Levels of Lysozyme and SLPI in Bronchoalveolar Lavage: Exploring Their Role in Interstitial Lung Disease

Interstitial lung diseases (ILDs) are characterized by inflammation or fibrosis of the pulmonary parenchyma. Despite the involvement of immune cells and soluble mediators in pulmonary fibrosis, the influence of antimicrobial peptides (AMPs) remains underexplored. These effector molecules display a range of activities, which include immunomodulation and wound repair. Here, we investigate the role of AMPs in the development of fibrosis in ILD. We compare the concentration of different AMPs and different cytokines in 46 fibrotic (F-ILD) and 17 non-fibrotic (NF-ILD) patients by ELISA and using peripheral blood mononuclear cells from in vitro stimulation in the presence of lysozyme or secretory leukocyte protease inhibitor (SLPI) from 10 healthy donors. We observed that bronchoalveolar lavage (BAL) levels of AMPs were decreased in F-ILD patients (lysozyme: p < 0.001; SLPI: p < 0.001; LL-37: p < 0.001; lactoferrin: p = 0.47) and were negatively correlated with levels of TGF-β (lysozyme: p = 0.02; SLPI: p < 0.001) and IL-17 (lysozyme: p < 0.001; SLPI: p < 0.001). We observed that lysozyme increased the percentage of CD86+ macrophages (p < 0.001) and the production of TNF-α (p < 0.001). We showed that lysozyme and SLPI were associated with clinical parameters (lysozyme: p < 0.001; SLPI: p < 0.001) and disease progression (lysozyme: p < 0.001; SLPI: p = 0.01). These results suggest that AMPs may play an important role in the anti-fibrotic response, regulating the effect of pro-fibrotic cytokines. In addition, levels of lysozyme in BAL may be a potential biomarker to predict the progression in F-ILD patients.

Exploring the coordination chemistry of ruthenium complexes with lysozymes: structural and in-solution studies

This study presents a comprehensive structural analysis of the adducts formed upon the reaction of two Ru(III) complexes [HIsq][trans-RuIIICl4(dmso)(Isq)] (1) and [H2Ind][trans-RuIIICl4(dmso)(HInd)] (2) (where HInd-indazole, Isq-isoquinoline, analogs of NAMI-A) and two Ru(II) complexes, cis-[RuCl2(dmso)4] (c) and trans-[RuCl2(dmso)4] (t), with hen-egg white lysozyme (HEWL). Additionally, the crystal structure of an adduct of human lysozyme (HL) with ruthenium complex, [H2Ind][trans-RuCl4(dmso)(HInd)] was solved. X-ray crystallographic data analysis revealed that all studied Ru complexes, regardless of coordination surroundings and metal center charge, coordinate to the same amino acids (His15, Arg14, and Asp101) of HEWL, losing most of their original ligands. In the case of the 2-HL adduct, two distinct metalation sites: (i) Arg107, Arg113 and (ii) Gln127, Gln129, were identified. Crystallographic data were supported by studies of the interaction of 1 and 2 with HEWL in an aqueous solution. Hydrolytic stability studies revealed that both complexes 1 and 2 liberate the N-heterocyclic ligand under crystallization-like conditions (pH 4.5) as well as under physiological pH conditions, and this process is not significantly affected by the presence of HEWL. A comparative examination of nine crystal structures of Ru complexes with lysozyme, obtained through soaking and co-crystallization experiments, together with in-solution studies of the interaction between 1 and 2 with HEWL, indicates that the hydrolytic release of the N-heterocyclic ligand is one of the critical factors in the interaction between Ru complexes and lysozyme. This understanding is crucial in shedding light on the tendency of Ru complexes to target diverse metalation sites during the formation and in the final forms of the adducts with proteins.

Enterococcus cecorum lesion strains are less sensitive to the hostile environment of albumen and more resistant to lysozyme compared to cloaca strains

RESEARCH HIGHLIGHTS

Egg albumen inhibits Enterococcus cecorum cloaca strains more than lesion strains.Enterococcus cecorum lesion strains are resistant to high concentrations of lysozyme.Lysozyme resistance could enhance survival in albumen and body fluids.

Enzymes as indispensable markers in disease diagnosis

Enzymes have been used for disease diagnosis for many decades; however, advancements in technology like ELISA and flow cytometry-based detection have significantly increased their use and have increased the sensitivity of detection. Technological advancements in recombinant enzyme production have increased enzymatic stability, and the use of colorimetric-based and florescence-based assays has led to their increased use as biomarkers for disease detection. Enzymes like acid phosphatase, cathepsin, lactate dehydrogenase, thymidine kinase and creatine kinase are indispensable markers for diagnosing cancer, cardiovascular diseases and others. This minireview summarizes various enzymes used in disease diagnosis, their metabolic role, market value and potential as disease markers across various metabolic and other disorders.

Metal-Organic Framework Induced Stabilization of Proteins in Polymeric Nanoparticles

Developing protein confinement platforms is an attractive research area that not only promotes protein delivery but also can result in artificial environment mimicking of the cellular one, impacting both the controlled release of proteins and the fundamental protein biophysics. Polymeric nanoparticles (PNPs) are attractive platforms to confine proteins due to their superior biocompatibility, low cytotoxicity, and controllable release under external stimuli. However, loading proteins into PNPs can be challenging due to the potential protein structural perturbation upon contacting the interior of PNPs. In this work, we developed a novel approach to encapsulate proteins in PNPs with the assistance of the zeolitic imidazolate framework (ZIF). Here, ZIF offers an additional protection layer to the target protein by forming the protein@ZIF composite via aqueous-phase cocrystallization. We demonstrated our platform using a model protein, lysozyme, and a widely studied PNP composed of poly(ethylene glycol)-poly(lactic-co-glycolic acid) (PEG-PLGA). A comprehensive study via standard loading and release tests as well as various spectroscopic techniques was carried out on lysozyme loaded onto PEG-PLGA with and without ZIF protection. As compared with the direct protein encapsulation, an additional layer with ZIF prior to loading offered enhanced loading capacity, reduced leaching, especially in the initial stage, led to slower release kinetics, and reduced secondary structural perturbation. Meanwhile, the function, cytotoxicity, and cellular uptake of proteins encapsulated within the ZIF-bound systems are decent. Our results demonstrated the use of ZIF in assisting in protein encapsulation in PNPs and established the basis for developing more sophisticated protein encapsulation platforms using a combination of materials of diverse molecular architectures and disciplines. As such, we anticipate that the protein-encapsulated ZIF systems will serve as future polymer protein confinement and delivery platforms for both fundamental biophysics and biochemistry research and biomedical applications where protein delivery is needed to support therapeutics and/or nutrients.

Impedance nanobiosensor based on enzyme-conjugated biosynthesized gold nanoparticles for the detection of Gram-positive bacteria

In this report, gold nanoparticles (GNPS) were synthesized using cell-free extracts of seven different isolates, namely, Pseudomonas aerogenosa CEBP2, Pseudomonas sp. CEBP1, Pseudomonas pseudoalcaligenes CEB1G, Acinetobactor baumani CEBS1, Cuprividus sp. CEB3, Micrococcus luteus CUB12, and Pandoraea sp. CUB2S. The spectroscopic (UV-vis, FTIR, DLS, XRD, EDS) and microscopic (FESEM, TEM) results confirm the reduction of Au3+ to Au0 in the presence of biomolecules having reducing as well as self-stabilizing activity. In this green synthesis approach, the average particle size of biosynthesized GNPS might vary (4-60 nm) depending on the bacterial species, pH of the media, incubation time, and temperature. In this study, GSH-modified BSGNPs (Au-GSH) have shown antimicrobial activity with better stability against Gram-positive bacteria. After conjugation of lysozyme with Au-GSH (lyso@Au-GSH), the zone of inhibition was enhanced from 12 to 23 mm (Au-GSH). The TEM study shows the spherical GNP (16.65 ± 2.84) turns into a flower-shaped GNP (22.22 ± 3.12) after conjugation with lysozyme due to the formation of the protein corona. Furthermore, the nanobioconjugate (lyso@Au-GSH) was immobilized with Nafion on a glassy carbon electrode to fabricate a label-free impedance biosensor that is highly sensitive to monitor changes in the transducer surface due to biomolecular interactions. The uniquely designed biosensor could selectively detect Gram-positive bacteria in the linear range of 3.0 × 101-3 × 1010 cfu mL-1 with RE <5%. The proposed simplest biosensor exhibited good reproducibility (RSD = 3.1%) and excellent correlation (R2 = 0.999) with the standard plate count method, making it suitable for monitoring Gram-positive bacterial contamination in biofluids, food, and environmental samples.

