| 1. |
- Andersson, Emil, et al.
(författare)
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Low pericyte coverage of endometrial microvessels in heavy menstrual bleeding correlates with the microvessel expression of VEGF-A.
- 2015
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Ingår i: International Journal of Molecular Medicine. - : Spandidos Publications. - 1791-244X .- 1107-3756. ; 35:2, s. 433-438
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Tidskriftsartikel (refereegranskat)abstract
- A prospective clinical study was carried out to investigate whether endometrial microvessels in patients with idiopathic heavy menstrual bleeding (HMB) of endometrial origin (HMB-E) are fragile due to low pericyte coverage. Idiopathic HMB-E is characterized by large endothelial cell gaps related to the microvascular overexpression of vascular endothelial growth factor (VEGF)-A and VEGF receptors 1-3. A total of 10 women with a normal menstrual cycle and a history of HMB of <5 years, and 17 healthy women with a normal menstrual cycle were recruited from the Karolinska University Hospital. Blood samples were obtained for hormone analysis and coagulation tests. Endometrial biopsies were collected in the proliferative or in the secretory phase. Pericyte coverage was assessed using immunohistochemical staining for smooth muscle actin-α (SMAα) and by image analysis (microvascular density) of endometrial biopsies from 10 patients with HMB-E and 17 healthy ovulating women (control subjects). Previously published data on endothelial cell gap size and the expression of VEGF receptors were used. Although microvascular density did not differ between the patients with HMB-E and the control subjects, the number of SMAα-positive microvessels in the proliferative phase was significantly (P=0.005) lower in the patients with HMB-E than in the control subjects. Moreover, the number of SMAα-positive microvessels in the control subjects was significantly fewer in the secretory (P=0.04) than in the proliferative phase, whereas this number did not differ among the patients with HMB-E regardless of phase. A significant negative correlation was observed between the number of VEGF-A-positive microvessels and microvessels with pericyte coverage (r=0.8; P=0.04). Finally, the endothelial cell layer was significantly thicker in the patients with HMB-E than in the control subjects. Thus, the upregulation of VEGF-A in idiopathic HMB-E is associated with a low pericyte coverage during the proliferative phase of intense angiogenesis, which may confer vessel fragility, possibly leading to excessive blood loss.
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| 2. |
- Astvaldsson, Asgeir, 1981-, et al.
(författare)
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Proximity Staining using Enzymatic Protein Tagging in Diplomonads
- 2019
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Ingår i: mSphere. - 2379-5042. ; 4:2
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Tidskriftsartikel (refereegranskat)abstract
- The diplomonads are a group of understudied eukaryotic flagellates whose most prominent member is the human pathogen Giardia intestinalis. Methods commonly used in other eukaryotic model systems often require special optimization in diplomonads due to the highly derived character of their cell biology. We have optimized a proximity labeling protocol using pea ascorbate peroxidase (APEX) as a reporter for transmission electron microscopy (TEM), to enable study of ultrastructural cellular details in diplomonads. Currently available TEM-compatible tags requires light-induced activation (1, 2) or are inactive in many cellular compartments (3) while ascorbate peroxidase has not been shown to have those limitations. Here we have optimized the in vivo activity of two versions of pea ascorbate peroxidase (APXW41F and APEX) using the diplomonad fish parasite Spironucleus salmonicida, a relative of G. intestinalis. We exploited the well-known peroxidase substrates, Amplex UltraRed and 3,3’-diaminobenzidine (DAB), to validate the activity of the two tags and argue that APEX is the most stable version to use in Spironucleus salmonicida. Next, we fused APEX to proteins with established localization to evaluate the activity of APEX in different cellular compartments of the diplomonad cell and used Amplex UltraRed as well as antibodies along with super-resolution microscopy to confirm the protein-APEX localization. The ultrastructural details of protein-APEX fusions were determined by TEM and we observed marker activity in all cellular compartments tested when using the DAB substrate. Finally, we show that the optimized conditions established for S. salmonicida can be used in the related diplomonad G. intestinalis.
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| 3. |
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| 4. |
- Bengtsson, Torbjörn, 1955-, et al.
(författare)
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Plantaricin NC8 αβ exerts potent antimicrobial activity against Staphylococcus spp. and enhances the effects of antibiotics
- 2020
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- The use of conventional antibiotics has substantial clinical efficacy, however these vital antimicrobial agents are becoming less effective due to the dramatic increase in antibiotic-resistant bacteria. Novel approaches to combat bacterial infections are urgently needed and bacteriocins represent a promising alternative. In this study, the activities of the two-peptide bacteriocin PLNC8 αβ were investigated against different Staphylococcus spp. The peptide sequences of PLNC8 α and β were modified, either through truncation or replacement of all L-amino acids with D-amino acids. Both L- and D-PLNC8 αβ caused rapid disruption of lipid membrane integrity and were effective against both susceptible and antibiotic resistant strains. The D-enantiomer was stable against proteolytic degradation by trypsin compared to the L-enantiomer. Of the truncated peptides, β1-22, β7-34 and β1-20 retained an inhibitory activity. The peptides diffused rapidly (2 min) through the bacterial cell wall and permeabilized the cell membrane, causing swelling with a disorganized peptidoglycan layer. Interestingly, sub-MIC concentrations of PLNC8 αβ substantially enhanced the effects of different antibiotics in an additive or synergistic manner. This study shows that PLNC8 αβ is active against Staphylococcus spp. and may be developed as adjuvant in combination therapy to potentiate the effects of antibiotics and reduce their overall use.
