The Experts below are selected from a list of 15555 Experts worldwide ranked by ideXlab platform
Kazuo Tanne - One of the best experts on this subject based on the ideXlab platform.
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synthesis of hyaluronan and superficial zone protein in Synovial Membrane cells modulated by fluid flow
European Journal of Oral Sciences, 2013Co-Authors: Tamami Yanagidasuekawa, Yuki Tanne, Kotaro Tanimoto, Tomomi Mitsuyoshi, Naoto Hirose, Shaoching Su, Kazuo Tanne, Eiji TanakaAbstract:Hyaluronan (HA) and superficial zone protein (SZP) distribute in joint structures and play a crucial role in joint lubrication. The aim of this study was to examine the effect of fluid flow on the synthesis of both HA and SZP in Synovial Membrane cells. Shear stress was applied by fluid flow to the rabbit Synovial Membrane cell line, HIG-82. The mRNA levels of HA synthase 2 (HAS2) , HA synthase 3 (HAS3), and SZP were examined by real-time PCR. The levels of HA and SZP protein were determined by sandwich ELISA and western blotting, respectively. The expression of SZP protein was increased by the application of low-magnitude shear stress, whereas high-magnitude shear stress decreased expression of SZP protein. Meanwhile, the level of HA protein in culture was decreased when high-magnitude shear stress was applied. The levels of both HAS2 and HAS3 mRNAs were down-regulated by high-magnitude shear stress, resulting in a significant decrease in HA concentration. In conclusion, it is shown that the application of shear stress to Synovial Membrane cells substantially affects the synthesis of both HA and SZP, which are inhibited if excessive stress is applied.
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Modulation of Hyaluronan Fragmentation by Interleukin-1 Beta in Synovial Membrane Cells
Annals of Biomedical Engineering, 2010Co-Authors: Kotaro Tanimoto, Yu Ching Huang, Yuki Tanne, Tomomi Mitsuyoshi, Eiji Tanaka, Takashi Kamiya, Nobuaki Tanaka, T. Yanagida, Kazuo TanneAbstract:Hyaluronan (HA) plays a crucial role in the lubricating and buffering properties of Synovial fluid. The purpose of this study was to examine the effects of interleukin (IL)-1β on HA degradation in cultured Synovial Membrane cells. The rabbit Synovial Membrane cell line HIG-82 was cultured with and without IL-1β. The amounts of HA of varying molecular weights in the medium were analyzed using high-performance liquid chromatography, the mRNA levels of HA synthase (HAS) and hyaluronidase (HYAL) were analyzed by means of real-time PCR, and HYAL activity was analyzed by HA zymography. The amounts of HA with a molecular weight lower than 300 kDa, and between 300 and 1900 kDa, in the culture medium of HIG-82 cells were significantly higher in the presence of IL-1β. However, the amount of HA with a molecular weight greater than 1900 kDa was significantly lower in the presence of IL-1β. Both HAS2 and HAS3 mRNA levels were upregulated by treatment with IL-1β. So, too, were the levels of HYAL1 and HYAL2 mRNA, which resulted in enhanced HYAL activity. However, HYAL activity was inhibited by transfection of HYAL2-siRNA. Our results suggest that IL-1β is a crucial factor in the fragmentation of HA in inflammatory joints.
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Effects of mechanical load on the expression and activity of hyaluronidase in cultured Synovial Membrane cells
Journal of Biomedical Materials Research - Part A, 2010Co-Authors: Reiko Kitamura, Yu Ching Huang, Yuki Tanne, Kotaro Tanimoto, Eiji Tanaka, Takashi Kamiya, Nobuaki Tanaka, Kazuo TanneAbstract:Hyaluronan (HA) has lubricating and buffering functions in joints. Mechanical load is a regulatory factor of HA metabolism in joints, and HA synthesis by Synovial Membrane cells is modulated by mechanical load. However, the effects of mechanical load on HA catabolism by hyaluronidase (HYAL) in Synovial Membrane cells remain unclear. The purpose of this study was to evaluate the effects of cyclic tensile load on the expression and activity of HYAL in Synovial Membrane cells. A cyclic tensile load of 22.8% cell elongation was applied to cultured rabbit Synovial Membrane cells for 3 to 48 h with or without cycloheximide. HYAL1 and HYAL2 mRNA levels were evaluated by means of real-time polymerase chain reaction (PCR) analysis. HYAL activity in the cell culture was analyzed by means of HA zymography with or without HYAL2-small interfering (si) RNA. Levels of both HYAL1 and HYAL2 mRNA were up-regulated significantly (p < 0.01) by the cyclic tensile load with or without cycloheximide. HYAL activity was detected in the loaded cell cultures and was suppressed substantially by HYAL2-siRNA. HYAL activity was undetectable in unloaded cell cultures. These results show that a cyclic tensile load induces the expression and activity of HYAL in Synovial Membrane cells, suggesting that increased HYAL by mechanical load affects HA catabolism in Synovial fluid.
