the intricate interplay between microbiota-derived bile acids and the pathogenesis of neurodegenerative diseases, thereby shedding light on potential therapeutic targets for neurodegenerative diseases.

Targeted ASO-mediated Atp1a2 knockdown in astrocytes reduces SOD1 aggregation and accelerates disease onset in mutant SOD1 mice.

Astrocyte-specific ion pump α2-Na+/K+-ATPase plays a critical role in the pathogenesis of amyotrophic lateral sclerosis (ALS). Here, we test the effect of Atp1a2 mRNA-specific antisense oligonucleotides (ASOs) to induce α2-Na+/K+-ATPase knockdown in the widely used ALS animal model, SOD1*G93A mice. Two ASOs led to efficient Atp1a2 knockdown and significantly reduced SOD1 aggregation in vivo. Although Atp1a2 ASO-treated mice displayed no off-target or systemic toxicity, the ASO-treated mice exhibited an accelerated disease onset and shorter lifespan than control mice. Transcriptomics studies reveal downregulation of genes involved in oxidative response, metabolic pathways, trans-synaptic signaling, and upregulation of genes involved in glutamate receptor signaling and complement activation, suggesting a potential role for these molecular pathways in de-coupling SOD1 aggregation from survival in Atp1a2 ASO-treated mice. Together, these results reveal a role for α2-Na+/K+-ATPase in SOD1 aggregation and highlight the critical effect of temporal modulation of genetically validated therapeutic targets in neurodegenerative diseases.

Chiral nanoparticle-remodeled gut microbiota alleviates neurodegeneration via the gut-brain axis.

Alzheimer's disease (AD) is characterized by amyloid-β accumulation in the brain and hyperphosphorylated tau aggregation, as well as neuroinflammation. The gut-brain axis has emerged as a therapeutic target in neurodegenerative diseases by modulating metabolic activity, neuroimmune functions and sensory neuronal signaling. Here we investigate interactions between orally ingested chiral Au nanoparticles and the gut microbiota in AD mice. Oral administration of chiral Au nanoparticles restored cognitive abilities and ameliorated amyloid-β and hyperphosphorylated tau pathologies in AD mice via alterations in the gut microbiome composition and an increase in the gut metabolite, indole-3-acetic acid, which was lower in serum and cerebrospinal fluid of patients with AD compared with age-matched controls. Oral administration of indole-3-acetic acid was able to penetrate the blood-brain barrier and alleviated cognitive decline and pathology including neuroinflammation in AD mice. These findings provide a promising therapeutic target for the amelioration of neuroinflammation and treatment of neurodegenerative diseases.

Unravelling of molecular biomarkers in synaptic plasticity of Alzheimer's disease: Critical role of the restoration of neuronal circuits.

Learning and memory storage are the fundamental activities of the brain. Aberrant expression of synaptic molecular markers has been linked to memory impairment in AD. Aging is one of the risk factors linked to gradual memory loss. It is estimated that approximately 13 million people worldwide will have AD by 2050. A massive amount of oxidative stress is kept under control by a complex network of antioxidants, which occasionally fails and results in neuronal oxidative stress. Increasing evidence suggests that ROS may affect many pathological aspects of AD, including Aβ accumulation, tau hyperphosphorylation, synaptic plasticity, and mitochondrial dysfunction, which may collectively result in neurodegeneration in the brain. Further investigation into the relationship between oxidative stress and AD may provide an avenue for effective preservation and pharmacological treatment of this neurodegenerative disease. In this review, we briefly summarize the cellular mechanism underlying Aβ induced synaptic dysfunction. Since oxidative stress is common in the elderly and may contribute to the pathogenesis of AD, we also shed light on the role of antioxidant and inflammatory pathways in oxidative stress adaptation, which has a potential therapeutic target in neurodegenerative diseases.

The Neuroprotective Role of TERT Influences the Expression of SOD1 in Motor Neurons and Mouse Brain: Implications for fALS

Amyotrophic lateral sclerosis (ALS) disease is characterized by degeneration of motor neurons and elevation of brain oxidative stress. Previous studies demonstrated the neuroprotective effects of Telomerase reverse transcriptase (TERT) from oxidative stress. We showed that increasing TERT expression in the brain of the Tg hSOD1G93A mouse ALS model attenuated the disease pathology and increased the survival of motor neurons exposed to oxidative stress. How TERT increased the survival of motor neurons exposed to oxidative stress is not yet clear. Here we investigated the consequence of TERT depletion in motor neuron cells under normal and oxidative stress conditions and in mouse brains of TERT knockout mice, on the expression and activity of SOD1 and catalase enzymes. Depletion of mouse TERT caused mitochondrial dysfunction and impaired catalase and SOD1 activity. Compensation with hTERT restored the activity of SOD1. SOD1 expression increased in the brain of TERT KO and in ALS mice and decreased in the brain of WT mice treated with telomerase-increasing compounds. We suggest that the ability of TERT to protect neurons from oxidative stress affects the expression and activity of SOD1, in a TERT-dependent manner, and supports the notion of TERT as a therapeutic target for neurodegenerative diseases like ALS.

