| In China, pneumoconiosis is one of the most serious ouccpational diseases, which is harmful to the health and life qualities of workers. Accodring to the latest statistics report,87.42%of the whole ouccpational diseases is the pneumoconiosis in2010, and the patients’ seniority was becoming shorter and shorter significantly. Researchers have been devoted to the pathogenesis of pneumoconiosis.Alveolar macrophage(AM) is the first effector cells involved in host defense and plays a vital role in the occurrence and development progress of pneumoconiosis. Some foreign researches showed that MARCO is related to the recognition and binding of free silica, and the expression level of MARCO on the surface of AM stimulated by free silica is increased.Not only free silisa,but also many other dusts can reduce pneumoconiosis.The number of pneumoconiosis caused by coal dusts is more than that of free silisa. Zinc oxide dusts is one of metal dust which are harmful to the lung. Therefore, based on the foreign researches, we are interested on the binding and phagocytosis ways of AMs to coal dusts and zinc oxide dusts. Therefore, this study aims to detect the effect of different particles on the expression levels of MARCO on the surface of the Rat AM and explore the binding and phagocytosis ways to these dusts.Objective:To detect the effect of the expression of MARCO on the surface of the Rat AM stimulated by free silica, coal dusts and zinc oxide dusts, and to explore the phagocytosis ways of coal dusts and theoretical basis for further study.Methods:1. The SD rat AMs were isolated and purified, then cultured in vitro by primary culture method under the suitable conditions. Inverted microscope was used to obsere the cell shapes.2. The activities of AMs stimulated by different concentrations of particle were detected by MTT colorimetry and then the particle levels exposed to AMs were determinated.3. The mRNA levels of MARCO were determined by Real-time PCR. 4. Western-blot analysis was used to detect the expressions of MARCO protein.5. The experimental values were analyzed by SPSS12.0. Homogeneity of variance was detected by Levene method, Multiple groups means were compared with single factor analysis of variance, and comparations between different groups were used q test. a=0.05was set as the test level.Results:1. The survival rate of rat AMs was above95%. After2hours cultivated,the AM adhered to the wall in a good condition.The purity of AMs was above90%.2. The effect of different particles to the AM activities.(1) SiO2:When the particle concentraions were25μg/ml,50μg/ml and100μg/ml, compared with the control group (0μg/ml) respectively, there were no significant difference (P>0.05). When the concentrations were150μg/ml and200μg/ml, the activity difference with the control group was significantly. Therefore, the consentration exposed to AMs was set as0μg/ml,25μg/ml,50μg/ml,75μg/ml and100μg/ml.(2) Coal dust:When the particle concentraion were50μg/ml,100μg/ml,200μg/mland400μg/ml, compared with the control group (0μg/ml) respectively, there were no significant difference (P>0.05). When the concentration was600μg/ml, the activity difference with the control group was significantly. Therefore, the consentration exposed to AMs was set as0μg/ml,50μg/ml,100μg/ml,200μg/ml and400μg/ml.(3) ZnO:When the particle concentraions were25μg/ml,50μg/ml and100μg/ml, compared with the control group (0μg/ml) respectively, there was no significant difference(P>0.05). When the concentration was300μg/ml and400μg/ml, the activity difference with the control group was significantly. Therefore, the consentration exposed to AMs was set as0μg/ml,50μg/ml,100μg/ml,150μg/ml and200μg/ml.3. The mRNA levels of MARCO determined by Real-time PCR:(1) SiO2:Compared with the control group, the mRNA expressions of MARCO in group50μg/ml,75μg/ml and100μg/ml were significantly increased (P<0.05). (2) Coal dust:Compared with the control group, the mRNA expressions of MARCO in group200μg/ml and400μg/ml were significantly increased (P<0.05).(3) ZnO:Compared with the control group, the mRNA expressions of MARCO in group100μg/ml,150μg/ml and200μg/ml were significantly increased (P＜.05).4. The expression of MARCO protein detected by western blot:(1) SiO2:Compared with the control group, the protein expression of MARCO in group75μg/ml and100μg/ml were significantly increased (P＜0.05).(2) Coal dust:Compared with the control group, the protein expressions of MARCO in group100μg/ml,200μg/ml and400μg/ml were significantly increased (Pμ0.05).(3) ZnO:Compared with the control group, the protein expression of MARCO in group150μg/ml and200μg/ml were significantly increased (P＜0.05).Conclusion:All the three kinds of particles can induce the increasing expression of MARCO, the phagocytolysis way to coal dust and zinc oxide is likely consistent with that of free silica-the dusts are likely phagocytosed by AM via MARCO. |
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