scholarly journals Global Transcriptional Profiling Reveals Novel Autocrine Functions of Interleukin 6 in Human Vascular Endothelial Cells

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Liza U. Ljungberg ◽  
Mulugeta M. Zegeye ◽  
Caroline Kardeby ◽  
Knut Fälker ◽  
Dirk Repsilber ◽  
...  

Background. Interleukin 6 (IL6) is a multifunctional cytokine produced by various cells, including vascular endothelial cells. IL6 has both pro- and non-/anti-inflammatory functions, and the response to IL6 is dependent on whether it acts via the membrane-bound IL6 receptor α (IL6Rα) (classic signaling) or the soluble form of the receptor (transsignaling). As human endothelial cells produce IL6 and at the same time express IL6Rα, we hypothesized that IL6 may have autocrine functions. Methods. Knockdown of IL6 in cultured human endothelial cells was performed using siRNA. Knockdown efficiency was evaluated using ELISA. RNA sequencing was employed to characterize the transcriptional consequence of IL6 knockdown, and Ingenuity Pathway Analysis was used to further explore the functional roles of IL6. Results. Knockdown of IL6 in cultured endothelial cells resulted in a 84-92% reduction in the release of IL6. Knockdown of IL6 resulted in dramatic changes in transcriptional pattern; knockdown of IL6 in the absence of soluble IL6Rα (sIL6Rα) led to differential regulation of 1915 genes, and knockdown of IL6 in the presence of sIL6Rα led to differential regulation of 1967 genes (fold change 1.5, false discovery rate<0.05). Pathway analysis revealed that the autocrine functions of IL6 in human endothelial cells are mainly related to basal cellular functions such as regulation of cell cycle, signaling, and cellular movement. Furthermore, we found that knockdown of IL6 activates functions related to adhesion, binding, and interaction of endothelial cells, which seem to be mediated mainly via STAT3. Conclusion. In this study, a large number of novel genes that are under autocrine regulation by IL6 in human endothelial cells were identified. Overall, our data indicate that IL6 acts in an autocrine manner to regulate basal cellular functions, such as cell cycle regulation, signaling, and cellular movement, and suggests that the autocrine functions of IL6 in human endothelial cells are mediated via IL6 classic signaling.

1981 ◽  
Author(s):  
R C Paton ◽  
R Guillot ◽  
Ph Passa

Reduced levels of prostaglandin I2 (PGI2) may contribute to the platelet hyper-reactivity and vascular complications found in diabetes mellitus. This study compared PGI2 production (PGI2-like activity and 6-keto-PGF1α levels) by vascular endothelial cells cultured in the presence of serum from 15 diabetics with proliferative retinopathy (5 treated by surgical hypophysectomy) and 15 sex-matched nondiabetic controls. Endothelial cells from human umbilical veins were cultured in M199 with either 20 % diabetic or control serum. At confluence, cultures were washed and stimulated with 0.1 NIH u/ml bovine thrombin. After 2 min incubation, the supernatant was tested for i)PGI2-like activity on ADP- induced platelet aggregation, results expressed as % inhibition and ii) 6-keto-PGF1α by radioimmunoassay, results expressed as nmol/ml. There was a significant correlation between PGI2-like activity and 6-keto-PGF-1α levels (r 0.78, p<0.001). The liberation of PGI2 from endothelial cells from different umbilical cords varied, but both PGI2-like activity (mean± SEM 21.9± 4.8 vs 28.3± 5.1 p<0.05) and 6-keto-PGF-1α (3.15± 0.68 vs 3.95 ±0.91 nmol/ml, p <0.05)were significantly lower in superantant from cells cultured in the presence of diabetic compared to control serum. PGI2 production was not significantly different in cells cultured with serum from hypophysectomised and nonhypophysectomised diabetics.These results suggest that serum from diabetics with proliferative retinopathy contains factors which impair the release or production of PGI2 by endothelial cells and that this effect is not mediated by the pituitary.


