Insights into the interaction and inhibitory action of palmatine on lysozyme fibrillogenesis: Spectroscopic and computational studies.

Interaction under amyloidogenic condition between naturally occurring protoberberine alkaloid palmatine and hen egg white lysozyme was executed by adopting spectrofluorometric and theoretical molecular docking and dynamic simulation analysis. In spetrofluorometric method, different types of experiments were performed to explore the overall mode and mechanism of interaction. Intrinsic fluorescence quenching of lysozyme (Trp residues) by palmatine showed effective binding interaction and also yielded different binding parameters like binding constant, quenching constant and number of binding sites. Synchronous fluorescence quenching and 3D fluorescence map revealed that palmatine was able to change the microenvironment of the interacting site. Fluorescence life time measurements strongly suggested that this interaction was basically static in nature. Molecular docking result matched with fluorimetric experimental data. Efficient drug like interaction of palmatine with lysozyme at low pH and high salt concentration prompted us to analyze its antifibrillation potential. Different assays and microscopic techniques were employed for detailed analysis of lysozyme amyloidosis.Thioflavin T(ThT) assay, Congo Red (CR) assay, 8-anilino-1-naphthalenesulfonic acid (ANS) assay, Nile Red (NR) assay, anisotropy and intrinsic fluorescence measurements confirmed that palmatine successfully retarded and reduced lysozyme fibrillation. Dynamic light scattering (DLS) and atomic force microscopy (AFM) further reiterated the excellent antiamyloidogenic potency of palmatine.

Antibacterial activity of lysozyme after association with carboxymethyl konjac glucomannan.

The unique high isoelectric point of lysozyme (LYZ) restricts its application in composite antibacterial coating due to the unfavorable liability to electrostatic interaction with other components. In this work, the antibacterial activity of a dispersible LYZ-carboxymethyl konjac glucomannan (CMKGM) polyelectrolyte complex was evaluated. Kinetic analysis revealed that, compared with free LYZ, the complexed enzyme exhibited decreased affinity (Km) but markedly increased Vmax against Micrococcus lysodeikticus, and QCM and dynamic light scattering analysis confirmed that the complex could bind with the substrate but in a much lower ratio. The complexation with CMKGM did not alter the antibacterial spectrum of LYZ, and the complex exerted antibacterial function by delaying the logarithmic growth phase and impairing the cell integrity of Staphylococcus aureus. Since the LYZ-CMKGM complex is dispersible in water and could be assembled easily, it has great potential as an edible coating in food preservation.

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.

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.

A CTL - Lys immune function maintains insect metamorphosis by preventing gut bacterial dysbiosis and limiting opportunistic infections.

BACKGROUND: Gut bacteria are beneficial to the host, many of which must be passed on to host offspring. During metamorphosis, the midgut of holometabolous insects undergoes histolysis and remodeling, and thus risks losing gut bacteria. Strategies employed by holometabolous insects to minimize this risk are obscure. How gut bacteria affect host insects after entering the hemocoel and causing opportunistic infections remains largely elusive. RESULTS: We used holometabolous Helicoverpa armigera as a model and found low Lactobacillus load, high level of a C-type lectin (CTL) gene CD209 antigen-like protein 2 (CD209) and its downstream lysozyme 1 (Lys1) in the midgut of the wandering stage. CD209 or Lys1 depletion increased the load of midgut Lactobacillus, which further translocate to the hemocoel. In particular, CD209 or Lys1 depletion, injection of Lactobacillus plantarum, or translocation of midgut L. plantarum into the hemocoel suppressed 20-hydroxyecdysone (20E) signaling and delayed pupariation. Injection of L. plantarum decreased triacylglycerol and cholesterol storage, which may result in insufficient energy and 20E available for pupariation. Further, Lysine-type peptidoglycan, the major component of gram-positive bacterial cell wall, contributed to delayed pupariation and decreased levels of triacylglycerols, cholesterols, and 20E, in both H. armigera and Drosophila melanogaster. CONCLUSIONS: A mechanism by which (Lactobacillus-induced) opportunistic infections delay insect metamorphosis was found, namely by disturbing the homeostasis of lipid metabolism and reducing 20E production. Moreover, the immune function of CTL - Lys was characterized for insect metamorphosis by maintaining gut homeostasis and limiting the opportunistic infections.

