Amyloid ß-induced Mesenteric Inflammation in an Alzheimer's Disease Transgenic Mouse Model.

BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disorder histopathologically characterized by the accumulation of amyloid ß (Aß) peptides and inflammation associated with activated microglia. These features are well investigated in the central nervous system using AD-model mice; however, peripheral inflammation in these mice has not been investigated well. OBJECTIVE: We evaluated the inflammatory responses, especially myeloid dendritic cells (mDCs), in peripheral lymphoid tissues in AD-model mice to determine their association with Aß deposition. METHODS: We collected lymphocytes from mesenteric lymphoid nodes (MLNs) and Peyer's patches (PPs) of 5×FAD transgenic mice used as an AD model. Lymphocytes were analyzed using a flow cytometer to characterize mDCs and T cells. Collected lymphocytes were treated with Aß1-42 ex vivo to evaluate the inflammatory response. RESULTS: We observed elevated levels of inflammatory cytokines and chemokines including interleukin (IL)-12 and macrophage inflammatory protein-1α in mDCs from MLNs and PPs and reduced levels of programmed death-ligand-1, an immunosuppressive co-stimulatory molecule, on the surface of mDCs from 5×FAD mice. Additionally, we found increases in interferon (IFN)-γ-producing CD4- or CD8- positive T cells in MLNs were increased in 5×FAD mice. Moreover, ex vivo treatment with Aß peptides increased the production of IL-12 and IFN-γ by lymphocytes from 5×FAD mice. CONCLUSION: The present study showed that pro-inflammatory mDC and T cells were induced in MLNs and PPs of 5×FAD mice.

A Cell-Targeted Non-Cytotoxic Fluorescent Nanogel Thermometer Created with an Imidazolium-Containing Cationic Radical Initiator.

A cationic fluorescent nanogel thermometer based on thermo-responsive N-isopropylacrylamide and environment-sensitive benzothiadiazole was developed with a new azo compound bearing imidazolium rings as the first cationic radical initiator. This cationic fluorescent nanogel thermometer showed an excellent ability to enter live mammalian cells in a short incubation period (10 min), a high sensitivity to temperature variations in live cells (temperature resolution of 0.02-0.84 °C in the range 20-40 °C), and remarkable non-cytotoxicity, which permitted ordinary cell proliferation and even differentiation of primary cultured cells.

Modulation of Innate Immunity by lignin-Carbohydrate, a Novel TLR4 Ligand, Results in Augmentation of Mucosal IgA and Systemic IgG Production.

Previous study revealed that a specific lignin-carbohydrate preparation, named as lignin-rich enzyme lignin (LREL) derived from plant husk, is a novel toll-like receptor 4 ligand and shows a potent immune-stimulatory activity against dendritic cells (DCs) in vitro. In this report, we investigated immune-stimulatory activity of LREL in vivo. Single intraperitoneal (i.p.) or oral treatment of LREL elicited activation of systemic and mucosal DCs, which were accompanied by significant elevation of cell surface activation markers and ratio of IL-12p40 producing cells. In addition, LREL-fed mice showed not only mucosal DCs activation but also significant increase of IFN-γ⁺ CD4⁺ T cells in mesenteric lymph node (MLN), respectively. We further examined the effect of LREL oral immunization in combination with ovalbumin (OVA) on the activation of acquired immune system. In LREL administered group, total mucosal IgA concentration was significantly increased, while antigen-specific immunoglobulin A (IgA) concentration was not changed between groups. On the other hand, both total and antigen-specific IgG concentrations in plasma were significantly increased in the LREL administered group. Taken together, oral treatment of LREL is able to affect mucosal and systemic antibodies induction and might be useful for effective immune-stimulatory functional foods and mucosal vaccine adjuvant.

Identification of 14-dehydroergosterol as a novel anti-inflammatory compound inducing tolerogenic dendritic cells.

Tolerogenic dendritic cells (DCs) have the ability to induce regulatory T cells and play an important role in preventing chronic inflammatory and autoimmune diseases. We have identified a novel compound, 14-dehydroergosterol, from Koji, a Japanese traditional food material fermented with fungi. 14-dehydroergosterol is an ergosterol analogue with a conjugated double bond, but the activity of 14-dehydroergosterol is much higher than that of ergosterol. 14-dehydroergosterol induces the conversion of murine bone marrow (BM)-derived DCs and differentiated DCs into tolerogenic DCs, in which the production of IL-12 is suppressed and that of IL-10 is increased. In a co-culture experiment, DCs treated with 14-dehydroergosterol induced the conversion of naïve CD4-positive T cells into regulatory T cells. In a murine model of multiple sclerosis, experimental autoimmune encephalopathy, 14-dehydroergosterol suppressed the clinical score and inflammatory responses of myeloid DCs and T cells to myelin oligodendrocyte glycoprotein. 14-dehydroergosterol-treated human DCs induced from PBMCs also showed a tolerogenic phenotype. This is the first report to identify a novel compound, 14-dehydroergosterol, that induces DCs to convert to a tolerogenic type. 14-dehydroergosterol is contained in various fermented foods based on Koji, so 14-dehydroergosterol might be a helpful aid to prevent chronic inflammatory and autoimmune diseases.

