| 1. |
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| 2. |
- Lundell, Anna, et al.
(författare)
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Structural basis for interactions between tenascins and lectican C-type lectin domains: evidence for a crosslinking role for tenascins.
- 2004
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Ingår i: Structure. - : Elsevier BV. - 0969-2126. ; 12:8, s. 1495-1506
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Tidskriftsartikel (refereegranskat)abstract
- The C-terminal G3 domains of lecticans mediate crosslinking to diverse extracellular matrix (ECM) proteins during ECM assembly, through their C-type lectin (CLD) subdomains. The structure of the rat aggrecan CLD in a Ca(2+)-dependent complex with fibronectin type III repeats 3-5 of rat tenascin-R provides detailed support for such crosslinking. The CLD loops bind Ca2+ like other CLDs, but no carbohydrate binding is observed or possible. This is thus the first example of a direct Ca(2+)-dependent protein-protein interaction of a CLD. Surprisingly, tenascin-R does not coordinate the Ca2+ ions directly. Electron microscopy confirms that full-length tenascin-R and tenascin-C crosslink hyaluronan-aggrecan complexes. The results are significant for the binding of all lectican CLDs to tenascin-R and tenascin-C. Comparison of the protein interaction surface with that of P-selectin in complex with the PGSL-1 peptide suggests that direct protein-protein interactions of Ca(2+)-binding CLDs may be more widespread than previously appreciated.
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| 3. |
- Olin, Anders, et al.
(författare)
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The proteoglycans aggrecan and Versican form networks with fibulin-2 through their lectin domain binding
- 2001
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 276:2, s. 1253-1261
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Tidskriftsartikel (refereegranskat)abstract
- Aggrecan, versican, neurocan, and brevican are important components of the extracellular matrix in various tissues. Their amino-terminal globular domains bind to hyaluronan, but the function of their carboxyl-terminal globular domains has long remained elusive. A picture is now emerging where the C-type lectin motif of this domain mediates binding to other extracellular matrix proteins. We here demonstrate that aggrecan, versican, and brevican lectin domains bind fibulin-2, whereas neurocan does not. As expected for a C-type lectin, the interactions are calcium-dependent, with K(D) values in the nanomolar range as measured by surface plasmon resonance. Solid phase competition assays with previously identified ligands demonstrated that fibulin-2 and tenascin-R bind the same site on the proteoglycan lectin domains. Fibulin-1 has affinity for the common site on versican but may bind to a different site on the aggrecan lectin domain. By using deletion mutants, the interaction sites for aggrecan and versican lectin domains were mapped to epidermal growth factor-like repeats in domain II of fibulin-2. Affinity chromatography and solid phase assays confirmed that also native full-length aggrecan and versican bind the lectin domain ligands. Electron microscopy confirmed the mapping and demonstrated that hyaluronan-aggrecan complexes can be cross-linked by the fibulins.
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| 4. |
- Stattin, Eva-Lena, et al.
(författare)
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A missense mutation in the aggrecan C-type lectin domain disrupts extracellular matrix interactions and causes dominant familial osteochondritis dissecans
- 2010
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Ingår i: American Journal of Human Genetics. - : Elsevier BV. - 0002-9297 .- 1537-6605. ; 86:2, s. 126-137
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Tidskriftsartikel (refereegranskat)abstract
- Osteochondritis dissecans is a disorder in which fragments of articular cartilage and subchondral bone dislodge from the joint surface. We analyzed a five-generation family in which affected members had autosomal-dominant familial osteochondritis dissecans. A genome-wide linkage analysis identified aggrecan (ACAN) as a prime candidate gene for the disorder. Sequence analysis of ACAN revealed heterozygosity for a missense mutation (c.6907G > A) in affected individuals, resulting in a p.V2303M amino acid substitution in the aggrecan G3 domain C-type lectin, which mediates interactions with other proteins in the cartilage extracellular matrix. Binding studies with recombinant mutated and wild-type G3 proteins showed loss of fibulin-1, fibulin-2, and tenascin-R interactions for the V2303M protein. Mass spectrometric analyses of aggrecan purified from patient cartilage verified that V2303M aggrecan is produced and present in the tissue. Our results provide a molecular mechanism for the etiology of familial osteochondritis dissecans and show the importance of the aggrecan C-type lectin interactions for cartilage function in vivo.
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| 5. |
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| 6. |
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| 7. |
- Aspberg, Anders, et al.
(författare)
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Cartilage proteoglycans
- 2016
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Ingår i: Cartilage: Volume 1: Physiology and Development. - Cham : Springer International Publishing. - 9783319295688 - 9783319295664 ; 1, s. 1-22
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Bokkapitel (refereegranskat)abstract
- Proteoglycans are key components of the cartilage extracellular matrix and essential for normal tissue function. The core protein and the glycosaminoglycan chains both contribute to function and provide different properties of the individual proteoglycans. This review is focused on the two main families of cartilage proteoglycans.The first of these is the lectican family, including aggrecan, versican, and the cartilage link protein. The aggregating proteoglycan network formed by aggrecan, link protein, and hyaluronan provides biomechanical properties that give the tissue its ability to withstand and distribute load.The second group discussed is the small leucine-rich repeat proteoglycan family, which includes decorin, biglycan, asporin, fibromodulin, lumican, keratocan, osteoadherin, proline-/arginine-rich end leucine-rich repeat protein, epiphycan, mimecan, opticin, chondroadherin, and chondroadherin-like. These proteoglycans bind collagens and are important regulators of cartilage extracellular matrix assembly. In addition, some of these proteoglycans bind and regulate growth factors and their receptors and regulate innate immunity through interactions with Toll-like receptors or the complement system.This review will give an overview of the structure and function of the different aggregating proteoglycans and small leucine-rich repeat proteoglycans in normal cartilage extracellular matrix.
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| 8. |
- Aspberg, Anders, et al.
(författare)
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Fibulin-1 is a ligand for the C-type lectin domains of aggrecan and versican
- 1999
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 274:29, s. 20444-20449
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Tidskriftsartikel (refereegranskat)abstract
- The aggregating proteoglycans (aggrecan, versican, neurocan, and brevican) are important components of many extracellular matrices. Their N-terminal globular domain binds to hyaluronan, but the function of their C-terminal region containing a C-type lectin domain is less clear. We now report that a 90-kDa protein copurifies with recombinant lectin domains from aggrecan and versican, but not from the brain-specific neurocan and brevican. Amino acid sequencing of tryptic peptides from this protein identified it as fibulin-1. This extracellular matrix glycoprotein is strongly expressed in tissues where versican is expressed (blood vessels, skin, and developing heart), and also expressed in developing cartilage and bone. It is thus likely to interact with these proteoglycans in vivo. Surface plasmon resonance measurements confirmed that aggrecan and versican lectin domains bind fibulin-1, whereas brevican and neurocan do not. As expected for a C-type lectin, the interactions with fibulin-1 are Ca2+-dependent, with KD values in the low nanomolar range. Using various deletion mutants, the binding site for aggrecan and versican lectin domains was mapped to the epidermal growth factor-like repeats in domain II of fibulin-1. No difference in affinity was found for deglycosylated fibulin-1, indicating that the proteoglycan C-type lectin domains bind to the protein part of fibulin-1.
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| 9. |
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| 10. |
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| 11. |
- Aspberg, Anders, et al.
(författare)
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The C-type lectin domains of lecticans, a family of aggregating chondroitin sulfate proteoglycans, bind tenascin-R by protein-protein interactions independent of carbohydrate moiety
- 1997
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Ingår i: Proceedings of the National Academy of Sciences. - 1091-6490. ; 94:19, s. 10116-10121
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Tidskriftsartikel (refereegranskat)abstract
- The lecticans are a family of chondroitin sulfate proteoglycans including aggrecan, versican, neurocan, and brevican. The C-terminal globular domains of lecticans are structurally related to selectins, consisting of a C-type lectin domain flanked by epidermal growth factor and complement regulatory protein domains. The C-type lectin domain of versican has been shown to bind tenascin-R, an extracellular matrix protein specifically expressed in the nervous system, and the interaction was presumed to be mediated by a carbohydrate-protein interaction. In this paper, we show that the C-type lectin domain of brevican, another lectican that is specifically expressed in the nervous system, also binds tenascin-R. Surprisingly, this interaction is mediated by a protein-protein interaction through the fibronectin type III domains 3-5 of tenascin-R, independent of any carbohydrates or sulfated amino acids. The lectin domains of versican and other lecticans also bind the same domain of tenascin-R by protein-protein interactions. Surface plasmon resonance analysis revealed that brevican lectin has at least a 10-fold higher affinity than the other lectican lectins. Tenascin-R is coprecipitated with brevican from adult rat brain extracts, suggesting that tenascin-R and brevican form complexes in vivo. These results demonstrate that the C-type lectin domain can interact with fibronectin type III domains through protein-protein interactions, and suggest that brevican is a physiological tenascin-R ligand in the adult brain.
