Decreased Prostaglandin E2 Production Research Articles

MiR-122 and the WNT/β-catenin pathway inhibit effects of both interleukin-1β and tumor necrosisfactor-α in articular chondrocytes in vitro.

Interleukin‐1β (IL‐1β), tumor necrosis factor‐α (TNF‐α), and WNT/β‐catenin signaling cause dysregulation of rat primary articular chondrocytes (rArCs), resulting in cartilage extracellular matrix destruction and osteoarthritis (OA) progression. microRNA (miR) miR‐122 represses these effects whereas miR‐451 exacerbates IL‐1β‐stimulated matrix metalloproteinase‐13 (MMP‐13) and prostaglandin E2 (PGE2) production. The goals of this study were to evaluate crosstalk between these signaling pathways and determine if miR‐122 and miR‐451 exert their protective/destructive effects through these pathways in an in vitro model of OA. Primary rArCs were treated with IL‐1β or TNF‐α for 24 h and total DNA, MMP‐13, and PGE2, as well as expression levels of miR‐122 and miR‐451 were measured. After 24‐h transfection with miR‐122, miR‐451, miR‐122‐inhibitor, or miR‐451‐inhibitor, rArCs were treated with or without TNF‐α for 24 h; total DNA, MMP‐13, and PGE2 were measured. Similarly, cells were treated with WNT‐agonist lithium chloride (LiCl), WNT‐antagonist XAV‐939 (XAV), or PKF‐118‐310 (PKF) with and without IL‐1β or TNF‐α stimulation. Both IL‐1β and TNF‐α‐stimulation increased MMP‐13 and PGE2 production. Transfection with miR‐122 prevented TNF‐α‐stimulated increases in MMP‐13 and PGE2 whereas transfection with miR‐451 did not change these levels. No differences were found in MMP‐13 or PGE2 production with miR‐122 or miR‐451 inhibitors. LiCl treatment decreased PGE2 production in cultures treated with TNF‐α, but not MMP‐13. XAV increased TNF‐α‐stimulated increases in PGE2 but not MMP‐13. LiCl reduced IL‐1β‐stimulated increases in MMP‐13 and PGE2. XAV and PKF increased IL‐1β‐stimulated increases in MMP‐13 and PGE2. In this in vitro OA model, miR‐122 protects against both IL‐1β and TNF‐α stimulated increases in MMP‐13 and PGE2 production. miR‐451 does not act through the TNF‐α pathway. The WNT/β‐catenin pathway regulates the effects of IL‐1β and TNF‐α stimulation. This study suggests that miR‐122 can be used as a treatment or prevention for OA.

Investigation into the anti-inflammatory properties of metformin in intervertebral disc cells.

IntroductionIntervertebral disc degeneration (IDD) is closely related to heightened inflammation in the annulus fibrosis (AF) and nucleus pulposus (NP) cells in the intervertebral disc. An imbalanced matrix homeostasis has been shown to contribute to disc degeneration and associated discogenic low back pain. Metformin, a diabetes medication, has been noted to exhibit anti‐inflammatory properties through upregulation of the AMPK pathway, leading to various anti‐inflammatory‐related responses in hepatocytes. However, it is still unclear how metformin influences disc cellular response to inflammatory stress and the corresponding mechanism. Hence, the objective of this study is to elucidate the effects of metformin on expression of key pro‐inflammatory, catabolic, and anabolic factors within rat AF cells in response to inflammatory stimulation and mechanical tensile stress.MethodsFive Fischer 344 rats were sacrificed and their spines isolated. AF cells were cultured and plated in flexible silicone membrane‐based six‐well plates. Wells were split into eight groups and subjected to metformin, IL‐1β, mechanical stretch, and combined treatments. Relative gene expressions of MMP‐13, COX‐2, iNOS, AGC, and Col1 were assessed with quantitative real‐time polymerase chain reaction (qRT‐PCR), and downstream prostaglandin E2 (PGE2) production was quantified with enzyme‐linked immunosorbent assay (ELISA). NF‐kB nuclear translocation was also quantified.ResultsMetformin in the presence of the combined stress treatments (M + IL/S) significantly increased Col1, COX‐2, and MMP‐13 gene expression, decreased PGE2 production compared to IL/S conditions alone. Metformin treatment of cultured rat annulus fibrosus cells significantly reduced the nuclear translocation of NF‐κB after 4 h of IL‐1β treatment from 43.1% in case of IL‐1β treatment down to 26.2% in the case of metformin + IL‐1β treatment.DiscussionThe lack of metformin‐mediated suppression of inflammatory response in the nonstretch groups indicates that metformin may be enacting its effects through a stretch‐dependent manner. These results suggest a foundation for pursuing further research into metformin's potential role as an anti‐inflammatory agent for curtailing intervertebral disc degeneration.

