Activation Of Beta Research Articles

Resting beta activation and trait motivation: Neurophysiological markers of motivated motor-action preparation

Based on Reinforcement Sensitivity Theory (Gray and McNaughton 2000), human behavior is influenced by systems of approach motivation, avoidance motivation, and a third regulatory system presiding over the other two. These systems mediate action and are likely related to neurophysiological markers of motor-action preparation. Previous research has found that lower levels of beta activity over the motor cortex are associated with greater motor-action preparation. The current study sought to test whether trait approach, avoidance, and regulatory control would relate to resting beta activity over the motor cortex, a measure of motor-action preparation. One hundred twenty-eight individuals completed measures of trait behavioral approach motivation and trait behavioral avoidance motivation (BIS/BAS; Carver and White 1994), as well as regulatory control (UPPS-P Impulsive Behaviour Scale; Whiteside et al. 2005). Then, resting EEG was recorded. Greater trait approach was negatively associated with resting beta activity. In contrast, greater trait impulsivity was associated with greater resting beta activity. Lower levels of resting beta activity in the motor cortex appear to be associated with traits related to deliberate motivated motor behaviors. Trait motor-action preparation seems to be an indicator of tendencies toward planful motivated behavior.

Derangements in adrenergic-adipokine signalling establish a neurohormonal basis for obesity-related heart failure with a preserved ejection fraction.

Among patients with heart failure and a preserved ejection (HFpEF), obesity is associated with a distinct phenotype that is characterized by adiposity-driven plasma volume expansion and cardiac overfilling, which is coupled with an impairment of ventricular distensibility. These pathophysiological abnormalities may be related to the increased actions of specific adipocyte-derived signalling molecules (aldosterone, neprilysin and leptin) that work in concert with increased renal sympathetic nerve traffic and activated beta2 -adrenergic receptors to promote sodium retention, microvascular rarefaction, cardiac fibrosis and systemic inflammation. This interplay leads to striking activation of the mineralocorticoid receptor, possibly explaining why obese patients with heart failure are most likely to benefit from spironolactone and eplerenone in large-scale clinical trials. Additionally, adipocytes express and release neprilysin, which (by degrading endogenous natriuretic peptides) can further promote plasma volume expansion and cardiac fibrosis. Heightened neprilysin activity may explain the low circulating levels of natriuretic peptides in obesity, the accelerated breakdown of natriuretic peptides in HFpEF, and the cardiac decompression following neprilysin inhibition in HFpEF patients who are obese. Furthermore, as adipose tissue accumulates and becomes dysfunctional, its secretion of leptin promotes renal sodium retention, microvascular changes and fibrotic processes in the heart, and systemic inflammation; these effects may be mediated or potentiated by the activation of beta2 -adrenergic receptors. These adrenergic-adipokine interactions provide a mechanistic framework for novel therapeutic strategies to alleviate the pathophysiological abnormalities of obesity-related HFpEF. Ongoing trials are well-positioned to test this hypothesis.

Three-generation family with novel contiguous gene deletion on chromosome 2p22 associated with thoracic aortic aneurysm syndrome.

Latent transforming growth factor binding proteins (LTBP) are a family of extracellular matrix glycoproteins that play an important role in the regulation of transforming growth factor beta (TGF-ß) activation. Dysregulation of the TGF-ß pathway has been implicated in the pathogenesis of inherited disorders predisposing to thoracic aortic aneurysms syndromes (TAAS) including Marfan syndrome (MFS; FBN1) and Loeys-Dietz syndrome (LDS; TGFBR1, TGFBR2, TGFB2, TGFB3, SMAD2, SMAD3). While these syndromes have distinct clinical criteria, they share clinical features including aortic root dilation and musculoskeletal findings. LTBP1 is a component of the TGF-ß pathway that binds to fibrillin-1 in the extracellular matrix rendering TGF-ß inactive. We describe a three-generation family case series with a heterozygous ∼5.1 Mb novel contiguous gene deletion of chromosome 2p22.3-p22.2 involving 11 genes, including LTBP1. The deletion has been identified in the proband, father and grandfather, who all have a phenotype consistent with a TAAS. Findings include thoracic aortic dilation, ptosis, malar hypoplasia, high arched palate, retrognathia, pes planus, hindfoot deformity, obstructive sleep apnea, and low truncal tone during childhood with joint laxity that progressed to reduced joint mobility over time. While the three affected individuals did not meet criteria for either MFS or LDS, they shared features of both. Although the deletion includes 11 genes, given the relationship between LTBP1, TGF-ß, and fibrillin-1, LTBP1 stands out as one of the possible candidate genes for the clinical syndrome observed in this family. More studies are necessary to evaluate the potential role of LTBP1 in the pathophysiology of TAAS.

