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Incorporation of endothelial progenitor cells in newly forming capillaries
Author(s) -
Otsu Keishi,
Quadri Sadiqa K.,
Bhattacharya Jahar
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a1459-a
Subject(s) - calcein , progenitor cell , matrigel , chemistry , microbiology and biotechnology , endothelial progenitor cell , cd146 , bone marrow , fluorescence , green fluorescent protein , biophysics , stem cell , in vitro , biology , biochemistry , immunology , membrane , physics , quantum mechanics , cd34 , gene
The contribution of endothelial progenitor cells (EPCs) to capillary formation remains unclear. We harvested EPCs from rat bone marrow. To characterize endothelial phenotype, we confirmed EPC expression of CD 34, Tie‐2 and VE‐cadherin and EPC uptake of DiI‐acetylated low‐density lipoprotein. To view by confocal microscopy, we stained EPCs with the mitochondria‐localizing dye, MitoTracker deep Red (MTdR). We seeded GFP‐expressing rat lung microvascular endothelial cells (RLMECs) and MTdR‐stained EPCs as 10:1, respectively, in Matrigel (n=4). After 24 h, EPC migrated into RLMEC‐derived neocapillaries. To determine intracellular communication (IC), we loaded neocapillaries with the water soluble fluorescent dye, calcein (622 Da) that diffuses freely across IC channels. In a single EPC, we first photobleached calcein fluorescence, then we quantified the fluorescence recovery in 20 min, resulting from calcein diffusion from adjoining RLMEC. Although in control neocapillaries, fluorescence recovery occurred to 17±10% (n=7, P<.05)), pretreating neocapillaries with the IC inhibitor, glycerrhetinic acid (5 μM) completely blocked fluorescence recovery (n=7, p<.05). We conclude, IC channels supported solute diffusion between RLMECs and EPCs. We propose, EPCs contribute to neocapillary formation by intercalation in the capillary wall and by establishing IC channels with native endothelial cells (Support: HL36024, HL57556).