TY - JOUR
T1 - Actin plays a role in both changes in cell shape and gene-expression associated with Schwann cell myelination
AU - Fernandez-Valle, Cristina
AU - Gorman, Douglas
AU - Gomez, Anna M.
AU - Bunge, Mary Bartlett
PY - 1997
Y1 - 1997
N2 - Schwann cell (SC) differentiation into a myelinating cell requires concurrent interactions with basal lamina and an axon destined for myelination. As SCs differentiate, they undergo progressive morphological changes and initiate myelin-specific gene expression. We find that disrupting actin polymerization with cytochalasin D (CD) inhibits myelination of SC/neuron cocultures. Basal lamina is present, neurons are healthy, and the inhibition is reversible. Electron microscopic analysis reveals that actin plays a role at two stages of SC differentiation. At 0.75-1.0 μg/ml CD, SCs do not differentiate and appear as 'rounded' cells in contact with axons. This morphology is consistent with disruption of actin filaments and cell shape changes. However, at 0.25 μg/ml CD, SCs partially differentiate; they elongate and segregate axons but generally fail to form one-to-one relationships and spiral around the axon. In situ hybridizations reveal that SCs in CD-treated cultures do not express mRNAs encoding the myelin-specific proteins 2',3'-cyclic nucleotide phosphodiesterase (CNP), myelin-associated glycoprotein (MAG), and PO. Our results suggest that at the lower CD dose, SCs commence differentiation as evidenced by changes in cell shape but are unable to elaborate myelin lamellae because of a lack of myelin-specific mRNAs. We propose that F-actin influences myelin-specific gene expression in SCs.
AB - Schwann cell (SC) differentiation into a myelinating cell requires concurrent interactions with basal lamina and an axon destined for myelination. As SCs differentiate, they undergo progressive morphological changes and initiate myelin-specific gene expression. We find that disrupting actin polymerization with cytochalasin D (CD) inhibits myelination of SC/neuron cocultures. Basal lamina is present, neurons are healthy, and the inhibition is reversible. Electron microscopic analysis reveals that actin plays a role at two stages of SC differentiation. At 0.75-1.0 μg/ml CD, SCs do not differentiate and appear as 'rounded' cells in contact with axons. This morphology is consistent with disruption of actin filaments and cell shape changes. However, at 0.25 μg/ml CD, SCs partially differentiate; they elongate and segregate axons but generally fail to form one-to-one relationships and spiral around the axon. In situ hybridizations reveal that SCs in CD-treated cultures do not express mRNAs encoding the myelin-specific proteins 2',3'-cyclic nucleotide phosphodiesterase (CNP), myelin-associated glycoprotein (MAG), and PO. Our results suggest that at the lower CD dose, SCs commence differentiation as evidenced by changes in cell shape but are unable to elaborate myelin lamellae because of a lack of myelin-specific mRNAs. We propose that F-actin influences myelin-specific gene expression in SCs.
KW - actin
KW - cytochalasin D
KW - in situ hybridization
KW - mRNA expression
KW - myelination
KW - Schwann cells
UR - http://www.scopus.com/inward/record.url?scp=0031031007&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0031031007&partnerID=8YFLogxK
U2 - 10.1523/jneurosci.17-01-00241.1997
DO - 10.1523/jneurosci.17-01-00241.1997
M3 - Article
C2 - 8987752
AN - SCOPUS:0031031007
VL - 17
SP - 241
EP - 250
JO - Journal of Neuroscience
JF - Journal of Neuroscience
SN - 0270-6474
IS - 1
ER -