The Experts below are selected from a list of 219 Experts worldwide ranked by ideXlab platform
Masaharu Noda - One of the best experts on this subject based on the ideXlab platform.
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purification characterization and developmental expression of a brain specific chondroitin sulfate Proteoglycan 6b4 Proteoglycan phosphacan
Neuroscience, 1995Co-Authors: Nobuaki Maeda, Atsuhiko Oohira, H Hamanaka, Masaharu NodaAbstract:Abstract A large brain-specific chondroitin sulfate Proteoglycan, identified with monoclonal antibody 6B4 (6B4 Proteoglycan/phosphacan), was isolated from rat brain. Soluble Proteoglycans in the phosphate-buffered saline extract from 20-day-old rat whole brain were fractionated by anion exchange chromatography and CsCl density gradient centrifugation. 6B4 Proteoglycan was further purified by gel filtration and additional ion exchange chromatography. The molecular mass of 6B4 Proteoglycan shifted from 800 to 300 × 10 3 mol. wt after chondroitinase ABC digestion. The core protein was substituted with chondroitin sulfate chains with an average molecular weight of 21, 000, keratan sulfate and HNK-1 carbohydrates. Glycosidase digestion of 6B4 Proteoglycan with O-glycanase, N-glycanase, endo-β-galactosidase, or keratanase did not remove the HNK-1 epitopes. The expression of 6B4 Proteoglycan was developmentally regulated in the rat cerebral cortex; appearing first at embryonic day 14, peaking at postnatal day 0, and persisting throughout adulthood at a lower level. Immunohistochemical analysis indicated that 6B4 Proteoglycan was distributed along the radial glial fibers and on the migrating neurons in the embryonal rat cerebrum. The radial glial fibers were stained intensely all along their length, but the neurons in the cortical plate were not stained in contrast to the moderate staining of the migrating neurons in the intermediate zone and the subplate. From postnatal day 5 to postnatal day 20, 6B4 Proteoglycan was present throughout the cortex. After postnatal day 30, staining of the neuropil was weakened, and the expression of 6B4 proteoglcyan was restricted around subsets of neurons. The positive neurons were mostly non-pyramidal cells (>95%) and were relatively concentrated in layers IV and VI of the primary somatosensory cortex. Immunohistochemical analysis of the dissociated cortical neurons indicated that 6B4 Proteoglycan was distributed on the cell bodies and neurites. 6B4 Proteoglycan strikingly promoted neurite extension of cortical neurons from embryonic day-16 rat embryos when coated on coverslips as a substrate. 6B4 Proteoglycan is a brain-specific chondroitin sulfate Proteoglycan which carries keratan sulfate and HNK-1 carbohydrates. The spatiotemporal expression profile and effects on the dissociated cerebral neurons suggest that 5B4 Proteoglycan plays important roles in the migration and differentiation of neurons in the immature cortex and also in the maintenance of subsets of neurons in the mature cortex.
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Multiple receptor‐like protein tyrosine phosphatases in the form of chondroitin sulfate Proteoglycan
FEBS letters, 1994Co-Authors: Nobuaki Maeda, H Hamanaka, Takafumi Shintani, Taeko Nishiwaki, Masaharu NodaAbstract:The possibility that some of the brain Proteoglycans are receptor-like protein tyrosine phosphatases (PTPases) was investigated. Membrane-bound Proteoglycan fractions were prepared from the postnuclear membrane fraction of 8-day-old rat brain by DEAE ion-exchange chromatography and CsCl density gradient centrifugation. The isolated Proteoglycan fractions showed high PTPase specific activities together with the typical PTPase characteristics. Renaturation experiments indicated that chondroitin sulfate Proteoglycans with 380- and 170-kDa core proteins carried the PTPase activity. The Proteoglycan with 380-kDa core protein was identified as RPTPβ/ζ bearing HNK-1 carbohydrate.
