[Expression of apoptosis related protein in transforming growth factors-beta signaling pathway and its effects on the cell apoptosis in the lung tissues after acute pulmonary embolism].
OBJECTIVE
To study the expression changes in apoptosis related protein in transforming growth factors-beta signaling pathway (ARTS) in the lung tissues in a rat acute pulmonary embolism (APE) model and its effects on cell apoptosis.


METHODS
A rat APE model was reproduced. Samples of lung tissues were harvested at time points of 1, 8, 24 and 48 hours after APE. Healthy rats were used as control. The changes in mRNA level of ARTS were identified by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), and the changes in its protein level, and also Bcl-2, Bcl-xL, XIAP and H2Ax proteins, which were related with ARTS-mediated cell apoptosis, were determined by Western blotting. Immunohistochemical method was employed to study the distribution and expression changes in ARTS in the lung tissue before and after APE. Apoptotic cells in lung tissue sections were identified by the terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) method.


RESULTS
At different time points, the mRNA levels and the protein levels of ARTS significantly increased in the lung tissues of rats with APE at 1 hour and 48 hours (P<0.05 or P<0.01). The immunohistochemical study showed that ARTS had low expression levels and could not be detected in the normal lung tissue, but it was up-regulated obviously at 48 hours after APE, mainly expressed in the bronchial epithelium and the lung alveolar epithelium. Apoptotic cells could be observed in the lung tissue by TUNEL after APE and at the same time when the lung tissue cells exhibited lower levels of the anti-apoptotic proteins Bcl-2, Bcl-xL, and XIAP, as compared with controls. Apoptosis level (as evaluated by H2Ax, apoptotic marker staining) in the lung tissue cells was obviously raised compared with controls (P<0.05 or P<0.01).


CONCLUSIONS
The expression of ARTS is up-regulated after APE, and ARTS-mediated apoptosis plays an important role in the cell apoptosis of lung tissue.
Department of Respiratory Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an 710033, Shanxi, China.
Sheng-Qing
SQ
Li
Wen
W
Jian
A-Ru
AR
Liu
Feng
F
Zhao
Xin-Yu
XY
Ti
Hai-Feng
HF
Ouyang
D000208:Acute Disease; D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism*; D004195:Disease Models, Animal; D008168:Lung / Q000378:metabolism* / Q000473:pathology; D011655:Pulmonary Embolism / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction
D051017:Apoptosis Regulatory Proteins; D012333:RNA, Messenger