Recombinant CXCL7 peptides and their mitogenic properties on fibroblasts. (A) Recombinant CXCL7 peptides LDGF and PBP were prepared and purified as described in “Materials and methods.” Western analysis of recombinant LDGF and PBP along with positive controls β-TG and NAP-2 are shown. (B) Proliferative response of primary marrow-derived fibroblasts to CXCL7 peptides (LDGF, PBP, β-TG, and NAP-2) as well as PDGF was measured using the MTT assay. Results are shown as a percentage of control cultures with no added peptides. Although there was increased proliferation evident with increasing concentration of PDGF, none of the CXCL7 peptides tested stimulated proliferation. Results are shown as mean of 3 samples ± SE.