Littérature scientifique sur le sujet « LACTOFERRIN (LF) »
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Articles de revues sur le sujet "LACTOFERRIN (LF)"
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Liang, Yifan, Shin-ichi Ikeda, Junhan Chen, Yan Zhang, Kazuno Negishi, Kazuo Tsubota et Toshihide Kurihara. « Myopia Is Suppressed by Digested Lactoferrin or Holo-Lactoferrin Administration ». International Journal of Molecular Sciences 24, no 6 (18 mars 2023) : 5815. http://dx.doi.org/10.3390/ijms24065815.
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Myopia is becoming a leading cause of vision impairment. An effective intervention is needed. Lactoferrin (LF) is a protein that has been reported to inhibit myopia progression when taken orally. This study looked at the effects of different forms of LF, such as native LF and digested LF, on myopia in mice. Mice were given different forms of LF from 3 weeks of age, and myopia was induced with minus lenses from 4 weeks of age. Results showed that mice given digested LF or holo-LF had a less elongated axial length and thinned choroid, compared to those given native-LF. Gene expression analysis also showed that the groups given native-LF and its derivatives had lower levels of certain cytokines and growth factors associated with myopia. These results suggest that myopia can be more effectively suppressed by digested LF or holo-LF than native-LF.
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León-Sicairos, Nidia, Magda Reyes-López, Cynthia Ordaz-Pichardo et Mireya de la Garza. « Microbicidal action of lactoferrin and lactoferricin and their synergistic effect with metronidazole inEntamoeba histolyticaThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin : Structure, Function, and Applications, and has undergone the Journal's usual peer review process. » Biochemistry and Cell Biology 84, no 3 (juin 2006) : 327–36. http://dx.doi.org/10.1139/o06-060.
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Lactoferrin (Lf), in its iron-free form, has been shown to inhibit the growth of pathogenic microorganisms. In the light of new agents to control amoebiasis, the microbicidal activity of human and bovine Lf and bovine lactoferricin (bLfcin, fragment 4–14), and of each combined with metronidazole, the main drug used in amoebiasis, was evaluated in trophozoites of Entamoeba histolytica. Both lactoferrins and bLfcin were able to kill amoebas in a concentration-dependent manner. This killing effect was modulated according to the culture age, pH, and temperature. Parasites obtained from the stationary phase were more susceptible to Lf than those from the early exponential phase. The effect of Lf and its derived peptide, bLfcin, was prevented by both Fe2+and Fe3+. However, the divalent cations Mg2+and Ca2+prevented the killing effect of Lf but not of bLfcin. A synergistic amoebicidal effect was found between metronidazole and human Lf, bovine Lf, or bLfcin. These data suggest that Lf and bLfcin might be used in amoebiasis if they are administered with a low dose of metronidazole to diminish the toxicity of this drug. Thus, Lf and bLfcin are therapeutically potential candidates for use as antiamoebics in patients.
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Hoek, K. S., J. M. Milne, P. A. Grieve, D. A. Dionysius et R. Smith. « Antibacterial activity in bovine lactoferrin-derived peptides. » Antimicrobial Agents and Chemotherapy 41, no 1 (janvier 1997) : 54–59. http://dx.doi.org/10.1128/aac.41.1.54.
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Several peptides sharing high sequence homology with lactoferricin B (Lf-cin B) were generated from bovine lactoferrin (Lf) with recombinant chymosin. Two peptides were copurified, one identical to Lf-cin B and another differing from Lf-cin B by the inclusion of a C-terminal alanine (lactoferricin). Two other peptides were copurified from chymosin-hydrolyzed Lf, one differing from Lf-cin B by the inclusion of C-terminal alanyl-leucine and the other being a heterodimer linked by a disulfide bond. These peptides were isolated in a single step from chymosin-hydrolyzed Lf by membrane ion-exchange chromatography and were purified by reverse-phase high-pressure liquid chromatography (HPLC). They were characterized by N-terminal Edman sequencing, mass spectrometry, and antibacterial activity determination. Pure lactoferricin, prepared from pepsin-hydrolyzed Lf, was purified by standard chromatography techniques. This peptide was analyzed against a number of gram-positive and gram-negative bacteria before and after reduction of its disulfide bond or cleavage after its single methionine residue and was found to inhibit the growth of all the test bacteria at a concentration of 8 microM or less. Subfragments of lactoferricin were isolated from reduced and cleaved peptide by reverse-phase HPLC. Subfragment 1 (residues 1 to 10) was active against most of the test microorganisms at concentrations of 10 to 50 microM. Subfragment 2 (residues 11 to 26) was active against only a few microorganisms at concentrations up to 100 microM. These antibacterial studies indicate that the activity of lactoferricin is mainly, but not wholly, due to its N-terminal region.
