Tau protein hyperphosphorylation in sporadic ALS with cognitive impairment

The authors have characterized frontal cortical tau protein in cognitively intact ( 4) and cognitively impaired (ALSci, 4) ALS patients and compared it with control ( 2) or Alzheimer disease (AD,1)- derived tau. The authors observed expression of both 3R and 4R tau isoforms; increased insoluble tau protein; phosphatase resistance; and hyperphosphorylation at T175, S208, and S210. Soluble tau from both AD and ALSci was also phosphorylated at S237. Tau hyperphosphorylation is associated with ALS.