| 1. |
- Lammi, Mikko J., 1961-, et al.
(författare)
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Regulation of oxygen tension as a strategy to control chondrocytic phenotype for cartilage tissue engineering and regeneration
- 2024
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Ingår i: Bioengineering. - : MDPI. - 2306-5354. ; 11:3
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Forskningsöversikt (refereegranskat)abstract
- Cartilage defects and osteoarthritis are health problems which are major burdens on health care systems globally, especially in aging populations. Cartilage is a vulnerable tissue, which generally faces a progressive degenerative process when injured. This makes it the 11th most common cause of global disability. Conservative methods are used to treat the initial phases of the illness, while orthopedic management is the method used for more progressed phases. These include, for instance, arthroscopic shaving, microfracturing and mosaicplasty, and joint replacement as the final treatment. Cell-based implantation methods have also been developed. Despite reports of successful treatments, they often suffer from the non-optimal nature of chondrocyte phenotype in the repair tissue. Thus, improved strategies to control the phenotype of the regenerating cells are needed. Avascular tissue cartilage relies on diffusion for nutrients acquisition and the removal of metabolic waste products. A low oxygen content is also present in cartilage, and the chondrocytes are, in fact, well adapted to it. Therefore, this raises an idea that the regulation of oxygen tension could be a strategy to control the chondrocyte phenotype expression, important in cartilage tissue for regenerative purposes. This narrative review discusses the aspects related to oxygen tension in the metabolism and regulation of articular and growth plate chondrocytes and progenitor cell phenotypes, and the role of some microenvironmental factors as regulators of chondrocytes.
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| 2. |
- Qu, Chengjuan, 1967-, et al.
(författare)
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Chondrocyte-specific gene expressions in human embryonic stem cells differentiated under feeder-free culture conditions
- 2017
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Ingår i: Current Regenerative Medicine. - : Bentham Science. - 2468-4244 .- 2468-4252. ; 7, s. 54-63
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Tidskriftsartikel (refereegranskat)abstract
- Background: Chondrogenic differentiation of human embryonic stem cells (hESCs) has been investigated by maintenance of 3-dimensional cultures in the presence of various exogenous growth factors added during defined stages of culture, or in cocultures with primary chondrocytes, which makes the cultivation process rather complex. Thus, there is a need for easier and more handy expansion and differentiation protocols.Objective: The present study is aimed to investigate the potential of hESCs for chondrogenic differentiation in simpler culture conditions.Methods: The hESCs were directly cultured for 3 weeks on feeder-free gelatin-coated plates in chondrocyte culture medium without any growth factor supplements after 6-day culture on feeder-free gelatin-coated plate with conditioned medium.Results: Immunocytochemical and gene expression analyses indicated that these human directly differentiated cells (hDDCs), which derived from the hESCs, abundantly expressed Sox9, aggrecan, and procollagen a1(II) mRNAs. Upon further passaging, the hDDCs behaved similarly to primary chondrocytes, although the aggrecan mRNA expressions were maintained at a relatively constant level throughout passaging. The procollagen a1(II) mRNAs expression was high in the beginning of the hDDC culture, but declined upon further passaging, which is typical for the primary chondrocytes. The hDDCs could be easily expanded in the monolayer culture using chondrocyte culture medium. Differentiation assays showed that the hDDCs could be differentiated towards chondrocytes, but not adipocytes or osteoblasts.Conclusion: Our data suggests that the chondrogenic gene expression could be induced in the directly differentiated hESCs without a need for chondrocyte coculture. In contrast, no osteogenic or adipogenic differentiation was observed.
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| 3. |
- Prittinen, Juha, 1989-, et al.
(författare)
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Effect of centrifugal force on the development of articular neocartilage with bovine primary chondrocytes
- 2019
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Ingår i: Cell and Tissue Research. - New York : Springer. - 0302-766X .- 1432-0878. ; 375:3, s. 629-639
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Tidskriftsartikel (refereegranskat)abstract
- A lot has been invested into understanding how to assemble cartilage tissue in vitro and various designs have been developed to manufacture cartilage tissue with native-like biological properties. So far, no satisfactory design has been presented. Bovine primary chondrocytes are used to self-assemble scaffold-free constructs to investigate whether mechanical loading by centrifugal force would be useful in manufacturing cartilage tissue in vitro. Six million chondrocytes were laid on top of defatted bone disks placed inside an agarose well in 50-ml culture tubes. The constructs were centrifuged once or three times per day for 15 min at a centrifugal force of 771×g for up to 4 weeks. Control samples were cultured under the same conditions without exposure to centrifugation. The samples were analysed by (immuno)histochemistry, Fourier transform infrared imaging, micro-computed tomography, biochemical and gene expression analyses. Biomechanical testing was also performed. The centrifuged tissues had a more even surface covering a larger area of the bone disk. Fourier transform infrared imaging analysis indicated a higher concentration of collagen in the top and bottom edges in some of the centrifuged samples. Glycosaminoglycan contents increased along the culture, while collagen content remained at a rather constant level. Aggrecan and procollagen α1(II) gene expression levels had no significant differences, while procollagen α2(I) levels were increased significantly. Biomechanical analyses did not reveal remarkable changes. The centrifugation regimes lead to more uniform tissue constructs, whereas improved biological properties of the native tissue could not be obtained by centrifugation.