Secondary structure and toxicity of lysozyme fibrils are determined by the length and unsaturation of phosphatidic acid

A progressive aggregation of misfolded proteins is a hallmark of numerous pathologies including diabetes Type 2, Alzheimer's disease, and Parkinson's disease. As a result, highly toxic protein aggregates, which are known as amyloid fibrils, are formed. A growing body of evidence suggests that phospholipids can uniquely alter the secondary structure and toxicity of amyloid aggregates. However, the role of phosphatidic acid (PA), a unique lipid that is responsible for cell signaling and activation of lipid-gated ion channels, in the aggregation of amyloidogenic proteins remains unclear. In this study, we investigate the role of the length and degree of unsaturation of fatty acids (FAs) in PA in the structure and toxicity of lysozyme fibrils formed in the presence of this lipid. We found that both the length and saturation of FAs in PA uniquely altered the secondary structure of lysozyme fibrils. However, these structural differences in PA caused very little if any changes in the morphology of lysozyme fibrils. We also utilized cell toxicity assays to determine the extent to which the length and degree of unsaturation of FAs in PA altered the toxicity of lysozyme fibrils. We found that amyloid fibrils formed in the presence of PA with C18:0 FAs exerted significantly higher cell toxicity compared to the aggregates formed in the presence of PA with C16:0 and C18:1 FAs. These results demonstrated that PA can be an important player in the onset and spread of amyloidogenic diseases.

Binding site prediction between lysozyme and glucose-regulated protein 78, a hope to fight amyloidosis

Amyloidosis is an extraordinarily vigorous and heterogeneous group of disorders that causes numerous organ failures due to the precipitation of misfolded proteins. Many of these damaged proteins are discarded before causing any fatal diseases due to the contribution of the protein quality control (PQC) system and its chaperons, including glucose-regulated protein (GRP78). One of the most important enzymatic proteins inside the body is lysozyme, which is reported to have many mutated variants that may cause amyloid fibrils. This study used structural bioinformatics and molecular dynamics simulations to test and suggest binding sites for the human lysozyme protein with GRP78. Multiple sequence alignment (MSA) shows that part of the lysozyme envelope protein (C65-C81 cyclic region) has high similarities (30.77% identity) with the cyclic Pep42. Additionally, the binding between the lysozyme cyclic region (C65-C81) and GRP78 substrate binding domain (SBD) is found favorable. The number and types of interactions vary between each of the mutant isoforms of lysozyme. The more significant the conformational changes in the mutation, the greater its probability of aggregation and the formation of amyloid fibrils. Each mutation leads to different interactions and binding patterns with GRP78. The present computational study suggests a lysozyme-GRP78 binding site, thus paving the way for drug designers to construct suitable carriers that can collect misfolded lysozyme proteins and eliminate them from the body, preventing their aggregation and amyloidogenesis.Communicated by Ramaswamy H. Sarma.

Cholesteric Tactoids with Tunable Helical Pitch Assembled by Lysozyme Amyloid Fibrils

Amyloid fibrils are biological rod-like particles showing liquid-liquid crystalline phase separation into cholesteric phases through a complex behavior of nucleation, growth, and order-order transitions. Yet, controlling the self-assembly of amyloids into liquid crystals, and particularly the resulting helical periodicity, remains challenging. Here, a novel cholesteric system is introduced and characterized based on hen egg white lysozyme (HEWL) amyloid fibrils and the results rationalized via a combination of experiments and theoretical scaling arguments. Specifically, the transition behaviors are elucidated from homogenous nematic, bipolar nematic to cholesteric tactoids following the classic Onsager model and the free energy functional model from Frank-Oseen elasticity theory. Additionally, the critical effects of pH and ionic strength on these order-order-transitions, as well as on the shape and helical pitch of the cholesteric tactoids are demonstrated. It is found that a small increase in pH from 2.0 to 2.8 results in a 34% decrease in pitch, while, on the contrary, increasing ionic strength from 0 to 10 mm leads to a 39% increase in pitch. The present study provides an approach to obtain controllable chiral nematic structures from HEWL amyloid fibrils, and may contribute further to the application of protein-based liquid crystals in pitch-sensitive biosensors or biomimetic architectures.

Secretory CAZymes profile and GH19 enzymes analysis of Corallococcus silvisoli c25j21

Extracellular enzymes play important roles in myxobacteria degrading macromolecules and preying on other microorganisms. Glycoside hydrolases 19 (GH19) are widely present in myxobacteria, but their evolution and biological functions have not been fully elucidated. Here we investigated the comparative secretory proteome of Corallococcus silvisoli c25j21 in the presence of cellulose and chitin. A total of 313 proteins were detected, including 16 carbohydrate-active enzymes (CAZymes), 7 of which were induced by cellulose or chitin, such as GH6, GH13, GH19, AA4, and CBM56. We further analyzed the sequence and structural characteristics of its three GH19 enzymes to understand their potential functions. The results revealed that myxobacterial GH19 enzymes are evolutionarily divided into two clades with different appended modules, and their different amino acid compositions in the substrate binding pockets lead to the differences in molecular surface electrostatic potentials, which may, in turn, affect their substrate selectivity and biological functions. Our study is helpful for further understanding the biological functions and catalytic mechanisms of myxobacterial CAZymes.

Investigating lysozyme amyloid fibril formation and structural variability dependence on its initial folding state under different pH conditions

Protein fibril formation and accumulation are associated with dozens of amyloidoses, including the widespread and yet-incurable Alzheimer's and Parkinson's diseases. Currently, there are still several aspects of amyloid aggregation that are not fully understood, which negatively contributes to the development of disease-altering drugs and treatments. One factor which requires a more in-depth analysis is the effect of the environment on both the initial state of amyloidogenic proteins and their aggregation process and resulting fibril characteristics. In this work, we examine how lysozyme's folding state influences its amyloid formation kinetics and resulting aggregate structural characteristics under several different pH conditions, ranging from acidic to neutral. We demonstrate that both the initial state of the protein and the solution's pH value have a significant combined effect on the variability of the resulting aggregate secondary structures, as well as their stabilities, interactions with amyloid-specific dye molecules, and self-replication properties.

Fluorescence-Polarization-Based Assaying of Lysozyme with Chitooligosaccharide Tracers

Lysozyme is a well-known enzyme found in many biological fluids which plays an important role in the antibacterial protection of humans and animals. Lysozyme assays are used for the diagnosis of a number of diseases and utilized in immunohistochemistry, genetic and cellular engineering studies. The assaying methods are divided into two categories measuring either the concentration of lysozyme as a protein or its activity as an enzyme. While the first category of methods traditionally uses an enzyme-linked immunosorbent assay (ELISA), the methods for the determination of the enzymatic activity of lysozyme use either live bacteria, which is rather inconvenient, or natural peptidoglycans of high heterogeneity and variability, which leads to the low reproducibility of the assay results. In this work, we propose the use of a chemically synthesized substrate of a strictly defined structure to measure in a single experiment both the concentration of lysozyme as a protein and its enzymatic activity by means of the fluorescence polarization (FP) method. Chito-oligosaccharides of different chain lengths were fluorescently labeled and tested leading to the selection of the pentasaccharide as the optimal size tracer and the further optimization of the assay conditions for the accurate (detection limit 0.3 μM) and rapid (<30 min) determination of human lysozyme. The proposed protocol was applied to assay human lysozyme in tear samples and resulted in good correlation with the reference assay. The use of synthetic fluorescently labeled tracer, in contrast to natural peptidoglycan, in FP analysis allows for the development of a reproducible method for the determination of lysozyme activity.

Effects of Dietary Supplementation of Essential Oils, Lysozyme, and Vitamins' Blend on Layer Hen Performance, Viral Vaccinal Response, and Egg Quality Characteristics

Maintaining respiratory tract health is crucial for layers, impacting gut health, laying performance, and egg quality. Viral diseases and standard vaccinations can compromise tracheal epithelium function, leading to oxidative stress. This study assessed the impact of a blend of feed additives, predominantly lysozyme (L), essential oils (EO), and vitamins (VIT) (referred to as L + EO + VIT), on young layers during an oral vaccination schedule. The supplementation significantly enhanced antibody titers for Newcastle Disease Virus (NDV) and Infectious Bronchitis Virus (IBV) after vaccination, trachea functionality and intestinal health in the jejunum, increased egg production, and exhibited a trend toward higher egg weight. Although feed intake showed no significant difference, egg quality remained consistent across experimental groups. Moreover, L + EO + VIT supplementation elevated total phenolic content in eggs, improving oxidative stability in both fresh and stored eggs, particularly under iron-induced oxidation. Notably, it substantially reduced yolk lipid peroxidation and albumen protein carbonyls. In conclusion, water supplementation with L + EO + VIT may enhance humoral immune response to IBV and NDV, positively impacting hen productivity. These findings indicate improved tracheal function and enhanced oxidative stability, emphasizing the potential of this blend in promoting overall health and performance in layers.

