| 1. |
- Karlsson, Camilla, 1977, et al.
(författare)
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Differentiation of human mesenchymal stem cells and articular chondrocytes: analysis of chondrogenic potential and expression pattern of differentiation-related transcription factors.
- 2007
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Ingår i: Journal of orthopaedic research : official publication of the Orthopaedic Research Society. - : Wiley. - 0736-0266. ; 25:2, s. 152-63
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Tidskriftsartikel (refereegranskat)abstract
- Mesenchymal stem cells (MSCs) are a candidate for replacing chondrocytes in cell-based repair of cartilage lesions. However, it has not been clarified if these cells can acquire the hyaline phenotype, and whether chondrocytes and MSCs show the same expression patterns of critical control genes in development. In order to study this, articular chondrocytes and iliac crest derived MSCs were allowed to differentiate in pellet mass cultures. Gene expression of markers for the cartilage phenotype, helix-loop-helix (HLH) transcription factors, and chondrogenic transcription factors were analyzed by real-time PCR. Matrix production was assayed using biochemical analysis for hydroxyproline, glycosaminoglycans, and immunohistochemistry for collagen types I and II. Significantly decreased expression of collagen type I was accompanied by increased expression of collagen types IIA and IIB during differentiation of chondrocytes, indicating differentiation towards a hyaline phenotype. Chondrogenesis in MSCs on the other hand resulted in up-regulation of collagen types I, IIA, IIB, and X, demonstrating differentiation towards cartilage of a mixed phenotype. Expression of HES1 increased significantly during chondrogenesis in chondrocytes while expression in MSCs was maintained at a low level. The HLH gene HES5 on the other hand was only detected in chondrocytes. Expression of ID1 decreased significantly in chondrocytes while the opposite was seen in MSCs. These findings suggest that chondrocytes and MSCs differentiated and formed different subtypes of cartilage, the hyaline and a mixed cartilage phenotype, respectively. Differentially regulated HLH genes indicated the possibility for HLH proteins in regulating chondrogenic differentiation. This information is important to understand the potential use of MSCs in cartilage repair.
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| 2. |
- Karlsson, Camilla, 1977, et al.
(författare)
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Notch and HES5 are regulated during human cartilage differentiation.
- 2007
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Ingår i: Cell and tissue research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 327:3, s. 539-51
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Tidskriftsartikel (refereegranskat)abstract
- The molecular mechanisms of cartilage differentiation are poorly understood. In a variety of tissues other than cartilage, members of the basic helix-loop-helix (bHLH) family of transcription factors have been demonstrated to play critical roles in differentiation. We have characterized the human bHLH gene HES5 and investigated its role during chondrogenesis. Blockage of the Notch signaling pathway with a gamma-secretase inhibitor has demonstrated that the human HES5 gene is a downstream marker of Notch signaling in articular chondrocytes. Markers for the Notch signaling pathway significantly decrease during cartilage differentiation in vitro. Cell proliferation assayed by using BrdU has revealed that blockage of Notch signaling is associated with significantly decreased proliferation. Northern blot and reverse transcription/polymerase chain reaction of a panel of various tissues have shown that HES5 is transcribed as a 5.4-kb mRNA that is ubiquitously expressed in diverse fetal and adult tissues. Articular cartilage from HES5(-/-) and wild-type mice has been analyzed by using various histological stains. No differences have been detected between the wild-type and HES5(-/-) mice. Our data thus indicate that the human HES5 gene is coupled to the Notch receptor family, that expression of Notch markers (including HES5) decreases during cartilage differentiation, and that the blockage of Notch signaling is associated with significantly decreased cell proliferation.
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| 3. |
- Karlsson, Camilla, 1977, et al.
(författare)
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Notch1, Jagged1, and HES5 are abundantly expressed in osteoarthritis.