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| 12. |
- Aspberg, Anders, et al.
(författare)
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The versican C-type lectin domain recognizes the adhesion protein tenascin-R
- 1995
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Ingår i: Proceedings of the National Academy of Sciences. - 1091-6490. ; 92:23, s. 10590-10594
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Tidskriftsartikel (refereegranskat)abstract
- The core proteins of large chondroitin sulfate proteoglycans contain a C-type lectin domain. The lectin domain of one of these proteoglycans, versican, was expressed as a recombinant 15-kDa protein and shown to bind to insolubilized fucose and GlcNAc. The lectin domain showed strong binding in a gel blotting assay to a glycoprotein doublet in rat brain extracts. The binding was calcium dependent and abolished by chemical deglycosylation treatment of the ligand glycoprotein. The versican-binding glycoprotein was identified as the cell adhesion protein tenascin-R, and versican and tenascin-R were both found to be localized in the granular layer of rat cerebellum. These results show that the versican lectin domain is a binding domain with a highly targeted specificity. It may allow versican to assemble complexes containing proteoglycan, an adhesion protein, and hyaluronan.
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| 13. |
- Aspberg, Johan, et al.
(författare)
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Estimating the Length of the Preclinical Detectable Phase for Open-Angle Glaucoma
- 2023
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Ingår i: JAMA Ophthalmology. - : American Medical Association (AMA). - 0003-9950 .- 2168-6165. ; 141:1, s. 48-54
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Tidskriftsartikel (refereegranskat)abstract
- IMPORTANCE: A 50% reduction of glaucoma-related blindness has previously been demonstrated in a population that was screened for open-angle glaucoma. Ongoing screening trials of high-risk populations and forthcoming low-cost screening methods suggest that such screening may become more common in the future. One would then need to estimate a key component of the natural history of chronic disease, the mean preclinical detectable phase (PCDP). Knowledge of the PCDP is essential for the planning and early evaluation of screening programs and has been estimated for several types of cancer that are screened for.OBJECTIVE: To estimate the mean PCDP for open-angle glaucoma.DESIGN, SETTING, AND PARTICIPANTS: A large population-based screening for open-angle glaucoma was conducted from October 1992 to January 1997 in Malmö, Sweden, including 32 918 participants aged 57 to 77 years. A retrospective medical record review was conducted to assess the prevalence of newly detected cases at the screening, incidence of new cases after the screening, and the expected clinical incidence, ie, the number of new glaucoma cases expected to be detected without a screening. The latter was derived from incident cases in the screened age cohorts before the screening started and from older cohorts not invited to the screening. A total of 2029 patients were included in the current study. Data were analyzed from March 2020 to October 2021.MAIN OUTCOMES AND MEASURES: The length of the mean PCDP was calculated by 2 different methods: first, by dividing the prevalence of screen-detected glaucoma with the clinical incidence, assuming that the screening sensitivity was 100% and second, by using a Markov chain Monte Carlo (MCMC) model simulation that simultaneously derived both the length of the mean PCDP and the sensitivity of the screening.RESULTS: Of 2029 included patients, 1352 (66.6%) were female. Of 1420 screened patients, the mean age at screening was 67.4 years (95% CI, 67.2-67.7). The mean length of the PCDP of the whole study population was 10.7 years (95% CI, 8.7-13.0) by the prevalence/incidence method and 10.1 years (95% credible interval, 8.9-11.2) by the MCMC method.CONCLUSIONS AND RELEVANCE: The mean PCDP was similar for both methods of analysis, approximately 10 years. A mean PCDP of 10 years found in the current study allows for screening with reasonably long intervals, eg, 5 years.
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| 14. |
- Aspberg, Johan, et al.
(författare)
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Intraocular Pressure Lowering Effect of Latanoprost as First-line Treatment for Glaucoma
- 2018
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Ingår i: Journal of glaucoma. - : Lippincott Williams & Wilkins. - 1057-0829 .- 1536-481X. ; 27:11, s. 976-980
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The purpose of this study was to assess the intraocular pressure (IOP) - reducing effect of latanoprost in treatment-naïve patients with newly detected open-angle glaucoma with no restriction of the level of untreated IOP.METHODS: Eighty-six patients (105 eyes) with a diagnosis of open-angle glaucoma received IOP-lowering therapy with latanoprost. The IOP reduction 1 and 3 months after initiation of treatment was recorded.RESULTS: Mean untreated IOP for all eyes was 26.2 mm Hg (ranging from 10 to 51 mm Hg). The mean pressure reduction was 7.9 mm Hg (28%), with equivalent average levels at 1 and 3 months. The reduction in IOP ranged from -2.3 to 25.3 mm Hg after 1 month, and from -1.3 to 33.3 mm Hg after 3 months. The pressure-lowering effect was considerably more pronounced in eyes with higher untreated IOP; the reduction increased by 0.55 mm Hg per mm Hg higher untreated IOP. Four eyes, with untreated IOP within statistically normal limits, had no or negative IOP-reduction. A regression model predicted that IOP reduction ended at untreated IOP≤16 mm Hg. Multiple regression analysis showed that an additional IOP-lowering effect of 1.28 mm Hg was achieved in eyes with pseudoexfoliation glaucoma.CONCLUSIONS: To the best of our knowledge, this paper is the first to report the IOP-reducing effect of latanoprost treatment at all untreated IOP levels in newly detected glaucoma patients. The effect was proportional to the untreated IOP at all levels above 16 mm Hg and better at higher untreated IOP levels, also in relative terms. Our results further confirm the indication of latanoprost as a first-line therapy for glaucoma.
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| 15. |
- Aspberg, Johan, et al.
(författare)
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Screening for open-angle glaucoma and its effect on blindness
- 2021
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Ingår i: American Journal of Ophthalmology. - : Elsevier BV. - 1879-1891 .- 0002-9394. ; 228, s. 106-116
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To evaluate the effect of population screening on low vision and blindness from open-angle glaucoma.DESIGN: Retrospective cohort study.STUDY POPULATION: A very large population based screening for glaucoma was conducted in Malmö, Sweden, from 1992 to 1997. A total of 42 497 subjects were invited, of which 32 918 were screened and 9579 non-responders, i.e. did not participate.METHODS: The records of glaucoma patients who had visited the Department of Ophthalmology at Malmö University Hospital, from Jan 1, 1987, to Dec 31, 2017, were reviewed. Patients diagnosed at or after the screening were assessed for moderate or severe vision impairment, which we call low vision, or blindness by the WHO definition. We corrected for selection bias by creating a group of potential screening participants from a comparison group of clinical patients.MAIN OUTCOME MEASURE: Risk ratio of the cumulative incidence for bilateral low vision or blindness caused by glaucoma in screened patients compared with the potential participants.RESULTS: The cumulative incidence of blindness was 0.17% in the screened population versus 0.32% among the potential participants; and for low vision 0.25% versus 0.53%. The risk ratio (95% CI) between the two was 0.52 (0.32-0.84) for blindness and 0.46 (0.31-0.68) for low vision. There were no differences in the proportion of potential confounders between the comparison group and the non-responders.CONCLUSIONS: Our results suggest that population screening may reduce bilateral low vision and blindness from glaucoma by about 50%.
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| 16. |
- Bengtsson, Boel, et al.
(författare)
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The glaucoma intensive treatment study : interim results from an ongoing longitudinal randomized clinical trial
- 2022
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Ingår i: Acta Ophthalmologica. - : John Wiley & Sons. - 1755-375X .- 1755-3768. ; 100:2, s. e455-e462
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The aim of the study was to determine the perimetric rate of glaucoma progression in the ongoing Glaucoma Intensive Treatment Study (GITS) after 3 years of follow-up.Design: This is a randomized, two-centre, prospective open-labelled treatment trial for open-angle glaucoma (OAG). Participants The participants of this study were treatment-naive patients with newly diagnosed OAG, aged 46-78 years, with early to moderate glaucomatous visual field loss scheduled to be followed for 5 years within the study.Methods: Patients were randomized to initial treatment with either topical monotherapy or with an intensive approach using drugs from three different classes, plus 360 degrees laser trabeculoplasty. Changes in treatment were allowed. Standard automated perimetry and tonometry were performed and side-effects documented. All results are presented using intention-to-treat analysis.Results: A total of 242 patients were randomized. After 3 years of follow-up, eight patients were lost to follow-up, six of whom were deceased. The median untreated baseline intraocular pressure (IOP) was 24 mmHg in both arms. The median IOP was almost constant over the 3 years of follow-up: approximate to 17 mmHg in the mono-arm and approximate to 14 mmHg in the multi-treatment arm. Treatment was intensified in 42% of the mono-treated patients and in 7% of the multi-treated patients. Treatment was reduced in 13% of the multi-treated patients. The median perimetric rate of progression was -0.5%/year in the mono-treated group and -0.1%/year in the multi-treated group (p = 0.03).Conclusion: The rate of disease progression was significantly slower in the multi-treated patients than in the mono-treated patients. Further follow-up will show whether this difference is sustained over time.
