Isolation and characterization of endothelial-to-mesenchymal transition cells in pulmonary arterial hypertension

Abstract

Endothelial-to-mesenchymal transition (EndMT) is a process in which endothelial cells lose polarity and cell-to cell contacts, and undergo a dramatic remodeling of the cytoskeleton. It has been implicated in initiation and progression of pulmonary arterial hypertension (PAH). However, the characteristics of cells which have undergone EndMT cells in vivo have not been reported and so remain unclear. To study this, sugen5416 and hypoxia (SuHx)-induced PAH was established in Cdh5-Cre/Gt(ROSA)26Sor/J double transgenic mice, in which GFP was stably expressed in pan-endothelial cells. After 3 wk of SuHx, flow cytometry and immunohistochemistry demonstrated CD144-negative and GFP-positive cells (complete EndMT cells) possessed higher proliferative and migratory activity compared with other mesenchymal cells. While CD144-positive and α-smooth muscle actin (α-SMA)-positive cells (partial EndMT cells) continued to express endothelial progenitor cell markers, complete EndMT cells were Sca-1-rich mesenchymal cells with high proliferative and migratory ability. When transferred in fibronectin-coated chamber slides containing smooth muscle media, α-SMA robustly expressed in these cells compared with cEndMT cells that were grown in maintenance media. Demonstrating additional paracrine effects, conditioned medium from isolated complete EndMT cells induced enhanced mesenchymal proliferation and migration and increased angiogenesis compared with conditioned medium from resident mesenchymal cells. Overall, these findings show that EndMT cells could contribute to the pathogenesis of PAH both directly, by transformation into smooth muscle-like cells with higher proliferative and migratory potency, and indirectly, through paracrine effects on vascular intimal and medial proliferation.

Nintedanib ameliorates experimental pulmonary arterial hypertension via inhibition of endothelial mesenchymal transition and smooth muscle cell proliferation

“…Moreover, the contribution of functional changes in smooth muscle cells of different phenotypes occurs particularly in the establish phase (24). On the other hand, a greater contribution of neointimal lesions than of medial wall thickness in the development of PAH was shown in an experimental model (14), and the role of EndMT in the progression of neointimal lesions has been recently suggested (10–13).…”

“…Vascular endothelial cells acquire a mesenchymal phenotype following exposure to several cytokines and growth factors, including transforming growth factor β (TGF-β), PDGF, and FGF which are induced by shear stress, hypoxia, and inflammation (10). EndMT-modified endothelial cells acquire additional characteristics of mesenchymal cells, and recent reports have indicated a critical role of EndMT in the development of PAH-specific neointimal lesions in PAs (11–13). Although both medial wall thickness and neointimal lesions in PAs are common pathological findings in PAH, a greater contribution of neointimal lesions in the elevation of pulmonary arterial pressure was reported in experimental PAH (14), suggesting an important involvement of EndMT.…”

EOFAZ inhibits endothelial‑to‑mesenchymal transition through downregulation of KLF4

“…Similarly, EndMT contributes to intimal hyperplasia and early-lesion formation in atherosclerosis (15). Furthermore, EndMT contributes to progression of PAH, atherosclerosis and wound healing (16). Therefore, in the present study, it was hypothesized that EndMT may accelerate the pathogenesis of vascular remodeling.…”

“…EndMT is tightly controlled by a series of signaling networks, similar to the epithelial-to-mesenchymal transition (38). EndMT is involved in intima formation and pulmonary vascular angiogenesis (16) and may contribute to cardiac fibrosis (39); similar results have been observed in diabetes mellitus-induced cardiac fibrosis (40) and further studies confirmed that EndMT contributes to fibrogenesis associated with exposure to TGF-β1 (41). consistent with these previous results, the present study demonstrated that HUVEcs underwent phenotypic and biological behavioral transitions following TGF-β1 exposure consistent with fibrogenesis.…”

CrossTalk opposing view: The mouse SuHx model is not a good model of pulmonary arterial hypertension

“…They noted the necessity to investigate EMT in a mouse model that is characterized by these lesions such as the prolyl hydroxylase domain‐containing enzyme 2 (PHD2)‐deficient mouse (Suzuki et al . ).…”