LPS-induced production of TNF-α and IL-6 in mast cells is dependent on p38 but independent of TTP

Crosstalk between Regnase-1 and -3 shapes mast cell survival and cytokine expression

Post-transcriptional regulation of immune-related transcripts by RNA-binding proteins (RBPs) impacts immune cell responses, including mast cell functionality. Despite their importance in immune regulation, the functional role of most RBPs remains to be understood. By manipulating the expression of specific RBPs in murine mast cells, coupled with mass spectrometry and transcriptomic analyses, we found that the Regnase family of proteins acts as a potent regulator of mast cell physiology. Specifically, Regnase-1 is required to maintain basic cell proliferation and survival, whereas both Regnase-1 and -3 cooperatively regulate the expression of inflammatory transcripts upon activation, with Tnf being a primary target in both human and mouse cells. Furthermore, Regnase-3 directly interacts with Regnase-1 in mast cells and is necessary to restrain Regnase-1 expression through the destabilization of its transcript. Overall, our study identifies protein interactors of endogenously expressed Regnase factors, characterizes the regulatory interplay between Regnase family members in mast cells, and establishes their role in the control of mast cell homeostasis and inflammatory responses.

Bacterial endotoxin lipopolysaccharides regulate gene expression in human colon cancer cells

OBJECTIVE

Lipopolysaccharide (LPS) is a major cell wall component of gram-negative bacteria. Colon bacteria contribute to LPS which promotes colon cancer metastasis. The objective of this study was to survey the effect of LPS on cell viability and gene expression of 55 molecular targets in human colon cancer cells.

RESULTS

LPS did not affect the viability of COLO 225 cells under the culture conditions but affected the expression of a number of genes important in inflammatory responses and cancer development. LPS increased TTP family, GLUT family and DGAT1 mRNA levels but decreased DGAT2a and DGAT2b expression in the human colon cancer cells. LPS also increased COX2, CXCL1, ELK1, ICAM1, TNFSF10 and ZFAND5 but decreased BCL2L1, CYP19A1 and E2F1 mRNA levels in the colon cancer cells. These data suggest that LPS has profound effects on gene expression in human colon cancer cells.

TNFR1 links TNF exocytosis to TNF production in allergen-activated RBL-2H3 cells

We previously reported that the maximal production of Tumor Necrosis Factor (TNF or TNFα) in antigen-activated RBL-2H3 cells (a tumor analog of mucosal mast cells) requires Munc13-4, a regulator of exocytic fusion. In this study, we investigated the involvement of various fusion catalysts in TNF production. We observed a strong correlation between the total TNF level and TNF exocytosis in RBL-2H3 cells. RT-qPCR shows that TNFR1 (TNF receptor 1) is the sole TNFR expressed in these cells, and that its transcription is upregulated upon allergen-mediated activation. Importantly, the addition of soluble TNFR1 inhibits antigen-elicited TNF production in a dosage-dependent fashion. Likewise, TNF production is diminished in the presence of TACE (TNFα Converting Enzyme) inhibitor KP-457, which prevents the generation of soluble TNF (sTNF). Together, these findings indicate that sTNF and TNFR1 function as autocrine agent and receptor respectively at the mast cell surface to boost TNF proliferation during allergic inflammation.

Identification and Characterization of a Novel Cathelicidin from Hydrophis cyanocinctus with Antimicrobial and Anti-Inflammatory Activity

The abuse of antibiotics and lack of new antibacterial drugs has led to the emergence of superbugs that raise fears of untreatable infections. The Cathelicidin family of antimicrobial peptide (AMP) with varying antibacterial activities and safety is considered to be a promising alternative to conventional antibiotics. In this study, we investigated a novel Cathelicidin peptide named Hydrostatin-AMP2 from the sea snake Hydrophis cyanocinctus. The peptide was identified based on gene functional annotation of the H. cyanocinctus genome and bioinformatic prediction. Hydrostatin-AMP2 showed excellent antimicrobial activity against both Gram-positive and Gram-negative bacteria, including standard and clinical Ampicillin-resistant strains. The results of the bacterial killing kinetic assay demonstrated that Hydrostatin-AMP2 had faster antimicrobial action than Ampicillin. Meanwhile, Hydrostatin-AMP2 exhibited significant anti-biofilm activity including inhibition and eradication. It also showed a low propensity to induce resistance as well as low cytotoxicity and hemolytic activity. Notably, Hydrostatin-AMP2 apparently decreased the production of pro-inflammatory cytokines in the LPS-induced RAW264.7 cell model. To sum up, these findings indicate that Hydrostatin-AMP2 is a potential peptide candidate for the development of new-generation antimicrobial drugs fighting against antibiotic-resistant bacterial infections.

