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This study aimed to increase the antifungal and insecticidal activities of NaD1, as an antimicrobial peptides (AMP), by improving its interaction with the fungal cell wall and chitin monomeric units in insect midguts. Hence, the chitin-binding domains (CBDs) of wheat germ agglutinin protein (WGA) were fused to either N- or C-terminus of NaD1 generating transgenic Nicotiana tabacum hairy roots (HRs). Molecular assessments confirmed the integration of NaD1 transgenes, their transcription and production of recombinant peptides in the HR lines. Total protein of (CBD)4-NaD1 and NaD1-(CBD)4 transgenic lines inhibited the growth of Pyricularia oryzae mycelium, suggesting that fusion of CBD to NaD1 can increase NaD1 half-life, leading to higher affinity toward cell wall chitin. Furthermore, feeding the third-instar larvae of Chilo suppressalis with both (CBD)4-NaD1 and NaD1-(CBD)4 extracts exhibited a higher mortality rate. Both NaD1-CBDs caused a significant decrease in trypsin (TRY) and chymotrypsin (CTR) activities in the larvae, while enhancing the activity of antioxidant enzymes CAT, POD, APX, and SOD. Therefore, feeding the larvae by total extract of NaD1-(CBD)4 and (CBD)4-NaD1 HR lines probably increased affinity to midgut chitin in C. suppressalis, enhancing insecticidal activities. Overall, the results indicate that recombinant peptides are effective in enhancing fungal and insect resistance. [ABSTRACT FROM AUTHOR]

Parsley is a commonly cultivated Apiaceae species of culinary and medicinal importance. Parsley has several recognized health benefits and the species has been utilized in traditional medicine since ancient times. Although parsley is among the most commonly cultivated members of Apiaceae, no systematic genomic research has been conducted on parsley. In the present work, parsley genome was sequenced using the long-read HiFi (high fidelity) sequencing technology and a draft contig assembly of 1.57 Gb that represents 80.9% of the estimated genome size was produced. The assembly was highly repeat-rich with a repetitive DNA content of 81%. The assembly was phased into a primary and alternate assembly in order to minimize redundant contigs. Scaffolds were constructed with the primary assembly contigs, which were used for the identification of AMP (antimicrobial peptide) genes. Characteristic AMP domains and 3D structures were used to detect and verify antimicrobial peptides. As a result, 23 genes (PcAMP1-23) representing defensin, snakin, thionin, lipid transfer protein and vicilin-like AMP classes were identified. Bioinformatic analyses for the characterization of peptide physicochemical properties indicated that parsley AMPs are extracellular peptides, therefore, plausibly exert their antimicrobial effects through the most commonly described AMP action mechanism of membrane attack. AMPs are attracting increasing attention since they display their fast antimicrobial effects in small doses on both plant and animal pathogens with a significantly reduced risk of resistance development. Therefore, identification and characterization of AMPs is important for their incorporation into plant disease management protocols as well as medicinal research for the treatment of multi-drug resistant infections. [ABSTRACT FROM AUTHOR]

Ticks are obligate hematophagous arthropods that transmit a wide range of pathogens to humans as well as wild and domestic animals. They also harbor a non-pathogenic microbiota, although our previous study has shown that the diverse bacterial microbiome in the midgut of Ixodes ricinus is quantitatively poor and lacks a core. In artificial infections by capillary feeding of ticks with two model bacteria (Gram-positive Micrococcus luteus and Gram-negative Pantoea sp.), rapid clearance of these microbes from the midgut was observed, indicating the presence of active immune mechanisms in this organ. In the current study, RNAseq analysis was performed on the midgut of I. ricinus females inoculated with either M. luteus or Pantoea sp. or with sterile water as a control. While no immune-related transcripts were upregulated by microbial inoculation compared to that of the sterile control, capillary feeding itself triggered dramatic transcriptional changes in the tick midgut. Manual curation of the transcriptome from the midgut of unfed I. ricinus females, complemented by the proteomic analysis, revealed the presence of several constitutively expressed putative antimicrobial peptides (AMPs) that are independent of microbial stimulation and are referred to here as 'guard' AMPs. These included two types of midgut-specific defensins, two different domesticated amidase effector 2 (Dae2), microplusin/ricinusin-related molecules, two lysozymes, and two gamma interferon-inducible lysosomal thiol reductases (GILTs). The in vitro antimicrobial activity assays of two synthetic mature defensins, defensin 1 and defensin 8, confirmed their specificity against Gram-positive bacteria showing exceptional potency to inhibit the growth of M. luteus at nanomolar concentrations. The antimicrobial activity of midgut defensins is likely part of a multicomponent system responsible for the rapid clearance of bacteria in the tick midgut. Further studies are needed to evaluate the role of other identified 'guard' AMPs in controlling microorganisms entering the tick midgut. [ABSTRACT FROM AUTHOR]

Background: The discovery of new prognostic biomarkers following spinal cord injury (SCI) is a rapidly growing field that could help uncover the underlying pathological mechanisms of SCI and aid in the development of new therapies. To date, this search has largely focused on the initial days after the lesion. However, during the subacute stage of SCI (weeks to months after the injury), there remains potential for sensorimotor recovery, and numerous secondary events develop in various organs. Additionally, the confounding effects of early interventions after the injury are less likely to interfere with the results. Methods: In this study, we conducted an untargeted proteomics analysis to identify biomarkers of recovery in blood serum samples during the subacute phase of SCI patients, comparing those with strong recovery to those with no recovery between 30 and 120 days. We analyzed the fraction of serum that is depleted of the most abundant proteins to unmask proteins that would otherwise go undetected. Linear models were used to identify peptides and proteins related to neurological recovery and we validated changes in some of these proteins using Enzyme-linked Immunosorbent Assay (ELISA). Results: Our findings reveal that differences in subacute recovery after SCI (from 30 to 120 days) are associated with an enrichment in proteins involved in inflammation, coagulation, and lipid metabolism. Technical validation using commercial ELISAs further confirms that high levels of SERPINE1 and ARHGAP35 are associated with strong neurological recovery, while high levels of CD300a and DEFA1 are associated with a lack of recovery. Conclusions: Our study identifies new candidates for biomarkers of neurological recovery and for novel therapeutic targets after SCI. [ABSTRACT FROM AUTHOR]

Patients with cirrhosis have intestinal barrier dysfunction but the role of the individual cell types in human small intestine is unclear. We performed single-nuclear RNA sequencing (snRNAseq) in the pinch biopsies of terminal ileum of four age-matched men [56 years, healthy control, compensated, early (ascites and lactulose use) and advanced decompensated cirrhosis (ascites and rifaximin use)]. Cell type proportions, differential gene expressions, cell-type specific pathway analysis using IPA, and cellular crosstalk dynamics were compared. Stem cells, enterocytes and Paneth cells were lowest in advanced decompensation. Immune cells like naive CD4 + T cells were lowest while ITGAE + cells were highest in advanced decompensation patients. MECOM had lowest expression in stem cells in advanced decompensation. Defensin and mucin sulfation gene (PAPSS2) which can stabilize the mucus barrier expression were lowest while IL1, IL6 and TNF-related genes were significantly upregulated in the enterocytes, goblet, and Paneth cells in decompensated subjects. IPA analysis showed higher inflammatory pathways in enterocytes, stem, goblet, and Paneth cells in decompensated patients. Cellular crosstalk analysis showed that desmosome, protease-activated receptors, and cadherin-catenin complex interactions were most perturbed in decompensated patients. In summary, the snRNAseq of the human terminal ileum in 4 subjects (1 control and three cirrhosis) identified multidimensional alteration in the intestinal barrier with lower stem cells and altered gene expression focused on inflammation, mucin sulfation and cell–cell interactions with cirrhosis decompensation. [ABSTRACT FROM AUTHOR]

