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The EFSA Panel on genetically modified organisms (GMO Panel) has previously assessed genetically modified (GM) sugar beet H7-1. This sugar beet was found to be as safe and nutritious as its conventional counterpart and commercial sugar beet varieties with respect to potential effects on human and animal health and the environment in the context of its intended uses. On 19 February 2021, European Commission requested EFSA to analyse new nucleic acid sequencing data and updated bioinformatics data for GM sugar beet H7-1 and to indicate whether the previous conclusions of the GMO Panel on safety of GM sugar beet H7-1 remain valid. The new sequencing data indicated seven nucleotide differences as compared to the sequence originally provided in applications EFSA-GMO-UK-2004-08 and EFSA-GMO-RX-006: five nucleotides in the 5' genomic flanking region and two nucleotides in the T-DNA region of the insert. Two mismatches between the originally submitted H7-1 event sequence and the plasmid sequence were confirmed by the newly obtained H7-1 sequence. Based on the analysis of the provided data, EFSA considers that the newly reported sequence differences are most likely attributed to sequencing errors in the originally reported sugar beet H7-1 event sequence. The new sequencing data and the bioinformatic analyses performed on the new sequence did not give rise to safety issues. Therefore, EFSA concludes that the original risk assessment of sugar beet H7-1 remains valid.

The GMO Panel has previously assessed genetically modified (GM) soybean BPS‐CV127‐9. This soybean was found to be as safe and nutritious as its conventional counterpart and commercial soybean varieties with respect to potential effects on human and animal health and the environment in the context of its intended uses. On 16 February 2018, European Commission requested EFSA to analyse new nucleic acid sequencing data and updated bioinformatics data for GM soybean BPS‐CV127‐9 and to indicate whether the previous conclusions of the GMO Panel on safety of GM soybean BPS‐CV127‐9 remain valid. The new sequencing data indicated a two nucleotide difference in the unannotated Arabidopsis genomic DNA sequence downstream of the 3′ untranslated region of the ahasl (also referred to as csr1‐2) gene as compared to the sequencing data originally provided. One of these nucleotide differences reported in the new nucleic acid sequencing data from GM soybean event BPS‐CV127‐9 was shown to be already present in the original plant material used for the risk assessment. However, for the other nucleotide difference reported, no evidence could be provided to differentiate between a sequencing error and point‐mutation. With the exception of bioinformatics analyses, the studies performed for the risk assessment of the single event soybean BPS‐CV127‐9 remain valid. The new sequencing data and the bioinformatics analyses performed on the new sequence did not give rise to safety issues. Therefore, EFSA concludes that the original risk assessment of soybean BPS‐CV127‐9 remains valid.

© 2020 European Food Safety Authority., Following the submission of application EFSA‐GMO‐RX‐002 under Regulation (EC) No 1829/2003 from Monsanto Company, the Panel on Genetically Modified Organisms of EFSA (GMO) was asked to deliver a scientific risk assessment on the data submitted in the context of the renewal of authorisation application for the herbicide‐tolerant genetically modified oilseed rape GT73. The data received in the context of this renewal application contained post‐market environmental monitoring reports, a systematic search and evaluation of literature, updated bioinformatic analyses and additional documents or studies performed by or on behalf of the applicant. The GMO Panel assessed these data for possible new hazards, modified exposure or new scientific uncertainties identified during the authorisation period and not previously assessed in the context of the original application. Under the assumption that the DNA sequence of the event in oilseed rape GT73 considered for renewal of authorisation is identical to the sequence of the originally assessed event, the GMO Panel concludes that there is no evidence in renewal application EFSA‐GMO‐RX‐002 for new hazards, modified exposure or scientific uncertainties that would change the conclusions of the original risk assessment on oilseed rape GT73.

