Evaluation of Congo Red Staining in Degenerating Porcine Photoreceptors In Vitro: Protective Effects by Structural and Trophic Support

Autor: Kjell Johansson, Dick Delbro, Anders Kvanta, Camilla Mohlin
Rok vydání: 2018
Předmět:
Zdroj: Journal of Histochemistry & Cytochemistry. 66:631-641
ISSN: 1551-5044
0022-1554
DOI: 10.1369/0022155418768222
Popis: Congo red (CR) is a histological stain used for the detection of extracellular amyloids mediating various neurodegenerative diseases. Given that damaged photoreceptors appear to degenerate similarly to other nerve cells, CR staining was evaluated in experimentally injured porcine retina. CR staining appeared mostly as discrete cytosolic deposits with no obvious plaque formation during the investigated time period. Increases of CR labeling coincided temporally with the known accumulation of mislocalized opsins and increases of cell death. Coculture, either with human retinal pigment epithelium (ARPE) or human neural progenitor (ReN) cells, was accompanied by a significant reduction of CR labeling. Of particular interest was the reduction of CR labeling in cone photoreceptors, which are important for the perception of color and fine details and afflicted in age-related macular degeneration (AMD). Electron microscopy revealed inclusions in the inner segment, cell body, and occasionally synaptic terminals of photoreceptor cells in cultured specimens. Closer examinations indicated the presence of different types of inclusions resembling protein aggregates as well as inclusion bodies. The current results indicate that injury-related response resulted in accumulation of CR deposits in photoreceptor cells, and that trophic and/or structural support attenuated this response.
Databáze: OpenAIRE