Inhibition Of IL-6 Expression Research Articles

Global Deletion of 11β-HSD1 Prevents Muscle Wasting Associated with Glucocorticoid Therapy in Polyarthritis.

Glucocorticoids provide indispensable anti-inflammatory therapies. However, metabolic adverse effects including muscle wasting restrict their use. The enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11β-HSD1) modulates peripheral glucocorticoid responses through pre-receptor metabolism. This study investigates how 11β-HSD1 influences skeletal muscle responses to glucocorticoid therapy for chronic inflammation. We assessed human skeletal muscle biopsies from patients with rheumatoid arthritis and osteoarthritis for 11β-HSD1 activity ex vivo. Using the TNF-α-transgenic mouse model (TNF-tg) of chronic inflammation, we examined the effects of corticosterone treatment and 11β-HSD1 global knock-out (11βKO) on skeletal muscle, measuring anti-inflammatory gene expression, muscle weights, fiber size distribution, and catabolic pathways. Muscle 11β-HSD1 activity was elevated in patients with rheumatoid arthritis and correlated with inflammation markers. In murine skeletal muscle, glucocorticoid administration suppressed IL6 expression in TNF-tg mice but not in TNF-tg11βKO mice. TNF-tg mice exhibited reductions in muscle weight and fiber size with glucocorticoid therapy. In contrast, TNF-tg11βKO mice were protected against glucocorticoid-induced muscle atrophy. Glucocorticoid-mediated activation of catabolic mediators (FoxO1, Trim63) was also diminished in TNF-tg11βKO compared to TNF-tg mice. In summary, 11β-HSD1 knock-out prevents muscle atrophy associated with glucocorticoid therapy in a model of chronic inflammation. Targeting 11β-HSD1 may offer a strategy to refine the safety of glucocorticoids.

Si-Based Hydrogen-Producing Nanoagent Protects Fetuses From Miscarriage Caused by Mother-to-Child Transmission

Mother-to-child transmission of viruses and bacteria increases the risk of miscarriage and various diseases in children. Such transmissions can result in infections and diseases in infants or the induction of an inflammatory immune response through the placenta. Recently, we developed a silicon (Si)-based hydrogen-producing nanoagent (Si-based agent) that continuously and effectively produces hydrogen in the body. Since medical hydrogen has antioxidative, anti-inflammatory, antiallergic, and antiapoptotic effects, we investigated the effects of our Si-based agent on mother-to-child transmission, with a focus on the rate of miscarriage. In pregnant mice fed a diet containing the Si-based agent, lipopolysaccharide (LPS)-induced miscarriage due to mother-to-child transmission was reduced and inflammation and neutrophil infiltration in the placenta were suppressed. We also found that the Si-based agent suppressed IL-6 expression in the placenta and induced the expression of antioxidant and antiapoptotic genes, such as Hmox1 and Ptgs2. The observed anti-inflammatory effects of the Si-based agent suggest that it may be an effective preventative or therapeutic drug for miscarriage or threatened miscarriage during pregnancy by suppressing maternal inflammation caused by bacterial and viral infections.

Bile Acids Elevated in Chronic Periaortitis Could Activate Farnesoid-X-Receptor to Suppress IL-6 Production by Macrophages.

Chronic periaortitis (CP) is a rare autoimmune disease without effective treatment. By analyzing the serum bile acid spectrum in 28 CP patients with the ultra-performance liquid chromatography-tandem mass spectrometry, we found that the bile acids were significantly altered in CP patients, with significant increases in chenodeoxycholic acid (CDCA) and glycochenodeoxycholic acid (GCDCA) and decrease in deoxycholic acid (DCA). Signaling pathway enrichment analysis from the RNA sequencing results suggested that the altered gene sets in PBMC of CP patients were associated with bile acid metabolism. Furthermore, we found that pathological concentration of CDCA could significantly inhibited IL-6 expression in RAW 264.7 cells after LPS stimulation. Since CDCA is a well-known natural high-affinity ligand for the bile acid receptor farnesoid-x-receptor (FXR) while GW4064 is the synthetic specific agonist of this receptor, we then revealed that GW4064 significantly decreased IL-6 expression in RAW 264.7 cells and bone marrow-derived macrophages but not in FXR-/- macrophages upon LPS stimulation. The western blot results with the anti-FXR antibody showed significantly increased expression in the nuclear proportion, suggesting that FXR agonist promoted the transportation of FXR into the nucleus but did not increase the FXR expression in macrophages. Dual-luciferase report assay and ChIP assay demonstrated that upon activation, FXR could directly bind to the promoter site of IL-6, leading to the decreased expression of IL-6. Thus, bile acids, especially CDCA, may operate to damp inflammation via FXR-mediated downregulation of IL-6 in mononuclear cells and provide a protective mechanism for CP patients.

