| 1. |
- Abdillahi, Suado M., et al.
(författare)
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Collagen VI Contains Multiple Host Defense Peptides with Potent In Vivo Activity
- 2018
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Ingår i: Journal of Immunology. - : AMER ASSOC IMMUNOLOGISTS. - 0022-1767 .- 1550-6606. ; 201:3, s. 1007-1020
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Tidskriftsartikel (refereegranskat)abstract
- Collagen VI is a ubiquitous extracellular matrix component that forms extensive microfibrillar networks in most connective tissues. In this study, we describe for the first time, to our knowledge, that the collagen VI von Willebrand factor type A like domains exhibit a broad-spectrum antimicrobial activity against Gram-positive and Gram-negative bacteria in human skin infections in vivo. In silico sequence and structural analysis of VWA domains revealed that they contain cationic and amphipathic peptide sequence motifs, which might explain the antimicrobial nature of collagen VI. In vitro and in vivo studies show that these peptides exhibited significant antibacterial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa through membrane disruption. Our findings shed new light on the role of collagen VI derived peptides in innate host defense and provide templates for development of peptide-based antibacterial therapies.
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| 2. |
- Abu-Humaidan, Anas, et al.
(författare)
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The epidermal growth factor receptor is a regulator of epidermal complement component expression and complement activation.
- 2014
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Ingår i: Journal of immunology. - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 192:7, s. 3355-3364
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Tidskriftsartikel (refereegranskat)abstract
- The complement system is activated in response to tissue injury. During wound healing, complement activation seems beneficial in acute wounds but may be detrimental in chronic wounds. We found that the epidermal expression of many complement components was only increased to a minor extent in skin wounds in vivo and in cultured keratinocytes after exposure to supernatant from stimulated mononuclear cells. In contrast, the epidermal expression of complement components was downregulated in ex vivo injured skin lacking the stimulation from infiltrating inflammatory cells but with intact injury-induced epidermal growth factor receptor (EGFR)-mediated growth factor response. In cultured primary keratinocytes, stimulation with the potent EGFR ligand, TGF-α, yielded a significant downregulation of complement component expression. Indeed, EGFR inhibition significantly enhanced the induction of complement components in keratinocytes and epidermis following stimulation with proinflammatory cytokines. Importantly, EGFR inhibition of cultured keratinocytes either alone or in combination with proinflammatory stimulus promoted activation of the complement system after incubation with serum. In keratinocytes treated solely with the EGFR inhibitor, complement activation was dependent on serum-derived C1q, whereas in keratinocytes stimulated with a combination of proinflammatory cytokines and EGFR inhibition, complement activation was found even with C1q-depleted serum. In contrast to human keratinocytes, EGFR inhibition did not enhance complement component expression or cause complement activation in murine keratinocytes. These data demonstrate an important role for EGFR in regulating the expression of complement components and complement activation in human epidermis and keratinocytes and, to our knowledge, identify for the first time a pathway important for the epidermal regulation of complement activation.
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| 3. |
- Adav, Sunil S., et al.
(författare)
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Studies on the Proteome of Human Hair - Identification of Histones and Deamidated Keratins
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Human hair is laminar-fibrous tissue and an evolutionarily old keratinization product of follicle trichocytes. Studies on the hair proteome can give new insights into hair function and lead to the development of novel biomarkers for hair in health and disease. Human hair proteins were extracted by detergent and detergent-free techniques. We adopted a shotgun proteomics approach, which demonstrated a large extractability and variety of hair proteins after detergent extraction. We found an enrichment of keratin, keratin-associated proteins (KAPs), and intermediate filament proteins, which were part of protein networks associated with response to stress, innate immunity, epidermis development, and the hair cycle. Our analysis also revealed a significant deamidation of keratin type I and II, and KAPs. The hair shafts were found to contain several types of histones, which are well known to exert antimicrobial activity. Analysis of the hair proteome, particularly its composition, protein abundances, deamidated hair proteins, and modification sites, may offer a novel approach to explore potential biomarkers of hair health quality, hair diseases, and aging.
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| 4. |
- Ali, Mohamad N., et al.
