Human adipose tissue contains erythroid progenitors expressing fetal hemoglobin

Table 1 Number of CFUs per 10⁵ CD45⁺ or CD45^- cells isolated from human adipose tissue stromal vascular fraction

	Freshly isolated cells			Liquid-cultured cells
	Normoxia		Hypoxia	Normoxia	Hypoxia
	With serum	Without serum	With serum	With serum
CD45+ cells
Total CFUs	1.53 ± 0.26b	1.55 ± 0.35b	1.79 ± 0.42b	10.13 ± 3.19ad	13.73 ± 3.93d
Erythroid colonies	0.59 ± 0.15b	0.80 ± 0.05b	0.72 ± 0.17b	5.93 ± 1.58ad	7.01 ± 1.39d
Myeloid colonies	0.94 ± 0.16b	0.75 ± 0.35a	1.01 ± 0.25a	4.20 ± 1.67ad	6.72 ± 3.17d
CD45- cells
Total CFUs	0.37 ± 0.08	0.42 ± 0.11	0.34 ± 0.19	2.68 ± 0.86d	7.91 ± 2.77d
Erythroid colonies	0.12 ± 0.03	0.12 ± 0.05	0.09 ± 0.06	2.01 ± 0.99d	4.70 ± 1.85d
Myeloid colonies	0.25 ± 0.05	0.30 ± 0.07	0.25 ± 0.21	0.67 ± 0.16d	3.21 ± 1.16d

CD45⁺ and CD45^- cells from the stromal vascular fraction that were freshly isolated or cultured in a serum-free liquid medium for 7 d were seeded in a methylcellulose-based medium with or without serum, and colony-forming units (CFUs) were scored under a microscope. The numbers of CFUs per 10⁵ cells are provided. The total CFU values correspond to the sum of erythroid and myeloid colonies. The myeloid colonies include CFU-GM, CFU-M and CFU-GEMM. The data are provided as the mean ± standard error of the mean. Isolated cells: normoxia with serum (n = 30-32), normoxia without serum (CD45⁺, n = 5; CD45^-, n = 16), hypoxia (n = 5); cultured cells (n = 5).

^aP < 0.05,

^bP < 0.01 vs CD45^- cells;

^dP < 0.01 CD45^- or CD45⁺ cultured cells vs their corresponding isolated cells.

Table 2 Mean fluorescence intensity of fetal hemoglobin and adult hemoglobin in hemoglobin-expressing erythroid cells

		HbF		HbA		HbF/HbF+HbA
		HbF+HbA- cells	HbF+HbA+ cells	HbF-HbA+ cells	HbF+HbA+ cells
CB CD34+ cells	A	124082 ± 10917	204968 ± 17070b	22139 ± 4457a	25171 ± 3211a	8.49 ± 1.40
	B	16989 ± 1382	21627 ± 1027	6139 ± 182a	5248 ± 398a	5.58 ± 0.38
PB CD34+ cells			23495 ± 1326	10746 ± 893	9496 ± 548	1.26 ± 0.14
SVF CD45- cells	A	90164 ± 23126	78566 ± 2697bcf	28229 ± 5204a	21022 ± 3720a	3.86 ± 0.71
	B	34612 ± 2701c	29051 ± 1514	9637 ± 1094	5433 ± 325a	5.92 ± 1.10
SVF CD45+ cells	A	61429 ± 4085c	47907 ± 2011bd	16388 ± 986	16668 ± 587a	3.53 ± 0.18
	B	20971 ± 4696	15731 ± 1875	8006 ± 1653	9219 ± 1533	3.46 ± 1.03

The mean fluorescence intensity values are expressed as the mean ± SE and correspond to the samples analyzed in Figure 2. Statistical significance:

^aP < 0.05,

^bP < 0.01 vs PB CD34⁺ cells;

^cP < 0.05,

^dP < 0.01 vs CB CD34⁺ cells;

^fP < 0. 05 CD45⁺ cells vs CD45^- cells. SVF: Stromal vascular fraction; CB: Cord blood; PB: Peripheral blood; HbF: Fetal hemoglobin; HbA: Adult hemoglobin.