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multiple receptor like protein tyrosine phosphatases in the form of chondroitin sulfate Proteoglycan
FEBS Letters, 1994Co-Authors: Nobuaki Maeda, H Hamanaka, Takafumi Shintani, Taeko Nishiwaki, Masaharu NodaAbstract:The possibility that some of the brain Proteoglycans are receptor-like protein tyrosine phosphatases (PTPases) was investigated. Membrane-bound Proteoglycan fractions were prepared from the postnuclear membrane fraction of 8-day-old rat brain by DEAE ion-exchange chromatography and CsCl density gradient centrifugation. The isolated Proteoglycan fractions showed high PTPase specific activities together with the typical PTPase characteristics. Renaturation experiments indicated that chondroitin sulfate Proteoglycans with 380- and 170-kDa core proteins carried the PTPase activity. The Proteoglycan with 380-kDa core protein was identified as RPTPβ/ζ bearing HNK-1 carbohydrate.
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chondroitin sulfate Proteoglycan
1994Co-Authors: Nobuaki Maeda, H Hamanaka, Takafumi Shintani, Taeko Nishiwaki, Masaharu NodaAbstract:The possibility that some of the brain Proteoglycans are receptor-like protein tyrosine phosphatases (PTPases) was investigated. Mem- brane-bound Proteoglycan fractions were prepared from the postnuclear membrane fraction of &day-old rat brain by DEAE ion-exchange chrom- atography and CsCl density gradient centrifugation. The isolated Proteoglycan fractions showed high PTPase specific activities together with the typical PTPase characteristics. Renaturation experiments indicated that chondroitin sulfate Proteoglycans with 380-and 170-kDa core proteins carried the PTPase activity. The Proteoglycan with 380-kDa core protein was identified as RPTP/S/( bearing HNK-1 carbohydrate.
Parakat Vijayagopal - One of the best experts on this subject based on the ideXlab platform.
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Effect of hypoxia and hypoxia/reoxygenation on Proteoglycan metabolism by vascular smooth muscle cells.
Atherosclerosis, 1999Co-Authors: Julio E. Figueroa, Theodore G. Sarphie, Frank W. Smart, D. Luke Glancy, Parakat VijayagopalAbstract:Abstract Hypoxia and hypoxia/reoxygenation are known to affect vascular smooth muscle cell physiology. In this study, we first investigated Proteoglycan synthesis by human aortic smooth muscle cells exposed to normoxia, hypoxia, or hypoxia/reoxygenation. We then compared the newly synthesized Proteoglycans from normoxic and hypoxic-reoxygenation cultures for their ability to bind low density lipoprotein (LDL). Confluent smooth muscle cells under normoxia, hypoxia, or hypoxia/reoxygenation were pulsed with [ 35 S]sulfate, and secreted and cell-associated Proteoglycans were analyzed. Secreted Proteoglycans in cultures exposed to hypoxia (4 h)/reoxygenation (19 h) increased 28% over those of cells continuously exposed to normoxia. Cell-associated Proteoglycans did not differ significantly between the two groups. In contrast, hypoxia (4 h) followed by a 30-min reoxygenation produced a 37% decrease in newly synthesized Proteoglycans. Hypoxia alone also resulted in a 24% decrease in secreted Proteoglycans and a 20% decrease in cell-associated Proteoglycans. Proteoglycans newly synthesized by smooth muscle cells exposed to normoxia and hypoxia/reoxygenation did not differ in their charge densities and molecular size but did differ in glycosaminoglycan composition. Exposure of smooth muscle cells to hypoxia/reoxygenation produced a 60% increase in a Proteoglycan subfraction that bound LDL with very high affinity. The incorporation of [ 3 H]leucine into total cellular protein decreased significantly following exposure of smooth muscle cells to hypoxia as well as hypoxia/reoxygenation. These results indicate that hypoxia and hypoxia/reoxygenation cause major alterations in Proteoglycan metabolism by vascular smooth muscle cells.
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Endothelial cell-conditioned medium modulates the synthesis and structure of Proteoglycans in vascular smooth muscle cells.