Simple Summary: Olive mill waste-water (OMWW) is a liquid waste produced by the olive oil industry that has been recently regarded as a good source of polyphenols. Phenolic molecules are among the most active secondary molecules in the gut for their antioxidant, anti-inflammatory and antimicrobial effects. They may also contribute to positively changing the distribution of gut microbial species, but their effects have not been widely explored in pigs. The intestinal porcine epithelial cell line IPEC-J2 represents a good model for the study of innate immunity and inflammatory response in animal intestinal diseases and has already been used to investigate the effect of phytogenic feed additives on swine intestinal epithelium. This study aimed to evaluate the in vitro effects of an OMWW extract enriched in polyphenols on Salmonella typhimurium (S. typhimurium) infection in IPEC-J2 cells. Polyphenols extracted from OMWW showed the ability to regulate the host–pathogen interaction by decreasing S. typhimurium invasiveness and modulating the expression of many innate immune genes. The dietary supplementation of olive oil by-products, including olive mill waste-water (OMWW) in animal diets, is a novel application that allows for their re-utilization and recycling and could potentially decrease the use of antibiotics, antimicrobial resistance risk in livestock species, and the occurrence of intestinal diseases. Salmonella serovar typhimurium is one of the most widespread intestinal pathogens in the world, causing enterocolitis in pigs. The aim of this study was to investigate the effect of an OMWW extract enriched in polyphenols (hydroxytyrosol and tyrosol) in the immune response of an intestinal porcine epithelial cell line (IPEC-J2) following S. typhimurium infection. Cells were pre-treated with OMWW-extract polyphenols (OMWW-EP, 0.35 and 1.4 µg) for 24 h and then infected with S. typhimurium for 1 h. We evaluated bacterial invasiveness and assayed IPEC-J2 gene expression with RT-qPCR and cytokine release with an ELISA test. The obtained results showed that OMWW-EP (1.4 µg) significantly reduced S. typhimurium invasiveness; 0.35 µg decreased the IPEC-J2 gene expression of IL1B, MYD88, DEFB1 and DEFB4A, while 1.4 µg down-regulated IL1B and DEFB4A and increased TGFB1. The cytokine content was unchanged in infected cells. This is the first study demonstrating the in vitro immunomodulatory and antimicrobial activity of OMWW extracts enriched in polyphenols, suggesting a protective role of OMWW polyphenols on the pig intestine and their potential application as feed supplements in farm animals such as pigs. [ABSTRACT FROM AUTHOR]

Termicin is an anti-fungal defensin that is disseminated from termite salivary glands. The peptide appears to be critical for the elimination with mutual grooming (allogrooming) of pathogenic spores (conidia) that have attached to the insect cuticle. There has been a recent selective sweep for an advantageous variant of this peptide in the subterranean termite Reticulitermes flavipes. We tested the anti-mycotic activity of a recombinant termicin corresponding with this variant against the conidia of different Metarhizium fungal isolates from soil close to foraging R. flavipes workers. Termicin was most effective against isolates that had previously been shown to elicit a relatively weak alarm response, as indicated by brief bouts of rapid longitudinal oscillatory movement (LOM). These isolates that elicited weak alarm were also the deadliest apparently because the survival of termites exposed to the fungus depends on a strong social immune response (LOMs and allogrooming). The selective pressure for a single termicin variant may have been driven by the most dangerous isolates that elicit a weak behavioral response. The correlation between termicin anti-fungal activity and LOM suggests that pathogen-associated molecular patterns that affect termite recognition of conidial contamination and the onset of elevated allogrooming also affect the vulnerability of conidia to the disruption of their cell membranes by termicin. [ABSTRACT FROM AUTHOR]

This study compares the use of antimicrobial peptides and cytokines in the diagnosis of individuals with adenomatous polyposis and other intestinal tumors. In this study 17 individuals with adenomatous polyposis and 80 patients with different forms of colorectal cancer were examined. An enzyme immunoassay was used to measure each patient's blood levels of IL-6, TNFα, and FABP. When compared to individuals with good-quality bowel tumors, patients with malignant bowel tumors had significantly higher levels of IL-6 and TNF-α on 4,5 and 3 occasions, respectively. A significant decrease in the FABP concentration is also observed in patients with malignant bone tumors on the related control. A notable rise in the number of persons with adenomatous polyposis with adenomatous polyposis, a significant increase in FABP was observed than with bowel tumors. Thus, all these markers can be used for early diagnosis and screening for bowel cancer. [ABSTRACT FROM AUTHOR]

Late spring frost is an important meteorological factor threatening the safe production of winter wheat in China. The young ear is the most vulnerable organ of the wheat plant to spring frost. To gain an insight into the mechanisms underpinning young wheat ears' tolerance to freezing, we performed a comparative proteome analysis of wheat varieties Xumai33 (XM33, freezing-sensitive) and Jimai22 (JM22, freezing-tolerant) under normal and freezing conditions using label-free quantitative proteomic techniques during the anther connective tissue formation phase (ACFP). Under freezing stress, 392 and 103 differently expressed proteins (DEPs) were identified in the young ears of XM33 and JM22, respectively, and among these, 30 proteins were common in both varieties. A functional characterization analysis revealed that these DEPs were associated with antioxidant capacity, cell wall modification, protein folding, dehydration response, and plant–pathogen interactions. The young ears of JM22 showed significantly higher expression levels of antioxidant enzymes, heat shock proteins, and dehydrin under normal conditions compared to those of XM33, which might help to prepare the young ears of JM22 for freezing stress. Our results lead to new insights into understanding the mechanisms in young wheat ears' response to freezing stress and provide pivotal potential candidate proteins required for improving young wheat ears' tolerance to spring frost. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Pesticide Science / Nongyaoxue Xuebao is the property of Chinese Journal of Pesticide Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Defensins and inflammation are innate immune barriers of the body against infectious pathogens. Searching for a compound that can inhibit infectious diseases by affecting human β‐defensin (HBD) and proinflammatory cytokines is the new trend in research to control bacterial infection. The aim of this study is to provide a natural compound, Filipendula glaberrima Nakai extract (FGE), which is able to induce the expression of an antimicrobial defensin as well as reduce inflammation. FGE induced the expression of HBD2 and HBD3 through activating both p38 and NF‐κB signaling pathways. Furthermore, FGE inhibited the expression of TNF‐α and IL‐6 via p38 and NF‐κB pathways in Staphylococcus aureus–stimulated THP1 cells. Injection of FGE alleviated cutaneous erythema and swelling caused by S. aureus injection in mice ears. Taken together, FGE could reduce bacterial infection by inducing the expression of defensin and anti‐inflammatory activity. [ABSTRACT FROM AUTHOR]

The objective of this work was to purify and evaluate the antifungal potential of peptides present in immature and ripe fruits of Capsicum chinense Jacq. (accession UENF 1706) on the medical importance yeasts. Initially the proteins of these seedless fruits were extracted, precipitated with ammonium sulfate at 70% saturation, followed by heating at 80 °C. Subsequently, the peptide-rich extract was fractionated by DEAE-Sepharose anion exchange. The whole process was monitored by tricine-SDS-PAGE. The results revealed that the fraction retained in anion exchange column, called D2, of immature and ripe fruits significantly inhibit the growth of Candida albicans and C. tropicalis yeasts. Due to the higher yield, the D2 fraction of immature fruits was selected for further purification by reverse phase chromatography on HPLC, where sixteen different fractions (H1-H16) were obtained and these were subjected to antifungal assay at 50 µg mL−1. Although almost all fractions tested had significant growth inhibition, the HI9 fraction inhibit 99% of the two yeasts tested. The effect of treatment with HI3, HI8, HI9, and HI14 fractions on the viability of yeast cells was analyzed due to their strong growth inhibition. We observed that only 50 μg mL−1 of the HI9 fraction is the lethal dose for 100% of the cells of C. albicans and C. tropicalis in the original assay. Although the HI9 fraction had a fungicidal effect on both tested yeasts, we only observed membrane permeabilization for C. tropicalis cells treated with 50 µg mL−1 of this fraction. Through mass spectrometry, we identified that the 6 kDa peptide band of HI9 fraction showed similarity with antimicrobial peptides belonging to the plant defensin family. [ABSTRACT FROM AUTHOR]

Insect has a highly developed innate immune system consisting of cellular and humoral responses. Antimicrobial peptides (AMPs) are the important components of the insect's humoral defense system and were first purified from the giant silk moth, Hyalophora cecropia L (Boman et al., 1980). For a variety of infections, they serve as the initial line of defense. AMPS are low molecular weight peptides and generally cationic in nature. Off late, the resistance of the pathogenic microbes towards established antibiotics have become a serious threat to global health. Over the years, an array of AMPs from natural sources has served as potent candidate against various infective agents viz. bacteria, fungi and viruses. These insect peptides not only exhibit antibacterial action by rupturing the microbial membrane but also prevent the development of drug resistance by microbes. Studies have shown AMPS to have synergistic effects with traditional antibiotics, providing an opportunity for combined therapy. Defensin, cecropins, drosocin, attacins, diptericins, ponericins, metchnikowins and melittin are a few classes of AMPs from insects that are currently isolated. However, the possibility of discovering new AMPs cannot be fully ruled out. Currently, 33 peptides are undergoing clinical trials, and 43% of the 77 AMPs are still in the preclinical stage (Makwana et al., 2023). Daptomycin and ovitavancin are two antibacterial lipopeptides that Food and Drug Administration has recently approved that are used for skin infection caused by bacteria. The present paper is an attempt to provide a comprehensive insight on antimicrobial peptides isolated from silk worm with reference to their structures, functions and possible mechanism of action. [ABSTRACT FROM AUTHOR]

