scholarly journals A Representative GIIA Phospholipase A2 Activates Preadipocytes to Produce Inflammatory Mediators Implicated in Obesity Development

Biomolecules ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1593
Author(s):  
Elbio Leiguez ◽  
Priscila Motta ◽  
Rodrigo Maia Marques ◽  
Bruno Lomonte ◽  
Suely Vilela Sampaio ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Phospholipase A2 ◽  
Proinflammatory Mediators ◽  
Ep4 Receptor ◽  
Prostaglandin Synthase ◽  
Proinflammatory Responses ◽  
Cox 2 ◽  
Ep3 Receptor ◽  
Cytosolic Pla2 ◽  
Adipose Tissue Cells

Adipose tissue secretes proinflammatory mediators which promote systemic and adipose tissue inflammation seen in obesity. Group IIA (GIIA)-secreted phospholipase A2 (sPLA2) enzymes are found to be elevated in plasma and adipose tissue from obese patients and are active during inflammation, generating proinflammatory mediators, including prostaglandin E2 (PGE2). PGE2 exerts anti-lipolytic actions and increases triacylglycerol levels in adipose tissue. However, the inflammatory actions of GIIA sPLA2s in adipose tissue cells and mechanisms leading to increased PGE2 levels in these cells are unclear. This study investigates the ability of a representative GIIA sPLA2, MT-III, to activate proinflammatory responses in preadipocytes, focusing on the biosynthesis of prostaglandins, adipocytokines and mechanisms involved in these effects. Our results showed that MT-III induced biosynthesis of PGE2, PGI2, MCP-1, IL-6 and gene expression of leptin and adiponectin in preadipocytes. The MT-III-induced PGE2 biosynthesis was dependent on cytosolic PLA2 (cPLA2)-α, cyclooxygenases (COX)-1 and COX-2 pathways and regulated by a positive loop via the EP4 receptor. Moreover, MT-III upregulated COX-2 and microsomal prostaglandin synthase (mPGES)-1 protein expression. MCP-1 biosynthesis induced by MT-III was dependent on the EP4 receptor, while IL-6 biosynthesis was dependent on EP3 receptor engagement by PGE2. These data highlight preadipocytes as targets for GIIA sPLA2s and provide insight into the roles played by this group of sPLA2s in obesity.

scholarly journals A Metalloproteinase Induces an Inflammatory Response in Preadipocytes with the Activation of COX Signalling Pathways and Participation of Endogenous Phospholipases A2

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 921
Author(s):  
Priscila Motta Janovits ◽  
Elbio Leiguez ◽  
Viviane Portas ◽  
Catarina Teixeira
Keyword(s):  
Adipose Tissue ◽  
Inflammatory Response ◽  
Phospholipase A2 ◽  
Proteolytic Enzymes ◽  
Inflammatory Diseases ◽  
Prostaglandin E ◽  
Monocyte Chemoattractant Protein 1 ◽  
Phospholipases A2 ◽  
Proinflammatory Mediators ◽  
Adipose Tissue Cells

Matrix metalloproteinases (MMPs) are proteolytic enzymes that have been associated with the pathogenesis of inflammatory diseases and obesity. Adipose tissue in turn is an active endocrine organ capable of secreting a range of proinflammatory mediators with autocrine and paracrine properties, which contribute to the inflammation of adipose tissue and adjacent tissues. However, the potential inflammatory effects of MMPs in adipose tissue cells are still unknown. This study investigates the effects of BmooMPα-I, a single-domain snake venom metalloproteinase (SVMP), in activating an inflammatory response by 3T3-L1 preadipocytes in culture, focusing on prostaglandins (PGs), cytokines, and adipocytokines biosynthesis and mechanisms involved in prostaglandin E2 (PGE2) release. The results show that BmooMPα-I induced the release of PGE2, prostaglandin I2 (PGI2), monocyte chemoattractant protein-1 (MCP-1), and adiponectin by preadipocytes. BmooMPα-I-induced PGE2 biosynthesis was dependent on group-IIA-secreted phospholipase A2 (sPLA2-IIA), cytosolic phospholipase A2-α (cPLA2-α), and cyclooxygenase (COX)-1 and -2 pathways. Moreover, BmooMPα-I upregulated COX-2 protein expression but not microsomal prostaglandin E synthase-1 (mPGES-1) expression. In addition, we demonstrate that the enzymatic activity of BmooMPα-I is essential for the activation of prostanoid synthesis pathways in preadipocytes. These data highlight preadipocytes as important targets for metalloproteinases and provide new insights into the contribution of these enzymes to the inflammation of adipose tissue and tissues adjacent to it.