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Takakura, Natsuko, Hiroyuki Wakabayashi, Hiroko Ishibashi, Susumu Teraguchi, Yoshitaka Tamura, Hideyo Yamaguchi et Shigeru Abe. « Oral Lactoferrin Treatment of Experimental Oral Candidiasis in Mice ». Antimicrobial Agents and Chemotherapy 47, no 8 (août 2003) : 2619–23. http://dx.doi.org/10.1128/aac.47.8.2619-2623.2003.
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ABSTRACT We assessed the potential of lactoferrin (LF), a multifunctional milk protein, for treatment of oral candidiasis with immunosuppressed mice, which have local symptoms characteristic of oral thrush. Oral administration of bovine LF in drinking water starting 1 day before the infection significantly reduced the number of Candida albicans in the oral cavity and the score of lesions on the tongue on day 7 after the inoculation. The symptomatic effect of LF was confirmed by macroscopic and microscopic observations of the tongue's surface. Similar effects were also observed upon administration of LF pepsin hydrolysate, but not lactoferricin B, an antimicrobial peptide of LF. The anticandidal activity of LF was evident on administration either in drinking water or by intragastric intubation with a stomach tube. These results suggest that the effect of LF in this oral candidiasis model is not due to direct antifungal action. In conclusion, LF could have potential as a food component supporting antifungal drug treatment.
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Caccavo, Domenico, Antonella Afeltra, Salvatore Pece, Giuseppe Giuliani, Marina Freudenberg, Chris Galanos et Emilio Jirillo. « Lactoferrin-Lipid A-Lipopolysaccharide Interaction : Inhibition by Anti-Human Lactoferrin Monoclonal Antibody AGM 10.14 ». Infection and Immunity 67, no 9 (1 septembre 1999) : 4668–72. http://dx.doi.org/10.1128/iai.67.9.4668-4672.1999.
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ABSTRACT Lactoferrin (LF) is a glycoprotein that exerts both bacteriostatic and bactericidal activities. The interaction of LF with lipopolysaccharide (LPS) of gram-negative bacteria seems to play a crucial role in the bactericidal effect. In this study, we evaluated, by means of an enzyme-linked immunosorbent assay, the binding of biotinylated LF to the S (smooth) and R (rough) (Ra, Rb, Rc, Rd1, Rd2, and Re) forms of LPS and different lipid A preparations. In addition, the effects of two monoclonal antibodies (AGM 10.14, an immunoglobulin G1 [IgG1] antibody, and AGM 2.29, an IgG2b antibody), directed against spatially distant epitopes of human LF, on the LF-lipid A or LF-LPS interaction were evaluated. The results showed that biotinylated LF specifically binds to solid-phase lipid A, as this interaction was prevented in a dose-dependent fashion by either soluble uncoupled LF or lipid A. The binding of LF to S-form LPS was markedly weaker than that to lipid A. Moreover, the rate of LF binding to R-form LPS was inversely related to core length. The results suggest that the polysaccharide O chain as well as oligosaccharide core structures may interfere with the LF-lipid A interaction. In addition, we found that soluble lipid A also inhibited LF binding to immobilized LPS, demonstrating that, in the whole LPS structure, the lipid A region contains the major determinant recognized by LF. AGM 10.14 inhibited LF binding to lipid A and LPS in a dose-dependent fashion, indicating that this monoclonal antibody recognizes an epitope involved in the binding of LF to lipid A or some epitope in its close vicinity. In contrast, AGM 2.29, even in a molar excess, did not prevent the binding of LF to lipid A or LPS. Therefore, AGM 10.14 may represent a useful tool for neutralizing selectively the binding of LF to lipid A. In addition, the use of such a monoclonal antibody could allow better elucidation of the consequences of the LF-lipid A interaction.