Exosomes derived from mesenchymal stem cells regulate Treg/Th17 balance in aplastic anemia by transferring miR-23a-3p.

Imbalanced Th17/Treg ratio is implicated in the pathogenesis of aplastic anemia. Studies have indicated that bone marrow-derived mesenchymal stem cells-derived exosomes (BMSC-Exo) could correct imbalanced Th17/Treg in aplastic anemia, but the mechanism remains not fully understand. This study was designed to investigate whether BMSC-Exo regulates the Th17/Treg balance in aplastic anemia by transferring miR-23a-3p. Here, miR-23a-3p inhibitor was utilized to knockdown the expression of miR-23a-3p in BMSC-Exo. A co-culture system of CD4+ T cells from aplastic anemia patients and BMSC-Exo was used to explore the effects of BMSC-Exo on the Th17/Treg balance and the underlying mechanism in aplastic anemia. The patients with aplastic anemia exhibited Th17/Treg imbalance favoring the Th17 cells. BMSC-Exo could balance the percentage of Th17 and Treg cells in aplastic anemia, but the effects of BMSC-Exo can be eliminated when miR-23a-3p expression was silenced in BMSCs. IL-6 was a direct target of miR-23a-3p. IL-6 overexpression could abrogate BMSC-Exo-induced balance in Th17/Treg ratio. Overall, BMSC-Exo could balance Th17/Treg ratio in aplastic anemia via suppressing IL-6 expression by transferring miR-23a-3p at least in part. These data indicated miR-23a-3p may be a potential target for the treatment of aplastic anemia. Our study may provide a new idea for the therapy of the disease.

RETRACTED ARTICLE: lncRNA HAND2-AS1 is downregulated in osteoarthritis and regulates IL-6 expression in chondrocytes

BackgroundOsteoarthritis (OA) is a leading cause of disability. The incidence of OA is progressively rising due to the diminishing levels of physical activity and ever-expanding aging population. However, the mainstay for OA treatment only can improve symptoms without delay the progression of this severe disease. This study aimed to explore the biological role and clinical function of lncRNA HAND2-AS1 in OA.MethodsBlood samples and synovial fluid were collected from OA patients and normal subjects. HAND2-AS1 expression was detected by qRT-PCR and IL-6 expression was detected by ELISA. The plasma levels of HAND2-AS1 were also detected in different ages, stages, and gender of OA patients and controls. Furthermore, the ROC curve was used to analyze whether HAND2-AS1 can distinguish OA patients from normal subjects. Also, Pearson correlation coefficient analysis was used to analyze the correlation between lncRNA HAND2-AS1 and IL-6. In addition, Western blot was used to detect the IL-6 level upon HAND2-AS1 over-expression in chondrocytes and qRT-PCR was used to detect the HAND2-AS1 level after endogenous IL-6 treatment.ResultsHAND2-AS1 and IL-6 were dysregulated in plasma and synovial fluid of OA patients. The expression of HAND2-AS1 in plasma of OA patients was decreased with aging and progression. Furthermore, HAND2-AS1 downregulation effectively distinguished OA patients from the healthy controls. Over-expression of HAND2-AS1 inhibited IL-6 expression in chondrocytes, while treatment with exogenous IL-6 did not affect HAND2-AS1 expression.ConclusionHAND2-AS1 effectively distinguished OA patients from the healthy controls and regulates IL-6 expression in human chondrocytes.Trial registrationChiCTR, ChiCTR2000038635. Registered 11 February 2019

