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Publication
Journal: Applied Spectroscopy
October/14/2012
Abstract
The interaction of lysozyme (Lyz)-conjugated silver (Ag) nanoparticles with (-)-epigallocatechin gallate (EGCG), one of the major components of green tea, has been investigated. Interaction of a protein with ligand/drug molecules perturbs the conformation of secondary and tertiary structures of the protein. We have demonstrated the conformational changes in the tertiary structures of the Lyz molecules on EGCG binding using surface-enhanced Raman scattering (SERS) and circular dichroism (CD) spectroscopic measurements. From the analysis of the amide I band of Lyz in SERS and CD spectra, the site of interaction of EGCG with protein molecules in Lyz-conjugated Ag particles has been identified. Spectroscopic evidence for the conformational response of Trp62 and Trp63, in the β-domain of the protein, to the binding of EGCG has been discussed.
Publication
Journal: Inorganic Chemistry
November/7/2017
Abstract
This study presents an implementation of the protein-ligand docking program GOLD and a generalizable method to predict the binding site and orientation of potential vanadium drugs. Particularly, theoretical methods were applied to the study of the interaction of two VIVO complexes with antidiabetic activity, [VIVO(pic)2(H2O)] and [VIVO(ma)2(H2O)], where pic is picolinate and ma is maltolate, with lysozyme (Lyz) for which electron paramagnetic resonance spectroscopy suggests the binding of the moieties VO(pic)2 and VO(ma)2 through a carboxylate group of an amino acid residue (Asp or Glu). The work is divided in three parts: (1) the generation of a new series of parameters in GOLD program for vanadium compounds and the validation of the method on five X-ray structures of VIVO and VV species bound to proteins; (2) the prediction of the binding site and enantiomeric preference of [VO(pic)2(H2O)] to lysozyme, for which the X-ray diffraction analysis displays the interaction of a unique isomer (i.e., OC-6-23-Δ) through Asp52 residue, and the subsequent refinement of the results with quantum mechanics/molecular mechanics methods; (3) the application of the same approach to the interaction of [VO(ma)2(H2O)] with lysozyme. The results show that convenient implementation of protein-ligand docking programs allows for satisfactorily reproducing X-ray structures of metal complexes that interact with only one coordination site with proteins and predicting with blind procedures relevant low-energy binding modes. The results also demonstrate that the combination of docking methods with spectroscopic data could represent a new tool to predict (metal complex)-protein interactions and have a general applicability in this field, including for paramagnetic species.
Publication
Journal: Biosensors
December/29/2020
Abstract
Herein we report the electropolymerization of a scopoletin based molecularly imprinted polymer (MIP) for the detection of lysozyme (Lyz), an enzymatic marker of several diseases in mammalian species. Two different approaches have been used for the imprinting of lysozyme based, respectively, on the use of a monomer-template mixture and on the covalent immobilization of the enzyme prior to polymer synthesis. In the latter case, a multi-step protocol has been exploited with preliminary functionalization of gold electrode with amino groups, via 4-aminothiophenol, followed by reaction with glutaraldehyde, to provide a suitable linker for lysozyme. Each step of surface electrode modification has been followed by cyclic voltammetry and electrochemical impedance spectroscopy, which has been also employed to test the electrochemical responses of the developed MIP. The sensors show good selectivity to Lyz and detect the enzyme at concentrations up to 292 mg/L (20 μM), but with different performances, depending on the used imprinting approach. An imprinting factor equal to 7.1 and 2.5 and a limit of detection of 0.9 mg/L (62 nM) and 2.1 mg/L (141 nM) have been estimated for MIPs prepared with and without enzyme immobilization, respectively. Competitive rebinding experiment results show that this sensing material is selective for Lyz determination. Tests were performed using synthetic saliva to evaluate the potential application of the sensors in real matrices for clinical purposes.
Keywords: MIP electropolymerization; MIP for protein; electrochemical sensors; impedimetric detection; lysozyme imprinting; polyscopletin.
Publication
Journal: Reproduction, Fertility and Development
August/22/2017
Abstract
Persistent mating-induced endometritis (PMIE) severely decreases fertility in horses. The aim of the present study was to evaluate differences between horses susceptible to PMIE and a control group in terms of the expression of selected immune response and effector genes, and the effects of oestrous cycle stage on this expression. Endometrial biopsies from 18 uterine samples of mares in the control group (eight in dioestrus, 10 in oestrus) and 16 PMIE-susceptible mares (four in dioestrus, 12 in oestrus) were analysed by quantitative real-time reverse transcription-polymerase chain reaction. Genes for pathogen recognition receptors Toll-like receptor 2 (TLR2) and NLR family CARD domain containing 5 (NLRC5), as well as tissue-specific inhibitor of metalloproteinase 1 (TIMP1), C-X-C motif chemokine ligand (CXCL) 9, CXCL10 and CXCL11 and uteroferrin were expressed at similar levels in the control group and in susceptible mares. Genes for C-C motif chemokine ligand 2 (CCL2) and the antimicrobial peptides secreted phospholipase A2 (sPLA2), lipocalin 2 and lactoferrin were all expressed at higher levels in susceptible compared with control mares. The expression of genes for the antimicrobial peptides equine β-defensin 1 (EBD1), lysozyme (LYZ) and secretory leukoprotease inhibitor (SLPI) was also higher in susceptible than control mares. The diagnostic sensitivity of assays for EBD1, LYZ and SLP1 gene expression to detect susceptibility to PMIE was estimated to be 100%, 94% and 100% respectively, with specificities of 83%, 78% and 78% respectively. When all three tests were positive, the specificity increased to 94%, with an overall sensitivity of 94%. The present study has yielded insights into pathophysiological changes in mares susceptible to PMIE and identified robust diagnostic markers (EBD1, LYZ and SLPI) for susceptibility to this disease.
