Chylomicron remnants: mediators of endothelial dysfunction?

2007 ◽  
Vol 35 (3) ◽  
pp. 442-445 ◽  
Author(s):  
C.P.D. Wheeler-Jones

Vascular disease is initiated by activation of the endothelium characterized by the predominance of pro-inflammatory and pro-coagulant changes in endothelial cells (ECs) referred to collectively as ‘endothelial dysfunction’. There is increasing evidence that lipoproteins of dietary origin modulate EC function and the use of artificial chylomicron remnant-like particles (CRLPs) in vitro is now beginning to shed light on the molecular mechanisms through which these particles influence cell behaviour. CRLPs enriched in n−6 PUFAs (polyunsaturated fatty acids) influence the production of vasoactive mediators by ECs in a pro-inflammatory manner. Thus CRLPs reduce the synthesis and release of nitric oxide and alter the balance of release of vasodilator versus vasoconstrictor eicosanoids. These changes are accompanied by induction of cyclo-oxygenase-2 expression and activity as well as increased expression of adhesion molecules and the antioxidant defence enzyme haem oxygenase-1. CRLPs also activate a number of intracellular signalling pathways, including NF-κB (nuclear factor κB) and MAPKs (mitogen-activated protein kinases), which may be involved in mediating their effects on gene expression. The effects of CRLPs on EC behaviour can also be modulated by the type of fat/oxidation status of the particles. These findings support the hypothesis that lipoproteins of dietary origin directly regulate molecular events in the vascular wall.

2014 ◽  
Vol 34 (4) ◽  
pp. 790-800 ◽  
Author(s):  
Eiji Horio ◽  
Tsuyoshi Kadomatsu ◽  
Keishi Miyata ◽  
Yasumichi Arai ◽  
Kentaro Hosokawa ◽  
...  

Objective— Cardiovascular disease (CVD), the most common morbidity resulting from atherosclerosis, remains a frequent cause of death. Efforts to develop effective therapeutic strategies have focused on vascular inflammation as a critical pathology driving atherosclerosis progression. Nonetheless, molecular mechanisms underlying this activity remain unclear. Here, we ask whether angiopoietin-like protein 2 (Angptl2), a proinflammatory protein, contributes to vascular inflammation that promotes atherosclerosis progression. Approach and Results— Histological analysis revealed abundant Angptl2 expression in endothelial cells and macrophages infiltrating atheromatous plaques in patients with cardiovascular disease. Angptl2 knockout in apolipoprotein E–deficient mice ( ApoE −/− / Angptl2 −/− ) attenuated atherosclerosis progression by decreasing the number of macrophages infiltrating atheromatous plaques, reducing vascular inflammation. Bone marrow transplantation experiments showed that Angptl2 deficiency in endothelial cells attenuated atherosclerosis development. Conversely, ApoE −/− mice crossed with transgenic mice expressing Angptl2 driven by the Tie2 promoter ( ApoE −/− /Tie2- Angptl2 Tg), which drives Angptl2 expression in endothelial cells but not monocytes/macrophages, showed accelerated plaque formation and vascular inflammation because of increased numbers of infiltrated macrophages in atheromatous plaques. Tie2- Angptl2 Tg mice alone did not develop plaques but exhibited endothelium-dependent vasodilatory dysfunction, likely because of decreased production of endothelial cell–derived nitric oxide. Conversely, Angptl2 −/− mice exhibited less severe endothelial dysfunction than did wild-type mice when fed a high-fat diet. In vitro, Angptl2 activated proinflammatory nuclear factor-κB signaling in endothelial cells and increased monocyte/macrophage chemotaxis. Conclusions— Endothelial cell–derived Angptl2 accelerates vascular inflammation by activating proinflammatory signaling in endothelial cells and increasing macrophage infiltration, leading to endothelial dysfunction and atherosclerosis progression.