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| 17. |
- Bengtsson, Boel, et al.
(författare)
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The Glaucoma Intensive Treatment Study (GITS), a randomized clinical trial : design, methodology and baseline data
- 2018
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Ingår i: Acta Ophthalmologica. - : John Wiley & Sons. - 1755-375X .- 1755-3768. ; 96:6, s. 557-566
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The primary objective of the ongoing Glaucoma Intensive Treatment Study (GITS) is to evaluate the effectiveness of immediate intensive treatment in comparison with the commonly recommended stepped regimen on the predicted visual field. The two treatment arms are also being compared regarding quality of life (QoL), intraocular pressure (IOP) reduction, frequency of reported side‐effects, adverse events and adherence to prescribed treatment.Design: A randomized, two‐centre, prospective open‐labelled treatment trial for open‐angle glaucoma.Participants: Individuals aged 40–78 years with previously untreated and newly diagnosed glaucoma with early to moderate visual field loss were eligible.Methods: Patients were randomized to initial treatment either using drug monotherapy in accordance with common glaucoma guidelines or using a more intensive approach including eyedrops containing drugs from three different classes combined with 360° laser trabeculoplasty. The patients are to be followed for 5 years at visits including standard automated perimetry, optical coherence tomography (OPT) and tonometry. Change of treatment is allowed and decided upon jointly with the patient as in conventional glaucoma management.Main outcome: The estimated predicted preserved visual field and QoL at end of expected lifetime.Results: A total of 242 patients, 45% females, mean age 68 years, were randomized. The median untreated IOP was 24 mm Hg, and the median visual field index (VFI), indicating the percentage of a full field, was 92%.Conclusion: Glaucoma Intensive Treatment Study is a clinical trial in which two groups of patients randomized to different initial intensities of IOP‐reducing treatment are being compared with regard to rate of visual field progression and prediction of serious glaucomatous visual field loss at estimated at end of life.
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| 18. |
- Bengtsson, E, et al.
(författare)
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The amino-terminal part of PRELP binds to heparin and heparan sulfate
- 2000
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 275:52, s. 40695-40702
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Tidskriftsartikel (refereegranskat)abstract
- PRELP (proline, arginine-rich end leucine-rich repeat protein) is an extracellular matrix leucine-rich repeat protein. The amino-terminal region of PRELP differs from that of other leucine-rich repeat proteins in containing a high number of proline and arginine residues. The clustered proline and basic residues are conserved in rat, bovine, and human PRELP. Although the function of PRELP is not yet known, the clustered arginine residues suggest a heparan sulfate/heparin-binding capacity. We show here that PRELP indeed binds heparin and heparan sulfate. Truncated PRELP without the amino-terminal region does not bind heparin. The dissociation constant for the interaction of PRELP with heparin was determined by an in solution binding assay and by surface plasmon resonance analysis to be in the range of 10-30 nm. A 6-mer heparin oligosaccharide was the smallest size showing binding to PRELP. The binding increased with increasing length up to an 18-mer and depended on the degree of sulfation of heparin as well as heparan sulfate. Sulfate groups at all positions were shown to be of importance for the binding. Fibroblasts bind PRELP, and this interaction is inhibited with heparin, suggesting a function for PRELP as a linker between the matrix and cell surface proteoglycans.
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| 19. |
- Bengtsson, Eva, et al.
(författare)
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The leucine-rich repeat protein PRELP binds fibroblast cell surface proteoglycans and enhances focal adhesion formation.
- 2016
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Ingår i: The Biochemical journal. - 1470-8728. ; 473:9, s. 1153-1164
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Tidskriftsartikel (refereegranskat)abstract
- PRELP is a member of the leucine-rich repeat family of extracellular matrix proteins in connective tissue. In contrast to other members of the family, the amino-terminal domain of PRELP has a high content of proline and positively charged amino acids. This domain has previously been shown to bind chondrocytes and to inhibit osteoclast differentiation. Here we show that PRELP mediates cell adhesion by binding to cell surface glycosaminoglycans. Thus, rat skin fibroblasts bound to full-length PRELP and to the amino-terminal part of PRELP alone, but not to truncated PRELP lacking the positively charged amino-terminal region. Cell attachment to PRELP was inhibited by addition of soluble heparin or heparan sulfate, by blocking sulfation of the fibroblasts, or by treating the cells with a combination of chondroitinase and heparinase. Using affinity chromatography, we identified syndecan-1, syndecan-4 and glypican-1 as cell surface proteoglycans binding to the amino-terminal part of PRELP. Finally, we show that the amino-terminal domain of PRELP in combination with the integrin-binding domain of fibronectin, but neither of the fragments alone, induced fibroblast focal adhesion formation. These findings provide support for a role of the amino-terminal region of PRELP as an important regulator of cell adhesion and behavior, which may be of importance in pathological conditions.
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| 20. |
- Bengtsson, Eva, et al.
(författare)
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The leucine-rich repeat protein PRELP binds perlecan and collagens and may function as a basement anchor.
- 2002
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 277:17, s. 15061-15068
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Tidskriftsartikel (refereegranskat)abstract
- PRELP is a heparin-binding leucine-rich repeat protein in connective tissue extracellular matrix. In search of natural ligands and biological functions of this molecule, we found that PRELP binds the basement membrane heparan sulfate proteoglycan perlecan. Also recombinant perlecan domains I and V carrying heparan sulfate bound PRELP, whereas other domains without glycosaminoglycan substitution did not. Heparin, but not chondroitin sulfate, inhibited the interactions. Glycosaminoglycan-free recombinant perlecan domain V and mutated domain I did not bind PRELP. The dissociation constants of the PRELP-perlecan interactions were in the range of 3-18 nM as determined by surface plasmon resonance. As expected, truncated PRELP, without the heparin-binding domain, did not bind perlecan. Confocal immunohistochemistry showed that PRELP outlines basement membranes with a location adjacent to perlecan. We also found that PRELP binds collagen type I and type II through its leucine-rich repeat domain. Electron microscopy visualized a complex with PRELP binding simultaneously to the triple helical region of procollagen I and the heparan sulfate chains of perlecan. Based on the location of PRELP and its interaction with perlecan heparan sulfate chains and collagen, we propose a function of PRELP as a molecule anchoring basement membranes to the underlying connective tissue.
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| 21. |
- Dimberg, Y, et al.
(författare)
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Effects of low-dose X-irradiation on mouse-brain aggregation cultures
- 1992
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Ingår i: International Journal of Radiation Biology. - : Informa UK Limited. - 0955-3002 .- 1362-3095. ; 61:3, s. 355-363
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Tidskriftsartikel (refereegranskat)abstract
- Biochemical and morphological differentiation in reaggregating mouse-brain cell cultures after low-dose radiation (0.5 Gy) in vitro was studied. Cells were irradiated on culture day 2, corresponding to embryonic day 15-16, and different glial and neuronal markers were followed through development to postnatal day 40. The shape and size of irradiated aggregates were more irregular and smaller compared with controls. Total amounts of DNA and protein were significantly lower in irradiated aggregates than in controls between days 8 and 20. After 30 days in culture activities of the glial markers glutamine synthetase (GS) and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP) were lower in X-irradiated aggregates than in controls. However, after 40 days the CNP activity in irradiated aggregates increased to levels above those of the controls. Irradiated and control aggregates did not differ significantly in neuronal marker enzyme activities, i.e. choline acetyltransferase (ChAT), acetylcholine esterase (AChE) and glutamic acid decarboxylase (GAD) measured on a per mg protein basis. On days 20 and 30 the amount of nerve growth factor (NGF) was two-fold higher in irradiated aggregates compared with non-irradiated ones, suggesting that, after irradiation, surviving cells in culture were induced to produce more NGF. After 40 days the amount of NGF in irradiated aggregates had decreased to the level found in the control aggregates.
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| 22. |
- Empere, Marta, et al.
