Lactoferrin gene expression and regulation: an overview

The Concentration of Lactoferrin in Breast Milk Correlates with Maternal Body Mass Index and Parity

Background: Lactoferrin (LF) is a multifunctional glycoprotein found in human milk and body fluids, which has been shown to play a vital role in regulating the immunity and supporting the intestinal health of infants. Aim: This study evaluated the association between maternal/parturient factors and LF concentration in the breast milk of Chinese mothers. Methods: 207 breast milk samples were collected from healthy mothers with in the first year of lactation. Maternal and parturient information was collected for these participants through questionnaires. The content of lactoferrin in breast milk was detected by liquid chromatography, and macronutrient concentration in breast milk was measured by human milk analyzer in only 109 samples. Results: Our findings demonstrated that the LF content was much higher within the first month of lactation than it was after that period (p < 0.05). When compared with normal and lean mothers, the LF content of obese mothers was considerably higher (p < 0.05). The parity and LF content showed a favorable correlation. The proportion of LF to total protein tended to decrease as lactation progressed. Protein, fat, dry matter, and energy content were significantly positively correlated with LF content (p < 0.001). Conclusion: Early breast milk tends to have a higher level of LF, and the change of LF concentration in breast milk is associated with the parity and body mass index of the mother.

Cathepsin L regulates oocyte meiosis and preimplantation embryo development

Early embryonic loss, caused by reduced embryo developmental competence, is the major cause of subfertility in humans and animals. This embryo developmental competence is determined during oocyte maturation and the first embryo divisions. Therefore, it is essential to identify the underlying molecules regulating these critical developmental stages. Cathepsin L (CTSL), a lysosomal cysteine protease, is involved in regulating cell cycle progression, proliferation and invasion of different cell types. However, CTSL role in mammalian embryo development is unknown. Using bovine in vitro maturation and culture systems, we show that CTSL is a key regulator for embryo developmental competence. We employed a specific CTSL detection assay in live cells to show that CTSL activity correlates with meiotic progression and early embryo development. Inhibiting CTSL activity during oocyte maturation or early embryo development significantly impaired oocyte and embryo developmental competence as evidenced by lower cleavage, blastocyst and hatched blastocyst rates. Moreover, enhancing CTSL activity, using recombinant CTSL (rCTSL), during oocyte maturation or early embryo development significantly improved oocyte and embryo developmental competence. Importantly, rCTSL supplementation during oocyte maturation and early embryo development significantly improved the developmental competence of heat-shocked oocytes/embryos which are notoriously known for reduced quality. Altogether, these results provide novel evidence that CTSL plays a pivotal role in regulating oocyte meiosis and early embryonic development.

The Multifaceted Roles of Bovine Lactoferrin: Molecular Structure, Isolation Methods, Analytical Characteristics, and Biological Properties

Bovine lactoferrin (bLF) is widely known as an iron-binding glycoprotein from the transferrin family. The bLF molecule exhibits a broad spectrum of biological activity, including iron delivery, antimicrobial, antiviral, immunomodulatory, antioxidant, antitumor, and prebiotic functions, thereby making it one of the most valuable representatives for biomedical applications. Remarkably, LF functionality might completely differ in dependence on the iron saturation state and glycosylation patterns. Recently, a violently growing demand for bLF production has been observed, mostly for infant formulas, dietary supplements, and functional food formulations. Unfortunately, one of the reasons that inhibit the development of the bLF market and widespread protein implementation is related to its negligible amount in both major sources─colostrum and mature milk. This study provides a comprehensive overview of the significance of bLF research by delineating the key structural characteristics of the protein and elucidating their impact on its physicochemical and biological properties. Progress in the development of optimal isolation techniques for bLF is critically assessed, alongside the challenges that arise during its production. Furthermore, this paper presents a curated list of the most relevant instrumental techniques for the characterization of bLF. Lastly, it discusses the prospective applications and future directions for bLF-based formulations, highlighting their potential in various fields.

Time to Kill and Time to Heal: The Multifaceted Role of Lactoferrin and Lactoferricin in Host Defense

Lactoferrin is an iron-binding glycoprotein present in most human exocrine fluids, particularly breast milk. Lactoferrin is also released from neutrophil granules, and its concentration increases rapidly at the site of inflammation. Immune cells of both the innate and the adaptive immune system express receptors for lactoferrin to modulate their functions in response to it. On the basis of these interactions, lactoferrin plays many roles in host defense, ranging from augmenting or calming inflammatory pathways to direct killing of pathogens. Complex biological activities of lactoferrin are determined by its ability to sequester iron and by its highly basic N-terminus, via which lactoferrin binds to a plethora of negatively charged surfaces of microorganisms and viruses, as well as to mammalian cells, both normal and cancerous. Proteolytic cleavage of lactoferrin in the digestive tract generates smaller peptides, such as N-terminally derived lactoferricin. Lactoferricin shares some of the properties of lactoferrin, but also exhibits unique characteristics and functions. In this review, we discuss the structure, functions, and potential therapeutic uses of lactoferrin, lactoferricin, and other lactoferrin-derived bioactive peptides in treating various infections and inflammatory conditions. Furthermore, we summarize clinical trials examining the effect of lactoferrin supplementation in disease treatment, with a special focus on its potential use in treating COVID-19.

Supplementation of broiler chicken diets with bovine lactoferrin improves growth performance, histological parameters of jejunum and immune-related gene expression

The aim of this study was to investigate the influence of dietary supplementation of bovine lactoferrin (bLF) on growth performance, carcass traits, histomorphology of jejunum, immune function and hepatic and splenic gene expression of interferon-gamma (IFN-γ) and interleukine-2 (IL-2) in broiler chickens. A total of 240 one-day-old Ross 308 male broiler chickens were randomly allotted into six dietary treatments with four replicate pens (10 chicks per pen) and fed experimental diet in 3 feeding phases (starter: d 0-10, grower: d 11-24 and finisher: d 25-42). The experimental treatments were (1) corn-soya bean meal-based basal diet (control), (2-5) basal diet supplemented with 200, 400, 600, 800 mg/kg bLF, respectively, and (6) basal diet supplemented with 200 mg/kg oxytetracycline (OTC). The average body weight gain (ABWG) of broilers fed 800 mg/kg bLF was 8.48% higher than those fed a corn-soybean meal-based diet during the starter period (d 0-10) (linear effect, p = 0.002; quadratic effect, p = 0.24). Average daily feed intake (ADFI) and the feed conversion ratio (FCR) were not affected (p>0.05) by bLF supplementation. At 42 days of age, the breast meat percentage and carcass yield of broilers fed 800 mg/kg bLF compared with the control group significantly increased by 9.51% and 6.03% respectively (p < 0.05). Compared with the chicks fed the control diet, the chicks fed diets supplemented with bLF had higher villus height, muscle thickness and villus surface area (p > 0.05). Dietary bLF inclusion increased the total immunoglobulin (IgT) titre against sheep red blood cells (SRBCs) antigen (linear effect, p = 0.031; quadratic effect, p = 0.035) and improved the phytohaemagglutinin-P (PHA-P)-skin test of broilers. Compared with the control, bLF enhanced the gene expression of IFN-γ in spleen (p = 0.048, linear effect, p = 0.009; quadratic effect, p = 0.093) and liver (p = 0.012, linear effect, p = 0.008; quadratic effect, p = 0.01) and IL-2 expression in spleen (p = 0.021, linear effect, p = 0.026; quadratic effect, p = 0.103). The bLF supplementation had no effect on IL-2 gene expression in liver (p > 0.05, linear effect, p = 0.213; quadratic effect, p = 0.159). In conclusion, we found that supplementation of broiler diets with 800 mg/kg bLF can improve the growth performance, carcass yield, cell-mediated and antibody-mediated immune responses and enhance the IL-2 and IFN-γ gene expression of broilers.