Background and Objectives Discovery of antibiotics has been one of the important achievements of mankind in the field of infectious diseases, although after a short time, the phenomenon of antibiotic resistance was created. Nowadays, there is a need for an innovation in the control of microbial infections such as the use of antimicrobial peptides. These peptides are abundantly found in neutrophils and since leukoreduction filters are a valuable source of these cells, it has been studied as an available option Materials and Methods In this experimental study, leukoreduction filters was selected by easy non-probability sampling method. First, leukocytes were extracted from leukoreduction filters and then neutrophils were isolated. Defensin peptide was extracted after sonication of neutrophils and was purified by HPLC. Staphylococcus aureus bacteria was cultured and the amount of bacterial inoculation was determined and the minimum inhibitory concentration was measured by macrodilution method. Microbial inhibition halo diameter size of defensin was determined for the intended bacteria. Results Using defensin standard, purified defensin peak was collected and the minimum inhibitory concentration was determined as 2.5 μg/mL on Staphylococcus aureus by macrodilution method. Microbial inhibition halo diameter size was calculated as 9 mm Conclusions The treatment of infectious diseases has faced a challenge with the widespread emergence of drug resistance, and the use of new innovations is inevitable. Defensin as an antimicrobial peptide is a suitable option that is abundantly found in neutrophils obtained from leukoreduction filters and is suggested for research on new antimicrobial drugs. [ABSTRACT FROM AUTHOR]

THE ELEVATING worldwide threatening antibiotic resistance, without effective antimicrobials for the prevention and treatment of infections, has put human health at very high risk. Plant defensins are cysteine -rich small cationic peptides, whose tertiary structure is greatly stable due to the presence of disulfide bonds. They exhibit significant antimicrobial activities. The defensin cDNA was successfully obtained from the total RNA extracted from Phaseolus vulgaris L. (Cv. Paulista) young green leaves, the CDS was efficiently cloned into pJET1.2/blunt cloning vector, and then subcloned into the prokaryotic expression vector pGEX -4 T -1. To facilitate defensin peptide purification, the sequence fragment was fused in -frame with a GST tag. The pGEX -4 T -1 containing recombinant defensin (pGEX -4 T - 1 -Pv -Def) was transformed into the E. coli strain BL21. Glutathione affinity chromatography method of purification yielded 3.7mg/L of recombinant peptide. Western blotting was made using anti -glutathione - S - transferase (GST) antibodies, to detect the production of Pv -Def peptide (of ~ 4kDa) linked to the GST tag (~ 26kDa) of an approximate total molecular weight ~30 KDa. The Pv -Def peptide was successfully cleaved from the GST -tag. The Pv -Def induced growth inhibition of multi -drug resistant (MDR) bacterial culture Klebsiella spp, E. coli and Staphylococcus aureus and fungal culture Aspergillus flavus and MDR Candida albicans. [ABSTRACT FROM AUTHOR]

Copyright of Feed Research is the property of Editorial Board of Feed Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We investigated the antimicrobial components in cow milk at dry off and postpartum and their contribution in preventing new high SCC at quarter level. Milk samples from 72 quarters of 19 lactating cows were collected at last milking before dry off and at 7 d after parturition. Milk yield of each cow was recorded and SCC, IgG, IgA, lactoferrin, lingual antimicrobial peptide (LAP), and S100A7 concentrations in each quarter milk sample were measured. The postpartum milk yield was significantly higher than that at dry off. The IgG, IgA and lactoferrin concentrations in milk at dry off were significantly higher than those at postpartum, whereas the LAP concentration was lower. Quarters with SCC < 300 000 cells/ml at both dry off and postpartum were classified as persistent low SCC (PL) whereas those that rose above that same threshold postpartum were classified as new high SCC (NH). At dry off, IgG and LAP concentrations in milk were significantly higher in PL than in NH. These results suggest that high LAP concentrations during the dry period may contribute toward the prevention of new high SCC. [ABSTRACT FROM AUTHOR]

Insect proteins have been proposed for human and animal food production. Safeguarding the health status of insects in mass rearing allows to obtain high‐quality products and to avoid severe economic losses due to entomopathogens. Therefore, new strategies for preserving insect health must be implemented. Modulation of the insect immune system through the diet is one such strategy. We evaluated gene expression of two antimicrobial peptides (one defensin and one cecropin) in Hermetia illucens (L.) (Diptera: Stratiomyidae) reared on different diets. Analyses were performed on prepupae and 10‐day‐old larvae reared on cereal‐ and municipal organic waste‐based diets and on only prepupae reared on a cereal‐based diet supplemented with sunflower, corn, or soybean oil. The inclusion of sunflower oil at different points in the cereal‐based diet was also evaluated. Moreover, diet‐driven differences in the inhibitory activity of the hemolymph were tested against Escherichia coli DH5α and Micrococcus yunnanensis HI55 using diffusion assays in solid media. Results showed that a municipal organic waste‐based diet produced a significant overexpression of antimicrobial peptides only in prepupae. Inclusion of vegetable oils caused an upregulation of at least one peptide, except for the corn oil. Higher expression of both genes was observed when sunflower oil was added 5 days before pupation. All hemolymph samples showed an inhibitory activity against bacteria colonies. Our results suggest that municipal organic waste‐based diet and vegetable oil‐added diet may successfully impact the immune system of H. illucens. Such alternatives may also exist for other species of economic interest. [ABSTRACT FROM AUTHOR]

Background: Antimicrobial peptides (AMPs) are active molecules in the human innate immune system, that participate in host defense and regulate the inflammation process. Previous reports have confirmed that antimicrobial peptides play a critical role in carcinogenesis. Objective: The present study aimed to evaluate the correlations between plasma concentrations of AMPs and spectrophotometric parameters of skin color in patients with basal cell carcinoma and compare the results with those of healthy controls. Methods: The plasma concentrations of cathelicidin and beta-defensin-2 in 100 patients (50 with skin cancer and 50 healthy control subjects) were measured, and skin color parameters were tested using a DermaSpectrophotometer. Results: In patients with basal cell carcinoma, the concentrations of cathelicidin and beta-defensin-2 were significantly higher than those in healthy controls. In healthy control patients, when erythema increases, the levels of cathelicidin and beta-defensin-2 also increase. The direction of the relationship is opposite in people with basal cell carcinoma—the concentration of antimicrobial peptides decreases and the level of erythema increases. Conclusion: A significantly higher level of plasma concentrations of cathelicidin and HBD-2 are correspondent to the presence of basal cell carcinoma. Skin cancer modifies the relationship between intensity of skin erythema and the levels of cathelicidin and HBD-2. This can be related to inadequate immunological response in patients with skin cancers. New direction of research may be pioneered in searching for cytokine or mast cells disorders. [ABSTRACT FROM AUTHOR]

Plant defensins including Medicago Sativa defensin 1 (MsDef1) are cysteine-rich antifungal peptides which are known for potent broad-spectrum antifungal activity against bacterial or fungal pathogens of plants. The antimicrobial activities of these cationic defensins are attributed to their capacity to bind to cell membranes to create potentially structural defects tin the cell membranes to interact with intracellular target (s) and mediates cytotoxic effects. Our earlier work identified Glucosylceramide (GlcCer) of fungus F. graminearum as a potential target for biological activity. Multi-drug resistant (MDR) cancer cells overexpress GlcCer on the surface of plasma membrane. Hence, MsDef1 may have a potential to bind to GlcCer of MDR cancer cells to induce cell death. We have characterized the three-dimensional structure of MsDef1 and the solution dynamics using of 15N-labeled MsDef1 nuclear magnetic resonance (NMR) spectroscopy which showed that GlcCer binds MsDef1 at two specific sites on the peptide molecule. The ability of MsDef1 to permeate MDR cancer cells was demonstrated by measuring the release of apoptotic ceramide in drug resistant MCF-7R cells. It was also shown that MsDef1 activated dual cell death pathways ceramide and Apoptosis Stimulating Kinase ASK1 by disintegrating GlcCer and oxidizing tumor specific biomarker thioredoxin (Trx) respectively. As a result, MsDef1 sensitizes MDR cancer cells to evoke a better response from Doxorubicin, a front-line chemotherapy for triple negative breast cancer (TNBC) treatment. The combination of MsDef1 and Doxorubicin induced 5 to10-fold greater apoptosis in vitro MDR cells MDA-MB-231R compared to either MsDef1 or Doxorubicin alone. Confocal microscopy revealed that MsDef1 facilitates a) influx of Doxorubicin in MDR cancer cells, b) preferential uptake by MDR cells but not by normal fibroblasts and breast epithelial cells (MCF-10A). These results suggest that MsDef1 targets MDR cancer cells and may find utility as a neoadjuvant chemotherapy. Hence, the extension of antifungal properties of MsDef1 to cancer my result in addressing the MDR problems in cancer. [ABSTRACT FROM AUTHOR]

