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At least 1,657 records · Page 92
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DOE OSTI2018

Serum levels of IL-17 are elevated in patients with acute gouty arthritis

Highlights: • We first identify IL-17 as a novel biomarker for acute gouty arthritis (AGA) with acute flares. • γδT cells, rather than Th17 cells, are the principal producers of IL-17 in AGA patients during the acute gout flares. • The serum levels of IL-17 are positively correlated with the activity of AGA and IL-1β. Acute gouty arthritis (AGA) is one of the most common forms of auto-inflammatory arthritis. IL-17 is a key proinflammatory cytokine which has been implicated in several autoimmune diseases. However, to date little is known about the role of IL-17 in AGA. In the present study, we show that serum IL-17 levels are significantly elevated in AGA patients early in the onset of symptoms of gout, and decrease gradually as symptoms diminish. Correlation analysis indicated that IL-17 expression is not only positively correlated with disease activity, but is also correlated with serum levels of IL-1β which plays a critical role in the differentiation of IL-17{sup -} γδT cells into IL-17{sup +}γδT cells. Flow cytometry analysis indicated that γδ T cells are a major source of IL-17 production during the early onset of AGA. We therefore identify IL-17 as a potential novel biomarker for AGA and suggest that targeting the γδ T cell/IL-17 immune axis is a potential strategy for treatment of acute flares of AGA.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Cyclosporin A inhibits adipogenic differentiation and regulates immunomodulatory functions of murine mesenchymal stem cells

Highlights: • CsA decreased BM-MSCs proliferation and increased cells apoptosis. • CsA inhibited BM-MSCs adipogenic differentiation. • CsA had no effect on the phenotype and osteogenic differentiation of BM-MSCs. • CsA inhibited BM-MSCs secreting IL-6 and promoted the expression of PD-L2. Aplastic anemia (AA) is generally considered as an immune-mediated bone marrow failure syndrome. Several studies show that bone marrow mesenchymal stem cells (BM-MSCs), as key cellular components of the bone marrow microenvironment, are also involved in the pathogenic mechanism of AA. Cyclosporin A (CsA) is a classic immunosuppressive drug for AA, and it specifically inhibits mammalian T cells by preventing activation of transcription factors involved in cytokine gene expression. However, little is known about the effect of CsA on the BM-MSCs. In this study, murine BM-MSCs were stimulated in the presence of CsA. Further, we found that CsA could inhibit murine BM-MSC proliferation and promote BM-MSC apoptosis, what's more CsA could inhibit adipogenic differentiation. Our study also showed that CsA could inhibit interleukin-6 expression in BM-MSCs, while promoting programmed death-ligand 2 expression. In conclusion, our results proposed that CsA may exert an effect on regulating the bone marrow environment by influencing BM-MSCs, which have a beneficial effect on treating AA.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

The suppressive effect of puerarin on atopic dermatitis-like skin lesions through regulation of inflammatory mediators in vitro and in vivo

Highlights: • Puerarin regulates inflammatory cytokine, such as IL-6, IL-5, and TNF-α in human keratinocyte cell line. • Puerarin attenuates inflammation related protein expression level in human keratinocyte cell line. • Puerarin improves DNCB-induced atopic skin condition by regulating of clinical signs and skin tissue injury. • Oral administration of puerarin recovers inflammatory cytokine secretion in DNCB-induced atopic dermatitis. Atopic dermatitis (AD) is one of the common inflammatory immune disorders. Puerarin is the main isoflavonoid obtained from the root of Pueraria lobata and has been known have ameliorative effects on diverse inflammatory diseases. However, the effects of puerarin on AD have not been uncovered. 2,4-dinitrochlorobenzene (DNCB) was used to induce atopic dermatitis(AD)-like skin lesions on BALB/c mice for 17 days. Further, the BALB/c mice were orally administered puerarin. Puerarin ameliorated DNCB-induced AD-like symptoms in the mice by regulating skin thickness, degranulation of mast cells, and serum immunoglobulin E (IgE). Human keratinocytes (HaCaT cells) were also used to clarify the effects of puerarin on the secretion of pro-inflammatory cytokines. Puerarin inhibited the secretion of inflammatory cytokines and chemokines. The aim of this study was to investigate the protective and alleviative effect of puerarin on AD in vitro and in vivo. The results in this study indicated that puerarin ameliorates AD-like skin lesion and skin inflammation via regulation of various atopic and inflammatory mediators. Therefore, puerarin might be useful in treating AD and other skin diseases.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Guanine and inosine nucleotides/nucleosides suppress murine T cell activation

