Figure 1
Potential sources of MSCs in tissue repair. During injury or disease tissue-resident MSCs (mesenchymal stromal/stem cells) can expand and provide trophic support for regeneration and/or differentiate to produce fibrosis, fatty degeneration or ectopic ossification or a combination of these. In addition, contribution to the fibrogenic cell pool by circulating “fibrocytes” originated from BM (bone marrow) and either EMT/EndMT (epithelial-mesenchymal transition/endothelial-mesenchymal transition) are proposed even though their existence, as well as the impact of their contribution to the deposition of fibrotic matrix, is controversial.