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Miyazawa, K., C. Mantel, L. Lu, D. C. Morrison et H. E. Broxmeyer. « Lactoferrin-lipopolysaccharide interactions. Effect on lactoferrin binding to monocyte/macrophage-differentiated HL-60 cells. » Journal of Immunology 146, no 2 (15 janvier 1991) : 723–29. http://dx.doi.org/10.4049/jimmunol.146.2.723.
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Abstract Lactoferrin (LF) has been implicated in a number of functions including the negative regulation of myelopoiesis in vitro and in vivo, an effect mediated by suppression of cytokine release from monocytes/macrophages. This suppression is abrogated by bacterial LPS. In the present study, HL-60 cells were induced to differentiate to monocytes/macrophages by 12-O-tetradecanoyl phorbol-13-acetate, and LF-binding assays were performed. After differentiation, HL-60 cells showed a twofold increase of LF-binding sites with no difference in the specificity or affinity of LF between pre- and post-differentiated cells. CD11a, CD11b, and CD11c Ag, which have been associated with specific binding sites for LPS on monocytes/macrophages, were also increased three- to fourfold after differentiation. With the use of this system, the effect of LPS on LF binding was studied. At 37 degrees C, LPS enhanced LF binding on HL-60 cells, especially after differentiation. Conversely, at 4 degrees C, LPS inhibited LF binding. There was little effect of temperature on LF binding in the absence of LPS. In the presence of polymyxin B sulfate, the enhanced LF binding by LPS was abrogated. Also, pretreatment with mAbCD11 and/or mAb5D3, which are associated with or directed against candidate LPS receptors, reduced LF binding. Cross-linking studies using an iodinated, photoactivatable LPS derivative ([125I]ASD-LPS) demonstrated directly the specific binding of LPS to LF. These data indicate a dichotomous nature of LF binding on monocyte/macrophage-differentiated HL-60 cells--one being mediated by specific LF receptors whereas the other is apparently mainly via LPS receptors after formation of an LF-LPS complex. These interactions, for which a model is proposed, help to explain the mechanism behind LPS abrogation of the myelopoietic suppressive effects of LF, and a situation that probably occurs during bacterial infection.
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Lopez, Veronica, Shannon L. Kelleher et Bo Lönnerdal. « Lactoferrin receptor mediates apo- but not holo-lactoferrin internalization via clathrin-mediated endocytosis in trophoblasts ». Biochemical Journal 411, no 2 (27 mars 2008) : 271–78. http://dx.doi.org/10.1042/bj20070393.
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LfR [Lf (lactoferrin) receptor] is expressed in most mammalian tissues, including placental trophoblasts, and is presumed to mediate the internalization of Lf. However, the physiological significance of trophoblast LfR is not understood. Using the CT (cytotrophoblast) cell model BeWo, we demonstrated that transfection with LfR siRNA (small interfering RNA) significantly decreased apo- but not holo-Lf uptake compared with mock-transfected controls and that apo- but not holo-Lf significantly increased MMP (matrix metalloproteinase)-2 activity. As Lf functionality is related to the presence (holo-Lf) or absence (apo-Lf) of iron within the Lf molecule, our results suggest that apo-Lf may play a role in cellular invasion. Moreover, we detected LfR (∼105 kDa) in association with the plasma membrane, and ligand blotting confirmed that Lf binds to a LfR of ∼105 kDa. Apo-Lf treatment significantly increased LfR abundance at the plasma membrane and internalization probably occurs via clathrin-mediated endocytosis through early and recycling endosomes, as LfR was co-localized with EEA1 (early endosome antigen 1) and TfR (transferrin receptor) using confocal microscopy, and hypertonic medium (0.4 M sucrose) significantly inhibited apo-Lf internalization. In summary, our data demonstrate that apo- but not holo-Lf is internalized by LfR and suggest that, following internalization via LfR, apo-Lf plays a role in CT invasiveness by inducing MMP-2 activity. Moreover, LfR facilitates apo-Lf uptake specifically through clathrin-mediated endocytosis into early endosomes and potentially into a recycling pathway. Taken together, our data provide a new dimension in understanding ligand-dependant function that may be directly related to the ability of LfR to selectively internalize apo- but not holo-Lf.