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| 5. |
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| 6. |
- Braniste, Viorica, et al.
(författare)
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The gut microbiota influences blood-brain barrier permeability in mice
- 2014
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Ingår i: Science Translational Medicine. - : American Association for the Advancement of Science. - 1946-6234 .- 1946-6242. ; 6:263, s. 263ra158-
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Tidskriftsartikel (refereegranskat)abstract
- Pivotal to brain development and function is an intact blood-brain barrier (BBB), which acts as a gatekeeper to control the passage and exchange of molecules and nutrients between the circulatory system and the brain parenchyma. The BBB also ensures homeostasis of the central nervous system (CNS). We report that germ-free mice, beginning with intrauterine life, displayed increased BBB permeability compared to pathogen-free mice with a normal gut flora. The increased BBB permeability was maintained in germ-free mice after birth and during adulthood and was associated with reduced expression of the tight junction proteins occludin and claudin-5, which are known to regulate barrier function in endothelial tissues. Exposure of germ-free adult mice to a pathogen-free gut microbiota decreased BBB permeability and up-regulated the expression of tight junction proteins. Our results suggest that gut microbiota-BBB communication is initiated during gestation and propagated throughout life.
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| 7. |
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| 8. |
- Docherty-Skogh, Ann-Charlott, et al.
(författare)
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Bone morphogenetic protein-2 delivered by hyaluronan-based hydrogel induces massive bone formation and healing of cranial defects in minipigs
- 2010
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Ingår i: Plastic and reconstructive surgery (1963). - 0032-1052 .- 1529-4242. ; 125:5, s. 1383-1392
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Tidskriftsartikel (refereegranskat)abstract
- Background: Reconstruction of large craniofacial bone defects is a challenge using bone transplants or alloplastic materials. The use of bone morphogenetic protein (BMP)-2 together with a suitable carrier is an attractive option that may facilitate new bone formation. The authors have developed a hydrogel that is formed in situ by the cross-linking of multifunctional hyaluronic acid and polyvinyl alcohol derivatives mixed with hydroxyapatite nanoparticles, in the presence of BMP-2. The aim of this study was to evaluate the suitability of the hydrogel as a carrier for BMP-2 in repairing critical size cranial defects in a minipig model. Methods: Cranial defects (2 × 4 cm) were created in 14 minipigs. The experimental groups were as follows: group 1, craniotomy and application of 5 ml of hydrogel with 1.25 mg of BMP-2 (n = 6); group 2, craniotomy and application of 5 ml of hydrogel without BMP-2 (n = 6); and group 3, craniotomy with no further treatment (n = 2). Results: After 3 months, computed tomographic and histologic examinations were performed. There was spontaneous ossification in the untreated group, but the healing was incomplete. The hydrogel alone demonstrated no further effects. The addition of 1.25 mg of BMP-2 to the hydrogel induced a greater than 100 percent increase in bone volume (p = 0.003) and complete healing of the defects. Histologic examination revealed compact lamellar bone in the BMP group without intertrabecular fibrous tissue, as was seen in the other groups. The hydrogel was resorbed completely within 3 months and, importantly, caused no inflammatory reaction. Conclusion: The injectable hydrogel may be favorable as a BMP-2 carrier for bone reconstruction.
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| 10. |
- Dubois, Louise, et al.
(författare)
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Human erythrocyte-derived nanovesicles can readily be loaded with doxorubicin and act as anticancer agents
- 2018
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Ingår i: Cancer Research Frontiers. - : Cancer Research Frontiers. - 2328-5249. ; 4:1, s. 13-26
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: In future therapeutics new formulas are needed that assure lower doses, fewer side effects, targeted administration and protection of the drug from degradation. In a first step to fulfil the requirements defined above, we carried out an in vitro study by developing a new procedure to encapsulate drugs using native vesicles first from prostasomes and then from erythrocyte membranes known to be well tolerated. The new method for production of drug delivery vesicles utilized osmotic loading of detergent resistant membranes (DRMs).Materials and methods: DRMs of prostasomes and prepared human erythrocyte membranes were extracted and separated in a sucrose gradient at a density of 1.10 g/mL containing 1% Triton X-100. These DRMs were characterized by electron microscopy (transmission and scanning EM) and loaded with low and high molecular compounds. PC3 prostate cancer cells were treated with doxorubicin loaded DRMs in triplicate. DAPI (nuclear fluorescent stain) was included and fluorescence microscopic pictures were taken before the cells were trypsinized and counted after 48h.Results: The content of the well separated band was observed ultrastructurally as small spherical, double layered membrane vesicles, (DRM vesicles) which harbored hyperosmolar sucrose of the gradient. Encapsulated hyperosmolar sucrose induced a transient osmotic lysis of the DRM vesicles when suspended in isotonic buffer containing loading molecules allowing vesicular inclusion. After this proof of concept, the method was finally employed for doxorubicin loading of DRM vesicles from human erythrocytes. When incubating such vesicles with PC3 cells a complete arrest of growth was observed in sharp contrast to PC3 cells incubated with plain doxorubicin in similar conditions.Conclusion: The present results open up new possibilities for using DRM vesicles as drug delivery vesicles.
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