After oral scrapie challenge, one of the early infection targets is the enteric nervous system (ENS), which, along with gut-associated lymphoid tissue (GALT), is a potential site of entry of prion proteins (PrP). We analysed the neurochemical code; nitric oxide synthase (nNOS), calbindin (CB) and glial fibrillary acid protein (GFAP) immunoreactivity (IR); of ileal myenteric (MP) and submucosal plexuses (SMP) from 25 Sarda breed sheep carrying various PrP genotypes (21 infected and 4 control subjects). We have recently described in detail the pattern of nNOS and CB expression of healthy sheep ileum ENS. In this respect, alteration of the normal patterns of expression of calcium binding proteins would be likely to have profound effects on neuronal cell physiology, perhaps preceding their death. The results indicate an impressive reduction of CB-IR in cells and fibres in both MP and SMP plexuses. In several animals we observed that CB-IR was localized only in neuronal nuclei. A dramatic reduction of nNOS-IR was observed in the MP of only two sheep. Furthermore, in some specimens there were restricted ganglionic areas showing GFAP-IR depletion, suggesting a possible role of enteric glia in the infection’s pathogenesis. The results let us speculate that the sheep ENS could be a site of neuronal degeneration, preceding that occurring at the central nervous system level.
Chiocchetti R., Clavenzani P., Mazzoni M., Albanese V., Di Guardo G., De Grossi L., et al. (2005). The sheep enteric nervous system after scrapie (PrPsc) experimental infection..
The sheep enteric nervous system after scrapie (PrPsc) experimental infection.
CHIOCCHETTI, ROBERTO;CLAVENZANI, PAOLO;MAZZONI, MAURIZIO;LALATTA COSTERBOSA, GIOVANNA
2005
Abstract
After oral scrapie challenge, one of the early infection targets is the enteric nervous system (ENS), which, along with gut-associated lymphoid tissue (GALT), is a potential site of entry of prion proteins (PrP). We analysed the neurochemical code; nitric oxide synthase (nNOS), calbindin (CB) and glial fibrillary acid protein (GFAP) immunoreactivity (IR); of ileal myenteric (MP) and submucosal plexuses (SMP) from 25 Sarda breed sheep carrying various PrP genotypes (21 infected and 4 control subjects). We have recently described in detail the pattern of nNOS and CB expression of healthy sheep ileum ENS. In this respect, alteration of the normal patterns of expression of calcium binding proteins would be likely to have profound effects on neuronal cell physiology, perhaps preceding their death. The results indicate an impressive reduction of CB-IR in cells and fibres in both MP and SMP plexuses. In several animals we observed that CB-IR was localized only in neuronal nuclei. A dramatic reduction of nNOS-IR was observed in the MP of only two sheep. Furthermore, in some specimens there were restricted ganglionic areas showing GFAP-IR depletion, suggesting a possible role of enteric glia in the infection’s pathogenesis. The results let us speculate that the sheep ENS could be a site of neuronal degeneration, preceding that occurring at the central nervous system level.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
