Effect of trypsinogen 16 on phenotypic switch of airway fibroblasts into myofibroblasts / 南方医科大学学报

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the relation between transdifferentiation of the airway myofibroblasts and the expression level of (trypsinogen16, TG16) in vitro and explore the mechanism of airway basement membrane thickening.</p><p><b>METHODS</b>The total lung proteins were extracted from normal and OVA-induced asthmatic mice and the protein expression profiles were analyzed with SDS-PAGE. The differentially expressed proteins were isolated for analysis with liquid chromatography-mass spectrometry. TG16 was cloned from mouse lung tissue and subcloned into the expression vector pcDNA3.0 to generate a pcDNA3-TG16 plasmid. The vectors were transfected into mouse embryonic fibroblast 3T3 cells and cultured in MEM in the presence of transforming growth factor-beta1 (TGF-beta1). The mRNA levels of alpha-actin and the housekeeping GAPDH gene were analyzed with RT-PCR. Using RNA interference, TG16 expression was suppressed and the resultant alpha-actin or GAPDH protein levels were analyzed using Western blotting.</p><p><b>RESULTS</b>In the total lung proteins from OVA-induced mice, a 25 000 Da protein was significantly enhanced in comparison with the protein profiles of normal mice. The protein band was identified to represent the protein of TG16. With TGF-beta1 stimulation, transfection with the plasmid pcDNA3-TG16 significantly suppressed the mRNA expression of alpha-actin (alpha-actin/GAPDH=1.78-/+0.50) in 3T3 cells as compared with the expression in cells transfected with pcDNA3.0 (3.20-/+1.36); transfection of the cells with TG16 stealth RNAi oligonucleotide to decrease TG16 mRNA level upregulated the protein level of alpha-actin (3.60-/+0.44) as compared with the alpha-actin protein level in 3T3 cells transfected with control oligonucleotide (2.78-/+0.50).</p><p><b>CONCLUSION</b>TG16 can inhibit the expression of alpha-actin in fibroblasts, which might be a protective mechanism in the progression of airway remodeling in asthma.</p>