Translational Advances in the Field of Pulmonary Hypertension Bench to Bedside: How Fundamental Discoveries in Science Are Advancing Our Understanding and Therapy of Pulmonary Arterial Hypertension

Identification of JPX-RABEP1 Pair as an Immune-Related Biomarker and Therapeutic Target in Pulmonary Arterial Hypertension by Bioinformatics and Experimental Analyses

Pulmonary arterial hypertension (PAH) is a pulmonary vascular disease characterized by pulmonary vascular remodeling and right heart enlargement the pathogenesis of PAH is complicated; no biologic-based therapy is available for the treatment of PAH, but recent studies suggest that inflammatory response and abnormal proliferation of pulmonary artery smooth muscle cells are the main pathogenic mechanism, while the role of immune-related long non-coding RNAs (lncRNAs) remains unclear. The aim of this study was to systematically analyze immune-related lncRNAs in PAH. Here, we downloaded a publicly available microarray data from PAH and control patients (GSE113439). A total of 243 up-regulated and 203 down-regulated differentially expressed genes (DEGs) were screened, and immune-related DEGs were further obtained from ImmPort. The immune-related lncRNAs were obtained by co-expression analysis of immune-related mRNAs. Then, immune-related lncRNAs-mRNAs network including 2 lncRNAs and 6 mRNAs was constructed which share regulatory miRNAs and have significant correlation. Among the lncRNA-mRNA pairs, one pair (JPX-RABEP1) was verified in the validating dataset GSE53408 and PAH mouse model. Furthermore, the immune cell infiltration analysis of the GSE113439 dataset revealed that the JPX-RABEP1 pair may participate in the occurrence and development of PAH through immune cell infiltration. Together, our findings reveal that the lncRNA-mRNA pair JPX-RABEP1 may be a novel biomarker and therapeutic target for PAH.

New Nitric Oxide Donor NCX 1443: Therapeutic Effects on Pulmonary Hypertension in the SAD Mouse Model of Sickle Cell Disease

Nitric oxide (NO) donors may be useful for treating pulmonary hypertension (PH) complicating sickle cell disease (SCD), as endogenous NO is inactivated by hemoglobin released by intravascular hemolysis. Here, we investigated the effects of the new NO donor NCX1443 on PH in transgenic SAD mice, which exhibit mild SCD without severe hemolytic anemia. In SAD and wild-type (WT) mice, the pulmonary pressure response to acute hypoxia was similar and was abolished by 100 mg/kg NCX1443. The level of PH was also similar in SAD and WT mice exposed to chronic hypoxia (9% O2) alone or with SU5416 and was similarly reduced by daily NCX1443 gavage. Compared with WT mice, SAD mice exhibited higher levels of HO-1, endothelial NO synthase, and PDE5 but similar levels of lung cyclic guanosine monophosphate. Cultured pulmonary artery smooth muscle cells from SAD mice grew faster than those from WT mice and had higher PDE5 protein levels. Combining NCX1443 and a PDE5 inhibitor suppressed the growth rate difference between SAD and WT cells and induced a larger reduction in hypoxic PH severity in SAD than in WT mice. By amplifying endogenous protective mechanisms, NCX1443 in combination with PDE5 inhibition may prove useful for treating PH complicating SCD.

S100A12 as a marker of worse cardiac output and mortality in pulmonary hypertension

BACKGROUND AND OBJECTIVE

Molecular biomarkers are needed to refine prognostication and phenotyping of pulmonary hypertension (PH) patients. S100A12 is an emerging biomarker of various inflammatory diseases. This study aims to determine the prognostic value of S100A12 in PH.

METHODS

Exploratory microarray analysis performed on peripheral blood mononuclear cells (PBMC) collected from idiopathic pulmonary fibrosis (IPF) patients suggested an association between S100A12 and both PH and mortality. So the current study was designed to evaluate for an association between S100A12 in peripheral blood collected from two well-phenotyped PH cohorts in two other centres to derive and validate an association between S100A12 protein serum concentrations and mortality.

RESULTS

The majority of the patients in the discovery and validation cohorts were either World Health Organization (WHO) group 1 (pulmonary arterial hypertension (PAH)) or 3 (lung disease-associated) PH. In the discovery PH cohort, S100A12 was significantly increased in patients with PH (n = 51) compared to controls (n = 22) (29.8 vs 15.7 ng/mL, P < 0.001) and negatively correlated with cardiac output (r = -0.58, P < 0.001) in PH patients. When S100A12 data were pooled from both cohorts, PAH and non-PAH PH patients had higher S100A12 compared to healthy external controls (32.6, 30.9, 15.7 ng/mL; P < 0.001). S100A12 was associated with an increased risk in overall mortality in PH patients in both the discovery (n = 51; P = 0.008) and validation (n = 40; P < 0.001) cohorts.

CONCLUSION

S100A12 levels are increased in PH patients and are associated with increased mortality.