Plasma SUMO1 Protein is Elevated in Alzheimer's Disease

Alzheimer's disease (AD) is the most common type of dementia in the elderly. The accumulation of amyloid-β peptides and tau proteins is the major pathogenic event of AD. There is accumulating evidence that both tau and amyloid-β linked to the small ubiquitin-like modifier (SUMO), which is increased in the brain of AD model mouse. The present study focused on the determination of SUMO1 protein level in AD blood plasma by the ELISA methods. We compared plasma from 80 dementia patients (average age 75.3 y), 89 persons with amnestic mild cognitive impairment (MCI) (average age 73.71 y),and 133 cognitively normal controls (average age 71.97 y). The plasma level of SUMO1 was significantly increased in dementia patients, as compared to control groups. The levels of SUMO1 correlated to decreased Mini-Mental State Examination (r =-0.123, p = 0.029). These results suggest that elevated plasma SUMO1 levels may be associated with AD.