JAK-STAT signaling pathway and rosacea / 中华皮肤科杂志

Studies have shown that rosacea is related to inflammatory factors, neurovascular function, micro-ecological environment and other factors. The Janus kinase (JAK) -signal transducer and activator of transcription (STAT) signaling pathway involves a variety of inflammatory cytokines, and plays an important role in cell proliferation, differentiation, apoptosis, angiogenesis and immune regulation. This review summarizes the JAK-STAT signaling pathway and explores its potential role in rosacea.

Effects of ferrocene position isomerization on the self-assembly behavior and antibacterial effect of coupled cationic peptides / 中国药房

OBJECTIVE To design the two isomers of ferrocene （Fc）-coupled cationic peptides （hereinafter referred to as “peptides”） [Fc-K（C8）FFHK and C8-K（Fc） FFHK] and the control peptide [C8-K（C8）FFHK]， and to explore the effects of Fc position isomerization on the self-assembly behavior and antibacterial effect of peptides. METHODS All isomerized peptides were prepared by standard solid-phase synthesis and purified by reversed-phase high-performance liquid chromatography. The stability of the peptide was analyzed by using UV spectrophotometry to detect UV absorption spectra， and Zeta potential analyzer to determine Zeta potential. The secondary structure was characterized by circular dichroism spectrum （CD）， Fourier transform infrared spectrometer （FTIR）， thioflavin T （ThT） fluorescence spectrum and transmission electron microscopy （TEM）. The differences in antibacterial activity and biocompatibility of the 2 kinds of isomerized peptides were evaluated by in vitro reactive oxygen species （ROS） generation test， growth curve determination test， plate method， cytotoxicity assay and hemolysis test. RESULTS Three peptides with purity higher than 95% were synthesized. The stability test results showed that the UV absorption spectra of Fc-K（C8）FFHK and C8-K（Fc）FFHK remained almost unchanged when placed at room temperature for 24 and 96 hours， and their Zeta potential were decreased by 0.3 mV and 0.5 mV， respectively. Secondary structure characterization results showed that Fc-K（C8）FFHK and C8-K（Fc）FFHK were self-assembled to form twisted nanoribbons and short nanofibers， respectively； C8-K（C8）FFHK was assembled into cylindrical nanofibers. The optical spectrum results showed that there were certain differences in the content of structures such as β-sheet and α-helix. The in vitro ROS generation test results showed that ROS generation efficiency of Fc-K（C8）FFHK at pH 6.0 was higher than C8-K（Fc）FFHK. The results of in vitro antibacterial activity showed that for methicillin-resistant Staphylococcus aureus， both the isomeric peptides had similar minimum inhibitory concentration （MIC） values of 50 μg/mL which were far lower than the control peptide （400 μg/mL）. To Escherichia coli， Fc-K（C8）FFHK had better antibacterial activity than C8-K（Fc）FFHK. Finally， cytotoxicity assay and hemolysis test results showed that both isomeric peptides had good biocompatibility. CONCLUSIONS By wangjingwen8021@163.com coupling Fc， the antibacterial activity of cationic self-assembled peptides can be improved. Regulating the position of Fc in the peptide sequence could regulate the self-assembly behavior and antibacterial effect of the self-assembled peptides.

An antibacterial peptides recognition method based on BERT and Text-CNN / 生物工程学报

Antimicrobial peptides (AMPs) are small molecule peptides that are widely found in living organisms with broad-spectrum antibacterial activity and immunomodulatory effect. Due to slower emergence of resistance, excellent clinical potential and wide range of application, AMP is a strong alternative to conventional antibiotics. AMP recognition is a significant direction in the field of AMP research. The high cost, low efficiency and long period shortcomings of the wet experiment methods prevent it from meeting the need for the large-scale AMP recognition. Therefore, computer-aided identification methods are important supplements to AMP recognition approaches, and one of the key issues is how to improve the accuracy. Protein sequences could be approximated as a language composed of amino acids. Consequently, rich features may be extracted using natural language processing (NLP) techniques. In this paper, we combine the pre-trained model BERT and the fine-tuned structure Text-CNN in the field of NLP to model protein languages, develop an open-source available antimicrobial peptide recognition tool and conduct a comparison with other five published tools. The experimental results show that the optimization of the two-phase training approach brings an overall improvement in accuracy, sensitivity, specificity, and Matthew correlation coefficient, offering a novel approach for further research on AMP recognition.