Highlights: • We investigated T-cell activation by guanine and inosine nucleotides/nucleosides. • They dose-dependently suppressed IL-2 production via T-cell receptor stimulation. • GTP, ITP, guanosine and inosine suppressed ConA-induced IL-2/IL-6 production. • They did not affect CD25 expression or ERK1/2 activation during T cell activation. • These nucleotides/nucleosides are candidate agents to treat inflammatory diseases. Damaged tissues and cells release intracellular purine nucleotides, which serve as intercellular signaling factors. We previously showed that exogenously added adenine nucleotide (250 μM ATP) suppressed the activation of murine splenic T lymphocytes. Here, we examined the effects of other purine nucleotides/nucleosides on mouse T cell activation. First, we found that pretreatment of mouse spleen T cells with 250 μM GTP, GDP, GMP, guanosine, ITP, IDP, IMP or inosine significantly reduced the release of stimulus-inducible cytokine IL-2. This suppression of IL-2 release was not caused by induction of cell death. Further studies with GTP, ITP, guanosine and inosine showed that pretreatment with these nucleotides/nucleosides also suppressed release of IL-6. However, these nucleotides/nucleosides did not suppress stimulus-induced phosphorylation of ERK1/2, suggesting that the suppression of the release of inflammatory cytokines does not involve inhibition of ERK1/2 signaling. In contrast to ATP pretreatment at the same concentration, guanine or inosine nucleotides/nucleosides did not attenuate the expression of CD25. Our findings indicate that exogenous guanine or inosine nucleotides/nucleosides can suppress inflammatory cytokine release from T cells, and may be promising candidates for use as supplementary agents in the treatment of T cell-mediated immune diseases.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Adipose-derived stem cells ameliorate colitis by suppression of inflammasome formation and regulation of M1-macrophage population through prostaglandin E2

Highlights: • PGE2 was remarkably increased in conditioned media from THP-1 co-cultured with ASCs. • ASCs induced M1 to M2 macrophage transition through PGE2. • ASCs suppressed secretion of inflammatory IL-1β and IL-18 through PGE2. • ASCs ameliorated colitis by decreasing the total number of macrophages. • ASCs relieved inflammation by decreasing the M1 macrophage population. Inflammatory bowel disease (IBD) is an idiopathic disease caused by a dysregulated immune response to intestinal microbes in an individual with a genetic predisposition. Therefore, alleviation of inflammation is very important to treat IBD. Mesenchymal stem cells (MSCs) have been highlighted as new candidates for treating autoimmune disease based on their immunomodulatory properties. In this study, we investigated the anti-inflammatory mechanism and therapeutic effects of adipose tissue-derived MSCs (ASCs) using THP-1 macrophages and dextran sodium sulfate (DSS)-induced mice with chronic colitis. LPS-treated THP-1 cells expressed mRNA of CD11b, an M1 macrophage marker, at day 2. However, THP-1 co-cultured with ASCs expressed mRNA of CD206, CD68, CCL18, legumain, and IL-10, markers of M2 macrophages. In THP-1 cells co-cultured with ASCs, precursor (pro)-IL-1β, Cox-2, and NLRP3 increased dramatically compared to LPS-treated THP-1 cells. Secretion of IL-1β and IL-18 was significantly inhibited by ASCs, but PGE2 production was highly increased in co-culture conditions of THP-1 and ASCs. IL-18 secretion was inhibited by PGE2 treatment, and PGE2 inhibited inflammasome complex (ASC/Cas-1/NLRP3) formation in THP-1 cells. In the DSS-induced chronic colitis model, ASCs ameliorated colitis by decreasing the total number of macrophages and the M1 macrophage population. Our results suggest that ASCs can suppress the inflammatory response by controlling the macrophage population, and ASCs may be therapeutically useful for the treatment of IBD.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Enterococcus faecalis lipoteichoic acid regulates macrophages autophagy via PI3K/Akt/mTOR pathway

