Fibroblasts share mesenchymal phenotypes with stem cells, but lack their differentiation and colony forming potential

Abstract

Although mesenchymal stem cells (MSCs) and fibroblasts have been well studied, differences between these two cell types are not fully understood. We therefore analyzed antigen and gene profiles, colony-forming ability, and differentiation potential of three human cell types: commercially available skin-derived fibroblasts (SDFs), adipose tissue-derived stem cells (ASCs), and embryonic lung fibroblasts (WI38). These three different types of cells exhibited a similar spindle-like shape and expressed MSC markers (CD44, CD73, and CD105). We further analyzed 90 stem cell-associated gene expressions by performing real time PCR and found a more similar gene expression pattern between ASCs and SDFs than between SDFs and WI38. In addition, SDFs and ASCs were capable to form colonies and differentiate into adipocytes, osteoblasts, and chondrocytes in vitro, but not WI38. In summary: 1) commercially available fibroblast preparations from skin consist of a significant number of cells with differentiation potential aside from terminally differentiated fibroblasts; 2) colony-forming capacity and differentiation potential are specific important properties that discriminate MSCs from fibroblasts (WI38) while conventional MSC properties such as MSC markers are unspecific for stem cells. Supported in part by P01GM066730, R01HL034708 (ZJB) from the NIH, Bethesda, MD. Supported in part by grant 543102.