Preparation, chemical structure, and immunostimulatory activity of a water-soluble heteropolysaccharide from Suillus granulatus fruiting bodies.

A water-soluble heteropolysaccharide (SGP2-1) was purified from Suillus granulatus fruiting bodies by anion-exchange chromatography and gel permeation chromatography. The structural characteristics were analyzed by high-performance gel permeation chromatography, high-performance liquid chromatography, Fourier transform infrared spectroscopy, gas chromatography-mass spectrometry, and nuclear magnetic resonance spectroscopy. The immunostimulatory activity was investigated using RAW 264.7 macrophages. Results showed that SGP2-1 with weight average molecular weight of 150.75 kDa was composed of mannose, glucose, and xylose. The backbone of SGP2-1 was mainly composed of â†’ 4)-α-Glcp-(1→, and the terminal group α-d-Glcp â†’ was linked to the main chain by O-6 position. SGP2-1 could significantly enhance pinocytic capacity, reactive oxygen species production, and cytokines secretion. SGP2-1 exerted immunomodulatory effects through interacting with toll-like receptor 2, and activating mitogen-activated protein kinase, phosphatidylinositol-3-kinase/protein kinase B, and nuclear factor-kappa B signaling pathways. These findings indicated that SGP2-1 could be explored as a potential immunomodulatory agent for application in functional foods.

Hippocampal dynamics of synaptic NF-kappa B during inhibitory avoidance long-term memory consolidation in mice.

Since the discovery that long-term memory is dependent on protein synthesis, several transcription factors have been found to participate in the transcriptional activity needed for its consolidation. Among them, NF-kappa B is a constitutive transcription factor whose nuclear activity has proven to be necessary for the consolidation of inhibitory avoidance in mice. This transcription factor has a wide distribution in the nervous system, with a well-reported presence in dendrites and synaptic terminals. Here we report changes in synaptosomal NF-kappa B localization and activity, during long-term memory consolidation. Activity comparison of synaptosomal and nuclear NF-kappa B, indicates different dynamics for both localizations. In this study we identify two pools of synaptosomal NF-kappa B, one obtained with the synaptoplasm (free fraction) and the second bound to the synaptosomal membranes. During the early steps of consolidation the first pool is activated, as the membrane associated transcription factor fraction increases and concomitantly the free fraction decreases. These results suggest that the activation of synaptic NF-kappa B and its translocation to membranes are part of the consolidation of long-term memory in mice.

Regulation of platelet responses triggered by Toll-like receptor 2 and 4 ligands is another non-genomic role of nuclear factor-kappaB.

INTRODUCTION: Platelets express Toll-like receptors (TLRs) that recognise molecular components of pathogens and, in nucleated cells, elicit immune responses through nuclear factor-kappaB (NF-κB) activation. We have shown that NF-κB mediates platelet activation in response to classical agonists, suggesting that this transcription factor exerts non-genomic functions in platelets. The aim of this study was to determine whether NF-κB activation is a downstream signal involved in TLR2 and 4-mediated platelet responses. MATERIAL AND METHODS: Aggregation and ATP release were measured with a Lumi-aggregometer. Fibrinogen binding, P-selectin and CD40 ligand (CD40L) levels and platelet-neutrophil aggregates were measured by cytometry. I kappa B alpha (IκBα) degradation and p65 phosphorylation were determined by Western blot and von Willebrand factor (vWF) by ELISA. RESULTS: Platelet stimulation with Pam3CSK4 or LPS resulted in IκBα degradation and p65 phosphorylation. These responses were suppressed by TLR2 and 4 blocking and synergised by thrombin. Aggregation, fibrinogen binding and ATP and vWF release were triggered by Pam3CSK4. LPS did not induce platelet responses per se, except for vWF release, but it did potentiate thrombin-induced aggregation, fibrinogen binding and ATP secretion. Pam3CSK4, but not LPS, induced P-selectin and CD40L expression and mixed aggregate formation. All of these responses, except for CD40L expression, were inhibited in platelets treated with the NF-κB inhibitors BAY 11-7082 or Ro 106-9920. CONCLUSION: TLR2 and 4 agonists trigger platelet activation responses through NF-κB. These data show another non-genomic function of NF-κB in platelets and highlight this molecule as a potential target to prevent platelet activation in inflammatory or infectious diseases.

The involvement of Nrf2 in the protective effects of diallyl disulfide on carbon tetrachloride-induced hepatic oxidative damage and inflammatory response in rats.

This study investigated the potential effect of diallyl disulfide (DADS) against carbon tetrachloride (CCl4)-induced oxidative hepatic damage and inflammatory response in rat liver. DADS at doses of 50 and 100 mg/kg/day was administered orally once daily for 5 days, prior to CCl4 administration. Pretreatment with DADS attenuated CCl4-induced elevated serum transaminase activities and histopathological alterations in liver. It prevented the hepatocellular apoptotic changes with induction of Bcl-2-associated X (Bax), cytochrome c, and caspase-3 caused by CCl4. An increase in the nuclear translocation of nuclear factor-kappaB (NF-κB) and phosphorylation of I kappaB alpha (IκBα) was observed in the livers of CCl4-treated rats that coincided with induction of inflammatory mediators or cytokines. In contrast, DADS inhibited NF-κB translocation and IκBα phosphorylation, and that subsequently decreased inflammatory mediators. Furthermore, DADS prevented CCl4-induced depletion of cytosolic nuclear factor E2-related factor 2 (Nrf2) and suppression of nuclear translocation of Nrf2, which, in turn, up-regulated phase II/antioxidant enzyme activities. Taken together, these results demonstrate that DADS increases the expression of phase II/antioxidant enzymes and simultaneously decreases the expression of inflammatory mediators in CCl4-induced liver injury. These findings indicate that DADS induces antioxidant defense mechanism by activating Nrf2 pathway and reduces inflammatory response by inhibiting NF-κB activation.

