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Cellular expression of an HMGCR promoter-CAT fusion gene in transgenic mouse brain: Evidence for a developmental regulation in oligodendrocytes
- Source :
- Glia. 11:35-46
- Publication Year :
- 1994
- Publisher :
- Wiley, 1994.
-
Abstract
- The HMGCR gene encodes the 3-hydroxy-3-methylglutaryl coenzyme A reductase, which is the key enzyme for cholesterol synthesis. Mice transgenic for the prokaryotic chloramphenicol acetyl transferase (CAT) reporter gene fused with a 5' Bam H1 fragment including the promoter sequence for murine HMGCR gene have been obtained. Homozygote transgenic mice were derived from a particular line selected for similar regulation of endogenous HMGCR and the transgene expression by nutritional conditions in different tissue. In addition, high expression of the transgene was evidenced in the brain. Cellular expression of the CAT gene in the central nervous system (CNS) was investigated by immunohistochemistry (IHC). This study was performed on frozen sections of the developing and adult brain, using a rabbit anti-CAT antiserum especially raised for that purpose. CAT expression was observed in some rare individuals in different neural cell types including Purkinje cells and astrocytes. But the most outstanding observation was the high level of CAT expression correlated with differentiated pattern of oligodendrocyte (Ol) distribution observed in white-matter tracts. Double and triple labeling for CAT and stage-specific antigens were performed on transgenic Ol-enriched preparations and cultures. This study showed a normal sequence of differentiation in the transgenic oligodendroglial cell lineage and demonstrated a strict correlation between late differentiation and activation of the CAT gene in these cells: CAT expression started in transgenic Ols between galactocerebroside (GC)-positive and myelin basic protein (MBP)-positive stages and was detected in MBP-positive cells during the myelination period. After myelination, the number of CAT-positive Ols decreased in the adult brain. These observations demonstrate a developmental regulation of the CAT transgene in Ols during myelination in CNS and reinforce the hypothesis of endogenous synthesis as major source of cholesterol during myelination.
- Subjects :
- Chloramphenicol O-Acetyltransferase
Genetically modified mouse
Transgene
Mice, Transgenic
Gene Expression Regulation, Enzymologic
Mice
Cellular and Molecular Neuroscience
Antibody Specificity
Genes, Reporter
Gene expression
medicine
Animals
Promoter Regions, Genetic
Myelin Sheath
Genetics
Regulation of gene expression
Reporter gene
biology
Antibodies, Monoclonal
Brain
Cell Differentiation
Immunohistochemistry
Oligodendrocyte
Myelin basic protein
Cell biology
Oligodendroglia
medicine.anatomical_structure
Neurology
biology.protein
Neuroglia
Hydroxymethylglutaryl CoA Reductases
Subjects
Details
- ISSN :
- 10981136 and 08941491
- Volume :
- 11
- Database :
- OpenAIRE
- Journal :
- Glia
- Accession number :
- edsair.doi.dedup.....227bde9189f8e0e7fa02a555b7c741cd