Highlights: • We established RAW264.7 expressing mRFP-GFP-LC3 to observe autophagy. • Our data shown Enterococcus faecalis LTA activates macrophage autophagy via PI3K/Akt/mTOR pathway. • Beclin1 is necessary in LTA-stimulated autophagy of macrophage. Enterococcus faecalis (E. faecalis) infection is considered an important etiological factor for the development of persistent apical periodontitis (PAP), but the exact mechanisms of autophagy between E. faecalis and immune cells remain unknown. In this study, we elucidated how E. faecalis lipoteichoic acid (LTA) is associated with macrophages autophagy. We found that E. faecalis LTA apparently activated macrophage autophagy with significant increase of autophagosomes and autophagy relative protein. Meanwhile, we noticed significantly decreasing expression of p-Akt and p-mTOR. However, these effect were absent in macrophages knockdown of Beclin1. In summary, these findings suggested E. faecalis LTA may increased macrophages autophagy via inhibiting PI3K/Akt/mTOR pathway and this process was Beclin1 dependent.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

TGF beta inhibits expression of SP-A, SP-B, SP-C, but not SP-D in human alveolar type II cells

Highlights: • TGF beta inhibits expression of SP-A, SP-B, SP-C, Fatty acid synthase, and ABCA3. • TGF beta does not inhibit the expression of SP-D. • TGF beta does not induce EMT changes in highly differentiated type II cells. TGF beta is a multifunctional cytokine that regulates alveolar epithelial cells as well as immune cells and fibroblasts. TGF beta inhibits surfactant protein A, B and C expression in fetal human lung and can inhibit type II cell proliferation induced by FGF7 (KGF). However, little is known about direct effects of TGF beta on adult human type II cells. We cultured alveolar type II cells under air/liquid interface conditions to maintain their state of differentiation with or without TGF beta. TGF beta markedly decreased expression of SP-A, SP-B, SP-C, fatty acid synthase, and the phospholipid transporter ABCA3. However, TGF beta increased protein levels of SP-D with little change in mRNA levels, indicating that it is regulated independently from other components of surfactant. TGF beta is a negative regulator of both the protein and the phospholipid components of surfactant. TGF beta did not induce EMT changes in highly differentiated human type II cells. SP-D is an important host defense molecule and regulated independently from the other surfactant proteins. Taken together these data are the first report of the effect of TGF beta on highly differentiated adult human type II cells. The effects on the surfactant system are likely important in the development of fibrotic lung diseases.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Interleukin-enhanced binding factor 2 interacts with NLRP3 to inhibit the NLRP3 inflammasome activation

Highlights: • The NLRP3 inflammasome activation is attenuated by PSMD10, BCL2L10, CTSS, and ILF2. • ILF2 represses inflammasome activation, pro-Casp-1 cleavege, and pro-IL-1β maturation. • ILF2 interacts with NLRP3 to inhibit the inflammasome activation in the cytoplasm. • ILF2 represses ATP-induced activation of endogenous NLRP3 inflammasome in macrophages. The activation of the NLRP3 inflammasome is a key process of host immune response that establishes the first line of defense against pathogen infections and cellular stresses, whereas excessive inflammasome activation may damage the hosts, and thus it must be precisely controlled. However, the mechanism underlying the repression of the NLRP3 inflammasome activation remains largely unknown. In this study, by establishing and using a reconstructed NLRP3 inflammasome activation system, we reveal that the NLRP3 inflammasome activation, pro-caspase-1 cleavage, and pro-interleukin-1β (pro-IL-1β) activation are repressed by the interleukin-enhanced binding factor 2 (ILF2). Further studies demonstrate that ILF2 represses the activation of NLRP3 inflammasome through interacting with the NACHT-associated domain (NAD) of NLRP3 and co-localized with NLRP3 in the cytoplasm of HEK293T cells. Finally, by generating a THP-1 cell line stably expressing ILF2 protein using the lentivirus infection system, we demonstrate that ILF2 represses ATP-induced activation of endogenous NLRP3 inflammasome in macrophages. Therefore, this study identifies a new role of ILF2 in the regulation of the NLRP3 inflammasome, and reveals a unique mechanism underlying the repression of the NLRP3 inflammasome activation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Intracellular calcium is a rheostat for the STING signaling pathway