Activation of estrogen receptor beta (ERβ) regulates the expression of N-cadherin, E-cadherin and β-catenin in androgen-independent prostate cancer cells.

The aim of the present study was to investigate the impact of the activation of estrogen receptors on expression and localization of N-cadherin, E-cadherin and non-phosphorylated β-catenin in androgen-independent prostate cancer cells (PC-3 and DU-145) and in human post pubertal prostate epithelial cells (PNT1A). Expression of N-cadherin was detected in PNT1A and PC-3 cells, but not in DU-145 cells. E-cadherin was detected only in DU-145 cells and β-catenin was detected in all cells studied. N-cadherin and β-catenin were located preferentially in the cellular membrane of PNT1A cells and in the cytoplasm of PC-3 cells. E-cadherin and β-catenin were located preferentially in the cellular membrane of DU-145 cells. 17β-estradiol (E2) or the ERα-selective agonist PPT did not affect the content and localization of N-cadherin in PC-3 and PNT1A cells or E-cadherin in DU-145 cells. In PC-3 cells, ERβ-selective agonist DPN decreased the expression of N-cadherin. DPN-induced downregulation of N-cadherin was blocked by pretreatment with the ERβ-selective antagonist (PHTPP), indicating that ERβ1 is the upstream receptor regulating the expression of N-cadherin. In DU-145 cells, the activation of ERβ1 by DPN increased the expression of E-cadherin. Taken together, these results suggest that activation of ERβ1 is required to maintain an epithelial phenotype in PC-3 and DU-145 cells. The activation of ERβ1 also increased the expression of β-catenin in cytoplasm of PC-3 and in the cellular membrane of DU-145 cells. In conclusion, our results indicate differential expression and localization of N-cadherin, E-cadherin and β-catenin in androgen-independent prostate cancer cells. The reduction of N-cadherin content by activation of ERβ, exclusively observed in androgen-independent prostate cancer cells (PC-3), may be related to the activation of signaling pathways, such as the release of β-catenin into the cytoplasm, translocation of β-catenin to the nucleus and activation of gene transcription.

Oral ingestion of plasmalogens can attenuate the LPS-induced memory loss and microglial activation

Plasmalogens (Pls) are the special phospholipids which were reported to be reduced in brain and blood samples of Alzheimer's disease (AD) patients, suggested a possibility that an oral ingestion of Pls may prevent the disease progression. Interestingly, the clinical study showed that the daily oral ingestion of Pls among the mild AD patients improved cognition. However, it is unknown of whether the oral ingestion of Pls inhibits the AD like changes in brain e.g., glial activation and accumulation of amyloid beta (Aβ) proteins. To elucidate the beneficial effects of the Pls oral ingestion, we have used the chronic lipopolysaccharide (LPS) injection model mice where the glial activation and Aβ accumulation were well reported. In the present study, we have found that the Pls drinking at the doses of 0.1 μg/ml and 10 μg/ml for 3 months attenuated the glial activation and accumulation of amyloid beta (Aβ) proteins in the murine brain. Interestingly, the LPS injection reduced the hippocampal dependent memory in the control mice but the groups of Pls drinking mice showed a better performance in the memory test, suggesting that oral intake of Pls can inhibit LPS-mediated memory loss associated with a reduction of glial activation and Aβ accumulation in the brain. We, therefore, suggest that the oral ingestion of Pls among the AD patients may also inhibit the glial activation resulting in the improvement of cognition.

