Mesenchymal stromal cell therapy reduces lung inflammation and vascular remodeling and improves hemodynamics in experimental pulmonary arterial hypertension

Experimental research has reported beneficial effects of mesenchymal stromal cell (MSC) therapy in pulmonary arterial hypertension (PAH). However, these studies either were based on prophylactic protocols or assessed basic remodeling features without evaluating possible mechanisms. We analyzed the effects of MSC therapy on lung vascular remodeling and hemodynamics and its possible mechanisms of action in monocrotaline (MCT)-induced PAH. Twenty-eight Wistar rats were randomly divided into two groups. In the PAH group, animals received MCT 60 mg/kg intraperitoneally, while a control group received saline (SAL) instead. On day 14, both groups were further randomized to receive 10 adipose-derived MSCs or SAL intravenously (n = 7/group). On day 28, right ventricular systolic pressure (RVSP) and the gene expression of mediators associated with apoptosis, inflammation, fibrosis, Smad-1 levels, cell proliferation, and endothelial-mesenchymal transition were determined. In addition, lung histology (smooth muscle cell proliferation and plexiform-like injuries), CD68 and CD163 macrophages, and plasma levels of vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) were evaluated. In the PAH group, adipose-derived MSCs, compared to SAL, reduced mean RVSP (29 ± 1 vs 39 ± 2 mmHg, p