Abstract
Chemical approaches and small molecules are considered as an inseparable pAdd Newart of regenerative medicine and stem-cell-based
therapies. Zinc (Zn) is a well-known trace element essential for normal spermatogenesis and has a regulatory role on the
expression of several genes in different tissues of the body. This study determines and compares the effects of organic (acetate,
ZnA) and inorganic Zinc (sulfate, ZnS) on the expression of a number of germ cell (GC)-specific genes in retinoic acid (RA)-
treated ram bone marrow mesenchymal stem cells (BM-MSCs). First, BM-MSCs were treated with 10 μM RA for 21 days, realtime RT-PCR and immunocytochemistry (ICC) confirmed the expression of the markers in treated cells. Then, in vitro-derived
GCs were treated with 1 μM of either ZnS or ZnA for one week. Treatment of in vitro-derived GCs with ZnA significantly
downregulated all tested genes. ZnS treatment also induced a significant downregulation in Piwil2 and Vasa, and a moderate
decrease in ITG b1 and Oct4 expression levels. Cells treated with ZnS or ZnA showed almost similar gene expression patterns.
Zn treatments appeared to make in vitro-derived GCs return to a state similar to the untreated MSCs. We also studied the effects of
simultaneous use of RA and one of zinc ions on BM-MSCs. The results showed that presence of organic or inorganic zinc in
culture medium containing RA inhibited BM-MSCs to differentiate into GCs. This study showed a new dimension of zinc effect
on stem cells which will be really helpful for establishment of novel strategies for Zn applications.
Keywords Mesenchymal stem cells . Germ cell markers . In vitro-derived germ cells . Retinoic acid . Zinc acetate . Zinc sulfate