(författare)
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Aggrecan governs intervertebral discs development by providing critical mechanical cues of the extracellular matrix
- 2023
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Ingår i: Frontiers in Bioengineering and Biotechnology. - : Frontiers Media SA. - 2296-4185. ; 11, s. 1-19
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Tidskriftsartikel (refereegranskat)abstract
- Aggrecan (ACAN) is localized in the intervertebral disc (IVD) in unique compartment-specific patterns where it contributes to the tissue structure and mechanical function together with collagens. The extracellular matrix (ECM) of the IVD undergoes degenerative changes during aging, misuse or trauma, which inevitably alter the biochemical and biomechanical properties of the tissue. A deeper understanding of these processes can be achieved in genetically engineered mouse models, taking into account the multifaceted aspects of IVD development. In this study, we generated aggrecan insertion mutant mice (AcaniE5/iE5) by interrupting exon 5 coding for the G1 domain of ACAN, and analyzed the morphological and mechanical properties of the different IVD compartments during embryonic development. Western blotting using an antibody against the total core protein failed to detect ACAN in cartilage extracts, whereas immunohistochemistry by a G1-specific antibody showed weak signals in vertebral tissues of AcaniE5/iE5 mice. Homozygous mutant mice are perinatally lethal and characterized by short snout, cleft palate and disproportionate dwarfism. Whole-mount skeletal staining and µ-CT analysis of AcaniE5/iE5 mice at embryonic day 18.5 revealed compressed vertebral bodies with accelerated mineralization compared to wild type controls. In AcaniE5/iE5 mice, histochemical staining revealed collapsed extracellular matrix with negligible sulfated glycosaminoglycan content accompanied by a high cellular density. Collagen type II deposition was not impaired in the IVD of AcaniE5/iE5 mice, as shown by immunohistochemistry. Mutant mice developed a severe IVD phenotype with deformed nucleus pulposus and thinned cartilaginous endplates accompanied by a disrupted growth plate structure in the vertebral body. Atomic force microscopy (AFM) imaging demonstrated a denser collagen network with thinner fibrils in the mutant IVD zones compared to wild type. Nanoscale AFM indentation revealed bimodal stiffness distribution attributable to the softer proteoglycan moiety and harder collagenous fibrils of the wild type IVD ECM. In AcaniE5/iE5 mice, loss of aggrecan resulted in a marked shift of the Young’s modulus to higher values in all IVD zones. In conclusion, we demonstrated that aggrecan is pivotal for the determination and maintenance of the proper stiffness of IVD and vertebral tissues, which in turn could play an essential role in providing developmental biomechanical cues.
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| 23. |
- Eriksson, P, et al.
(författare)
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Neonatal exposure to DDT and its fatty acid conjugate: effects on cholinergic and behavioural variables in the adult mouse
- 1990
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Ingår i: NeuroToxicology. - 1872-9711. ; 11:2, s. 345-354
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Tidskriftsartikel (refereegranskat)abstract
- We have recently observed that DDT and a DDT metabolite, DDOH, conjugated to a fatty acid, palmitic acid, DDOH-PA, affects muscarinic cholinergic receptors (MAChR) in the neonatal mouse brain when given to suckling mice during rapid brain growth. This early exposure of the neonatal mouse also affects the behaviour of the animals as adults. When DDT and DDOH-PA was given as a single low oral dose of 1.4 mumol/kg body weight, DDT (0.5 mg), DDOH-PA (0.7 mg) and a 20% fat emulsion vehicle (10 ml) per kg body weight to 10-day-old NMRI mice, behavioural tests at adult age of four months, indicated disruption of a simple, non-associative learning process, i.e. habituation, in both DDT and DDOH-PA treated mice. There was also a significant increase in the potassium evoked release of ACh from slices of cerebral cortex and a tendency towards a decrease in the density of MAChR in mice receiving DDT. These effects in the adult mice could not be correlated to the concentration of DDT in the adult brain since DDT one month after its administration to the 10-day-old mouse no longer is present in the brain.
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| 24. |
- Geng, Hui, et al.
(författare)
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Cartilage oligomeric matrix protein deficiency promotes early onset and the chronic development of collagen-induced arthritis.
- 2008
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Ingår i: Arthritis Research and Therapy. - London : Springer Science and Business Media LLC. - 1478-6362 .- 1478-6354. ; 10:6
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: INTRODUCTION: Cartilage oligomeric matrix protein (COMP) is a homopentameric protein in cartilage. The development of arthritis, like collagen-induced arthritis (CIA), involves cartilage as a target tissue. We have investigated the development of CIA in COMP-deficient mice. METHODS: COMP-deficient mice in the 129/Sv background were backcrossed for 10 generations against B10.Q mice, which are susceptible to chronic CIA. COMP-deficient and wild-type mice were tested for onset, incidence, and severity of arthritis in both the collagen and collagen antibody-induced arthritis models. Serum anti-collagen II and anti-COMP antibodies as well as serum COMP levels in arthritic and wild-type mice were measured by enzyme-linked immunosorbent assay. RESULTS: COMP-deficient mice showed a significant early onset and increase in the severity of CIA in the chronic phase, whereas collagen II-antibody titers were similar in COMP-deficient and wild-type controls. COMP antibodies were not found in wild-type mice. Finally, COMP-deficient and wild-type mice responded similarly to collagen antibody-induced arthritis, indicating no difference in how collagen II antibodies interact with COMP-deficient cartilage during the initial stages of arthritis. CONCLUSIONS: COMP deficiency enhances the early onset and development of chronic arthritis but does not affect collagen II autoimmunity. These findings accentuate the importance of COMP in cartilage stability.
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| 25. |
- Geng, Hui, et al.
(författare)
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Cartilage oligomeric matrix protein specific antibodies are pathogenic
- 2012
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Ingår i: Arthritis Research & Therapy. - London : BioMed Central (BMC). - 1478-6362 .- 1478-6354. ; 14:4
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Cartilage oligomeric matrix protein (COMP) is a major non-collagenous component of cartilage. Earlier, we developed a new mouse model for rheumatoid arthritis using COMP. This study was undertaken to investigate the epitope specificity and immunopathogenicity of COMP-specific monoclonal antibodies (mAbs). METHODS: B cell immunodominant regions on the COMP molecule were measured with a novel enzyme-linked immunosorbent assay using mammalian expressed full-length mouse COMP as well as a panel of recombinant mouse COMP fragments. 18 mAbs specific to COMP were generated and the pathogenicity of mAbs was investigated by passive transfer experiments. RESULTS: B cell immunodominant epitopes were localized within 4 antigenic domains of the COMP but with preferential response to the epidermal growth factor (EGF)-like domain. Some of our anti-COMP mAbs showed interactions with the native form of COMP, which is present in cartilage and synovium. Passive transfer of COMP-specific mAbs enhanced arthritis when co-administrated with a sub-arthritogenic dose of a mAb specific to collagen type II. Interestingly, we found that a combination of 5 COMP mAbs was capable of inducing arthritis in naive mice. CONCLUSIONS: We have identified the specificities of mAbs to COMP and their contribution to the development of arthritis. These findings will further improve our understanding of the autoantibody mediated immunopathologies occurring widely in rheumatoid arthritis (RA), as well as in other autoimmune disorders.
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| 26. |
- Gonçalves, Isabel, et al.
(författare)
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Osteomodulin Gene Expression Is Associated with Plaque Calcification, Stability, and Fewer Cardiovascular Events in the CPIP Cohort
- 2022
-
Ingår i: Stroke. - 0039-2499 .- 1524-4628. ; 53:3, s. 79-84
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Tidskriftsartikel (refereegranskat)abstract
- Background: Stable atherosclerotic plaques are characterized by thick fibrous caps of smooth muscle cells, collagen, and macrocalcifications. Identifying factors of plaque stability is necessary to design drugs to prevent plaque rupture and symptoms. Osteomodulin, originally identified in bones, is expressed by bone synthesizing osteoblasts and involved in mineralization. In the present study, we analyzed osteomodulin expression in human carotid plaques, its link with plaque phenotype, calcification, and future cardiovascular events. Methods: Osteomodulin gene expression (OMD; n=82) was determined by RNA sequencing and osteomodulin protein levels by immunohistochemistry (n=45) in carotid plaques obtained by endarterectomy from patients with or without cerebrovascular symptoms from the CPIP (Carotid Plaque Imaging Project) cohort, Skåne University Hospital, Sweden. Plaque components were assessed by immunohistochemistry, RNA sequencing, and multiplex analysis. Patients were followed for cardiovascular events or cardiovascular death during a median of 57 or 70 months, respectively, using national registers. Results: OMD levels were increased in plaques from asymptomatic patients compared to symptomatics. High OMD levels were associated with fewer cardiovascular events during follow-up. OMD correlated positively with smooth muscle α-actin (ACTA2; r=0.73, P=10-13) and collagen (COL1A2; r=0.4, P=0.0002), but inversely with CD68 gene expression (r=-0.67, P=10-11), lipids (r=-0.37, P=0.001), intraplaque hemorrhage (r=-0.32, P=0.010), inflammatory cytokine, and matrix metalloproteinase plaque contents. OMD was positively associated with MSX2 (Msh Homeobox 2) (r=0.32, P=0.003), a marker of preosteoblast differentiation, BMP4 (bone morphogenetic protein) (r=0.50, P=0.000002) and BMP6 (r=0.47, P=0.000007), plaque calcification (r=0.35, P=0.016), and was strongly upregulated in osteogenically stimulated smooth muscle cells, which was further increased upon BMP stimulation. Osteomodulin protein was present in calcified regions. Osteomodulin protein levels were associated with plaque calcification (r=0.41, P=0.006) and increased in macrocalcified plaques. Conclusions: These data show that osteomodulin mRNA and protein levels are associated with plaque calcification in human atherosclerosis. Furthermore, osteomodulin mRNA, but not protein levels, is associated with plaque stability.
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| 27. |
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| 28. |
- Happonen, Kaisa, et al.
