Interleukin-1 induces major phenotypic changes in human skin microvascular endothelial cells

Abstract

To determine the role of the pleiotropic cytokine interleukin-1 (IL-1) on the activation of endothelial cells during inflammation and angiogenesis, pure populations of human dermal microvascular endothelial cells (HDMEC) were obtained by immunoaffinity purification using Ulex europaeus agglutinin-1 and platelet endothelial cell adhesion molecule-1 (PECAM-1) antibody. Exposure of HDMEC to IL-1beta induced morphologic and physiologic changes characterized by 1) phenotypic modulation of endothelial cells from epithelioid to spindle-shaped cells accompanied by reorganization of vimentin filaments; 2) gradual decrease to a complete absence of the endothelial cell markers von Willebrand factor (vWf) and PECAM-1; and 3) increased capability to form tubule-like structures when overlaid with collagen gels. The IL-1 effect on cell morphology, growth, and decrease of endothelial cell antigens was potentiated by basic fibroblast growth factor (bFGF). Similar results were observed in mitotically arrested gamma-irradiated cells demonstrating that the spindle-shaped cells observed after IL-1 stimulation were derived from epithelioid endothelial cells and that DNA synthesis was not required to effect these changes. Immunostaining with an antibody specific for human fibroblasts was negative and further confirmed the endothelial cell origin of the spindle-shaped cells. These data demonstrate that IL-1 can induce phenotypic changes in HDMEC from epithelioid to spindle-shaped, mesenchymal-like cells, that these cells are more susceptible to stimulation by bFGF, and that they lose biochemical and functional properties characteristic of epithelioid HDMEC.

Mature Vascular Endothelium Can Give Rise to Smooth Muscle Cells via Endothelial-Mesenchymal Transdifferentiation

“…13,14,24 This is an interesting detail because, for example, dermal microvascular ECs are described as very susceptible to transdifferentiation into mesenchymal cells. 21 Thus, our data would support the assumption that the mesenchymal cells, often observed in primary EC cultures, are not the result of contamination but are often the result of transdifferentiation.…”

Endothelial Fate Mapping in Mice With Pulmonary Hypertension

“…On healing of the wound, SMA-positive myofibroblast cells persisted in the culture, leading Karasek and colleagues [41][42][43] to conclude that the myofibroblasts were derived from dermal microvascular endothelial cells. In this mouse model of experimental pulmonary hypertension, injury to pulmonary endothelial cells by MCTP eventually leads to activation of a program of smooth muscle gene expression.…”

Human Endothelial Cell Life Extension by Telomerase Expression

“…Human aortic endothelial cells (HAECs), human coronary arterial endothelial cells (HCAECs), and part of HDMECs for making hTERT1 were purchased from Clonetics. hTERT3 was established in our laboratory by preparation of primary HDMECs from neonatal foreskin as described previously (29,30). Growth media were from EBM-2 (or EBM) MV BulletKit (Clonetics).…”

“…5A are representative of all large vessel hTERT-EC lines and indicate no alteration in growth rates with continuous passage in vitro. Although mitotic rates were not analyzed in detail, simultaneous growth curves of parental HDMECs at PDL 10 and hTERT(ϩ) HDMECs at PDL 65 generated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method (30) showed no significant differences during a 7-day period. Similar to previous studies in human skin fibroblast and RPE lines produced by hTERT expression (26,27) hTERT(ϩ) EC lines are contact-inhibited and exhibited normal pRb phosphorylation patterns in response to confluency-induced growth arrest (Fig.…”