Determination of mTOR activity depending on donor age of mesenchymal stem cells isolated from adipose tissue

Abstract

Purpose: Aging in living organisms is an inevitable physiological consequence. Cellular senescence occurs not only in cells that have completed their differentiation, but also in stem cells. Mammalian target of Rapamycin protein complex (mTOR) has an important role in cell growth and metabolism. The mTOR, which plays an important role in cell proliferation, also regulates cellular aging and directs the bioenergetic infrastructure. The aim of the study is to determine the mTOR expression of mesenchymal stem cell (MSC) obtained from adipose tissue depending on the donor age. Materials and methods: Six-week-old pubertal rats were named Group 1 (n=6), 10-12-week-old reproductive period rats were named Group 2 (n=6), and 20-month-old rats were named Group 3 (n=6). The isolation of MSC was performed by primary explant culture method from adipose tissue taken from groups. Characterization and differentiation experiments were performed in MSC obtained. The activity of mTOR (mTORC1 and mTORC2) in MSC was determined by qRT-PCR method. Caspase 3, 8, 9, Bax and Bcl-2 expressions were evaluated by Real-time polymerase chain reaction (qRT-PCR) method. Results: In our study, it was determined that the highest expression of apoptotic markers was in Group 1 and the lowest expression was in Group 2. When mTOR expression was evaluated, mTORC1 was found to be highest in Group 2 and lowest in Group 1. mTORC2 expression in Group 1 was lower than in other groups. Although the expression of mTORC1 and mTORC2 in Group 3 was not as high as in Group 2, it was statistically significant (p<0.05). Conclusion: In this study, we found that both mTORC1 and mTORC2 are differentially expressed in stem cells depending on donor age. Further studies are needed to better understand the functional consequences of this difference. © 2023, Pamukkale University. All rights reserved.