[Effect of low-concentration paclitaxel on collagen deposition outside rat pulmonary artery smooth muscle cells and related mechanism].

OBJECTIVE: To study the effect of low-concentration paclitaxel (PTX) on transforming growth factor-β1 (TGF-β1)-induced collagen deposition outside rat pulmonary artery smooth muscle cells (PASMCs) and related mechanism.
METHODS: Primary rat PASMCs were divided into a blank control group (n=3), a model group (n=3), and a drug intervention group (n=3). No treatment was given for the blank control group. The model group was treated with TGF-β1 with a final concentration of 10 ng/mL. The drug intervention group was treated with PTX with a final concentration of 100 nmol/L in addition to the treatment in the model group. MTT colorimetry was used to measure cell proliferation. Quantitative real-time PCR was used to measure the relative mRNA expression of collagen type I (COL-I) and collagen type III (COL-III). ELISA was used to measure the OD value of COL-I and COL-III proteins. Western blot was used to measure the relative protein expression of COL-I, COL-III, and the key proteins of the TGF-β1/Smad3 signaling pathway (Smad3 and p-Smad3).
RESULTS: Compared with the blank control group, the model group had significant increases in proliferation ability, relative mRNA and protein expression of COL-I and COL-III, and relative protein expression of p-Smad3 (P<0.05). Compared with the model group, the drug intervention group had significant reductions in the above indicators, but which were still higher than those in the blank control group (P<0.05). There was no significant difference in the relative protein expression of Smad3 among the three groups (P>0.05).
CONCLUSIONS: Low-concentration PTX exerts a marked inhibitory effect on TGF-β1-induced collagen deposition outside PASMCs, possibly by regulating the phosphorylation of Smad3 protein.