Long non-coding RNAs with essential roles in neurodegenerative disorders.

Recently, with the advent of high-resolution and high-throughput sequencing technologies, an increasing number of long non-coding RNAs (lncRNAs) have been found to be involved in the regulation of neuronal function in the central nervous system with specific spatiotemporal patterns, across different neurodegenerative diseases. However, the underlying mechanisms of lncRNAs during neurodegeneration remain poorly understood. This review provides an overview of the current knowledge of the biology of lncRNAs and focuses on introducing the latest identified roles, regulatory mechanisms, and research status of lncRNAs in Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. Finally, this review discusses the potential values of lncRNAs as diagnostic biomarkers and therapeutic targets for neurodegenerative diseases, hoping to provide broader implications for developing effective treatments.

Virtual Screening-Accelerated Discovery of a Phosphodiesterase 9 Inhibitor with Neuroprotective Effects in the Kainate Toxicity In Vitro Model.

In the central nervous system, some specific phosphodiesterase (PDE) isoforms modulate pathways involved in neuronal plasticity. Accumulating evidence suggests that PDE9 may be a promising therapeutic target for neurodegenerative diseases. In the current study, computational techniques were used to identify a nature-inspired PDE9 inhibitor bearing the scaffold of an isoflavone, starting from a database of synthetic small molecules using a ligand-based approach. Furthermore, docking studies supported by molecular dynamics investigations allowed us to evaluate the features of the ligand-target complex. In vitro assays confirmed the computational results, showing that the selected compound inhibits the enzyme in the nanomolar range. Additionally, we evaluated the expression of gene and protein levels of PDE9 in organotypic hippocampal slices, observing an increase following exposure to kainate (KA). Importantly, the PDE9 inhibitor reduced CA3 damage induced by KA in a dose-dependent manner in organotypic hippocampal slices. Taken together, these observations strongly support the potential of the identified nature-inspired PDE9 inhibitor and suggest that such a molecule could represent a promising lead compound to develop novel therapeutic tools against neurological diseases..

Neuroprotective Effects of Zerumbone on H2O2-Induced Oxidative Injury in Human Neuroblastoma SH-SY5Y Cells.

Oxidative stress is recognized as one of the main reasons for cellular damage and neurodegenerative diseases. Zerumbone is one of the sesquiterpenoid compounds in the essential oil of Zingiber zerumbet Smith. Zerumbone exhibits various physiological activities, such as anticancer, antioxidant, and antibacterial effects. However, studies on the neuroprotective efficacy of zerumbone and the mechanism behind it are lacking. In this study, we explored the neuroprotective efficacy of zerumbone and its mechanism in hydrogen peroxide-treated human neuroblastoma SH-SY5Y cells. H2O2 treatment (400 μM) for 24 h enhanced the generation of intracellular reactive oxygen species (ROS) compared to untreated cells. By contrast, zerumbone treatment significantly suppressed the production of intracellular ROS. Zerumbone significantly inhibited H2O2-induced nitric oxide production and expression of inflammation-related genes. Moreover, zerumbone decreased H2O2-induced mitogen-activated protein kinase (MAPK) protein expression. Various hallmarks of apoptosis in H2O2-treated cells were suppressed in a dose-dependent manner through downregulation of the Bax/Bcl-2 expression ratio by zerumbone. Since activation of AMP-activated kinase (AMPK) is a promising therapeutic target for neurodegenerative diseases, we also investigated the mammalian target of rapamycin (mTOR) as part of the autophagy mechanism in H2O2-treated SH-SY5Y cells. In this study, zerumbone upregulated the expression of Sirtuin 1 (SIRT1) and p-AMPK (which were downregulated by the H2O2 treatment) and downregulated p-mTOR. Altogether, our results propose that inhibition of apoptosis and inflammation by autophagy activation plays an important neuroprotective role in H2O2-treated SH-SY5Y cells. Zerumbone may thus be a potent dietary agent that reduces the onset and progression, as well as prevents neurodegenerative diseases.