Milk Bioactive Compounds and Gut Microbiota Modulation: The Role of Whey Proteins and Milk Oligosaccharides.

A strong correlation between the occurrence of various pathological conditions and intestinal dysbiosis is supported by a range of strong evidence. Vice versa, many pathologies have been shown, in turn, to be responsible for alterations in the gut microbiota, a condition that can worsen illness outcomes and response to therapies. For these reasons, great efforts have been made, and studies are still ongoing, to elucidate the mechanisms underlying gut microbiota alterations and to search for pharmacologic or other strategies that can effectively restore the gut microbiota. In this narrative review, we examined the most significant literature on the role of some milk bioactive compounds, such as milk oligosaccharides and whey proteins, in modulating the composition of the gut microbiota and the underlying mechanisms of action, with the aim of investigating the impact of the microbiota changes mediated by these milk bioactive molecules on human health, and their potential use as therapeutics to treat or adjuvate the treatment of gut dysbiosis and associated pathologies.

Investigating the toxic mechanism of iron oxide nanoparticles-induced oxidative stress in tadpole (Duttaphrynus melanostictus): A combined biochemical and molecular study.

Metal oxide nanomaterials have toxicity towards aquatic organisms, especially microbes and invertebrates, but little is known about their impact on amphibians. We conducted a study on Duttaphrynus melanostictus (D. melanostictus) tadpoles to explore the chronic toxicity effects of iron oxide nanoparticles (IONPs) and the underlying mechanisms of IONPs-induced oxidative stress. IONPs exposure led to increased iron accumulation in the blood, liver, and kidneys of tadpoles, significantly affecting blood parameters and morphology. Higher IONPs concentrations (10 and 50 mg L-1) triggered reactive oxygen species generation, resulting in lipid peroxidation, oxidative stress, and pronounced toxicity in tadpoles. The activity levels of antioxidant enzymes/proteins (SOD, CAT, albumin, and lysozyme) decreased after IONPs exposure, and immunological measures in the blood serum were significantly reduced compared to the control group. Molecular docking analysis revealed that IONPs primarily attached to the surface of SOD/CAT/albumin/lysozyme through hydrogen bonding and hydrophobic forces. Overall, this study emphasizes the ability of IONPs to induce oxidative damage by decreasing immunological profiles such as ACH50 (34.58 ± 2.74 U mL-1), lysozyme (6.94 ± 0.82 U mL-1), total Ig (5.00 ± 0.35 g dL-1), total protein (1.20 ± 0.17 g dL-1), albumin (0.52 ± 0.01 g dL-1) and globulin (0.96 ± 0.01 g dL-1) and sheds light on their potential toxic effects on tadpoles.

Antimicrobial properties of triazolato terpyridine Pd(II) and Pt(II) complexes formed by [3+2] cycloaddition coupling reaction.

Modern classes of antimicrobials are crucial because most drugs in development today are basically antibiotic derivatives. Even though a large number of metal-based compounds have been studied as antimicrobial agents, relatively few studies have examined the antimicrobial properties of Pd(II) and Pt(II) compounds. The [3+2] cycloaddition reactions of [M(N3)L]PF6 (M = Pd(II) and Pt(II); L = 4'-(2-pyridyl)-2,2':6',2″-terpyridine) with 4,4,4-trifluoro-2-butynoic acid ethyl ester gave the corresponding triazolate complexes. The reaction products were fully characterized with a variety of analytical and spectroscopic tools including X-ray crystallographic analysis. The crystal structure of [Pd(triazolatoCF3,COOCH2CH3)L]PF6 provided cut-off evidence that the kinetically formed N1-triazolato isomer favoured the isomerization to the thermodynamically stable N2-analogue. The experimental work was complemented with computational work to get an insight into the nature of the predominant triazolate isomer. The lysozyme binding affinity of the triazolate complexes was examined by mass spectrometry. An analysis of the lysozyme Pd(II) adducts suggests a coordinative covalent mode of binding via the loss of the triazolato ligand. The free ligand and its triazolate complexes displayed selective toxicity against Candida albicans and Cryptococcus neoformans, while no cytotoxicity was observed against the normal human embryonic kidney cell line.

Bifunctional MNPs@UIO-66-Arg core-shell-satellite nanocomposites for enrichment of phosphopeptides.

