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Mesenchymal Stem Cell Surface Antigen SB‐10 Corresponds to Activated Leukocyte Cell Adhesion Molecule and Is Involved in Osteogenic Differentiation
Author(s) -
Bruder Scott P.,
Ricalton Nancy S.,
Boynton Raymond E.,
Connolly Timothy J.,
Jaiswal Neelam,
Zaia Joseph,
Barry Frank P.
Publication year - 1998
Publication title -
journal of bone and mineral research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.882
H-Index - 241
eISSN - 1523-4681
pISSN - 0884-0431
DOI - 10.1359/jbmr.1998.13.4.655
Subject(s) - alcam , mesenchymal stem cell , microbiology and biotechnology , biology , cell adhesion molecule , chemistry
Bone marrow contains a rare population of mesenchymal stem cells (MSCs) capable of giving rise to multiple mesodermal tissues including bone, cartilage, tendon, muscle, and fat. The cell surface antigen recognized by monoclonal antibody SB‐10 is expressed on human MSCs but is lost during their developmental progression into differentiated phenotypes. Here we report on the immunopurification of the SB‐10 antigen and its identification as activated leukocyte‐cell adhesion molecule (ALCAM). Mass spectrometry establishes that the molecular mass of ALCAM is 80,303 ± 193 Da and that it possesses 17,763 ± 237 Da of N ‐linked oligosaccharide substituents. Molecular cloning of a full‐length cDNA from a MSC expression library demonstrates nucleotide sequence identity with ALCAM. We also identified ALCAM homologs in rat, rabbit, and canine MSCs, each of which is over 90% identical to human ALCAM in their peptide sequence. The addition of antibody SB‐10 F ab fragments to human MSCs undergoing osteogenic differentiation in vitro accelerated the process, thereby implicating a role for ALCAM during bone morphogenesis and adding ALCAM to the group of cell adhesion molecules involved in osteogenesis. Together, these results provide evidence that ALCAM plays a critical role in the differentiation of mesenchymal tissues in multiple species across the phylogenetic tree.