Western blotting of cell body or neurite homogenates were performed as described previously.27 (link) In addition to NAMPT (1 : 2000, Enzo Life Sciences, Exeter, UK), mouse monoclonal anti-histone H1 (1 : 500; Millipore, Nottingham, UK), and mouse monoclonal anti β-actin (1 : 5000; Abcam, Cambridge, UK) were used as loading controls for the cell body and the neurite fraction, respectively. For quantification, western blotting for NMNAT2 (2.0 μg/ml, Abcam) was performed as described in.16 (link) Western blotting band intensities were determined and analysed with the ImageJ software (National Institutes of Health, Bethesda, MD, USA). Western blotting of HEK293T or PC12 cell homogenates were performed as described,27 (link) and blots were probed with an anti-his antibody (Sigma, H1029).