CD200Fc reduces LPS-induced IL-1β activation in human cervical cancer cells by modulating TLR4-NF-κB and NLRP3 inflammasome pathway

Cervical carcinoma induces NLRP3 inflammasome activation and IL-1ß release in human peripheral blood monocytes affecting patients' overall survival

PURPOSE

Our group previously demonstrated that genetic variants in inflammasome genes contribute to protection against the establishment of human papilloma virus (HPV)-associated cervical carcinoma (CC). The objective of this study was to better understand the contribution of inflammasome and its cytokines in the CC microenvironment.

METHODS

The inflammasome activation was analyzed in CC tumoral cell lines and healthy donors (HD)' monocytes in co-culture. In vitro results were then compared to CC patients' public databases.

RESULTS

CC cells did not produce IL-1ß or IL-18 themselves, however, when in co-culture with HD monocytes, induced IL-1ß release in those leucocytes. Inflammasome activation appears to be partially dependent on the NLRP3 receptor. Public data analysis revealed that IL1B expression is increased in the CC compared to normal uterine cervix, and that patients with high IL1B expression had a shorter overall survival.

CONCLUSION

CC microenvironment can activate the inflammasome and IL-1ß release in surrounding monocytes, which could be detrimental for CC prognosis.

Impact of NLRP3 gene polymorphisms (rs10754558 and rs10733113) on HPV infection and cervical cancer in southern Chinese population

OBJECTIVE

Mutations in the NLRP3gene have previously been linked to certain forms of cancer, but there have not been any specific studies examining the association between NLRP3 polymorphisms and cervical cancer (CC). This study was therefore designed to investigate the effect of NLRP3 gene polymorphisms on HPV infection and cervical cancer in southern Chinese population.

METHODS

Multiplex PCR and next-generation sequencing approaches were used to assess the NLRP3 rs10754558 and rs10733113 polymorphisms in 404 cervical lesion patients, including 227 diagnosed with CC and 177 diagnosed with cervical intraepithelial neoplasia(CIN), with 419 healthy female controls being included for comparison. Correlations between the rs10754558 and rs10733113 genotypes and alleles in these patients and CC and CIN were then analyzed.

RESULTS

No correlations were found between NLRP3 rs10754558 and rs10733113 and human papillomavirus(HPV) infection status. Relative to the healthy control group, the NLRP3 rs10754558 GG genotype, CG + GG genotype, and G allele frequencies were significantly increased among patients with cervical lesions (CC and CIN) (OR = 1.815,P = 0.013;OR = 1.383, P = 0.026; OR = 1.284, P = 0.014,respectively), whereas no such differences were observed for rs10733113. A higher cervical lesion risk was detected for patients over the age of 45 exhibiting the rs10754558 GG genotype (OR = 1.848, P = 0.040). Additionally, the risk of CC was elevated in patients with the rs10754558 GG genotype or the G allele relative to patients with the CC genotype or the C allele(OR = 1.830, P = 0.029; OR = 1.281, P = 0.039). The rs10733113 genotypes or alleles were not significantly associated with CC risk (P > 0.05). No association between rs10754558 and rs10733113 genotypes and CC patient clinicopathological features were observed (P > 0.05). Serum NLRP3, IL-1β, and IL-18 levels were significantly elevated in CC patients relative to healthy controls(P < 0.05). Relative to the CC genotype, CC patients harboring the rs10754558 GG genotype exhibited significantly elevated IL-1β and IL-18 levels(P < 0.05).

CONCLUSION

The rs10754558 polymorphism in the NLRP3 gene may contribute to an elevated risk of CC, although it is not significantly correlated with HPV infection and CC progression.

Mechanism of inflammasomes in cancer and targeted therapies

Inflammasomes, composed of the nucleotide-binding oligomerization domain(NOD)-like receptors (NLRs), are immune-functional protein multimers that are closely linked to the host defense mechanism. When NLRs sense pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs), they assemble into inflammasomes. Inflammasomes can activate various inflammatory signaling pathways, including nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways, and produce a large number of proinflammatory cytokines, which are closely associated with multiple cancers. They can also accelerate the occurrence and development of cancer by providing suitable tumor microenvironments, promoting tumor cell proliferation, and inhibiting tumor cell apoptosis. Therefore, the exploitation of novel targeted drugs against various inflammasomes and proinflammatory cytokines is a new idea for the treatment of cancer. In recent years, more than 50 natural extracts and synthetic small molecule targeted drugs have been reported to be in the research stage or have been applied to the clinic. Herein, we will overview the mechanisms of inflammasomes in common cancers and discuss the therapeutic prospects of natural extracts and synthetic targeted agents.

