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RESEARCH REPORT |
Department of Orthodontics and Craniofacial Developmental Biology, Hiroshima University Graduate School of Biomedical Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan;
* corresponding author, tkotaro{at}hiroshima-u.ac.jp
| ABSTRACT |
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KEY WORDS: hyaluronan HAS synovial membrane TMJ transforming growth factor
| INTRODUCTION |
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Transforming growth factor beta (TGF-ß), a 25-kDa disulfide-linked dimeric protein, is a general stimulator of connective tissue formation and increases the amounts of several connective tissue components, such as collagens (Sporn et al., 1987), fibronectin (Varga et al., 1987), and dermatan sulfate proteoglycan (Bassols and Massague, 1988). Among the isoforms of TGF-ß, TGF-ß1 is known to be a potent mediator of HA synthesis in fibroblasts (Heldin et al., 1989; Westergren-Thorsson et al., 1990). Previous studies showed that the level of TGF-ß1 in synovial fluid was increased in the knee joint with trauma (Wei and Messner, 1998), rheumatoid arthritis (Olsson et al., 2001), and osteoarthrosis (Fahlgren et al., 2001). An increase in the level of TGF-ß1 was also demonstrated in the synovial fluid of patients with temporomandibular disorders (Fang et al., 1999). TGF-ß1 stimulates cartilage matrix synthesis in injured cartilage and osteoarthritis (Trippel, 1995; van den Berg, 1995; Wei and Messner, 1998). It is suggested from these findings that TGF-ß1 may be induced during the repair process of damaged joints and may play an important role in the improvement of intra-articular pathologic status.
It is essential, in the repair of joints, that the biomechanical properties of synovial fluid, such as viscoelasticity and lubrication, controlled by high-molecular-weight HA, be improved. Injection of high-molecular-weight HA into the joint was found to be effective for the treatment of arthritis (Balazs and Denlinger, 1989). At present, however, we do not fully understand whether synovial membrane cells have the potential to control HA synthesis mediated by TGF-ß1. Recently, three putative HA synthase (HAS1, HAS2, and HAS3) genes have been cloned in mice and humans, and their characteristics have been partially clarified (Itano et al., 1999). HAS1 and HAS2 polymerize HA chains of similar large size (up to 2000 kDa), whereas HAS3 produces shorter chains (from 200 to 300 kDa) (Itano et al., 1999). However, the effects of TGF-ß1 on the expression of HAS mRNAs and the relevant HA synthesis have not been clarified in synovial membrane fibroblasts treated with TGF-ß1.
We conducted the present study to investigate the effects of TGF-ß1 on the mRNA expression of HAS isoforms and the production of various molecular weights of HA in cultured fibroblasts derived from rabbit TMJ synovial membrane.
| MATERIALS & METHODS |
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Quantification of HA
The conditioned medium and cell layer were collected from the cultures at 0, 12, 24, 48, and 72 hrs after the application of TGF-ß1. HA in the cell layer was purified by the method established previously (Papakonstantinou et al., 1995). The cell layer was washed briefly with ice-cold phosphate-buffered saline and harvested by scraping. Lipids were extracted with 1 mL of 1:2 (vol/vol) chloroform/methanol, and then all hydrolytic enzymes were inactivated. After the samples were mixed with 1 mL of 0.1 M Tris/HCl (pH 8.0)/1 mM CaCl2, protein digestion was carried out with 0.1 KU pronase (Sigma) for 72 hrs at 37°C. The sample was then adjusted to contain 150 mM NaCl and 10 mM MgCl2, and DNA was digested with 400 KU DNase I (Takara, Otsu, Japan) for 16 hrs at 37°C. The concentration of CaCl2 was adjusted to 1 mM, and the reaction was stopped with 0.1 KU pronase. The samples were adjusted to pH 10.0 and subjected to elimination reaction with 1 M MaBH4 for 16 hrs at 45°C. Samples were then neutralized with 50% (vol/vol) acetic acid.
The pre-treated cell layer and conditioned medium were moved into disposable extraction columns (Bond Elut SCX and BondElut SAX; GL Sciences, Tokyo, Japan). After being mixed with 1 mL of 50% MeOH and 5 mL H2O, the solvents were eluted by 3 mL of 50 mM MeOH/HCl. After drying, the solvents in 500 µL of 0.1 M NaCl were filtrated with a 0.45-µm millipore filter (Gelman Sciences, Ann Arbor, MI, USA).
