Search results for "PEPTIDE"
showing 10 items of 4589 documents
Effect of nitrogen limitation and nature of the feed upon Oenococcus oeni metabolism and extracellular protein production
2005
Aims: The aim of the study was to characterize the effect of various nitrogen sources on Oenococcus oeni growth, carbon source utilization, extracellular protease activity and extracellular proteins. More generally, the goal is to understand how nitrogen-based additives might act to enhance malolactic fermentation in wine. Methods and Results: Five yeast extracts were used. As the amino acid and nitrogen analyses revealed, they were similar in global amino acid composition, except for arginine level. Nevertheless the ratio of amino acids between free/bound, and low/high molecular weight fractions were highly different. One of the yeast extracts led to a significant protease activity in th…
Arginine-rich peptides are blockers of VR-1 channels with analgesic activity
2000
Vanilloid receptors (VRs) play a fundamental role in the transduction of peripheral tissue injury and/or inflammation responses. Molecules that antagonize VR channel activity may act as selective and potent analgesics. We report that synthetic arginine-rich hexapeptides block heterologously expressed VR-1 channels with submicromolar efficacy in a weak voltage-dependent manner, consistent with a binding site located near/at the entryway of the aqueous pore. Dynorphins, natural arginine-rich peptides, also blocked VR-1 activity with micromolar affinity. Notably, synthetic and natural arginine-rich peptides attenuated the ocular irritation produced by topical capsaicin application onto the eye…
Isolation and characterization of a complement-activating lipid extracted from human atherosclerotic lesions.
1990
The major characteristics of human atherosclerotic lesions are similar to those of a chronic inflammatory reaction, namely fibrosis, mesenchymal cell proliferation, the presence of resident macrophages, and cell necrosis. Atherosclerosis exhibits in addition the feature of lipid (mainly cholesterol) accumulation. The results of the present report demonstrate that a specific cholesterol-containing lipid particle present in human atherosclerotic lesions activates the complement system to completion. Thus, lipid could represent a stimulatory factor for the inflammatory reaction, whose underlying mechanistic basis may be, at least in part, complement activation. The complement-activating lipid …
Atherogenic properties of enzymatically degraded LDL: selective induction of MCP-1 and cytotoxic effects on human macrophages.
1998
Abstract —The mechanisms underlying the selective accumulation of macrophages in early atherosclerotic lesions are poorly understood but are likely to be related to specific properties of altered low density lipoprotein (LDL) deposited in the subendothelium. Enzymatic, nonoxidative degradation of LDL converts the lipoprotein to a potentially atherogenic moiety, enzymatically altered LDL (E-LDL), which activates complement and is rapidly taken up by human macrophages via a scavenger receptor–dependent pathway. Immunohistological evidence indicates that E-LDL is present in an extracellular location in the early lesion. We report that E-LDL causes massive release of monocyte chemotactic prote…
Complement and atherogenesis: The unknown connection
1999
The question why low-density lipoprotein (LDL) stranded in the subendothelium of arteries should acquire the proinflammatory properties that initiate and sustain atherogenesis has puzzled researchers for decades. The most popular concept contends that oxidative processes are crucial because oxidized LDL (ox-LDL) produced in vitro has atherogenic properties and small amounts of it are found in atherosclerotic lesions. Recently, a possible role for vascular infections has also been considered because infectious agents, in particular Chlamydia pneumoniae, are sometimes present in the lesions. Here, evidence is summarized for a different concept of atherogenesis, which evolves from the fact tha…
JAK3/STAT5/6 Pathway Alterations Are Associated with Immune Deviation in CD8+ T Cells in Renal Cell Carcinoma Patients
2010
To investigate the molecular mechanisms underlying altered T cell response in renal cell carcinoma (RCC) patients, we compared autologous and allogeneic CD8(+) T cell responses against RCC line from RCC patients and their HLA-matched donors, using mixed lymphocyte/tumor cell cultures (MLTCs). In addition, we analyzed the expression of molecules associated with cell cycle regulation. Autologous MLTC responder CD8(+) T cells showed cytotoxic activity against RCC cell lines; however the analysis of the distribution of CD8(+) T-cell subsets revealed that allogenic counterparts mediate superior antitumor efficacy. In RCC patients, a decreased proliferative response to tumor, associated with defe…
The mitochondrial‐derived peptide MOTS ‐c: a player in exceptional longevity?
2015
Mitochondrial-derived peptides (MDP) are encoded by functional short open reading frames in the mitochondrial DNA (mtDNA). These include humanin, and the recently discovered mitochondrial open reading frame of the 12S rRNA-c (MOTS-c). Although more research is needed, we suggest that the m.1382A>C polymorphism located in the MOTS-c encoding mtDNA, which is specific for the Northeast Asian population, may be among the putative biological mechanisms explaining the high longevity of Japanese people. 5.760 JCR (2015) Q1, 36/187 Cell biology, 3/49 Geriatrics & gerontology UEM
Pharmacological blockade of the fatty acid amide hydrolase (FAAH) alters neural proliferation, apoptosis and gliosis in the rat hippocampus, hypothal…
2015
Endocannabinoids participate in the control of neurogenesis, neural cell death and gliosis. The pharmacological effect of the fatty acid amide hydrolase (FAAH) inhibitor URB597, which limits the endocannabinoid degradation, was investigated in the present study. Cell proliferation (phospho-H3(+) or BrdU(+) cells) of the main adult neurogenic zones as well as apoptosis (cleaved caspase-3(+)), astroglia (GFAP(+)), and microglia (Iba1(+) cells) were analyzed in the hippocampus, hypothalamus and striatum of rats intraperitoneally treated with URB597 (0.3 mg/kg/day) at one dose/4-days resting or 5 doses (1 dose/day). Repeated URB597 treatment increased the plasma levels of the N-acylethanolamine…
Modulation of dendritic cells and macrophages : implication in cancer and atherosclerosis
2010
During my thesis, I studied the cytotoxic function of dendritic cells (DC) from cancer patients and compared it to DC from healthy donors. Our results indicate that human monocyte-derived DC can acquire strong cytotoxic activity toward tumor cells after activation with low dose of LPS. The cytotoxic potential of DC derived from cancer patients was almost the same as the one generated from healthy donors. We identified the tumor cell killing mechanism which involves peroxynitrite release. After killing of cancer cells, DC are capable of engulfing dead tumor cell fragments and overexpress the costimulatory molecules necessary for T cell proliferation. A second study consisted in an analysis o…
Invasive Observation by Atomic Force Microscope of a Langmuir-Blodgett Monolayer of Gramicidin
2002
The properties of gramicidin, a linear antibiotic polypeptide of 15 amino acids, have been studied at the air-water interface. Analysis of the pressure-area isotherm is not able to conclude about the conformational behavior of gramicidin in the monolayer. Langmuir-Blodgett deposition of gramicidin layers onto a mica substrate has been developed for atomic force microscopy (AFM) observations. At high pressure of deposition, the gramicidin monolayer is composed of dimers perpendicular to the surface. The possibility of removing the half upper part of this dimer monolayer with the AFM tip is more in favor of a structure of single-stranded helical dimers.