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- Kurenkova, A. D., et al.
(författare)
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Notch Signaling Regulates the Chondrogenic Potential of Both Articular Chondrocytes and Their Progenitors During Expansion
- 2023
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Ingår i: Stem Cells. - 1066-5099. ; 41:6, s. 658-671
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Tidskriftsartikel (refereegranskat)abstract
- Articular cartilage has a limited capacity for self-repair and clinical approaches to cartilage regeneration are needed. The only such approach developed to date involves an expansion of primary autologous chondrocytes in culture, followed by their reimplantation into a cartilage defect. However, because of the formation of fibrocartilage instead of hyaline cartilage, the outcome is often not satisfactory. It happens due to the de-differentiation of chondrocytes during the expansion step. Indeed, articular chondrocytes are non-proliferative and require partial or complete dedifferentiation before actively proliferating. In recent years stem/progenitor cells in articular cartilage (artSPCs) have been described. These cells maintain their own population and renew articular cartilage in sexually mature mice. artSPCs can, theoretically, be superior to chondrocytes, for repairing damaged cartilage. Accordingly, here, we searched for conditions that allow rapid expansion of both artSPCs and chondrocytes with simultaneous preservation of their ability to form hyaline cartilage. Among the modulators of Wnt, Notch, and FGF signaling and of cell adhesion screened, only fibronectin and modulators of the Notch pathway promoted the rapid expansion of artSPCs. Surprisingly, both inhibition and activation of the pathway had this effect. However, only inhibition of Notch during expansion facilitated the chondrogenic potential of both artSPCs and primary chondrocytes, whereas activation of this pathway abrogated this potential entirely. This effect was the same for murine and human cells. Our present observations indicate that Notch signaling is the major regulator of the chondrogenic capacity of both artSPCs and chondrocytes during their expansion.
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- Batkovskyte, D., et al.
(författare)
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Al-Gazali Skeletal Dysplasia Constitutes the Lethal End of ADAMTSL2-Related Disorders
- 2023
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Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 0884-0431 .- 1523-4681. ; 38:5, s. 692-706
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Tidskriftsartikel (refereegranskat)abstract
- Lethal short-limb skeletal dysplasia Al-Gazali type (OMIM %601356), also called dysplastic cortical hyperostosis, Al-Gazali type, is an ultra-rare disorder previously reported in only three unrelated individuals. The genetic etiology for Al-Gazali skeletal dysplasia has up until now been unknown. Through international collaborative efforts involving seven clinical centers worldwide, a cohort of nine patients with clinical and radiographic features consistent with short-limb skeletal dysplasia Al-Gazali type was collected. The affected individuals presented with moderate intrauterine growth restriction, relative macrocephaly, hypertrichosis, large anterior fontanelle, short neck, short and stiff limbs with small hands and feet, severe brachydactyly, and generalized bone sclerosis with mild platyspondyly. Biallelic disease-causing variants in ADAMTSL2 were detected using massively parallel sequencing (MPS) and Sanger sequencing techniques. Six individuals were compound heterozygous and one individual was homozygous for pathogenic variants in ADAMTSL2. In one of the families, pathogenic variants were detected in parental samples only. Overall, this study sheds light on the genetic cause of Al-Gazali skeletal dysplasia and identifies it as a semi-lethal part of the spectrum of ADAMTSL2-related disorders. Furthermore, we highlight the importance of meticulous analysis of the pseudogene region of ADAMTSL2 where disease-causing variants might be located.
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- Hammarsjo, A, et al.
(författare)
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Novel KIAA0753 mutations extend the phenotype of skeletal ciliopathies
- 2017
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Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7:1, s. 15585-
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Tidskriftsartikel (refereegranskat)abstract
- The skeletal ciliopathies are a heterogeneous group of disorders with a significant clinical and genetic variability and the main clinical features are thoracic hypoplasia and short tubular bones. To date, 25 genes have been identified in association with skeletal ciliopathies. Mutations in the KIAA0753 gene have recently been associated with Joubert syndrome (JBTS) and orofaciodigital (OFD) syndrome. We report biallelic pathogenic variants in KIAA0753 in four patients with short-rib type skeletal dysplasia. The manifestations in our patients are variable and ranging from fetal lethal to viable and moderate skeletal dysplasia with narrow thorax and abnormal metaphyses. We demonstrate that KIAA0753 is expressed in normal fetal human growth plate and show that the affected fetus, with a compound heterozygous frameshift and a nonsense mutation in KIAA0753, has an abnormal proliferative zone and a broad hypertrophic zone. The importance of KIAA0753 for normal skeletal development is further confirmed by our findings that zebrafish embryos homozygous for a nonsense mutation in kiaa0753 display altered cartilage patterning.
