Mulipotent cells in tissue repair

The capacity of bone marrow derived stem (BMSC) cells (hemopoietic or mesenchymal) to differentiate into parencyhmal cells or structures in solid organs remains controversial. We have used bone marrow Chimerism techniques using different cellular markers of bone marrow cells to study the contribution of bone marrow stem cells to organ repair in the kidney. Importantly we have shown that BMSCs do not repair injured epithelial structures in the kidney but circulating precursor cells may make contributions to the regeneration of vascular beds in the kidney by differentiating into endothelial cells. Further subpopulations of circulating precursor cells may contribute directly to tissue fibrosis called fibrocytes.  We are studying these bone marrow derived precursor cells and their contribution to fibrosis.  The presence of multipotent mesenchymal cells in the skin and brain is widely accepted, but the presence of such a precursor cells in the mammalian kidney remains elusive. We are using lineage-tracing methods to identify candidate mesenchymal cells in the kidney that have multi-potent properties.  Our studies are currently focused on fibrocytes, their contribution to fibrosis in the kidney. Using transgenic mice to lineage trace cells in fibrotic models of human diseases we are studying the precursor cells that give rise to interstitial myofibroblasts.