Adipogenic characterization of immortalized CD55(+) progenitor cells from human white adipose tissue.

BACKGROUND: Mature adipocytes are difficult to study ex vivo, prompting the use of human adipose progenitor cells (hAPCs). However, hAPCs undergo replicative senescence, limiting their utility in long-term studies. METHODS: We inserted human telomerase reverse transcriptase (TERT) into the AAVS1 locus of CD55+ hAPCs derived from abdominal subcutaneous adipose tissue, and characterized the cells before and after adipogenic differentiation. RESULTS: TERT-hAPCs retained proliferative and adipogenic capacities for over 80 passages, comparable to early-passage wild type hAPCs. Transcriptomic and proteomic analyses confirmed strong adipocyte gene expression. Functionally, TERT-hAPCs responded to insulin and lipolytic stimuli (isoprenaline, dibutyryl cAMP, TNF-α). They adapted well to both 2D and 3D cultures, with improved adipogenesis under spheroid conditions. CONCLUSION: Immortalization of CD55+ hAPCs yields cells with stable proliferative and adipogenic capacity across passages. Being cryopreservable and suitable for both 2D and 3D cultures, TERT-hAPCs offer a reliable, reusable model system for adipocyte studies using cells with a consistent genetic background.