Cyclooxygenase Products Research Articles

In vitro immune-enhancing effects of Platycodon grandiflorum combined with Salvia plebeian via MAPK and NF-κB signaling in RAW264.7 cells.

The immune-enhancing activity of the combination of Platycodon grandiflorum and Salvia plebeian extracts (PGSP) was evaluated through macrophage activation using RAW264.7 cells. PGSP (250-1000 μg/mL) showed a higher release of NO in a dose-dependent manner. The results showed that PGSP could significantly stimulate the production of PGE2, COX-2, TNF-α, IL-1β, and IL-6 in RAW264.7 cells and promote iNOS, COX-2, TNF-α, IL-1β, IL-4, and IL-6 mRNA expression. Western blot analysis demonstrated that the protein expression of iNOS and COX-2 and the phosphorylation of ERK, JNK, p38, and NF-κB p65 were greatly increased in PGSP-treated cells. PGSP also promoted the phagocytic activity of RAW264.7 cells. All these results indicated that PGSP might activate macrophages through MAPK and NF-κB signaling pathways. Taken together, PGSP may be considered to have immune-enhancing activity and might be used as a potential immune-enhancing agent.

Brown Adipose Tissue Activation in Humans Increases Plasma Levels of Lipid Mediators.

Activation of brown adipose tissue (BAT) thermogenesis improves insulin sensitivity and is beneficial in obesity. Emerging evidence indicates that BAT activation increases lipid mediators that play autocrine and endocrine roles to regulate metabolism and inflammation. The goal of the study was to determine the relationship between 2 distinct approaches of BAT activation (cold exposure and mirabegron treatment) with lipid mediators in humans. Healthy female subjects (n = 14) were treated with the β3-adrenergic receptor agonist mirabegron (100 mg) daily for 28 days. A subset of female subjects (n = 8) was additionally exposed to cold temperatures (14-16 °C) for 2 hours using a cooling vest prior to initiating mirabegron treatment. A panel of lipid mediators was assessed in plasma using targeted liquid chromatography-tandem mass spectrometry, and their relationship to anthropometric and metabolic parameters was determined. Activation of BAT with cold exposure acutely increased levels of lipoxygenase and cyclooxygenase products, including 12-hydroxyeicosapentaenoic acid, 12-hydroxyeicosatetraenoic acid (HETE), 5-HETE, 14-hydroxydocosahexaenoic acid (HDHA), an isomer of maresin 2 (MaR2), 17-HDHA, protectin D1 (PD1), and prostaglandin E2. Mirabegron treatment similarly increased these products acutely, although levels of some mediators were blunted after chronic mirabegron treatment. Selected lipid mediators, including an MaR2 isomer, 17-HDHA, 5-HETE, and 15-HETE, positively correlated with nonesterified fatty acids and negatively correlated with the respiratory quotient, while PD1, 15-HETE, and 5-HETE positively correlated with adiponectin. These results indicate that selected lipid mediators may serve as biomarkers of BAT activation.

Cyclooxygenase-2/prostaglandin E2 pathway regulates infectious bronchitis virus replication in avian macrophages.