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- Kaucka, M., et al.
(författare)
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Altered developmental programs and oriented cell divisions lead to bulky bones during salamander limb regeneration
- 2022
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- There are major differences in duration and scale at which limb development and regeneration proceed, raising the question to what extent regeneration is a recapitulation of development. We address this by analyzing skeletal elements using a combination of micro-CT imaging, molecular profiling and clonal cell tracing. We find that, in contrast to development, regenerative skeletal growth is accomplished based entirely on cartilage expansion prior to ossification, not limiting the transversal cartilage expansion and resulting in bulkier skeletal parts. The oriented extension of salamander cartilage and bone appear similar to the development of basicranial synchondroses in mammals, as we found no evidence for cartilage stem cell niches or growth plate-like structures during neither development nor regeneration. Both regenerative and developmental ossification in salamanders start from the cortical bone and proceeds inwards, showing the diversity of schemes for the synchrony of cortical and endochondral ossification among vertebrates. Normal limb development relies on synchronized formation of cartilage and bone. Here, the authors show that in salamander limb regeneration these processes are decoupled: ossification occurs after the final size of regenerating cartilage is reached, allowing fast regeneration and leading to bulky bones.
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- Chagin, A S, et al.
(författare)
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Estrogen receptor-beta inhibits skeletal growth and has the capacity to mediate growth plate fusion in female mice.
- 2004
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Ingår i: Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research. - 0884-0431. ; 19:1, s. 72-7
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Tidskriftsartikel (refereegranskat)abstract
- To determine the long-term role of ER beta in the regulation of longitudinal bone growth, appendicular and axial skeletal growth was followed and compared in female ER beta-/-, ER alpha-/-, and ER alpha-/- beta-/- mice. Our results show that ER beta inhibits appendicular and axial skeletal growth and has the capacity to induce fusion of the growth plates. INTRODUCTION: Estrogen affects skeletal growth and promotes growth plate fusion in humans. In rodents, the growth plates do not fuse after sexual maturation, but prolonged treatment with supraphysiological levels of estradiol has the capacity to fuse the growth plates. It should be emphasized that the estrogen receptor (ER) alpha-/- and the ER alpha-/- beta-/-, but not the ER beta-/-, mouse models have clearly increased serum levels of estradiol. MATERIALS AND METHODS: The skeletal growth was monitored by X-ray and dynamic histomorphometry, and the growth plates were analyzed by quantitative histology, calcein double labeling, bromodeoxyuridine (BrdU) incorporation, and TUNEL assay in 4- and 18-month-old female ER beta-/-, ER alpha-/-, and ER alpha-/- beta-/- mice. RESULTS: Young adult (4-month-old) ER beta-/- mice demonstrated an increased axial- and appendicular-skeletal growth, supporting the notion that ER beta inhibits skeletal growth in young adult female mice. Interestingly, the growth plates were consistently fused in the appendicular skeleton of 18-month-old female ER alpha-/- mice. This fusion of growth plates, caused by a prolonged exposure to supraphysiological levels of estradiol in female ER alpha-/- mice, must be mediated through ER beta because old ER alpah-/- beta-/- mice displayed unchanged, unfused growth plates. CONCLUSIONS: Our results confirm that ER beta is a physiological inhibitor of appendicular- and axial-skeletal growth in young adult female mice. Furthermore, we made the novel observation that ER beta, after prolonged supraphysiological estradiol exposure, has the capacity to mediate growth plate fusion in old female mice.
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| 16. |
- Newton, P. T., et al.
