The precision of cellular processes is intrinsically limited, which implies that cells naturally make mistakes. In addition, cells are exposed to a multitude of stresses, both internal and environmental, which can induce molecular damage. This can occur at many levels: at the DNA level, for example as a result of DNA replication errors or exposure to mutagenizing agents; at the RNA level, from errors that arise during transcription or post-transcriptional processing; and at the protein level, owing to defects in protein-folding pathways.
To minimize or prevent the accumulation of such damage, cells have developed cytoprotective quality control systems. These prevent errors from occurring, by safeguarding the molecular systems that orchestrate these processes. If damage has occurred, they detect damaged or abnormal macromolecules and initiate either their repair or their degradation. In addition, quality control systems can trigger more ‘global’ stress responses that increase a cell’s capacity to cope with stress when local responses are not sufficient. Notably, a failure to carry out these cytoprotective responses has been linked to ageing and disease, including neurodegeneration caused by the accumulation of misfolded protein aggregates.
Almost certainly the body internal environment is very important in this protective process. This is very much dependent upon nutrition. However with regard to nutrition and cytoprotection many poorly based claims are made for the protective capability of this and that nutrient. Inspired guesses, modest experimental studies and a cheerful wishfulness are the order of the day.
However this is an exciting area for science based studies.
Georg Stoecklin & Bernd Bukau 2013 Telling right from wrong in life — cellular quality control Nature Reviews Molecular Cell Biology 14, 613