Infectious bronchitis virus (IBV) is a significant respiratory pathogen that affects chickens worldwide. As an avian coronavirus, IBV leads to productive infection in chicken macrophages. However, the effects of IBV infection in macrophages on cyclooxygenase-2 (COX-2) expression are still to be elucidated. Therefore, we investigated the role of IBV infection on the production of COX-2, an enzyme involved in the synthesis of prostaglandin E2 (PGE2) in chicken macrophages. The chicken macrophage cells were infected with two IBV strains, and the cells and culture supernatants were harvested at predetermined time points to measure intracellular and extracellular IBV infection. IBV infection was quantified as has been the COX-2 and PGE2 productions. We found that IBV infection enhances COX-2 production at both mRNA and protein levels in chicken macrophages. When a selective COX-2 antagonist was used to reduce the COX-2 expression in macrophages, we observed that IBV replication decreased. When IBV-infected macrophages were treated with PGE2 receptor (EP2 and EP4) inhibitors, IBV replication was reduced. Upon utilizing a selective COX-2 antagonist to diminish PGE2 expression in macrophages, a discernible decrease in IBV replication was observed. Treatment of IBV-infected macrophages with a PGE2 receptor (EP2) inhibitor resulted in a reduction in IBV replication, whereas the introduction of exogenous PGE2 heightened viral replication. Additionally, pretreatment with a Janus-kinase two antagonist attenuated the inhibitory effect of recombinant chicken interferon (IFN)-γ on viral replication. The evaluation of immune mediators, such as inducible nitric oxide (NO) synthase (iNOS), NO, and interleukin (IL)-6, revealed enhanced expression following IBV infection of macrophages. In response to the inhibition of COX-2 and PGE2 receptors, we observed a reduction in the expressions of iNOS and IL-6 in macrophages, correlating with reduced IBV infection. Overall, IBV infection increased COX-2 and PGE2 production in addition to iNOS, NO, and IL-6 expression in chicken macrophages in a time-dependent manner. Inhibition of the COX-2/PGE2 pathway may lead to increased macrophage defence mechanisms against IBV infection, resulting in a reduction in viral replication and iNOS and IL-6 expressions. Understanding the molecular mechanisms underlying these processes may shed light on potential antiviral targets for controlling IBV infection.

Effect of curcumin on formalin-induced muscle pain in male rats: role of local cyclooxygenase system.

Investigating the mechanisms responsible for pain processing of natural and synthetic chemical compounds is necessary to optimize pain management. Curcumin (Cur), the active ingredient of turmeric, exhibits potent analgesic and anti-inflammatory properties by employing multiple mechanisms at the local peripheral, spinal and supra-spinal levels. This study was aimed to investigate the effect of oral administration of Cur on muscle pain induced by intramuscular (IM) injection of formalin. To explore the possible local mechanisms, a cyclooxygenase (COX) inhibitor, diclofenac (Dic) and a COX product, prostaglandin E2 (PGE2), were applied. The IM injection of formalin (25.00 µL, 2.50%) into the gastrocnemius muscle induced two distinct phases of hind leg flinching. A short-lasting (10 min) hind leg lifting was observed following IM injection of PGE2 (2 µg kg-1, 25.00 µL). Oral administration of Cur (25.00 and 100 mg kg-1) and IM injection of 40.00 µg kg-1 Dic attenuated formalin and PGE2 induced nociceptive behaviors. Contra-lateral IM injection of Dic did not change muscle pain induced by ipsilateral IM injection of formalin and PGE2. The second phase of formalin induced flinching as well as PGE2 evoked lifting were more suppressed when 40.00 µg kg-1 Dic and 100 mg kg-1 Cur were used together. Locomotor activity was not changed by the above-mentioned treatments. It was concluded that the reducing effect of muscle pain of Cur might be related to the local inhibition of COX.

Exploring the Anti-Inflammatory Potential of Ajuga integrifolia Leaves Extract: In Vitro Dual Inhibition of Cyclooxygenase and Lipoxygenase Enzymes.

This study investigated the anti-inflammatory properties of Ajuga integrifolia, an herbal preparation. Qualitative and quantitative phytochemical analyses were conducted to identify active compounds in the preparation. The researchers also assessed its ability to inhibit the production of pro-inflammatory enzymes, cyclooxygenases (COX-1, COX-2), and lipoxygenase (5-LOX) in vitro. The extracts demonstrated dose-dependent inhibition of these enzymes, with some extracts showing IC50 values comparable to standard anti-inflammatory drugs. The ethanol extract exhibited significant inhibition of 5-LOX (52.99 μg/mL), compared to the standard drug zileuton (32.41 μg/mL), while the inhibition of COX-1 (66.00 μg/mL) and COX-2 (71.62 μg/mL) was comparable to the standard drug indomethacin (40.57 and 54.39 μg/mL, respectively). These findings suggest that A. integrifolia has the potential to be used as a herbal remedy for treating inflammatory conditions. By inhibiting pro-inflammatory enzymes, the extracts may effectively reduce inflammation and promote tissue healing or repair. The inhibition potential of extract of this plant can be taken as a good candidate of anti-inflammatory agent.

Nicotinic acetylcholine receptor-mediated effects of varenicline on LPS-elevated prostaglandin and cyclooxygenase levels in RAW 264.7 macrophages.