(författare)
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Regulation of complement by COMP allows for a novel molecular diagnostic principle in rheumatoid arthritis.
- 2010
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Ingår i: Arthritis and Rheumatism. - : Wiley. - 1529-0131 .- 0004-3591. ; 62:12, s. 3574-3583
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE:: Cartilage oligomeric matrix protein (COMP) is a structural component of cartilage where it catalyzes collagen fibrillogenesis. Elevated amounts of COMP are found in serum during increased turnover of cartilage associated with active joint diseases, such as rheumatoid arthritis (RA) and osteoarthritis (OA). In this study we investigated the ability of COMP to regulate complement. Such capacity was previously shown for some cartilage proteins. METHODS:: Regulation of complement by COMP was studied using functional assays in vitro. Interactions between complement proteins and COMP were investigated using direct binding assays and electron microscopy. Circulating COMP and COMP-C3b complexes in serum and synovial fluid from RA and OA patients and healthy controls were measured using a novel ELISA. RESULTS:: We show in vivo evidence of complement activation by released COMP in the general circulation of patients with RA, but not OA patients. We found that COMP induces activation and deposition of C3b and C9 specifically via the alternative pathway of complement, which is attributable to a direct interaction between COMP and properdin. Furthermore, COMP inhibits the classical and the lectin complement pathways due to direct interaction with the stalk region of C1q and mannose-binding lectin, respectively. CONCLUSION:: COMP is the first extracellular matrix protein for which an active role is demonstrated in inflammation in vivo where it can activate one complement pathway at the same time as it has the potential to inhibit another. The net outcome of these interactions is most likely determined by the type of released COMP-fragments, which may be disease-specific.
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| 29. |
- Heijl, Anders, et al.
(författare)
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The effect of different criteria on the number of patients blind from open-angle glaucoma
- 2011
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Ingår i: BMC Ophthalmology. - : Springer Science and Business Media LLC. - 1471-2415. ; 11:31
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The prevalence of blindness and visual impairment from glaucoma is influenced by the criteria used to define these entities, which differ between countries and regions, as well as among published reports. The objective of the present study was to ascertain the extent to which different criteria of blindness and visual impairment influence estimates of the number of patients classified as blind or visually impaired by glaucoma in a clinic-based population. Methods: We conducted a retrospective chart review of 914 patients with open-angle glaucoma to compare numbers of patients identified as visually impaired with and without considering visual field status. We also compared proportions classified using World Health Organisation (WHO) and United States (US) blindness criteria, and applying a new US Social Security Administration (SSA) disability criterion: perimetric mean deviation (MD) <= -22 dB. Results: Forty patients (4.4%) were bilaterally blind from glaucoma by the WHO criteria. Fifty-two (5.7%) were blind by the the US criterion. Assessing only visual acuity, 14 (1.5%) patients were blind by the WHO criteria and 24 (2.6%) by the US definition. Eighty-five (9.3%) met the US SSA disability criterion. Among those, 52 were impaired also by the WHO definition. No patients impaired according to the WHO criteria had MD values better than -22 dB. Conclusions: Excluding visual field status will seriously underestimate the prevalence of glaucoma blindness. In our patient population, 30% more patients were classified as blind by the US than by the WHO definition. Also, 60% more were identified as visually impaired by the US SSA criterion than by the WHO criteria. Visual field assessment is vital to determine visual impairment caused by glaucoma.
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| 30. |
- Heinegård, Dick, et al.
(författare)
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Glycosylated matrix protein
- 2002
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Ingår i: Connective tissue and its heritable disorders: molecular, genetic, and medical aspects, 2nd edition. - Hoboken, NJ, USA : John Wiley & Sons, Inc.. - 9780471251859 ; , s. 271-291
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Connective tissues have many features in common, including resisting and dissipating mechanical load and providing shape, as well as acting to provide barriers regulating water flow and diffusibility of macromolecules. In this chapter we have chosen to focus on cartilage and bone, covering many aspects of connective tissues. We give special focus to the noncollagenous proteins in their matrices.
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| 31. |
- Heinegård, Dick, et al.
(författare)
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Glycosylated Matrix Proteins
- 2002
-
Ingår i: Connective Tissue and Its Heritable Disorders: Molecular, Genetic and Medical Aspects. - Hoboken, NJ, USA : John Wiley & Sons, Inc.. - 9780471251859 - 9780471221920 ; , s. 271-291
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Connective tissues have many features in common, including resisting and dissipating mechanical load and providing shape, as well as acting to provide barriers regulating water flow and diffusibility of macromolecules. In this chapter we have chosen to focus on cartilage and bone, covering many aspects of connective tissues. We give special focus to the noncollagenous proteins in their matrices.
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| 32. |
- Isogai, Z, et al.
(författare)
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Versican interacts with fibrillin-1 and links extracellular microfibrils to other connective tissue networks
- 2002
-
Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 277:6, s. 4565-4572
-
Tidskriftsartikel (refereegranskat)abstract
- Fibrillin-containing microfibrils are polymeric structures that are difficult to extract from connective tissues. Proteolytic digestion of tissues has been utilized to release microfibrils for study. Few of the molecules that connect microfibrils to other elements in the matrix have been identified. In this study, electron microscopic immunolocalization of anti-versican antibodies in tissues and in extracted microfibrils demonstrated that the C-terminal region of versican is found associated with fibrillin microfibrils. Extraction of microfibrils followed by treatment of microfibrils under dissociating conditions suggested that the versican C terminus is covalently bound to microfibrils. Binding assays using recombinant fibrillin-1 polypeptides and recombinant lectican lectin domains indicated that the versican lectin domain binds to specific fibrillin-1 polypeptides. The versican lectin domain also bound to molecules comigrating with authentic fibrillin-1 monomers in anassay using cell culture medium. In assays using microfibrils, the versican lectin domain demonstrated preferential binding compared with other lecticans. Binding was calcium-dependent. The binding site for versican in microfibrils is most likely within a region of fibrillin-1 between calcium-binding epidermal growth factor-like domains 11 and 21. Human mutations irk this region can result in severe forms of the Marfan syndrome ("neonatal" Marfan syndrome). The connection between versican and fibrillin microfibrils may be functionally significant, particularly in cardiovascular tissues.
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| 33. |
- Kadefors, Måns, et al.
(författare)
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Dipeptidyl peptidase 4 expression is not associated with an activated fibroblast phenotype in idiopathic pulmonary fibrosis
- 2022
-
Ingår i: Frontiers in Pharmacology. - : Frontiers Media SA. - 1663-9812. ; 13, s. 1-12
-
Tidskriftsartikel (refereegranskat)abstract
- Dipeptidyl peptidase 4 (DPP4) has been proposed as a marker for activated fibroblasts in fibrotic disease. We aimed to investigate whether a profibrotic DPP4 phenotype is present in lung tissue from patients with idiopathic pulmonary fibrosis (IPF). The presence of DPP4 + fibroblasts in normal and IPF lung tissue was investigated using flow cytometry and immunohistology. In addition, the involvement of DPP4 in fibroblast activation was examined in vitro, using CRISPR/Cas9 mediated genetic inactivation to generate primary DPP4 knockout lung fibroblasts. We observed a reduced frequency of primary DPP4 + fibroblasts in IPF tissue using flow cytometry, and an absence of DPP4 + fibroblasts in pathohistological features of IPF. The in vivo observations were supported by results in vitro showing a decreased expression of DPP4 on normal and IPF fibroblasts after profibrotic stimuli (transforming growth factor β) and no effect on the expression of activation markers (α-smooth muscle actin, collagen I and connective tissue growth factor) upon knockout of DPP4 in lung fibroblasts with or without activation with profibrotic stimuli.
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| 34. |
- Kalamajski, Sebastian, et al.
(författare)
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Asporin competes with decorin for collagen binding, binds calcium and promotes osteoblast collagen mineralization
- 2009
-
Ingår i: Biochemical Journal. - 0264-6021. ; 423, s. 53-59
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Tidskriftsartikel (refereegranskat)abstract
- The interactions of the ECM (extracellular matrix) protein asporin with ECM components have previously not been investigated. Here, we show that asporin binds collagen type I. This binding is inhibited by recombinant asporin fragment LRR (leucine-rich repeat) 10-12 and by full-length decorin, but not by biglycan. We demonstrate that the polyaspartate domain binds calcium and regulates hydroxyapatite formation in vitro. In the presence of asporin, the number of collagen nodules, and mRNA of osteoblastic markers Osterix and Runx2 were increased. Moreover, decorin or the collagen-binding asporin fragment LRR 10-12 inhibited the pro-osteoblastic activity of full-length asporin. Our results suggest that asporin and decorin compete for binding to collagen and that the polyaspartate in asporin directly regulates collagen mineralization. Therefore asporin has a role in osteoblast-driven collagen biomineralization activity. We also show that asporin can be expressed in Escherichia coli (Rosettagami (TM)) with correctly positioned cysteine bridges, and a similar system can possibly be used for the expression of other SLRPs (small LRR proteoglycans/proteins).
