Dataset Information

Endogenous Transmembrane TNF-Alpha Protects Against Premature Senescence in Endothelial Colony Forming Cells.

ABSTRACT: Transmembrane tumor necrosis factor-? (tmTNF-?) is the prime ligand for TNF receptor 2, which has been shown to mediate angiogenic and blood vessel repair activities in mice. We have previously reported that the angiogenic potential of highly proliferative endothelial colony-forming cells (ECFCs) can be explained by the absence of senescent cells, which in mature endothelial cells occupy >30% of the population, and that exposure to a chronic inflammatory environment induced premature, telomere-independent senescence in ECFCs.The goal of this study was to determine the role of tmTNF-? in the proliferation of ECFCs.Here, we show that tmTNF-? expression on ECFCs selects for higher proliferative potential and when removed from the cell surface promotes ECFC senescence. Moreover, the induction of premature senescence by chronic inflammatory conditions is blocked by inhibition of tmTNF-? cleavage. Indeed, the mechanism of chronic inflammation-induced premature senescence involves an abrogation of tmTNF/TNF receptor 2 signaling. This process is mediated by activation of the tmTNF cleavage metalloprotease TNF-?-converting enzyme via p38 MAP kinase activation and its concurrent export to the cell surface by means of increased iRhom2 expression.Thus, we conclude that tmTNF-? on the surface of highly proliferative ECFCs plays an important role in the regulation of their proliferative capacity.

SUBMITTER: Green LA

PROVIDER: S-EPMC4867129 | biostudies-literature | 2016 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Endogenous Transmembrane TNF-Alpha Protects Against Premature Senescence in Endothelial Colony Forming Cells.

Green Linden A LA Njoku Victor V Mund Julie J Case Jaime J Yoder Mervin M Murphy Michael P MP Clauss Matthias M

Circulation research 20160413 10

<h4>Rationale</h4>Transmembrane tumor necrosis factor-α (tmTNF-α) is the prime ligand for TNF receptor 2, which has been shown to mediate angiogenic and blood vessel repair activities in mice. We have previously reported that the angiogenic potential of highly proliferative endothelial colony-forming cells (ECFCs) can be explained by the absence of senescent cells, which in mature endothelial cells occupy >30% of the population, and that exposure to a chronic inflammatory environment induced pre ...[more]

PMID: 27076598

Similar Datasets

Project description:BackgroundAccelerated cellular senescence within the nucleus pulposus (NP) region is a common feature of disc degeneration. Our previous work indicated that TNF-α promoted NP cell senescence. Although the intervertebral disc has been reported to be an estrogen-sensitive tissue, it is unclear whether estrogen can inhibit premature senescence of NP cells.ObjectiveTo investigate whether 17beta-estradiol (E2) can attenuate TNF-α-induced premature senescence of NP cells and the potential mechanism behind this regulatory process.MethodsIsolated NP cells and intact intervertebral discs from healthy rats were cultured with or without TNF-α, E2 or their combination. The pan estrogen receptor (ER) antagonist ICI 182780 was used to investigate the role of ER. Direct and indirect indicators including cell proliferation, SA-β-Gal activity, telomerase activity, cell cycle, and the expression of matrix macromolecules (aggrecan and collagen II) and senescence markers (p16 and p53) were used to evaluate the premature senescence of NP cells. Additionally, intracellular reactive oxygen species (ROS) and NF-κB/p65 activity were also detected in the NP cell cultures.ResultsIn the NP cell cultures, E2 significantly increased cell proliferation potency, telomerase activity and the expression of matrix macromolecules but attenuated SA-β-Gal activity, senescence marker (p53 and p16) expression and G1 cycle arrest in TNF-α-treated NP cells. Furthermore, E2 inhibited ROS generation and phospho-NF-κB/p65 expression in the TNF-α-treated NP cells. However, the ER antagonist ICI 182780 abolished the effects of E2 on TNF-α-treated NP cells. In the disc organ cultures, E2 also significantly increased matrix synthesis, whereas it decreased senescence marker (p53 and p16) expression, which could be abolished by the ER antagonist ICI 182780.ConclusionThe interaction between E2 and ER can attenuate TNF-α-induced premature senescence of rat NP cells through interfering with the ROS/NF-κB pathway.

Project description:Artificial small-diameter vascular grafts remain an unmet need in modern medicine, due to the thrombosis and neointimal hyperplasia that plague currently available synthetic devices. Tissue engineering techniques, including in vitro endothelialization, could offer a solution to this problem. A potential minimally invasive source of patient autologous endothelium is endothelial colony-forming cells (ECFCs), endothelial-like outgrowth products of circulating progenitors. While ECFCs respond to shear stress similar to mature endothelial cells (ECs), their response to luminal topographic micropatterning (TMP), a biomaterial modification with the potential to flow-independently, enhance the attachment, migration, gene expression, and function of mature ECs, remains unstudied. In this study, case-matched carotid endothelial cells (CaECs) and blood-derived ECFCs are statically cultured on polyurethane substrates with micropatterned pitches (pitch = peak to peak distance) ranging from 3-to 14 μm. On all pattern pitches tested, both CaECs and ECFCs showed significant and robust alignment to the angle of the micropatterns. Using a novel cell-by-cell image analysis technique, it was found that actin fibers similarly and significantly aligned to the angle of micropatterned features on all pitches tested. Microtubules analyzed through the same novel approach showed significant alignment on most pitches examined, with a greater variation in fiber angle overall. Interestingly, only CaECs showed significant cellular elongation, and notably to a lower degree than previously seen either in vivo due to flow or in vitro due to spatial growth restriction micropatterning, but consistent with earlier studies of TMP. Neither cell type displayed any significant micropattern-driven changes in the expression of KLF-2 or the downstream adhesion molecules it regulates. These results demonstrate that TMP flow-independently affects ECFC morphology, but that alignment alone is insufficient to drive protective changes in EC and ECFC function.

Dataset Information

Endogenous Transmembrane TNF-Alpha Protects Against Premature Senescence in Endothelial Colony Forming Cells.

Publications

Endogenous Transmembrane TNF-Alpha Protects Against Premature Senescence in Endothelial Colony Forming Cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets