Hyaluronan Regulates Neuronal and Immune Function in the Rat Small Intestine and Colonic Microbiota after Ischemic/Reperfusion Injury.

Background: Intestinal ischemia and reperfusion (IRI) injury induces acute and long-lasting damage to the neuromuscular compartment and dysmotility. This study aims to evaluate the pathogenetic role of hyaluronan (HA), a glycosaminoglycan component of the extracellular matrix, as a modulator of the enteric neuronal and immune function and of the colonic microbiota during in vivo IRI in the rat small intestine.

Methods: mesenteric ischemia was induced in anesthetized adult male rats for 60 min, followed by 24 h reperfusion.

The medicinal leech as a valuable model for better understanding the role of a TLR4-like receptor in the inflammatory process.

Despite extensive investigation focused on both the molecular characteristics and the expression level of Toll-like receptors (TLRs) during the inflammatory response in vertebrates, few data are available in the literature on the role of these proteins in invertebrate's immune response. Here, we propose the medicinal leech as a valuable model to better elucidate the role of TLR4 and its related products, such as tumor necrosis factor (TNF-α), after activation of the leech peripheral immune system with the endogenous medicinal leech recombinant allograft inflammatory factor-1 (rHmAIF-1) or with an exogenous stimulus, such as lipopolysaccharide (LPS). Our results indicate that activated macrophages (HmAIF-1) and granulocytes (CD11b) express both TLR4 and its coreceptor CD14.

MiR-146a induction by cyanobacterial lipopolysaccharide antagonist (CyP) mediates endotoxin cross-tolerance.

Endotoxin tolerance is a phenomenon characterized by a reduced capacity of monocytes and macrophages to respond to repeated stimulation with lipopolysaccharide (LPS) which has been suggested to represent a way of controlling the intensity and duration of innate immune response. During endotoxin tolerance, monocytes undergo functional re-programming primarily by epigenetic regulation. Recently, micro-RNA (miR)-146a has been demonstrated to be the major player of the negative regulation of the pro-inflammatory response, affecting TNF-α production.

The Effect of Cyanobacterial LPS Antagonist (CyP) on Cytokines and Micro-RNA Expression Induced by LPS.

Lipopolysaccharide (LPS) from (Pg-LPS) is a key bacterial structure involved in the maintenance of a chronic pro-inflammatory environment during periodontitis. Similar to other gram-negative LPS, Pg-LPS induces the release of pro-inflammatory cytokines through interaction with Toll-Like Receptor 4 (TLR4) and is able to stimulate negative TLR4 regulatory pathways, such as those involving microRNA (miRNA). In this work, we employed CyP, an LPS with TLR4-MD2 antagonist activity obtained from the cyanobacterium , to study the effects on pro-inflammatory cytokine production and miRNA expression in human monocytic THP-1 cells stimulated with Pg-LPS or LPS (Ec-LPS).

Natural Products with Toll-Like Receptor 4 Antagonist Activity.

Toll-Like Receptors (TLRs) are the innate immunity receptors that play an activating role when interacting with molecules released by bacteria and viruses (PAMPs, pathogen-associated molecular patterns) or with molecules released by injured cells and tissues (DAMPs, danger-associated molecular patterns). TLR triggering leads to the induction of proinflammatory cytokines and chemokines, driving the activation of both innate and adaptive immunity. In particular, Toll-Like Receptor 4 (TLR4) has been described to be involved in the inflammatory processes observed in several pathologies (such as ischemia/reperfusion injury, neuropathic pain, neurodegenerative diseases, and cancer).

Effects of the gut-liver axis on ischaemia-mediated hepatocellular carcinoma recurrence in the mouse liver.

Background & Aims: There is growing evidence that liver graft ischemia-reperfusion (I/R) is a risk factor for hepatocellular carcinoma (HCC) recurrence, but the mechanisms involved are unclear. Herein, we tested the hypothesis that mesenteric congestion resulting from portal blood flow interruption induces endotoxin-mediated Toll-like receptor 4 (Tlr4) engagement, resulting in elevated liver cancer burden. We also assessed the role of remote ischemic preconditioning (RIPC) in this context.

Neurodegenerative diseases: The immunological perspective.

Increasing evidence supports the notion that the neurodegenerative process occurring in Alzheimer's disease (AD), Parkinson's disease (PD) and Amyotrophic Lateral Sclerosis (ALS) does not only imply the neuronal compartment but also involves a strong interaction with the immunological cells of the Central Nervous System (CNS), primarily microglia. Starting from the observation that the neurodegenerative disorders are frequent in elderly individuals, who have an immunological background that possibly favors this process, it is evident that a dysregulation of innate immune response triggered by misfolded and aggregated proteins, or by endogenous molecules released by injured neurons, directly contributes to disease pathogenesis and progression. There are important differences in the immunological processes occurring in AD, PD, ALS involving microglial function.