Publication
Journal: CNS Neuroscience and Therapeutics
November/22/2020
Abstract
Aims: To identify transcriptome signatures underlying epileptogenesis in temporal lobe epilepsy (TLE).
Methods: Robust rank aggregation analysis was used to integrate multiple microarrays in rodent models of TLE and determine differentially expressed genes (DEGs) in acute, latent, and chronic stages. Functional annotation and protein-protein interaction analysis were performed to explore the potential functions of the DEGs and identify hub genes with the highest intramodular connectivity. The association between hub genes and hippocampal sclerosis/seizure frequency was analyzed using publicly available RNA-sequencing datasets from TLE patients. We subsequently established a pilocarpine-induced status epilepticus (SE) model in rats and validated mRNA expression of hub genes by quantitative reverse transcription PCR (qRT-PCR).
Results: The DEGs in the acute, latent, and chronic phases of TLE in animal models were prominently enriched in inflammatory response. Hub genes identified in the acute phase mainly participated in biological processes including inflammation, blood-brain barrier damage, and cell adhesion. The hub genes in the latent phase were related to microglia/macrophage activation (Emr1 and Aif1) and phagocytosis (Cd68, Tyrobp, and Lyz). In the chronic phase, the hub genes were associated with activation of complements and microglia/macrophages. We further found that some hub genes identified in human TLE, such as Tlr2, Lgals3, and Stat3, were positively correlated with seizure frequency. Other hub genes, including Lgals3 and Serpine1, were associated with hippocampus sclerosis. qRT-PCR analysis confirmed that the mRNA levels of hub genes in rat hippocampus were significantly up-regulated after SE induction.
Conclusions: Our integrated analysis identified hub genes in different stages of epilepsy. The functional annotations suggest that the activation and phagocytic activities of microglia/macrophages may play critical roles in epileptogenesis of TLE.
Keywords: epileptogenesis; microarray; robust rank aggregation; temporal lobe epilepsy.
Publication
Journal: Nanoscale
November/3/2016
Abstract
Mesoporous silica nano-channel (MCM-41) based molecular switching of a biologically important anticancer drug, namely, ellipticine (EPT) has been utilized to probe its efficient loading onto MCM-41, and its subsequent release to intra-cellular biomolecules, like DNA. By exploiting various spectroscopic techniques (like, steady state fluorescence, time-resolved fluorescence and circular dichroism), it has been shown that EPT can be easily translocated from MCM-41 to DNA without using any external stimulant. Blue emission of EPT in a polar aprotic solvent, i.e., dichloromethane (DCM), completely switches to green upon loading inside MCM-41 due to the conversion from a neutral to a protonated form of the drug inside nano-pores. Powder X-ray diffraction (PXRD), N2 gas adsorption and confocal fluorescence microscopy results confirm the adsorption of EPT inside the nano-pores of MCM-41. Here, the lysozyme (Lyz) protein has been utilized as a pore blocker of MCM-41 in order to prevent premature drug release. Interestingly, EPT is released to DNA even from the EPT-MCM-Lyz composite system, and results in intensification of green fluorescence. Electron microscopy results reveal the formation of a distinctive garland kind of morphology involving MCM-41 and DNA probably through non-covalent interactions, and this is believed to be responsible for the DNA assisted release of drug molecules from silica nano-pores. Confocal laser scanning microscopy (CLSM) imaging revealed that EPT-MCM is successfully internalized into the HeLa cervical cancer cells and localized into the nucleus. Cell viability assay results infer that EPT-MCM and EPT-MCM-Lyz showed much improved efficacy in HeLa cancer cells compared to free ellipticine.
Publication
Journal: International Journal of Biological Macromolecules
October/13/2017
Abstract
Co-aggregation plays an important role in processing protein-rich food materials under heterogeneous conditions. The main cause of co-aggregation is an electrostatic attraction between oppositely charged molecules. This study investigated thermal aggregation of β-lactoglobulin (BLG) (pI=5.1) and lysozyme (LYZ) (pI=10.7) as a model for the heterogeneous conditions of a protein solution. BLG and LYZ were more aggregated in the mixture than in the single solutions. Co-aggregation of the BLG-LYZ mixture was not observed below 60°C at which temperature BLG and LYZ retained their native structures. Adding sugars, salts, or amino acids to the BLG-LYZ mixture during the heat treatment revealed the co-aggregation process as follows. (i) All additives tested suppressed both the nucleation and growth of aggregates. (ii) Salts affected nucleation stage to the same degree, except arginine hydrochloride (Arg). (iii) Arg specifically suppressed both nucleation and growth of aggregates. These results indicate that co-aggregation in a protein mixture is more sensitive to the partial unfolding of proteins than that in a single protein solution, due to the presence of electrostatic attraction between different molecules. These results provide new insight into protein aggregation as well as the molecular mechanism of additives under heterogeneous conditions.