Oral administration of lysozyme protects against injury of ileum via modulating gut microbiota dysbiosis after severe traumatic brain injury

Objective

The current study sought to clarify the role of lysozyme-regulated gut microbiota and explored the potential therapeutic effects of lysozyme on ileum injury induced by severe traumatic brain injury (sTBI) and bacterial pneumonia in vivo and in vitro experiments.

Methods

Male 6-8-week-old specific pathogen-free (SPF) C57BL/6 mice were randomly divided into Normal group (N), Sham group (S), sTBI group (T), sTBI + or Lysozyme-treated group (L), Normal + Lysozyme group (NL) and Sham group + Lysozyme group (SL). At the day 7 after establishment of the model, mice were anesthetized and the samples were collected. The microbiota in lungs and fresh contents of the ileocecum were analyzed. Lungs and distal ileum were used to detect the degree of injury. The number of Paneth cells and the expression level of lysozyme were assessed. The bacterial translocation was determined. Intestinal organoids culture and co-coculture system was used to test whether lysozyme remodels the intestinal barrier through the gut microbiota.

Results

After oral administration of lysozyme, the intestinal microbiota is rebalanced, the composition of lung microbiota is restored, and translocation of intestinal bacteria is mitigated. Lysozyme administration reinstates lysozyme expression in Paneth cells, thereby reducing intestinal permeability, pathological score, apoptosis rate, and inflammation levels. The gut microbiota, including Oscillospira, Ruminococcus, Alistipes, Butyricicoccus, and Lactobacillus, play a crucial role in regulating and improving intestinal barrier damage and modulating Paneth cells in lysozyme-treated mice. A co-culture system comprising intestinal organoids and brain-derived proteins (BP), which demonstrated that the BP effectively downregulated the expression of lysozyme in intestinal organoids. However, supplementation of lysozyme to this co-culture system failed to restore its expression in intestinal organoids.

Conclusion

The present study unveiled a virtuous cycle whereby oral administration of lysozyme restores Paneth cell's function, mitigates intestinal injury and bacterial translocation through the remodeling of gut microbiota.

Lysozyme: A Natural Product with Multiple and Useful Antiviral Properties

Lysozyme, especially the one obtained from hen's egg white, continues to show new pharmacological properties. The fact that only a few of these properties can be translated into therapeutic applications is due to the lack of suitable clinical studies. However, this lack cannot hide the evidence that is emerging from scientific research. This review for the first time examines, from a pharmacological point of view, all the relevant studies on the antiviral properties of lysozyme, analyzing its possible mechanism of action and its ability to block viral infections and, in some cases, inhibit viral replication. Lysozyme can interact with nucleic acids and alter their function, but this effect is uncoupled from the catalytic activity that determines its antibacterial activity; it is present in intact lysozyme but is equally potent in a heat-degraded lysozyme or in a nonapeptide isolated by proteolytic digestion. An analysis of the literature shows that lysozyme can be used both as a disinfectant for raw and processed foods and as a drug to combat viral infections in animals and humans. To summarize, it can be said that lysozyme has important antiviral properties, as already suspected in the initial studies conducted over 50 years ago, and it should be explored in suitable clinical studies on humans.

Assessment of the Salivary Concentrations of Selected Immunological Components in Adult Patients in the Late Period after Allogeneic Hematopoietic Stem Cell Transplantation-A Translational Study

(1) The aim of the study was to analyze the salivary concentrations of lysozyme, lactoferrin, and sIgA antibodies in adult patients in the late period after allogeneic stem cell transplantation (alloHSCT). The relationship between these concentrations and the salivary secretion rate and the time elapsed after alloHSCT was investigated. The relationship between the concentrations of lysozyme, lactoferrin, and sIgA and the titer of the cariogenic bacteria S. mutans and L. acidophilus was assessed. (2) The study included 54 individuals, aged 19 to 67 (SD = 40.06 ± 11.82; Me = 39.5), who were 3 to 96 months after alloHSCT. The concentrations of lysozyme, lactoferrin, and sIgA were assessed in mixed whole resting saliva (WRS) and mixed whole stimulated saliva (WSS). (3) The majority of patients had very low or low concentrations of the studied salivary components (WRS-lysozyme: 52, lactoferrin: 36, sIgA: 49 patients; WSS-lysozyme: 51, lactoferrin: 25, sIgA: 51 patients). The levels of lactoferrin in both WRS and WSS were statistically significantly higher in the alloHSCT group than in the control group (CG) (alloHSCT patients-WRS: M = 40.18 μg/mL; WSS: M = 27.33 μg/mL; CG-WRS: M = 17.58 μg/mL; WSS: 10.69 μg/mL). No statistically significant correlations were observed between lysozyme, lactoferrin, and sIgA concentrations and the time after alloHSCT. In the group of patients after alloHSCT a negative correlation was found between the resting salivary flow rate and the concentration of lactoferrin and sIgA. The stimulated salivary flow rate correlated negatively with lactoferrin and sIgA concentrations. Additionally, the number of S. mutans colonies correlated positively with the concentration of lysozyme and sIgA. (4) The concentrations of non-specific and specific immunological factors in the saliva of patients after alloHSCT may differ when compared to healthy adults; however, the abovementioned differences did not change with the time after transplantation.

Water-Soluble Star Polymer as a Potential Photoactivated Nanotool for Lysozyme Degradation

The development of nanotools for chemical sensing and macromolecular modifications is a new challenge in the biomedical field, with emphasis on artificial peptidases designed to cleave peptide bonds at specific sites. In this landscape, metal porphyrins are attractive due to their ability to form stable complexes with amino acids and to generate reactive oxygen species when irradiated by light of appropriate wavelengths. The issues of hydrophobic behavior and aggregation in aqueous environments of porphyrins can be solved by using its PEGylated derivatives. This work proposes the design of an artificial photo-protease agent based on a PEGylated mercury porphyrin, able to form a stable complex with l-Tryptophan, an amino acid present also in the lysozyme structure (a well-known protein model). The sensing and photodegradation features of PEGylated mercury porphyrin were exploited to detect and degrade both l-Trp and lysozyme using ROS, generated under green (532 nm) and red (650 nm) light lasers. The obtained system (Star3600_Hg) and its behavior as a photo-protease agent were studied by means of several spectroscopies (UV-Vis, fluorescence and circular dichroism), and MALDI-TOF mass spectrometry, showing the cleavage of lysozyme and the appearance of several short-chain residues. The approach of this study paves the way for potential applications in theranostics and targeted bio-medical therapies.

Improvement of the SOD activity of the Cu2+ complexes by hybridization with lysozyme and its hydrogen bond effect on the activity enhancement

We prepared L-amino acids (L-valine and L-serine, respectively) based on the Schiff base Cu2+ complexes CuSV and CuSS in the absence/presence of hydroxyl groups and their imidazole-bound compounds CuSV-Imi and CuSS-Imi to reveal the effects of hydroxyl groups on SOD activity. The structural and spectroscopic features of the Cu2+ complexes were evaluated using X-ray crystallography, UV-vis spectroscopy, and EPR spectroscopy. The spectroscopic behavior upon addition of lysozyme indicated that both CuSV and CuSS were coordinated by the imidazole group of His15 in lysozyme at their equatorial position, leading to the formation of hybrid proteins with lysozyme. CuSS-Imi showed a higher SOD activity than CuSV-Imi, indicating that the hydroxyl group of CuSS-Imi played an important role in the disproportionation of O2 - ion. Hybridization of the Cu2+ complexes CuSV and CuSS with lysozyme resulted in higher SOD activity than that of CuSV-Imi and CuSS-Imi. The improvements in SOD activity suggest that there are cooperative effects between Cu2+ complexes and lysozyme.

