Investigation of lactotransferrin messenger RNA expression levels as an anti-type 2 asthma biomarker.

BACKGROUND: Lactotransferrin (LTF) has an immunomodulatory function, and its expression levels are associated with asthma susceptibility. OBJECTIVES: We sought to investigate LTF messenger RNA (mRNA) expression levels in human bronchial epithelial cells (BECs) as an anti-type 2 (T2) asthma biomarker. METHODS: Association analyses between LTF mRNA expression levels in BECs and asthma-related phenotypes were performed in the Severe Asthma Research Program (SARP) cross-sectional (n = 155) and longitudinal (n = 156) cohorts using a generalized linear model. Correlation analyses of mRNA expression levels between LTF and all other genes were performed by Spearman correlation. RESULTS: Low LTF mRNA expression levels were associated with asthma susceptibility and severity (P < .025), retrospective and prospective asthma exacerbations, and low lung function (P < 8.3 × 10-3). Low LTF mRNA expression levels were associated with high airway T2 inflammation biomarkers (sputum eosinophils and fractional exhaled nitric oxide; P < 8.3 × 10-3) but were not associated with blood eosinophils or total serum IgE. LTF mRNA expression levels were negatively correlated with expression levels of TH2 or asthma-associated genes (POSTN, NOS2, and MUC5AC) and eosinophil-related genes (IL1RL1, CCL26, and IKZF2) and positively correlated with expression levels of TH1 and inflammation genes (IL12A, MUC5B, and CC16) and TH17-driven cytokines or chemokines for neutrophils (CXCL1, CXCL6, and CSF3) (P < 3.5 × 10-6). CONCLUSIONS: Low LTF mRNA expression levels in BECs are associated with asthma susceptibility, severity, and exacerbations through upregulation of airway T2 inflammation. LTF is a potential anti-T2 biomarker, and its expression levels may help determine the balance of eosinophilic and neutrophilic asthma.

Tear nanoDSF Denaturation Profile Is Predictive of Glaucoma.

Primary open-angle glaucoma (POAG) is a frequent blindness-causing neurodegenerative disorder characterized by optic nerve and retinal ganglion cell damage most commonly due to a chronic increase in intraocular pressure. The preservation of visual function in patients critically depends on the timeliness of detection and treatment of the disease, which is challenging due to its asymptomatic course at early stages and lack of objective diagnostic approaches. Recent studies revealed that the pathophysiology of glaucoma includes complex metabolomic and proteomic alterations in the eye liquids, including tear fluid (TF). Although TF can be collected by a non-invasive procedure and may serve as a source of the appropriate biomarkers, its multi-omics analysis is technically sophisticated and unsuitable for clinical practice. In this study, we tested a novel concept of glaucoma diagnostics based on the rapid high-performance analysis of the TF proteome by differential scanning fluorimetry (nanoDSF). An examination of the thermal denaturation of TF proteins in a cohort of 311 ophthalmic patients revealed typical profiles, with two peaks exhibiting characteristic shifts in POAG. Clustering of the profiles according to peaks maxima allowed us to identify glaucoma in 70% of cases, while the employment of artificial intelligence (machine learning) algorithms reduced the amount of false-positive diagnoses to 13.5%. The POAG-associated alterations in the core TF proteins included an increase in the concentration of serum albumin, accompanied by a decrease in lysozyme C, lipocalin-1, and lactotransferrin contents. Unexpectedly, these changes were not the only factor affecting the observed denaturation profile shifts, which considerably depended on the presence of low-molecular-weight ligands of tear proteins, such as fatty acids and iron. Overall, we recognized the TF denaturation profile as a novel biomarker of glaucoma, which integrates proteomic, lipidomic, and metallomic alterations in tears, and monitoring of which could be adapted for rapid non-invasive screening of the disease in a clinical setting.

Lactoferrin as a regenerative agent: The old-new panacea?

