The Experts below are selected from a list of 45 Experts worldwide ranked by ideXlab platform
Cody Bunger - One of the best experts on this subject based on the ideXlab platform.
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phenol red inhibits chondrogenic differentiation and affects osteogenic differentiation of human mesenchymal stem cells in vitro
Stem Cell Reviews and Reports, 2013Co-Authors: Helle Lysdahl, Anette Baatrup, Anna Bay Nielsen, Casper Bindzus Foldager, Cody BungerAbstract:The purpose with this study was to investigate the effect of phenol red (PR) on chondrogenic and osteogenic differentiation of human mesenchymal stem cells (hMSCs). hMSCs were differentiated into chondrogenic and osteogenic directions in DMEM with and without PR for 2, 7, 14, 21, and 28 days. Gene expression of chondrogenic and osteogenic markers were analyzed by RT-qPCR. The presence of proteoglycans was visualized histologically. Osteogenic matrix deposition and mineralization were examined measuring the alkaline phophatase activity and calcium deposition. During chondrogenic differentiation PR decreased sox9, Collagen Type 2, aggrecan on day 14 and 21 (P < 0.05), and proteoglycan synthesis on day 21 and 28. Collagen Type 10 was decreased on day 21 (P < 0.05). During osteogenic differentiation PR increased alkaline phosphatase on day 7 while decreased on day 21 (P < 0.05). PR increased Collagen Type 1 on day 7, 14, and day 21 (P < 0.05). The alkaline phosphatase activity was increased after 2, 7, and 14 days (P < 0.05). The deposition of calcium was decreased on day 21 (P < 0.05). Our results indicate that PR should be removed from the culture media when differentiating hMSCs into chondrogenic and osteogenic directions due to the effects on these differentiation pathways.
Kazunori Yasuda - One of the best experts on this subject based on the ideXlab platform.
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Gene expression profile of the cartilage tissue spontaneously regenerated in vivo by using a novel double-network gel: Comparisons with the normal articular cartilage
BMC Musculoskeletal Disorders, 2011Co-Authors: Ryusei Imabuchi, Yoshihiro Ohmiya, Hyuck Joon Kwon, Shin Onodera, Nobuto Kitamura, Takayuki Kurokawa, Jian Ping Gong, Kazunori YasudaAbstract:Background We have recently found a phenomenon that spontaneous regeneration of a hyaline cartilage-like tissue can be induced in a large osteochondral defect by implanting a double-network (DN) hydrogel plug, which was composed of poly-(2-Acrylamido-2-methylpropanesulfonic acid) and poly-(N, N'-Dimetyl acrylamide), at the bottom of the defect. The purpose of this study was to clarify gene expression profile of the regenerated tissue in comparison with that of the normal articular cartilage. Methods We created a cylindrical osteochondral defect in the rabbit femoral grooves. Then, we implanted the DN gel plug at the bottom of the defect. At 2 and 4 weeks after surgery, the regenerated tissue was analyzed using DNA microarray and immunohistochemical examinations. Results The gene expression profiles of the regenerated tissues were macroscopically similar to the normal cartilage, but showed some minor differences. The expression degree of COL2A1, COL1A2, COL10A1, DCN, FMOD, SPARC, FLOD2, CHAD, CTGF, and COMP genes was greater in the regenerated tissue than in the normal cartilage. The top 30 genes that expressed 5 times or more in the regenerated tissue as compared with the normal cartilage included Type-2 Collagen, Type-10 Collagen, FN, vimentin, COMP, EF1alpha, TFCP2, and GAPDH genes. Conclusions The tissue regenerated by using the DN gel was genetically similar but not completely identical to articular cartilage. The genetic data shown in this study are useful for future studies to identify specific genes involved in spontaneous cartilage regeneration.
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Gene expression profile of the cartilage tissue spontaneously regenerated in vivo by using a novel double-network gel: comparisons with the normal articular cartilage.