Monoamine Oxidase-B Inhibitor Reduction in Pro-Inflammatory Cytokines Mediated by Inhibition of cAMP-PKA/EPAC Signaling

Mucosal epithelial cell integrity is an important component of innate immunity and it protects the host from an environment rich in microorganisms. Virulence factors from Gram-negative bacteria [e.g. lipopolysaccharide (LPS)] induce significant pro-inflammatory cytokine expression. Monoamine oxidase (MAO) inhibitors reduce cytokine expression in a variety of inflammatory models and may therefore have therapeutic potential for a number of inflammatory diseases. We tested the anti-inflammatory therapeutic potential of a recently developed reversible MAO-B inhibitor (RG0216) with reduced transport across the blood–brain barrier. In an epithelial cell culture model, RG0216 significantly decreased LPS-induced interleukin (IL)-6 and IL-1β gene and protein expression and was as effective as equimolar concentrations of deprenyl (an existing irreversible MAO-B inhibitor). Hydrogen peroxide and modulating dopamine receptor signaling had no effect on cytokine expression. We showed that LPS-induced expression of IL-6 and IL-1β was cAMP dependent, that IL-6 and IL-1β expression were induced by direct cAMP activation (forskolin) and that RG0216 and deprenyl effectively reduced cAMP-mediated cytokine expression. Targeted protein kinase A (PKA) and Exchange Protein Activated by cAMP (EPAC) activation regulated IL-6 and IL-1β expression, albeit in different ways, but both cytokines were effectively decreased with RG0216. RG0216 reduction of LPS-induced cytokine expression occurred by acting downstream of the cAMP-PKA/EPAC signaling cascade. This represents a novel mechanism by which MAO-B selective inhibitors regulate LPS-induced IL-6 and IL-1β expression.

Design and optimisation of a small-molecule TLR2/4 antagonist for anti-tumour therapy

In anti-tumour therapy, the toll-like receptor 2/4 (TLR2/4) signalling pathway has been a double-edged sword. TLR2/4 agonists are commonly considered adjuvants for immune stimulation, whereas TLR2/4 antagonists demonstrate more feasibility for anti-tumour therapy under specific chronic inflammatory situations. In individuals with cancer retaliatory proliferation and metastasis after surgery, blocking the TLR2/4 signalling pathway may produce favourable prognosis for patients. Therefore, here, we developed a small-molecule co-inhibitor that targets the TLR2/4 signalling pathway. After high-throughput screening of a compound library containing 14 400 small molecules, followed by hit-to-lead structural optimisation, we finally obtained the compound TX-33, which has effective inhibitory properties against the TLR2/4 signalling pathways. This compound was found to significantly inhibit multiple pro-inflammatory cytokines released by RAW264.7 cells. This was followed by TX-33 demonstrating promising efficacy in subsequent anti-tumour experiments. The current results provide a novel understanding of the role of TLR2/4 in cancer and a novel strategy for anti-tumour therapy.

Targeting the NLRP3 Inflammasome as a New Therapeutic Option for Overcoming Cancer

Inflammasomes are multiprotein complexes that regulate the maturation and secretion of the proinflammatory cytokines interleukin-1beta (IL-1β and interleukin-18 (IL-18) in response to various intracellular stimuli. As a member of the inflammasomes family, NLRP3 is the most studied and best characterized inflammasome and has been shown to be involved in several pathologies. Recent findings have made it increasingly apparent that the NLRP3 inflammasome may also play a central role in tumorigenesis, and it has attracted attention as a potential anticancer therapy target. In this review, we discuss the role of NLRP3 in the development and progression of cancer, offering a detailed summary of NLRP3 inflammasome activation (and inhibition) in the pathogenesis of various forms of cancer. Moreover, we focus on the therapeutic potential of targeting NLRP3 for cancer therapy, emphasizing how understanding NLRP3 inflammasome-dependent cancer mechanisms might guide the development of new drugs that target the inflammatory response of tumor-associated cells.