(författare)
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TFPI-2 protects against gram-negative bacterial infection
- 2018
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 9:SEP
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Tidskriftsartikel (refereegranskat)abstract
- Tissue factor pathway inhibitor-2 (TFPI-2) has previously been characterized as an endogenous anticoagulant. TFPI-2 is expressed in the vast majority of cells, mainly secreted into the extracellular matrix. Recently we reported that EDC34, a C-terminal peptide derived from TFPI-2, exerts a broad antimicrobial activity. In the present study, we describe a previously unknown antimicrobial mode of action for the human TFPI-2 C-terminal peptide EDC34, mediated via binding to immunoglobulins of the classes IgG, IgA, IgE, and IgM. In particular the interaction of EDC34 with the Fc part of IgG is of importance since this boosts interaction between the immunoglobulin and complement factor C1q. Moreover, we find that the binding increases the C1q engagement of the antigen-antibody interaction, leading to enhanced activation of the classical complement pathway during bacterial infection. In experimental murine models of infection and endotoxin challenge, we show that TFPI-2 is up-regulated in several organs, including the lung. Correspondingly, TFPI-2-/- mice are more susceptible to pulmonary Pseudomonas aeruginosa bacterial infection. No anti-coagulant role of TFPI-2 was observed in these models in vivo. Furthermore, in vivo, the mouse TFPI-2-derived C-terminal peptide VKG24, a homolog to human EDC34 is protective against systemic Escherichia coli bacterial infection. Moreover, in sputum from cystic fibrosis patients TFPI-2 C-terminal fragments are generated and found associated with immunoglobulins. Together our data describe a previously unknown host defense mechanism and therapeutic importance of TFPI-2 against invading Gram-negative bacterial pathogens.
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| 5. |
- Allhorn, Maria, et al.
(författare)
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Heme-Scavenging Role of alpha1-Microglobulin in Chronic Ulcers.
- 2003
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Ingår i: Journal of Investigative Dermatology. - : Elsevier BV. - 1523-1747 .- 0022-202X. ; 121:3, s. 640-646
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Tidskriftsartikel (refereegranskat)abstract
- Chronic venous ulcers are characterized by chronic inflammation. Heme and iron, originating from blood cell hemolysis as well as extravascular necrosis, have been implicated as important pathogenic factors due to their promotion of oxidative stress. It was recently reported that the plasma and tissue protein alpha1-microglobulin is involved in heme metabolism. The protein binds heme, and a carboxy-terminally processed form, truncated alpha1-microglobulin, also degrades heme. Here, we show the presence of micromolar levels of heme and free iron in chronic leg ulcer fluids. Micromolar amounts of alpha1-microglobulin was also present in the ulcer fluids and bound to added radiolabeled heme. Truncated alpha1-microglobulin was found in the ulcer fluids and exogenously added alpha1-microglobulin was processed into the truncated alpha1-microglobulin form. Histochemical analysis of chronic wound tissue showed the presence of iron deposits, heme/porphyrins in infiltrating cells basement membranes and fibrin cuffs around vessels, and alpha1-microglobulin ubiquitously distributed but especially abundant in basement membranes around vessels and at fibrin cuffs. Our results suggest that alpha1-microglobulin constitutes a previously unknown defense mechanism against high heme and iron levels during skin wound healing. Excessive heme and iron, which are not buffered by alpha1-microglobulin, may underlie the chronic inflammation in chronic ulcers.
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| 6. |
- Andersson, Emma, et al.
(författare)
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Antimicrobial activities of heparin-binding peptides.
- 2004
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Ingår i: European Journal of Biochemistry. - : Wiley. - 0014-2956. ; 271:6, s. 1219-1226
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Tidskriftsartikel (refereegranskat)abstract
- Antimicrobial peptides are effector molecules of the innate immune system. We recently showed that the human antimicrobial peptides alpha-defensin and LL-37 bind to glycosaminoglycans (heparin and dermatan sulphate). Here we demonstrate the obverse, i.e. structural motifs associated with heparin affinity (cationicity, amphipaticity, and consensus regions) may confer antimicrobial properties to a given peptide. Thus, heparin-binding peptides derived from laminin isoforms, von Willebrand factor, vitronectin, protein C inhibitor, and fibronectin, exerted antimicrobial activities against Gram-positive and Gram-negative bacteria. Similar results were obtained using heparin-binding peptides derived from complement factor C3 as well as consensus sequences for heparin-binding (Cardin and Weintraub motifs). These sequence motifs, and additional peptides, also killed the fungus Candida albicans. These data will have implications for the search for novel antimicrobial peptides and utilization of heparin-protein interactions should be helpful in the identification and purification of novel antimicrobial peptides from complex biological mixtures. Finally, consensus regions may serve as templates for de novo synthesis of novel antimicrobial molecules.