Introduction: The purpose of this study is to delineate anti-inflammatory and antioxidant potential of varenicline, a cigarette smoking cessation aid, on decreasing lipopolysaccharide (LPS)-elevated proinflammatory cytokines in RAW 264.7 murine macrophage cultures which we showed earlier to occur via cholinergic anti-inflammatory pathway (CAP) activation. To this end, we investigated the possible suppressive capacity of varenicline on LPS-regulated cyclooxygenase (COX-1 and COX-2) via α7 nicotinic acetylcholine receptor (α7nAChR) activation using the same in vitro model. Materials and Methods: In order to test anti-inflammatory effectiveness of varenicline, the levels of COX isoforms and products (PGE2, 6-keto PGF1α, a stable analog of PGI2, and TXA2) altered after LPS administration were determined by Enzyme Linked Immunosorbent Assay (ELISA). The antioxidant effects of varenicline were assessed by measuring reductions in reactive oxygen species (ROS) using a fluorometric intracellular ROS assay kit. We further investigated the contribution of nAChR subtypes by using non-selective and/or selective α7nAChR antagonists. The results were compared with that of conventional anti-inflammatory medications, such as ibuprofen, celecoxib and dexamethasone. Results: Varenicline significantly reduced LPS-induced COX-1, COX-2 and prostaglandin levels and ROS to an extent similar to that observed with anti-inflammatory agents used. Discussion: Significant downregulation in LPS-induced COX isoforms and associated decreases in PGE2, 6-keto PGF1α, and TXA2 levels along with reduction in ROS may be partly mediated via varenicline-activated α7nAChRs.

MSC secretome from amniotic fluid halts IL-1β and TNF-α inflammation via the ERK/MAPK pathway, promoting cartilage regeneration in OA in vitro.

Osteoarthritis (OA) is a degenerative disease that causes chronic pain and disability worldwide. This disease is mainly caused by IL-1β and TNF-α, which lead to cartilage degradation and inhibit the repair capacity of damaged cartilage. Recent studies have shown that amniotic fluid mesenchymal stem cells (AF-MSCs) secrete proteins that can effectively help in the treatment of cartilage damaged by OA. However, the underlying mechanism is still unclear. Therefore, the aim of this study was to investigate the effects and mechanisms behind the healing properties of the AF-MSC secretome (AFS-se) under OA conditions. This study involved growing chondrocyte progenitor cells (CPCs) and traumatized cartilage tissues in the presence of the cytokines IL-1β and TNF-α, which mimic OA conditions. AFS-se was then added to the culture medium to determine its effect on the CPCs and cartilage. Cell migration, endogenous cell outgrowth, the expression of chondrogenic and anabolic genes, and the mechanism of proteins in the NF-κB and MAPK signaling pathways were examined in this study. AFS-se inhibited the inflammatory effects of IL-1β and TNF-α by significantly reducing ERK phosphorylation in the MAPK signaling pathway and decreasing downstream proinflammatory COX2 products. The impaired CPCs recovered their ability to migrate, and endogenous CPCs in injured osteoarthritic cartilage were able to regrow in response to inflammatory stimuli. Additionally, the expression of anabolic genes such as Col I, Col II, and IGF1 was restored in defective CPCs. In conclusion, this study demonstrated that AFS-se has therapeutic effects on OA by inhibiting the inflammatory functions of IL-1β and TNF-α through protein phosphorylation in the MAPK pathway while also promoting the regenerative and self-repair functions of CPCs in traumatized cartilage.

Cyclooxygenase-2 as potential intervention target of leprosy reactions: a systematic review

Background: Leprosy reaction is an acute inflammatory of leprosy complication that potentially cause disability. Prompt and appropriate treatment is needed to prevent this permanent neurological complication. As inflammation of this reaction is mediated by cyclooxygenase-2 (COX-2), therefore targeting this substance may potential to prevent disability. This systematic review aimed to define COX-2 as a potential target of intervention in leprosy reaction. Method: Medline, Cochrane library, PubMed, and Google scholar databases were searched for articles published at any time. Observational study and clinical trial, comparative, prospective, retrospective, and descriptive study were extracted, analyzed, and discussed. Results: We found 6 studies that met the inclusion and exclusion criteria, with 104 participants with leprosy reactions and 143 comparators included in this review. In leprosy reactions, COX-2 expression was found in the vessels and nerves of the dermis and subcutis. Macrophages are cell mostly abundantly expressing COX-2. The COX-2 expression was found higher in the leprosy reaction compare to the non-leprosy reaction. Genetically, genes PTGS2 and TNFAIP6 encode COX-2 production also tend to increase especially in type 1 reaction. Conclusions: Preclinically and genetically, COX-2 is a potential target for intervention of leprosy reaction.