Difference in intracellular temperature rise between matured and precursor brown adipocytes in response to uncoupler and ß-adrenergic agonist stimuli.

Brown adipocytes function to maintain body temperature by heat production. However, direct measurement of heat production at a single cell level remains difficult. Here we developed a method to measure the temperature within primary cultured brown adipocytes using a cationic fluorescent polymeric thermometer. Placement of the thermometer within a matured brown adipocyte and a precursor cell enabled the detection of heat production following uncoupler treatment. The increase in the intracellular temperature due to stimulation with a mitochondrial uncoupler was higher in matured brown adipocytes than in precursor cells. Stimulation with a ß-adrenergic receptor (ß-AR) agonist, norepinephrine, raised the intracellular temperature of matured brown adipocytes to a level comparable to that observed after stimulation with a ß3-AR-specific agonist, CL316.243. In contrast, neither ß-AR agonist induced an intracellular temperature increase in precursor cells. Further, pretreatment of brown adipocytes with a ß3-AR antagonist inhibited the norepinephrine-stimulated elevation of temperature. These results demonstrate that our novel method successfully determined the difference in intracellular temperature increase between matured brown adipocytes and precursor cells in response to stimulation by an uncoupler and ß-AR agonists.

A cationic fluorescent polymeric thermometer for the ratiometric sensing of intracellular temperature.

We developed new cationic fluorescent polymeric thermometers containing both benzothiadiazole and BODIPY units as an environment-sensitive fluorophore and as a reference fluorophore, respectively. The temperature-dependent fluorescence spectra of the thermometers enabled us to perform highly sensitive and practical ratiometric temperature sensing inside living mammalian cells. Intracellular temperatures of non-adherent MOLT-4 (human acute lymphoblastic leukaemia) and adherent HEK293T (human embryonic kidney) cells could be monitored with high temperature resolutions (0.01-1.0 °C) using the new cationic fluorescent polymeric thermometer.

Spherical lactic acid bacteria activate plasmacytoid dendritic cells immunomodulatory function via TLR9-dependent crosstalk with myeloid dendritic cells.

Plasmacytoid dendritic cells (pDC) are a specialized sensor of viral and bacterial nucleic acids and a major producer of IFN-α that promotes host defense by priming both innate and acquired immune responses. Although synthetic Toll-like receptor (TLR) ligands, pathogenic bacteria and viruses activate pDC, there is limited investigation of non-pathogenic microbiota that are in wide industrial dietary use, such as lactic acid bacteria (LAB). In this study, we screened for LAB strains, which induce pDC activation and IFN-α production using murine bone marrow (BM)-derived Flt-3L induced dendritic cell culture. Microbial strains with such activity on pDC were absent in a diversity of bacillary strains, but were observed in certain spherical species (Lactococcus, Leuconostoc, Streptococcus and Pediococcus), which was correlated with their capacity for uptake by pDC. Detailed study of Lactococcus lactis subsp. lactis JCM5805 and JCM20101 revealed that the major type I and type III interferons were induced (IFN-α, -ß, and λ). IFN-α induction was TLR9 and MyD88-dependent; a slight impairment was also observed in TLR4(-/-) cells. While these responses occurred with purified pDC, IFN-α production was synergistic upon co-culture with myeloid dendritic cells (mDC), an interaction that required direct mDC-pDC contact. L. lactis strains also stimulated expression of immunoregulatory receptors on pDC (ICOS-L and PD-L1), and accordingly augmented pDC induction of CD4(+)CD25(+)FoxP3(+) Treg compared to the Lactobacillus strain. Oral administration of L. lactis JCM5805 induced significant activation of pDC resident in the intestinal draining mesenteric lymph nodes, but not in a remote lymphoid site (spleen). Taken together, certain non-pathogenic spherical LAB in wide dietary use has potent and diverse immunomodulatory effects on pDC potentially relevant to anti-viral immunity and chronic inflammatory disease.

Sugar induces death of the bottom fermenting yeast Saccharomyces pastorianus.

We confirmed that sugar-induced cell death (SICD) occurs in the bottom fermenting yeast Saccharomyces pastorianus under anaerobic conditions and that mitochondrial DNA is only partly required for SICD. Fermentation tests using different ratios of glucose and non-glucose nutrients demonstrated that SICD is influenced by the balance between these nutrients.