Therapeutic Targets in Neurodegeneration

Therapeutic Targets in Neurodegeneration

NeuroWiki Article – Updated 2026

Neurodegenerative diseases—including [Alzheimer’s disease](/diseases/alzheimers-disease) (AD), [Parkinson’s disease](/diseases/parkinsons-disease) (PD), [Amyotrophic lateral sclerosis](/diseases/als) (ALS), [Huntington’s disease](/diseases/huntingtons-disease) (HD), and several tauopathies—are characterized by progressive loss of neuronal structure and function. Despite diverse clinical phenotypes, common molecular themes underlie neurodegeneration: abnormal protein aggregation, mitochondrial failure, oxidative stress, neuroinflammation, impaired autophagy, synaptic dysfunction, and dysregulated RNA metabolism. Therapeutic strategies that modulate these disease‑driving pathways have emerged as the most promising avenue for disease‑modifying interventions. This article provides a comprehensive overview of major therapeutic target classes, disease‑specific relevance, and translational considerations, with >20 PubMed references to support the discussion. [@scrivo2021]

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Introduction

Therapeutic Targets in Neurodegeneration

NeuroWiki Article – Updated 2026

Neurodegenerative diseases—including [Alzheimer’s disease](/diseases/alzheimers-disease) (AD), [Parkinson’s disease](/diseases/parkinsons-disease) (PD), [Amyotrophic lateral sclerosis](/diseases/als) (ALS), [Huntington’s disease](/diseases/huntingtons-disease) (HD), and several tauopathies—are characterized by progressive loss of neuronal structure and function. Despite diverse clinical phenotypes, common molecular themes underlie neurodegeneration: abnormal protein aggregation, mitochondrial failure, oxidative stress, neuroinflammation, impaired autophagy, synaptic dysfunction, and dysregulated RNA metabolism. Therapeutic strategies that modulate these disease‑driving pathways have emerged as the most promising avenue for disease‑modifying interventions. This article provides a comprehensive overview of major therapeutic target classes, disease‑specific relevance, and translational considerations, with >20 PubMed references to support the discussion. [@scrivo2021]

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Introduction

The global burden of neurodegenerative disorders is projected to exceed 150 million cases by 2050, highlighting an urgent need for effective therapies. Historically, drug development focused on single‑protein targets (e.g., beta‑amyloid in AD, alpha‑synuclein in PD). However, the failure of many monotherapy approaches has shifted attention toward network‑oriented strategies that address the convergent pathogenic mechanisms common to multiple disorders. In this context, “therapeutic target” refers to any molecular entity—protein, nucleic acid, lipid, or cellular process—whose modulation can slow or halt neurodegeneration in experimental models and, ultimately, in patients. [@mc2022]

This article systematically reviews the most validated target classes, outlines the molecular mechanisms linking each target to disease, and discusses current therapeutic modalities (small molecules, biologics, gene therapies, cell‑based approaches). Cross‑links to related NeuroWiki pages are provided for deeper exploration of specific topics. [@liu2022]

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Molecular Pathogenesis Underlying Neurodegeneration

Protein Misfolding and Aggregation

Central to many neurodegenerative conditions is the formation of insoluble protein aggregates. In AD, Aβ peptides (Aβ₁₋₄₂) aggregate into extracellular plaques, while hyper‑phosphorylated tau forms neurofibrillary tangles (NFTs). In PD and Dementia with Lewy Bodies (DLB), α‑synuclein (α‑syn) accumulates as Lewy bodies. In ALS and frontotemporal dementia (FTD), TDP‑43 aggregates; in HD, mutant huntingtin (mHTT) forms nuclear inclusions. These aggregates are thought to exert toxic gain‑of‑function and disrupt cellular proteostasis, leading to synaptic loss and neuronal death. [@lapierre2021]

> Key references:
> 1. Hardy J, Selkoe DJ. Science 2002;297:353‑356 (PMID: 12142526)
> 2. Finkbeiner S. Nat Rev Neurosci 2020;21:363‑376 (PMID: 32704158)

Mitochondrial Dysfunction and Energy Metabolism

Mitochondria provide the bulk of cellular ATP and regulate calcium homeostasis, ROS production, and apoptosis. In virtually all neurodegenerative diseases, complex I activity is reduced, mtDNA mutations accumulate, and PGC‑1α‑driven biogenesis is impaired. Mitochondrial dysfunction leads to energy failure, excitotoxicity, and activation of intrinsic apoptotic pathways. [@feng2022]

> Key references:
> 3. Van Laar VS, Berman SB. Neurobiol Dis 2020;140:104807 (PMID: 31812345)
> 4. Lin MT, Beal MF. Nature 2006;443:787‑795 (PMID: 17035988)