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Drozhzhyna, G. I., et T. A. Veliksar. « Lactoferrin : Invisible Eye Defender ». International scientific-practical journal Ophthalmology, no 1 (12) (2021) : 73–84. http://dx.doi.org/10.30702/ophthalmology31032021-12.1.73-84/048.8.
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The main protective proteins that are synthesized by eye cells are lactoferrin (Lf), lysozyme, immunoglobulin-A, and tear lipocalins. It has been proven that Lf is contained in biological fluids and mucous membranes of various organs; this highlights the importance of this protein in the first line of defense from pathogenic microorganisms. Lf is a non-heme iron-binding chelating glycoprotein from the transferrin family. Lf carries out bactericidal, fungicidal, antiviral, antioxidant and transport functions, prevents the formation of free radicals, inhibits lipid peroxidation, activates enzymes of the antioxidant system. Lf is contained in tears in the highest concentration (about 2 mg/ml, 25% of tear proteins), the average concentration is 1.42 mg/ml. Lf is an important component providing homeostasis of the ocular surface, modulates the activity of T-lymphocytes and macrophages in infections, prevents the multiplication of pathogenic microflora, the development of inflammation, protects the integrity of the cornea, promotes healing from microtraumas, controls the level of iron in the lacrimal fluid, and protects against toxins. These properties of Lf open up prospects for its application in the treatment of chronic diseases of the ocular surface and, in particular, dry eye disease. Lf concentration in tears decreases during sleep, with age, in dry eye disease, keratitis and conjunctivitis, when using contact lenses, that increase the risk of developing eye infections. The first results of the application of ophthalmic drops Lacto (NOVAX® PHARMA) showed good tolerance and therapeutic efficacy in the treatment of inflammatory diseases of the ocular surface. Keywords: lactoferrin, tear, antimicrobial, immunomodulatory, anti-inflammatory properties, ocular surface.
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Icriverzi, Madalina, Valentina Dinca, Magdalena Moisei, Robert W. Evans, Mihaela Trif et Anca Roseanu. « Lactoferrin in Bone Tissue Regeneration ». Current Medicinal Chemistry 27, no 6 (16 mars 2020) : 838–53. http://dx.doi.org/10.2174/0929867326666190503121546.
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: Among the multiple properties exhibited by lactoferrin (Lf), its involvement in bone regeneration processes is of great interest at the present time. A series of in vitro and in vivo studies have revealed the ability of Lf to promote survival, proliferation and differentiation of osteoblast cells and to inhibit bone resorption mediated by osteoclasts. Although the mechanism underlying the action of Lf in bone cells is still not fully elucidated, it has been shown that its mode of action leading to the survival of osteoblasts is complemented by its mitogenic effect. Activation of several signalling pathways and gene expression, in an LRPdependent or independent manner, has been identified. Unlike the effects on osteoblasts, the action on osteoclasts is different, with Lf leading to a total arrest of osteoclastogenesis. : Due to the positive effect of Lf on osteoblasts, the potential use of Lf alone or in combination with different biologically active compounds in bone tissue regeneration and the treatment of bone diseases is of great interest. Since the bioavailability of Lf in vivo is poor, a nanotechnology- based strategy to improve the biological properties of Lf was developed. The investigated formulations include incorporation of Lf into collagen membranes, gelatin hydrogel, liposomes, loading onto nanofibers, porous microspheres, or coating onto silica/titan based implants. Lf has also been coupled with other biologically active compounds such as biomimetic hydroxyapatite, in order to improve the efficacy of biomaterials used in the regulation of bone homeostasis. : This review aims to provide an up-to-date review of research on the involvement of Lf in bone growth and healing and on its use as a potential therapeutic factor in bone tissue regeneration.
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Liu, Zhen-Shu, et Po-Wen Chen. « Featured Prebiotic Agent : The Roles and Mechanisms of Direct and Indirect Prebiotic Activities of Lactoferrin and Its Application in Disease Control ». Nutrients 15, no 12 (15 juin 2023) : 2759. http://dx.doi.org/10.3390/nu15122759.