Fluid-Phase Endocytosis and Lysosomal Degradation of Bovine Lactoferrin in Lung Cells

The iron-binding protein lactoferrin and the cell-penetrating peptides derived from its sequence utilise endocytosis to enter different cell types. The full-length protein has been extensively investigated as a potential therapeutic against a range of pathogenic bacteria, fungi, and viruses, including SARS-CoV-2. As a respiratory antiviral agent, several activity mechanisms have been demonstrated for lactoferrin, at the extracellular and plasma membrane levels, but as a protein that enters cells it may also have intracellular antiviral activity. Characterisation of lactoferrin’s binding, endocytic traffic to lysosomes, or recycling endosomes for exocytosis is lacking, especially in lung cell models. Here, we use confocal microscopy, flow cytometry, and degradation assays to evaluate binding, internalisation, endocytic trafficking, and the intracellular fate of bovine lactoferrin in human lung A549 cells. In comparative studies with endocytic probes transferrin and dextran, we show that lactoferrin binds to negative charges on the cell surface and actively enters cells via fluid-phase endocytosis, in a receptor-independent manner. Once inside the cell, we show that it is trafficked to lysosomes where it undergoes degradation within two hours. These findings provide opportunities for investigating both lactoferrin and derived cell-penetrating peptides activities of targeting intracellular pathogens.

Lactoferrin Induces Erythropoietin Synthesis and Rescues Cognitive Functions in the Offspring of Rats Subjected to Prenatal Hypoxia

The protective effects of recombinant human lactoferrin rhLF (branded “CAPRABEL™”) on the cognitive functions of rat offspring subjected to prenatal hypoxia (7% O₂, 3 h, 14th day of gestation) have been analyzed. About 90% of rhLF in CAPRABEL was iron-free (apo-LF). Rat dams received several injections of 10 mg of CAPRABEL during either gestation (before and after the hypoxic attack) or lactation. Western blotting revealed the appearance of erythropoietin (EPO) alongside the hypoxia-inducible factors (HIFs) in organ homogenates of apo-rhLF-treated pregnant females, their embryos (but not placentas), and in suckling pups from the dams treated with apo-rhLF during lactation. Apo-rhLF injected to rat dams either during pregnancy or nurturing the pups was able to rescue cognitive deficits caused by prenatal hypoxia and improve various types of memory both in young and adult offspring when tested in the radial maze and by the Novel Object Recognition (NOR) test. The data obtained suggested that the apo-form of human LF injected to female rats during gestation or lactation protects the cognitive functions of their offspring impaired by prenatal hypoxia.

Olive Oil Improves While Trans Fatty Acids Further Aggravate the Hypomethylation of LINE-1 Retrotransposon DNA in an Environmental Carcinogen Model

DNA methylation is an epigenetic mechanism that is crucial for mammalian development and genomic stability. Aberrant DNA methylation changes have been detected not only in malignant tumor tissues; the decrease of global DNA methylation levels is also characteristic for aging. The consumption of extra virgin olive oil (EVOO) as part of a balanced diet shows preventive effects against age-related diseases and cancer. On the other hand, consuming trans fatty acids (TFA) increases the risk of cardiovascular diseases as well as cancer. The aim of the study was to investigate the LINE-1 retrotransposon (L1-RTP) DNA methylation pattern in liver, kidney, and spleen of mice as a marker of genetic instability. For that, mice were fed with EVOO or TFA and were pretreated with environmental carcinogen 7,12-dimethylbenz[a]anthracene (DMBA)-a harmful substance known to cause L1-RTP DNA hypomethylation. Our results show that DMBA and its combination with TFA caused significant L1-RTP DNA hypomethylation compared to the control group via inhibition of DNA methyltransferase (DNMT) enzymes. EVOO had the opposite effect by significantly decreasing DMBA and DMBA + TFA-induced hypomethylation, thereby counteracting their effects.

Mini Review: Lactoferrin-binding protein of Streptococcus in Bovine Mastitis

Bovine mastitis is an udder inflammation mostly found in dairy cattle that causes enormous economic losses. Streptococcus is a bacterium that is often found in mastitis, including Streptococcus agalactiae, Streptococcus dysgalactiae, and Streptococcus uberis. These three species have lactoferrinbinding protein (LBP) as one of their virulence factors. Lactoferrin is a host innate immune protein that acts as antibacterial, immunomodulator, anti-adhesion, and has iron-binding properties. The LBP on the surface of Streptococcus could bind to lactoferrin produced by host cells. Uniquely, the three Streptococcus bacteria showed different responses to lactoferrin. The lactoferrin-LBP bound on S. agalactiae and S. dysgalactiae was known to inhibit their penetration ability into the host epithelial cells, on the contrary, in S. uberis it could enhance their ability to invade the cells. This paper aims to review the role of the lactoferrin-binding protein of Streptococcus in bovine mastitis.

Antimicrobial and Prebiotic Activity of Lactoferrin in the Female Reproductive Tract: A Comprehensive Review

Women’s intimate health depends on several factors, such as age, diet, coexisting metabolic disorders, hormonal equilibrium, sexual activity, drug intake, contraception, surgery, and personal hygiene. These factors may affect the homeostasis of the internal environment of the genital tract: the vulva, vagina and cervix. This equilibrium is dependent on strict and complex mutual interactions between epithelial cells, immunocompetent cells and microorganisms residing in this environment. The microbiota of the genital tract in healthy women is dominated by several species of symbiotic bacteria of the Lactobacillus genus. The bacteria inhibit the growth of pathogenic microorganisms and inflammatory processes by virtue of direct and multidirectional antimicrobial action and, indirectly, by the modulation of immune system activity. For the homeostasis of the genital tract ecosystem, antimicrobial and anti-inflammatory peptides, as well as proteins secreted by mucus cells into the cervicovaginal fluid, have a fundamental significance. Of these, a multifunctional protein known as lactoferrin (LF) is one of the most important since it bridges innate and acquired immunity. Among its numerous properties, particular attention should be paid to prebiotic activity, i.e., exerting a beneficial action on symbiotic microbiota of the gastrointestinal and genital tract. Such activity of LF is associated with the inhibition of bacterial and fungal infections in the genital tract and their consequences, such as endometritis, pelvic inflammation, urinary tract infections, miscarriage, premature delivery, and infection of the fetus and newborns. The aim of this article is to review the results of laboratory as well as clinical trials, confirming the prebiotic action of LF on the microbiota of the lower genital tract.

The Detection of Bovine Estrus by Lactoferrin Monoclonal Antibody

Simple Summary

This study aimed to develop monoclonal antibodies with high specificity against bovine lactoferrin, which we have previously demonstrated to be overexpressed in bovine cervical mucus during estrus. Using an enzyme-linked immunosorbent assay, we observed that our monoclonal exhibited strong affinity for bovine lactoferrin protein. In addition, upon testing the new heat detection kits based on our antibody on 12 Korean native cows, we demonstrated an accurate detection of estrus during estrous synchronization. This is the first report of a non-invasive method to detect estrous using antibodies that bind to physiological material in cows. The results of this study suggest that the antibodies and a fabricated heat detection kit can be utilized to improve estrous detection in the cattle industry.

