Peroxisome proliferator-activated receptor ? inhibits pulmonary hypertension targeting store-operated calcium entry.

ABSTRACT: In this study, we investigated the role of peroxisome proliferator-activated receptor ? (PPAR?) on store-operated calcium entry (SOCE) and expression of the main store-operated calcium channel (SOCCs) components, canonical transient receptor potential (TRPC) in chronic hypoxia (CH)-induced pulmonary hypertension (CHPH) rat models. Small interfering RNA (siRNA) knockdown and adenoviral overexpression strategies were constructed for loss-of-function and gain-of-function experiments. PPAR? agonist rosiglitazone attenuates the pathogenesis of CHPH and suppresses Hif-1?, TRPC1, TRPC6 expression in the distal pulmonary arteries (PA), and SOCE in freshly isolated rat distal pulmonary arterial smooth muscle cells (PASMCs). By comprehensive use of knockdown and overexpression studies, and bioinformatical analysis of the TRPC gene promoter and luciferase reporter assay, we demonstrated that PPAR? exerts roles of anti-proliferation, anti-migration, and pro-apoptosis in PASMCs, likely by inhibiting the elevated SOCE and TRPC expression. These effects were inhibited under the conditions of hypoxia or Hif-1? accumulation. We also found that under hypoxia, accumulated Hif-1? protein acts as upstream of suppressed PPAR? level; however, targeted PPAR? rescue acts as negative feedback on suppressing Hif-1? level and Hif-1? mediated signaling pathway. PPAR? inhibits CHPH by targeting SOCE and TRPC via inhibiting Hif-1? expression and signaling transduction.Rosiglitazone protects PH by normalizing RVSP but not right ventricle hypotrophy. PPAR? inhibits PASMCs proliferation via targeting SOCE and TRPC by suppressing Hif-1?. PPAR? and Hif-1? share mutual inhibitory regulation in PASMCs. PPAR? restoration might be a beneficial strategy for PH treatment.

SUBMITTER: Wang Y 

PROVIDER: S-EPMC4334731 | biostudies-literature | 2015 Mar

REPOSITORIES: biostudies-literature