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Lactoferrin (LF) is a glycoprotein found in mammalian milk, and lactoferricin is a peptide derived from LF hydrolysate. Both LF and lactoferricin (LFcin) have diverse functions that could benefit mammals. Bovine LF (BLF) and BLFcin exhibit a wide range of antimicrobial activities, but most probiotic strains are relatively resistant to their antibacterial effects. BLF and BLF hydrolysate can promote the growth of specific probiotics depending on the culture conditions, the dose of BLF or BLF-related peptides, and the probiotic strains used. BLF supplementation has been shown to modulate several central molecular pathways or genes in Lacticaseibacillus rhamnosus GG under cold conditions, which may explain the prebiotic roles of BLF. LF alone or in combination with selected probiotics can help control bacterial infections or metabolic disorders, both in animal studies and in human clinical trials. Various LF-expressing probiotics, including those expressing BLF, human LF, or porcine LF, have been developed to facilitate the combination of LFs with specific probiotics. Supplementation with LF-expressing probiotics has positive effects in animal studies. Interestingly, inactivated LF-expressing probiotics significantly improved diet-induced nonalcoholic fatty liver disease (NAFLD) in a mouse model. This review highlights the accumulated evidence supporting the use of LF in combination with selected LF-resistant probiotics or LF-expressing probiotics in the field.
Thèses sur le sujet "LACTOFERRIN (LF)"
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AMBIKA, KM. « ROLE OF LACTOSMART AS A NOVEL THERAPEUTIC AGENT IN ANTIMICROBIAL DEFENSE ». Thesis, DELHI TECHNOLOGICAL UNIVERSITY, 2021. http://dspace.dtu.ac.in:8080/jspui/handle/repository/18433.
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The emergence of multi – drug resistance (MDR ) in microorganisms against
antibiotics has become a global problem [1,2,3]. Various conventional drugs with
promised efficacy and specificity are unable to withstand the threat of antibiotic drug
resistance [4,5,6].
The rising crisis of MDR bacteria has led to the channelization of relevant
research in the direction of antimicrobial molecules from natural sources as potential
novel antibiotics. The spectrum of innate immune proteins and their potent
fragments herald a promising approach to fight the problem of drug resistance. Among
the natural antimicrobial proteins, Lactoferrin (LF) has been identified as a potent
host defense system based on its wide spectrum bactericidal and bacteriostatic activities
[7,8,9,10,11,12,13] . In the past , several studies have demonstrated the antibacterial and
antifungal effects of LF and its derivative peptides, for instance, lactoferricin B
[14,15,16,17,18,19] and lactoferrampin [20,21].
Structurally, LF consists of two iron bound lobes, N -lobe (1-333) and C -lobe
(345-692) [22,23,24,25]. Amongst the two lobes , the highly cationic properties of N- lobe
are responsible for membrane disruption by interacting with anionic components
present on bacterial surface [26,27]. It has been established that the lipid A component
of the LPS is a known drug target for antimicrobial therapeutics [ 28,29]. One of the
mechanisms by which Lf acts as an antimicrobial agent is through binding to pathogen
associated molecular patterns (PAMP) such as Lipopolysaccharide (LPS), thereby
disrupting the bacterial membrane integrity and activating the chemical signaling pathway[30-
32]. This leads to the secretion of pro- inflammatory responses which down regulates the release of cytokine production [33,34]. In the past, it had been
reported that LF binds to LPS with its hexameric sequence present in the 18 - loop region
of the lactoferricin [35-37] .
In the present study , we have performed the partial digestion of LF with trypsin
which generates a potent antimicrobial molecule of the size of about 21kDa (85-281).
We have proposed its name as Lactosmart due to its higher potency against pathogens
when compared to native LF as a whole protein . The lactosmart has been tested for
antibacterial and antifungal properties along with its inhibitory potential of biofilm
formation by Pseudomonas aeruginosa through established assays [41]. Our primary
focus was on the comparison of LPS binding properties of lactosmart with native LF
using surface plasmon resonance technique . The docking and molecular dynamics
simulations (MD) studies with LPS have also been performed to further substantiate our
claims. Through our studies , we have demonstrated that LF sequesters LPS through
two binding sites which are situated on the N- lobe.
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Séon, Aurélia Anne. « Evaluation des effets de la lactoferrine sur la microflore gastro-intestinale, sur l'utilisation digestive des nutriments et sur les performances zootechniques du porcelet, et étude microbiologique avec quelques peptides antimicrobiens ». Paris 6, 2003. http://www.theses.fr/2003PA066401.
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