Publication
Journal: Investigative Ophthalmology and Visual Science
June/17/2021
Abstract
Purpose: For this study we aimed to understand if retinal pigment epithelial (RPE) cells express antimicrobial peptide lysozyme as a mechanism to protect the neuroretina from blood-borne pathogens.
Methods: The expression of lysozyme in human and mouse RPE cells was examined by RT-PCR or immune (cyto)histochemistry in cell cultures or retinal sections. RPE cultures were treated with different concentrations of Pam3CSK4, lipopolysaccharides (LPS), staphylococcus aureus-derived peptidoglycan (PGN-SA), Poly(I:C), and Poly(dA:dT). The mRNA expression of lysozyme was examined by qPCR and protein expression by ELISA. Poly(I:C) was injected into the subretinal space of C57BL/6J mice and eyes were collected 24 hours later and processed for the evaluation of lysozyme expression by confocal microscopy. Bactericidal activity was measured in ARPE19 cells following LYZ gene deletion using Crispr/Cas9 technology.
Results: The mRNA and protein of lysozyme were detected in mouse and human RPE cells under normal conditions, although the expression levels were lower than mouse microglia BV2 or human monocytes THP-1 cells, respectively. Immunohistochemistry showed punctate lysozyme expression inside RPE cells. Lysozyme was detected by ELISA in normal RPE lysates, and in live bacteria-treated RPE supernatants. Treatment of RPE cells with Pam3CSK4, LPS, PGN-SA, and Poly(I:C) enhanced lysozyme expression. CRISPR/Cas9 deletion of lysozyme impaired bactericidal activity of ARPE19 cells and reduced their response to LPS and Poly(I:C) stimulation.
Conclusions: RPE cells constitutively express antimicrobial peptide lysozyme and the expression is modulated by pathogenic challenges. RPE cells may protect the neuroretina from blood-borne pathogens by producing antimicrobial peptides, such as lysozyme.
Publication
Journal: Journal of Dairy Science
May/13/2021
Abstract
The newborn gut undergoes rapid colonization by commensal microorganisms and possible exposure to pathogens. The contribution of colostrum intake to host protection is well known; however, limited research exists on the intestinal innate immunity corresponding to colostrum intake during the passive immune transfer period in newborn ruminants. The aim of this study was to investigate the changes in bacterial community and expression of genes encoding toll-like receptors (TLR), mucins (MUC), antimicrobial peptides, and tight junctions in the jejunum of lambs that were fed colostrum during the first 24 h of life. Twenty-seven newborn lambs were used in this study, of which 18 lambs were bottle-fed pooled bovine colostrum within the first 2 h after birth to obtain an intake of approximately 8% of body weight. Lambs were slaughtered at 12 (n = 9) and 24 h (n = 9) after birth. The remaining 9 lambs without any feeding were slaughtered at 30 min after birth (0 h). Tissue and ligated segment samples from the jejunum were collected immediately after the lambs were slaughtered. The bacterial profile in the ligated jejunum segment was assessed using amplicon sequencing. The gene expression in the jejunum tissue was determined using quantitative real-time PCR. The relative abundances of Escherichia-Shigella, Lactobacillus, Lactococcus, and Streptococcus increased, whereas those of Sphingomonas, Phyllobacterium, Bradyrhizobium, and Rudaea decreased during the first 24 h of life. Expression of TLR2 and β-defensin 109-like was upregulated at 12 h after birth (P < 0.05), but a recovery was detected at 24 h; TLR3, TLR5, LYZ, MUC1, MUC13, MUC20, and CLDN7 showed a higher expression level in samples taken at 24 h than in those taken at 0 h. In addition, expression level of CLDN1, CLDN4, and the junctional adhesion molecule-1 tended to be higher at 24 h than at 0 h after birth. Correlation analysis indicated that TLR2 expression was negatively correlated with the relative abundance of Lactobacillus and Bradyrhizobium, whereas TLR5 expression was positively correlated with the relative abundance of Escherichia-Shigella and Pelagibacterium. These results suggest that TLR, MUC, antimicrobial peptides, and CLDN act together and play an important role in intestinal defense during the passive immune transfer period. They are potentially associated with microbial colonization. The findings from this study provide novel information to elucidate the role of colostrum components in regulating the development of the intestinal mucosal immune barrier in newborn lambs during the passive immune transfer period.
Keywords: bovine colostrum; mucin; tight junction; toll-like receptor.
