HLA-B35 and dsRNA induce endothelin-1 via activation of ATF4 in human microvascular endothelial cells.
Endothelin 1 (ET-1) is a key regulator of vascular homeostasis. We have recently reported that the presence of Human antigen class I, HLA-B35, contributes to human dermal microvascular endothelial cell (HDMEC) dysfunction by upregulating ET-1 and proinflammatory genes. Likewise, a Toll-like receptor...
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2013-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3575387?pdf=render |
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| author | Stefania Lenna Izabela Chrobak G Alessandra Farina Fernando Rodriguez-Pascual Santiago Lamas Robert Lafyatis Raffaella Scorza Maria Trojanowska |
| author_facet | Stefania Lenna Izabela Chrobak G Alessandra Farina Fernando Rodriguez-Pascual Santiago Lamas Robert Lafyatis Raffaella Scorza Maria Trojanowska |
| author_sort | Stefania Lenna |
| collection | DOAJ |
| description | Endothelin 1 (ET-1) is a key regulator of vascular homeostasis. We have recently reported that the presence of Human antigen class I, HLA-B35, contributes to human dermal microvascular endothelial cell (HDMEC) dysfunction by upregulating ET-1 and proinflammatory genes. Likewise, a Toll-like receptor 3 (TLR3) ligand, Poly(I:C), was shown to induce ET-1 expression in HDMECs. The goal of this study was to determine the molecular mechanism of ET-1 induction by these two agonists. Because HLA-B35 expression correlated with induction of Binding Immunoglobulin Protein (BiP/GRP78) and several heat shock proteins, we first focused on ER stress and unfolded protein response (UPR) as possible mediators of this response. ER stress inducer, Thapsigargin (TG), HLA-B35, and Poly(I:C) induced ET-1 expression with similar potency in HDMECs. TG and HLA-B35 activated the PERK/eIF2α/ATF4 branch of the UPR and modestly increased the spliced variant of XBP1, but did not affect the ATF6 pathway. Poly(I:C) also activated eIF2α/ATF4 in a protein kinase R (PKR)-dependent manner. Depletion of ATF4 decreased basal expression levels of ET-1 mRNA and protein, and completely prevented upregulation of ET-1 by all three agonists. Additional experiments have demonstrated that the JNK and NF-κB pathways are also required for ET-1 upregulation by these agonists. Formation of the ATF4/c-JUN complex, but not the ATF4/NF-κB complex was increased in the agonist treated cells. The functional role of c-JUN in responses to HLA-B35 and Poly(I:C) was further confirmed in ET-1 promoter assays. This study identified ATF4 as a novel activator of the ET-1 gene. The ER stress/UPR and TLR3 pathways converge on eIF2α/ATF4 during activation of endothelial cells. |
| first_indexed | 2024-12-23T13:10:15Z |
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| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-23T13:10:15Z |
| publishDate | 2013-01-01 |
| publisher | Public Library of Science (PLoS) |
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| spelling | doaj.art-e7c442256298469fb6aeeef0d68cdccb2022-12-21T17:45:46ZengPublic Library of Science (PLoS)PLoS ONE1932-62032013-01-0182e5612310.1371/journal.pone.0056123HLA-B35 and dsRNA induce endothelin-1 via activation of ATF4 in human microvascular endothelial cells.Stefania LennaIzabela ChrobakG Alessandra FarinaFernando Rodriguez-PascualSantiago LamasRobert LafyatisRaffaella ScorzaMaria TrojanowskaEndothelin 1 (ET-1) is a key regulator of vascular homeostasis. We have recently reported that the presence of Human antigen class I, HLA-B35, contributes to human dermal microvascular endothelial cell (HDMEC) dysfunction by upregulating ET-1 and proinflammatory genes. Likewise, a Toll-like receptor 3 (TLR3) ligand, Poly(I:C), was shown to induce ET-1 expression in HDMECs. The goal of this study was to determine the molecular mechanism of ET-1 induction by these two agonists. Because HLA-B35 expression correlated with induction of Binding Immunoglobulin Protein (BiP/GRP78) and several heat shock proteins, we first focused on ER stress and unfolded protein response (UPR) as possible mediators of this response. ER stress inducer, Thapsigargin (TG), HLA-B35, and Poly(I:C) induced ET-1 expression with similar potency in HDMECs. TG and HLA-B35 activated the PERK/eIF2α/ATF4 branch of the UPR and modestly increased the spliced variant of XBP1, but did not affect the ATF6 pathway. Poly(I:C) also activated eIF2α/ATF4 in a protein kinase R (PKR)-dependent manner. Depletion of ATF4 decreased basal expression levels of ET-1 mRNA and protein, and completely prevented upregulation of ET-1 by all three agonists. Additional experiments have demonstrated that the JNK and NF-κB pathways are also required for ET-1 upregulation by these agonists. Formation of the ATF4/c-JUN complex, but not the ATF4/NF-κB complex was increased in the agonist treated cells. The functional role of c-JUN in responses to HLA-B35 and Poly(I:C) was further confirmed in ET-1 promoter assays. This study identified ATF4 as a novel activator of the ET-1 gene. The ER stress/UPR and TLR3 pathways converge on eIF2α/ATF4 during activation of endothelial cells.http://europepmc.org/articles/PMC3575387?pdf=render |
| spellingShingle | Stefania Lenna Izabela Chrobak G Alessandra Farina Fernando Rodriguez-Pascual Santiago Lamas Robert Lafyatis Raffaella Scorza Maria Trojanowska HLA-B35 and dsRNA induce endothelin-1 via activation of ATF4 in human microvascular endothelial cells. PLoS ONE |
| title | HLA-B35 and dsRNA induce endothelin-1 via activation of ATF4 in human microvascular endothelial cells. |
| title_full | HLA-B35 and dsRNA induce endothelin-1 via activation of ATF4 in human microvascular endothelial cells. |
| title_fullStr | HLA-B35 and dsRNA induce endothelin-1 via activation of ATF4 in human microvascular endothelial cells. |
| title_full_unstemmed | HLA-B35 and dsRNA induce endothelin-1 via activation of ATF4 in human microvascular endothelial cells. |
| title_short | HLA-B35 and dsRNA induce endothelin-1 via activation of ATF4 in human microvascular endothelial cells. |
| title_sort | hla b35 and dsrna induce endothelin 1 via activation of atf4 in human microvascular endothelial cells |
| url | http://europepmc.org/articles/PMC3575387?pdf=render |
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