The Effect of Elasticity of Gelatin Nanoparticles on the Interaction with Macrophages

Gelatin is a biocompatible, biodegradable, cheap, and nontoxic material, which is already used for pharmaceutical applications. Nanoparticles from gelatin (GNPs) are considered a promising delivery system for hydrophilic and macromolecular drugs. Mechanical properties of particles are recognized as an important parameter affecting drug carrier interaction with biological systems. GNPs offer the preparation of particles with different stiffness. GNPs were loaded with Fluorescein isothiocyanate-labeled 150 kDa dextran (FITC-dextran) yielding also different elastic properties. GNPs were visualized using atomic force microscopy (AFM), and force-distance curves from the center of the particles were evaluated for Young's modulus calculation. The prepared GNPs have Young's moduli from 4.12 MPa for soft to 9.8 MPa for stiff particles. Furthermore, cytokine release (IL-6 and TNF-α), cell viability, and cell uptake were determined on macrophage cell lines from mouse (RAW 264.7) and human (dTHP-1 cells, differentiated human monocytic THP-1 cells) origin for soft and stiff GNPs. Both particle types showed good cell compatibility and did not induce IL-6 and TNF-α release from RAW 264.7 and dTHP-1 cells. Stiffer GNPs were internalized into cells faster and to a larger extent.

Identification of Bcl2 as a Stably Expressed qPCR Reference Gene for Human Colon Cancer Cells Treated with Cottonseed-Derived Gossypol and Bioactive Extracts and Bacteria-Derived Lipopolysaccharides

Cottonseed contains many bioactive molecules including plant polyphenols. Cottonseed value might be increased by providing high-value bioactive polyphenols for improving nutrition and health. However, there was a lack of molecular evidence for cottonseed bioactivity in mammalian cells. One widely used method for evaluating the bioactivity of natural products is quantitative real-time-PCR (qPCR). The selection of stably expressed internal reference genes is a crucial task of qPCR assay for data analysis. The rationale for reference gene selection is that a lower standard deviation of the cycle of threshold (Cq) among the treatments indicates a more stable expression of the gene. The objective of this study was to select reference genes in human colon cancer cells (COLO 205) treated with cottonseed-derived gossypol and bioactive extracts along with bacterial endotoxin lipopolysaccharides (LPS). SYBR Green qPCR was used to analyze the mRNA levels of a wide range of biomarkers involved in glucose transport, lipid biosynthesis, inflammatory response, and cancer development. qPCR data (10,560 Cq values) were generated from 55 genes analyzed from 64 treatments with triplicate per treatment for each gene. The data showed that B-cell lymphoma 2 (Bcl2) mRNA was the most stable among the 55 mRNAs analyzed in the human colon cancer cells. Glyceraldehyde 3 phosphate dehydrogenase (Gapdh) and ribosome protein L32 (Rpl32) mRNAs were not good qPCR references for the colon cancer cells. These observations were consistent regardless of the treatment comparison between gossypol and LPS, glanded and glandless seed extracts, seed coat and kernel extracts, or treatment for 8 and 24 h. These results suggest that Bcl2 is a preferable reference gene for qPCR assays in human colon cancer cells treated with cottonseed-derived gossypol and bioactive extracts as well as LPS. The extensive qPCR results firmly support the conclusion that the Bcl2 gene is stably expressed at the mRNA level in the human colon cancer cells regardless of the treatment, suggesting that Bcl2 gene expression is not regulated at the mRNA level but at the post-transcriptional level. These results should facilitate studies designated to evaluate bioactivity on gene expression regulation by cottonseed molecules and other natural and synthetic molecules for nutrition and health uses.

LPS Guides Distinct Patterns of Training and Tolerance in Mast Cells

Mast cells (MCs) are tissue-resident, long lived innate immune cells with important effector and immunomodulatory functions. They are equipped with an eclectic variety of receptors that enable them to sense multiple stimuli and to generate specific responses according on the type, strength and duration of the stimulation. Several studies demonstrated that myeloid cells can retain immunological memory of their encounters – a process termed ‘trained immunity’ or ‘innate immune memory’. As MCs are among the one of first cells to come into contact with the external environment, it is possible that such mechanisms of innate immune memory might help shaping their phenotype and effector functions; however, studies on this aspect of MC biology are still scarce. In this manuscript, we investigated the ability of MCs primed with different stimuli to respond to a second stimulation with the same or different ligands, and determined the molecular and epigenetic drivers of these responses. Our results showed that, while the stimulation with IgE and β-glucan failed to induce either tolerant or trained phenotypes, LPS conditioning was able to induce a profound and long-lasting remodeling of the signaling pathways involved in the response against LPS or fungal pathogens. On one side, LPS induced a strong state of unresponsiveness to secondary LPS stimulation due to the impairment of the PI3K-AKT signaling pathway, which resulted in the reduced activation of NF-κB and the decreased release of TNF-α and IL-6, compared to naïve MCs. On the other side, LPS primed MCs showed an increased release of TNF-α upon fungal infection with live Candida albicans, thus suggesting a dual role of LPS in inducing both tolerance and training phenotypes depending on the secondary challenge. Interestingly, the inhibition of HDAC during LPS stimulation partially restored the response of LPS-primed MCs to a secondary challenge with LPS, but failed to revert the increased cytokine production of these cells in response to C. albicans. These data indicate that MCs, as other innate immune cells, can develop innate immune memory, and that different stimulatory environments can shape and direct MC specific responses towards the dampening or the propagation of the local inflammatory response.

