Jeong June Choi

Activation of selective transcription factors and cytokines by water-soluble extract from Lentinus lepideus.

We isolated a water-soluble extract, PG101, from cultured mycelia of Lentinus lepideus. Treatment of human peripheral blood mononuclear cells (PBMCs) with PG101 increased levels of TNF-α, IL-1β, IL-10, and IL-12 by 100- to 1000-fold, whereas GM-CSF and IL-18 were activated by an order of magnitude. On the contrary, IFN-γ and IL-4 were not affected. The response to PG101 occurred in a dose- and time-dependent manner. From the human PBMCs treated with PG101, TNF-α was a first cytokine to be activated, detectable at 2 hr post-treatment followed by IL-1β at 6 hr post-treatment. IL-12 and IL-10 were the next to follow. GM-CSF and IL-18 both showed significant increases 24 hr after treatment. When PBMCs were sorted into various cell types, monocyte/macrophages, but not T and B cells, were the major target cell type responsive to PG101. Consistent with this result, the profile of cytokine expression upon PG101 treatment was comparable between PBMCs and a human promonocytic cell line (U937), whereas cell lines of T cell and myeloid origins did not respond to PG101. Data from a transient transfection assay involving specific reporter plasmids indicated that cellular transcription factor such as NF-κB, but not AP-1, was highly activated by PG101. Results from a gel retardation assay and the experiment involving a specific NF-κB inhibitor confirmed the involvement of NF-κB. Despite its significant biological effect on various cytokines, PG101 remained nontoxic in both rats and PBMCs even at a biological concentration approximately 20 times greater. PG101 demonstrates great potential as a therapeutic immune modulator.

Induction of pacemaker currents by DA-9701, a prokinetic agent, in interstitial cells of Cajal from murine small intestine

The interstitial cells of Cajal (ICC) are pacemaking cells required for gastrointestinal motility. The possibility of whether DA-9701, a novel prokinetic agent formulated with Pharbitis Semen and Corydalis Tuber, modulates pacemaker activities in the ICC was tested using the whole cell patch clamp technique. DA-9701 produced membrane depolarization and increased tonic inward pacemaker currents in the voltage-clamp mode. The application of flufenamic acid, a non-selective cation channel blocker, but not niflumic acid, abolished the generation of pacemaker currents induced by DA-9701. Pretreatment with a Ca2+-free solution and thapsigargin, a Ca2+-ATPase inhibitor in the endoplasmic reticulum, abolished the generation of pacemaker currents. In addition, the tonic inward currents were inhibited by U-73122, an active phospholipase C inhibitor, but not by GDP-β-S, which permanently binds G-binding proteins. Furthermore, the protein kinase C inhibitors, chelerythrine and calphostin C, did not block the DA-9701-induced pacemaker currents. These results suggest that DA-9701 might affect gastrointestinal motility by the modulation of pacemaker activity in the ICC, and the activation is associated with the non-selective cationic channels via external Ca2+ influx, phospholipase C activation, and Ca2+ release from internal storage in a G protein-independent and protein kinase C-independent manner.

Enhancement of repopulation and hematopoiesis of bone marrow cells in Irradiated mice by oral administration of PG101, a water-soluble extract from Lentinus lepideus

PG101 is a water-soluble extract from Lentinus lepideus. It is a potential biological response modifier that activates selective cytokines in vitro, mainly by controlling cellular transcription factor NF-κB. Effects of PG101 were tested on bone marrow cells in irradiated mice. Mice were irradiated with a dose of 6 Gy and were given PG101 by gavages daily for 24 days. In PG101-treated mice, the number of colony-forming cells, including colony-forming units (CFU)-granulocytes/macrophages (GM) and erythroid burst-forming units (BFU-E), were increased to almost the levels seen in nonirradiated control as early as 8 days after irradiation. Two-color flow cytometric analysis using antibodies to ER-MP12 and ER-MP20 suggested that in the bone marrow cell population, PG101 increased the number of granulocytes (ER-MP12-20med) and myeloid progenitors (ER-MP12+20+). Analysis of surface c-Kit and Gr-1 proteins in bone marrow cells indicated that PG101 might induce differentiation of progenitor cells to granulocytes and/or proliferation of the committed cells. Lastly, oral administration of PG101 highly increased serum levels of GM-CSF, IL-6, and IL-1β. Interestingly, the level of TNF-α was elevated by irradiation in control mice, but was maintained at the background level in PG101-treated mice, suggesting that PG101 might effectively suppress TNF-α-related pathologic conditions. Our results strongly suggest the great potential of PG101 as an immune enhancer during radiotherapy and/or chemotherapy.

Blockade of Atopic Dermatitis-Like Skin Lesions by DA-9102, a Natural Medicine Isolated from Actinidia arguta, in the Mg-Deficiency Induced Dermatitis Model of Hairless Rats

DA-9102 isolated from Actinidia arguta is a candidate of natural medicine currently under Phase II clinical trial for atopic dermatitis in Korea. In this study, spontaneous dermatitis was induced by magnesium deficiency in hairless rats and this system was applied to assess the suppressive effects of DA-9102 on atopic dermatitis-like skin disease. Oral administration of DA-9102 at a dose of 100 mg/kg for 16 days substantially suppressed the occurrence of spontaneous dermatitis. Eczematous skin lesions, water loss and scratching behavior were significantly decreased by DA-9102 in a dose-dependent manner. Infiltration of inflammatory cells into the skin and pathologic remodeling of the epidermis and dermis were much less than the Mg-def. group. Results from flow cytometry analysis of peripheral blood mononuclear cells indicated that DA-9102 suppressed activation of leukocytes. The decrease in the number of CD45RA+ cells was accompanied by a lower level of IgE in DA-9102 treated rats, and the reduction in the number of CD11b+ cells by DA-9102 in both periphery and skin was significant. Further, DA-9102 not only suppressed the mRNA expression of TH2 cytokines including IL-4 and IL-10 in the lymph node but it also decreased the levels of inflammatory mediators such as nitric oxide and leukotriene B4 (LTB4) in the serum. Taken together, these results suggest that DA-9102 is an orally applicable potent immune modulator capable of controlling the occurrence of atopic dermatitis-like skin disease.

