scholarly journals NADPH Oxidase 5 Induces Changes in the Unfolded Protein Response in Human Aortic Endothelial Cells and in Endothelial-Specific Knock-in Mice

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 194
Author(s):  
Adriana Cortés ◽  
Álvaro Pejenaute ◽  
Javier Marqués ◽  
Íñigo Izal ◽  
Silvia Cenoz ◽  
...  

Oxidative stress constitutes a key molecular mechanism in the development of cardiovascular diseases. A potential relationship between reactive oxygen species (ROS) driven by the NADPH oxidase family (NOX) and the unfolded protein response (UPR) has been postulated. Nevertheless, there is a lack of information about the crosstalk between NOX5 homologue and the UPR in a cardiovascular context. The main aim was to analyze NOX5-mediated ROS effects in the UPR and its importance in cardiovascular diseases. To this effect, we used an adenoviral NOX5-β overexpression model in human aortic endothelial cells (HAEC) and a conditional endothelial NOX5 knock-in mouse. Using expression arrays, we investigated NOX5-induced genomic changes in HAEC. Compared with the control HAEC, 298 genes were differentially expressed. Gene ontology analysis revealed the activation of numerous cellular routes, the most relevant being the UPR pathway. Using real-time PCR and Western Blot experiments, we confirmed that NOX5 overexpression induced changes in the expression of the UPR components, which were associated with increased apoptosis. Moreover, in endothelial-specific NOX5 knock-in mice, we found changes in the expression of the UPR components genes. In these mice, myocardial infarction was performed by permanent coronary artery ligation; however, NOX5 expression was not associated with differences in the UPR components mRNA levels. In these animals, we found significant associations between the UPR components gene expression and echocardiographic parameters. Our data support the idea that NOX5-derived ROS may modulate the UPR pathway in endothelial cells, which might play a relevant role in cardiac physiology.

2018 ◽  
Vol 120 ◽  
pp. S101
Author(s):  
Álvaro Pejenaute Martinez de Lizarrondo ◽  
Adriana Cortés Jiménez ◽  
Eduardo Ansorena Artieda ◽  
Silvia Cenoz Zubillaga ◽  
Carlos de Miguel Vázquez ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaomei Liu ◽  
Yanyan Guo ◽  
Jun Wang ◽  
Liangliang Zhu ◽  
Linlin Gao

Accumulating evidence suggests that fetal growth restriction (FGR) leads to the development of diabetes mellitus in adults. The aim of this study was to investigate the effect of protein malnutrition in utero on the pancreatic unfolded protein response (UPR) pathway in FGR offspring. An FGR model was developed by feeding a low-protein diet to pregnant rats throughout gestation. Eighty-four UPR pathway components in the pancreas were investigated by quantitative PCR arrays and confirmed by qPCR and western blotting. Activating transcription factor (Atf4 and Atf6), herpud1, protein kinase R-like endoplasmic reticulum kinase (Perk), X-box binding protein 1 (Xbp1), and the phosphorylation of eIF2α were upregulated, while cyclic AMP-responsive element-binding protein 3-like protein was markedly downregulated in FGR fetuses compared with controls. Investigation in adult offspring revealed temporal changes, for most UPR factors restored to normal, except that dysregulation of Atf6 and Creb3l3 maintained until adulthood. Moreover, autophagy was suppressed in FGR fetal pancreas and may be associated with decreased activation of AMP-activated protein kinase (Ampk). Apoptosis regulators Bax and cleaved-caspase 3 and 9 were upregulated in FGR fetal pancreas. Given that islet size and number were decreased in FGR fetus, we speculated that the aberrant intrauterine milieu impaired UPR signaling in fetal pancreas development. Whether these alterations early in life contribute to the predisposition of FGR fetuses to adult metabolic disorders invites further exploration.


2006 ◽  
Vol 26 (11) ◽  
pp. 2490-2496 ◽  
Author(s):  
Peter S. Gargalovic ◽  
Nima M. Gharavi ◽  
Michael J. Clark ◽  
Joanne Pagnon ◽  
Wen-Pin Yang ◽  
...  

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Zehra Irshad ◽  
Mingzhan Xue ◽  
Amal Ashour ◽  
James R. Larkin ◽  
Paul J. Thornalley ◽  
...  

2007 ◽  
Vol 177 (6) ◽  
pp. 1017-1027 ◽  
Author(s):  
Alicia A. Bicknell ◽  
Anna Babour ◽  
Christine M. Federovitch ◽  
Maho Niwa

The unfolded protein response (UPR) pathway helps cells cope with endoplasmic reticulum (ER) stress by activating genes that increase the ER's functional capabilities. We have identified a novel role for the UPR pathway in facilitating budding yeast cytokinesis. Although other cell cycle events are unaffected by conditions that disrupt ER function, cytokinesis is sensitive to these conditions. Moreover, efficient cytokinesis requires the UPR pathway even during unstressed growth conditions. UPR-deficient cells are defective in cytokinesis, and cytokinesis mutants activate the UPR. The UPR likely achieves its role in cytokinesis by sensing small changes in ER load and making according changes in ER capacity. We propose that cytokinesis is one of many cellular events that require a subtle increase in ER function and that the UPR pathway has a previously uncharacterized housekeeping role in maintaining ER plasticity during normal cell growth.


