Biological role of lactoferrin

Potentials of Natural Antioxidants in Reducing Inflammation and Oxidative Stress in Chronic Kidney Disease

Chronic kidney disease (CKD) presents a substantial global public health challenge, with high morbidity and mortality. CKD patients often experience dyslipidaemia and poor glycaemic control, further exacerbating inflammation and oxidative stress in the kidney. If left untreated, these metabolic symptoms can progress to end-stage renal disease, necessitating long-term dialysis or kidney transplantation. Alleviating inflammation responses has become the standard approach in CKD management. Medications such as statins, metformin, and GLP-1 agonists, initially developed for treating metabolic dysregulation, demonstrate promising renal therapeutic benefits. The rising popularity of herbal remedies and supplements, perceived as natural antioxidants, has spurred investigations into their potential efficacy. Notably, lactoferrin, Boerhaavia diffusa, Amauroderma rugosum, and Ganoderma lucidum are known for their anti-inflammatory and antioxidant properties and may support kidney function preservation. However, the mechanisms underlying the effectiveness of Western medications and herbal remedies in alleviating inflammation and oxidative stress occurring in renal dysfunction are not completely known. This review aims to provide a comprehensive overview of CKD treatment strategies and renal function preservation and critically discusses the existing literature's limitations whilst offering insight into the potential antioxidant effects of these interventions. This could provide a useful guide for future clinical trials and facilitate the development of effective treatment strategies for kidney functions.

Predictive value of fecal calprotectin and lactoferrin levels for negative outcomes in Clostridioides difficile infection

PURPOSE

We investigated the role of fecal calprotectin (FC) and lactoferrin (FL) as predictive biomarkers in Clostridioides difficile infection (CDI).

METHODS

We assembled a prospective cohort including all patients with a laboratory-confirmed CDI diagnosis between January and December 2017. FL and FC levels were measured at diagnosis by commercial ELISA and EIA kits. We investigated the diagnostic accuracy of FC and FL to predict CDI recurrence and severity (study outcomes) and explored optimal cut-off values in addition to those proposed by the manufacturers (200 µg/g and 7.2 µg/mL, respectively).

RESULTS

We included 170 CDI cases (152 first episodes and 18 recurrences). The rates of recurrence (first episodes only) and severity (entire cohort) were 9.2% (14/152) and 46.5% (79/170). Both FL and FC levels were significantly higher in patients who developed study outcomes. Optimal cut-off values for FC and FL to predict CDI recurrence were 1052 µg/g and 6.0 µg/mL. The optimal cut-off value for FC yielded higher specificity (60.9%) and positive predictive value (PPV) (16.9%) than that proposed by the manufacturer. Regarding CDI severity, the optimal cut-off value for FC (439 µg/g) also provided higher specificity (43.9%) and PPV (54.1%) than that of the manufacturer, whereas the optimal cut-off value for FL (4.6 µg/mL) resulted in an improvement of PPV (57.5%).

CONCLUSION

By modifying the thresholds for assay positivity, the measurement of FC and FL at diagnosis is useful to predict recurrence and severity in CDI. Adding these biomarkers to current clinical scores may help to individualize CDI management.

Synergistic Effect of Retinoic Acid and Lactoferrin in the Maintenance of Gut Homeostasis

Lactoferrin (LF) is a glycoprotein that binds to iron ions (Fe2+) and other metallic ions, such as Mg2+, Zn2+, and Cu2+, and has antibacterial and immunomodulatory properties. The antibacterial properties of LF are due to its ability to sequester iron. The immunomodulatory capability of LF promotes homeostasis in the enteric environment, acting directly on the beneficial microbiota. LF can modulate antigen-presenting cell (APC) biology, including migration and cell activation. Nonetheless, some gut microbiota strains produce toxic metabolites, and APCs are responsible for initiating the process that inhibits the inflammatory response against them. Thus, eliminating harmful strains lowers the risk of inducing chronic inflammation, and consequently, metabolic disease, which can progress to type 2 diabetes mellitus (T2DM). LF and retinoic acid (RA) exhibit immunomodulatory properties such as decreasing cytokine production, thus modifying the inflammatory response. Their activities have been observed both in vitro and in vivo. The combined, simultaneous effect of these molecules has not been studied; however, the synergistic effect of LF and RA may be employed for enhancing the secretion of humoral factors, such as IgA. We speculate that the combination of LF and RA could be a potential prophylactic alternative for the treatment of metabolic dysregulations such as T2DM. The present review focuses on the importance of a healthy diet for a balanced gut and describes how probiotics and prebiotics with immunomodulatory activity as well as inductors of differentiation and cell proliferation could be acquired directly from the diet or indirectly through the oral administration of formulations aimed to maintain gut health or restore a eubiotic state in an intestinal environment that has been dysregulated by external factors such as stress and a high-fat diet.

One advantageous reflection of iron metabolism in context of normal physiology and pathological phases

PURPOSE (BACKGROUND)

The presented review is an updating of Iron metabolism in context of normal physiology and pathological phases. Iron is one of the vital elements in humans and associated into proteins as a component of heme (e.g. hemoglobin, myoglobin, cytochromes proteins, myeloperoxidase, nitric oxide synthetases), iron sulfur clusters (e.g. respiratory complexes I-III, coenzyme Q10, mitochondrial aconitase, DNA primase), or other functional groups (e.g. hypoxia inducible factor prolyl hydroxylases). All these entire iron-containing proteins ar e needed for vital cellular and organismal functions together with oxygen transport, mitochondrial respiration, intermediary and xenobiotic metabolism, nucleic acid replication and repair, host defense, and cell signaling.

METHODS (METABOLIC STRATEGIES)

Cells have developed metabolic strategies to import and employ iron safely. Regulatory process of iron uptake, storage, intracellular trafficking and utilization is vital for the maintenance of cellular iron homeostasis. Cellular iron utilization and intracellular iron trafficking pathways are not well established and very little knowledge about this. The predominant organs, which are associated in the metabolism of iron, are intestine, liver, bone marrow and spleen. Iron is conserved, recycled and stored. The reduced bioavailability of iron in humans has developed extremely efficient mechanisms for iron conservation. Prominently, the losses of iron cannot considerably enhance through physiologic mechanisms, even if iron intake and stores become excessive. Loss of iron is balanced or maintained from dietary sources.

RESULTS (OUTCOMES)

Numerous physiological abnormalities are associated with impaired iron metabolism. These abnormalities are appeared in the form of several diseases. There are duodenal ulcer, inflammatory bowel disease, sideroblastic anaemia, congenital dyserythropoietic anemias and low-grade myelodysplastic syndromes. Hereditary hemochromatosis and anaemia are two chronic diseases, which are responsible for disturbing the iron metabolism in various tissues, including the spleen and the intestine. Impairment in hepatic hepcidin synthesis is responsible for chronic liver disease, which is grounding from alcoholism or viral hepatitis. This condition directs to iron overload that can cause further hepatic damage. Iron has important role in several infectious diseases are tuberculosis, malaria trypanosomatid diseases and acquired immunodeficiency syndrome (AIDS). Iron is also associated with Systemic lupus erythematosus [SLE], cancer, Alzheimer's disease (AD) and post-traumatic epilepsy.

CONCLUSION

Recently, numerous research studies are gradually more dedicated in the field of iron metabolism, but a number of burning questions are still waiting for answer. Cellular iron utilization and intracellular iron trafficking pathways are not well established and very little knowledge about this. Increased information of the physiology of iron homeostasis will support considerate of the pathology of iron disorders and also make available the support to advance treatment.