Biochimica et biophysica acta, 1992Co-Authors: Parakat Vijayagopal, Henry P. Ciolino, Gerald S. BerensonAbstract:Abstract We studied the effect of bovine endothelial cell-conditioned medium on Proteoglycan synthesis by bovine aorta smooth muscle cells. Confluent cultures were incubated with [35S]sulfate, [3H]glucosamine or [3H]serine in medium alone (control), or medium that had been conditioned on confluent endothelial cells. Metabolically labelled Proteoglycans secreted into the culture medium and associated with the cell layer were quantified. During a 24 h incubation, endothelial cell-conditioned medium increased [35S]sulfate and [3H]glucosamine incorporation into medium and col-layer Proteoglycans by 59% and 95%, respectively, above controls. [3H]Serine incorporation into Proteoglycan core protein was increased by 150%. The effect of endothelial cell-conditioned medium on [35S]sulfate incorporation was concentration dependent. The stimulatory effects of the conditioned medium were abolished by cycloheximide and actinomycin D, inhibitors of protein synthesis and transcription, respectively. Endothelial cell-conditioned medium caused no significant change in the degradation or secretion of Proteoglycans, indicating that the increase in Proteoglycans was due to increased de novo synthesis. TGF-β neutralizing antibody inhibited 22% of the stimulatory effect of the conditioned medium, suggesting that part of the stimulation was mediated by TGF-β. Ion-exchange chromatography of [35S]Proteoglycans in the culture medium of smooth muscle cells yielded two major peaks at 0.52 and 0.57 M NaCl in both control and experimental cultures. In both cases the second peak, which represented approx. 80% of the total radioactivity, contained isometric chondroitin sulfate Proteoglycan with chondroitin sulfate and dermatan sulfate accounting for 90% and 10% of the isomers, respectively. The isomeric chondroitin sulfate Proteoglycan was fractionated byn hydrodynamic size on Sepharose CL-4B, resulting in three fractions (A, B and C). Analytical column chromatography of fractions A and B on Sepharose CL-2B demonstrated that Proteoglycans from cultures incubated with endothelial cell-conditioned medium were larger in size than those from control cultures (Mr fraction A, 1700 000, compared with 1200 000 Mr; fraction B, 540 000, compared with 390 000). The molecular weights of the core proteins were unchanged. The larger size of Proteoglycan A in cultures exposed to endothelial cell-conditioned medium was due to an increase in both the glycosaminoglycan chain number (29 compared to 25) and molecular mass (Mr 52 000, compared to 40 000). The hydrodynamic size of the glycosaminoglycans in Proteoglycan B of control and experimental cultures was identical (Mr 40 000). Therefore, the increase in the molecular mass of this Proteoglycan was attributable to an increase in glycosaminoglycan chain number (12 compared to 9). These results indicate that endothelial cell-conditioned medium contains factor(s) which can modulate the synthesis and structure of Proteoglycans in cultured vascular smooth muscle cells.
Nobuaki Maeda - One of the best experts on this subject based on the ideXlab platform.
