| 1. |
- Huttu, Mari, et al.
(författare)
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Effects of medium and temperature on cellular responses in the superficial zone of hypo-osmotically challenged articular cartilage.
- 2012
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Ingår i: Journal of Functional Biomaterials. - Basel, Switzerland : MDPI AG. - 2079-4983. ; 3:3, s. 544-555
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Tidskriftsartikel (refereegranskat)abstract
- Osmotic loading of articular cartilage has been used to study cell-tissue interactions and mechanisms in chondrocyte volume regulation in situ. Since cell volume changes are likely to affect cell's mechanotransduction, it is important to understand how environmental factors, such as composition of the immersion medium and temperature affect cell volume changes in situ in osmotically challenged articular cartilage. In this study, chondrocytes were imaged in situ with a confocal laser scanning microscope (CLSM) through cartilage surface before and 3 min and 120 min after a hypo-osmotic challenge. Samples were measured either in phosphate buffered saline (PBS, without glucose and Ca(2+)) or in Dulbecco's modified Eagle's medium (DMEM, with glucose and Ca(2+)), and at 21 °C or at 37 °C. In all groups, cell volumes increased shortly after the hypotonic challenge and then recovered back to the original volumes. At both observation time points, cell volume changes as a result of the osmotic challenge were similar in PBS and DMEM in both temperatures. Our results indicate that the initial chondrocyte swelling and volume recovery as a result of the hypo-osmotic challenge of cartilage are not dependent on commonly used immersion media or temperature.
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| 2. |
- Kaarniranta, Kai, et al.
(författare)
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Neuronal cells show regulatory differences in the hsp70 gene response.
- 2002
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Ingår i: Brain Research. Molecular Brain Research. - : Elsevier. - 0169-328X .- 1872-6941. ; 101:1-2, s. 136-140
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Tidskriftsartikel (refereegranskat)abstract
- The synthesis of heat shock proteins (Hsps), encoded by heat shock genes, is increased in response to various stress stimuli. Hsps function as molecular chaperones, they dissociate cytotoxic stress-induced protein aggregates within cells and ensure improved survival. Induction of heat shock genes is mainly regulated at the transcriptional level. The stress responsive transcription factor, heat shock factor 1 (HSF1), is involved in the transcriptional induction of the heat shock genes. Our objective was to examine how hsp70 genes are regulated in different transformed and primary neurons upon exposure to elevated temperature. Our findings reveal that the Hsp70 response is regulated at the translational level in Neuro-2a neuroblastoma cells, while the IMR-32 neuroblastoma cells respond to stress by the classical HSF1-driven transcriptional regulatory mechanism. Primary rat hippocampal neurons show a lack of HSF1 and induction of the hsp70 gene. These observations suggest that neuronal cells display different hsp70 gene expression patterns which range from undetected response to transcriptional and posttranscriptional regulation during heat stress.
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| 3. |
- Nelimarkka, Lassi, et al.
(författare)
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Expression of small extracellular chondroitin/dermatan sulfate proteoglycans is differentially regulated in human endothelial cells.
- 1997
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Ingår i: Journal of Biological Chemistry. - : Elsevier BV. - 0021-9258 .- 1083-351X. ; 272:19, s. 12730-12737
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Tidskriftsartikel (refereegranskat)abstract
- We have examined the expression of the small extracellular chondroitin/dermatan sulfate proteoglycans (CS/DS PGs), biglycan, decorin, and PG-100, which is the proteoglycan form of colony stimulating factor-1, in the human endothelial cell line EA.hy 926. We have also examined whether modulation of the phenotype of EA.hy 926 cells by tumor necrosis factor-alpha (TNF-alpha) is associated with specific changes in the synthesis of these PGs. We demonstrate that EA.hy 926 cells, when they form monolayer cultures typical of macrovascular endothelial cells, express and synthesize detectable amounts of biglycan and PG-100, but not decorin. On SDS-polyacrylamide gel electrophoresis both PGs behave like proteins of the relative molecular weight of approximately 250,000. TNF-alpha that changed the morphology of the cells from a polygonal shape into a spindle shape and that also stimulated the detachment of the cells from culture dish, markedly decreased the net synthesis of biglycan, whereas the net synthesis of PG-100 was increased. These changes were parallel with those observed at the mRNA level of the corresponding PGs. The proportions of the different sulfated CS/DS disaccharide units of PGs were not affected by TNF-alpha. Several other growth factors/cytokines, such as interferon-gamma, fibroblast growth factors-2 (FGF-2) and -7 (FGF-7), interleukin-1beta, and transforming growth factor-beta, unlike TNF-alpha, modulated neither the morphology nor the biglycan expression of EA.hy 926 cells under the conditions used in the experiments. However, PG-100 expression was increased also in response to FGF-2 and -7 and transforming growth factor-beta. None of the above cytokines, including TNF-alpha, was able to induce decorin expression in the cells. Our results indicate that the regulatory elements controlling the expression of the small extracellular CS/DS PGs in human endothelial cells are different.