Inhibition of macrophage migration inhibitory factor alleviates LPS-induced inflammation response of HEI-OC1 cells via suppressing NF-κB signaling

Sudden sensorineural hearing loss (SSNHL) is acute and unexplained. Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine in several inflammatory diseases. However, its role in SSNHL remains elusive. Lipopolysaccharide (LPS) was used to induce the inflammatory response of murine auditory cells, HEI-OC1. Silencing of MIF in HEI-OC1 cells was achieved by transfection of short hairpin RNA against MIF. 740Y-P and IMD0354 were used to stimulate the PI3K pathway and suppress the NF-κB pathway, respectively. RT-qPCR and western blotting were used to examine MIF and cyclooxygenase 2 (COX2) expression in LPS-treated HEI-OC1 cells. ELISA was employed to assess prostaglandin E2 (PGE2) concentrations. MIF was upregulated in LPS-treated HEI-OC1 cells. MIF knockdown reduced PGE2 synthesis and COX2 expression in LPS-treated HEI-OC1 cells. Moreover, MIF knockdown suppressed activation of the PI3K/AKT and NF-κB pathway in LPS-treated HEI-OC1 cells. Additionally, inhibition of MIF decreased PGE2 production and COX2 expression via inactivation of the NF-κB pathway. Inhibition of MIF alleviated LPS-induced inflammation in HEI-OC1 cells via inactivating the NF-κB signaling, which might provide a better understanding for SSNHL development.

Effects of Lactobacillus curvatus MG5246 on inflammatory markers in Porphyromonas gingivalis lipopolysaccharide-sensitized human gingival fibroblasts and periodontitis rat model.

This study investigated the effects of Lactobacillus curvatus MG5246 on periodontitis inflammation. Cell-free supernatants (CFS) prepared from L. curvatus MG5246 decreased prostaglandin E2 production and cyclooxygenase-2 gene expression by 60% and 78% in Porphyromonas gingivalis-lipopolysaccharide stimulated human gingival fibroblasts at 400μg/mL. Gene expressions of tumor necrosis factor-α, interleukin-6, matrix metalloproteinases, and chemokines were significantly downregulated by CFS treatment (p < 0.05). L. curvatus MG5246 (2 × 108CFU/day, 8weeks) administration significantly improved alveolar bone loss in the ligature-induced periodontitis rat model. Elevated mRNA expression of the receptor activator of nuclear factor-κB ligand/osteoprotegerin ratio in the gingival tissue was significantly decreased by L. curvatus MG5246 administration (p < 0.05). Moreover, L. curvatus MG5246 showed sufficient tolerance in simulated gastrointestinal conditions (gastric tolerance: 89.48%, intestinal tolerance: 98.62%) and did not show antibiotic resistance and hemolytic activity. Therefore, L. curvatus MG5246 has the potential as novel oral probiotics.

Angiotensin II and Arachidonyl‐2′‐chloroethylamide effects on Nuclear factor kappa B and Prostaglandin E2

Objective : To determine the effect of Angiotensin (Ang) II and Arachidonyl-2′-chloroethylamide (ACEA) on nuclear factor kappa B (NFkB) activation and prostaglandin E2 (PGE2) production in rat astrocytes. Background :Neuroinflammation is a hallmark of numerous diseases including neurogenic hypertension. NFkB and PGE2 have been shown to mediate proinflammatory processes. We investigated the effect of Ang II and ACEA, a selective agonist of the CB1R, on NFkB phosphorylation and PGE2 production in astrocytes. Further, we investigated whether differences in NFkB phosphorylation and PGE2 production were observed in Wistar astrocytes compared to astrocytes isolated from the spontaneously hypertensive rat (SHR). Methods Brainstem and cerebellum astrocytes were prepared from 2-3day old rat pups. Quiescent cells were treated with 100nM Ang II or 10nM ACEA for varying time intervals. Phosphorylated (p)NFkB protein levels were measured by western blotting and PGE2 levels by ELISA. Results Ang II and ACEA had contrasting effects on NFkB phosphorylation and PGE2 production. ACEA showed significant NFkB activation predominantly in Wistar astrocytes whereas Ang II showed significant NFkB activation mainly in SHR astrocytes at similar time points. Ang II increased PGE2 production with higher levels produced in SHR compared to Wistar astrocytes. ACEA both increased and decreased PGE2 production depending on the brain region. Conclusion These results provide insight on early molecular changes in astrocytes from Wistar as compared to prehypertensive SHRs. We demonstrated that both Ang II and ACEA induced NFkB activation in astrocytes. However, Ang II potently induced PGE2 production compared to ACEA. It is plausible that ACEA could potentially counter these Ang II effects on PGE2 production. Further studies are required to understand these early molecular changes in SHRs, and the molecular mechanisms by which both Ang II and ACEA elicit their effects.