Authors
Publication
Journal: Fish and Shellfish Immunology
December/12/2019
Abstract
Nocardia seriolae, a Gram-positive pathogen, has been identified as the causative agent of fish nocardiosis. DNA vaccination has been proven to be effective in conferring protection against bacterial infection in fish. The 30S ribosomal protein S1 (RpsA) and 50S ribosomal protein L7/L12 (RplL) were identified to be the common immunodominant antigens of three fish pathogenic Nocardia (N. seriolae, N. salmonicida and N. asteroids) by immunoproteomics profiling in our previous study. In current study, the immunogenicity and protective efficacy of two DNA vaccines encoding RplL and RpsA were evaluated and compared in hybrid snakehead. The results showed vaccination of hybrid snakehead with the pcDNA-RplL and pcDNA-RpsA DNA vaccines provided protective efficacy with relative percentage survival (RPS) of 78.31% and 71.08%, respectively. Meanwhile, the immune response of hybrid snakehead induced by these two DNA vaccines were investigated, and it revealed that the non-specific immunity parameters (serum lysozyme (LYZ), peroxidase (POD), acid phosphatase (ACP), alkaline phosphatase (AKP) and superoxide dismutase (SOD) activities), specific antibody (IgM) production and immune-related genes expression (MHCIα, MHCIIα, CD4, CD8α, IL-1β and TNFα) were significantly increased compared with the corresponding control groups after immunization. Taken together, these results indicated that both pcDNA-RplL and pcDNA-RpsA DNA vaccines could boost the innate, humoral and cellular immune responses in hybrid snakehead and show highly protective efficacy against fish nocardiosis, suggesting that ribosomal proteins RplL and RpsA were promising candidates for DNA vaccines and it will promote the vaccine development against fish nocardiosis.
Publication
Journal: Journal of Chromatography A
February/12/2019
Abstract
In this paper, we have developed a novel method for the preparation of covalently connected capillary coatings in which diazotized poly (vinyl alcohol-b-styrene) (diazo-P(VA-b-St)) was used as a photosensitive coating agent. Firstly, the diazo-P(VA-b-St) coating was self-assembled on the inner surface of the capillary, and then irradiated by ultraviolet (UV) light to convert the ionic bonding into covalent bonding through the unique photochemical reaction of diazo groups. The covalently connected coatings inhibited the protein adsorption on the inner surface of the capillary, as a result, the baseline protein separation of ribonuclease A (RNase A), lysozyme (Lyz) and bovine serum albumin (BSA) were attained by utilizing the capillary electrophoresis (CE). The covalently connected diazo-P(VA-b-St) capillary coatings have greater CE separation performance with magnificent repeatability and enhanced stability, when compared with non-covalently coated or bare capillaries. This strategy to synthesize photosensitive diazo-P(VA-b-St) capillary coatings for their use in capillary electrophoresis separation of proteins is highly environment-friendly as it does not involve the use of extremely noxious and moisture penetrating coatings of silane.
Publication
Journal: Fish Physiology and Biochemistry
March/5/2020
Abstract
Effects of dietary Lactobacillus plantarum (KC426951) on growth and innate responses of Nile tilapia Oreochromis niloticus were evaluated in biofloc technology system and stagnant-renewal culture system (SRCS). The 90-day-long experiment contained four treatments: SRCS without probiotic (T1), SRCS with probiotic (T2), biofloc without probiotic (T3), and biofloc with probiotic (T4). The administration dose of probiotic was 2 × 108 CFU kg-1 diet. At the end of experiment, the mean final weights, specific growth rates, feed conversion ratios, and total biomass were significantly (P < 0.05) better in BFT treatments, with no significant effect of probiotic on these parameters in both culture systems. Meanwhile, skin mucosal parameters including total protein (TP), lysozyme (LYZ), alkaline phosphatase (ALP), and protease (PRO) activity were significantly enhanced following probiotic supplementation. T4 treatment displayed a significantly higher LYZ and ALP activity in mucus versus other treatments. Also, serum alternative complement activity was significantly heightened in probiotic-supplemented fish. Superoxide dismutase activity in T4 was detected higher than that of SRCS groups. The results of the current study demonstrated the enhancement of some mucosal and serum innate responses of Nile tilapia in both culture systems upon L. plantarum (KC426951) supplementation.
Publication
Journal: Bioelectrochemistry
April/9/2021
Abstract
A novel, sensitive and selective electrochemical sensor based on epitope-imprinted polydopamine (PDA) was developed for ovalbumin (OVA) detection. Molecularly imprinted polydopamine was synthesized on an AuNP-coated screen-printed carbon electrode (SPCE) via electropolymerization in the presence of OVA IgE-binding epitope as the template. Key process parameters including template concentration, electropolymerization cycle, pH, time required for template removal and rebinding were optimized. Electrochemical detection of OVA was performed by differential pulse voltammetry (DPV) in 5 mM K3Fe(CN)6 and 0.1 M KCl as the supporting electrolyte. Under optimized conditions, the sensor demonstrated excellent sensitivity toward OVA with linear range from 23.25 to 232.50 nM (1 to 10 ppm), limit of detection (LOD) of 10.76 nM (0.46 ppm), and limit of quantification (LOQ) of 35.87 nM (1.54 ppm). The sensor also exhibited good selectivity against other proteins such as human serum albumin (HSA), bovine serum albumin (BSA), and lysozyme (LYZ). OVA in wine samples was detected with RSD of 5.63-10.82%, and recovery percentage of 104.74-105.96%. The developed method can be easily adapted to detect other allergic proteins in the food supply chain.
