Induction of premature senescence in human fibroblasts through endoplasmic reticulum stress: protection by phenolic diterpenes
Year: 2013
Type: dissertation
Abstract: Population ageing is increasing worldwide due to the increase of lifespan and to sociological reasons. This is however associated with a higher incidence of age-related chronic disorders, such as neurodegenerative and cardiovascular diseases, diabetes and cancer. Therefore, new approaches to promote a healthy ageing are needed. The accumulation of damaged and misfolded proteins are present during the ageing process and known to be associated with endoplasmic reticulum (ER) stress and to the progression of many age-related diseases. Based on this, an in vitro method to induce premature senescence in normal human fibroblasts through induction of ER stress was developed in the present study in order to test potential anti-ageing compounds that acts by dealing with protein damage and associated ER stress. Tunicamycin (TUN) was successfully used to induce ER stress in normal diploid human skin fibroblasts since it triggered the unfolded protein response (UPR) signaling, as shown by the up-regulation of BiP, ATF6- α, CHOP and spliced XBP1. Treatment of fibroblasts with TUN significantly inhibited cell growth without inducing cell death (even by apoptosis), and it affected cell morphology in a way that resembled a senescent phenotype. Induction of premature senescence was confirmed by the appearance of several markers of cellular senescence, such as induction of G1 arrest, presence of SA β-Gal positive cells, increased cells’ green autofluorescence and expression of p16. Finally, this model was used to test the potential protective effect of carnosic acid - a natural phenolic diterpene. Although preliminary, the results suggested us that carnosic acid is able to prevent against the TUN-induced premature senescence corroborating the anti-ageing potential of this compound shown by previous results from the group. This work contributed to the development of a new model of induction of premature senescence in human fibroblasts, which can then be used to test compounds applicable for nutritional ageing interventions.
Author: Ana L. Alves
Language: English
Subfield: Cell Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2260633561