IL-37 Confers Anti-Tumor Activity by Regulation of m6A Methylation

N6-methyladenosine (m6A) is a common transcriptomic modification in cancer. Recently, it has been found to be involved in the regulation of non-small cell lung cancer (NSCLC) formation and metastasis. Interleukin 37 (IL-37) plays a crucial protective role in lung cancer. In our previous studies, we found that IL-37 is a potential novel tumor suppressor by inhibiting IL-6 expression to suppress STAT3 activation and decreasing epithelial-to-mesenchymal transition. Moreover, we found that treatment of IL-37 in lung cancer cells induced widespread and dynamic RNA m6A methylation. The effects of RNA m6A methylation of IL-37 treatment require further study. However, the functions of RNA m6A methylation of IL-37 treatment still await elucidation. Using MeRIP-seq and RNA-seq, we uncovered a unique m6A methylation profile in the treatment of IL-37 on the A549 cell line. We also showed the expression of m6A writers METTL3, METTL14, and WTAP and erasers ALKBH5 and FTO in A549 cells and lung cancer tissues after the treatment of IL-37. This study showed that IL-37 could lead to changes in m6A methylation level and related molecule expression level in A546 cells and may downregulate the proliferation by inhibiting Wnt5a/5b pathway in A549 cells. We conclude that IL-37 suppresses tumor growth through regulation of RNA m6A methylation in lung cancer cells.

TLT2 Suppresses Th1 Response by Promoting IL-6 Production in Monocyte Through JAK/STAT3 Signal Pathway in Tuberculosis.

The function of triggering receptor expressed on myeloid cell-like transcript 2 (TLT2) has not been characterized and their role in pulmonary tuberculosis (TB) remains unclear. In this study, we found that surface TLT2 was up-regulated in human monocytes of patients with active TB compared to healthy subjects. In vitro, TLT2 expression was induced in human monocyte cell line THP-1 cells after bacillus Calmette-Guérin (BCG) or Mycobacterium tuberculosis (Mtb) H37Rv infection. Knockdown of TLT2 by siRNA transfection suppressed IL-6 expression, whereas over-expression of TLT2 increased IL-6 production in THP-1 cells infected by H37Rv. TLT2+CD14+ monocytes produced higher level of IL-6 compared to TLT2– subset in active TB patients. Western blot and immunocoprecipitation revealed that TLT2 interacted with kinase JAK1/JAK2/Tyk2 to enhance STAT3 phosphorylation. Moreover, we showed that tyrosine residues 297 and 315 of TLT2 cytoplasmic domain were involved in STAT3 activation. In monocyte/CD4+ T cell co-culture assay, blockage of TLT2 fusion protein facilitated IFN-γ production by CD4+ T cells. Plate count assay showed that monocyte-mediated bacterial killing was promoted by TLT2 fusion protein. In vivo treatment with TLT-2 fusion protein reduced IL-6 production by macrophage but increased IFN-γ production by CD4+ T cell in H37Rv and BCG infected mice. Furthermore, TLT2 fusion protein attenuated inflammation, and reduced bacterial load in lung of infected mice. Together, these findings demonstrate that TLT2 negatively regulates Th1 response against mycobacterial infection, which promotes IL-6 production through JAK/STAT3 signal pathway.

Mesenchymal Stromal Cells Suppress Hippocampal Neuron Autophagy Stress Induced by Hypoxic-Ischemic Brain Damage: The Possible Role of Endogenous IL-6 Secretion.

Background Increasing evidence has revealed that mesenchymal stromal cell (MSC) transplantation alleviates hypoxic-ischemic brain damage (HIBD) induced neurological impairments via immunomodulating astrocyte antiapoptosis effects. However, it remains unclear whether MSCs regulate neuron autophagy following HIBD. Results In the present study, MSC transplantation effectively ameliorated learning-memory function and suppressed stress-induced hippocampal neuron autophagy in HIBD rats. Moreover, the suppressive effects of MSCs on autophagy were significantly weakened following endogenous IL-6 silencing in MSCs. Suppressing IL-6 expression also significantly increased p-AMPK protein expression and decreased p-mTOR protein expression in injured hippocampal neurons. Conclusion Endogenous IL-6 in MSCs may reduce autophagy in hippocampal neurons partly through the AMPK/mTOR pathway.

