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1.
Article in Chinese | WPRIM | ID: wpr-1013577

ABSTRACT

Parasitic diseases caused by protozoan and helminth infections are still widespread across the world, notably in tropical and subtropical areas, which threaten the children and adult health. Long-term use of anti-parasitic drugs may result in reduced drug susceptibility and even drug resistance. Antimicrobial peptides have been demonstrated to inhibit parasite growth and development, which has potential antiparasitic values. LL-37, the only human antimicrobial peptide in the cathelicidin family, has been widely investigated. This paper reviews the progress of researches on the antiparasitic activity of LL-37, and discusses the prospects of LL-37 in the research of parasites.

2.
Article in Chinese | WPRIM | ID: wpr-1006551

ABSTRACT

ObjectiveMolecular docking and animal experiments were employed to explore the protective effect and mechanism of Da Chengqitang (DCQD) on intestinal barrier in septic mice. MethodText mining method was used to screen the active ingredients in DCQD. AutoDock Tools and Discovery Studio were used to study the interactions of active components with the core target proteins [claudin-1, tumor necrosis factor (TNF)-α, interleukin (IL)-6, endogenous antimicrobial peptide mCRAMP, Toll-like receptor 4 (TLR4), and myeloid differentiation primary response gene 88 (MyD88)] in sepsis. Fifty C57BL/6 mice were randomized into sham, model, low- and high-dose (4 g∙kg-1 and 8 g∙kg-1) DCQD, and ulinastatin groups (n=10). Before, during, and after the day of modeling surgery, each group was administrated with corresponding drugs. The mice in other groups except the model group were subjected to modeling by cecal ligation and puncture. Enzyme-linked immunosorbent assay (ELISA) was used measure the serum level of D-lactic acid to assess intestinal mucosa permeability. Hematoxylin-eosin staining was employed to observe the histopathological changes in the ileum and assess the intestinal mucosal damage and inflammatory infiltration. Western blotting was employed to determine the expression levels of tight junction proteins claudin-1 and occludin in the ileal tissue, which were indicative of the bowel barrier function. The TNF-α and IL-6 levels were measured by ELISA to assess the intestinal inflammation. The expression of mCRAMP in the ileal tissue was observed by immunohistochemistry. The mRNA levels of mCRAMP, TLR4, and MyD88 in mouse ileal tissue were determined by Real-time polymerase chain reaction, on the basis of which the mechanism of DCQD in protecting the intestinal barrier of septic mice was explored. ResultMolecular docking results showed that most of the 10 active ingredients of DCQD that were screened out by text mining could bind to sepsis targets by van der Waals force, hydrogen bonding, and other conjugated systems. The results of animal experiments showed that compared with the model group, low- or high-dose DCQD lowered the D-lactic acid level in the serum (P<0.01), alleviated damage to the ileal tissue and mucosal edema, protected the small intestine villus integrity, reduced inflammatory cell infiltration, promoted the expression of claudin-1 (P<0.01), lowered the IL-6 level (P<0.01), up-regulated the mRNA and protein levels of mCRAMP (P<0.01), and down-regulated the mRNA and protein levels of TLR4 and MyD88 (P<0.01) in the ileal tissue. In addition, high-dose DCQD lowered the TNF-α level and promoted the expression of occludin in the ileum tissue (P<0.01), and low-dose DCQD up-regulated the protein level of occludin in the ileum tissue (P<0.05). ConclusionDCQD has a protective effect on intestinal barrier in septic mice. It can reduce intestinal inflammation, repair intestinal mucosal damage, improve the tight junction protein level, and reduce intestinal mucosal permeability by up-regulating the mRNA and protein levels of mCRAMP and the down-regulating the expression of genes in the TLR4/MyD88 pathway.

3.
Article | IMSEAR | ID: sea-228991

ABSTRACT

The biocontrol potential of Bacillus spp. clearly indicated by several authors are presented crop wise. The understanding of mechanism of action of Bacillus spp. against phytopathogens is essential to support their biocontrol potential. In this regard the various mechanism of action of Bacillus is elaborately discussed with suitable subheadings along with their plant growth promoting ability. The available literature presented below as review strongly emphasized their distinct biocontrol potential coupled with plant growth promoting effect through their various behavioral, biological, biochemical, induction of resistance, role of antimicrobial peptide genes etc.

