Differential properties of human stromal cells from bone marrow, adipose, liver and cardiac tissues

Abstract

Mesenchymal stromal cells (MSC) typically derived from bone marrow (BM), cord blood (CB) and adipose tissue, are being evaluated in clinical trials for a range of diseases. However, it is unclear whether MSCs from different tissues are similar in phenotype and function. We have isolated MSCs from several tissues including bone marrow (BM), heart (HS), adipose (AS) and liver (LS) and compared the morphology, phenotype and functional properties of these cell populations. Under identical culture conditions, cell morphology was similar and the phenotype was identical, namely positive for CD105+/CD73+/CD90+ but negative for CD45/CD34. Furthermore, all MSC lines could differentiate into osteogenic and adipogenic cells. However, in co-culture studies with tumor and normal cells we detected differences in functional responses. K562 cells on BMMSCs, AS and LS exhibited significant proliferation while little proliferation was observed with HS with loss of viability. Co-culture of the MSCs with CB MNCs revealed varied hematopoietic cell proliferation on BMMSCs, AS and LS while HS inhibited proliferation. Additionally, colony forming functional analysis of cell progeny revealed a disparate proliferation of CFU-GM colonies on BMMSCs, AS and LS. Interestingly though, HS maintained progenitor populations similar to BMMSCs suggesting maintenance of quiescent populations. These data suggest that although morphology, phenotype and differentiation characteristics of different MSCs are similar, different secretory profiles exist that promote different functional properties with neighboring cells. It further suggests that HS may significantly impact tumor cell growth and transplantation of BMMSCs into the heart could potentially lead to a more tumor supportive microenvironment.