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| 7. |
- Andersson, Madelene, et al.
(författare)
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Development of an experimental ex vivo wound model to evaluate antimicrobial efficacy of topical formulations
- 2021
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 22:9
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Tidskriftsartikel (refereegranskat)abstract
- Wound infections are considered a major cause for wound-associated morbidity. There is a high demand for alternative, robust, and affordable methods that can provide relatable and repro-ducible results when testing topical treatments, both in research and in the pharmaceutical industry. Here we present an ex vivo wound infection model using porcine skin and a burn wounding method, allowing for the efficacy evaluation of topical antimicrobial formulations. Utilizing this model, we demonstrate the potential of topical treatments after infecting the wounds with clinically significant bacteria, P. aeruginosa and S. aureus. We show that the method is compatible with several analytical tools used to analyze infection and antimicrobial effects. Both bacterial strains success-fully infected the wound surface, as well as deeper regions of the tissue. Quantification of viable bacteria on the wound surface and in the tissue, longitudinal measurements of bioluminescence, fluorescence microscopy, and scanning electron microscopy were used to confirm the effects of an-tibacterial treatments. Furthermore, we show that biofilms are formed on the wound surface, indi-cating that the demonstrated method mirrors typical in vivo infections.
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| 8. |
- Banas, Magdalena, et al.
(författare)
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Chemerin Is an Antimicrobial Agent in Human Epidermis
- 2013
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:3
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Tidskriftsartikel (refereegranskat)abstract
- Chemerin, a chemoattractant ligand for chemokine-like receptor 1 (CMKLR1) is predicted to share similar tertiary structure with antibacterial cathelicidins. Recombinant chemerin has antimicrobial activity. Here we show that endogenous chemerin is abundant in human epidermis, and that inhibition of bacteria growth by exudates from organ cultures of primary human skin keratinocytes is largely chemerin-dependent. Using a panel of overlapping chemerin-derived synthetic peptides, we demonstrate that the antibacterial activity of chemerin is primarily mediated by Val 66 -Pro 85, which causes direct bacterial lysis. Therefore, chemerin is an antimicrobial agent in human skin.
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| 9. |
- Baranska-Rybak, W, et al.
(författare)
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Glycosaminoglycans inhibit the antibacterial activity of LL-37 in biological fluids
- 2006
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Ingår i: Journal of Antimicrobial Chemotherapy. - : Oxford University Press (OUP). - 1460-2091 .- 0305-7453. ; 57:2, s. 260-265
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The antibacterial activity of antimicrobial peptides is influenced by various factors such as salt content, pH and the presence of proteins. In this study, we explored the antibacterial action of the human cathelicidin LL-37 in physiologically relevant conditions, i.e. various human wound fluids, human plasma fractions and serum. Methods: Radial diffusion assays using Staphylococcus aureus and Escherichia coli were employed for the study of antibacterial effects of LL-37 in the presence of 12 different wound fluids, citrate-, heparin- or EDTA-plasma, or human serum. Glycosaminoglycan content of wound fluids was determined by an Alcian Blue-binding assay. Protein content of wound fluids was measured by the Bradford method. A slot-binding assay was used to study the effects of inhibitors on the interaction between LL-37 and glycosaminoglycans. Results: Five of twelve wound fluids derived from acute wounds showed marked inhibitory effects on the antibacterial action of LL-37. The inhibition was significantly correlated with high glycosaminoglycan content in wound fluid. Analogous to these findings, heparin-plasma strongly inhibited the antibacterial effect of LL-37. The interaction between LL-37 and glycosaminoglycans was abrogated by the cationic polymers DEAE-dextran and chitosan, yielding increased activity of LL-37. Conclusions: Glycosaminoglycan-rich biological fluids inhibit the antibacterial effects of LL-37. Furthermore, polycations that bind to glycosaminoglycans increase the antibacterial activities of endogenous antimicrobial peptides in glycosaminoglycan-containing biological fluids.
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| 10. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 11. |
- Belfrage, Emma, et al.