Negative regulation of IL-8 in human astrocytes depends on β-catenin while positive regulation is mediated by TCFs/LEF/ATF2 interaction

Expression of cytokines/chemokines is tightly regulated at the transcription level. This is crucial in the central nervous system to maintain neuroimmune homeostasis. IL-8 a chemoattractant, which recruits neutrophils, T cells, and basophils into the brain in response to inflammation and/or injury is secreted predominantly by neurons, microglia, and astrocytes. Here, we investigated the mechanism by which astrocytes regulate IL-8 expression. We demonstrate that while β-catenin negatively regulated IL-8 transcription, its canonical transcriptional partners, members of the TCF/LEF transcription factors (TCF1, TCF3, TCF4 and LEF1) and Activating transcription factor 2 (ATF2) positively regulated IL-8 transcription. We further identified a putative TCF/LEF binding site at −175nt close to the minimal transcription region on the IL-8 promoter, mutation of which caused a significant reduction in IL-8 promoter activity. Chromatin immunoprecipitation demonstrated binding of TCF1, TCF4, LEF1 and ATF2 on the IL-8 promoter suggesting that TCFs/LEF partner with ATF2 to induce IL-8 transcription. These findings demonstrate a novel role for β-catenin in suppression of IL-8 expression and for TCFs/LEF/ATF2 in inducing IL-8. These findings reveal a unique mechanism by which astrocytes tightly regulate IL-8 expression.

Th17/Treg imbalance is associated with reduced indoleamine 2,3 dioxygenase activity in childhood allergic asthma

BackgroundThe differentiation of CD4+ lymphocytes Th17/regulatory T cells (Treg) and indoleamine 2,3-dioxygenase (IDO) is associated with the pathogenesis of allergic asthma. Basic research has shown that IDO is likely a “switch” of the transition from Th17 cells to Tregs under certain conditions. However, no relevant clinical studies have been reported on the association between IDO activity and Th17/Treg imbalance in children with allergic asthma. The goal of this study was to test whether indoleamine 2,3 dioxygenase (IDO) participates in the pathogenesis of pediatric allergic asthma by influencing Th17/regulatory T cell (Treg) differentiation and related cytokines.MethodsThirty-three children with allergic asthma and 33 healthy children were selected. The subjects were evaluated via a pulmonary function test, a skin prick test, and an eosinophil count. Peripheral blood was collected to measure Th17/Treg percentages and related cytokine levels. Blood and induced sputum were obtained to measure the IDO level.ResultsCompared with the control group, the patient group had an obvious Th17/Treg imbalance; their IDO levels were significantly lower, their IL-17 and IL-6 levels were markedly higher, and their IL-10 and TGF-β levels were markedly lower than those of the control group. The IDO levels in both blood and induced sputum were negatively correlated with the Th17/Treg ratio.ConclusionsA significant correlation was observed between IDO activity and Th17/Treg imbalance in children with allergic asthma. IDO may upregulate Treg numbers by stimulating IL-10 production and inhibiting IL-6 expression. Therefore, IDO may be a molecular switch that leads to the conversion of Th17 cells to Tregs, thus playing a potentially protective role in the pathogenesis of asthma.Trial registration This study was approved by the Chinese Clinical Trial Registry with registration number ChiCTR-COC-15006080 and was reviewed and approved by the Ethics Committee of Southwest Hospital. The name of registration: The effect of indoleamine 2,3 dioxygenase (IDO) on Regulation of Th17/Treg Differentiation in Childhood Asthma. Date of registration: 14/03/2015. URL of trial registry record: http://www.chictr.org.cn

Pharmacodynamic and Metabolomics Studies on the Effect of Kouyanqing Granule in the Treatment of Phenol-Induced Oral Ulcer Worsened by Sleep Deprivation.