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purification characterization and developmental expression of a brain specific chondroitin sulfate Proteoglycan 6b4 Proteoglycan phosphacan
Neuroscience, 1995Co-Authors: Nobuaki Maeda, Atsuhiko Oohira, H Hamanaka, Masaharu NodaAbstract:Abstract A large brain-specific chondroitin sulfate Proteoglycan, identified with monoclonal antibody 6B4 (6B4 Proteoglycan/phosphacan), was isolated from rat brain. Soluble Proteoglycans in the phosphate-buffered saline extract from 20-day-old rat whole brain were fractionated by anion exchange chromatography and CsCl density gradient centrifugation. 6B4 Proteoglycan was further purified by gel filtration and additional ion exchange chromatography. The molecular mass of 6B4 Proteoglycan shifted from 800 to 300 × 10 3 mol. wt after chondroitinase ABC digestion. The core protein was substituted with chondroitin sulfate chains with an average molecular weight of 21, 000, keratan sulfate and HNK-1 carbohydrates. Glycosidase digestion of 6B4 Proteoglycan with O-glycanase, N-glycanase, endo-β-galactosidase, or keratanase did not remove the HNK-1 epitopes. The expression of 6B4 Proteoglycan was developmentally regulated in the rat cerebral cortex; appearing first at embryonic day 14, peaking at postnatal day 0, and persisting throughout adulthood at a lower level. Immunohistochemical analysis indicated that 6B4 Proteoglycan was distributed along the radial glial fibers and on the migrating neurons in the embryonal rat cerebrum. The radial glial fibers were stained intensely all along their length, but the neurons in the cortical plate were not stained in contrast to the moderate staining of the migrating neurons in the intermediate zone and the subplate. From postnatal day 5 to postnatal day 20, 6B4 Proteoglycan was present throughout the cortex. After postnatal day 30, staining of the neuropil was weakened, and the expression of 6B4 proteoglcyan was restricted around subsets of neurons. The positive neurons were mostly non-pyramidal cells (>95%) and were relatively concentrated in layers IV and VI of the primary somatosensory cortex. Immunohistochemical analysis of the dissociated cortical neurons indicated that 6B4 Proteoglycan was distributed on the cell bodies and neurites. 6B4 Proteoglycan strikingly promoted neurite extension of cortical neurons from embryonic day-16 rat embryos when coated on coverslips as a substrate. 6B4 Proteoglycan is a brain-specific chondroitin sulfate Proteoglycan which carries keratan sulfate and HNK-1 carbohydrates. The spatiotemporal expression profile and effects on the dissociated cerebral neurons suggest that 5B4 Proteoglycan plays important roles in the migration and differentiation of neurons in the immature cortex and also in the maintenance of subsets of neurons in the mature cortex.
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Multiple receptor‐like protein tyrosine phosphatases in the form of chondroitin sulfate Proteoglycan
FEBS letters, 1994Co-Authors: Nobuaki Maeda, H Hamanaka, Takafumi Shintani, Taeko Nishiwaki, Masaharu NodaAbstract:The possibility that some of the brain Proteoglycans are receptor-like protein tyrosine phosphatases (PTPases) was investigated. Membrane-bound Proteoglycan fractions were prepared from the postnuclear membrane fraction of 8-day-old rat brain by DEAE ion-exchange chromatography and CsCl density gradient centrifugation. The isolated Proteoglycan fractions showed high PTPase specific activities together with the typical PTPase characteristics. Renaturation experiments indicated that chondroitin sulfate Proteoglycans with 380- and 170-kDa core proteins carried the PTPase activity. The Proteoglycan with 380-kDa core protein was identified as RPTPβ/ζ bearing HNK-1 carbohydrate.
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multiple receptor like protein tyrosine phosphatases in the form of chondroitin sulfate Proteoglycan
FEBS Letters, 1994Co-Authors: Nobuaki Maeda, H Hamanaka, Takafumi Shintani, Taeko Nishiwaki, Masaharu NodaAbstract:The possibility that some of the brain Proteoglycans are receptor-like protein tyrosine phosphatases (PTPases) was investigated. Membrane-bound Proteoglycan fractions were prepared from the postnuclear membrane fraction of 8-day-old rat brain by DEAE ion-exchange chromatography and CsCl density gradient centrifugation. The isolated Proteoglycan fractions showed high PTPase specific activities together with the typical PTPase characteristics. Renaturation experiments indicated that chondroitin sulfate Proteoglycans with 380- and 170-kDa core proteins carried the PTPase activity. The Proteoglycan with 380-kDa core protein was identified as RPTPβ/ζ bearing HNK-1 carbohydrate.
