DYSTROGLYCAN EXPRESSION IN THE WILD-TYPE AND MDX MOUSE NEURAL RETINA - SYNAPTIC COLOCALIZATION WITH DYSTROPHIN, DYSTROPHIN-RELATED PROTEIN BUT NOT LAMININ
F. Montanaro et al., DYSTROGLYCAN EXPRESSION IN THE WILD-TYPE AND MDX MOUSE NEURAL RETINA - SYNAPTIC COLOCALIZATION WITH DYSTROPHIN, DYSTROPHIN-RELATED PROTEIN BUT NOT LAMININ, Journal of neuroscience research, 42(4), 1995, pp. 528-538
Alpha- and beta-dystroglycan (alpha- and beta-DG) are members of a dys
trophin-associated glycoprotein complex (DGC) in skeletal muscle which
binds to agrin and laminin, and has been postulated to be involved in
myoneural synapse formation. The absence of functional dystrophin in
Duchenne muscular dystrophy (DMD) and in one of its animal models, the
mdx mouse, leads to a reduction of alpha- and beta-DG in muscle, and
is often associated with mental retardation and abnormal retinal synap
tic transmission in DMD. Using immunohistochemistry, we find that alph
a- and beta-DG are expressed in the outer plexiform layer of both wild
type and mdx retina, where both dystrophin and dystrophin-related pro
tein (DRP), but not laminin are present. In situ hybridization identif
ies two neuronal populations, photoreceptors and retinal ganglion cell
s, that express DG mRNA. alpha and beta-DG are also expressed in the i
nner limiting membrane and around blood vessels where they colocalize
with laminin and DRP. Western blot analysis revealed the expression of
several dystrophin isoforms in wild type and mdx retina, possibly exp
laining the unaltered expression of alpha- and beta-dystroglycan in th
e mdx central nervous system (CNS), Our results support the hypothesis
that (alpha- and beta-DG can interact with dystrophin and DRP in the
CNS and perform functions analogous to those of the DGC in muscle. (C)
1995 Wiley-Liss, Inc.