Abstract

To improve reproductive performance in cattle, the accurate detection of estrus and optimization of insemination relative to ovulation are necessary. However, poor heat detection by farm staff leads to a decreased conception rate, thus inflicting economic damage to the beef and dairy industries. This study aimed to develop monoclonal antibodies (mAb) that can specifically bind to the bovine lactoferrin (bLF) protein, which we have previously demonstrated to be overexpressed in bovine cervical mucus during estrus. Female rats were intraperitoneally immunized with bLF protein as the antigen. Anti-bLF mAbs were then purified by affinity chromatography, and their binding affinity for the bLF antigen was examined using ELISA. We found a high binding affinity between mAbs and bLF. Finally, we developed a rapid bovine heat detection kit using the anti-bLF mAbs that we generated and tested on cervical mucus from 12 cows (estrous synchronization, n = 2; natural cycling, n = 10). We found that the kits accurately detected estrus. Overall, our fabricated heat detection kit based on rat anti-bLF mAbs could pave the way for the development of potent tools for heat detection devices for dairy cattle, thereby preventing economic loss.

A prospective on multiple biological activities of lactoferrin contributing to piglet welfare

Piglets, especially weaning piglets, show a lower level of immunity and higher morbidity and mortality, owing to their rapid growth, physiological immaturity, and gradual reduction of maternal antibodies, which seriously affects their growth and thus, value. It is important that piglets adapt to nutrient digestion and absorption and develop sound intestinal function and colonization with gut microbiota as soon as possible during their early life stage. Lactoferrin is a natural glycoprotein polypeptide that is part of the transferrin family. It is widely found in mucosal secretions such as saliva and tears, and most highly in milk and colostrum. As a multifunctional bioactive protein and a recommended food additive, lactoferrin is a potential alternative therapy to antibiotics and health promoting additive for piglet nutrition and development. It is expected that lactoferrin, as a natural food additive, could play an important role in maintaining pig health and development. This review examines the following known beneficial effects of lactoferrin: improves the digestion and capacity for absorption in the intestinal tract; promotes the absorption of iron and reduces the incidence of iron deficiency anemia; regulates intestinal function and helps to balance the microbial biota; and enhances the resistance to disease of the piglets via modulating and enhancing the immune system.

Lactoferrin in the Prevention and Treatment of Intestinal Inflammatory Pathologies Associated with Colorectal Cancer Development

The connection between inflammation and cancer is well-established and supported by genetic, pharmacological and epidemiological data. The inflammatory bowel diseases (IBDs), including Crohn's disease and ulcerative colitis, have been described as important promoters for colorectal cancer development. Risk factors include environmental and food-borne mutagens, dysbalance of intestinal microbiome composition and chronic intestinal inflammation, with loss of intestinal epithelial barrier and enhanced cell proliferation rate. Therapies aimed at shutting down mucosal inflammatory response represent the foundation for IBDs treatment. However, when applied for long periods, they can alter the immune system and promote microbiome dysbiosis and carcinogenesis. Therefore, it is imperative to find new safe substances acting as both potent anti-inflammatory and anti-pathogen agents. Lactoferrin (Lf), an iron-binding glycoprotein essential in innate immunity, is generally recognized as safe and used as food supplement due to its multifunctionality. Lf possesses a wide range of immunomodulatory and anti-inflammatory properties against different aseptic and septic inflammatory pathologies, including IBDs. Moreover, Lf exerts anti-adhesive, anti-invasive and anti-survival activities against several microbial pathogens that colonize intestinal mucosa of IBDs patients. This review focuses on those activities of Lf potentially useful for the prevention/treatment of intestinal inflammatory pathologies associated with colorectal cancer development.

COVID-19 during Pregnancy and Postpartum

Coronavirus Disease 2019 (COVID-19) triggered by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection has been declared a pandemic by the World Health Organization (WHO) on March 11, 2020. Oxidative stress and its related metabolic syndromes are potential risk factors in the susceptibility to, and severity of COVID-19. In concert with the earliest reports of COVID-19, obstetricians started to diagnose and treat SARS-CoV-2 infections during pregnancy ("COVID-19-Pregnancy"). High metabolic demand to sustain normal fetal development increases the burden of oxidative stress in pregnancy. Intracellular redox changes intertwined with acute phase responses at the maternal-fetal interface could amplify during pregnancy. Interestingly, mother-to-fetus transmission of SARS-CoV-2 has not been detected in most of the COVID-19-Pregnancy cases. This relative absence of vertical transmission may be related to the presence of lactoferrin in the placenta, amniotic fluid, and lacteal secretions. However, the cytokine-storm induced during COVID-19-Pregnancy may cause severe inflammatory damage to the fetus, and if uncontrolled, may later result in autism spectrum-like disorders and brain development abnormalities in neonates. Considering this serious health threat to child growth and development, the prevention of COVID-19 during pregnancy should be considered a high priority. This review summarizes the intricate virulence factors of COVID-19 and elucidate its pathobiological spectrum during pregnancy and postpartum periods with a focus on the putative and complex roles of endogenous and exogenous lactoferrin in conferring immunological advantage to the host.

Metabolic Health in Obese Subjects-Is There a Link to Lactoferrin and Lactoferrin Receptor-Related Gene Polymorphisms?

This study aimed to evaluate the association of genetic variants in lactoferrin (LTF) metabolism-related genes with the prevalence of metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUHO). In total, 161 MHO and 291 MUHO subjects were recruited to the study. The following polymorphisms were genotyped: low-density lipoprotein receptor-related protein (LRP) 2 rs2544390, LRP1 rs4759277, LRP1 rs1799986, LTF rs1126477, LTF rs2239692 and LTF rs1126478. We found significant differences in the genotype frequencies of LTF rs2239692 between MHO and MUHO subjects, with the CT variant associated with lower odds of developing metabolic syndrome than the TT variant. In the total population, significant differences in body weight and waist circumference (WC) were identified between LTF rs1126477 gene variants. A similar association with WC was observed in MUHO subjects, while significant differences in body mass index and low-density lipoprotein cholesterol levels were discovered between LTF rs1126477 gene variants in MHO subjects. Besides, there were significant differences in diastolic blood pressure between LRP1 rs1799986 gene variants in MUHO subjects, as well as in WC and high-density lipoprotein cholesterol levels between LRP1 rs4759277 gene variants in MHO subjects. In conclusion, selected lactoferrin and lactoferrin receptor-related gene variants may be associated with the prevalence of metabolically healthy or metabolically unhealthy obesity.

Association of polymorphic variant of exons 6 and 11 of lactoferrin gene with mastitis in Murrah buffalo

Lactoferrin is one of the important candidate genes for mastitis resistance in dairy animals. The gene is located on Bos taurus autosome (BTA) 22 and consists of 17 exons spanning over 34.5 kb of genomic DNA. The present study was undertaken to identify allelic variant in exons 6 and 11 of lactoferrin gene and to analyze association with incidence of clinical mastitis in Murrah buffalo. The amplification of exons 6 and 11 of lactoferrin gene yielded 301 and 131 bp amplicon size. Comparison of nucleotide sequence of exonic region of lactoferrin gene with Bos taurus (NCBI accession number AC_000179.1) revealed 6 mutations; among them 3 were in coding DNA sequence and remaining 3 were in flanking intronic region. All these mutations were found in exon 6 and synonymous in nature without affecting the sequence of amino acid. PCR-restriction fragment length polymorphism (RFLP) analysis of 301 bp amplicon using FokI restriction enzyme exhibited polymorphic pattern with two genotypes (AA and AB) with respective frequency of 0.625 and 0.375. The frequencies of two alleles, A and B were estimated as 0.81 and 0.19 respectively. RE Hpy188I and HinfI used for digestion of exon 11 had exhibited monomorphic pattern. The chi-square (χ2) analysis revealed significant association between incidence of clinical mastitis and genetic variant of exon 6 and animals with AA genotype were found to be less susceptible to mastitis. The findings indicate potential scope for incorporation of lactoferrin gene in selection and breeding of Murrah buffaloes for improved genetic resistance to mastitis.