4.
Chinese Journal of Biotechnology ; (12): 304-317, 2023.
Article in Chinese | WPRIM | ID: wpr-970376

ABSTRACT

Candida albicans is one of the major causes of invasive fungal infections and a serious opportunistic pathogen in immunocompromised individuals. The antimicrobial peptide AMP-17 has prominent anti-Candida activity, and proteomic analysis revealed significant differences in the expression of cell wall (XOG1) and oxidative stress (SRR1) genes upon the action of AMP-17 on C. albicans, suggesting that AMP-17 may exert anti-C. albicans effects by affecting the expression of XOG1 and SRR1 genes. To further investigate whether XOG1 and SRR1 genes were the targets of AMP-17, C. albicans xog1Δ/Δ and srr1Δ/Δ mutants were constructed using the clustered regulatory interspaced short palindromic repeats-associated protein 9 (CRISPR/Cas9) system. Phenotypic observations revealed that deletion of two genes had no significant effect on C. albicans growth and biofilm formation, whereas XOG1 gene deletion affected in vitro stress response and mycelium formation of C. albicans. Drug sensitivity assay showed that the MIC80 values of AMP-17 against xog1Δ/Δ and srr1Δ/Δ mutants increased from 8 μg/mL (for the wild type C. albicans SC5314) to 16 μg/mL, while the MIC80 values against srr1Δ/Δ: : srr1 revertants decreased to the level of the wild type SC5314. In addition, the ability of AMP-17 to inhibit biofilm formation of both deletion strains was significantly reduced compared to that of wild type SC5314, indicating that the susceptibility of the deletion mutants to AMP-17 was reduced in both the yeast state and during biofilm formation. These results suggest that XOG1 and SRR1 genes are likely two of the potential targets for AMP-17 to exert anti-C. albicans effects, which may facilitate further exploration of the antibacterial mechanism of novel peptide antifungal drugs.


Subject(s)
Humans , Candida albicans , Antimicrobial Peptides , Proteomics , Peptides/pharmacology , Transcription Factors/metabolism , Antifungal Agents/pharmacology
5.
Article in Chinese | WPRIM | ID: wpr-973705

ABSTRACT

Malaria remains a major global public health concern, and nearly half of the global populations are still at risk of malaria infection. However, continuous emergence and spread of drug-resistant malaria parasite strains lead to ineffectiveness of conventional antimalarials. Therefore, development of novel antimalarial agents is of urgent need for malaria elimination. As an important component of the host natural immune defense system, antibacterial peptides provide the first line of defense against pathogenic invasion, and the mechanism of preferentially attacking the cell membrane makes them difficult to develop drug resistance. Antimicrobial peptides are therefore considered as a promising candidate for novel antimalarial agents. This review summarizes the advances in researches on antimicrobial peptides with antimalarial actions and discusses the potential of antimalarial peptides as novel antimalarials.

6.
Chinese Journal of Dermatology ; (12): 630-635, 2023.
Article in Chinese | WPRIM | ID: wpr-994524

ABSTRACT

Objective:To investigate the counteractive effect of mouse dermal fibroblasts (MdFBs) during their adipogenic differentiation against Staphylococcus aureus infection, and to explore its mechanisms. Methods:MdFBs were obtained from newborn C57BL/6 mice, and their adipogenic differentiation was induced by culture in an adipogenic medium for 48 hours. Real-time fluorescence-based quantitative PCR (RT-PCR) was performed to determine the mRNA expression of cathelicidin antimicrobial peptide (CAMP) on days 0-6 during the adipogenic differentiation of MdFBs, and Western blot analysis to determine the protein expression of CAMP in the culture supernatant of MdFBs during their adipogenic differentiation. MdFBs were divided into 4 groups: co-stimulation group stimulated by S. aureus suspensions and cultured in an adipogenic medium, adipogenic control group cultured in an adipogenic medium, S. aureus-stimulation group stimulated by S. aureus suspensions and cultured in a common medium, and control group stimulated by phosphate-buffered saline and cultured in a common medium; Western blot analysis and RT-PCR were conducted to determine the protein and mRNA expression of CAMP. S. aureus (5 × 10 4 CFU/ml) was cultured with the culture supernatant of MdFBs after 5-day adipogenic differentiation (adipogenic group), and the growth activity was evaluated every 2 hours during 10 - 24 hours after the start of co-culture; S. aureus cultured with the culture supernatant of MdFBs in a common medium served as the normal control group, and that cultured with cell-free culture supernatant served as the negative control group. Differences between groups were assessed using unpaired t-test or analysis of variance. Results:Significant differences were observed in the relative mRNA expression of CAMP among different time points (days 0, 1, 2, 4, and 6) during the adipogenic differentiation of MdFBs (1.14 ± 0.74, 68.04 ± 12.72, 683.12 ± 38.06, 1 390.68 ± 226.21, 454.57 ± 204.12, F = 50.08, P < 0.001) ; the CAMP mRNA expression was significantly higher on days 1, 2, 4, and 6 than on day 0 ( t = 9.09, 31.03, 10.63, 3.85, respectively, all P < 0.05), and showed an initial rise and subsequent fall during days 0 - 6. The CAMP protein expression in the culture supernatant of MdFBs peaked on days 2-5 and subsequently decreased. Significant differences were observed in the mRNA and protein expression of CAMP among the control group, S. aureus-stimulation group, adipogenic control group and co-stimulation group (mRNA: 0.08 ± 0.02, 0.38 ± 0.10, 0.49 ± 0.11, 0.80 ± 0.03, respectively, F = 43.25, P < 0.05; protein: 0.433 ± 0.176, 0.574 ± 0.176, 1.007 ± 0.176, 1.217 ± 0.176, respectively, F = 46.79, P < 0.05), and the relative mRNA and protein expression of CAMP was significantly higher in the co-stimulation group than in the adipogenic control group, S. aureus-stimulation group and control group (all P < 0.05). At 10 hours during culture, the growth activity of S. aureus was significantly lower in the adipogenic group (0.053 ± 0.015) than in the normal control group and negative control group (0.109 ± 0.015, 0.106 ± 0.015, t = 11.30, 13.26, respectively, both P < 0.05) ; during 10 - 24 hours, the growth activity of S. aureus also showed a significant decrease in the adipogenic group compared with the normal control group and negative control group (all P < 0.05) . Conclusion:MdFBs secreted CAMP during the adipogenic differentiation, and could inhibit the proliferation of S. aureus.

