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The N-degron pathway is a proteolytic system in which the N-terminal degrons (N-degrons) of proteins, such as arginine (Nt-Arg), induce the degradation of proteins and subcellular organelles via the ubiquitin-proteasome system (UPS) or macroautophagy/autophagy-lysosome system (hereafter autophagy). Here, we developed the chemical mimics of the N-degron Nt-Arg as a pharmaceutical means to induce targeted degradation of intracellular bacteria via autophagy, such as Salmonella enterica serovar Typhimurium (S. Typhimurium), Escherichia coli, and Streptococcus pyogenes as well as Mycobacterium tuberculosis (Mtb). Upon binding the ZZ domain of the autophagic cargo receptor SQSTM1/p62 (sequestosome 1), these chemicals induced the biogenesis and recruitment of autophagic membranes to intracellular bacteria via SQSTM1, leading to lysosomal degradation. The antimicrobial efficacy was independent of rapamycin-modulated core autophagic pathways and synergistic with the reduced production of inflammatory cytokines. In mice, these drugs exhibited antimicrobial efficacy for S. Typhimurium, Bacillus Calmette–Guérin (BCG), and Mtb as well as multidrug-resistant Mtb and inhibited the production of inflammatory cytokines. This dual mode of action in xenophagy and inflammation significantly protected mice from inflammatory lesions in the lungs and other tissues caused by all the tested bacterial strains. Our results suggest that the N-degron pathway provides a therapeutic target in host-directed therapeutics for a broad range of drug-resistant intracellular pathogens. Abbreviations: ATG: autophagy-related gene; BCG: Bacillus Calmette–Guérin; BMDMs: bone marrow-derived macrophages; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; CFUs: colony-forming units; CXCL: C-X-C motif chemokine ligand; EGFP: enhanced green fluorescent protein; IL1B/IL-1β: interleukin 1 beta; IL6: interleukin 6; LIR: MAP1LC3/LC3-interacting region; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; Mtb: Mycobacterium tuberculosis; MTOR: mechanistic target of rapamycin kinase; NBR1: NBR1 autophagy cargo receptor; OPTN: optineurin; PB1: Phox and Bem1; SQSTM1/p62: sequestosome 1; S. Typhimurium: Salmonella enterica serovar Typhimurium; TAX1BP1: Tax1 binding protein 1; TNF: tumor necrosis factor; UBA: ubiquitin-associated.

In the N-degron pathway, N-recognins recognize cognate substrates for degradation via the ubiquitin (Ub)-proteasome system (UPS) or the autophagy-lysosome system (hereafter autophagy). We have recently shown that the autophagy receptor SQSTM1/p62 (sequestosome 1) is an N-recognin that binds the N-terminal arginine (Nt-Arg) as an N-degron to modulate autophagic proteolysis. Here, we show that the N-degron pathway mediates pexophagy, in which damaged peroxisomal fragments are degraded by autophagy under normal and oxidative stress conditions. This degradative process initiates when the Nt-Cys of ACAD10 (acyl-CoA dehydrogenase family, member 10), a receptor in pexophagy, is oxidized into Cys sulfinic (CysO2) or sulfonic acid (CysO3) by ADO (2-aminoethanethiol (cysteamine) dioxygenase). Under oxidative stress, the Nt-Cys of ACAD10 is chemically oxidized by reactive oxygen species (ROS). The oxidized Nt-Cys2 is arginylated by ATE1-encoded R-transferases, generating the RCOX N-degron. RCOX-ACAD10 marks the site of pexophagy via the interaction with PEX5 and binds the ZZ domain of SQSTM1/p62, recruiting LC3+-autophagic membranes. In mice, knockout of either Ate1 responsible for Nt-arginylation or Sqstm1/p62 leads to increased levels of peroxisomes. In the cells from patients with peroxisome biogenesis disorders (PBDs), characterized by peroxisomal loss due to uncontrolled pexophagy, inhibition of either ATE1 or SQSTM1/p62 was sufficient to recover the level of peroxisomes. Our results demonstrate that the Cys-N-degron pathway generates an N-degron that regulates the removal of damaged peroxisomal membranes along with their contents. We suggest that tannic acid, a commercially available drug on the market, has a potential to treat PBDs through its activity to inhibit ATE1 R-transferases. Abbreviations: ACAA1, acetyl-Coenzyme A acyltransferase 1; ACAD, acyl-Coenzyme A dehydrogenase; ADO, 2-aminoethanethiol (cysteamine) dioxygenase; ATE1, arginyltransferase 1; CDO1, cysteine dioxygenase type 1; ER, endoplasmic reticulum; LIR, LC3-interacting region; MOXD1, monooxygenase, DBH-like 1; NAC, N-acetyl-cysteine; Nt-Arg, N-terminal arginine; Nt-Cys, N-terminal cysteine; PB1, Phox and Bem1p; PBD, peroxisome biogenesis disorder; PCO, plant cysteine oxidase; PDI, protein disulfide isomerase; PTS, peroxisomal targeting signal; R-COX, Nt-Arg-CysOX; RNS, reactive nitrogen species; ROS, reactive oxygen species; SNP, sodium nitroprusside; UBA, ubiquitin-associated; UPS, ubiquitinproteasome system.