Lack of associations between lactoferrin (LTF) and mannose-binding lectin 2 (MBL2) gene polymorphism and dental caries susceptibility

Objective

With the development of human genomics, the genetic factors associated with dental caries have receiving increasing attention. This study was performed to evaluate the relationship between lactoferrin (LTF) and mannose-binding lectin 2 (MBL2) gene single nucleotide polymorphisms (SNPs) and dental caries susceptibility in Chinese children.

Methods

This prospective case–control study included 360 unrelated children (aged 12–15 years) who received oral health examinations and questionnaire surveys. The children were divided into two groups by counting the numbers of decayed, missing, and filled teeth (DMFT/dmft): case group (n = 162, DMFT/dmft ≥ 1) and control group (n = 198, DMFT/dmft = 0); non-invasive saliva samples were collected to extract genomic DNA. Six SNPs (rs2073495C/G, rs1042073C/T, rs10865941C/T, and rs1126477A/G in LTF; rs7096206C/G and rs7095891G/A in MBL2) were tested by mass spectrometry.

Results

The study included 360 individuals with (85 boys and 77 girls) and without a history of caries (96 boys and 102 girls). There were no statistically significant differences in alleles and genotypes among the six SNPs between the two groups.

Conclusion

There is no evidence that polymorphisms of LTF and MBL2 genes are associated with dental caries susceptibility in populations from northwest China; further confirmation is needed with larger sample sizes.

Human Antimicrobial Peptides as Therapeutics for Viral Infections

Successful in vivo infection following pathogen entry requires the evasion and subversion of multiple immunological barriers. Antimicrobial peptides (AMPs) are one of the first immune pathways upregulated during infection by multiple pathogens, in multiple organs in vivo. In humans, there are many classes of AMPs exhibiting broad antimicrobial activities, with defensins and the human cathelicidin LL-37 being the best studied examples. Whereas historically the efficacy and therapeutic potential of AMPs against bacterial infection has been the primary focus of research, recent studies have begun to elucidate the antiviral properties of AMPs as well as their role in regulation of inflammation and chemoattraction. AMPs as therapeutic tools seem especially promising against emerging infectious viral pathogens for which no approved vaccines or treatments are currently available, such as dengue virus (DENV) and Zika virus (ZIKV). In this review, we summarize recent studies elucidating the efficacy and diverse mechanisms of action of various classes of AMPs against multiple viral pathogens, as well as the potential use of human AMPs in novel antiviral therapeutic strategies.

Negative elongation factor is essential for endometrial function

Pausing of RNA polymerase II (Pol II) during early transcription, mediated by the negative elongation factor (NELF) complex, allows cells to coordinate and appropriately respond to signals by modulating the rate of transcriptional pause release. Promoter proximal enrichment of Pol II occurs at uterine genes relevant to reproductive biology; thus, we hypothesized that pausing might impact endometrial response by coordinating hormonal signals involved in establishing and maintaining pregnancy. We deleted the NELF-B subunit in the mouse uterus using PgrCre (NELF-B UtcKO). Resulting females were infertile. Uterine response to the initial decidual stimulus of NELF-B UtcKO was similar to that of control mice; however, subsequent full decidual response was not observed. Cultured NELF-B UtcKO stromal cells exhibited perturbances in extracellular matrix components and also expressed elevated levels of the decidual prolactin Prl8a2, as well as altered levels of transcripts encoding enzymes involved in prostaglandin synthesis and metabolism. Because endometrial stromal cell decidualization is also critical to human reproductive health and fertility, we used small interfering to suppress NELF-B or NELF-E subunits in cultured human endometrial stromal cells, which inhibited decidualization, as reflected by the impaired induction of decidual markers PRL and IGFBP1. Overall, our study indicates NELF-mediated pausing is essential to coordinate endometrial responses and that disruption impairs uterine decidual development during pregnancy.-Hewitt, S. C., Li, R., Adams, N., Winuthayanon, W., Hamilton, K. J., Donoghue, L. J., Lierz, S. L., Garcia, M., Lydon, J. P., DeMayo, F. J., Adelman, K., Korach, K. S. Negative elongation factor is essential for endometrial function.

Genetic Polymorphisms in LTF/EcoRI and TLR4/AluI loci as candidates for milk and reproductive performance assessment in Holstein cattle

The aim of this study was to explore the genetic polymorphisms in LTF/EcoRI and TLR4/AluI loci and their association with milk and reproductive performance in Holstein cattle. A randomly selected 800 Holstein dairy cows from two dairy farms (400 animals each) in Egypt were used. Based on the two farm records, association between LTF/EcoRI genotypes and milk performance traits (order of lactation, daily milk yield, days in milk, corrected milk at 305 day and dry period) was carried out. Meanwhile, exploring of TLR4/AluI genotypes effect was done on data for reproductive performance (age at first freshening, calving interval, number of services per conception, ovarian rebound and days open). DNA was extracted from blood samples collected from Holstein dairy cows of the both farms and restriction analysis of 301-bp PCR products of LTF gene revealed two genotypes: AA genotype (301 bp) and AB genotype (301, 201 and 100 bp). Meanwhile, restriction analysis of 382-bp PCR products of TLR4 gene digested with AluI yielded two alleles (A and B) and three genotypes (AA, AB and BB). The A allele was indicated by two bands at 300 and 82 bp, and the B allele resulted in three fragments of 160, 140 and 82 bp. There was a significant association (p ≤ 0.05) between LTF genotypes and milk performance traits except for days in milk. The TLR4 genotypes had significant effects (p ≤ 0.05) on age at first freshening, calving interval, number of services per conception, ovarian rebound and days open. Ordinal logistic regression statistical model also revealed that it is possible to calculate high reproductive performance traits and to predict favourable dairy cows based on LTF and TLR4 genotypes. This research reveals the effectiveness of LTF/EcoRI and TLR4/AluI loci as candidates for reproductive performance assessment in Holstein cattle.

Molecular mechanisms of embryonic implantation in mammals: Lessons from the gene manipulation of mice

BACKGROUND

Human infertility has become a serious and social issue all over the world, especially in developed countries. Numerous types of assisted reproductive technology have been developed and are widely used to treat infertility. However, pregnancy outcomes require further improvement. It is essential to understand the cross-talk between the uterus (mother) and the embryo (fetus) in pregnancy, which is a very complicated event.

METHODS

The mammalian uterus requires many physiological and morphological changes for pregnancy-associated events, including implantation, decidualization, placentation, and parturition, to occur. Here is discussed recent advances in the knowledge of the molecular mechanisms underlying these reproductive events - in particular, embryonic implantation and decidualization - based on original and review articles.

MAIN FINDINGS RESULTS

In mice, embryonic implantation and decidualization are regulated by two steroid hormones: estrogen and progesterone. Along with these hormones, cytokines, cell-cycle regulators, growth factors, and transcription factors have essential roles in implantation and decidualization in mice.

CONCLUSION

Recent studies using the gene manipulation of mice have given considerable insight into the molecular mechanisms underlying embryonic implantation and decidualization. However, as most of the findings are based on mice, comparative research using different mammalian species will be useful for a better understanding of the species-dependent differences that are associated with reproductive events, including embryonic implantation.