Lactoferrin (Lf) possesses various biological properties and therapeutic potentials being a perspective anti-inflammatory, antibacterial, antiviral, antioxidant, antitumor, and immunomodulatory agent. A significant body of literature has also demonstrated that Lf modulates regenerative processes in different anatomical structures, such as bone, cartilage, skin, mucosa, cornea, tendon, vasculature, and adipose tissue. Hence, this review collected and analyzed the data on the regenerative effects of Lf, as well as paid specific attention to their molecular basis. Furthermore, tissue and condition-specific activities of different Lf types as well as problems of their delivery to the targeted organs were discussed. The authors strongly hope that this review will stimulate researchers to focus on the highlighted topics thus accelerating the progress of Lf's wider clinical application.

Modification of lactoferrin by peroxynitrite reduces its antibacterial activity and changes protein structure.

Lactoferrin (LF) is a multifunctional protein that plays important physiological roles as one of the most concentrated proteins in many human and other mammalian fluids and tissues. In particular, LF provides antibacterial properties to human milk, saliva, and tear fluid. LF also protects against stress-induced lipid peroxidation at inflammation sites through its iron-binding ability. Previous studies have shown that LF can be efficiently nitrated via biologically relevant mediators such as peroxynitrite (ONOO- ), which are also present at high intracellular concentrations during inflammation and nitrosative stress. Here, we examine changes in antibacterial properties and structure of LF following ONOO- treatment. The reaction induces nitration of tyrosine and tryptophan residues, which are commonly used as biomarker molecules for several diseases. Treatment with ONOO- at a 10/1 M ratio of ONOO- to tyrosine inhibited all antibacterial activity exhibited by native LF. Secondary structural changes in LF were assessed using circular dichroism spectroscopy. Nitration products with and without the addition of Fe3+ show significant reduction in alpha-helical properties, suggesting partial protein unfolding. Iron-binding capacity of LF was also reduced after treatment with ONOO- , suggesting a decreased ability of LF to protect against cellular damage. LC-MS/MS spectrometry was used to identify LF peptide fragments nitrated by ONOO- , including tyrosine residue Y92 located in the iron-binding region. These results suggest that posttranslational modification of LF by ONOO- could be an important pathway to exacerbate infection, for example, in inflamed tissues and to reduce the ability of LF to act as an immune responder and decrease oxidative damage.

Association of LTF, ENAM, and AMELX polymorphisms with dental caries susceptibility: a meta-analysis.

BACKGROUND: This meta-analysis evaluated the association of LTF, ENAM, and AMELX polymorphisms with dental caries susceptibility. METHODS: We searched the Scopus, PubMed/Medline, Web of Science, and Cochrane Library databases to retrieve articles published by October 2019. Review Manager 5.3 software was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs). The results of publication bias tests were retrieved by Comprehensive Meta-Analysis 2.0 software. RESULTS: A total of 150 relevant records were identified; out of which, 16 were entered into the analysis (4 studies assessed LTF, 11 ENAM, and 11 AMELX polymorphisms). Of all polymorphisms, there was a significant association only between ENAM rs3796704 polymorphism and dental caries susceptibility. Both ENAM rs3796704 and AMELX rs17878486 polymorphisms had a significant association with dental caries risk in the Caucasian ethnicity and the studies including caries-free control group. CONCLUSIONS: The results of this meta-analysis showed that the G allele and the GG genotype of ENAM rs3796704 were associated with an increased risk of caries in the case group compared with the control group. But there was no association between LTF rs1126478, ENAM (rs1264848 and rs3796703), and AMELX (rs946252, rs17878486, and rs2106416) polymorphisms and dental caries susceptibility.

The Fine Art of Destruction: A Guide to In-Depth Glycoproteomic Analyses-Exploiting the Diagnostic Potential of Fragment Ions.

