Project description:Endothelial-to-mesenchymal transition (EndMT) is a dynamic transformation process that has a functional impact upon pathological vascular remodelling. The molecular mechanisms that govern EndMT remain largely unknown. By induction of EndMT in human primary endothelial cells (EC), using a combination of transforming growth factor-β2 (TGF-b2) and interleukin-1b (IL-1β), we identified the dramatic loss of the lncRNA MIR503HG, as a common signature across multiple primary EC types. Targeted depletion of MIR503HG spontaneously induced EndMT. Overexpression of MIR503HG repressed EndMT despite TGF-β2 and IL-1β co-stimulation. RNA-seq was carried out to identify the changes in gene expression induced by MIR503HG overexpression. We showed that over 25% of the EndMT-transcriptome signature was inhibited upon MIR503HG overexpression. Crucially, phenotypic changes induced by MIR503HG were independent of the functional regulation of miR-503 and miR-424, both harbored within the MIR503HG locus. Collectively, we identify the lncRNA MIR503HG as an essential regulator of EndMT.
Project description:Intraflagellar transport protein 88 (Ift88) is required for ciliogenesis and shear stress-induced dissolution of cilia in embryonic endothelial cells coincides with endothelial-to-mesenchymal transition (EndMT) in the developing heart. EndMT is also suggested to underlie heart and lung fibrosis, however, the mechanism linking endothelial Ift88, its effect on EndMT and organ fibrosis remains mainly unexplored. We silenced Ift88 in endothelial cells (ECs) in vitro and generated endothelial cell-specific Ift88-knockout mice (Ift88endo) in vivo to evaluate EndMT and its contribution towards organ fibrosis, respectively. Ift88-silencing in ECs led to mesenchymal cells-like changes in endothelial cells. The expression level of the endothelial markers (CD31, Tie-2 and VE-cadherin) were significantly reduced with a concomitant increase in the expression level of mesenchymal markers (αSMA, N-Cadherin and FSP-1) in Ift88-silenced ECs. Increased EndMT was associated with increased expression of profibrotic Collagen I expression and increased proliferation in Ift88-silenced ECs. Loss of Ift88 in ECs was further associated with increased expression of Sonic Hedgehog signaling effectors. In vivo, endothelial cells isolated from the heart and lung of Ift88endo mice demonstrated loss of Ift88 expression in the endothelium. The Ift88endo mice were born in expected Mendelian ratios without any adverse cardiac phenotypes at baseline. Cardiac and pulmonary endothelial cells isolated from the Ift88endo mice demonstrated signs of EndMT and bleomycin treatment exacerbated pulmonary fibrosis in Ift88endo mice. Pressure overload stress in the form of aortic banding did not reveal a significant difference in cardiac fibrosis between Ift88endo mice and control mice. Our findings demonstrate a novel association between endothelial cilia with EndMT and cell proliferation and also show that loss of endothelial cilia-associated increase in EndMT contributes specifically towards pulmonary fibrosis.
Project description:BackgroundAltered adipokine secretion in dysfunctional adipose tissue facilitates the development of atherosclerotic diseases including lower extremity peripheral artery disease (PAD). Asprosin is a recently identified adipokine and displays potent regulatory role in metabolism, but the relationship between asprosin and lower extremity PAD remains uninvestigated.Methods33 type 2 diabetes mellitus (T2DM) patients (DM), 51 T2DM patients with PAD (DM + PAD) and 30 healthy normal control (NC) volunteers were recruited and the blood samples were collected for detecting the circulatory asprosin level and metabolomic screening. RNA sequencing was performed using the aorta tissues from the type 2 diabetic db/db mice and human umbilical vein endothelial cells (HUVECs) were treated with asprosin to determine its impact on the endothelial-to-mesenchymal transition (EndMT).ResultsThe circulating levels of asprosin in DM + PAD group were significantly higher than that of NC group and the DM group. Circulating asprosin level was remarkably negatively correlated with ankle-brachial index (ABI), even after adjusting for age, sex, body mass index (BMI) and other traditional risk factors of PAD. Logistic regression analysis revealed that asprosin is an independent risk factor for PAD and receiver-operator characteristic (ROC) curve determined a good sensitivity (74.5%) and specificity (74.6%) of asprosin to distinguish PAD. Data from metabolomics displayed a typical characteristics of de novo amino acid synthesis in collagen protein production by myofibroblasts in patients with PAD and activation of TGF-β signaling pathway appeared in the aortic tissue of db/db mice. Asprosin directly induces EndMT in HUVECs in a TGF-β-dependent manner as TGF-β signaling pathway inhibitor SB431542 erased the promotional effect of asprosin on EndMT.ConclusionsElevated circulatory asprosin level is an independent risk factor of lower extremity PAD and might serve as a diagnostic marker. Mechanistically, asprosin directly induces EndMT that participates in vascular injury via activation of TGF-β signaling pathway. Trial registration This trial was registered at clinicaltrials.gov as NCT05068895.