Preparation and in vitro evaluation of antibacterial peptides from Plutella xylostella poly(lactic-co-glycolic acid) nanoparticles / 中草药

Objective: To prepare the antibacterial peptides from Plutella xylostella-loaded nanoparticles based on poly(lactic-co- glycolic acid) (CA-PLGA-NPs) and evaluate its physicochemical property and in vitro release. Methods: CA-PLGA-NPs were prepared by S/W/O/W double emulsion method combined with high-pressure homogenization. The morphology, particle size, polydispersion index (PDI), drug loading, encapsulation efficiency (EE), and in vitro release of the nanoparticles were studied. Results: CA-PLGA-NPs were spherical or similarly spherical, and the average particle size, PDI, drug loading, and EE were (358.76 ± 22.51) nm, 0.168 1 ± 0.012 2, (10.50 ± 0.28)%, and (60.92 ± 1.58)%, respectively. And burst phenomenon was not significant. The drug delivery stable phase was 2-10 d. Conclusion: S/W/O/W double emulsion method combined with high pressure homogenization method is suitable for the preparation of CA-PLGA-NPs, and provides a pharmaceutical basis for CA administration.

Progresses on marine antimicrobial activity proteins / 中国生化药物杂志

Due to the particularity of marine ecological environment, many marine lives have developed and accumulated a large amount of biological molecules with special chemical structures and physiological activities, representing an important resource for the development of marine drugs. Generally, the marine antibacterial proteins are mainly identified from the marine microorganisms, invertebrates and fish.In this review, the progresses on marine antibacterial peptides and antimicrobial activity proteins are briefly summarized.

Lisozima: Actividad antibacteriana y alergenicidad / Lysozyme: Antibacterial Activity and Allergenicity

Desde que la lisozima fue descubierta por Alexander Fleming en 1922, muchos son los trabajos que se han lleva-do a cabo para describir las distintas actividades biológicas de esta proteína como son su actividad antibacteria-na, antiviral, antinflamatoria, analgésica, antitumoral y antioxidante. Su actividad antibacteriana frente a bacterias Gram-positivas es la actividad más ampliamente estudiada. Muchas investigaciones se han realizado para ampliar el espectro antibacteriano y poder atacar bacterias Gram-negativas. Se han llevado a cabo modificacio-nes térmicas, químicas, enzimáticas, mutaciones genéticas y efectos sinérgicos con otros compuestos, y se consiguió exitosamente ampliar el espectro antibacteriano, proponiendo en todos los casos que dicha actividad es independiente de su a ctividad enzimática natural. En este trabajo destacamos todas las propiedades estructura-les de la lisozima y sus principales actividades biológicas y las investigaciones que se han llevado a cabo para potenciar dichas actividades.

Since ly sozyme was discovered by Alexander Fleming in1922, many papers have been published on the different biological activities of this protein, such as its antibacterial, antiviral, anti-inflammatory, analgesic, antitumor andantioxidant properties. Its antibacterial activity againstGram-positive bacteria is the most widely studied. Much research has been done to widen the antibacterial spectrumand to attack the Gram-negative bacteria. Thermal, chemical and enzymatic modifications, as well as genetic mutations and synergistic effects, with other compounds have been made. The antibacterial spectrum was success fully widened in all cases, suggesting that this activity is independent of its natural enzymatic activity. In this paper we describe t he structural properties of lysozyme and its main biological activities, and also the research that has been carried out to maximize these activitie.