Background: The body and head lice of humans are conspecific, but only the body louse functions as a vector to transmit bacterial pathogens such as Bartonella quintana. Both louse subspecies have only two antimicrobial peptides, defensin 1 and defensin 2. Consequently, any differences in the molecular and functional properties of these two louse subspecies may be responsible for the differential vector competence between them. Methods: To elucidate the molecular basis of vector competence, we compared differences in the structural properties and transcription factor/microRNA binding sites of the two defensins in body and head lice. Antimicrobial activity spectra were also investigated using recombinant louse defensins expressed via baculovirus. Results: The full-length amino acid sequences of defensin 1 were identical in both subspecies, whereas the two amino acid residues in defensin 2 were different between the two subspecies. Recombinant louse defensins showed antimicrobial activities only against the representative Gram-positive Staphylococcus aureus but not against either Gram-negative Escherichia coli or the yeast Candida albicans. However, they did show considerable activity against B. quintana, with body louse defensin 2 being significantly less potent than head louse defensin 2. Regulatory sequence analysis revealed that the gene units of both defensin 1 and defensin 2 in body lice possess decreased numbers of transcription factor-binding sites but increased numbers of microRNA binding sites, suggesting relatively lower transcription activities of body louse defensins. Conclusions: The significantly lower antibacterial activities of defensin 2 along with the reduced probability of defensin expression in body lice likely contribute to the relaxed immune response to B. quintana proliferation and viability, resulting in higher vector competence of body lice compared to head lice. [ABSTRACT FROM AUTHOR]

Cryptdin-4 (crp4) is an enteric α-defensin derived from mice, and is a main mediator of immunity to oral infections and a determinant of the composition of the intestinal microbiota. Structurally, crp4 exists in two states: the oxidized form (crp4oxi), constrained by three invariant disulfide bonds, and the reduced form (crp4red) with six free thiol groups, both of which exist in the intestinal tract. In this study, the antibacterial mechanisms of crp4 in both forms under aerobic and anaerobic conditions were investigated using Escherichia coli (E. coli), an anaerobic facultative bacterium, as a model. Fluorescent dye studies revealed that both crp4oxi and crp4red exhibited antimicrobial activity against cells cultured under aerobic conditions via rapid membrane depolarization. Furthermore, the antioxidant treatment experiments suggested that only crp4oxi exhibited antimicrobial activity by the induction and accumulation of reactive oxygen species (ROS). However, under anaerobic culture conditions, the ability of both forms to disrupt the function of bacterial membranes decreased and activity was greatly reduced, but crp4red maintained some antimicrobial activity. This activity may be due to the inhibition of intracellular functions by DNA binding. Altogether, these data indicate that, according to its redox structure and the environmental redox conditions, crp4 could perform different antimicrobial activities via different mechanisms. [ABSTRACT FROM AUTHOR]

Purpose of Review: Defensin-polyproline–linked proteins are relevant allergens in Asteraceae pollen. Depending on their prevalence and amount in the pollen source, they are potent allergens, as shown for the major mugwort pollen allergen Art v 1. Only a few allergenic defensins have been identified in plant foods, such as peanut and celery. This review provides an overview of structural and immunological features, IgE cross-reactivity, and diagnostic and therapeutic options regarding allergenic defensins. Recent Findings: We present and critically review the allergenic relevance of pollen and food defensins. The recently identified Api g 7 from celeriac and other allergens potentially involved in Artemisia pollen-related food allergies are discussed and related to clinical severity and allergen stability. To specify Artemisia pollen-related food allergies, we propose the term "defensin-related food allergies" to account for defensin-polyproline–linked protein-associated food syndromes. Summary: There is increasing evidence that defensins are the causative molecules in several mugwort pollen-associated food allergies. A small number of studies have shown IgE cross-reactivity of Art v 1 with celeriac, horse chestnut, mango, and sunflower seed defensins, while the underlying allergenic molecule remains unknown in other mugwort pollen-associated food allergies. As these food allergies can cause severe allergic reactions, identification of allergenic food defensins and further clinical studies with larger patient cohorts are required. This will allow molecule-based allergy diagnosis and a better understanding of defensin-related food allergies to raise awareness of potentially severe food allergies due to primary sensitization to Artemisia pollen. [ABSTRACT FROM AUTHOR]

Silicon (Si) is known to protect plants from a variety of environmental and biological stressors. The mode of action for these Si responses is unclear. In this study, a family of 14 histidine-rich defensin genes (HRDs) in Nicotiana tabacum, previously described as Defensin 19-like were identified and induced following Si treatment. These genes formed the Nicotiana tabacum histidine-rich defensin 1 (NtHRD1) family. All but one of the NtHRD1 genes were induced in roots with Si treatment, with different members showing differential regulation in upper and lower roots. More than 60% of the NtHRD1 genes showed induced expression with Si treatment in leaves from the upper portion of the plant, while only two genes showed induced expression in lower leaves. Histidine-rich defensins are a newly described group of plant cis-defensins that may play roles in both antimicrobial activity and metal binding. Induction of these genes in N. tabacum following Si treatment could explain some of the beneficial properties of this nutrient. [ABSTRACT FROM AUTHOR]

Introduction: Production of different antimicrobial peptides (AMPs) is one of the insect's prominent defense strategies, regulated mainly by Toll and immune deficiency (IMD) humoral pathways. Here we focused mainly on two AMPs of Phlebotomus papatasi, vector of Leishmania major parasites, their association with the relish transcription factor and the effective participation on Leishmania infection. Methods and results: We further characterized the role of previously described gut-specific P. papatasi defensin (PpDef1) and identified the second defensin (PpDef2) expressed in various sand fly tissues. Using the RNAi-mediated gene silencing, we report that the silencing of PpDef1 gene or simultaneous silencing of both defensin genes (PpDef1 and PpDef2) resulted in increased parasite levels in the sand fly (detectable by PCR) and higher sand fly mortality. In addition, we knocked down relish, the sole transcription factor of the IMD pathway, to evaluate the association of the IMD pathway with AMPs expression in P. papatasi. We demonstrated that the relish gene knockdown reduced the expression of PpDef2 and attacin, another AMP abundantly expressed in the sand fly body. Conclusions: Altogether, our experiments show the importance of defensins in the sand fly response toward L. major and the role of the IMD pathway in regulating AMPs in P. papatasi. [ABSTRACT FROM AUTHOR]

Acute liver failure (ALF) is a rare and severe disease, which, despite continuous advances in medicine, is still characterized by high mortality (65-85%). Very often, a liver transplant is the only effective treatment for ALF. Despite the implementation of prophylactic vaccinations in the world, the viral background of ALF is still a problem and leads to many deaths. Depending on the cause of ALF, it is sometimes possible to reverse this condition with appropriate therapies, which is why the search for effective antiviral agents seems to be a very desirable direction of research. Defensins, which are our natural antimicrobial peptides, have a very high potential to be used as therapeutic agents for infectious liver diseases. Previous studies on the expression of human defensins have shown that increased expression of human α and β-defensins in HCV and HBV infections is associated with a better response to treatment. Unfortunately, conducting clinical trials for ALF is very difficult due to the severity of the disease and the low incidence, therefore animal models are important for the development of new therapeutic strategies. One of the best animal models that has real reference to research on acute liver failure (ALF) is rabbit hemorrhagic disease in rabbits caused by the Lagovirus europaeus virus. So far, there have been no studies on the potential of defensins in rabbits infected with Lagovirus europaeus virus. [ABSTRACT FROM AUTHOR]