Expression of miRNAs in Pre-Schoolers with Autism Spectrum Disorders Compared with Typically Developing Peers and Its Effects after Probiotic Supplementation

Alteration of the microbiota-gut-brain axis has been recently recognized as a possible contributor to the physiopathology of autism spectrum disorder (ASD). In this context, microRNA (miRNAs) dysfunction, implicated both in several neuropathological conditions including ASD and in different gastrointestinal disorders (GIDs), could represent an important modulating factor. In this contextual framework, we studied the transcriptional profile of specific circulating miRNAs associated with both ASD (miR-197-5p, miR-424-5p, miR-500a-5p, miR-664a-5p) and GID (miR-21-5p, miR-320a-5p, miR-31-5p, miR-223-5p) in a group of pre-schoolers with ASD and in typically developing (TD) peers. In the ASD group, we also assessed the same miRNAs after a 6-month supplementation with probiotics and their correlation with plasma levels of zonulin and lactoferrin. At baseline, the expression of miRNAs involved in ASD were significantly reduced in ASD pre-schoolers vs. TD controls. Regarding the miRNAs involved in GID, the expression levels of miR-320-5p, miR-31-5p, and miR-223-5p were significantly higher in ASD than in TD subjects, whereas miR-21-5p showed significantly reduced expression in the ASD group vs. TD group. Supplementation with probiotics did not significantly change the expression of miRNAs in the ASD population. We found a significative negative correlation between zonulin and miR-197-5p and miR-21-5p at baseline, as well as between lactoferrin and miR-223-5p after 6 months of probiotic supplementation. Our study confirms the presence of an altered profile of the miRNAs investigated in ASD versus TD peers that was not modified by supplementation with probiotics.

Impact of COVID-19 vaccination on saliva immune barriers: IgA, lysozyme, and lactoferrin

Understanding the role of salivary constituents, such as lactoferrin, lysozyme, and secretory immunoglobulin A (sIgA), in immune protection and defense mechanisms against microbial invasion and colonization of the airways is important in light of the ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. The salivary immune barrier in individuals affected by COVID-19 may contribute to disease prognosis. Thus, the aim of the present review is to evaluate the effect of COVID-19 vaccines on the immunological composition of saliva. IgA antibodies generated by vaccination can neutralize the virus at mucosal surfaces, whereas antimicrobial peptides, such as lysozyme and lactoferrin, have broad-spectrum antimicrobial activity. Collectively, these components contribute to the protective immune response of the oral cavity and may help minimize viral transmission as well as the severity of COVID-19. Measuring the levels of these components in the saliva of COVID-19-vaccinated individuals can help in evaluating the vaccine's ability to induce mucosal immunity, and it might also provide insights into whether saliva can be used in diagnostics or surveillance for monitoring immune responses following vaccination. This also has implications for viral transmission.

Therapeutic potential of lactoferrin-coated iron oxide nanospheres for targeted hyperthermia in gastric cancer

Lactoferrin (LF) is a non-heme iron-binding glycoprotein involved in the transport of iron in blood plasma. In addition, it has many biological functions, including antibacterial, antiviral, antimicrobial, antiparasitic, and, importantly, antitumor properties. In this study, we have investigated the potential of employing lactoferrin-iron oxide nanoparticles (LF-IONPs) as a treatment modality for gastric cancer. The study confirms the formation of LF-IONPs with a spherical shape and an average size of 5 ± 2 nm, embedded within the protein matrix. FTIR and Raman analysis revealed that the Fe-O bond stabilized the protein particle interactions. Further, we conducted hyperthermia studies to ascertain whether the proposed composite can generate a sufficient rise in temperature at a low frequency. The results confirmed that we can achieve a temperature rise of about 7 °C at 242.4 kHz, which can be further harnessed for gastric cancer treatment. The particles were further tested for their anti-cancer activity on AGS cells, with and without hyperthermia. Results indicate that LF-IONPs (10 µg/ml) significantly enhance cytotoxicity, resulting in the demise of 67.75 ± 5.2% of cells post hyperthermia, while also exhibiting an inhibitory effect on cell migration compared to control cells, with the most inhibition observed after 36 h of treatment. These findings suggest the potential of LF-IONPs in targeted hyperthermia treatment of gastric cancer.

How Can We Best Diagnose Severity Levels of Dry Eye Disease: Current Perspectives

Dry eye disease (DED) is a common ocular condition, but the diagnosis relative to other ocular conditions and the evaluation of severity of the condition has often been difficult. This challenge can be due to clinical signs and symptoms not always correlating with each other. An understanding of the various components which create the condition, as well as the diagnostic measures used to evaluate these components, is useful to the clinician working with DED patients. This review paper will discuss traditional diagnostic options, diagnostic imaging, and Advanced Point of Care testing capabilities to determine the severity level of dry eye disease more adequately.

The abundances of LTF and SOD2 in amniotic fluid are potential biomarkers of gestational age and preterm birth

Neonates who are born preterm (PT) are usually characterized by immature physiological development, and preterm birth (PTB) is the leading cause of neonatal morbidity and mortality if intensive medical care is not available to PTB neonates. Early prediction of a PTB enables medical personnel to make preparations in advance, protecting the neonate from the subsequent health risks. Therefore, many studies have worked on identifying invasive or noninvasive PT biomarkers. In this study, we collected amniocentesis-derived (at the second trimester of gestation) amniotic fluid (AF) samples. At delivery, AF samples were classified into PTB or full-term birth (FTB). We first applied protein mass spectrometry technology to globally screen AF proteins, followed by specific protein validation with ELISA. We identified four protein biomarkers of PTB, including lactotransferrin (LTF), glutathione-disulfide reductase (GSR), myeloperoxidase (MPO) and superoxide dismutase 2 (SOD2). Further analyses demonstrated that their abundances were negatively correlated with neonatal weight and gestational age. In addition, by mimicking survival rate analysis widely used in tumor biology, we found that LTF and SOD2 were prognostic factors of gestational age, with higher levels denoting shorter gestational age. Finally, using the abundances of the four protein biomarkers, we developed a prediction model of PTB with an auROC value of 0.935 (sensitivity = 0.94, specificity = 0.89, p value = 0.0001). This study demonstrated that the abundances of specific proteins in amniotic fluid were not only the prognostic factors of gestational age but also the predictive biomarkers of PTB. These four AF proteins enable identification of PTB early in the second trimester of gestation, facilitating medical intervention to be applied in advance.

Proteomic analysis of sialoliths from calcified, lipid and mixed groups as a source of potential biomarkers of deposit formation in the salivary glands

Salivary stones, also known as sialoliths, are formed in a pathological situation in the salivary glands. So far, neither the mechanism of their formation nor the factors predisposing to their formation are known despite several hypotheses. While they do not directly threaten human life, they significantly deteriorate the patient's quality of life. Although this is not a typical research material, attempts are made to apply various analytical tools to characterise sialoliths and search for the biomarkers in their proteomes. In this work, we used mass spectrometry and SWATH-MS qualitative and quantitative analysis to investigate the composition and select proteins that may contribute to solid deposits in the salivary glands. Twenty sialoliths, previously characterized spectroscopically and divided into the following groups: calcified (CAL), lipid (LIP) and mixed (MIX), were used for the study. Proteins unique for each of the groups were found, including: for the CAL group among them, e.g. proteins from the S100 group (S100 A8/A12 and P), mucin 7 (MUC7), keratins (KRT1/2/4/5/13), elastase (ELANE) or stomatin (STOM); proteins for the LIP group-transthyretin (TTR), lactotransferrin (LTF), matrix Gla protein (MPG), submandibular gland androgen-regulated protein 3 (SMR3A); mixed stones had the fewest unique proteins. Bacterial proteins present in sialoliths have also been identified. The analysis of the results indicates the possible role of bacterial infections, disturbances in calcium metabolism and neutrophil extracellular traps (NETs) in the formation of sialoliths.