- 2008
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Ingår i: Cells, tissues, organs. - : S. Karger AG. - 1422-6421 .- 1422-6405. ; 188:3, s. 287-98
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Notch signalling controls differentiation and proliferation in various cell types and is associated with several diseases. We investigated the localization and regulation of several Notch markers in human osteoarthritic (OA) cartilage as well as identified genes controlled by Notch signalling. METHODS: Immunolocalization and real-time PCR analysis of Notch markers in healthy and OA articular cartilage were performed. Genes regulated by Notch signalling were studied using microarray. Cytokine-induced transcription of Notch markers was analyzed using real-time PCR and its effect on cellular localization of the intracellular domain of Notch1 (NICD1) was investigated using immunohistochemistry, subcellular fractionation, and transfection. The effect of NFkappaB activation on HES5 transcription was studied using the NFkappaB inhibitor pyrrolidine dithiocarbamate. RESULTS: Notch signalling was activated in OA cartilage and Notch1, Jagged1, and HES5 were abundantly expressed compared to healthy cartilage. Notch signalling regulated the expression of several genes associated with OA, like interleukin-8, lubricin, CD10, matrix metalloproteinase-9, and bone morphogenetic protein-2. Cytokines significantly affected the expression of several Notch markers and repressed expression of HES5, but did not affect the cellular localization of NICD1. CONCLUSION: Notch signalling is dysregulated in OA, inducing and repressing transcription of genes that could potentially partly contribute to the OA phenotype.
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| 4. |
- Apelgren, Peter, et al.
(författare)
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Chondrocytes and stem cells in 3D-bioprinted structures create human cartilage in vivo.
- 2017
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 12:12
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Tidskriftsartikel (refereegranskat)abstract
- Cartilage repair and replacement is a major challenge in plastic reconstructive surgery. The development of a process capable of creating a patient-specific cartilage framework would be a major breakthrough. Here, we described methods for creating human cartilage in vivo and quantitatively assessing the proliferative capacity and cartilage-formation ability in mono- and co-cultures of human chondrocytes and human mesenchymal stem cells in a three-dimensional (3D)-bioprinted hydrogel scaffold. The 3D-bioprinted constructs (5 × 5 × 1.2 mm) were produced using nanofibrillated cellulose and alginate in combination with human chondrocytes and human mesenchymal stem cells using a 3D-extrusion bioprinter. Immediately following bioprinting, the constructs were implanted subcutaneously on the back of 48 nude mice and explanted after 30 and 60 days, respectively, for morphological and immunohistochemical examination. During explantation, the constructs were easy to handle, and the majority had retained their macroscopic grid appearance. Constructs consisting of human nasal chondrocytes showed good proliferation ability, with 17.2% of the surface areas covered with proliferating chondrocytes after 60 days. In constructs comprising a mixture of chondrocytes and stem cells, an additional proliferative effect was observed involving chondrocyte production of glycosaminoglycans and type 2 collagen. This clinically highly relevant study revealed 3D bioprinting as a promising technology for the creation of human cartilage.
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| 5. |
- Apelgren, Peter, et al.
(författare)
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Skin Grafting on 3D Bioprinted Cartilage Constructs In Vivo
- 2018
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Ingår i: Plastic and Reconstructive Surgery-Global Open. - : Ovid Technologies (Wolters Kluwer Health). - 2169-7574. ; 6:9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Three-dimensional (3D) bioprinting of cartilage is a promising new technique. To produce, for example, an auricle with good shape, the printed cartilage needs to be covered with skin that can grow on the surface of the construct. Our primary question was to analyze if an integrated 3D bioprinted cartilage structure is a tissue that can serve as a bed for a full-thickness skin graft. Methods: 3D bioprinted constructs (10x10x1.2mm) were printed using nanofibrillated cellulose/alginate bioink mixed with mesenchymal stem cells and adult chondrocytes and implanted subcutaneously in 21 nude mice. Results: After 45 days, a full-thickness skin allograft was transplanted onto the constructs and the grafted construct again enclosed subcutaneously. Group 1 was sacrificed on day 60, whereas group 2, instead, had their skin-bearing construct uncovered on day 60 and were sacrificed on day 75 and the explants were analyzed morphologically. The skin transplants integrated well with the 3D bioprinted constructs. A tight connection between the fibrous, vascularized capsule surrounding the 3D bioprinted constructs and the skin graft were observed. The skin grafts survived the uncovering and exposure to the environment. Conclusions: A 3D bioprinted cartilage that has been allowed to integrate in vivo is a sufficient base for a full-thickness skin graft. This finding accentuates the clinical potential of 3D bioprinting for reconstructive purposes.