NLRP3 Inflammasome and Its Critical Role in Gynecological Disorders and Obstetrical Complications

Inflammasomes, intracellular, multimeric protein complexes, are assembled when damage signals stimulate nucleotide-binding oligomerization domain receptors (NLRs). Several inflammasomes have been reported, including the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3), NLRP1, NLRP7, ice protease-activating factor (IPAF), absent in melanoma 2 (AIM2) and NLR family CARD domain-containing protein 4 (NLRC4). Among these inflammasomes, the NLRP3 inflammasome is the most well-studied in terms of structure and function. Unlike other inflammasomes that can only be activated by a finite number of pathogenic microorganisms, the NLRP3 inflammasome can be activated by the imbalance of the internal environment and a large number of metabolites. The biochemical function of NLRP3 inflammasome is to activate cysteine-requiring aspartate proteinase-1 (caspase-1), which converts pro-IL-1β and pro-IL-18 into their active forms, namely, IL-1β and IL-18, which are then released into the extracellular space. The well-established, classic role of NLRP3 inflammasome has been implicated in many disorders. In this review, we discuss the current understanding of NLRP3 inflammasome and its critical role in gynecological disorders and obstetrical complications.

The role of Toll-like receptor 4 signaling pathway in ovarian, cervical, and endometrial cancers

Toll-like receptors (TLRs) are critical sensors related to inflammation and tumorigenesis. Among all subtypes, the TLR4 is a highly described transmembrane protein involved in the inflammatory process. The TLR4/myeloid differentiation factor 88 (MyD88) signaling pathway has been implicated in oncogenic events in several tissues and is associated with survival of patients. Through activation, TLR4 recruits adaptor proteins, i.e., MyD88 or TRIF, to triggers canonical and non-canonical signaling pathways that result in distinct immune responses. In most cancer cells, uncontrolled TLR4 signaling modifies the tumor microenvironment to proliferate and evade immune surveillance. By contrast, TLR4 activation can produce antitumor activities, thereby inhibiting tumor growth and enhancing the proper immune response. We review herein recent approaches on the role of the TLR4 signaling pathway and discuss potential candidates for gynecological cancer therapies; among these agents, natural and synthetic compounds have been tested both in vitro and in vivo. Since TLR4 ligands have been investigated as effective immune-adjuvants in the context of these aggressive malignancies, we described how TLR4 signaling controls part of the tumor-related inflammatory process and which are the new targeting molecules implicated in the regulation of tumorigenicity in ovarian, cervical, and endometrial cancers.

Estrogen-regulated CD200 inhibits macrophage phagocytosis in endometriosis

OBJECTIVES

Endometriosis (EMS) is a benign disease that is related to estrogen, immune disorders and inflammation. The purpose of this research was to determine the expression of CD200 in EMS and to clarify its role in the pathogenesis of the disease.

METHODS

The levels of serum CD200 in patients with and without EMS were determined by ELISA. Furthermore, the expression of CD200 in normal eutopic endometrium and ectopic endometrium was detected by immunohistochemistry and western blotting. The CD200 receptor (CD200R) in macrophages in peritoneal fluid (pMØ) obtained from controls and patients with EMS was examined by western blotting. CD200 expression in human endometrial stromal cells (HESCs) stimulated with 17β-estradiol (E₂) was measured by western blotting. Furthermore, macrophages were stimulated with different concentrations of CD200 and the effect on phagocytosis was analyzed.

RESULTS

The plasma CD200 levels of patients with EMS was significantly increased compared with controls (P = 0.0173, 95%CI [18.75, 159.6]). Compared with normal eutopic endometrium, the expression of CD200 was significantly increased in ectopic endometrial tissues. The CD200R expression in pMØ obtained from patients with EMS was increased compared with the controls (P = 0.0244). CD200 expression in HESCs stimulated with E₂ was up-regulated. As the levels of CD200 increased, macrophage phagocytosis in vitro gradually decreased.