1998 ◽  
Vol 18 (4) ◽  
pp. 1967-1977 ◽  
Author(s):  
Ajith A. Welihinda ◽  
Witoon Tirasophon ◽  
Sarah R. Green ◽  
Randal J. Kaufman

ABSTRACT Cells respond to the accumulation of unfolded proteins in the endoplasmic reticulum (ER) by increasing the transcription of the genes encoding ER-resident chaperone proteins. Ire1p is a transmembrane protein kinase that transmits the signal from unfolded proteins in the lumen of the ER by a mechanism that requires oligomerization andtrans-autophosphorylation of its cytoplasmic-nucleoplasmic kinase domain. Activation of Ire1p induces a novel spliced form ofHAC1 mRNA that produces Hac1p, a transcription factor that is required for activation of the transcription of genes under the control of the unfolded-protein response (UPR) element. Searching for proteins that interact with Ire1p in Saccharomyces cerevisiae, we isolated PTC2, which encodes a serine/threonine phosphatase of type 2C. The Ptc2p interaction with Ire1p is specific, direct, dependent on Ire1p phosphorylation, and mediated through a kinase interaction domain within Ptc2p. Ptc2p dephosphorylates Ire1p efficiently in an Mg2+-dependent manner in vitro. PTC2 is nonessential for growth and negatively regulates the UPR pathway. Strains carrying null alleles ofPTC2 have a three- to fourfold-increased UPR and increased levels of spliced HAC1 mRNA. Overexpression of wild-type Ptc2p but not catalytically inactive Ptc2p reduces levels of splicedHAC1 mRNA and attenuates the UPR, demonstrating that the phosphatase activity of Ptc2p is required for regulation of the UPR. These results demonstrate that Ptc2p downregulates the UPR by dephosphorylating Ire1p and reveal a novel mechanism of regulation in the UPR pathway upstream of the HAC1 mRNA splicing event.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Elena Vladykoskaya ◽  
Petra Haberzettl ◽  
Yonis Ahmed ◽  
Bradford G Hill ◽  
Srinivas D Sithu ◽  
...  

Endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) are associated with atherosclerosis. Expression of UPR target genes such as activating transcription factor 3 (ATF3) and ATF4 is markedly increased in human atherosclerotic lesions. Staining for these proteins co-localizes with the staining with antibodies that recognize the aldehydic epitopes of oxidized LDL, suggesting that lipid-derived aldehydes could be involved in mediating ER stress and UPR. We examined the role of phospholipid aldehyde, 1-palmitoyl-2-(5-oxovaleroyl)- sn -glycero-3-phosphocholine (POVPC), unsaturated lipid-derived aldehydes- 4-hydroxy, trans -2-nonenal (HNE) and acrolein in the induction of ER-stress and UPR in human aortic endothelial cells (HAEC) and human umbical vein endothelial cells (HUVEC). POVPC, HNE and acrolein (10 –25 μM) increased the phosphorylation of eIF2α (eukaryotic initiation factor-2α) by 1.5–5 fold (P<0.001) and induced its downstream effector proteins - ATF4 (1.5–3.5 fold; P<0.001) and ATF3 (4–10 fold; P<0.0001). Incubation of HAEC with these aldehydes also increased the adhesion of THP-1 cells (monocyte) to HAEC by 1.4–1.6 fold (P<0.01). Moreover, incubation of endothelial cells with POVPC increased the mRNA level of the pro-inflammatory cytokine IL-8 by >25 fold (P<0.0001). Chemical chaperone, phenyl butyric acid (PBA), diminished aldehydes-induced expression of ATF3 and ATF4 proteins, endothelial cell-monocyte adhesion and IL-8 formation by 80–95% (P<0.001). POVPC (10–25 μM) also activated JNK by (3–6 fold) in HAEC. Reduction of POVPC to its corresponding alcohol, 1-palmitoyl-2-(5-hydroxyvaleroyl)- sn -glycero-3-phosphocholine (PHVPC) inhibited JNK activation by 74 ± 14 % (P<0.001). Pharmacological inhibition of JNK, inhibited the aldehyde-induced induction of ATF3 and ATF4 proteins by 70–90 % (P<0.001) but not the phosphorylation of eIF2α, and PBA inhibited the POVPC-induced JNK activation by 85 ± 11 % (P<0.001). These data suggest that lipoprotein oxidation products activate endothelial cells in part by inducing ER-stress and their inflammatory signaling could be attenuated by chemical chaperones of protein folding.


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