Desde que a lisozima foi descoberta por AlexandreFleming em 1922, muitos são os trabalhos que foram realizados para descrever as diferentes atividades biológicas desta proteína, como são sua atividade bacteriana, antiviral, anti-inflamatória, analgésica, antitumoral e antioxidante. Sua atividade antibacteriana frente a bactérias Gram-positivas é a atividade mais amplamente estudada. Muitas pesquisas foram realizadas para ampliar o espectroanti bacteriano e poder atacar bactérias Gram-negativas.Foram realizadas modificações térmicas, químicas,enzimáticas, mutações genéticas e efeitos sinérgicos com outros compostos, e obteve-se com sucesso ampliar o espectro antibacteriano, propondo em todos os casos que tal atividade é independente da sua atividade enzimática natural.Neste trabalho destacamos todas as propriedades estruturais da lisozima e suas principais atividades biológicas e as pesquisas que foram realizadas para potenciar tais atividades.

Comparative antimicrobial activity of two new mutacins / Actividad microbiana comparativa de dos nuevas mutacinas

OBJECTIVES: To compare the in vitro activity of mutacins D-123.1 and F-59.1 against different bacteria including antibiotic-resistant strains, in order to evaluate their application potential. DESIGN AND METHODS: The antibacterial activity spectrum of purified F-59.1 and the MIC and MBC of F-59.1 and D-123.1 against target bacteria were determined. RESULTS: Most bacteria were inhibited by the purified mutacins. Mutacin F-59.1 shows a relatively wide activity spectrum. Mutacin D-123.1 has low Minimum Inhibitory Concentrations [MICs] (0.25-4 µ/ml) against human pathogens while F-59.1 has higher MICs (3.2-12.8 fig/ml) mainly against food-borne pathogens. CONCLUSION: The effectiveness of mutacins D-123.1 and F-59.1 against human and food-borne pathogens is demonstrated. Mutacin D-123.1 shows potential as a new antibiotic while F-59.1 shows promising application in food products. ABBREVIATIONS: MALDI-TOF MS, matrix assisted laser desorption ionisation-time of flight mass spectrometry; MB(I)C, minimum bactericidal (inhibitory) concentrations; OD, optical density; RP-HPLC, reverse-phase high-pressure liquid chromatography; TSBYE, trypticase soy broth yeast extract.

OBJETIVOS: Comparar la actividad in vitro de las mutacinas D-123.1 y F-59.1 frente a diferentes bacterias incluyendo las cepas resistentes a los antibióticos, a fin de evaluar el potencial de su aplicación. DISEÑO Y MÉTODOS: Se determinó el espectro de actividad antibacteriana de F-59.1 purificada y la CIM y la CBM de F-59.1 y D-123.1 frente a determinadas bacterias. RESULTADOS: La mayor parte de las bacterias eran inhibidas por las mutacinas purificadas. La mutacina F-59.1 muestra un espectro de actividad relativamente amplio. La mutacina D-123.1 posee bajas concentraciones de inhibición mínimas [CIM] (0.25-4 fig/ml) contra los patógenos humanos, mientras que el F-59.1 posee concentraciones CIM más altas (3.2-12.8 fig/ml) principalmente frente a los patógenos alimentarios. CONCLUSIÓN: Queda demostrada la efectividad de las mutacinas D-123.1 y F-59.1 frente a los patógenos humanos y alimentarios. La mutacina D-123.1 muestra poseer un potencial como nuevo antibiótico, en tanto que F-59.1 se presenta como una aplicación promisoria en relación con los productos alimentarios. ABREVIATURAS: MALDI-TOF MS, espectrometría de masas con desorción/ionización mediante láser asistida por matriz asociada a un analizador de tiempo de vuelo (del inglés: matrix assisted laser desorption ionisation-time de flight mass spectrometry). CIM: concentración inhibitoria mínima (inglés MIC). CBM: concentración bactericida mínima (inglés MBC). DO: densidad óptica (inglés OD); RP-HPLC: cromatografía líquida de alta resolución en fase revertida; TSBYE:caldo tripticasa soya- extracto de levadura.