CONCLUSIONS

CD200 is an estrogen-induced molecule that impairs macrophage phagocytosis and may contribute to the immune escape of ectopic lesions in EMS.

NOD-like receptor signaling in inflammation-associated cancers: From functions to targeted therapies

BACKGROUND

Recently, many studies have reported that some botanicals and natural products were able to regulate NOD-like receptor signaling. NOD-like receptors (NLRs) have been established as crucial regulators in inflammation-associated tumorigenesis, angiogenesis, cancer cell stemness and chemoresistance. NLRs specifically sense pathogen-associated molecular patterns and respond by activating other signaling regulators, including Rip2 kinase, NF-κB, MAPK and ASC/caspase-1, leading to the secretion of various cytokines.

PURPOSE

The aim of this article is to review the molecular mechanisms of NOD-like receptor signaling in inflammation-associated cancers and the NLRs-targeted botanicals and synthetic small molecules in cancer intervention.

RESULTS

Aberrant activation of NLRs occurs in various cancers, orchestrating the tissue microenvironment and potentiating neoplastic risk. Blocking NLR inflammasome activation by botanicals or synthetic small molecules may be a valuable way to prevent cancer progression. Moreover, due to the roles of NLRs in regulating cytokine production, NLR signaling may be correlated with senescence-associated secretory phenotype.

CONCLUSION

In this review, we discuss how NLR signaling is involved in inflammation-associated cancers, and highlight the NLR-targeted botanicals and synthetic small molecules in cancer intervention.

NLRP3 inflammasome activation by estrogen promotes the progression of human endometrial cancer

Background

Activation of NLPR3 inflammasome is associated with the development and progression of some types of malignant tumors, but its role in endometrial cancer is unclear. This study aimed to investigate the expression and function of NLRP3 inflammasome in endometrial cancer.

Materials and methods

 The expression levels of NLRP3, its inflammasome components and estrogen receptor β in endometrial cancer and paired non-tumor tissues were detected. The effects of NLPR3 silencing or overexpression on the proliferation, migration, and invasion of Ishikawa and HEC-1A cells were determined. The impact of NLPR3 silencing on the growth of implanted tumors was determined in vivo. The effects of estrogen on NLPR3 inflammasome activation and Ishikawa cell proliferation were determined.

Results

The upregulation of NLRP3, ASC, caspase-1, and IL-1β was associated with the progression of endometrial cancer and poor survival. NLPR3 silencing inhibited the proliferation, migration, and invasion of endometrial cancer cells while NLPR3 overexpression had opposite effects. NLPR3 silencing reduced IL-1β and caspase-1 expression and the growth of implanted endometrial tumors, accompanied by decreased pro-IL-1β maturation. Estrogen enhanced NLPR3, ERβ, pro-IL-1β, IL-1β expression, and endometrial cancer cell proliferation, which were mitigated by treatment with ERβ inhibitor but not ERα inhibitor.

Conclusion

Our results suggest that estrogen acts through ERβ to enhance the activation of NLPR3 inflammasome and promote the progression of endometrial cancer. NLPR3 inflammasome may be a new therapeutic target for endometrial cancer.

NOD-like receptors: major players (and targets) in the interface between innate immunity and cancer

Innate immunity comprises several inflammation-related modulatory pathways which receive signals from an array of membrane-bound and cytoplasmic pattern recognition receptors (PRRs). The NLRs (NACHT (NAIP (neuronal apoptosis inhibitor protein), C2TA (MHC class 2 transcription activator), HET-E (incompatibility locus protein from Podospora anserina) and TP1 (telomerase-associated protein) and Leucine-Rich Repeat (LRR) domain containing proteins) relate to a large family of cytosolic innate receptors, involved in detection of intracellular pathogens and endogenous byproducts of tissue injury. These receptors may recognize pathogen-associated molecular patterns (PAMPs) and/or danger-associated molecular patterns (DAMPs), activating host responses against pathogen infection and cellular stress. NLR-driven downstream signals trigger a number of signaling circuitries, which may either initiate the formation of inflammasomes and/or activate nuclear factor κB (NF-κB), stress kinases, interferon response factors (IRFs), inflammatory caspases and autophagy. Disruption of those signals may lead to a number of pro-inflammatory conditions, eventually promoting the onset of human malignancies. In this review, we describe the structures and functions of the most well-defined NLR proteins and highlight their association and biological impact on a diverse number of cancers.

