Amyloidogenic processing of the amyloid precursor protein (APP) forms the amyloid-β peptide (Aβ) component of pathognomonic extracellular plaques of AD. Additional early cortical changes in AD include neuroinflammation and elevated iron levels. Activation of the innate immune system in the brain is a neuroprotective response to infection; however, persistent neuroinflammation is linked to AD neuropathology by uncertain mechanisms.
View Article and Find Full Text PDFObjective: To describe the effect of robotic locomotor training (RLT) and activity-based training (ABT) on cardiovascular indices during various physiological positions in individuals with spinal cord injury.
Design: Randomized controlled pilot study.
Setting: Private practice: Therapy & Beyond Centre - Walking with Brandon Foundation, Sports Science Institute of South Africa, Cape Town, South Africa.
Hephaestin (Hp) is a trans-membrane protein, which plays a critical role in intestinal iron absorption. Hp was originally identified as the gene responsible for the phenotype of sex-linked anaemia in the mouse. The mutation in the protein causes accumulation of dietary iron in duodenal cells, causing severe microcytic hypochromic anaemia.
View Article and Find Full Text PDFPurpose: This study discussed the reports by participants in a randomised controlled trial of a novel intervention for spinal cord injury (SCI) rehabilitation in Cape Town, South Africa.
Materials And Methods: Sixteen participants were randomised to rehabilitation involving the use of robotic locomotor training, a novel technology, or to a group receiving an activity-based intervention. All participants were interviewed before the intervention and at six months follow-up.
The potential of mesenchymal stem cells (MSCs) for implantology and cell-based therapy represents one of the major ongoing research subjects within the last decades. In bone regeneration applications, the various environmental factors including bioactive compounds such as growth factors, chemicals and physical characteristics of biointerfaces are the key factors in controlling and regulating osteogenic differentiation from MSCs. In our study, we have investigated the influence of Lactoferrin (Lf) and Hydroxyapatite (HA) embedded within a biodegradable PEG-PCL copolymer on the osteogenic fate of MSCs, previous studies revealing an anti-inflammatory potential of the coating and osteogenic differentiation of murine pre-osteoblast cells.
View Article and Find Full Text PDFAmong 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.
View Article and Find Full Text PDFCapillary electrophoresis coupled with an inductively coupled plasma mass spectrometer was applied for the first time to determine the binding constant of human transferrin (Tf) for tetravalent plutonium. The experiments were carried out in a buffer 2-(N-morpholino)ethanesulfonic acid (MES) at pH 6, 0.1 M NaCl and at a temperature of 25 °C.
View Article and Find Full Text PDFHepcidin is the key regulator of systemic iron homeostasis. The iron-sensing mechanisms and the role of intracellular iron in modulating hepatic hepcidin secretion are unclear. Therefore, we created a novel cell line, recombinant-TfR1 HepG2, expressing iron-response-element-independent TFRC mRNA to promote cellular iron-overload and examined the effect of excess holotransferrin (5g/L) on cell-surface TfR1, iron content, hepcidin secretion and mRNA expressions of TFRC, HAMP, SLC40A1, HFE and TFR2.
View Article and Find Full Text PDFObjective: To explore hereditary haemochromatosis (HH) patients' perspectives on genetic information, namely the types of sources used, preferred or trusted.
Methods: A survey online was conducted by the European Federation of Associations of Patients with Haemochromatosis (EFAPH) and applied to members of nine National Associations.
Results: From a total of 1019 validated questionnaires, 895 respondents had performed a genetic testing for HH.
In this work, antitumor compounds, lactoferrin [recombinant iron-free (Apo-rLf)], cisplatin (Cis) or their combination were embedded within a biodegradable polycaprolactone (PCL) polymer thin film, by a modified approach of a laser-based technique, matrix-assisted pulsed laser evaporation (MAPLE). The structural and morphological properties of the deposited hybrid films were analyzed by Fourier-transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM). The in vitro effect on the cells' morphology and proliferation of murine melanoma B16-F10 cells was investigated and correlated with the films' surface chemistry and topography.
View Article and Find Full Text PDFLactoferrin (Lf) was shown to exhibit its antiviral activity at an early phase of viral infection and a mechanism whereby the protein interacts with host cell surface molecules has been suggested. In this study, human Lf (HLf) and seven HLf-derived synthetic peptides (HLP) corresponding to the N-terminal domain of the native protein (1-47 amino acids sequence) were assayed for their capacity to prevent hepatitis B virus (HBV) infection and replication using the HepaRG and HepG2.2.
View Article and Find Full Text PDFBiochim Biophys Acta
March 2012
Background: The bacteriostatic activity of the transferrin family has been known since the early 1960's. The possession of high affinity iron(III)-binding sites and the existence of a specific membrane-bound receptor, have led to the present understanding of serum transferrin acting as the major iron transporter between cells in vertebrate systems. Iron chelators can interact with transferrin, either by directly donating iron or by removing iron from the protein; both interactions have relevance for haematology.
