Comprehensive identification of signaling pathways for idiopathic pulmonary arterial hypertension

Abstract

Whole exome sequencing (WES) was used in the research of familial pulmonary arterial hypertension (FPAH). CAV1 and KCNK3 were found as two novel candidate genes of FPAH. However, few pathogenic genes were identified in idiopathic pulmonary arterial hypertension (IPAH). We conducted WES in 20 unrelated IPAH patients who did not carry the known PAH-pathogenic variants among BMPR2, CAV1, KCNK3, SMAD9, ALK1, and ENG. We found a total of 4,950 variants in 3,534 genes, including 4,444 single-nucleotide polymorphisms and 506 insertions/deletions (InDels). Through the comprehensive and multilevel analysis, we disclosed several novel signaling cascades significantly connected to IPAH, including variants related to cadherin signaling pathway, dilated cardiomyopathy, glucose metabolism, immune response, mucin-type O-glycosylation, phospholipase C (PLC)-activating G protein-coupled receptor (GPCR) signaling pathway, vascular contraction and generation, and voltage-dependent Ca2+ channels. We also conducted validation studies in five mutant genes related to PLC-activating GPCR signaling pathway potentially involved in intracellular calcium regulation through Sanger sequencing for mutation accuracy, qRT-PCR for mRNA stability, immunofluorescence for subcellular localization, Western blotting for protein level, Fura-2 imaging for intracellular calcium, and proliferation analysis for cell function. The validation experiments showed that those variants in CCR5 and C3AR1 significantly increased the rise of intracellular calcium and the variant in CCR5 profoundly enhanced proliferative capacity of human pulmonary artery smooth muscle cells. Thus, our study suggests that multiple genetically affected signaling pathways take effect together to cause the formation of IPAH and the development of right heart failure and may further provide new therapy targets or putative clues for the present treatments such as limited therapeutic effectiveness of Ca2+ channel blockers.

Pulmonary hypertension in developing countries: Limiting factors in time to diagnosis, specialised medications and contextualised recommendations

“… [2] This has given PH what is known as the ‘cancer-like’ feature. [31] To a certain extent, these complex pathway interactions [32] make PH a much more complex disease. PH cannot be attenuated with only vasodilators, and therefore the most efficacious treatment regimens for PH comprise several specialised medications that target multiple molecular pathways.…”

The Impact of Sex Chromosomes in the Sexual Dimorphism of Pulmonary Arterial Hypertension

“…The development of high-throughput sequencing approaches led to novel causal genes and additional pathways involved in PAH susceptibilities such as pathogenic or likely pathogenic genetic variants in potassium channels [potassium two pore domain channel subfamily K 3 (KCNK3), ATP Binding Cassette Subfamily C Member 8 (ABCC8), transcription factors [T-Box Transcription Factor 4 (TBX4) and SRY-Box Transcription Factor 17 (SOX17) [40][41][42][43][44][45] . Recently, Hodgson et al reported the association of the heterozygous mutations in the gene encoding the growth differentiation factor 2 (GDF2) and in two ligands for the BMPR2, the BMP type 9 and type 10, resulting in BMP9 loss of function and PAH 46 .…”

Calcium Sensing Receptor Variants Increase Pulmonary Hypertension Susceptibility

“…Study approval, population, methods, and statistical analysis are described in details in Supplemental Material and previous reports. 3,4,10,[13][14][15][16][17][18][19][20][21][22]…”