Background Triggering receptor expressed on myeloid cells 2 (TREM2) signaling is considered to regulate anti-inflammatory responses in macrophages, dendritic cell maturation, osteoclast development, induction of obesity, and Alzheimer’s disease pathogenesis. However, little is known regarding the effect of TREM2 on natural killer (NK) cells. Results Here, we demonstrated for the first time that CD3−CD122+NK1.1+ precursor NK (pNK) cells expressed TREM2 and their population increased in TREM2-overexpressing transgenic (TREM2-TG) mice compared with that in female C57BL/6 J wild type (WT) mice. Both NK cell-activating receptors and NK cell-associated genes were expressed at higher levels in various tissues of TREM2-TG mice than in WT mice. In addition, bone marrow-derived hematopoietic stem cells (HSCs) of TREM2-TG mice (TG-HSCs) successfully differentiated into NK cells in vitro, with a higher yield from TG-HSCs than from WT-HSCs. In contrast, TREM2 signaling inhibition by TREM2-Ig or a phosphatidylinositol 3-kinase (PI3K) inhibitor affected the expression of the NK cell receptor repertoire and decreased the expression levels of NK cell-associated genes, resulting in significant impairment of NK cell differentiation. Moreover, in melanoma-bearing WT mice, injection of bone marrow cells from TREM2-TG mice exerted greater antitumor effects than that with cells from WT control mice. Conclusions Collectively, our data clearly showed that TREM2 promoted NK cell development and tumor regression, suggesting TREM2 as a new candidate for cancer immunotherapy.

Triggering receptor expressed on myeloid cells 2 (TREM2) is a cell surface receptor expressed on macrophages, microglial cells, and pre-osteoclasts, and that participates in diverse cellular function, including inflammation, bone homeostasis, neurological development, and coagulation. In spite of the indispensable role of the TREM2 protein in the maintenance of immune homeostasis and osteoclast differentiation, the exact ligand for TREM2 has not yet been identified. Here, we report a putative TREM2 ligand which is secreted from MC38 cells and identified as a cyclophilin A (CypA). A specific interaction between CypA and TREM2 was shown at both protein and cellular levels. Exogenous CypA specifically interacted and co-localized with TREM2 in RAW264.7 cells, and the physical interactions were shown to regulate TREM2 signaling transduction. The Pro144 residue in the extracellular domain of TREM2 was found to be the specific binding site of CypA. When considered together, this provides evidence that CypA interacts specifically with TREM2 as a potent ligand.