ALK3-SMAD1/5 Signaling Mediates the BMP2-Induced Decrease in PGE2 Production in Human Endometrial Stromal Cells and Decidual Stromal Cells.

BMP2 is a critical factor that is involved in the processes of embryo implantation and uterine decidualization. The expression of cyclooxygenase (COX) and subsequent prostaglandin E2 (PGE2) production are critical for successful pregnancy. However, it is not clear whether BMP2 can regulate the production of PG during endometrial decidualization. The aim of this study was to investigate the effects of BMP2 on COX-1 expression and PGE2 production as well as the underlying molecular mechanisms in the human endometrium. Immortalized human endometrial stromal cells (HESCs) and human decidual stromal cells (HDSCs) were used as the study model to investigate the effects of BMP2-induced cellular activities. Our results showed that BMP2 treatment significantly decreased PGE2 production by downregulating COX-1 expression in both human endometrial stromal and decidual stromal cells. Additionally, BMP2 induced an increase in the levels of phosphorylated SMAD1/5/8, and this effect was completely abolished by the addition of the inhibitors DMH-1 and dorsomorphin, but not by SB431542. Knocking down ALK3 completely reversed the BMP2-induced downregulation of COX-1. Moreover, concomitantly knocking down SMAD1 and SMAD5 completely reversed the BMP2-induced downregulation of COX-1. Our results indicated that BMP2 decreased PGE2 production by downregulating COX-1 expression, most likely through the ALK3/SMAD1-SMAD5 signaling pathway in human endometrial stromal and human decidual stromal cells. These findings deepen our understanding of the functional role of BMP2 in the regulation of endometrial decidualization in humans.

In vitro cytotoxicity of montelukast in HAPI and SH-SY5Y cells

Montelukast is a cysteinyl leukotriene (CysLT) receptor antagonist with efficacy against a variety of diseases, including asthma and inflammation-related conditions. However, various neuropsychiatric events (NEs) suspected to be related to montelukast have been reported recently, with limited understanding on their association and underlying mechanisms. This study aimed to investigate whether montelukast can induce neuroinflammation and neurotoxicity in microglial HAPI cells and neural SH-SY5Y cells. The present study also compared the effects of montelukast with a 5-lipoxygenase inhibitor (zileuton) and a cyclooxygenase-2 inhibitor (celecoxib) to better understand modulation of related pathways. HAPI or SH-SY5Y cells were treated with the indicated drugs (3.125 μM–100 μM) for 24 h to investigate drug-induced neuroinflammation and neurotoxicity. Montelukast induced cytotoxicity in HAPI cells (50–100 μM), accompanied with caspase-3/7 activation, prostaglandin E2 (PGE2) release, and reactive oxygen species (ROS) production. Whilst both montelukast and zileuton down-regulated CysLT release in HAPI cells, zileuton did not significantly affect cell viability or inflammatory and oxidative factors. Celecoxib decreased HAPI cell viability (6.25–100 μM), accompanied with increasing caspase-3/7 activation and ROS production, but in contrast to montelukast increased CysLT release and decreased PGE2 production. Similar to observations in HAPI cells, both montelukast and celecoxib (50–100 μM) but not zileuton produced toxicity in SH-SY5Y neuroblastoma cells. Similarly, CM from HAPI cells treated with either montelukast or zileuton produced toxicity in SH-SY5Y cells. The results of the current study show the capability of montelukast to directly induce toxicity and inflammation in HAPI cells, possibly through the involvement of PGE2 and ROS, and toxicity in undifferentiated SH-SY5Y neuroblastoma cells. The current study highlights the importance of consideration between benefit and risk of montelukast usage and provides references for future investigation on decreasing montelukast-related NEs.