Alteration in gene expression profiles of thymoma: Genetic differences and potential novel targets

BACKGROUND

This study was conducted to investigate the gene expression profiles associated with thymoma to better understand the molecular mechanism underlying the pathogenesis of thymoma.

METHODS

Eight patients with thymomas (type A, AB, B1, and B2) and four controls with thymic cysts were analyzed using microarray profiling to identify changes in gene expression.

RESULTS

Across all of our samples, 2319 messenger RNAs were upregulated and 2776 were downregulated in thymomas relative to thymic cysts. Gene ontology and pathway analyses revealed that a large number of genes participate in cellular functions, among which MHC class II protein complex assembly, assembly with peptide antigen, calcium activated phosphatidylcholine scrambling, and release of cytoplasmic sequestered NF-κB were dysregulated, whereas intestinal immune network for immunoglobulin A production, cytokine-cytokine receptor interaction, the calcium signaling pathway, and pathways related to autoimmune diseases were downregulated.

CONCLUSIONS

Our results revealed gene expression differences between thymomas and thymic cysts, and identified key candidate genes/pathways that might be used as diagnostic markers and potential therapeutic targets to treat cancer metastasis.

Role of the NLRP3 inflammasome in cancer

Inflammasomes are large intracellular multi-protein signalling complexes that are formed in the cytosolic compartment as an inflammatory immune response to endogenous danger signals. The formation of the inflammasome enables activation of an inflammatory protease caspase-1, pyroptosis initiation with the subsequent cleaving of the pro-inflammatory cytokines interleukin (IL)-1β and proIL-18 to produce active forms. The inflammasome complex consists of a Nod-like receptor (NLR), the adapter apoptosis-associated speck-like (ASC) protein, and Caspase-1. Dysregulation of NLRP3 inflammasome activation is involved tumor pathogenesis, although its role in cancer development and progression remains controversial due to the inconsistent findings described. In this review, we summarize the current knowledge on the contribution of the NLRP3 inflammasome on potential cancer promotion and therapy.

Sulfur dioxide attenuates sepsis-induced cardiac dysfunction via inhibition of NLRP3 inflammasome activation in rats

OBJECTIVE

Sulfur dioxide (SO₂) plays an important role in maintaining homeostasis of cardiovascular system. This study was aimed to investigate cardioprotective effects of SO₂ on in the rat and the underlying mechanism.

METHODS AND RESULTS

Sepsis model induced by cecal ligation and puncture (CLP) in rats were used. SO₂ donor (NaHSO₃/Na₂SO₃, 1:3 M/M) was administered intraperitoneally at a dose of 85 mg/kg. Primary neonatal rat cardiac ventricular myocytes (NRCMs) were stimulated with LPS (1 mg/mL) in presence or absence of different concentrations of SO₂ (10, 50 and 100 μmol/L). SO₂ donor could restore the decreased levels of SO₂ in plasma and heart of septic rats. SO₂ exhibited dramatic improvement in cardiac functions. At 24 h after CLP, SO₂ treatments decreased the number of TUNEL-positive cells, Bax/Bcl-2 ratio and activity of caspase-3. Moreover CLP-induced inflammatory response was also relieved by SO₂. In NRCMs, SO₂ could suppress the LPS-induced myocardial injury, leading to an increase in cell viability, a decrease in LDH and apoptotic rate. Western blot showed that the expression of TLR4, NLRP3, and Caspase-1 were obviously increased in myocardial tissue of CLP group or in NRCMs of LPS group, while SO₂ significantly inhibited the CLP-induced or LPS-induced TLR4, NLRP3, and Caspase-1 expression.

CONCLUSION

SO₂ attenuated sepsis-induced cardiac dysfunction likely in association with the inhibiting inflammation via TLR4/NLRP3 signaling pathway.

