Objective To investigate whether cigarette smoke promote endoplasmic reticulum associated apoptosis gene Caspase-12 expression. Methods Forty adult male Wistar rats were randomly divided into four groups, ie. group A ( control group) , group B ( exposed to cigarette smoke for two months) ,group C ( exposed to cigarette smoke for four months) , and group D ( exposed to cigarette smoke for four months, then quit smoking for one month) . The COPD rat model was established with passive smoking.Percentage of forced expiratory volume in first 0. 3 second to forced vital capacity ( FEV0. 3 /FVC) and peak expiratory flow ( PEF) were measured. Reverse transcriptase-polymerase chain reaction ( RT-PCR) was used to determine the mRNA expression of Caspase-12. Immunohistochemistry and Western blot were used todetermine the protein expression of Caspase-12. Caspase-12-fluorometric-assay-kit was used to determine Caspase-12 activity. Results The pulmonary function decreased ( P lt; 0. 05) and the lung structure was damaged in the group B compared with the group A. The lung function markedly decreased( P lt; 0. 05) andthe lung structure was obviously damaged in the group C compared with the group B. The pulmonary function had minor improvement( P gt; 0. 05) , and the lung structure injury was also significant in the group D in contrast with the group C. The expression and activity of Caspase-12 were remarkably increased in the group B compared with the group A( P lt; 0. 05) , elevated significantly in the group C compared with the group B ( P lt; 0. 05) , decreased slightly in the group D compared with the group C ( P gt; 0. 05 ) . Conclusion Cigarette smoke promotes the development of COPD by inducing the endoplasmic reticulum associated apoptosis gene Caspase-12 expression.
Objective To study the expression of human Runt-related transcription factor 1 (RUNX1) in rat airway epithelial cells stimulated by cigarette smoking extract (CSE), and explore the role of RUNX1 in regulating epithelial-mesenchymal transition (EMT). Methods Primary rat bronchial epithelial cells were cultured by enzyme digestion and stimulated with different concentrations of CSE. The viability of cells was detected by CCK-8 to explore the appropriate concentration of CSE. After the cells were treated with CSE, the Runx1 interference and overexpression vectors were constructed and transfected into the cells to silence or overexpress the Runx1 gene. Immunocytochemical method was used to detect RUNX1 expression and Western blot analysis was used to detect the expression of RUNX1, nuclear factor-κB (NF-κB), Snail, E-cadherin, and vimentin. Results The survival rate of bronchial epithelial cells could be reduced by CSE, and the degree of reduction was directly positively correlated to the concentration of CSE. After CSE stimulation, the expression level of E-cadherin in primary rat bronchial epithelial cells decreased significantly (P<0.05); the expression levels of RUNX1, NF-κB, Snail and vimentin significantly increased (P<0.05). After interfering with RUNX1 gene, the expression level of E-cadherin was up-regulated (P<0.05), and the expression levels of NF-κB, Snail and vimentin were down-regulated (P<0.05). After overexpression of RUNX1 gene, the expression level of E-cadherin decreased (P<0.05), and the expression levels of NF-κB, Snail and vimentin increased (P<0.05). Conclusions CSE promotes the expression of RUNX1 in rat airway epithelial cells. RUNX1 might regulate EMT process by involving in the regulation of NF-κB /Snail expression.