Activation of EP4 receptors contributes to prostaglandin E2-mediated stimulation of renal sensory nerves

2004 ◽  
Vol 287 (6) ◽  
pp. F1269-F1282 ◽  
Author(s):  
Ulla C. Kopp ◽  
Michael Z. Cicha ◽  
Kazuhiro Nakamura ◽  
Rolf M. Nüsing ◽  
Lori A. Smith ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Sensory Nerve ◽  
Nerve Fibers ◽  
Prostaglandin E ◽  
Ep4 Receptor ◽  
Pelvic Wall ◽  
Ep4 Receptor Antagonist ◽  
Cox 2 ◽  
Ep3 Receptor ◽  
Stimulation Of

Induction of cyclooxygenase-2 (COX-2) in the renal pelvic wall increases prostaglandin E2 (PGE2) leading to stimulation of cAMP production, which results in substance P (SP) release and activation of renal mechanosensory nerves. The subtype of PGE receptors involved, EP2 and/or EP4, was studied by immunohistochemistry and renal pelvic administration of agonists and antagonists of EP2 and EP4 receptors. EP4 receptor-like immunoreactivity (LI) was colocalized with calcitonin gene-related peptide (CGRP)-LI in dorsal root ganglia (DRGs) at Th9-L1 and in nerve terminals in the renal pelvic wall. Th9-L1 DRG neurons also contained EP3 receptor-LI and COX-2-LI, each of which was colocalized with CGRP-LI in some neurons. No renal pelvic nerves contained EP3 receptor-LI and only very few nerves COX-2-LI. The EP1/EP2 receptor antagonist AH-6809 (20 μM) had no effect on SP release produced by PGE2 (0.14 μM) from an isolated rat renal pelvic wall preparation. However, the EP4 receptor antagonist L-161,982 (10 μM) blocked the SP release produced by the EP2/EP4 receptor agonist butaprost (10 μM) 12 ± 2 vs. 2 ± 1 and PGE2, 9 ± 1 vs. 1 ± 0 pg/min. The SP release by butaprost and PGE2 was similarly blocked by the EP4 receptor antagonist AH-23848 (30 μM). In anesthetized rats, the afferent renal nerve activity (ARNA) responses to butaprost 700 ± 100 and PGE2·780 ± 100%·s (area under the curve of ARNA vs. time) were unaffected by renal pelvic perfusion with AH-6809. However, 1 μM L-161,982 and 10 μM AH-23848 blocked the ARNA responses to butaprost by 94 ± 5 and 78 ± 10%, respectively, and to PGE2 by 74 ± 16 and 74 ± 11%, respectively. L-161,982 also blocked the ARNA response to increasing renal pelvic pressure 10 mmHg, 85 ± 5%. In conclusion, PGE2 increases renal pelvic release of SP and ARNA by activating EP4 receptors on renal sensory nerve fibers.