WITHDRAWN: Bufalin enhances ABT-737 efficacy through Mcl-1 degradation in non-small cell lung cancer cells

// Wen-yu Di 1 , Guang-jian Lu 2 , Bao-cai Lu 3 , Li-na Wang 4 , Jing-hang Zhang 1 , Jian Yu 1 , Wei Su 1 , Xiao-hong Kang 5,* and Ping Lu 5,* 1 Department of Pathology, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang 453003, China 2 Department of Laboratory, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, 453003, China 3 Department of ENT, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, 453003, China 4 Quality Controlling Office, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, 453003, China 5 Department of Oncology, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, 453003, China * These authors have contributed equally Correspondence: Xiao-hong Kang, email: kxhhgd@163.com Ping Lu, email: lpkxhdoctor@126.com Keywords : bualin; ABT-737; Mcl-1; non-small cell lung cancer; GSK-3β; Ku70 Received: August 21, 2017     Accepted: December 04, 2017     Epub: December 22, 2017 Abstract Mcl-1, an anti-apoptotic Bcl-2 family member, is often overexpressed in non-small cell lung cancer (NSCLC) and renders resistance to ABT-737 therapy. Bufalin, a natural cardiac glycoside extracted from Venenum Bufonis , has been reported to induce apoptosis in various tumor cells. In the present study, we discovered that bufalin functioned as a suppressor of Mcl-1. Bufalin significantly enhanced ABT-737-mediated apoptosis in A549 and H1975 cells by suppressing Mcl-1. Overexpression of Mcl-1 diminished apoptosis induced by combination of bufalin and ABT-737. Furthermore, bufalin strongly promoted Mcl-1 protein degradation via activation of GSK-3β and suppression of Ku70. However, expression of exogenous Ku70 and GSK-3β inhibitor resulted in increased levels of Mcl-1 and abrogated attenuated the apoptosis induced by bufalin. Finally, bufalin also sensitized NSCLC cells to ABT-737 treatment by suppressing Mcl-1 in vivo . Taken together, our studies suggest bufalin can potentiate ABT-737 lethality in human non-small cell lung cancer cells through Ku70- and GSK-3β-mediated Mcl-1 degradation.

Nuclear factor-kappa beta activation and monocyte-endothelial adhesion lead to chemerin induced endothelial cell inflammation

Nuclear factor-kappa beta activation and monocyte-endothelial adhesion lead to chemerin induced endothelial cell inflammation

Macrophage recruitment, but not interleukin 1 beta activation, enhances noise-induced hearing damage

It has been suggested that macrophages or inflammatory monocytes participate in the pathology of noise-induced hearing loss (NIHL), but it is unclear how extensively these cells contribute to the development of temporary and/or permanent NIHL. To address this question, we used clodronate liposomes to deplete macrophages and monocytes. After clodronate liposome injection, mice were exposed to 4-kHz octave band noise at 121 dB for 4 h. Compared to vehicle-injected controls, clodronate-treated mice exhibited significantly reduced permanent threshold shifts at 4 and 8 kHz and significantly smaller outer hair cell losses in the lower-apical cochlear turn. Following noise exposure, the stria vascularis had significantly more cells expressing the macrophage-specific protein F4/80, and this effect was significantly suppressed by clodronate treatment. These F4/80-positive cells expressed interleukin 1 beta (IL-1β), which noise exposure activated. However, IL-1β deficient mice did not exhibit significant resistance to intense noise when compared to wild-type mice.These findings suggest that macrophages that enter the cochlea after noise exposure are involved in NIHL, whereas IL-1β inhibition does not reverse this cochlear damage. Therefore, macrophages may be a promising therapeutic target in human sensorineural hearing losses such as NIHL.

Estrogen Receptor β Mediated Neuroprotective Efficacy of Cicer microphyllum Seed Extract in Global Hypoxia.