1999 ◽  
Vol 19 (4) ◽  
pp. 2763-2772 ◽  
Author(s):  
Francesc Viñals ◽  
Jacques Pouysségur

ABSTRACT Like other cellular models, endothelial cells in cultures stop growing when they reach confluence, even in the presence of growth factors. In this work, we have studied the effect of cellular contact on the activation of p42/p44 mitogen-activated protein kinase (MAPK) by growth factors in mouse vascular endothelial cells. p42/p44 MAPK activation by fetal calf serum or fibroblast growth factor was restrained in confluent cells in comparison with the activity found in sparse cells. Consequently, the induction of c-fos, MAPK phosphatases 1 and 2 (MKP1/2), and cyclin D1 was also restrained in confluent cells. In contrast, the activation of Ras and MEK-1, two upstream activators of the p42/p44 MAPK cascade, was not impaired when cells attained confluence. Sodium orthovanadate, but not okadaic acid, restored p42/p44 MAPK activity in confluent cells. Moreover, lysates from confluent 1G11 cells more effectively inactivated a dually phosphorylated active p42 MAPK than lysates from sparse cells. These results, together with the fact that vanadate-sensitive phosphatase activity was higher in confluent cells, suggest that phosphatases play a role in the down-regulation of p42/p44 MAPK activity. Enforced long-term activation of p42/p44 MAPK by expression of the chimera ΔRaf-1:ER, which activates the p42/p44 MAPK cascade at the level of Raf, enhanced the expression of MKP1/2 and cyclin D1 and, more importantly, restored the reentry of confluent cells into the cell cycle. Therefore, inhibition of p42/p44 MAPK activation by cell-cell contact is a critical step initiating cell cycle exit in vascular endothelial cells.


2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Huafang Wang ◽  
Xiaohang Ye ◽  
Haowen Xiao ◽  
Ni Zhu ◽  
Cong Wei ◽  
...  

Protein tyrosine phosphatases (PTPs) act as key regulators in various cellular processes such as proliferation, differentiation, and migration. Our previous research demonstrated that non-receptor-typed PTP21 (PTPN21), a member of the PTP family, played a critical role in the proliferation, cell cycle, and chemosensitivity of acute lymphoblastic leukemia cells. However, the role of PTPN21 in the bone marrow microenvironment has not yet been elucidated. In the study, we explored the effects of PTPN21 on human bone marrow-derived mesenchymal stem cells (BM-MSCs) via lentiviral-mediated overexpression and knock-down of PTPN21 in vitro. Overexpressing PTPN21 in BM-MSCs inhibited the proliferation through arresting cell cycle at the G0 phase but rendered them a higher osteogenic and adipogenic differentiation potential. In addition, overexpressing PTPN21 in BM-MSCs increased their senescence levels through upregulation of P21 and P53 and dramatically changed the levels of crosstalk with their typical target cells including immunocytes, tumor cells, and vascular endothelial cells. BM-MSCs overexpressing PTPN21 had an impaired immunosuppressive function and an increased capacity of recruiting tumor cells and vascular endothelial cells in a chemotaxis transwell coculture system. Collectively, our data suggested that PTPN21 acted as a pleiotropic factor in modulating the function of human BM-MSCs.


2003 ◽  
Vol 23 (9) ◽  
pp. 1535-1540 ◽  
Author(s):  
E. Karin Arkenbout ◽  
Maaike van Bragt ◽  
Eric Eldering ◽  
Chris van Bree ◽  
Jos M. Grimbergen ◽  
...  

2000 ◽  
Vol 275 (5) ◽  
pp. 3637-3644 ◽  
Author(s):  
Etsu Suzuki ◽  
Daisuke Nagata ◽  
Masao Yoshizumi ◽  
Masao Kakoki ◽  
Atsuo Goto ◽  
...  

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