Highlights: • BAPTA-AM treatment inhibits the STING translocation and its downstream signaling. • Ionomycin treatment suppresses the STING translocation and signaling through the influx of extracellular calcium. • Knockout of DRP1, the mitochondrial fission mediator, hinders the ionomycin-mediated inhibition of STING activity. • DRP1 regulates ionomycin-induced elevation of intracellular calcium levels. Stimulator of IFN genes (STING) is essential for the DNA-sensing innate immune pathway. Recently, evidence is emerging that suggests STING also plays important roles in autoimmunity, cancer therapy, and senescence. Although a multitude of post-translational modifications that regulate the STING pathway have been discovered, the cellular events that guide STING translocation remain unclear. Here, we show, paradoxically, that both BAPTA-AM-mediated calcium depletion and ionomycin-induced calcium elevation suppress STING translocation and STING-mediated IFN-β production. We demonstrate that the mitochondria fission mediator DRP1 is crucial for ionomycin-induced inhibition of IFN-β production. Furthermore, knockout of DRP1 suppressed ionomycin-induced increases in calcium as well as mitochondrial fragmentation. Collectively, our findings reveal that the induction of STING signaling is contingent on a fine-tuning of intracellular calcium levels.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Uncovering transcription factor and microRNA risk regulatory pathways associated with osteoarthritis by network analysis

Osteoarthritis (OA) is the most common form of joint disease. The development of inflammation have been considered to play a key role during the progression of OA. Regulatory pathways are known to play crucial roles in many pathogenic processes. Thus, deciphering these risk regulatory pathways is critical for elucidating the mechanisms underlying OA. We constructed an OA-specific regulatory network by integrating comprehensive curated transcription and post-transcriptional resource involving transcription factor (TF) and microRNA (miRNA). To deepen our understanding of underlying molecular mechanisms of OA, we developed an integrated systems approach to identify OA-specific risk regulatory pathways. In this study, we identified 89 significantly differentially expressed genes between normal and inflamed areas of OA patients. We found the OA-specific regulatory network was a standard scale-free network with small-world properties. It significant enriched many immune response-related functions including leukocyte differentiation, myeloid differentiation and T cell activation. Finally, 141 risk regulatory pathways were identified based on OA-specific regulatory network, which contains some known regulator of OA. The risk regulatory pathways may provide clues for the etiology of OA and be a potential resource for the discovery of novel OA-associated disease genes.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

ALK is required for NLRP3 inflammasome activation in macrophages

Highlights: • ALK promotes LPS-induced NLRP3 priming. • ALK promotes ATP-induced NLRP3 activation. • ALK promotes NLRP3-NEK7 complex formation. • ALK-mediated lipid peroxidation promotes NLRP3 activation. The NLRP3 inflammasome is a key mediator of host immune responses through the induction of pyroptosis and the release of cytokines. Although the pathologic role of inflammasome in infection and sterile inflammation is well known, the mechanism and regulation of NLRP3 inflammasome activation remains obscure. Here, we report that anaplastic lymphoma kinase (ALK) is a novel regulator of NLRP3 inflammasome activation in macrophages. Pharmacologic or genetic inhibition of ALK through targeted drugs (ceritinib and lorlatinib) or RNAi blocked extracellular ATP-induced NLRP3 inflammasome activation in macrophages. Mechanically, ALK-mediated NF-κB activation was required for the priming step of NLRP3 upregulation, whereas ALK-mediated lipid peroxidation contributed to the sensing step of NLRP3-NEK7 complex formation. These studies indicate that inhibition of ALK could be utilized to treat NLRP3-related inflammatory diseases.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Neutralization of Pseudomonas auruginosa Exotoxin A by human neutrophil peptide 1

Highlights: • Human Neutrophil Peptide 1 directly binds and neutralizes Exotoxin A of Pseudomonas aeruginosa. • The molecular determinants of binding of HNP-1 to the toxin are surface-exposed. • These findings allows for the design of more potent anti-toxin peptides. Pseudomonas aeruginosa produces a large number of virulence factors, including the extracellular protein, Exotoxin A (ETA). Human Neutrophil Peptide 1 (HNP1) neutralizes the Exotoxin A. HNP1 belongs to the family of α-defensins, small effector peptides of the innate immune system that combat against microbial infections. Neutralization of bacterial toxins such as ETA by HNP1 is a novel biological function in addition to direct killing of bacteria. In this study, we report on the interaction between HNP-1 and Exotoxin A at the molecular level to allow for the design and development of potent antibacterial peptides as alternatives to classical antibiotics.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Bisphenol A-elicited miR-146a-5p impairs murine testicular steroidogenesis through negative regulation of Mta3 signaling