A facile and mild method based on self-assembled lysozyme (LYZ) to fabricate bifunctional MNPs@UIO-66-Arg core-shell-satellite nanocomposites (CSSNCs) is reported for the high-efficiency enrichment of phosphopeptides. Under physiological conditions, LYZ rapidly self-assembled into a robust coating on Fe3O4@SiO2 magnetic nanoparticles (MNPs) with abundant surface functional groups, which effectively mediate heterogeneous nucleation and growth of UIO-66 nanocrystals. Well-defined MNPs@UIO-66 CSSNCs with stacked pores, showing high specific surface area (333.65 m2 g- 1) and low mass transfer resistance, were successfully fabricated by fine-tuning of the reaction conditions including reaction time and acetic acid content. Furthermore, the UIO-66 shells were further modified with arginine to obtain bifunctional MNPs@UIO-66-Arg CSSNCs. Thanks to the unique morphology and synergistic effect of Zr-O clusters and guanidine groups, the bifunctional MNPs@UIO-66-Arg CSSNCs exhibited outstanding enrichment performance for phosphopeptides, delivering a low limit of detection (0.1 fmol), high selectivity (ß-casein/BSA, mass ratio 1:2000), and good capture capacity (120 mg g- 1). The mechanism for phosphopeptides capture may attribute to the hydrogen bonds, electrostatic interactions, and Zr-O-P bonds between phosphate groups in peptides and guanidyl/Zr-O clusters on bifunctional MNPs@UIO-66-Arg CSSNCs. In addition, the small stacking pores on the core-shell-satellite architecture may selectively capture phosphopeptides with low molecular weight, eliminating interference of other large molecular proteins in complex biological samples.

A rare case of lysozyme-induced anaphylaxis in a child with egg allergy.

We report an unusual case of anaphylaxis induced by the lysozyme-containing over-the-counter-drug Lysopaine®, which contains 20 mg lysozyme hydrochloride and 1.5 mg cetylpyridinium chloride, in a 9-year-old child with allergy to hen's egg as well as multiple IgE-mediated food allergies. The involvement of lysozyme was confirmed by positive skin prick tests for Lysopaine® and the presence of specific IgE against lysozyme. Our case highlights the importance of properly educating allergic patients to recognize allergens, even minor ones. Despite the presence of lysozyme in various food and drug products, it is not necessarily perceived as an allergenic protein by patients with egg allergy, and the labeling may be misleading, thereby exposing patients to potentially severe reactions.

Biophysical insight into anti-amyloidogenic nature of novel ionic Co(II)(phen)(H2O)4]+[glycinate]- chemotherapeutic drug candidate against human lysozyme aggregation.

In the recent past, there has been an ever-increasing interest in the search for metal-based therapeutic drug candidates for protein misfolding disorders (PMDs) particularly neurodegenerative disorders such as Alzheimer's, Parkinson's, Prion's diseases, and amyotrophic lateral sclerosis. Also, different amyloidogenic variants of human lysozyme (HL) are involved in hereditary systemic amyloidosis. Metallo-therapeutic agents are extensively studied as antitumor agents, however, they are relatively unexplored for the treatment of non-neuropathic amyloidoses. In this work, inhibition potential of a novel ionic cobalt(II) therapeutic agent (CoTA) of the formulation [Co(phen)(H2O)4]+[glycinate]- is evaluated against HL fibrillation. Various biophysical techniques viz., dye-binding assays, dynamic light scattering (DLS), differential scanning calorimetry (DSC), electron microscopy, and molecular docking experiments validate the proposed mechanism of inhibition of HL fibrillation by CoTA. The experimental corroborative results of these studies reveal that CoTA can suppress and slow down HL fibrillation at physiological temperature and pH. DLS and 1-anilino-8-naphthalenesulfonate (ANS) assay show that reduced fibrillation in the presence of CoTA is marked by a significant decrease in the size and hydrophobicity of the aggregates. Fluorescence quenching and molecular docking results demonstrate that CoTA binds moderately to the aggregation-prone region of HL (Kb = 6.6 × 104 M-1), thereby, inhibiting HL fibrillation. In addition, far-UV CD and DSC show that binding of CoTA to HL does not cause any change in the stability of HL. More importantly, CoTA attenuates membrane damaging effects of HL aggregates against RBCs. This study identifies inorganic metal complexes as a therapeutic intervention for systemic amyloidosis.