(författare)
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Role of Mannose-binding Lectin and Association with Microbial Sensitization in a Cohort of Patients with Atopic Dermatitis
- 2023
-
Ingår i: Acta Dermato-Venereologica. - : Medical Journals Sweden AB. - 1651-2057 .- 0001-5555. ; 103, s. 1-5
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Tidskriftsartikel (refereegranskat)abstract
- Atopic dermatitis is a relapsing inflammatory skin condition, in which bacteria, fungi and viruses may colonize the skin and aggravate the condition. Mannose-binding lectin is part of the innate immune system. Polymorphism in the mannose-binding lectin gene can result in deficiency of mannose-binding lectin, which may affect defence against microbes. The aim of this study was to investigate whether polymorphisms in the mannose-binding lectin gene affect the extent of sensitization to common skin microbes, the skin barrier function, or the severity of the disease in a cohort of patients with atopic dermatitis. Genetic testing of mannose-binding lectin polymorphism was performed in 60 patients with atopic dermatitis. The disease severity, skin barrier function, and serum levels of specific immunoglobulin E against skin microbes were measured. In patients with low mannose-binding lectin genotype (group 1) 6 of 8 (75%) were sensitized to Candida albicans, compared to 14 of 22 (63.6%) patients with intermediate mannose-binding genotype (group 2) and 10 of 30 (33.3%) patients with high mannose-binding genotype (group 3). Group 1 (low mannose-binding lectin) was more likely to be sensitized to Candida albicans compared with group 3 (high mannose-binding lectin) (odds ratio 6.34, p-value 0.045). In this cohort of patients with atopic dermatitis, mannose-binding lectin deficiency was associated with increased sensitization to Candida albicans.
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| 12. |
- Braun, Katharina, et al.
(författare)
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Membrane interactions of mesoporous silica nanoparticles as carriers of antimicrobial peptides
- 2016
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797 .- 1095-7103. ; 475, s. 161-170
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Tidskriftsartikel (refereegranskat)abstract
- Membrane interactions are critical for the successful use of mesoporous silica nanoparticles as delivery systems for antimicrobial peptides (AMPs). In order to elucidate these, we here investigate effects of nanoparticle charge and porosity on AMP loading and release, as well as consequences of this for membrane interactions and antimicrobial effects. Anionic mesoporous silica particles were found to incorporate considerable amounts of the cationic AMP LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES (LL-37), whereas loading is much lower for non-porous or positively charged silica nanoparticles. Due to preferential pore localization, anionic mesoporous particles, but not the other particles, protect LL-37 from degradation by infection-related proteases. For anionic mesoporous nanoparticles, membrane disruption is mediated almost exclusively by peptide release. In contrast, non-porous silica particles build up a resilient LL-37 surface coating due to their higher negative surface charge, and display largely particle-mediated membrane interactions and antimicrobial effects. For positively charged mesoporous silica nanoparticles, LL-37 incorporation promotes the membrane binding and disruption displayed by the particles in the absence of peptide, but also causes toxicity against human erythrocytes. Thus, the use of mesoporous silica nanoparticles as AMP delivery systems requires consideration of membrane interactions and selectivity of both free peptide and the peptide-loaded nanoparticles, the latter critically dependent on nanoparticle properties.
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| 13. |
- Bysell, Helena, et al.
(författare)
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Binding and release of consensus peptides by poly(acrylic acid) microgels
- 2009
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Ingår i: Biomacromolecules. - : American Chemical Society. - 1525-7797 .- 1526-4602. ; 10:8, s. 2162-2168
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Tidskriftsartikel (refereegranskat)abstract
- The interaction between positively charged consensus peptides and poly(acrylic acid) microgels was investigated with micromanipulator-assisted light microscopy and confocal laser scanning microscopy. Peptide binding and release was monitored by microgel deswelling and swelling for monodisperse multiples of heparin-binding Cardin and Weintraub motifs, (AKKARA)(n) (1 <= n <= 4) and (ARKKAAKA)(n) (1 <= n <= 3), as well as the corresponding titratable (AHHAHA)(4) and (AHHHAAHA)(3) peptides (A, K. R and H, refering to alanine, lysine, arginine, and histidine, respectively). When fully charged, these peptides distribute homogenously throughout the microgels and display concentration-dependent deswelling, which increases with increasing peptide length. Both (AKKARA)(4) and (ARKKAAKA)(3) display potent and fast microgel deswelling but only marginal subsequent electrolyte-induced desorption. In contrast, reducing the peptide charge for (AHHAHA)(4) and (AHHHAAHA)(3) at neutral and high pH, or the peptide length, substantially reduces the peptide affinity for the microgels and facilitates rapid peptide release. Taken together, the results also show that quite short peptides of moderate charge density interact strongly and cause extensive gel deswelling of oppositely charged microgels, precluding peptide release. They also show, however, that desirable triggered release can be achieved with peptides of lower charge density.
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| 14. |
- Bysell, Helena, et al.