Evaluation of COX-2 production, anticancer efficacy against MCF-7 cell lines, and antioxidant activity of Garcinia conicarpa, a novel endemic species of the Western Ghats

Evaluation of COX-2 production, anticancer efficacy against MCF-7 cell lines, and antioxidant activity of Garcinia conicarpa, a novel endemic species of the Western Ghats

Immune Enhancement Effects of Neutral Lipids, Glycolipids, Phospholipids from Halocynthia aurantium Tunic on RAW264.7 Macrophages.

Fractionated lipids of Halocynthia aurantium (Pyuridae) have been demonstrated to possess anti-inflammatory properties. However, their modulatory properties have not been reported yet. Thus, the objective of this study was to determine immune enhancing effects of fractionated lipids from H. aurantium tunic on macrophage cells. The tunic of H. aurantium was used to isolate total lipids, which were then subsequently separated into neutral lipids, glycolipids, and phospholipids. RAW264.7 cells were stimulated with different concentrations (0.5, 1.0, 2.0, and 4.0%) of each fractionated lipid. Cytotoxicity, production of NO, expression levels of immune-associated genes, and signaling pathways were then determined. Neutral lipids and glycolipids significantly stimulated NO and PGE2 production and expression levels of IL-1β, IL-6, TNF-α, and COX-2 in a dose-dependent manner, while phospholipids ineffectively induced NO production and mRNA expression. Furthermore, it was found that both neutral lipids and glycolipids increased NF-κB p-65, p38, ERK1/2, and JNK phosphorylation, suggesting that these lipids might enhance immunity by activating NF-κB and MAPK signaling pathways. In addition, H. aurantium lipids-induced TNF-α expression was decreased by blocking MAPK or NF-κB signaling pathways. Phagocytic activity of RAW 264.7 cells was also significantly enhanced by neutral lipids and glycolipids. These results suggest that neutral lipids and glycolipids from H. aurantium tunic have potential as immune-enhancing materials.

Total Lipid Extracts of Honeybee Drone Larvae Are Modulated by Extraction Temperature and Display Consistent Anti-Inflammatory Potential.

Honeybee drone larvae are male bees that develop from unfertilized eggs and play a role in colony reproduction. The nutritional value of honeybee drone larvae is due to their high protein, lipid, and other nutrient contents, making them a profitable food source for humans in some cultures. Drone larvae lipids (DLLs) contribute to drone development; however, few studies have explored their substantial compositions and bioactive functions. In this study, we carried out DLL lipidomics analysis using UPLC-Q-Exactive-Orbitrap-MS prior to in vitro anti-inflammatory activity analysis. The results highlighted the importance of the extraction temperature on the DLL composition. A total of 21 lipids were found in the DLL extract, mostly categorized into five groups: nine phospholipids, three sphingolipids, two neutral lipids, one plant glycoglycerolipid, four lipid acyl, and others. Drying extraction at -20 °C produced more sphingolipids, phospholipids, and unsaturated fatty acids. Of 37 fatty acids, 18 were displayed at -20 °C degrees, as shown by GC-MS quantitative analysis. Myristic (246.99 ± 13.19 μg/g), palmitic (1707.87 ± 60.53 μg/g), stearic (852.32 ± 24.17 μg/g), and oleic (2463.03 ± 149.61 μg/g) acids were the predominant fatty acids. Furthermore, we examined the significant in vitro anti-inflammatory effects of DLL (-20 °C) using lipopolysaccharide (LPS)-challenged RAW264.7 cells. Nitric oxide (NO) and reactive oxygen (ROS) production and mRNA expression of IL-6, IL-10, COX-2, and iNOS were significantly decreased, demonstrating the anti-inflammatory function of DLL. Overall, this study provided insight into the lipid composition of DLL, revealed the influence of temperature, and explored the functionality of DLL (-20 °C), allowing for further application of DLLs as functional foods.

