scholarly journals Pathophysiology of Intracranial Aneurysms

Stroke ◽  
2020 ◽  
Vol 51 (8) ◽  
pp. 2505-2513 ◽  
Author(s):  
Jan Rodemerk ◽  
Andreas Junker ◽  
Bixia Chen ◽  
Daniela Pierscianek ◽  
Philipp Dammann ◽  
...  
Keyword(s):  
Intracranial Aneurysms ◽  
Image Features ◽  
Iron Deposition ◽  
Blue Staining ◽  
Prostaglandin E ◽  
Ultra High Field ◽  
Explorative Study ◽  
Cox 2 ◽  
Magnetic Resonance Imaging Mri ◽  
Prostaglandin H

Background and Purpose: The pathophysiology of development, growth, and rupture of intracranial aneurysms (IAs) is only partly understood. Cyclooxygenase 2 (COX-2) converts arachidonic acid to prostaglandin H 2 , which, in turn, is isomerized to prostaglandin E 2 . In the human body, COX-2 plays an essential role in inflammatory pathways. This explorative study aimed to investigate COX-2 expression in the wall of IAs and its correlation to image features in clinical (1.0T, 1.5T, and 3.0T) magnetic resonance imaging (MRI) and ultra-high-field 7T MRI. Methods: The study group comprised 40 patients with partly thrombosed saccular IAs. The cohort included 17 ruptured- and 24 unruptured IAs, which had all been treated microsurgically. Formaldehyde-fixed paraffin-embedded samples were immunohistochemically stained with a monoclonal antibody against COX-2 (Dako, Santa Clara, CA; Clone: CX-294). We correlated Perls Prussian blue staining, MRI, and clinical data with immunohistochemistry, analyzed using the Trainable Weka Segmentation algorithm. Results: Aneurysm dome size ranged between 2 and 67 mm. The proportion of COX-2 positive cells ranged between 3.54% to 85.09%. An upregulated COX-2 expression correlated with increasing IA dome size ( P =0.047). Furthermore, there was a tendency of higher COX-2 expression in most ruptured IAs ( P =0.064). At all field strengths, MRI shows wall hypointensities due to iron deposition correlating with COX-2 expression ( P =0.022). Conclusions: Iron deposition and COX-2 expression in IAs walls correlate with signal hypointensity in MRI, which might, therefore, serve as a biomarker for IA instability. Furthermore, as COX-2 was also expressed in small unruptured IAs, it could be a potential target for specific medical treatment.

Expressions of cyclooxygenase-2 (COX-2) and prostaglandin E receptors (EPs) in gallbladder carcinoma (GBca)-association with tumor progression

2001 ◽  
Vol 120 (5) ◽  
pp. A573-A573
Author(s):  
J SHODA ◽  
T ASANO ◽  
T KAWAMOTO ◽  
Y MATSUZAKI ◽  
N TANAKA ◽  
...  
Keyword(s):  
Tumor Progression ◽  
Gallbladder Carcinoma ◽  
Cyclooxygenase 2 ◽  
Prostaglandin E ◽  
Cox 2

scholarly journals Intracellular prostaglandin E2 contributes to hypoxia-induced proximal tubular cell death

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Coral García-Pastor ◽  
Selma Benito-Martínez ◽  
Ricardo J. Bosch ◽  
Ana B. Fernández-Martínez ◽  
Francisco J. Lucio-Cazaña
Keyword(s):  
Hypoxia Inducible Factor ◽  
Renal Diseases ◽  
Prostaglandin E ◽  
Relevant Factor ◽  
Tubular Injury ◽  
Proximal Tubular Cells ◽  
Tubular Cells ◽  
Proximal Tubular ◽  
Cox 2 ◽  
Induced Apoptosis