Cloning of MSI-78 Gene in Escherichia coli DH5? and Identification of Positive Recombinant / 中华医院感染学杂志

OBJECTIVE To clone the MSI-78 gene for the purpose of providing evidence for further studies in prokaryotic expression and activities of antimicrobial peptides. METHODS According to the amino acid sequences of MSI-78,the MSI-78 gene was designed favorable for the Escherichia coli codons. After EcoRⅠand PstⅠ disgestion,cohesive ends were added to both ends respectively and the MSI-78 gene was synthesized by chemical methods. Then,the MSI-78 gene was ligated with pUC-18,transformed into the E. coli DH5?. Through filtration of ? complementary screening,the positive recombinant was finally identified by enzyme digestion of ECORⅠand ECORⅠ/PstⅠ and by PCR. RESULTS The MSI-78 gene was ligated with pUC-18 and transformed into the E. coli DH5?. As a result,MSI-78 gene was cloned in E. coli DH5? successfully. CONCLUSIONS The cloning of the MSI-78 gene provides evidence for further studies of its prokaryotic expression and activities of antimicrobial peptides.

Antibacterial Cecropin and Its Application on Transgenic Plants for Bacterium Resistance / 中国生物工程杂志

Cecropin is a kind of heat-durable and broad-spectrum antibacterial polypeptides which has strong effect against bacteria,fungi,virus and some pathogenic microorganisms.Today Cecropin has been widely applied into plant genetic engineering,antiviral study,and inhibiting tumor cell proliferation.Its Structure-function relationship,antibacterial mechanism,and the application on transgenic plants for bacterium resistance was reviewed.Expression of Cecropin in plants has a great application potential in bacterium resistance.Deep analyses and research of molecular structure and action mechanism can promote the transgenic plants antibacterial research.

Antimicrobial Peptides: Antibacterial Mechanism and Therapeutic Use / 微生物学通报

Antimicrobial peptides, a cluster of small peptides secreted by the majority of creatures, have been demonstrated with activity against a wide range of microorganisms including bacteria, protozoa, yeast, fungi, viruses and even tumor cells. These peptides have some features such as broad spectrum , high effi-cacy and stability, little drug resistance. A lack of new antibiotics combined with emerging multi-drug resis-tance issues demands that new antimicrobial strategies be explored for treating these infections. It has been proposed that the antimicrobial peptides might form the foundation for a new class of clinically useful an-timicrobials. We review the advantages of these molecules in construction features and bioactivity, with the focus on the mechanism and clinical applications.

Isolation and Purification of Antibacterial Peptides from the Larvae Secretion of Housefly and the Characteristics / 中国寄生虫学与寄生虫病杂志

Objective To isolate and purify the antibacterial peptides from larvae secretion of housefly (Musca domestica) and study their partial characteristics. Methods Protein isolation and purification were performed by routine process, namely, ultrafiltration, solid phase extraction (SPE) and reversed-phase high-performance liquid chroma-tography (RP-HPLC). The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the antibacterial peptides were examined. The antibacterial effect of peptides was studied in nutritive medium with different pH value(pH 5.0-10.0), divalent cations (Mg2+: (0.5?10-3～10.0?10-3)mol/L, Na+、K+: (10?10-3～100?10-3)mol/L), and serum content(12.5%～75%). Results Molecular weight of the peptides was about Mr 3 000-30 000 after ultrafiltration. The fractions eluted with 20%, 30%, 70%, and 80% of acetonitrile (ACN) all showed antibacterial activity by solid phase extraction. The fractions eluted with 70% ACN showed strongest and stablest antibacterial activity which was further purified by RP-HPLC. Two sub-fractions appeared at around RT 15.5 min and 18.5 min were obtained with antibacterial activity. The MIC to those standard Escherichia coli, Pseudomonas aerugirwsa, Staphylococcus aureas, and Bacillus subtilis was 32.7380, 16.3688, 65.4750 and 32.7380?g/ml respectively. In the nutritive medium of pH 6.0-9.0, different divalent cations and serum content, the increment of A570 in experiment groups was less than 0.05, while that of the control group was greater than 0.3 (P