2.6. β-Hexosaminidase Release Assay

β-hexosaminidase activity was determined as previously described [26]. Briefly, 20 μL aliquots of supernatants and cell lysates derived from cells triggered as indicated were incubated for 90 min, at 37 °C, with 50 μL substrate solution consisting of 1.3 mg/mL p-nitrophenyl-N-acetyl-β-D-glucosaminide in 0.1 M citrate (pH 4.5). Subsequently, reactions were stopped by the addition of 180 μL 0.2 M glycine (pH 10.7), and optical density was measured at 405 nm, by an absorbance microplate reader (Infinite F50, Tecan, Männedorf, Switzerland).