2019 ◽  
Vol XIV (1) ◽  
Author(s):  
R.E. Kalinin ◽  
I.A. Suchkov ◽  
N.V. Korotkova ◽  
N.D. Mzhavanadze

2001 ◽  
Vol 280 (2) ◽  
pp. L354-L362 ◽  
Author(s):  
Pamela M. Lindroos ◽  
Yi-Zhe Wang ◽  
Annette B. Rice ◽  
James C. Bonner

Upregulation of the platelet-derived growth factor (PDGF) receptor-α (PDGFR-α) is a mechanism of myofibroblast hyperplasia during pulmonary fibrosis. We previously identified interleukin (IL)-1β as a major inducer of the PDGFR-α in rat pulmonary myofibroblasts in vitro. In this study, we report that staurosporine, a broad-spectrum kinase inhibitor, upregulates PDGFR-α gene expression and protein. A variety of other kinase inhibitors did not induce PDGFR-α expression. Staurosporine did not act via an IL-1β autocrine loop because the IL-1 receptor antagonist protein did not block staurosporine-induced PDGFR-α expression. Furthermore, staurosporine did not activate a variety of signaling molecules that were activated by IL-1β, including nuclear factor-κB, extracellular signal-regulated kinase, and c-Jun NH2-terminal kinase. However, both staurosporine- and IL-1β-induced phosphorylation of p38 mitogen-activated protein kinase and upregulation of PDGFR-α by these two agents was inhibited by the p38 inhibitor SB-203580. Finally, staurosporine inhibited basal and PDGF-stimulated mitogenesis over the same concentration range that induced PDGFR-α expression. Collectively, these data demonstrate that staurosporine is a useful tool for elucidating the signaling mechanisms that regulate PDGFR expression in lung connective tissue cells and possibly for evaluating the role of the PDGFR-α as a growth arrest-specific gene.


Author(s):  
Liping Su ◽  
Xiaocen Kong ◽  
Sze Jie Loo ◽  
Yu Gao ◽  
Jean-Paul Kovalik ◽  
...  

Induced pluripotent stem cells derived cells (iPSCs) not only can be used for personalized cell transfer therapy, but also can be used for modeling diseases for drug screening and discovery in vitro. Although prior studies have characterized the function of rodent iPSCs derived endothelial cells (ECs) in diabetes or metabolic syndrome, feature phenotypes are largely unknown in hiPSC-ECs from patients with diabetes. Here, we used hiPSC lines from patients with type 2 diabetes mellitus (T2DM) and differentiated them into ECs (dia-hiPSC-ECs). We found that dia-hiPSC-ECs had disrupted glycine homeostasis, increased senescence, and impaired mitochondrial function and angiogenic potential as compared with healthy hiPSC-ECs. These signature phenotypes will be helpful to establish dia-hiPSC-ECs as models of endothelial dysfunction for understanding molecular mechanisms of disease and for identifying and testing new targets for the treatment of endothelial dysfunction in diabetes.


2020 ◽  
Vol 11 (12) ◽  
Author(s):  
Ze-nan Zheng ◽  
Guang-zhao Huang ◽  
Qing-qing Wu ◽  
Heng-yu Ye ◽  
Wei-sen Zeng ◽  
...  

AbstractOral squamous cell carcinoma (OSCC) is the most common oral cancer. The molecular mechanisms of this disease are not fully understood. Our previous studies confirmed that dysregulated function of long non-coding RNA (lncRNA) AC007271.3 was associated with a poor prognosis and overexpression of AC007271.3 promoted cell proliferation, migration, invasion, and inhibited cell apoptosis in vitro, and promoted tumor growth in vivo. However, the underlying mechanisms of AC007271.3 dysregulation remained obscure. In this study, our investigation showed that AC007271.3 functioned as competing endogenous RNA by binding to miR-125b-2-3p and by destabilizing primary miR-125b-2, resulted in the upregulating expression of Slug, which is a direct target of miR-125b-2-3p. Slug also inhibited the expression of E-cadherin but N-cadherin, vimentin, and β-catenin had no obvious change. The expression of AC007271.3 was promoted by the canonical nuclear factor-κB (NF-κB) pathway. Taken together, these results suggested that the classical NF-κB pathway-activated AC007271.3 regulates EMT by miR-125b-2-3p/Slug/E-cadherin axis to promote the development of OSCC, implicating it as a novel potential target for therapeutic intervention in this disease.