The unambiguous mass spectrometric identification and characterization of glycopeptides is crucial to elucidate the micro- and macroheterogeneity of glycoproteins. Here, combining lower and stepped collisional energy fragmentation for the in-depth and site-specific analysis of N- and O-glycopeptides is proposed. Using a set of four representative and biopharmaceutically relevant glycoproteins (IgG, fibrinogen, lactotransferrin, and ribonuclease B), the benefits and limitations of the developed workflow are highlighted and a state-of-the-art blueprint for conducting high-quality in-depth N- and O-glycoproteomic analyses is provided. Further, a modified and improved version of cotton hydrophilic interaction liquid chromatography-based solid phase extraction for glycopeptide enrichment is described. For the unambiguous identification of N-glycopeptides, the use of a conserved yet, rarely employed-fragmentation signature [Mpeptide +H+0,2 X GlcNAc]+ is proposed. It is shown for the first time that this fragmentation signature can consistently be found across all N-glycopeptides, but not on O-glycopeptides. Moreover, the use of the relative abundance of oxonium ions to retrieve glycan structure information, for example, differentiation of hybrid- and high-mannose-type N-glycans or differentiation between antenna GlcNAc and bisecting GlcNAc, is systematically and comprehensively evaluated. The findings may increase confidence and comprehensiveness in manual and software-assisted glycoproteomics.

Re-expression of Lactotransferrin, a candidate tumor suppressor inactivated by promoter hypermethylation, impairs the malignance of oral squamous cell carcinoma cells.

BACKGROUND: Lactotransferrin (LTF) has been confirmed to act as a tumor suppressor in multiple cancers; however, its roles in oral squamous cell carcinoma (OSCC), one of malignant head and neck carcinomas, has not been explored. METHODS: Here, the expression of LTF in OSCC tissues and TCA8113 cells was detected with RT-PCR, qPCR, and IHC. And the correlation between LTF expression and OSCC metastasis was assessed. MS-PCR was performed to reveal the methylation status in promoter regions of LTF both in OSCC tissue samples and cells. The influences of 5-Aza-Cdc treatment to the methylation status and expression levels of LTF were also analyzed. At last, the functions of LTF in OSCC progression were demonstrated by MTT analysis, clone formation assay, and cell cycle analysis in TCA8113 cells with forced ectopic expression of LTF. RESULTS: LTF showed a low or null expression pattern in OSCC tissues and cells, at least partially, due to the hypermethylated status in promoter regions for 5-Aza-Cdc, a methyltransferase inhibitor, could restore the expression of LTF in TCA8113 cells. And the expression level of LTF exhibited a negative correlation with OSCC metastasis. CONCLUSIONS: Re-expression of LTF inhibited the growth, proliferation, as well as cell cycle progression of TCA8113 cells. In conclusion, hypermethylation contributes much to LTF inactivation in OSCC. And LTF can partially reverse the malignant phenotypes of OSCC cells and may be served as a potential target for diagnosis and therapy of OSCC in future.

Identification and experimental validation of ferroptosis-related gene lactotransferrin in age-related hearing loss.

Objective: To reveal the relationship between ARHL and ferroptosis and screen ferroptosis-related genes (FRGs) in ARHL. Methods: Bioinformatics were used to analyze the hub genes and molecular mechanism of ferroptosis in the aging cochleae. Senescence ß-galactosidase staining, iron content detection, and micro malondialdehyde (MDA) assay kits were used to measure ß-galactosidase activity, and expression of Fe2+ and MDA, respectively. Fluorescence microscope was used for immunofluorescence assay of hub genes. Western blot was used to verify the expression of hub genes in HEI-OC1 cells, cochlear explants, and cochleae of C57BL/6J mice. Data were expressed as mean ± SD of at least three independent experiments. Results: The analysis of bioinformatics confirmed that lactotransferrin (LTF) is the hub gene and CEBPA-miR-130b-LTF network is the molecular mechanism for cochlear ferroptosis. Compared with the control group, the experiments proved that the indicators of ferroptosis, including Fe2+, MDA, and LTF were differentially expressed in aging HEI-OC1 cells, aging cochlear explants, and aging cochleae. Conclusion: These results demonstrate that ferroptosis plays an important role in ARHL, and LTF is a potential therapeutic target for ARHL via regulating cochlear ferroptosis.

