Protoporphyrin IX-Dependent Antiviral Effects of 5-Aminolevulinic Acid against Feline Coronavirus Type II.

5-Aminolevulinic acid (5-ALA), a non-proteinogenic amino acid, is an intermediate in the biosynthesis of heme and exerts antiviral effects against feline coronavirus (FCoV); however, the underlying mechanisms remain unclear. In the biosynthesis of heme, 5-ALA is condensed and converted to protoporphyrin IX (PpIX), which is then transformed into heme by the insertion of ferrous iron. Previous research has suggested that the metabolites generated during heme biosynthesis contribute to the antiviral effects of 5-ALA.

A Highly Conserved Region in BRCA2 Suppresses the RAD51-Interaction Activity of BRC Repeats.

Mammary tumors are the most prevalent type of tumors in female dogs. Breast cancer 2, early onset () malignant mutations are associated with tumorigenesis in humans and dogs. BRCA2 plays a pivotal role in homologous recombination repair by recruiting RAD51 recombinase to DNA damage sites to maintain genome stability.

BRCA2 C-Terminal RAD51-Binding Domain Confers Resistance to DNA-Damaging Agents.

Breast cancer type 2 susceptibility (BRCA2) protein is crucial for initiating DNA damage repair after chemotherapy with DNA interstrand crosslinking agents or X-ray irradiation, which induces DNA double-strand breaks. BRCA2 contains a C-terminal RAD51-binding domain (CTRBD) that interacts with RAD51 oligomer-containing nucleofilaments. In this study, we investigated CTRBD expression in cells exposed to X-ray irradiation and mitomycin C treatment.

Identification of the core motif of the BRCA2 C-terminal RAD51-binding domain by comparing canine and human BRCA2.

Mammary tumors are the most common tumors in women and non-spayed female dogs. One of the reasons for mammary tumors is mutations of the tumor suppressor gene, BRCA2. BRCA2 participates in homologous recombination repair by interacting with the RAD51 recombinase.

Heme-binding ability of bovine milk proteins.

Bovine milk proteins bind calcium and some bind other metal ions or heme. The examination of heme-binding proteins in colostrum and milk using hemin-agarose beads (HA) showed α-casein, κ-casein and lactoferrin (Lf) to be heme-binding proteins. α-Casein and Lf are iron- and heme-binding proteins, and α- and κ-casein bind to HA, as does Lf.

Binding of Immunoglobulin G to Protoporphyrin IX and Its Derivatives: Evidence the Fab Domain Recognizes the Protoporphyrin Ring.

Immunoglobulin G (IgG) is known to bind zinc via the Fc domain. In this study, biotinylated protoporphyrin IX (PPIX) was incubated with human IgG and then zinc-immobilized Sepharose beads (Zn-beads) were added to the mixture. After washing the beads, the binding of biotinylated PPIX with IgG trapped on Zn-beads was detected using alkaline phosphatase (ALP)-labeled avidin.

Heme-binding of bovine lactoferrin: the potential presence of a heme-binding capacity in an ancestral transferrin gene.

Lactoferrin (Lf) and transferrin (Tf) are iron-binding proteins that can bind various metal ions. This study demonstrates the heme-binding activity of bovine Lf and Tf using biotinylated hemin. When both proteins were coated on separate plate wells, each directly bound biotinylated hemin.

Inhibitory effect of transferrin on serum zinc measurement.

Bovine apo-transferrin (Tf) dose-dependently inhibited zinc (Zn) measurement if apo-Tf was added to a Zn standard solution followed by Zn measurement using a commercial Zn assay kit. Incubation of apo-Tf with zinc sulfate results in loss of Tf to inhibit Zn measurement, probably due to the binding of Tf with Zn. After treatment of Zn-binding Tf with ethylenediaminetetraacetic acid (EDTA) to generate apo-Tf, Zn measurement was even more strongly inhibited.

Binding Analysis of Human Immunoglobulin G as a Zinc-Binding Protein.

Human immunoglobulin G (IgG) binding with zinc ions was examined using zinc ions immobilized on chelating Sepharose beads (Zn-beads). Human IgG bound to Zn-beads but not to Sepharose beads (control beads). Mouse, rat, bovine and equine IgGs also bound to Zn-beads, similar to human IgG.

Iron and Ferritin Levels in the Serum and Milk of Bovine Leukemia Virus-Infected Dairy Cows.

Iron metabolism was examined in 15 bovine leukemia virus (BLV)-infected dairy cows (2.6-7.8 years old).

Physiological implications of mammalian ferritin-binding proteins interacting with circulating ferritin and a new aspect of ferritin- and zinc-binding proteins.

Serum ferritin levels are relatively low (<1 µg/ml) and serum ferritin generally disappears rapidly from the circulation (t 1/2 < 10 min). There are various mammalian ferritin-binding proteins (FBPs) in the blood. Ferritin is cleared by direct uptake by ferritin receptors and by indirect receptor-mediated uptake of FBP complexed with ferritin.

Reduced canine BRCA2 expression levels in mammary gland tumors.

Background: Mammary tumors are the most common tumor type in intact female dogs. Recently, the breast cancer 2 early onset (BRCA2) gene was proposed to be associated with tumorigenesis in dogs. The expression level of BRCA2 is important for its DNA repair function in mammalian cells, and its expression level is linked to tumorigenesis in mammary tissue.

Analysis of the binding of bovine and human fibrinogen to ferritin: evidence that fibrinogen is a common ferritin-binding protein in mammals.

