Calcitriol modulates the effects of bone marrow-derived mesenchymal stem cells on macrophage functions.
OBJECTIVE
Some evidence showed that calcitriol has an important role in regulating growth and differentiation of mesenchymal stem cells (MSCs). However, the interaction between mesenchymal stem cells and macrophage is not clear yet. The current study was done to investigate the in vitro effects of calcitriol on the interactions between bone marrow-derived MSCs and rat macrophages.


METHODS
MSCs were isolated from rat bone marrow and pulsed with different concentrations of calcitriol (50, 100 and 200 nanomolar) for 24, 48 and 72 hr. Then, mesenchymal stem cells were co-cultured with macrophages for 4 hr. Finally, macrophages were evaluated for ability to uptake neutral red, phagocytosis activity against opsonized yeast, respiratory burst and viability.


RESULTS
Our data showed that bone marrow-derived MSCs pulsed with calcitriol may cause a significant increase in uptake of neutral red and phagocytic activity of opsonized heat killed baker's yeast. Moreover, treatment of MSCs with calcitriol enhanced macrophage viability. Nevertheless, the respiratory burst of macrophages was significantly reduced in macrophages co-cultured with calcitriol-treated MSCs compared to control group.


CONCLUSIONS
Calcitriol may accelerate and potentiate anti-inflammatory M2 macrophage polarization by MSCs.
Department of Microbiology, Veterinary Faculty, Urmia University, Urmia, Iran.
Bahman Mansouri
BM
Motlagh
Department of Microbiology, Veterinary Faculty, Urmia University, Urmia, Iran.
Nahideh Afzale
NA
Ahangaran
Department of Microbiology, Veterinary Faculty, Urmia University, Urmia, Iran.
Seyyed Meysam Abtahi
SM
Froushani
Calcitriol; Macrophage; Mesenchymal stem cell