Description
Rationale: Schistosomiasis is one of the most common causes of pulmonary arterial hypertension worldwide, but the pathogenic mechanism by which the host inflammatory response contributes to vascular remodeling is unknown. We sought to identify signaling pathways that play protective or pathogenic roles in experimental Schistosoma-induced pulmonary vascular disease by whole-lung transcriptome analysis. Methods: Wildtype mice were experimentally exposed to S. mansoni ova by intraperitoneal sensitization followed by tail vein augmentation, and the phenotype assessed by right ventricular catheterization and tissue histology, RNA and protein analysis. Whole-lung transcriptome analysis by microarray and RNA sequencing was performed, the latter analyzed using 2 bioinformatic methods. Functional testing of the candidate IL-6 pathway was determined using IL6-knockout mice and the STAT3 inhibitor STI-201. Results: Wild-type mice exposed to S. mansoni had increased right ventricular systolic pressure and thickness of the pulmonary vascular media. Whole lung transcriptome analysis identified the IL6-STAT3-NFATc2 pathway as being upregulated, which was confirmed by PCR and immunostaining of lung tissue from S. mansoni-exposed mice and patients who died of the disease. Mice lacking IL6 or treated with STI-201 developed pulmonary hypertension associated with significant intima remodeling after exposure to S. mansoni. Conclusions: Whole lung transcriptome analysis identified upregulation of the IL6-STAT3-NFATc2 pathway, and IL6 signaling was found to be protective against Schistosoma-induced intimal remodeling.