The solvents were analyzed by means of high-performance liquid chromatography (HPLC: Waters 600E; Waters, Milford, MA, USA) with gel filtration columns (Ohpak KB-804 for the fraction under 1000 kDa, Ohpak KB-806 for the fraction 1000~20,000 kDa; Shodex, Tokyo, Japan). Elution was carried out with 0.1 mM NaCl at a flow rate of 1.0 mL/min. The column effluent was monitored by a differential refractometer (RI DETECTOR 504R; GL Sciences). The accumulation levels of various molecular weights of HA were quantified based on the calibration curves for pure HAs of 300 and 1900 kDa supplied by Denki Kagaku Kogyo (Tokyo, Japan).
Real-time Polymerase Chain-reaction (PCR) Analysis
Total RNA was extracted from the cultured fibroblasts at 0, 1, 3, 6, and 12 hrs after stimulation with TGF-ß1, and the first-strand cDNA was synthesized as described above. For each target gene, primers and the corresponding probes labeled with the reporter dye FAM (6-carboxyfluorescein) were selected with the use of Primer Express software (PE Applied Biosystems, Foster, CA, USA). The Table
shows the sequences of the primers and probes for HAS2, HAS3, and glyceraldehyde 3-phosphate dehydrogenase (G3PDH).
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Statistical Analysis
Means and standard deviations were calculated from the data obtained and then subjected to a Students t test.
| RESULTS |
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The expression of HAS2 mRNA was significantly enhanced after six-hour stimulation with TGF-ß1 (0.1 ng/mL, p < 0.05; 1100 ng/mL, p < 0.01), and reached a maximum 13-fold increase at the dose of 10 ng/mL relative to the controls (Fig. 2A
). Treatment with TGF-ß1 of 10 ng/mL induced a substantial increase in HAS2 mRNA with a maximum 13-fold increase after the six-hour stimulation as compared with the controls, which decrease after 12-hour stimulation (Fig. 2B
). In contrast, the expression of HAS3 mRNA was slightly decreased by TGF-ß1 stimulation (0.1100 ng/mL) without any significant differences between the two groups (Fig. 2C
). The expression of HAS3 mRNA was decreased to 0.6 times after one- to six-hour stimulation with TGF-ß1 (10 ng/mL) as compared with the controls, and recovered to the control levels after 12 hrs (Fig. 2D
).
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| DISCUSSION |
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The accumulation of HA, high-molecular-weight HA in particular, was enhanced by the stimulation of TGF-ß1 in fibroblasts derived from the rabbit TMJ synovial membrane, as is the case in fibroblasts derived from human knee joints (Haubeck et al., 1995). Furthermore, HAS2 mRNA was remarkably up-regulated by the TGF-ß1 treatment. These findings suggest that the accumulation of high-molecular-weight HA induced by TGF-ß1 treatment is caused by the up-regulation of HAS2 in the TMJ. Since high-molecular-weight HA is essential for maintaining the viscoelasticity of synovial fluid (Kobayashi et al., 1994), the enhancement of HA synthesis by HAS2 may improve the biomechanical function of synovial joints.
In contrast, low-molecular-weight HA causes a decrease in the viscoelasticity of synovial fluid and modulates the immune or inflammatory processes (McKee et al., 1996; Hodge-Dufour et al., 1997). An imbalance of synthesis and degradation of HA caused by various pathological conditions leads to the accumulation of low-molecular-weight HA in joint fluid (Bjelle et al., 1983). The pathological accumulation of low-molecular-weight HA is suggested to be due to various degrading mechanisms, such as depolymerization with reactive oxygen species (McNeil et al., 1985) and enzymatic cleavage (Orkin and Toole, 1980), and acceleration of low-molecular-weight HA synthesis by HAS3. Such pro-inflammatory cytokines as interleukin-1 beta and tumor necrosis factor-alpha markedly enhance the gene expression of HAS3 as well as HAS2 in cultured human orbital fibroblasts (Kaback and Smith, 1999), gingival fibroblasts (Ijuin et al., 2001), and rabbit knee synovial membrane fibroblasts (Tanimoto et al., 2001).