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| 4. |
- Qu, Cheng-Juan, 1967-, et al.
(författare)
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Effects of glucosamine sulfate on intracellular UDP-hexosamine and UDP-glucuronic acid levels in bovine primary chondrocytes.
- 2007
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Ingår i: Osteoarthritis and Cartilage. - : Saunders Elsevier. - 1063-4584 .- 1522-9653. ; 15:7, s. 773-779
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To analyze the effects of exogenously added glucose (Glc), glucosamine (GlcN) and glucosamine sulfate (GS) on the intracellular UDP-hexoses (UDP-Hex), UDP-N-acetylhexosamines (UDP-HexN) and UDP-glucuronic acid (UDP-GlcA) levels in bovine primary chondrocytes.METHODS: Chondrocytes were incubated with different concentrations of Glc, GlcN and GS either in high- or low-glucose DMEM for up to 120min to analyze the intracellular levels of UDP-Hex, UDP-GlcA and UDP-HexN by a reversed-phase high-performance liquid chromatography-electrospray ionization mass spectrometry analysis. Glycosaminoglycan (GAG) synthesis rate and aggrecan mRNA expression levels were quantified using (35)S-sulfate incorporation assay and quantitative real-time RT-PCR, respectively. The cells were cultivated for 2 days or 8 days before UDP-sugar analysis.RESULTS: Levels of UDP-HexN and UDP-GlcA were unchanged at 10microM concentration of GS in low-glucose DMEM, while addition of 1mM GlcN or GS in low-glucose DMEM for 10min increased UDP-HexN level. The highest intracellular level of UDP-HexN was reached at 30min after addition of 1mM GS to the cells. The intracellular contents of UDP-HexN and UDP-GlcA related to UDP-Hex were higher after prolonged cultivation of chondrocytes for 8 days compared with 2-day-old cultures. Aggrecan mRNA expression and GAG synthesis remained at control level after the cells were treated with 10, 100microM or 1mM of GS for 24h.CONCLUSION: Physiologically relevant level of GS could not increase the intracellular UDP-HexN and UDP-GlcA levels in bovine primary chondrocyte, while longer-time culture itself appeared to increase the intracellular UDP-HexN and UDP-GlcA levels.
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| 5. |
- Li, Chunyan, et al.
(författare)
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Pathways related to mitochondrial dysfunction in cartilage of endemic osteoarthritis patients in China
- 2012
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Ingår i: Science China Life Sciences. - : Springer Science+Business Media B.V.. - 1674-7305 .- 1869-1889. ; 55:12, s. 1057-1063
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Tidskriftsartikel (refereegranskat)abstract
- n this paper, we present the first evidence of differences in the mitochondria-related gene expression profiles of adult articular cartilage derived from patients with Kashin-Beck disease and normal controls. The expression of 705 mitochondria-related genes was analyzed by mitochondria-related gene expression analysis and ingenuity pathways analysis. Mitochondria-related gene expression analysis identified 9 up-regulated genes in Kashin-Beck disease based on their average expression ratio. Three canonical pathways involved in oxidative phosphorylation, apoptosis signaling and pyruvate metabolism were identified, which indicate the involvement of mitochondrial dysfunction in the pathogenesis of Kashin-Beck disease.
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| 6. |
- Sahlman, Janne, et al.