METTL16-SENP3-LTF axis confers ferroptosis resistance and facilitates tumorigenesis in hepatocellular carcinoma.

BACKGROUND: Ferroptosis, characterized by iron-dependent lipid peroxidation, emerges as a promising avenue for hepatocellular carcinoma (HCC) intervention due to its tumor susceptibility. RNA N6-methyladenosine (m6A) modification has been involved in several types of regulated cell death. However, the roles and molecular mechanisms of m6A-related regulators in HCC cell ferroptosis remain unclear. METHODS: By examining a series of m6A modification enzymes upon ferroptosis induction or inhibition, we identified METTL16 as a novel ferroptotic repressor in HCC cells. The roles of METTL16 on ferroptosis and HCC development were investigated in multiple cell lines, human HCC organoids, subcutaneous xenografts and MYC/Trp53-/- HCC model in hepatocyte-specific Mettl16 knockout and overexpression mice. The underlying mechanism was elucidated with MeRIP/RIP-qPCR, luciferase assay, Co-IP assay and Mass Spectrometry. The clinical significance and relevance were evaluated in human samples. RESULTS: High METTL16 expression confers ferroptosis resistance in HCC cells and mouse models, and promotes cell viability and tumor progression. Mechanistically, METTL16 collaborates with IGF2BP2 to modulate SENP3 mRNA stability in an m6A-dependent manner, and the latter impedes the proteasome-mediated ubiquitination degradation of Lactotransferrin (LTF) via de-SUMOylation. Elevated LTF expression facilitates the chelation of free iron and reduces liable iron pool level. SENP3 and LTF are implicated in METTL16-mediated HCC progression and anti-ferroptotic effects both in vivo and in vitro. Clinically, METTL16 and SENP3 expression were positively correlated, and high METTL16 and SENP3 expression predicts poor prognosis in human HCC samples. CONCLUSIONS: Our study reveals a new METTL16-SENP3-LTF signaling axis regulating ferroptosis and driving HCC development. Targeting this axis is a promising strategy for sensitizing ferroptosis and against HCC.

Digestive Profiles of Human Milk, Recombinant Human and Bovine Lactoferrin: Comparing the Retained Intact Protein and Peptide Release.

Lactoferrin (LF) is a major component of human milk. LF supplementation (currently bovine) supports the immune system and helps maintain iron homeostasis in adults. No recombinant human lactoferrin (rhLF) is available for commercial food use. To determine the extent to which rhLF (Effera™) produced by Komagataella phaffii digests similarly to hmLF, a validated in vitro digestion protocol was carried out. Bovine LF (bLF) was used as an additional control, as it is approved for use in various food categories. This study compared the extent of intact protein retention and the profile of peptides released in hmLF, bLF and rhLF (each with low and high iron saturation) across simulated adult gastric and intestinal digestion using gel electrophoresis, ELISA and LC-MS. Intact LF retention across digestion was similar across LF types, but the highest iron-saturated hmLF had greater retention in the simulated gastric fluid than all other sample types. Peptides identified in digested hmLF samples strongly correlated with digested rhLF samples (0.86 < r < 0.92 in the gastric phase and 0.63 < r < 0.70 in the intestinal phase), whereas digested bLF samples were significantly different. These findings support the potential for rhLF as a food ingredient for human consumption.

Tissue-resident macrophages specifically express Lactotransferrin and Vegfc during ear pinna regeneration in spiny mice.