DNA methylation and transcriptome aberrations mediated by ERα in mouse seminal vesicles following developmental DES exposure

Early transient developmental exposure to an endocrine active compound, diethylstilbestrol (DES), a synthetic estrogen, causes late-stage effects in the reproductive tract of adult mice. Estrogen receptor alpha (ERα) plays a role in mediating these developmental effects. However, the developmental mechanism is not well known in male tissues. Here, we present genome-wide transcriptome and DNA methylation profiling of the seminal vesicles (SVs) during normal development and after DES exposure. ERα mediates aberrations of the mRNA transcriptome in SVs of adult mice following neonatal DES exposure. This developmental exposure impacts differential diseases between male (SVs) and female (uterus) tissues when mice reach adulthood due to most DES-altered genes that appear to be tissue specific during mouse development. Certain estrogen-responsive gene changes in SVs are cell-type specific. DNA methylation dynamically changes during development in the SVs of wild-type (WT) and ERα-knockout (αERKO) mice, which increases both the loss and gain of differentially methylated regions (DMRs). There are more gains of DMRs in αERKO compared with WT. Interestingly, the methylation changes between the two genotypes are in different genomic loci. Additionally, the expression levels of a subset of DES-altered genes are associated with their DNA methylation status following developmental DES exposure. Taken together, these findings provide an important basis for understanding the molecular and cellular mechanism of endocrine-disrupting chemicals (EDCs), such as DES, during development in the male mouse tissues. This unique evidence contributes to our understanding of developmental actions of EDCs in human health.

Role of Lactobacilli and Lactoferrin in the Mucosal Cervicovaginal Defense

The innate defense system of the female mucosal genital tract involves a close and complex interaction among the healthy vaginal microbiota, different cells, and various proteins that protect the host from pathogens. Vaginal lactobacilli and lactoferrin represent two essential actors in the vaginal environment. Lactobacilli represent the dominant bacterial species able to prevent facultative and obligate anaerobes outnumber in vaginal microbiota maintaining healthy microbial homeostasis. Several mechanisms underlie the protection exerted by lactobacilli: competition for nutrients and tissue adherence, reduction of the vaginal pH, modulation of immunity, and production of bioactive compounds. Among bioactive factors of cervicovaginal mucosa, lactoferrin, an iron-binding cationic glycoprotein, is a multifunctional glycoprotein with antibacterial, antifungal, antiviral, and antiparasitic activities, recently emerging as an important modulator of inflammation. Lactobacilli and lactoferrin are largely under the influence of female hormones and of paracrine production of various cytokines. Lactoferrin is strongly increased in lower genital tract mucosal fluid of women affected by Neisseria gonorrheae, Chlamydia trachomatis, and Trichomonas vaginalis infections promoting both innate and adaptive immune responses. In vaginal dysbiosis characterized by low amounts of vaginal lactobacilli and increased levels of endogenous anaerobic bacteria, the increase in lactoferrin could act as an immune modulator assuming the role normally played by the healthy microbiota in vaginal mucosa. Then lactoferrin and lactobacilli may be considered as biomarkers of altered microbial homeostasis at vaginal level. Considering the shortage of effective treatments to counteract recurrent and/or antibiotic-resistant bacterial infections, the intravaginal administration of lactobacilli and lactoferrin could be a novel efficient therapeutic strategy and a valuable tool to restore mucosal immune homeostasis.

Host Antimicrobial Peptides: The Promise of New Treatment Strategies against Tuberculosis

Tuberculosis (TB) continues to be a devastating infectious disease and remerges as a global health emergency due to an alarming rise of antimicrobial resistance to its treatment. Despite of the serious effort that has been applied to develop effective antitubercular chemotherapies, the potential of antimicrobial peptides (AMPs) remains underexploited. A large amount of literature is now accessible on the AMP mechanisms of action against a diversity of pathogens; nevertheless, research on their activity on mycobacteria is still scarce. In particular, there is an urgent need to integrate all available interdisciplinary strategies to eradicate extensively drug-resistant Mycobacterium tuberculosis strains. In this context, we should not underestimate our endogenous antimicrobial proteins and peptides as ancient players of the human host defense system. We are confident that novel antibiotics based on human AMPs displaying a rapid and multifaceted mechanism, with reduced toxicity, should significantly contribute to reverse the tide of antimycobacterial drug resistance. In this review, we have provided an up to date perspective of the current research on AMPs to be applied in the fight against TB. A better understanding on the mechanisms of action of human endogenous peptides should ensure the basis for the best guided design of novel antitubercular chemotherapeutics.

Identification of the protective mechanisms of Lactoferrin in the irradiated salivary gland

Radiotherapy is commonly used in patients with head and neck cancer, and usually results in irreversible salivary glands damage and hypofunction. It is therefore important to manage such irradiation to prevent damage to the salivary glands. A previous study showed that Lactoferrin (LF) has a radioprotective effect, but the mechanism was not determined in salivary glands. In the present study, we investigated the detailed radioprotective effect of LF using both ex vivo submandibular salivary gland organ culture and ICR male mice in vivo. We found that LF had effects on both cell proliferation and CyclinD1-mediated cell-cycle progression which were regulated via the ERK1/2 and AKT signal transduction pathways. In addition, LF affected acinar cell structure and function after irradiation. These findings suggest that LF may be a useful agent to prevent irradiation effects in salivary glands.

Lactoferrin concentration in breast milk of mothers of low-birth-weight newborns

OBJECTIVES

Lactoferrin (LF) is a breast milk glycoprotein with protective effects against neonatal infections, mainly in premature and low-birth-weight (LBW) neonates. The aims of this study were to determine LF concentration in breast milk of mothers of LBW infants during the first 2 months postpartum, and to identify the factors associated with LF concentration.

STUDY DESIGN

Prospective study conducted as a part of an ongoing clinical trial in three Neonatal Units in Peru. We included 346 mothers of neonates with a birth weight <2000 g. We measured LF concentration in four stages of lactation using a commercial enzyme-linked immunosorbent assay kit. Multivariate analysis was performed to assess the association between maternal and neonatal factors, and LF concentration.

RESULTS

We collected 695 milk samples. LF mean concentration±standard deviation was 14.92±7.96 mg ml^-1 in colostrum (n=277), 10.73±5.67 in transitional milk (n=55), 10.34±6.27 at 1 month (n=259) and 8.52±6.47 at 2 months (n=104). There was a significant difference in LF concentration between different stages of lactation (P<0.001). Mothers with higher LF concentration in colostrum had higher values in the following 2 months. High maternal income and multiple gestation were significantly associated with higher LF levels; in contrast, maternal peripartum infections and male neonatal gender were associated with lower LF levels.

CONCLUSIONS

LF concentration in breast milk of mothers of LBW infants was high and remained elevated even at 1 and 2 months postpartum. LF concentration in colostrum was higher in mothers with higher income and multiple pregnancies, and lower in mothers with peripartum infections.