(författare)
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Effect of hydrophobicity on the interaction between antimicrobial peptides and poly(acrylic acid) microgels
- 2010
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 114:3, s. 1307-1313
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Tidskriftsartikel (refereegranskat)abstract
- The influence of peptide hydrophobicity on the interaction between antimicrobial peptides and poly(acrylic, acid) microgels wits studied by end-tagging the kininogen-derived antimicrobial peptide GKHKNKGKKNGKHNGWK (GKH17) and its truncated variant KNKGKKNGKH (KNK10) with oligotryptophan groups of different lengths. Microgel deswelling and reswelling in response to peptide binding and release was studied by micromanipulator-assisted light- and fluorescence microscopy, peptide uptake in microgels was determined from solution depletion measurements, and peptide oligomerization was monitored by fluorescence spectroscopy. Results showed that oligomerizition/aggregation of the hydrophobically end-tagged peptides is either absent or characterized by exposure of the tryptophan residues to the aqueous ambient, the latter suggesting small aggregation numbers. In addition, peptide uptake and affinity to the poly(acrylic acid) microgels increase with the number of trypthophan residues in the hydrophobic end tag, whereas peptide-induced microgel deswelling kinetics did not display this tag-length dependence to the same extent. Instead, long end tags resulted in anomalous shell formation, opposing further peptide-induced network deswelling. Theoretical modeling suggested that the deswelling kinetics in response to peptide binding is largely controlled by stagnant layer diffusion, but also that for peptides with Sufficiently long hydrophobic tags, the shell constitutes an additional diffusion barrier, thus resulting in slower microgel deswelling. In addition, GKH17 and KNK10 peptides lacking the tryptophan end tags were Substantially released on reducing peptide-microgel electrostatic interactions through addition of salt, an effect more pronounced for the shorter KNK10 peptide, whereas the hydrophobically end-tagged peptides remained bound to the microgels also at high ionic strength.
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| 15. |
- Cheng, Fang, et al.
(författare)
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Patterns of uronosyl epimerization and 4-/6-O-sulphation in chondroitin/dermatan sulphate from decorin and biglycan of various bovine tissues
- 1994
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Ingår i: Glycobiology. - 1460-2423. ; 4:5, s. 685-696
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Tidskriftsartikel (refereegranskat)abstract
- Dermatan sulphate is a co-polymer of two types of disaccharide repeats: D-glucuronate-N-acetylgalactosamine and L-iduronate-N-acetylgalactosamine. The former can be O-sulphated at C-4 or C-6 of the galactosamine, whereas the latter contains almost exclusively 4-O-sulphated galactosamine. A minor proportion of the L-iduronate may be O-sulphated at C-2. Chondroitin sulphate has no L-iduronate-containing repeats. We have used our recently developed methods for sequence analysis of galactosaminoglycans to investigate the structure of dermatan/chondroitin sulphates of the proteoglycans decorin and biglycan derived from various bovine tissues, like dermis, sclera, tendon, aorta, cartilage and bone. The glycan chains, radioiodinated at the reducing end, were partially cleaved with specific enzymes (chondroitin lyases), and subjected to high-resolution polyacrylamide gel electrophoresis, blotting and autoradiography to identify fragments extending from the labelled reducing end to the point of cleavage. We used chondroitin B lyase to identify the location of L-iduronate, chondroitin AC-I lyase to locate D-glucuronate and chondroitin C lyase to cleave where D-glucuronate residues were succeeded by 6-O-sulphated N-acetylgalactosamine. We could demonstrate tissue-specific, periodic and wave-like patterns of distribution for the two epimeric uronic acids, as well as specific patterns of sulphation in dermatan sulphates derived from either decorin or biglycan. For example, some dermatan sulphates contained D-glucuronate-rich domains that were always 6-sulphated (scleral decorin), others were always 4-sulphated (decorin from bovine dermis, cartilage and bone; biglycan from aorta) or 6-sulphated near the linkage region, but 4-sulphated in more distal domains (decorin from porcine dermis and bovine tendon). Decorin from bone and articular cartilage, as well as biglycan from articular and nasal cartilage, carried largely chondroitin sulphate chains, but also some dermatan sulphate, whereas galactosaminoglycan chains derived from aggrecan of nasal cartilage were free of L-iduronate. Decorin and biglycan from the same tissue (articular cartilage or sclera) had similar glycan chains. The two side chains in a biglycan molecule are probably also similar to one another. The portion of the glycan chains nearest to the core protein was substituted with charged groups to a variable degree, which may correlate with the structural features of the main chain.