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| 35. |
- Kalamajski, Sebastian, et al.
(författare)
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The decorin sequence SYIRIADTNIT binds collagen type I.
- 2007
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 282:22, s. 16062-16067
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Tidskriftsartikel (refereegranskat)abstract
- Decorin belongs to the small leucine-rich repeat proteoglycan family, interacts with fibrillar collagens, and regulates the assembly, structure, and biomechanical properties of connective tissues. The decorin-collagen type I-binding region is located in leucine-rich repeats 5–6. Site-directed mutagenesis of this 54-residue-long collagen-binding sequence identifies Arg-207 and Asp-210 in leucine-rich repeat 6 as crucial for the binding to collagen. The synthetic peptide SYIRIADTNIT, which includes Arg-207 and Asp-210, inhibits the binding of full-length recombinant decorin to collagen in vitro. These collagen-binding amino acids are exposed on the exterior of the beta-sheet-loop structure of the leucine-rich repeat. This resembles the location of interacting residues in other leucine-rich repeat proteins.
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| 36. |
- Kvist, Alexander, et al.
(författare)
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Chondroitin sulfate perlecan enhances collagen fibril formation - Implications for perlecan chondrodysplasias
- 2006
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 281:44, s. 33127-33139
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Tidskriftsartikel (refereegranskat)abstract
- Inactivation of the perlecan gene leads to perinatal lethal chondrodysplasia. The similarity to the phenotypes of the Col2A1 knock-out and the disproportionate micromelia mutation suggests perlecan involvement in cartilage collagen matrix assembly. We now present a mechanism for the defect in collagen type II fibril assembly by perlecan-null chondrocytes. Cartilage perlecan is a heparin sulfate or a mixed heparan sulfate/ chondroitin sulfate proteoglycan. The latter form binds collagen and accelerates fibril formation in vitro, with more defined fibril morphology and increased fibril diameters produced in the presence of perlecan. Interestingly, the enhancement of collagen fibril formation is independent on the core protein and is mimicked by chondroitin sulfate E but neither by chondroitin sulfate D nor dextran sulfate. Furthermore, perlecan chondroitin sulfate contains the 4,6-disulfated disaccharides typical for chondroitin sulfate E. Indeed, purified glycosaminoglycans from perlecan-enriched fractions of cartilage extracts contain elevated levels of 4,6-disulfated chondroitin sulfate disaccharides and enhance collagen fibril formation. The effect on collagen assembly is proportional to the content of the 4,6- disulfated disaccharide in the different cartilage extracts, with growth plate cartilage glycosaminoglycan being the most efficient enhancer. These findings demonstrate a role for perlecan chondroitin sulfate side chains in cartilage extracellular matrix assembly and provide an explanation for the perlecan-null chondrodysplasia.
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| 37. |
- Kvist, Alexander, et al.
(författare)
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The major basement membrane components localize to the chondrocyte pericellular matrix - A cartilage basement membrane equivalent?
- 2008
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Ingår i: Matrix Biology. - : Elsevier BV. - 1569-1802 .- 0945-053X. ; 27:1, s. 22-33
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we demonstrate that articular cartilage chondrocytes are surrounded by the defining basement membrane proteins laminin, collagen type IV, nidogen and perlecan, and suggest that these form the functional equivalent of a basement membrane. We found by real-time PCR that mouse chondrocytes express these four cardinal components of basement membranes and demonstrated by immunohistochemistry that the proteins are present in bovine and mouse cartilage tissues and are deposited in a thin pericellular structure. Immunoelectron microscopy confirmed high laminin concentration in the pericellular matrix. In cartilage from newborn mice, basement membrane components are widespread in the territorial and interterritorial matrix, while in mature cartilage of adult mice the basement membrane components are localized mainly to a narrow pericellular zone. With progression into old age, this layer becomes less distinct, especially in areas of obvious mechanical attrition. Interestingly, individual laminin subunits were located in different zones of the cartilage, with laminin α1 showing preferential localization around a select population of superficial layer chondrocytes. We propose that the chondrocyte, like several other cell types of mesenchymal origin, is surrounded by the functional equivalent of a basement membrane. This structure is presumably involved in maintaining chondrocyte phenotype and viability and may well allow a new understanding of cartilage development and provide clues to the progression of degenerative joint disorders.
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| 38. |
- Linden, Christina, et al.
(författare)
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Initial intraocular pressure reduction by mono‐ versus multi‐therapy in patients with open‐angle glaucoma : results from the Glaucoma Intensive Treatment Study
- 2018
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Ingår i: Acta Ophthalmologica. - : John Wiley & Sons. - 1755-375X .- 1755-3768. ; 96:6, s. 567-572
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To study newly diagnosed glaucoma patients given mono‐ or multi‐therapy regarding differences in initial intraocular pressure (IOP) reduction, target IOP levels reached and influence of untreated baseline IOP on IOP reduction.Methods: Patients newly diagnosed with manifest primary open‐angle glaucoma and included in the Glaucoma Intensive Treatment Study (GITS) were randomized to immediate intensive treatment with any of three different IOP‐lowering substances supplied in two bottles plus 360° laser trabeculoplasty or to conventional stepwise treatment starting with a single‐drug. Intraocular pressure reduction was analysed 1 month after initiation of treatment.Results: One hundred eighteen patients (143 eyes) received mono‐therapy and 122 patients (152 eyes) multi‐therapy. Median baseline IOP was 24.0 (min: 9.7, max: 56.0) mmHg in mono‐therapy eyes and 24.0 (min: 12.3, max: 48.5) mmHg in multi‐therapy eyes (p = 0.56). After 1 month in the two groups, respectively, values for median IOP reduction were 6.3 (range: −5.3–31.0) and 11.0 (range: 0.7–34.5) mmHg, and for mean relative decline 26.8 (range: −32.0–55.4) and 46.0 (range: 4.6–81.6) % (p = 0.000). A larger proportion of the multi‐therapy patients reached each target IOP level (p = 0.000). The higher the baseline IOP, the larger the observed pressure reduction, considering both absolute and relative figures. The effect was more pronounced in eyes with multi‐therapy than in those with mono‐therapy (p = 0.000). For every mmHg higher IOP at baseline, the IOP was reduced by an additional 0.56 (mono‐therapy) or 0.84 (multi‐therapy) mmHg.Conclusion: Intensive treatment led to considerably greater IOP reduction than mono‐therapy. Among patients with IOP ≥30 mmHg at diagnosis an IOP of <16 was reached in 2/3 of those with multi‐therapy but in none with mono‐therapy. The IOP reduction was highly dependent on the untreated IOP level.
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| 39. |
- Liu, Guanghui, et al.
(författare)
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Moraxella catarrhalis Evades Host Innate Immunity via Targeting Cartilage Oligomeric Matrix Protein.
- 2016
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 196:3, s. 1249-1258
-
Tidskriftsartikel (refereegranskat)abstract
- Moraxella catarrhalis is a respiratory tract pathogen commonly causing otitis media in children and acute exacerbations in patients suffering from chronic obstructive pulmonary disease. Cartilage oligomeric matrix protein (COMP) functions as a structural component in cartilage, as well as a regulator of complement activity. Importantly, COMP is detected in resident macrophages and monocytes, alveolar fluid, and the endothelium of blood vessels in lung tissue. We show that the majority of clinical isolates of M. catarrhalis (n = 49), but not other tested bacterial pathogens, bind large amounts of COMP. COMP interacts directly with the ubiquitous surface protein A2 of M. catarrhalis. Binding of COMP correlates with survival of M. catarrhalis in human serum by inhibiting bactericidal activity of the complement membrane attack complex. Moreover, COMP inhibits phagocytic killing of M. catarrhalis by human neutrophils. We further observed that COMP reduces bacterial adhesion and uptake by human lung epithelial cells, thus protecting M. catarrhalis from intracellular killing by epithelial cells. Taken together, our findings uncover a novel mechanism that M. catarrhalis uses to evade host innate immunity.
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| 40. |
- Lorenzo, Pilar, et al.
(författare)
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Identification and characterization of asporin. a novel member of the leucine-rich repeat protein family closely related to decorin and biglycan
- 2001
-
Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 276:15, s. 12201-12211
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Tidskriftsartikel (refereegranskat)abstract
- Asporin, a novel member of the leucine-rich repeat family of proteins, was partially purified from human articular cartilage and meniscus. Cloning of human and mouse asporin cDNAs revealed that the protein is closely related to decorin and biglycan. It contains a putative propeptide, 4 amino-terminal cysteines, 10 leucine-rich repeats, and 2 C-terminal cysteines. In contrast to decorin and biglycan, asporin is not a proteoglycan. Instead, asporin contains a unique stretch of aspartic acid residues in its amino-terminal region. A polymorphism was identified in that the number of consecutive aspartate residues varied from 11 to 15. The 8 exons of the human asporin gene span 26 kilobases on chromosome 9q31.1-32, and the putative promoter region lacks TATA consensus sequences. The asporin mRNA is expressed in a variety of human tissues with higher levels in osteoarthritic articular cartilage, aorta, uterus, heart, and liver. The deduced amino acid sequence of asporin was confirmed by mass spectrometry of the isolated protein resulting in 84% sequence coverage. The protein contains an N-glycosylation site at Asn(281) with a heterogeneous oligosaccharide structure and a potential O-glycosylation site at Ser(54). The name asporin reflects the aspartate-rich amino terminus and the overall similarity to decorin.
