XCT790 Inhibits Rat Vascular Smooth Muscle Cells Proliferation Through Down-regulating The Expression Of Estrogen-related Receptor α

ObjectiveAbnormal proliferation of vascular smooth muscle cells (VSMCs) plays an important role in several pathological processes of cardiovascular diseases. In this study, the effects of XCT790, a potent and selective inverse agonist of estrogen-related receptor a (ERRα), on rat VSMCs proliferation and related signaling pathways were investigated in order to learn whether ERRa could be a novel potential target to therapeutic approaches treating cardiovascular diseases.MethodsThe rat thoracic aorta VSMCs were cultured by tissue explants adherence method. The 3rd-8th generation cells proliferation were induced by 10% FBS and prepared for the following experiment. The VSMCs were divided into different groups and treated with XCT790. The proliferative activity of VSMCs was determined by CCK-8 kit. The mRNA levels of ERRα, PGC-1α, OPN and MCAD were assayed by RT-PCR. The protein levels of ERRα and p-ERK1/2 were evaluated by Western blotting. The protein expression of VEGF was detected by ELISA. All of the data were expressed as x±s and analyzed by SPSS 19.0 software. One-way ANOVA and LSD-/were performed to analyze the data of different groups. P<0.05 was considered significant difference, and P<0.01 was considered very significant difference.Results1. The tissue explants adherence method was convenient, reliable and economical, by which the rat thoracic aorta VSMCs were cultured with good activity. The 3rd-8th generation cells with high purity and quality were suitable for the following experiment treated with XCT790.2. XCT790 inhibited rat VSMCs proliferation, in a dose-dependent manner at the dose range from 5 to 20 μmol/L (P<0.05) and in a time-dependent manner at the dose range from 10 to 20 μmol/L (P<0.05).3. XCT790 inhibited the mRNA and protein expressions of ERRa in VSMCs, in a time-and dose-dependent manner at the dose range from 10 to 20 μmol/L (P<0.05).4. XCT790 down-regulated the mRNA levels of PGC-1α, OPN and MCAD, three target genes of ERRα, in a time-and dose-dependent manner at the dose range from 10 to 20 μmol/L (P<0.05).5. XCT790 down-regulated the protein level of VEGF secreted by VSMCs, in a time-and dose-dependent manner at the dose range from 5 to 20 umol/L (P<0.05).6. XCT790 down-regulated the protein level of p-ERK1/2 in VSMCs, which inhibited the phosphorylation of ERK, in a time-and dose-dependent manner at the dose range from 10 to 20 μmol/L (P<0.05).ConclusionsXCT790 inhibits VSMCs proliferation by down-regulating the gene levels of ERRa and its target genes, as well as the ERK signaling pathway, suggesting that ERRa may be a novel potential target for therapeutic approaches to inhibit VSMCs proliferation, which plays an important role in several cardiovascular diseases.