Yield and Composition Variations of the Milk from Different Camel Breeds in Saudi Arabia

With the increasing interest in the identification of differences between camel breeds over the last decade, this study was conducted to estimate the variability of milk production and composition of four Saudi camel breeds during different seasons. Milk records were taken two days per week from females of Majahem, Safra, Wadha, and Hamra breeds distributed over Saudi Arabia. The milk yield during winter indicated that the weekly average of the Wadha breed was significantly lower (27.13 kg/week) than Majahem and Hamra breeds. The Safra breed had the lowest milk yield (30.7 kg/week) during summer. During winter, the Hamra breed had a lower content of all analyzed milk components except proteins and was characterized by a lower pH than the milk of the other breeds. However, the Hamra breed had significantly higher contents of milk fat and lactose than the other breeds during summer, with the corresponding values of 3.87 and 4.86%, respectively. Milk collected during winter from Majahem, Safra, and Wadha breeds was characterized by a significant increase in all milk components and milk pH. Finally, the isoelectric focusing analysis revealed noticeable variability of casein purified from camel milk within the different Saudi breeds, with the highest significant value of 2.29 g per 100 mL recorded for the Wadha breed.

Natural Immunomodulators Treat the Cytokine Storm in SARS-CoV-2

Recently, the world has been dealing with a destructive global pandemic Coronavirus disease 2019 (COVID-19) infection, since 2020; there were millions of infections and hundreds of thousands of deaths worldwide. With sequencing generations of the virus, around 60% are expected to become infected during the pandemic. Unfortunately, no drug or vaccine has been approved because no real evidence from clinical trials in treatment was reached. According to current thinking, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mortality is caused by a cytokine storm syndrome in patients with hyper-inflammatory conditions, resulting in acute respiratory distress and finally death. In this review, we discuss the various types of natural immune-modulatory agents and their role in the management of SARS-CoV-2, and cytokine storm syndrome. For example, Polyphenols as natural products can block the binding of SARS-CoV-2 spike protein to host cell receptor ACE2, stop viral entry into the host cell and block viral RNA replication. Also, saikosaponins (A, B2, C, and D), triterpene glycosides, which are isolated from medicinal plants exert antiviral action against HCoV-22E9, and Houttuynia cordata water extract has antiviral effects on SARS-CoV. Moreover, eucalyptus oil has promising potential for COVID-19 prevention and treatment. There is an urgent need for research to improve the function of the human immune system all over the world. As a result, actions for better understanding and improving the human immune system are critical steps toward mitigating risks and negative outcomes. These approaches will be strongly recommended for future emerging viruses and pathogens.

Probiotics to prevent necrotizing enterocolitis in very low birth weight infants: A network meta-analysis

Objective

This study aims to review the evidence for the optimal regimen of probiotics for the prevention of necrotizing enterocolitis (NEC) in very low birth weight infants.

Design

Through searching PubMed, EMBASE, Cochrane Library, and Web of Science till September 30, 2022, only randomized controlled trials were included to evaluate the optimal regimen of probiotics for the prevention of NEC in very low birth weight infants. The methodological quality of the included studies was assessed by the Cochrane risk of bias assessment tool (RoB 2), and the collected data were analyzed accordingly using Stata software.

Results

Twenty-seven RCTs were included, and the total sample size used in the study was 529. The results of the network meta-analysis showed that Bovine lactoferrin + Lactobacillus rhamnosus GG (RR 0.03; 95% CI 0.00-0.35), Lactobacillus rhamnosus + Lactobacillus plantarum + Lactobacillus casei + Bifidobacterium lactis (RR 0.06; 95% CI 0.00-0.70), Bifidobacterium lactis + inulin (RR 0.16; 95% CI 0.03-0.91) were superior to the control group (Bifidobacterium lactis + Bifidobacterium longum) in reducing the incidence of NEC. The reduction in the incidence of NEC were as follows: Bovine lactoferrin + Lactobacillus rhamnosus GG (SUCRA 95.7%) > Lactobacillus rhamnosus + Lactobacillus plantarum + Lactobacillus casei + Bifidobacterium lactis (SUCRA 89.4%) > Bifidobacterium lactis + inulin (SUCRA 77.8%).

Conclusions

This network meta-analysis suggests that Lactobacillus rhamnosus GG combined with bovine lactoferrin maybe the most recommended regimen for the prevention of NEC in very low birth weight infants.

Lactoferrin for COVID-19 prevention, treatment, and recovery

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), a unique beta-coronavirus, has caused the most serious outbreak of the last century at the global level. SARS-CoV-2 infections were firstly reported in the city of Wuhan in China in 2019 and this new disease was named COVID-19 by World Health Organization (WHO). As this novel disease can easily be transmitted from one individual to another via respiratory droplets, many nations around the world have taken several precautions regarding the reduction in social activities and quarantine for the limitation of the COVID-19 transmission. SARS-CoV-2 is known to cause complications that may include pneumonia, acute respiratory distress syndrome (ARDS), multi-organ failure, septic shock, and death. To prevent and treat COVID-19, some significant studies have been conducted since the outbreak. One of the most noticeable therapeutic approaches is related to a multifunctional protein, lactoferrin. Lactoferrin (Lf) is an 80 kDa cationic glycoprotein that has a great range of benefits from improving the immunity to antiviral effects due to its unique characteristics such as the iron-binding ability. This review summarizes the characteristics of SARS-CoV-2 and the potential applications of Lf for the prevention, treatment, and recovery of COVID-19.

Effect of in vitro gastrointestinal digestion on the antibacterial activity of bioactive dairy formulas supplemented with lactoferrin against Cronobacter sakazakii

Milk is a source of proteins with high nutritional value and relevant biological activities. Bioactive milk proteins, like lactoferrin, are important for newborn development and can also be used as ingredients in functional products to improve health. Lactoferrin is essential in infant’s diet, since protects against infections and promotes immune system maturation. Bovine lactoferrin is used to supplement formula milk in order to strengthen baby’s defences against some pathogenic bacteria. Thus, lactoferrin supplemented formula can be a barrier against emergent pathogens, such as Cronobacter sakazakii, which has caused great concern in the last few years. Milk proteins generate bioactive peptides in the digestion process, and it is known that industrial processing can modify their susceptibility to digestion. Treatments such as heating have been shown to denature whey proteins and make them more easily digestible. Therefore, the aim of this study was to analyze the effect of technological treatments and gastrointestinal digestion on the antibacterial activity against C. sakazakii of proteins present in dairy formulas supplemented with lactoferrin. Commercial bovine lactoferrin has been shown to have antibacterial activity against C. sakazakii, both in the native state and after static in vitro gastrointestinal digestion. In addition, the digests obtained from dairy formulas subjected to technological treatments, either homogenization or pasteurization, have higher antibacterial activity than non-treated formulas. The release of low molecular weight peptides during the in vitro gastric digestion is probably the cause that would explain the enhanced antibacterial activity of the digested dairy formulas.

Immunomodulatory Effect of Human Lactoferrin on Toll-like Receptors 2 Expression as Therapeutic Approach for Keratoconus

Keratoconus (KC) is a corneal disorder whose etiology shares a close relationship with Lactoferrin (LTF) dysregulation and Toll-like Receptors 2 (TLR2) overexpression. This study shows how these two important biomarkers are clinically and molecularly interrelated, increasing knowledge about KC pathophysiology, and opening the door to future therapies. In this prospective clinical study, serum and tear LTF concentrations were quantified in 90 KC patients and 60 controls. A correlation analysis with multiple blood and tear immunoinflammatory mediators, and KC-associated tomographic parameters, was performed. An in vitro study using HEK-BlueTMhTLR2 cell cultures was also conducted to determine the expression and functionality of TLR2 under the influence of LTF treatment. As a result, a LTF decreased was observed in KC patients compared to controls (p < 0.0001), evidencing the strong correlation with TLR2 overexpression at systemic and ocular surface level, with inflammatory mediator upregulation and with KC severity. In stimulated cell cultures, TLR2 expression was decreased using 2 mg/mL of LTF. The levels of secreted embryonic alkaline phosphatase (SEAP) and interleukin-8 (IL-8) were also reduced in supernatants after LTF treatment. As conclusions, the dysregulation of LTF and TLR2 in the ocular surface of KC patients contributes to KC severity by maintaining a detrimental chronic immune−inflammatory state. The immunomodulatory properties of LTF on TLR2 expression suggest its potential as a therapeutic approach for KC.