7.
Article in Chinese | WPRIM | ID: wpr-996510

ABSTRACT

ObjectiveTo investigate the effect and mechanism of Aconiti Lateralis Radix Praeparata-Cinnamomi Cortex in regulating the intestinal function in the rat model of slow transit constipation (STC) due to yang deficiency via the vasoactive intestinal peptide (VIP)/cathelicidin antimicrobial peptide (cAMP)/protein kinase A (PKA)/aquaporin (AQP) pathway. MethodSD rats were randomized into 6 groups (n=6), including a control group, a model group, high-, medium-, and low-dose Aconiti Lateralis Radix Praeparata-Cinnamomi Cortex groups, and a prucalopride group. Other groups except the control group were treated with loperamide hydrochloride combined with ice water by gavage for the modeling of STC due to yang deficiency. The number of fecal pellets, time to the first black stool defecation, fecal water content, intestinal propulsion rate, and score of fecal properties were recorded in each group. At the end of the treatment, the colon was stained with hematoxylin-eosin (HE) to reveal the histopathological changes and Alcian blue/periodic acid-Schiff (AB-PAS) to reveal the secretion of colonic mucus. The enzyme-linked immunosorbent assay (ELISA) was employed to measure the level of VIP in the serum. The mRNA level of AQP in the colon was measured by polymerase chain reaction (Real-time PCR). Immunohistochemical staining was performed to observe the expression of AQPs in the colon and kidney tissues. Western blot was performed to determine the protein levels of cAMP, PKA, and VIP in the colon tissue. ResultCompared with the control group, the model group had longer time to the first black stool defecation, reduced fecal pellets and water content, reduced Bristol Stool Form Scale score and intestinal propulsion rate, and constipation aggravated(P<0.01). Moreover, increased the intestinal lesions, reduced the mucus secretion, reduce the serum VIP level, up-regulated the expression levels of AQP1 in the colon and kidney tissues, inhibited the expression of AQP3 and AQP9(P<0.01)., and down-regulated the protein levels of cAMP, PKA, and VIP in the colon tissue. Compared with the model group, the high-dose Aconiti Lateralis Radix Praeparata-Cinnamomi Cortex group had shortened time to the first black stool defecation, increased fecal pellets and water content, increased Bristol Stool Form Scale score and intestinal propulsion rate, and alleviated constipation symptoms. Moreover, high-dose Aconiti Lateralis Radix Praeparata-Cinnamomi Cortex reduced the intestinal lesions, increased the mucus secretion, elevated the serum VIP level(P<0.01)., down-regulated the expression levels of AQP1 in the colon and kidney tissues, promoted the expression of AQP3 and AQP9(P<0.05,P<0.01), and up-regulated the protein levels of cAMP, PKA, and VIP in the colon tissue. The medium- and low-dose groups had weaker effect than the high-dose group(P<0.01). ConclusionHigh-dose Aconiti Lateralis Radix Praeparata-Cinnamomi Cortex can improve the intestinal motility and balance the intestinal water and fluid metabolism by up-regulating the VIP/cAMP/PKA/AQP pathway, thereby mitigating the constipation symptoms in the rat model of slow transit constipation due to yang deficiency.