Biotransformed grape pomace as a potential source of anti-inflammatory polyphenolics: Effects in Caco-2 cells

Grape pomace is rich in polymeric phenolic compounds and glycosides. Enzymatic treatments may change grape pomace’s phenolic composition, producing monomers and aglycones. The aims of this study were to evaluate if tannase-biotransformed grape pomace extracts have improved intestinal anti-inflammatory activity using an in vitro colon model and to analyze significant differences between white grape pomace, and mixed grape pomace varieties, due to the absence of a pomace fermentation process during white wine production. No differences were observed in the cytotoxicity caused by different extracts. All extracts, before and after biotransformation at 100 and 200 μg/mL (dry extract w/v) had comparable efficacy in reducing reactive oxygen species production in Caco-2 cells. After treatment and induction of inflammation using an interleukin 1β (IL-1β) challenge, tannase-treated white grape pomace extract at 200 μg/mL was the most efficient treatment in down-regulating nuclear factor kappa B activation by 40%, compared to control. On the other hand, tannase-treated mixed grape pomace extract significantly decreased prostaglandin E2 production by 81% and interleukin-8 by 61%, being more effective than white grape pomace extract. Overall, both grape pomace extracts after biotransformation were more potent in the amelioration of IL-1β-induced inflammation in Caco-2 cells. White grape pomace extract did not show higher anti-inflammatory activity than mixed grape pomace. In general, the biotransformation improved the anti-inflammatory effect in Caco-2 cells, indicating that the application of a bioprocess in grape residues may contribute to the development of new ingredients and nutraceuticals with anti-inflammatory potential.

Inhibition of mPGES-1 or COX-2 Results in Different Proteomic and Lipidomic Profiles in A549 Lung Cancer Cells.

Pharmacological inhibition of microsomal prostaglandin E synthase (mPGES)-1 for selective reduction in prostaglandin E2 (PGE2) biosynthesis is protective in experimental models of cancer and inflammation. Targeting mPGES-1 is envisioned as a safer alternative to traditional non-steroidal anti-inflammatory drugs (NSAIDs). Herein, we compared the effects of mPGES-1 inhibitor Compound III (CIII) with the cyclooxygenase (COX)-2 inhibitor NS-398 on protein and lipid profiles in interleukin (IL)-1β-induced A549 lung cancer cells using mass spectrometry. Inhibition of mPGES-1 decreased PGE2 production and increased PGF2α and thromboxane B2 (TXB2) formation, while inhibition of COX-2 decreased the production of all three prostanoids. Our proteomics results revealed that CIII downregulated multiple canonical pathways including eIF2, eIF4/P70S6K, and mTOR signaling, compared to NS-398 that activated these pathways. Moreover, pathway analysis predicted that CIII increased cell death of cancer cells (Z = 3.8, p = 5.1E−41) while NS-398 decreased the same function (Z = −5.0, p = 6.5E−35). In our lipidomics analyses, we found alterations in nine phospholipids between the two inhibitors, with a stronger alteration in the lysophospholipid (LPC) profile with NS-398 compared to CIII. Inhibition of mPGES-1 increased the concentration of sphinganine and dihydroceramide (C16:0DhCer), while inhibition of COX-2 caused a general decrease in most ceramides, again suggesting different effects on cell death between the two inhibitors. We showed that CIII decreased proliferation and potentiated the cytotoxic effect of the cytostatic drugs cisplatin, etoposide, and vincristine when investigated in a live cell imaging system. Our results demonstrate differences in protein and lipid profiles after inhibition of mPGES-1 or COX-2 with important implications on the therapeutic potential of mPGES-1 inhibitors as adjuvant treatment in cancer. We encourage further investigations to illuminate the clinical benefit of mPGES-1 inhibitors in cancer.

Cyclooxygenase inhibitors potentiate receptor tyrosine kinase therapies in bladder cancer cells in vitro.