Keywords: Epitope imprinting; Gold nanoparticles; Ovalbumin; Polydopamine; Screen printed carbon electrode.
Publication
Journal: Colloids and Surfaces B: Biointerfaces
August/18/2015
Abstract
A new strategy for synthesis of superparamagnetic molecularly imprinted polymer nanospheres (MIPNSs) for efficient protein recognition is described here. Homogeneous hydroxyl group functionalized Fe3O4/polymethyl methacrylate (PMMA) composite nanospheres were prepared using improved miniemulsion polymerization. Uniform superparamagnetic MIPNSs were obtained via self-polymerization of dopamine (DA) on the surface of Fe3O4/PMMA composite nanospheres in the presence of lysozyme (lyz) template. The as-synthesized Fe3O4/PMMA/PDA MIPNSs had average diameters of 180 nm, high saturation magnetization and a good magnetic response. The lyz-imprinted Fe3O4/PMMA/PDA MIPNSs exhibited specific recognition and efficient adsorption capacity toward lyz template. The amount of lyz adsorbed onto the lyz-imprinted Fe3O4/PMMA/PDA MIPNSs was about 4 times greater than that of the Fe3O4/PMMA/PDA non-imprinted polymer nanospheres (NIPNSs) and about 14, 5, and 5 times greater than that of BSA, BHb, and cyt C, respectively.
Publication
Journal: Frontiers in Immunology
November/12/2018
Abstract
Trauma combined with hemorrhagic shock (HS/T) leads to systemic inflammation, which results in organ injury. Toll-like Receptor 4 (TLR4)-signaling activation contributes to the initiation of inflammatory pathways following HS/T but its cell-specific roles in this setting are not known. We assessed the importance of TLR4 on leukocytes of myeloid lineage and dendritic cells (DCs) to the early systemic inflammatory response following HS/T. Mice were subjected to HS/T and 20 inflammatory mediators were measured in plasma followed by Dynamic Bayesian Network (DBN) Analysis. Organ damage was assessed by histology and plasma ALT levels. The role of TLR4 was determined using TLR4-/-, MyD88-/-, and Trif-/- C57BL/6 (B6) mice, and by in vivo administration of a TLR4-specific neutralizing monoclonal antibody (mAb). The contribution of TLR4 expressed by myeloid leukocytes and DC was determined by generating cell-specific TLR4-/- B6 mice, including Lyz-Cre × TLR4loxP/loxP, and CD11c-Cre × TLR4loxP/loxP B6 mice. Adoptive transfer of bone marrow-derived TLR4+/+ or TLR4-/- DC into TLR4-/- mice confirmed the contribution of TLR4 on DC to the systemic inflammatory response after HS/T. Using both global knockout mice and the TLR4-blocking mAb 1A6 we established a central role for TLR4 in driving systemic inflammation. Using cell-selective TLR4-/- B6 mice, we found that TLR4 expression on both myeloid cells and CD11chigh DC is required for increases in systemic cytokine levels and organ damage after HS/T. We confirmed the capacity of TLR4 on CD11chigh DC to promote inflammation and liver damage using adoptive transfer of TLR4+/+ conventional (CD11chigh) DC into TLR4-/- mice. DBN inference identified CXC chemokines as proximal drivers of dynamic changes in the circulating levels of cytokines/chemokines after HS/T. TLR4 on DC was found to contribute selectively to the elevations in these proximal drivers. TLR4 on both myeloid cells and conventional DC is required for the initial systemic inflammation and organ damage in a mouse model of HS/T. This includes a role for TLR4 on DC in promoting increases in the early inflammatory networks identified in HS/T. These data establish DC along with macrophages as essential to the recognition of tissue damage and stress following tissue trauma with HS.
Publication
Journal: Analytical Chemistry
January/7/2021
Abstract
Proteins are utilized across many biomedical and pharmaceutical industries; therefore, methods for rapid and accurate monitoring of protein aggregation are needed to ensure proper product quality. Although these processes have been previously studied, it is difficult to comprehensively evaluate protein folding and aggregation by traditional characterization techniques such as atomic force microscopy (AFM), electron microscopy, or X-ray diffraction, which require sample pre-treatment and do not represent native state proteins in solution. Herein, we report early tracking of lysozyme (Lyz) aggregation states by using single-particle collision electrochemistry (SPCE) of silver nanoparticle (AgNP) redox probes. The method relies on monitoring the rapid interaction of Lyz with AgNPs, which decreases the number of single AgNPs available for collisions and ultimately the frequency of oxidative impacts in the chronoamperometric profile. When Lyz is in a non-aggregated monomeric form, the protein forms a homogeneous coverage onto the surface of AgNPs, stabilizing the particles. When Lyz is aggregated, part of the AgNP surface remains uncoated, promoting the agglomeration of Lyz-AgNP conjugates. The frequency of AgNP impacts decreases with increasing aggregation time, providing a metric to track protein aggregation. Visualizations of integrated oxidation charge-transfer data displayed significant differences between the charge transfer per impact for AgNP samples alone and in the presence of non-aggregated and aggregated Lyz with 99% confidence using parametric ANOVA tests. Electrochemical results revealed meaningful associations with UV-vis, circular dichroism, and AFM, demonstrating that SPCE can be used as an alternative method for studying protein aggregation. This electrochemical technique could serve as a powerful tool to indirectly evaluate protein stability and screen protein samples for formation of aggregates.