Hypoxia induced oxidative stress and neurodegeneration in the hippocampus has been implicated for memory impairment in conditions like stroke, ischemia and hypobaric hypoxia. The present study, aimed at investigating the potential of ethanolic extract of Cicer microphyllum seeds (CSE) for amelioration of global hypoxia induced neurodegeneration in CA1 region of hippocampus. CSE supplementation considerably reduced neurodegeneration and dendritic atrophy in CA1 neurons along with improvement of memory in hypoxic rats. This effect of CSE was partly attributed to its antioxidant activity resulting in reduction of lipid peroxidation, protein oxidation and DNA damage during exposure to chronic hypoxia. CSE also promoted dendritic arborization through activation of estrogen receptor beta (ERβ) and phosphorylation of extracellular signal regulated kinase (ERK1/2) which was independent of brain derived neurotrophic factor (BDNF) mediated signalling mechanisms. Extra nuclear activation of ERK1/2 by ERβ resulted in phosphorylation of cyclic AMP response element binding protein (CREB) leading to increased expression of PSD-95.These molecular alterations translated to behavioural changes in CSE administered hypoxic animals that performed better in Morris Water Maze Task as compared to vehicle treated hypoxic animals. Toxicological studies show NOEAL > 2000mg/kg b.w. for oral administration of CSE indicating its safety for consumption. Our findings not only suggest the neuroprotective potential of CSE in hypoxia but also provide evidence for involvement of estrogen receptor and pCREB mediated nootropic effect of the extract.

Distribution and chemical composition of estrogen receptor β neurons in the paraventricular nucleus of the female and male mouse hypothalamus.

Activation of estrogen receptor beta (ERβ)-expressing neurons regulates the mammalian stress response via the hypothalamic-pituitary-adrenal (HPA) axis. These neurons densely populate the paraventricular nucleus of the hypothalamus (PVN). Recent research has revealed striking differences between rat and mouse PVN cytochemistry, but careful exploration of PVN ERβ neurons in mice has been hindered by a lack of specific ERβ antisera. Therefore, we used male and female transgenic mice expressing EGFP under the control of the mouse ERβ promoter (ERβ-EGFP) to examine the chemical architecture of PVN ERβ cells. Using immunohistochemistry, we found that 90% of ERβ-immunoreactivity (-ir) colocalized with EGFP. Cellular colocalization of EGFP with neuropeptides, transcription modulators, and neuronal tracers was examined throughout the PVN. ERβ-EGFP cells expressed oxytocin more abundantly in the rostral (71 ± 3%) than caudal (33 ± 8%) PVN. Arginine vasopressin colocalized with EGFP more often in females (18 ± 3%) than males (4 ± 1%). Moreover, estrogen receptor α-ir colocalized with ERβ-EGFP at low levels (15 ± 3%). Using a corticotropin releasing hormone-cre driver X tdTomato reporter mouse, we found a moderate colocalization with ERβ-ir (48 ± 16%) in the middle PVN. Peripheral injection of fluorogold revealed that the rostral PVN ERβ-EGFP cells are neuroendocrine neurons whereas non-neuroendocrine (presumably pre-autonomic) ERβ-EGFP neurons predominated in the posterior PVN. These data demonstrate chemoarchitectural differences in ERβ neurons of the mouse PVN that are different from that previously described for the rat, thus, elucidating potential neuronal pathways involved in the regulation of the HPA axis in mice.

Alternative microglial activation is associated with cessation of progressive dopamine neuron loss in mice systemically administered lipopolysaccharide

Inflammation arising from central and/or peripheral sources contributes to the pathogenesis of multiple neurodegenerative diseases including Parkinson's disease (PD). Emerging data suggest that differential activation of glia could lead to the pathogenesis and progression of PD. Here, we sought to determine the relationship between lipopolysaccharide (LPS) treatment, loss of dopaminergic neurons and differential activation of glia. Using a model of repeated injections with LPS (1mg/kg, i.p. for 4days), we found that LPS induced a 34% loss of dopamine neurons in the substantia nigra 19days after initiation of treatment, but no further cell loss was observed at 36days. LPS induced a strong pro-inflammatory response with increased mRNA expression of pro-inflammatory markers, including tumor necrosis factor-α (4.8-fold), inducible nitric oxide synthase (2.0-fold), interleukin-1 beta (8.9-fold), interleukin-6 (10.7-fold), and robust glial activation were observed at 1day after final dose of LPS. These pro-inflammatory genes were then reduced at 19days after treatment, when there was a rise in the anti-inflammatory genes Ym1 (1.8-fold) and arginase-1 (2.6-fold). Additionally, 36days after the last LPS injection there was a significant increase in interleukin-10 (2.1-fold) expression. The qPCR data results were supported by protein data, including cytokine measurements, western blotting, and immunofluorescence in brain microglia. Taken together, these data demonstrate that progressive neurodegeneration in the substantia nigra following LPS is likely arrested by microglia shifting to an anti-inflammatory phenotype. Thus, strategies to promote resolution of neuroinflammation may be a promising avenue to slow the progressive loss of dopamine neurons in PD.