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Molecular cloning of rabbit hyaluronic acid synthases and their expression patterns in Synovial Membrane and articular cartilage.
Biochimica et biophysica acta, 2001Co-Authors: Shigeru Ohno, Kotaro Tanimoto, Nobuaki Tanaka, Chise Ijuin, K. Honda, Katsumi Fujimoto, T. Doi, M. Nakahara, Kazuo TanneAbstract:cDNAs for hyaluronic acid synthases (HAS2 and HAS3) were cloned from a cDNA library of cultured rabbit Synovial Membrane cells. The cDNA encoding the open reading frame of rabbit HAS2 and HAS3 was 1659 nucleotides in length with a predicted molecular mass of about 63 kDa. The amino acid sequence showed that the rabbit HAS2 was 98.7 and 98.4%, and HAS3 was 98.2 and 97.5% identical with human and mouse forms of the proteins, respectively. The predicted sequences for hyaluronic acid (HA) binding motifs and the catalytic domains related to beta 1-4 and beta 1-3 linkages, essential for HA synthesis, were almost conserved in both rabbit HAS2 and HAS3, similarly to human and mouse HASs. RT-PCR analysis and in situ hybridization revealed that the mRNA of HAS2 was highly expressed in the Synovial Membrane and articular cartilage, whereas the expression of HAS3 mRNA was slightest in these tissues. Thus, it is demonstrated that rabbit HASs are highly conserved in sequence content as compared to the human and mouse homologues described previously, and that HAS2 is predominantly expressed in the Synovial Membrane and articular cartilage, but HAS3 is not.
Kotaro Tanimoto - One of the best experts on this subject based on the ideXlab platform.
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synthesis of hyaluronan and superficial zone protein in Synovial Membrane cells modulated by fluid flow
European Journal of Oral Sciences, 2013Co-Authors: Tamami Yanagidasuekawa, Yuki Tanne, Kotaro Tanimoto, Tomomi Mitsuyoshi, Naoto Hirose, Shaoching Su, Kazuo Tanne, Eiji TanakaAbstract:Hyaluronan (HA) and superficial zone protein (SZP) distribute in joint structures and play a crucial role in joint lubrication. The aim of this study was to examine the effect of fluid flow on the synthesis of both HA and SZP in Synovial Membrane cells. Shear stress was applied by fluid flow to the rabbit Synovial Membrane cell line, HIG-82. The mRNA levels of HA synthase 2 (HAS2) , HA synthase 3 (HAS3), and SZP were examined by real-time PCR. The levels of HA and SZP protein were determined by sandwich ELISA and western blotting, respectively. The expression of SZP protein was increased by the application of low-magnitude shear stress, whereas high-magnitude shear stress decreased expression of SZP protein. Meanwhile, the level of HA protein in culture was decreased when high-magnitude shear stress was applied. The levels of both HAS2 and HAS3 mRNAs were down-regulated by high-magnitude shear stress, resulting in a significant decrease in HA concentration. In conclusion, it is shown that the application of shear stress to Synovial Membrane cells substantially affects the synthesis of both HA and SZP, which are inhibited if excessive stress is applied.
