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As the main composition of combustion, black carbon (BC) is becoming more and more noticeable at home and abroad. Ozone-oxidized black carbon (oBC) was produced through aging of ozone, one of the near-surface pollutants, to black carbon. And oBC was found to be more oxidation and cell toxicity when compared with BC. Besides, as a key cell of immunity, whether CD4(+) T cell would involve in lung inflammation induced by particular matter is still unclear. This study aims to observe the effect of oBC on lung damage in mice and discuss how the functional MAP4K4 defect CD4(+) T cells (conditional knockout of MAP4K4) presents its role in this process. In our study, MAP4K4 deletion in CD4(+) T cells (MAP4K4 cKO) could increase cell number of macrophages, lymphocytes and neutrophils in bronchoalveolar lavage fluid (BALF) exposed to oBC. MAP4K4 deletion in CD4(+) T cell also affected CD4(+) T cell differentiation in mediastinal lymph nodes after oBC stimulation. The number of CD4(+) IL17(+) T cell increased obviously. The levels of IL-6 mRNA of lung in MAP4K4 cKO mice was higher than that in wild type mice after exposed to oBC, while the level of IL-6 in BALF had the same trend. Histological examination showed that MAP4K4 deletion in CD4(+) T cells affected lung inflammation induced by oBC. Results indicated that MAP4K4 cKO in CD4(+) T cells upgraded the level of inflammation in lung when exposed to oBC, which may be connected to the CD4(+) T cell differentiation and JNK, ERK and P38 pathways., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Objectives: To investigate whether let-7 g (miRNA) was involved in doxorubicin-induced cardiotoxicity., Methods: Rats were treated with doxorubicin at increasing doses (0mg/kg, 6 mg/kg, 12 mg/kg, 18 mg/kg). Heart rate, pulse pressure and plasma cardiac troponin T concentrations were measured. Primary cultured myocardial cells were incubated with DOX at increasing concentrations (0 μmol/l, 0.004 μmol/l, 0.02 μmol/l, 0.1 μmol/l, 0.5 μmol/l) for 24h. Cellular viability and the beat frequency were measured. For both rats and cultured cells, miRNA content was measured by real-time reverse-transcription PCR., Results: All DOX-treated rats had a decrease in heart rate, an increase in pulse pressure compared with control group after injections (p<0.05). Concentration of cTnT was increased significantly in 18 mg/kg group. Content of let-7 g decreased significantly (p<0.05) in 18 mg/kg group in vivo and all the doxorubicin treated group in vitro., Conclusions: The down regulation of let-7 g in the myocardial-injury model suggests that let-7 g may play an important role in the development of cardiac disease., (Copyright © 2012. Published by Elsevier B.V.)