Skip to main content
. 2016 Apr 13;17(4):553. doi: 10.3390/ijms17040553

Figure 3.

Figure 3

Human bone marrow microenvironment: CD271+ mesenchymal stromal cells form a delicate arborizing reticular network that is enriched around vasculature, are in contact with the majority of CD34+ hematopoietic progenitor/stem cells, and coexpress the chemokine CXCL12. Bone marrow iron is stored within HO1-expressing CD163+ macrophages, which are also in contact with CD271+ MSCs. (A) Double immunofluorescence (DIF) for CD271 (green) and CD34 (red) with DAPI-counterstained nuclei (blue) in bone marrow involved by MDS, refractory anemia with excess blasts-2. Note the close apposition of delicate MSC cytoplasmic extensions with CD34+ blasts; original magnification 60×; scale bar 25 μm; (B) DIF for CD271 (red), CXCL12 (green), nuclei (blue) in bone marrow involved by MDS, refractory anemia with isolated deletion 5q. Note CD271+ MSCs (m) that are positive for CXCL12, as well as a brightly CXCL12+ capillary (c) with closely apposed CD271+ MSCs; original magnification 60×; scale bar 25 μm (C) DIF for heme oxygenase-1 (green), CD271 (red) and nuclei (blue) in bone marrow involved by MDS, refractory anemia. Within the intact marrow, heme oxygenase-1 (HO1) is largely restricted to CD163+ macrophages, which contact numerous cells around their main body and through stellate projections; original magnification 20×; scale bar 50 μm; (D) DIF for HO1 (green), CD271 (red), and nuclei (blue) in bone marrow involved by MDS, refractory anemia with excess blasts-1. Note the intimate proximity of HO1+ macrophages and CD271+ MSCs original magnification 40×; scale bar 25 μm.