Pheophytin a and chlorophyll a suppress neuroinflammatory responses in lipopolysaccharide and interferon-γ-stimulated BV2 microglia.

AIMS Microglia-mediated inflammation is associated with pathogenesis of various neuronal disorders. This study investigated inhibitory effects of pheophytin a (PP) and chlorophyll a (CP) on neuroinflammation and underlying cellular mechanisms in microglia cells. MAIN METHODS BV2 murine microglia cells were stimulated by lipopolysaccharide (LPS, 100 ng/mL) and interferon (IFN)-γ (10 U/mL). The productions of nitric oxide (NO) and expressions of proinflammatory cytokines and chemokines were determined by ELISA and RT-PCR. Western blot and confocal microscopy were applied to analyze activation of transcription factors and mitogen activated protein kinase (MAPK). KEY FINDINGS PP and CP significantly reduced the levels of NO, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and chemokines including macrophage inhibitory protein (MIP)-1α, macrophage chemoattractant protein (MCP)-1 and IFN-γ inducible protein (IP)-10 in BV2 cells stimulated with LPS and IFN-γ (LI). The nuclear expression of p65 NF-κB was significantly suppressed, which was accompanied by reduced the levels of IFN-β, phospho-STAT-1, and interferon regulatory factor (IRF)-1. Activation of extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK) but not p38 MAPK were prominently suppressed by PP and/or CP. SIGNIFICANCE PP and CP may suppress inflammatory responses by inhibiting NF-κB activation and type I IFN signaling pathway. These result suggested that PP and CP have potential as anti-inflammatory agents for microglia-mediated neuroinflammatory disorders.

Secreted tryptophanyl-tRNA synthetase as a primary defence system against infection.

The N-terminal truncated form of a protein synthesis enzyme, tryptophanyl-tRNA synthetase (mini-WRS), is secreted as an angiostatic ligand. However, the secretion and function of the full-length WRS (FL-WRS) remain unknown. Here, we report that the FL-WRS, but not mini-WRS, is rapidly secreted upon pathogen infection to prime innate immunity. Blood levels of FL-WRS were increased in sepsis patients, but not in those with sterile inflammation. FL-WRS was secreted from monocytes and directly bound to macrophages via a toll-like receptor 4 (TLR4)–myeloid differentiation factor 2 (MD2) complex to induce phagocytosis and chemokine production. Administration of FL-WRS into Salmonella typhimurium-infected mice reduced the levels of bacteria and improved mouse survival, whereas its titration with the specific antibody aggravated the infection. The N-terminal 154-amino-acid eukaryote-specific peptide of WRS was sufficient to recapitulate FL-WRS activity and its interaction mode with TLR4–MD2 is now suggested. Based on these results, secretion of FL-WRS appears to work as a primary defence system against infection, acting before full activation of innate immunity.

Oral administration of SSC201, a medicinal herbal formula, suppresses atopic dermatitis-like skin lesions.

Atopic dermatitis (AD) is a chronic inflammatory skin disease, which requires safe and effective treatment. In this study, we evaluated the effects of SSC201, a herbal formulation consisting of Stemonae Radix, Spirodelae Herba, and Cnidii Fructus, on the development of AD induced by 2,4-dinitrochlorobenzene in the NC/Nga murine model. Oral administration of SSC201 significantly reduced the severity of dermatitis and the tendency of mice to scratch their lesions. SSC201 significantly reduced the thickening of the epidermis/dermis and the infiltration of T cells, eosinophils, and mast cells into the dermis. These results were supported by findings of reduced numbers of CD4(+), CCR3(+), and CD117(+)FcɛRIα(+) cells in the skin. Furthermore, SSC201 significantly decreased the number of CD4(+), CD8(+), and CD3(+)CD69(+) T cells in lymph nodes. SSC201 not only decreased the plasma levels of immunoglobulin E (IgE) and the numbers of IgE-producing B cells (B220(+)CD23(+)), but also reduced the number of eosinophils and the levels of eotaxin as well as concentrations of thymus and activation-regulated chemokine in the periphery. Splenic levels of Th2 cytokines, including interleukin (IL)-4, IL-5, and IL-13, were reduced, whereas the levels of IL-12, a Th1 cytokine, were increased. Taken together, our data suggest that SSC201 may be an effective therapeutic agent for the treatment of AD.

Corrigendum: Secreted tryptophanyl-tRNA synthetase as a primary defence system against infection

Nature Microbiology 2, 16191 (2016); published online 17 October 2016; corrected 23 January 2017 In the original version of this Article, three author names were spelt incorrectly. The three names have now been corrected to Hye Jung Park, Jae-Hyun Lee and Jung-Won Park in all versions of the Article.