Publication
Journal: Fish and Shellfish Immunology
December/3/2018
Abstract
Skin ulceration syndrome in sea cucumbers is an infectious bacterial disease with fast and high mortality. This study investigated the protection of chicken egg yolk antibodies (IgY) on skin ulcer syndrome in sea cucumbers induced by intraperitoneally injecting Shewanella marisflavi AP629. Inactivated whole S. marisflavi AP629 cells were used as an immunogen to immunize laying hens. The highest titer of the obtained specific IgY by ELISA was 1:90000. Specific IgY significantly inhibited the growth of S. marisflavi AP629 in a liquid medium, dose-dependent manner at concentrations ranging from 0.5 to 2 mg/mL. Results obtained from scanning electron microscopy and confocal laser scanning microscopy showed that specific IgY could make bacteria agglutinate and damage the cell membrane of S. marisflavi AP629, resulting in a decrease of bacterial viability. Sea cucumbers treated with 25, 5, and 1 mg/mL anti-S. marisflavi AP629 IgY could achieve survival rates of 77.5%, 50%, and 22.5% at day 12 when the infection and injection therapy were carried out at the same time, respectively. However, survival rates of sea cucumbers treated with 25 mg/mL of nonspecific IgY were only 7.5% at day 12. All sea cucumbers in the positive control group died within twelve days after bacterial inoculation. Levels of the five humoral immune factors (LYZ, ACP, NOS, SOD, CAT) released by coelomocytes were significantly increased in the specific IgY group compared to the nonspecific IgY and positive control groups within 12 h. However, the activities of LYZ, ACP, and SOD decreased rapidly at the 48 h time point in the specific IgY group, indicating that specific IgY treatment could shorten the time needed to restore balance in sea cucumber immune systems. Oral prophylaxis with egg yolk powders was that all sea cucumbers were challenged with 4.2 × 106 CFU S. marisflavi AP629 by intraperitoneal injection after 60 days of feeding. Survival rates of diets containing 10%, 5%, and 1% specific egg yolk powder were 57.5%, 52.5%, and 30% by day 12, respectively, and the survival rate was 27.5% for the nonspecific group and 22.5% for the positive control group. After feeding for 60 days, enzyme activities of LZY, NOS, and SOD were all significantly enhanced in sea cucumbers fed with specific egg yolk powder when compared to the control group (p < 0.05). This study demonstrated that the phagocytic activities of coelomocytes were significantly stimulated after specific IgY treatment over that of nonspecific IgY or without IgY treatments in sea cucumbers (p < 0.05). Overall, our results revealed that anti-S. marisflavi AP629 IgY has a positive immunomodulatory effect on sea cucumbers infected with S. marisflavi AP629.
Publication
Journal: Comparative Biochemistry and Physiology Part - C: Toxicology and Pharmacology
January/20/2020
Abstract
Bisphenol A (BPA) is a well-known phenolic environmental estrogen, widely distributed in the aquatic environment, which poses a toxic risk to the health of aquatic organisms. This study aimed to assess the effect of BPA on common carp gills by analyzing oxidative stress, ion equilibrium and immune response. Fish were exposed to five concentrations of BPA (0, 0.01, 0.1, 0.5, and 2 mg/L) for 30 days. Then gills were collected to assay biochemical parameters and gene expression. The results showed that BPA could decrease the levels of total antioxidant capacity (T-AOC), catalase (CAT), glutathione (GSH) and glutathione S-transferase (GST) and increase the levels of superoxide dismutase (SOD), malondialdehyde (MDA) and 8-hydroxy-2 deoxyguanosine (8-OHdG). The gene expression showed that BPA (2 mg/L) could affect the nuclear erythroid 2-related factor 2 (nrf2) signaling pathway, upregulate the gene expression of nrf2 and heme oxygenase 1 (ho-1). Meanwhile, BPA was found to change the activity of Na+/K+ ATPase, and increased the concentrations of Na+ and Ca2+ in gills of common carp. Also, high BPA concentration (0.5 or 2 mg/L) exposure increased the activity of alkaline phosphatase (AKP), blocked mRNA level of lysozyme-c (c-lyz), activated Toll-like receptors (TLRs) signaling pathway, enhanced the mRNA levels of toll-like receptor 2 (tlr2), receptor 4 (tlr4), myeloid differentiation factor 88 (myd88), interferon regulatory factor 3 (irf3), interleukin 1β (il-1β), interleukin 6 (il-6) and interleukin 10 (il-10). Overall, these results suggested that high BPA could induce oxidative damage, ion imbalance, immunosuppression and inflammatory response in gills of common carp.