Oral ulcers are the most prevalent oral mucosal diseases globally, and no specific treatment schemes are currently available due to the complexity of oral ulcer diseases. Sleep deprivation increases the risk of a deterioration in oral health. Kouyanqing Granule (KYQG) has been used for decades in China to treat inflammatory diseases of the mouth and throat associated with the hyperactivity of fire due to yin deficiency syndrome. However, the mechanisms underlying the effects of KYQG in the treatment of oral ulcers are still unclear. The aims of this study were to investigate whether KYQG treatment could attenuate the symptoms of oral ulcers worsened by sleep deprivation and identify the involved metabolic pathways. First, we conducted chemical profiling of KYQG via UPLC–MS analysis. We then combined pharmacological and metabolomics approaches in a phenol-induced rat model of oral ulcers worsened by sleep deprivation. A total of 79 compounds were initially identified. Our observations showed that KYQG treatment induced a significantly higher healing rate in oral ulcers worsened by sleep deprivation. KYQG significantly reduced the levels of 5-HT and GABA in serum, and only decreased the 5-HT level in brain tissue after phenol injury followed by sleep deprivation. Moreover, KYQG administration significantly suppressed systemic inflammation by inhibiting TNF-α, IL-1β, IL-6, IL-18, and MCP-1. Immunohistochemical analysis further revealed that KYQG inhibited IL-6 expression in buccal mucosa tissues. KYQG treatment also significantly decreased the serum levels of ACTH, CORT, IgM, and 8-OHdG. Serum metabolomics analysis showed that a total of 30 metabolites showed significant differential abundances under KYQG intervention, while metabolic pathway analysis suggested that the altered metabolites were associated with the dysregulation of eight metabolic pathways. Taken together, our results indicated that KYQG attenuates the symptoms of oral ulcers worsened by sleep deprivation probably through the regulation of the neuroimmunoendocrine system, oxidative stress levels, and tryptophan metabolism. This study also provides a novel approach for addressing the increased health risks resulting from sleep deficiency using an herbal medicine formula.

Synthesis and evaluation of substituted phenyl cycloalkylureas and bioisosteres as IL-6 expression inhibitors

Inflammation is an important, normal, and complex host defense response to injury, autoimmune responses or infectious agents. However, chronic inflammation is associated with diseases like rheumatoid arthritis, cancers, cardiovascular diseases, diabetes, and obesity, and over 60% of deaths worldwide. Interleukine-6 is one of the key proinflammatory cytokines involved in inflammation processes and therefore considered as a valuable drug target. We have prepared three series of new drugs referred to as substituted phenyl cycloalkylureas (PcAUs), phenyl cycloalkylthioureas (PcATUs) and phenyl cycloalkylsquaramides (PcASs), respectively. PcAUs and PcATUs were prepared by nucleophilic addition of 3 or 4-tert-butyl, 3- or 4-cyclohexyl and 3- or 4-iodoaniline to a suitable cycloalkylisocyanate or cycloalkylisothiocyanate. PcASs were prepared by nucleophilic addition of the aforementioned anilines to diethoxysquarate. The resulting alkoxysquarates were further reacted with selected cycloalkylamines to produce the desired PcASs. The antiproliferative activity of PcAUs, PcATUs and PcASs was evaluated in human keratinocytes and human skin fibroblasts. Most compounds at the exception of 4f, 4f′, 4f″, 5f, 5f′, 5f″, 6f, and 6f′, 6f″ that are bearing a 3-cyclohexyl group did not exhibit significant antiproliferative activities at concentration <30 µM. At 10 µM, PcAUs 4b-4e, 5b, 5e, and 6e inhibited IL-6 expression by more than 70% in HaCaT cells, which is equivalent to or greater than ibuprofen used as a positive control. These PcAUs showed a good metabolic stability in presence of human liver microsomes. Our results are suggesting PcAUs as a new molecular template for the development of potentially useful IL-6 expression inhibitors for the treatment of inflammation-related diseases.

IL-6 expression promoted by Poly(I:C) in cervical cancer cells regulates cytokine expression and recruitment of macrophages.

