scholarly journals Bioactivity and Bactericidal Mechanism of Histidine-Rich β-Hairpin Peptide Against Gram-Negative Bacteria

2019 ◽  
Vol 20 (16) ◽  
pp. 3954 ◽  
Author(s):  
Na Dong ◽  
Chensi Wang ◽  
Tingting Zhang ◽  
Lei Zhang ◽  
Chenyu Xue ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Gram Negative ◽  
Cell Selectivity ◽  
Tnf Α ◽  
New Type ◽  
Cell Membrane Disruption ◽  
Bacterial Cell Membrane ◽  
And Function

Antibacterial peptides (APMs) are a new type of antibacterial substance. The relationship between their structure and function remains indistinct; in particular, there is a lack of a definitive and fixed template for designing new antimicrobial peptides. Previous studies have shown that porcine Protegrin-1 (PG-1) exhibits considerable antimicrobial activity and cytotoxicity. In this study, to reduce cytotoxicity and increase cell selectivity, we designed histidine-rich peptides based on the sequence template RR(XY)2XDPGX(YX)2RR-NH2, where X represents I, W, V, and F. The results showed that the peptides form more β-hairpin structures in a lipid-rich environment that mimics cell membranes. Among them, the antimicrobial peptide HV2 showed strong antibacterial activity against Gram-negative strains and almost no toxicity to normal cells. The results of our analysis of its antibacterial mechanism showed that peptide HV2 acts on the bacterial cell membrane to increase its permeability, resulting in cell membrane disruption and death. Furthermore, peptide HV2 inhibited bacterial movement in a concentration-dependent manner and had a more robust anti-inflammatory effect by inhibiting the production of TNF-α. In summary, peptide HV2 exhibits high bactericidal activity and cell selectivity, making it a promising candidate for future use as an antibiotic.

scholarly journals IL-34 affects fibroblast-like synoviocyte proliferation, apoptosis and function by regulating IL-17

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xin Li ◽  
Yimeng Lei ◽  
Ziyu Gao ◽  
Gang Wu ◽  
Wei Gao ◽  
...  
Keyword(s):  
Hypoxia Inducible Factor ◽  
Annexin V ◽  
Chronic Inflammatory Disease ◽  
Angiogenic Factor ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Tnf Α ◽  
Proliferation And Apoptosis ◽  
Factor Α ◽  
And Function

AbstractRheumatoid arthritis (RA) is a chronic inflammatory disease characterized by proliferation and insufficient apoptosis of fibroblast-like synoviocytes (FLSs).The biology and functions of interleukin (IL)-34 are only beginning to be uncovered. We previously demonstrated IL-34 could upregulate the expression of IL-17 in RA patients. In this study, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry of Annexin V and PI staining were performed to assess cell proliferation and apoptosis progression in RA-FLSs after stimulated with increasing concentrations of IL-34, respectively. Inflammatory cytokines and angiogenic factors were measured using quantitative real-time PCR, Western blotting and ELISA. We explored the association between IL-34 and RA-FLS proliferation and apoptosis in the context of RA. Stimulating RA-FLSs with different concentrations of IL-34 significantly promoted the proliferation and inhibited the apoptosis of RA-FLSs in a concentration-dependent manner. Neutralization of IL-17 with the IL-17 inhibitor plumbagin (PB) reduced the effects of IL-34. Proinflammatory cytokine (IL-17A IL-6 and tumor necrosis factor-α, TNF-α) and angiogenic factor (vascular endothelial growth factor, VEGF and hypoxia-inducible factor-1α, HIF-1α) expression was markedly upregulated in RA-FLSs stimulated by IL-34. PB-mediated inhibition of IL-17A also decreased the expression of IL-6, TNF-α, HIF-1α and VEGF in RA-FLSs. Taken together, these findings suggest that targeting IL-34 production in RA-FLSs may be a therapeutic strategy for RA.

scholarly journals Bioactivity-Guided Extract Optimization of Osmanthus fragrans var. aurantiacus Leaves and Anti-Inflammatory Activities of Phillyrin

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1545
Author(s):  
Hwa-Young Song ◽  
Da-Eun Jeong ◽  
Mina Lee
Keyword(s):  
Biological Activities ◽  
Radical Scavenging ◽  
No Production ◽  
Dependent Manner ◽  
Optimal Method ◽  
Concentration Dependent Manner ◽  
Osmanthus Fragrans ◽  
Tnf Α ◽  
Anti Inflammatory ◽  
Extracellular Regulated Kinase

