The inner tissue was weighed, placed in a small beaker, minced and homogenized in PBS (ratio 1:3, w/v) kept on ice during the procedure. The homogenates were obtained using a Potter–Elvehjem homogenizer and centrifuged at 9000g for 20 min at 4 C in an Eppendorf 5810R centrifuge equipped with a F45-30-11 Rotor. The obtained supernatants (fraction S9) were immediately aliquoted and stored frozen at 80 C until used.