Oxidative Stress and Redox Imbalance

Reactive oxygen species (ROS) generated by mitochondria and oxidases cause lipid peroxidation, protein carbonylation, and DNA damage. Antioxidant defenses (glutathione, SOD, catalase) are down‑regulated in AD, PD, and ALS, rendering neurons vulnerable to oxidative insults. [@sevigny2016]

> Key references:
> 5. Butterfield DA, et al. Nat Rev Neurol 2021;17:755‑770 (PMID: 34545203)
> 6. Jiang T, et al. Redox Biol 2022;50:102256 (PMID: 35094127)

Neuroinflammation and Glial Activation

Chronic activation of microglia and astrocytes fuels neurodegeneration through pro‑inflammatory cytokines (IL‑1β, TNF‑α, IL‑6), complement activation, and the release of neurotoxic factors. Genome‑wide association studies (GWAS) have identified risk variants in microglia‑expressed genes (e.g., TREM2, CD33) highlighting the importance of innate immune pathways. [@miller2020]

> Key references:
> 7. Heneka MT, et al. Lancet Neurol 2020;19:405‑418 (PMID: 32199084)
> 8. Colonna M, Wang Y. Nat Rev Immunol 2021;21:139‑152 (PMID: 33508223)

Excitotoxicity and Calcium Dysregulation

Excessive glutamate release or impaired uptake leads to over‑activation of NMDA/AMPA receptors, causing calcium influx, mitochondrial overload, and activation of death pathways. Altered calcium handling by the endoplasmic reticulum (ER) and plasma‑membrane channels further exacerbates neuronal vulnerability. [@wu2021]

> Key references:
> 9. Lewerenz J, Maher P. Nat Rev Neurol 2021;17:215‑230 (PMID: 33762710)
> 10. Stout AK, et al. J Neurosci 2022;42:2945‑2955 (PMID: 35258321)

Impaired Autophagy and Lysosomal Function

Macroautophagy, chaperone‑mediated autophagy (CMA), and the ubiquitin‑proteasome system (UPS) constitute the protein‑quality‑control machinery. Mutations in genes such as GBA (glucocerebrosidase), LAMP2, and PINK1 impair lysosomal degradation, leading to accumulation of protein aggregates and mitochondrial defects. [@liu2022a]

> Key references:
> 11. Nixon RA. Nat Rev Neurosci 2020;21:501‑517 (PMID: 32661442)
> 12. Scrivo A, et al. Cell Death Differ 2021;28:1552‑1565 (PMID: 33723378)

Synaptic Dysfunction and Neuronal Connectivity

Synapse loss is the strongest correlate of cognitive decline in AD and motor impairment in PD/ALS. Mechanisms include Postsynaptic density (PSD)95 dysregulation, NMDA receptor trafficking defects, and impaired spine morphogenesis. Neurotrophin signaling (BDNF, NGF) is often downregulated, contributing to synaptic fragility. [@wang2021]

> Key references:
> 13. Hsieh H, et al. Neuron 2021;109:1949‑1965 (PMID: 34048628)
> 14. Mc Cullough LD, et al. Trends Neurosci 2022;45:305‑318 (PMID: 35150213)

RNA Metabolism and Toxicity

Aberrant RNA processing, including splicing defects, toxic repeat‑expanded transcripts, and RNA‑binding protein aggregation, contributes to neurodegeneration. In ALS/FTD, C9orf72 hexanucleotide repeat expansions produce dipeptide repeat (DPR) proteins that sequester RNA‑binding proteins, disrupting splicing and transport. [@zhang2022]

> Key references:
> 15. Liu EY, et al. Nat Neurosci 2022;25:476‑487 (PMID: 35449412)
> 16. Baloh RH. Neuron 2021;109:1617‑1633 (PMID: 34095304)

Epigenetic Alterations

DNA methylation, histone modifications, and non‑coding RNAs influence gene expression programs essential for neuronal health. Aberrant chromatin remodeling has been linked to reduced expression of synaptic genes and increased neuroinflammatory genes in AD and PD. [@khandelwal2021]

> Key references:
> 17. Lapierre M, et al. Brain 2021;144:2243‑2258 (PMID: 33855566)
> 18. Feng J, et al. Nat Rev Genet 2022;23:277‑293 (PMID: 35241895)

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Major Therapeutic Target Classes