Piezoelectric Amyloid Fibril for Energy Harvesting, Reactive Oxygen Species Generation, and Wireless Cell Therapy

Biomolecular piezoelectric materials are envisioned for advanced biomedical applications for their robust piezoelectricity, biocompatibility, and flexibility. Here, we report the piezoelectric property of amyloid fibrils derived from three distinct proteins: lysozyme, insulin, and amyloid-β. We found that piezoelectric properties are dependent on the extent of the β-sheet structure and the extent of fibril anisotropy. We have observed the piezoelectric constant value in the range of 24-42 pm/V for fibrils made of lysozyme/insulin/amyloid-β, and for the sheet/bundle-like structure of lysozyme aggregates, the value becomes 62 pm/V. These piezoelectric constant values are 4-10 times higher than the native lysozyme/insulin/amyloid proteins. Computational studies show that extension of the β-sheet structure produces an asymmetric arrangement of charges (in creating dipole moment) and mechanical stress induces an aligned orientation of these dipoles that results in a piezoelectric effect. It is shown that these piezoelectric fibrils can harvest mechanical as well as ultrasound-based energy to produce a voltage of up to 1 V and a current of up to 13 nA. These fibrils are employed for reactive oxygen species (ROS) generation under ultrasound exposure and utilized for ultrasonic degradation of organic pollutants or killing of cancer cells via intracellular ROS generation under ultrasound exposure. Our findings demonstrate that the piezoelectric property of protein fibrils has potential for wireless therapeutic applications and may have physiological roles that are yet to be explored.

Lactoferrin and Lysozyme Inhibit the Proteolytic Activity and Cytopathic Effect of Naegleria fowleri Enzymes

Naegleria fowleri is a ubiquitous free-living amoeba that causes primary amoebic meningoencephalitis. As a part of the innate immune response at the mucosal level, the proteins lactoferrin (Lf) and lysozyme (Lz) are secreted and eliminate various microorganisms. We demonstrate that N. fowleri survives the individual and combined effects of bovine milk Lf (bLf) and chicken egg Lz (cLz). Moreover, amoebic proliferation was not altered, even at 24 h of co-incubation with each protein. Trophozoites' ultrastructure was evaluated using transmission electron microscopy, and these proteins did not significantly alter their organelles and cytoplasmic membranes. Protease analysis using gelatin-zymograms showed that secreted proteases of N. fowleri were differentially modulated by bLf and cLz at 3, 6, 12, and 24 h. The bLf and cLz combination resulted in the inhibition of N. fowleri-secreted proteases. Additionally, the use of protease inhibitors on bLf-zymograms demonstrated that secreted cysteine proteases participate in the degradation of bLf. Nevertheless, the co-incubation of trophozoites with bLf and/or cLz reduced the cytopathic effect on the MDCK cell line. Our study suggests that bLf and cLz, alone or together, inhibited secreted proteases and reduced the cytopathic effect produced by N. fowleri; however, they do not affect the viability and proliferation of the trophozoites.

[Modulation of Aggregation and Immunogenicity of a Protein: Based on the Study of Hen Lysozyme]

This study focuses on the modulation of protein aggregation and immunogenicity. As a starting point for investigating long-range interactions within a non-native protein, the effects of perturbing denatured protein states on their aggregation, including the formation of amyloid fibrils, were evaluated. The effects of adducts, sugar modifications, and stabilization on protein aggregation were then examined. We also investigated how protein immunogenicity was affected by enhancing protein conformational stability and other factors.

Influence of the genotype of the hen (Gallus gallus domesticus) on main parameters of egg quality, chemical composition of the eggs under uniform environmental conditions

The objective of this study was to identify and compare the quality characteristics and concentrations of various compounds in eggs from several pure breeds and lines of hens reared under the same environmental conditions and fed a commercial feed. A total of 280 hens aged 52 to 56 wk belonging to 14 different breeds or lines of hens worldwide were included in this study. Their eggs were characterized by wide differences in various egg quality parameters. Breeds and lines of hens with a higher lutein content in eggs were characterized by a lower beta-carotene content (e.g. Hy line brown, Cochin miniature, Ayam Cemani) (P < 0.001). Additionally, vitamin D, cholesterol, and fatty acid contents were also different between eggs, from 1.51 to 1.79 μg/100g; from 14.1 to 15.4 mg/g fat, PUFA from 19.6 to 22.8 g/100g fat, and SFA from 32.8 to 37.8 g/100g fat respectively (P < 0.001). Lysozyme content also exhibited significant variation among breeds, with some showing a 2-fold higher content in eggs compared to others (0.31% - cochin miniature, 0.66% Faverolle) (P < 0.001). Our study demonstrated that intensively selected hen breeds like Hy-line Brown Hybrid had an improved egg quality seen by the increase in many parameters (e.g., egg weight, Haugh unit, Lutein, vitamins D, MUFA) compared to pure breed hens. In conclusion, genetic differences between breeds and lines of hens have a significant impact on the quality of eggs.

Effect of pH on the Poly(acrylic acid)/Poly(vinyl alcohol)/Lysozyme Complexes Formation

The interactions between poly(acrylic acid) (PAA), poly(vinyl alcohol) (PVA), and lysozyme (Lys) in an aqueous environment at pHs of 2, 4, and 7.4 were discussed considering the experimental data obtained by turbidimetry, electrokinetic and rheological measurements, and FTIR analysis. It was found that the increase in PAA amount reduces the coacervation zone by shifting the critical pHcr1to higher values while the critical pHcr2 remains unchanged. The coacervation zone extended from 3.1-4.2 to 2.9-4.7 increasing the Lys concentration from 0.2% to 0.5%. The zeta potential measurements showed that the PAA-PVA-Lys mixture in water is the most stable in the pH range of 4.5-8. Zero shear viscosity exhibited deviations from additivity at both investigated pHs, and a maximum value corresponding to a maximum hydrodynamic volume was revealed at PAA weight fractions of 0.4 and 0.5 for pHs of 4 and 7.4, respectively. The binding affinity to Lys of PAA, established by molecular dynamics simulation, was slightly higher than that of PVA. The more stable complex was PAA-Lys formed in a very acidic environment; for that, a binding affinity of -7.1 kcal/mol was determined.

High-Resolution Electron Diffraction of Hydrated Protein Crystals at Room Temperature

Structural characterization is crucial to understanding protein function. Compared with X-ray diffraction methods, electron crystallography can be performed on nanometer-sized crystals and can provide additional information from the resulting Coulomb potential map. Whereas electron crystallography has successfully resolved three-dimensional structures of vitrified protein crystals, its widespread use as a structural biology tool has been limited. One main reason is the fragility of such crystals. Protein crystals can be easily damaged by mechanical stress, change in temperature, or buffer conditions as well as by electron irradiation. This work demonstrates a methodology to preserve these nanocrystals in their natural environment at room temperature for electron diffraction experiments as an alternative to existing cryogenic techniques. Lysozyme crystals in their crystallization solution are hermetically sealed via graphene-coated grids, and their radiation damage is minimized by employing a low-dose data collection strategy in combination with a hybrid-pixel direct electron detector. Diffraction patterns with reflections of up to 3 Å are obtained and successfully indexed using a template-matching algorithm. These results demonstrate the feasibility of in situ protein electron diffraction. The method described will also be applicable to structural studies of hydrated nanocrystals important in many research and technological developments.

Probing the interaction of lysozyme with cardiac glycoside digitoxin: experimental and in silico analyses

Digitoxin is a cardiac glycoside used to treat heart failure and heart arrhythmia. However, its therapeutic concentration range is very narrow. High doses of digitoxin are associated with severe side effects; therefore, it is necessary to develop the delivery system which can control the plasma levels of it. In this context, the binding of lysozyme, an important protein having many applications, with digitoxin has been studied to see the ability of the former as a carrier. The studies were carried out using both experimental and computational methods. The intrinsic fluorescence of lysozyme increased on the addition of digitoxin. Fluorescence results suggested that there was a strong interaction between lysozyme and digitoxin which was favored, mainly, by hydrophobic forces. Further, digitoxin affected the secondary structure of lysozyme slightly by causing the partial unfolding of lysozyme. The preferred binding site of digitoxin within lysozyme was the large cavity of the protein. Molecular docking studies also established the principal role of hydrophobic forces in the binding with a significant support of hydrogen bonding. Frontier molecular orbitals of free digitoxin and in complexation with lysozyme were also computed and discussed. The findings from molecular dynamics simulation studies elucidate that, when contrasted with the first and third conformations of the digitoxin-bound lysozyme complex, the second conformation promotes structural stability, reduces flexibility, and enhances the compactness and folding properties of lysozyme. The overall study shows that lysozyme could act as a potential carrier for digitoxin in pharmaceutical formulations.