© 2020 European Food Safety Authority., Soybean MON 87705 × MON 87708 × MON 89788 (three‐event stack soybean) was produced by conventional crossing to combine three single soybean events: MON 87705, MON 87708 and MON 89788. This combination is intended to alter the fatty acid profile in the seed (in particular increasing the levels of oleic acid) and tolerance to glyphosate‐based and dicamba herbicides. The Genetically Modified Organisms Panel previously assessed the three single soybean events and did not identify safety concerns. No new data on the single soybean events, leading to modification of the original conclusions on their safety have been identified. The molecular characterisation, comparative analysis (agronomic, phenotypic and compositional characteristics) and the outcome of the toxicological, allergenicity and nutritional assessment indicate that the combination of the single soybean events and of the newly expressed proteins in the three‐event stack soybean does not give rise to food and feed safety and nutritional concerns. In the case of accidental release of viable three‐event stack soybean seeds into the environment, this would not raise environmental safety concerns. The post‐market environmental monitoring plan and the reporting intervals are in line with the intended uses of soybean MON 87705 × MON 87708 × MON 89788. Considering the altered fatty acid profile of the three‐event stack soybean, a proposal for post‐market monitoring needs to be provided by the applicant. The GMO Panel notes that in the context of this application EFSA‐GMO‐NL‐2015‐126 the applicant did not provide a 90‐day study on MON 87705 soybean in line with the applicable legal requirements. Therefore, the GMO Panel is not in the position to finalise the risk assessment of soybean MON 87705 × MON 87708 × MON 89788 under the current regulatory frame.

Background Complement is likely to have a role in refractory generalised myasthenia gravis, but no approved therapies specifically target this system. Results from a phase 2 study suggested that eculizumab, a terminal complement inhibitor, produced clinically meaningful improvements in patients with anti-acetylcholine receptor antibody-positive refractory generalised myasthenia gravis. We further assessed the efficacy and safety of eculizumab in this patient population in a phase 3 trial. Methods We did a phase 3, randomised, double-blind, placebo-controlled, multicentre study (REGAIN) in 76 hospitals and specialised clinics in 17 countries across North America, Latin America, Europe, and Asia. Eligible patients were aged at least 18 years, with a Myasthenia Gravis-Activities of Daily Living (MG-ADL) score of 6 or more, Myasthenia Gravis Foundation of America (MGFA) class II-IV disease, vaccination against Neisseria meningitides, and previous treatment with at least two immunosuppressive therapies or one immunosuppressive therapy and chronic intravenous immunoglobulin or plasma exchange for 12 months without symptom control. Patients with a history of thymoma or thymic neoplasms, thymectomy within 12 months before screening, or use of intravenous immunoglobulin or plasma exchange within 4 weeks before randomisation, or rituximab within 6 months before screening, were excluded. We randomly assigned participants (1:1) to either intravenous eculizumab or intravenous matched placebo for 26 weeks. Dosing for eculizumab was 900 mg on day 1 and at weeks 1, 2, and 3; 1200 mg at week 4; and 1200 mg given every second week thereafter as maintenance dosing. Randomisation was done centrally with an interactive voice or web-response system with patients stratified to one of four groups based on MGFA disease classification. Where possible, patients were maintained on existing myasthenia gravis therapies and rescue medication was allowed at the study physician's discretion. Patients, investigators, staff, and outcome assessors were masked to treatment assignment. The primary efficacy endpoint was the change from baseline to week 26 in MG-ADL total score measured by worst-rank ANCOVA. The efficacy population set was defined as all patients randomly assigned to treatment groups who received at least one dose of study drug, had a valid baseline MG-ADL assessment, and at least one post-baseline MG-ADL assessment. The safety analyses included all randomly assigned patients who received eculizumab or placebo. This trial is registered with ClinicalTrials.gov, number NCT01997229. Findings Between April 30, 2014, and Feb 19, 2016, we randomly assigned and treated 125 patients, 62 with eculizumab and 63 with placebo. The primary analysis showed no significant difference between eculizumab and placebo (least-squares mean rank 56·6 [SEM 4·5] vs 68·3 [4·5]; rank-based treatment difference -11·7, 95% CI -24·3 to 0·96; p=0·0698). No deaths or cases of meningococcal infection occurred during the study. The most common adverse events in both groups were headache and upper respiratory tract infection (ten [16%] for both events in the eculizumab group and 12 [19%] for both in the placebo group). Myasthenia gravis exacerbations were reported by six (10%) patients in the eculizumab group and 15 (24%) in the placebo group. Six (10%) patients in the eculizumab group and 12 (19%) in the placebo group required rescue therapy. Interpretation The change in the MG-ADL score was not statistically significant between eculizumab and placebo, as measured by the worst-rank analysis. Eculizumab was well tolerated. The use of a worst-rank analytical approach proved to be an important limitation of this study since the secondary and sensitivity analyses results were inconsistent with the primary endpoint result; further research into the role of complement is needed. Funding Alexion Pharmaceuticals.