The aim of this study was to identify the optimal extraction conditions for leaves of Osmanthus fragrans var. aurantiacus. Inhibitory effects of various extracts on NO production were compared. Antioxidant evaluations for total phenol and flavonoid contents were carried out using various extracts of O. fragrans var. aurantiacus leaves obtained under optimal extraction conditions that showed the greatest effect on NO production. The optimal method for extracting O. fragrans var. aurantiacus leaves resulted in an extract named OP OFLE. OP OFLE showed DPPH and ABTS radical scavenging activities in a concentration-dependent manner. Phillyrin (PH) was isolated as a major compound from OP OFLE by HPLC/DAD analysis. OP OFLE and PH reduced inducible nitric oxide (iNOS) and cyclooxygenase (COX)-2 protein expression and downregulated proinflammatory cytokines such as interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor (TNF)-α in LPS-stimulated RAW 264.7 and HT-29 cells. To determine the signal pathway involved in the inhibition of NO production, a Western blot analysis was performed. Results showed that OP OFLE decreased phosphorylation of extracellular regulated kinase (pERK) 1/2 and the expression of nuclear factor-kappa B (NF-κB). Our results suggest that extracts of O. fragrans var. aurantiacus leaves and its major components have biological activities such as antioxidative and anti-inflammatory properties.

scholarly journals Effects of irbesartan on phenotypic alterations in monocytes and the inflammatory status of hypertensive patients with left ventricular hypertrophy

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jingsi Zhang ◽  
Lina Yang ◽  
Yanchun Ding
Keyword(s):  
Ventricular Hypertrophy ◽  
Target Organ Damage ◽  
Organ Damage ◽  
Left Ventricular ◽  
Target Organ ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Hypertensive Patients ◽  
Inflammatory Status ◽  
Tnf Α

Abstract Background Circulating monocytes and tissue macrophages play complex roles in the pathogenesis of hypertension and the resulting target organ damage. In this study, we observed alterations in the monocyte phenotype and inflammatory state of hypertensive patients with left ventricular hypertrophy (LVH) and studied the effects of irbesartan in these patients. This study might reveal a novel mechanism by which irbesartan alleviates LVH, and it could provide new targets for the prevention and treatment of hypertensive target organ damage. Methods CD163 and CD206 expression on monocytes and IL-10 and TNF-α levels in the serum of hypertensive patients with or without LVH and of healthy volunteers were detected. Furthermore, we treated monocytes from the LVH group with different concentrations of irbesartan, and then, CD163, CD206, IL-10 and TNF-α expression was detected. Results We found, for the first time, that the expression of CD163, CD206 and IL-10 in the LVH group was lower than that in the non-LVH group and healthy control group, but the TNF-α level in the LVH group was significantly higher. Irbesartan upregulated the expression of CD163 and CD206 in hypertensive patients with LVH in a concentration-dependent manner. Irbesartan also increased the expression of IL-10 and inhibited the expression of TNF-α in monocyte culture supernatants in a concentration-dependent manner. Conclusions Our data suggest that inflammation was activated in hypertensive patients with LVH and that the monocyte phenotype was mainly proinflammatory. The expression of proinflammatory factors increased while the expression of anti-inflammatory factors decreased. Irbesartan could alter the monocyte phenotype and inflammatory status in hypertensive patients with LVH. This previously unknown mechanism may explain how irbesartan alleviates LVH. Trail registration The study protocols were approved by the Ethical Committee of the Second Affiliated Hospital of Dalian Medical University. Each patient signed the informed consent form.

scholarly journals Modulatory Effects of Osthole on Lipopolysaccharides-Induced Inflammation in Caco-2 Cell Monolayer and Co-Cultures with THP-1 and THP-1-Derived Macrophages

Nutrients ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 123
Author(s):  
Natalia K. Kordulewska ◽  
Justyna Topa ◽  
Małgorzata Tańska ◽  
Anna Cieślińska ◽  
Ewa Fiedorowicz ◽  
...  
Keyword(s):  
Gene Expression ◽  
Inflammatory Reaction ◽  
Wide Spectrum ◽  
Cell Monolayer ◽  
In Vivo Studies ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Tnf Α

