共查询到20条相似文献,搜索用时 31 毫秒
1.
Esmeralda N Blaney Davidson Elly L Vitters Wim B van den Berg Peter M van der Kraan 《Arthritis research & therapy》2006,8(3):R65-8
Cartilage damage in osteoarthritis (OA) is considered an imbalance between catabolic and anabolic factors, favoring the catabolic
side. We assessed whether adenoviral overexpression of transforming growth factor-β (TGFβ) enhanced cartilage repair and whether
TGFβ-induced fibrosis was blocked by local expression of the intracellular TGFβ inhibitor Smad7. We inflicted cartilage damage
by injection of interleukin-1 (IL-1) into murine knee joints. After 2 days, we injected an adenovirus encoding TGFβ. On day
4, we measured proteoglycan (PG) synthesis and content. To examine whether we could block TGFβ-induced fibrosis and stimulate
cartilage repair simultaneously, we injected Ad-TGFβ and Ad-Smad7. This was performed both after IL-1-induced damage and in
a model of primary OA. In addition to PG in cartilage, synovial fibrosis was measured by determining the synovial width and
the number of procollagen I-expressing cells. Adenoviral overexpression of TGFβ restored the IL-1-induced reduction in PG
content and increased PG synthesis. TGFβ-induced an elevation in PG content in cartilage of the OA model. TGFβ-induced synovial
fibrosis was strongly diminished by simultaneous synovial overexpression of Smad7 in the synovial lining. Of great interest,
overexpression of Smad7 did not reduce the repair-stimulating effect of TGFβ on cartilage. Adenoviral overexpression of TGFβ
stimulated repair of IL-1- and OA-damaged cartilage. TGFβ-induced synovial fibrosis was blocked by locally inhibiting TGFβ
signaling in the synovial lining by simultaneously transfecting it with an adenovirus overexpressing Smad7. 相似文献
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Blaney Davidson EN Scharstuhl A Vitters EL van der Kraan PM van den Berg WB 《Arthritis research & therapy》2005,7(6):R1338-R1347
Osteoarthritis (OA) is a common joint disease, mainly effecting the elderly population. The cause of OA seems to be an imbalance
in catabolic and anabolic factors that develops with age. IL-1 is a catabolic factor known to induce cartilage damage, and
transforming growth factor (TGF)-beta is an anabolic factor that can counteract many IL-1-induced effects. In old mice, we
observed reduced responsiveness to TGF-beta-induced IL-1 counteraction. We investigated whether expression of TGF-beta and
its signaling molecules altered with age. To mimic the TGF-beta deprived conditions in aged mice, we assessed the functional
consequence of TGF-beta blocking. We isolated knee joints of mice aged 5 months or 2 years, half of which were exposed to
IL-1 by intra-articular injection 24 h prior to knee joint isolation. Immunohistochemistry was performed, staining for TGF-beta1,
-2 or -3, TGF-betaRI or -RII, Smad2, -3, -4, -6 and -7 and Smad-2P. The percentage of cells staining positive was determined
in tibial cartilage. To mimic the lack of TGF-beta signaling in old mice, young mice were injected with IL-1 and after 2 days
Ad-LAP (TGF-beta inhibitor) or a control virus were injected. Proteoglycan (PG) synthesis (35S-sulfate incorporation) and PG content of the cartilage were determined. Our experiments revealed that TGF-beta2 and -3 expression
decreased with age, as did the TGF-beta receptors. Although the number of cells positive for the Smad proteins was not altered,
the number of cells expressing Smad2P strongly dropped in old mice. IL-1 did not alter the expression patterns. We mimicked
the lack of TGF-beta signaling in old mice by TGF-beta inhibition with LAP. This resulted in a reduced level of PG synthesis
and aggravation of PG depletion. The limited response of old mice to TGF-beta induced-IL-1 counteraction is not due to a diminished
level of intracellular signaling molecules or an upregulation of intracellular inhibitors, but is likely due to an intrinsic
absence of sufficient TGF-beta receptor expression. Blocking TGF-beta distorted the natural repair response after IL-1 injection.
In conclusion, TGF-beta appears to play an important role in repair of cartilage and a lack of TGF-beta responsiveness in
old mice might be at the root of OA development. 相似文献
3.