Biomarkers for the Evaluation of Pouch Inflammation: A Systematic Review

Background

Ileal pouch inflammation is a common problem following ileal pouch-anal anastomosis (IPAA). Despite its prevalence, diagnosis remains multimodal and requires endoscopy. The use of biomarkers in the prediction of and/or association with pouchitis has not been well characterized. We performed a systematic review to summarize the available evidence.

Method

A search of Ovid, MEDLINE, Cochrane Library, EMBASE, and Web of Science was conducted. Inclusion criteria included studies evaluating biomarkers for the evaluation and prediction of inflammation in patients with IPAA utilizing pouchoscopy as the gold standard. Exclusion criteria included studies on the role of the microbiome or genetic markers.

Results

A total of 28 studies, 5 case-control studies, and 23 observational cohort studies were identified. Fecal biomarkers were assessed in 23 studies, of which fecal calprotectin was the most commonly studied with sensitivities ranging from 57% to 92% and specificities from 19% to 92%. Six studies examined serum biomarkers. None of the serum biomarkers demonstrated a high sensitivity or specificity in association with pouch inflammation. Six studies described the longitudinal assessment of biomarkers. Of these studies, only three reported a predictive role of biomarkers in diagnosing endoscopic inflammation.

Conclusions

Biomarkers have emerged as a potential option to improve the management of pouchitis given the relative ease of sampling compared to pouchoscopy. Unfortunately, the evaluated biomarkers have not consistently demonstrated accuracy in predicting inflammation. Moreover, these biomarkers have not been reliably shown to be sensitive or specific in association with endoscopic pouch inflammation to merit their widespread use in clinical practice.

Lactoferrin improves the immune response and resistance of silver carp, a hematological, light (histochemical and immunohistochemical), fluorescent, and scanning electron microscopic study

Lactoferrin is a multifunctional protein that has roles in iron metabolism, cell generation and differentiation, and antibacterial, antiviral, and antiparasitic activity. The study aim was to evaluate the effect of dietary lactoferrin powder on the innate immune response and disease resistance of silver carp (Hypophthalmichthys molitrix) infected with Vibrio vulnificus. The study also investigates immune cells in different organs including gills, intestine, spleen, liver, and pancreas using light, scan electron microcopy. Two diet regimes, a basic diet and a 600-mg/kg bovine lactoferrin-supplemented diet were used. The fish were fed for 30 successive days. We included 270 apparently healthy silver carp (H. Molitrix) with an average body weight of 10 ± 2 g/fish. Addition of lactoferrin to the diet led to an increase in the activity of non-specific immune parameters; lymphocytes, and in the monocytes percentage, and in total protein, serum globulin, and albumin, with a corresponding increase in phagocytic activities and indices. The histological analysis revealed increase immune cells such as lymphocytes in intestine, rodlet cells in liver, gills, and pancreas, and the macrophages in liver, pancreas as well as spleen. The lactoferrin-supplemented diet significantly increased survival and disease resistance following V. vulnificus challenge, which seemed to correspond to an enhancement of non-specific immune functions in H. molitrix. RESEARCH HIGHLIGHTS: The study evaluates the effect of dietary lactoferrin powder on the innate immune response and disease resistance of silver carp (Hypophthalmichthys molitrix) infected with Vibrio vulnificus. The study also investigates immune cells in different organs including gills, intestine, spleen, liver, and pancreas using light, scan electron microcopy. Lactoferrin increases the activity of nonspecific immune parameters; lymphocytes, and in the monocytes percentage, and in total protein, serum globulin, and albumin, with a corresponding increase in phagocytic activities and indices. The histological analysis revealed increase immune cells such as lymphocytes in intestine, rodlet cells in liver, gills, and pancreas, and the macrophages in liver, pancreas as well as spleen.

Disease Tolerance during Viral-Bacterial Co-Infections

Disease tolerance has emerged as an alternative way, in addition to host resistance, to survive viral-bacterial co-infections. Disease tolerance plays an important role not in reducing pathogen burden, but in maintaining tissue integrity and controlling organ damage. A common co-infection is the synergy observed between influenza virus and Streptococcus pneumoniae that results in superinfection and lethality. Several host cytokines and cells have shown promise in promoting tissue protection and damage control while others induce severe immunopathology leading to high levels of morbidity and mortality. The focus of this review is to describe the host cytokines and innate immune cells that mediate disease tolerance and lead to a return to host homeostasis and ultimately, survival during viral-bacterial co-infection.

A Peptide Bond from the Inter-lobe Segment in the Bilobal Lactoferrin Acts as a Preferred Site for Cleavage for Serine Proteases to Generate the Perfect C-lobe: Structure of the Pepsin Hydrolyzed Lactoferrin C-lobe at 2.28 Å Resolution

C-lobe represents the C-terminal half of lactoferrin which is a bilobal 80 kDa iron binding glycoprotein. The two lobes are designated as N-lobe (Ser1-Glu333) and C-lobe (Arg344-Arg689). The N- and C-lobes are connected by a 10-residue long α-helical peptide (Thr334-Thr343). Both lobes adopt similar conformations and have identical iron binding sites. The bilobal lactoferrin was hydrolyzed in a limited proteolysis using pepsin at pH 2.0. It produced a 40 kDa and fully functional C-lobe which was purified and crystallized at pH 8.0. The structure determination revealed that the structure contained residues from Tyr342 to Arg689 representing a fully functional monoferric C-lobe. It showed that pepsin cleaved lactoferrin at the peptide bond Arg341-Tyr342 which is part of the inter-lobe decapeptide. Interestingly, the two previously determined structures of the enzymatically produced C-lobe using trypsin and proteinase K also cleaved lactoferrin at the same peptide bond Arg341-Tyr342. This was a striking result as the three enzymes, pepsin, trypsin and proteinase K have different specificity requirements and yet they cleaved the bilobal lactoferrin at the same peptide bond and generated an identical and fully functional C-lobe. This shows that the observed cleavage site in lactoferrin adopts a highly favourable conformation for proteolysis. It is noteworthy that the three enzymes with different specificities cut the protein at the same peptide bond which may be of physiological significance because the antibacterial action of lactoferrin is extended further through the C-lobe.

Detecting Periprosthetic Joint Infection by Using Mass Spectrometry

BACKGROUND

Novel methods for diagnosing periprosthetic joint infection (PJI) are currently being explored. Mass spectrometry (MS) is an approach that can detect whole-protein changes in synovial fluid and may represent a promising method.

METHODS

Between March 2017 and July 2018, we successively collected synovial fluid samples from patients who were undergoing diagnostic hip or knee aspiration because PJI was suspected. A PJI diagnosis was based on the modified Musculoskeletal Infection Society (MSIS) criteria. Cluster analysis and receiver operating characteristic (ROC) curves were used to evaluate the results, which were quantitatively confirmed with parallel reaction monitoring in another patient group who underwent aspiration between August 2018 and January 2019.

RESULTS

A total of 117 synovial samples, including 51 PJI and 66 non-PJI samples, were analyzed with liquid chromatography-tandem MS (LC-MS/MS). The cluster analysis sensitivity and specificity based on differentially expressed proteins were 0.961 (95% confidence interval [CI], 0.854 to 0.993) and 0.924 (95% CI, 0.825 to 0.972), respectively. Myeloid nuclear differentiation antigen (MNDA) and polymorphonuclear leukocyte serine protease 3 (PRTN3) were the 2 most important markers for detecting PJI. The areas under the curves (AUCs) of MNDA and PRTN3 were 0.969 (95% CI, 0.936 to 1.000) and 0.900 (95% CI, 0.844 to 0.956), respectively. When MNDA and PRTN3 were combined as variables of a predictive model to diagnose PJI, the AUC reached 0.975 (95% CI, 0.943 to 1.000). Our parallel reaction monitoring-based quantitative analysis of another 40 synovial samples confirmed this result.