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Modulation of Hyaluronan Fragmentation by Interleukin-1 Beta in Synovial Membrane Cells
Annals of Biomedical Engineering, 2010Co-Authors: Kotaro Tanimoto, Yu Ching Huang, Yuki Tanne, Tomomi Mitsuyoshi, Eiji Tanaka, Takashi Kamiya, Nobuaki Tanaka, T. Yanagida, Kazuo TanneAbstract:Hyaluronan (HA) plays a crucial role in the lubricating and buffering properties of Synovial fluid. The purpose of this study was to examine the effects of interleukin (IL)-1β on HA degradation in cultured Synovial Membrane cells. The rabbit Synovial Membrane cell line HIG-82 was cultured with and without IL-1β. The amounts of HA of varying molecular weights in the medium were analyzed using high-performance liquid chromatography, the mRNA levels of HA synthase (HAS) and hyaluronidase (HYAL) were analyzed by means of real-time PCR, and HYAL activity was analyzed by HA zymography. The amounts of HA with a molecular weight lower than 300 kDa, and between 300 and 1900 kDa, in the culture medium of HIG-82 cells were significantly higher in the presence of IL-1β. However, the amount of HA with a molecular weight greater than 1900 kDa was significantly lower in the presence of IL-1β. Both HAS2 and HAS3 mRNA levels were upregulated by treatment with IL-1β. So, too, were the levels of HYAL1 and HYAL2 mRNA, which resulted in enhanced HYAL activity. However, HYAL activity was inhibited by transfection of HYAL2-siRNA. Our results suggest that IL-1β is a crucial factor in the fragmentation of HA in inflammatory joints.
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Effects of mechanical load on the expression and activity of hyaluronidase in cultured Synovial Membrane cells
Journal of Biomedical Materials Research - Part A, 2010Co-Authors: Reiko Kitamura, Yu Ching Huang, Yuki Tanne, Kotaro Tanimoto, Eiji Tanaka, Takashi Kamiya, Nobuaki Tanaka, Kazuo TanneAbstract:Hyaluronan (HA) has lubricating and buffering functions in joints. Mechanical load is a regulatory factor of HA metabolism in joints, and HA synthesis by Synovial Membrane cells is modulated by mechanical load. However, the effects of mechanical load on HA catabolism by hyaluronidase (HYAL) in Synovial Membrane cells remain unclear. The purpose of this study was to evaluate the effects of cyclic tensile load on the expression and activity of HYAL in Synovial Membrane cells. A cyclic tensile load of 22.8% cell elongation was applied to cultured rabbit Synovial Membrane cells for 3 to 48 h with or without cycloheximide. HYAL1 and HYAL2 mRNA levels were evaluated by means of real-time polymerase chain reaction (PCR) analysis. HYAL activity in the cell culture was analyzed by means of HA zymography with or without HYAL2-small interfering (si) RNA. Levels of both HYAL1 and HYAL2 mRNA were up-regulated significantly (p < 0.01) by the cyclic tensile load with or without cycloheximide. HYAL activity was detected in the loaded cell cultures and was suppressed substantially by HYAL2-siRNA. HYAL activity was undetectable in unloaded cell cultures. These results show that a cyclic tensile load induces the expression and activity of HYAL in Synovial Membrane cells, suggesting that increased HYAL by mechanical load affects HA catabolism in Synovial fluid.
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Molecular cloning of rabbit hyaluronic acid synthases and their expression patterns in Synovial Membrane and articular cartilage.
Biochimica et biophysica acta, 2001Co-Authors: Shigeru Ohno, Kotaro Tanimoto, Nobuaki Tanaka, Chise Ijuin, K. Honda, Katsumi Fujimoto, T. Doi, M. Nakahara, Kazuo TanneAbstract:cDNAs for hyaluronic acid synthases (HAS2 and HAS3) were cloned from a cDNA library of cultured rabbit Synovial Membrane cells. The cDNA encoding the open reading frame of rabbit HAS2 and HAS3 was 1659 nucleotides in length with a predicted molecular mass of about 63 kDa. The amino acid sequence showed that the rabbit HAS2 was 98.7 and 98.4%, and HAS3 was 98.2 and 97.5% identical with human and mouse forms of the proteins, respectively. The predicted sequences for hyaluronic acid (HA) binding motifs and the catalytic domains related to beta 1-4 and beta 1-3 linkages, essential for HA synthesis, were almost conserved in both rabbit HAS2 and HAS3, similarly to human and mouse HASs. RT-PCR analysis and in situ hybridization revealed that the mRNA of HAS2 was highly expressed in the Synovial Membrane and articular cartilage, whereas the expression of HAS3 mRNA was slightest in these tissues. Thus, it is demonstrated that rabbit HASs are highly conserved in sequence content as compared to the human and mouse homologues described previously, and that HAS2 is predominantly expressed in the Synovial Membrane and articular cartilage, but HAS3 is not.
Stanislaw Moskalewski - One of the best experts on this subject based on the ideXlab platform.