The details of how macrophages control different healing trajectories (regeneration vs. scar formation) remain poorly defined. Spiny mice (Acomys spp.) can regenerate external ear pinnae tissue, whereas lab mice (Mus musculus) form scar tissue in response to an identical injury. Here, we used this dual species system to dissect macrophage phenotypes between healing modes. We identified secreted factors from activated Acomys macrophages that induce a pro-regenerative phenotype in fibroblasts from both species. Transcriptional profiling of Acomys macrophages and subsequent in vitro tests identified VEGFC, PDGFA, and Lactotransferrin (LTF) as potential pro-regenerative modulators. Examining macrophages in vivo, we found that Acomys-resident macrophages secreted VEGFC and LTF, whereas Mus macrophages do not. Lastly, we demonstrate the requirement for VEGFC during regeneration and find that interrupting lymphangiogenesis delays blastema and new tissue formation. Together, our results demonstrate that cell-autonomous mechanisms govern how macrophages react to the same stimuli to differentially produce factors that facilitate regeneration.

Novel Lactotransferrin-Derived Antimicrobial Peptide LF-1 Inhibits the Cariogenic Virulence Factors of Streptococcus mutans.

We previously developed a novel lactotransferrin-derived antimicrobial peptide, LF-1, with selective antibacterial activity against the characteristic cariogenic bacterium Streptococcus mutans. This study further investigated the effects of LF-1 on the cariogenic virulence factors of S. mutans and evaluated the changes in virulence-associated enzymes and genes; the viability, acidogenicity, and aciduricity of planktonic S. mutans; and initial colonisation and biofilm formation after treatment with LF-1. The method of qRT-PCR was used to evaluate S. mutans virulence-associated gene expression. LF-1 interfered with the cell viability of S. mutans within 6 h. LF-1 inhibited the acidogenicity and aciduricity of S. mutans, with reduced lactic acid production and survival in a lethal acidic environment, and inactivated lactate dehydrogenase and F1F0-ATPase activity. LF-1 decreased surface-adherent S. mutans within 60 min and inhibited S. mutans biofilm formation, where scanning electron microscopy and confocal laser scanning microscopy showed reduced extracellular matrix and bacteria. LF-1 downregulates S. mutans virulence-associated gene expression. LF-1 inhibited the growth and cariogenic virulence factors of S. mutans in vitro with a reduction in key enzymatic activity and downregulation of virulence-associated gene expression. LF-1 has promising application prospects in the fight against S. mutans and dental caries.

Lactotransferrin promotes intervertebral disc degeneration by regulating Fas and inhibiting human nucleus pulposus cell apoptosis.

BACKGROUND: In recent years, intervertebral disc (IVD) degeneration (IDD) has increased in age. There is still a lack of effective treatment in clinics, which cannot improve the condition of IDD at the level of etiology. OBJECTIVE: To explore IDD pathogenesis at the cellular and gene levels and investigate lactotransferrin (LTF) expression in IDD patients and its possible mechanism. METHODS: We downloaded the IDD data set from the Gene Expression Omnibus (GEO) database, screened the differentially expressed genes (DEGs) and hub genes and performed Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis to construct a protein-protein interaction (PPI) network. Subsequently, we verified LTF's regulatory mechanism through cell experiments. IL-1ß was used to intervene in nucleus pulposus cells (NPCs) to construct the IDD cell model, and LTF and Fas expression was detected by qRT-PCR. LTF inhibitor, Fas inhibitor, LTF mimic, and Fas mimic were used to intervene in each group. Western blotting was used to detect Fas, Caspase-3, Bax, and Bcl-2 expression. RESULTS: A total of 131 DEGs and 10 hub genes were screened. LTF mRNA in the IDD model was significantly higher than that in the control group, while Fas' mRNA was significantly lower. When LTF was upregulated or downregulated in NPCs, apoptosis marker expression showed the opposite trend. The rescue test showed that LTF and Fas' overexpression greatly enhanced NPC apoptosis. CONCLUSION: LTF promotes IDD progression by regulating Fas in NPCs, and it may be an effective gene therapy target.