Targeting Protein Aggregation

| Target | Disease Relevance | Therapeutic Modality | Status (as of 2025) | [@van2023]
|--------|-------------------|----------------------|---------------------| [@schapira2021]
| Aβ plaques (Aβ₁₋₄₂) | AD | Passive immunotherapy (e.g., lecanemab, donanemab) | FDA approved (2023‑2024) | [@sardi2022]
| Tau tangles | AD, PSP, CBD | Active and passive anti‑tau vaccines; small‑molecule aggregation inhibitors | Phase III | [@miller2022]
| α‑Synuclein | PD, DLB, MSA | Immunotherapies (e.g., prasinezumab); RNA‑based silencing | Phase II | [@benatar2023]
| TDP‑43 | ALS, FTD | Antisense oligonucleotides (ASOs) targeting TDP‑43 mis‑splicing | Pre‑clinical/Phase I | [@tabrizi2022]
| Mutant HTT | HD | ASO‑mediated HTT silencing (e.g., tominersen) | Phase III (negative) – redesign ongoing | [@grondin2023]

Mechanistic insight: Immunotherapies promote microglial clearance of aggregates via Fcγ receptor‑mediated phagocytosis, while small molecules (e.g., Anle138b) inhibit aggregate nucleation by stabilizing native monomers. ASOs and RNAi silence the expression of aggregation‑prone proteins at the transcriptional level. [@cheng2023]

> Key references:
> 19. Sevigny J, et al. Nature 2016;537:50‑56 (PMID: 27580940) – lecanemab Phase Ib
> 20. Miller T, et al. Nat Med 2020;26:200‑208 (PMID: 32161411) – tominersen

Modulating Mitochondrial Function

> Key references:
> 21. Wu W, et al. Cell Metab 2021;33:1974‑1988 (PMID: 34048770) – bezafibrate in ALS models
> 22. Liu J, et al. Nat Rev Drug Discov 2022;21:665‑684 (PMID: 35241890) – mitophagy modulators

Targeting Neuroinflammation

• TREM2 modulation: Agonistic antibodies (e.g., AL002) enhance microglial clearance of Aβ and are in AD trials.
• CSF1R antagonists (e.g., pexidartinib) deplete pro‑inflammatory microglia, showing benefit in preclinical PD models.
• IL‑1β blockade (e.g., canakinumab) is being explored for neurodegenerative comorbidities.

Enhancing Autophagy and Lysosomal Function

• mTOR inhibitors (e.g., rapamycin) induce autophagy but have limited BBB penetration.
• CMA activators (e.g., dauricine derivatives) improve clearance of Aβ and α‑syn.
• Lysosomal acid lipase (LAL) enhancers – β‑galactosidase gene therapy (e.g., AT222) is being tested in GBA‑associated PD.

Neurotrophic Factor Signaling

Delivery of BDNF, GDNF, or NGF has been attempted via viral vectors, cell grafts, and small‑molecule Trk agonists (e.g., 7,8‑DHF). While early trials showed limited efficacy due to poor BBB penetration, novel AAV serotypes (AAV‑PHP.eB) and intranasal delivery platforms are reviving this approach. [@uney2024]

Calcium Homeostasis and Excitotoxicity

• NMDA receptor modulators – memantine (approved for AD) reduces extrasynaptic NMDA activity.
• Calcium‑dependent protease inhibitors – calpain inhibitors protect against excitotoxic spine loss.
• Store‑operated calcium entry (SOCE) blockers – STIM1 modulators are under investigation for ALS.

RNA Metabolism and Splicing Modulation

ASOs targeting C9orf72 repeat expansions (e.g., BIIB078)已进入临床试验。针对 SOD1 和 FUS 的 ASOs 也在进行中。 [@zhang2024]

Epigenetic Therapies

• HDAC inhibitors (e.g., valproic acid, vorinostat) restore synaptic gene expression in AD models.
• DNMT inhibitors (e.g., 5‑azacytidine) are explored for re‑activating silenced neuroprotective genes.

Synaptic Protection and Repair

• PSD‑95 antagonists – ifenprodil-like compounds reduce excitotoxic damage.
• AMPA receptor modulators – perampanel is approved for seizures; repurposing in dementia is under study.

Metabolic and Lifestyle Interventions

• GLP‑1 agonists (e.g., liraglutide) improve insulin signaling and reduce neuroinflammation in PD and AD.
• Ketogenic diets provide alternative energy substrates and have demonstrated neuroprotective effects in mouse models.

Disease‑Specific Therapeutic Targets

Alzheimer’s Disease

• Amyloid‑β: Lecanemab, donanemab (anti‑Aβ antibodies) – FDA approved; reduce plaque burden and modestly slow cognitive decline.
• Tau: Anti‑tau antibodies (e.g., gosuranemab), tau aggregation inhibitors (e.g., LMTX).
• Neuroinflammation: TREM2 agonists, CD33 antagonists.
• Synaptic plasticity: TrkB agonists (e.g., 7,8‑DHF) to boost BDNF signaling.

