FIG. 1.

Hypoxia increases proliferation capacity and decreases senescence in tissue-derived multilineage progenitor cells (hADMPCs). (A) Growth profiles of hADMPCs under normoxic (red square) and hypoxic (blue square) conditions. The population doubling level (PDL) was determined to be 0 when cells were isolated from human adipose tissue. Cells were maintained until they reached PDL13–15 (passage 3) and then split into four aliquots of equal cell densities. PDL was calculated based on the total cell number at each passage. (B) Detection of normoxic (Nx) and hypoxic (Hx) cells by flow cytometry after incorporation of EdU. (C) Percentages of apoptotic cells with sub-G1 DNA under Nx and Hx conditions. The results are presented as the mean of three independent experiments. (D) hADMPCs cultured under Nx and Hx conditions were harvested by trypsin-EDTA and then imaged using a phase-contrast microscope. Arrowheads indicate cells with a larger and more irregular shape. (E) Cells expanded under Nx and Hx conditions were stained with SA-β-gal. (F) Cellular reactive oxygen species detection by the oxidative stress indicator CM-H₂DCFDA in hADMPCs under Nx or Hx. Data are presented as the mean fluorescence intensity of three independent experiments. Error bars indicate SD. **P<0.01 indicates significant difference (independent t-test) between Nx and Hx. Scale bars; 100 μm. Color images available online at www.liebertpub.com/scd