Antibiotic-resistant pathogens have become a great universal health concern. Antimicrobial peptides (AMPs) are small amphipathic and cationic polypeptides with high therapeutic potential against various microorganisms containing drug-resistant strains. Two major groups of these peptides, which have antibacterial activity against Gram-positive and Gram-negative bacteria, antiviral activity, and even antifungal activity, are defensins and cathelicidins. Hybridization of various AMPs is an appropriate approach to achieving new fusion AMPs with high antibacterial activity but low cellular toxicity. In the current research, the amino-acid sequence of human cathelicidin LL-37 (2-31) and Human beta-defensin (hBD)-129 were combined, and the fusion protein was evaluated by bioinformatics tool. The designed AMP gene sequence was commercially synthesized and cloned in the pET-28a expression vector. The LL-37/hBD-129 fusion protein was expressed in E.coli BL21-gold (DE3). The expression of the recombinant protein was evaluated using the SDS-PAGE method. The LL37/hBD-129 was successfully expressed as a recombinant hybrid AMP in E.coli BL21-gold (DE3) strain. Purification of the expressed AMP was performed by Ni–NTA column affinity chromatography, and the purified AMP was validated using the Western blot technic. Finally, the antimicrobial activity of the fusion AMP against Staphylococcus aureus and Escherichia coli bacteria was assessed. Based on the in silico analysis and experimental evaluations, the fusion AMP showed a significant antimicrobial effect on E. coli and Staphylococcus aureus bacteria. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to define the antimicrobial peptide (AMP) expression pattern of the equine ocular surface and amniotic membrane using a targeted qPCR approach and 3'Tag‐sequencing. It will serve as a reference for future studies of ocular surface innate immunity and amniotic membrane therapies. Procedures: A targeted qPCR approach was used to investigate the presence of orthologs for three of the most highly expressed beta‐defensins (DEFB1, DEFB4B, and DEFB103A) of the human ocular surface and amniotic membrane in equine corneal epithelium, conjunctiva, and amniotic membrane. 3'Tag‐sequencing was performed on RNA from one sample of corneal epithelium, conjunctiva, and amniotic membrane to further characterize their AMP expression. Results: Equine corneal epithelium, conjunctiva, and amniotic membrane expressed DEFB1, DEFB4B, and DEFB103A. DEFB103A was expressed at the highest amounts in corneal epithelium, while DEFB4B was most highly expressed in conjunctiva and amniotic membrane. 3'Tag‐sequencing from all three tissues confirmed these findings and identified expression of five additional beta‐defensins, 11 alpha‐defensins and two cathelicidins, with the alpha‐defensins showing higher normalized read counts than the beta‐defensins. Conclusions: This study identified AMP expression in the equine cornea and conjunctiva, suggesting that they play a key role in the protection of the equine eye, similar to the human ocular surface. We also determined that equine amniotic membrane expresses a substantial number of AMPs suggesting it could potentiate an antimicrobial effect as a corneal graft material. Future studies will focus on defining the antimicrobial activity of these AMPs and determining their role in microbial keratitis. [ABSTRACT FROM AUTHOR]

Both defensin and inflammation are part of the human innate immune system that responds rapidly to pathogens. The combination of defensins with pro- or anti-inflammatory effects can be a potential research direction for the treatment of infection by pathogens. This study aimed to identify whether MSF (Miracle Synergy material made using Filipendula glaberrima), a probiotic lysate of Filipendula glaberrima extracts fermented with Lactiplantibacillus plantarum K8, activates the expression of human β-defensin (HBD2 and HBD3) to protect the host against pathogens and inhibit inflammation caused by S. aureus, in vitro with Western blot analysis, qRT-PCR and in vivo studies with a mouse model were used to evaluate the effects of MSF. The MSF treatment induced HBD2 and HBD3 expression via the p38 and NF-κB pathways. Furthermore, MSF treatment significantly reduced the expression of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-8), also through p38 and NF-κB in S. aureus-induced inflammatory condition. MSF treatment remarkably reduced erythema in mice ears caused by the injection of S. aureus, while K8 lysate treatment did not initiate a strong recovery. Taken together, MSF induced the expression of HBD2 and HDB3 and activated anti-inflammatory activity more than the probiotic lysates of L. plantarum K8. These findings show that MSF is a potential defensin inducer and anti-inflammatory agent. [ABSTRACT FROM AUTHOR]

Background: Immunoglobulin A (IgA) nephropathy is a disorder of the immune system affecting kidney function, and genome‐wide association studies (GWAS) have defined numerous loci with associated variation, all implicating components of innate or adaptive immunity. Among these, single nucleotide polymorphisms (SNPs) in a region including the multiallelic copy number variation (CNV) of DEFA1A3 are associated with IgA nephropathy in both European and Asian populations. At present, the precise factors underlying the observed associations at DEFA1A3 have not been defined, although the key alleles differ between Asian and European populations, and multiple independent factors may be involved even within a single population. Methods: In this study, we measured DEFA1A3 copy number in UK family trios with an offspring affected by IgA nephropathy, used the population distributions of joint SNP–CNV haplotypes to infer the likely segregation in trios, and applied transmission disequilibrium tests (TDT) to examine joint SNP–CNV haplotypes for over‐ or undertransmission into affected offspring from heterozygous parents. Results and Conclusions: We observed overtransmission of 3‐copy class 2 haplotypes (raw p = 0.029) and some evidence for under‐transmission of 3‐copy class 1 haplotypes (raw p = 0.051), although these apparent effects were not statistically significant after correction for testing of multiple haplotypes. [ABSTRACT FROM AUTHOR]

Antimicrobial peptides (AMP) are essential components of innate immunity with a broad range of antimicrobial activities against bacteria, viruses, and fungi. The aim of this study was to investigate AMP expression in the upper gastrointestinal tract in normal and pathological metabolic states in humans. Furthermore, we examined the correlation between vitamin D levels and AMP expression in the same cohort. Serum concentrations of 25-hydroxyvitamin D3 were measured, and mRNA expression of β-defensins HBD-1, -2, -3, -4, α-defensins HD-5 and -6 and cathelicidin in the upper gastrointestinal tract epithelia were determined by quantitative RT-PCR in 31 individuals (10 with type 2 diabetes, 10 with insulin resistance, and 11 healthy controls). The majority of the cohort showed low vitamin D concentrations, which were negatively correlated with mRNA expression levels of HBD-3 in corpus mucosa. HBD-1 and HBD-3 mRNA were expressed in corpus mucosa, with the former significantly decreased in patients with diabetes. Hence, we conclude that type 2 diabetes is associated with reduced AMP expression in the upper gastrointestinal tract, which might contribute towards epithelial barrier dysfunction and increased bacterial translocation in these patients. [ABSTRACT FROM AUTHOR]

Antibiotics are often used to treat oral infections. Unfortunately, excessive antibiotic use can adversely alter oral microbiomes and promote the development of antibiotic-resistant microorganisms, which can be difficult to treat. An alternate approach could be to induce the local transcription and expression of endogenous oral antimicrobial peptides (AMPs). To assess the feasibility and benefits of this approach, we conducted literature searches to identify (i) the AMPs expressed in the oral cavity; (ii) the methods used to induce endogenous AMP expression; and (iii) the roles that expressed AMPs may have in regulating oral inflammation, immunity, healing, and pain. Search results identified human neutrophil peptides (HNP), human beta defensins (HBD), and cathelicidin AMP (CAMP) gene product LL-37 as prominent AMPs expressed by oral cells and tissues. HNP, HBD, and LL-37 expression can be induced by micronutrients (trace elements, elements, and vitamins), nutrients, macronutrients (mono-, di-, and polysaccharides, amino acids, pyropeptides, proteins, and fatty acids), proinflammatory agonists, thyroid hormones, and exposure to ultraviolet (UV) irradiation, red light, or near infrared radiation (NIR). Localized AMP expression can help reduce infection, inflammation, and pain and help oral tissues heal. The use of a specific inducer depends upon the overall objective. Inducing the expression of AMPs through beneficial foods would be suitable for long-term health protection. Additionally, the specialized metabolites or concentrated extracts that are utilized as dosage forms would maintain the oral and intestinal microbiome composition and control oral and intestinal infections. Inducing AMP expression using irradiation methodologies would be applicable to a specific oral treatment area in addition to controlling local infections while regulating inflammatory and healing processes. [ABSTRACT FROM AUTHOR]