CONCLUSIONS

MS could be a powerful tool for diagnosing PJI using proteome information or 2 specific markers, MNDA and PRTN3. The parallel reaction monitoring strategy simplified the PJI detection process and provided quantitative results with similar conclusions.

CLINICAL RELEVANCE

The clinical application of MS adds a new powerful tool for the diagnosis of PJI, and the parallel reaction monitoring strategy lays a foundation for the clinical application of MS.

LEVEL OF EVIDENCE

Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Odorant-binding proteins in canine anal sac glands indicate an evolutionarily conserved role in mammalian chemical communication

Background

Chemical communication is an important aspect of the behavioural ecology of a wide range of mammals. In dogs and other carnivores, anal sac glands are thought to convey information to conspecifics by secreting a pallet of small volatile molecules produced by symbiotic bacteria. Because these glands are unique to carnivores, it is unclear how their secretions relate to those of other placental mammals that make use of different tissues and secretions for chemical communication. Here we analyse the anal sac glands of domestic dogs to verify the secretion of proteins and infer their evolutionary relationship to those involved in the chemical communication of non-carnivoran mammals.

Results

Proteomic analysis of anal sac gland secretions of 17 dogs revealed the consistently abundant presence of three related proteins. Homology searches against online databases indicate that these proteins are evolutionary related to ‘odorant binding proteins’ (OBPs) found in a wide range of mammalian secretions and known to contribute to chemical communication. Screening of the dog’s genome sequence show that the newly discovered OBPs are encoded by a single cluster of three genes in the pseudoautosomal region of the X-chromosome. Comparative genomic screening indicates that the same locus is shared by a wide range of placental mammals and that it originated at least before the radiation of extant placental orders. Phylogenetic analyses suggest a dynamic evolution of gene duplication and loss, resulting in large gene clusters in some placental taxa and recurrent loss of this locus in others. The homology of OBPs in canid anal sac glands and those found in other mammalian secretions implies that these proteins maintained a function in chemical communication throughout mammalian evolutionary history by multiple shifts in expression between secretory tissues involved in signal release and nasal mucosa involved in signal reception.

Conclusions

Our study elucidates a poorly understood part of the biology of a species that lives in close association with humans. In addition, it shows that the protein repertoire underlying chemical communication in mammals is more evolutionarily stable than the variation of involved glands and tissues would suggest.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12862-021-01910-w.

An in silico, structural, and biological analysis of lactoferrin of different mammals

Lactoferrin (LF) belongs to the family of transferrins having multifunctional roles associated with the immune system of animals. To follow the aims for this study was selected 20 sequences of LF from mammalian species to evaluate the chemical, biological, and structural properties. Bioinformatics approaches used programs such as MAFFT for sequence alignment; PartitionFinder and MrBayes for phylogenetic approaches; I-TASSER, PROCHECK, Molecular Operating Environment (MOE), SWISS Model server, Peptide DB and Expasy ProtParam to estimate the physicochemical properties, to model the protein and predicted secondary structures. A phylogenic analysis shows species with genetic similarities clustered by complexity and unique grouping between Capra hircus, Macaca mulatta, and Myotis lucifugus, since they presented more amino acids but not overall changes in the iron-binding sites or biological aspects. Structural deviations in these clusters obtained in LF from those species were found in residues 46 (position 406-450), that is part of alpha-helix, and 37 (position 295-331), that is part of the beta-sheets. Our predicted model can be used to investigate more about structural aspects of LF and be applied for medicinal research.

The critical roles of iron during the journey from fetus to adolescent: Developmental aspects of iron homeostasis

Iron is indispensable for human life. However, it is also potentially toxic, since it catalyzes the formation of harmful oxidative radicals in unbound form and may facilitate pathogen growth. Therefore, iron homeostasis needs to be tightly regulated. Rapid growth and development require large amounts of iron, while (especially young) children are vulnerable to infections with iron-dependent pathogens due to an immature immune system. Moreover, unbalanced iron status early in life may have effects on the nervous system, immune system and gut microbiota that persist into adulthood. In this narrative review, we assess the critical roles of iron for growth and development and elaborate how the body adapts to physiologically high iron demands during the journey from fetus to adolescent. As a first step towards the development of clinical guidelines for the management of iron disorders in children, we summarize the unmet needs regarding the developmental aspects of iron homeostasis.

Potential Protective Protein Components of Cow's Milk against Certain Tumor Entities

Milk and dairy products, especially from cow's milk, play a major role in the daily human diet. It is therefore hardly surprising that the subject of milk is being extensively researched and that many effects of individual milk components have been characterized as a result. With the wealth of results available today, the influence of milk on the development of various types of cancer and, in particular, its often protective effects have been shown both in vitro and in vivo and in the evaluation of large-scale cohort and case-control studies. Various caseins, diverse whey proteins such as α-lactalbumin (α-LA), bovine α-lactalbumin made lethal to tumor cells (BAMLET), β-lactoglobulin (β-LG), or bovine serum albumin (BSA), and numerous milk fat components, such as conjugated linoleic acid (CLA), milk fat globule membrane (MFGM), or butyrate, as well as calcium and other protein components such as lactoferrin (Lf), lactoferricin (Lfcin), and casomorphines, show antitumor or cytotoxic effects on cells from different tumor entities. With regard to a balanced and health-promoting diet, milk consumption plays a major role in a global context. This work provides an overview of what is known about the antitumoral properties of proteins derived from cow's milk and their modes of action.

Role of Atypical Chemokines and Chemokine Receptors Pathways in the Pathogenesis of COPD

Chronic obstructive pulmonary disease (COPD) represents a heightened inflammatory response in the lung generally resulting from tobacco smoking-induced recruitment and activation of inflammatory cells and/or activation of lower airway structural cells. Several mediators can modulate activation and recruitment of these cells, particularly those belonging to the chemokines (conventional and atypical) family. There is emerging evidence for complex roles of atypical chemokines and their receptors (such as high mobility group box 1 (HMGB1), antimicrobial peptides, receptor for advanced glycosylation end products (RAGE) or toll-like receptors (TLRs)) in the pathogenesis of COPD, both in the stable disease and during exacerbations. Modulators of these pathways represent potential novel therapies for COPD and many are now in preclinical development. Inhibition of only a single atypical chemokine or receptor may not block inflammatory processes because there is redundancy in this network. However, there are many animal studies that encourage studies for modulating the atypical chemokine network in COPD. Thus, few pharmaceutical companies maintain a significant interest in developing agents that target these molecules as potential antiinflammatory drugs. Antibody-based (biological) and small molecule drug (SMD)-based therapies targeting atypical chemokines and/or their receptors are mostly at the preclinical stage and their progression to clinical trials is eagerly awaited. These agents will most likely enhance our knowledge about the role of atypical chemokines in COPD pathophysiology and thereby improve COPD management.

The potential for Lactoferrin to reduce SARS-CoV-2 induced cytokine storm

The COVID-19 pandemic is a serious global health threat caused by severe acute respiratory syndrome of coronavirus 2 (SARS-CoV-2). Symptoms of COVID-19 are highly variable with common hyperactivity of immune responses known as a "cytokine storm". In fact, this massive release of inflammatory cytokines into in the pulmonary alveolar structure is a main cause of mortality during COVID-19 infection. Current management of COVID-19 is supportive and there is no common clinical protocol applied to suppress this pathological state. Lactoferrin (LF), an iron binding protein, is a first line defense protein that is present in neutrophils and excretory fluids of all mammals, and is well recognized for its role in maturation and regulation of immune system function. Also, due to its ability to sequester free iron, LF is known to protect against insult-induced oxidative stress and subsequent "cytokine storm" that results in dramatic necrosis within the affected tissue. Review of the literature strongly suggests utility of LF to silence the "cytokine storm", giving credence to both prophylactic and therapeutic approaches towards combating COVID-19 infection.

