ABSTRACT
AIM:To investigate the relationship between transforming growth factor-β(TGF-β)/Smads signa-ling pathway and pulmonary arterial endothelial-mesenchymal transition(EndoMT)in hypoxia-hypercapnia pulmonary hy-pertension(HHPH)process and the regulatory effect of Yiqi-Wenyang-Huoxue-Huatan formula(YWHHF).METHODS:Healthy male SD rats were randomly divided into 5 groups:normal control(N)group,hypoxia-hypercapnia(HH)group, high-dose YWHHF(YH)group,middle-dose YWHHF(YM)group and low-dose YWHHF(YL)group.The rats in N group was housed in normoxic environment,and the rats in the other 4 groups were housed in hypoxia-hypercapnia environ-ment(9%~11%O2and 5%~6%CO2)for 4 weeks,8 h/d,6 d/week.The excess water vapor was absorbed by anhy-drous CaCl2,and CO2was absorbed by sodium hydroxide.The rats in YWHHF groups were put into the oxygen chamber before the same volume of YWHHF at different concentrations were given(200 g/L for YH group,100 g/L for YM group and 50 g/L for YL group).The average pulmonary artery pressure and the average carotid artery pressure were measured during the operation.After operation,the right ventricular free wall and left ventricle plus interventricular septum were col -lected for determining the right ventricular hypertrophy index.Moreover,the morphological changes of the lung tissues were observed under light microscope.The mRNA and protein levels of α-smooth muscle actin(α-SMA),CD31,TGF-β1 and Smad2/3,and the protein level of p-Smad2/3 were detected by RT-PCR and Western blot.RESULTS:Compared with N group,the pulmonary artery mean pressure,the mRNA and protein expression of α-SMA,TGF-β1 and Smad2/3,and the protein level of p-Smad2/3 were increased, the levels of CD31 were decreased(P<0.05), and the lung tissue damage was observed in the other 4 groups.Compared with HH group,the pulmonary artery mean pressure,the mRNA and protein expression of α-SMA,TGF-β1 and Smad2/3,and the protein level of p-Smad2/3 were decreased, while the mRNA and protein levels of CD31 were increased.Moreover,the lung tissue damage was reduced in YH,YM and YL groups.CON-CLUSION:TGF-β/Smads pathway may be involved in the process of EndoMT under hypoxia and hypercapnia condition, and YWHHF may reduce EndoMT by inhibiting the expression of TGF-β/Smads pathway-related molecules.
ABSTRACT
The aim of the present study was to investigate whether metallothionein was involved in the protection of lung ischemic preconditioning (IP) against lung ischemia-reperfusion (I/R) injury. Adult male Sprague-Dawley rats were randomly divided into 3 groups based upon the intervention (n=8): control group (C), lung I/R group (I/R), lung I/R+IP group (IP). At the end of the experiment, the content of metallothionein was tested in lung tissue. Blood specimens collected from the arteria carotis were tested for the contents of malondialdehyde (MDA), the activities of superoxide dismutase (SOD) and myeloperoxidase (MPO). The pneumocyte apoptosis index (AI) was determined by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL). Ultrastructural changes of lung tissue were observed by using transmission electron microscope. The results showed that in I/R group, the content of metallothionein was decreased (P<0.05), the content of MDA and MPO activity were increased (P<0.01), and SOD activity was decreased (P<0.01), compared with those in control group. IP treatment significantly increased the content of metallothionein (P<0.01), attenuated the MDA level (P<0.05) and MPO activity (P<0.01), and improved SOD activity (P<0.01) in blood serum. The number of TUNEL-positive cells in IP group was significantly reduced compared with that in I/R group (P<0.01). There were abnormal ultrastructural changes in I/R group, which were markedly reversed in IP group. In conclusion, IP may protect lung against I/R injury by inducing the expression of metallothionein.