A. Stieber et al., THE FRAGMENTED NEURONAL GOLGI-APPARATUS IN AMYOTROPHIC-LATERAL-SCLEROSIS INCLUDES THE TRANS-GOLGI-NETWORK - FUNCTIONAL IMPLICATIONS, Acta Neuropathologica, 95(3), 1998, pp. 245-253
The Golgi apparatus (GA) of spinal cord motor neurons is fragmented in
sporadic amyotrophic lateral sclerosis (ALS), and in asymptomatic and
symptomatic transgenic mice expressing the G93A mutation of the gene
of the human Cu,Zn superoxide dismutase, found in certain cases of fam
ilial ALS (FALS) [Gonatas NK (1994) Am J Pathol 145:751-761; Mourelato
s Z, et al. (1996) Proc Natl Acad Sci USA 93:5472-5477]. A similar fra
gmentation of the GA has been described in cells treated with microtub
ule-depolymerizing drugs, where the organelle is functional and contai
ns both Golgi stacks and trans-Golgi network (TGN), the compartment of
exit and targeting of proteins processed by the GA. To gain a better
definition of the structure of the fragmented neuronal GA in ALS, four
cases of sporadic ALS with numerous Bunina bodies in spinal cord moto
r neurons were stained with antibodies against human TGN and against t
he lumenal and cytoplasmic domains of MG160, a protein of the medial c
isternae of the GA. The fragmented GA was stained with the three antib
odies, indicating the presence of both Golgi stacks and TGN. Furthermo
re, the staining of the fragmented GA by the antiserum against the cyt
oplasmic domain of MG160 indicates that the fragmentation of the GA is
not the result of a terminal and global cytoplasmic lytic event. The
Bunina bodies were not stained by the anti-MG160 antibodies, suggestin
g that they are not derived from the GA. The perikarya of neurons with
fragmented GA showed normal immunoreactivity with antibodies against
the heavy neurofilament subunit and alpha-tubulin. However, because of
the lack of appropriate antibodies the localization of proteins such
as spectrin, ankyrin, centractin and others which link the microtubule
s with the GA were not done. The findings support the hypothesis that,
in ALS, the fragmented neuronal GA is functional. Additional work wit
h animal models of ALS may establish whether the fragmentation of the
GA is a sign of early degeneration or a compensatory reaction of the i
njured motor neuron.