| 231. |
- Svensson, Daniel, et al.
(författare)
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Human endogenous peptide p33 inhibits detrimental effects of LL-37 on osteoblast viability
- 2015
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Ingår i: Journal of Periodontal Research. - : John Wiley & Sons. - 0022-3484 .- 1600-0765. ; 50:1, s. 80-88
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Tidskriftsartikel (refereegranskat)abstract
- Background and Objective: High levels of the antimicrobial peptide, LL-37, are detected in gingival crevicular fluid from patients with chronic periodontitis. LL-37 not only shows antimicrobial activity but also affects host-cell viability. The objective of the present study was to identify endogenous mechanisms that antagonize the detrimental effects of LL-37 on osteoblast viability, focusing on the human peptide p33 expressed on the surface of various cell types. Material and Methods: Human osteoblast-like MG63 cells and human hFOB1.19 osteoblasts were treated with or without LL-37 in the presence or absence of p33. Recombinant human p33 was expressed in an Escherichia coli expression system. Lactate dehydrogenase (LDH) was assessed using an enzymatic spectrophotometric assay. DNA synthesis was determined by measuring [3H]-thymidine incorporation. Cell number was assessed by counting cells in a Bu€rker chamber. Intracellular Ca2+ was monitored by recording Fluo 4-AM fluorescence using a laser scanning confo- cal microscope. Cellular expression of p33 was determined by western blotting. Results: LL-37 caused a concentration-dependent release of LDH from human osteoblasts, showing a half-maximal response value (EC50) of 4 lM and a rapid and sustained rise in the intracellular Ca2+ concentration of osteoblasts, sug- gesting that LL-37 forms pores in the cell membrane. p33 (10 lM) inhibited the LL-37-induced LDH release and LL-37-evoked rise in intracellular Ca2+ con- centration, suggesting that p33 prevents LL-37-induced permeabilization of the cell membrane. Moreover, p33 blocked LL-37-induced attenuation of osteoblast numbers. Also, mucin antagonized, at concentrations representative for nonsti- mulated whole saliva, LL-37-evoked LDH release, whilst cationic endogenous polyamines had no impact on LL-37-induced LDH release from osteoblasts. Conclusions: The endogenous peptide p33 prevents LL-37-induced reduction of human osteoblast viability. Importantly, this mechanism may protect the osteo- blasts from LL-37-induced cell damage in patients suffering from chronic peri- odontitis associated with high levels of LL-37 locally.
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| 232. |
- Svensson, Daniel, et al.
(författare)
-
LL-37-induced host cell cytotoxicity depends on cellular expression of the globular C1q receptor (p33).
- 2016
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Ingår i: The Biochemical journal. - 1470-8728. ; 473, s. 87-98
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Tidskriftsartikel (refereegranskat)abstract
- The human host-defense peptide LL-37 not only displays antimicrobial activity but also immune modulating properties that trigger intracellular signaling events in host cells. Since the cytolytic activity of high LL-37 concentrations affects cell viability, the function of LL-37 requires tight regulation. Eukaryotic cells therefore benefit from protective measures to prevent harmful effects of LL-37. p33, also known as globular C1q receptor, is reported to act as an LL-37 antagonist by binding the peptide thereby reducing its cytotoxic activity. In this report, we show that high levels of endogenous p33 correlate with an increased viability in human cells treated with LL-37. Sub-cellular localization analysis showed p33 distribution at the mitochondria, the plasma membrane and in the cytosol. Strikingly, cytosolic over-expression of p33 significantly antagonized detrimental effects of LL-37 on cell fitness, while the reverse effect was observed by siRNA-induced down-regulation of p33. However, modulation of p33 expression had no effect on LL-37-induced plasma membrane pore forming capacity pointing to an intracellular mechanism. A scavenging function of intracellular p33 is further supported by co-immunoprecipitation experiments, showing a direct interaction between intracellular p33 and LL-37. Thus, our findings support an important role of intracellular p33 in maintaining cell viability by counteracting LL-37-induced cytotoxicity.
