Stem Cell Interaction with Somatic Niche May Hold the Key to Fertility Restoration in Cancer Patients
Figure 1
VSELs and OGSCs in adult mammalian ovary. (a) Immunolocalization of OCT-4, a stem cell marker on mouse ovarian cell smear using polyclonal antibody raised against C-terminal domain of OCT-4 (magnification 20x). Two distinct populations of stem cells were observed nuclear OCT-4 positive VSELs (arrow) and cytoplasmic OCT-4 positive OGSCs (asterisk). Inset is representative of the two stem cell populations by confocal microscopy using propidium iodide (PI) as a counterstain (magnification 63x with 5x optical zoom). VSEL has yellow stained nuclei as a result of co-localization of FITC labeled OCT-4 and PI whereas OGSC has distinct PI-stained red nuclei and cytoplasmic OCT-4. (b) Relative expression of Oct-4 and Oct-4A (transcript specific for pluripotent state) mRNA levels in normal mouse ovary by Q-PCR analysis. The levels of Oct-4A transcript in comparison to total Oct-4 were significantly lower suggesting that the VSELs positive for Oct-4A are less abundant compared to OGSCs. (c) H & E staining of human perimenopausal ovary surface epithelium smear showing the presence of RBCs, very small VSELs (arrow), and slightly bigger OGSCs (asterisk; present either as isolated cells or as clusters termed “germ cell nests” in developing ovary) (magnification 40x). Note the high nucleo-cytoplasmic ratio in stem cells with intense nuclear Hematoxylin staining.