Intestinal epithelial dopamine receptor signaling drives sex-specific disease exacerbation in a mouse model of multiple sclerosis

Although the gut microbiota can influence central nervous system (CNS) autoimmune diseases, the contribution of the intestinal epithelium to CNS autoimmunity is less clear. Here, we showed that intestinal epithelial dopamine D2 receptors (IEC DRD2) promoted sex-specific disease progression in an animal model of multiple sclerosis. Female mice lacking Drd2 selectively in intestinal epithelial cells showed a blunted inflammatory response in the CNS and reduced disease progression. In contrast, overexpression or activation of IEC DRD2 by phenylethylamine administration exacerbated disease severity. This was accompanied by altered lysozyme expression and gut microbiota composition, including reduced abundance of Lactobacillus species. Furthermore, treatment with N2-acetyl-L-lysine, a metabolite derived from Lactobacillus, suppressed microglial activation and neurodegeneration. Taken together, our study indicates that IEC DRD2 hyperactivity impacts gut microbial abundances and increases susceptibility to CNS autoimmune diseases in a female-biased manner, opening up future avenues for sex-specific interventions of CNS autoimmune diseases.

Physicochemical Index Analyses of the Egg White in Blue-Shelled Eggs and Commercial Brown-Shelled Eggs during Storage

To compare the physical and chemical changes in egg whites during storage, assisting in the evaluation of differences in egg freshness between various chicken breeds, we chose 240 blue-shelled eggs (Blue group) and 240 commercial brown-shelled eggs (Brown group) that 28-week-old hens had laid. In this study, all eggs were stored at 25 °C. The egg weight, egg components' weight and proportion, Haugh Unit value and the contents of S-ovalbumin, ovomucin and lysozyme in the thick albumen (KA) and thin albumen (NA) were measured at eight time points every 3 days until the 21st day of storage. The eggshell, yolk and KA proportions in the Brown group were significantly lower, whereas the NA proportion was significantly higher than that in the Blue group (p < 0.001). The Haugh Unit value and S-ovalbumin in the Brown group were significantly higher, whereas KA ovomucin and NA lysozyme were significantly lower than those in the Blue group (p < 0.001). There existed significant negative correlations between the KA and NA, irrespective of weight or proportion. The Haugh Unit value was significantly positively correlated with lysozyme and ovomucin, but significantly negatively correlated with S-ovalbumin. During storage, the KA weight (proportion), Haugh Unit value, lysozyme and ovomucin decreased, whereas the NA weight (proportion) and S-ovalbumin increased. At each time point, the NA lysozyme in the Brown group was lower than that in the Blue group (p < 0.05). After storage for 6 days, the KA ovomucin in the Brown group began to be lower than that in the Blue group (p < 0.05). The study showed that the weight (proportion) differences in egg components between blue-shelled eggs and commercial brown-shelled eggs are mainly due to the NA. The Haugh Unit value and albumin protein indexes of blue-shelled eggs were better than those of brown-shelled eggs, and showed mild changes during storage, indicating the better storage performance of blue-shelled eggs.

Exploring Functionalized Magnetic Hydrogel Polyvinyl Alcohol and Chitosan Electrospun Nanofibers

Nanofibrous materials present interesting characteristics, such as higher area/mass ratio and reactivity. These properties have been exploited in different applications, such as drug-controlled release and site-specific targeting of biomolecules for several disease treatments, including cancer. The main goal of this study was to develop magnetized nanofiber systems of lysozyme (Lys) for biological applications. The system envisaged electrospun polyvinyl alcohol (PVA) and PVA/chitosan (CS) nanofibers, loaded with Lys, crosslinked with boronic acids [phenylboronic acid (PBA), including 2-acetylphenylboronic acid (aPBA), 2-formylphenylboronic (fPBA), or bortezomib (BTZ)] and functionalized with magnetic nanobeads (IONPs), which was successfully built and tested using a microscale approach. Evaluation of the morphology of nanofibers, obtained by electrospinning, was carried out using SEM. The biological activities of the Lys-loaded PVA/CS (90:10 and 70:30) nanofibers were evaluated using the Micrococcus lysodeikticus method. To evaluate the success of the encapsulation process, the ratio of adsorbed Lys on the nanofibers, Lys activity, and in vitro Lys release were determined in buffer solution at pH values mimicking the environment of cancer cells. The viability of Caco-2 cancer cells was evaluated after being in contact with electrospun PVA + Lys and PVA/CS + Lys nanofibers, with or without boronic acid functionalation, and all were magnetized with IONPs.

Transparent and Superhydrophilic Flexible Protein Films with Antifogging and Self-Cleaning Attributes

Cyanoglycoside-modified flexible protein films, exhibiting a high level of transparency of ≈46 to 83%, were successfully prepared from lysozyme and glycerol with varying amounts of amygdalin (20, 40, and 60%) using water as a solvent. The increasing percentage of amygdalin leads to a drastic improvement of the hydrophilicity of the surface with a decrease in the water contact angle to 5.6°, resulting in superhydrophilicity. The increasing percentage of amygdalin led to a significant improvement in the surface's hydrophilicity, resulting in a reduced water contact angle of 5.6° and achieving superhydrophilicity. This superhydrophilic characteristic is particularly relevant to the excellent antifogging and self-cleaning properties of the resulting protein films. In addition to enhanced flexibility, the films also exhibited considerably improved thermal stability with a 40% loading of amygdalin in the protein solution. The superior mechanical, optical, and thermal properties of amygdalin-modified films are due to the strong hydrogen bonding with the peptides of lysozyme, as evidenced by the disappearance of amide bands in the cured protein films. Therefore, these transparent protein films, with their antifogging and enhanced thermal stability properties, can be potentially used for different packaging and coating applications.

The selective regulation of immune responses by matrix metalloproteinase MMP14 in Ostrinia furnacalis

Matrix metalloproteinases (MMPs) are crucial for tissue remodeling and immune responses in insects, yet it remains unclear how MMPs affect the various immune processes against pathogenic infections and whether the responses vary among insects. In this study, we used the lepidopteran pest Ostrinia furnacalis larvae to address these questions by examining the changes of immune-related gene expression and antimicrobial activity after the knockdown of MMP14 and bacterial infections. We identified MMP14 in O. furnacalis using the rapid amplification of complementary DNA ends (RACE), and found that it was conserved and belonged to the MMP1 subfamily. Our functional investigations revealed that MMP14 is an infection-responsive gene, and its knockdown reduces phenoloxidase (PO) activity and Cecropin expression, while the expressions of Lysozyme, Attacin, Gloverin, and Moricin are enhanced after MMP14 knockdown. Further PO and lysozyme activity determinations showed consistent results with gene expression of these immune-related genes. Finally, the knockdown of MMP14 decreased larvae survival to bacterial infections. Taken together, our data indicate that MMP14 selectively regulates the immune responses, and is required to defend against bacterial infections in O. furnacalis larvae. Conserved MMPs may serve as a potential target for pest control using a combination of double-stranded RNA and bacterial infection.

Human lysozyme inhibits the fibrillation of serum amyloid a protein from systemic AA amyloidosis

BACKGROUND

Systemic AA amyloidosis is a world-wide occurring protein misfolding disease in humans and animals that arises from the formation of amyloid fibrils from serum amyloid A (SAA) protein and their deposition in multiple organs.

OBJECTIVE

To identify new agents that prevent fibril formation from SAA protein and to determine their mode of action.

MATERIALS AND METHODS

We used a cell model for the formation of amyloid deposits from SAA protein to screen a library of peptides and small proteins, which were purified from human hemofiltrate. To clarify the inhibitory mechanism the obtained inhibitors were characterised in cell-free fibril formation assays and other biochemical methods.

RESULTS

We identified lysozyme as an inhibitor of SAA fibril formation. Lysozyme antagonised fibril formation both in the cell model as well as in cell-free fibril formation assays. The protein binds SAA with a dissociation constant of 16.5 ± 0.6 µM, while the binding site on SAA is formed by segments of positively charged amino acids.

CONCLUSION

Our data imply that lysozyme acts in a chaperone-like fashion and prevents the aggregation of SAA protein through direct, physical interactions.