Proteomic characterization of canine seminal plasma

The present study was conducted to identify the major proteome of the sperm-rich fraction and prostatic fraction of canine seminal plasma. Three semen samples from four healthy dogs were obtained by digital manipulation. The pre-sperm fraction, sperm-rich fraction and prostatic fraction were separated from each ejaculate. Immediately after sperm analysis, a protease inhibitor was added to the sperm-rich fraction and prostatic fraction, and the fractions were separately centrifuged and frozen at -80 °C. The samples were thawed, re-centrifuged, and the total protein concentration was determined. Samples were subjected to 1D SDS-PAGE and Coomassie-blue stained gels, were analyzed by Quantity One 1D Analysis Software. Bands detected in the gels were excised and proteins subjected to digestion with trypsin. Proteins were identified by nano-HPLC-MS and tools of bioinformatics. Tandem mass spectrometry allowed the detection of 268 proteins in the gels of sperm-rich fraction and prostatic fraction of canine ejaculate. A total of 251 proteins were common to the sperm-rich and prostatic fractions, while 17 proteins were present in the sperm-rich fraction and absent in the prostatic fraction. The intensity of the bands detected in range 1 and 2 represented 46.5% of all of the band intensities detected in the 1D gels for proteins of the sperm-rich fraction and 53.0% of all bands in the prostatic fraction. Arginine esterase and lactotransferrin precursor were the protein with the highest intensity observed in the both fractions. Among the proteins present only in the sperm-rich fraction, the proteins UPF0764 protein C16orf89 homolog and epididymal-specific lipocalin-9 were the most abundant. In conclusion, canine sperm-rich fraction and prostatic fraction express a very diverse set of proteins, with unique biochemical properties and functions. Moreover, although most proteins are common to both sperm-rich fraction and prostatic fraction, there are some exclusive proteins in sperm-rich fraction.

Characterization of the cervical mucus plug in mares

The cervical mucus plug (CMP) is believed to play an integral role in the maintenance of pregnancy in the mare, primarily by inhibiting microbial entry. Unfortunately, very little is known about its composition or origin. To determine the proteomic composition of the CMP, we collected CMPs from mares (n = 4) at 9 months of gestation, and proteins were subsequently analyzed by nano-LC–MS/MS. Results were searched against EquCab2.0, and proteomic pathways were predicted by Ingenuity Pathway Analysis. Histologic sections of the CMP were stained with H&E and PAS. To identify the origin of highly abundant proteins in the CMP, we performed qPCR on endometrial and cervical mucosal mRNA from mares in estrus, diestrus as well as mares at 4 and 10 m gestation on transcripts for lactotransferrin, uterine serpin 14, uteroglobin, uteroferrin, deleted in malignant brain tumors 1 and mucins 4, 5b and 6. Overall, we demonstrated that the CMP is composed of a complex milieu of proteins during late gestation, many of which play an important role in immune function. Proteins traditionally considered to be endometrial proteins were found to be produced by the cervical mucosa suggesting that the primary source of the CMP is the cervical mucosa itself. In summary, composition of the equine CMP is specifically regulated not only during pregnancy but also throughout the estrous cycle. The structural and compositional changes serve to provide both a structural barrier as well as a physiological barrier during pregnancy to prevent infection of the fetus and fetal membranes.

Transcriptomic Insights into the Response of Placenta and Decidua Basalis to the CpG Oligodeoxynucleotide Stimulation in Non-Obese Diabetic Mice and Wild-Type Controls

Intrauterine infection is one of the most frequent causes of miscarriage. CpG oligodeoxynucleotide (CpG ODN) can mimic intrauterine infection. CpG ODN-induced embryo-resorption was observed consistently in the NK-cell deficient non-obese diabetic (NOD) mice but not in the wild-type (WT) mice. To elucidate the molecular mechanisms of differential pregnancy outcomes, differentially expressed genes (DEGs) in the placenta and decidua basalis was revealed by RNA-Seq with CpG ODN or control ODN treatment. Common DEGs in the WT and NOD mice were enriched in antimicrobial/antibacterial humoral responses that may be activated as a primary response to bacterial infection. The susceptibility to CpG ODN-induced embryo-resorption in the NOD mice might mainly be attributed to M1 macrophage polarization and the immunodeficient status, such as the down-regulation in antigen processing and presentation, allograft rejection, and natural killer cell mediated cytotoxicity. In contrast, the WT mice with normal immune systems could activate multiple immune responses and be resistant to CpG ODN-induced embryo-resorption, such as M2 macrophage differentiation and activation regulated by complement component C1q and peroxisome proliferation-activated receptor (PPAR) signaling pathways. Collectively, this study suggests that the immunodeficient status of NOD mice and the macrophage polarization regulated by C1q and PPAR signaling might be the basis for differential pregnancy outcomes between the NOD and WT mice.

Acute phase proteins as promising biomarkers: Perspectives and limitations for human and veterinary medicine

Acute phase proteins (APPs) are highly conserved plasma proteins that are increasingly secreted by the liver in response to a variety of injuries, independently of their location and cause. APPs favor the systemic regulation of defense, coagulation, proteolysis, and tissue repair. Various APPs have been applied as general diagnostic parameters for a long time. Through proteomic techniques, more and more APPs have been discovered to be differentially altered. Since they are not consistently explainable by a stereotypic hepatic expression of sets of APPs, most of these results have unfortunately been neglected or attributed to the nonspecificity of the acute phase reaction. Moreover, it appears that various extrahepatic tissues are also able to express APPs. These extrahepatic APPs show focally specific roles in tissue homeostasis and repair and are released primarily into interstitial and distal fluids. Since these focal proteins might leak into the circulatory system, mixtures of hepatic and extrahepatic APP species can be expected in blood. Hence, a selective alteration of parts of APPs might be expected. There are several hints on multiple molecular forms and fragments of tissue-derived APPs. These differences offer the chance for multiple selective determinations. Thus, specific proteoforms might indeed serve as tissue-specific disease indicators.

Lactoferrin affects the adherence and invasion of Streptococcus dysgalactiae ssp. dysgalactiae in mammary epithelial cells

Streptococcus dysgalactiae ssp. dysgalactiae is an important causative agent of bovine mastitis worldwide. Lactoferrin is an innate immune protein that is associated with many functions including immunomodulatory, antiproliferative, and antimicrobial properties. This study aimed to investigate the interactions between lactoferrin and a clinical bovine mastitis isolate, Strep. dysgalactiae ssp. dysgalactiae DPC5345. Initially a deliberate in vivo bovine intramammary challenge was performed with Strep. dysgalactiae DPC5345. Results demonstrated a significant difference in lactoferrin mRNA levels in milk cells between the control and infused quarters 7h postinfusion. Milk lactoferrin levels in the Strep. dysgalactiae DPC5345 infused quarters were significantly increased compared with control quarters at 48h postinfusion. In vitro studies demonstrated that lactoferrin had a bacteriostatic effect on the growth of Strep. dysgalactiae DPC5345 and significantly decreased the ability of the bacteria to internalize into HC-11 mammary epithelial cells. Confocal microscopy images of HC-11 cells exposed to Strep. dysgalactiae and lactoferrin further supported this effect by demonstrating reduced invasion of bacteria to HC-11 cells. The combined data suggest that a bovine immune response to Strep. dysgalactiae infection includes a significant increase in lactoferrin expression in vivo, and based on in vitro data, lactoferrin limits mammary cell invasion of this pathogen by binding to the bacteria and preventing its adherence.

Secreted multifunctional Glyceraldehyde-3-phosphate dehydrogenase sequesters lactoferrin and iron into cells via a non-canonical pathway

Lactoferrin is a crucial nutritionally important pleiotropic molecule and iron an essential trace metal for all life. The current paradigm is that living organisms have evolved specific membrane anchored receptors along with iron carrier molecules for regulated absorption, transport, storage and mobilization of these vital nutrients. We present evidence for the existence of non-canonical pathway whereby cells actively forage these vital resources from beyond their physical boundaries, by secreting the multifunctional housekeeping enzyme Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) into the extracellular milieu. This effect’s an autocrine/paracrine acquisition of target ligand into the cell. Internalization by this route is extensively favoured even by cells that express surface receptors for lactoferrin and involves urokinase plasminogen activator receptor (uPAR). We also demonstrate the operation of this phenomenon during inflammation, as an arm of the innate immune response where lactoferrin denies iron to invading microorganisms by chelating it and then itself being sequestered into surrounding host cells by GAPDH.