Cottonseed extracts regulate gene expression in human colon cancer cells

Cotton plant provides economically important fiber and cottonseed, but cottonseed contributes 20% of the crop value. Cottonseed value could be increased by providing high value bioactive compounds and polyphenolic extracts aimed at improving nutrition and preventing diseases because plant polyphenol extracts have been used as medicinal remedy for various diseases. The objective of this study was to investigate the effects of cottonseed extracts on cell viability and gene expression in human colon cancer cells. COLO 225 cells were treated with ethanol extracts from glanded and glandless cottonseed followed by MTT and qPCR assays. Cottonseed extracts showed minor effects on cell viability. qPCR assay analyzed 55 mRNAs involved in several pathways including DGAT, GLUT, TTP, IL, gossypol-regulated and TTP-mediated pathways. Using BCL2 mRNA as the internal reference, qPCR analysis showed minor effects of ethanol extracts from glanded seed coat and kernel and glandless seed coat on mRNA levels in the cells. However, glandless seed kernel extract significantly reduced mRNA levels of many genes involved in glucose transport, lipid biosynthesis and inflammation. The inhibitory effects of glandless kernel extract on gene expression may provide a useful opportunity for improving nutrition and healthcare associated with colon cancer. This in turn may provide the potential of increasing cottonseed value by using ethanol extract as a nutrition/health intervention agent.

High FODMAP diet causes barrier loss via lipopolysaccharide-mediated mast cell activation

Fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) are carbohydrates thought to contribute to the symptoms of IBS. A diet in high in FODMAPs (HFM) induces gastrointestinal symptoms in patients with irritable bowel syndrome (IBS), and a diet low in FODMAPs (LFM) improves symptoms in up to 60% of patients with IBS. However, the mechanism by which FODMAPs affect IBS symptoms is unclear. We showed that mice fed on a HFM diet have mast cell activation and colonic barrier loss. Using mast cell–deficient mice with and without mast cell reconstitution, we showed that HFM-mediated colonic barrier loss is dependent on TLR4-dependent mast cell activation. In in vitro studies, we demonstrated that IBS fecal supernatant stimulates mast cells significantly more compared with fecal supernatant from healthy controls. This effect of IBS fecal supernatant on mast cell stimulation is ameliorated in the absence of the TLR4 receptor and after a LFM diet. We found that a LFM diet improves colonic barrier function and reduces mast cell activation while decreasing fecal LPS levels. Our findings indicate that a HFM diet causes mast cell activation via LPS, which in turn leads to colonic barrier loss, and a LFM diet reverses these pathophysiologic mucosal changes.

Features of Neutrophils From Atopic and Non-Atopic Elite Endurance Runners

We collected peripheral blood from thirty-nine elite male endurance runners at rest (24 hours after the last exercise session) and used the Allergy Questionnaire for Athletes score and plasma specific IgE level to separate them into atopic and non-atopic athletes. Neutrophils obtained from atopic and non-atopic athletes were subsequently stimulated in vitro with fMLP (N-formyl-methionyl-leucyl-phenylalanine), LPS (lipopolysaccharide), or PMA (phorbol 12-myristate 13-acetate). Neutrophils from non-atopic runners responded appropriately to LPS, as evidenced by the production of pro (IL-8, TNF-α, and IL-6) and anti-inflammatory (IL-10) cytokines. Neutrophils from atopic elite runners exhibited lower responses to LPS stimulus as indicated by no increase in IL-1β, TNF-α, and IL-6 production. Neutrophils from non-atopic and atopic runners responded similarly to fMLP stimulation, indicating that migration function remained unaltered. Both groups were unresponsive to PMA induced reactive oxygen species (ROS) production. Training hours and training volume were not associated with neutrophil IgE receptor gene expression or any evaluated neutrophil function. Since non-atopic runners normally responded to LPS stimulation, the reduced neutrophil response to the stimuli was most likely due to the atopic state and not exercise training. The findings reported are of clinical relevance because atopic runners exhibit a constant decline in competition performance and are more susceptible to invading microorganisms.

