Role of Cytoskeleton Proteins in the Morphological Changes During Apoptotic Cell Death of Cerebellar Granule Neurons

Abstract

Cytoskeleton proteins are substrates for proteases and further apoptotic death. We evaluated the participation of cytoskeleton in morphological changes during cell death induced by two apoptotic conditions, potassium deprivation (K5) and staurosporine, in cerebellar granule neurons (CGC). We found that K5 induced somatic damage, but neurites were relatively preserved, which corresponded to the reorganization of actin and α-tubulin in neurites. Staurosporine (STS) induced an early alteration of neurites with reorganization of cytoskeleton proteins in somas. Caspase inhibitor ZVAD totally inhibited STS-induced α-tubulin reorganization and partially blocked STS-induced actin reorganization. α-tubulin and actin reorganization induced by K5 was affected by ZVAD. Calpain inhibitor (IC1) did not affect α-tubulin or actin reorganization induced by STS, K5 or ionomycin. Neither ZVAD, nor IC1 changed α-tubulin or actin levels upon K5 treatment. STS increased α-tubulin and actin levels, but neither ZVAD nor IC1 changed α-tubulin levels upon STS treatment. In contrast, ZVAD reduced the STS-induced increase of actin. These results suggest that CGC cytoskeleton proteins undergo a differential expression and reorganization depending on the apoptotic condition.

Biochemical Characterization of a Caspase-3 Far-red Fluorescent Probe for Non-invasive Optical Imaging of Neuronal Apoptosis

“…The occurrence of basal caspase-3 activity in lysates from CGC is consistent with the fact that, in these culture conditions, cells slowly die by apoptosis within 3 or 4 days (Gonzalez et al 1997). Other proteases such as calpain (Ortega and Moran 2011) or caspase-1 (Tanaka et al 1998) are also activated when CGC enter apoptosis. Inhibitors directed against several proteases ensured that QCASP3.2 cleavage in cerebellar neurons was specifically due to the presence of active caspase-3.…”

Involvement of the proteasome and caspase activation in hippocampal long-term depression induced by the serine protease subtilisin

“…A second group of slices was incubated in Z-VAD(OMe)-FMK at 100M for 2-6h before transferring to the recording chamber. These higher concentrations have been found necessary by some authors to produce complete caspase inhibition (Perez-de-la-Cruz et al, 2010;Gerace et al 2012;Ortega and Moran, 2011) Analysis of variance of the six data points from 45-50 minutes and from 75-80 minutes in Z-VAD(OMe)-fmk-treated slices compared with controls showed no significant difference between the two sets of curves ( Fig. 1A-E).…”

Effect of Staurosporine in the Morphology and Viability of Cerebellar Astrocytes: Role of Reactive Oxygen Species and NADPH Oxidase

“…In some studies, cytoskeletal disruptors such as nocodazole promote apoptosis of neuronal cells, suggesting that cytoskeletal alteration could be a signal during the initial phases of apoptosis [13–17]. We have previously shown in cerebellar neurons that cytoskeletal proteins undergo a differential reorganization depending on the apoptotic condition [8]; also, cytoskeletal breakdown has been shown to be involved in neuronal apoptosis [9]. Although the morphological changes related to apoptosis are documented in neurons, the precise mechanisms involving the cytoskeletal changes during the progression of apoptosis are not well explored in astrocytes.…”