Targeting the NLRP3 Inflammasome-Related Pathways via Tianeptine Treatment-Suppressed Microglia Polarization to the M1 Phenotype in Lipopolysaccharide-Stimulated Cultures

An increasing body of evidence postulates that microglia are the main mediators of inflammation-related disorders, including depression. Since activated microglia produce a wide range of pro- and anti-inflammatory factors, the modulation of M1/M2 microglial polarization by antidepressants may be crucial in the treatment of depression. The current paper aimed to investigate the impact of tianeptine on the microglia’s viability/death parameters, and on M1/M2 microglial activation in response to lipopolysaccharide (LPS) stimulation. Furthermore, the molecular mechanisms via which tianeptine affected the LPS-evoked changes were investigated. The results revealed that tianeptine had partially protective effects on the changes in microglia viability/death evoked by LPS. Tianeptine attenuated microglia activation by decreasing the expression of cluster of differentiation 40 (CD40), and major histocompatibility complex class II (MHC II) markers, as well as the release of pro-inflammatory factors: interleukin (IL)-1β, IL-18, IL-6, tumor necrosis factor alpha (TNF-α), and chemokine CC motif ligand 2 (CCL2), and the production of nitric oxide and reactive oxygen species. In contrast, we did not observe an impact of tianeptine on M2 microglia measured by IL-4, IL-10, TGF-β, and insulin-like growth factor 1 (IGF-1) expression. Moreover, we demonstrated an inhibitory effect of tianeptine on the LPS-induced activation of the nucleotide-binding oligomerization domain-like (NOD-like) receptor pyrin-containing 3 inflammasome (NLRP3) inflammasome subunits, NLRP3 and caspase-1, as well as the ability of tianeptine to reduce Toll-like receptor 4 (TLR4) levels, as well as the phosphorylation of extracellular signal-related kinases 1 and 2 (ERK1/2) and of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Collectively, we demonstrated that tianeptine has protective properties and inhibits M1 polarization, thus attenuating the production of inflammatory mediators. Moreover, we found that M1 microglia suppression may be related to the NLRP3 inflammasome and TLR4 signaling. These findings suggest that a better understanding of the multifaceted mechanisms of tianeptine action on microglia may increase the effectiveness of therapy, where inflammation is a central hallmark.

FNDC5 attenuates adipose tissue inflammation and insulin resistance via AMPK-mediated macrophage polarization in obesity

BACKGROUND

Obesity-induced chronic inflammation is critical in the pathogenesis of insulin resistance, and the recruitment and proinflammatory activation of adipose tissue macrophages (ATMs) is important for the development of this process. Here, we examined the effects of fibronectin type III domain-containing 5 (FNDC5) on inflammation and insulin resistance in high-fat diet-induced obese mice.

MATERIALS AND METHODS

Male wild-type (WT) and FNDC5^-/- mice were fed with standard chow (Ctrl) or high fat diet (HFD) for 20 weeks to induce obesity and insulin resistance. Firstly, effects of FNDC5 gene deletion on obesity, insulin resistance, macrophage accumulation and polarization and adipose tissue inflammation were determined in mice. Secondly, the macrophage polarity shift was further examined with flow cytometry in isolated stromal vascular fraction (SVF). Thirdly, the effects of exogenous FNDC5 on lipopolysaccharide (LPS)-induced macrophage polarization, inflammation and the underlying signaling mechanism were investigated in RAW264.7 macrophages and primary mouse peritoneal cavity macrophages (PMs). Finally, the therapeutic effects of FNDC5 overexpression were examined in HFD-induced obese WT and FNDC5^-/- mice.

RESULTS

FNDC5 gene deletion aggravated obesity, insulin resistance, fat accumulation and inflammation accompanied with enhanced AMPK inhibition, macrophages recruitment and M1 polarization in mice fed with HFD. Exogenous FNDC5 inhibited LPS-induced M1 macrophage polarization and inflammatory cytokine production via AMPK phosphorylation in both RAW264.7 macrophages and PMs. FNDC5 overexpression attenuated insulin resistance, AMPK inhibition, M1 macrophage polarization and inflammatory cytokine production in adipose tissue of obese WT and FNDC5^-/- mice.