Hydroxyapatite-Coated SPIONs and Their Influence on Cytokine Release

Hydroxyapatite- or calcium phosphate-coated iron oxide nanoparticles have a high potential for use in many biomedical applications. In this study, a co-precipitation method for the synthesis of hydroxyapatite-coated nanoparticles (SPION^HAp), was used. The produced nanoparticles have been characterized by dynamic light scattering, X-ray diffraction, vibrating sample magnetometry, Fourier transform infrared spectrometry, atomic emission spectroscopy, scanning electron microscopy, transmission electron microscopy, selected area diffraction, and energy-dispersive X-ray spectroscopy. The results showed a successful synthesis of 190 nm sized particles and their stable coating, resulting in SPION^HAp. Potential cytotoxic effects of SPION^HAp on EL4, THP-1, and Jurkat cells were tested, showing only a minor effect on cell viability at the highest tested concentration (400 µg Fe/mL). The results further showed that hydroxyapatite-coated SPIONs can induce minor TNF-α and IL-6 release by murine macrophages at a concentration of 100 µg Fe/mL. To investigate if and how such particles interact with other substances that modulate the immune response, SPION^HAp-treated macrophages were incubated with LPS (lipopolysaccharides) and dexamethasone. We found that cytokine release in response to these potent pro- and anti-inflammatory agents was modulated in the presence of SPION^HAp. Knowledge of this behavior is important for the management of inflammatory processes following in vivo applications of this type of SPIONs.

Cytokines Stimulated by IL-33 in Human Skin Mast Cells: Involvement of NF-κB and p38 at Distinct Levels and Potent Co-Operation with FcεRI and MRGPRX2

The IL-1 family cytokine IL-33 activates and re-shapes mast cells (MCs), but whether and by what mechanisms it elicits cytokines in MCs from human skin remains poorly understood. The current study found that IL-33 activates CCL1, CCL2, IL-5, IL-8, IL-13, and TNF-α, while IL-1β, IL-6, IL-31, and VEGFA remain unaffected in cutaneous MCs, highlighting that each MC subset responds to IL-33 with a unique cytokine profile. Mechanistically, IL-33 induced the rapid (1–2 min) and durable (2 h) phosphorylation of p38, whereas the phosphorylation of JNK was weaker and more transient. Moreover, the NF-κB pathway was potently activated, as revealed by IκB degradation, increased nuclear abundance of p50/p65, and vigorous phosphorylation of p65. The activation of NF-κB occurred independently of p38 or JNK. The induced transcription of the cytokines selected for further study (CCL1, CCL2, IL-8, TNF-α) was abolished by interference with NF-κB, while p38/JNK had only some cytokine-selective effects. Surprisingly, at the level of the secreted protein products, p38 was nearly as effective as NF-κB for all entities, suggesting post-transcriptional involvement. IL-33 did not only instruct skin MCs to produce selected cytokines, but it also efficiently co-operated with the allergic and pseudo-allergic/neurogenic activation networks in the production of IL-8, TNF-α, CCL1, and CCL2. Synergism was more pronounced at the protein than at the mRNA level and appeared stronger for MRGPRX2 ligands than for FcεRI. Our results underscore the pro-inflammatory nature of an acute IL-33 stimulus and imply that especially in combination with allergens or MRGPRX2 agonists, IL-33 will efficiently amplify skin inflammation and thereby aggravate inflammatory dermatoses.

Gossypol decreased cell viability and down-regulated the expression of a number of genes in human colon cancer cells

Plant polyphenol gossypol has anticancer activities. This may increase cottonseed value by using gossypol as a health intervention agent. It is necessary to understand its molecular mechanisms before human consumption. The aim was to uncover the effects of gossypol on cell viability and gene expression in cancer cells. In this study, human colon cancer cells (COLO 225) were treated with gossypol. MTT assay showed significant inhibitory effect under high concentration and longtime treatment. We analyzed the expression of 55 genes at the mRNA level in the cells; many of them are regulated by gossypol or ZFP36/TTP in cancer cells. BCL2 mRNA was the most stable among the 55 mRNAs analyzed in human colon cancer cells. GAPDH and RPL32 mRNAs were not good qPCR references for the colon cancer cells. Gossypol decreased the mRNA levels of DGAT, GLUT, TTP, IL families and a number of previously reported genes. In particular, gossypol suppressed the expression of genes coding for CLAUDIN1, ELK1, FAS, GAPDH, IL2, IL8 and ZFAND5 mRNAs, but enhanced the expression of the gene coding for GLUT3 mRNA. The results showed that gossypol inhibited cell survival with decreased expression of a number of genes in the colon cancer cells.