Vitamin D deficiency and severe asthma.

Vitamin D has received tremendous amount of attention recently due to the ever-increasing reports of association between vitamin D deficiency and a wide range of conditions, from cancer to fertility to longevity. The fascination of disease association with vitamin D deficiency comes from the relatively easy solution to overcome such a risk factor, that is, either by increase in sun exposure and/or diet supplementation. Many reviews have been written on a protective role of vitamin D in asthma and related morbidities; here, we will summarize the epidemiological evidence supporting a role of vitamin D against hallmark features of severe asthma, such as airway remodeling and asthma exacerbations. Furthermore, we discuss data from in vitro and in vivo studies which provide insights on the potential mechanisms of how vitamin D may protect against severe asthma pathogenesis and how vitamin D deficiency may lead to the development of severe asthma. Approximately 5-15% of asthmatic individuals suffer from the more severe forms of disease in spite of aggressive therapies and they are more likely to have irreversible airflow obstruction associated with airway remodeling. At present drugs commonly used to control asthma symptoms, such as corticosteroids, do not significantly reverse or reduce remodeling in the airways. Hence, if vitamin D plays a protective role against the development of severe asthma, then the most effective therapy may simply be a healthy dose of sunshine.

Comparison of the Activities of NF-kappa B and I kappa B alpha in Patients with Rheumatoid Arthritis and Osteoarthritis / 대한정형외과연구학회지

PURPOSE: The nuclear factor-kappa B (NF-kappa B) has been known to regulate the inflammatory and immune process by transcription of inflammatory intermediates. The purpose of the present study is to show the difference in activity of NF-kappa B and its inhibitory factor-I kappa B alpha in patients with rheumatoid arthritis, osteoarthritis and normal control subjects. MATERIALS AND METHODS: Synovial membrane samples were obtained at the time of orthopedic surgery from the knees of 7 patients with RA and 7 patients with OA. Two control samples were obtained from an amputee with no history of arthritis. We designed the primer of the subunit p65 of NF-kappa B and I kappa B alpha, measured the activity of them by RT-PCR, and analyzed the expression of NF-kappa B by immunohistochemical staining. RESULTS: From the results of RT-PCR, the expression levels of NF-kappa B was found to be higher in synovial tissues obtained from patients with RA than from synovial tissue obtained from patients with OA, and the least from the control group. The expression levels of I kappa B alpha were not different statistically among the three groups. Immunohistochemical staining for the NF-kappa B was dominant in synovial tissue from patients with RA. The result of immunohistochemical staining was similar to the results of RT-PCR for NF-kappa B. The localization of the staining was predominantly nuclear. CONCLUSION: In this study, activity of NF-kappa B of rheumatoid arthritis was higher than the other group, but expressions of I kappa B alpha were no different between the diseases. Further studies about specific inhibitors of NF-kappa B will benefit the development of rheumatoid arthritis regimens with greater efficacy.

Effect of FK506 and Cyclosporin A on I(kappa)B(alpha) Degradation and IKK Pathway in Bronchial Epithelial Cells, Monocytes, Lymphocytes and Alveolar Macrophages / 결핵

BACKGROUND: Cyclosporin A(CsA) and tacrolimus(FK506) have been widely used as immunosuppressants. The effects of CsA, or FK506, on the IkappaB/NF-kappaB pathway have been shown to vary according to the cell type. However, their effects on the IkappaB/NF-kappaB pathway have not been reported in bronchial epithelial cells. In this study, the effects of CsA and FK506 on the IkappaB/NF-kappaB pathway in bronchial epithelial cells, monocytes, lymphocytes and alveolar macrophages were evaluated. The relationship between their effects on the IkappaB/NF-kappaB pathway and IkappaB kinase(IKK) activity was also investigated. METHODS: BEAS-2B and A549 cells, pulmonary alveolar macrophages, peripheral blood monocytes and lymphocytes were used. The cells were pre-treated with CsA, or FK506, for various time periods, followed by stimulation with TNF-alpha, LPS or IL-1beta. The I(kappa)B(alpha) expressions were assayed by Western blot analyses. The IKK activity was evaluated by an in vitro immune complex kinase assay, using GST-I(kappa)B(alpha) as the substrate. RESULTS: Neither CsA nor FK506 affected the level of I(kappa)B(alpha) expression in any of the cell types used in this study. CsA pre-treatment inhibited the TNFalpha-induced I(kappa)B(alpha) degradation in bronchial epithelial cells. In contrast, the TNFalpha-induced I(kappa)B(alpha) degradation was not affected by FK506 pre-treatment. However, FK506 suppressed the cytokine-induced I(kappa)B(alpha) degradation in the pulmonary alveolar macrophages, peripheral blood monocytes and lymphocytes. The inhibitory effect of CsA, or FK506, on I(kappa)B(alpha) degradation was not related to IKK. CONCLUSIONS: CsA and FK506 suppressed the I(kappa)B(alpha) degradation in bronchial epithelial cells, mono. cytes, lymphocytes and alveolar macrophages, so this may not be mediated through IKK.