The GMO Panel has previously assessed genetically modified (GM) carnation FLO‐40689‐6 and concluded that there is no scientific reason to consider that the import, distribution and retailing in the EU of carnation FLO‐40689‐6 cut flowers for ornamental use will cause any adverse effects on human health or the environment. On 27 October 2017, the European Commission requested EFSA to analyse new nucleic acid sequencing data and updated bioinformatics data for carnation FLO‐40689‐6 and to indicate whether the conclusions of the GMO Panel on the previously assessed GM carnation FLO‐40689‐6 remain valid. The new sequencing data indicated the correction of one nucleotide compared to the sequencing data originally provided. The new sequence was corrected by removal of one nucleotide from the polylinker region in locus 1. The removal of this base pair reported in the new nucleic acid sequencing data for carnation FLO‐40689‐6 has been already present in the original plant material used for the risk assessment. Thus, with the exception of bioinformatics analyses, the studies performed for the risk assessment of GM carnation FLO‐40689‐6 remain valid. The new sequencing data and the bioinformatic analyses performed on the new sequence, did not give rise to safety issues. Therefore, EFSA concludes that the original risk assessment of carnation FLO‐40689‐6 remains valid.

The GMO Panel has previously assessed genetically modified (GM) carnation FLO‐40685‐2 and concluded that there is no scientific reason to consider that the import, distribution and retailing in the EU of carnation FLO‐40685‐2 cut flowers for ornamental use will cause any adverse effects on human health or the environment. On 7 November 2017, European Commission requested EFSA to analyse new nucleic acid sequencing data and updated bioinformatics data for carnation FLO‐40685‐2 and to indicate whether the conclusions of the GMO Panel on the previously assessed GM carnation FLO‐40685‐2 remain valid. The new sequencing data indicated an additional three base pairs compared to the sequencing data originally provided: one base pair addition to the polyA tail of each of the two inserted flavonoid 3',5'–hydroxylase elements and one base pair addition to the sequence of one of the two D8 promoters in locus 1. These sequence differences are located outside the coding sequence for the newly expressed proteins and the base pairs described as differences in the new nucleic acid sequencing data for carnation FLO‐40685‐2 were reported to have been already present in the original plant material used for the risk assessment. Thus, with the exception of bioinformatics analyses, the studies performed for the risk assessment of GM carnation FLO‐40685‐2 remain valid. The new sequencing data and the bioinformatics analyses performed on the new sequence did not give rise to safety issues. Therefore, EFSA concludes that the original risk assessment of carnation FLO‐40685‐2 remains valid.

The trabecular extracellular matrix (ECM) forms a three-dimensional scaffold to stabilize the bone marrow, provide substrates for cell-matrix interactions and retain, present or release signals to modulate hematopoietic stem and progenitor cell development. However, the impact of trabecular ECM components on hematopoiesis has been poorly studied. Using collagen IX alpha1 - deficient (Col9a1(−/−)) mice, we revealed that a lack of collagen IX alpha1 results in a disorganized trabecular network enriched in fibronectin, and in a reduction in myeloid cells, which was accompanied by a decrease in colony-stimulating factor 1 receptor expression on monocytes from the bone marrow. In contrast, B-cell numbers in the bone marrow and T-cell numbers in the thymus remained unchanged. Alterations in the bone marrow microenvironment may not only reduce myeloid cell numbers, but also have long-term implications for myeloid cell function. Mice were infected with Listeria moncytogenes to analyze the function of myeloid cells. In this case, an inadequate macrophage-dependent clearance of bacterial infections was observed in Col9a1(−/−) mice in vivo. This was mainly caused by an impaired interferon-gamma/tumor necrosis factor-alpha-mediated activation of macrophages. The loss of collagen IX alpha1 therefore destabilizes the trabecular bone network, impairs myeloid cell differentiation, and affects the innate immune response against Listeria.