AbstractProximal tubular cells (PTC) are particularly vulnerable to hypoxia-induced apoptosis, a relevant factor for kidney disease. We hypothesized here that PTC death under hypoxia is mediated by cyclo-oxygenase (COX-2)-dependent production of prostaglandin E2 (PGE2), which was confirmed in human proximal tubular HK-2 cells because hypoxia (1% O2)-induced apoptosis (i) was prevented by a COX-2 inhibitor and by antagonists of prostaglandin (EP) receptors and (ii) was associated to an increase in intracellular PGE2 (iPGE2) due to hypoxia-inducible factor-1α-dependent transcriptional up-regulation of COX-2. Apoptosis was also prevented by inhibitors of the prostaglandin uptake transporter PGT, which indicated that iPGE2 contributes to hypoxia-induced apoptosis (on the contrary, hypoxia/reoxygenation-induced PTC death was exclusively due to extracellular PGE2). Thus, iPGE2 is a new actor in the pathogenesis of hypoxia-induced tubular injury and PGT might be a new therapeutic target for the prevention of hypoxia-dependent lesions in renal diseases.

scholarly journals Processed Scutellaria baicalensis Georgi Extract Alleviates LPS-Induced Inflammatory and Oxidative Stress through a Crosstalk between NF-κB and KEAP1/NRF2 Signaling in Macrophage Cells

2021 ◽  
Vol 11 (13) ◽  
pp. 6055
Author(s):  
Akhtar Ali ◽  
En-Hyung Kim ◽  
Jong-Hyun Lee ◽  
Kang-Hyun Leem ◽  
Shin Seong ◽  
...  
Keyword(s):  
Scutellaria Baicalensis ◽  
Raw 264.7 Cells ◽  
Prostaglandin E ◽  
Scutellaria Baicalensis Georgi ◽  
Anticancer Effects ◽  
Tnf Α ◽  
Clinical Benefits ◽  
Anti Oxidant ◽  
Cox 2 ◽  
Anti Inflammatory

Prolonged inflammation results in chronic diseases that can be associated with a range of factors. Medicinal plants and herbs provide synergistic benefits based on the interaction of multiple phytochemicals. The dried root of Scutellaria baicalensis Georgi and its compounds possess anti-inflammatory, anti-oxidative, and anticancer effects. Processing is a traditional method to achieve clinical benefits by improving therapeutic efficacy and lowering toxicity. In this study, we investigated the anti-inflammatory and anti-oxidant effect of processed Scutellaria baicalensis Georgi extract (PSGE) against lipopolysaccharide (LPS) stimulated RAW 264.7 cells. Data using Griess assay and ELISA showed that PSGE decreased nitric oxide and prostaglandin E2 (PGE2) levels against LPS. PSGE treatment up-regulated 15-hydroxyprostaglandin dehydrogenase (PGDH), while cyclooxygenase (COX)-2 and microsomal prostaglandin E synthase (mPGES)-1 expression did not change. Interestingly, PGE2 inhibition was regulated by prostaglandin catabolic enzyme 15-PGDH rather than COX-2/mPGES-1, enzymes essential for PGE2 synthesis. Additionally, PSGE-suppressed LPS-induced IL-6 and TNF-α production through NF-κB signaling. NF-κB release from an inactive complex was inhibited by HO-1 which blocked IκBα phosphorylation. The ROS levels lowered by PSGE were measured with the H2DCFDA probe. PSGE activated NRF2 signaling and increased antioxidant Hmox1, Nqo1, and Txn1 gene expression, while reducing KEAP1 expression. In addition, pharmacological inhibition of HO-1 confirmed that the antioxidant enzyme induction by PSGE was responsible for ROS reduction. In conclusion, PSGE demonstrated anti-inflammatory and anti-oxidant effects due to NRF2/HO-1-mediated NF-κB and ROS inhibition.

scholarly journals SAT0315 INHIBITION OF MICROSOMAL PROSTAGLANDIN E SYNTHASE-1 (MPGES-1) BY GS-248 REDUCES PROSTAGLANDIN E2 BIOSYNTHESIS WHILE INCREASING PROSTACYCLIN IN HUMAN SUBJECTS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1103.2-1103
Author(s):  
C. Edenius ◽  
G. Ekström ◽  
J. Kolmert ◽  
R. Morgenstern ◽  
P. Stenberg ◽  
...  
Keyword(s):  
Whole Blood ◽  
Vascular Tone ◽  
Ex Vivo ◽  
Prostaglandin E ◽  
Maximum Plasma ◽  
Prostaglandin E Synthase ◽  
Cox 2 ◽  
Anti Inflammatory ◽  
Oral Doses ◽  
Microsomal Prostaglandin E Synthase

