Figure 1.

Aged Human BM Shows an Increased Density of Adipocytes, CD34+ HSPCs, and Maturing Myeloid Cells

(A) Representative images of an H&E stain of a middle-aged adult BM (total bone marrow area) and quantification of non-bone and hematopoietic area. Non-bone area (yellow area) excluding trabeculae (asterisk). Hematopoietic area (red area) excluding trabeculae (asterisk) and adipocytes (arrow). Scale bar, 100 μm. IHC staining, DAB; counterstain, hematoxylin. 20× magnification.

(B) Percentage of BM hematopoietic area in both age groups: 50–64 years (n = 7) versus 65–92 years (n = 5), p = 0.03.

(C) Representative IHC images (original) of adipocytes, NGFR+ BMSCs, CD34+ HSPCs, and maturing myeloid cells in BM biopsies from hematologically healthy patients aged 50–64 and 65–92 years. Each image is accompanied by its objects’ identification outline image produced by CellProfiler (Image Analysis). Scale bar, 200 μm.

(D) Adipocyte density in patients aged 50–64 years (n = 7) and 65–92 years (n = 5). p = 0.03.

(E) NGFR+ BMSC density: 50–64 years (n = 7) versus 65–92 years (n = 7), p = 0.14.

(F) Association between CD34+ HSPCs and age. Pearson correlation test, r = 0.71, n = 10.

(G) Maturing myeloid cell density: 50–64 (n = 7) and 65–92 years (n = 5), p = 0.01.