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| 6. |
- Apelgren, Peter, et al.
(författare)
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Skin Grafting on 3D Bioprinted Cartilage Constructs In Vivo
- 2018
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Ingår i: Plastic and Reconstructive Surgery - Global Open. - 2169-7574. ; 6:9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Three-dimensional (3D) bioprinting of cartilage is a promising new technique. To produce, for example, an auricle with good shape, the printed cartilage needs to be covered with skin that can grow on the surface of the construct. Our primary question was to analyze if an integrated 3D bioprinted cartilage structure is a tissue that can serve as a bed for a full-thickness skin graft. Methods: 3D bioprinted constructs (10x10x1.2mm) were printed using nanofibrillated cellulose/alginate bioink mixed with mesenchymal stem cells and adult chondrocytes and implanted subcutaneously in 21 nude mice. Results: After 45 days, a full-thickness skin allograft was transplanted onto the constructs and the grafted construct again enclosed subcutaneously. Group 1 was sacrificed on day 60, whereas group 2, instead, had their skin-bearing construct uncovered on day 60 and were sacrificed on day 75 and the explants were analyzed morphologically. The skin transplants integrated well with the 3D bioprinted constructs. A tight connection between the fibrous, vascularized capsule surrounding the 3D bioprinted constructs and the skin graft were observed. The skin grafts survived the uncovering and exposure to the environment. Conclusions: A 3D bioprinted cartilage that has been allowed to integrate in vivo is a sufficient base for a full-thickness skin graft. This finding accentuates the clinical potential of 3D bioprinting for reconstructive purposes.
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| 7. |
- Asp, Julia, 1973, et al.
(författare)
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Changes in p14(ARF) do not play a primary role in human chondrosarcoma tissues.
- 2001
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Ingår i: International journal of cancer. Journal international du cancer. - 0020-7136. ; 93:5, s. 703-5
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Tidskriftsartikel (refereegranskat)abstract
- The locus encoding the tumor suppressor p16 has been found to code for a second, different protein. This protein, p14(ARF), has been shown to protect p53 from degradation. Like p16, its gene is often altered in different cancers. In this study, the first unique exon, exon 1 beta, of p14(ARF), has been studied in 22 chondrosarcoma tissues using polymerase chain reaction, DNA sequencing and methylation-specific polymerase chain reaction. One chondrosarcoma was found to have exon 1 beta homozygously deleted, but neither mutations nor methylations were found in any of the chondrosarcomas. This indicates that genetic changes of p14(ARF) are a rare event in chondrosarcoma.
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| 8. |
- Asp, Julia, 1973, et al.
(författare)
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Evaluation of p16 and Id1 status and endogenous reference genes in human chondrosarcoma by real-time PCR.
- 2005
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Ingår i: International journal of oncology. - 1019-6439. ; 27:6, s. 1577-82
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Tidskriftsartikel (refereegranskat)abstract
- Both the tumour suppressor, p16, and the helix-loop-helix transcription factor, Id1, have been assigned roles in tumour growth in general and appear to be involved in chondrosarcoma. Id1 has further been found to repress the expression of p16. Therefore, the mRNA expression of these two genes was studied by real-time PCR in a search for prognostic markers in human chondrosarcoma. To get reliable quantitative data, however, the choice of endogenous reference gene for use in the assay is important. Therefore, eleven different endogenous reference genes were evaluated in chondrosarcoma cells and articular chondrocytes. 18S rRNA appeared to be the best choice to use as endogenous reference gene, since it was suitable for both kinds of cells. Several of the other reference genes tested showed variation between individuals or between normal chondrocytes and chondrosarcoma cells. This demonstrates the importance of using a correct endogenous reference gene to get reliable results from quantitative measurements. Both p16 and Id1 showed varied gene expression patterns among the samples and none of these genes could be significantly correlated to prognosis.
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| 9. |
- Boreström, Cecilia, 1974, et al.
(författare)
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Footprint-Free Human Induced Pluripotent Stem Cells From Articular Cartilage With Redifferentiation Capacity: A First Step Toward a Clinical-Grade Cell Source.