Poly(I:C) is a promising adjuvant for cancer treatment vaccines to enhance the host anti‐tumour immune response. However, the roles of poly(I:C) in the cervical cancer microenvironment and local immune reactions are not well understood. In this study, we investigated the roles of poly(I:C) in the cervical cancer. We analysed the cytokine transcription and secretion of cervical cancer cell lines and THP‐1–derived macrophages after poly(I:C) treatment, respectively. These results revealed that IL‐6 was significantly up‐regulated, and this up‐regulation was partly dose dependent. poly(I:C)‐stimulated supernatant of cervical cancer cells promoted M1‐type cytokine IL‐1β and IL‐6 expression of THP‐1–derived macrophages, but inhibited the expression of M2‐type cytokine, IL‐10 and CCL22. The recruitment of THP‐1–derived macrophages by poly(I:C)‐stimulated cervical cancer cell supernatant was also enhanced. Inhibition of IL‐6 expression in cervical cancer cells by siRNA transfection almost completely reversed the effects of poly(I:C) treatment. Finally, we found that phosphorylation of the NF‐κB signalling pathway in cervical cancer cells occurred quickly after poly(I:C) treatment. Moreover, the NF‐κB signalling pathway inhibitor PDTC significantly inhibited poly(I:C)‐induced IL‐6 expression. Taken together, these results suggest that poly(I:C) might regulate the effects of cervical cancer cells on tumour‐infiltrated macrophages, and subsequently promote a pro‐inflammatory tumour microenvironment.

1,25-dihydroxyvitamin D3 suppresses lipopolysaccharide-induced interleukin-6 production through aryl hydrocarbon receptor/nuclear factor-\u03baB signaling in oral epithelial cells

BackgroundAntiinflammatory effect of 1,25-dihydroxyvitamin D3 (1,25D3) has been reported in periodontitis, but the exact mechanisms remain unclear. Oral epithelial cells are recently highlighted as an important regulator of inflammation in this disease. This in vitro study was established to investigate the effect of 1,25D3 on key proinflammatory cytokine IL-6 production and aryl hydrocarbon receptor (AhR)/nuclear factor-κB (NF-κB) signaling in oral epithelial cells upon the stimulation of lipopolysaccharide (LPS) from periodontal pathogens.MethodsOKF6/TERT-2 oral keratinocytes were incubated with LPS and different concentrations of 1,25D3, and levels of IL-6 production were determined using enzyme-linked immunosorbent assay (ELISA). Expression of vitamin D receptor (VDR), and activation of AhR was examined using western blot analysis, and phosphorylation of NF-κB was detected using cell-based protein phosphorylation ELISA.Results1,25D3 inhibited LPS-induced IL-6 overexpression in OKF6/TERT-2 cells. Additionally, 1,25D3 increased VDR expression and AhR activation, and repressed NF-κB phosphorylation. Furthermore, 1,25D3 suppressed IL-6 expression and enhanced VDR expression and regulated AhR/NF-κB signaling activation in a dose-dependent manner after 48 h treatment.ConclusionsThese results suggest that 1,25D3 may inhibit LPS-induced IL-6 overexpression in human oral epithelial cells through AhR/NF-κB signaling. Our findings may provide an explanation for the antiinflammatory effect and therapeutic benefit of 1,25D3 in periodontitis.

Alterations in IL-6/STAT3 Signaling by Korean Mistletoe Lectin Regulate the Self-Renewal Activity of Placenta-Derived Mesenchymal Stem Cells.

Korean mistletoe (Viscum album L. var. coloratum) lectin (VCA) is known as an anticancer drug. However, it is not clear whether VCA affects the self-renewal activity of mesenchymal stem cells (MSCs). Therefore, the objectives of this study were to analyze the effect of VCA on the proliferation of MSCs and expression of stemness markers. We also evaluated the usefulness of placenta-derived MSCs (PD-MSCs) as a screening tool. VCA was stably administered to MSCs, and analyzed self-renewal activities. The effect of IL-6 signaling on MSC proliferation was explored by quantitative methylation-specific PCR (qMSP) and western blot analysis. Compared with the control condition, low concentrations of VCA (10 pg/mL) induced an increase in the self-renewal activity of MSCs. Interestingly, a low concentration of VCA promoted IL-6 signaling in PD-MSCs through altered IL-6/STAT3 gene methylation. Furthermore, inhibition of IL-6 expression in PD-MSCs using an anti-IL-6 antibody caused a decrease in their self-renewal activity through IL-6/STAT3 signaling by altering IL-6/STAT3 gene methylation. These findings provide helpful data for understanding the mechanism of MSC self-renewal via VCA and show that VCA may be useful as a functional natural product for developing efficient therapies using placenta-derived stem cells.