Background:Microsomal prostaglandin E synthase-1 (mPGES-1) catalyzes the formation prostaglandin (PG) E2from cyclooxygenase derived PGH2(1, 2). Inhibition of mPGES-1 leads to reduction of pro-inflammatory PGE2, while in vessels there is a concomitant increase of vasoprotective prostacyclin (PGI2) via shunting of PGH2(3,4). Apart from relieving symptoms in experimental animal models of inflammation, inhibitors of mPGES-1 cause relaxation of human medium sized arteries(4)and resistance arteries(5). The prostaglandin profile following mPGES-1 inhibition, explains the anti-inflammatory effects and also opens for the possibility of treating inflammatory diseases with concomitant vasculopathies. GS-248 is a potent and selective inhibitor of mPGES-1 exhibiting sub-nanomolar IC50in human whole bloodex vivo.Objectives:To evaluate safety, tolerability, pharmacokinetics and pharmacodynamics of GS-248.Methods:Healthy males and females (age 18–73 years) were included in the study. Six cohorts were administrated single oral doses of 1-300mg GS-248 (n=36) or placebo (n=12), three cohorts were administered once daily doses of 20-180mg GS-248 (n=18) or placebo (n=12) over ten days. In addition, 8 subjects were treated in a separate cohort with 200mg celecoxib bid for ten days. Blood samples were drawn for measurement of GS-248 exposure and production of PGE2after LPS incubationex vivo. The content of PGE2and PGI2metabolites was measured in urine. All analyses were performed by LC-MS/MS.Results:GS-248 was safe and well tolerated at all tested dose levels. Maximum plasma concentration was achieved 1 - 2.5 hours after dosing, and half-life was about 10 hours. Induced PGE2formationex vivo,catalyzed by mPGES-1, was completely inhibited for 24 hours after a single low dose (40mg) of GS-248. In urine, GS-248 dose-dependently reduced the excretion of PGE2metabolite by more than 50% whereas the excretion of PGI2metabolite increased more than twice the baseline levels. In the celecoxib cohort urinary metabolites of both PGE2and PGI2were reduced with approx 50%.Conclusion:GS-248 at investigated oral doses was safe and well tolerated. There was a sustained inhibition of LPS induced PGE2formation in whole blood. In urine, there was a metabolite shift showing reduced PGE2and increased PGI2, while celecoxib reduced both PGE2and PGI2metabolites. This suggests that selective inhibition of mPGES-1 results in systemic shunting of PGH2to PGI2formation, leading to anti-inflammatory and vasodilatory effects, while preventing platelet activation. The results warrant further evaluation of GS-248 in inflammatory conditions with vasculopathies such as Digital Ulcers and Raynaud’s Phenomenon in Systemic Sclerosis.References:[1]Korotkova M, Jakobsson PJ. Persisting eicosanoid pathways in rheumatic diseases. Nat Rev Rheumatol. 2014;10:229-41[2]Bergqvist F, Morgenstern R, Jakobsson PJ. A review on mPGES-1 inhibitors: From preclinical studies to clinical applications. Prostaglandins Other Lipid Mediat. 2019;147:106383[3]Kirkby NS, et al. Mechanistic definition of the cardiovascular mPGES-1/COX-2/ADMA axis. Cardiovasc Res. 2020[4]Ozen G, et al. Inhibition of microsomal PGE synthase-1 reduces human vascular tone by increasing PGI2: a safer alternative to COX-2 inhibition. Br J Pharmacol. 2017;174:4087-98[5]Larsson K, et al. Biological characterization of new inhibitors of microsomal PGE synthase-1 in preclinical models of inflammation and vascular tone. Br J Pharmacol. 2019;176:4625-38Disclosure of Interests:Charlotte Edenius Shareholder of: Gesynta Pharma, Consultant of: Gesynta Pharma,, Gunilla Ekström Shareholder of: Gesynta Pharma, Consultant of: Gesynta Pharma,, Johan Kolmert Consultant of: Gesynta Pharma,, Ralf Morgenstern Shareholder of: Gesynta Pharma, Employee of: Gesynta Pharma, Patric Stenberg Shareholder of: Gesynta Pharma, Employee of: Gesynta Pharma, Per-Johan Jakobsson Shareholder of: Gesynta Pharma, Grant/research support from: Gesynta Pharma, AstraZeneca,, Göran Tornling Shareholder of: Gesynta Pharma, Vicore Pharma,, Consultant of: Gesynta Pharma, Vicore Pharma, AnaMar