8.
Article in Chinese | WPRIM | ID: wpr-964470

ABSTRACT

@#Antimicrobial peptides have antibacterial effects on various pathogenic microorganisms, including natural antimicrobial peptides and synthetic antimicrobial peptides. According to the structure of natural antimicrobial peptides, synthetic antimicrobial peptides can be obtained by recombining different functional domains, adjusting the original amino acid sequence, or completely redesigning the peptides from scratch. Antimicrobial peptides can inhibit the growth of various cariogenic microorganisms and the formation of microbial biofilms. They also reduce acid production and acid resistance of microorganisms. Natural antimicrobial peptide genes can be used as genetic susceptibility markers for predicting the development of caries, thus, showing potential applications in the prevention and treatment of dental caries. The instability of natural antimicrobial peptides and the inability to achieve targeted sustained release limit their application in the prevention and treatment of oral caries. Synthetic antimicrobial peptides can enhance their stability and the antibacterial effect. Synthetic antimicrobial peptides can also be polymerized with common oral adhesives to reduce the incidence of microleakage after filling treatment for caries and to prevent the occurrence of secondary caries. The pH-sensitive antimicrobial peptides are slowly released to promote remineralization in the process of caries. However, the safety and biocompatibility of synthetic antimicrobial peptides are worse than those of natural antimicrobial peptides. Moreover, the combined effect of antibacterial peptides and anticaries drugs, such as fluoride, is still uncertain. Therefore, in this paper, we will review the design methods, application and underlying mechanisms of antimicrobial peptides to introduce novel methods and ideas for the prevention and treatment of dental caries.

9.
Article | IMSEAR | ID: sea-216061

ABSTRACT

Objectives: To compare the serum vitamin D and serum cathelicidin antimicrobial peptide (CAMP) levels among tuberculosis patients and healthy subjects and to determine the association between serum vitamin D and cathelicidin in tuberculosis. Materials and Methods: This is a case-control study carried out at the pulmonary medicine and pediatrics departments of a tertiary care hospital in Chengalpattu. The study included 180 tuberculosis cases and 90 control subjects of both sexes between the age group of 1 to 80 years. Serum was used to estimate vitamin D and CAMP. The study was analyzed using SPSS version 21 (IBM Corp. Armonk, New York). The results were evaluated using the chi-square test at a 95% confidence interval, and P value <.05 was considered highly significant. Results: This study observed vitamin D deficiency, vitamin D insufficiency, and optimum vitamin D among 55%, 41%, and 3.89% tuberculosis cases, respectively. Similarly, vitamin D deficiency, vitamin D insufficiency, and optimum vitamin D were seen in 40%, 50%, and 10% healthy controls, respectively. Conclusion: This study found no association between serum vitamin D and serum CAMP levels in tuberculosis patients and healthy controls.

10.
Article in Chinese | WPRIM | ID: wpr-1015724

ABSTRACT

Mytilus is a bivalve species with important economic and ecosystem value over worldwide. Mytilus antimicrobial peptides‚ with strong molecular diversity‚ has become a research focus. Two novel antimicrobial peptides were identified from Mytilus‚ with structural features that similar to arthropod defensins. However‚ the functional features and the immune mechanism of these two mussel defensins are unknown. For this reason‚ the two novel defensins‚ Arthropod like defensn-1 and -2 (ALD-1 and ALD-2‚ respectively)‚ were studied for the sequence features‚ expression profiles‚ and the dynamic expression pattern after different microbe induction. In addition‚ solid phase chemical synthesis technology was used for the synthesis of these two novel ALDs‚ and the function of synthesized peptides of ALD was verified. The results indicated that‚ two ALDs of M. coruscus have classical structure features similar to those of other arthropod defensins. These two ALDs are mainly presented in the tissues of mantle and digestive gland of mussel. The results also suggest that ALD-1 was expressed at higher levels in the gonads of males than in females (P<0. 05). The expression of two ALDs is developmentally regulated‚and both ALD-1 and ALD-2 were undetectable in larvae‚ but can be detected with high expression level at adult mussel with age of six months. The dynamic changes in the expression level of two ALDs after microbial induction were examined‚ and the results showed a marked increase in expression level observed in vivo for both ALDs. Interestingly‚ two ALDs showed different sensitivities to different microbes‚ indicating very complex responses during the mussel immune response. This observation strongly suggests the existence of different recognition mechanism or signal transduction pathway in mussels for the expression of ALD-1 and ALD-2. Moreover‚ both of two chemical synthesized ALDs showed significant antimicrobial activities against five tested microbes with an inhibition ratio of 20%-80%. These results provided basis for understanding the molecule mechanism of Mytilus immunology‚ and the function of novel Mytilus defensins‚ and thusly provided basis for the development of molecular resource for mussel antimicrobial peptides.

