Fig. 3.

Promoter SNPs −1899T/G and −1785G/C significantly altered S1PR3 promoter activity and responses to inflammatory factors in vitro. The S1PR3 promoter fragments with specific allele as well as the coexistence of 2 alleles at these loci were subcloned into pGL3-basic vector and transfected into human pulmonary artery endothelial cells. Promoter activity was detected by luciferase activity assay upon exposure to growth medium with 10% serum, with or without 100 ng/ml TNF-α challenges. Promoter activity with −1899G or/and −1785C was significantly decreased, especially upon response to TNF-α, compared with the promoter with major alleles −1899T and −1785G (*P < 0.05 vs. S1PR3 −1899T/−1785G with the same concentration of TNF-α; #P < 0.05 vs. S1PR3 −1899T/−1785G without TNF-α).