Type I Interferon α/β Receptor-Mediated Signaling Negatively Regulates Antiviral Cytokine Responses in Murine Bone-Marrow-Derived Mast Cells and Protects the Cells from Virus-Induced Cell Death

Mast cells (MCs) are critical for initiating inflammatory responses to pathogens including viruses. Type I interferons (IFNs) that exert their antiviral functions by interacting with the type I IFN receptor (IFNAR) play a central role in host cellular responses to viruses. Given that virus-induced excessive toxic inflammatory responses are associated with aberrant IFNAR signaling and considering MCs are an early source of inflammatory cytokines during viral infections, we sought to determine whether IFNAR signaling plays a role in antiviral cytokine responses of MCs. IFNAR-intact, IFNAR-blocked, and IFNAR-knockout (IFNAR^−/−) bone-marrow-derived MCs (BMMCs) were treated in vitro with a recombinant vesicular stomatitis virus (rVSVΔm51) to assess cytokine production by these cells. All groups of MCs produced the cytokines interleukin-6 and tumor necrosis factor-α in response to rVSVΔm51. However, production of the cytokines was lowest in IFNAR-intact cells as compared with IFNAR^−/− or IFNAR-blocked cells at 20 h post-stimulation. Surprisingly, rVSVΔm51 was capable of infecting BMMCs, but functional IFNAR signaling was able to protect these cells from virus-induced death. This study showed that BMMCs produced pro-inflammatory cytokines in response to rVSVΔm51 and that IFNAR signaling was required to down-modulate these responses and protect the cells from dying from viral infection.

A new zinc chelator, IPZ-010 ameliorates postoperative ileus

Zinc was discovered to be a novel second messenger in immunoreactive cells. We synthesized a novel free zinc chelator, IPZ-010. Here, we investigated the effects of IPZ-010 in a mouse postoperative ileus model and determined the effects of zinc signal inhibition as a new therapeutic strategy against postoperative ileus. Zinc waves were measured in bone marrow-derived mast cells (BMMCs) loaded with a zinc indicator, Newport green. Degranulation and cytokine expression were measured in BMMCs and bone marrow-derived macrophages (BMDMs). Postoperative ileus model mice were established with intestinal manipulation. Mice were treated with IPZ-010 (30 mg/kg, s.c. or p.o.) 1 h before and 2 h and 4 h after intestinal manipulation. Gastrointestinal transit, inflammatory cell infiltration, and expression of inflammatory mediators were measured. Free zinc waves occurred following antigen stimulation in BMMCs and were blocked by IPZ-010. IPZ-010 inhibited interleukin-6 secretion and degranulation in BMMCs. IPZ-010 inhibited tumor necrosis factor-α mRNA expression in BMMCs stimulated with lipopolysaccharide or adenosine triphosphate, whereas IPZ-010 had no effects on tumor necrosis factor-α mRNA expression in BMDMs stimulated with lipopolysaccharide or adenosine triphosphate. In postoperative ileus model mice, IPZ-010 inhibited leukocyte infiltration and cytokine expression, which ameliorated gastrointestinal transit. Furthermore, ketotifen (1 mg/kg) induced similar effects as IPZ-010. These effects were not amplified by co-administration of IPZ-010 and ketotifen. IPZ-010 inhibited zinc waves, resulting in inhibition of inflammatory responses in activated BMMCs in vitro. Targeting zinc waves in inflammatory cells may be a novel therapeutic strategy for treating postoperative ileus.

Modulating Inflammation in Monocytes Using Capillary Fiber Organic Electronic Ion Pumps

An organic electronic ion pump (OEIP) delivers ions and drugs from a source, through a charge selective membrane, to a target upon an electric bias. Miniaturization of this technology is crucial and will provide several advantages, ranging from better spatiotemporal control of delivery to reduced invasiveness for implanted OEIPs. To miniaturize OEIPs, new configurations have been developed based on glass capillary fibers filled with an anion exchange membrane (AEM). Fiber capillary OEIPs can be easily implanted in proximity to targeted cells and tissues. Herein, the efficacy of such a fiber capillary OEIP for modulation of inflammation in human monocytes is demonstrated. The devices are located on inflammatory monocytes and local delivery of salicylic acid (SA) is initiated. Highly localized SA delivery results in a significant decrease in cytokine (tumor necrosis factor alpha and interleukin 6) levels after lipopolysaccharide stimulation. The findings-the first use of such capillary OEIPs in mammalian cells or systems-demonstrate the utility of the technology for optimizing transport and delivery of different therapeutic substances at low concentrations, with the benefit of local and controlled administration that limits the adverse effect of oral/systemic drug delivery.