Selective antibacterial activity of a novel lactotransferrin-derived antimicrobial peptide LF-1 against Streptococcus mutans.

OBJECTIVE: Streptococcus mutans is a key pathogen involved in the development of caries lesions. Previously, we developed a novel lactotransferrin-derived antimicrobial peptide LF-1 with potential selective activity against S. mutans. This study aimed to further confirm the selectivity of LF-1 by investigating its effect on S. mutans membrane. DESIGN: The effects of LF-1 on the viability of human gingival fibroblasts (HGFs) and three common oral Streptococcus (S. mutans, S. sanguinis, and S. gordonii) were evaluated and its structural characteristics were analysed using eukaryotic and prokaryotic membrane-simulated liposomes. Membrane affinity of LF-1 to the three streptococci strains was evaluated using the 3',3'-dipropylthiadicarbocyanine iodide experiment, hydrophobicity assay, and flow cytometry analysis. Transmission electron microscopy (TEM) was used to observe morphological changes in the three streptococcal membranes after LF-1 treatment. RESULTS: LF-1 displayed lower cytotoxicity to HGFs and selective antibacterial activity against S. mutans. LF-1 exhibited a typical α-helix structure and showed a tryptophan fluorescence blue shift in the prokaryotic membrane-simulated model. The most notable LF-1 induced changes occurred in the membrane potential and hydrophobicity of S. mutans among the three streptococci strains. Furthermore, the fluorescence of fluorescein isothiocyanate-labelled LF-1 was higher in S. mutans than in the other species. TEM showed that 16 µmol/L LF-1 could induce mesosome-like structures in S. mutans, whereas no significant morphological changes occurred in the other species. CONCLUSION: LF-1 has selective affinity for and antibacterial activity against S. mutans with strong membrane disrupting ability, highlighting the potential of LF-1 as a crucial antibacterial agent in caries prevention.

Transcytosis of Galectin-3 in Mouse Intestine.

The GlycoLipid-Lectin (GL-Lect) hypothesis provides a conceptual framework to explain how endocytic pits are built in processes of clathrin-independent endocytosis. According to this hypothesis, oligomeric cellular or pathogenic lectins interact with glycosylated plasma membrane lipids in a way such as to drive the formation of tubular endocytic pits that then detach to generate clathrin-independent endocytic carriers for the cellular uptake of cellular or pathogenic products. This process operates in a complementary manner to the conventional clathrin pathway for biological function linked to cell polarity. Up to date, the premises of the GL-Lect hypothesis have been based on model membrane and cell culture experiments. It has therefore become urgent to extend its exploration to complex organisms. In the current protocol, we describe methods to study the endocytosis and transcytosis of a key driver of the GL-Lect mechanism, the cellular galectin-3, and of one of its cargoes, lactotransferrin, in enterocytes of the intact jejunum of mice. In a step-by-step manner, we present the generation of fluorescent endocytic ligands, tissue preparation for cellular uptake measurements, binding and internalization assays, tissue fixation and preparation for sectioning, light and electron microscopical observations, and quantification of data by image processing. Pitfalls are discussed to optimize the chances of success with the described methods.

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.

Quantitative N-glycoproteome analysis of bovine milk and yogurt.

Post-translational modification structure of food's proteins might be changed during processing, thereby affecting the nutritional characteristics of the food product. In this study, differences in protein N-glycosylation patterns between milk and yogurt were quantitatively compared based on glycopeptide enrichment, liquid chromatography separation, and tandem mass spectrometry analysis. A total of 181 N-glycosites were identified, among which 142 were quantified in milk and yogurt. Significant alterations in the abundance of 13 of these N-glycosites were evident after the fermentation of milk into yogurt. Overall, the N-glycosylation status of the majority of milk proteins remained relatively unchanged in yogurt, suggesting that their conformations, activities, and functions were maintained despite the fermentation process. Among the main milk proteins, N241 of cathepsin D and N358 of lactoperoxidase were markedly reduced after undergoing lactic acid fermentation to produce yogurt. Furthermore, a comparative analysis of current and previously reported N-glycoproteomic data revealed heterogeneity in the N-glycosylation of milk proteins. To sum up, a quantitative comparison of the N-glycoproteomes of milk and yogurt was presented here for the first time, providing evidence that the fermentation process of yogurt could cause changes in the N-glycosylation of certain milk proteins.