Publication
Journal: Biological Trace Element Research
September/11/2017
Abstract
The current study was conducted to investigate the effect of zinc supplementation on the growth performance, intestinal morphology, and the transcription of the barrier function related genes in Pekin ducks. Seven-hundred and sixty-eight 1-day-old Pekin ducks were randomly assigned into six dietary treatments. Each treatment had eight replicates with 16 ducks per replicates. The ducks were fed either a corn-soybean meal basal diet or basal diets supplemented with 15, 30, 60, 120, and 240 mg zinc/kg from zinc sulfate. This experiment lasted for 5 weeks, and the jejunum sample were harvested at 14 and 35 days of age. Results have shown that diets supplemented with zinc significantly increased the duck body weight, average daily gain, and average daily feed intake in different period of experiment (P < 0.05); feed to gain ratio was decreased as the zinc level increased (P < 0.05). Zinc supplementation increased the villus height and decreased the crypt depth in jejunum of ducks (P < 0.05) at 14 and 35 days of age. The transcription of tight junction protein CLDN1, OCND, ZO-1, and ZO-3 in jejunum were increased (P < 0.05), and the messenger RNA (mRNA) levels of leak protein CLDN2 were decreased as the dietary zinc level increased (P < 0.05) at 14 and 35 days of age. The mRNA levels of chemical barrier-related genes MUC2 and TFF-2 in jejunum at 14 and 35 days of age were increased (P < 0.05) by zinc supplementation, and so did the transcription of immunological barrier-related genes lgA, pIgR, LYZ, and AvBD2 (P < 0.05). In conclusion, dietary zinc supplementation exhibited growth-promoting effect on Pekin duck, improved intestinal morphology, and enhanced the intestinal barrier integrity.
Publication
Journal: Archives of Oral Biology
June/5/2021
Abstract
Objective: To determine the antibacterial effects of different saliva-substitutes-containing-lysozyme(LYZ) or-lactoferrin(LF) on Streptococcus mutans(S. mutans) in comparison with human saliva.
Design: In vitro wound-healing assay was performed with L929 mouse fibroblast cell line by using various concentrations of LYZ and LF to determine optimum concentrations and to confirm do not show any cytotoxicity of proteins according to cell culture studies. Antibacterial effect was assessed by determining Minimum Inhibitory Concentrations for all groups on S.mutans. Bacterial adhesion of S. mutans for 4 h on hydroxyapatite(HAP) discs after application of different saliva substitutes was evaluated. The formulations were:saliva-substitute(Group SS);saliva-substitute-containing-Lactoferrin(Group SSLF);saliva-substitute-containing-Lysozyme(Group SSLYZ). Human saliva was control group(Group HS).
Results: In vitro wound healing assay results showed that, when added into the cell culture media, LYZ and LF significantly increase 48 -h scratch wound closure compared to the cell culture media(p < 0.0001). At the end of second day, samples treated with both between 2.5-100 μg/mL LF and 5-200 μg/mL LYZ were found to have significant wound healing effect(p < 001). It was observed that saliva-substitutes-containing-LYZ or-LF had antibacterial effects on S.mutans. Bacterial adhesion on HAP discs was observed significantly higher in control group than in study groups. The amount of adhered S. mutans was significantly higher in Group SS than other study groups(p < 0.0001). However, no statistically significant difference was found between the number of bacteria adhered to HAP discs between SSLYZ and SSLF groups(p > 0.05).
Conclusions: The study of cell viability and wound healing was great significance in the optimum concentrations of LYZ and LF. Among formulations, saliva-substitutes-containing-LYZ or-LF exhibited higher inhibitory effect on S.mutans.
Keywords: Lactoferrin; Lysozyme; S. mutans; Saliva substitute; Wound healing.
Publication
Journal: Fish and Shellfish Immunology
February/7/2021
Abstract
The present study was carried out to investigate the effects of different levels of dietary bovine lactoferrin (BLF) or chitosan nanoparticles (CHN) alone or in combinations on the serum biochemical indices, antioxidative capacity, transcriptomic responses, immunity, and resistance of Nile tilapia (Oreochromis niloticus) against challenge with Aeromonas hydrophila. Fish were fed on the basal diet with no supplements and served as control (CTR), and six experimental diets containing different levels of BLF (800 and 1200 mg per kg diet), CHN (500 and 1000 mg per kg diet), and combinations of both (400 mg BLF plus 250 mg CHN per kg diet, and 600 mg BLF plus 500 mg CHN per kg diet) for 45 days. At the end of the experiment, serum, and tissue specimens (liver and kidney) were collected, and finally, fish in all groups were challenged with A. hydrophila and observed for another ten days for determination of the RPS. Compared to the CTR group, no significant differences were recorded in the TP, ALB, GLO, BUN, and CREAT values among all treatments. Serum LYZ, ALT, AST, and ALP enzyme activities were significantly increased in all experimental groups over the CTR (P < 0.05), and their highest values were recorded in the combined treatments. Moreover, dietary supplementation with CHN (1000 mg/kg) and combined treatments significantly increased the SOD, CAT, and GSH-Px enzyme activities compared with other groups (P < 0.05). Similarly, the highest mRNA expression levels of IGF-1 gene in liver, and IL-1β, and IFN-γ genes in kidneys were recorded in CHN (1000 mg/kg) and combined treatments more than other experimental groups. Interestingly, no, or mild histopathological alterations were noticed in the hepatopancreas and posterior kidney of the treated groups. A significantly higher RPS was identified in the combined treatments challenged with A. hydrophila compared with the CTR group. This study exemplifies the positive impacts of dietary supplementation with BLF or CHN alone or combinations on the antioxidative status, immunity, and disease resistance of Nile tilapia.