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| 41. |
- Martínez, Marycarmen Arévalo, et al.
(författare)
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Vascular smooth muscle–specific YAP/TAZ deletion triggers aneurysm development in mouse aorta
- 2023
-
Ingår i: JCI Insight. - 2379-3708. ; 8:17
-
Tidskriftsartikel (refereegranskat)abstract
- Inadequate adaption to mechanical forces, including blood pressure, contributes to development of arterial aneurysms. Recent studies have pointed to a mechanoprotective role of YAP and TAZ in vascular smooth muscle cells (SMCs). Here, we identified reduced expression of YAP1 in human aortic aneurysms. Vascular SMC–specific knockouts (KOs) of YAP/TAZ were thus generated using the integrin α8–Cre (Itga8-Cre) mouse model (i8-YT-KO). i8-YT-KO mice spontaneously developed aneurysms in the abdominal aorta within 2 weeks of KO induction and in smaller arteries at later times. The vascular specificity of Itga8-Cre circumvented gastrointestinal effects. Aortic aneurysms were characterized by elastin disarray, SMC apoptosis, and accumulation of proteoglycans and immune cell populations. RNA sequencing, proteomics, and myography demonstrated decreased contractile differentiation of SMCs and impaired vascular contractility. This associated with partial loss of myocardin expression, reduced blood pressure, and edema. Mediators in the inflammatory cGAS/STING pathway were increased. A sizeable increase in SOX9, along with several direct target genes, including aggrecan (Acan), contributed to proteoglycan accumulation. This was the earliest detectable change, occurring 3 days after KO induction and before the proinflammatory transition. In conclusion, Itga8-Cre deletion of YAP and TAZ represents a rapid and spontaneous aneurysm model that recapitulates features of human abdominal aortic aneurysms.
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| 42. |
- Melin Fürst, Camilla, et al.
(författare)
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The C-type lectin of the aggrecan g3 domain activates complement.
- 2013
-
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:4
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Tidskriftsartikel (refereegranskat)abstract
- Excessive complement activation contributes to joint diseases such as rheumatoid arthritis and osteoarthritis during which cartilage proteins are fragmented and released into the synovial fluid. Some of these proteins and fragments activate complement, which may sustain inflammation. The G3 domain of large cartilage proteoglycan aggrecan interacts with other extracellular matrix proteins, fibulins and tenascins, via its C-type lectin domain (CLD) and has important functions in matrix organization. Fragments containing G3 domain are released during normal aggrecan turnover, but increasingly so in disease. We now show that the aggrecan CLD part of the G3 domain activates the classical and to a lesser extent the alternative pathway of complement, via binding of C1q and C3, respectively. The complement control protein (CCP) domain adjacent to the CLD showed no effect on complement initiation. The binding of C1q to G3 depended on ionic interactions and was decreased in D2267N mutant G3. However, the observed complement activation was attenuated due to binding of complement inhibitor factor H to CLD and CCP domains. This was most apparent at the level of deposition of terminal complement components. Taken together our observations indicate aggrecan CLD as one factor involved in the sustained inflammation of the joint.
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| 43. |
- Muller, Catharina, et al.
(författare)
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Quantitative proteomics at different depths in human articular cartilage reveals unique patterns of protein distribution.
- 2014
-
Ingår i: Matrix Biology. - : Elsevier BV. - 1569-1802 .- 0945-053X. ; 40:Sep 1, s. 34-45
-
Tidskriftsartikel (refereegranskat)abstract
- The articular cartilage of synovial joints ensures friction-free mobility and attenuates mechanical impact on the joint during movement. These functions are mediated by the complex network of extracellular molecules characteristic for articular cartilage. Zonal differences in the extracellular matrix (ECM) are well recognized. However, knowledge about the precise molecular composition in the different zones remains limited. In the present study, we investigated the distribution of ECM molecules along the surface-to-bone axis, using quantitative non-targeted as well as targeted proteomics.\ In a discovery approach, iTRAQ mass spectrometry was used to identify all extractable ECM proteins in the different layers of a human lateral tibial plateau full thickness cartilage sample. A targeted MRM mass spectrometry approach was then applied to verify these findings and to extend the analysis to four medial tibial plateau samples. In the lateral tibial plateau sample, the unique distribution patterns of 70 ECM proteins were identified, revealing groups of proteins with a preferential distribution to the superficial, intermediate or deep regions of articular cartilage. The detailed analysis of selected 29 proteins confirmed these findings and revealed similar distribution patterns in the four medial tibial plateau samples. The results of this study allow, for the first time, an overview of the zonal distribution of a broad range of cartilage ECM proteins and open up further investigations of the functional roles of matrix proteins in the different zones of articular cartilage in health and disease.
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| 44. |
- Peters, Dorothea, et al.
(författare)
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Threat to fixation and vision-related quality of life in early open-angle glaucoma : results from the Glaucoma Intensive Treatment Study
- 2023
-
Ingår i: Acta Ophthalmologica. - : John Wiley & Sons. - 1755-375X .- 1755-3768. ; 101:1, s. 74-80
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To determine the effect of glaucomatous visual field (VF) damage close to the point of fixation, called threat-to-fixation (TTF), on vision-related quality of life (VRQoL) in open-angle glaucoma.Methods: A total of 239 patients from the Glaucoma Intensive Treatment Study (GITS) were included in this analysis. The second VF of patients with newly diagnosed primarily early glaucoma was evaluated for the presence or absence of TTF. TTF was defined as VF loss including one or more of the four innermost test points depressed at p < 1% in the total deviation probability map of Humphrey 24–2 SITA Standard visual fields. VRQoL was evaluated using Rasch-analysed National Eye Institute Visual Function Questionnaire 25 (NEI VFQ-25) scores. The correlation between VRQoL and TTF was evaluated using uni- and multivariable regression analyses.Results: TTF was present in at least one eye in 115 patients (48%); located in the superior hemifield alone in 47% (54 of 115), in the inferior hemifield alone in 23% (27 of 115), and in 30% (34 of 115) in both hemifields. The median Rasch-calibrated NEI VFQ-25 scores were identical when comparing patients with TTF (VRQoL score 66, 95% CI: 23–100) and those with no-TTF (VRQoL score 66, 95% CI: 21–100) (p = 0.925). Neither the presence of TTF (R2 = −0.004, p = 0.968) nor the location of TTF (R2 = 0.023, p = 0.103) was significantly correlated to Rasch-calibrated NEI VFQ-25 scores.Conclusion: The presence of TTF did not influence VRQoL, as measured by the NEI-VFQ-25, in this relatively large group of patients with mainly early glaucoma.
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| 45. |
- Quattromani, Miriana Jlenia, et al.
(författare)
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Extracellular Matrix Modulation Is Driven by Experience-Dependent Plasticity During Stroke Recovery
- 2018
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Ingår i: Molecular Neurobiology. - : Springer Science and Business Media LLC. - 0893-7648 .- 1559-1182. ; 55:3, s. 2196-2213
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Tidskriftsartikel (refereegranskat)abstract
- Following stroke, complete cellular death in the ischemic brain area may ensue, with remaining brain areas undergoing tissue remodelling to various degrees. Experience-dependent brain plasticity exerted through an enriched environment (EE) promotes remodelling after central nervous system injury, such as stroke. Post-stroke tissue reorganization is modulated by growth inhibitory molecules differentially expressed within the ischemic hemisphere, like chondroitin sulfate proteoglycans found in perineuronal nets (PNNs). PNNs in the neocortex predominantly enwrap parvalbumin-containing GABAergic (PV/GABA) neurons, important in sensori-information processing. Here, we investigate how extracellular matrix (ECM) proteases and their inhibitors may participate in the regulation of PNN integrity during stroke recovery. Rats were subjected to photothrombotic stroke in the motor cortex, and functional deficits were assessed at 7 days of recovery. Sham and stroked rats were housed in either standard or EE conditions for 5 days, and infarct volumes were calculated. PNNs were visualized by immunohistochemistry and counted in the somatosensory cortex of both hemispheres. mRNA expression levels of ECM proteases and protease inhibitors were assessed by RT-qPCR and their activity analyzed by gel zymography. PNNs and protease activity were also studied in brains from stroke patients where similar results were observed. EE starting 2 days after stroke and continuing for 5 days stimulated behavioral recovery of limb-placement ability without affecting infarct size. EE promoted a decrease of PNNs around PV/GABA neurons and a concomitant modulation of the proteolytic activity and mRNA expression of ECM proteases and protease inhibitors in the somatosensory cortex. This study provides molecular targets for novel therapies that could support rehabilitation of stroke patients.