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Synovial Membrane asks for independence
Folia morphologica, 2014Co-Authors: Stanislaw Moskalewski, A. Osiecka-iwan, E. Jankowska-steifer, A. HycAbstract:Synovial Membrane is traditionally considered as a part of the joint capsule. It, however, differs from fibrous part of the capsule in development, structure, function, vascularisation, innervation and involvement in pathological processes. Moreover, in some areas, it even does not contact with the fibrous capsule. Thus, it appears that the Synovial Membrane should be considered as an independent organ and not as the lining of the joint capsule.
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Pro- and anti-inflammatory cytokines increase hyaluronan production by rat Synovial Membrane in vitro.
International journal of molecular medicine, 2009Co-Authors: Anna Hyc, Anna Osiecka-iwan, Justyna Niderla-bielińska, Ewa Jankowska-steifer, Stanislaw MoskalewskiAbstract:Synovial Membrane consists of fibroblasts and macrophages forming the Synovial lining supported by vascularized subsynovium. Each of these components may specifically react to a particular stimulus. Thus, reactions of isolated Synovial cells may not correspond to that of intact tissue. We characterized the production of hyaluronan (HA) by rat Synovial Membrane exposed in vitro to pro- and anti- inflammatory cytokines and compared it with previous results obtained with isolated fibroblasts. Synovial Membrane dissected from one knee joint served as a control to that from the opposite knee exposed to IL-1s, TGF-s1, TNF-·, IFN-A or IL-4 for 24 h. The HA content was determined by ELISA, and hyaluronan synthase (HAS) mRNA by real-time PCR. The size distribution of the HA chain was evaluated by agarose gel electrophoresis. The HA content in the freshly dissected Synovial Membrane was ~1 μg and decreased to 0.1 μg after incubation, while in the medium it increased from 0 to 3 to 5 μg. All cytokines stimulated production of HA. The strongest effect was observed in the case of TNF-·. The level of HAS1 and HAS2 mRNA increased 2-fold during a 12-h incubation while that of HAS3 decreased. The distribution of the HA chain length did not differ in the medium from the control and stimulated Membranes. Transfer of the Synovial Membrane from the HA-rich Synovial fluid into the medium stimulated release of HA from the Membrane and increased HAS expression and HA production. Thus, the Synovial Membrane acts as a sensor reacting to changes in HA concentration in its environment. Pro- inflammatory cytokines stimulate production of HA in intact Synovial Membranes similarly as in cultures of rheumatoid fibroblasts. In contrast, our results suggest that the response to anti-inflammatory cytokines (TGF-s1 and IL-4) of the whole Synovial Membrane differs from that of isolated fibroblasts.
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Preparation of rat Synovial Membrane for studies of cytokine secretion.
Folia histochemica et cytobiologica, 2007Co-Authors: Anna Hyc, Anna Osiecka-iwan, Piotr Dziunycz, Stanislaw MoskalewskiAbstract:The objective of this work was to devise an in vitro system for studies on cytokine secretion by Synovial Membrane treated as a whole organ with various synoviocyte populations. Synovial Membrane from knee joints of WAG rats was dissected and incubated in culture medium without serum for 4 - 48 h. The level of IL-1alpha was determined in Synovial lysates and IL-6 in culture medium. The Synovial Membrane from left and right knee joint of the same rat produced similar amount of cytokines both in lysates and in the medium. Synovial Membrane stimulated by LPS for 4 or 24 h gave significantly stronger cytokine response than the Membrane from the opposite (control) knee. After 48 h incubation of Synovial Membrane drastic drop in cytokine level was noted, which indicated on deterioration of the Membranes. The test may be useful in studies on factors affecting cytokine secretion by synoviocytes.
Eiji Tanaka - One of the best experts on this subject based on the ideXlab platform.
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synthesis of hyaluronan and superficial zone protein in Synovial Membrane cells modulated by fluid flow
European Journal of Oral Sciences, 2013Co-Authors: Tamami Yanagidasuekawa, Yuki Tanne, Kotaro Tanimoto, Tomomi Mitsuyoshi, Naoto Hirose, Shaoching Su, Kazuo Tanne, Eiji TanakaAbstract:Hyaluronan (HA) and superficial zone protein (SZP) distribute in joint structures and play a crucial role in joint lubrication. The aim of this study was to examine the effect of fluid flow on the synthesis of both HA and SZP in Synovial Membrane cells. Shear stress was applied by fluid flow to the rabbit Synovial Membrane cell line, HIG-82. The mRNA levels of HA synthase 2 (HAS2) , HA synthase 3 (HAS3), and SZP were examined by real-time PCR. The levels of HA and SZP protein were determined by sandwich ELISA and western blotting, respectively. The expression of SZP protein was increased by the application of low-magnitude shear stress, whereas high-magnitude shear stress decreased expression of SZP protein. Meanwhile, the level of HA protein in culture was decreased when high-magnitude shear stress was applied. The levels of both HAS2 and HAS3 mRNAs were down-regulated by high-magnitude shear stress, resulting in a significant decrease in HA concentration. In conclusion, it is shown that the application of shear stress to Synovial Membrane cells substantially affects the synthesis of both HA and SZP, which are inhibited if excessive stress is applied.