CONCLUSIONS

FNDC5 attenuates adipose tissue inflammation and insulin resistance via AMPK-mediated macrophage polarization in HFD-induced obesity. FNDC5 plays several beneficial roles in obesity and may be used as a therapeutic regimen for preventing inflammation and insulin resistance in obesity and diabetes.

CD200fc enhances anti-tumoral immune response and inhibits visceral metastasis of breast carcinoma

CD200 is a widely expressed cell surface glycoprotein that inhibits excessive inflammation in autoimmunity, transplantation, and viral infections. We previously observed that visceral metastasis of highly aggressive and inflammatory 4THM breast carcinoma cells was markedly decreased in CD200 transgenic mice. The goal of this study was to determine whether exogenous exposure to CD200fc mimics the effects of endogenously over expressed CD200. Female BALB/c mice were injected with CD200fc two times a week for five times. Injection was started two days after orthotopic injection of 4THM cells. Tumor infiltrating Gr1+Cd11b+ cells were decreased while CD8+ cells were increased in CD200fc-treated animals. CD200fc injection significantly decreased lung and liver metastasis and the growth of primary tumors. CD200fc injection enhanced the tumor-induced IFN-g response while suppressing the IL-10 response. We observed excessive basal IL-6 secretion in MLC which was significantly decreased in CD200fc treated mice 12 days after injection of 4TM cells. These results are in accord with previous data from CD200 transgenic mice, and demonstrate for the first time that CD200 analogues might have therapeutic potential in the treatment of aggressive breast carcinoma which induces excessive systemic inflammation.

CD200Fc Attenuates Retinal Glial Responses and RGCs Apoptosis After Optic Nerve Crush by Modulating CD200/CD200R1 Interaction

To explore the hypothesis that CD200Fc, a CD200R1 agonist with anti-inflammatory properties, will inhibit retinal glial cells hyperactivation and retinal ganglion cells (RGCs) apoptosis after optic nerve injury. CD200Fc was immediately administered after optic nerve crush (ONC) once by intravitreal injection. Rats were euthanized at 5 days after ONC. The density of RGCs was counted by immunostaining of retina flat mounts for Brn3a. TUNEL assay, immunoblotting analysis of ionized calcium-binding adapter molecule 1(iba1) (microglia marker) and glial fibrillary acidic protein (GFAP) (astrocytes and Müller cells marker), RT-PCR analysis of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), monocyte chemotactic protein 1 (MCP-1), tumor necrosis factor-α (TNF-α), interleukin (IL)-8 and IL-10, ELISA measure protein levels of inflammatory cytokines and western blot analysis of CD200 and CD200R1 were evaluated. CD200Fc treatment suppressed ONC-induced RGCs loss through inhibition of RGCs apoptosis. Additionally, expression of glial cells activation markers GFAP and iba1 and production of pro-inflammatory cytokines (COX-2, iNOS, MCP-1, TNF-α, IL-8) were decreased in CD200Fc treated animals after ONC. Meanwhile, anti-inflammatory cytokine IL-10 was increased by CD200Fc treatment in ONC-induced rat retina. Finally, we found that CD200Fc significantly inhibited ONC-induced increased in expression of CD200 and raised the already high basal CD200R1 expression in the rat retina after ONC. Our results demonstrated that the anti-inflammatory effects of CD200Fc in ONC rats model through inhibited the activation of retinal glial cells via the interaction between CD200 and CD200R1, and the neuroprotective effects of CD200Fc on RGCs thought inhibited its apoptosis.

Integrating the dysregulated inflammasome-based molecular functionome in the malignant transformation of endometriosis-associated ovarian carcinoma