Lipopolysaccharydes (LPS) are responsible for the intestinal inflammatory reaction, as they may disrupt tight junctions and induce cytokines (CKs) secretion. Osthole has a wide spectrum of pharmacological effects, thus its anti-inflammatory potential in the LPS-treated Caco-2 cell line as well as in Caco-2/THP-1 and Caco-2/macrophages co-cultures was investigated. In brief, Caco-2 cells and co-cultures were incubated with LPS to induce an inflammatory reaction, after which osthole (150–450 ng/mL) was applied to reduce this effect. After 24 h, the level of secreted CKs and changes in gene expression were examined. LPS significantly increased the levels of IL-1β, -6, -8, and TNF-α, while osthole reduced this effect in a concentration-dependent manner, with the most significant decrease when a 450 ng/mL dose was applied (p < 0.0001). A similar trend was observed in changes in gene expression, with the significant osthole efficiency at a concentration of 450 ng/μL for IL1R1 and COX-2 (p < 0.01) and 300 ng/μL for NF-κB (p < 0.001). Osthole increased Caco-2 monolayer permeability, thus if it would ever be considered as a potential drug for minimizing intestinal inflammatory symptoms, its safety should be confirmed in extended in vitro and in vivo studies.

scholarly journals Increased Anti-Inflammatory Effects on LPS-Induced Microglia Cells by Spirulina maxima Extract from Ultrasonic Process

2019 ◽  
Vol 9 (10) ◽  
pp. 2144 ◽  
Author(s):  
Woon Yong Choi ◽  
Jae-Hun Sim ◽  
Jung-Youl Lee ◽  
Do Hyung Kang ◽  
Hyeon Yong Lee
Keyword(s):  
Mrna Expression ◽  
Dependent Manner ◽  
Spirulina Maxima ◽  
Concentration Dependent Manner ◽  
Quantitative Correlation ◽  
Tnf Α ◽  
Ultrasonic Process ◽  
Anti Inflammatory ◽  
Low Cytotoxicity ◽  
High Concentrations

The Spirulina maxima exact from a non-thermal ultrasonic process (UE) contains 17.5 mg/g of total chlorophyll, compared to 6.24 mg/g of chlorophyll derived from the conventional 70% ethanol extraction at 80 °C for 12 h (EE). The UE also showed relatively low cytotoxicity against murine microglial cells (BV-2) and inhibited the production of the inflammatory mediators, NO and PGE2. The UE also effectively suppresses both mRNA expression and the production of pro-inflammatory cytokines, such as TNF-α, IL-6 and IL-1β, in a concentration-dependent manner. Notably, TNF-α gene and protein production were most strongly down-regulated, while IL-6 was the least affected by all ranges of treatment concentrations. This work first demonstrated a quantitative correlation between mRNA expression and the production of cytokines, showing that suppression of TNF-α gene expression was most significantly correlated with its secretion. These results clearly proved that the anti-inflammatory effects of Spirulina extract from a nonthermal ultrasonic process, which yielded high concentrations of intact forms of chlorophylls, were increased two-fold compared to those of conventional extracts processed at high temperature.

scholarly journals Modulatory Effect of Chelidonium majus Extract and Its Alkaloids on LPS-Stimulated Cytokine Secretion in Human Neutrophils

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 842 ◽  
Author(s):  
Sylwia Zielińska ◽  
Monika Ewa Czerwińska ◽  
Magdalena Dziągwa-Becker ◽  
Andrzej Dryś ◽  
Mariusz Kucharski ◽  
...  
Keyword(s):  
Biological Activities ◽  
Cytokine Secretion ◽  
Human Neutrophils ◽  
Root Extract ◽  
Dependent Manner ◽  
Chelidonium Majus ◽  
Concentration Dependent Manner ◽  
Cytotoxic Effects ◽  
Tnf Α ◽  
High Cytotoxicity

Due to certain differences in terms of molecular structure, isoquinoline alkaloids from Chelidonium majus engage in various biological activities. Apart from their well-documented antimicrobial potential, some phenanthridine and protoberberine derivatives as well as C. majus extract present with anti-inflammatory and cytotoxic effects. In this study, the LC–MS/MS method was used to determine alkaloids, phenolic acids, carboxylic acids, and hydroxybenzoic acids. We investigated five individually tested alkaloids (coptisine, berberine, chelidonine, chelerythrine, and sanguinarine) as well as C. majus root extract for their effect on the secretion of IL-1β, IL-8, and TNF-α in human polymorphonuclear leukocytes (neutrophils). Berberine, chelidonine, and chelerythrine significantly decreased the secretion of TNF-α in a concentration-dependent manner. Sanguinarine was found to be the most potent inhibitor of IL-1β secretion. However, the overproduction of IL-8 and TNF-α and a high cytotoxicity for these compounds were observed. Coptisine was highly cytotoxic and slightly decreased the secretion of the studied cytokines. The extract (1.25–12.5 μg/mL) increased cytokine secretion in a concentration-dependent manner, but an increase in cytotoxicity was also noted. The alkaloids were active at very low concentrations (0.625–2.5 μM), but their potential cytotoxic effects, except for chelidonine and chelerythrine, should not be ignored.