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.

Novel lactotransferrin-derived synthetic peptides suppress cariogenic bacteria in vitro and arrest dental caries in vivo: [Novel lactotransferrin-derived anticaries peptides].

Objectives: The aim of the study was to design and synthesise novel lactotransferrin-derived antimicrobial peptides (AMPs) with enhanced antibacterial activity against cariogenic bacteria. Methods: We obtained the LF-1 (WKLLRKAWKLLRKA) and LF-2 (GKLIWKLLRKAWKLLRKA) AMPs, based on the N-terminal functional sequence of lactotransferrin, and characterised their physicochemical properties and secondary structure. Their antibacterial activity against caries-associated bacteria was evaluated using bacterial susceptibility and time-killing assays, as well as transmission electron microscopy (TEM). The antibiofilm activity against Streptococcus mutans biofilms was determined using biofilm susceptibility assays and confocal laser scanning microscopy (CLSM). A rodent model of dental caries was adopted to evaluate their anticaries effectiveness in vivo. Results: Both peptides possessed an α-helical structure with excellent amphipathicity. LF-1 was effective against S. mutans and Actinomyces species, whereas LF-2 showed more potent antibacterial activity than LF-1 against a broader spectrum of tested strains. Both peptides inhibited the formation of S. mutans biofilm starting at 8 µmol/L and exerted effective eradication of S. mutans in preformed biofilms. Both peptides exhibited satisfactory biocompatibility and exerted significant anticaries effects in a rodent model. Conclusion s: Both lactotransferrin-derived peptides displayed strong antimicrobial activity against cariogenic bacteria and S. mutans biofilm in vitro and effectively inhibited dental caries in vivo.

Lactotransferrin Downregulation Drives the Metastatic Progression in Clear Cell Renal Cell Carcinoma.

: Clear cell renal cell carcinoma (ccRCC) is the main type of RCC, which is the most common type of malignant kidney tumor in adults. A subpopulation (>30%) of ccRCC patients develop metastasis; however, the molecular mechanism remains largely unknown. Here, we found that LTF, the gene encoding lactotransferrin, is dramatically downregulated in primary tumors compared to normal tissues derived from ccRCC patients deposited in The Cancer Genome Atlas (TCGA) database and is a favorable prognostic marker. Moreover, LTF downregulation appears to be more dominant in metastatic ccRCC. LTF overexpression suppresses migration ability in A498 ccRCC cells with high metastatic potential, whereas LTF knockdown fosters cellular migration in poorly metastatic ccRCC cells. Gene set enrichment analysis demonstrated that LTF expression inversely correlates with the progression of epithelial-mesenchymal transition (EMT) in ccRCC, which was further confirmed by RT-PCR experiments. Therapeutically, the administration of recombinant LTF protein significantly suppresses the cell migration ability and lung metastatic potential of ACHN cells, as well as LTF-silenced A498 cells. The gene knockdown of lipoprotein receptor-related protein 1 (LRP1) robustly blocked recombinant LTF protein-induced inhibition of cellular migration and gene expression of EMT markers in ACHN cells. LTF downregulation and LRP1 upregulation combined predicted a poor overall survival rate in ccRCC patients compared to that with either factor alone. Our findings uncover a new mechanism by which LTF may interact with LRP1 to inhibit metastatic progression in ccRCC and also reveal the therapeutic value of recombinant LTF protein in treating metastatic ccRCC.