PurposeReceptor tyrosine kinase inhibitors (RTKIs) are used as targeted therapies for patients diagnosed with cancer with highly expressed receptor tyrosine kinases (RTKs), including the platelet-derived growth factor receptor (PDGFR) and c-Kit receptor. Resistance to targeted therapies is partially due to the activation of alternative pro-survival signaling pathways, including cyclooxygenase (COX)-2. In this study, we validated the effects of two RTKIs, axitinib and AB1010, in combination with COX inhibitors on the V-akt murine thymoma oncogene homolog 1 (Akt) and COX-2 signaling pathways in bladder cancer cells.MethodsThe expression of several RTKs and their downstream signaling targets was analyzed by Western blot (WB) analysis in human and canine bladder transitional cell carcinoma (TCC) cell lines. The effects of RTKIs and COX inhibitors in bladder TCC cells were assessed by MTS for cell viability, by Caspase-3/7 and Annexin V assay for apoptosis, by WB analysis for detection of COX-2 and Akt signaling pathways, and by enzyme-linked immunosorbent assay for detection of prostaglandin E2 (PGE2) levels.ResultsAll tested TCC cells expressed the c-Kit and PDGFRα receptors, except human 5637 cells that had low RTKs expression. In addition, all tested cells expressed COX-1, COX-2, Akt, extracellular signal regulated kinases 1/2, and nuclear factor kappa-light-chain-enhance of activated B cells proteins, except human UM-UC-3 cells, where no COX-2 expression was detected by WB analysis. Both RTKIs inhibited cell viability and increased apoptosis in a dose-dependent manner in tested bladder TCC cells, which positively correlated with their expression levels of the PDGFRα and c-Kit receptors. RTKIs increased the expression of COX-2 in h-5637 and K9TCC#1Lillie cells. Co-treatment of indomethacin inhibited AB1010-induced COX-2 expression leading to an additive effect in inhibition of cell viability and PGE2 production in tested TCC cells.ConclusionCo-treatment of RTKIs with indomethacin inhibited cell viability and AB1010-induced COX-2 expression resulting in decreased PGE2 production in tested TCC cells. Thus, COX inhibition may further potentiate RTKIs therapies in bladder cancer.

Preconditioning of murine mesenchymal stem cells synergistically enhanced immunomodulation and osteogenesis

BackgroundMesenchymal stem cells (MSCs) are capable of immunomodulation and tissue regeneration, highlighting their potential translational application for treating inflammatory bone disorders. MSC-mediated immunomodulation is regulated by proinflammatory cytokines and pathogen-associated molecular patterns such as lipopolysaccharide (LPS). Previous studies showed that MSCs exposed to interferon gamma (IFN-γ) and the proinflammatory cytokine tumor necrosis factor alpha (TNF-α) synergistically suppressed T-cell activation.MethodsIn the current study, we developed a novel preconditioning strategy for MSCs using LPS plus TNF-α to optimize the immunomodulating ability of MSCs on macrophage polarization.ResultsPreconditioned MSCs enhanced anti-inflammatory M2 macrophage marker expression (Arginase 1 and CD206) and decreased inflammatory M1 macrophage marker (TNF-α/IL-1Ra) expression using an in-vitro coculture model. Immunomodulation of MSCs on macrophages was significantly increased compared to the combination of IFN-γ plus TNF-α or single treatment controls. Increased osteogenic differentiation including alkaline phosphate activity and matrix mineralization was only observed in the LPS plus TNF-α preconditioned MSCs. Mechanistic studies showed that increased prostaglandin E2 (PGE2) production was associated with enhanced Arginase 1 expression. Selective cyclooxygenase-2 inhibition by Celecoxib decreased PGE2 production and Arginase 1 expression in cocultured macrophages.ConclusionsThe novel preconditioned MSCs have increased immunomodulation and bone regeneration potential and could be applied to the treatment of inflammatory bone disorders including periprosthetic osteolysis, fracture healing/nonunions, and osteonecrosis.

Cytokine-mediated Differential Regulation of Cyclooxygenase-2, High Mobility Group Box 1 Protein and Matrix Metalloproteinase-9 Expression in Fibroblast-like Synovial Cells

Persistent joint inflammation and pain with concomitant joint erosion, characterize Rheumatoid Arthritis (RA). We used a Fibroblast-like Synovial (FLS) cell line derived from a female rabbit, as a model system for studying the initiation and attenuation of conditions of RA in vitro. We used two pro-inflammatory cytokines, TNFα and IL-1β to examine potential inflammatory responses and cartilage erosion exerted by each cytokine alone and/or in combination. We determined the expression levels of cytokine-induced expression of Cyclooxygenase-2 (COX-2), production of Prostaglandin E2 (PGE2), release of high mobility group box-1 (HMGB1) protein and the activity of Metalloproteinase-9 (MMP-9) in FLS cells. Treatment with TNFα alone increased HMGB1 release levels, MMP-9 activity, COX-2 expression and PGE2 production in both concentration- and exposure time-dependent manner. But treatment with a low concentration of TNF-α in combination with an equivalent concentration of IL-1β produced similar levels of COX-2 expression and PGE2 production compared with the same concentration of TNF-α alone. This suggests that the effects observed could only be due to the TNFα. IL-1β did not affect COX-2 expression in a concentration-dependent manner compared to media control. Treatment with indomethacin or NS392 significantly decreased TNFα-induced COX-2 expression coupled with decreased PGE2 production and MMP-9 expression. In addition, anti-TNFα decreased HMGB1 release level, PGE2 production and MMP-9 expression, which support a critical role for TNFα-induced TNF Receptor (TNFR) activation for these effects. Overall, our results support treatment approaches in RA that attenuate the effects of TNFα-induced TNFR stimulation on MMP-9 and PGE2 production with HMGB1 release for a more efficacious therapy.