Lactoferrin causes IgA and IgG2b isotype switching through betaglycan binding and activation of canonical TGF-β signaling

Lactoferrin (LF), a pleiotropic iron-binding glycoprotein, is known to modulate the humoral immune response. However, its exact role in Ig synthesis has yet to be elucidated. In this study, we investigated the effect of LF on Ig production by mouse B cells and its underlying mechanisms. LF, like transforming growth factor (TGF)-β1, stimulated B cells to produce IgA and IgG2b, while downregulating other isotypes. Using limiting dilution analysis, LF was shown to increase the frequency of IgA-secreting B-cell clones. This was paralleled by an increase in Ig germ-line α (GLα) transcripts, indicating that LF plays a role as an IgA switch factor. Interestingly, LF directly interacted with betaglycan (TGF-β receptor III, TβRIII) and in turn induced phosphorylation of TβRI and Smad3 through formation of the TβRIII/TβRII/TβRI complex, leading to IgA isotype switching. Peroral administration of LF increased intestinal/serum IgA production as well as number of IgA plasma cells in lamina propria. Finally, we found that LF has an adjuvant activity when nontoxigenic Salmonella typhimurium was inoculated perorally, conferring protection against intragastrical infection of toxigenic S. typhimurium. These results suggest that LF has an important effect on the mucosal/systemic IgA response and can contribute to protection against intestinal pathogens.

Identification of polymorphism in exons 7 and 12 of lactoferrin gene and its association with incidence of clinical mastitis in Murrah buffalo

Lactoferrin gene is one of the important candidate genes for mastitis resistance. The gene is located on chromosome BTA 22 and consists of 17 exons spanning over 34.5 kb of genomic DNA. The present study was undertaken with the objectives to identify allelic variants in exons 7 and 12 of lactoferrin gene and to analyze association between its genetic variants and incidence of clinical mastitis in Murrah buffalo. The amplification of exons 7 and 12 of lactoferrin gene yielded amplicons of 232- and 461-bp sizes. PCR-restriction fragment length polymorphism (RFLP) analysis of 232-bp amplicon using BccI restriction enzyme revealed three genotypes (AA, AB, and BB) with frequencies of 0.62, 0.22, and 0.16, respectively. The frequencies of two alleles, A and B, were estimated as 0.73 and 0.27. Hpy188I-RFLP for 461-bp amplicon revealed polymorphism with three genotypes, CC, CD, and DD, with respective frequencies of 0.06, 0.39, and 0.56, whereas frequencies for C and D alleles were 0.25 and 0.75. The chi-square (χ(2)) analysis revealed a significant association between incidence of clinical mastitis and genetic variants of exon 7, and animals of AA genotype of exon 7 were found to be least susceptible to mastitis. The findings indicate potential scope for incorporation of lactoferrin gene in selection and breeding of Murrah buffaloes for improved genetic resistance to mastitis.

Association of polymorphism within LTF gene promoter with lactoferrin concentration in milk of Holstein cows

This study analyzed the association between single nucleotide polymorphism (A/C) in position -28 located in the TATA box of LTF gene and the lactoferrin concentration in bovine milk secreted by healthy and infected udders. Out of 241, 69 cows were selected into the experimental group and were divided into 3 groups according to mean value of somatic cell count (SCC): I < 180,000 cells/mL, II: 180,000-350,000 cells/mL and III > 350,000 cells/mL. In each SCC group, three LTF genotypes: AA, AC and CC were identified by PCR-SSCP method. A total of 604 milk samples were collected monthly and lactoferrin concentration was measured by ELISA. The 1-way ANOVA within SCC groups was performed to estimate association of -28 A/C genotypes with mean lactoferrin concentration per lactation. In the group of healthy cows (< 180,000 cells/mL) LTF concentration in milk cows with the AA genotype (107.58 ± 17.92 μg/mL) was significantly higher than in homozygotes CC (52.09 ± 19.01 μg/mL). Unexpectedly, in cows with elevated SCC (> 350,000 cells/mL) we observed a significant opposite relationship (207.21 ± 28.50 in CC vs 115.0 ± 28.6 μg/mL in AA). We hypothesized that a promoter with allele C, which cannot be recognized as a TATA sequence is becoming more accessible for other transcription factors, which may induce alternative LTF gene expression. We assume that our results demonstrate a very interesting effect of differential gene expression depending on polymorphism in a key regulatory motif (TATA box) and also on the health status of mammary tissues.

Lactoferrin gene variants, their expression in the udder and mastitis susceptibility in dairy cattle

Lactoferrin gene (LF) is regarded as one of the potential markers of mastitis susceptibility/resistance in dairy cattle. The study’s aim was therefore, to investigate the feasibility of two single nucleotide polymorphisms (SNP), placed in the 5′-flanking region and 3′-untranslated region of the LF gene, to serve as mastitis markers. The associations between these SNP and the expression of LF, both on mRNA and protein level, were estimated in the milk of Polish Holstein-Friesian cows. The relationships between polymorphisms and cows’ estimated breeding values (EBV) for somatic cell count were also calculated. It was shown that both polymorphisms have a significant impact on lactoferrin content in milk, and that LF+32 SNP is associated with the cow’s EBV for somatic cell count. No association between SNP chosen for the study and lactoferrin mRNA abundance in milk somatic cells was observed. We propose LF+32 SNP for a molecular marker of mastitis resistance in dairy cows.

Innate Humoral Defense Factors

Although innate immunity came into the research spotlight in the late 1990s when its instructive role in the adaptive immune response was recognized, innate humoral defense factors have a much older history. The exocrine secretions of the body contain a plethora of distinct soluble factors (lysozyme, lactoferrin, peroxidases, proline-rich proteins, histatins, etc.) that protect the body from mucosal microbial pathogens. More recent studies have established that the humoral arm of innate immunity contains a heterogeneous group of pattern-recognition molecules (e.g., pentraxins, collectins, and ficolins), which perform diverse host-defense functions, such as agglutination and neutralization, opsonization, control of inflammation, and complement activation and regulation. These pattern-recognition molecules, which act as functional predecessors of antibodies (“ante-antibodies”), and the classic soluble innate defense factors form an integrated system with complementary specificity, action, and tissue distribution, and they are the subject of this chapter.

Diethylstilbestrol (DES)-stimulated hormonal toxicity is mediated by ERα alteration of target gene methylation patterns and epigenetic modifiers (DNMT3A, MBD2, and HDAC2) in the mouse seminal vesicle

BACKGROUND

Diethylstilbestrol (DES) is a synthetic estrogen associated with adverse effects on reproductive organs. DES-induced toxicity of the mouse seminal vesicle (SV) is mediated by estrogen receptor α (ERα), which alters expression of seminal vesicle secretory protein IV (Svs4) and lactoferrin (Ltf) genes.

OBJECTIVES

We examined a role for nuclear receptor activity in association with DNA methylation and altered gene expression.

METHODS

We used the neonatal DES exposure mouse model to examine DNA methylation patterns via bisulfite conversion sequencing in SVs of wild-type (WT) and ERα-knockout (αERKO) mice.