Characteristics of hen egg white lysozyme, strategies to break through antibacterial limitation, and its application in food preservation: A review.

Hen egg white lysozyme (HEWL) is used as a food additive in China due to its outstanding antibacterial properties. It is listed as GRAS grade (generally recognized as safe) by the United States Food and Drug Administration (FDA, US) and has been extensively researched and used in food preservation. And the industrial production of HEWL already been realized. Given the complex food system that can affect the antibacterial activity of HEWL, and the limitations of HEWL itself on Gram-negative bacteria. Based on the structure and main biological characteristics of HEWL, this paper focuses on reviewing methods to enhance the stability and antibacterial properties of HEWL. Immobilization tactics such as chemically driven self-assembly, embedding and adsorption address the restriction of poor HEWL antibacterial activity effected by external factors. Both intermolecular and intramolecular modification strategies break the bactericidal deficiencies of HEWL itself. It also comprehensively analyzes the current application status and future prospects of HEWL in the food preservation. There was limited research on the biological methods in modifying HEWL. If the HEWL is genetically engineered, it can broaden its antimicrobial spectrum, improve its other biological activities, so as to further expand its application in the food industry. At present, research on HEWL mainly focused on its antibacterial properties, whereas its application in anti-inflammatory and antioxidant effects also presented great potential.

Controlled Release of Lysozyme Using Polyvinyl Alcohol-Based Polymeric Nanofibers Generated by Electrospinning.

Polymeric nanofibers generated via electrospinning offer a promising platform for drug delivery systems. This study examines the application of electrospun polyvinyl alcohol (PVA) nanofibers for controlled lysozyme (LZM) delivery. By using various PVA grades, such as the degree of polymerization/hydrolysis, this study investigates their influence on nanofiber morphology and drug-release characteristics. LZM-loaded PVA monolithic nanofibers having 50% drug content exhibit efficient entrapment, wherein rapid dissolution is achieved within 30 min. The initial burst of LZM from the nanofiber was reduced as the LZM content was lowered. The initial dissolution is greatly influenced by the choice of PVA grade used; fully hydrolyzed PVA nanofibers demonstrate controlled release due to the reduced water solubility of PVA. Furthermore, coaxial electrospinning, which creates core-shell nanofibers with polycaprolactone as a controlled release layer, enables sustained LZM release over an extended period. This study confirms a correlation between PVA characteristics and controlled drug release and provides valuable insights into tailoring nanofiber properties for pharmaceutical applications.

Diffusiophoresis of Macromolecules within the Framework of Multicomponent Diffusion.

Diffusiophoresis is the isothermal migration of a colloidal particle through a liquid caused by a cosolute concentration gradient. Although diffusiophoresis was originally introduced using hydrodynamics, it can also be described by employing the framework of multicomponent diffusion. This not only enables the extraction of diffusiophoresis coefficients from measured multicomponent-diffusion coefficients but also their theoretical interpretation using fundamental thermodynamic and transport parameters. This review discusses the connection of diffusiophoresis with the 2 × 2 diffusion-coefficient matrix of ternary liquid mixtures. Specifically, diffusiophoresis is linked to the cross-term diffusion coefficient characterizing diffusion of colloidal particles due to cosolute concentration gradient. The other cross-term, which describes cosolute diffusion due to the concentration gradient of colloidal particles, is denoted as osmotic diffusion. Representative experimental results on diffusiophoresis and osmotic diffusion for polyethylene glycol and lysozyme in the presence of aqueous salts and osmolytes are described. These data were extracted from ternary diffusion coefficients measured using precision Rayleigh interferometry at 25 °C. The preferential-hydration and electrophoretic mechanisms responsible for diffusiophoresis are examined. The connection of diffusiophoresis and osmotic diffusion to preferential-interaction coefficients, Onsager reciprocal relations, Donnan equilibrium and Nernst-Planck equations are also discussed.

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.

Probing the toxic effect of chlorpyrifos as an environmental pollutant on the structure and biological activity of lysozyme under physiological conditions.