SIRT1 inhibits transforming growth factor beta-induced apoptosis in glomerular mesangial cells via Smad7 deacetylation 总被引:2,自引:0,他引:2
Kume S Haneda M Kanasaki K Sugimoto T Araki S Isshiki K Isono M Uzu T Guarente L Kashiwagi A Koya D 《The Journal of biological chemistry》2007,282(1):151-158
SIRT1, a class III histone deacetylase, is considered a key regulator of cell survival and apoptosis through its interaction with nuclear proteins. In this study, we have examined the likelihood and role of the interaction between SIRT1 and Smad7, which mediates transforming growth factor beta (TGFbeta)-induced apoptosis in renal glomerular mesangial cells. Immunoprecipitation analysis revealed that SIRT1 directly interacts with the N terminus of Smad7. Furthermore, SIRT1 reversed acetyl-transferase (p300)-mediated acetylation of two lysine residues (Lys-64 and -70) on Smad7. In mesangial cells, the Smad7 expression level was reduced by SIRT1 overexpression and increased by SIRT1 knockdown. SIRT1-mediated deacetylation of Smad7 enhanced Smad ubiquitination regulatory factor 1 (Smurf1)-mediated ubiquitin proteasome degradation, which contributed to the low expression of Smad7 in SIRT1-overexpressing mesangial cells. Stimulation by TGFbeta or overexpression of Smad7 induced mesangial cell apoptosis, as assessed by morphological apoptotic changes (nuclear condensation) and biological apoptotic markers (cleavages of caspase3 and poly(ADP-ribose) polymerase). However, TGFbeta failed to induce apoptosis in Smad7 knockdown mesangial cells, indicating that Smad7 mainly mediates TGFbeta-induced apoptosis of mesangial cells. Finally, SIRT1 overexpression attenuated both Smad7- and TGFbeta-induced mesangial cell apoptosis, whereas SIRT1 knockdown enhanced this apoptosis. We have concluded that Smad7 is a new target molecule for SIRT1 and SIRT1 attenuates TGFbeta-induced mesangial cell apoptosis through acceleration of Smad7 degradation. Our results suggest that up-regulation of SIRT1 deacetylase activity is a potentially useful therapeutic strategy for prevention of TGFbeta-related kidney disease through its effect on cell survival. 相似文献
4.
The cascade of phosphorylation is a pivotal event in transforming growth factor beta (TGFbeta) signaling. Reversible phosphorylation regulates fundamental aspects of cell activity. TGFbeta-induced Smad7 binds to type I receptor (TGFbeta type I receptor; TbetaRI) functioning as a receptor kinase antagonist. We found Smad7 interacts with growth arrest and DNA damage protein, GADD34, a regulatory subunit of the protein phosphatase 1 (PP1) holoenzyme, which subsequently recruits catalytic subunit of PP1 (PP1c) to dephosphorylate TbetaRI. Blocking Smad7 expression by RNA interference inhibits association of GADD34-PP1c complex with TbetaRI, indicating Smad7 acts as an adaptor protein in the formation of the PP1 holoenzyme that targets TbetaRI for dephosphorylation. SARA (Smad anchor for receptor activation) enhances the recruitment PP1c to the Smad7-GADD34 complex by controlling the specific subcellular localization of PP1c. Importantly, GADD34-PP1c recruited by Smad7 inhibits TGFbeta-induced cell cycle arrest and mediates TGFbeta resistance in responding to UV light irradiation. The dephosphorylation of TbetaRI mediated by Smad7 is an effective mechanism for governing negative feedback in TGFbeta signaling. 相似文献
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The matricellular protein connective tissue growth factor (CCN2) is considered a faithful marker of fibroblast activation in wound healing and in fibrosis. CCN2 is induced during activation of hepatic stellate cells (HSC). Here, we investigate the molecular basis of CCN2 gene expression in HSC. Fluoroscence activated cell sorting was used to investigate CCN2 expression in HSC in vivo in mice treated with CCl(4). CCN2 and TGF-beta mRNA expression were assessed by polymerase chain reaction as a function of culture-induced activation of HSC. CCN2 promoter/reporter constructs were used to map cis-acting elements required for basal and TGFbeta-induced CCN2 promoter activity. Real-time polymerase chain reaction analysis was used to further clarify signaling pathways required for CCN2 expression in HSC. CCl(4) administration in vivo increased CCN2 production by HSC. In vitro, expression of CCN2 and TGF-beta mRNA were concommitantly increased in mouse HSC between days 0 and 14 of culture. TGFbeta-induced CCN2 promoter activity required the Smad and Ets-1 elements in the CCN2 promoter and was reduced by TGFbeta type I receptor (ALK4/5/7) inhibition. CCN2 overexpression in activated HSC was ALK4/5/7-dependent. As CCN2 overexpression is a faithful marker of fibrogenesis, our data are consistent with the notion that signaling through TGFbeta type I receptors such as ALK5 contributes to the activation of HSC and hence ALK4/5/7 inhibition would be expected to be an appropriate treatment for liver fibrosis. 相似文献