Keywords: Antioxidant enzymes; Bovine lactoferrin; Chitosan nanoparticles; Disease resistance; Nile tilapia.
Publication
Journal: Frontiers in Physiology
October/11/2020
Abstract
Atrial fibrillation (AF), known as the most common arrhythmia in the developed world, affects 1.5-2.0% of the population. Numerous basic studies have been carried out to identify the roles of electric and structural remodeling in the pathophysiological changes of AF, but more explorations are required to further understand the mechanisms of AF development. Proteomics enables researchers to identify protein alterations responsible for the pathological developing progresses of diseases. Compared to the genome, the proteome is closely related to the disease phenotype and can better manifest the progression of diseases. In this study, AF patients proteomically analyzed to identify possible mechanisms. Totally 20 patients undergoing cardiac surgery (10 with paroxysmal AF and 10 with persistent AF) and 10 healthy subjects were recruited. The differentially expressed proteins identified here included AKR1A1, LYZ, H2AFY, DDAH1, FGA, FGB, LAMB1, LAMC1, MYL2, MYBPC3, MYL5, MYH10, HNRNPU, DKK3, COPS7A, YWHAQ, and PAICS. These proteins were mainly involved in the development of structural remodeling. The differently expressed proteins may provide a new perspective for the pathological process of AF, and may enable useful targets for drug interference. Nevertheless, more research in terms of multi-omics is required to investigate possible implicated molecular pathways of AF development.
Keywords: atrial fibrillation; mechanism; proteins; proteomics; structural remodeling.
Publication
Journal: PLoS ONE
January/7/2020
Abstract
Mesenteric fat is a visceral fat depot that increases with cattle maturity and can be influenced by diet. There may be a relationship between the accumulation of mesenteric fat and feed efficiency in beef cattle. The purpose of this study was to identify genes that may be differentially expressed in steers with high and low BW gain and feed intake. RNA-Seq was used to evaluate the transcript abundance of genes in the mesenteric fat from a total of 78 steers collected over 5 different cohorts. A meta-analysis was used to identify genes involved with gain, feed intake or the interaction of both phenotypes. The interaction analysis identified 11 genes as differentially expressed. For the main effect of gain, a total of 87 differentially expressed genes (DEG) were identified (PADJ<0.05), and 24 were identified in the analysis for feed intake. Genes identified for gain were involved in functions and pathways including lipid metabolism, stress response/protein folding, cell proliferation/growth, axon guidance and inflammation. The genes for feed intake did not cluster into pathways, but some of the DEG for intake had functions related to inflammation, immunity, and/or signal transduction (JCHAIN, RIPK1, LY86, SPP1, LYZ, CD5, CD53, SRPX, and NF2). At PADJ<0.1, only 4 genes (OLFML3, LOC100300716, MRPL15, and PUS10) were identified as differentially expressed in two or more cohorts, highlighting the importance of evaluating the transcriptome of more than one group of animals and incorporating a meta-analysis. This meta-analysis has produced many mesenteric fat DEG that may be contributing to gain and feed intake in cattle.
Publication
Journal: Environmental Science & Technology
August/20/2018
Abstract
We investigated the relationship between silica scaling and protein fouling in reverse osmosis (RO). Flux decline caused by combined scaling and fouling was compared with those by individual scaling or fouling. Bovine serum albumin (BSA) and lysozyme (LYZ), two proteins with opposite charges at typical feedwater pH, were used as model protein foulants. Our results demonstrate that water flux decline was synergistically enhanced when silica and protein were both present in the feedwater. For example, flux decline after 500 min was far greater in combined silica scaling and BSA fouling experiments (55 ± 6% decline) than those caused by silica (11 ± 2% decline) or BSA (9 ± 1% decline) alone. Similar behavior was observed with silica and LYZ, suggesting that this synergistic effect was independent of protein charge. Membrane characterization by scanning electron microscopy and Fourier transform infrared spectroscopy revealed distinct foulant layers formed by BSA and LYZ in the presence of silica. A combination of dynamic light scattering, transmission electron microscopy , and energy dispersive X-ray spectroscopy analyses further suggested that BSA and LYZ facilitated the formation of aggregates with varied chemical compositions. As a result, BSA and LYZ were likely to play different roles in enhancing flux decline in combined scaling and fouling. Our study suggests that the coexistence of organic foulants, such as proteins, largely alters scaling behavior of silica, and that accurate prediction of RO performance requires careful consideration of foulant-scalant interactions.
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