Publications by authors named "Demet S Guden"

The orphan receptor, G protein-coupled receptor (GPR) 75, which has been shown to mediate various effects of 20-hydroxyeicosatetraenoic acid (20-HETE), is considered as a therapeutic target in the treatment of cardiovascular diseases in which changes in the production of 20-HETE play a key role in their pathogenesis. Our previous studies showed that 20-HETE mimetic, N -(20-hydroxyeicosa-5[Z],14[Z]-dienoyl)glycine (5,14-HEDGE), protects against vascular hyporeactivity, hypotension, tachycardia, and arterial inflammation induced by lipopolysaccharide (LPS) in rats. This study tested the hypothesis that the GPR75 signaling pathway mediates these effects of 5,14-HEDGE in response to systemic exposure to LPS.

View Article and Find Full Text PDF

The present study aimed to explore the contribution of mammalian target of rapamycin (mTOR) in deoxycorticosterone acetate (DOCA) salt-induced hypertension and related pathophysiological changes in cardiovascular and renal tissues. DOCA salt loading resulted in an increase in systolic blood pressure, diastolic blood pressure, and mean blood pressure along with the activity of ribosomal protein S6, the effector protein of mTOR. Treatment with rapamycin, the selective inhibitor of mTOR, initiated at the fourth week of DOCA- salt administration normalized the systolic blood pressure and attenuated ribosomal protein S6 activity in the heart, aorta, and kidney.

View Article and Find Full Text PDF

Objectives: Serum or plasma levels of C-reactive protein (CRP) and high-sensitivity CRP (CRP) are widely used clinical markers of inflammation in other branches of medicine, whereas its clinical use in psychiatry has been limited to research studies. We aimed to assess the possibility of using CRP/CRP in psychiatric practice. This is a review and evaluation of various lines of evidence supporting the concept of CRP as a biomarker for psychiatric disorders in certain conditions.

View Article and Find Full Text PDF

It has been clearly indicated that osteoarthritis (OA) is an inflammatory and degenerative disease that could be promoted by Rho-kinase (ROCK); however, little is known about the role of ROCK/inhibitor κB alpha (IκB-α)/nuclear factor-κB (NF-κB) p65 pathway activation in interleukin-1β (IL-1β) induced inflammatory response and oxidative stress in primary human chondrocytes. To test this hypothesis, we focused on determining ROCK-II, IκB-α, p-IκB-α, NF-κB p65, p-NF-κB p65, IL-6, tumor necrosis factor alpha (TNF-α), cyclooxygenase-2 (COX-2), p22, and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subtype 4 (NOX4) protein expression, ROCK-II activity, NADPH oxidase levels, and total antioxidant capacity (TAC) in the presence and absence of ROCK-inhibitor fasudil. IL-1β (2 ng·mL, 24 h) increased the expression of ROCK-II, p-IκB-α, NF-κB p65, p-NF-κB p65, IL-6, TNF-α, COX-2, and p22 proteins, and decreased the expression of IκB-α, and the NOX4 protein level did not alter.

View Article and Find Full Text PDF

Neuroinflammation plays a critical role during sepsis triggered by microglial activation. Mammalian target of rapamycin (mTOR) has gained attraction in neuroinflammation, however, the mechanism remains unclear. Our goal was to assess the effects of mTOR inhibition by rapamycin on inflammation, microglial activation, oxidative stress, and apoptosis associated with the changes in the inhibitor-κB (IκB)-α/nuclear factor-κB (NF-κB)/hypoxia-inducible factor-1α (HIF-1α) pathway activity following a systemic challenge with lipopolysaccharide (LPS).