BMC musculoskeletal disorders, 2011Co-Authors: Ryusei Imabuchi, Yoshihiro Ohmiya, Shin Onodera, Nobuto Kitamura, Takayuki Kurokawa, Hyuck Joon Kwon, Jian Ping Gong, Kazunori YasudaAbstract:We have recently found a phenomenon that spontaneous regeneration of a hyaline cartilage-like tissue can be induced in a large osteochondral defect by implanting a double-network (DN) hydrogel plug, which was composed of poly-(2-Acrylamido-2-methylpropanesulfonic acid) and poly-(N, N'-Dimetyl acrylamide), at the bottom of the defect. The purpose of this study was to clarify gene expression profile of the regenerated tissue in comparison with that of the normal articular cartilage. We created a cylindrical osteochondral defect in the rabbit femoral grooves. Then, we implanted the DN gel plug at the bottom of the defect. At 2 and 4 weeks after surgery, the regenerated tissue was analyzed using DNA microarray and immunohistochemical examinations. The gene expression profiles of the regenerated tissues were macroscopically similar to the normal cartilage, but showed some minor differences. The expression degree of COL2A1, COL1A2, COL10A1, DCN, FMOD, SPARC, FLOD2, CHAD, CTGF, and COMP genes was greater in the regenerated tissue than in the normal cartilage. The top 30 genes that expressed 5 times or more in the regenerated tissue as compared with the normal cartilage included Type-2 Collagen, Type-10 Collagen, FN, vimentin, COMP, EF1alpha, TFCP2, and GAPDH genes. The tissue regenerated by using the DN gel was genetically similar but not completely identical to articular cartilage. The genetic data shown in this study are useful for future studies to identify specific genes involved in spontaneous cartilage regeneration.
Helle Lysdahl - One of the best experts on this subject based on the ideXlab platform.
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phenol red inhibits chondrogenic differentiation and affects osteogenic differentiation of human mesenchymal stem cells in vitro
Stem Cell Reviews and Reports, 2013Co-Authors: Helle Lysdahl, Anette Baatrup, Anna Bay Nielsen, Casper Bindzus Foldager, Cody BungerAbstract:The purpose with this study was to investigate the effect of phenol red (PR) on chondrogenic and osteogenic differentiation of human mesenchymal stem cells (hMSCs). hMSCs were differentiated into chondrogenic and osteogenic directions in DMEM with and without PR for 2, 7, 14, 21, and 28 days. Gene expression of chondrogenic and osteogenic markers were analyzed by RT-qPCR. The presence of proteoglycans was visualized histologically. Osteogenic matrix deposition and mineralization were examined measuring the alkaline phophatase activity and calcium deposition. During chondrogenic differentiation PR decreased sox9, Collagen Type 2, aggrecan on day 14 and 21 (P < 0.05), and proteoglycan synthesis on day 21 and 28. Collagen Type 10 was decreased on day 21 (P < 0.05). During osteogenic differentiation PR increased alkaline phosphatase on day 7 while decreased on day 21 (P < 0.05). PR increased Collagen Type 1 on day 7, 14, and day 21 (P < 0.05). The alkaline phosphatase activity was increased after 2, 7, and 14 days (P < 0.05). The deposition of calcium was decreased on day 21 (P < 0.05). Our results indicate that PR should be removed from the culture media when differentiating hMSCs into chondrogenic and osteogenic directions due to the effects on these differentiation pathways.
Matthias Geyer - One of the best experts on this subject based on the ideXlab platform.