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| 16. |
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| 17. |
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| 18. |
- Cöster, Lars, et al.
(författare)
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Structure of proteoheparan sulfates from fibroblasts. Confluent and proliferating fibroblasts produce at least three types of proteoheparan sulfates with functionally different core proteins
- 1986
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 261:26, s. 12079-12088
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Tidskriftsartikel (refereegranskat)abstract
- [3H]Leucine- and [35S]sulfate-labeled proteoheparan sulfates were isolated from postconfluent or proliferating cultures of human skin fibroblasts. Cell layers were solubilized by Triton X-100, and transferrin-binding macromolecules were isolated by affinity chromatography. Proteoglycans with no affinity for transferrin were purified by using ion-exchange and gel permeation chromatography. Postconfluent cells synthesize a proteoheparan sulfate of Mr 350,000 (as determined by gel permeation chromatography) which has affinity for transferrin as well as for octyl-Sepharose. Its core protein (Mr 180,000) consists of two disulfide-bonded polypeptides of Mr 90,000. This species was not detected in cultures of proliferating cells. Proliferating and confluent cells also synthesize other forms of proteoheparan sulfates (Mr 200,000-400,000) which have no affinity for transferrin. However, most of them have affinity for octyl-Sepharose. The core protein of proteoheparan sulfates made by proliferating cells has Mr 50,000. A smaller form (Mr 250,000) of this proteoglycan was solubilized by Triton X-100, whereas a larger form (Mr 400,000) remained associated with the pericellular matrix. A third type of proteoheparan sulfate (Mr 200,000) without affinity for transferrin nor octyl-Sepharose was associated with postconfluent cell layers but not with proliferating ones. Its core protein has Mr 35,000. Heparan sulfate oligosaccharides (Mr 6,000 or higher) were found in proliferating cells but not in postconfluent ones.
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| 19. |
- Dahlman, Anna, et al.
(författare)
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Thrombin-derived C-terminal peptide reduces Candida-induced inflammation and infection in vitro and in vivo
- 2021
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Ingår i: Antimicrobial Agents and Chemotherapy. - 0066-4804. ; 65:11
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Tidskriftsartikel (refereegranskat)abstract
- Infections due to the opportunistic fungus Candida have been on the rise in the last decades, especially in immunocompromised individuals and hospital settings. Unfortunately, the treatments available today are limited. Thrombin-derived C-terminal peptide (TCP-25) is an antimicrobial peptide (AMP) with antibacterial and immunomodulatory effects. In this work, we, for the first time, demonstrate the ability of TCP-25 ability to counteract Candida in vitro and in vivo. Using a combination of viable count assay (VCA), radial diffusion assay (RDA), and fluorescence and transmission electron microscopy analyses, TCP-25 was found to exert a direct fungicidal activity. An inhibitory activity of TCP-25 on NF-kB activation induced by both zymosan alone and heat-killed C. albicans was demonstrated in vitro using THP-1 cells, and in vivo using NF-kB reporter mice. Moreover, the immunomodulatory property of TCP-25 was further substantiated in vitro by analyzing cytokine responses in human blood stimulated with zymosan, and in vivo employing a zymosan-induced peritonitis model in C57BL/6 mice. The therapeutic potential of TCP-25 was demonstrated in mice infected with luminescent C. albicans. Finally, the binding between TCP-25 and zymosan was investigated using circular dichroism spectroscopy and intrinsic fluorescence analysis. Taken together, our results show that TCP-25 has a dual function by inhibiting Candida as well as the associated zymosan-induced inflammation. The latter function is accompanied by a change in secondary structure upon binding to zymosan. TCP-25, therefore, shows promise as a novel drug candidate against Candida infections.
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| 20. |
- Datta, A., et al.
