Effect Of Caveolin-1 On The Decreasion Of The Proliferation Of Airway Smooth Muscle Cells Induced By Curcumine

Bronchial asthma, characterized by airway inflammation, airway hyperresponsiveness and airway remodeling is a chronic airway inflammation disease in which varied cells are involved. Many compositions of airway have changed in chronic inflammatory change, such as extracellular matrix deposition, smooth muscle hyperplasia and that lead to the airway reconstruction. Airway reconstruction is one of the main reasons of small airway obstruction and also relates closely to the airway hyperresponsiveness and the severity of asthma. Airway remodelling causes the change of airway structure including smooth muscle hypertrophy and hyperplasia, subepithelial basement membrane thickening and fibrosis, glandular hypertrophy, goblet cell hyperplasia and airway epithelial cell incrassation, and so on. Airway smooth muscle cell(sASMCs) hyperplasia is considered as the most important factor of hyperresponsiveness and asthma severity. ASMCs hyperplasia can lead to irreversible airflow obstruction and sustained airway hyperresponsiveness. Curbing the excessive ASMCs hyperplasia is the basic way to treat stubborn asthma. The key mechanism of ASMCs hyperplasia is unclear now. Our group found that curcumin could inhibit PDGF-induced hyperplasia of ASMCs but the specific mechanisms of this inhibition is unclear. In recent years, caveolae/caveolin-1 was reaserched hotly in the hyperplasia of cells. Therefore, to research the roles of caveolae/caveolin-1 in curcumin's inhibiting the hyperplasia of ASMCs can not only clear the mechanism of curcumin's inhibition on hyperplasia of ASMCs, but also provide a new target on prevention and treatment of asthma. ? Object: To detect the impact and mechanism of curcumin on the hyperplasia of ASMCs with or without the existence of caveolin-1, based on the in-vitro cultured rat ASMCs. Methods: ASMCs are cultivated by the method of enzyme digestion associating with tissue adhere in the original generation rats, and then theα-actin is identified by indirect immunofluorescence in the smooth muscle cells. The position of caveolin-1 in ASMCs is located by indirect immunofluorescence. Cells are pretreated with MβCD to destroy the caveolae structure on the membrane, and the influence on ASMCs' hyperplasia is then detected by the cell count and CCK-8. The expression of caveolin-1 protein was tested by western blot in control group, PDGF proliferation group, PDGF plus curcumin treatment group, and the mRNA expression level was tested by reverse transcription-polymerase chain reaction(RT-PCR) in these groups. Results: (1)Caveolin-1 exists in the cytomembrane of ASMCs revealed by immunofluorescence. (2)ASMCs proliferates compared with the control group used by PDGF in the method of cell count and CCK-8 (p<0.05). When ASMCs was pretreated with MβCD for an hour and then added curcumin, effect of curcumin inhibiting cell proliferation on ASMC was weakened(p<0.05). (3)The expression of caveolin-1 protein in PDGF plus curcumin treatment group significantly increased compared to PDGF group(p<0.01). (4) The expression of caveolin-1 mRNA was obviously increased in PDGF plus curcumin group compared to PDGF group by RT-PCR(p<0.05). On the contrary, the expression of ERK mRNA was obviously decreased(p<0.05). Conclusions: Improved ASMCs original generation cultivation is successfully used to culture original ASMCs of rats. Caveolin-1 exists on the membrane of ASMCs. The effect of curcumin inhibiting cell proliferation is weakened after the cholesterol structure of cytomembrane had been destroied by MβCD. Curcumin may inhibit the proliferation of ASMC by regulating the expression of caveolin-1.