Optineurin is colocalized with ubiquitin in Marinesco bodies

Excerpt

Marinesco bodies (MBs) were originally described in 1902 [11]. They are small, spherical intranuclear inclusions that are observed in neurons of the substantia nigra (SN) and locus coeruleus (LC). They have traditionally been considered to be benign. However, there is increasing evidence that they may be an early signal of neuronal dysfunction. They appear in neurons with a high content of melanin, suggesting their association with particular oxidative processes. They are ubiquitinated [1], indicating contents targeted for degradation through the ubiquitin-proteasomal pathway. Their numbers increase with age in both humans [2, 19] and monkeys [10, 17]. This contrasts with losses during aging of SN and LC neurons. More than 40% of SN neurons can be lost without onset of extrapyramidal signs [4, 13]. Why these neurons drop out with aging is unknown but oxidative stress from high levels of catecholamine turnover is a possibility. …