2005 ◽  
Vol 33 (4) ◽  
pp. 701-704 ◽  
Author(s):  
K. Kashfi ◽  
B. Rigas

Nitric-oxide-donating aspirin (NO-ASA), consisting of ASA (aspirin) plus an -ONO2 moiety linked to it via a molecular spacer, is a new drug for cancer prevention. NO-ASA seems to overcome the low potency and toxicity of traditional ASA. The -ONO2 moiety is responsible for releasing NO, and it appears to be required for biological activity. In studies in vitro, NO-ASA inhibits the growth of colon, pancreatic, prostate, lung, skin, leukaemia and breast cancer cells, and is up to 6000-fold more potent than traditional ASA. This effect is owing to cell kinetics [inhibition of proliferation, induction of apoptosis (multiple criteria) and blocking the G1 to S cell-cycle transition] and cell signalling [inhibition of Wnt signalling (IC50=0.2 μM), inhibition of NF-κB (nuclear factor κB) activation (IC50=7.5 μM), inhibition of nitric oxide synthase-2 expression (IC50=48 μM), inhibition of MAPK (mitogen-activated protein kinase) signalling (IC50=10 μM) and induction of cyclo-oxygenase-2 at approx. 10 μM]. In studies in vivo, NO-ASA inhibits intestinal carcinogenesis in Min mice (tumour multiplicity was reduced by 59% after 3 weeks, with no effect in control animals and no side effects) and in the N-nitrosobis(2-oxopropyl)amine model of pancreatic cancer, where there was an 89% reduction in NO-ASA (3000 p.p.m. in the diet)-treated animals (P<0.001). There was no statistically significant effect by traditional ASA at equimolar doses. Our data indicate that NO-ASA is a highly promising agent for the prevention and/or treatment of cancer.


2016 ◽  
Vol 311 (2) ◽  
pp. L421-L432 ◽  
Author(s):  
Sarah K. Sasse ◽  
Mohammed O. Altonsy ◽  
Vineela Kadiyala ◽  
Gaoyuan Cao ◽  
Reynold A. Panettieri ◽  
...  

Airway smooth muscle is a major target tissue for glucocorticoid (GC)-based asthma therapies, however, molecular mechanisms through which the GC receptor (GR) exerts therapeutic effects in this key airway cell type have not been fully elucidated. We previously identified the nuclear factor-κB (NF-κB) inhibitor, A20 (TNFAIP3), as a mediator of cytokine repression by glucocorticoids (GCs) in airway epithelial cells and defined cooperative regulation of anti-inflammatory genes by GR and NF-κB as a key mechanistic underpinning of airway epithelial GR function. Here, we expand on these findings to determine whether a similar mechanism is operational in human airway smooth muscle (HASM). Using HASM cells derived from normal and fatal asthma samples as an in vitro model, we demonstrate that GCs spare or augment TNF-mediated induction of A20 ( TNFAIP3), TNIP1, and NFKBIA, all implicated in negative feedback control of NF-κB-driven inflammatory processes. We applied chromatin immunoprecipitation and reporter analysis to show that GR and NF-κB directly regulate A20 expression in HASM through cooperative induction of an intronic enhancer. Using overexpression, we show for the first time that A20 and its interacting partner, TNIP1, repress TNF signaling in HASM cells. Moreover, we applied small interfering RNA-based gene knockdown to demonstrate that A20 is required for maximal cytokine repression by GCs in HASM. Taken together, our data suggest that inductive regulation of A20 by GR and NF-κB contributes to cytokine repression in HASM.