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chondroitin sulfate Proteoglycan
1994Co-Authors: Nobuaki Maeda, H Hamanaka, Takafumi Shintani, Taeko Nishiwaki, Masaharu NodaAbstract:The possibility that some of the brain Proteoglycans are receptor-like protein tyrosine phosphatases (PTPases) was investigated. Mem- brane-bound Proteoglycan fractions were prepared from the postnuclear membrane fraction of &day-old rat brain by DEAE ion-exchange chrom- atography and CsCl density gradient centrifugation. The isolated Proteoglycan fractions showed high PTPase specific activities together with the typical PTPase characteristics. Renaturation experiments indicated that chondroitin sulfate Proteoglycans with 380-and 170-kDa core proteins carried the PTPase activity. The Proteoglycan with 380-kDa core protein was identified as RPTP/S/( bearing HNK-1 carbohydrate.
H Hamanaka - One of the best experts on this subject based on the ideXlab platform.
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purification characterization and developmental expression of a brain specific chondroitin sulfate Proteoglycan 6b4 Proteoglycan phosphacan
Neuroscience, 1995Co-Authors: Nobuaki Maeda, Atsuhiko Oohira, H Hamanaka, Masaharu NodaAbstract:Abstract A large brain-specific chondroitin sulfate Proteoglycan, identified with monoclonal antibody 6B4 (6B4 Proteoglycan/phosphacan), was isolated from rat brain. Soluble Proteoglycans in the phosphate-buffered saline extract from 20-day-old rat whole brain were fractionated by anion exchange chromatography and CsCl density gradient centrifugation. 6B4 Proteoglycan was further purified by gel filtration and additional ion exchange chromatography. The molecular mass of 6B4 Proteoglycan shifted from 800 to 300 × 10 3 mol. wt after chondroitinase ABC digestion. The core protein was substituted with chondroitin sulfate chains with an average molecular weight of 21, 000, keratan sulfate and HNK-1 carbohydrates. Glycosidase digestion of 6B4 Proteoglycan with O-glycanase, N-glycanase, endo-β-galactosidase, or keratanase did not remove the HNK-1 epitopes. The expression of 6B4 Proteoglycan was developmentally regulated in the rat cerebral cortex; appearing first at embryonic day 14, peaking at postnatal day 0, and persisting throughout adulthood at a lower level. Immunohistochemical analysis indicated that 6B4 Proteoglycan was distributed along the radial glial fibers and on the migrating neurons in the embryonal rat cerebrum. The radial glial fibers were stained intensely all along their length, but the neurons in the cortical plate were not stained in contrast to the moderate staining of the migrating neurons in the intermediate zone and the subplate. From postnatal day 5 to postnatal day 20, 6B4 Proteoglycan was present throughout the cortex. After postnatal day 30, staining of the neuropil was weakened, and the expression of 6B4 proteoglcyan was restricted around subsets of neurons. The positive neurons were mostly non-pyramidal cells (>95%) and were relatively concentrated in layers IV and VI of the primary somatosensory cortex. Immunohistochemical analysis of the dissociated cortical neurons indicated that 6B4 Proteoglycan was distributed on the cell bodies and neurites. 6B4 Proteoglycan strikingly promoted neurite extension of cortical neurons from embryonic day-16 rat embryos when coated on coverslips as a substrate. 6B4 Proteoglycan is a brain-specific chondroitin sulfate Proteoglycan which carries keratan sulfate and HNK-1 carbohydrates. The spatiotemporal expression profile and effects on the dissociated cerebral neurons suggest that 5B4 Proteoglycan plays important roles in the migration and differentiation of neurons in the immature cortex and also in the maintenance of subsets of neurons in the mature cortex.
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Multiple receptor‐like protein tyrosine phosphatases in the form of chondroitin sulfate Proteoglycan
FEBS letters, 1994Co-Authors: Nobuaki Maeda, H Hamanaka, Takafumi Shintani, Taeko Nishiwaki, Masaharu NodaAbstract:The possibility that some of the brain Proteoglycans are receptor-like protein tyrosine phosphatases (PTPases) was investigated. Membrane-bound Proteoglycan fractions were prepared from the postnuclear membrane fraction of 8-day-old rat brain by DEAE ion-exchange chromatography and CsCl density gradient centrifugation. The isolated Proteoglycan fractions showed high PTPase specific activities together with the typical PTPase characteristics. Renaturation experiments indicated that chondroitin sulfate Proteoglycans with 380- and 170-kDa core proteins carried the PTPase activity. The Proteoglycan with 380-kDa core protein was identified as RPTPβ/ζ bearing HNK-1 carbohydrate.
