• Loss of proteostasis Proteostasis denotes protein homeostasis, which includes the maintenance of stable functional proteins. Upon aging, proteostasis weakens. Aging cells accumulate misfolded and impaired proteins as a result of the functional decay in their protein homeostasis (proteostasis) mechanism, causing a lowered cellular viability and the development of protein misfolding diseases generically known as proteinopathies or protein conformational diseases, such as Alzheimer's and Huntington's diseases. The main participants in proteostasis preservation are the chaperones, the ubiquitin-proteasome, and the lysosome-autophagy proteolytic systems. They take care of misfolded proteins, whether being refolded into the original stable conformation or being eradicated from the cell through proteolysis. Chaperones help de novo synthesized proteins and unfolded proteins to achieve their stable folded status. If folding happens to be unachievable, chaperones target the unfolded/misfolded protein for degradation by the proteasome or in lysosomes. The elimination of the misfolded proteins from the cytosol takes place either by degradation in lysosomes through autophagy or expulsion outside the cell by means of exosomes. All these systems function in a synchronized way to restore the structure of misfolded proteins or to remove and degrade them entirely, thus preventing the accumulation of damaged materials. However, multiple studies have revealed that proteostasis is changed with aging.