DNA damage induced by Strontium-90 exposure at low concentrations in mesenchymal stromal cells: the functional...

⁹⁰Sr is one of the radionuclides released after nuclear accidents that can significantly impact human health in the long term. ⁹⁰Sr accumulates mostly in the bones of exposed populations. Previous research has shown that exposure induces changes in bone physiology both in humans and in mice. We hypothesize that, due to its close location with bone marrow stromal cells (BMSCs), ⁹⁰Sr could induce functional damage to stromal cells that may explain these biological effects due to chronic exposure to ⁹⁰Sr. The aim of this work was to verify this hypothesis through the use of an in vitro model of MS5 stromal cell lines exposed to 1 and 10 kBq.mL^-1 of ⁹⁰Sr. Results indicated that a 30-minute exposure to ⁹⁰Sr induced double strand breaks in DNA, followed by DNA repair, senescence and differentiation. After 7 days of exposure, MS5 cells showed a decreased ability to proliferate, changes in cytokine expression, and changes in their ability to support hematopoietic progenitor proliferation and differentiation. These results demonstrate that chronic exposure to a low concentration of ⁹⁰Sr can induce functional changes in BMSCs that in turn may explain the health effects observed in following chronic ⁹⁰Sr exposure.