CXCR4 expression in MSC cultures. (A) RT-PCR for CXCR4 expression using the sets of primers for the 668-bp amplicon (left panel) and β-actin expression (right panel). Lane 1 indicates PHA-activated PBMCs; lanes 2 to 4, MSC cultures passage 1 to 2; and lane 5, negative control. (B) RT-PCR for β-actin (top panel) and CXCR4 (bottom panel) expression. Lanes 1 to 2 indicate PHA-activated PBMCs; lanes 3 to 7, MSC cultures at passage 5 to 8; and lane 8, negative control. (C) A representative example of extracellular expression of CXCR4 in MSC cultures by antibody staining (right panel) and isotype-matched control (left panel). FSC indicates forward scatter. (D) A representative example of intracellular expression of CXCR4 in MSC cultures (i, isotype-matched control; ii, CXCR4 antibody staining) and in CD34⁺ bone marrow cells (iii, isotype-matched control; iv, CXCR4 antibody staining). (E) Western blot analysis using an anti-CXCR4 antibody alone (top left panel) or preadsorbed with a peptide blocking the antibody's binding domain (top right panel) and β-actin expression (bottom panels). Lane 1 indicates Jurkat cell line; and lanes 2 to 3, MSC cultures. (F) Western blot analysis of cellular extracts from MSC cultures treated with PNGase to remove N-glycosylation. Lane 1 indicates Jurkat cell line; lanes 2 and 4, MSC cultures following treatment with PNGase; and lanes 3 and 5, MSC cultures in absence of PNGase.