Cellular response to hypoxia involves signaling via Smad proteins

Blood ◽  
2003 ◽  
Vol 101 (6) ◽  
pp. 2253-2260 ◽  
Author(s):  
Hong Zhang ◽  
Hasan O. Akman ◽  
Eric L. P. Smith ◽  
Jin Zhao ◽  
Joanne E. Murphy-Ullrich ◽  
...  

The transforming growth factor-β (TGF-β) family of cytokines regulates vascular development and inflammatory responses. We have recently shown that exposure of human umbilical vein endothelial cells (HUVECs) to hypoxia (1% O2) increases gene expression and bioactivation of TGF-β2 and induces its downstream effectors, Smad proteins (Smads), to associate with DNA. In the present study, we show that hypoxia-induced TGF-β2 gene expression is dependent on thrombospondin-1–mediated bioactivation of latent TGF-β. Blocking TGF-β2 but not TGF-β1 in hypoxic endothelial cell cultures inhibited induction of the TGF-β2 gene, indicating that an autocrine mechanism driven by bioactivation of TGF-β2 leads to its gene expression in hypoxic HUVECs. Exposure of HUVECs to hypoxia resulted in phosphorylation and nuclear transportation of Smad2 and Smad3 proteins as well as stimulation of transcriptional activities of Smad3 and the transcription factor hypoxia-inducible factor-1α and culminated in up-regulation of TGF-β2 gene expression. Autocrine regulation of TGF-β2 production in hypoxia may involve cross-talk between Smad3 and HIF-1α signaling pathways, and could be an important mechanism by which endothelial cells respond to hypoxic stress.

2017 ◽  
Vol 12 (10) ◽  
pp. 1934578X1701201 ◽  
Author(s):  
In-Chul Lee ◽  
Jong-Sup Bae

Sulforaphane (SFN) is produced when the enzyme myrosinase transforms glucoraphanin upon damage to the plant such as from chewing and effective in preventing carcinogenesis, diabetes, and inflammatory responses. Transforming growth factor β-induced protein (TGFBIp) is an extracellular matrix protein whose expression in several cell types is greatly increased by TGF-β. TGFBIp is released by human umbilical vein endothelial cells (HUVECs) and functions as a mediator of experimental sepsis. We hypothesized that SFN could reduce TGFBIp-mediated severe inflammatory responses in human endothelial cells and mice. Here, we investigated the anti-septic effects and underlying mechanisms of SFN against TGFBIp-mediated septic responses. SFN effectively inhibited lipopolysaccharide-induced release of TGFBIp and suppressed TGFBIp-mediated septic responses. In addition, SFN suppressed cecal ligation and puncture (CLP)-induced sepsis lethality and pulmonary injury. In conclusion, SFN suppressed TGFBIp-mediated and CLP-induced septic responses. Therefore, SFN could be a potential therapeutic agent for treatment of various severe vascular inflammatory diseases via inhibition of the TGFBIp signaling pathway.


2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Wen-cai Zhang ◽  
Yan-ge Wang ◽  
Zheng-feng Zhu ◽  
Fang-qin Wu ◽  
Yu-dong Peng ◽  
...  

Objective. To investigate the role of CD4+CD25+T cells (Tregs) in protecting fine particulate matter (PM-) induced inflammatory responses, and its potential mechanisms.Methods. Human umbilical vein endothelial cells (HUVECs) were treated with graded concentrations (2, 5, 10, 20, and 40 µg/cm2) of suspension of fine particles for 24h. For coculture experiment, HUVECs were incubated alone, with CD4+CD25−T cells (Teff), or with Tregs in the presence of anti-CD3 monoclonal antibodies for 48 hours, and then were stimulated with or without suspension of fine particles for 24 hours. The expression of adhesion molecules and inflammatory cytokines was examined.Results. Adhesion molecules, including vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1), and inflammatory cytokines, such as interleukin (IL-) 6 and IL-8, were increased in a concentration-dependent manner. Moreover, the adhesion of human acute monocytic leukemia cells (THP-1) to endothelial cells was increased and NF-κB activity was upregulated in HUVECs after treatment with fine particles. However, after Tregs treatment, fine particles-induced inflammatory responses and NF-κB activation were significantly alleviated. Transwell experiments showed that Treg-mediated suppression of HUVECs inflammatory responses impaired by fine particles required cell contact and soluble factors.Conclusions. Tregs could attenuate fine particles-induced inflammatory responses and NF-κB activation in HUVECs.