The impact of thermal processing on the simulated infant gastrointestinal digestion, bactericidal and anti-inflammatory activity of bovine lactoferrin - An in vitro study

Lactoferrin (LF) is a multifunctional glycoprotein which, when thermally processed, undergoes significant physicochemical changes. The link between such changes and the bioactivity of LF is not well characterised and requires much research. In this work, bovine LF solutions (1%, w/v, protein, pH 7) were thermally processed using high temperature short time conditions (72, 80, 85 or 95 °C with 15 s holding times). Following this, it was shown that LF and heat induced LF aggregates were largely resistant to simulated infant gastric, but not intestinal, digestion. Also, the efficacy of LF bactericidal activity, and inhibition of lipopolysaccharide-induced NF-κB activation were negatively impacted by thermal processing. This study confirmed that the efficacy of LF bio-functionalities was affected by the extent of heat-induced changes in protein structure whereby processing conditions of least severity (i.e. pasteurisation) had the least impact on bioactivity.

Addition of lactoferrin and substance P in a chitin/PLGA-CaSO4 hydrogel for regeneration of calvarial bone defects

Calcium-based injectable hydrogels with various bioactive active molecules possess a great potential for bone regeneration. Herein, we have synthesized a chitin-PLGA-calcium sulfate hydrogel (CSG) containing bioactive molecules - lactoferrin (LF) and substance P (SP). SEM and XRD analysis revealed that CS crystal growth was altered with the addition of LF. Rheological measurements indicated that the injectability of the hydrogels was maintained after the addition of LF, however, there was a reduction in storage modulus after LF addition. The addition of LF increased stem cell proliferation whereas, SP enhanced the cell migration. Osteogenic gene expression revealed that LF concentration at 25 μg/mg of CSG was optimal for a favourable outcome. To this optimized LF containing CSG, SP was incorporated and 0.05 μg/mg was found to be most effective (CSG-L3S2) in vitro studies. Further, the μ-CT and histological studies confirmed that CSG-L3S2 showed enhanced bone regeneration compared to the controls in critical-sized calvarial defect of mice. Thus the results indicate that a combination of the chemotactic agent (SP), pleiotropic growth protein (LF), and CS in the chitin-PLGA hydrogel could be a promising approach for non-load bearing bone defects.

Lactotransferrin-Related Breast Amyloidosis: Report of a First Case

Breast amyloidosis is a rare condition which is mostly associated with hematological disorders or hereditary genetic disorders. Imaging findings of breast amyloidosis can mimic malignancy, which often leads to biopsy or excision of the lesion. Here, we presented a case of localized lactotransferrin-related breast amyloidosis in an elderly female patient. Histologic examination revealed extensive involvement of breast lobules by amorphous amyloid materials, with attenuation of lobular structures and prominent calcifications. Positive immunostains for myoepithelial cells helped to exclude the possibility of invasive carcinoma. The patient had no hematologic malignancy besides immunoglobulin G lambda monoclonal gammopathy of undetermined significance. Mass spectrometry of the breast amyloid identified lactotransferrin and no immunoglobulin or its light chain. On follow-up, the patient showed no recurrence of the breast lesion after local excision nor showed other systematic comorbidities, indicating the benign nature of the lesion. This first report of lactotransferrin-related amyloidosis may represent a special type of localized breast amyloidosis that has no correlation with systematic disorders.

Importance of Bioactive Substances in Sheep's Milk in Human Health

Sheep's milk is an important source of bioactive substances that have health-promoting functions for the body. The valuable composition of sheep's milk is due to the high content of fatty acids, immunoglobulins, proteins, hormones, vitamins and minerals. Many biopeptides found in milk have antibacterial, antiviral and anti-inflammatory properties. The bioactive substances of sheep's milk also show anticancer properties. Sheep's milk, thanks to its content of CLA and orotic acid, prevents the occurrence of type 2 diabetes, Alzheimer's disease and cancer. Sheep's milk, as a product rich in bioactive substances, can be used as a medical aid to support the body in the fight against neurological and cancer diseases.

Recombinant human lactoferrin carrying humanized glycosylation exhibits antileukemia selective cytotoxicity, microfilament disruption, cell cycle arrest, and apoptosis activities

Lactoferrin has gained extensive attention due to its ample biological properties. In this study, recombinant human lactoferrin carrying humanized glycosylation (rhLf-h-glycan) expressed in the yeast Pichia pastoris SuperMan5, which is genetically glycoengineered to efficiently produce functional humanized glycoproteins inclosing (Man)5(GlcNAc)2 Asn-linked glycans, was analyzed, inspecting its potential toxicity against cancer cells. The live-cell differential nuclear staining assay was used to quantify the rhLf-h-glycan cytotoxicity, which was examined in four human cell lines: acute lymphoblastic leukemia (ALL) CCRF-CEM, T-cell lymphoblastic lymphoma SUP-T1, cervical adenocarcinoma HeLa, and as control, non-cancerous Hs27 cells. The defined CC50 values of rhLf-h-glycan in CCRF-CEM, SUP-T1, HeLa, and Hs27 cells were 144.45 ± 4.44, 548.47 ± 64.41, 350 ± 14.82, and 3359.07 ± 164 µg/mL, respectively. The rhLf-h-glycan exhibited a favorable selective cytotoxicity index (SCI), preferentially killing cancer cells: 23.25 for CCRF-CEM, 9.59 for HeLa, and 6.12 for SUP-T1, as compared with Hs27 cells. Also, rhLf-h-glycan showed significant antiproliferative activity (P < 0.0001) at 24, 48, and 72 h of incubation on CCRF-CEM cells. Additionally, it was observed via fluorescent staining and confocal microscopy that rhLf-h-glycan elicited apoptosis-associated morphological changes, such as blebbing, nuclear fragmentation, chromatin condensation, and apoptotic bodies in ALL cells. Furthermore, rhLf-h-glycan-treated HeLa cells revealed shrinkage of the microfilament structures, generating a speckled/punctuated pattern and also caused PARP-1 cleavage, a hallmark of apoptosis. Moreover, in ALL cells, rhLf-h-glycan altered cell cycle progression inducing the G2/M phase arrest, and caused apoptotic DNA fragmentation. Overall, our findings revealed that rhLf-h-glycan has potential as an anticancer agent and therefore deserves further in vivo evaluation.

Antimicrobial peptides against colorectal cancer-a focused review

Despite recent advances in the treatment of colorectal cancer (CRC), low patient survival rate due to emergence of drug resistant cancer cells, metastasis and multiple deleterious side effects of chemotherapy, is a cause of public concern globally. To negate these clinical conundrums, search for effective and harmless novel molecular entities for the treatment of CRC is an urgent necessity. Since antimicrobial peptides (AMPs) are part of innate immunity of living beings, it is quite imperative to look for essential attributes of these peptides which may contribute to their effectiveness against carcinogenesis. Once identified, those characteristics can be suitably modified using several synthetic and computational techniques to further enhance their selectivity and pharmacokinetic profiles. Hence, this review analyses scientific reports describing the antiproliferative action of AMPs derived from several sources, particularly focusing on various colon cancer in vitro/in vivo investigations. On perusal of the literature, it appears that AMPs based therapeutics would definitely find special place in CRC therapy in future either alone or as an adjunct to chemotherapy provided some necessary alterations are made in their natural structures to make them more compatible with modern clinical practice. In this context, further in-depth research is warranted in adequate in vivo models.

