Associations of Bovine Fetal Adipose Tissue-Derived Mesenchymal Stem/Stromal Cells and Germ Cell Marker Expression in Testicular Organoids.

Organoids serve as three-dimensional structures that offer spatial support and mimic cellular niches for experimental studies. The spatial and temporal association of fetal bovine adipose tissue-derived mesenchymal stem/stromal cells (AT-MSCs) with the expression of germ cell (GC) markers was evaluated in testicular organoids (TOs+AT-MSCs) under the effect of retinoic acid and testosterone (0.2, 2 and 20 µM). TOs+AT-MSCs were developed by the co-culture of Leydig, Sertoli, and peritubular myoid cells and PKH26+AT-MSCs and were analyzed for the expression of DAZL, STRA8 and UCHL1. TOs+AT-MSCs treated with 1 µM of retinoic acid and 2 or 20 µM of testosterone maintained their diameter after day 7 of culture. Pearson correlation coefficients (PCCs) of PKH26 and DAZL were higher (p < 0.05) at days 7 and 21 in TOs+AT-MSCs treated with 1 µM retinoic acid and 0.2 or 2 µM of testosterone, respectively. PCCs of PKH26 and STRA8 or UCHL1 were higher (p < 0.05) at days 14 and 21 in TOs+AT-MSCs treated with 1 µM retinoic acid and 0.2 or 2 µM of testosterone. Thus, exposure to 1 µM of retinoic acid and 2 µM of testosterone resulted in a similar diameter with respect to the control and spatial and temporal association of AT-MSCs and DAZL, STRA8 and UCHL1 markers in TOs+AT-MSCs.