The epigenetic effects on expression of non-coding RNAs (e.g. microRNAs) of environmental toxin bisphenol A (BPA) have extended our understanding of the etiology of human reproductive disorders including hypospermatogenesis and androgen deficiency. BPA-induced miR-146a-5p is a potent regulator of endocrine and immune homeostasis, but its role in testis remain unexplored. We show here that in murine testis, miR-146a-5p was exclusively expressed in interstitial Leydig cells (LCs). This expression was significantly induced by BPA exposure. Consequently, the elevated miR-146a-5p exacerbated the deleterious effects of BPA on testicular steroidogenesis. Mechanistically, miR-146a-5p repressed the expression of Mta3, a pivotal chromatin remodeling transcription factor recently involved in controlling the steroidogenic activity, via directly targeting its 3′UTR. This repression thereafter rendered LCs more sensitive to BPA-elicited inhibitory effects. Conversely, ectopic expression of hMTA3 successfully rescued miR-146a-5p-elicited inhibitory effects on testicular steroidogenesis in BPA-challenged LCs. Taken together, the available data provide novel evidence that deregulation of testicular miR-146a-5p/Mta3 cascade mediates, at least in part, the steroidogenic dysfunction caused by BPA exposure.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Identification and characterization of the zinc finger protein SjZF in Schistosoma japonicum

Highlights: • The zinc finger protein SjZF in S. japonicum was identified and characterized. • SjZF was mainly located in the intestinal tract of adult worms and the vitelline glands of females. • The rSjZF induced significant protection against S. japonicum infection in mouse. Schistosomiasis represents one of the most prevalent parasitic infections affecting over 249 million people worldwide. The pathological damage is mainly caused by the eggs laid by female schistosomes. Zinc finger proteins (ZFPs) usually play critical roles in many biological functions. In this study, we cloned, identified and characterized the zinc finger protein SjZF of Schistosoma japonicum. SjZF ortholog proteins were also identified in S. mansoni, S. haematobium, Opisthorchis viverrini and O. sinensis. Fluorescence localization showed that SjZF was particularly expressed in the worm gut of both genders and the vitelline glands of females. In vitro RNAi assay indicated that decreased expression of SjZF could affect the survival rate of adult worms. The immune protection assay indicated that rSjZF did partially protect mice with 54.8% reduction in the worm burden and 34.1% reduction in the liver eggs. Taken in concert, our preliminary results suggest that SjZF may be a potential vaccine candidate for schistosomiasis and may further provide evidence for a possible role of SjZF in the development of schistosomes.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Amelioration of UVB-induced oxidative stress and inflammation in fat-1 transgenic mouse skin

ω-3 polyunsaturated fatty acids (PUFAs), which are abundant in fish oils, are known to scavenge lipid peroxyl radicals and potentiate host immune defence. As UVB-induced oxidative stress and inflammation have been implicated in apoptotic cell death, this study was aimed to investigate the anti-inflammatory, anti-oxidative, and anti-apoptotic capacity of fat-1 transgenic mice capable of converting ω-6 to ω-3 PUFAs. Wild-type (WT) C57BL/6 mice and fat-1 mice were maintained on the AIN-93 diet supplemented with 10% safflower oil rich in ω-6 PUFAs for 5 weeks. The ω-3/ω-6 PUFA ratio was significantly higher in the dorsal skin of fat-1 mice than that in the WT mice. Upon single exposure to UVB (5.0 kJ/m{sup 2}) radiation, fat-1 mice showed inflammatory as well as oxidative tissue damage and the expression of pro-inflammatory enzymes, cyclooxygenases-2 and inducible nitric oxide synthase in the skin to a much lesser extent than the WT mice. The protection of fat-1 mice from UVB-induced skin inflammation was associated with decreased phosphorylation of STAT3. Moreover, UVB-induced apoptosis was attenuated in fat-1 mouse skin. In comparison to WT animals, higher levels of Nrf2 and its target proteins, such as heme oxygenase-1, NAD(P)H:quinone oxidoreductase-1 and thioredoxin-1, were found in the skin of fat-1 mice.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

MiR-616-3p promotes angiogenesis and EMT in gastric cancer via the PTEN/AKT/mTOR pathway