The mechanisms that regulate cell death and inflammation play an important role in liver disease and cancer. Receptor-interacting protein kinase 1 (RIPK1) induces apoptosis and necroptosis via kinase-dependent mechanisms and exhibits kinase-independent prosurvival and proinflammatory functions. Here, we have used genetic mouse models to study the role of RIPK1 in liver homeostasis, injury, and cancer. While ablating either RIPK1 or RelA in liver parenchymal cells (LPCs) did not cause spontaneous liver pathology, mice with combined deficiency of RIPK1 and RelA in LPCs showed increased hepatocyte apoptosis and developed spontaneous chronic liver disease and cancer that were independent of TNF receptor 1 (TNFR1) signaling. In contrast, mice with LPC-specific knockout of Ripk1 showed reduced diethylnitrosamine-induced (DEN-induced) liver tumorigenesis that correlated with increased DEN-induced hepatocyte apoptosis. Lack of RIPK1 kinase activity did not inhibit DEN-induced liver tumor formation, showing that kinase-independent functions of RIPK1 promote DEN-induced hepatocarcinogenesis. Moreover, mice lacking both RIPK1 and TNFR1 in LPCs displayed normal tumor formation in response to DEN, demonstrating that RIPK1 deficiency decreases DEN-induced liver tumor formation in a TNFR1-dependent manner. Therefore, these findings indicate that RIPK1 cooperates with NF-κB signaling to prevent TNFR1-independent hepatocyte apoptosis and the development of chronic liver disease and cancer, but acts downstream of TNFR1 signaling to promote DEN-induced liver tumorigenesis.

Many skin disorders are associated with increased numbers of activated mast cells and are worsened by stress; however, the mechanism underlying these processes is not understood. Corticotropin-releasing hormone (CRH) is secreted under stress from the hypothalamus, but also in the skin, where it induces mast cell activation and vascular permeability. We investigated the effect of CRH in a number of animal models by using i.v. Evans blue extravasation as a marker of vascular permeability. Intradermal CRH is among the most potent peptides at 100 nM, its effect being nearly comparable to that of neurotensin (NT). Pretreatment of skin injection sites with the NT receptor antagonist SR48692 blocks CRH-induced vascular permeability, which is diminished in NT−/− mice, implying that NT is necessary for the effect of CRH. CRH and NT precursor mRNA are shown to be expressed in both dorsal root ganglia and skin, whereas the latter also expresses mRNA for prohormone convertase 5, an enzyme that cleaves pro-NT into its active form. We also show that the effect of both CRH and NT is absent in W/Wvmast cell-deficient mice; however, only a fraction of skin mast cells express CRH receptors, as shown by FACS analysis of CRH receptor (CRHR) and c-kitdouble-positive disaggregated mouse skin mast cells. These findings suggest that CRH induces skin vascular permeability through NT acting on mast cells and that both peptides should be considered in the pathogenesis of skin disorders exacerbated by stress.

Certain skin disorders, such as contact dermatitis and chronic urticaria, are characterized by inflammation involving mast cells and worsen by stress. The underlying mechanism of this effect, however, is not known. The skin appears to have the equivalent of a hypothalamic–pituitary–adrenal (HPA) axis, including local expression of corticotropin-releasing hormone (CRH) and its receptors (CRH-R). We have reported that acute stress and intradermal administration of CRH stimulate skin mast cells and increase vascular permeability through CRH-R1 activation. In this study, we investigated the expression of CRH-R1, the main CRH-R subtype in human skin, and the mast cell related gene histidine decarboxylase (HDC), which regulates the production of histamine, in normal and pathological skin biopsies. Quantitative real time PCR revealed that chronic urticaria expresses high levels of CRH-R1 and HDC as compared to normal foreskin, breast skin and cultured human keratinocytes. The lichen simplex samples had high expression of CRH-R1, but low HDC. These results implicate CRH-R in chronic urticaria, which is often exacerbated by stress.

Mast cells participate in allergies, and also in immunity and inflammation by secreting proinflammatory cytokines. Flavonoids are naturally occurring polyphenolic plant compounds, one group of which -- the flavonols, inhibits histamine and some cytokine release from rodent basophils and mast cells. However, the effect of flavonols on proinflammatory mediator release and their possible mechanism of action in human mast cells is not well defined. Human umbilical cord blood-derived cultured mast cells (hCBMCs) grown in the presence of stem cell factor (SCF) and interleukin (IL)-6 were preincubated for 15 min with the flavonols quercetin, kaempferol, myricetin and morin (0.01, 0.1, 1, 10 or 100 microM), followed by activation with anti-IgE. Secretion was quantitated for IL-6, IL-8, tumor necrosis factor-alpha (TNF-alpha), histamine and tryptase levels. Release of IL-6, IL-8 and TNF-alpha was inhibited by 82-93% at 100 microM quercetin and kaempferol, and 31-70% by myricetin and morin. Tryptase release was inhibited by 79-96% at 100 microM quercetin, kampferol and myricetin, but only 39% by morin; histamine release was inhibited 52-77% by the first three flavonols, but only 28% by morin. These flavonols suppressed intracellular calcium ion elevations in a dose-response manner, with morin being the weakest; they also inhibited phosphorylation of the calcium-insensitive protein kinase C theta (PKC theta). Flavonol inhibition of IgE-mediated proinflammatory mediator release from hCBMCs may be due to inhibition of intracellular calcium influx and PKC theta signaling. Flavonols may therefore be suitable for the treatment of allergic and inflammatory diseases.

