TSPO mRNA and protein expression in reactive microglia. (A) Strong induction of TSPO mRNA levels in isolated microglial cells from MacGreen/Rs1h-/Y mice compared to MacGreen mice. (B) TSPO protein induction in total retinas from MacGreen/Rs1h-/Y mice compared to MacGreen mice. (C) Temporal TSPO mRNA expression profiling shows a high early postnatal expression level and continuous decline to low levels in adult mouse retinas. (D , E) LPS activation of BV-2 microglial cells leads to the induction of TSPO transcripts (D) and protein (E). Data show mean ± SD (n = 3/group, measured in triplicates) **P <0.01 MacGreen/Rs1h-/Y versus MacGreen; ***P <0.001 BV-2 + 50 ng/ml LPS versus BV-2. LPS, lipopolysaccharide; TSPO, translocator protein (18 kDa).