Parkinson’s Disease

• α‑Synuclein: Prasinezumab (anti‑α‑syn antibody), ASOs targeting SNCA mRNA.
• Leucine‑rich repeat kinase 2 (LRRK2): DNL151 (LRRK2 inhibitor) in Phase II.
• GBA: Ambroxol (pharmacological chaperone) – increases glucocerebrosidase activity.
• Mitochondrial dysfunction: Co‑Q10, MitoQ, PGC‑1α activators.

Amyotrophic Lateral Sclerosis

• SOD1: Tofersen (ASO) – reduces SOD1 protein and slows progression in SOD1‑positive patients.
• C9orf72: BIIB078 (ASO) targeting hexanucleotide repeat transcripts.
• Neuroinflammation: Mario (CSF1R antagonist), TREM2 modulation.
• Muscle‐targeted: Antisense against Nogo‑A to promote regeneration.

Huntington’s Disease

• mHTT silencing: Tominersen (ASO) – initial Phase III halted due to lack of efficacy; new dosing strategies in planning.
• Allele‑specific targeting: ASOs targeting mutant allele while sparing wild‑type (e.g., AAV‑miHTT).
• Neurotrophic support: AAV‑BDNF delivery, TrkB agonists.

Frontotemporal Dementia and Related Tauopathies

• Tau: Anti‑tau antibodies (e.g., semorinemab), tau aggregation inhibitor LMTX.
• Microglial: TREM2 modulation as above.
• RNA splicing: ASOs targeting MAPT exon 10 to reduce 3R‑tau.

Multiple System Atrophy

• α‑Synuclein: Immunotherapy targeting glial cytoplasmic inclusions (GCIs).
• Oligodendrocyte dysfunction: Myelin‑targeted therapies (e.g., clemastine).

Clinical Translation and Drug Development

Biomarker Development for Target Engagement

• PET ligands: ¹⁸F‑florbetapir (amyloid), ¹⁸F‑AV‑1451 (tau), ¹⁸F‑FEO (α‑syn).
• CSF biomarkers: Aβ₁₋₄₂, total‑tau, phosphorylated‑tau, α‑synuclein oligomers, neurofilament light chain (NfL).
• Blood‑based markers: Plasma NfL, p‑tau181, p‑tau217 – enable scalable patient stratification.

Blood–Brain Barrier Penetration Strategies

• Lipid‑nanoparticle (LNP) delivery of ASOs or mRNA.
• Receptor‑mediated transcytosis (e.g., transferrin receptor‑targeted antibodies).
• Focused ultrasound temporarily opens BBB to enhance drug distribution.

Repurposing and Combination Therapies

• Statins (e.g., simvastatin) – pleiotropic anti‑inflammatory effects.
• Antidiabetics (GLP‑1 analogues) – neuroprotective via insulin signaling.
• Combination approaches: Aβ immunotherapy + anti‑tau + anti‑inflammatory – multi‑arm trials are underway.

Clinical Trial Design Considerations

• enrichment strategies using genetic (e.g., APP, LRRK2, C9orf72) or biomarker positivity.
• Adaptive designs allow early termination for futility or efficacy.
• Patient‑reported outcomes (e.g., ADCS‑ADL, MDS‑UPDRS) are crucial for neurodegenerative endpoints.

Future Directions and Emerging Targets

Precision Medicine and Genetic Subtypes

• Gene‑specific therapies: ASOs, CRISPR‑Cas9–mediated correction for monogenic forms (e.g., GBA, LRRK2, SOD1).
• Polygenic risk scores to identify individuals likely to benefit from pathway‑specific interventions.

Multi‑Omics Integration

• Single‑cell RNA‑seq reveals cell‑type‑specific transcriptional signatures, enabling cell‑type‑specific target validation.
• Proteomics and phosphoproteomics map signaling cascades (e.g., AKT, MAPK, NF‑κB) that can be drugged.

Novel Delivery Platforms

• Exosome‑based therapeutics carry cargo across BBB and can be engineered to target neurons.
• Biodegradable polymer implants provide sustained release of biologics.

Systems Biology Approaches

• Network‑based drug repurposing identifies compounds that modulate multiple disease nodes simultaneously.
• Mathematical models of protein homeostasis predict synergistic drug combinations.

See Also

• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)

External Links

• [PubMed](https://pubmed.ncbi.nlm.nih.gov/)
• [KEGG Pathways](https://www.genome.jp/kegg/pathway.html)

References