(författare)
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Premature vertebral endplate ossification and mild disc degeneration in mice after inactivation of one allele belonging to the Col2a1 gene for Type II collagen.
- 2001
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Ingår i: Spine. - : Lippincott Williams & Wilkins. - 0362-2436 .- 1528-1159. ; 26:23, s. 2558-2565
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Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN: Skeletal tissues of mice with an inactivated allele of the Col2a1 gene for Type II collagen ("heterozygous knockout") were studied.OBJECTIVE: To determine whether a heterozygous inactivation of the Col2a1 gene has a role in the etiology of spine disorders such as disc degeneration.SUMMARY OF BACKGROUND DATA: Mutations in the COL2A1, COL11A1, COL11A2, and COL9A2 genes have been linked to spine disorders. However, the mechanism by which genetic factors lead to disc degeneration still are largely unknown.METHODS: Spine tissues were studied using radiograph analyses; conventional, quantitative, and polarized light microscopy; immunohistochemistry for the major extracellular components, and in situ hybridization for procollagens alpha1(I) and alpha1(II). Voluntary running activity also was monitored in half of the mice.RESULTS: As the findings showed, 1-month-old heterozygous knockout mice had shorter limb bones, skulls, and spines, as well as thicker and more irregular vertebral endplates, which calcified earlier than in the control mice. They also had a lower concentration of glycosaminoglycans in the anulus fibrosus, in the endplates, and in the vertebral bone than the controls. These features in the heterozygous knockout mice were compensated by the age of 15 months. However, the long bones and skulls of the mature heterozygous mice remained shorter than those of the controls. Gene-deficient mice used the running wheel less. However, physical exercise did not induce any marked structural changes in the skeleton.CONCLUSION: Mice with heterozygous knockout of Col2a1 show subtle early skeletal manifestations that bear some resemblance to those of human spine disorders.
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| 7. |
- Wang, Shuang, et al.
(författare)
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Genome-wide gene expression analysis suggests an important role of suppressed immunity in pathogenesis of Kashin-Beck disease.
- 2012
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 7:1, s. e28439-
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To investigate the differences between the gene expression profiles in peripheral blood mononuclear cells (PBMC) from normal controls and patients with Kashin-Beck disease (KBD).METHODS: Twenty KBD patients and 12 normal subjects were selected from a KBD-endemic area and divided into four pairs of KBD vs. control (KBD, n = 5 per pair; control, n = 3 per pair). RNAs were respectively isolated from KBD PBMCs and normal PBMCs. Gene expression profiles were analyzed by oligonucleotide microarray. The gene expression profiles in PBMCs from KBD patients and normal controls were compared and the differentially expressed genes were identified. The obtained microarray data was further confirmed by using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR).RESULTS: Approximately 501 genes, corresponding to 2.4% of the total probe transcripts, showed a 2-fold change in differential expression. 19.4% (97 out of 501)of the differentially expressed genes were commonly detected in all the four pairs. Among the 97 differentially expressed genes, 83 genes were up-regulated and 14 genes were down-regulated, compared with those in the normal controls. Some differentially expressed genes were found to be related to functions such as immunity, metabolism, apoptosis, cystoskeleton and cell movement, and extracellular matrix. The validity of our microarray data were supported by the results of qRT-PCR assay.CONCLUSION: Differences in the PBMC gene expression profile between the KBD patients and the normal controls exhibited a similar pattern among all the four pairs of microarrays examined, indicating that the suppressed immunity may play an important role in the pathogenesis of KBD.
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| 8. |
- Wang, Xi, et al.