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| 233. |
- Svensson, Daniel, et al.
(författare)
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Secretory leukocyte protease inhibitor regulates human periodontal ligament cell production of pro-inflammatory cytokines
- 2017
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Ingår i: Inflammation Research. - : Springer Science and Business Media LLC. - 1023-3830 .- 1420-908X. ; 66:9, s. 823-831
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Regulation of immune-like cell properties of periodontal ligament (PDL) cells is not understood. We investigate the importance of secretory leukocyte protease inhibitor (SLPI) for production of pro-inflammatory cytokines in human PDL cells. Materials and methods: PDL cells were isolated from teeth extracted for orthodontic reasons. Cellular location of SLPI was investigated by immunocytochemistry. Cytokine transcript and protein expression were assessed by quantitative real-time RT-PCR and Western blotting. SLPI gene activity was knocked-down by siRNA. NF-κB signaling was assessed by measuring IκBα, and phosphorylated p65 and p105 protein expression. Results: PDL cells showed cytoplasmic expression of SLPI. Cellular expression level of SLPI negatively correlated to LPS-induced stimulation of IL-6 and MCP-1. Both SLPI gene activity and protein were reduced by about 70% in PDL cells treated with SLPI siRNA compared to cells treated with non-coding construct. Treatment with SLPI siRNA was associated with up-regulation of both basal and LPS-stimulated IL-6, MCP-1 and TLRs mRNA expression. The up-regulation of MCP-1 transcript in SLPI siRNA-treated cells was confirmed on protein level. SLPI siRNA-treatment enhanced the phosphorylated NF-κB p105 protein expression. Conclusions: SLPI regulates PDL cell pro-inflammatory cytokine expression and modulates NF-κB signaling, suggesting that SLPI governs the immune cell-like properties of PDL cells.
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| 234. |
- Svensson, Daniel, et al.
(författare)
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Sesquiterpene lactones from Ambrosia arborescens Mill. inhibit pro-inflammatory cytokine expression and modulate NF-κB signaling in human skin cells
- 2018
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Ingår i: Phytomedicine. - : Elsevier BV. - 0944-7113. ; 50, s. 118-126
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Tidskriftsartikel (refereegranskat)abstract
- Background: Ambrosia arborescens has been used in Andean traditional medicine to reduce problems associated with various inflammatory diseases and conditions, although the underlying mechanism is unknown. Hypothesis/purpose: The sesquiterpene lactones (SLs) coronopilin and damsin, which are major secondary metabolites of A. arborescens, have anti-inflammatory activity by attenuation of IL-6 and MCP-1 expression and inhibition of NF-κB in human dermal fibroblasts (HDFa) and human keratinocytes (HaCaT). Study design: In order to confirm a high concentration of damsin and coronopilin in the plant material, a quantitative method was developed. The effect of the pure compounds on cytokine and NF-κB expression was examined, as well as their effects on HDFa and HaCaT cell morphology and viability. Methods: Coronopilin and damsin were quantified by HPLC-DAD analysis, from EtOAc extracts of the aerial parts of A. arborescens. Cell morphology was investigated by phase-contrast microscopy and cell viability by the MTT assay. IL-6 and MCP-1 cytokine gene expression was assessed by quantitative real-time RT-PCR in LPS stimulated cells. The NF-κB pathway was studied through western blotting of the phosphorylated forms of p65 and p50/p105, as well as the non-phosphorylated IκB. Dexamethasone was used as positive control. Results: Dry aerial parts contained 12.3 mg/g and 13.4 mg/g of coronopilin and damsin, respectively. Treatment with either compound (1–10 µM) for 24 h attenuated LPS-induced mRNA expression of the pro-inflammatory cytokine IL-6 and the chemokine MCP-1 in HDFa cells. The down-regulation of MCP-1 mRNA induced by coronopilin and damsin was confirmed on the protein level. Damsin reduced phosphorylated p65 and p105 subunits in HDFa cells. Neither coronopilin nor damsin affected HDFa cell morphology and viability within the used concentration range (1–10 µM). Also, in HaCaT cells, treatment with damsin (1–10 µM) for 24 h inhibited the MCP-1 expression, and damsin thereby attenuated cytokine expression both in HDFa and HaCaT cells. Conclusion: We show that coronopilin and damsin from A. arborescens inhibit pro-inflammatory IL-6 and MCP-1 expression in human skin cells via NF-κB inhibition, suggesting that they may be useful for antagonizing inflammatory conditions of the human skin.