WNT-β Catenin Signaling as a Potential Therapeutic Target for Neurodegenerative Diseases: Current Status and Future Perspective.

Wnt/β-catenin (WβC) signaling pathway is an important signaling pathway for the maintenance of cellular homeostasis from the embryonic developmental stages to adulthood. The canonical pathway of WβC signaling is essential for neurogenesis, cell proliferation, and neurogenesis, whereas the noncanonical pathway (WNT/Ca2+ and WNT/PCP) is responsible for cell polarity, calcium maintenance, and cell migration. Abnormal regulation of WβC signaling is involved in the pathogenesis of several neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), and spinal muscular atrophy (SMA). Hence, the alteration of WβC signaling is considered a potential therapeutic target for the treatment of neurodegenerative disease. In the present review, we have used the bibliographical information from PubMed, Google Scholar, and Scopus to address the current prospects of WβC signaling role in the abovementioned neurodegenerative diseases.

Pharmacological Inhibition of Ferroptosis as a Therapeutic Target for Neurodegenerative Diseases and Strokes.

Emerging evidence suggests that ferroptosis, a unique regulated cell death modality that is morphologically and mechanistically different from other forms of cell death, plays a vital role in the pathophysiological process of neurodegenerative diseases, and strokes. Accumulating evidence supports ferroptosis as a critical factor of neurodegenerative diseases and strokes, and pharmacological inhibition of ferroptosis as a therapeutic target for these diseases. In this review article, the core mechanisms of ferroptosis are overviewed and the roles of ferroptosis in neurodegenerative diseases and strokes are described. Finally, the emerging findings in treating neurodegenerative diseases and strokes through pharmacological inhibition of ferroptosis are described. This review demonstrates that pharmacological inhibition of ferroptosis by bioactive small-molecule compounds (ferroptosis inhibitors) could be effective for treatments of these diseases, and highlights a potential promising therapeutic avenue that could be used to prevent neurodegenerative diseases and strokes. This review article will shed light on developing novel therapeutic regimens by pharmacological inhibition of ferroptosis to slow down the progression of these diseases in the future.

Rutin modified selenium nanoparticles reduces cell oxidative damage induced by H2O2 by activating Nrf2/HO-1 signaling pathway.

Oxidative damage of neurons is one of the key pathological markers of Alzheimer's disease (AD), which eventually leads to neuronal apoptosis and loss. Nuclear factor E2-related factor 2 (Nrf2) is a key regulator of antioxidant response and is considered to be an important therapeutic target for neurodegenerative diseases. In this study, the selenated derivative of antioxidant rutin (Se-Rutin) was synthesized with sodium selenate (Na2SeO3) as raw material by a simple electrostatic-compound in situ selenium reduction method. The effects of Se-Rutin on H2O2 induced oxidative damage in Pheochromocytoma PC12 cells were evaluated by cell viability, apoptosis, reactive oxygen species level and the expression of antioxidant response element (Nrf2). The results showed that H2O2 treatment significantly increased the level of apoptosis and reactive oxygen species, while the level of Nrf2 and HO-1 decreased. However, Se-Rutin significantly reduced H2O2 induced apoptosis and cytotoxicity, and increased the expression of Nrf2 and HO-1, both of which were better than that of pure rutin. Therefore, the activation of Nrf2/HO-1 signaling pathway may be the basis of Se-Rutin's anti-oxidative damage to AD.

Design and Synthesis of a Mitochondrial-Targeted JNK Inhibitor and Its Protective Effect on Parkinson's Disease Phenotypes.

C-Jun N-terminal kinase (JNK) is a key mediator involved in a variety of physiological processes. JNK activation is regulated in a complex manner by upstream kinases and phosphatases, and plays an important role in physiological processes such as the immune response and neuronal function. Therefore, JNK has become a therapeutic target for neurodegenerative diseases, ankylosing spondylitis, psoriasis, arthritis and other diseases. Inhibition of JNK activation in mitochondria holds great potential for Parkinson's disease (PD) therapy. However, no specific mitochondrial-targeted JNK inhibitor has been reported. We have developed a mitochondrial-targeted JNK inhibitor, P2, by linking a mitochondrial-specific cell-penetrating peptide to SP600125 (SP), a commercialized specific inhibitor of JNK. We found that P2 specifically inhibited mitochondrial JNK phosphorylation instead of nuclear JNK signaling. Further studies showed that P2 effectively rescued PD phenotypes both in vitro and in vivo, thus indicating that it is a potential therapeutic for PD.