Background: Triggering receptor expressed on myeloid cells 2 (TREM2) signaling is considered to regulate anti-inflammatory responses in macrophages, dendritic cell maturation, osteoclast development, induction of obesity, and Alzheimer’s disease pathogenesis. However, little is known regarding the effect of TREM2 on natural killer (NK) cells.Results: Here, we demonstrated for the first time that CD3-CD122+NK1.1+ precursor NK (pNK) cells expressed TREM2 and their population increased in TREM2-overexpressing transgenic (TREM2-TG) mice compared with that in female C57BL/6J wild type (WT) mice. Both NK cell-activating receptors and NK cell-associated genes were expressed at higher levels in various tissues of TREM2-TG mice than in WT mice. In addition, bone marrow-derived hematopoietic stem cells (HSCs) of TREM2-TG mice (TG-HSCs) successfully differentiated into NK cells in vitro, with a higher yield from TG-HSCs than from WT-HSCs. In contrast, TREM2 signaling inhibition by TREM2-Ig or a phosphatidylinositol 3-kinase (PI3K) inhibitor affected the expression of the NK cell receptor repertoire and decreased the expression levels of NK cell-associated genes, resulting in significant impairment of NK cell differentiation. Moreover, in melanoma-bearing WT mice, injection of bone marrow cells from TREM2-TG mice exerted greater antitumor effects than that with cells from WT control mice.Conclusions: Collectively, our data clearly showed that TREM2 promoted NK cell development and tumor regression, suggesting TREM2 as a new candidate for cancer immunotherapy.

TREM2 (triggering receptor expressed on myeloid cells) is involved in the development of malignancies. However, the function of TREM2 in colorectal cancer has not been clearly elucidated. Here, we investigated TREM2 function for the first time in colorectal epithelial cancer cells and demonstrated that TREM2 is a novel tumor suppressor in colorectal carcinoma. Blockade of TREM2 significantly promoted the proliferation of HT29 colorectal carcinoma cells by regulating cell cycle-related factors, such as p53 phosphorylation and p21 and cyclin D1 protein levels. HT29 cell migration was also increased by TREM2 inhibition via MMP9 (matrix metalloproteinase 9) expression upregulation. Furthermore, we found that the tumor suppressor effects of TREM2 were associated with Wnt/&beta, catenin and extracellular signal-regulated kinase (ERK) signaling. Importantly, the effect of TREM2 in the suppression of tumor development was demonstrated by in vivo and in vitro assays, as well as in human colon cancer patient tissue arrays. Overall, our results identify TREM2 as a potential prognostic biomarker and therapeutic target for colorectal cancer.

Natural killer (NK) cells have been well known to play a critical role in innate immunity, but they are also capable of regulating adaptive immunity through the induction of T cell-mediated memory response and B cell-mediated autoimmune response. NK cells are differentiated from hematopoietic stem cells (HSCs) in the bone marrow (BM), and a series of surface molecules are expressed on NK cells in a differentiation stage-specific manner. Axl receptor tyrosine kinase is originally identified as homeostatic regulators for antigen-presenting cells, and its ligand, growth-arrest-specific gene 6 (Gas6), has been reported to promote cell survival, proliferation, and migration, but their regulatory role in the development and effector function of NK cells is not yet fully understood. In this study, to investigate whether Axl is required for the regulation of NK cell development, the expression of mature NK (mNK) cell-specific receptors and NK cell-associated genes was analyzed in the differentiated HSCs-derived NK cells in vitro and the NK cells harvested from Axl-/- mice. We found that agonistic anti-Axl antibody or recombinant Gas6 specifically upregulated the expression of mNK cell-specific receptors, such as LY49A, Ly49G2, Ly49C/F/I, NKG2A/C/E (1.5- to 3.5-fold increase), and NK cell-associated genes, such as IL-2Rβ (2.3- or 2.4-fold increase), Perforin (4.1- or 2.1-fold increase), IL-15Rα (2.14- or 2.04-fold increase), and IFN-γ (3.3- or 2.8-fold increase) compared to each isotype control, whereas it was abrogated by treatment of Axl-Ig. Anti-Axl antibody or rGas6 also induced a 2.5- or 1.9-fold increase in the proliferation of developing NK cells compared to each control, respectively. mNK cell populations expressing mNK cell-specific receptors were reduced about twofold in NK cells differentiated from HSCs of Axl-/- mice compared with those of wild-type mice. Furthermore, the triggering of Axl signaling by agonistic anti-Axl antibody promoted the cytolytic activity (1.5- to 1.9-fold increase) against target tumor cells. In B16F10 melanoma-bearing mice, the number of metastatic colonies was decreased by 83 % by the administration of mNK cells treated with anti-Axl antibody compared to control Ig. These data suggest that Axl plays an essential role in the regulation of NK cell development as well as NK effector function.