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| 235. |
- Svensson, Daniel, et al.
(författare)
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The host defense peptide LL-37 is detected in human parotid and submandibular/sublingual saliva and expressed in glandular neutrophils
- 2018
-
Ingår i: European Journal of Oral Sciences. - : Blackwell Munksgaard. - 0909-8836 .- 1600-0722. ; 126:2, s. 93-100
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Tidskriftsartikel (refereegranskat)abstract
- The human host defense peptide, LL-37, is an important player in the first line of defense against invading microorganisms. LL-37 and its precursor, hCAP18, have been detected in unstimulated whole saliva but no reports showing hCAP18/LL-37 in isolated, parotid, and/or submandibular/sublingual saliva have been presented. Here, we measured the levels of hCAP18/LL-37 in human parotid and submandibular/sublingual saliva and investigated the expression of hCAP18/LL-37 in parotid and submandibular gland tissue. Parotid and submandibular/sublingual saliva was collected from healthy volunteers, and the levels of hCAP18/LL-37 in saliva were analyzed by dot blot, ELISA, and western blotting. Cellular expression of hCAP18/LL-37 in human parotid and submandibular glands was investigated by immunohistochemistry. Immunoreactivity for hCAP18/LL-37 was detected in both parotid and submandibular/sublingual saliva of all individuals. The concentration of hCAP18/LL-37 was similar in parotid and submandibular/sublingual saliva, and was determined by densitometric scanning of each dot and normalization to the total protein concentration of each sample, and by ELISA. Double immunohistochemistry revealed that intravascular neutrophils of both parotid and submandibular glands express hCAP18/LL-37. For the first time, we demonstrate hCAP18/LL-37 in isolated human parotid and submandibular/sublingual saliva and expression of hCAP18/LL-37 in glandular intravascular neutrophils, indicating that neutrophils of the major salivary glands contribute to the LL-37 content of whole saliva.
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| 236. |
- Svensson, Daniel, et al.
(författare)
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Vitamin D-induced up-regulation of human keratinocyte cathelicidin anti-microbial peptide expression involves retinoid X receptor α
- 2016
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Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; , s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- The biologically active form of vitamin D, 1α,25-dihydroxyvitamin D3 (1,25D3), has been reported to positively regulate the human cathelicidin anti-microbial peptide (CAMP) gene coding for LL-37, but the mechanisms are not completely understood. We have determined the expression of CAMP, vitamin D receptor (VDR), and the retinoid X receptor (RXR) isoforms in human skin and gingival tissue biopsies and investigated the signaling pathways involved in 1,25D3-induced upregulation of CAMP. Human skin and gingival biopsies exhibited few VDR-immunoreactive cells within the stratum basale, whereas rat colon enterocytes (positive control) possessed abundant VDR immunoreactivity. Nuclear VDR immunoreactivity was demonstrated in human skin keratinocytes (HaCaT cells). Gene analysis revealed that human skin biopsies expressed higher levels of both CAMP and RXRα mRNA than human gingival biopsies, whereas VDR and RXRβ transcript levels were similar in skin and gingiva. In HaCaT cells, treatment with 1,25D3 (5 nM and 1 μM) for 4 and 24 h up-regulated CAMP mRNA several fold, and treatment with 1,25D3 for 24 h increased protein expression of the pro-form of LL-37 (hCAP-18) by about 13 times. The 1,25D3-evoked stimulation of HaCaT CAMP expression was associated with attenuated VDR mRNA and protein expression. Treatment with RXRα short interfering RNA reversed the 1,25D3-induced CAMP expression in HaCaT cells, showing that RXRα is involved in the up-regulation of CAMP by 1,25D3. We conclude that the 1,25D3-evoked stimulation of CAMP expression in human skin keratinocytes is dependent on RXRα but is not associated with the up-regulation of VDR expression.