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Modulation of Hyaluronan Fragmentation by Interleukin-1 Beta in Synovial Membrane Cells
Annals of Biomedical Engineering, 2010Co-Authors: Kotaro Tanimoto, Yu Ching Huang, Yuki Tanne, Tomomi Mitsuyoshi, Eiji Tanaka, Takashi Kamiya, Nobuaki Tanaka, T. Yanagida, Kazuo TanneAbstract:Hyaluronan (HA) plays a crucial role in the lubricating and buffering properties of Synovial fluid. The purpose of this study was to examine the effects of interleukin (IL)-1β on HA degradation in cultured Synovial Membrane cells. The rabbit Synovial Membrane cell line HIG-82 was cultured with and without IL-1β. The amounts of HA of varying molecular weights in the medium were analyzed using high-performance liquid chromatography, the mRNA levels of HA synthase (HAS) and hyaluronidase (HYAL) were analyzed by means of real-time PCR, and HYAL activity was analyzed by HA zymography. The amounts of HA with a molecular weight lower than 300 kDa, and between 300 and 1900 kDa, in the culture medium of HIG-82 cells were significantly higher in the presence of IL-1β. However, the amount of HA with a molecular weight greater than 1900 kDa was significantly lower in the presence of IL-1β. Both HAS2 and HAS3 mRNA levels were upregulated by treatment with IL-1β. So, too, were the levels of HYAL1 and HYAL2 mRNA, which resulted in enhanced HYAL activity. However, HYAL activity was inhibited by transfection of HYAL2-siRNA. Our results suggest that IL-1β is a crucial factor in the fragmentation of HA in inflammatory joints.
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Effects of mechanical load on the expression and activity of hyaluronidase in cultured Synovial Membrane cells
Journal of Biomedical Materials Research - Part A, 2010Co-Authors: Reiko Kitamura, Yu Ching Huang, Yuki Tanne, Kotaro Tanimoto, Eiji Tanaka, Takashi Kamiya, Nobuaki Tanaka, Kazuo TanneAbstract:Hyaluronan (HA) has lubricating and buffering functions in joints. Mechanical load is a regulatory factor of HA metabolism in joints, and HA synthesis by Synovial Membrane cells is modulated by mechanical load. However, the effects of mechanical load on HA catabolism by hyaluronidase (HYAL) in Synovial Membrane cells remain unclear. The purpose of this study was to evaluate the effects of cyclic tensile load on the expression and activity of HYAL in Synovial Membrane cells. A cyclic tensile load of 22.8% cell elongation was applied to cultured rabbit Synovial Membrane cells for 3 to 48 h with or without cycloheximide. HYAL1 and HYAL2 mRNA levels were evaluated by means of real-time polymerase chain reaction (PCR) analysis. HYAL activity in the cell culture was analyzed by means of HA zymography with or without HYAL2-small interfering (si) RNA. Levels of both HYAL1 and HYAL2 mRNA were up-regulated significantly (p < 0.01) by the cyclic tensile load with or without cycloheximide. HYAL activity was detected in the loaded cell cultures and was suppressed substantially by HYAL2-siRNA. HYAL activity was undetectable in unloaded cell cultures. These results show that a cyclic tensile load induces the expression and activity of HYAL in Synovial Membrane cells, suggesting that increased HYAL by mechanical load affects HA catabolism in Synovial fluid.
Nobuaki Tanaka - One of the best experts on this subject based on the ideXlab platform.