Pioglitazone reduces inflammatory responses of human adipocytes to factors secreted by monocytes/macrophages

2009 ◽  
Vol 296 (5) ◽  
pp. E1076-E1084 ◽  
Author(s):  
Paska A. Permana ◽  
Weiyang Zhang ◽  
Martin Wabitsch ◽  
Pamela Fischer-Posovszky ◽  
William C. Duckworth ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Inflammatory Responses ◽  
Cell Types ◽  
Beneficial Effects ◽  
Proinflammatory Responses ◽  
Glucose Tolerant ◽  
Visceral Adipose ◽  
Adipose Tissue Cells ◽  
In Vitro Data

Infiltration of monocyte-derived macrophages into adipose tissue may contribute to tissue and systemic inflammation and insulin resistance. We hypothesized that pioglitazone (Pio) could specifically reduce the inflammatory response of adipocytes to factors released by monocytes/macrophages. We show that macrophage factors (Mφ-factors) greatly increase expression levels of proinflammatory adipokines, chemokines, and adhesion molecules in human subcutaneous and visceral adipose tissue (SAT and VAT) as well as in adipocytes (up to several hundredfold of control). Compared with SAT, VAT showed enhanced basal and Mφ-factor-induced inflammatory responses. Mφ-factors also induced greater lipolysis in adipocytes, as assessed by concentrations of glycerol released from the cells (196 ± 13 vs. 56 ± 7 μM in control, P < 0.05). Pretreatment of adipose tissue or adipocytes with Pio reduced these responses to Mφ-factors (by 13–86%, P < 0.05) and prevented Mφ-factor suppression of adiponectin expression. Furthermore, Pio pretreatment of adipocytes and macrophages tended to further reduce inflammatory responses of adipocytes to Mφ-factors and monocyte adhesion to Mφ-factor-activated adipocytes. In support of these in vitro data, media conditioned by monocytes isolated from impaired glucose-tolerant subjects treated with Pio (compared with placebo) induced release of lower concentrations of proinflammatory adipokines and glycerol (100 ± 7 vs. 150 ± 15 μM, P < 0.05) from adipocytes. In summary, Pio decreases inflammatory responses in adipose tissue/cells induced by monocytes/macrophages by acting on either or both cell types. These beneficial effects of Pio may attenuate proinflammatory responses resulting from monocyte/macrophage infiltration into adipose tissue and suppress tissue inflammation resulting from the interaction between both cell types.

scholarly journals COXIBs and 2,5-dimethylcelecoxib counteract the hyperactivated Wnt/β-catenin pathway and COX-2/PGE2/EP4 signaling in glioblastoma cells

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Aleksandra Majchrzak-Celińska ◽  
Julia O. Misiorek ◽  
Nastassia Kruhlenia ◽  
Lukasz Przybyl ◽  
Robert Kleszcz ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Viability ◽  
Methylation Level ◽  
Molecular Mechanisms ◽  
Methylation Status ◽  
Receptor Expression ◽  
Cell Cycle Distribution ◽  
Ep4 Receptor ◽  
Cox 2 ◽  
The Impact

Abstract Background Glioblastoma (GBM) is the deadliest and the most common primary brain tumor in adults. The invasiveness and proliferation of GBM cells can be decreased through the inhibition of Wnt/β-catenin pathway. In this regard, celecoxib is a promising agent, but other COXIBs and 2,5-dimethylcelecoxib (2,5-DMC) await elucidation. Thus, the aim of this study was to analyze the impact of celecoxib, 2,5-DMC, etori-, rofe-, and valdecoxib on GBM cell viability and the activity of Wnt/β-catenin pathway. In addition, the combination of the compounds with temozolomide (TMZ) was also evaluated. Cell cycle distribution and apoptosis, MGMT methylation level, COX-2 and PGE2 EP4 protein levels were also determined in order to better understand the molecular mechanisms exerted by these compounds and to find out which of them can serve best in GBM therapy. Methods Celecoxib, 2,5-DMC, etori-, rofe- and valdecoxib were evaluated using three commercially available and two patient-derived GBM cell lines. Cell viability was analyzed using MTT assay, whereas alterations in MGMT methylation level were determined using MS-HRM method. The impact of COXIBs, in the presence and absence of TMZ, on Wnt pathway was measured on the basis of the expression of β-catenin target genes. Cell cycle distribution and apoptosis analysis were performed using flow cytometry. COX-2 and PGE2 EP4 receptor expression were evaluated using Western blot analysis. Results Wnt/β-catenin pathway was attenuated by COXIBs and 2,5-DMC irrespective of the COX-2 expression profile of the treated cells, their MGMT methylation status, or radio/chemoresistance. Celecoxib and 2,5-DMC were the most cytotoxic. Cell cycle distribution was altered, and apoptosis was induced after the treatment with celecoxib, 2,5-DMC, etori- and valdecoxib in T98G cell line. COXIBs and 2,5-DMC did not influence MGMT methylation status, but inhibited COX-2/PGE2/EP4 pathway. Conclusions Not only celecoxib, but also 2,5-DMC, etori-, rofe- and valdecoxib should be further investigated as potential good anti-GBM therapeutics.