Alcohol abuse and disorder of granulopoiesis

Granulocytes are the major type of phagocytes constituting the front line of innate immune defense against bacterial infection. In adults, granulocytes are derived from hematopoietic stem cells in the bone marrow. Alcohol is the most frequently abused substance in human society. Excessive alcohol consumption injures hematopoietic tissue, impairing bone marrow production of granulocytes through disrupting homeostasis of granulopoiesis and the granulopoietic response. Because of the compromised immune defense function, alcohol abusers are susceptible to infectious diseases, particularly septic infection. Alcoholic patients with septic infection and granulocytopenia have an exceedingly high mortality rate. Treatment of serious infection in alcoholic patients with bone marrow inhibition continues to be a major challenge. Excessive alcohol consumption also causes diseases in other organ systems, particularly severe alcoholic hepatitis which is life threatening. Corticosteroids are the only therapeutic option for improving short-term survival in patients with severe alcoholic hepatitis. The existence of advanced alcoholic liver diseases and administration of corticosteroids make it more difficult to treat serious infection in alcoholic patients with the disorder of granulopoieis. This article reviews the recent development in understanding alcohol-induced disruption of marrow granulopoiesis and the granulopoietic response with the focus on progress in delineating cell signaling mechanisms underlying the alcohol-induced injury to hematopoietic tissue. Efforts in exploring effective therapy to improve patient care in this field will also be discussed.

P38 is involved in immune response by regulating inflammatory cytokine expressions in the Pacific oyster Crassostrea gigas

P38 mitogen-activated protein kinases are serine/threonine protein kinases reportedly involved in the innate immunity of vertebrates and invertebrates. In the present study, a P38 homolog (CgP38) was characterized from the Pacific oyster Crassostrea gigas. The full-length cDNA of CgP38 was of 1515 bp containing a 1101 bp open reading frame. A serine/threonine protein kinase (S_TKc) domain with a conserved Thr-Gly-Tyr motif and an ATRW substrate-binding site was found in the deduced amino acid sequence of CgP38. CgP38 shared a close evolutionary relationship with ChP38 from the Hong Kong oyster Crassostrea hongkongensis. The transcript levels of CgP38 in hemocytes increased significantly from 12 h to 48 h after lipopolysaccharide (LPS) stimulation and from 12 h to 24 h after Vibrio splendidus stimulation. The phosphorylation level of CgP38 in oyster hemocytes increased significantly at 2 h after LPS stimulation. CgP38 positively regulated the expression of interleukins, such as CgIL17-1, CgIL17-2, CgIL17-3, CgIL17-4 and CgIL17-6, and tumor necrosis factor CgTNF after LPS or V. splendidus stimulation. These results suggested that CgP38 participated in oyster immune response by regulating the expressions of inflammatory cytokines.

Causal Relationship between Diet-Induced Gut Microbiota Changes and Diabetes: A Novel Strategy to Transplant Faecalibacterium prausnitzii in Preventing Diabetes

The incidence of metabolic disorders, including diabetes, has elevated exponentially during the last decades and enhanced the risk of a variety of complications, such as diabetes and cardiovascular diseases. In the present review, we have highlighted the new insights on the complex relationships between diet-induced modulation of gut microbiota and metabolic disorders, including diabetes. Literature from various library databases and electronic searches (ScienceDirect, PubMed, and Google Scholar) were randomly collected. There exists a complex relationship between diet and gut microbiota, which alters the energy balance, health impacts, and autoimmunity, further causes inflammation and metabolic dysfunction, including diabetes. Faecalibacterium prausnitzii is a butyrate-producing bacterium, which plays a vital role in diabetes. Transplantation of F. prausnitzii has been used as an intervention strategy to treat dysbiosis of the gut’s microbial community that is linked to the inflammation, which precedes autoimmune disease and diabetes. The review focuses on literature that highlights the benefits of the microbiota especially, the abundant of F. prausnitzii in protecting the gut microbiota pattern and its therapeutic potential against inflammation and diabetes.

IL-33 regulates cytokine production and neutrophil recruitment via the p38 MAPK-activated kinases MK2/3

IL-33 is an IL-1-related cytokine that can act as an alarmin when released from necrotic cells. Once released, it can target various immune cells including mast cells, innate lymphoid cells and T cells to elicit a Th2-like immune response. We show here that bone marrow-derived mast cells produce IL-13, IL-6, TNF, GM-CSF, CCL3 and CCL4 in response to IL-33 stimulation. Inhibition of the p38 MAPK, or inhibition or knockout of its downstream kinases MK2 and MK3, blocked the production of these cytokines in response to IL-33. The mechanism downstream of MK2/3 was cytokine specific; however, MK2 and MK3 were able to regulate TNF and GM-CSF mRNA stability. Previous studies in macrophages have shown that MK2 regulates mRNA stability via phosphorylation of the RNA-binding protein TTP (Zfp36). The regulation of cytokine production in mast cells was, however, independent of TTP. MK2/3 were able to phosphorylate the TTP-related protein Brf1 (Zfp36 l1) in IL-33-stimulated mast cells, suggesting a mechanism by which MK2/3 might control mRNA stability in these cells. In line with its ability to regulate in vitro IL-33-stimulated cytokine production, double knockout of MK2 and 3 in mice prevented neutrophil recruitment following intraperitoneal injection of IL-33.