Project description:Inflammatory-mediated pathological processes in the endothelium arise as a consequence of the dysregulation of vascular homeostasis. Of particular importance are mediators produced by stimulated monocytes/macrophages inducing activation of endothelial cells (ECs). This is manifested by excessive soluble pro-inflammatory mediator production and cell surface adhesion molecule expression. Nitro-fatty acids are endogenous products of metabolic and inflammatory reactions that display immuno-regulatory potential and may represent a novel therapeutic strategy to treat inflammatory diseases. The purpose of our study was to characterize the effects of nitro-oleic acid (OA-NO2) on inflammatory responses and the endothelial-mesenchymal transition (EndMT) in ECs that is a consequence of the altered healing phase of the immune response.The effect of OA-NO2 on inflammatory responses and EndMT was determined in murine macrophages and murine and human ECs using Western blotting, ELISA, immunostaining, and functional assays.OA-NO2 limited the activation of macrophages and ECs by reducing pro-inflammatory cytokine production and adhesion molecule expression through its modulation of STAT, MAPK and NF-?B-regulated signaling. OA-NO2 also decreased transforming growth factor-?-stimulated EndMT and pro-fibrotic phenotype of ECs. These effects are related to the downregulation of Smad2/3.The study shows the pleiotropic effect of OA-NO2 on regulating EC-macrophage interactions during the immune response and suggests a role for OA-NO2 in the regulation of vascular endothelial immune and fibrotic responses arising during chronic inflammation.These findings propose the OA-NO2 may be useful as a novel therapeutic agent for treatment of cardiovascular disorders associated with dysregulation of the endothelial immune response.
Project description:Arsenic exposure represents a major health concern increasing cancer risks, yet the mechanism of arsenic carcinogenesis has not been elucidated. We and others recently reported that cell malignant transformation by arsenic is accompanied by epithelial to mesenchymal transition (EMT). However, the role of EMT in arsenic carcinogenesis is not well understood. Although previous studies showed that short term exposure of endothelial cells to arsenic stimulated angiogenesis, it remains to be determined whether cells that were malignantly transformed by long term arsenic exposure have a pro-angiogenic effect. The objective of this study was to investigate the effect of arsenic-transformed human bronchial epithelial cells that underwent EMT on angiogenesis and the underlying mechanism. It was found that the conditioned medium from arsenic-transformed cells strongly stimulated tube formation by human umbilical vein endothelial cells (HUVECs). Moreover, enhanced angiogenesis was detected in mouse xenograft tumor tissues resulting from inoculation of arsenic-transformed cells. Mechanistic studies revealed that ?-catenin was activated in arsenic-transformed cells up-regulating its target gene expression including angiogenic-stimulating vascular endothelial growth factor (VEGF). Stably expressing microRNA-200b in arsenic-transformed cells that reversed EMT inhibited ?-catenin activation, decreased VEGF expression and reduced tube formation by HUVECs. SiRNA knockdown ?-catenin decreased VEGF expression. Adding a VEGF neutralizing antibody into the conditioned medium from arsenic-transformed cells impaired tube formation by HUVECs. Reverse transcriptase-PCR analysis revealed that the mRNA levels of canonical Wnt ligands were not increased in arsenic-transformed cells. These findings suggest that EMT in arsenic-transformed cells promotes angiogenesis through activating ?-catenin-VEGF pathway.