2002 ◽  
Vol 92 (3) ◽  
pp. 1152-1158 ◽  
Author(s):  
Scott Earley ◽  
Leif D. Nelin ◽  
Louis G. Chicoine ◽  
Benjimen R. Walker

Nitric oxide (NO) attenuates hypoxia-induced endothelin (ET)-1 expression in cultured umbilical vein endothelial cells. We hypothesized that NO similarly attenuates hypoxia-induced increases in ET-1 expression in the lungs of intact animals and reasoned that potentially reduced ET-1 levels may contribute to the protective effects of NO against the development of pulmonary hypertension during chronic hypoxia. As expected, hypoxic exposure (24 h, 10% O2) increased rat lung ET-1 peptide and prepro-ET-1 mRNA levels. Contrary to our hypothesis, inhaled NO (iNO) did not attenuate hypoxia-induced increases in pulmonary ET-1 peptide or prepro-ET-1 mRNA levels. Because of this surprising finding, we also examined the effects of NO on hypoxia-induced increases in ET peptide levels in cultured cell experiments. Consistent with the results of iNO experiments, administration of the NO donor S-nitroso- N-acetyl-penicillamine to cultured bovine pulmonary endothelial cells did not attenuate increases in ET peptide levels resulting from hypoxic (24 h, 3% O2) exposure. In additional experiments, we examined the effects of NO on the activity of a cloned ET-1 promoter fragment containing a functional hypoxia inducible factor-1 binding site in reporter gene experiments. Whereas moderate hypoxia (24 h, 3% O2) had no effect on ET-1 promoter activity, activity was increased by severe hypoxic (24 h, 0.5% O2) exposure. ET-1 promoter activity after S-nitroso- N-acetyl-penicillamine administration during severe hypoxia was greater than that in normoxic controls, although activity was reduced compared with that in hypoxic controls. These findings suggest that hypoxia-induced pulmonary ET-1 expression is unaffected by NO.


2003 ◽  
Vol 77 (21) ◽  
pp. 11822-11832 ◽  
Author(s):  
Rajas V. Warke ◽  
Kris Xhaja ◽  
Katherine J. Martin ◽  
Marcia F. Fournier ◽  
Sunil K. Shaw ◽  
...  

ABSTRACT Endothelial cells are permissive to dengue virus (DV) infection in vitro, although their importance as targets of DV infection in vivo remains a subject of debate. To analyze the virus-host interaction, we studied the effect of DV infection on gene expression in human umbilical vein endothelial cells (HUVECs) by using differential display reverse transcription-PCR (DD-RTPCR), quantitative RT-PCR, and Affymetrix oligonucleotide microarrays. DD identified eight differentially expressed cDNAs, including inhibitor of apoptosis-1, 2′-5′ oligoadenylate synthetase (OAS), a 2′-5′ OAS-like (OASL) gene, galectin-9, myxovirus protein A (MxA), regulator of G-protein signaling, endothelial and smooth muscle cell-derived neuropilin-like protein, and phospholipid scramblase 1. Microarray analysis of 22,000 human genes confirmed these findings and identified an additional 269 genes that were induced and 126 that were repressed more than fourfold after DV infection. Broad functional responses that were activated included the stress, defense, immune, cell adhesion, wounding, inflammatory, and antiviral pathways. These changes in gene expression were seen after infection of HUVECs with either laboratory-adapted virus or with virus isolated directly from plasma of DV-infected patients. Tumor necrosis factor alpha, OASL, and MxA and h-IAP1 genes were induced within the first 8 to 12 h after infection, suggesting a direct effect of DV infection. These global analyses of DV effects on cellular gene expression identify potentially novel mechanisms involved in dengue disease manifestations such as hemostatic disturbance.