Blockade of the IL-1R1/TLR4 pathway mediates disease-modification therapeutic effects in a model of acquired epilepsy.

We recently discovered that forebrain activation of the IL-1 receptor/Toll-like receptor (IL-1R1/TLR4) innate immunity signal plays a pivotal role in neuronal hyperexcitability underlying seizures in rodents. Since this pathway is activated in neurons and glia in human epileptogenic foci, it represents a potential target for developing drugs interfering with the mechanisms of epileptogenesis that lead to spontaneous seizures. The lack of such drugs represents a major unmet clinical need.

Toll-like receptor 4-dependent glial cell activation mediates the impairment in memory establishment induced by β-amyloid oligomers in an acute mouse model of Alzheimer's disease.

Background: Amyloid-β oligomers (AβO) are species mainly involved in the synaptic and cognitive dysfunction in Alzheimer's disease. Although their action has been described mainly at neuronal level, it is now clear that glial cells govern synaptic activity in their resting state, contributing to new learning and memory establishment. In contrast, when activated, they may lead to synaptic and cognitive dysfunction.

The Role of Toll-Like Receptor 4 in Infectious and Noninfectious Inflammation.

Toll-like receptor 4 (TLR4) belongs to the family of pattern recognition receptors (PRRs). They are highly conserved receptors that recognize conserved pathogen-associated molecular patterns (PAMPs), thus representing the first line of defense against infections. TLR4 has been long recognized as the sensing receptor for gram-negative lipopolysaccharide (LPS).

Phase I-II study of hypofractionated simultaneous integrated boost using volumetric modulated arc therapy for adjuvant radiation therapy in breast cancer patients: a report of feasibility and early toxicity results in the first 50 treatments.

Background: To report results in terms of feasibility and early toxicity of hypofractionated simultaneous integrated boost (SIB) approach with Volumetric Modulated Arc Therapy (VMAT) as adjuvant treatment after breast-conserving surgery.

Methods: Between September 2010 and May 2011, 50 consecutive patients presenting early-stage breast cancer were submitted to adjuvant radiotherapy with SIB-VMAT approach using RapidArc in our Institution (Istituto Clinico Humanitas ICH). Three out of 50 patients were irradiated bilaterally (53 tumours in 50 patients).

Neuroprotective effects of toll-like receptor 4 antagonism in spinal cord cultures and in a mouse model of motor neuron degeneration.

Sustained inflammatory reactions are common pathological events associated with neuron loss in neurodegenerative diseases. Reported evidence suggests that Toll-like receptor 4 (TLR4) is a key player of neuroinflammation in several neurodegenerative diseases. However, the mechanisms by which TLR4 mediates neurotoxic signals remain poorly understood.

Coadministration of the cyanobacterial lipopolysaccharide antagonist CyP with antibiotic inhibits cytokine production by an in vitro meningitis model infected with Neisseria meningitidis.

Objectives: In this study, the objective was to determine the anti-inflammatory properties of CyP, a cyanobacterial lipopolysaccharide (LPS) antagonist, used in combination with antibiotic chemotherapy during infection of an in vitro meningitis model infected with Neisseria meningitidis (meningococcus).

Methods: Monocultures of human meningioma cells and meningioma-primary human macrophage co-cultures were infected with meningococci (10(2)-10(8) cfu/monolayer) or treated with isolated outer membranes or purified LPS (0.1-100 ng/monolayer) from N.

Therapeutic potential of new antiinflammatory drugs.

Experimental and clinical findings have shown in the past decade that specific proinflammatory mediators and their cognate receptors are upregulated in epileptic brain tissue. In particular, the IL-1 receptor (R)/Toll-like receptor (TLR) signaling pathways are activated in experimental models of seizures and in human epileptic tissue from drug-resistant patients. Pharmacological targeting of these proinflammatory pathways using selective receptor antagonists, or the use of transgenic mice with perturbed cell signaling, demostrated that the activation of IL-1R type 1 and TLR4 by their respective endogenous ligands, i.

Effect of the lipopolysaccharide antagonist Planktothrix sp. FP1 cyanobacterial extract on human polymorphonuclear leukocytes.

CyP is a lipopolysaccharide (LPS)-like molecule extracted from the freshwater cyanobacterium Oscillatoria planktothrix FP1, which has been reported to be a potent competitive inhibitor of bacterial LPS. In the present study the ability of CyP to affect human polymorphonuclear leukocyte (PMN) function was investigated. PMNs were isolated from venous blood by standard density-gradient centrifugation.