PGE2 imbalance in diabetic mice impairs dendritic cell maturation and favors methicillin-resistant S. aureus skin infection

Abstract Diabetics are more prone to Staphylococcus aureus skin infection than healthy individuals. Neutrophil recruitment and apoptosis are hallmarks of S. aureus infections. Ingestion of infected apoptotic cells (IAC) by dendritic cells (DC) lead to secretion of Th17-related cytokines and prostaglandin E2 (PGE2). We speculate that hyperglycemia inhibits DC migration to the lymph nodes, in a manner dependent on PGE2 levels and impairs Th17 differentiation during MRSA skin infection in type 1 diabetic mice (T1D). Control and T1D mice were subcutaneously (s.c.) infected with 5×106 MRSA CFU. T1D mice showed increased lesion and bacterial load and decreased Th17 population in the skin than nondiabetic mice. We next determined if decreased Th17 correlates with deficient DC migration to draining LN. To track DC migration, mice received s.c. FarRed to stain the skin cells. Our results show that T1D had lower percentage and number of FarRed+DCs+ in the LN than controls.. Impaired DC migration and Th17 differentiation in T1D correlated with decreased skin PGE2 levels. When BMDCs were cultured in high glucose, we observed decreased PGE2 production, migration and maturation after recognition of MRSA-IAC when compared to BMDC kept in normal glucose. Topical treatment with PGE analog (Misoprostol), restored skin DC migration, Th17 differentiation, increased anti-microbial peptides, decreased CFU loads and lesion size in T1D. These data suggest that PGE2 imbalance in hyperglycemia impairs DC migration to LN and fail to mount Th17 responses leading to increased lesions and delayed healing in MRSA skin infections. Misoprostol may be a promising candidate to improve innate and adaptive immune responses in diabetic skin infections.

Ibuprofen-conjugated hyaluronate/polygalacturonic acid hydrogel for the prevention of epidural fibrosis.

The formation of fibrous tissue is part of the natural healing response following a laminectomy. Severe scar tissue adhesion, known as epidural fibrosis, is a common cause of failed back surgery syndrome. In this study, by combining the advantages of drug treatment with a physical barrier, an ibuprofen-conjugated crosslinkable polygalacturonic acid and hyaluronic acid hydrogel was developed for epidural fibrosis prevention. Conjugation was confirmed and measured by 1D(1)H NMR spectroscopy.Invitroanalysis showed that the ibuprofen-conjugated polygalacturonic acid-hyaluronic acid hydrogel showed low cytotoxicity. In addition, the conjugated ibuprofen decreased prostaglandin E2production of the lipopolysaccharide-induced RAW264.7 cells. Histological data ininvivostudies indicated that the scar tissue adhesion of laminectomized male adult rats was reduced by the application of our ibuprofen-conjugated polygalacturonic acid-hyaluronic acid hydrogel. Its use also reduced the population of giant cells and collagen deposition of scar tissue without inducing extensive cell recruitment. The results of this study therefore suggest that the local delivery of ibuprofenviaa polygalacturonic acid-hyaluronic acid-based hydrogel reduces the possibility of epidural fibrosis.

Resveratrol attenuates inflammation-induced hyperexcitability of trigeminal spinal nucleus caudalis neurons associated with hyperalgesia in rats.