Several inflammatory skin conditions, including atopic dermatitis (AD) and psoriasis, are exacerbated by stress. Recent evidence suggests that crosstalk between mast cells, neurons and keratinocytes might be involved in such exacerbation. Mast cells are distributed widely in the skin, are present in increased numbers in AD and are located in close proximity to substance P- or neurotensin-containing neurons. Corticotropin-releasing factor (CRF), its structurally related peptide urocortin (Ucn) and their receptors are also present in the skin and their levels are increased following stress. Human mast cells synthesize and secrete both CRF and Ucn in response to immunoglobulin E receptor (FcepsilonRI) crosslinking. Mast cells also express CRF receptors, activation of which leads to the selective release of cytokines and other pro-inflammatory mediators. Thus, we propose that CRF receptor antagonists could be used together with natural molecules, such as retinol and flavonoids, to inhibit mast cell activation and provide new therapeutic options for chronic inflammatory conditions exacerbated by stress.

Problem: Mast cells are critical in allergic and inflammatory diseases such as interstitial cystitis, which is often clinically associated with or mistaken as endometriosis. Mast cells had previously been reported to be increased at sites of endometriosis, and tryptase may contribute to the fibrosis and inflammation characterizing endometriosis. Method of study: This is a pilot study of mast cell numbers and its activation in endometriosis biopsies (n = 10) by immunostaining for mast cell tryptase, corticotropin-releasing hormone (CRH) and urocortin (Ucn). Results: This is the first report that tryptase positive mast cells were not only increased (64–157 mast cells/mm2) in human endometriosis, but also highly activated (89%) in areas strongly stained positive for CRH/Ucn. Normal endometrium was weakly positive for both CRH/Ucn. Conclusion: High numbers of activated mast cells are present in endometriosis sites that were strongly positive for CRH/Ucn. CRH and Ucn may activate mast cells and contribute to the fibrosis and inflammation in endometriosis.

Stress activates the hypothalamic-pituitary-adrenal axis through CRH, leading to production of glucocorticoids that down-regulate immune responses. However, acute stress also has proinflammatory effects. We previously showed that restraint stress, as well as CRH and its structurally related urocortin (Ucn), could activate mast cells and trigger mast cell-dependent vascular permeability. Here we show for the first time that human cord blood-derived cultured mast cells (hCBMC) at 10 wk, but not at 2 wk, are immunocytochemically positive for CRH and Ucn; human leukemic mast cells are weakly positive for both peptides. The ability of these mast cells to synthesize CRH and Ucn was confirmed by showing mRNA expression with RT-PCR. hCBMC (8–14 wk) synthesize and store 1–10 ng/106 cells (10–20 μg/g) of both CRH and Ucn detected by ELISA of cell homogenates. Stimulation of IgE-sensitized hCBMC with anti-IgE results in secretion of most CRH and Ucn. These findings indicate that mast cells are not only the target, but also a potential source of CRH and Ucn that could have both autocrine and paracrine functions, especially in allergic inflammatory disorders exacerbated by stress.

There is increasing evidence that CRH, which is the principal neuroregulator of the hypothalamic-pituitary-adrenocortical axis, is also involved in the mechanism of human labor. The human myometrium has been shown to express several high affinity CRH receptors, although the identities of the CRH receptor subtypes have yet to be identified. To investigate further the expression of the CRH receptor in human myometrium, we used RT-PCR, fluorescent in situ hybridization and immunofluorescence to identify and localize the four subtypes, 1α, 1β, 2α, and the variant C, of the CRH receptor. Interestingly, the CRH receptor subtypes in myometrium exhibit differential expression patterns; in human pregnant myometrium at term all four receptor-subtypes were expressed, whereas only the 1α- and 1β-receptor subtypes were found in the nonpregnant myometrium. This would suggest that CRH, acting via different receptor subtypes, is able to exert different actions on the myometrium in the pregnant state compared to the nonpr...

