GENETIC INTEGRITY OF HUMAN ADIPOSE DERIVED MESENCHYMAL STROMAL CELLS FROM FACE AND ABDOMEN IN LONG-TERM CULTURE AND UVB RADIATION.

Abstract

<h3>Background</h3> Adipose tissue-derived mesenchymal stromal cells (ADSCs) are one of the most used sources of stem cells for basic and clinical research, mainly due to their ease of obtaining and great availability when compared with other sources. However, several factors may compromise ADSCs‘ genetic integrity, such as the anatomical location of the adipose tissue (AT), cell culture expansion, and environmental stressors such as UVB radiation. Loss of genetic integrity is associated with a decrease in cell quality for experiments and therapeutic applications. Therefore, in this study, we comparatively evaluated the presence of γ-H2AX, a marker of DNA double-strand breaks, in human facial and abdominal ADSCs during long periods of cultivation under standard conditions or exposed to UVB radiation. <h3>Methods</h3> ADSCs were obtained from female donors of facial AT (N=3) and abdominal AT (N=3). We evaluated the presence of γ-H2AX in facial and abdominal ADSCs in early (P2-P5), medium (P12-P18), and late (P25-P35) passages, under standard culture conditions and after 48 hours of exposure to 30 mJ/cm2 UVB. <h3>Results</h3> γ-H2AX expression gradually increased in both cell types under standard culture conditions. Facial and abdominal ADSCs similarly expressed γ-H2AX in early (15.1 ± 14.6% and 14.8 ± 10.4%, respectively) and late passages (61.1 ± 20% and 73 ± 13.5%, respectively). In medium passages, the presence of γ-H2AX was significantly greater in facial than in abdominal ADSCs (P = 0.019). Upon UVB radiation, γ-H2AX was significantly 1.3 times and 1.2 times higher in abdominal ADSCs in the early and medium passages, respectively (P = 0.01), but both cell types showed similar late passages levels (90% and 96% in ADSCs facial and abdominal, respectively). <h3>Conclusion</h3> Our findings indicate that DNA damage occurs similarly between facial and abdominal ADSCs under standard culture conditions. However, UVB radiation generates a greater increase in DNA double-strand breaks in abdominal rather than facial ADSCs, suggesting that facial cells might be more resistant to UVB radiation. Future studies will further investigate if facial and abdominal cells respond differently to environmental stressors.