Related Experiment Videos
The mRNA encoding the scrapie agent protein is present in a variety of non-neuronal cells
H R Brown1, N L Goller, R D Rudelli
1New York State Institute for Basic Research in Developmental Disabilities, Staten Island 10314.
Abstract:
PrP 27-30, a unique protease-resistant protein associated with scrapie infectivity, derives from the proteolytic cleavage of a larger precursor encoded by a host gene. To identify sites of PrP biosynthesis, in situ hybridization was done using cloned PrP cDNA as a probe. In rodent brain, PrP mRNA was expressed in neurons, ependymal cells, choroid plexus epithelium, astrocytes, pericytes, endothelial cells and meninges of both scrapie-infected and uninfected animals. PrP mRNA was also detected in vitro in isolated brain microglia cells. Pulmonary cells and heart muscle cells contained high levels of this mRNA. Hybridization was not detected in spleen, confirming earlier RNA blot experiments indicating extremely low levels of PrP mRNA in this tissue. Results indicate that PrP mRNA is a normal component in a variety of non-neuronal tissues and may explain the origin of the amyloid plaques present in the subependymal region of scrapie-infected brain.
Insights
Prion protein (PrP) mRNA is normally found in various non-neuronal tissues, including lung and heart muscle. This widespread expression may explain amyloid plaque formation in scrapie-infected brains.
Area of Science:
- Neuroscience
- Molecular Biology
- Pathology
Background:
- Prion protein (PrP) 27-30 is a protease-resistant protein linked to scrapie infectivity.
- It originates from a larger precursor encoded by a host gene.
Purpose of the Study:
- To pinpoint the sites of PrP biosynthesis.
- To investigate the distribution of PrP mRNA in various tissues.
Main Methods:
- In situ hybridization was employed using cloned PrP cDNA as a probe.
- Analysis was performed on rodent brain tissue (scrapie-infected and uninfected) and isolated cells.
- Additional tissues like lung, heart, and spleen were examined.
Main Results:
- PrP mRNA was detected in neurons, glial cells (astrocytes, microglia), ependymal cells, choroid plexus epithelium, pericytes, endothelial cells, and meninges in rodent brains.
- High levels of PrP mRNA were found in pulmonary and heart muscle cells.
- No hybridization was observed in spleen tissue.
Conclusions:
- PrP mRNA is a normal component of numerous non-neuronal tissues.
- The presence of PrP mRNA in these tissues might contribute to the formation of amyloid plaques in the subependymal region of scrapie-infected brains.