The coexistence of endometriosis (ES) with ovarian clear cell carcinoma (CCC) or endometrioid carcinoma (EC) suggested that malignant transformation of ES leads to endometriosis associated ovarian carcinoma (EAOC). However, there is still lack of an integrating data analysis of the accumulated experimental data to provide the evidence supporting the hypothesis of EAOC transformation. Herein we used a function-based analytic model with the publicly available microarray datasets to investigate the expression profiling between ES, CCC, and EC. We analyzed the functional regularity pattern of the three type of samples and hierarchically clustered the gene sets to identify key mechanisms regulating the malignant transformation of EAOC. We identified a list of 18 genes (NLRP3, AIM2, PYCARD, NAIP, Caspase-4, Caspase-7, Caspase-8, TLR1, TLR7, TOLLIP, NFKBIA, TNF, TNFAIP3, INFGR2, P2RX7, IL-1B, IL1RL1, IL-18) closely related to inflammasome complex, indicating an important role of inflammation/immunity in EAOC transformation. We next explore the association between these target genes and patient survival using Gene Expression Omnibus (GEO), and found significant correlation between the expression levels of the target genes and the progression-free survival. Interestingly, high expression levels of AIM2 and NLRP3, initiating proteins of inflammasomes, were significantly correlated with poor progression-free survival. Immunohistochemistry staining confirmed a correlation between high AIM2 and high Ki-67 in clinical EAOC samples, supporting its role in disease progression. Collectively, we established a bioinformatic platform of gene-set integrative molecular functionome to dissect the pathogenic pathways of EAOC, and demonstrated a key role of dysregulated inflammasome in modulating the malignant transformation of EAOC.

BCL6 attenuates renal inflammation via negative regulation of NLRP3 transcription

Renal inflammation contributes to the pathogeneses of hypertension. This study was designed to determine whether B-cell lymphoma 6 (BCL6) attenuates renal NLRP3 inflammasome activation and inflammation and its underlying mechanism. Male spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) were used in the present study. Angiotensin (Ang) II or lipopolysaccharides (LPS) was used to induce inflammation in HK-2 cells, a human renal tubular epithelial (RTE) cell line. NLRP3 inflammasome was activated and BCL6 was downregulated in the kidneys of SHR. Either Ang II or LPS suppressed BCL6 expression in HK-2 cells. BCL6 overexpression in HK-2 cells attenuated Ang II-induced NLRP3 upregulation, inflammation and cell injury. The inhibitory effects of BCL6 overexpression on NLRP3 expression and inflammation were also observed in LPS-treated HK-2 cells. BCL6 inhibited the NLRP3 transcription via binding to the NLRP3 promoter. BCL6 knockdown with shRNA increased NLRP3 and mature IL-1β expression levels in both PBS- or Ang II-treated HK-2 cells but had no significant effects on ASC, pro-caspase-1 and pro-IL-1β expression levels. BCL6 overexpression caused by recombinant lentivirus expressing BCL6 reduced blood pressure in SHR. BCL6 overexpression prevented the upregulation of NLRP3 and mature IL-1β expression levels in the renal cortex of SHR. The results indicate that BCL6 attenuates Ang II- or LPS-induced inflammation in HK-2 cells via negative regulation of NLRP3 transcription. BCL6 overexpression in SHR reduced blood pressure, NLRP3 expression and inflammation in the renal cortex of SHR.

Comprehensive assessment of association between TLR4 gene polymorphisms and cancer risk: a systematic meta-analysis

Previous studies have explored the association between toll-like receptor 4 (TLR4) polymorphisms and risk of various cancers, but the results remained controversial. To obtain an assessment of the effect of TLR4 polymorphisms (rs4986790, rs4986791 and rs11536889) on cancer risk, fifty-five articles (containing 20107 cases and 28244 controls) were recruited for meta-analysis. Our result indicated that two Single Nucleotide Polymorphisms (SNP) in TLR4 were associated with decreased cancer risk for rs4986791: OR = 0.764, 95% CI: 0.652-0.894, P = 0.001 in allele model; OR = 0.769, 95%CI: 0.650-0.909, P = 0.002 in recessive model; OR = 0.505, 95% CI: 0.352-0.726, P = 0.000 in dominant model; for 11536889: OR = 0.927, 95% CI: 0.872–0.984, P = 0.013 in allele model; OR = 0.926, 95% CI: 0.862–0.944,P = 0.034 in recessive model. In terms of subgroup analyses sorted by ethnicity, only polymorphism of rs4986791 had a significant influence on decrease of cancer risk among both Caucasian and Asian populations. The findings suggested that TLR4 polymorphisms may serve as a genetic risk factor for cancers.