CRH and its structurally related peptide urocortin (Ucn) are released under stress. Ucn is a potent agonist for CRH-receptor 2 (CRH-R2), which is strongly expressed in rodent heart. Stress induces Ucn mRNA expression in the heart, where it may be cardioprotective. However, increasing evidence indicates that Ucn may also have pro-inflammatory actions. Here, we show that neonatal rat cardiomyocytes express CRH-R2 by western blot analysis and Ucn induces interleukin-6 (IL-6) release in a time- and dose-dependent fashion. Ucn stimulates activation of ERK and p38 MAP kinases, while both MEK1 and p38 inhibitor block Ucn-induced IL-6 release. Ucn also activates nuclear factor kappa B (NF-κB) and a NF-κB inhibitor blocks Ucn-induced IL-6 release. Finally, the CRH-R antagonists α-helical (9–41) CRH and astressin-2B completely inhibit Ucn-induced IL-6 release, as well as activation of ERK, p38, and NF-κB. These findings indicate that Ucn induces IL-6 synthesis and release from neonatal rat cardiomyocytes. Our findings suggest that even though Ucn may confirm some protection on cardiomyocyte survival, it can also release IL-6, which is an independent risk factor for acute coronary syndrome. The precise role of cardiac Ucn in vivo remains to be elucidated.

T cell receptor (TCR) signaling to IKB kinase (IKK)/NFKB is controlled by PKC theta-dependent activation of the Carma1, Bcl10, and Malt1 (CBM) complex. Antigen-induced phosphorylation of BcI10 has been reported, but its physiological function is unknown. Here we show that the putative downstream kinase IKK beta is required for initial CBM complex formation. Further, upon engagement of IKK beta/Malt1/Bcl10 with Carma1, IKK beta phosphorylates Bcl10 in the C terminus and thereby interferes with Bcl10/Malt1 association and Bcl10-mediated IKK gamma ubiquitination. Mutation of the IKK beta phosphorylation sites on Bcl10 enhances expression of NF-kappa B target genes IL-2 and TNF alpha after activation of primary T cells. Thus, our data provide evidence that IKK beta serves a dual role upstream of its classical substrates, the I kappa B proteins. While being essential for triggering initial CBM complex formation, IKK beta-dependent phosphorylation of Bcl10 exhibits a negative regulatory role in T cell activation.

Corticotropin-releasing hormone (CRH) is secreted under stress and regulates the hypothalamic-pituitary-adrenal (HPA) axis; it is also secreted outside the brain where it exerts proinflammatory effects, possibly through mast cell activation. Mast cells are necessary for allergic reactions, but are increasingly implicated in acquired immunity and inflammatory diseases worsened by stress. Acute stress and intradermal CRH induced murine skin mast cell activation and increased vascular permeability that was absent in W/Wv mast cell deficient mice. The presence of functional CRH receptors (CRH-R) was recently reported on human mast cells. Here, we studied the expression of CRH-R1 and CRH-R2 by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and fluorescent immunocytochemistry in human umbilical cord blood-derived cultured mast cells (hCBMCs) treated with Interleukin (IL)-1, IL-4 or lipopolysaccharide (LPS). Ten week-old hCBMCs cultured in the presence of Stem cell factor (SCF) and IL-6 were positive for both CRH-R1 and CRH-R2. However, the expression of only CRH-R2 mRNA and protein was induced by priming hCBMCs with IL-4 for the last three weeks of culture. Further analysis of the CR-H R2 mRNA expression showed that addition of IL-1 or LPS for 6 h increased only CRH-R2 gene expression. CRH had negligible effect on IL-6 secretion from non-primed hCBMCs, but induced release from IL-4 primed cells. Interestingly, LPS alone increased IL-6 release in non-primed cells, but lost this effect in primed cells. These results further implicate mast cells and CRH in either initiating or potentiating inflammatory diseases, especially those affected by stress.