L-Arginine reduces downstream vascular contractility after flow-diverting device deployment: A preliminary study in a rabbit model

2021 ◽  
pp. 159101992110251
Author(s):  
Jennifer Ayers-Ringler ◽  
Praveen Kolumam Parameswaran ◽  
Zenith Khashim ◽  
Daying Dai ◽  
Yong-Hong Ding ◽  
...  
Keyword(s):  
Intracranial Aneurysms ◽  
Rabbit Model ◽  
Organ Bath ◽  
Potential Mechanism ◽  
Vascular Contractility ◽  
Arginine Hydrochloride ◽  
Preliminary Study ◽  
Cox 2 ◽  
Device Deployment ◽  
Flow Diverters

Background Flow diverters (FDs) are an effective treatment for intracranial aneurysms, though not free from hemorrhagic complications. A previous study demonstrated increased vascular contractility after FD-implantation as a potential mechanism of distal complications. Our study aimed to investigate whether L-arginine medication affects vascular contractility following FD deployment in a rabbit model. Methods FDs were implanted in the aorta of normal rabbits (+FD, n = 10), with sham-operated aorta as controls (n = 5). L-Arginine was given in the drinking water (2.25% L-arginine hydrochloride) of half of the +FD animals (+FD/+Arg). Force contraction vascular contractility studies were performed on the aortic rings proximal and distal to the FD using an organ bath. Total eNOS, eNOS(pS1177), eNOS(pT495), COX-2, and S100A4 were quantified by western analysis on total protein lysates from aortic segments, normalizing to GAPDH. Results Mean vascular contractility was 53% higher in distal relative to proximal aortic segments (P = 0.0038) in +FD animals, but were not significantly different in +FD/+Arg animals, or in sham-operated controls. The +FD animals expressed significantly reduced levels of eNOS(pS1177) than sham-operated controls (P = 0.0335), while both the +FD and +FD/+Arg groups had reduced levels of eNOS(pT495) relative to sham-operated controls (P = 0.0331 and P = 0.0311, respectively). Conclusion These results suggest that L-arginine medication reduces distal vascular contractility after FD treatment via nitric oxide production and thus might mitigate risk for downstream complications.

scholarly journals Validating Linear Systems Analysis for Laminar fMRI: Temporal Additivity for Stimulus Duration Manipulations

2020 ◽  
Author(s):  
Jelle A. van Dijk ◽  
Alessio Fracasso ◽  
Natalia Petridou ◽  
Serge O. Dumoulin
Keyword(s):  
Systems Theory ◽  
Linear Systems ◽  
Blood Oxygenation ◽  
Ultra High Field ◽  
Feedback Information ◽  
Oxygenation Level ◽  
Early Visual Cortex ◽  
Magnetic Resonance Imaging Mri ◽  
And Function ◽  
The Relationship

AbstractAdvancements in ultra-high field (7 T and higher) magnetic resonance imaging (MRI) scanners have made it possible to investigate both the structure and function of the human brain at a sub-millimeter scale. As neuronal feedforward and feedback information arrives in different layers, sub-millimeter functional MRI has the potential to uncover information processing between cortical micro-circuits across cortical depth, i.e. laminar fMRI. For nearly all conventional fMRI analyses, the main assumption is that the relationship between local neuronal activity and the blood oxygenation level dependent (BOLD) signal adheres to the principles of linear systems theory. For laminar fMRI, however, directional blood pooling across cortical depth stemming from the anatomy of the cortical vasculature, potentially violates these linear system assumptions, thereby complicating analysis and interpretation. Here we assess whether the temporal additivity requirement of linear systems theory holds for laminar fMRI. We measured responses elicited by viewing stimuli presented for different durations and evaluated how well the responses to shorter durations predicted those elicited by longer durations. We find that BOLD response predictions are consistently good predictors for observed responses, across all cortical depths, and in all measured visual field maps (V1, V2, and V3). Our results suggest that the temporal additivity assumption for linear systems theory holds for laminar fMRI. We thus show that the temporal additivity assumption holds across cortical depth for sub-millimeter gradient-echo BOLD fMRI in early visual cortex.