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multiple receptor like protein tyrosine phosphatases in the form of chondroitin sulfate Proteoglycan
FEBS Letters, 1994Co-Authors: Nobuaki Maeda, H Hamanaka, Takafumi Shintani, Taeko Nishiwaki, Masaharu NodaAbstract:The possibility that some of the brain Proteoglycans are receptor-like protein tyrosine phosphatases (PTPases) was investigated. Membrane-bound Proteoglycan fractions were prepared from the postnuclear membrane fraction of 8-day-old rat brain by DEAE ion-exchange chromatography and CsCl density gradient centrifugation. The isolated Proteoglycan fractions showed high PTPase specific activities together with the typical PTPase characteristics. Renaturation experiments indicated that chondroitin sulfate Proteoglycans with 380- and 170-kDa core proteins carried the PTPase activity. The Proteoglycan with 380-kDa core protein was identified as RPTPβ/ζ bearing HNK-1 carbohydrate.
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chondroitin sulfate Proteoglycan
1994Co-Authors: Nobuaki Maeda, H Hamanaka, Takafumi Shintani, Taeko Nishiwaki, Masaharu NodaAbstract:The possibility that some of the brain Proteoglycans are receptor-like protein tyrosine phosphatases (PTPases) was investigated. Mem- brane-bound Proteoglycan fractions were prepared from the postnuclear membrane fraction of &day-old rat brain by DEAE ion-exchange chrom- atography and CsCl density gradient centrifugation. The isolated Proteoglycan fractions showed high PTPase specific activities together with the typical PTPase characteristics. Renaturation experiments indicated that chondroitin sulfate Proteoglycans with 380-and 170-kDa core proteins carried the PTPase activity. The Proteoglycan with 380-kDa core protein was identified as RPTP/S/( bearing HNK-1 carbohydrate.
Peter Ghosh - One of the best experts on this subject based on the ideXlab platform.
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effects of transforming growth factor beta on Proteoglycan synthesis by cell and explant cultures derived from the knee joint meniscus
Osteoarthritis and Cartilage, 1995Co-Authors: Simon Collier, Peter GhoshAbstract:Repair of meniscal tears depends in part upon the ability of the resident fibrochondrocytes to produce new extracellular matrix molecules including Proteoglycans. Three culture systems have been used to investigate Proteoglycan production by meniscal fibrochondrocytes from the inner, middle and outer zones of medial and lateral menisci of the sheep stifle joint. Cultures of meniscal explants, monolayered cells, and cells encapsulated in alginate beads were labeled with 35SO4H2 for 48 h in the absence and presence of transforming growth factor beta (TGF beta) and the Proteoglycans were analysed by Sephacryl S-1000 chromatography. In general, the lateral meniscus produced more Proteoglycan than the medial. Explants from the inner and middle zones produced predominantly aggrecan-like Proteoglycan, together with a smaller Proteoglycan population eluting with an average distribution coefficient of around 0.65. The outer meniscal zones synthesized less Proteoglycan overall, the majority of which consisted of the smaller Proteoglycans. These characteristic Proteoglycan size profiles obtained with explant cultures also were preserved when cells isolated from the respective zones were cultured in alginate beads. Monolayer cell cultures, however, produced almost entirely small Proteoglycans, regardless of their zone of origin. Chromatography of chondroitinase AC and ABC digested samples indicated that the small Proteoglycan population comprised mostly dermatan sulphate-containing Proteoglycans. In all meniscal zones and in all culture systems, TGF beta stimulated Proteoglycan production by up to 100% and the Proteoglycans were slightly larger. TGF beta also stimulated cell division in fibrochondrocyte monolayer cultures. Long term intermittent stimulation of alginate bead cultures with TGF beta resulted in large increases in Proteoglycan synthesis, increased aggregation of large Proteoglycan monomers, and an increase in the production of the larger of two small Proteoglycans, putatively, biglycan.