LncRNA DILC participates in rheumatoid arthritis by inducing apoptosis of fibroblast-like synoviocytes and down-regulating IL-6.

IL-6 produced by human fibroblast-like synoviocytes (HFLS) promotes rheumatoid arthritis (RA), while lncRNA DILC regulates liver cancer stem cells by inhibiting IL-6. Therefore, lncRNA DILC may participate in RA. In the present study, we found that plasma lncRNA DILC was down-regulated, while IL-6 was up-regulated in RA patients than in healthy controls. Plasma levels of lncRNA DILC and IL-6 were significantly and inversely correlated only in RA patients. Overexpression of lncRNA DILC resulted in promoted apoptosis of HFLS isolated from RA patients, while lncRNA DILC siRNA silencing played an opposite role. In addition, overexpression of lncRNA DILC also resulted in inhibited IL-6 expression in HFLS isolated from RA patients. Therefore, lncRNA DILC may participate in RA by inducing apoptosis of HFLS and down-regulating IL-6.

CSTP1 inhibits IL-6 expression through targeting Akt/FoxO3a signaling pathway in bladder cancer cells

CSTP1, a recently identified protein phosphotase, is frequently repressed in bladder cancers. Previous results showed that CSTP1 over-expression inhibited cell cycle progression and promoted apoptosis through dephosphorylating Akt kinase at Ser473 site in bladder cancer cells, but the mechanisms how CSTP1 exerted tumor suppressive activity remains unclear. In this study, we analyzed the gene expression profile changes that affected by CSTP1 overexpression by microarray, and reported that CSTP1 decreased IL-6 expression/secretion in bladder cancer cells and re-expression of IL-6 abrogated CSTP1's tumor suppressive activity. We also found that FoxO3a occupy IL-6 gene promoter and repressed IL mRNA transcription. Further results showed that decreased expression of IL-6 in CSTP1-overexpressing cells inactivated Stat3 transcriptional factor, which resulted in the down-regulation of cyclin D1, Bcl-xl expression. Spearman correlation analysis revealed that the mRNA level of CSTP1 correlated inversely with that of IL-6 in bladder cancer tissues. In conclusion, our studies revealed that protein phosphotase CSTP1 inhibited IL-6 expression through targeting Akt/FoxO3a signaling pathway and IL-6 inactivated Stat3 was necessary for CSTP1's tumor suppressive function.

670: Mesenchymal stem cells suppress inflammatory cytokines in lipopolysaccharide exposed preterm human pregnant myometrial cells

