Biochemical Effects of Some Endoplasmic Reticulum Stress Inducers on Mesenchymal Stem Cells in vitro

Our studies aimed the effects of some endoplasmic reticulum stress inducers (thapsigargin, a Ca2+-ATP-ase inhibitor; tunicamycin, a protein N-glycosylation inhibitor; brefeldin A, a protein transport inhibitor; paraquat, an enhancer of reactive oxygen species production; A23187, a Ca2+ ionophore), as well as some antioxidants (N-acetylcysteine; dithiothreitol, a disulfide bond formation inhibitor) on apoptosis of cultured rat mesenchymal stem cells. The analyze of obtained results evidenced that paraquat, a common and effective herbicide, induced the apoptosis of the isolated rat mesenchymal stem cells in a larger proportion as compared to other chemicals as follows: paraquat > thapsigargin > tunicamycin congruent to A23187 > brefeldin A. Dithiothreitol was effective as a reducer of mesenchymal stem cells apoptosis when was administered as co-treatment for paraquat for 24 h. In contrast, N-acetylcysteine, another potent antioxidant, had no protective effects against paraquat apoptotic effects.