Eosinophil Activation Status in Separate Compartments and Association with Asthma.

Asthma is frequently characterized by eosinophil-rich airway inflammation. Airway eosinophilia is associated with asthma exacerbations and likely plays a part in airway remodeling. Eosinophil recruitment from the bloodstream depends on circulating eosinophils becoming activated, which leads to eosinophil arrest on activated endothelium, extravasation, and continued movement through the bronchial tissue by interaction with the extracellular matrix (ECM). Circulating eosinophils can exist at different activation levels, which include non-activated or pre-activated (sensitized or “primed”). Further, the bloodstream may lack pre-activated cells, due to such eosinophils having arrested on endothelium or extravasated into tissue. Increased expression, and in some instances, decreased expression of cell-surface proteins, including CD44, CD45, CD45R0, CD48, CD137, neuropeptide S receptor, cytokine receptors, Fc receptors, and integrins (receptors mediating cell adhesion and migration by interacting with ligands on other cells or in the ECM), and activated states of integrins or Fc receptors on blood eosinophils have been reported to correlate with aspects of asthma. A subset of these proteins has been reported to respond to intervention, e.g., with anti-interleukin (IL)-5. How these surface proteins and the activation state of the eosinophil respond to other interventions, e.g., with anti-IL-4 receptor alpha or anti-IL-13, is unknown. Eosinophil surface proteins suggested to be biomarkers of activation, particularly integrins, and reports on correlations between eosinophil activation and aspects of asthma are described in this review. Intermediate activation of beta1 and beta2 integrins on circulating eosinophils correlates with decreased pulmonary function, airway inflammation, or airway lumen eosinophils in non-severe asthma. The correlation does not appear in severe asthma, likely due to a higher degree of extravasation of pre-activated eosinophils in more severe disease. Bronchoalveolar lavage (BAL) eosinophils have highly activated integrins and other changes in surface proteins compared to blood eosinophils. The activation state of eosinophils in lung tissue, although likely very important in asthma, is largely unknown. However, some recent articles, mainly on mice but partly on human cells, indicate that tissue eosinophils may have a surface phenotype(s) different from that of sputum or BAL eosinophils.

Human plasma fibronectin promotes proliferation and differentiation of odontoblast.

Objective To assess the effect of fibronectin (Fn) and porcine type I collagen (PCOL) on odontoblast-like cells in vitro.Material and Methods Rat odontoblast-like cells (MDPC-23 cells) were inoculated and cultured on Fn-coated or type I collagen-coated substrates. Proliferation assay, alkaline phosphatase activity (ALP activity), mRNA expression of hard tissue-forming markers, and Alizarin red staining were investigated over a period of 10 days.Results Cells maintained a high proliferation activity on Fn and PCOL even at a low seeding concentration (0.5×104/mL) as demonstrated by CCK-8 assay. The proliferation activity of cells on Fn increases in a concentration-dependent manner while it reached a plateau after 10 µg/mL. Cells adopted long, thin and spindle shape on Fn(10-50) and PCOL. Parallel actin filaments were observed in MDPC-23 cells cultured on Fn and PCOL. ALP activity was markedly up-regulated on Fn and PCOL-coated surfaces. Importantly, gene expression of BSP (Fn10: 2.44±0.32; Fn20: 3.05±0.01; Fn30: 2.90±0.21; Fn40: 2.74±0.30; Fn50: 2.64±0.12; PCOL: 2.20±0.03) and OCN (Fn10: 2.52±0.23; Fn20: 2.28±0.24; Fn30: 2.34±0.21; Fn40: 2.34±0.25; Fn50: 2.20±0.22; PCOL: 1.56±0.16) was significantly enhanced on Fn and PCOL substrates as compared with control; moreover, expression of integrin beta 1 (ITGB1), an ubiquitous cell surface receptor was augmented in Fn(10-50) and PCOL groups simultaneously. In accordance with the ALP activity and gene expression data, calcific deposition in cells grown on Fn(10-50) and PCOL was observed as well.Conclusion Despite the limitation of this study, the findings indicate that a surface coating of Fn enhances the proliferation, differentiation and mineralization of odontoblast-like cells by activation of integrin beta 1 (ITG B1). The promoting effects of Fn on MDPC-23 cells were achieved at a comparatively lower coating concentration than type I collagen (300 µg/mL). Specifically, it is suggested that the optimum coating concentration of Fn to be 10 µg/mL.