(författare)
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Role of Aromatic Amino Acids in Lipopolysaccharide and Membrane Interactions of Antimicrobial Peptides for use in Plant Disease Control
- 2016
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 291:25, s. 13301-13317
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Tidskriftsartikel (refereegranskat)abstract
- KYE28(KYEITTIHNLFRKLTHRLFRRNFGYTLR), the representative sequence of helix D of heparin co-factor II, was demonstrated to be potent against agronomically important Gram-negative plant pathogens X. vesicatoria and X. oryzae,capable of inhibiting disease symptoms in detached tomato leaves. NMR studies in presence of lipopolysaccharide provided structural insights into the mechanisms underlying this, notably in relation to outer membrane permeabilisation. The three-dimensional solution structure of KYE28 in LPS is characterised by a N-ter helical segment, an intermediate loop and an extended C-ter. The two termini are in close proximity to each other via aromatic packing interactions, while the positively charged residues formed an exterior polar shell. To further demonstrate the importance of the aromatic residues for this, a mutant peptide KYE28A, with Ala substitutions at F11, F19, F23 and Y25 showed attenuated antimicrobial activity at high salt concentrations, as well as lower membrane disruption and LPS binding abilities compared to KYE28. In contrast to KYE28, KYE28A adopted an opened out helical structure in LPS with extended N- and C-ter and a small break in between the helical segments. Aromatic packing interactions were completely lost, although hydrophobic interaction between the side chains of hydrophobic residues were still partly retained, imparting an amphipathic character and explaining its residual antimicrobial activity and LPS binding as observed from ellipsometry and ITC. We thus present important structural aspects of KYE28, constituting an aromatic zipper, of potential importance, for the development of novel plant protection agents and therapeutic agents.
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| 21. |
- Duong, Dinh Thuy, et al.
(författare)
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Pronounced peptide selectivity for melanoma through tryptophan end-tagging
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Effects of oligotryptophan end-tagging on the uptake of arginine-rich peptides into melanoma cells was investigated under various conditions and compared to that into non-malignant keratinocytes, fibroblasts, and erythrocytes, also monitoring resulting cell toxicity. In parallel, biophysical studies on peptide binding to, and destabilization of, model lipid membranes provided mechanistic insight into the origin of the selectivity between melanoma and non-malignant cells. Collectively, the results demonstrate that W-tagging represents a powerful way to increase selective peptide internalization in melanoma cells, resulting in toxicity against these, but not against the non-malignant cells. These effects were shown to be due to increased peptide adsorption to the outer membrane in melanoma cells, caused by the presence of anionic lipids such as phosphatidylserine and ganglioside GM1, and to peptide effects on mitochondria membranes and resulting apoptosis. In addition, the possibility of using W-tagged peptides for targeted uptake of nanoparticles/drug carriers in melanoma was demonstrated, as was the possibility to open up the outer membrane of melanoma cells in order to facilitate uptake of low Mw anticancer drugs, here demonstrated for doxorubicin.
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| 22. |
- Eklund, Yvonne, et al.
(författare)
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Mycosis Fungoides: A Retrospective Study of 44 Swedish Cases.
- 2016
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Ingår i: Acta Dermato-Venereologica. - : Medical Journals Sweden AB. - 1651-2057 .- 0001-5555. ; 96:5, s. 669-673
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Tidskriftsartikel (refereegranskat)abstract
- Mycosis fungoides (MF) is a primary cutaneous T-cell lymphoma with slow disease progression. There is a lack of descriptive data from Sweden concerning patients with this diagnosis. This study extracted data on patients admitted to the dermatology department at Lund University Hospital, Sweden from 1996 to 2010. Forty-four patients with clinically and histopathologically verified MF were identified during the period, with a mean follow-up time of 5.6 years. Median age at initial diagnosis was 64 years. In several cases other skin diseases preceded MF onset, such as non-specific dermatitis (32%) and parapsoriasis (30%). The majority of patients (86%, n = 38) had limited-stage (IA-IB) disease at the time of diagnosis. Overall response rate to psoralen plus ultraviolet A (PUVA) treatment was 81%. In adnexal MF, a trend to higher rate of progression to an advanced stage was observed when compared with non-adnexal disease (40% and 21%, respectively). Increased levels of soluble interleukin-2 (IL-2) receptor correlated with disease stage, being elevated in advanced stages or adnexal disease, but almost never in early non-adnexal limited-stage disease. Overall mortality was 25%, but only 11% could be verified as caused by MF.
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| 23. |
- Fazil, Mobashar Hussain Urf Turabe, et al.
