Degeneration of injured cells: granules in cloudy swelling

[Asmaa Mohammad]

Hello,
I am doing a pathology course this year, and while reading about reversible injury of cells (degeneration), i came across this part related to cloudy swelling of cells when injured:

'The cell is swollen and the cytoplasm appears granular.'

I understand why cells swell, but can't get from where come these granules. I googled it and found that those granules are albuminous ones, but still I don't know how they form inside the cell.

Any help would be appreciated.

Thanks in advance!

 

[Andrew Mason]

These stress granules are RNA-protein aggregates. The granules appear to be associated with the absence of RNA binding proteins in the nucleus and the accumulation of them in granular form in the cell cytoplasm.

Granules in brain cells are associated with certain neurological diseases such as ALS and certain forms of dementia:
see: https://www.cell.com/fulltext/S0092-8674(13)00946-X
https://academic.oup.com/brain/article/141/5/1236/4985461
https://mcb.asm.org/content/26/15/5744

A recent paper from the University of Saskatchewan associates extra-nuclear cytoplasmic granules of a defective RNA binding protein (hnRNP A1) with multiple-sclerosis (see:https://www.ncbi.nlm.nih.gov/pubmed/30190085).

The appearance of these RNA-protein granules seems to be part of a natural regulatory process that allows a cell to recover when stressed: https://mcb.asm.org/content/mcb/26/15/5744.full.pdf

AM