Synthesis, Characterization, and in vitro Anti-Inflammatory Activity of Novel Ferrocenyl(Piperazine-1-Yl)Methanone-based Derivatives.

Inflammation is closely related to the occurrence and development of various diseases in the clinical scope. Finding effective anti-inflammatory agents is of great significance for clinical treatment. A series of novel ferrocenyl(piperazine-1-yl)methanone-based sulfamides and carboxamides were synthesized to discover potent anti-inflammatory agents. The compounds were characterized by 1H NMR, 13C NMR, and MS spectra. Compound 5h was further determined by single crystal X-ray diffraction. All the target compounds were screened for anti-inflammatory activity by evaluating the inhibition effect of LPS-induced NO production in RAW264.7 macrophages. The novel compound (4i) is the preliminary anti-inflammatory mechanism detected by western blot. In a multi-stage screening campaign, compound 4i was shortlisted, which exhibited physicochemical properties suitable for human administration. Among them, compound 4i was found to be most potent in inhibiting NO production (IC50 = 7.65 μM) with low toxicity. This compound also exhibited significant inhibition of the production of iNOS and COX-2. Preliminary mechanism studies indicated that compound 4i could inhibit the activation of the LPS-induced TLR4/NF-κB signaling pathway. The promising anti-inflammatory activity of compound 4i compared with the reference drug suggests that this compound may contribute as a lead compound in the search for new potential anti-inflammatory agents.

Deep phenotyping of the lipidomic response in COVID-19 and non-COVID-19 sepsis.

Lipids may influence cellular penetrance by viral pathogens and the immune response that they evoke. We deeply phenotyped the lipidomic response to SARs-CoV-2 and compared that with infection with other pathogens in patients admitted with acute respiratory distress syndrome to an intensive care unit (ICU). Mass spectrometry was used to characterise lipids and relate them to proteins, peripheral cell immunotypes and disease severity. Circulating phospholipases (sPLA2, cPLA2 (PLA2G4A) and PLA2G2D) were elevated on admission in all ICU groups. Cyclooxygenase, lipoxygenase and epoxygenase products of arachidonic acid (AA) were elevated in all ICU groups compared with controls. sPLA2 predicted severity in COVID-19 and correlated with TxA2, LTE4 and the isoprostane, iPF2α-III, while PLA2G2D correlated with LTE4. The elevation in PGD2, like PGI2 and 12-HETE, exhibited relative specificity for COVID-19 and correlated with sPLA2 and the interleukin-13 receptor to drive lymphopenia, a marker of disease severity. Pro-inflammatory eicosanoids remained correlated with severity in COVID-19 28 days after admission. Amongst non-COVID ICU patients, elevations in 5- and 15-HETE and 9- and 13-HODE reflected viral rather than bacterial disease. Linoleic acid (LA) binds directly to SARS-CoV-2 and both LA and its di-HOME products reflected disease severity in COVID-19. In healthy marines, these lipids rose with seroconversion. Eicosanoids linked variably to the peripheral cellular immune response. PGE2, TxA2 and LTE4 correlated with T cell activation, as did PGD2 with non-B non-T cell activation. In COVID-19, LPS stimulated peripheral blood mononuclear cell PGF2α correlated with memory T cells, dendritic and NK cells while LA and DiHOMEs correlated with exhausted T cells. Three high abundance lipids - ChoE 18:3, LPC-O-16:0 and PC-O-30:0 - were altered specifically in COVID. LPC-O-16:0 was strongly correlated with T helper follicular cell activation and all three negatively correlated with multi-omic inflammatory pathways and disease severity. A broad based lipidomic storm is a predictor of poor prognosis in ARDS. Alterations in sPLA2, PGD2 and 12-HETE and the high abundance lipids, ChoE 18:3, LPC-O-16:0 and PC-O-30:0 exhibit relative specificity for COVID-19 amongst such patients and correlate with the inflammatory response to link to disease severity.

