Aging mechanism of replicative senescent human adipose-derived stem cells

Abstract

Objective To explore the aging mechanisms of human adult adipose-derived stem cells (hADSCs) in vitro. Methods The hADSCs came from the production of normal patients with liposuction. The hADSCs were cultured in the 37℃ incubator and passed until the cells were senescent. The senescence-associated β-gal staining (SA-β-gal) and histone protein γH2AX staining were carried out in both young and old hADSCs. The quantitative real-time PCR (qRT-PCR) was conducted to check the difference of the transcription function of the young and old hADSCs. Results The cultured hADSCs would be the senescent cells when the PD number was more than 35. The aging cells became big and had large flat nuclei and much more lososomes in the cytoplasm. The SA-β-gal staining and γH2AX staining were mostly positive in the aging hADSCs (PD>35) compared with the self-renewing hADSCs (PD<20). The qRT-PCR results showed that the transcription levels of Nanog and Oct4 gene were very low in aging hADSCs compared with the self-renewing ones. Conclusions The hADSCs will be senescent (SEN) when cultured and passed in vitro for long time and the aging process is similar to that of stem cells in vivo. The aging model of hADSCs can be established by this method and will be very useful in the anti-aging drug, regeneration medicine, tissue engineering and stem cell therapy. Key words: Adipose-derived stem cells; Senescence; Cell culture; Aging mechanism