Treatment of mice with TAT peptides.

WT and R6/2 mice at 12 weeks of age received 2 i.p. injections 24 hours apart of either TAT-Pro-ADAM10^709–729 (2 nmol/g) or TAT-Ala-ADAM10^709–729 peptide (2 nmol/g) diluted at 0.5 mg/ml in sterile saline solution. The cell-permeable peptide TAT-Pro-ADAM10^709–729 was obtained by linking the 11 amino acids of the human immunodeficiency virus TAT transporter sequence to the 21 amino-acid sequence corresponding to ADAM10 proline-rich domains (NH2-YGRKKRRQRRRPKLPPPKPLPGTLKRRRPPQP-COOH). TAT-Ala-ADAM10^709–729 peptide, in which all proline residues were mutated into alanine (NH2-YGRKKRRQRRRAKLAAAKALAGTLKRRRAAQA-COOH), was used as control (27, 28). The TAT-Pro-ADAM10^709–729 inhibitory peptide and TAT-Ala-ADAM10^709–729 control peptide were generated by PolyPeptide and were maintained at 4°C while lyophilized. Once solubilized, solutions were maintained at –20°C for a maximum of 1 week. For biochemical analyses, animals were euthanized 24 hours after the second injection by dislocation and the brains were rapidly removed for dissection of striatal and cortical tissues. For behavioral analysis, mice were tested for the fear-conditioning test 24 hours after the second injection.