Non Homologous End Joining In Neurodegeneration plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.
Non Homologous End Joining In Neurodegeneration represents a key pathological mechanism in neurodegenerative diseases. This page explores the molecular and cellular processes involved, their contribution to disease progression, and therapeutic implications.
Non-homologous end joining (NHEJ) is the primary pathway for repairing double-strand breaks (DSBs) in DNA. Unlike homologous recombination, NHEJ directly ligates DNA ends without requiring sequence homology, making it error-prone but active throughout the cell cycle.
| Protein |
Function |
Neurodegeneration Relevance |
| Ku70/Ku80 |
DNA end binding |
Essential for initiation |
| DNA-PKcs |
Kinase, alignment |
Regulatory role |
| XRCC4 |
Scaffold protein |
Structural support |
| Ligase IV |
DNA ligation |
Final ligation step |
| XLF/Cernunnos |
Stabilization |
Bridge formation |
| Artemis |
End processing |
Nuclease activity |
flowchart TD
A[Double-Strand Break] --> B[Ku70/Ku80 Binding]
B --> C[DNA-PKcs Recruitment]
C --> D[DNA End Processing]
D --> E[Artemis Nuclease]
E --> F[XRCC4/Ligase IV Recruitment]
F --> G[Ligation]
G --> H[DNA Repair Complete]
D --> I[Microhomology-Mediated]
I --> J[Alternative NHEJ]
NHEJ dysfunction in Alzheimer's disease:
- DSB accumulation — Impaired repair
- Ku70/Ku80 decline — Reduced binding
- Ligase IV dysfunction — Impaired ligation
- Neuronal vulnerability — Post-mitotic stress
- Reduced NHEJ activity in AD brain
- Ku70/Ku80 levels decreased
- DNA-PKcs activation impaired
- Cognitive decline correlates with repair deficits
NHEJ in Parkinson's disease:
- Mitochondrial DSBs — Increased mtDNA damage
- Environmental toxins — MPTP, rotenone affect repair
- α-Synuclein — Interferes with repair machinery
- LRRK2 — Regulates DNA-PKcs
- NHEJ efficiency reduced in PD
- Ku70/Ku80 expression decreased
- PINK1 affects nuclear DNA repair
- PARK7 interacts with NHEJ
- NHEJ enhancement strategies
- DNA-PKcs activators
- Ku70/Ku80 expression modulation
NHEJ in Huntington's disease:
- Repeat expansions — NHEJ contributes to instability
- MSH3 role — Affects repair pathway choice
- DNA polymerase θ — Alternative NHEJ
- Age of onset — NHEJ gene modifiers
- DNA ligase IV variants affect onset
- Alternative NHEJ promotes expansion
- MSH3 knockout reduces expansion
- Therapeutic targeting possible
NHEJ in ALS:
- Oxidative stress — High ROS increases DSBs
- DNA repair capacity — Limited in motor neurons
- SOD1 — Mutant SOD1 affects repair
- C9orf72 — RNA foci interfere with repair
- Reduced NHEJ activity
- Ku80 expression decreased
- DNA ligase IV dysfunction
- Therapeutic potential
NHEJ efficiency declines with age:
- Reduced protein levels — Ku, Ligase IV
- Decreased activity — Reduced efficiency
- Accumulated damage — DSBs increase
- Neuronal dysfunction — Contributes to aging
- Age is primary risk factor
- Repair decline accelerates pathology
- Therapeutic intervention possible
When classical NHEJ fails:
- Microhomology use — 2-25 bp sequences
- PARP1 dependent — Different from c-NHEJ
- LIG3 — Alternative ligase
- Error-prone — Chromosomal rearrangements
- Increased in neurodegeneration
- Contributes to genomic instability
- Potential therapeutic target
| Target |
Approach |
Status |
| DNA-PKcs |
Activators |
Preclinical |
| Ku70/Ku80 |
Expression enhancers |
Research |
| Ligase IV |
Stabilizers |
Investigational |
| LIG3 |
Modulators |
Early stage |
- Ku70/Ku80 delivery
- Ligase IV expression
- DNA-PKcs optimization
- NHEJ enhancement + antioxidant therapy
- DNA repair + autophagy
- Metabolic support + repair activation
Non Homologous End Joining In Neurodegeneration plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.
The study of Non Homologous End Joining In Neurodegeneration has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
- McKinnon et al., DNA repair in neurons (2021)
- Iyama et al., NHEJ in the nervous system (2020)
- Sanjana et al., DNA repair in AD (2019)
- Cabelof et al., Age-related DNA repair decline (2022)
- Lee et al., NHEJ in HD (2023)