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| 46. |
- Rasmuson, Erika, et al.
(författare)
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Laser trabeculoplasty in newly diagnosed multi-treated glaucoma patients
- 2021
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Ingår i: Acta Ophthalmologica. - : John Wiley & Sons. - 1755-375X .- 1755-3768. ; 99:3, s. 269-274
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To evaluate the intraocular pressure (IOP)‐lowering effect of laser trabeculoplasty (LTP) in eyes which IOP had been substantially reduced by intensive topical treatment for one week.Methods: Patients with newly diagnosed open‐angle glaucoma were randomized to treatment with three IOP‐lowering substances. One week later, 360° argon or selective LTP was performed. IOP was measured before LTP and at one‐, three‐, six‐ and 12‐month post‐LTP. The patients were part of the Glaucoma Intensive Treatment Study (GITS).Results: Mean IOP (± SD) in 152 eyes of 122 patients was 14.0 (± 3.5) mmHg just before LTP. For every mmHg higher IOP prior to LTP, the IOP was reduced by an additional 0.6 mmHg at 12 months. The IOP was significantly reduced at all follow‐up visits from −2.6 (± 3.1) mmHg at one month to −2.1 (± 3.8) mmHg at 12 months in eyes with pre‐LTP IOP ≥ 15 mmHg, while no significant IOP reduction was seen in eyes with pre‐LTP IOP < 15 mmHg. Older age, argon LTP and male sex were associated with larger IOP reduction after 12 months, whereas presence of exfoliation syndrome was associated with a smaller IOP reduction. No severe complications were reported.Conclusion: Success of LTP was highly dependent on the IOP level prior to LTP treatment. A sustained significant IOP reduction was seen in eyes with pre‐LTP IOP ≥ 15 mmHg whereas no such effect was seen in eyes with pre‐LTP IOP < 15 mmHg. Thus, LTP can be considered in eyes with multi‐treatment when target pressure of < 15 mmHg is not achieved.
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| 47. |
- Rasmuson, Erika, et al.
(författare)
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Long-term follow-up of laser trabeculoplasty in multi-treated glaucoma patients
- 2024
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Ingår i: Acta Ophthalmologica. - : John Wiley & Sons. - 1755-375X .- 1755-3768. ; 102:2, s. 179-185
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To evaluate the long-term effect of laser trabeculoplasty (LTP) in patients randomized to multi-treatment in the Glaucoma Intensive Treatment Study (GITS).Methods: Patients with untreated newly diagnosed open-angle glaucoma were treated with three intraocular pressure (IOP)-lowering substances for 1 week and then 360 degrees argon or selective LTP was performed. IOP was measured just before LTP and repeatedly during the 60-month study period. Our previous report on 12 months follow-up data revealed no effect of LTP in eyes having an IOP <15 mmHg before the laser treatment.Results: Before LTP, the mean IOP +/- standard deviation in all 152 study-eyes of 122 multi-treated patients was 14.0 +/- 3.5 mmHg. Three eyes of three deceased patients were lost to follow-up during the 60 months. After exclusion of eyes that received increased therapy during follow-up, the IOP was significantly reduced at all visits up to 48 months in eyes with pre-LTP IOP >= 15 mmHg; 2.6 +/- 3.1 mmHg at 1 month and 1.7 +/- 2.8 mmHg at 48 months, n = 56 and 48, respectively. No significant IOP reduction was seen in eyes with pre-LTP IOP <15 mmHg. Seven eyes, i.e., <13%, with pre-LTP IOP >= 15 mmHg at baseline had required increased IOP-lowering therapy at 48 months.Conclusion: LTP performed in multi-treated patients may provide a useful IOP reduction that is maintained over several years. This was true on a group level when the initial IOP was >= 15 mmHg, but if the pre-laser IOP was lower than that, chances of LTP success were small.
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| 48. |
- Rydén, Martin, et al.
(författare)
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A human meniscus explant model for studying early events in osteoarthritis development by proteomics
- 2023
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Ingår i: Journal of Orthopaedic Research. - 0736-0266. ; 41:12, s. 2765-2778
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Tidskriftsartikel (refereegranskat)abstract
- Degenerative meniscus lesions have been associated with both osteoarthritis etiology and its progression. We, therefore, sought to establish a human meniscus ex vivo model to study the meniscal response to cytokine treatment using a proteomics approach. Lateral menisci were obtained from five knee-healthy donors. The meniscal body was cut into vertical slices and further divided into an inner (avascular) and outer region. Explants were either left untreated (controls) or stimulated with cytokines. Medium changes were conducted every 3 days up to Day 21 and liquid chromatography–mass spectrometry was performed at all the time points for the identification and quantification of proteins. Mixed-effect linear regression models were used for statistical analysis to estimate the effect of treatments versus control on protein abundance. Treatment by IL1ß increased release of cytokines such as interleukins, chemokines, and matrix metalloproteinases but a limited catabolic effect in healthy human menisci explants. Further, we observed an increased release of matrix proteins (collagens, integrins, prolargin, tenascin) in response to oncostatin M (OSM) + tumor necrosis factor (TNF) and TNF+interleukin-6 (IL6) + sIL6R treatments, and analysis of semitryptic peptides provided additional evidence of increased catabolic effects in response to these treatments. The induced activation of catabolic processes may play a role in osteoarthritis development.
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| 49. |
- Rämisch, Sebastian, et al.
(författare)
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Crystal structure of human chondroadherin : Solving a difficult molecular-replacement problem using de novo models
- 2017
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Ingår i: Acta Crystallographica Section D: Structural Biology. - 2059-7983. ; 73:1, s. 53-63
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Tidskriftsartikel (refereegranskat)abstract
- Chondroadherin (CHAD) is a cartilage matrix protein that mediates the adhesion of isolated chondrocytes. Its protein core is composed of 11 leucine-rich repeats (LRR) flanked by cysteine-rich domains. CHAD makes important interactions with collagen as well as with cell-surface heparin sulfate proteoglycans and α2β1 integrins. The integrin-binding site is located in a region of hitherto unknown structure at the C-terminal end of CHAD. Peptides based on the C-terminal human CHAD (hCHAD) sequence have shown therapeutic potential for treating osteoporosis. This article describes a still-unconventional structure solution by phasing with de novo models, the first of a β-rich protein. Structure determination of hCHAD using traditional, though nonsystematic, molecular replacement was unsuccessful in the hands of the authors, possibly owing to a combination of low sequence identity to other LRR proteins, four copies in the asymmetric unit and weak translational pseudosymmetry. However, it was possible to solve the structure by generating a large number of de novo models for the central LRR domain using Rosetta and multiple parallel molecular-replacement attempts using AMPLE. The hCHAD structure reveals an ordered C-terminal domain belonging to the LRRCT fold, with the integrin-binding motif (WLEAK) being part of a regular α-helix, and suggests ways in which experimental therapeutic peptides can be improved. The crystal structure itself and docking simulations further support that hCHAD dimers form in a similar manner to other matrix LRR proteins.The structure of human chondroadherin (hCHAD), a 359-amino-acid protein with 11 leucine-rich repeats, has been solved by molecular replacement using de novo models of a 195-residue segment and the AMPLE pipeline. This demonstrates that even a fairly large β-rich protein is tractable to solution using de novo modelling. The structure of the C-terminal domain of hCHAD reveals the conformation of a medically relevant peptide.
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| 50. |
- Sinkeviciute, Dovile, et al.
(författare)
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A novel biomarker of MMP-cleaved prolargin is elevated in patients with psoriatic arthritis
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Psoriatic arthritis (PsA) is a chronic musculoskeletal inflammatory disease found in up to 30% of psoriasis patients. Prolargin—an extracellular matrix (ECM) protein present in cartilage and tendon—has been previously shown elevated in serum of patients with psoriasis. ECM protein fragments can reflect tissue turnover and pathological changes; thus, this study aimed to develop, validate and characterize a novel biomarker PROM targeting a matrix metalloproteinase (MMP)-cleaved prolargin neo-epitope, and to evaluate it as a biomarker for PsA. A competitive ELISA was developed with a monoclonal mouse antibody; dilution- and spiking-recovery, inter- and intra-variation, and accuracy were evaluated. Serum levels were evaluated in 55 healthy individuals and 111 patients diagnosed with PsA by the CASPAR criteria. Results indicated that the PROM assay was specific for the neo-epitope. Inter- and intra- assay variations were 11% and 4%, respectively. PROM was elevated (p = 0.0003) in patients with PsA (median: 0.24, IQR: 0.19–0.31) compared to healthy controls (0.18; 0.14–0.23) at baseline. AUROC for separation of healthy controls from PsA patients was 0.674 (95% CI 0.597–0.744, P < 0.001). In conclusion, MMP-cleaved prolargin can be quantified in serum by the PROM assay and has the potential to separate patients with PsA from healthy controls.
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