Roles of Endogenous Growth Factors and Small Peptides in In Situ Tissue Regeneration

Endogenous adult or tissue stem cells reserved in the tissue and organs of the body may be utilized for tissue regeneration in situ, without elaborate ex vivo cell culture if small molecules or growth factors regulating stem cell self-renewal and trafficking are identified. Those candidate molecules may be more efficiently and immediately treated to the patients with emergency care, such as strokes and acute myocardial infarction, by utilizing patients' own stem cells through a mechanism of stem cell mobilization and homing. Several growth factors and peptides, such as stromal cell-derived factor 1 (SDF-1), vascular endothelial growth factor (VEGF), granulocyte-colony stimulating factor (G-CSF), and Substance-P, known to mobilize progenitor cells like hematopoietic stem cells (HSCs), endothelial precursor cells (EPCs), and bone marrow stromal cells (BMSCs) from the bone marrow and facilitate tissue repair in well-defined animal models, will be reviewed in the context of stem cell trafficking and tissue repair, and a couple of experimental strategies to monitor kinetics of stem cell mobilization and homing using animal injury models will be introduced.