The effects of daucosterol have been identified in cancer therapy and neuronal diseases. However, the regulatory function of daucosterol in DSS-induced colitis has not yet been investigated. In this study, we evaluated the immunological and therapeutic effects of daucosterol in a mouse model of dextran sulfate sodium (DSS)-induced colitis. Unlike vehicle mice, mice pre- or post-treated with daucosterol showed inhibition of body weight loss and the decrease in the disease activity index (DAI). In addition, daucosterol treatment rescued the DSS-induced decrease in colon length and disruption of the epithelial lining. Furthermore, it reduced DSS-induced production of reactive oxygen species (ROS), infiltration of macrophages, and expression of pro-inflammatory cytokines such as TNF-α, IL-6, and IL-1β. Mice with colitis showed a decreased population of Foxp3+ cells, which was upregulated by daucosterol treatment. Furthermore, daucosterol increased natural killer (NK) cell activity and inhibited excessive IgA levels in mice with DSS-induced colitis. Collectively, our findings demonstrated that daucosterol significantly alleviated DSS-induced colitis, indicating the possibility of daucosterol as a therapeutic option for colitis.

BiP and other endoplasmic reticulum (ER)-resident proteins are thought to be metabolically stable and to function primarily in the ER lumen. We sought to assess how the abundance of these proteins dynamically fluctuates in response to various stresses and how their subpopulations are relocated to non-ER compartments such as the cytosol. We showed that the molecular chaperone BiP (also known as GRP78) was short-lived under basal conditions and ER stress. The turnover of BiP was in part driven by its amino-terminal arginylation (Nt-arginylation) by the arginyltransferase ATE1, which generated an autophagic N-degron of the N-end rule pathway. ER stress elicited the formation of R-BiP, an effect that was increased when the proteasome was also inhibited. Nt-arginylation correlated with the cytosolic relocalization of BiP under the types of stress tested. The cytosolic relocalization of BiP did not require the functionality of the unfolded protein response or the Sec61- or Derlin1-containing translocon. A key inhibitor of the turnover and Nt-arginylation of BiP was HERP (homocysteine-responsive ER protein), a 43-kDa ER membrane-integrated protein that is an essential component of ER-associated protein degradation. Pharmacological inhibition of the ER-Golgi secretory pathway also suppressed R-BiP formation. Finally, we showed that cytosolic R-BiP induced by ER stress and proteasomal inhibition was routed to autophagic vacuoles and possibly additional metabolic fates. These results suggest that Nt-arginylation is a posttranslational modification that modulates the function, localization, and metabolic fate of ER-resident proteins.

TREM2 plays a critical role in the alleviation of Alzheimer’s disease by promoting Aβ phagocytosis by microglia, but the detailed molecular mechanism underlying TREM2-induced direct phagocytic activity of Aβ remains to be revealed. We found that learning and memory functions were improved in aged TREM2 TG mice, with the opposite effects in KO mice. The amount of phagocytosed Aβ was significantly reduced in the primary microglia of KO mice. CD36 expression in primary microglia was greater in TG than in WT mice but was substantially decreased in KO mice. The expression of C/EBPα, an upstream transcriptional activator of CD36, was also elevated in primary microglia of TG mice but decreased in KO mice. The transcription of CD36 was markedly increased by TREM2 overexpression, and this effect was suppressed by a mutation of the C/EBPα binding site on the CD36 promoter. The TREM2-induced expression of CD36 and C/EBPα was inhibited by treatment with PI3K/AKT signaling blockers, and phosphorylation of AKT was elevated in TREM2-overexpressing BV2 cells. The present study provides evidence that TREM2 is required for preventing loss of memory and learning in Alzheimer’s disease by regulating C/EBPα-dependent CD36 expression and the consequent Aβ phagocytosis.

Enalapril and nifedipine are used as antihypertensive drugs; however, the therapeutic target molecules regulated by enalapril and nifedipine have yet to be fully identified. The aim of this study was to identify novel target genes that are specifically regulated by enalapril and nifedipine in tissues from spontaneously hypertensive rats (SHR) using DNA microarray analysis. We found that administration of SHR with enalapril and nifedipine differentially regulated 33 genes involved in the pathogenesis of cardiovascular diseases. Furthermore, we identified 16 genes that have not previously been implicated in cardiovascular diseases, including interleukin-24 (IL-24). Among them, exogenous administration of IL-24 attenuated the expression of vascular inflammation and hypertension-related genes induced by H2O2 treatment in mouse vascular smooth muscle (MOVAS) cells. This study provides valuable information for the development of novel antihypertensive drugs. In addition, the genes identified may be of use as biomarkers and therapeutic targets for cardiovascular diseases, including hypertension.