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| 4. |
- Lammi, Mikko, 1961-, et al.
(författare)
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Challenges in fabrication of tissue-engineered cartilage with correct cellular colonization and extracellular matrix assembly
- 2018
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Ingår i: International Journal of Molecular Sciences. - : MDPI. - 1661-6596 .- 1422-0067. ; 19:9
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Forskningsöversikt (refereegranskat)abstract
- A correct articular cartilage ultrastructure regarding its structural components and cellularity is important for appropriate performance of tissue-engineered articular cartilage. Various scaffold-based, as well as scaffold-free, culture models have been under development to manufacture functional cartilage tissue. Even decellularized tissues have been considered as a potential choice for cellular seeding and tissue fabrication. Pore size, interconnectivity, and functionalization of the scaffold architecture can be varied. Increased mechanical function requires a dense scaffold, which also easily restricts cellular access within the scaffold at seeding. High pore size enhances nutrient transport, while small pore size improves cellular interactions and scaffold resorption. In scaffold-free cultures, the cells assemble the tissue completely by themselves; in optimized cultures, they should be able to fabricate native-like tissue. Decellularized cartilage has a native ultrastructure, although it is a challenge to obtain proper cellular colonization during cell seeding. Bioprinting can, in principle, provide the tissue with correct cellularity and extracellular matrix content, although it is still an open question as to how the correct molecular interaction and structure of extracellular matrix could be achieved. These are challenges facing the ongoing efforts to manufacture optimal articular cartilage.
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| 5. |
- Florea, Cristina, et al.
(författare)
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A combined experimental atomic force microscopy-based nanoindentation and computational modeling approach to unravel the key contributors to the time-dependent mechanical behavior of single cells
- 2017
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Ingår i: Biomechanics and Modeling in Mechanobiology. - : Springer Berlin/Heidelberg. - 1617-7959 .- 1617-7940. ; 16:1, s. 297-311
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Tidskriftsartikel (refereegranskat)abstract
- Cellular responses to mechanical stimuli are influenced by the mechanical properties of cells and the surrounding tissue matrix. Cells exhibit viscoelastic behavior in response to an applied stress. This has been attributed to fluid flow-dependent and flow-independent mechanisms. However, the particular mechanism that controls the local time-dependent behavior of cells is unknown. Here, a combined approach of experimental AFM nanoindentation with computational modeling is proposed, taking into account complex material behavior. Three constitutive models (porohyperelastic, viscohyperelastic, poroviscohyperelastic) in tandem with optimization algorithms were employed to capture the experimental stress relaxation data of chondrocytes at 5 % strain. The poroviscohyperelastic models with and without fluid flow allowed through the cell membrane provided excellent description of the experimental time-dependent cell responses (normalized mean squared error (NMSE) of 0.003 between the model and experiments). The viscohyperelastic model without fluid could not follow the entire experimental data that well (NMSE = 0.005), while the porohyperelastic model could not capture it at all (NMSE = 0.383). We also show by parametric analysis that the fluid flow has a small, but essential effect on the loading phase and short-term cell relaxation response, while the solid viscoelasticity controls the longer-term responses. We suggest that the local time-dependent cell mechanical response is determined by the combined effects of intrinsic viscoelasticity of the cytoskeleton and fluid flow redistribution in the cells, although the contribution of fluid flow is smaller when using a nanosized probe and moderate indentation rate. The present approach provides new insights into viscoelastic responses of chondrocytes, important for further understanding cell mechanobiological mechanisms in health and disease.
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| 6. |
- Lei, Jian, et al.