scholarly journals Sargassum fulvellumProtects HaCaT Cells and BALB/c Mice from UVB-Induced Proinflammatory Responses

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Chan Lee ◽  
Gyu Hwan Park ◽  
Eun Mi Ahn ◽  
Chan-Ik Park ◽  
Jung-Hee Jang
Keyword(s):  
Nitric Oxide ◽  
Ethanol Extract ◽  
Prostaglandin E ◽  
Hacat Cells ◽  
Uvb Irradiation ◽  
Proinflammatory Mediators ◽  
Sargassum Fulvellum ◽  
Cox 2 ◽  
Anti Inflammatory ◽  
Skin Damages

Ultraviolet (UV) radiation has been reported to induce cutaneous inflammation such as erythema and edema via induction of proinflammatory enzymes and mediators.Sargassum fulvellumis a brown alga of Sargassaceae family which has been demonstrated to exhibit antipyretic, analgesic, antiedema, antioxidant, antitumor, fibrinolytic, and hepatoprotective activities. The purpose of this study is to investigate anti-inflammatory effects of ethylacetate fraction of ethanol extract ofSargassum fulvellum(SFE-EtOAc) in HaCaT keratinocytes and BALB/c mice. In HaCaT cells, SFE-EtOAc effectively inhibited UVB-induced cytotoxicity (60 mJ/cm2) and the expression of proinflammatory proteins such as cyclooxygenase-2 (COX-2), tumor necrosis factor-α(TNF-α), and inducible nitric oxide synthase (iNOS). Furthermore, SFE-EtOAc significantly reduced UVB-induced production of proinflammatory mediators including prostaglandin E2(PGE2) and nitric oxide (NO). In BALB/c mice, topical application of SFE-EtOAc prior to UVB irradiation (200 mJ/cm2) effectively suppressed the UVB-induced protein expression of COX-2, iNOS, and TNF-αand subsequently attenuated generation of PGE2and NO as well. In another experiment, SFE-EtOAc pretreatment suppressed UVB-induced reactive oxygen species production and exhibited an antioxidant potential by upregulation of antioxidant enzymes such as catalase and Cu/Zn-superoxide dismutase in HaCaT cells. These results suggest that SFE-EtOAc could be an effective anti-inflammatory agent protecting against UVB irradiation-induced skin damages.

scholarly journals Adipose tissue inflammation and metabolic dysfunction: a clinical perspective

2013 ◽  
Vol 15 (1) ◽  
Author(s):  
Charmaine S. Tam ◽  
Leanne M. Redman
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Low Grade ◽  
Metabolic Dysfunction ◽  
Adipose Tissue Inflammation ◽  
Tissue Inflammation ◽  
Proinflammatory Mediators ◽  
Low Grade Inflammation

AbstractObesity is characterized by a state of chronic low-grade inflammation due to increased immune cells, specifically infiltrated macrophages into adipose tissue, which in turn secrete a range of proinflammatory mediators. This nonselective low-grade inflammation of adipose tissue is systemic in nature and can impair insulin signaling pathways, thus, increasing the risk of developing insulin resistance and type 2 diabetes. The aim of this review is to provide an update on clinical studies examining the role of adipose tissue in the development of obesity-associated complications in humans. We will discuss adipose tissue inflammation during different scenarios of energy imbalance and metabolic dysfunction including obesity and overfeeding, weight loss by calorie restriction or bariatric surgery, and conditions of insulin resistance (diabetes, polycystic ovarian syndrome).

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