Thrombin-Induced COX-2 Expression and PGE2 Synthesis in Human Tracheal Smooth Muscle Cells: Role of PKCδ/Pyk2-Dependent AP-1 Pathway Modulation.

In this study, we confirmed that thrombin significantly increases the production of COX-2 and PGE2 in human tracheal smooth muscle cells (HTSMCs), leading to inflammation in the airways and lungs. These molecules are well-known contributors to various inflammatory diseases. Here, we investigated in detail the involved signaling pathways using specific inhibitors and small interfering RNAs (siRNAs). Our results demonstrated that inhibitors targeting proteins such as protein kinase C (PKC)δ, proline-rich tyrosine kinase 2 (Pyk2), c-Src, epidermal growth factor receptor (EGFR), phosphatidylinositol 3-kinase (PI3K), or activator protein-1 (AP-1) effectively reduced thrombin-induced COX-2 and PGE2 production. Additionally, transfection with siRNAs against PKCδ, Pyk2, c-Src, EGFR, protein kinase B (Akt), or c-Jun mitigated these responses. Furthermore, our observations revealed that thrombin stimulated the phosphorylation of key components of the signaling cascade, including PKCδ, Pyk2, c-Src, EGFR, Akt, and c-Jun. Thrombin activated COX-2 promoter activity through AP-1 activation, a process that was disrupted by a point-mutated AP-1 site within the COX-2 promoter. Finally, resveratrol (one of the most researched natural polyphenols) was found to effectively inhibit thrombin-induced COX-2 expression and PGE2 release in HTSMCs through blocking the activation of Pyk2, c-Src, EGFR, Akt, and c-Jun. In summary, our findings demonstrate that thrombin-induced COX-2 and PGE2 generation involves a PKCδ/Pyk2/c-Src/EGFR/PI3K/Akt-dependent AP-1 activation pathway. This study also suggests the potential use of resveratrol as an intervention for managing airway inflammation.

Activity-guided isolation and identification of antiherpesvirus and antineuroinflammatory active terpenoids from Artemisia vulgaris L. based on the LC-MS/MS molecular network

Seven undescribed terpenoids, comprising two guaiane-type sesquiterpene lactones (1−2), one eucalyptol-type sesquiterpene (3), one monolactone (4), and three triterpenoids (5−7), along with 35 known analogues, were isolated from the leaves of Artemisia vulgaris L. Their structures and configurations were analysed by extensive spectroscopy. Compounds 1, 2, 8−10, 13, 17, 19, and 28 showed antineuroinflammatory activity, and compounds 1 and 2 revealed remarkable antineuroinflammatory effects, with an IC50 value of 2.2 ± 0.1 and 1.6 ± 0.1 μM, more potent than the positive control drug dexamethasone. Furthermore, compounds 1 and 2 could inhibit the expression of BV-2 inflammatory genes (IL-6, TNF-α, IL-1β) induced by LPS, downregulate the critical inflammatory protein production of iNOS and COX-2. The anti-HSV-1 activity screening revealed that compounds 28, 29 and 38 exhibited inhibitory activity against HSV-1 proliferation. Particularly, compound 28 exhibited a significant anti-HSV-1 effect, inhibiting the proliferation of HSV-1 and acyclovir-resistant strains of HSV-1/153 and HSV-1/Blue. Our research identified compounds 1, 2, and 28 from A. vulgaris., which could potentially serve as lead compounds for antineuroinflammatory and anti-HSV-1 activities.

Novel molecule BBC0901 inhibits BRD4 and acts as a catabolic regulator in the pathogenesis of osteoarthritis