Bone marrow derived mesenchymal stem cells (MSC) exert immunosuppressive effects that have broadened the treatment of inflammatory conditions such as myocardial infraction, multiple sclerosis and diabetes. Intrauterine infection associated with inflammation is a cause of preterm birth (PTB). Lipopolysaccharide (LPS)-based models of PTB increase levels of pro-inflammatory cytokine IL-6. MSC exert suppression through anti-inflammatory cytokine TGF-β1. We have previously reported that MSC can suppress the inflammatory response in term human myometrial (MYO) cells (AJOG 689) The objective of this study was to determine the cytokine response in human pregnant preterm myometrial cells exposed to LPS and treated with MSC. Preterm (PT) and term (T) human myometrial tissues were obtained at the time of cesarean delivery. The LPS model of PTB involved exposing MYO cells to 5 μg/ml LPS for 4 h followed by 1 μg/ml LPS for 24 h. These MYO cells were then treated with MSC for 24 h. Cell culture supernatants were collected to measure IL-6 and TGF-β1 levels by ELISA. Comparisons between groups was performed using two way ANOVA. PT cells were obtained from 4 women 34-35 weeks pregnant and T cells from 3 women 38-39 weeks pregnant. In unexposed MYO cells, basal levels of IL-6 were significantly higher in PT than T cells, (PT MYO: 1267.3 ± 435.7 vs. T MYO: 203.1 ± 90.9, pg/ml, p<0.01, Fig 1). When exposed to LPS, PT cells expressed significantly higher IL-6 levels compared to unexposed PT cells, (LPS: 3335.8 ± 280.4 vs. PT MYO: 1267.3 ± 435.7 pg/ml, p< 0.01). Treatment with MSC significantly suppressed IL-6 expression in PT cells exposed to LPS (LPS 3335.8 ± 280.4 vs LPS+MSC: 525.2 ± 78.3 pg/ml, p<0.01). MSC treatment resulted in significantly increased levels of TGF-β1 with and without exposure to LPS, (LPS+MSC: 884.7 ± 179.4 vs. MSC: 881.2 ±139.0 vs. PT MYO: 40.8 ± 3.5 pg/ml, p<0.01, Fig 2). Suppressive effects of MSC was significantly higher in PT than in T cells. In our LPS model of PTB, MSC treatment resulted in a 6-fold suppression in inflammatory cytokine IL-6 and a 20-fold increase in anti-inflammatory cytokine TGF-β1. Therefore, these immunosuppressive potential of MSC provide innovative opportunities for cell mediated therapeutics in inflammation-based PTB.

Preussins with Inhibition of IL-6 Expression from Aspergillus flocculosus 16D-1, a Fungus Isolated from the Marine Sponge Phakellia fusca.

New pyrrolidine alkaloids, preussins C-I (1-7) and (11 R)/(11 S)-preussins J and K (8 and 9), were isolated from the sponge-derived fungus Aspergillus flocculosus 16D-1. The structures and configurations of these preussins were elucidated by detailed spectroscopic analysis, modified Mosher's method, and comparisons with literature data. These compounds showed strong to moderate inhibitory activity toward IL-6 production in lipopolysaccharide-induced THP-1 cells with IC50 values ranging from 0.11 to 22 μM, but were inactive against normal tumor cell lines and fungi.

Astaxanthin Inhibits Mitochondrial Dysfunction and Interleukin-8 Expression in Helicobacter pylori-Infected Gastric Epithelial Cells.

Helicobacter pylori (H. pylori) infection leads to gastric inflammation, peptic ulcer and gastric carcinoma. H. pylori activates NADPH oxidase and increases reactive oxygen species (ROS), which induce NF-κB activation and IL-8 expression in gastric epithelial cells. Dysfunctional mitochondria trigger inflammatory cytokine production. Peroxisome proliferator-activated receptors-γ (PPAR-γ) regulate inflammatory response. Astaxanthin is a powerful antioxidant that protects cells against oxidative stress. The present study was aimed at determining whether astaxanthin inhibits H. pylori-induced mitochondrial dysfunction, NF-κB activation, and IL-8 expression via PPAR-γ activation in gastric epithelial cells. Gastric epithelial AGS cells were treated with astaxanthin, NADPH oxidase inhibitor apocynin and PPAR-γ antagonist GW9662, and infected with H. pylori. As a result, H. pylori caused an increase in intracellular and mitochondrial ROS, NF-κB activation and IL-8 expression, but decreased mitochondrial membrane potential and ATP level. Astaxanthin inhibited H. pylori-induced alterations (increased ROS, mitochondrial dysfunction, NF-κB activation, and IL-8 expression). Astaxanthin activated PPAR-γ and its target gene catalase in H. pylori-infected cells. Apocynin reduced ROS and inhibited IL-8 expression while astaxanthin did not affect NADPH oxidase activity. Inhibitory effects of astaxanthin on ROS levels and IL-8 expression were suppressed by addition of GW9662. In conclusion, astaxanthin inhibits H. pylori-induced mitochondrial dysfunction and ROS-mediated IL-8 expression by activating PPAR-γ and catalase in gastric epithelial cells. Astaxanthin may be beneficial for preventing oxidative stress-mediated gastric inflammation-associated H. pylori infection.