11.
J. biomed. eng ; Sheng wu yi xue gong cheng xue za zhi;(6): 1247-1253, 2022.
Article in Chinese | WPRIM | ID: wpr-970664

ABSTRACT

Antimicrobial peptides (AMPs) are a class of peptides widely existing in nature with broad-spectrum antimicrobial activity. It is considered as a new alternative to traditional antibiotics because of its unique mechanism of antimicrobial activity. The development and application of natural AMPs are limited due to their drawbacks such as low antimicrobial activity and unstable metabolism. Therefore, the design and optimization of derived peptides based on natural antimicrobial peptides have become recent research hotspots. In this paper, we focus on ribosomal AMPs and summarize the design and optimization strategies of some related derived peptides, which include reasonable primary structure modification, cyclization strategy and computer-aided strategy. We expect to provide ideas for the design and optimization of antimicrobial peptides and the development of anti-infective drugs through analysis and summary in this paper.


Subject(s)
Antimicrobial Cationic Peptides/chemistry , Antimicrobial Peptides , Drug Design , Anti-Infective Agents/pharmacology , Anti-Bacterial Agents
12.
Mem. Inst. Oswaldo Cruz ; 117: e220025, 2022. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1386354

ABSTRACT

BACKGROUND Mycobacterium leprae, the causative agent of Hansen's disease, causes neural damage through the specific interaction between the external phenolic glycolipid-1 (PGL-1) and laminin subunit alpha-2 (LAMA2) from Schwann cells. OBJECTIVE To design a LAMA2-based peptide that targets PGL-1 from M. leprae. METHODS We retrieved the protein sequence of human LAMA2 and designed a specific peptide using the Antimicrobial Peptide Database and physicochemical parameters for antimycobacterial peptide-lipid interactions. We used the AlphaFold2 server to predict its three-dimensional structure, AUTODOCK-VINA for docking, and GROMACS programs for molecular dynamics simulations. FINDINGS We analysed 52 candidate peptides from LAMA2, and subsequent screening resulted in a single 60-mer peptide. The mapped peptide comprises four β-sheets and a random coiled region. This peptide exhibits a 45% hydrophobic ratio, in which one-third covers the same surface. Molecular dynamics simulations show that our predicted peptide is stable in aqueous solution and remains stable upon interaction with PGL-1 binding. In addition, we found that PGL-1 has a preference for one of the two faces of the predicted peptide, which could act as the preferential binding site of PGL-1. MAIN CONCLUSIONS Our LAMA2-based peptide targeting PGL-1 might have the potential to specifically block this key molecule, suggesting that the preferential region of the peptide is involved in the initial contact during the attachment of leprosy bacilli to Schwann cells.

13.
Electron. j. biotechnol ; Electron. j. biotechnol;50: 16-22, Mar. 2021. ilus, tab
Article in English | LILACS | ID: biblio-1292419

ABSTRACT

BACKGROUND: Cecropin P1, acting as an antimicrobial, has a broad-spectrum antibacterial activity with some antiviral and antifungal properties. It is a promising natural alternative to antibiotics which is originally isolated from the pig intestinal parasitic nematode Ascaris suum. Many studies have shown that Cecropin P1 is helpful for the prevention or treatment of clinical diseases. Therefore, it is very necessary to establish a safe, nontoxic, and efficient expression method of Cecropin P1. RESULTS: The results indicated that the recombinant protein was about 5.5 kDa showed by Tricine­SDS­ PAGE and Western blot. And Cecropin P1 was efficiently secreted and expressed after 12 h of induction, with an increasing yield over the course of the induction. Its maximum concentration was 7.83 mg/L after concentration and purification. In addition, in vitro experiments demonstrated that Cecropin P1 not only exerted a strong inhibitory effect on Escherichia coli, Salmonella sp., Shigella sp., and Pasteurella sp., but also displayed an antiviral activity against PRRSV NADC30-Like strain. CONCLUSIONS: Collectively, the strategy of expressing Cecropin P1 in Saccharomyces cerevisiae is harmless, efficient, and safe for cells. In addition, the expressed Cecropin P1 has antiviral and antibacterial properties concurrently.