P7C3 inhibits GSK3\u03b2 activation to protect dopaminergic neurons against neurotoxin-induced cell death in vitro and in vivo

Parkinson’s disease (PD) is the second most prevalent neurodegenerative disease. Although its pathogenesis remains unclear, mitochondrial dysfunction plays a vital role in the pathology of PD. P7C3, an aminopropyl carbazole, possesses a significant neuroprotective ability in several neurodegenerative disorders, including PD. Here, we showed that P7C3 stabilized mitochondrial membrane potential, reduced reactive oxygen species production, and inhibited cytochrome c release in MES23.5 cells (a dopaminergic (DA) cell line) exposed to 1-methyl-4-phenylpyridinium (MPP+). In MES23.5 cells, P7C3 inhibited glycogen synthase kinase-3 beta (GSK3β) activation induced by MPP+. P7C3 also inhibited p53 activity and repressed Bax upregulation to protect cells from MPP+ toxicity. In addition, the activation of p53 was significantly attenuated with the inhibition of GSK3β activity by P7C3. Furthermore, P7C3 blocked GSK3β and p53 activation in the midbrain, and prevented DA neuronal loss in the substantia nigra in 1-methyl-4-phenyl-1,2,3,4-tetrahydropyridine mice. Thus, our study demonstrates that P7C3 protects DA neurons from neurotoxin-induced cell death by repressing the GSK3β-p53-Bax pathway both in vitro and in vivo, thus providing a theoretical basis for P7C3 in the potential clinical treatment of PD.

Myeloid differentiation factor 88 is up-regulated in epileptic brain and contributes to experimental seizures in rats

Accumulating evidence supports that activation of inflammatory pathways is a crucial factor contributing to the pathogenesis of seizures. In particular, the activation of interleukin-1 beta (IL-1β) system exerts proconvulsant effects in a large variety of seizure models. Myeloid differentiation factor 88 (MyD88) is a critical adaptor protein in the signaling cascade elicited by IL-1β. The present study aimed to investigate the expression pattern of MyD88 in rat models of seizures and in patients with refractory temporal lobe epilepsy (TLE), and to study the role of MyD88 in epileptic seizures. Our results revealed that MyD88 was up-regulated in the hippocampus of rats in the lithium-pilocarpine model of acute seizures. Importantly, MyD88 overexpression was also significantly present in the brain from chronic epileptic rats and the temporal neocortex specimens from drug-resistant TLE patients. In the acute seizure model, both the behavioral and electrographic seizure activities were record and analyzed in rats for 90min, starting immediately after pilocarpine injection. ST2825, a synthetic MyD88 inhibitor, was administered intracerebroventricularly (2.5–5.0–10μg in 2μl) 20min before pilocarpine injection. We found that ST2825 at doses of 5μg and 10μg significantly inhibited the pilocarpine-induced behavioral and electrographic seizures. Moreover, 10μg ST2825 prevented the proconvulsant actions of IL-1β. As previous evidence suggested that IL-1β proconvulsant effects was mediated by enhancing the phosphorylation level of the NR2B subunit of N-methyl-d-aspartate (NMDA) receptor, we then probed whether this molecular was involved in the effect of the pharmacological inhibition. Our results revealed that 10μg ST2825 markedly reversed the increased Tyr1472-phosphorylation of the NR2B subunit of NMDA receptor observed in the proconvulsant conditions of IL-1β and in seizures induced by pilocarpine alone. These findings indicate that altered expression of MyD88 might contribute to the pathogenesis of seizures and targeting of this adaptor protein might represent a novel therapeutic strategy to suppress seizure activities.