Palmoplantar pustulosis (PPP) is a chronic inflammatory skin disease characterised by neutrophilic granulocyte (neutrophil)-filled pustules on the palms and soles. The pathogenesis of PPP is poorly understood. This study conducted an identification of the immune mediators associated with PPP and an exploration of apremilast treatment effects on them. We screened for immune mediators elevated in blood taken from 68 patients with PPP versus control participants and included the most promising parameters in the protocol of phase the 2, multicentre study of apremilast (PDE4 inhibitor) in 21 patients with moderate-to-severe PPP (APLANTUS; EudraCT 2016-005122-11) for respective analysis of blood and skin samples of study patients. We investigated stimulated neutrophils and three-dimensional reconstituted epidermis cultures. Interleukin (IL)-19 was found to be the most upregulated immune mediator in the blood of PPP patients. IL-19 serum levels were independent of patients' age, gender, and BMI but were associated with strongly upregulated cutaneous IL-19 expression and correlated with the number of palmoplantar pustules. In patients participating in the APLANTUS study, apremilast reduced pustules more effectively than erythema and scaling. Moreover, this treatment significantly reduced IL-19 blood and skin levels. The reduction in IL-19 blood levels at week 4 correlated with the reduction in pustule counts at week 20 (end of treatment). IL-19 was expressed by neutrophils activated in vitro and induced CXCL6, a neutrophil-attracting chemokine, in epidermis models. This work demonstrates elevated IL-19 levels in the blood and skin of PPP patients and suggests a relevant role of this cytokine in the appearance of pustules in this disorder. It also suggests the suitability of IL-19 blood levels as a predictive biomarker for the treatment response of PPP patients, which should be validated in further studies. [ABSTRACT FROM AUTHOR]

Introduction: Colorectal cancer (CRC) is a serious threat to human health. Screening new biomarkers can provide basis for improving the prognosis and individualized treatment of CRC. Although some members of the defensin family were found increased in pancreatic cancer and CRC, their exact function and clinical significance remain unclear. Methods: In this study, the expression, correlation, mutation, and functional enrichment of several defensin family members in pancreatic cancer and CRC were analyzed using tumor public databases and verified in several patients. Results: Results showed no significant correlation between the expression levels of DEFA1-4 and CRC. The expression levels of DEFA5 and DEFA6 significantly increased in CRC tissues compared with those in normal tissues. DEFA5 may be associated with better prognosis of CRC, while DEFA6 may be associated with poor prognosis. Immunohistochemistry (IHC) experiments showed that the expression of DEFA6 was significantly higher in adenoma than in normal mucosa and slightly higher in carcinoma than in normal mucosa. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis found that DEFAs were closely related to hsa05202: transcriptional misregulation in cancer and Hsa04015: Rap1 signaling pathway. DEFA5 may be a stable and good prognostic marker, and DEFA6 may be a poor prognostic marker in CRC of metastasis. Conclusion: Overall, DEFA5 and DEFA6 have a certain degree of sensitivity and specificity in predicting CRC. [ABSTRACT FROM AUTHOR]

BACKGROUND Reproductive tract infection is an important factor leading to male and female infertility. Among female infertility factors, microbial and viral infections are the main factors affecting female reproductive health and causing tubal infertility, ectopic tubal pregnancy and premature delivery. Among male infertility factors, 13–15% of male infertility is related to infection. Defensins are cationic antibacterial and antiviral peptides, classified into α-defensins, β-defensins and θ-defensins. Humans only have α-defensins and β-defensins. Apart from their direct antimicrobial functions, defensins have an immunomodulatory function and are involved in many physiological processes. Studies have shown that defensins are widely distributed in the female reproductive tract (FRT) and male reproductive tract (MRT), playing a dual role of host defence and fertility protection. However, to our knowledge, the distribution, regulation and function of defensins in the reproductive tract and their relation to reproduction have not been reviewed. OBJECTIVE AND RATIONALE This review summarizes the expression, distribution and regulation of defensins in the reproductive tracts to reveal the updated research on the dual role of defensins in host defence and the protection of fertility. SEARCH METHODS A systematic search was conducted in PubMed using the related keywords through April 2022. Related data from original researches and reviews were integrated to comprehensively review the current findings and understanding of defensins in the human reproductive system. Meanwhile, female and male transcriptome data in the GEO database were screened to analyze defensins in the human reproductive tracts. OUTCOMES Two transcriptome databases from the GEO database (GSE7307 and GSE150852) combined with existing researches reveal the expression levels and role of the defensins in the reproductive tracts. In the FRT, a high expression level of α-defensin is found, and the expression levels of defensins in the vulva and vagina are higher than those in other organs. The expression of defensins in the endometrium varies with menstrual cycle stages and with microbial invasion. Defensins also participate in the local immune response to regulate the risk of spontaneous preterm birth. In the MRT, a high expression level of β-defensins is also found. It is mainly highly expressed in the epididymal caput and corpus, indicating that defensins play an important role in sperm maturation. The expression of defensins in the MRT varies with androgen levels, age and the status of microbial invasion. They protect the male reproductive system from bacterial infections by neutralizing lipopolysaccharide and downregulating pro-inflammatory cytokines. In addition, animal and clinical studies have shown that defensins play an important role in sperm maturation, motility and fertilization. WIDER IMPLICATIONS As a broad-spectrum antimicrobial peptide without drug resistance, defensin has great potential for developing new natural antimicrobial treatments for reproductive tract infections. However, increasing evidence has shown that defensins can not only inhibit microbial invasion but can also promote the invasion and adhesion of some microorganisms in certain biological environments, such as human immunodeficiency virus. Therefore, the safety of defensins as reproductive tract anti-infective drugs needs more in-depth research. In addition, the modulatory role of defensins in fertility requires more in-depth research since the current conclusions are based on small-size samples. At present, scientists have made many attempts at the clinical transformation of defensins. However, defensins have problems such as poor stability, low bioavailability and difficulties in their synthesis. Therefore, the production of safe, effective and low-cost drugs remains a challenge. [ABSTRACT FROM AUTHOR]

The black soldier fly (BSF), Hermetia illucens L. (Diptera: Stratiomyidae), has a great bioconversion potential and ability to develop on diverse substrates. Although the use of catering waste and food by-products containing meat and fish would reduce the footprint of the insect sector, to date, in Europe, their use is still facing legal obstacles for insects as food and feed. Since a major request from the EU insect sector is to diversify the spectrum of allowed substrates, and considering that variations in diet composition could influence insect immune responses, we evaluated the impact of different catering wastes on BSF prepupae immunity. Insects were reared on five diets: one based on feed for laying hens and four based on catering waste containing (i) fruits and vegetables; (ii) fruits, vegetables and bread; (iii) fruit, vegetables, bread and dairy products; (iv) fruits, vegetables, bread, meat and fish. The gene expression of two antimicrobial peptides (AMPs), one defensin and one cecropin, was assessed. Moreover, the hemolymph inhibitory activity against Escherichia coli DH5α and Micrococcus yunnanensis HI55 was evaluated using diffusion assays in solid media. The up-regulation of both AMPs' encoding genes was observed in insects fed a bread-added and dairy product-added diet. All hemolymph samples showed inhibitory activity against both bacteria, affecting the colony size and number. The obtained results show how catering waste positively influences the H. illucens immune system. The possibility of modulating AMP expression levels through the diet opens up new perspectives in the management of insect health in mass rearings. [ABSTRACT FROM AUTHOR]

Alarmins exist outside cells and are early warning signals to the immune system; as such, alarmin receptors are widely distributed on various immune cells. Alarmins, proinflammatory molecular patterns associated with tissue damage, are usually released into the extracellular space, where they induce immune responses and participate in the damage and repair processes of mucosal diseases. In the stomach, gastric alarmin release has been shown to be involved in gastric mucosal inflammation, antibacterial defense, adaptive immunity, and wound healing; moreover, this release causes damage and results in the development of gastric mucosal diseases, including various types of gastritis, ulcers, and gastric cancer. Therefore, it is necessary to understand the role of alarmins in gastric mucosal diseases. This review focuses on the contribution of alarmins, including IL33, HMGB1, defensins and cathelicidins, to the gastric mucosal barrier and their role in gastric mucosal diseases. Here, we offer a new perspective on the prevention and treatment of gastric mucosal diseases. [ABSTRACT FROM AUTHOR]

Studies on phylogeography and population structure of Ixodes ricinus have been carried out in Europe for decades, but the number of specimens from the Middle East included in these analyses is relatively small, despite the wide distribution of the species in this area. This study aimed to clarify the phylogenetic positions of I. ricinus from Turkey as well as to investigate the presence of Ixodes inopinatus in Anatolia. For this purpose, one mitochondrial (mt 16S rDNA) and one nuclear gene (defensin) were used to generate molecular data from I. ricinus samples, which were collected from 17 locations across the species' distributional range in Turkey. Bayesian inference was used to investigate phylogenetic relationships. Globally, the mt 16S rDNA lineages correspond to the lineages revealed by defensin; I. ricinus and I. inopinatus sequences clustered separately. However, a discordant genetic pattern was observed between the phylogenetic position of turkish I. ricinus revealed by nuclear versus mitochondrial genes. All Turkish haplotypes of mt 16SrDNA clustered with I. ricinus samples from Europe, which might be the result of extensive gene flow between populations of Europe and the Middle East. On the other hand, a sample from Thrace Region grouped within I. inopinatus clade. Thus, the occurrence of I. inopinatus in Turkey was demonstrated for the first time using molecular data. Moreover, four individuals were found to be heterozygous for the defensin. The potential evolutionary processes that underlie this observed discrepancy between the phylogenetic trees of two genes have been discussed. [ABSTRACT FROM AUTHOR]