Osteoarthritis (OA) is induced by matrix degradation and inflammation mediated by bromo-domain-containing protein 4 (BRD4)-dependent catabolic factors. BRD4 acts as both a transcriptional regulator and an epigenetic reader. BBC0901 was identified as an inhibitor of BRD4 using a DNA-encoded library screening system. We aimed to demonstrate the effects of BBC0901 on OA pathogenesis by in vitro, ex vivo, and in vivo analyses. BBC0901 inhibited the expression of catabolic factors that degrade cartilage without significantly affecting the viability of mouse articular chondrocytes. Additionally, ex vivo experiments under conditions mimicking OA showed that BBC0901 suppressed extracellular matrix degradation. RNA sequencing analysis of gene expression patterns showed that BBC0901 inhibited the expression of catabolic factors, such as matrix metalloproteinases (MMPs) and cyclooxygenase (COX)2, along with reactive oxygen species (ROS) production. Furthermore, intra-articular (IA) injection of BBC0901 into the knee joint blocked osteoarthritic cartilage destruction by inhibition of MMP3, MMP13, COX2, interleukin (IL)6, and ROS production, thereby obstructing the nuclear factor kappa-light-chain-enhancer of activated B cell and mitogen activated protein kinase signaling. In conclusion, BBC0901-mediated BRD4 inhibition prevented OA development by attenuating catabolic signaling and hence, can be considered a promising IA therapeutic for OA.

KDM2B regulates inflammation and oxidative stress of sepsis via targeting NF-κB and AP-1 pathways.

The kidney is an easily affected organ with sepsis which is a main underlying cause of acute kidney injury (AKI). Histone-modifying lysine-specific demethylase 2B (KDM2B) is involved in numerous pathological processes, such as cell senescence and tumor development. However, the role of KDM2B in sepsis-induced AKI is unclear. To investigate the role of KDM2B on cell viability, inflammation and oxidative stress of sepsis-associated AKI, and the involved signaling pathways. An AKI model in vitro was established through lipopolysaccharide (LPS)-induction in HK-2 cells. Western blots were performed to evaluate the expression of KDM2B, cyclooxygenase 2 (COX2), inducible nitric oxide synthase (iNOS), p65, c-Jun and c-Fos, as well as p65 phosphorylation. Cell viability was measured using CCK-8 kit. ELISA was performed to analyze the production of layered double hydroxide (LDH), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-18, vascular cell adhesion molecule-1 (VCAM-1), superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH), and H2 O2 . The qPCR was used to evaluate the transcription level of TNF-α, IL-1β, IL-18, and VCAM-1. KDM2B knockdown alleviated LPS-induced cytotoxicity, decreased LDH release, and improved cell viability. KDM2B knockdown reduced concentration of inflammation-related molecules including TNF-α, IL-1β, IL-18, and VCAM-1, and inhibited their transcription. Moreover, KDM2B knockdown promoted the quantity of SOD and GSH, while declined the production of MDA, H2 O2 , COX2, and iNOS. Further, KDM2B played a role in LPS-induced HK-2 cell injury by activating nuclear factor κB (NF-κB) and activator protein 1 (AP-1) pathways. KDM2B knockdown reduced cytotoxicity, inflammation and oxidative stress in LPS-induced AKI via inhibiting NF-κB and AP-1 pathways, indicating KDM2B may be a promising therapeutic target for the treatment of sepsis-associated AKI.

Herbal melanin modulates PGE2 and IL-6 gastroprotective markers through COX-2 and TLR4 signaling in the gastric cancer cell line AGS

We reported a gastric anti-ulcerogenic effect of the Nigella sativa (L.)-derived herbal melanin (HM) using rat models. However, the molecular mechanisms underlying this HM gastroprotective effect remain unknown. Cyclooxygenase-2 (COX-2)-catalyzed prostaglandin E2 (PGE2) and toll-like receptor 4 (TLR4)-mediated interleukin-6 (IL-6) production and secretion play major roles in gastric mucosal protection. In the current study, the human gastric carcinoma epithelial cell line AGS was used as a model to investigate the effect of HM on TLR4, COX-2, glycoprotein mucin 4 protein and gene expression using immuno-cyto-fluorescence staining, Western blot technology, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Gastroprotective markers PGE2 and IL-6 production and secretion were also assessed using an enzyme-linked immunosorbent assay (ELISA). Bacterial lipopolysaccharides (LPS), well-known inducers of TLR4, COX-2, PGE2 and IL-6 expression, were used as a positive control. We showed that HM upregulated its main receptor TLR4 gene and protein expression in AGS cells. HM increased, in a dose- and time-dependent manner, the secretion of PGE2 and the expression of COX-2 mRNA and protein, which was detected in the nucleus, cytoplasm and predominantly at the intercellular junctions of the AGS cells. In addition, HM enhanced IL-6 production and secretion, and upregulated the mucin 4 gene expression, the hallmarks of gastroprotection. To check whether HM-induced PGE2 and IL-6 through TLR4 signaling and COX-2 generated, AGS cells were pre-treated with a TLR4 signaling inhibitor TAK242 and the COX-2 inhibitor NS-398. A loss of the stimulatory effects of HM on COX-2, PGE2 and IL-6 production and secretion was observed in TAK242 and NS-398-pre-treated AGS cells, confirming the role of TLR4 signaling and COX-2 generated in the HM gastroprotective effects. In conclusion, our results showed that HM enhances TLR4/COX-2-mediated secretion of gastroprotective markers PGE2 and IL-6, and upregulates mucin 4 gene expression in the human gastric epithelial cell line AGS, which may contribute to the promising beneficial gastroprotective effect of HM for human gastric prevention and treatment.