Benzoxazole derivatives suppress lipopolysaccharide-induced mast cell activation

Mast cells are central regulators of allergic inflammation that function by releasing various proallergic inflammatory mediators, including histamine, eicosanoids and proinflammatory cytokines. Occasionally, bacterial infections may initiate or worsen allergic inflammation. A number of studies have indicated that activation of lipoxygenase in mast cells positive regulates allergic inflammatory responses by generating leukotrienes and proinflammatory cytokines. In the present study, the effects of benzoxazole derivatives on the lipopolysaccharide (LPS)‑induced expression of proinflammatory cytokines, production of histamine and surface expression of co‑stimulatory molecules on bone marrow-derived mast cells (BMMCs) were studied. The benzoxazole derivatives significantly reduced the expression of interleukin (IL)‑1β, IL‑6, IL‑13, tumor necrosis factor‑α, perilipin (PLIN) 2, and PLIN3 in BMMCs treated with LPS. Furthermore, histamine production was suppressed in BMMCs treated with LPS, or treated with phorbol-12-myristate-13-acetate/ionomycin. Benzoxazole derivatives marginally affected the surface expression of cluster of differentiation (CD)80 and CD86 on BMMCs in the presence of LPS, although LPS alone did not increase the expression of those proteins. Therefore, benzoxazole derivatives inhibited the secretion of proinflammatory cytokines in mast cells and may be potential candidate anti‑allergic agents to suppress mast cell activation.

Changes in protein expression profiles in bovine endometrial epithelial cells exposed to E. coli LPS challenge

E. coli is one of the most frequently involved bacteria in uterine diseases. Lipopolysaccharide (LPS) is a component of the outer membrane of Gram-negative bacteria involved in pathogenic processes leading to post-partum metritis and endometritis in cattle. It also causes inflammation of the endometrium. The increase of cell proliferation by LPS is part of the inflammatory process. The aim of this study was to investigate possible changes in protein expression in relation to the proliferative response of bEECs after challenge with E. coli-LPS. In vitro culture of bEECs was performed from cow genital tracts collected at a slaughterhouse. In passage 5, bEECs from each of 9 cows (3 series of 3 cows) were exposed to 0, 8, and 16 μg ml^-1 LPS for 72 h. At time 0 and 72 h later, attached cells/living cells were counted and for each time and LPS dosage, cells were frozen for proteomic analyses. All samples from the 3 series were analyzed by 2-D gel electrophoresis coupled to MALDI-TOF/TOF mass spectrometry. The samples from the first series were subjected to shotgun nLC-MS/MS analysis. From the whole differential proteomics analysis, 38 proteins were differentially expressed (p < 0.05 to p < 0.001) following exposure to LPS. Among them, twenty-eight were found to be up-regulated in the LPS groups in comparison to control groups and ten were down-regulated. Differentially expressed proteins were associated with cell proliferation and apoptosis, transcription, destabilization of cell structure, oxidative stress, regulation of histones, allergy and general cell metabolism pathways. The de-regulations induced by LPS were consistent with the proliferative phenotype and indicated strong alterations of several cell functions. In addition, some of the differentially expressed proteins relates to pathways activated at the time of implantation. The specific changes induced through those signals may have negative consequences for the establishment of pregnancy.

Effects of bitter melon (Momordica charantia L.) on the gut microbiota in high fat diet and low dose streptozocin-induced rats

The effects on gut microbiota of type 2 diabetic rats fed a bitter melon formulation (BLSP, a lyophilized superfine powder) were investigated. BLSP treatment significantly reduced fasting blood glucose levels (p < 0.05) and serum insulin levels (p < 0.05) of the diabetic rats. The gut microbiota of treated and control rats were profiled by PCR amplification and pyrosequencing of 16S rRNA genes (V3-V9 region). BLSP significantly reduced the ratio of Firmicutes to Bacteroidetes in diabetic rats, while the relative abundances of Ruminococcaceae, Bacteroides and Ruminococcus were significantly lowered in BLSP-treated rats compared to diabetic rats. Additionally, BLSP significantly suppressed the activation of MAPK (JNK and p38). The results indicate that BLSP can significantly modify the proportions of particular gut microbiota in diabetic rats without disturbing the normal population diversity. By suppressing the activation of MAPK signaling pathway, a BLSP containing diet may ameliorate type 2 diabetes.

