Effect of zinc ions on differentiation of bone marrow-derived mesenchymal stem cells to male germ cells and some germ cell-specific gene expression in rams.

This is the first report to describe the effects of zinc (Zn) ions on the expression of germ cell (GC) genes from bone marrow-derived mesenchymal stem cells (BM-MSCs). Zn plays an important role in germinal epithelium maintenance, testosterone secretion, differentiation of GCs, and spermatogenesis. In addition, several studies have suggested that MSCs have the potential for differentiation into numerous cells types, including male GCs. In this study, we have treated passage-3 ram BM-MSCs with 0.14 μg/ml Zn sulfate (ZnSO₄) for a period of 21 days with the intent to determine whether Zn treatment can stimulate MSCs to differentiate into male GCs in vitro. We also sought to determine the type of changes seen in MSCs by Zn treatment. Differentiation into male GCs was evaluated by the assessment of expressions of the following GC-specific markers: VASA, PIWIL2, OCT4, beta1 INTEGRIN (ITG b1), DAZL (by reverse transcription polymerase chain reaction (RT-PCR) and quantitative RT-PCR), and PGP 9.5 (by immunocytochemistry). Also studied were morphological characteristics and changes in alkaline phosphatase activity. Interestingly, Zn upregulated the expressions of VASA and ITG b1 but downregulated PIWIL2 and OCT4. DAZL and PGP 9.5 were not expressed in the treatment group. According to our results, Zn ions did not stimulate BM-MSCs to transdifferentiate into male GCs; however, it changed the expression of GC genes in BM-MSCs. It can be concluded that a possible mechanism by which Zn ions can increase male fertility is by regulation of the expression of testis GC-specific genes in the differentiation process and spermatogenesis.