Highlights: • 1, miR-616-3p was up-regulated in GC cell lines and tissues, indicating a poor prognosis. • 2, miR-616-3p promoted angiogenesis and EMT in vitro. • 3, miR-616-3p exerted its biological function might through AKT/mTOR pathway by targeting PTEN. • 4, miR-616-3p might be a potential therapeutic target in GC. Dysregulation of microRNAs has been demonstrated to be involved in a variety of biological events related to cancer, including proliferation, metastasis, angiogenesis and immune escape. MiR-616-3p is located on the chromosome region 12q13.3, however, its potential role and clinical implications in gastric cancer remain poorly understood. The current study aimed to investigate the potential role of miR-616-3p in gastric cancer. The results showed that miR-616-3p was up-regulated in cancer tissues. Higher expression of miR-616-3p in tumor tissues also predicted poor prognosis. Furthermore, loss- and gain-of-function in vitro revealed that miR-616-3p promoted angiogenesis and EMT in gastric cancer cells. Mechanistically, further analysis demonstrated that the effects of miR-616-3p on metastasis and angiogenesis occurred through the down-regulation of PTEN, a direct target of miR-616-3p. We propose that the restoration of PTEN expression may block miR-616-3p-induced EMT and angiogenesis. Collectively, our findings suggest that the miR-616-3p-PTEN signaling axis might be a potential therapeutic target for gastric cancer.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Quercetin inhibits the poly(dA:dT)-induced secretion of IL-18 via down-regulation of the expressions of AIM2 and pro-caspase-1 by inhibiting the JAK2/STAT1 pathway in IFN-γ-primed human keratinocytes

Highlights: • Pre-treatment with Quercetin inhibited poly(dA:dT)-induced IL-18 secretion in IFN-γ-primed keratinocytes. • Pre-treatment with Quercetin inhibited expression of AIM2 and pro-caspase-1 in poly(dA:dT)-treated and IFN-γ–primed keratinocytes. • Pre-treatment with Quercetin inhibited the JAK2/STAT1 pathway in poly(dA:dT)-treated and IFN-γ–primed keratinocytes. Quercetin, a polyphenol, belongs to a class of flavonoids that exerts anti-inflammatory effects. Interleukin (IL)-18 is a member of the IL-1 family cytokine that regulates immune responses and is implicated in various inflammatory skin diseases. Absent in melanoma 2 (AIM2) is a cytosolic double-stranded (ds) DNA sensor that recognizes the dsDNA of a microbial or host origin. Binding of dsDNA to AIM2 simulates caspase-1-dependent inflammasome activity, which leads to the production of IL-1β and IL-18. Increased levels of AIM2 have been observed in patients with inflammatory skin diseases. In the current study, we investigated the issue of whether or how Quercetin attenuates poly (dA:dT), a synthetic analog of microbial dsDNA, -induced IL-18 secretion in IFN-γ-primed human keratinocytes. Treatment with 5 and 10 μM of Quercetin inhibited the poly (dA:dT)-induced secretion of IL-18 after IFN-γ priming and before poly (dA:dT)-induced AIM2 activation. In addition, treatment with Quercetin at 10 μM, significantly inhibited the phosphorylation of JAK2 and STAT1, and the nuclear translocation of phosphorylated STAT1 in poly (dA:dT)-treated and IFN-γ-primed keratinocytes. These results suggest that treatment with Quercetin inhibits the poly (dA:dT)-induced secretion of IL-18 via down-regulation of the expressions of AIM2 and pro-caspase-1 by inhibiting the JAK2/STAT1 pathway in IFN-γ-primed keratinocytes.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Profiling of bioactive lipids in different dendritic cell subsets using an improved multiplex quantitative LC-MS/MS method

Highlights: • We improved a LC-MS/MS method to measure many mediators simultaneously. • Conventional DCs produce inflammatory lipids (leukotrienes) preferentially. • RA-DCs produce PGI{sub 2}, PGE{sub 2}, and TXA{sub 2} preferentially. Lipids are an energy source and key components of the cell membrane; however, they are also bioactive mediators of physiological and pathophysiological phenomena. Quantification of bioactive lipids is not easy because they have diverse chemical properties and are present in trace amounts. Here, we improved a multiplex method of quantifying bioactive lipids, thereby enabling measurement of 90 compounds simultaneously. We then used this system to quantify bioactive lipids produced by two subsets of dendritic cells (DCs): all-trans retinoic acid-treated DCs (RA-DCs) (a type of tolerogenic DC (tDC)) and conventional DCs (cDCs). We found that cDCs produced inflammatory lipid mediators such as leukotrienes, whereas RA-DCs produced anti-inflammatory lipid mediators such as prostaglandin I{sub 2}. Consistent with this, cDCs expressed larger amounts of mRNA encoding 5-lipoxygenase and LTA{sub 4} hydrolase (both responsible for leukotriene biosynthesis) and RA-DCs produced larger amounts of mRNA encoding prostaglandin I{sub 2} synthase. Taken together, the results suggest that the method is useful for clarifying the roles of bioactive lipids during immune responses.

60 APPLIED LIFE SCIENCES↗