RESULTS

The DNA methylation status at four specific CpGs (-160, -237, -306, and -367) in the Svs4 gene promoter changed during mouse development from methylated to unmethylated, and DES prevented this change at 10 weeks of age in WT SV. At two specific CpGs (-449 and -459) of the Ltf gene promoter, DES altered the methylation status from methylated to unmethylated. Alterations in DNA methylation of Svs4 and Ltf were not observed in αERKO SVs, suggesting that changes of methylation status at these CpGs are ERα dependent. The methylation status was associated with the level of gene expression. In addition, gene expression of three epigenetic modifiers-DNMT3A, MBD2, and HDAC2-increased in the SV of DES-exposed WT mice.

CONCLUSION

DES-induced hormonal toxicity resulted from altered gene expression of Svs4 and Ltf associated with changes in DNA methylation that were mediated by ERα. Alterations in gene expression of DNMT3A, MBD2, and HDAC2 in DES-exposed male mice may be involved in mediating the changes in methylation status in the SV.

CITATION

Li Y, Hamilton KJ, Lai AY, Burns KA, Li L, Wade PA, Korach KS. 2014. Diethylstilbestrol (DES)-stimulated hormonal toxicity is mediated by ERα alteration of target gene methylation patterns and epigenetic modifiers (DNMT3A, MBD2, and HDAC2) in the mouse seminal vesicle. Environ Health Perspect 122:262-268; http://dx.doi.org/10.1289/ehp.1307351.

Parity-dependent association between TNF-α and LTF gene polymorphisms and clinical mastitis in dairy cattle

BACKGROUND

One major problem in dairy cattle husbandry is the prevalence of udder infections. In today's breeding programmes, top priority is being given to making animal evaluation more cost-effective and reliable and less time-consuming. We proposed tumor necrosis factor α (TNF-α), lactoferrin (LTF) and macrophage-expressed lysozyme (mLYZ) genes as potential DNA markers in the improvement of immunity to mastitis.This study included 588 Polish Holstein-Friesian cows kept on one farm located in the north-western region of Poland. All clinical cases of mastitis in the herd under study were recorded by a qualified veterinarian employed by the farm. The following indicators were applied to determine udder immunity to mastitis in the cows under study: morbidity rate (MR), duration of mastitis (DM) and extent of mastitis (EM). TNF-α, mLYZ and LTF genotypes were identified by real-time PCR method, using SimpleProbe technology. Due to the very low frequency of mLYZ allele T, the gene was excluded from further analysis.A statistical analysis of associations between TNF-α and LTF genes and immunity to mastitis were performed using three models: 1) a parity-averaged model including only additive effects of the genes; 2) a parity-averaged model including both additive and epistatic effects of the genes; and 3) a parity-specific model including only additive effects of the genes.

RESULTS

With the first and second models it was revealed that the genes effects on the applied indicators of immunity to mastitis were non-significant whereas with the third one the effects were found to be statistically significant. Particularly noteworthy was the finding that the effects of TNF-α and LTF varied depending on age (parity). The alleles which were linked to high immunity to mastitis in lower parities appeared to be less favourable in higher parities.

CONCLUSIONS

These interactions might be related to inflamm-ageing, that is an increased susceptibility to infection due to immune system deregulation that progresses with age. Such pattern of interactions makes it impossible to use the genes in question in marker-assisted selection aimed at reducing heritable susceptibility to mastitis. This is because the immune mechanisms behind resistance to infections proved to be too complex.

Lactoferrin: Antimicrobial activity and therapeutic potential

Lactoferrin is a highly conserved protein from an evolutionary perspective, with a wide range of roles related to protection from infection and promotion of nutritional status. Infection, malnutrition and intestinal pathologies are key inter-related problems, represent important threats to survival and are associated with adverse long-term health outcomes after preterm birth. Lactoferrin is available as a commercial extract from bovine milk and offers potential as a therapeutic intervention for preterm infants modulating infections and intestinal pathologies. In this review we explore the structure, direct antimicrobial effects, modification of host immune function and gastrointestinal effects of lactoferrin. Current trial data are reviewed, and research priorities and challenges identified and discussed.

Expression of a dominant negative estrogen receptor alpha variant in transgenic mice accelerates uterine cancer induced by the potent estrogen diethylstilbestrol

ERΔ3 transgenic mice expressing a dominant negative estrogen receptor α (ERα) variant lacking the second zinc finger in the DNA binding domain were developed to examine its potential to inhibit estrogen action in vivo. To investigate if ERΔ3 expression influences uterine carcinogenesis, ERΔ3 transgenic mice were exposed to diethylstilbestrol (DES) on post-natal days 1-5. Neonatal DES treatment induced uterine adenocarcinomas in 81% of 8-month-old ERΔ3 mice compared to 49% of wild-type females (p<0.016). ERΔ3 did not inhibit the expression of the estrogen-responsive progesterone receptor and lactoferrin genes in the presence of ERα or modify their expression in ERα knockout (αERKO) mice. Higher circulating 17β-estradiol levels and non-classical signaling by ERΔ3 may be related to the earlier incidence of uterine cancer. These findings indicate that expression of this ERα variant can influence determining events in uterine cancer development and its natural occurrence in the human uterus would unlikely be protective.

GATA4 is a critical regulator of gonadectomy-induced adrenocortical tumorigenesis in mice

In response to gonadectomy certain inbred mouse strains develop sex steroidogenic adrenocortical neoplasms. One of the hallmarks of neoplastic transformation is expression of GATA4, a transcription factor normally present in gonadal but not adrenal steroidogenic cells of the adult mouse. To show that GATA4 directly modulates adrenocortical tumorigenesis and is not merely a marker of gonadal-like differentiation in the neoplasms, we studied mice with germline or conditional loss-of-function mutations in the Gata4 gene. Germline Gata4 haploinsufficiency was associated with attenuated tumor growth and reduced expression of sex steroidogenic genes in the adrenal glands of ovariectomized B6D2F1 and B6AF1 mice. At 12 months after ovariectomy, wild-type B6D2F1 mice had biochemical and histological evidence of adrenocortical estrogen production, whereas Gata4(+/-) B6D2F1 mice did not. Germline Gata4 haploinsufficiency exacerbated the secondary phenotype of postovariectomy obesity in B6D2F1 mice, presumably by limiting ectopic estrogen production in the adrenal glands. Amhr2-cre-mediated deletion of floxed Gata4 (Gata4(F)) in nascent adrenocortical neoplasms of ovariectomized B6.129 mice reduced tumor growth and the expression of gonadal-like markers in a Gata4(F) dose-dependent manner. We conclude that GATA4 is a key modifier of gonadectomy-induced adrenocortical neoplasia, postovariectomy obesity, and sex steroidogenic cell differentiation.

Lactoferrin a multiple bioactive protein: an overview

BACKGROUND

Lactoferrin (Lf) is an 80kDa iron-binding glycoprotein of the transferrin family. It is abundant in milk and in most biological fluids and is a cell-secreted molecule that bridges innate and adaptive immune function in mammals. Its protective effects range from anticancer, anti-inflammatory and immune modulator activities to antimicrobial activities against a large number of microorganisms. This wide range of activities is made possible by mechanisms of action involving not only the capacity of Lf to bind iron but also interactions of Lf with molecular and cellular components of both hosts and pathogens.

SCOPE OF REVIEW

This review summarizes the activities of Lf, its regulation and potential applications.

MAJOR CONCLUSIONS

The extensive uses of Lf in the treatment of various infectious diseases in animals and humans has been the driving force in Lf research however, a lot of work is required to obtain a better understanding of its activity.

GENERAL SIGNIFICANCE

The large potential applications of Lf have led scientists to develop this nutraceutical protein for use in feed, food and pharmaceutical applications. This article is part of a Special Issue entitled Molecular Mechanisms of Iron Transport and Disorders.