Subject(s)
Peptides/pharmacology , Saccharomyces cerevisiae/drug effects , Anti-Bacterial Agents/pharmacology , Antiviral Agents/pharmacology , Peptides/chemistry , In Vitro Techniques , Recombinant Proteins , Microbial Sensitivity Tests , Blotting, Western
14.
Article in Chinese | WPRIM | ID: wpr-878429

ABSTRACT

OBJECTIVES@#To evaluate the effects of antimicrobial peptide GH12 designed @*METHODS@#The cariogenic three-species biofilm consis-ted of the cariogenic @*RESULTS@#The biomass and density of the cariogenic three-species biofilm treated with GH12 decreased compared with those of the control. The number of @*CONCLUSIONS@#GH12 can reduce the number of


Subject(s)
Humans , Biofilms , Dental Caries , In Situ Hybridization, Fluorescence , Pore Forming Cytotoxic Proteins , Streptococcus mutans
15.
Chinese Journal of Biotechnology ; (12): 2890-2902, 2021.
Article in Chinese | WPRIM | ID: wpr-887851

ABSTRACT

The evolution, structure and antigenic epitopes prediction of Rana dybowskii antimicrobial peptide dybowskin-1ST were carried out using bioinformatics software available online. Its antibacterial mechanism and structural properties were analyzed, and its activity was verified by applying wound healing assay in mice and bacteriostatic assay in vitro. This provides the theoretical basis for the improvement of parental peptide and the development of novel derivative peptides. The software MEGA_X were used to conduct homology alignment and to construct a phylogenetic tree. The online software ProtParam, ProtScale, PeptideCutter, signal, TMHMM Server were respectively used to predict the physicochemical parameters, hydrophilia/hydrophobicity, shear sites, signal peptides, and transmembrane domains of dybowskin-1ST. The online software SOPMA, Jpred4, DNAstar Protean were used to predict the secondary structure of dybowskin-1ST, and SWISS-MODEL, I-TASSER were used to predict the tertiary structure. ABCpred and SYFPEITHI were respectively used to predict its B-and T-cell epitopes. The effect of dybowskin-1ST on the wound healing was observed on experimental mice. Kirby-Bauer method and dilution method were used to determine the bacteriostatic activity of dybowskin-1ST. The dybowskin-1ST consists of 59 amino acid residues, of which leucine accounts for 16.9%, with a molecular formula of C₃₁₈H₅₁₀N₈₀O₉₃S₂. Its theoretical isoelectric point is 5.10 and the charge is -2. The dybowskin-1ST and dybowskin-1CDYa are closely related phylogenetically. The secondary structure of dybowskin-1ST predicted by the three methods were similar, which consisted of α-helix (44.07%), extended strand (16.95%), β-turns (3.39%), and random coil (35.39%). The prediction of tertiary structure showed that dybowskin-1ST was mainly composed of α-helix, and it was regarded as a hydrophilic protein with signal peptide sequence. Subcellular localization analysis showed that the probability of secreting the mitochondrial targeted peptides was 0.944. Dybowskin-1ST is an extracellular protein with no transmembrane structure region, but contains seven phosphorylation sites, three T-cell epitopes and eight B-cell epitopes. The dybowskin-1ST promoted wound healing and effectively inhibited the growth of Escherichia coli and Staphylococcus aureus. However, it had limited antibacterial activity against fungi and drug-resistant bacteria. Although the structure of dybowskin-1ST is rich in α-helix, the verification experiments showed that its antibacterial ability needs to be enhanced. The reason may be that it is a negatively charged and hydrophilic protein, and amino acid modification with the aim of increasing the number of positive charges and changing the hydrophobicity may be used to obtain derived peptides with enhanced activity.


Subject(s)
Animals , Mice , Amino Acid Sequence , Phylogeny , Pore Forming Cytotoxic Proteins , Protein Structure, Secondary , Ranidae
16.
Acta Pharmaceutica Sinica B ; (6): 100-111, 2021.
Article in English | WPRIM | ID: wpr-881127

