Marinobufagenin regulates permeability and gene expression of brain endothelial cells

Abstract

Marinobufagenin (MBG) is a cardiotonic steroid that increases in the circulation in preeclampsia. Preeclampsia and eclampsia are associated with cerebral edema. Therefore, we examined the effects of MBG on human brain microvascular endothelial cells (HBMEC) in vitro. MBG enhanced the permeability of HBMEC monolayers at 1-, 10-, and 100-nM doses, but had no effect at 0.1 nM. Agilent Human Gene Expression microarrays were utilized in these studies. MBG treatment (10 nM for 12 h) downregulated concentrations of the soluble VEGFR transcript sFLT by 59% but did not alter those of FLTv3 mRNA (determined by quantitative PCR). When treated and control HBMEC transcriptomes were interrogated on microarrays, 1,069 genes appeared to be regulated by MBG. Quantitative RT-PCR confirmed that MBG treatment upregulated ENKUR mRNA concentrations by 57%. Its protein product interacts with calmodulin and calcium channel proteins. MBG treatment downregulated several genes whose protein products are involved in cell adhesion (ITGA2B, FERMT1, CLDN16, and TMEM207) and cell signaling (GRIN2C, SLC8A1, and ESR1). The level of downregulation ranged from 22 to 66%. Altogether, MBG actively enhanced the permeability of HBMEC monolayers while downregulating genes involved in adhesion. MBG treatment had variable effects on ENKUR, GRIN2C, and SLC8A1 genes, all associated with calcium transport. These studies provide the basis for future investigations of MBG actions in normal physiology and disease.

Marinobufagenin inhibits glioma growth through sodium pump α1 subunit and ERK signaling‐mediated mitochondrial apoptotic pathway

“…The authors demonstrated that MBG could cause disruption of endothelial cell junction integrity, and this supports that MBG increases vascular permeability in endothelial cells for the first time. In addition, Ing et al [25] found that MBG enhanced the permeability of human brain microvascular endothelial cells (HBMECs). They also found that MBG could downregulate certain genes involved in adhesion in the endothelial monolayers obtained from the human brain.…”

Synthetic Receptors Induce Anti Angiogenic and Stress Signaling on Human First Trimester Cytotrophoblast Cells

“…Plasma levels of MBG, but not EO, become elevated in patients with moderate PE [25]. In addition to the effects of MBG on Na + K + ATPase and fibrotic signaling, MBG has also been shown to interfere with the proliferation, migration, and invasion of cytotrophoblast (CTB) cells [26,27,28] and to disrupt endothelial cell junctions [29,30]. Recently, we demonstrated that CINO impedes Sw.71 CTB cell line function via cell cycle arrest and apoptotic signaling [31].…”

“…MBG levels are elevated in most PE patients. In vitro data demonstrate the effects of MBG on endothelial function [30] and cell growth [53] and, importantly, on proliferative and angiogenic signalling in CTB cells [26,27,28]. Compelling data from multiple animal models, in which MBG levels are elevated prior to the onset of preE, suggests that MBG may represent a relevant target for preE therapeutics.…”

Cancerous Protein Network That Inhibits the Tumor Suppressor Function of WW Domain-Containing Oxidoreductase (WWOX) by Aberrantly Expressed Molecules

“…TMEM207 expression is strictly regulated in human tissues and cells. TMEM207 mRNA is found in human kidney (36) and brain microvascular endothelial cells (37); low levels are found in other cells and tissues, except intestinal goblet cells (23, 38). …”