Proline‐rich peptide (CgPrp) and defensin (CgDef), oyster (Crassostrea gigas)‐originated antimicrobial peptides (AMPs), were produced by the recombinant technique in Komagataella phaffii GS115 cells. For this purpose, the nucleotide sequences encoding the CgPrp and CgDef peptides were synthesized by the recursive PCR technique, and ligated in pPICZaA expression vector. Additionally, the expression cassettes of pPICZαA‐CgDef and pPICZαA‐CgPrp were combined using in vitro multimer ligation strategy to construct the coexpression vector pPICZaA‐CgPrp‐CgDef. The expression and coexpression vectors transformed into K. phaffii GS115 cells by electroporation. At the end of the 0.5% methanol‐induced expression stage for 96 h, the recombinant peptides were purified from the culture medium. The concentrations of purified peptides were changed between 1.05 and 1.21 mg/L. The recombinant peptides successfully inhibited the growth of tested Gram‐positive bacterial strains belonging to Staphylococcus aureus, methicillin‐resistant S. aureus (MRSA), Listeria monocytogenes, and Bacillus cereus. The minimum inhibitory concentrations (MIC) of recombinant CgPrp, CgDef, and CgPrp‐CgDef peptides against tested bacteria were in the range of 12.50–25.00, 18.75–75.00, and 5.80–11.60 pg/μl, respectively. The results of the study proved that the recombinant CgPrp, CgDef, and CgPrp‐CgDef peptides expressed in K. phaffii might have good potential for the inhibition of common Gram‐positive pathogenic bacteria, including drug‐resistant MRSA. [ABSTRACT FROM AUTHOR]

A concerning global health issue is the growing incidence of antibiotic resistance in skin and soft tissue infection. This study aimed to assess the healing potential of topically applied Saccharomyces boulardii on excisional skin wound infected with Staphylococcus aureus using a rat model. The wounded animals were divided into three groups; group 1: uninfected untreated, group 2: infected untreated and group 3: infected S. boulardii-treated. Treatment commenced 2 days post infection. Parameters studied were wound microbial load, rate of wound contraction, serum C-reactive protein (CRP) level and rat β-defensin 1 (RBD-1) gene expression. Staphylococcal bacterial load decline was significantly (p < 0.05) higher in group 3 when compared to group 2 at day 5, 6 and 7 accompanied by a growing of S. boulardii load on the animals of group 3. A complete wound closure (100%) was monitored in study group 3 at day 7 in comparison to the control groups, where partial healing was achieved (67.10 and 91.74% in group 1 and 2 respectively). No significant difference of CRP level among the three groups was encountered indicating no influence of S. boulardii on this protein. RBD-1 gene expression in group 3 was found higher than the two control groups (p < 0.05 and < 0.01 in comparison to group 1 and group 2 respectively). Topical application of S. boulardii was shown able to enhance wound healing and competitively exclude the infecting pathogen. The increased antimicrobial peptide gene expression in S. boulardii treated group might contribute to its healing potential. [ABSTRACT FROM AUTHOR]

Problem: Cervical insufficiency (CI) is associated with intra‐amniotic infection or inflammation. Antimicrobial peptides (AMPs) in amniotic fluid may protect the fetus against microbial invasion, giving their broad‐spectrum microbiocidal properties. We evaluated changes in amniotic fluid AMP expression in women with CI and assessed whether these changes are related to their pregnancy outcomes. Method of Study: We evaluated amniotic fluid human neutrophil peptide 3 (HNP‐3), human β‐defensin‐2 (hBD‐2), and LL‐37 levels in 66 women with CI and 25 normal controls at 16–24 weeks of gestation. The CI group was divided into short cervix and cervical dilation groups, and the cervical dilation group was further divided into preterm and full‐term delivery groups according to the pregnancy outcomes, and AMP expression was analyzed in each group. Results: : HNP‐3 and hBD‐2 levels were higher in women with CI than in normal controls and in the cervical dilation as compared to the short cervix group. Among women with cervical dilation, 22 delivered at full‐term, and 23 had spontaneous preterm births. The hBD‐2 level in amniotic fluid mid‐pregnancy was higher in the full‐term delivery than in the preterm delivery groups. However, LL‐37 levels in amniotic fluid were low in women with CI and normal controls. Conclusions: : Amniotic fluid HNP‐3 and hBD‐2 levels increased in women with CI compared with normal controls. Moreover, increased amniotic fluid hBD‐2 levels mid‐pregnancy were associated with favorable pregnancy outcomes in women with CI. AMPs in the amniotic fluid may participate in host defense against ascending infection in women with CI. [ABSTRACT FROM AUTHOR]

Defensins represent an integral part of the innate immune system to ward off potential pathogens. The study used a rat model to investigate mechanisms by which sodium butyrate (NaB) regulates β‐defensin to inhibit lipopolysaccharide (LPS)‐induced nephrotoxicity. We found that NaB alleviated LPS‐induced renal structural damage, as judged by reduced renal lesions and improved glomerular vascular structure. In addition, elevated levels of indicators of kidney damage creatinine and blood urine nitrogen, inflammatory mediators TNF‐α, and IL‐6 dropped after NaB administration. Rat β‐defensin 2 (rBD2), as estimated by mRNA level, was significantly higher in LPS‐treated kidneys, whereas the changes of rBD2 reduced in NaB‐treated kidneys. In addition, NaB alleviated LPS‐induced increase in TLRs mRNA expression. Mechanistically, the present study indicates that NaB has nephroprotective activity resulting from modulation of TLR2/4 to regulate rBD2 expression hence curbing inflammation. Practical applications: In practice, adding NaB to diet can improve animal performance. Our results suggest that dietary supplementation of NaB increases animal feed intake and improves the body's defense ability to relieve inflammation caused by bacteria. Especially in the age of resistance prohibition, sodium butyrate can partially replace antibiotics to induce the expression of body defensin. It may become a health care product to enhance the body's immunity. [ABSTRACT FROM AUTHOR]

Leaf-cutting ants depend on mutualistic fungi to survive. An infection that massively affects the workers compromising the proper maintenance of the fungus, or that can attack the fungus garden, can be fatal to the colony. Thus, leaf-cutting ants have evolved a complex defense system composed of both innate individual immunity and collective immunity to protect the colony against potential threats. To characterize the collective and individual immunity of Atta cephalotes workers to Metarizhium anisopliae we assessed the hygienic behavior and the expression of antimicrobial peptides of A. cephalotes workers triggered by Metarizhium anisopliae spores. As a control challenge, workers were treated with water. Regardless of whether the challenge was with water or spore suspension, A. cephalotes workers displayed an immediate response characterized by an increase in time spent both self-grooming and collective grooming along with a reduction in time spent fungus-grooming. The individual immunity triggered the expression of abaecin as early as 24 hours post-infection, exclusively in workers challenged with M. anisopliae. In contrast, the level of expression of defensin remained constant. These results suggest that upon being challenged with a suspension of M. anisopliae spores, A. cephalotes workers deploy both collective and individual immunity to produce a response against the invader. However, when the spores of M. anisopliae are applied as liquid suspension collective immunity deploys a generic strategy, while individual immunity shows a specific response against this entomopathogen. [ABSTRACT FROM AUTHOR]

Background: Ticks are hematophagous parasites that transmit an extensive range of pathogens to their vertebrate hosts. Ticks can destroy invading microorganisms or alleviate infection via their rudimentary but orchestrated innate immune system. Antimicrobial peptides (AMPs) are important components of tick innate immunity. Among these humoral effector molecules, defensins are well-studied and widely identified in various species of Ixodidae (hard ticks) and Argasidae (soft ticks). This review was aimed at presenting the characterization of tick defensins from structure-based taxonomic status to antimicrobial function. Main text: All published papers written in English from 2001 to May 2022 were searched through PubMed and Web of Science databases with the combination of relevant terms on tick defensins. Reports on identification and characterization of tick defensins were included. Of the 329 entries retrieved, 57 articles were finally eligible for our scoping review. Tick defensins mainly belong to the antibacterial ancient invertebrate-type defensins of the cis-defensins superfamily. They are generally small, cationic, and amphipathic, with six cysteine residues forming three intra-molecular disulfide bonds. Tick defensins primarily target membranes of a variety of pathogens, including Gram-positive and Gram-negative bacteria, fungi, viruses, and protozoa. Since tick defensins have a high degree of variability, we summarize their common biological properties and enumerate representative peptides. Along with the various and potent antimicrobial activities, the role of tick defensins in determining vector competence is discussed. Conclusions: Due to their broad-spectrum antimicrobial activities, tick defensins are considered novel candidates or targets for controlling infectious diseases. [ABSTRACT FROM AUTHOR]