ABSTRACT

@#The antimicrobial peptide APKGVQGPNG (named YD), a natural peptide originating from Bacillus amyloliquefaciens CBSYD1, exhibited excellent antibacterial and antioxidant properties in vitro. These characteristics are closely related to inflammatory responses which is the central trigger for liver fibrosis. However, the therapeutic effects of YD against hepatic fibrosis and the underlying mechanisms are rarely studied. In this study, we show that YD improved liver function and inhibited the progression of liver fibrosis by measuring the serum transaminase activity and the expression of α-smooth muscle actin and collagen I in carbon tetrachloride-induced mice. Then we found that YD inhibited the level of miR-155, which plays an important role in inflammation and liver fibrosis. Bioinformatics analysis and luciferase reporter assay indicate that Casp12 is a new target of miR-155. We demonstrate that YD significantly decreases the contents of inflammatory cytokines and suppresses the NF-κB signaling pathway. Further studies show that transfection of the miR-155 mimic in RAW264.7 cells partially reversed the YD-mediated CASP12 upregulation, the downregulated levels of inflammatory cytokines, and the inactivation of the NF-κB pathways. Collectively, our study indicates that YD reduces inflammation through the miR-155–Casp12–NF-κB axis during liver fibrosis and provides a promising therapeutic candidate for hepatic fibrosis.

17.
Chinese Critical Care Medicine ; (12): 626-629, 2021.
Article in Chinese | WPRIM | ID: wpr-909373

ABSTRACT

Sepsis is a life-threatening organ dysfunction due to the dysregulation of host responses during infection. Severe systemic inflammatory response syndrome (SIRS) is the primary pathophysiological feature. Despite the classical antibiotic therapies play an important role in sepsis, the emergence of multi-resistant bacteria makes a greater challenge in clinical. Antimicrobial peptides (AMP) which consist of small cationic peptides, can be found in most organisms. As a result of their board-spectrum antibacterial activities and immunoregulatory functions, AMPs may have an excellent effect on the treatment of sepsis. In this review, we will discuss the basic role of AMPs in sepsis treatment and their application prospect and the challenges which need to be resolved in order to provide ideas for clinical application of AMPs.

18.
Mem. Inst. Oswaldo Cruz ; 116: e200587, 2021. tab, graf
Article in English | LILACS | ID: biblio-1287343

ABSTRACT

BACKGROUND The inappropriate use of antibiotics has led to the accelerated growth of resistance to antibiotics. The search for new therapeutic strategies (i.e., antimicrobial peptides-AMPs) has thus become a pressing need. OBJECTIVE Characterising and evaluating Sarconesiopsis magellanica larval fat body-derived AMPs. METHODS Fat body extracts were analysed by reversed-phase high-performance liquid chromatography (RP-HPLC); mass spectrometry was used for characterising the primary structure of the AMPs so found. ProtParam (Expasy) was used for analysing the AMPs' physico-chemical properties. Synthetic AMPs' antibacterial activity was evaluated. FINDINGS Four new AMPs were obtained and called sarconesin III, IV, V and VI. Sarconesin III had an α-helix structure and sarconesins IV, V and VI had linear formations. Oligomer prediction highlighted peptide-peptide interactions, suggesting that sarconesins III, V and VI could form self-aggregations when in contact with the microbial membrane. AMPs synthesised from their native molecules' sequences had potent activity against Gram-positive bacteria and, to a lesser extent, against Gram-negative and drug-resistant bacteria. Sarconesin VI was the most efficient AMP. None of the four synthetic AMPs had a cytotoxic effect. MAIN CONCLUSIONS S. magellanica larval fat body-derived antimicrobial peptides are an important source of AMPs and could be used in different antimicrobial therapies and overcoming bacterial resistance.


Subject(s)
Animals , Diptera , Fat Body , Microbial Sensitivity Tests , Pore Forming Cytotoxic Proteins , Calliphoridae , Larva , Anti-Bacterial Agents/pharmacology
19.
Rev. colomb. cienc. pecu ; 33(1): 32-43, Jan.-Mar. 2020. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1156301

ABSTRACT

Abstract Background: Shrimp farming is evolving from semi-intensive to hyper-intensive systems with biofloc technology and water recirculation systems. Objective: To evaluate the transcriptional response promoted by biofloc on shrimp (Litopenaeus vannamei) under a recirculating aquaculture system (RAS). Methods: Quantitative real-time RT-PCR was used to monitor seven key genes related to the immune system in shrimp post-larvae, reared in a RAS with and without biofloc (BF and no- BF). In addition, we present for the first time nucleotide sequences of ADP-ribosylation factor 4 (LvArf4) from Litopenaeus vannamei. Results: Transcripts for penaeidin3 (Pen3), penaeidin4 (Pen4), crustin, and Toll receptor (LvToll) genes were up-regulated between 3 and 24 h in both systems, and tumor necrosis factor receptor-associated factor 6 (TRAF6) in no-BF as an early response. Regarding differential expression between treatments, 13 occurrences were encountered. Nine that were higher in BF than in no-BF and four higher in no-BF than in BF. In some sample times, expression of Pen3, crustin, LvToll, TRAF6, IMD, and LvArf4 was higher in BF than in no-BF and in others, expression of Pen3, Pen4, and TRAF6 was higher in no-BF than in BF. Conclusions: BF modulates the transcription of genes related to the immune response in shrimp as an early response. However, the RAS with no-BF promotes a similar response.


