An Overview of DNA Repair in Amyotrophic Lateral Sclerosis

Table 1

Levels and activity of DNA repair proteins in motor neurons of ALS patients and disease animal models.

Protein	Function	Activity in ALS	References
		↓ in ALS motor cortex	[20]
Apurinic/apyrimidinic endonuclease 1 (APEX1)	DNA endonuclease (BER pathway)	↑ in ALS motor cortex and spinal cord motor neurons	[24]
		↓ in spinal cord motor neurons of SOD1 transgenic mice	[25]
		↓ mitochondrial activity in ALS motor neurons	[21]
8-Oxoguanine DNA glycosylase (OGG1)	DNA glycosylase that specifically removes 8-oxoguanine from the DNA (BER pathway)	↑ nuclear levels in spinal cord motor neurons of SOD1 transgenic mice	[26]
		= unchanged mitochondrial levels in spinal cord motor neurons of SOD1 transgenic mice	[26]
DNA polymerase γ (Pol γ)	Mitochondrial DNA polymerase (BER pathway)	↓ in spinal cord motor neurons of SOD1 transgenic mice	[26]
		↑ expression in astrocytes of the spinal cord of ALS patients	[27]
Poly-ADP-ribose polymerase-1 (PARP1)	Recognition of DNA damage (DNA repair)	↓ expression in motor neurons of the spinal cord of ALS patients	[28]
		↑ expression in motor cortex, parietal cortex, and cerebellum of ALS patients	[28]
DNA excision repair protein ERCC-1	Repair protein primarily involved in NER pathway	Errc1 knock-out mice showed age-related motor neuron degeneration	[29]