Michail S. Davidov Livres

The localization of the intermediate filament protein nestin in testicular cells marked a significant step in identifying mural cells (pericytes and vascular smooth muscle cells) as the stem/progenitor cells of adult Leydig cells. Our research demonstrated the specific proliferation of vascular progenitors, which subsequently transdifferentiate into steroidogenic Leydig cells, acquiring neuronal and glial properties. This suggests a common origin for both fetal and adult Leydig cell populations. Pericytes, found throughout the body, have established stem/progenitor cell characteristics in various organs. Under suitable conditions, these dormant stem cells in the vascular niche can activate, proliferate, migrate, and differentiate into various somatic cell types. Given that most mesenchymal stem/progenitor cells share similarities with pericytes and some are derived from them, we propose that mesenchymal stem cells in the perivascular niche are descendants of pericytes. This positions pericytes as potential ancestor cells for all adult stem cells in the organism. Additionally, early stem cells from embryogenesis, like pericytes, display both mesodermal and neural progeny, which may account for the neuroendocrine properties of Leydig cells.