Lactobacillus fermentum IM12 attenuates inflammation in mice by inhibiting NF-κB-STAT3 signalling pathway.

In the present study, we isolated Lactobacillus fermentum IM12 from human gut microbiota, which strongly inhibited interleukin (IL)-6 expression and STAT3 activation in lipopolysaccharide (LPS)-stimulated murine peritoneal macrophages, and examined its anti-inflammatory effect in mice with carrageenan-induced hind-paw oedema (CIE) or 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis (TIC). Oral administration of IM12 (0.2×109, 1×109 or 5×109 cfu/mouse, once a day for 3 days) in mice with CIE significantly suppressed the increase of oedema volume and thickness, as well as myeloperoxidase activity and IL-6, IL-17, NO, and prostaglandin E2 levels in the carrageenan-stimulated paw. Treatment with IM12 (1×109 cfu/mouse, once a day for 3 days) in mice with TIC significantly suppressed colon shortening, and myeloperoxidase activity and IL-6 and IL-17 levels. Treatment with IM12 in mice with CIE or TIC also suppressed the expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2, as well as activation of nuclear factor kappa beta (NF-κB) and signal transducer and activator of transcription 3 (STAT3). Furthermore, IM12 significantly inhibited the expression of iNOS, and COX-2, as well as activation of NF-κB in LPS-stimulated mouse peritoneal macrophages. The inflammatory effect of heat-inactivated IM12 was significantly different to that of live IM12 in mice with TIC, although anti-inflammatory effect of IM12 was reduced by heat treatment. Based on these findings, IM12 may attenuate inflammation by inhibiting NF-κB-STAT3 signalling pathway.

A Novel Ligand of Toll-like Receptor 4 From the Sheath of Wuchereria bancrofti Microfilaria Induces Proinflammatory Response in Macrophages.

Lymphatic filariasis, frequently caused from Wuchereria bancrofti infection, is endemic in several parts of the globe and responsible for human health problems and socioeconomic loss to a large extent. Inflammatory consequences originating from host-parasite interaction play a major role in the disease pathology and allied complications. The identity of the key mediator of this process is yet unknown in filarial research. Microfilarial protein (MfP) was isolated from the sheath of W. bancrofti microfilariae through ultrafiltration, followed by chromatographic separation. Expression of signaling molecules was studied by enzyme-linked immunosorbent assay and immunoblotting. Binding of MfP to Toll-like receptor 4 (TLR4) was determined by co-immunoprecipitation, fluorescein isothiocyanate-probing, and surface plasmon resonance analysis. We found that MfP (approximately 70 kDa) binds to macrophage-TLR4 and triggers nuclear factor kappa beta activation that upregulates secretion of proinflammatory cytokines. Microfilarial protein failed to induce inflammation in either TLRKO macrophage or macrophage treated with TLR4 inhibitor, indicating that MfP acts through TLR4. We have also detected phenotypic transformation of macrophages from anti-inflammatory (M2) to proinflammatory (M1) subtype after incubation with MfP. Microfilarial protein appears to be a new ligand of TLR4 from W. bancrofti. Determination of its functional attributions in the host-parasite relationship, especially immunopathogenesis of filarial infection, may improve our understanding.

NG2 glial cells regulate neuroimmunological responses to maintain neuronal function and survival

NG2-expressing neural progenitor cells (i.e., NG2 glial cells) maintain their proliferative and migratory activities even in the adult mammalian central nervous system (CNS) and produce myelinating oligodendrocytes and astrocytes. Although NG2 glial cells have been observed in close proximity to neuronal cell bodies in order to receive synaptic inputs, substantive non-proliferative roles of NG2 glial cells in the adult CNS remain unclear. In the present study, we generated NG2-HSVtk transgenic rats and selectively ablated NG2 glial cells in the adult CNS. Ablation of NG2 glial cells produced defects in hippocampal neurons due to excessive neuroinflammation via activation of the interleukin-1 beta (IL-1β) pro-inflammatory pathway, resulting in hippocampal atrophy. Furthermore, we revealed that the loss of NG2 glial cell-derived hepatocyte growth factor (HGF) exacerbated these abnormalities. Our findings suggest that NG2 glial cells maintain neuronal function and survival via the control of neuroimmunological function.