The RNA-binding protein TTP is a global post-transcriptional regulator of feedback control in inflammation

RNA-binding proteins (RBPs) facilitate post-transcriptional control of eukaryotic gene expression at multiple levels. The RBP tristetraprolin (TTP/Zfp36) is a signal-induced phosphorylated anti-inflammatory protein guiding unstable mRNAs of pro-inflammatory proteins for degradation and preventing translation. Using iCLIP, we have identified numerous mRNA targets bound by wild-type TTP and by a non-MK2-phosphorylatable TTP mutant (TTP-AA) in 1 h LPS-stimulated macrophages and correlated their interaction with TTP to changes at the level of mRNA abundance and translation in a transcriptome-wide manner. The close similarity of the transcriptomes of TTP-deficient and TTP-expressing macrophages upon short LPS stimulation suggested an effective inactivation of TTP by MK2, whereas retained RNA-binding capacity of TTP-AA to 3′UTRs caused profound changes in the transcriptome and translatome, altered NF-κB-activation and induced cell death. Increased TTP binding to the 3′UTR of feedback inhibitor mRNAs, such as Ier3, Dusp1 or Tnfaip3, in the absence of MK2-dependent TTP neutralization resulted in a strong reduction of their protein synthesis contributing to the deregulation of the NF-κB-signaling pathway. Taken together, our study uncovers a role of TTP as a suppressor of feedback inhibitors of inflammation and highlights the importance of fine-tuned TTP activity-regulation by MK2 in order to control the pro-inflammatory response.

Anti-CD40 antibody and toll-like receptor 3 ligand restore dendritic cell-mediated anti-tumor immunity suppressed by morphine

The influence of morphine on host immunity and the underlying mechanism are still unclear. In the current study, we investigated the influence of morphine on dendritic cells (DCs), its possible mechanism of action, and the molecules that could reverse these effects. Morphine suppressed DC maturation, antigen presenting abilities, and the ability to activate antigen-specific CD8(+) T cells. Morphine-treated DCs also secreted higher concentrations of IL-10, but lower IL-6 and TNF-α. Morphine-treated DCs showed decreased ERK1/2 phosphorylation and reduced p38 dephosphorylation. The in vivo administration of immuno-modulators, anti-CD40 Ab and TLR3 ligand-poly(I:C), enhanced antigen-specific immunity, promoted the anti-tumor effects, and prolonged the survival of morphine-treated, tumor-bearing mice by promoting the maturation and function of BMM-derived DCs by enhancing ERK1/2 phosphorylation and p38 dephosphorylation. We concluded that morphine can inhibit DC-mediated anti-tumor immunity by suppressing DC maturation and function. Immuno-modulators, such as anti-CD40 Abs and TLR agonists, can restore the DC-mediated anti-tumor immunity. Use of immuno-modulators could serve as a useful approach to overcome the immunocompromised state generated by morphine.

Nonreceptor tyrosine kinases ITK and BTK negatively regulate mast cell proinflammatory responses to lipopolysaccharide

BACKGROUND

Mast cells are indispensable for LPS-induced septic hypothermia, in which TNF-α plays an essential role to initiate septic responses. ITK and BTK regulate mast cell responses to allergens, but their roles in mast cell responses in LPS-induced sepsis are unclear.

OBJECTIVE

We sought to investigate the roles of ITK and BTK in mast cell responses during LPS-induced septic inflammation.

METHODS

Mice (genetically modified or bone marrow-derived mast cell-reconstituted Sash) were given LPS to induce septic hypothermia in the presence or absence of indicated inhibitors. Flow cytometry was used to determine LPS-induced cell influx and TNF-α production in peritoneal cells. Microarray was used for genomewide gene expression analysis on bone marrow-derived mast cells. Quantitative PCR and multiplex were used to determine transcribed and secreted proinflammatory cytokines. Microscopy and Western blotting were used to determine activation of signal transduction pathways.

RESULTS

The absence of ITK and BTK leads to exacerbation of LPS-induced septic hypothermia and neutrophil influx. Itk(-/-)Btk(-/-) mast cells exhibit hyperactive preformed and LPS-induced TNF-α production, and lead to more severe LPS-induced septic hypothermia when reconstituted into mast cell-deficient Sash mice. LPS-induced nuclear factor kappa B, Akt, and p38 activation is enhanced in Itk(-/-)Btk(-/-) mast cells, and blockage of phosphatidylinositol-4,5-bisphosphate 3-kinase, Akt, or p38 downstream mitogen-activated protein kinase interacting serine/threonine kinase 1 activation significantly suppresses TNF-α hyperproduction and attenuates septic hypothermia.

CONCLUSIONS

ITK and BTK regulate thermal homeostasis during septic response through mast cell function in mice. They share regulatory function downstream of Toll-like receptor 4/LPS in mast cells, through regulating the activation of canonical nuclear factor kappa B, phosphatidylinositol-4,5-bisphosphate 3-kinase/Akt, and p38 signaling pathways.