(författare)
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A C-terminal peptide of TFPI-1 facilitates cytosolic delivery of nucleic acid cargo into mammalian cells
- 2020
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Ingår i: Biochimica et Biophysica Acta - Biomembranes. - : Elsevier BV. - 0005-2736. ; 1862:2
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Tidskriftsartikel (refereegranskat)abstract
- Efficient intracellular nucleic acid delivery into mammalian cells remains a long-standing challenge owing to poor cell permeability and uptake of naked nucleic acids across the cell membrane and limited cargo stability. Conventional delivery methods have several drawbacks, such as cytotoxicity, limited cell-type applicability, low efficiency, hindrances that limit the potential of oligonucleotide delivery in functional genomics, therapeutics and diverse research applications. Thus, new approaches that are robust, safe, effective and valid across multiple cell types are much needed. Here, we demonstrate that GGL27, a TFPI-1-derived novel cationic host defence peptide, facilitates the delivery of nucleic acid cargo into the cytosol of a range of mammalian cells. The GGL27 peptide is non-cytotoxic and is internalized in a broad range of mammalian cell-types, including transformed cell lines and primary cells. GGL27 spontaneously forms complexes with nucleic acids of variable sizes, protects them from nuclease degradation, and delivers cargo effectively. Together, our observations demonstrate the versatile cell-penetrating property of GGL27, providing an excellent template for developing a simple, non-toxic peptide-based cytosolic delivery tool for wide use in biomedical research.
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| 24. |
- Fransson, L Å, et al.
(författare)
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Effects of cycloheximide, brefeldin A, suramin, heparin and primaquine on proteoglycan and glycosaminoglycan biosynthesis in human embryonic skin fibroblasts
- 1992
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Ingår i: Biochimica et Biophysica Acta. - 0006-3002. ; 1137:3, s. 287-297
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Tidskriftsartikel (refereegranskat)abstract
- (1) We have isolated radiolabelled proteoglycans and glycosaminoglycans produced by human embryonic skin fibroblasts in the presence of (a) cycloheximide to inhibit protein synthesis or (b) brefeldin A to impede transport between the endoplasmic reticulum and the Golgi complex or (c) suramin, heparin or primaquine to interfere with internalization, recycling and degradation. Effects on glycosaminoglycan synthesis were assayed separately by using exogenous p-nitrophenyl beta-D-xylopyranoside (and [3H]galactose) or 125I-labelled p-hydroxyphenyl beta-D-xylopyranoside as initiators. (2) Inhibition of protein synthesis or blocking of transport to the Golgi complex prevented production of most of the proteoglycans with one exception: Cell-associated heparan sulphate-proteoglycan was still produced at 20% of the control level. (3) Treatment with suramin or heparin resulted in decreased deposition of proteoglycan in the pericellular matrix but increased accumulation of cell-associated proteoglycan. Primaquine blocked all proteoglycan synthesis. (4) In the presence of cycloheximide, exogenous beta-D-xyloside initiated galactosaminoglycan production. In contrast, in brefeldin A-treated cells, synthesis was completely abolished. Not even formation of the linkage-region trisaccharide could be detected. (5) These results suggest that exogenous xyloside enters the endoplasmic reticulum and is subsequently transported to the trans-Golgi complex where all further steps involved in glycosaminoglycan assembly takes place. (6) Heparan sulphate proteoglycan produced by brefeldin A-treated cells could be derived from (a) an intracellular pool of preformed core protein located to the trans-Golgi complex, or (b) resident proteoglycan that was either deglycanated/reglycanated or chain-extended. As combined treatment with suramin and brefeldin A markedly reduced cell-associated proteoglycan production, the latter possibility is favoured.
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| 25. |
- Fransson, Lars-Åke, et al.
(författare)
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Oligosaccharide mapping of proteoglycan-bound and xyloside-initiated dermatan sulfate from fibroblasts
- 1991
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Ingår i: Glycoconjugate Journal. - 1573-4986. ; 8:2, s. 108-115
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Tidskriftsartikel (refereegranskat)abstract
- The copolymeric structure of dermatan sulfate chains synthesized by skin fibroblasts has been examined. Chains initiated onto exogeneous p-nitrophenyl-beta-D-xylopyranoside or attached to protein in a large proteoglycan, PG-L, and two small proteoglycans, PG-S1 and PG-S2, have been compared by using high resolution electrophoresis and gel chromatography of oligosaccharides generated by specific enzymatic or chemical degradations. The results confirm that chains attached to PG-L are glucuronate-rich, whereas novel findings indicate that chains attached to either of the two PG-S variants yield closely similar oligosaccharide maps, have approximately equal glucuronate and iduronate content and contain over 90% 4-sulfated disaccharide repeating units. Dermatan sulfate chains built onto xyloside at concentrations of 50 microM and below have a copolymeric structure similar to that of chains from the two PG-S variants. These findings indicate that the polymer-modifying machinery can generate chains with extended iduronate-containing repeats also when the xylose primer is not linked to core protein.
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