(författare)
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Abnormal expression of chondroitin sulfate sulfotransferases in the articular cartilage of pediatric patients with Kashin-Beck disease
- 2020
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Ingår i: Histochemistry and Cell Biology. - : Springer Science and Business Media LLC. - 0948-6143 .- 1432-119X. ; 153:3, s. 153-164
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study is to investigate the expression of enzymes involved in the sulfation of articular cartilage from proximal metacarpophalangeal (PMC) joint cartilage and distal metacarpophalangeal (DMC) joint cartilage in children with Kashin-Beck disease (KBD). The finger cartilage samples of PMC and DMC were collected from KBD and normal children aged 5-14 years old. Hematoxylin and eosin staining as well as immunohistochemical staining were used to observe the morphology and quantitate the expression of carbohydrate sulfotransferase 3 (CHST-3), carbohydrate sulfotransferase 12 (CHST-12), carbohydrate sulfotransferase 13 (CHST-13), uronyl 2-O-sulfotransferase (UST), and aggrecan. In the results, the numbers of chondrocyte decreased in all three zones of PMC and DMC in the KBD group. Less positive staining cells for CHST-3, CHST-12, CHST-13, UST, and aggrecan were observed in almost all three zones of PMC and DMC in KBD. The positive staining cell rates of CHST-12 were higher in superficial and middle zones of PMC and DMC in KBD, and a significantly higher rate of CHST-13 was observed only in superficial zone of PMC in KBD. In conclusion, the abnormal expression of chondroitin sulfate sulfotransferases in chondrocytes of KBD children may provide an explanation for the cartilage damage, and provide therapeutic targets for the treatment.
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| 7. |
- Kaitainen, Salla, et al.
(författare)
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TiO2 coating promotes human mesenchymal stem cell proliferation without the loss of their capacity for chondrogenic differentiation
- 2013
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Ingår i: Biofabrication. - : Institute of Physics (IOP). - 1758-5090 .- 1758-5082. ; 5:2, s. 025009-
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Tidskriftsartikel (refereegranskat)abstract
- Human mesenchymal stem cells (hMSCs) are used in applications, which may require a large amount of cells; therefore, efficient expansion of the cells is desired. We studied whether TiO2 coating on plastic cell culture dishes could promote proliferation of hMSCs without adverse effects in chondrogenic differentiation. TiO2-films were deposited on polystyrene dishes and glass coverslips using an ultrashort pulsed laser deposition technique. Human MSCs from three donors were expanded on them until 95% confluence, and the cells were evaluated by morphology, immunocytochemistry and quantitative RT-PCR (qRT-PCR). The chondrogenic differentiation in pellets was performed after cultivation on TiO2-coated dishes. Chondrogenesis was evaluated by histological staining of proteoglycans and type II collagen, and qRT-PCR. Human MSC-associated markers STRO-1, CD44, CD90 and CD146 did not change after expansion on TiO2-coated coverslips. However, the cell number after a 48h-culture period was significantly higher on TiO2-coated culture dishes. Importantly, TiO2 coating caused no significant differences in the proteoglycan and type II collagen staining of the pellets, or the expression of chondrocyte-specific genes in the chondrogenesis assay. Thus, the proliferation of hMSCs could be significantly increased when cultured on TiO2-coated dishes without weakening their chondrogenic differentiation capacity. The transparency of TiO2-films allows easy monitoring of the cell growth and morphology under a phase-contrast microscope.
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| 8. |
- Qu, Chengjuan, 1967-, et al.
(författare)
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Chondrogenic differentiation of human pluripotent stem cells in chondrocyte co-culture
- 2013
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Ingår i: International Journal of Biochemistry and Cell Biology. - : Elsevier. - 1357-2725 .- 1878-5875. ; 45:8, s. 1802-1812
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Tidskriftsartikel (refereegranskat)abstract
- Chondrogenic differentiation of human embryonic (hESCs) or induced pluripotent stem cells (hiPSCs) has been achieved in embryoid bodies (EBs) by adding selected growth factors to the medium. Also chondrocyte-secreted factors have been considered to promote the chondrogenic differentiation. Hence, we studied whether co-culture with primary chondrocytes can induce hESCs or hiPSCs to differentiate into chondrocyte lineage. Co-culture of hESCs or hiPSCs was established in a transwell insert system in feeder-free culture conditions, while hESCs or hiPSCs grown alone in the wells were used as controls. After 3-week co-culture with weekly replenished chondrocytes, the chondrogenically committed cells (hCCCs) were evaluated by morphology, immunocytochemistry, quantitative real-time RT-PCR, and analysis of chondrogenic, osteogenic and adipogenic differentiation markers. The expressions of chondrocyte- and pluripotency-associated genes were frequently measured during the monolayer expansion of hCCCs from passage 1 to 10. Human CCCs displayed morphology similar to chondrocytes, and expressed chondrocyte-associated genes, which were declined following passaging, similarly to passaged chondrocytes. They also formed a chondrogenic cell pellet, and differentiated into chondrocytic cells, which secreted abundant extracellular matrix. Human CCCs also proliferated rapidly. However, they did not show osteogenic or adipogenic differentiation capacity. Our results show that co-culture of hESCs or hiPSCs with primary chondrocytes could induce specific chondrogenic differentiation.
