Figure 5.

Megakaryocytes from the bone marrow of Gata1^low mice contain more TGF-β1, LCN2, and CXCL1 than the corresponding cells from the wild-type littermates. (A) Representative sections from the bone marrow of wild-type and Gata1^low littermates immunostained with antibodies per TGF-β1, LCN2, and CXCL1 showing the level of these cytokines in endothelial cells, osteoblasts, megakaryocytes, and neutrophils (all indicated by arrows) recognized by morphological criteria as indicated. Semiquantitative estimates (−, +, ++, or +++) of the intensity of the staining in each population is indicated on the top left. Original magnification 40×. Representative sections stained only with the primary antibody are shown in Figure S6 (Supplementary Materials) as negative controls. (B) Quantification of TGF-β1, LCN2, and CXCL1 expressing MKs of wild-type and Gata1^low mice. Frequency of total megakaryocytes, levels of fibrosis (as control), and percent of megakaryocytes expressing high levels of TGF-β1, LCN2, and CXCL1 in bone marrow section from Gata1^low and wild-type littermates, as indicated. The content of proinflammatory cytokines in the megakaryocytes was quantified as described in Figure S2 (Supplementary Materials) using five randomly selected areas per femur from three–four mice per experimental group. Statistical analysis was performed by t-test, and statistically significant p values among groups are indicated within the panels. Abbreviations: TGF-β1: transforming growth factor β1; LCN2: lipocalin-2; WT: wild-type; MKs: megakaryocytes.