Alpha-Melanocyte Stimulating Hormone Protects against Cytokine-Induced Barrier Damage in Caco-2 Intestinal Epithelial Monolayers.

Alpha-melanocyte-stimulating hormone (α-MSH) is a potent anti-inflammatory peptide with cytoprotective effect in various tissues. The present investigation demonstrates the ability of α-MSH to interact with intestinal epithelial cell monolayers and mitigate inflammatory processes of the epithelial barrier. The protective effect of α-MSH was studied on Caco-2 human intestinal epithelial monolayers, which were disrupted by exposure to tumor necrosis factor-α and interleukin-1β. The barrier integrity was assessed by measuring transepithelial electric resistance (TEER) and permeability for marker molecules. Caco-2 monolayers were evaluated by immunohistochemistry for expression of melanocortin-1 receptor and tight junction proteins ZO-1 and claudin-4. The activation of nuclear factor kappa beta (NF-κB) was detected by fluorescence microscopy and inflammatory cytokine expression was assessed by flow cytometric bead array cytokine assay. Exposure of Caco-2 monolayers to proinflammatory cytokines lowered TEER and increased permeability for fluorescein and albumin, which was accompanied by changes in ZO-1 and claudin-4 immunostaining. α-MSH was able to prevent inflammation-associated decrease of TEER in a dose-dependent manner and reduce the increased permeability for paracellular marker fluorescein. Further immunohistochemistry analysis revealed proinflammatory cytokine induced translocation of the NF-κB p65 subunit into Caco-2 cell nuclei, which was inhibited by α-MSH. As a result the IL-6 and IL-8 production of Caco-2 monolayers were also decreased with different patterns by the addition of α-MSH to the culture medium. In conclusion, Caco-2 cells showed a positive immunostaining for melanocortin-1 receptor and α-MSH protected Caco-2 cells against inflammatory barrier dysfunction and inflammatory activation induced by tumor necrosis factor-α and interleukin-1β cytokines.

Palmitic acid increases invasiveness of pancreatic cancer cells AsPC-1 through TLR4/ROS/NF-κB/MMP-9 signaling pathway

Pancreatic cancer (PC) is an aggressive malady with proclivity for early metastasis. Overexpression of toll-like receptor 4 (TLR4) in pancreatic ductal adenocarcinoma, the most common type of pancreatic malignancy, correlates to tumor size, lymph node involvement, venous invasion and pathological stage. Lipopolysaccharides (LPS) are natural TLR4 ligands that have been shown to increase the invasive ability of PC cells. However, rapid inactivation of circulating LPS and low systemic absorption of inhaled LPS from the bronchoalveolar compartment make other agonists such as saturated fatty acids more suitable to be considered for TLR4-related cell invasiveness. Interestingly, PC risk was strongly associated to intake of saturated fat from animal food sources, in particular to consumption of saturated palmitic acid (PA). In the present study, we investigated the influence of PA on the invasive capacity of human PC cells AsPC-1. Using specific inhibitors, we found that PA stimulation of these tumor cells induced a TLR4-mediated cell invasion. Our results also indicate that the signaling events downstream of TLR4 involved generation of reactive oxygen species, activation of nuclear factor-kappa beta, and secretion and activation of matrix metalloproteinase 9 (MMP-9). Furthermore, PA stimulation decreased the levels of the micro RNA 29c (miR-29c). Of note, while inhibition of miR-29c increased MMP-9 mRNA levels, MMP-9 secretion and activation, and invasiveness, miR-29c mimic abrogated all these PA-stimulated effects. These results strongly suggest that miR-29c could be an attractive potential pharmacological agent for antitumoral therapy in PC.