[Toxic Effects of Long-term Exposure to PM2.5 and Protective Effects of Chitosan on Bone Marrow Hematopoietic Environment of the Mice].

OBJECTIVE To investigate the toxic damage and possible mechanism of chronic exposure of ambient particulate matter (PM2.5) to the marrow micro-environment of the mice, and the protective effect of chitooligosaccharides. METHODS Mice were treated with different doses (150, 300, 600 mg/kg) of chitosan after exposure to PM2.5, and then the mice were divided into: high dose group, medium dose group, low dose group according to the given dose, and the model group and the drug group were set as well. The productions of inflammatory cytokines IL-2, IL-8, TPO and VCAM-1 in marrow tissues were detected by ELISA, the expression of CXCL12 and CXCR4 protein in bone marrow tissues were measured by Western blot. RESULTS Compared with the mice in control group, IL-2 secretion and CXCL12 expression were decreased in the bone marrow of PM2.5 infected mice, while the secretion of IL-8, TPO and VCAM-1 were significantly increased, and CXCR4 expression was significantly up-regulated (P<0.05). Compared with the mice in control group, drug group and other dose groups, IL-2 secretion in the bone marrow of the mice in high-dose group was significantly increased, and IL-8, TPO and VCAM-1 secretion were significantly decreased (P<0.05). CONCLUSION Chronic exposure of PM2.5 shows some toxicity effect on marrow micro-environment. Chitosan oligosaccharide can reduce the pathologic damage of bone marrow and the toxicity to bone marrow microenvironment caused by PM2.5 at a certain extent.