View Article and Find Full Text PDFBackground: It is over 60years since the discovery and isolation of the serum ferroxidase ceruloplasmin. In that time much basic information about the protein has been elucidated including its catalytic and kinetic properties as an enzyme, expression, sequence and structure. The importance of its biological role is indicated in genetic diseases such as aceruloplasminemia where its function is lost through mutation.
View Article and Find Full Text PDFBackground: Animal-free recombinant proteins provide a safe and effective alternative to tissue or serum-derived products for both therapeutic and biomanufacturing applications. While recombinant insulin and albumin already exist to replace their human counterparts in cell culture media, until recently there has been no equivalent for serum transferrin.
Results: The first microbial system for the high-level secretion of a recombinant transferrin (rTf) has been developed from Saccharomyces cerevisiae strains originally engineered for the commercial production of recombinant human albumin (Novozymes' Recombumin® USP-NF) and albumin fusion proteins (Novozymes' albufuse®).
We previously detected a membrane-bound, copper-containing oxidase that may be involved in iron efflux in BeWo cells, a human placental cell line. We have now identified a gene encoding a predicted multicopper ferroxidase (MCF) with a putative C-terminal membrane-spanning sequence and high sequence identity to hephaestin (Heph) and ceruloplasmin (Cp), the other known vertebrate MCF. Molecular modeling revealed conservation of all type I, II, and III copper-binding sites as well as a putative iron-binding site.
View Article and Find Full Text PDFAm J Physiol Gastrointest Liver Physiol
September 2010
Hepcidin expression in vivo is regulated in proportion to iron status (i.e., increased by iron loading and decreased in iron deficiency).
View Article and Find Full Text PDFA number of studies have reported the anti-tumoral activity of lactoferrin, a property mediated by a variety of mechanisms such as inhibitory effects on tumor cell growth, NK cell activation, and enhancement of apoptosis. Liposomes are known to be an efficient drug delivery system which can enhance the therapeutic potential of the encapsulated compounds. We have used positively charged liposomes composed of phosphatidylcholine (PC), dioleoylphosphatidylethanolamine (DOPE), cholesterol (Chol) and stearylamine (SA) (6:1:2:1 M ratio) as a carrier system for bovine iron-free Lf (ApoBLf), and compared the in vitro effect of free and liposome-entrapped ApoBLf on the growth and morphology of murine melanoma B16-F10 cells.
View Article and Find Full Text PDFMelanotransferrin (MTf) is a member of the transferrin (Tf) family of iron (Fe)-binding proteins that was first identified as a cell-surface marker of melanoma. Although MTf has a high-affinity Fe-binding site that is practically identical to that of serum Tf, the protein does not play an essential role in Fe homeostasis and its precise molecular function remains unclear. A Zn(II)-binding motif, distinct from the Fe-binding site, has been proposed in human MTf based on computer modelling studies.
View Article and Find Full Text PDFFollowing its identification as a liver-expressed antimicrobial peptide, the hepcidin peptide was later shown to be a key player in iron homoeostasis. It is now proposed to be the 'iron hormone' which, by interacting with the iron transporter ferroportin, prevents further iron import into the circulatory system. This conclusion was reached using the corresponding synthetic peptide, emphasizing the functional importance of the mature 25-mer peptide, but omitting the possible functionality of its maturation.
View Article and Find Full Text PDFComp Biochem Physiol B Biochem Mol Biol
May 2008
Lactoferrin (LF) is an iron-binding glycoprotein found in different biological fluids of mammals and in neutrophils. It has been proposed to be involved in many functions, including protection from pathogens. In this work, purification of lactoferrin using an ion-exchange chromatography (SP-Sepharose) was attempted for the milk of the following animals: sheep (Ovis aries), goat (Capra hircus), camel (Camelus bactrianus), alpaca (Lama pacos), elephant (Elephas maximus) and grey seal (Halichoerus grypus), as well as human (Homo sapiens).
View Article and Find Full Text PDFCyclization of R- and W-rich hexapeptides has been found to enhance specifically the antimicrobial activity against Gram-negative Escherichia coli. To gain insight into the role of the bacterial outer membrane in mediating selectivity, we assayed the activity of cyclic hexapeptides derived from the parent sequence c-(RRWWRF) against several E. coli strains and Bacillus subtilis, L-form bacteria, and E.
View Article and Find Full Text PDFCurrent iron chelation therapy consists primarily of DFO (desferrioxamine), which has to be administered via intravenous infusion, together with deferiprone and deferasirox, which are orally-active chelators. These chelators, although effective at decreasing the iron load, are associated with a number of side effects. Grady suggested that the combined administration of a smaller bidentate chelator and a larger hexadentate chelator, such as DFO, would result in greater iron removal than either chelator alone [Grady, Bardoukas and Giardina (1998) Blood 92, 16b].
View Article and Find Full Text PDFDespite its importance in iron-overload diseases, little is known about the composition of plasma non-transferrin-bound iron (NTBI). Using 30-kDa ultrafiltration, plasma from thalassemic patients consisted of both filterable and non-filterable NTBI, the filterable fraction representing less than 10% NTBI. Low filterability could result from protein binding or NTBI species exceeding 30 kDa.
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