Regulatory effect of nanoparticles on Endoplasmic Reticulum
(ER)
The endoplasmic reticulum is a cellular compartment involved in protein
folding and maturation (Zid et al.). It
is particularly involved in the suppression of protein aggregation
through multiple levels by maintaining the accuracy of accurate
transcription of DNA to RNA and then the translation of RNA to proteins
as well as chaperons of nascent and unfolded proteins
(Ellgaard, Molinari, & Helenius, 1999).
The main limiting stage in the biogenesis of both transmembrane or
secretory proteins is the folding process in the ER. The chaperones and
folding enzymes are responsible for different stages of quality control
and protein folding processes (Naidoo &
Brown, 2012). The reduced efficacy of chaperones and foldases by aging
lead to the cumulation of abnormal proteins in the ER and finally
trigger the activation of unfolded protein response, which is related to
ER-stress (Berridge, 2002). This triggers
some of the protective cellular responses, including the up-regulation
of some chaperones to promote the restoration of protein structures,
proteolysis of misfolded proteins, and attenuation of protein
translation (Brown & Naidoo, 2010).
By increasing the age, the potency of processing the abnormal proteins
decreases following the diminished components of the ER stress and UPR
tools. This inefficient protein refolding process leads to
age-associated disorders, such as neurodegenerative deteriorations,
vascular inflammation, atherosclerosis, and a variety of cancer diseases
(Forman, Lee, & Trojanowski, 2003;
Johnson et al., 2008).
Drugs or nanomaterials can alleviate the ER stress through improving the
accurate folding of proteins, modulating the efficiency of ER-related
degradation, and increasing the recognition of misfolded proteins that
may lead to the prevention of age-related diseases and disorders
(Naidoo & Brown, 2012). There has been
no report of nanoparticle stress inhibition in the ER with the aim of
delaying or treating aging. Therefore, it can be considered as a new
research target for this purpose.