- 2014
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Ingår i: Stem cells translational medicine. - : Oxford University Press (OUP). - 2157-6564 .- 2157-6580. ; 3:4, s. 433-447
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Tidskriftsartikel (refereegranskat)abstract
- Human induced pluripotent stem cells (iPSCs) are potential cell sources for regenerative medicine; however, clinical applications of iPSCs are restricted because of undesired genomic modifications associated with most reprogramming protocols. We show, for the first time, that chondrocytes from autologous chondrocyte implantation (ACI) donors can be efficiently reprogrammed into iPSCs using a nonintegrating method based on mRNA delivery, resulting in footprint-free iPSCs (no genome-sequence modifications), devoid of viral factors or remaining reprogramming molecules. The search for universal allogeneic cell sources for the ACI regenerative treatment has been difficult because making chondrocytes with high matrix-forming capacity from pluripotent human embryonic stem cells has proven challenging and human mesenchymal stem cells have a predisposition to form hypertrophic cartilage and bone. We show that chondrocyte-derived iPSCs can be redifferentiated in vitro into cartilage matrix-producing cells better than fibroblast-derived iPSCs and on par with the donor chondrocytes, suggesting the existence of a differentiation bias toward the somatic cell origin and making chondrocyte-derived iPSCs a promising candidate universal cell source for ACI. Whole-genome single nucleotide polymorphism array and karyotyping were used to verify the genomic integrity and stability of the established iPSC lines. Our results suggest that RNA-based technology eliminates the risk of genomic integrations or aberrations, an important step toward a clinical-grade cell source for regenerative medicine such as treatment of cartilage defects and osteoarthritis.
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| 10. |
- Brisby, Helena, 1965, et al.
(författare)
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The presence of local mesenchymal progenitor cells in human degenerated intervertebral discs and possibilities to influence these in vitro: A descriptive study in humans
- 2013
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Ingår i: Stem Cells and Development. - : Mary Ann Liebert Inc. - 1547-3287 .- 1557-8534. ; 22:5, s. 804-814
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Tidskriftsartikel (refereegranskat)abstract
- Low back pain is common and degenerated discs are believed to be a major cause. In non-degenerated intervertebral discs(IVDs) presence of stem-/progenitor cells was recently reported in different mammals (rabbit,rat,pig). Understanding processes of disc degeneration and regenerative mechanisms within degenerated discs(DDs) is important. The aim of the study was to examine presence of local stem-/progenitor cells in human DDs and if these cell-populations could respond to paracrin stimulation in vitro. Tissue biopsies from the IVD region (L3-S1) was collected from 15 patients, age 34-69 years, undergoing surgery (spinal fusion) and mesenchymal stem cells (MSCs)(iliac crest) from two donors. Non-degenerated disc cells were collected from one donor(scoliosis) and chordoma tissue was obtained from(positive control, stem cell markers) two donors. The IVD biopsies were investigated for gene- and protein expression of: OCT3/4, CD105, CD90, STRO-1 and NOTCH1. DD cell cultures(pellet mass) were performed with conditioned media from MSCs and non-degenerated IVD cells. Pellets were investigated after 7, 14, 28 days for the same stem cell markers as above. Gene expression of OCT3/4 and STRO-1 was detected in 13/15 patient samples, CD105 in 14/15 samples and CD90 and NOTCH1 was detected 15/15 samples. Immunohistochemistry analysis supported findings on protein level, in cells sparsely distributed in DDs tissues. DDs cell-cultures displayed more undifferentiated appearance with increased expression of CD105, CD90, STRO-1, OCT3/4, NOTCH1 and JAGGED1 which was observed when cultured in conditioned cell-culture media from MSC compared to cell-cultures cultured with conditioned media from non-degenerated disc cells. Expression of OCT3/4(multipotency marker) and NOTCH1(regulator of cell fate), MSC- markers CD105, CD90 and STRO-1 indicate that primitive cell populations are present within DDs. Furthermore, the possibility to influence cells from DDs by by paracrin signalling /soluble factors from MSCs and from non-degenerated IVD cells was observed in vitro indicating that repair processes within human degenerated discs may be stimulated.
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