Reactive Oxygen Species and Their Involvement in Red Blood Cell Damage in Chronic Kidney Disease

Reactive oxygen species (ROS) released in cells are signaling molecules but can also modify signaling proteins. Red blood cells perform a major role in maintaining the balance of the redox in the blood. The main cytosolic protein of RBC is hemoglobin (Hb), which accounts for 95-97%. Most other proteins are involved in protecting the blood cell from oxidative stress. Hemoglobin is a major factor in initiating oxidative stress within the erythrocyte. RBCs can also be damaged by exogenous oxidants. Hb autoxidation leads to the generation of a superoxide radical, of which the catalyzed or spontaneous dismutation produces hydrogen peroxide. Both oxidants induce hemichrome formation, heme degradation, and release of free iron which is a catalyst for free radical reactions. To maintain the redox balance, appropriate antioxidants are present in the cytosol, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and peroxiredoxin 2 (PRDX2), as well as low molecular weight antioxidants: glutathione, ascorbic acid, lipoic acid, α-tocopherol, β-carotene, and others. Redox imbalance leads to oxidative stress and may be associated with overproduction of ROS and/or insufficient capacity of the antioxidant system. Oxidative stress performs a key role in CKD as evidenced by the high level of markers associated with oxidative damage to proteins, lipids, and DNA in vivo. In addition to the overproduction of ROS, a reduced antioxidant capacity is observed, associated with a decrease in the activity of SOD, GPx, PRDX2, and low molecular weight antioxidants. In addition, hemodialysis is accompanied by oxidative stress in which low-biocompatibility dialysis membranes activate phagocytic cells, especially neutrophils and monocytes, leading to a respiratory burst. This review shows the production of ROS under normal conditions and CKD and its impact on disease progression. Oxidative damage to red blood cells (RBCs) in CKD and their contribution to cardiovascular disease are also discussed.

Optimized lactoferrin as a highly promising treatment for intracerebral hemorrhage: Pre-clinical experience

Intracerebral hemorrhage (ICH) is the deadliest form of stroke for which there is no effective treatment, despite an endless number of pre-clinical studies and clinical trials. The obvious therapeutic target is the neutralization of toxic products of red blood cell (RBC) lysis that lead to cytotoxicity, inflammation, and oxidative damage. We used rigorous approaches and translationally relevant experimental ICH models to show that lactoferrin-(LTF)-based monotherapy is uniquely robust in reducing brain damage after ICH. Specifically, we designed, produced, and pharmacokinetically/toxicologically characterized an optimized LTF, a fusion of human LTF and the Fc domain of human IgG (FcLTF) that has a 5.8-fold longer half-life in the circulation than native LTF. Following dose-optimization studies, we showed that FcLTF reduces neurological injury caused by ICH in aged male/female mice, and in young male Sprague Dawley (SD) and spontaneously hypertensive rats (SHR). FcLTF showed a remarkably long 24-h therapeutic window. In tissue culture systems, FcLTF protected neurons from the toxic effects of RBCs and promoted microglia toward phagocytosis of RBCs and dead neurons, documenting its pleotropic effect. Our findings indicate that FcLTF is safe and effective in reducing ICH-induced damage in animal models used in this study.

Encapsulation of Lactoferrin for Sustained Release Using Particles from Gas-Saturated Solutions

The particles from gas saturated solutions (PGSS) process were performed to encapsulate lactofer-rin, an iron-binding milk glycoprotein, using supercritical carbon dioxide (scCO2). A natural en-teric polymer, shellac, was used as a coating material of lactoferrin carried out by the PGSS pro-cess. Conditions were optimized by applying different temperatures (20–50 °C) and pressures (8–10 MPa) and the particles were evaluated for particle shape and size, lactoferrin encapsulation ef-ficiency, Fourier transform infrared (FTIR) spectroscopy to confirm lactoferrin entrapment and in vitro dissolution studies at different pH values. Particles with an average diameter of 75.5 ± 7 μm were produced with encapsulation efficiency up to 71 ± 2%. Furthermore, particles that showed high stability in low pH (pH 1.2) and a sustained release over time (t2h = 75%) in higher pH (pH 7.4) suggested an effective encapsulation process for the protection of lactoferrin from gastric di-gestion.

In-vitro inhibitory effect of maternal breastmilk components on rotavirus vaccine replication and association with infant seroconversion to live oral rotavirus vaccine

BACKGROUND

Despite contributing to a significant reduction in rotavirus associated diarrhoea in highly burdened low- and middle-income countries, live attenuated, oral rotavirus vaccines have lower immunogenicity and efficacy in these settings in comparison to more developed countries. Breastmilk has been implicated among factors contributing to this lowered oral vaccine efficacy. We conducted in-vitro experiments to investigate the inhibitory effects of maternal antibody and other non-antibody components in breastmilk on rotavirus vaccine strain (Rotarix) multiplication in MA104 cell culture system and assessed associations with in-vivo vaccine seroconversion in vaccinated infants.

METHODS

Breastmilk samples were collected from mothers before routine rotavirus vaccination of their infant at 6 weeks of age. For each sample, whole breastmilk, purified IgA, purified IgG and IgG and IgA depleted breastmilk samples were prepared as exposure preparations. A 96 well microtitre plate was set up for each sample including a control in which only MA104 cells were grown as well as a virus control with MA104 cells and virus only. The outcome of interest was 50% inhibition dilution of each of the exposure preparations calculated as the titer at which 50% of virus dilution was achieved. Samples from 30 women were tested and correlated to vaccine seroconversion status of the infant. HIV status was also correlated to antiviral breastmilk proteins.

RESULTS

The mean 50% inhibitory dilution titer when whole breastmilk was added to virus infected MA104 cells was 14.3 (95% CI: 7.1, 22.7). Incubation with purified IgG resulted in a mean 50% inhibitory dilution of 5 (95%CI -1.6, 11.6). Incubating with purified IgA resulted in a mean 50% inhibitory dilution of 6.5 (95% CI -0.7, 13.7) and IgG and IgA depleted breastmilk did not yield any inhibition with a titer of 1.06 (95%CI 0.9, 1.2). Higher milk IgA levels contributed to a failure of infants to seroconvert. HIV was also not associated with any antiviral breastmilk proteins.

DISCUSSION AND CONCLUSION

Whole breastmilk and breastmilk purified IgG and IgA fractions showed inhibitory activity against the rotavirus vaccine Rotarix™ whilst IgA and IgG depleted breastmilk with non-antibody breastmilk fraction failed to show any inhibition activity in-vitro. These findings suggest that IgA and IgG may have functional inhibitory properties and indicates a possible mechanism of how mothers in rotavirus endemic areas with high titres of IgA and IgG may inhibit viral multiplication in the infant gut and would potentially contribute to the failure of their infants to serocovert. There was not association of HIV with either lactoferrin, lactadherin or tenascin-C concentrations.

Iron at the host-microbe interface

Iron is an essential micronutrient for nearly all living organisms. In addition to facilitating redox reactions, iron is bound by metalloproteins that participate in a variety of biological processes. As the bioavailability of free iron in host environments is extremely low, iron lies at the center of a battle for nutrients between microbes and their host. Mucosal surfaces such as the respiratory and gastrointestinal tracts are constantly exposed to commensal and pathogenic microorganisms. Whereas a key strategy of mammalian antimicrobial defense is to deprive microbes of iron, pathogens and some commensals have evolved effective strategies to circumvent iron limitation. Here we provide an overview of mechanisms underpinning the tug-of-war for iron between microbes and their host, with a particular focus on mucosal surfaces.

Lactoferrin Concentration in Human Tears and Ocular Diseases: A Meta-Analysis

Purpose

To evaluate the potential of lactoferrin (Lf) as a diagnostic biomarker for ocular diseases using a meta-analytic approach.

Methods

All original studies reporting an estimate of the average Lf concentration in healthy subjects and those affected by ocular diseases were searched up to March 2020. The DerSimonian and Laird method was used to calculate the random effects pooled mean difference and the corresponding 95% confidence interval (CI) in Lf concentration between healthy subjects and those affected by dry eye (DE), Sjögren syndrome (SS), and diabetic retinopathy, separately. The presence of between-study heterogeneity was evaluated using the Cochran's Q test and the I2 index. Stratified analyses were performed to assess potential sources of heterogeneity and influence and cumulative analyses to evaluate the robustness of the results obtained. Publication bias was also evaluated using funnel plot and the Egger's test.