Vascular calcification is a hallmark of cardiovascular disease. Interleukin-24 (IL-24) has been known to suppress tumor progression in a variety of human cancers. However, the role of IL-24 in the pathophysiology of diseases other than cancer is unclear. We investigated the role of IL-24 in vascular calcification. IL-24 was applied to a β-glycerophosphate (β-GP)-induced rat vascular smooth muscle cell (VSMC) calcification model. In this study, IL-24 significantly inhibited β-GP-induced VSMC calcification, as determined by von Kossa staining and calcium content. The inhibitory effect of IL-24 on VSMC calcification was due to the suppression of β-GP-induced apoptosis and expression of calcification and osteoblastic markers. In addition, IL-24 abrogated β-GP-induced activation of the Wnt/β-catenin pathway, which plays a key role in the pathogenesis of vascular calcification. The specificity of IL-24 for the inhibition of VSMC calcification was confirmed by using a neutralizing antibody to IL-24. Our results suggest that IL-24 inhibits β-GP-induced VSMC calcification by inhibiting apoptosis, the expression of calcification and osteoblastic markers, and the Wnt/ β-catenin pathway. Our study may provide a novel mechanism of action of IL-24 in cardiovascular disease and indicates that IL-24 is a potential therapeutic agent in VSMC calcification.

Recent advances in the field of nanoscience have enabled the preparation of high-surface-area supported catalysts with precise control over the individual structural components. As such, a range of factors that affect the catalytic reactivity, such as the size, shape, and composition of the nanoparticles (NPs), have been identified. Herein, high-surface-area model catalysts that were based on colloidal Pd NPs and a hexagonally ordered mesoporous carbon support were prepared and the impact of various organic capping agents for the Pd NPs on their catalytic activity towards Suzuki coupling reactions was investigated. Colloidal Pd NPs (diameter: 3 nm) were synthesized with different organic capping agents, oleylamine (OA) and trioctylphosphine (TOP), and they were subsequently incorporated into the mesopores of CMK-3 mesoporous carbon to yield OA-Pd/CMK-3 and TOP-Pd/CMK-3 nanocatalysts, respectively. The OA-Pd/CMK-3 catalyst was treated with acetic acid to generate a supported catalyst with surfactant-free Pd NPs (OA-Pd/CMK-3-A). Structural characterization revealed that the Pd NPs were uniformly dispersed throughout the mesopores of the CMK-3 support and the particle size and crystallinity of the Pd NPs were preserved following the incorporation. All of the Pd/CMK-3 nanocatalysts exhibited higher activity than commercial activated carbon supported Pd catalysts in Suzuki coupling reactions. The catalytic activities of the three Pd/CMK-3 nanocatalysts were in the following order: OA-Pd/CMK-3-A>OA-Pd/CMK-3>TOP-Pd/CMK-3. This result suggested that the presence and type of surfactants had a significant effect on the catalytic activity. The OA-Pd/CMK-3-A catalyst also showed high activity for various substrates and good recycling ability in Suzuki coupling reactions.

Bacterial β-(1,3)-glucan has more advantages in terms of cost, yield and efficiency than that derived from mushrooms, plants, yeasts and fungi. We have previously developed a novel and high-yield β-(1,3)-glucan produced by Agrobacterium sp. R259. This study aimed to elucidate the functional mechanism and therapeutic efficacy of bacterial β-(1,3)-glucan in dextran sulfate sodium (DSS)-induced inflammatory bowel disease (IBD).Mice were orally pretreated with bacterial β-(1,3)-glucan at daily doses of 2.5 or 5mg/kg for 2 weeks. After 6 days of DSS treatment, clinical assessment of IBD severity and expression of pro-inflammatory cytokines were evaluated. In vivo cell proliferation was examined by immunohistochemistry using Ki-67 and ER-TR7 antibodies. The frequency of regulatory T cells (Tregs) was analyzed by flow cytometry. Natural killer (NK) activity and IgA level were evaluated using NK cytotoxicity assay and ELISA.The deterioration of body weight gain, colonic architecture, disease score and histological score was recovered in DSS-induced IBD mice when pretreated with bacterial β-(1,3)-glucan. The recruitment of macrophages and the gene expression of proinflammatory cytokines, such as IL-1β, IL-6 and IL-17A/F, were markedly decreased in the colon of β-(1,3)-glucan-pretreated mice. β-(1,3)-Glucan induced the recovery of Tregs in terms of their frequency in DSS-induced IBD mice. Intriguingly, β-(1,3)-glucan reversed the functional defects of NK cells and excessive IgA production in DSS-induced IBD mice.We conclude that bacterial β-(1,3)-glucan prevented the progression of DSS-induced IBD by recovering the reduction of Tregs, functional defect of NK cells and excessive IgA production.