Both human and horse fibrinogen are heme-binding proteins, and horse fibrinogen also exhibits heme-mediated ferritin binding. This study found that bovine and human fibrinogen are heme-mediated ferritin-binding proteins and demonstrated direct binding of bovine ferritin to protoporphyrin (PPIX) and its derivatives or to Zn ions. Binding of bovine and human fibrinogen to bovine spleen ferritin coated on microtiter plate wells was detected using an anti-human fibrinogen antibody, and this binding was inhibited in a dose-dependent manner by hemin (iron-PPIX) and also inhibited by Zn-PPIX.

Autotaxin as a novel, tissue-remodeling-related factor in regressing corpora lutea of cycling rats.

Autotaxin (ATX) generates lysophosphatidic acid (LPA) from glycerophospholipid via lysophospholipase D (lysoPLD) activity in cooperation with phospholipase A. We studied its expression and possible functional roles in the ovary of nonfertile cycling rats. Immunohistochemistry revealed that ATX was located predominantly in luteal steroidogenic cells of corpora lutea (CL), but not in any follicles.

The presence of heat-labile factors interfering with binding analysis of fibrinogen with ferritin in horse plasma.

Background: Horse fibrinogen has been identified as a plasma specific ferritin-binding protein. There are two ways in the binding of ferritin-binding protein with ferritin: one is direct binding and the other is indirect binding which is heme-mediated. The aim of this study was to analyze the binding between horse fibrinogen and ferritin.

Factors influencing measurement of serum iron concentration in dogs: diurnal variation and hyperferritinemia.

We evaluated diurnal variation and hyperferritinemia as factors that influence the values of serum iron concentration in dogs, using the International Committee for Standardization in Hematology (ICSH) colorimetric method. Serum iron levels were significantly higher in the morning than in the evening in 6 clinically healthy beagle dogs, and the maximum decrease in serum iron concentration was 47.3%.

Functional binding analysis of human fibrinogen as an iron- and heme-binding protein.

Human fibrinogen is a metal ion-binding protein, but its mechanism of binding with iron and heme has not been elucidated in detail. In this study, human fibrinogen was immobilized on CNBr-activated Sepharose 4B beads. The fibrinogen beads bound hemin (iron-protoporphyrin IX: PPIX) as well as iron ion released from ferrous ammonium sulfate (FAS) more efficiently than Sepharose 4B beads alone.

Change in serum ferritin concentration in experimentally induced anemia of chronic inflammation in dogs.

In veterinary medicine, hyperferritinemia is often observed in dogs with various diseases (e.g., histiocytic sarcoma and immune-mediated hemolytic anemia) without evidence of iron overload.

Change of antibody levels to ferritin in the sera of foals after birth: possible passive transfer of maternal anti-ferritin autoantibody via colostrum and age-related anti-ferritin autoantibody production.

Antibody (immunoglobulin G (IgG), IgM or IgA) levels relative to ferritin in six foal sera (three male and three female) after birth (day 0 and 2, 6, 10, 20, 28, 36, 40, 52 and 56 weeks of age) were semi-quantitatively measured with normalization with antibody activity to ferritin in one adult horse serum. After addition of horse spleen ferritin to the serum sample, the complex formed between antibodies to ferritin in the serum and ferritin was co-immunoprecipitated using antibody to horse spleen ferritin. Antibody classes of the co-immnoprecipitate were detected with antibodies specific for horse IgG, IgM or IgA heavy chain.

Measurement of ferritin and anti-ferritin autoantibodies in serum and colostrum of Holstein and Japanese Black cows.

Anti-ferritin autoantibody is a ferritin-binding protein commonly found in mammals; it is thought to form an immune complex with ferritin and thereby mediate the rapid clearance of circulating ferritin. The aim of this study is to determine concentrations of ferritin and anti-ferritin autoantibodies (immunoglobulin (Ig)M, IgG and IgA) in serum and colostrum of Holstein (H) and Japanese Black (JB) cows within 24 h of normal calving. Blood and colostrum samples were collected from cows of various ages (2-11 years) and calving number (1-8 live births).

Binding analysis of ferritin with heme using α-casein and biotinylated-hemin: detection of heme-binding capacity of Dpr derived from heme synthesis-deficient Streptococcus mutans.

Bacterial and mammalian ferritins are known to bind heme. The use of α-casein and biotinylated hemin could be applicable to detection of protein-bound heme and of proteins with heme-binding capacity, respectively. Although commercial horse spleen ferritin and purified horse spleen ferritin (L:H subunit ratio=4) bound to an α-casein-coated plate, and this binding could be inhibited by hemin, recombinant iron-binding protein (rDpr), derived from heme-deficient Streptococcus mutans and expressed in Escherichia coli, did not bind to an α-casein-coated plate.

Development of a sandwich enzyme-linked immunosorbent assay to detect and measure serum levels of canine ferritin.

We established a homologous sandwich enzyme-linked immunosorbent assay (ELISA) to measure serum levels of canine ferritin. Our assay uses a rabbit anti-canine heart ferritin polyclonal antibody, and canine heart ferritin as a standard. Serum ferritin concentration in healthy dogs (n=163) was 789 ± 284 ng/ml (mean ± standard deviation), a value higher than reported previously.

Effects of the missense mutations in canine BRCA2 on BRC repeat 3 functions and comparative analyses between canine and human BRC repeat 3.

Mammary tumors are the most common tumor type in both human and canine females. Mutations in the breast cancer susceptibility gene, BRCA2, have been found in most cases of inherited human breast cancer. Similarly, the canine BRCA2 gene locus has been associated with mammary tumors in female dogs.