Objectives To observe the effect of Ruanmailing component of traditional Chinese medicine on the reorganisation of cofilin, twinfilin-1, profilin-1 induced by platelet-derived growth factor (PDGF) in vascular smooth muscle cell (VSMC) from rats.
Methods Cultured VSMCs were derived from rat thoracic aorta. VSMCs were identified by a-actin monoclonal antibody. Ruanmailing serum was prepared from rats after 5 days of drug garage. The rearrangement of cofilin, twinfilin-1 and profilin-1 were respectively detected by Dylight488, Alexa Flour633 and Cy3 labelled antibodies under confocal microscope.
The effect of Ruanmailing on the actin and cofilin in VSMC. Compared with the control, after PDGF stimulation, VSMC became fusiform. The actin cytoskeleton was remodelled. The stress fibre were distributed intensively in cytoplasm. The expression of lamellipodia became obvious. The expression of cofilin was also increased. The co-localisation of cofilin and actin was shown in cytoplasm and lamellipodia. They were most expressed at the leading edge of VSMC in fibrillar form.
However, after treatment with 10% Ruaimailing, the actin filament was depolomarised. The stress fibre was decreased greatly and arranged loosely. Both the lamellipodia and cofilin was lessened significantly. Much less actin filament and cofilin was distributed in the lamellipodia.
The effect of Ruanmailing on reorganisation of cofilin, twinfilin-1 and profilin-1 induced by PDGF in VSMC. In comparison with the control, after the intervention by PDGF, VSMC became polygon. The expression of lamellipodia was enhanced visibly. The three actin binding proteins were elevated and redistributed in cytoplasm. The range of cofilin and twinfilin-1 was even extended to the lamellipodia area at the leading edge of VSMC from the prior cytoplasmic region near to the cell nucleus. Beyond the enhanced expression zone in cytoplasm, the expression of profilin-1 was also upregulated in the lamellipodia. Whereas, after management with 10% Ruaimailing, the expression of all the three proteins were declined significantly and discontinued, “spot” “sand” “honeycomb” accumulated in cytoplasm.
The expression of cofilin, twinfilin-1 and profilin-1 could be upregulated by PDGF.
Except that the stress fibre and lamellipodia could be descreased by Ruanmailing, it was also involved in regulating the process of polymerisation and depolymerisation of the actin filament through the inhibition and redistribution of cofilin, twinfilin-1 and profilin-1 to suppress the morphological changes induced by PDGF in VSMC.