EUK-207 protects human intestinal microvascular endothelial cells (HIMEC) against irradiation-induced apoptosis through the Bcl2 pathway

Abstract

Aim To elucidate the signaling mechanisms involved in the protective effect of EUK-207 against irradiation-induced cellular damage and apoptosis in human intestinal microvasculature endothelial cells (HIMEC). Methods HIMECs were irradiated and treated with EUK-207. Using hydroethidine and DCF-DA fluorescent probe the intracellular superoxide and reactive oxygen species (ROS) were determined. By real-time PCR and western blotting caspase-3, Bcl2 and Bax genes and proteins were analyzed. Proliferation was determined by [3H]-thymidine uptake. Immunofluorescence staining was used for translocation of p65 NFκB subunit. Key finding Irradiation increased ROS production, apoptosis, Bax, Caspase3 and NFkB activity in HIMEC and inhibited cell survival/growth/proliferation. EUK-207 restored the endothelial functions, markedly inhibited the ROS, up-regulated the Bcl2 and down-regulated Bax and prevented NFκB caspase 3 activity in HIMEC. Significance HIMEC provide a novel model to define the effect of irradiation induced endothelial dysfunction. Our findings suggest that EUK-207 effectively inhibits the damaging effect of irradiation.

Identification of Endothelial-to-Mesenchymal Transition as a Potential Participant in Radiation Proctitis

“…Protection from radiation effects by a superoxide dismutase mimetic reveals that irradiated HIMECs are subject to an oxidant microenvironment. 33 These features of endothelial cell oxidative stress, apoptosis, and global functional modifications after irradiation have been demonstrated in more common macrovascular and microvascular cell lines after radiation exposure. 12,34,35 The innovative concept in the present study was to determine whether radiation-induced phenotypic changes in HIMECs resemble EndoMT and whether this process participates in radiation-induced intestinal fibrosis.…”

“…11 In this study, we demonstrated that irradiated HIMECs derived from normal human colonic mucosa show increased expression of endothelial cell activation markers, such as tissue factor, plasminogen activator inhibitor-type 1, or Eselectin, and increased stress fiber formation. Otterson et al 33 showed that irradiation of HIMECs induced cell apoptosis and stress fiber formation, decreased cell migration in a scratch injury model in vitro, and reduced in vitro tube-like structure formation. Protection from radiation effects by a superoxide dismutase mimetic reveals that irradiated HIMECs are subject to an oxidant microenvironment.…”

Dickkopf-1, the Wnt antagonist, is induced by acidic pH and mediates epithelial cellular senescence in human reflux esophagitis

“…Proliferation was assessed by [ 3 H]thymidine uptake, as described elsewhere (39), or by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, as suggested by the manufacturer (Roche Diagnostics, Indianapolis, IN). Cells were seeded into 96-well plates (2 ϫ 10 4 /well) and, on the following day (day 0), treated with rhDkk1 or anti-Dkk1 Ab at the indicated concentrations.…”

TNF system in eutopic endometrium from women with endometriosis

“…In addition, the almost absent apoptosis in the eutopic and ectopic endometria coincided with TNFR1 protein reduction during the late secretory phase, allowing the survival and growth of the menstrual debris outside the uterus reported in endometriosis [3,4]. It is known that TNF, via its membrane receptors, may activates several processes leading to the activation of AP1 and NFκB transcription factors, which implicate the induction of several target genes involved in cell proliferation, inflammation and cell death in many tissues [20,22]. We previously reported the augmented NFκB binding to κB DNA sequence in the target genes in control endometria, and on the contrary, the reduced binding in eutopic endometria from women with endometriosis during the late secretory phase [20].…”