PKCϵ has an alcohol-binding site in its second cysteine-rich regulatory domain

2009 ◽  
Vol 421 (3) ◽  
pp. 405-413 ◽  
Author(s):  
Joydip Das ◽  
Satyabrata Pany ◽  
Ghazi M. Rahman ◽  
Simon J. Slater
Keyword(s):  
Protein Kinase ◽  
Binding Site ◽  
Maximum Effect ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Kinase C ◽  
C1 Domain ◽  
Pkc Protein Kinase C ◽  
And Function

Alcohols regulate the expression and function of PKC (protein kinase C), and it has been proposed that an alcohol-binding site is present in PKCα in its C1 domain, which consists of two cysteine-rich subdomains, C1A and C1B. A PKCϵ-knockout mouse showed a significant decrease in alcohol consumption compared with the wild-type. The aim of the present study was to investigate whether an alcohol-binding site could be present in PKCϵ. Here we show that ethanol inhibited PKCϵ activity in a concentration-dependent manner with an EC50 (equilibrium ligand concentration at half-maximum effect) of 43 mM. Ethanol, butanol and octanol increased the binding affinity of a fluorescent phorbol ester SAPD (sapintoxin-D) to PKCϵC1B in a concentration-dependent manner with EC50 values of 78 mM, 8 mM and 340 μM respectively, suggesting the presence of an allosteric alcohol-binding site in this subdomain. To identify this site, PKCϵC1B was photolabelled with 3-azibutanol and 3-azioctanol and analysed by MS. Whereas azibutanol preferentially labelled His236, Tyr238 was the preferred site for azioctanol. Inspection of the model structure of PKCϵC1B reveals that these residues are 3.46 Å (1 Å=0.1 nm) apart from each other and form a groove where His236 is surface-exposed and Tyr238 is buried inside. When these residues were replaced by alanine, it significantly decreased alcohol binding in terms of both photolabelling and alcohol-induced SAPD binding in the mutant H236A/Y238A. Whereas Tyr238 was labelled in mutant H236A, His236 was labelled in mutant Y238A. The present results provide direct evidence for the presence of an allosteric alcohol-binding site on protein kinase Cϵ and underscore the role of His236 and Tyr238 residues in alcohol binding.

Differential inhibition of inflammatory cytokine release from cultured alveolar macrophages from smokers and non smokers by No2

1997 ◽  
Vol 16 (10) ◽  
pp. 577-588 ◽  
Author(s):  
Tiziana Dandrea ◽  
Ba Tu ◽  
Anders Blomberg ◽  
Thomas Sandström ◽  
Magnus Sköld ◽  
...  
Keyword(s):  
Steady State ◽  
Alveolar Macrophages ◽  
Exposure Model ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Tnf Α ◽  
Dependent Inhibition ◽  
Steady State Levels ◽  
Dose Dependent

Human alveolar macrophages (AMs) obtained from smokers and non-smokers by bronchoalveolar lavage (BAL) were subjected to various concentrations of NO2 in an inverted monolayer exposure model. Culture super natants were collected 4 h after the exposure and assayed for secreted TNF-α, IL-1β, IL-8 and MIP-1α. The steady state levels of the mRNAs for these cytokines were also analysed in the cells. The adherence of BAL cells to plastic prior to exposure to the gas elevated the steady state mRNA levels of all four cytokines tested in smoker's cells and that of TNF-α and IL-1β, but not IL-8 (MIP-1α not tested), in non-smoker's cells. Interestingly, adherent cells from non-smokers released circa 15-, 3-,1.5- and 3-fold the amounts of IL-1β, IL-8, TNF-α and MIP-1α, respectively, than smoker's cells during control incubation or exposure to air. A 20 min exposure to NO2 (5 or 20 p.p.m.) did not increase the secretion of any of the cytokines from either cell type. In contrast, NO2 caused a concentration- dependent inhibition of the secretion of all cytokines except IL-1β from smoker's cells. Additionally, NO2 greatly diminished the release of all cytokines in response to further treatment with lipopolysaccharide (LPS). In contrast, only the secretion of TNF-α from non-smoker's cells was inhibited by the gas in a concentration- dependent manner, whilst LPS-induced secretion of the cytokines was not affected by the gas. The steady state levels of the respective mRNAs for each of the cytokines were not significantly affected in smoker's cells by exposure to NO2, except for a negative, dose-dependent trend in the case of TNF-α. Nitrogen dioxide also failed to elevate the levels of the mRNAs in non-smoker's cells but, again, tended to diminish the levels, particularly of IL-1β mRNA. However, exposure to the gas inhibited LPS- induced accumulation of cytokine mRNAs in smoker's cells only. The data suggest that macrophage-derived cytokine mediators of the sepsis response may not play a role in the generation of NO2-induced inflammation in the human lung. Conversely, the gas seems to non-specifically inhibit the release and/or production of cytokines, particularly from smoker's cells, at the post-transcrip tional level, and impairs the ability of the cells to increase the transcription and release of the cytokines in response to bacterial LPS. The fact that NO2 seriously impaired the already diminished capacity of smoker's cells to release several important pro-inflammatory cytokines, both under control conditions and in response to LPS, strongly suggest that the inhalation of NO2 in cigarette smoke may contribute to impairing host defence against infection in the lung.