However, the gene expression of HAS3 was not affected by TGF-ß1 in the cultured synovial membrane fibroblasts in the present study. Although a constant level of low-molecular-weight HA was detected in both the cell layer and conditioned medium, no significant differences in the HA levels were found between the TGF-ß1-treated and control groups during the experimental period. It was demonstrated that some hyaluronidases are expressed and exert activity in normal fibroblasts (Huey et al., 1990). The catabolic action for HA may thus be exerted in the normal state in cultured fibroblasts derived from the synovial membrane. Since there has been no evidence to demonstrate that TGF-ß1 induces the degradation of HA, it would be reasonable to assume that TGF-ß1 may not cause the accumulation of low-molecular-weight HA different from the effects of pro-inflammatory cytokines on HA accumulation.
These findings suggest that TGF-ß1 is capable of enhancing the synthesis of only high- but not low-molecular-weight HA, by selective up-regulation of HAS2 mRNA. The availability of TGF-ß1 for the treatment of TMJ arthritis has not been confirmed, but it can be speculated that the injection of TGF-ß1 in combination with pumping manipulation would be effective for the treatment of TMJ arthritis. The amount of TGF-ß1 for the treatment may be substantially less than that of sodium hyaluronate currently used for joint diseases. Further investigation would be expected to clarify the effectiveness of TGF-ß1 for the treatment of patients with TMJ arthritis.
In conclusion, it is shown that TGF-ß1 may contribute to the accumulation of high-molecular-weight HA needed for the maintenance of the viscoelasticity and lubrication of synovial fluid by enhancing HAS2 expression in the synovial membrane fibroblasts in TMJ.
| ACKNOWLEDGMENTS |
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Received March 9, 2003; Last revision October 1, 2003; Accepted October 1, 2003
| REFERENCES |
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Bassols A, Massague J (1988). Transforming growth factor beta regulates the expression and structure of extracellular matrix chondroitin/dermatan sulfate proteoglycans. J Biol Chem 263:30393045.
Bjelle A, Andersson T, Granath K (1983). Molecular weight distribution of hyaluronic acid of human synovial fluid in rheumatic diseases. Scand J Rheumatol 12:133138.[ISI][Medline]
Fahlgren A, Andersson B, Messner K (2001). TGF-beta1 as a prognostic factor in the process of early osteoarthrosis in the rabbit knee. Osteoarthritis Cartilage 9:195202.[ISI][Medline]
Fang PK, Ma XC, Ma DL, Fu KY (1999). Determination of interleukin-1 receptor antagonist, interleukin-10, and transforming growth factor-beta1 in synovial fluid aspirates of patients with temporomandibular disorders. J Oral Maxillofac Surg 57:922928; discussion 928929.
Hamerman D, Wood DD (1984). Interleukin 1 enhances synovial cell hyaluronate synthesis. Proc Soc Exp Biol Med 177:205210.[Abstract]
Haubeck HD, Kock R, Fischer DC, Van de Leur E, Hoffmeister K, Greiling H (1995). Transforming growth factor beta 1, a major stimulator of hyaluronan synthesis in human synovial lining cells. Arthritis Rheum 38:669677.[ISI][Medline]
Heldin P, Laurent TC, Heldin CH (1989). Effect of growth factors on hyaluronan synthesis in cultured human fibroblasts. Biochem J 258:919922.[ISI][Medline]
Hodge-Dufour J, Noble PW, Horton MR, Bao C, Wysoka M, Burdick MD, et al. (1997). Induction of IL-12 and chemokines by hyaluronan requires adhesion-dependent priming of resident but not elicited macrophages. J Immunol 159:24922500.
Huey G, Moiin A, Stern R (1990). Levels of [3H]glucosamine incorporation into hyaluronic acid by fibroblasts is modulated by culture conditions. Matrix 10(2):7583.[ISI][Medline]
Ijuin C, Ohno S, Tanimoto K, Honda K, Tanne K (2001). Regulation of hyaluronan synthase gene expression in human periodontal ligament cells by tumour necrosis factor-alpha, interleukin-1beta and interferon-gamma. Arch Oral Biol 46:767772.[ISI][Medline]
Itano N, Sawai T, Yoshida M, Lenas P, Yamada Y, Imagawa M, et al. (1999). Three isoforms of mammalian hyaluronan synthases have distinct enzymatic properties. J Biol Chem 274:2508525092.