View Article and Find Full Text PDF

Epoxyeicosatrienoic acids (EETs) have anti-inflammatory effects and soluble epoxide hydrolase (sEH) inhibition might be a useful therapeutic approach to manage inflammatory disorders. The purpose of the study was to investigate whether nucleotide-binding and oligomerization domain-like receptor (NLR) C4 inflammasome-related pro-inflammatory and anti-inflammatory signaling pathways in the central nervous system (CNS) participates in the effect of trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl)urea (TPPU), a potent sEH inhibitor, to prevent hyperalgesia in the LPS-induced pain mouse model. The latency of pain within 30 s was measured by the hot plate test in male mice injected with saline, lipopolysaccharide (LPS) (10 mg/kg), and/or TPPU (0.

View Article and Find Full Text PDF

A selective RXR agonist, bexarotene, has been shown to have anti-inflammatory, anti-nociceptive, and neuroprotective effects in several models of numerous neurological diseases characterized by systemic inflammation. The mechanisms underlying these effects remains unknown. To elucidate these mechanisms, we investigated whether the TLR4/MyD88/TAK1/NF-κB/COX-2 signaling pathway in the CNS mediates the effect of bexarotene to prevent hyperalgesia in the LPS-induced inflammatory pain mouse model.

View Article and Find Full Text PDF

We aimed to determine the effect of soluble epoxide hydrolase (sEH) inhibition on chronic experimental autoimmune encephalomyelitis (EAE), a murine model of multiple sclerosis (MS), associated with changes in inflammasome-dependent and -independent inflammatory and anti-inflammatory pathways in the CNS of mice. C57BL/6 mice were used to induce chronic EAE by using an injection of MOG peptide/PT. Animals were observed daily and scored for EAE signs for 25 days after immunization.

View Article and Find Full Text PDF

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Septic shock, the most common form of vasodilatory shock, is a subset of sepsis in which circulatory and cellular/metabolic abnormalities are severe enough to increase mortality. Inflammatory shock constitutes the hallmark of sepsis, but also a final common pathway of any form of severe long-term tissue hypoperfusion.

View Article and Find Full Text PDF

Mammalian target of rapamycin (mTOR) has been recognized with potential immunomodulatory properties playing an important role in various physiopathological processes including ischemia-reperfusion (I/R) injury. I/R injury stimulate reactive oxygen and nitrogen species by activating nicotinamide adenine dinucleotide phosphate oxidase and inducible nitric oxide synthase, respectively. Controversial results have been obtained in different I/R models following localized I/R; however, the precise role of the mTOR signaling pathway remains undefined.

View Article and Find Full Text PDF

We have previously demonstrated that the activation of the spleen tyrosine kinase (Syk)/inhibitory-κB (IκB)-α/nuclear factor-κB (NF-κB) p65 signalling pathway contributes to hypotension and inflammatory response in a rat models of zymosan (ZYM)-induced non-septic shock. The purpose of this study was to further examine the possible mechanism underlying the effect of inhibition of Syk by BAY61-3606 via NF-κB activity at the level of nuclear translocation regarding the production of vasodilator and proinflammatory mediators in lipopolysaccharide (LPS) (septic)- and ZYM (non-septic)-induced shock. Administration of LPS (10 mg/kg, ip) or ZYM (500 mg/kg, ip) to male Wistar rats decreased mean arterial pressure and increased heart rate that was associated with an increase in the activities of cyclooxygenase and nitric oxide synthase, tumour necrosis factor-α, and interleukin-8 levels, and NF-κB activation and nuclear translocation in sera and/or cardiovascular and renal tissues.

View Article and Find Full Text PDF

Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors that can activate or inhibit the expression of many target genes by forming a heterodimer complex with the retinoid X receptor (RXR). The aim of this study was to investigate effects of bexarotene, a selective RXRα agonist, on the changes in renal, cardiac, hepatic, and pulmonary expression/activity of inducible nitric oxide synthase (iNOS) and cytochrome P450 (CYP) 4F6 in relation to PPARα/β/γ-RXRα heterodimer formation in a rat model of septic shock. Rats were injected with dimethyl sulfoxide or bexarotene 1 h after administration of saline or lipopolysaccharide (LPS).