Introduction Interleukin-18 (IL-18), a member of the IL-1 cytokine super-family, has been known to interferon-g-inducing factor and plays a critical role in angiogenesis, bone metabolism, metabolic syndrome, inflammatory and immune response. However, the role of IL-18 in the melanin synthesis of B16F10 melanoma cells has not been investigated. Methods B16F10 cells were treated with IL-18 and/or for 5 days, and were then dissolved in 1N NaOH in 10% DMSO at 80 °C for 1 h. The relative melanin contents were determined by measuring the absorbance at 405 nm using an ELISA reader. Expression of IL-18, IL-18R and melanogenesis-related genes was examined by real time PCR. Results Here, we found that IL-18 significantly induced the melanin synthesis in B16F10 cells, and anti-IL-18 abrogated IL-18-induced melanin synthesis. We also observed that anti-IL-18 decreased gene and protein expression of microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein (TRP)-1, and dopachrome tautomerase (Dct) stimulated by IL-18. In addition, anti-IL-18 reduced IL-18-induced phosphorylation of mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK). Conclusion Taken together, these results suggest that IL-18 may be involved in regulation of the melanin synthesis in B16F10 cells via the ERK pathway.

Introduction The mulberry belongs to the Morus genus of the Moraceae family. There are 24 species of Morus, with at least 100 known varieties. Methods RAW 264.7 cells were pretreated with mulberry or mulberry derivatives for 2 h, and then stimulated with lipopolysaccharide (LPS). Gene expression of proinflammatory cytokines were determined by RT-PCR. The levels of NO were determined by measuring the amount of nitrate using Griess reagents, and absorption was measured at 570 nm. Intracellular ROS levels were evaluated using a DCFH-DA fluorescent probe by flow cytometry. Results We found that mulberry derivatives inhibited the gene expression of proinflammatory cytokines including IL-6, IL-1b, TNF-aand COX-2 in Raw264.7 cells stimulated with lipopolysaccharide (LPS). In addition, LPS-induced intracellular ROS and NO levels were decreased in Raw264.7 cells treated with mulberry derivatives compared with those in mulberry. Conclusion These data suggest that mulberry derivatives showed anti-inflammatory activity by reducing intracellular ROS and NO production via suppression of proinflammatory cytokine expression, and mulberry derivatives may be useful for the prevention and therapy of inflammation-related diseases.

Introduction Axl receptor tyrosine kinase (Axl) has been known to play a crucial role in cell survival, proliferation, and migration, but little is known about its regulatory role in the migration of gd T cells. Here we investigated the role of Axl in the migration of intraepithelial gd T cells. Methods Primary intraepithelial lymphocytes (IELs) and gdT cells were isolated from 6 to 8 weeks old WT and Axl-deficient mice. Gene expression of IL-7Ra, CCR5, CCR9 and integrin aEb7 was examined by realtime-PCR. IEL phenotype was analyzed by flow cytometry. For adoptive transfer, primary IELs isolated from donors were injected into orbital vein of recipient mice after 6 weeks. Results The gd T cell population and absolute cell number was increased in IELs of Axl-deficient mice compared to them of wild type mice but not in other tissues. In addition, up-regulation of IL-7Ra, CCR5, CCR9 and integrin aEbexpression was observed in both IELs and gd T cells purified from IELs of Axl-deficient mice. The adoptive transfer of IELs of Axl-deficientmice to RAG-deficientmice induced the increased migration of gdT cells. Conclusion Our findings suggest that Axl is required for the migration of intestinal gd T cells by the transcriptional regulation of IL-7Ra, CCR5, CCR9 and integrin aEb7.