scholarly journals Antioxidant activity of pineal methoxyindoles on hepatocyte plasmatic membrane

2019 ◽  
Vol 2 (1) ◽  
pp. 161-174
Author(s):  
Marcos C Reyes-Gonzales ◽  
Eduardo Esteban-Zubero ◽  
Laura López-Pingarrón ◽  
María Soledad Soria ◽  
Desiree Pereboom ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Membrane ◽  
Membrane Fluidity ◽  
Membrane Lipid ◽  
Hydroxyl Group ◽  
Dependent Manner ◽  
Protective Effects ◽  
Concentration Dependent Manner ◽  
Plasmatic Membrane ◽  
Membrane Rigidity

Antioxidant effect of several pineal derived molecules has been well documented. Here, the protective effects of 5-methoxytryptophol (5-MTOH) and 5-methoxyindol-3-acetic acid (5-MIAA) on hepatic cell membrane lipid peroxidation and cell membrane rigidity induced by FeCl3 plus ascorbic acid have been systemically investigated. The membrane fluidity was evaluated by fluorescence spectroscopy, malondialdehyde (MDA) and 4-hydroxyalkenals (4-HDA) concentrations and carbonyl groups of protein were measured as the parameters of lipid and protein damage, respectively. Results showed that oxidative stress increased membrane rigidity, MDA and 4-HDA concentrations as well as carbonyl content in a concentration-dependent manner. 5-MTOH, but not 5-MIAA, significantly attenuated these oxidative indecies. In absence of oxidative stress, none of these methoxyindoleamines modified the content of MDA, 4-HDA or carbonylation. However 5-MIAA at its highest concentration slightly modified membrane fluidity. The results suggest that structural modification of C3 in the methoxyindoleamine, that is, the carboxyl group replaced by hydroxyl group in this site could improve the ability of 5-methoxyindoleamine derivatives to preserve membrane fluidity of cells which are under oxidative stress. 

scholarly journals Antiproliferative effects of porins extracted from Klebsiella pneumoniae on HL-60, NIH/3T3 and Human foreskin fibroblast cell (HFFC) lines measured by ELISA method

2010 ◽  
Vol 4 (1) ◽  
pp. 28-35
Author(s):  
Amir H. Al–Shammary ◽  
Essam F. Al-Jumaily ◽  
Nidhal Abdulmohymen
Keyword(s):  
Klebsiella Pneumoniae ◽  
Outer Membrane ◽  
Outer Membrane Proteins ◽  
Primary Source ◽  
Gram Negative Bacteria ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Gram Negative ◽  
Isolation And Purification ◽  
Antiproliferative Effects

Approximately, 50% of the dry mass of the outer membrane of gram-negative bacteria consists of proteins, and more than 20 immunochemically distinct proteins (termed outer membrane proteins [OMPs]) have been identified. An identified local strain of Klebsiella pneumoniae was used as a primary source for the isolation and purification of porins. Multiple concentrations of purified porins (5, 10, 15, 20, 25) g/ml were incubated with three different cell lines for (24, 72 , 120) hrs, after the end of the incubation periods, the cells were treated with Cell proliferation ELISA, BrdU (colorimetric) kit to evaluate the antiproliferative effects of porins. The results revealed that porins are potent antiproliferative agent in a time and concentration dependent manner and thus could greatly affect prokaryote-eukaryote interaction as well as the whole inflammatory process resulted after infection with gram negative bacteria.

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