View Article and Find Full Text PDF

Mammalian target of rapamycin (mTOR), a serine/threonine kinase regulate variety of cellular functions including cell growth, differentiation, cell survival, metabolism, and stress response, is now appreciated to be a central regulator of immune responses. Because mTOR inhibitors enhanced the anti-inflammatory activities of regulatory T cells and decreased the production of proinflammatory cytokines by macrophages, mTOR has been a pharmacological target for inflammatory diseases. In this study, we examined the role of mTOR in the production of proinflammatory and vasodilator mediators in zymosan-induced non-septic shock model in rats.

View Article and Find Full Text PDF

Spleen tyrosine kinase (Syk), a non-receptor tyrosine kinase, plays an important role in allergic diseases and inflammation. Syk triggers several intracellular signalling cascades including Toll-like receptor signalling to activate inflammatory responses following fungal infection but the role of this enzyme in zymosan (ZYM)-induced non-septic shock and its impacts on hypotension and inflammation in rats is not well understood. This study was conducted to determine the effects of Syk inhibition on ZYM-induced alterations in the expression and/or activities of Syk, inhibitor ĸB (IĸB)-α, and nuclear factor-ĸB (NF-ĸB) p65.

View Article and Find Full Text PDF

Mammalian target of rapamycin (mTOR), a serine/threonine kinase plays an important role in various pathophysiological processes including cancer, metabolic diseases, and inflammation. Although mTOR participates in Toll-like receptor 4 signalling in different cell types, the role of this enzyme in sepsis pathogenesis and its effects on hypotension and inflammation in endotoxemic rats remains unclear. In this study we investigated the effects of mTOR inhibition on lipopolysaccharide (LPS)-induced changes on expressions and/or activities of ribosomal protein S6 (rpS6), an mTOR substrate, nuclear factor-κB (NF-κB) p65, inhibitor κB (IκB)-α, inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 with production of nitric oxide, peroxynitrite, prostacyclin, and tumor necrosis factor (TNF)-α and activity of myeloperoxidase (MPO), which results in hypotension and inflammation.

View Article and Find Full Text PDF

The nucleotide-binding domain and leucine-rich repeat protein 3 (NLRP3), an intracellular signaling molecule that senses many environmental- and pathogen/host-derived factors, has been implicated in the pathogenesis of several diseases associated with inflammation. It has been suggested that NLRP3 inflammasome inhibitors may have a therapeutic potential in the treatment of NLRP3-related inflammatory diseases. The aim of this study was to determine whether inhibition of NLRP3 inflammasome prevents inflammatory hyperalgesia induced by lipopolysaccharide (LPS) in mice as well as changes in expression/activity of nuclear factor κB (NF-κB), caspase-1/11, nicotinamide adenine dinucleotide phosphate oxidase (NOX), and endothelial/neuronal/inducible nitric oxide synthase (eNOS/nNOS/iNOS) that may regulate NLRP3/apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC)/pro-caspase-1 inflammasome formation and activity by using a selective NLRP3 inflammasome inhibitor, MCC950.

View Article and Find Full Text PDF

Objectives: We have previously demonstrated that downregulation of the MyD88/TAK1-dependent signaling pathway associated with increased CYP4A1 expression and 20-HETE formation participates in the protective effect of N-(20-hydroxyeicosa-5[Z],14[Z]-dienoyl)glycine (5,14-HEDGE), a 20-HETE mimetic, against vascular hyporeactivity, hypotension, tachycardia, inflammation, and mortality in a rodent model of septic shock. The aim of this study was to determine whether increased renal and cardiovascular expression of PPARα/β/γ and RXRα associated with decreased expression and/or activity of AP-1 and importin-α3 participates in the protective effect of 5,14-HEDGE in response to systemic administration of lipopolysaccharide (LPS).

Methods: Conscious male Wistar rats received saline (4 ml/kg) or LPS (10 mg/kg) at time 0.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessionskou6r59nrn0vis3keepgto7rn2lifm2): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once