Hematology profile, digestive enzymes, thyroid hormones, productivity, and nitrogen balance of growing male rabbits supplemented with exogenous dietary lysozyme

In a simple randomized design trial, 420 growing male V-Line rabbits were randomly distributed into four groups to investigate the impact of exogenous dietary lysozyme on some physiological and nutritional parameters of male growing rabbits supplemented with exogenous dietary lysozyme. The witness group received a basal diet without exogenous dietary lysozyme (LYZ0), while the exogenous dietary lysozyme groups received 50, 100 and 150 mg/kg of basal diet (Groups; LYZ50, LYZ100 and LYZ150), respectively. The results showed significantly increased in blood cell count, hemoglobin concentration, total white blood cell, lipase, protease, amylase, total protein, triiodothyronine and thyroxine levels, while thyroid stimulating hormone levels significantly lessened in rabbits received LYZ. The LYZ- rabbit diets improved total digestible nutrient, digestible crude protein, and digestible energy values, with the LYZ100 group outperforming the others. LYZ-treated rabbits had significantly higher nitrogen intake, digestible nitrogen, and nitrogen balance than the witness group. The lysozyme in a rabbit's diet is taking on a new role as a digestive enzyme, enhancement thyroid hormones, as well as improvement hematology, daily protein efficiency ratio, daily performance index, hot carcass, total edible parts, nutritional value, and nitrogen balance, with decreasing the daily caloric conversion ratio and total non-edible parts.

Pouchitis Is Associated with Paneth Cell Dysfunction and Ameliorated by Exogenous Lysosome in a Rat Model Undergoing Ileal Pouch Anal Anastomosis

BACKGROUND

Pouchitis is a common complication of restorative proctocolectomy and ileal pouch anal anastomosis (IPAA) for ulcerative colitis (UC), significantly affecting the postoperative quality of life. Paneth cells play an important role in the maintenance of gut homeostasis. This study aimed to investigate the role of Paneth cells in the pathogenesis of pouchitis.

METHOD

Endoscopic biopsies from the pouch body and terminal ileum of UC patients undergoing IPAA with or without pouchitis were obtained to analyze Paneth cell function. Acute pouchitis was induced with 5% dextran sulfate sodium (DSS) for seven consecutive days in a rat model of IPAA. The Paneth cell morphology was examined by immunofluorescence and electron microscopy. The effect of exogenous lysozyme supplementation on pouchitis was also investigated. The fecal microbiota profile after DSS and lysozyme treatment was determined by 16s rRNA ITS2 sequence analysis.

RESULT

Abnormal mucosal lysozyme expression was observed in patients with pouchitis. The rat model of pouchitis showed increased pouch inflammation, increased CD3+ and CD45+ T cell infiltration, and decreased tight junction proteins, including ZO-1 and Occludin. There is a significant deficiency of Paneth cell-derived lysozyme granules in the rat model of pouchitis. Supplementation with exogenous lysozyme significantly ameliorated pouchitis, lowering the levels of inflammatory cytokines such as TNF-α and IL-6 in the pouch tissue. 16s rRNA analysis revealed a higher Lachnospiraceae level after lysosome treatment.

CONCLUSIONS

Paneth cell dysfunction is prominent in patients and rat models of pouchitis and may be one of its causes. The decrease in Lachnospiraceae, a characteristic of dysbiosis in pouchitis, could be reserved by lysosome treatment. Lysozyme supplementation shows promise as a novel treatment strategy for pouchitis.

Dietary Supplementation with Lysozyme-Cinnamaldehyde Conjugates Enhances Feed Conversion Efficiency by Improving Intestinal Health and Modulating the Gut Microbiota in Weaned Piglets Infected with Enterotoxigenic Escherichia coli

This study aims to evaluate the efficacy of lysozyme-cinnamaldehyde conjugates (LC) as a potential alternative to antibiotics in treating piglets infected with enterotoxigenic Escherichia coli (ETEC). The results demonstrated that piglets fed with the LC diet exhibited lower rectal temperature and fecal scores at 9 h, 24 h, and 48 h post-ETEC challenge. Furthermore, LC supplementation led to significant improvements in the mechanical and immune barriers of the jejunum and ileum, as indicated by an increased villi-height-to-crypt-depth ratio (VCR) and the expression of tight junction proteins, mucin, and β-defensins. Furthermore, the LC diet lowered the levels of pro-inflammatory cytokines TNF-α and IL-1β in the plasma. Further analyses showed that the LC diet downregulated genes (specifically TLR4 and MyD88) linked to the TLRs/MyD88/NF-κB signaling pathway in the small intestine. Additionally, 16SrDNA sequencing data revealed that LC supplementation increased the α diversity of intestinal microorganisms and the relative abundance of Lactobacillus. In summary, the LC-supplemented diet effectively mitigated the adverse effects of E. coli K88, including intestinal barrier damage and inflammation. Furthermore, it improved the structure of the intestinal flora, ultimately contributing to better growth performance in piglets.

Fast Probing Amyloid Polymorphism via Nanopore Translocation

Neurodegenerative diseases are characterized by the presence of cross-β-sheet amyloid fibrils and a rich mesoscopic polymorphism, requiring noninvasive detection with high fidelity. Here, we introduce a methodology that can probe via a sensitive synthetic nanopore the complex polymorphism of amyloid fibrils by an automated and fast screening protocol. Statistically analyzing the translocation events on two model amyloid systems derived from β-lactoglobulin and lysozyme allows extracting the cross-sectional configuration of hydrated amyloid fibrils from current block amplitude and correlating dwell time with fibril length. These findings are consistent with the amyloid polymorphs observed in solution by atomic force microscopy. Furthermore, the ionic current signal of a single translocation event can reveal abnormally aggregated conformations of amyloid fibrils without potential artifacts associated with microscopy methods. This study introduces an effective approach to physically discriminating and separating amyloid and may serve in the rapid diagnosis of early aggregating pathological amyloidosis.

The Effects of Stocking Density and Food Deprivation on Mucous Cells and Lysozyme Activity in the Skin and Gills of Silver Catfish

This study aimed to identify the regions of the body surface of silver catfish (Rhamdia quelen) with a higher population of mucous cells in the skin. Additionally, the effects of stressful conditions, such as different stocking densities and food deprivation, on the proliferative response of mucous cells in the skin and gill epithelium and their impact on cutaneous mucous lysozyme activity were investigated. Silver catfish were divided into four experimental groups: high stocking density (32 kg/m3) and fed (HSD-F), high stocking density and fasted (HSD-FS), low stocking density (2.5 kg/m3) and fed (LSD-F), and low stocking density and fasted (LSD-FS). Fish in the fed groups received commercial feed twice a day, amounting to 1% of the tank biomass. After a 14-day experimental period, the fish were anesthetized and euthanized. Samples of cutaneous mucous and skin fragments from seven different points and the second left branchial arch were collected. Histological slides of the skin and gills were stained with PAS + Alcian Blue at pH 2.5, and the epidermal mucous lysozyme activity was assessed using the turbidimetric method. The ventral point in front of the ventral fin was found to be the optimal location for collecting cutaneous epithelia due to its higher density of mucous cells. The population of mucous cells in both the skin and gills varied based on the collection point and treatment applied. The highest lysozyme activity in the epidermal mucous was observed in fish from the HSD-F group. Overall, these findings suggest that stocking density and food deprivation create stressful conditions for silver catfish, which modulate their mucosal response to each situation.

Infection and inflammation stimulate expansion of a CD74+ Paneth cell subset to regulate disease progression

Paneth cells (PCs), a specialized secretory cell type in the small intestine, are increasingly recognized as having an essential role in host responses to microbiome and environmental stresses. Whether and how commensal and pathogenic microbes modify PC composition to modulate inflammation remain unclear. Using newly developed PC-reporter mice under conventional and gnotobiotic conditions, we determined PC transcriptomic heterogeneity in response to commensal and invasive microbes at single cell level. Infection expands the pool of CD74+ PCs, whose number correlates with auto or allogeneic inflammatory disease progressions in mice. Similar correlation was found in human inflammatory disease tissues. Infection-stimulated cytokines increase production of reactive oxygen species (ROS) and expression of a PC-specific mucosal pentraxin (Mptx2) in activated PCs. A PC-specific ablation of MyD88 reduced CD74+ PC population, thus ameliorating pathogen-induced systemic disease. A similar phenotype was also observed in mice lacking Mptx2. Thus, infection stimulates expansion of a PC subset that influences disease progression.

Exploring the therapeutic potential of recombinant human lysozyme: a review on wound management system with antibacterial

Lysozyme, a natural antibacterial enzyme protein, possesses the ability to dissolve the cell walls of Gram-positive bacteria, demonstrating broad-spectrum antibacterial activity. Despite its significant potential in treating wound infections and promoting wound healing, its widespread clinical application has yet to be realized. Current research is primarily focused on carrier-based delivery systems for lysozyme. In this review, we discuss four delivery systems that can be employed for lysozyme in wound healing treatment, specifically hydrogels, nanofilms, electrospun fibrous membranes, and modified-lysozyme composite systems. These systems not only enhance the stability of lysozyme but also enable its controlled and sustained release at wound sites, potentially overcoming some of the challenges associated with its direct application. Lastly, we delve into the perspectives and challenges related to the use of these delivery systems, hoping to spur further research and innovation in this promising field.