scholarly journals Capsaicin, a TRPV1 Ligand, Suppresses Bone Resorption by Inhibiting the Prostaglandin E Production of Osteoblasts, and Attenuates the Inflammatory Bone Loss Induced by Lipopolysaccharide

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Megumi Kobayashi ◽  
Kenta Watanabe ◽  
Satoshi Yokoyama ◽  
Chiho Matsumoto ◽  
Michiko Hirata ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Transient Receptor Potential ◽  
Interleukin 1 ◽  
Osteoclast Differentiation ◽  
Bone Diseases ◽  
Prostaglandin E ◽  
Transient Receptor Potential Vanilloid ◽  
Cox 2

Capsaicin, a transient receptor potential vanilloid type 1 (TRPV1) ligand, regulates nerve-related pain-sensitive signals, inflammation, and cancer growth. Capsaicin suppresses interleukin-1-induced osteoclast differentiation, but its roles in bone tissues and bone diseases are not known. This study examined the effects of capsaicin on inflammatory bone resorption and prostaglandin E (PGE) production induced by lipopolysaccharide (LPS) in vitro and on bone mass in LPS-treated mice in vivo. Capsaicin suppressed osteoclast formation, bone resorption, and PGE production induced by LPS in vitro. Capsaicin suppressed the expression of cyclooxygenase-2 (COX-2) and membrane-bound PGE synthase-1 (mPGES-1) mRNAs and PGE production induced by LPS in osteoblasts. Capsaicin may suppress PGE production by inhibiting the expression of COX-2 and mPGES-1 in osteoblasts and LPS-induced bone resorption by TRPV1 signals because osteoblasts express TRPV1. LPS treatment markedly induced bone loss in the femur in mice, and capsaicin significantly restored the inflammatory bone loss induced by LPS in mice. TRPV1 ligands like capsaicin may therefore be potentially useful as clinical drugs targeting bone diseases associated with inflammatory bone resorption.

Coordinate control of prostaglandin E2 synthesis and uptake by hyperosmolarity in renal medullary interstitial cells

2006 ◽  
Vol 290 (3) ◽  
pp. F641-F649 ◽  
Author(s):  
Michael L. Pucci ◽  
Shinichi Endo ◽  
Teruhisa Nomura ◽  
Run Lu ◽  
Cho Khine ◽  
...  
Keyword(s):  
Cell Surface ◽  
Characteristic Time ◽  
Water Deprivation ◽  
Interstitial Cells ◽  
Time Dependent ◽  
Prostaglandin E ◽  
Coordinate Control ◽  
Time Period ◽  
Cox 2 ◽  
Net Release

During water deprivation, prostaglandin E2 (PGE2), formed by renal medullary interstitial cells (RMICs), feedback inhibits the actions of antidiuretic hormone. Interstitial PGE2 concentrations represent the net of both PGE2 synthesis by cyclooxygenase (COX) and PGE2 uptake by carriers such as PGT. We used cultured RMICs to examine the effects of hyperosmolarity on both PG synthesis and PG uptake in the same RMIC. RMICs expressed endogenous PGT as assessed by mRNA and immunoblotting. RMICs rapidly took up [3H]PGE2 to a level 5- to 10-fold above background and with a characteristic time-dependent “overshoot.” Inhibitory constants ( Ki) for various PGs and PGT inhibitors were similar between RMICs and the cloned rat PGT. Increasing extracellular hyperosmolarity to the range of 335–485 mosM increased the net release of PGE2 by RMICs, an effect that was concentration dependent, maximal by 24 h, reversible, and associated with increased expression of COX-2. Over the same time period, there was decreased cell-surface activity of PGT due to internalization of the transporter. With continued exposure to hyperosmolarity over 7–10 days, PGE2 release remained elevated, COX-2 returned to baseline, and PGT-mediated uptake became markedly reduced. Our findings suggest that hyperosmolarity induces coordinated changes in COX-2-mediated PGE2 synthesis and PGT-mediated PGE2 uptake in RMICs.

Sign in / Sign up

Export Citation Format

Share Document