Long non-coding RNAs influence the transcriptome in pulmonary arterial hypertension: the role of PAXIP1-AS1.

In idiopathic pulmonary arterial hypertension (IPAH), global transcriptional changes induce a smooth muscle cell phenotype characterised by excessive proliferation, migration, and apoptosis resistance. Long non-coding RNAs (lncRNAs) are key regulators of cellular function. Using a compartment-specific transcriptional profiling approach, we sought to investigate the link between transcriptional reprogramming by lncRNAs and the maladaptive smooth muscle cell phenotype in IPAH. Transcriptional profiling of small remodelled arteries from 18 IPAH patients and 17 controls revealed global perturbations in metabolic, neuronal, proliferative, and immunological processes. We demonstrated an IPAH-specific lncRNA expression profile and identified the lncRNA PAXIP1-AS1 as highly abundant. Comparative transcriptomic analysis and functional assays revealed an intrinsic role for PAXIP1-AS1 in orchestrating the hyperproliferative and migratory actions of IPAH smooth muscle cells. Further, we showed that PAXIP1-AS1 mechanistically interferes with the focal adhesion axis via regulation of expression and phosphorylation of its downstream target paxillin. Overall, we show that changes in the lncRNA transcriptome contribute to the disease-specific transcriptional landscape in IPAH. Our results suggest that lncRNAs, such as PAXIP1-AS1, can modulate smooth muscle cell function by affecting multiple IPAH-specific transcriptional programmes. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Jandl K ，Thekkekara Puthenparampil H ，Marsh LM ，Hoffmann J ，Wilhelm J ，Veith C ，Sinn K ，Klepetko W ，Olschewski H ，Olschewski A ，Brock M ，Kwapiszewska G ... -  《-》

LncRNA PAXIP1-AS1 fosters the pathogenesis of pulmonary arterial hypertension via ETS1/WIPF1/RhoA axis.

Song R ，Lei S ，Yang S ，Wu SJ ... -  《-》

LncRNA-TCONS_00034812 in cell proliferation and apoptosis of pulmonary artery smooth muscle cells and its mechanism.

Long noncoding RNAs (lncRNAs) have been discovered to be playing important role in various biological processes. However, the contribution of lncRNAs to pulmonary artery hypertension (PAH) remains largely unknown. Pulmonary vascular remodeling is an important pathological feature of PAH, leading to increased vascular resistance and reduced compliance. Here, we investigated the biological role of lncRNAs in PAH. Differences in the lncRNAs and mRNAs between hypoxia PAH rats and normoxia rats were screened using microarray analysis. The results showed that 36 lncRNAs and 519 mRNAs were upregulated in the pulmonary arteries (PAs) of hypoxia PAH rats, whereas 111 lncRNAs and 246 mRNAs were downregulated. Expressions of the screened lncRNAs, including TCONS_00034812, were validated by real-time PCR. We revealed that the expression of TCONS_00034812 was significantly downregulated in PAs of PAH rats and hypoxia pulmonary artery smooth muscle cells (PASMCs). TCONS_00034812 knockdown promoted proliferation and inhibited apoptosis of PASMCs in vitro. Moreover, TCONS_00034812 regulated PASMCs function in vitro. We found that TCONS_00034812 increased the expression of transcription factors Stox1. TCONS_00034812 and Stox1 knockdown mediated PASMCs function through MAPK signaling. Our findings imply lncRNA as a critical regulator in PAH and demonstrate the potential of gene therapy and drug development for treating PAH. The present study reveals a novel mechano responsive lncRNA-TCONS_00034812, which modulates PASMCs proliferation and apoptosis, and participates in vascular remodeling during PAH.

Liu Y ，Sun Z ，Zhu J ，Xiao B ，Dong J ，Li X ... -  《-》

DNA microarray and signal transduction analysis in pulmonary artery smooth muscle cells from heritable and idiopathic pulmonary arterial hypertension subjects.

Pulmonary arterial hypertension (PAH) is characterized by increased pulmonary vascular smooth muscle contraction and proliferation. Here, we analyze genome-wide mRNA expression in human pulmonary arterial smooth muscle cells (HPASMC) isolated from three control, three hereditary (HPAH), and three idiopathic PAH (IPAH) subjects using the Affymetrix Human Gene ST 1.0 chip. The microarray analysis reveals the expression of 537 genes in HPAH and 1024 genes in IPAH changed compared with control HPASMC. Among those genes, 227 genes show similar directionality of expression in both HPAH and IPAH HPASMC. Ingenuity™ Pathway Analysis (IPA) suggests that many of those genes are involved in cellular growth/proliferation and cell cycle regulation and that signaling pathways such as the mitotic activators, polo-like kinases, ATM signaling are activated under PAH conditions. Furthermore, the analysis demonstrates downregulated mRNA expression of certain vasoactive receptors such as bradykinin receptor B2 (BKB2R). Using real time PCR, we verified the downregulated BKB2R expression in the PAH cells. Bradykinin-stimulated calcium influx is also decreased in PAH PASMC. IPA also identified transcriptional factors such p53 and Rb as downregulated, and FoxM1 and Myc as upregulated in both HPAH and IPAH HPASMC. The decreased level of phospho-p53 in PAH cells was confirmed with a phospho-protein array; and we experimentally show a dysregulated proliferation of both HPAH and IPAH PASMC. Together, the microarray experiments and bioinformatics analysis highlight an aberrant proliferation and cell cycle regulation in HPASMC from PAH subjects. These newly identified pathways may provide new targets for the treatment of both hereditary and idiopathic PAH.

Yu J ，Wilson J ，Taylor L ，Polgar P ... -  《-》

Mining the Stiffness-Sensitive Transcriptome in Human Vascular Smooth Muscle Cells Identifies Long Noncoding RNA Stiffness Regulators.

Vascular extracellular matrix stiffening is a risk factor for aortic and coronary artery disease. How matrix stiffening regulates the transcriptome profile of human aortic and coronary vascular smooth muscle cells (VSMCs) is not well understood. Furthermore, the role of long noncoding RNAs (lncRNAs) in the cellular response to stiffening has never been explored. This study characterizes the stiffness-sensitive (SS) transcriptome of human aortic and coronary VSMCs and identifies potential key lncRNA regulators of stiffness-dependent VSMC functions. Aortic and coronary VSMCs were cultured on hydrogel substrates mimicking physiological and pathological extracellular matrix stiffness. Total RNAseq was performed to compare the SS transcriptome profiles of aortic and coronary VSMCs. We identified 3098 genes (2842 protein coding and 157 lncRNA) that were stiffness sensitive in both aortic and coronary VSMCs (false discovery rate <1%). Hierarchical clustering revealed that aortic and coronary VSMCs grouped by stiffness rather than cell origin. Conservation analyses also revealed that SS genes were more conserved than stiffness-insensitive genes. These VSMC SS genes were less tissue-type specific and expressed in more tissues than stiffness-insensitive genes. Using unbiased systems analyses, we identified MALAT1 as an SS lncRNA that regulates stiffness-dependent VSMC proliferation and migration in vitro and in vivo. This study provides the transcriptomic landscape of human aortic and coronary VSMCs in response to extracellular matrix stiffness and identifies novel SS human lncRNAs. Our data suggest that the SS transcriptome is evolutionarily important to VSMCs function and that SS lncRNAs can act as regulators of stiffness-dependent phenotypes.

Yu CK ，Xu T ，Assoian RK ，Rader DJ ... -  《-》