[Bone morphogenetic protein type II receptor gene promoter mutation-142G > A in a patient with familial pulmonary arterial hypertension].

OBJECTIVE

To investigate the relation between bone morphogenetic protein type II receptor (BMPR2) gene promoter mutation and pulmonary arterial hypertension (PAH).

METHODS

Peripheral blood samples were collected from a 36-year-old female patient with familial PAH (FPAH), 19 idiopathic PAH (IPAH) patients, and 50 healthy controls. DNA sequencing was conducted for the position -2022 bp upstream of the promoter transcription start point of BMPR2 gene. Two fragments carrying BMPR2 promoter mutation -142A and wild -142G allele were amplified and cloned respectively into the pGL3-basic dual-luciferase reporter gene vector, thus generating two luciferase reporter constructs: pGL3-BMPR2-wild recombinant plasmid (carrying -142G allele) and pGL3-BMPR2-mut recombinant plasmid (carrying -142A allele). Human pulmonary arterial smooth muscle cells (HPASMCs) and human pulmonary arterial endothelial cells (HPAECs) were cultured and transfected with pGL3-BMPR2-wild and pGL3-BMPR2-mut recombinant plasmids respectively. The transcriptional activity levels of these 2 recombinant plasmids were measured by Veritas Microplate Luminometer, and were calculated as the ratio of firefly luciferase activity to Renilla luciferase activity. The binding sites for transcriptional factors on the flanking sequence of the wild and mutant BMPR2 gene promoter regions were analyzed by using the MAPPER Search Engine.

RESULTS

A mutation -142G > A in the promoter region of BMPR2 gene was found in this female patient with FPAH. The transcriptional activity levels of the BMPR2 promoter carrying -142A allele in the HPASMCs and HPAECs were (9.58 +/- 3.85) and (59.07 +/- 25.54) respectively, both significantly lower than those of the BMPR2 promoter carrying -142G allele [(16.80 +/- 3.55) and (115.58 +/- 38.02) respectively, both P < 0.05]. The binding site of specificity protein 3, the potential transcriptional factor, was deleted in the BMPR2 promoter carrying -142A allele compared to the BMPR2 promoter carrying -142G allele.

CONCLUSION

BMPR2 promoter mutation -142G > A may be associated with FPAH.