The pervasive use of pesticides like chlorpyrifos (CPY) has been associated with deleterious effects on biomolecules, posing significant risks to environmental integrity, public health, and overall ecosystem equilibrium. Accordingly, in this study, we investigated the potential binding interaction between the well-conserved enzyme, lysozyme (LSZ), and CPY through various spectroscopic techniques and molecular modeling. The UV-vis absorption and fluorescence experiments confirmed the complex formation and static quenching of the intrinsic fluorescence intensity. LSZ revealed a singular binding site for CPY, with binding constants around 105 M-1 across different temperature ranges. Analysis of thermodynamic parameters showed the spontaneous nature of the complexation process, while also revealing the pivotal role of hydrophobic interactions in stabilizing the LSZ-CPY system. According to circular dichroism and Fourier transform infrared studies, CPY binding changed the secondary structure of LSZ by boosting α-helix presence and reducing the levels of ß-sheet and ß-turn content. Further, CPY decreased the stability and activity of LSZ. Computational docking delineated the specific and highly preferred binding site of CPY within the structure of LSZ. Molecular dynamic simulation indicated the enduring stability of the LSZ/CPY complex and revealed structural modifications in the LSZ after binding with CPY. This research provides a detailed understanding of the intermolecular dynamics between CPY and LSZ, concurrently elucidating the molecular-level implications for the potential hazards of pesticides in the natural environment.

[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.

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.

From phyllosphere to insect cuticles: silkworms gather antifungal bacteria from mulberry leaves to battle fungal parasite attacks.

BACKGROUND: Bacterial transfers from plants to insect herbivore guts have been well investigated. However, bacterial exchanges between plant phyllospheres and insect cuticles remain unclear, as does their related biological function. RESULTS: Here, we report that the cuticular bacterial loads of silkworm larvae quickly increased after molting and feeding on the white mulberry (Morus alba) leaves. The isolation and examination of silkworm cuticular bacteria identified one bacterium Mammaliicoccus sciuri that could completely inhibit the spore germination of fungal entomopathogens Metarhizium robertsii and Beauveria bassiana. Interestingly, Ma. sciuri was evident originally from mulberry leaves, which could produce a secreted chitinolytic lysozyme (termed Msp1) to damage fungal cell walls. In consistency, the deletion of Msp1 substantially impaired bacterial antifungal activity. Pretreating silkworm larvae with Ma. sciuri cells followed by fungal topical infections revealed that this bacterium could help defend silkworms against fungal infections. Unsurprisingly, the protective efficacy of ΔMsp1 was considerably reduced when compared with that of wild-type bacterium. Administration of bacterium-treated diets had no negative effect on silkworm development; instead, bacterial supplementation could protect the artificial diet from Aspergillus contamination. CONCLUSIONS: The results of this study evidence that the cross-kingdom transfer of bacteria from plant phyllospheres to insect herbivore cuticles can help protect insects against fungal parasite attacks. Video Abstract.

Lysozyme promotes renal fibrosis through the JAK/STAT3 signal pathway in diabetic nephropathy.

Introduction: Diabetic nephropathy (DN) is a leading cause of kidney failure. Lysozyme (LYZ) is an essential component of innate immunity and exhibits antibacterial properties. However, LYZ has been reported to induce nephropathy, implying a possible association between impaired renal function and lysozyme expression. Material and methods: Bioinformatics analysis was used to predict the hub gene associated with DN, and the differential expression of the hub gene was confirmed using a mouse model. A mouse model of streptozotocin (STZ)-induced diabetic nephropathy was established to investigate the correlation between DN and LYZ expression, and the functionality of LYZ was verified through knockdown and overexpression experiments conducted in vivo. Immunohistochemistry (IHC) was utilized to assess fibrosis-related markers and cytokines, while Masson staining was performed to assess renal fibrosis. Fibroblast proliferation was assessed using the Cell Counting Kit-8 (CCK-8) assay. The role of the JAK pathway was confirmed using the JAK inhibitor AG490, and Western blot was used to investigate the underlying mechanisms. Results: Mechanistically, 25 mM glucose promotes the expression of LYZ in fibroblastic cells, and LYZ may in turn promote the proliferation of renal interstitial fibroblasts. Western blot shows that glucose can activate STAT3 in an LYZ-dependent manner, and the JAK inhibitor AG490 can partially suppress LYZ-induced STAT3 activation. Furthermore, in vivo observations have revealed that overexpression of LYZ is associated with the senescent phenotype of renal tubular epithelial cells (RTECs). Conclusions: Lysozyme promotes kidney fibrosis via the JAK/STAT3 signaling pathway in diabetic nephropathy, and glucose may promote fibroblast proliferation by promoting LYZ auto-secretion.