Project description:RationaleEndothelial cells have the ability to undergo endothelial-mesenchymal transitions (EndMTs), by which they acquire a mesenchymal phenotype and stem cell-like characteristics. We previously found that EndMTs occurred in the endothelium deficient in matrix γ-carboxyglutamic acid protein enabling endothelial cells to contribute cells to vascular calcification. However, the mechanism responsible for initiating EndMTs is not fully understood.ObjectiveTo determine the role of specific serine proteases and sex determining region Y-box 2 (Sox2) in the initiation of EndMTs.Methods and resultsIn this study, we used in vivo and in vitro models of vascular calcification to demonstrate that serine proteases and Sox2 are essential for the initiation of EndMTs in matrix γ-carboxyglutamic acid protein-deficient endothelium. We showed that expression of a group of specific serine proteases was highly induced in endothelial cells at sites of vascular calcification in Mgp null aortas. Treatment with serine protease inhibitors decreased both stem cell marker expression and vascular calcification. In human aortic endothelial cells, this group of serine proteases also induced EndMTs, and the activation of proteases was mediated by Sox2. Knockdown of the serine proteases or Sox2 diminished EndMTs and calcification. Endothelial-specific deletion of Sox2 decreased expression of stem cell markers and aortic calcification in matrix γ-carboxyglutamic acid protein-deficient mice.ConclusionsOur results suggest that Sox2-mediated activation of specific serine proteases is essential for initiating EndMTs, and thus, may provide new therapeutic targets for treating vascular calcification.
Project description:The endothelial-to-mesenchymal transition (EndoMT) is involved in the complex pathogenesis of renal fibrosis. The soluble proteoglycan endothelial cell-specific molecule 1 (ESM1) is significantly upregulated in many tumor cells and cirrhosis-related disease. The role of ESM1 in renal fibrosis is unknown. This study investigates the role of ESM1 in renal fibrosis, using an in vivo unilateral ureteral obstruction (UUO) mouse model of renal fibrosis and in vitro mouse kidney MES 13 cells overexpressing ESM1. We observed that ESM1 overexpression significantly increased the motility and migration of MES 13 cells, independent of cell viability. In ESM1-overexpressing MES 13 cells, we also observed elevated expression of mesenchymal markers (N-cadherin, vimentin, matrix metallopeptidase 9 (MMP9)) and the fibrosis marker ?-smooth muscle actin (?-SMA) and decreased expression of the endothelial marker vascular endothelial cadherin (VE-cadherin) and CD31. In a mouse model of fibrosis induced by unilateral ureter obstruction, we observed time-dependent increases in ESM1, ?-SMA, and vimentin expression and renal interstitial collagen fibers in kidney tissue samples. These results suggest that ESM1 may serve as an EndoMT marker of renal fibrosis progression.
Project description:PGC1α oppositely regulates cancer metastasis in melanoma, breast, and pancreatic cancer; however, little is known about its impact on lung cancer metastasis. Transcriptome and in vivo xenograft analysis show that a decreased PGC1α correlates with the epithelial-mesenchymal transition (EMT) and lung cancer metastasis. The deletion of a single Pgc1α allele in mice promotes bone metastasis of KrasG12D-driven lung cancer. Mechanistically, PGC1α predominantly activates ID1 expression, which interferes with TCF4-TWIST1 cooperation during EMT. Bioinformatic and clinical studies have shown that PGC1α and ID1 are downregulated in lung cancer, and correlate with a poor survival rate. Our study indicates that TCF4-TWIST1-mediated EMT, which is regulated by the PGC1α-ID1 transcriptional axis, is a potential diagnostic and therapeutic target for metastatic lung cancer.