Comparison of periosteal, adipose, and dermal CD146+ human pericytes

Human pericytes demonstrate multilineage differentiation potential, and their descendants participate in tissue homeostasis and repair. Increasing evidence from developmental biology and tissue engineering suggest that regional specification by tissue of origin exists among human pericytes. Here, we sought to define the differentiation of CD146+ human pericytes from skeletal and soft tissue sources. Uncultured CD146+CD31-CD45- pericytes were derived by fluorescent activated cell sorting from human periosteum, adipose, or dermal tissue. Periosteal CD146+CD31-CD45- cells retained canonical features of pericytes, including cell surface marker expression, multilineage differentiation potential, and paracrine induced tubulogenesis. Periosteal pericytes demonstrated a striking tendency to undergo osteoblastogenesis, while soft tissue pericytes did not in vitro or in vivo. Microarray analysis demonstrated substantive differences between periosteal pericytes in comparison to their soft tissue pericyte counterparts. In sum, skeletal and soft tissue pericytes differ in their relative lineage differentiation potential and ability to form bone. Human tissues were microdissected, digested, and FACS sorted to derived a CD146+CD31-CD45- pericyte population, and cells were expanded in standard growth medium (DMEM, 10% FBS, 1% pen/strep) and nucleic acid isolated at subconfluency Human periosteum, subcutaneous adipose tissue, or dermis was obtained from human tissues (n=3 biologic replicates per site, 9 total), enzymatically digested, and a CD146+CD31-CD45- pericyte population was purified by fluorescent activated cell sorting. Cells were expanded at 37°C in a humidified atmosphere containing 95% air and 5% CO2. All cells were cultured in DMEM medium with 10% fetal bovine serum (FBS) and 1% penicillin/streptomycin. Medium was changed every three d, and nucleic acid was harvested at subconfluency.