ABSTRACT
Objective@#To investigate the changes in the levels of interleukin-6 (IL-6) and let-7e in rats induced by coal mine dust, so as to provide the basis for the mechanism of coal worker's pneumoconiosis (CWP).@*Methods@#Sixty-four clean and healthy male Sprague-Dawley rats were randomly divided into the control group, coal dust group, mixed dust group (mixed coal and silica dust) and quartz group. The rats in the control group were exposed to 1 mL physiological saline by non-exposure tracheal perfusion, and the rats in the dust-exposed groups were exposed to 1 mL dust suspension. Rats were sacrificed by anesthesia after 1 month and 6 months, lung tissue was observed using hematoxylin-eosin staining, the pathological change in the lungs was scored using the Szapiel scoring system, the levels of IL-6 in the bronchoalveolar lavage fluid were detected using enzyme-linked immunosorbent assay, and the expression of let-7e was determined by quantitative real-time PCR.@*Results@#A month after exposure, a small amount of coal spots and inflammatory exudation were observed in the lung tissue of the coal dust group and the mixed dust group. The quartz group showed tissue structure destruction and mild fibrosis and thickening of alveolar septum. Six months after exposure, there were more coal spots and slightly thickened alveolar septum in the coal dust group, and hyperplasia of pulmonary interstitial fibers, destruction of alveolar structure and silica nodules were observed in the mixed dust group. In the quartz group, the alveolar structure was obviously destroyed, the interstitial fiber proliferation was significant and silica nodules were seen. Two-factor analysis of variance showed that the interaction between duration of exposure and dust type significantly influenced the pathological score of lung tissue, IL-6 levels, and let-7e expression levels (P<0.05). Under the same dust type, the pathological score of lung tissue and IL-6 levels were higher at 6 months after exposure than at 1 month, while the relative expression of let-7e was lower at 6 months after exposure than at 1 month (all P<0.05). Under the same duration of exposure, the pathological score of lung tissue and IL-6 levels were higher in the dust-exposed groups than in the control group, while the relative expression of let-7e was lower in the dust-exposed groups than in the control group (all P<0.05).@*Conclusions@#Coal dust can cause an increase in levels of IL-6 and a decrease in let-7e expression in rats. The type of dust and duration of exposure can interactively affect IL-6 and let-7e.
ABSTRACT
This research aimed to explore the molecular mechanism of microRNA (miR)-106b in cell apoptosis of atherosclerosis (AS). Human aortic endothelial cells (HAECs) were divided into control group, oxidized-low-density lipoproteins (ox-LDL) group, miR-106b NC+ox-LDL group, miR-106b mimics+ox-LDL group, miR-106b mimics+PTEN+ox-LDL group, and miR-106b mimics+empty+ox-LDL group. Real-time fluorescence quantitative polymerase chain reaction, cholecystokinin, TdT-mediated biotinylated nick end-labeling assay, luciferase reporter gene assay, and flow cytometry analysis were performed to determine the morphology, proliferation, and apoptosis in HSECs. Moreover, the levels of phosphatase and tensin homolog deleted on chromosome 10 (PTEN), Bcl-2, p-P13K, and p-AKT in HAECs were detected by western blot. MiR-106b was down-regulated in ox-LDL-induced HAECs. PTEN was the target gene of miR-106b-5p. Overexpression of PTEN inhibited the anti-apoptotic effect of miR-106b. Compared with the control group, the proportion and number of HAECs apoptosis and Bax, caspase-3, and caspase-9 expression in ox-LDL and miR-106b mimics+PTEN+ox-LDL groups were significantly increased (all P<0.05). Moreover, the activity of HAECs and Bcl-2 were decreased significantly (all P<0.05). Overexpression of miR-106b in ox-LDL-induced AS inhibited endothelial cell apoptosis. Furthermore, miR-106b might activate the PI3K/AKT pathway by down-regulating the expression of PTEN in ox-LDL-induced HAECs.