BackgroundResveratrol, a component of red wine, has been reported to decrease prostaglandin E2 production by inhibiting the cyclooxygenase-2 cascade and to modulate various voltage-dependent ion channels, suggesting that resveratrol could attenuate inflammatory hyperalgesia. However, the effects of resveratrol on inflammation-induced hyperexcitability of nociceptive neurons in vivo remain to be determined. Thus, the aim of the present study was to determine whether daily systemic administration of resveratrol to rats attenuates the inflammation-induced hyperexcitability of spinal trigeminal nucleus caudalis wide-dynamic range neurons associated with hyperalgesia.ResultsInflammation was induced by injection of complete Freund’s adjuvant into the whisker pad. The threshold of escape from mechanical stimulation applied to whisker pad in inflamed rats was significantly lower than in control rats. The decreased mechanical threshold in inflamed rats was restored to control levels by daily systemic administration of resveratrol (2 mg/kg, i.p.). The mean discharge frequency of spinal trigeminal nucleus caudalis wide-dynamic range neurons to both nonnoxious and noxious mechanical stimuli in inflamed rats was significantly decreased after resveratrol administration. In addition, the increased mean spontaneous discharge of spinal trigeminal nucleus caudalis wide-dynamic range neurons in inflamed rats was significantly decreased after resveratrol administration. Similarly, resveratrol significantly diminished noxious pinch-evoked mean after discharge frequency and occurrence in inflamed rats. Finally, resveratrol restored the expanded mean size of the receptive field in inflamed rats to control levels.ConclusionThese results suggest that chronic administration of resveratrol attenuates inflammation-induced mechanical inflammatory hyperalgesia and that this effect is due primarily to the suppression of spinal trigeminal nucleus caudalis wide dynamic range neuron hyperexcitability via inhibition of both peripheral and central cyclooxygenase-2 cascade signaling pathways. These findings support the idea of resveratrol as a potential complementary and alternative medicine for the treatment of trigeminal inflammatory hyperalgesia without side effects.

Cinnamon polyphenols increase oxygen‐glucose deprivation of decreased PGE2 production by upregulation of SIRT1 and alleviation of the anti‐inflammatory effects (830.11)

Prostaglandin E2 (PGE2) is an important mediator of many biological functions, including vasodilation, both anti‐ and proinflammatory actions, and modulation of sleep/wake cycles. It is well known that cinnamon polyphenols have anti‐oxidant properties and that oxidative stress damages endothelial cells. We investigated the mechanisms underlying protective effects of an aqueous extract of cinnamon, high in polyphenols, in 3 hr oxygen‐glucose deprivation (OGD) treated mouse brain microvascular endothelial (bEnd.3) cells. Immunoprecipitation/Western blotting and immunofluorescent analyses showed that OGD/reperfusion down regulated PGE2 secretion into the media and cellular PGE2 expression. Cinnamon polyphenols reversed these damages and also induced sirtuin (SIRT)1 expression. Further studies showed that the effects were reversed by a SIRT1 inhibitor IV. Cinnamon polyphenols also inhibited the expression of the anti‐apoptotic protein, Bcl‐xl, and induced the expression of the pro‐apoptotic protein, Bax, in OGD treated cells. The OGD‐induced inflammatory factors, TNF‐α and phospho‐Nf‐kB p65, were suppressed by cinnamon polyphenols. Taken together, these results suggest protective roles of cinnamon on PGE2 production and that cinnamon polyphenols may be neuroprotectants for ischemia‐related injury.Grant Funding Source: This work was supported in part by a USDA Cooperative Research and Development Agreement (CRADA No.5

Cryotherapy suppresses tendon inflammation in an animal model

Cryotherapy (or cold treatment) has been a popular treatment to relieve pain caused by injuries to tissues such as tendons. However, the exact mechanisms behind the beneficial effects of cryotherapy in tendons remain largely unclear. As prostaglandin E2 (PGE2) is known to be a major mediator of acute inflammation in tissues, which is related to tissue pain, we hypothesized that the beneficial effects of cryotherapy in tendons are mediated by downregulation of PGE2 levels. To test this hypothesis, we applied cold treatment to mouse patellar and Achilles tendons using two animal models: exhaustive mouse treadmill running and acute mouse tendon injury by needle penetration. We then measured the levels of PGE2 and protein expression levels of COX-2, an enzyme responsible for PGE2 production in tissues, under both experimental conditions. We found that treadmill running increased PGE2 levels in both patellar and Achilles tendons compared to control mice without running. Cold treatment for 30 min after treadmill running was sufficient to reduce PGE2 levels to near baseline control levels in both tendons. An extension of cold treatment to 60 min resulted only in a marginal decrease in patellar tendons, but a marked decrease in Achilles tendons. Moreover, COX-2 protein levels in both tendons were also lowered by cold treatment, suggesting that the reduction of PGE2 levels in tendons by cold treatment is at least in part due to the decreased COX-2 expression. Similarly, in the acutely injured tendons, 30 min of cold treatment after needle penetration reduced PGE2 levels when compared to the controls at room temperature (22°C). This decrease was sustained up to at least 3 h after the administration of cryotherapy. Given that PGE2 is a known pain sensitiser, the results of this study suggest that the ability of cold treatment to reduce pain may be attributable to its ability to decrease PGE2 production in tendons.