2019 ◽  
Vol 20 (3) ◽  
pp. 458 ◽  
Author(s):  
Fernanda Ursoli Ferreira ◽  
Lucas Eduardo Botelho Souza ◽  
Carolina Hassibe Thomé ◽  
Mariana Tomazini Pinto ◽  
Clarice Origassa ◽  
...  

The endothelial-to-mesenchymal transition (EndMT) is a biological process where endothelial cells (ECs) acquire a fibroblastic phenotype after concomitant loss of the apical-basal polarity and intercellular junction proteins. This process is critical to embryonic development and is involved in diseases such as fibrosis and tumor progression. The signaling pathway of the transforming growth factor β (TGF-β) is an important molecular route responsible for EndMT activation. However, it is unclear whether the anatomic location of endothelial cells influences the activation of molecular pathways responsible for EndMT induction. Our study investigated the molecular mechanisms and signaling pathways involved in EndMT induced by TGF-β2 in macrovascular ECs obtained from different sources. For this purpose, we used four types of endothelial cells (coronary artery endothelial cells, CAECs; primary aortic endothelial cells PAECs; human umbilical vein endothelia cells, HUVECs; and human pulmonary artery endothelial cells, HPAECs) and stimulated with 10 ng/mL of TGF-β2. We observed that among the ECs analyzed in this study, PAECs showed the best response to the TGF-β2 treatment, displaying phenotypic changes such as loss of endothelial marker and acquisition of mesenchymal markers, which are consistent with the EndMT activation. Moreover, the PAECs phenotypic transition was probably triggered by the extracellular signal–regulated kinases 1/2 (ERK1/2) signaling pathway activation. Therefore, the anatomical origin of ECs influences their ability to undergo EndMT and the selective inhibition of the ERK pathway may suppress or reverse the progression of diseases caused or aggravated by the involvement EndMT activation.


2015 ◽  
Vol 4 (5) ◽  
pp. 1250-1259 ◽  
Author(s):  
Nuan P. Cheah ◽  
Jeroen L.A. Pennings ◽  
Jolanda P. Vermeulen ◽  
Roger W.L. Godschalk ◽  
Frederik J. van Schooten ◽  
...  

Aldehydes cause gene expression changes for genes associated with cardiovascular disease. Exposure to aldehydes from tobacco smoke needs to be controlled.


1998 ◽  
Vol 95 (16) ◽  
pp. 9506-9511 ◽  
Author(s):  
James N. Topper ◽  
Maria R. DiChiara ◽  
Jonathan D. Brown ◽  
Amy J. Williams ◽  
Dean Falb ◽  
...  

The transforming growth factor-β (TGF-β) superfamily of growth factors and cytokines has been implicated in a variety of physiological and developmental processes within the cardiovascular system. Smad proteins are a recently described family of intracellular signaling proteins that transduce signals in response to TGF-β superfamily ligands. We demonstrate by both a mammalian two-hybrid and a biochemical approach that human Smad2 and Smad4, two essential Smad proteins involved in mediating TGF-β transcriptional responses in endothelial and other cell types, can functionally interact with the transcriptional coactivator CREB binding protein (CBP). This interaction is specific in that it requires ligand (TGF-β) activation and is mediated by the transcriptional activation domains of the Smad proteins. A closely related, but distinct endothelial-expressed Smad protein, Smad7, which does not activate transcription in endothelial cells, does not interact with CBP. Furthermore, Smad2,4–CBP interactions involve the COOH terminus of CBP, a region that interacts with other regulated transcription factors such as certain signal transduction and transcription proteins and nuclear receptors. Smad–CBP interactions are required for Smad-dependent TGF-β-induced transcriptional responses in endothelial cells, as evidenced by inhibition with overexpressed 12S E1A protein and reversal of this inhibition with exogenous CBP. This report demonstrates a functional interaction between Smad proteins and an essential component of the mammalian transcriptional apparatus (CBP) and extends our insight into how Smad proteins may regulate transcriptional responses in many cell types. Thus, functional Smad–coactivator interactions may be an important locus of signal integration in endothelial cells.


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