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Ongaro A Pellati A Masieri FF Caruso A Setti S Cadossi R Biscione R Massari L Fini M De Mattei M 《Bioelectromagnetics》2011,32(7):543-551
This study investigated the effects of pulsed electromagnetic fields (PEMFs) on proteoglycan (PG) metabolism of human articular cartilage explants from patients with osteoarthritis (OA). Human cartilage explants, recovered from lateral and medial femoral condyles, were classified according to the International Cartilage Repair Society (ICRS) and graded based on Outerbridge scores. Explants cultured in the absence and presence of IL-1β were treated with PEMF (1.5 mT, 75 Hz) or IGF-I alone or in combination for 1 and 7 days. PG synthesis and release were determined. Results showed that explants derived from lateral and medial condyles scored OA grades I and III, respectively. In OA grade I explants, after 7 days exposure, PEMF and IGF-I significantly increased (35) S-sulfate incorporation 49% and 53%, respectively, compared to control, and counteracted the inhibitory effect of IL 1β (0.01 ng/ml). The combined exposure to PEMF and IGF-I was additive in all conditions. Similar results were obtained in OA grade III cartilage explants. In conclusion, PEMF and IGF-I augment cartilage explant anabolic activities, increase PG synthesis, and counteract the catabolic activity of IL-1β in OA grades I and III. We hypothesize that both IGF-I and PEMF have chondroprotective effects on human articular cartilage, particularly in early stages of OA. 相似文献
12.
Nabbe KC van Lent PL Holthuysen AE Sloëtjes AW Koch AE Radstake TR van den Berg WB 《Arthritis research & therapy》2005,7(2):R392-R401
During immune-complex-mediated arthritis (ICA), severe cartilage destruction is mediated by Fcγ receptors (FcγRs) (mainly
FcγRI), cytokines (e.g. IL-1), and enzymes (matrix metalloproteinases (MMPs)). IL-13, a T helper 2 (Th2) cytokine abundantly
found in synovial fluid of patients with rheumatoid arthritis, has been shown to reduce joint inflammation and bone destruction
during experimental arthritis. However, the effect on severe cartilage destruction has not been studied in detail. We have
now investigated the role of IL-13 in chondrocyte death and MMP-mediated cartilage damage during ICA. IL-13 was locally overexpressed
in knee joints after injection of an adenovirus encoding IL-13 (AxCAhIL-13), 1 day before the onset of arthritis; injection
of AxCANI (an empty adenoviral construct) was used as a control. IL-13 significantly increased the amount of inflammatory
cells in the synovial lining and the joint cavity, by 30% to 60% at day 3 after the onset of ICA. Despite the enhanced inflammatory
response, chondrocyte death was diminished by two-thirds at days 3 and 7. The mRNA level of FcγRI, a receptor shown to be
crucial in the induction of chondrocyte death, was significantly down-regulated in synovium. Furthermore, MMP-mediated cartilage
damage, measured as neoepitope (VDIPEN) expression using immunolocalization, was halved. In contrast, mRNA levels of MMP-3,
-9, -12, and -13 were significantly higher and IL-1 protein, which induces production of latent MMPs, was increased fivefold
by IL-13. This study demonstrates that IL-13 overexpression during ICA diminished both chondrocyte death and MMP-mediated
VDIPEN expression, even though joint inflammation was enhanced. 相似文献
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CCN2 is necessary for adhesive responses to transforming growth factor-beta1 in embryonic fibroblasts 总被引:10,自引:0,他引:10
Shi-wen X Stanton LA Kennedy L Pala D Chen Y Howat SL Renzoni EA Carter DE Bou-Gharios G Stratton RJ Pearson JD Beier F Lyons KM Black CM Abraham DJ Leask A 《The Journal of biological chemistry》2006,281(16):10715-10726
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Blaney Davidson EN Vitters EL van Lent PL van de Loo FA van den Berg WB van der Kraan PM 《Arthritis research & therapy》2007,9(5):R102
Bone morphogenetic protein-2 (BMP-2) has been proposed as a tool for cartilage repair and as a stimulant of chondrogenesis.