Introduction Triggering receptor expressed on myeloid cells-2 (TREM-2) is a cell surface receptor that participates in diverse cellular functions including inflammation, bone homeostasis and neurological development. We examined the effects of TREM-2 on experimentally induced inflammatory bowel disease (IBD) in mice. Methods Wild type (WT) and TREM2 transgenic (TREM2 TG) mice were administrated with dextran sulfate sodium (DSS) to induce IBD. The gene expression of proinflammatory cytokines were examined using RT-PCR and histopathological analysis was performed by H&E staining. The population of regulatory T cells was analyzed by flow cytometry. Results We found that body weight and colon length were remarkably decreased by treatment of DSS in TREM2-TG mice compared with WT littermates. Gene expression of proinflammatory cytokines including TNF-a, IL-1b, IL-17F, and IL-6 was increased in colonic tissue of DSS-treated TREM2-TG mice. In addition, recruitment of immune cells into colon tissue was also increased by DSS treatment in TREM2-TG mice, but population of regulatory T cells was decreased. Conclusion Our data suggest that TREM2 may be involved in the pathogenesis of IBD by upregulating proinflammatory cytokines due to the reduction of regulatory T cells.

Introduction The abnormal growth of vascular smooth muscle cells induced by reactive oxygen species is considered as a major pathogenic process in vascular diseases. Interleukin-10 family of cytokines is known to inhibit cancer cell growth through induction of cell cycle arrest and apoptosis. However, the role of interleukin-10 family of cytokines in ROS-induced VSMC growth has not been investigated yet. Methods Mouse vascular aorta smooth muscle cells were treated with H 2 O 2 . The cell cycle and intracellular ROS production was examined using flow cytometry analysis, and mRNA expression of VEGF and PDGF was investigated by RT-PCR and Real time PCR. Protein expression of PI3K/Akt and Erk was determined by western blot analysis Results We found that interleukin-10 family of cytokines inhibited the growth of mouse vascular aorta smooth muscle cells treated with H 2 O 2 by inducing the arrest of cell cycle at G0/G1 phase through the regulation of p21 and cyclin D1. Furthermore, interleukin-10 family of cytokines suppressed the mRNA expression of VEGF and PDGF, which subsequently reduced an elevated level of migration in response to H 2 O 2 . Interestingly, interleukin-10 family of cytokines attenuated H 2 O 2 -induced ROS production due to the upregulated mRNA expression of TRX-1 and PRX-2. Signaling through protein tyrosine kinases and mitogen-activated protein kinases is required for ROS-mediated activation of VSMCs. Consistently, we also showed that H 2 O 2 -induced PI3K/Akt and Erk signaling pathways were blocked by interleukin-10 family of cytokines. Conclusion Our data suggest a novel mechanism that interleukin-10 family of cytokines suppresses growth of normal VSMCs stimulated by H 2 O 2 through inhibiting ROS production via PI3K/Akt and Erk signaling pathways.

Introduction Stomach ulcer is an illness that affects a considerable number of people worldwide. We investigated the effect of hydroxy-omeprazole on indomethacin-induced gastric injury in mice. Methods Gastric injury was induced by oral injection of indomethacin. Hydroxy-omeprazole (3 mg/kg) was given to B6 mice once daily for up to 7 days; the first dose was given 6 h after indomethacin administration. The mice were sacrificed on the fourth and seventh days, 4 h after administering the last dose of the samples. Results Total immunoglobulin G and A levels were increased in sera and fecal extracts of mice administrated with indomethacin and hydroxy-omeprazole compared with mice administrated with indomethacin alone.In histopathological analysis, immune cell infiltration on indomethacin-induced ulcerated gastric tissues was prevented by administration of hydroxy-omeprazole.In addition, hydroxy-omeprazole suppressed gene expression of inflammatory cytokines including COX, IL-1band IL-6 in indomethacin-induced ulcerated gastric tissues. Conclusion These results suggest that hydroxy-omeprazole ameliorated gastric injury by inhibiting expression of inflammatory cytokines.