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Modulation of Hyaluronan Fragmentation by Interleukin-1 Beta in Synovial Membrane Cells
Annals of Biomedical Engineering, 2010Co-Authors: Kotaro Tanimoto, Yu Ching Huang, Yuki Tanne, Tomomi Mitsuyoshi, Eiji Tanaka, Takashi Kamiya, Nobuaki Tanaka, T. Yanagida, Kazuo TanneAbstract:Hyaluronan (HA) plays a crucial role in the lubricating and buffering properties of Synovial fluid. The purpose of this study was to examine the effects of interleukin (IL)-1β on HA degradation in cultured Synovial Membrane cells. The rabbit Synovial Membrane cell line HIG-82 was cultured with and without IL-1β. The amounts of HA of varying molecular weights in the medium were analyzed using high-performance liquid chromatography, the mRNA levels of HA synthase (HAS) and hyaluronidase (HYAL) were analyzed by means of real-time PCR, and HYAL activity was analyzed by HA zymography. The amounts of HA with a molecular weight lower than 300 kDa, and between 300 and 1900 kDa, in the culture medium of HIG-82 cells were significantly higher in the presence of IL-1β. However, the amount of HA with a molecular weight greater than 1900 kDa was significantly lower in the presence of IL-1β. Both HAS2 and HAS3 mRNA levels were upregulated by treatment with IL-1β. So, too, were the levels of HYAL1 and HYAL2 mRNA, which resulted in enhanced HYAL activity. However, HYAL activity was inhibited by transfection of HYAL2-siRNA. Our results suggest that IL-1β is a crucial factor in the fragmentation of HA in inflammatory joints.
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Effects of mechanical load on the expression and activity of hyaluronidase in cultured Synovial Membrane cells
Journal of Biomedical Materials Research - Part A, 2010Co-Authors: Reiko Kitamura, Yu Ching Huang, Yuki Tanne, Kotaro Tanimoto, Eiji Tanaka, Takashi Kamiya, Nobuaki Tanaka, Kazuo TanneAbstract:Hyaluronan (HA) has lubricating and buffering functions in joints. Mechanical load is a regulatory factor of HA metabolism in joints, and HA synthesis by Synovial Membrane cells is modulated by mechanical load. However, the effects of mechanical load on HA catabolism by hyaluronidase (HYAL) in Synovial Membrane cells remain unclear. The purpose of this study was to evaluate the effects of cyclic tensile load on the expression and activity of HYAL in Synovial Membrane cells. A cyclic tensile load of 22.8% cell elongation was applied to cultured rabbit Synovial Membrane cells for 3 to 48 h with or without cycloheximide. HYAL1 and HYAL2 mRNA levels were evaluated by means of real-time polymerase chain reaction (PCR) analysis. HYAL activity in the cell culture was analyzed by means of HA zymography with or without HYAL2-small interfering (si) RNA. Levels of both HYAL1 and HYAL2 mRNA were up-regulated significantly (p < 0.01) by the cyclic tensile load with or without cycloheximide. HYAL activity was detected in the loaded cell cultures and was suppressed substantially by HYAL2-siRNA. HYAL activity was undetectable in unloaded cell cultures. These results show that a cyclic tensile load induces the expression and activity of HYAL in Synovial Membrane cells, suggesting that increased HYAL by mechanical load affects HA catabolism in Synovial fluid.
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Molecular cloning of rabbit hyaluronic acid synthases and their expression patterns in Synovial Membrane and articular cartilage.
Biochimica et biophysica acta, 2001Co-Authors: Shigeru Ohno, Kotaro Tanimoto, Nobuaki Tanaka, Chise Ijuin, K. Honda, Katsumi Fujimoto, T. Doi, M. Nakahara, Kazuo TanneAbstract:cDNAs for hyaluronic acid synthases (HAS2 and HAS3) were cloned from a cDNA library of cultured rabbit Synovial Membrane cells. The cDNA encoding the open reading frame of rabbit HAS2 and HAS3 was 1659 nucleotides in length with a predicted molecular mass of about 63 kDa. The amino acid sequence showed that the rabbit HAS2 was 98.7 and 98.4%, and HAS3 was 98.2 and 97.5% identical with human and mouse forms of the proteins, respectively. The predicted sequences for hyaluronic acid (HA) binding motifs and the catalytic domains related to beta 1-4 and beta 1-3 linkages, essential for HA synthesis, were almost conserved in both rabbit HAS2 and HAS3, similarly to human and mouse HASs. RT-PCR analysis and in situ hybridization revealed that the mRNA of HAS2 was highly expressed in the Synovial Membrane and articular cartilage, whereas the expression of HAS3 mRNA was slightest in these tissues. Thus, it is demonstrated that rabbit HASs are highly conserved in sequence content as compared to the human and mouse homologues described previously, and that HAS2 is predominantly expressed in the Synovial Membrane and articular cartilage, but HAS3 is not.