Resumen Antecedentes: Los cultivos de camarón están evolucionando de sistemas semi-intensivos a hiper-intensivos con biofloc y con recirculación. Objetivo: Evaluar la respuesta transcripcional promovida por el biofloc en un sistema acuícola con recirculación (SAR). Métodos: Monitoreamos mediante RT-PCR cuantitativo siete genes relacionados con el sistema inmune en postlarvas de camarón cultivadas en un SAR con y sin biofloc (BF y no-BF). Además, presentamos por primera vez la secuencia de nucleótidos del factor de ribosilación 4 de ADP (LvArf4) de Litopenaeus vannamei. Resultados: Los genes penaeidina3 (Pen3), penaeidina4 (Pen4), Crustina y Toll (LvToll) se sobre-expresaron entre las 3 y 24 h en ambos sistemas, y el factor 6 asociado al factor de necrosis tumoral (TRAF6) en BF como una respuesta temprana. Con respecto a la expresión diferencial entre los tratamientos, se presentaron 13 ocurrencias. Nueve donde el BF fue mayor que sin-BF y cuatro donde el no-BF fue mayor que el BF. La expresión fue más alta en BF que en no-BF en Pen3, Crustin, LvToll, TRAF6, IMD y LvArf4. En contraste, la expresión fue mayor en no-BF en Pen3, Pen4 y TRAF6. Conclusión: el BF modula la transcripción de los genes relacionados con la respuesta inmune en camarón como una respuesta temprana. Sin embargo, el SAR sin-BF promueve una respuesta similar.


Resumo Antecedentes: A criação de camarões está evoluindo de sistemas semi-intensivos para hiper-intensivos como tecnologia de bioflocos e sistemas de recirculação. Objetivo: Avaliar a resposta transcricional promovida pelo biofloco em um sistema de aquicultura recirculante (SAR). Métodos: Utilizamos RT-PCR quantitativo em tempo real para monitorar sete genes-chave relacionados ao sistema imune em pós-larvas de camarão, criados em SAR com e sem bioflocos (BF e no-BF). Além disso, apresentamos pela primeira vez sequências nucleotídicas do fator de ribosilação do ADP 4 (LvArf4) de Litopenaeus vannamei. Resultados: Os resultados mostraram que o Penaeidina3 (PEN3), Penaeidina4 (Pen4), Crustina e Toll genes (LvToll) foram sobre-expressos entre 3 e 24 h em ambos os sistemas, e o Factor de Necrose do Receptor 6 associado e protuberância (TRAF6) no BF como uma resposta precoce. Com relação à expressão diferencial entre tratamentos, 13 ocorrências foram apresentadas. Nove onde o BF foi maior do que os não-BF e quatro onde o não-BF foi maior do que o BF. A expressão foi maior do que em BF não-BF em Pen3, Crustin, LvToll, TRAF6, IMD e LvArf4. Em contraste, a expressão foi mais elevada no não-BF em Pen3, Pen4 e TRAF6. Conclusões: O BF modula a transcrição de resposta imune relacionada no camarão como um genes de resposta precoce. No entanto, o SAR não BF promove uma resposta semelhante.

20.
Article | IMSEAR | ID: sea-210681

ABSTRACT

A novel antimicrobial cyclic peptide, Brucyclin, was rationally designed from the original antibacterial plant peptide,Brucin. The chemically synthesized Brucyclin consists of amino acid sequence; (NH2- Gln-His-Thr-Leu-Cys-MetCys-Gly-Gly-Ala-Thr-Trp-COOH), with a molecular mass of m/z 1290. In the antimicrobial assay with 31 strainsof pathogenic microorganisms, the peptide exhibited the most antimicrobial activity with a minimum inhibitoryconcentration (MIC) values ranging from 50 to 100 μg/ml against two strains of Gram-negative bacteria (Vibriocholera non O1, non O139 and Klebsiella oxytoca), one strain of Gram-positive bacterium (Bacillus subtilis), andone strain of yeast (Candida albicans), respectively. Structural analysis of Brucyclin indicated that it has a neutralcharge with a hydrophobicity ratio of 50% and pI value of 6.72, respectively. The results from this study suggested thatthe Brucyclin is a new antibiotic peptide that might be an alternative potent drug for treatment of various infectiousdiseases caused by pathogenic microorganisms.

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