CD133+ cells in pulmonary arterial hypertension

Abstract

Circulating mononuclear cells may play an important role for the vascular remodelling in pulmonary arterial hypertension (PAH), but studies addressing multiple progenitor populations are rare and inconsistent. We used a comprehensive fluorescence-activated cell sorting analysis of circulating mononuclear cells in 20 PAH patients and 20 age-and sex-matched controls, and additionally analysed CD133+ cells in the lung tissue of five PAH transplant recipients and five healthy controls (donor lungs). PAH patients were characterised by increased numbers of circulating CD133+ cells and lymphopenia as compared with control. In PAH, CD133+ subpopulations positive for CD117 or CD45 were significantly increased, whereas CD133+CD309+, CD133+CXCR2+ and CD133+CD31+ cells were decreased. In CD133+ cells, SOX2, Nanog, Ki67 and CXCR4 were not detected, but Oct3/4 mRNA was present in both PAH and controls. In the lung tissue, CD133+ cells included three main populations: type 2 pneumocytes, monocytes and undifferentiated cells without significant differences between PAH and controls. In conclusion, circulating CD133+ progenitor cells are elevated in PAH and consist of phenotypically different subpopulations that may be up-or downregulated. This may explain the inconsistent results in the literature. CD133+ type 2 pneumocytes in the lung tissue are not associated with circulating CD133+ mononuclear cells.