Damage To Murine Bone Marrow Stromal Cells After The Administration Of High-dose MTX And Effects Of Ligustrazine On It

Bone marrow stromal cells (BMSC) play a key role in the support and regulation of hematopoiesis. While high-dose chemotherapy (HDC) significantly increases the remission rate in some cancers, it can lead to the long-term deficits in hematopoietic reconstitution which may be a result, in part, of damage to bone marrow stromal cells. Previous studies have shown that ligustrazine can improve the hematopoietic environment in immune-induced aplastic anemia mice. In this report we studied the damage to murine BMSC induced by the administration of high-dose chemotherapeutic agent―methotrexate (MTX), and we furthermore explored the effects of ligustrazine on the damaged BMSC resulted from the injection of high-dose MTX.In parallel cultures in vitro we observed the growth and the morphology of BMSC, counted the number of colony forming unit-fibroblasts (CFU-F), examined the adhesive function of confluent BMSC layer, and observed the growth of colony forming unit-mixed hematopoietic cells on the BMSC layer following the injection with increasing dose of MTX in mice or the exposure cultured BMSC in vitro to increasing concentration of MTX or the administration of increasing dose of ligustrazine in mice whose BMSC were damaged by high-dose MTX.The results showed that after the treatment of high dose or highconcentration of MTX, the morphology of BMSC was scattered, the growth was inhibited, the number of CFU-F was reduced, the adhesive function of BMSC layer was significantly weakened, and the growth of colony forming unit-mixed hematopoietic cells on the BMSC layer was inhibited. The changes appeared on the 14th day, became very significant on the 21st day, and remained on the 35th day after HDC in animal experiments. And the changes were more significant in higher concentration of MTX group than in lower concentration group in in vitro experiments. The results also showed that after the treatment of ligustrazine in mice whose BMSC were damaged by high-dose MTX, the morphology of BMSC was tended to be like the normal group, the growth was speeded up, the number of CFU-F was increased, the adhesive function of BMSC layer was significantly enhanced, the growth of colony forming unit-mixed hematopoietic cells on the BMSC layer was speeded up, and the count of white blood cells was increased. The changes were more significant in higher dose of ligustrazine group than in lower dose group.These results suggest that murine BMSC can be directly damaged by high dose or high concentration of MTX, which appears more lately, lasts for longer in animal experiments and shows concentration dependence on MTX in in vitro experiments. These results also suggest that ligustrazine can improve the morphology, growth and function of damaged murine BMSC induced by high dose of MTX, which shows dose dependence upon ligustrazine and may play a positive role in hematopoietic reconstitution.