Expression of stem cell markers: OCT4, KIT, ITGA6, and ITGB1 in the male germinal epithelium

Abstract

Efforts have been made for the isolation and characterization of human stem spermatogonia (SG) which would be of major interest for fertility preservation in oncologic patients. We evaluated the expression of mammalian SG stem cell markers, KIT, OCT4, integrin alpha 6 (ITGA6), and integrin beta 1 (ITGB1) as possible indicators for the isolation of those cells in humans. Two different types of SG were individually isolated by micromanipulation from testicular biopsies of men with conserved spermatogenesis. Expression of mRNA showed the absence of KIT and ITGB1 markers in SG. By immunocytochemistry (IC), protein expression for KIT and integrins revealed two types of SG populations, negative (type-1) and positive (type-2). By immunohistochemistry (IH), protein expression for KIT and ITGB1 also revealed two kinds of SG populations, negative (SG A-dark) and positive (SG A-pale). Results suggest that in humans it may be possible to obtain pure populations of stem SG by using negative KIT(-)/ITGB1(-) sorting.