Rhein alleviates advanced glycation end products (AGEs)-induced inflammatory injury of diabetic cardiomyopathy in vitro and in vivo models.

In diabetic patients, diabetic cardiomyopathy (DCM) is one of the most common causes of death. The inflammatory response is essential in the pathogenesis of DCM. Rhein, an anthraquinone compound, is extracted from the herb rhubarb, demonstrating various biological activities. However, it is unclear whether rhein has an anti-inflammatory effect in treating DCM. In our research, we investigated the anti-inflammatory properties as well as its possible mechanism. According to the findings in vitro, rhein could to exert an anti-inflammatory effect by reducing the production of NO, TNF-α, PGE2, iNOS, and COX-2 in RAW264.7 cells that had been stimulated with advanced glycosylation end products (AGEs). In addition, rhein alleviated H9C2 cells inflammation injury stimulated by AGEs/macrophage conditioned medium (CM). In vivo have depicted that continuous gavage of rhein could improve cardiac function and pathological changes. Moreover, it could inhibit the accumulation of AGEs and infiltration of inflammatory factors inside the heart of rats having DCM. Mechanism study showed rhein could suppress IKKβ and IκB phosphorylation via down-regulating TRAF6 expression to inhibit NF-κB pathway in AGEs/CM-induced H9C2 cells. Moreover, the anti-inflammation effect of rhein was realized through down-regulation phosphorylation of JNK MAPK. Furthermore, we found JNK MAPK could crosstalk with NF-κB pathway by regulating IκB phosphorylation without affecting IKKβ activity. And hence, the protective mechanism of rhein may involve the inhibiting of the TRAF6-NF/κB pathway, the JNK MAPK pathway, and the crosstalk between the two pathways. These results suggested that rhein may be a promising drug candidate in anti-inflammation and inflammation-related DCM therapy.

Palmitic Acid Modulates Microglial Cell Response to Metabolic Endotoxemia in an In Vitro Study.

Metabolic endotoxemia (ME) is characterized by a 2-3-fold increase in blood endotoxin levels and low-grade systemic inflammation without apparent infection. ME is usually accompanied by metabolic syndrome, characterized by central obesity and hyperlipidemia. According to numerous studies, ME may lead to functional brain disorders, including cognitive decline, depression, and dementia. In the current in vitro study, we aimed to determine the direct and indirect impact of endotoxin (LPS) and palmitic acid (PA), representing saturated fatty acids, on the inflammatory and oxidative stress response in the human microglial HMC3 cells unstimulated and stimulated with IFNγ. The study's results revealed that direct HMC3 cell exposition to endotoxin and PA increased inflammatory response measured as levels of IL-6 and MCP-1 released into the medium and PGE2 levels in cell lysates. Moreover, direct HMC3 cell treatment with PA and LPS induced oxidative stress, i.e., ROS and COX-2 production and lipid peroxidation. On the contrary, an indirect effect of LPS and PA on microglial cells, assessed as the impact of macrophage metabolites, was much lower regarding the inflammatory response, although still associated with oxidative stress. Interestingly, IFNγ had a protective effect on microglial cells, reducing the production of pro-inflammatory mediators and oxidative stress in HMC3 cells treated directly and indirectly with LPS and PA.