Toll-like receptor 4 and high-mobility group box-1 are involved in ictogenesis and can be targeted to reduce seizures.

Brain inflammation is a major factor in epilepsy, but the impact of specific inflammatory mediators on neuronal excitability is incompletely understood. Using models of acute and chronic seizures in C57BL/6 mice, we discovered a proconvulsant pathway involving high-mobility group box-1 (HMGB1) release from neurons and glia and its interaction with Toll-like receptor 4 (TLR4), a key receptor of innate immunity. Antagonists of HMGB1 and TLR4 retard seizure precipitation and decrease acute and chronic seizure recurrence.

Meconium-induced release of cytokines is mediated by the TRL4/MD-2 complex in a CD14-dependent manner.

Objective: Meconium, the first intestinal discharge of the newborn, contains material accumulated during fetal life. Meconium activates complement and CD14 and may induce a systemic inflammatory response. Toll-like receptors are classical pattern-recognition receptors recognizing both exogenous and host-derived ligands.

A biosensor for all D-amino acids using evolved D-amino acid oxidase.

Determination of the D-amino acid content in foods and in biological samples is a very important task. In order to achieve this goal we developed a biosensor employing the flavoenzyme D-amino acid oxidase from the yeast Rhodotorula gracilis. To produce a device in which the D-amino acid composition does not alter the results, both the wild-type and a number of mutants obtained by rational design and directed evolution approaches were used.

Cyanobacterial LPS antagonist (CyP)-a novel and efficient inhibitor of Escherichia coli LPS-induced cytokine response in the pig.

Toll-like receptors are essential pattern-recognition receptors of the innate immune system. They recognize a range of conserved molecules of invading microorganisms. The innate immune system is developed to protect the host, but can be deleterious if activated uncontrolled or inappropriate, such as in sepsis with Gram-negative bacteria.

A cyanobacterial lipopolysaccharide antagonist inhibits cytokine production induced by Neisseria meningitidis in a human whole-blood model of septicemia.

Septicemia caused by Neisseria meningitidis is characterized by increasing levels of meningococcal lipopolysaccharide (Nm-LPS) and cytokine production in the blood. We have used an in vitro human whole-blood model of meningococcal septicemia to investigate the potential of CyP, a selective Toll-like receptor 4 (TLR4)-MD-2 antagonist derived from the cyanobacterium Oscillatoria planktothrix FP1, for reducing LPS-mediated cytokine production. CyP (> or = 1 microg/ml) inhibited the secretion of the proinflammatory cytokines tumor necrosis factor alpha, interleukin-1beta (IL-1beta), and IL-6 (by >90%) and chemokines IL-8 and monocyte chemoattractant protein 1 (by approximately 50%) induced by the treatment of blood with pure Nm-LPS, by isolated outer membranes, and after infection with live meningococci of different serogroups.

Neutropenic enterocolitis: is there a right timing for surgery? Assessment of a clinical case.

Neutropenic enterocolitis is a severe and potentially life-threatening complication that may affect patients undergoing chemotherapy for acute leukemia or lymphoma. These patients may develop systemic sepsis through bacterial or fungal translocation across the intestinal wall. In many cases neutropenic enterocolitis is confined to the cecum, but the entire colon is sometimes involved.

Colorectal cancer: what has changed in diagnosis and treatment over the last 50 years?

Aims And Background: This overview focuses on what has changed in the diagnosis and treatment of colorectal cancer over the last 50 years.

Methods: The most important international registers (SEER, European and Italian) as well as the literature have been consulted. Furthermore, many prognostic factors are analyzed with the aim to understand the reasons why 5-year survival has improved over the last two decades.

alpha-Synuclein protects SH-SY5Y cells from dopamine toxicity.

Dopaminergic human neuroblastoma SH-SY5Y cells were stably transformed to increase expression of alpha-synuclein, a Parkinson's disease-related protein. Transformed cells were more resistant to oxidative insults, showing a cytoprotective role of alpha-synuclein. The expression of redox chaperonins (DJ-1, HSP70, and 14-3-3) was evaluated by Western blotting.

A cyanobacterial LPS antagonist prevents endotoxin shock and blocks sustained TLR4 stimulation required for cytokine expression.

Toll-like receptors (TLRs) function as primary sensors that elicit coordinated innate immune defenses through recognition of microbial products and induction of immune and proinflammatory genes. Here we report the identification and biological characterization of a lipopolysaccharide (LPS)-like molecule extracted from the cyanobacterium Oscillatoria Planktothrix FP1 (cyanobacterial product [CyP]) that is not stimulatory per se but acts as a potent and selective antagonist of bacterial LPS. CyP binds to MD-2 and efficiently competes with LPS for binding to the TLR4-MD-2 receptor complex.