In healthy cartilage, BMP-2 is hardly present, whereas it is highly expressed during osteoarthritis. To assess its function
in cartilage, BMP-2 was overexpressed in healthy murine knee joints and the effects on proteoglycan (PG) synthesis and degradation
were evaluated. Moreover, the contribution of BMP in repairing damage induced by interleukin-1 (IL-1) was investigated. Ad-BMP-2
was injected intra-articularly into murine knee joints, which were isolated 3, 7, and 21 days after injection for histology,
immunohistochemistry, and autoradiography. In addition, patellar and tibial cartilage was isolated for RNA isolation or measurement
of PG synthesis by means of 35SO4
2- incorporation. To investigate the role for BMP-2 in cartilage repair, cartilage damage was induced by intra-articular injection
of IL-1. After 2 days, Ad-BMP-2, Ad-BMP-2 + Ad-gremlin, Ad-gremlin, or a control virus was injected. Whole knee joints were
isolated for histology at day 4 or patellae were isolated to measure 35SO4
2- incorporation. BMP-2 stimulated PG synthesis in patellar cartilage on all days and in tibial cartilage on day 21. Aggrecan
mRNA expression had increased on all days in patellar cartilage, with the highest increase on day 7. Collagen type II expression
showed a similar expression pattern. In tibial cartilage, collagen type II and aggrecan mRNA expression had increased on days
7 and 21. BMP-2 overexpression also induced increased aggrecan degradation in cartilage. VDIPEN staining (indicating matrix
metalloproteinase activity) was elevated on day 3 in tibial cartilage and on days 3 and 7 in patellar cartilage, but no longer
was by day 21. Increased NITEGE staining (indicating aggrecanase activity) was found on days 7 and 21. In IL-1-damaged patellar
cartilage, BMP-2 boosted PG synthesis. Blocking of BMP activity resulted in a decreased PG synthesis compared with IL-1 alone.
This decreased PG synthesis was associated with PG depletion in the cartilage. These data show that BMP-2 boosts matrix turnover
in intact and IL-damaged cartilage. Moreover, BMP contributes to the intrinsic repair capacity of damaged cartilage. Increased
matrix turnover might be functional in replacing matrix molecules in the repair of a damaged cartilage matrix. 相似文献
17.
Triptolide suppresses proinflammatory cytokine-induced matrix metalloproteinase and aggrecanase-1 gene expression in chondrocytes 总被引:8,自引:0,他引:8
Liacini A Sylvester J Zafarullah M 《Biochemical and biophysical research communications》2005,327(1):320-327
A hallmark of rheumatoid- and osteoarthritis (OA) is proinflammatory cytokine-induced degeneration of cartilage collagen and aggrecan by matrix metalloproteinases (MMPs) and aggrecanases (ADAMTS). Effects of the Chinese herb, Tripterygium wilfordii Hook F (TWHF), on cartilage and its anti-arthritic mechanisms are poorly understood. This study investigated the impact of a purified derivative of TWHF, PG490 (triptolide), on cytokine-stimulated expression of the major cartilage damaging proteases, MMP-3, MMP-13, and ADAMTS4. PG490 inhibited cytokine-induced MMP-3, MMP-13 gene expression in primary human OA chondrocytes, bovine chondrocytes, SW1353 cells, and human synovial fibroblasts. Triptolide was effective at low doses and blocked the induction of MMP-13 by IL-1 in human and bovine cartilage explants. TWHF extract and PG490 also suppressed IL-1-, IL-17-, and TNF-alpha-induced expression of ADAMTS-4 in bovine chondrocytes. Thus, PG490 could protect cartilage from MMP- and aggrecanase-driven breakdown. The immunosuppressive, cartilage protective, and anti-inflammatory properties could make PG490 potentially a new therapeutic agent for arthritis. 相似文献
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Jun Li Daniel J Gorski Wendy Anemaet Jennifer Velasco Jun Takeuchi John D Sandy Anna Plaas 《Arthritis research & therapy》2012,14(3):R151