Kaback LA, Smith TJ (1999). Expression of hyaluronan synthase messenger ribonucleic acids and their induction by interleukin-1beta in human orbital fibroblasts: potential insight into the molecular pathogenesis of thyroid-associated ophthalmopathy. J Clin Endocrinol Metab 84:40794084.
Kobayashi Y, Okamoto A, Nishinari K (1994). Viscoelasticity of hyaluronic acid with different molecular weights. Biorheology 31:235244.[ISI][Medline]
Laurent TC, Fraser JR (1992). Hyaluronan. FASEB J 6:23972404.[Abstract]
Leutenegger CM, von Rechenberg B, Huder JB, Zlinsky K, Mislin C, Akens MK, et al. (1999). Quantitative real-time PCR for equine cytokine mRNA in nondecalcified bone tissue embedded in methyl methacrylate. Calcif Tissue Int 65:378383.[ISI][Medline]
McKee CM, Penno MB, Cowman M, Burdick MD, Strieter RM, Bao C, et al. (1996). Hyaluronan (HA) fragments induce chemokine gene expression in alveolar macrophages. The role of HA size and CD44. J Clin Invest 98:24032413.[ISI][Medline]
McNeil JD, Wiebkin OW, Betts WH, Cleland LG (1985). Depolymerisation products of hyaluronic acid after exposure to oxygen-derived free radicals. Ann Rheum Dis 44:780789.
Meyer FA, Yaron I, Yaron M (1990). Synergistic, additive, and antagonistic effects of interleukin-1 beta, tumor necrosis factor alpha, and gamma-interferon on prostaglandin E, hyaluronic acid, and collagenase production by cultured synovial fibroblasts. Arthritis Rheum 33:15181525.[ISI][Medline]
Olsson N, Ulfgren AK, Nilsson G (2001). Demonstration of mast cell chemotactic activity in synovial fluid from rheumatoid patients. Ann Rheum Dis 60:187193.
Orkin RW, Toole BP (1980). Isolation and characterization of hyaluronidase from cultures of chick embryo skin- and muscle-derived fibroblasts. J Biol Chem 255:10361042.
Papakonstantinou E, Karakiulakis G, Roth M, Block LH (1995). Platelet-derived growth factor stimulates the secretion of hyaluronic acid by proliferating human vascular smooth muscle cells. Proc Natl Acad Sci USA 92:98819885.
Sporn MB, Roberts AB, Wakefield LM, de Crombrugghe B (1987). Some recent advances in the chemistry and biology of transforming growth factor-beta. J Cell Biol 105:10391045.
Tanimoto K, Ohno S, Fujimoto K, Honda K, Ijuin C, Tanaka N, et al. (2001). Proinflammatory cytokines regulate the gene expression of hyaluronic acid synthetase in cultured rabbit synovial membrane cells. Connect Tissue Res 42:187195.[ISI][Medline]
Trippel SB (1995). Growth factor actions on articular cartilage. J Rheumatol Suppl 43:129132.[Medline]
van den Berg WB (1995). Growth factors in experimental osteoarthritis: transforming growth factor beta pathogenic? J Rheumatol Suppl 43:143145.[Medline]
Varga J, Rosenbloom J, Jimenez SA (1987). Transforming growth factor beta (TGF beta) causes a persistent increase in steady-state amounts of type I and type III collagen and fibronectin mRNAs in normal human dermal fibroblasts. Biochem J 247:597604.[ISI][Medline]
Wei X, Messner K (1998). Age- and injury-dependent concentrations of transforming growth factor-beta 1 and proteoglycan fragments in rabbit knee joint fluid. Osteoarthritis Cartilage 6:1018.[ISI][Medline]
Werb Z, Burleigh MC (1974). A specific collagenase from rabbit fibroblasts in monolayer culture. Biochem J 137:373385.[ISI][Medline]
Westergren-Thorsson G, Sarnstrand B, Fransson LA, Malmstrom A (1990). TGF-beta enhances the production of hyaluronan in human lung but not in skin fibroblasts. Exp Cell Res 186:192195.[ISI][Medline]
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