2013 ◽  
Vol 19 (1) ◽  
pp. 17-31 ◽  
Author(s):  
Mariana Figuera-Losada ◽  
Camilo Rojas ◽  
Barbara S. Slusher

Complex biological processes such as inflammation, cell death, migration, proliferation, and the release of biologically active molecules can be used as outcomes in phenotypic assays during early stages of drug discovery. Although target-based approaches have been widely used over the past decades, a disproportionate number of first-in-class drugs have been identified using phenotypic screening. This review details phenotypic assays based on inhibition of microglial activation and their utility in primary and secondary screening, target validation, and pathway elucidation. The role of microglia, both in normal as well as in pathological conditions such as chronic neurodegenerative diseases, is reviewed. Methodologies to assess microglia activation in vitro are discussed in detail, and classes of therapeutic drugs known to decrease the proinflammatory and cytotoxic responses of activated microglia are appraised, including inhibitors of glutaminase, cystine/glutamate antiporter, nuclear factor κB, and mitogen-activated protein kinases.


Reproduction ◽  
2013 ◽  
Vol 146 (6) ◽  
pp. R217-R227 ◽  
Author(s):  
Tessa Lord ◽  
R John Aitken

With extended periods of time following ovulation, the metaphase II stage oocyte experiences deterioration in quality referred to as post-ovulatory oocyte ageing. Post-ovulatory ageing occurs both in vivo and in vitro and has been associated with reduced fertilization rates, poor embryo quality, post-implantation errors and abnormalities in the offspring. Although the physiological consequences of post-ovulatory oocyte ageing have largely been established, the molecular mechanisms controlling this process are not well defined. This review analyses the relationships between biochemical changes exhibited by the ageing oocyte and the symptoms associated with the ageing phenotype. We also discuss molecular events that are potentially involved in orchestrating post-ovulatory ageing with a particular focus on the role of oxidative stress. We propose that oxidative stress may act as the initiator for a cascade of events that create the aged oocyte phenotype. Specifically, oxidative stress has the capacity to cause a decline in levels of critical cell cycle factors such as maturation-promoting factor, impair calcium homoeostasis, induce mitochondrial dysfunction and directly damage multiple intracellular components of the oocyte such as lipids, proteins and DNA. Finally, this review addresses current strategies for delaying post-ovulatory oocyte ageing with a particular focus on the potential use of compounds such as caffeine or selected antioxidants in the development of more refined media for the preservation of oocyte integrity during IVF procedures.


2000 ◽  
Vol 28 (2) ◽  
pp. 7-12 ◽  
Author(s):  
M. M. Manson ◽  
K. A. Holloway ◽  
L. M. Howells ◽  
E. A. Hudson ◽  
S. M. Plummer ◽  
...  

For a disease such as cancer, where a number of alterations to normal cell function accumulate over time, there are several opportunities to inhibit, slow down or even reverse the process. Many of the changes which drive the disease process occur in cell-signalling pathways that regulate proliferation and apoptosis. As our knowledge of these complicated signalling networks improves, it is becoming clear that many molecules, both drugs and naturally occurring dietary constituents, can interact beneficially with deregulated pathways. Aspirin and other non-steroidal anti-inflammatory drugs, as well as natural compounds present in plants such as green vegetables and tea, can modulate signalling by affecting kinase activity and therefore phosphorylation of key molecules. Examples of pathways which can be modulated by these agents include activation of the transcription factor nuclear factor κB by tumour promoters or cytokines, signalling by growth factors through the growth-factor receptor/extracellular-regulated protein kinase pathways and by a number of other molecules through the stress-activated c-Jun N-terminal kinase and p38 pathways. These mitogen-activated protein kinase pathways regulate a number of transcription factors including c-Fos and c-Jun. Evidence exists, at least from in vitro experiments, that by targeting such pathways, certain dietary compounds may be able to restore abnormal rates of apoptosis and proliferation to more normal levels.


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