Plants are a promising platform for recombinant protein production. Here we propose a novel approach to increase the level of viral vector-mediated recombinant protein synthesis. This approach is based on the hypothesis that antiviral protection is weakened during the antibacterial cellular response. We suggested that introduced to the cell foreign nuclear localized proteins, including effectors such as bacterial nucleomodulins, can interfere with the import of cellular nuclear proteins and launch antibacterial defense reactions, creating favorable conditions for cytoplasmic virus reproduction. Here, we performed synthesis of an artificial nuclear protein—red fluorescent protein (mRFP) fused with a nuclear localization sequence (NLS)—in plant cells as a mimetic of a bacterial effector. Superproduction of mRFP:NLS induced Nicotiana benthamiana γ-thionin (NbγThio) mRNA accumulation. Both NLS-containing protein synthesis and increased NbγThio expression stimulated reproduction of the viral vector based on the genome of crucifer-infecting tobacco mosaic virus (crTMV) in N. benthamiana leaves. We isolated the NbγThio gene promoter (PrγThio) and showed that PrγThio activity sharply increased in response to massive synthesis of GFP fused with NLS. We conclude that NLS-induced PrγThio activation and increased accumulation of Nbγthio mRNA led to the stimulation of GFP expression from crTMV: GFP vector in the transient expression system. [ABSTRACT FROM AUTHOR]

Microbial keratitis is a common cause of ocular pain and visual impairment worldwide. The ocular surface has a relatively paucicellular microbial community, mostly found in the conjunctiva, while the cornea would be considered relatively sterile. However, in patients with microbial keratitis, the cornea can be infected with multiple pathogens including Staphylococcus aureus , Pseudomonas aeruginosa , and Fusarium sp. Treatment with topical antimicrobials serves as the standard of care for microbial keratitis, however, due to high rates of pathogen resistance to current antimicrobial medications, alternative therapeutic strategies must be developed. Multiple studies have characterized the expression and activity of antimicrobial peptides (AMPs), endogenous peptides with key antimicrobial and wound healing properties, on the ocular surface. Recent studies and clinical trials provide promise for the use of AMPs as therapeutic agents. This article reviews the repertoire of AMPs expressed at the ocular surface, how expression of these AMPs can be modulated, and the potential for harnessing the AMPs as potential therapeutics for patients with microbial keratitis. [ABSTRACT FROM AUTHOR]

Pollen nutrition is critical for the development and well-being of the honeybee. Previous studies have compared the effect of pollen and carbohydrate-only diet on honeybee physiology. The effect of a monofloral versus polyfloral diet on the African honeybee (Apis mellifera scutellata) is poorly understood. This knowledge is critical as diversity-rich habitats are being altered to less diverse environments through increased urbanization and intensified agricultural activities, particularly in sub-Saharan Africa. Here, we report how lowly diverse (LD) and highly diverse (HD) pollen diets influence honeybee life-history traits and physiology. To achieve this, we fed caged bees with the two pollen diets and tested their effects on the parameters of survival, body weight, pollen consumption, and immune response. HD-fed bees had significantly higher survival and greater pollen consumption than LD-fed bees. However, LD-fed bees were heavier than HD-fed bees. The correlation between body weight gain and pollen consumption was expressed strongly in HD-fed bees than in LD-fed bees. Overall, our findings reveal the benefits that the highly diverse polyfloral diets provide to honeybee workers. This study shows how pollen diversity influences honeybee life-history traits, thus informing the need for conserving the biodiversity of environments for safeguarding the health of honeybees and other pollinators. [ABSTRACT FROM AUTHOR]

Peanut (Arachis hypogea L.) bacterial wilt (BW) is a devastating disease caused by Ralstonia solanacearum that results in severe yield and quality losses. Plant defensins are short cysteine-rich peptides with antimicrobial activity. The role of defensin genes (AhDef) in peanut is unclear. A genome-wide investigation of AhDef genes was undertaken, and 12 identified AhDef genes were classified into two groups containing the gamma-thionin domain formed by four disulfide pairs: Cys1-Cys8, Cys2-Cys5, Cys3-Cys6, and Cys4-Cys7. In silico analysis revealed that AhDef genes showed highly conserved architectural features and contained cis-elements associated with phytohormone signaling and defense responses. A highly resistant cultivar, H108 (R) and a susceptible accession, H107 (S) were tested by R. solanacearum inoculation. H108 (R) showed fewer symptoms than H107 (S) owing to inhibition of bacterial reproduction and spread in the vascular bundles of roots and stems. In a transcriptomic expression profile, AhDef genes, particularly AhDef1.6 and AhDef2.2, were up-regulated in H108 (R) compared with H107 (S) under R. solanacearum infection and phytohormone treatment. Subcellular localization showed that the AhDef1.6 and AhDef2.2 proteins were both expressed specifically on the plasma membrane. Overexpression of protein fusion AhDef2.2-YFP in Nicotiana benthamiana and peanut leaves increased resistance to R. solanacearum, suggesting its role in response to BW infection. AhDef2.2 may be valuable for peanut resistance breeding. [ABSTRACT FROM AUTHOR]

The binding of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) spike protein to the angiotensin‐converting enzyme 2 (ACE2) receptor expressed on the host cells is a critical initial step for viral infection. This interaction is blocked through competitive inhibition by soluble ACE2 protein. Therefore, developing high‐affinity and cost‐effective ACE2 mimetic ligands that disrupt this protein–protein interaction is a promising strategy for viral diagnostics and therapy. We employed human and plant defensins, a class of small (2–5 kDa) and highly stable proteins containing solvent‐exposed alpha‐helix, conformationally constrained by two disulfide bonds. Therefore, we engineered the amino acid residues on the constrained alpha‐helix of defensins to mimic the critical residues on the ACE2 helix 1 that interact with the SARS‐CoV‐2 spike protein. The engineered proteins (h‐deface2, p‐deface2, and p‐deface2‐MUT) were soluble and purified to homogeneity with a high yield from a bacterial expression system. The proteins demonstrated exceptional thermostability (Tm 70.7°C), high‐affinity binding to the spike protein with apparent Kd values of 54.4 ± 11.3, 33.5 ± 8.2, and 14.4 ± 3.5 nM for h‐deface2, p‐deface2, and p‐deface2‐MUT, respectively, and were used in a diagnostic assay that detected SARS‐CoV‐2 neutralizing antibodies. This work addresses the challenge of developing helical ACE2 mimetics by demonstrating that defensins provide promising scaffolds to engineer alpha‐helices in a constrained form for designing of high‐affinity ligands. [ABSTRACT FROM AUTHOR]

Background: Innate immunity plays an important role in deciding the severity of coronavirus disease 2019 (COVID-19) and disease outcomes. Defensins are antimicrobial peptides that are produced by epithelial cells in mucosal locations and play a key role in innate immunity. Understanding COVID-19 mucosal agents and their role in disease severity is critical for developing therapeutic options and identification of prognostic markers for COVID-19. Objective: In this study, we aimed to determine the role of β-defensin-1 in patients with COVID-19 and compare it with that of the control group, as well as to look into the link between β-defensin-1 and oral hygiene and disease severity. Methods: This case-control study included 50 patients with COVID-19 and 35 controls of similar ages and sexes. From November 2020 to January 2021, the patients were admitted to Baghdad Teaching Hospital/Medical City. The simplified oral hygiene index was used to determine oral hygiene status. Blood samples were obtained from all subjects (patients and controls), and the serum levels of β-defensin-1 were measured using enzyme-linked immunosorbent assay (ELISA). Results: Findings showed a non-significant reduction (P > 0.05) in the β-defensin-1 level among patients compared with that of the controls. In addition, patients with severe disease had a significantly lower level of β-defensin-1 than those with mild disease. There were no significant variations in the levels of β-defensin-1 between patients with good oral hygiene and those with poor oral hygiene (P > 0.05). Conclusions: The reduction in β-defensin-1 levels indicates an abnormal immune response in these patients and may require a new treatment option for this condition in the future. Furthermore, in patients with severe disease, a considerable drop in β-defensin-1 might be used as an indicator of illness severity. [ABSTRACT FROM AUTHOR]