How can we use bone marrow–derived cells to improve renal function?
The work by these 2 groups raises several interesting and important questions. First, why is the degree to which bone marrow–derived cells differentiate into renal epithelial cells so different in the different studies? Are the previous reports incorrect, as suggested by the Duffield et al. study (10), or is differentiation of bone marrow–derived cells and/or their fusion with resident tubular cells an uncommon but real occurrence that is dependent upon distinct experimental conditions, as supported by the present study by Lin et al. (12)? Based on our recent studies using transplantation of male bone marrow into female recipients, we agree with Duffield and colleagues (10) that the prior β-gal studies markedly over-represented the contribution of bone marrow–derived cells to the repopulation of ischemically injured tubules during the repair process, although our reasoning behind this conclusion is somewhat different from that of Duffield et al. In our work, significant numbers of β-ga