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osteoarthritis and cartilage effects of transforming growth factor beta on Proteoglycan synthesis by cell and explant cultures derived from the knee joint meniscus
1995Co-Authors: Simon Collier, Peter Ghosh, Raymond PurvesAbstract:Summary Repair of meniscal tears depends in part upon the ability of the resident fibrochondrocytes to produce new extracellular matrix molecules including Proteoglycans. Three culture systems have been used to investigate Proteoglycan production by meniscal fibrochondrocytes from the inner, middle and outer zones of medial and lateral menisci of the sheep stifle joint. Cultures of meniscal explants, monolayered cells, and cells encapsulated in alginate beads were labeled with 3~SO4H~ for 48h in the absence and presence of tranforming growth factor beta (TGFfl) and the Proteoglycans were analysed by Sephacryl S-1000 chromatography. In general, the lateral meniscus produced more Proteoglycan than the medial. Explants from the inner and middle zones produced predominantly aggrecan-like Proteoglycan, together with a smaller Proteoglycan population eluting with an average distribution coefficient of around 0.65. The outer meniscal zones synthesized less Proteoglycan overall, the majority of which consisted of the smaller Proteoglycans. These characteristic Proteoglycan size profiles obtained with explant cultures also were preserved when cells isolated from the respective zones were cultured in alginate beads. Monolayer cell cultures, however, produced almost entirely small Proteoglycans, regardless of their zone of origin. Chromatography of chondroitinase AC and ABC digested samples indicated that the small Proteoglycan population comprised mostly dermatan sulphate-containing Proteoglycans. In all meniscal zones and in all culture systems, TGFfl stimulated Proteoglycan production by up to 100% and the Proteoglycans were slightly larger. TGFfl also stimulated cell division in fibrochondrocyte monolayer cultures. Long term intermittent stimulation of alginate bead cultures with TGFfl resulted in large increases in Proteoglycan synthesis, increased aggregation of large Proteoglycan monomers, and an increase in the production of the larger of two small Proteoglycans, putatively, biglycan.
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comparison of the effects of non steroidal anti inflammatory drugs nsaids on Proteoglycan synthesis by articular cartilage explant and chondrocyte monolayer cultures
Biochemical Pharmacology, 1991Co-Authors: Simon Collier, Peter GhoshAbstract:Abstract Experiments were conducted to study Proteoglycan biosynthesis by rabbit articular chondrocytes cultured in the presence of NSAIDs and 35 SO 2− 4 for up to 8 days. Both articular cartilage explants and confluent chondrocyte monolayer culture models were used. Medium was changed every 2 days and the [ 35 SO 4 ]Proteoglycans which had accumulated in the medium and the extracellular matrix during the culture intervals were assayed separately. In long-term experiments, drugs were removed on day 8, and Proteoglycan production during a 10–12 day culture interval also was assayed. The drugs studied were diclofenac, indomethacin, ketoprofen, piroxicam and tiaprofenic acid, at concentrations of 0, 0.1, 1, 10, 50 and 100μg/mL. Whereas Proteoglycan production by cell cultures was maximal early in the culture period, explants produced more Proteoglycans as time progressed. The highest concentrations of all of the drugs, especially diclofenac and indomethacin, inhibited Proteoglycan secretion by both cell and explant cultures. However, after removal of the drugs from the cultures, suppressed Proteoglycan production reversed to levels equivalent to, or higher than controls in the cell cultures, but largely persisted in explant cultures. About 70–80% of Proteoglycans produced by explants were retained in the matrix, whereas about 80–90% of Proteoglycans produced by cell cultures were secreted into the medium. Where drugs inhibited Proteoglycan production, the levels were reduced by approximately the same proportions in both extracellular matrix and culture medium fractions. Of the NSAIDs examined only ketoprofen demonstrated a stimulatory effect on PG synthesis in explant cultures at a physiological concentration (0.1μg/mL).