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| 237. |
- Svensson, Daniel, et al.
(författare)
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Vitamin D3 modulates the innate immune response through regulation of the hCAP-18/LL-37 gene expression and cytokine production.
- 2016
-
Ingår i: Inflammation Research. - : Springer Science and Business Media LLC. - 1420-908X .- 1023-3830. ; 65:1, s. 25-32
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Forskningsöversikt (refereegranskat)abstract
- The steroid hormone metabolite of vitamin D3, 1α,25-dihydroxyvitamin D3 (1,25D3), promotes osteogenic activity and regulates calcium and phosphate metabolism, which are actions regarded as classical vitamin D-regulated functions. Besides its role in these processes, 1,25D3 also seems implicated in the host defense against microbial/pro-inflammatory attacks. Low serum levels of vitamin D3 (vitamin D deficiency) are associated with osteoporosis and increased risk of fractures but also inflammatory diseases and their disease progression, presumably via mechanisms associated with 1,25D3-evoked modulation of the innate immune system. 1,25D3 has been reported to modulate many inflammatory responses, suggesting that it regulates multiple transcriptional targets within the inflammatory system.
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| 238. |
- Svensson, Elisabeth, et al.
(författare)
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Mood effects of diazepam and caffeine.
- 1980
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Ingår i: Psychopharmacology. - 0033-3158. ; 67:1, s. 73-80
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Tidskriftsartikel (refereegranskat)abstract
- Changes in mood after administration of Diazepam and Caffeine were analyzed. Six aspects were studied: pleasantness, activation, extraversion, calmness, social orientation and control. In addition to this check list, mood ratings using magnitude estimation of selected adjectives were obtained. It was found that Diazepam decreased feelings of activation and extraversion and increased calmness. Caffeine had no clear effects on the check list, but on the magnitude estimation scale some effects opposite to those of Diazepam were observed. Men reported a higher degree of pleasantness than women after administration of Diazepam. No differences in heart rate were found. Few distinct scale values were utilized on the magnitude estimation scale and the discriminative power was found to be larger for the check list than for the magnitude estimation scale.
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| 239. |
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| 240. |
- Svensson, G, et al.
(författare)
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Quantitative measurements of collateral arterial blood flow in nonarterialized rat liver grafts.
- 1994
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Ingår i: Transplant international : official journal of the European Society for Organ Transplantation. - 0934-0874. ; 7:2, s. 136-9
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Tidskriftsartikel (refereegranskat)abstract
- The early development of arterial blood flow in the grafted liver after orthotopic liver transplantation in the rat without reconstruction of the hepatic artery was studied. Arterial liver blood flow was measured on day 21 after transplantation with NEN-TRAC microspheres (size 15.5 +/- 0.1 microns) and labelled with 103Ru. The arterial liver blood flow in the grafted liver was 0.778 +/- 0.247 ml/min per gram for transplanted rats after 21 days. One day after transplantation, the blood flow was only 0.006 +/- 0.002 ml/min per gram. The results of this study demonstrate that there was no arterial blood flow on day 1 after transplantation, as expected, but that there was a high arterial blood flow in the transplanted liver by day 21. This was also supported by the angiographic findings. The early development of arterial blood flow via collaterals may account for the excellent results that we and others have attained in orthotopic liver transplantation without rearterialization in the rat.
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