Mesenchymal stem cells are defined in vitro by the ability to form fibroblastic colony and differentiate into adipocytes, osteocytes, and chondrocytes. Although PDGFRα⁺ cells are thought to be the origin of mesenchymal stem cells in various tissues, their roles in each organ have not been elucidated. Here, we compared characters of PDGFRα⁺ cells derived from several organs such as lung, liver, small intestine, heart, subcutaneous fat, and skeletal muscle to clarify their specific functions in each organ.
We first compared differentiation potentials of PDGFRα⁺ cells residing in various tissues. We cultured PDGFRα⁺ cells isolated from each tissue by FACS and induced them to differentiate into several mesenchymal lineages. Consequently, each PDGFRα⁺ population showed distinct differentiation potential. To investigate their roles in respective organs, we performed RNA-Seq and revealed that PDGFRα⁺ cells have gene expression patterns unique to their original organ, suggesting that they have specific functions depending on the tissue where they reside. Among these tissues, we focused on skeletal muscle because PDGFRα⁺ cells in muscle have been shown to be essential for homeostatic muscle maintenance. Using Using RNA-seq data of PDGFRα⁺ cells from various tissues of young and aged mice, we identified several genes that are specifically expressed in PDGFRα⁺ cells derived from young muscles. We expect that these genes play important roles to maintain muscle integrity and we will pursue a study to elucidate their functions.