(författare)
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A radical switch in clonality reveals a stem cell niche in the epiphyseal growth plate
- 2019
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 567:7747
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Tidskriftsartikel (refereegranskat)abstract
- Longitudinal bone growth in children is sustained by growth plates, narrow discs of cartilage that provide a continuous supply of chondrocytes for endochondral ossification(1). However, it remains unknown how this supply is maintained throughout childhood growth. Chondroprogenitors in the resting zone are thought to be gradually consumed as they supply cells for longitudinal growth(1,2), but this model has never been proved. Here, using clonal genetic tracing with multicolour reporters and functional perturbations, we demonstrate that longitudinal growth during the fetal and neonatal periods involves depletion of chondroprogenitors, whereas later in life, coinciding with the formation of the secondary ossification centre, chondroprogenitors acquire the capacity for self-renewal, resulting in the formation of large, stable monoclonal columns of chondrocytes. Simultaneously, chondroprogenitors begin to express stem cell markers and undergo symmetric cell division. Regulation of the pool of self-renewing progenitors involves the hedgehog and mammalian target of rapamycin complex 1 (mTORC1) signalling pathways. Our findings indicate that a stem cell niche develops postnatally in the epiphyseal growth plate, which provides a continuous supply of chondrocytes over a prolonged period.
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| 17. |
- Tong, D. M., et al.
(författare)
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A Shared Epitope of Collagen Type XI and Type II Is Recognized by Pathogenic Antibodies in Mice and Human with Arthritis
- 2018
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Collagen XI (CXI) is a heterotrimeric molecule with triple helical structure in which the alpha 3(XI) chain is identical to the alpha 1(II) chain of collagen II (CII), but with extensive posttranslational modifications. CXI molecules are intermingled in the cartilage collagen fibers, which are mainly composed of CII. One of the alpha chains in CXI is shared with CII and contains the immunodominant T cell epitope, but it is unclear whether there are shared B cell epitopes as the antibodies tend to recognize the triple helical structures. Methods: Mice expressing the susceptible immune response gene A(q) were immunized with CII or CXI. Serum antibody responses were measured, monoclonal antibodies were isolated and analyzed for specificity to CII, CXI, and triple helical collagen peptides using bead-based multiplex immunoassays, enzyme-linked immunosorbent assays, and Western blots. Arthritogenicity of the antibodies was investigated by passive transfer experiments. Results: Immunization with CII or CXI leads to a strong T and B cell response, including a cross-reactive response to both collagen types. Immunization with CII leads to severe arthritis in mice, with a response toward CXI at the chronic stage, whereas CXI immunization induces very mild arthritis only. A series of monoclonal antibodies to CXI were isolated and of these, the L10D9 antibody bound to both CXI and CII equally strong, with a specific binding for the D3 epitope region of alpha 3(XI) or alpha 1(II) chain. The L10D9 antibody binds cartilage in vivo and induced severe arthritis. In contrast, the L5F3 antibody only showed weak binding and L7D8 antibody has no binding to cartilage and did not induce arthritis. The arthritogenic L10D9 antibody bound to an epitope shared with CII, the triple helical D3 epitope. Antibody levels to the shared D3 epitope were elevated in the sera from mice with arthritis as well as in rheumatoid arthritis. Conclusion: CXI is immunologically not exposed in healthy cartilage but contains T and B cell epitopes cross-reactive with CII, which could be activated in both mouse and human arthritis and could evoke an arthritogenic response.
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| 25. |
- Iravani, M., et al.
(författare)
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Effects of the selective GPER1 agonist G1 on bone growth
- 2019
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Ingår i: Endocrine Connections. - 2049-3614. ; 8:9, s. 1302-1309
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Tidskriftsartikel (refereegranskat)abstract
- Estrogens may affect bone growth locally or systemically via the known estrogen receptors ESR1, ESR2 and G protein-coupled estrogen receptor 1 (GPER1). Mouse and human growth plate chondrocytes have been demonstrated to express GPER1 and ablation of this receptor increased bone length in mice. Therefore, GPER1 is an attractive target for therapeutic modulation of bone growth, which has never been explored. To investigate the effects of activated GPER1 on the growth plate, we locally exposed mouse metatarsal bones to different concentrations of the selective GPER1 agonist G1 for 14 days ex vivo. The results showed that none of the concentrations of G1 had any direct effect on metatarsal bone growth when compared to control. To evaluate if GPER1 stimulation may systemically modulate bone growth, ovariectomized C57BL/6 mice were treated with G1 or beta-estradiol (E2). Similarly, G1 did not influence tibia and femur growth in treated mice. As expected, E2 treatment suppressed bone growth in vivo. We conclude that ligand stimulation of GPER1 does not influence bone growth in mice.
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