Mast cells are critical for allergic reactions, but also for innate or acquired immunity and inflammatory conditions that worsen by stress. Corticotropin-releasing hormone (CRH), which activates the hypothalamic-pituitary-adrenal axis under stress, also has proinflammatory peripheral effects possibly through mast cells. We investigated the expression of CRH receptors and the effects of CRH in the human leukemic mast cell (HMC-1) line and human umbilical cord blood-derived mast cells. We detected mRNA for CRH-R1α, 1β, 1c, 1e, 1f isoforms, as well as CRH-R1 protein in both cell types. CRH-R2α (but not R2β or R2γ) mRNA and protein were present only in human cord blood-derived mast cells. CRH increased cAMP and induced secretion of vascular endothelial growth factor (VEGF) without tryptase, histamine, IL-6, IL-8, or TNF-α release. The effects were blocked by the CRH-R1 antagonist antalarmin, but not the CRH-R2 antagonist astressin 2B. CRH-stimulated VEGF production was mediated through activation of adenylate cyclase and increased cAMP, as evidenced by the fact that the effect of CRH was mimicked by the direct adenylate cyclase activator forskolin and the cell-permeable cAMP analog 8-bromo-cAMP, whereas it was abolished by the adenylate cyclase inhibitor SQ22536. This is the first evidence that mast cells express functional CRH receptors and that CRH can induce VEGF secretion selectively. CRH-induced mast cell-derived VEGF could, therefore, be involved in chronic inflammatory conditions associated with increased VEGF, such as arthritis or psoriasis, both of which worsen by stress.

Mast cells participate in allergies, and also in immunity and inflammation by secreting proinflammatory cytokines. Flavonoids are naturally occurring polyphenolic plant compounds, one group of which -- the flavonols, inhibits histamine and some cytokine release from rodent basophils and mast cells. However, the effect of flavonols on proinflammatory mediator release and their possible mechanism of action in human mast cells is not well defined. Human umbilical cord blood-derived cultured mast cells (hCBMCs) grown in the presence of stem cell factor (SCF) and interleukin (IL)-6 were preincubated for 15 min with the flavonols quercetin, kaempferol, myricetin and morin (0.01, 0.1, 1, 10 or 100 microM), followed by activation with anti-IgE. Secretion was quantitated for IL-6, IL-8, tumor necrosis factor-alpha (TNF-alpha), histamine and tryptase levels. Release of IL-6, IL-8 and TNF-alpha was inhibited by 82-93% at 100 microM quercetin and kaempferol, and 31-70% by myricetin and morin. Tryptase release was inhibited by 79-96% at 100 microM quercetin, kampferol and myricetin, but only 39% by morin; histamine release was inhibited 52-77% by the first three flavonols, but only 28% by morin. These flavonols suppressed intracellular calcium ion elevations in a dose-response manner, with morin being the weakest; they also inhibited phosphorylation of the calcium-insensitive protein kinase C theta (PKC theta). Flavonol inhibition of IgE-mediated proinflammatory mediator release from hCBMCs may be due to inhibition of intracellular calcium influx and PKC theta signaling. Flavonols may therefore be suitable for the treatment of allergic and inflammatory diseases.

Mast cells are critical in allergic and inflammatory diseases such as interstitial cystitis, which is often clinically associated with or mistaken as endometriosis. Mast cells had previously been reported to be increased at sites of endometriosis, and tryptase may contribute to the fibrosis and inflammation characterizing endometriosis.This is a pilot study of mast cell numbers and its activation in endometriosis biopsies (n = 10) by immunostaining for mast cell tryptase, corticotropin-releasing hormone (CRH) and urocortin (Ucn).This is the first report that tryptase positive mast cells were not only increased (64-157 mast cells/mm(2)) in human endometriosis, but also highly activated (89%) in areas strongly stained positive for CRH/Ucn. Normal endometrium was weakly positive for both CRH/Ucn.High numbers of activated mast cells are present in endometriosis sites that were strongly positive for CRH/Ucn. CRH and Ucn may activate mast cells and contribute to the fibrosis and inflammation in endometriosis.

Interleukin-17 (now known as IL-17A), is a homodimer of two 155 amino acid chains secreted by CD4+ activated memory T cells (CD45+ RO+) and is available as a glycosylated 20- to 30-kDa homodimeric peptide. Human IL-17 shows amino acid sequence identity of 62.5 and 58% to the mouse and rat sequences, respectively. IL-17 can regulate the function of a variety of cell types, plays an important role in the maturation of hematopoietic progenitor cells, and induces production of proinflammatory mediators. Here, for the first time, we summarize the biological effects of IL-17 and its family members as important players of T cell-mediated immune responses and underline the important implications of this cytokine in inflammation and degenerative diseases.