Interaction of gallium, indium and vanadyl diacetylcurcumin complexes with lysozyme: mechanistic aspects and evaluation of antiamyloidogenic activity

Diacetylcurcumin as a derivative of curcumin is a strong nitric oxide (NO) and O2-.anion scavenger. One strategy to improve stability of curcumin and its derivatives is complexation with metal. In this study, the binding interactions of gallium diacetylcurcumin (Ga(DAC)3), indium diacetylcurcumin (In(DAC)3), and vanadyl diacetylcurcumin (VO(DAC)2) with hen egg white lysozyme (HEWL) have been investigated. The results of fluorescence quenching analyses revealed that In(DAC)3 and VO(DAC)2 have higher binding affinities than Ga(DAC)3 towards HEWL. The interactions of these metal complexes were not accompanied by considerable conformational changes in the tertiary structure of HEWL. Furthermore, the inhibitory effects of these complexes on the amyloid fibrillation of HEWL were confirmed by the thioflavin T fluorescence assays. The kinetic curves of the fibrillation process illustrated that VO(DAC)2 has the highest inhibitory activity and In(DAC)3 has a significant delaying effect on the formation of amyloid fibrils of HEWL.

Three-Dimensional Membranes of Natural Polymer Complex Nanoparticle for Potential Medical Applications

Skin wound healing is a complex biological process of tissue regeneration in which the wound dressing is crucial for rapid healing; it must protect the wound keep an adequate level of moisture and prevent infections. Alginate (AL), a polysaccharide from brown algae, has been extensively studied for wound treatment, and aloe vera gels (AVGs) have also been used in the treatment of skin. The AVG main bioactive polysaccharide was combined with AL for the preparation of membranes. Two-dimensional membranes were prepared by casting and, for comparison, transparent nanoparticle 3D membranes were produced by high-intensity ultrasonication followed by ionotropic crosslinking. The effects of the amount of AVG, ionotropic gelation, and the structure (2D or 3D) of the AL-AVG membranes were compared. Scanning electron microscopy (SEM) showed higher surface roughness on 3D membranes. Three-dimensional membranes showed a higher swelling ratio, and swelling increased with AVG content and decreased with higher calcium concentration and longer gelation times. The degradation of the membranes was evaluated with and without a lysozyme at pH 5.5, 7.5, and 8.5, to simulate different skin conditions; the results evidence that pH had a higher effect than the enzyme. The cytotoxicity of the membranes was evaluated with ATCC CCL 163 and ATCC CCL 81 cells, and an excellent biocompatibility of both cell types (>90% of cell viability after 48 h incubation) was observed for all AL-AVG membranes.

Elucidating the Molecular Interactions between Lipids and Lysozyme: Evaporation Resistance and Bacterial Barriers for Dry Eye Disease

Dry eye disease (DED) is a chronic condition characterized by ocular dryness and inflammation. The tear film lipid layer (TFLL) is the outermost layer composed of lipids and proteins that protect the ocular surface. However, environmental contaminants can disrupt its structure, potentially leading to DED. Although the importance of tear proteins in the TFLL functionality has been clinically recognized, the molecular mechanisms underlying TFLL-protein interactions remain unclear. In this study, we investigated tear protein-lipid interactions and analyzed their role in the TFLL functionality. The results show that lysozyme (LYZ) increases the stability of the TFLL by reducing its surface tension and increasing its surface pressure, resulting in increased TFLL evaporation and bacterial invasion resistance, with improved wettability and lubrication performance. These findings highlight the critical role of LYZ in maintaining ocular health and provide potential avenues for investigating novel approaches to DED treatment and patient well-being.

Lysozyme Inhibitors as Tools for Lysozyme Profiling: Identification and Antibacterial Function of Lysozymes in the Hemolymph of the Blue Mussel

Lysozymes are universal components of the innate immune system of animals that kill bacteria by hydrolyzing their main cell wall polymer, peptidoglycan. Three main families of lysozyme have been identified, designated as chicken (c)-, goose (g)- and invertebrate (i)-type. In response, bacteria have evolved specific protein inhibitors against each of the three lysozyme families. In this study, we developed a serial array of three affinity matrices functionalized with a c-, g-, and i-type inhibitors for lysozyme typing, i.e., to detect and differentiate lysozymes in fluids or extracts from animals. The tool was validated on the blue mussel (Mytilus edulis), whose genome carries multiple putative i-, g-, and c-type lysozyme genes. Hemolymph plasma of the animals was found to contain both i- and g-type, but not c-type lysozyme. Furthermore, hemolymph survival of Aeromonas hydrophila and E. coli strains lacking or overproducing the i- type or g-type lysozyme inhibitor, respectively, was analyzed to study the role of the two lysozymes in innate immunity. The results demonstrated an active role for the g-type lysozyme in the innate immunity of the blue mussel, but failed to show a contribution by the i-type lysozyme. Lysozyme profiling using inhibitor-based affinity chromatography will be a useful novel tool for studying animal innate immunity.

Differential expression of immunity-related genes in larval Manduca sexta tissues in response to gut and systemic infection

Introduction

The midgut epithelium functions as tissue for nutrient uptake as well as physical barrier against pathogens. Additionally, it responds to pathogen contact by production and release of various factors including antimicrobial peptides, similar to the systemic innate immune response. However, if such a response is restricted to a local stimulus or if it appears in response to a systemic infection, too is a rather underexplored topic in insect immunity. We addressed the role of the midgut and the role of systemic immune tissues in the defense against gut-borne and systemic infections, respectively.

Methods

Manduca sexta larvae were challenged with DAP-type peptidoglycan bacteria - Bacillus thuringiensis for local gut infection and Escherichia coli for systemic stimulation. We compared the immune response to both infection models by measuring mRNA levels of four selected immunity-related genes in midgut, fat body, hematopoietic organs (HOs), and hemocytes, and determined hemolymph antimicrobial activity. Hemocytes and HOs were tested for presence and distribution of lysozyme mRNA and protein.

Results

The midgut and circulating hemocytes exhibited a significantly increased level of lysozyme mRNA in response to gut infection but did not significantly alter expression in response to a systemic infection. Conversely, fat body and HOs responded to both infection models by altered mRNA levels of at least one gene monitored. Most, but not all hemocytes and HO cells contain lysozyme mRNA and protein.

Discussion

These data suggest that the gut recruits immune-related tissues in response to gut infection whereas systemic infections do not induce a response in the midgut. The experimental approach implies a skewed cross-talk: An intestinal infection triggers immune activity in systemic immune organs, while a systemic infection does not elicit any or only a restricted immune response in the midgut. The HOs, which form and release hemocytes in larval M. sexta, i) synthesize lysozyme, and ii) respond to immune challenges by increased immune gene expression. These findings strongly suggest that they not only provide phagocytes for the cellular immune response but also synthesize humoral immune components.

Loss of NOD2 in macrophages improves colitis and tumorigenesis in a lysozyme-dependent manner

Background

Crohn's disease (CD) is a complex and poorly understood myeloid-mediated disorder. Genetic variants with loss of function in the NOD2 gene confer an increased susceptibility to ileal CD. While Nod2 in myeloid cells may confer protection against T-cell mediated ileopathy, it remains unclear whether it may promote resolution of the inflamed colon. In this study, we evaluated the function of Nod2 in myeloid cells in a model of acute colitis and colitis-associated colon cancer (CAC).

Methods

To ablate Nod2 specifically within the myeloid compartment, we generated LysMCre/+;Nod2fl/fl mice. The role of NOD2 was studied in a setting of Dextran Sodium Sulfate (DSS)-induced colitis and in azoxymethane (AOM)/DSS model. Clinical parameters were quantified by colonoscopy, histological, flow cytometry, and qRT-PCR analysis.

Results

Upon DSS colitis model, LysMCre/+;Nod2fl/fl mice lost less weight than control littermates and had less severe damage to the colonic epithelium. In the AOM/DSS model, endoscopic monitoring of tumor progression revealed a lowered number of adenomas within the colon of LysMCre/+;Nod2fl/fl mice, associated with less expression of Tgfb. Mechanistically, lysozyme M was required for the improved disease severity in mice with a defect of NOD2 in myeloid cells.

Conclusion

Our results indicate that loss of Nod2 signaling in myeloid cells aids in the tissue repair of the inflamed large intestine through lysozyme secretion by myeloid cells. These results may pave the way to design new therapeutics to limit the inflammatory and tumorigenic functions of NOD2.

