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. 2000 Jul 15;20(14):5339-45.
doi: 10.1523/JNEUROSCI.20-14-05339.2000.

Bax inactivation in lurcher mutants rescues cerebellar granule cells but not purkinje cells or inferior olivary neurons

F Selimi  1 , M W Vogel, J Mariani
Affiliations

Bax inactivation in lurcher mutants rescues cerebellar granule cells but not purkinje cells or inferior olivary neurons

F Selimi et al. J Neurosci. .

Abstract

Lurcher is a gain-of-function mutation in the delta2 glutamate receptor gene (Grid2) that turns the receptor into a leaky ion channel. The expression of the Lurcher gene in heterozygous (Grid2(Lc/+)) mutants induces the death of almost all Purkinje cells starting from the second postnatal week. Ninety percent of the granule cells and 60-75% of the inferior olivary neurons die because of the loss of their _target neurons, the Purkinje cells. The apoptotic nature of the neurodegeneration has been demonstrated previously by the presence of activated caspase-3 and DNA fragmentation. Bax, a pro-apoptotic gene of the Bcl-2 family, has been shown to be involved in developmental neuronal death. To study the role of Bax in Grid2(Lc/+) neurodegeneration, double mutants with Grid2(Lc/)+ mice and Bax knock-out mice (Bax-/-) were generated. Bax deletion had no effect on the death of Purkinje cells and inferior olivary neurons, although a temporary rescue of some Purkinje cells could be detected in P15 Grid2(Lc/)+;Bax-/- animals. From postnatal day 15 (P15) to P60, the number of granule cells in Grid2(Lc/)+;Bax-/-mice did not significantly change and was significantly increased compared with the number found in Grid2(Lc/)+;Bax+/+ mice. Granule cell number in P60 Grid2(Lc/)+;Bax-/- mice corresponded to 70% of the number found in wild-type mice. Our results show that Bax inactivation in Grid2(Lc/+) mice does not rescue intrinsic Purkinje cell death or the _target-related cell death of olivary neurons, but Bax inactivation does inhibit persistently _target-related cell death in cerebellar granule cells.

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Figures

Fig. 1.
Fig. 1.
Bax inactivation in Lurcher mice rescues granule cells but not Purkinje cells. Midsagittal cerebellar sections (10-μm-thick) of 1-month-old animals were immunostained using an anti-calbindin antibody specifically labeling Purkinje cells and counterstained with cresyl violet-thionin. InGrid2Lc/+; Bax+/+control mice (A), a massive loss of Purkinje cells and granule cells is detected. Purkinje cells have degenerated as well in Grid2Lc/+; Bax−/− double mutant mice (B), but an increased number of cresyl violet-stained granule cells are observed. Purkinje cells are atrophic with thicker dendrites in bothGrid2Lc/+; Bax+/+control (C) andGrid2Lc/+;Bax−/− (D) double mutant mice.
Fig. 2.
Fig. 2.
Neurodegeneration in the inferior olive of Lurcher mice is not inhibited by Bax inactivation. Coronal sections (10-μm-thick) of the brainstem were stained using cresyl violet-thionin. Comparison of the inferior olive in wild-type mice (A, delineated by a dotted line) andGrid2Lc/+; Bax+/+ (B) control mice shows a massive degeneration of neurons in the mutant. This neurodegeneration is also observed in Grid2Lc/+;Bax−/− double mutants (C) and makes the subnuclei of the inferior olive hardly recognizable in contrast to wild-type.
Fig. 3.
Fig. 3.
Morphology of the cerebellum of control Lurcher and Bax knock-out Lurcher mice at P15 and 2 months. Purkinje cell death has already begun at P15 fromGrid2Lc/+;Bax+/+controls (A) as well asGrid2Lc/+;Bax−/− double mutant mice (C), as shown by the presence of gaps in the Purkinje cell layer. The surface of the internal granule cell layer is persistently increased at 2 months inGrid2Lc/+;Bax−/− double mutant mice (D) when compared withGrid2Lc/+;Bax+/+control animals (B).
Fig. 4.
Fig. 4.
Quantitative analysis of neuronal death in the cerebellum of Bax knock-out Lurcher mice.A, Purkinje cell number per half-cerebellum was assessed using anti-calbindin immunostained cerebellar sections.B, Granule cell number per half-cerebellum was estimated multiplying the area of the internal granule cell layer by the average density of granule cells. Asterisks indicate that numbers found inGrid2Lc/+;Bax−/− double mutant mice are statistically different from numbers found inGrid2Lc/+;Bax+/+ mice (p < 0.05, ANOVA followed by post hoc Newman–Keuls test analysis). Error bars indicate SEM (n = 3–5). C, Averaged laterolateral distribution of the Purkinje cell population in P15 aged mutants of both genotypes. The mean Purkinje cell counts per homologous parasagittal section are plotted against the distance from the midline (percentage). Cell numbers inGrid2Lc/+;Bax−/− double mutants are significantly higher than inGrid2Lc/+;Bax+/+ mice without any effect of the laterolateral position (two-factor ANOVA). Each point represents mean ± SEM (for some points, the error bar is smaller than the dot).
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References

    1. Adams JM, Cory S. The bcl-2 protein family: arbiters of cell survival. Science. 1998;281:1322–1326. - PubMed
    1. Allsopp TE, Wyatt S, Paterson HF, Davies AM. The proto-oncogene bcl-2 can selectively rescue neurotrophic factor-dependent neurons from apoptosis. Cell. 1993;73:295–307. - PubMed
    1. Antonsson B, Conti F, Ciavatta A, Montessuit S, Lewis S, Martinou I, Bernasconi L, Bernard A, Mermod JJ, Mazzei G, Maundrell K, Gambale F, Sadoul R, Martinou JC. Inhibition of Bax channel-forming activity by Bcl-2. Science. 1997;277:370–372. - PubMed
    1. Batistatou A, Merry DE, Korsmeyer SJ, Greene LA. Bcl-2 affects survival but not neuronal differentiation of PC12 cells. J Neurosci. 1993;13:4422–4428. - PMC - PubMed
    1. Bonfanti L, Strettoi E, Chierzi S, Cenni MC, Liu X-H, Martinou J-C, Maffei L, Rabacchi SA. Protection of retinal ganglion cells from natural and axotomy-induced cell death in neonatal transgenic mice overexpressing bcl-2. J Neurosci. 1996;16:4186–4194. - PMC - PubMed

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