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AB0100 The Role of Delta/Notch like Egf-Related Receptor in Chondrogenesis of Human Mesenchymal Stem Cells
Annals of the Rheumatic Diseases, 2014Co-Authors: L. Berninger, A. Balkenhol, Ulf Müller-ladner, Elena Neumann, Matthias GeyerAbstract:Background The Delta/Notch like EGF-related receptor (DNER) is a single-pass transmembrane protein with characteristic EGF-like repeats in the extracellular domain, similar to those of the Notch receptor and its ligand Delta. DNER is an activator of the Notch signaling pathway, which plays a major role in cell fate determination and differentiation. In our previous study, an overexpression of DNER was observed in lesional areas of human osteoarthritic articular cartilage when compared to unaffected zones of the same tissue. Objectives Based on these findings we analyzed the role of DNER in the chondrogenic differentiation of human mesenchymal stem cells (hMSC). Methods HMSCs were nucleofected with an overexpression vector for DNER and a control vector. Chondrogenic differentiation of the hMSCs was performed in a pellet mass culture system for 28 days. The culture medium was supplemented with transforming growth factor beta 3 (TGF-β3) and dexamethasone. Overexpression of DNER and the effect on specific chondrogenic markers like aggrecan, Collagen Type 1 and 2, Sox9, Collagen Type 10 were analyzed with immunohistochemical staining and semi-quantitative real-time PCR. Chondrogenesis of the hMSCs was monitored using alcian blue staining. Results Alcian blue staining increased over time assuming chondrogenic differentiation of the hMSCs. Histologically, an overexpression of DNER was detected 7 days after nucleofection and remained stable during chondrogenesis, whereas no staining of DNER could be detected in the mock-transfected cells (ctr cells). Collagen 1 expression was higher in the ctr cells at the beginning of chondrogenesis compared to the pDNER-nucleofected cells (pDNER cells) and decreased in both over time. Collagen 2 was slightly expressed from day 21 in the ctr and pDNER cells. Sox9 was greater expressed in the ctr cells at the beginning of chondrogenesis and decreased in a time-dependent manner. In pDNER cells the Sox9 expression increased at day 14 and remained stable over time. The Collagen 10 level is constantly higher in the pDNER nucleofected cells compared to the ctr cells. In both, the expression increased in a time-dependent manner. Aggrecan expression increased during chondrogenesis in the ctr and pDNER cells but the expression was higher in the pDNER nucleofected cells on day 28. The semi-quantitative real-time PCR data confirmed the overexpression of DNER 2 days after nucleofection and the effect, that Collagen 1 expression is downregulated and Collagen 2 expression upregulated in the pDNER transfected cells compared to control until day 14. Conclusions Since DNER overexpression led to a downregulation of Collagen Type 1 in the hMSCs, while the expression of Collagen Type 2 and aggrecan were upregulated, our results support the idea that DNER might positively influence chondrogenesis and exert a reparative role during OA pathophysiology. This promotion might be regulated via an intermediate overexpression of Collagen Type 10. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.5616
Wiltrud Richter - One of the best experts on this subject based on the ideXlab platform.
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Intermittent PTHrP(1–34) Exposure Augments Chondrogenesis and Reduces Hypertrophy of Mesenchymal Stromal Cells
Stem cells and development, 2014Co-Authors: Jennifer Fischer, Antje Aulmann, Verena Dexheimer, Tobias Grossner, Wiltrud RichterAbstract:PhenoType instability and premature hypertrophy prevent the use of human mesenchymal stromal cells (MSCs) for cartilage regeneration. Aim of this study was to investigate whether intermittent supplementation of parathyroid hormone-related protein (PTHrP), as opposed to constant treatment, can beneficially influence MSC chondrogenesis and to explore molecular mechanisms below catabolic and anabolic responses. Human MSCs subjected to chondrogenic induction in high-density culture received PTHrP(1-34), forskolin, dbcAMP, or PTHrP(7-34) either constantly or via 6-h pulses (three times weekly), before proteoglycan, Collagen Type II, and X deposition; gene expression; and alkaline phosphatase (ALP) activity were assessed. While constant application of PTHrP(1-34) suppressed chondrogenesis of MSCs, pulsed application significantly increased Collagen Type 2 (COL2A1) gene expression and the Collagen Type II, proteoglycan, and DNA content of pellets after 6 weeks. Collagen Type 10 (COL10A1) gene expression was little affected but Indian hedgehog (IHH) expression and ALP activity were significantly downregulated by pulsed PTHrP. A faster response to PTHrP exposure was recorded for ALP activity over COL2A1 regulation, suggesting that signal duration is critical for catabolic versus anabolic reactions. Stimulation of cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signaling by forskolin reproduced major effects of both treatment modes, whereas application of PTHrP(7-34) capable of protein kinase C (PKC) signaling was ineffective. Pulsed PTHrP exposure of MSCs stimulated chondrogenesis and reduced endochondral differentiation apparently uncoupling chondrogenic matrix deposition from hypertrophic marker expression. cAMP/PKA was the major signaling pathway triggering the opposing effects of both treatment modes. Intermittent application of PTHrP represents an important novel means to improve chondrogenesis of MSCs and may be considered as a supporting clinical-treatment mode for MSC-based cartilage defect regeneration.