Preventive Effects of a Kampo Medicine, Kakkonto, on Inflammatory Responses via the Suppression of Extracellular Signal-Regulated Kinase Phosphorylation in Lipopolysaccharide-Treated Human Gingival Fibroblasts

Periodontal disease is accompanied by inflammation of the gingiva and destruction of periodontal tissues, leading to alveolar bone loss in severe clinical cases. The chemical mediator prostaglandin E2 (PGE2) and cytokines such as interleukin- (IL-)6 and IL-8 have been known to play important roles in inflammatory responses and tissue degradation. In the present study, we investigated the effects of a kampo medicine, kakkonto (TJ-1), on the production of prostaglandin E2 (PGE2), IL-6, and IL-8 by human gingival fibroblasts (HGFs) treated with lipopolysaccharide (LPS) from Porphyromonas gingivalis. Kakkonto concentration dependently suppressed LPS-induced PGE2 production but did not alter basal PGE2 levels. In contrast, kakkonto significantly increased LPS-induced IL-6 and IL-8 production. Kakkonto decreased cyclooxygenase- (COX-)1 activity to approximately 70% at 1 mg/mL but did not affect COX-2 activity. Kakkonto did not affect cytoplasmic phospholipase A2 (cPLA2), annexin1, or LPS-induced COX-2 expression. Kakkonto suppressed LPS-induced extracellular signal-regulated kinase (ERK) phosphorylation, which is known to lead to ERK activation and cPLA2 phosphorylation. These results suggest that kakkonto decreased PGE2 production by inhibition of ERK phosphorylation which leads to inhibition of cPLA2 phosphorylation and its activation. Therefore, kakkonto may be useful to improve gingival inflammation in periodontal disease.

Peroxisome proliferator-activated receptor γ agonist suppresses human telomerase reverse transcriptase expression and aromatase activity in eutopic endometrial stromal cells from endometriosis

ObjectiveTo investigate the effect of peroxisome proliferator activated receptor γ (PPARγ) agonist on the cell proliferation properties and expression of human telomerase reverse transcriptase (hTERT) and aromatase in cultured endometrial stromal cell (ESC) from patients with endometriosis.MethodsHuman endometrial tissues were obtained from women with endometriosis and healthy women (controls) using endometrial biopsy. Isolated ESCs were cultured and the cell proliferation was measured by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay and expression of hTERT, aromatase, and cyclooxygenase (COX)-2 by western blotting according to the addition of rosiglitazone (PPARγ agonist).ResultsWe demonstrate that the cultured ESCs of endometriosis showed hTERT protein overexpression and increased cellular proliferation, which was inhibited by rosiglitazone, in a dose-dependent manner. At the same time, PPARγ agonist also inhibited aromatase and COX-2 expression, resulting in decreased prostaglandin E2 production in the ESCs of endometriosis.ConclusionThis study suggests that PPARγ agonist plays an inhibitory role in the proliferative properties of eutopic endometrium with endometriosis by down-regulation of hTERT and COX-2 expression; this could be a new treatment target for endometriosis.

Thymoquinone (TQ) regulates cyclooxygenase-2 expression and prostaglandin E2 production through PI3kinase (PI3K)/p38 kinase pathway in human breast cancer cell line, MDA-MB-231

Thymoquinone (TQ), a drug extracted from the black seeds of Nigella sativa, has been shown to exhibit anti-inflammatory, anti-oxidant, and anti-neoplastic effects in numerous cancer cells. The effects of TQ on cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) production in MDA-MB-231, however, remain poorly understood. Western blot analysis and immunofluorescence staining were performed to study the expression levels of inflammation regulatory proteins in MDA-MB-231. PGE2 assay was conducted to explore the TQ-induced production of PGE2. In this study, we investigated the effects of TQ on COX-2 expression and PGE2 production in MDA-MB-231. TQ significantly induced COX-2 expression and increased PGE2 production in a dose-dependent manner, as determined by a Western blot analysis and PGE2 assay. Furthermore, the activation of Akt and p38 kinase, respectively, was up-regulated in TQ treated cells. Inhibition of p38 kinase with SB203580 and PI3kinase (PI3K) with LY294002 abolished TQ-caused COX-2 expression and decreased PGE2 production. These results collectively demonstrate that TQ effectively modulates COX-2 expression and PGE2 production via PI3K and p38 kinase pathways in the human breast cancer cell line MDA-MB-231.