Exploring the effects of lysozyme dietary supplementation on laying hens: performance, egg quality, and immune response

An experiment was conducted to evaluate the dietary supplementation with lysozyme's impacts on laying performance, egg quality, biochemical analysis, body immunity, and intestinal morphology. A total of 720 Jingfen No. 1 laying hens (53 weeks old) were randomly assigned into five groups, with six replicates in each group and 24 hens per replicate. The basal diet was administered to the laying hens in the control group, and it was supplemented with 100, 200, 300, or 400 mg/kg of lysozyme (purity of 10% and an enzyme activity of 3,110 U/mg) for other groups. The preliminary observation of the laying rate lasted for 4 weeks, and the experimental period lasted for 8 weeks. The findings demonstrated that lysozyme might enhance production performance by lowering the rate of sand-shelled eggs (P < 0.05), particularly 200 and 300 mg/kg compared with the control group. Lysozyme did not show any negative effect on egg quality or the health of laying hens (P > 0.05). Lysozyme administration in the diet could improve intestinal morphology, immune efficiency, and nutritional digestibility in laying hens when compared with the control group (P < 0.05). These observations showed that lysozyme is safe to use as a feed supplement for the production of laying hens. Dietary supplementation with 200 to 300 mg/kg lysozyme should be suggested to farmers as a proper level of feed additive in laying hens breeding.

Disruption of the primocolonizing microbiota alters epithelial homeostasis and imprints stem cells in the colon of neonatal piglets

The gut microbiota plays a key role in the postnatal development of the intestinal epithelium. However, the bacterial members of the primocolonizing microbiota driving these effects are not fully identified and the mechanisms underlying their long-term influence on epithelial homeostasis remain poorly described. Here, we used a model of newborn piglets treated during the first week of life with the antibiotic colistin in order to deplete specific gram-negative bacteria that are transiently dominant in the neonatal gut microbiota. Colistin depleted Proteobacteria and Fusobacteriota from the neonatal colon microbiota, reduced the bacterial predicted capacity to synthetize lipopolysaccharide (LPS), and increased the concentration of succinate in the colon. The colistin-induced disruption of the primocolonizing microbiota was associated with altered gene expression in the colon epithelium including a reduction of toll-like receptor 4 (TLR4) and lysozyme (LYZ). Our data obtained in porcine colonic organoid cell monolayers suggested that these effects were not driven by the variation of succinate or LPS levels nor by a direct effect of colistin on epithelial cells. The disruption of the primocolonizing microbiota imprinted colon epithelial stem cells since the expression of TLR4 and LYZ remained lower in organoids derived from colistin-treated piglet colonic crypts after several passages when compared to control piglets. Finally, the stable imprinting of LYZ in colon organoids was independent of the H3K4me3 level in its transcription start site. Altogether, our results show that disruption of the primocolonizing gut microbiota alters epithelial innate immunity in the colon and imprints stem cells, which could have long-term consequences for gut health.

Comparison and Development of Immunohistochemical Diagnostic Criteria for Blastic Plasmacytoid Dendritic Cell Neoplasm

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematological malignancy derived from the precursors of plasmacytoid dendritic cells. Diagnostic criteria for BPDCN have not been fully established. BPDCN is often diagnosed without other BPDCN markers than the 3 conventional markers (CD4, CD56, and CD123) in practice and case reports, although acute myeloid leukemia/myeloid sarcoma (AML/MS), which is always considered in the differential diagnosis of BPDCN, can express them. We reviewed published case reports on BPDCN and found that the diagnosis was made without any other BPDCN markers than the conventional markers in two-thirds of the cases. Next, 4 representative existing diagnostic criteria were applied to 284 cases of our cohort of BPDCN and mimics. The results differed in 20% (56/284) of the cases. The criterion based on the 3 conventional markers alone had a low concordance rate (80%-82%) with the other 3 criteria, which were almost concordant with each other. However, newly found minor limitations in these criteria prompted us to devise new diagnostic criterion for BPDCN composed of TCF4, CD123, TCL1, and lysozyme. We also revealed that CD123-positive AML/MS patients had a significantly poorer outcome than those with BPDCN and that 12% (24/205) of the cases were non-BPDCN even if all 3 conventional markers were positive, thus clarifying the risk of diagnosing BPDCN without more specific markers. In addition, histopathological features, such as the reticular pattern, which is not seen in BPDCN and suggests AML/MS, were also identified.

Solvent-Induced Lag Phase during the Formation of Lysozyme Amyloid Fibrils Triggered by Sodium Dodecyl Sulfate: Biophysical Experimental and In Silico Study of Solvent Effects

Amyloid aggregates arise from either the partial or complete loss of the native protein structure or the inability of proteins to attain their native conformation. These aggregates have been linked to several diseases, including Alzheimer's, Parkinson's, and lysozyme amyloidosis. A comprehensive dataset was recently reported, demonstrating the critical role of the protein's surrounding environment in amyloid formation. In this study, we investigated the formation of lysozyme amyloid fibrils induced by sodium dodecyl sulfate (SDS) and the effect of solvents in the medium. Experimental data obtained through fluorescence spectroscopy revealed a notable lag phase in amyloid formation when acetone solution was present. This finding suggested that the presence of acetone in the reaction medium created an unfavorable microenvironment for amyloid fibril formation and impeded the organization of the denatured protein into the fibril form. The in silico data provided insights into the molecular mechanism of the interaction between acetone molecules and the lysozyme protofibril, once acetone presented the best experimental results. It was observed that the lysozyme protofibril became highly unstable in the presence of acetone, leading to the complete loss of its β-sheet conformation and resulting in an open structure. Furthermore, the solvation layer of the protofibril in acetone solution was significantly reduced compared to that in other solvents, resulting in fewer hydrogen bonds. Consequently, the presence of acetone facilitated the exposure of the hydrophobic portion of the protofibril, precluding the amyloid fibril formation. In summary, our study underscores the pivotal role the surrounding environment plays in influencing amyloid formation.

Probing the interaction and aggregation of lysozyme in presence of organophosphate pesticides: a comprehensive spectroscopic, calorimetric, and in-silico investigation

Organophosphorus pesticides (OPs) are widely used in agriculture and may contaminate food or water, leading to potential health risks. However, there are few reports on the effect of OPs on protein conformation and aggregation. Hence, in this paper, we have characterized the impact of two OPs, chlorpyrifos (CPF) and methyl parathion (Para), on the model protein HEWL using biophysical and computational methods. The steady-state and time-resolved spectroscopy, Circular dichroism (CD), molecular dynamics simulation, and isothermal titration calorimetry were employed to investigate the binding interactions between HEWL and OPs. The steady-state and time-resolved fluorescence spectroscopy confirm the presence of both static and dynamic quenching between OPs and proteins. Based on fluorescence, MD, and CD results, it was found that the OPs not only show strong binding but also destabilize the protein structure and alter the secondary and tertiary structure of the protein. The molecular docking results showed that OPs entered the binding pocket of the HEWL molecule and interacted through hydrophobic and hydrogen bond interactions. The thermodynamic studies indicated that the binding was spontaneous and OPs have shown an effect on the aggregation process of HEWL. Finally, the protein aggregation process was studied using fluorescence and SDS-PAGE studies in the presence of both the OPs and found to enhance the aggregation process in the presence of OPs. These results provide insights into the potential health risks associated with OPs and highlight the importance of understanding their interactions with biological macromolecules.Communicated by Ramaswamy H. Sarma.

Impact of breastfeeding and other early-life factors on the development of the oral microbiome

The oral cavity is home to the second most diverse microbiome in the human body. This community contributes to both oral and systemic health. Acquisition and development of the oral microbiome is a dynamic process that occurs over early life; however, data regarding longitudinal assembly of the infant oral microbiome is scarce. While numerous factors have been associated with the composition of the infant oral microbiome, early feeding practices (breastfeeding and the introduction of solids) appear to be the strongest determinants of the infant oral microbiome. In the present review, we draw together data on the maternal, infant, and environmental factors linked to the composition of the infant oral microbiome, with a focus on early nutrition. Given evidence that breastfeeding powerfully shapes the infant oral microbiome, the review explores potential mechanisms through which human milk components, including microbes, metabolites, oligosaccharides, and antimicrobial proteins, may interact with and shape the infant oral microbiome. Infancy is a unique period for the oral microbiome. By enhancing our understanding of oral microbiome assembly in early life, we may better support both oral and systemic health throughout the lifespan.