Mitochondrial proteome analysis reveals depression of the Ndufs3 subunit and activity of complex I in diabetic rat brain

► In brain mitochondria of STZ diabetic rats a severe decrement of the Ndufs3 subunit of complex I subunit is found. ► The mRNA level of Ndufs3 is also reduced in type-1 diabetic rat brain. ► The depressed expression of the Ndufs3 subunit is associated with a strong decrement of the catalytic activity of complex I. ► The severe impairment of the complex I activity can represent a critical factor to the onset of the diabetic encephalopathy.