Results

The pooled mean differences in Lf concentrations between healthy subjects and those with DE, Sjögren syndrome, and diabetic retinopathy were respectively 0.62 (95% CI, 0.35-0.89) for DE, 3.78 (95% CI, -6.64 to 14.17), and 0.19 (95% CI, -4.00 to 4.39). Regarding DE, the stratified analysis showed that geographical area (P value Q test < 0.0001) and sample size (P < 0.0005) were sources of heterogeneity. Moreover, no study substantially influenced the results obtained and the pooled mean difference became statistically significant after a sample size of 220. Publication bias may affect the results of DE.

Conclusions

The results of the current meta-analysis suggest that Lf level in tears is a good candidate as dry eye syndrome diagnostic biomarker.

Lactoferrin-Derived Peptide Lactofungin Is Potently Synergistic with Amphotericin B

Lactoferrin (LF) is an iron-binding glycoprotein with broad-spectrum antimicrobial activity. Previously, we discovered that LF synergistically enhanced the antifungal efficacy of amphotericin B (AMB) across a variety of yeast species and subsequently hypothesized that this synergy was enhanced by the presence of small peptides derived from the whole LF molecule. In this study, LF was digested with pepsin under a range of conditions. The resulting hydrolysates exhibited enhanced synergy with AMB compared to its synergy with undigested LF. Samples were analyzed using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry, and 14 peptides were identified. The sequences of these peptides were predicted by matching their molecular weights to those of a virtual digest with pepsin. The relative intensities of predicted peptides in each hydrolysate were compared with the activity of the hydrolysate, and the structural and physicochemical properties of the peptides were assessed. From this, a 30-residue peptide was selected for synthesis and dubbed lactofungin (LFG). Pure LFG was highly synergistic with AMB, outperforming native LF in all fungal species tested. With potential for further structural and chemical improvements, LFG is an excellent lead for development as an antifungal adjuvant.

Lactoferrin, a multi-functional glycoprotein: Active therapeutic, drug nanocarrier & targeting ligand

Recent progress in protein-based nanomedicine, inspired by the success of Abraxane® albumin-paclitaxel nanoparticles, have resulted in novel therapeutics used for treatment of challenging diseases like cancer and viral infections. However, absence of specific drug targeting, poor pharmacokinetics, premature drug release, and off-target toxicity are still formidable challenges in the clinic. Therefore, alternative protein-based nanomedicines were developed to overcome those challenges. In this regard, lactoferrin (Lf), a glycoprotein of transferrin family, offers a promising biodegradable well tolerated material that could be exploited both as an active therapeutic and drug nanocarrier. This review highlights the major pharmacological actions of Lf including anti-cancer, antiviral, and immunomodulatory actions. Delivery technologies of Lf to improve its pries and enhance its efficacy were also reviewed. Moreover, different nano-engineering strategies used for fabrication of drug-loaded Lf nanocarriers were discussed. In addition, the use of Lf for functionalization of drug nanocarriers with emphasis on tumor-targeted drug delivery was illustrated. Besides its wide application in oncology nano-therapeutics, we discussed the recent advances of Lf-based nanocarriers as efficient platforms for delivery of anti-parkinsonian, anti-Alzheimer, anti-viral drugs, immunomodulatory and bone engineering applications.

Lactoferrin and hematoma detoxification after intracerebral hemorrhage

In this minireview we discuss the role of lactoferrin (LTF) in detoxifying hematoma after intracerebral hemorrhage (ICH). Subsequent to ICH, neutrophils enter the ICH-affected brain, where they release various granule contents, including LTF. LTF is an iron-binding glycoprotein that binds Fe³⁺ with high affinity. Unlike other iron-binding proteins, LTF can retain Fe³⁺ at the low pH associated with inflamed tissue. LTF's ability to sequester Fe³⁺ is of particular importance to ICH pathogenesis, because large quantities of free iron, which is pro-oxidative and pro-inflammatory, are generated in the ICH-affected brain owing to blood hemolysis. LTF delivered to ICH-affected brain, either as a therapeutic agent or through infiltrated polymorphonuclear neutrophils (cells containing high levels of LTF), could limit the pathogenesis of ICH. LTF is a protein with a high isoelectric point (8.7), a property that enables it to bind to negatively-charged apoptotic cells or proteins. Here, LTF could act as a bridging molecule that couples the apoptotic cells to LTF receptors on the cellular membranes of microglia/macrophages to facilitate the efferocytosis/erythrophagocytosis of apoptotic cells and damaged red blood cells. Thus, by virtue of sequestrating iron and facilitating efferocytosis, LTF may contribute to hematoma detoxification and hematoma/inflammation resolution after ICH.

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.

Bovine lactoferrin enhances the efficacy of levofloxacin-based triple therapy as first-line treatment of Helicobacter pylori infection: an in vitro and in vivo study

Objectives

To evaluate the in vitro antimicrobial/antivirulence action of bovine lactoferrin and its ability to synergize with levofloxacin against resistant Helicobacter pylori strains and to analyse the effect of levofloxacin, amoxicillin and esomeprazole with and without bovine lactoferrin as the first-line treatment for H. pylori infection.

Methods

The bovine lactoferrin antimicrobial/antivirulence effect was analysed in vitro by MIC/MBC determination and twitching motility against six clinical H. pylori strains and a reference strain. The synergism was evaluated using the chequerboard assay. The prospective therapeutic trial was carried out on two separate patient groups, one treated with esomeprazole/amoxicillin/levofloxacin and the other with esomeprazole/amoxicillin/levofloxacin/bovine lactoferrin. Treatment outcome was determined with the [¹³C]urea breath test.

Results

In vitro, bovine lactoferrin inhibited the growth of 50% of strains at 10 mg/mL and expressed 50% bactericidal effect at 40 mg/mL. The combination of levofloxacin and bovine lactoferrin displayed a synergistic effect for all strains, with the best MIC reduction of 16- and 32-fold for levofloxacin and bovine lactoferrin, respectively. Bovine lactoferrin at one-fourth MIC reduced microbial motility significantly for all strains studied. In the in vivo study, 6 of 24 patients recruited had treatment failure recorded with esomeprazole/amoxicillin/levofloxacin (75% success, 95% CI 57.68%–92.32%), and in the group with esomeprazole/amoxicillin/levofloxacin/bovine lactoferrin, 2 out of 53 patients recruited had failure recorded (96.07% success, 95% CI 90.62%–101.38%).

Conclusions

Bovine lactoferrin can be considered a novel potentiator for restoring susceptibility in resistant H. pylori strains. Bovine lactoferrin added to a triple therapy in first-line treatment potentiates the therapeutic effect.

New insights into the systemic effects of oral lactoferrin: transcriptome profiling

The immunomodulatory nature of lactoferrin (LF) derives from its ability to bridge innate and adaptive immunity in obtaining physiological equilibrium. LF is an attractive molecule for treatment of diseases that compromise immune homeostasis. Oral delivery is a preferable method for LF administration; however, its bioavailability is affected by protein degradation and absorption. The aim of this study was to evaluate the systemic effects of orally and intravenously (IV) administered recombinant human LF (rhLF) on blood cell transcriptome profiling. Rats were administered a single dose of rhLF by gavage or IV. The transcriptome profiles from the control and the rhLF-treated rats after 3, 6, and 24 h were analyzed using a Clariom D microarray. The results showed differentially expressed genes in response to IV as well as oral administered rhLF including coding and noncoding RNAs. Moreover, a comparison of the differentially expressed genes between oral and IV administration of LF, after 6 h, revealed that the majority (72.8%) of the genes altered in response to oral administration of rhLF were the same as for the IV treatment. The pathway profiles showed similarities in up-regulation of specific genes involved in oxidative stress and inflammatory responses for both routes of treatments. These findings provide evidence of the systemic signal transduction effects of orally administered rhLF.