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| 9. |
- Wang, Pan, et al.
(författare)
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Genome-wide study identifies the regulatory glycosyltransferase genes networks and signaling pathways from Keshan disease
- 2014
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Ingår i: Journal of Health Science. - : David Publishing Company. ; 2:4, s. 165-173
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Tidskriftsartikel (refereegranskat)abstract
- KD (Keshan disease) is an endemic cardiomyopathy occurring only in China. Its pathogenesis is unclear till now. In the study, gene expression profiles of the PBMC (peripheral blood mononuclear cell) derived respectively from KD patients and healthy in KD areas were compared. Total RNA was isolated, amplified, labeled and hybridized to Agilent 4 × 44 K Whole Human Genome Oligonucleotide Microarray. Significant canonical pathways were analyzed by IPA (ingenuity pathway analysis) to identify differently expressed genes and pathways involved in the cardiovascular system development and function. Quantitative RT-PCR was applied tofurther validate our microarray results. Eighty-three up-regulated (ratios ≥ 2.0) and nine down-regulated glycosyltransferase genes (ratios ≤ 0.5) in PBMC in KD patients were detected by significance analysis of microarrays. Two significant canonical pathways from glycosyltransferase gene expression profiles were screened by IPA. The results of qRT-PCR show that four up-regulated (BMP1/7/10 and FGF18) and one down-regulated (BMP2) genes are consistent with those in microarray experiment, confirming the validity of the microarray data. Based on the results of the study, it is suggested that bone morphogenetic proteins and fibroblast growth factors might play an important role in the pathogenesis of KD. This further helps us to understand the pathogenesis of KD, as well as dilated cardiomyopathy
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| 10. |
- Qu, Chengjuan, 1967-
(författare)
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Articular cartilage proteoglycan biosynthesis and sulfation
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Glucosamine (GlcN) and glucosamine sulfate (GS) have been used to treat the patients with osteoarthritis(OA) as a disease-modifying agent. Previousin vitro studies have focused on the effects of GlcN or GSon cartilage metabolism, whereas in vivo studies have investigated their potential for the treatment of OA. Although these results have raised promises of the disease-modifying effects of GlcN or GS, the cellular mechanisms behind these proposed effects are not clear. In general, the effectiveness of GS in thetreatment of OA as a symptomatic and as a disease-modifying agent is a matter of debate. Loss of proteoglycans (PGs) in OA could be partly due to deficient water binding e.g., by undersulfation of glycosaminoglycans (GAGs). In this study, the molar ratios of chondroitin sulfate (CS)disaccharide isoforms were analyzed with fluorophore-assisted carbohydrate electrophoresis to investigate the hypothesis that sulfate deficiency is involved with the development of bovine and human OA. Our present results indicate that the molar ratio of non-sulfated CS disaccharide in human samples was much lower than that detected in bovine samples, and it did not increase in human OA samples. Conversely, this ratio significantly decreased in bovine OA samples. Furthermore, the steady-state levels of aggrecan mRNA expression and sulfated GAG synthesis were analyzed by using Northern blot assay, quantitative real time reverse transcription polymerase chain reaction and[35S]sulfate incorporation analyses in bovine primary chondrocyte cultures. Aggrecan which is a large CS-PG of cartilage provides osmotic resistance for the cartilage helping it to absorb the compressive loads. Loss of PGs is a major cause of joint dysfunction and disability in OA. However, our results from 25 individual animals showed that none of the different forms of hexosamines, nor the GS salt, could stimulate aggrecan mRNA expression or GAG synthesis in bovine primary chondrocytes. Glucosamine is produced intracellularly from endogenous glucose, and is one of the basic sugar structures required for CS synthesis. It is converted to UDP-glucuronic acid (GlcA) and UDP-N-acetylgalactosamine (UDP-GalNAc) before use for the synthesis of CS polysaccharide chain. If exogenous GS is made available to the cultured cells, it can be directly incorporated into the CS synthesis by UDP-GalNAc via GlcN-6-phosphate bypassing fructose-6-phosphate. Thus, the levels of intracellular UDP-N-acetylhexosamines and UDP-GlcA were explored with reversed-phase high-performance liquid chromatography-electrospray ionization mass spectrometry in bovine primary chondrocytes to analyze whether a physiologically attainable level of GS could stimulate CS synthesis by increasing intracellular UDP-sugar levels. Our present results with the cells from nine individual animals did not support this hypothesis. In conclusion, bovine and human articular cartilage PGs were not undersulfated in the early stage of OA. Exogenous GS did not increase steady state levels of aggrecan mRNA expression, GAG synthesis or intracellular levels of nucleotide-activated precursors of GAG synthesis in bovine primary chondrocytes.
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