(författare)
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Comparison of the major cell populations among osteoarthritis, Kashin-Beck disease and healthy chondrocytes by single-cell RNA-seq analysis
- 2021
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Ingår i: Cell Death and Disease. - : Springer Nature. - 2041-4889. ; 12:6
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Tidskriftsartikel (refereegranskat)abstract
- Chondrocytes are the key target cells of the cartilage degeneration that occurs in Kashin-Beck disease (KBD) and osteoarthritis (OA). However, the heterogeneity of articular cartilage cell types present in KBD and OA patients and healthy controls is still unknown, which has prevented the study of the pathophysiology of the mechanisms underlying the roles of different populations of chondrocytes in the processes leading to KBD and OA. Here, we aimed to identify the transcriptional programmes and all major cell populations in patients with KBD, patients with OA and healthy controls to identify the markers that discriminate among chondrocytes in these three groups. Single-cell RNA sequencing was performed to identify chondrocyte populations and their gene signatures in KBD, OA and healthy cells to investigate their differences as related to the pathogenetic mechanisms of these two osteochondral diseases. We performed immunohistochemistry and quantitative reverse-transcription PCR (qRT-PCR) assays to validate the markers for chondrocyte population. Ten clusters were labelled by cell type according to the expression of previously described markers, and one novel population was identified according to the expression of a new set of markers. The homeostatic and mitochondrial chondrocyte populations, which were identified by the expression of the unknown markers MT1X and MT2A and MT-ND1 and MT-ATP6, were markedly expanded in KBD. The regulatory chondrocyte population, identified by the expression of CHI3L1, was markedly expanded in OA. Our study allows us to better understand the heterogeneity of chondrocytes in KBD and OA and provides new evidence of differences in the pathogenetic mechanisms between these two diseases.
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| 9. |
- Wu, Cuiyan, et al.
(författare)
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Long noncoding RNA expression profile reveals lncRNAs signature associated with extracellular matrix degradation in kashin-beck disease
- 2017
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Kashin-Beck disease (KBD) is a deformative, endemic osteochondropathy involving degeneration and necrosis of growth plates and articular cartilage. The pathogenesis of KBD is related to gene expression and regulation mechanisms, but long noncoding RNAs (lncRNAs) in KBD have not been investigated. In this study, we identified 316 up-regulated and 631 down-regulated lncRNAs (≥ 2-fold change) in KBD chondrocytes using microarray analysis, of which more than three-quarters were intergenic lncRNAs and antisense lncRNAs. We also identified 232 up-regulated and 427 down-regulated mRNAs (≥ 2-fold change). A lncRNA-mRNA correlation analysis combined 343 lncRNAs and 292 mRNAs to form 509 coding-noncoding gene co-expression networks (CNC networks). Eleven lncRNAs were predicted to have cis-regulated target genes, including NAV2 (neuron navigator 2), TOX (thymocyte selection-associated high mobility group box), LAMA4 (laminin, alpha 4), and DEPTOR (DEP domain containing mTOR-interacting protein). The differentially expressed mRNAs in KBD significantly contribute to biological events associated with the extracellular matrix. Meanwhile, 34 mRNAs and 55 co-expressed lncRNAs constituted a network that influences the extracellular matrix. In the network, FBLN1 and LAMA 4 were the core genes with the highest significance. These novel findings indicate that lncRNAs may play a role in extracellular matrix destruction in KBD.
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| 10. |
- Lammi, Mikko, 1961-, et al.
(författare)
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Nivelrikon välittäjäaineet [Mediators of osteoarthritis]
- 2008
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Ingår i: Duodecim. - 0012-7183. ; 124:16, s. 1876-1884
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Forskningsöversikt (refereegranskat)abstract
- Normaalissa rustossa vallitsee tasapainotila kudosta tuottavien ja hajottavien prosessien kesken, mutta nivelrikossa painopiste siirtyy katabolian suuntaan. Nivelrikon etiologiaa ei tunneta, mutta sen syntyyn liittyy joukko tekijöitä, jotka johtavat väliaineen lisääntyneeseen hajoamiseen ja vähentyneeseen väliainetuotantoon, rustosolujen apoptoosiin, muutoksiin rustonalaisessa luussa ja nivelkalvon tulehdukseen. Nivelrikkoa välittävistä liukoisista tekijöistä ovat parhaiten tunnettuja tulehdusta moduloivat sytokiinit ja niiden aktivoimat tekijät, kuten metalloproteinaasit ja aggrekanaasit. Myös typpioksidin ja eikosanoidien yhteys nivelrikkoon on hyvin osoitettu. Viimeaikaiset tutkimukset ovat tuoneet esiin myös monia uusia tekijöitä, joilla todennäköisesti on merkitystä nivelrikon patologiassa. Nämä löydökset antavat pohjaa uudenlaisille hoitostrategioille.
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