The Experts below are selected from a list of 19086 Experts worldwide ranked by ideXlab platform
Arnold I Caplan - One of the best experts on this subject based on the ideXlab platform.
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repair of large full thickness articular cartilage defects with allograft articular chondrocytes embedded in a Collagen Gel
1998Co-Authors: Shigeyuki Wakitani, Tatsuhiko Goto, Randell G Young, Joseph M Mansour, Victor M Goldberg, Arnold I CaplanAbstract:Full-thickness articular cartilage defects are a major clinical problem; however, presently there is no treatment available to regeneratively repair these lesions. The current therapeutic approach is to drill the base of the defect to expose the subchondral bone with its cells and growth factors. This usually results in a repair tissue of fibrocartilage that functions poorly in the loaded joint environment. The use of phenotypically appropriate chondrocytes embedded in a Collagen Gel delivery vehicle may provide a method that could be used to repair full-thickness articular cartilage defects with functionally satisfactory hyaline cartilage. Allograft articular chondrocytes embedded in a type I Collagen Gel were transplanted into large ( 6 × 3 × 3 mm), full-thickness articular cartilage defects in condylar and patellar weightbearing surfaces to develop clinically applicable methods to repair articular cartilage defects. Chondrocytes were isolated from the articular cartilage of 4-week-old New Zealand rabbi...
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articular cartilage repair rabbit experiments with a Collagen Gel biomatrix and chondrocytes cultured in it
1998Co-Authors: Sadahito Kawamura, Shigeyuki Wakitani, Arnold I Caplan, Tomoatsu Kimura, Akira Maeda, Konsei Shino, Takahiro OchiAbstract:To repair a full-thickness articular cartilage defect in rabbit knees, we developed a technique of using a Collagen Gel hardened by cultured allogeneic chondrocytes in it. the Gel-chondrocyte composite accumulated an intense metachromatic matrix, and had elasticity and stiffness enough to be shaped easily after 2 weeks' culture in vitro. It was implanted into full-thickness articular cartilage defects. Histologic evaluation was performed up to 6 months after surgery, using a histologic grading scale composed of 5 categories.In the Gel-chondrocyte composite implanted group, good repair was observed from as early as 1 day up to 6 months. on the other hand, in the empty control group, no repair was observed 1 day to 2 weeks after the defects were made. At 4 weeks, some repair occurred, but even at 6 months the repair was not good.
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repair of large full thickness articular cartilage defects with allograft articular chondrocytes embedded in a Collagen Gel
1998Co-Authors: Shigeyuki Wakitani, Tatsuhiko Goto, Randell G Young, Joseph M Mansour, Victor M Goldberg, Arnold I CaplanAbstract:Full-thickness articular cartilage defects are a major clinical problem; however, presently there is no treatment available to regeneratively repair these lesions. The current therapeutic approach is to drill the base of the defect to expose the subchondral bone with its cells and growth factors. This usually results in a repair tissue of fibrocartilage that functions poorly in the loaded joint environment. The use of phenotypically appropriate chondrocytes embedded in a Collagen Gel delivery vehicle may provide a method that could be used to repair full-thickness articular cartilage defects with functionally satisfactory hyaline cartilage. Allograft articular chondrocytes embedded in a type I Collagen Gel were transplanted into large (6 x 3 x 3 mm), full-thickness articular cartilage defects in condylar and patellar weight-bearing surfaces to develop clinically applicable methods to repair articular cartilage defects. Chondrocytes were isolated from the articular cartilage of 4-week-old New Zealand rabbits and embedded in type I Collagen Gels. This composite was transplanted into a full-thickness defect on the medial femoral condyle and patellar groove of adolescent host rabbits. The repair cartilage was assessed histologically by a semiquantitative scoring system and biomechanically with a microindentation technique of specimens 4-48 weeks after chondrocyte transplantation. Defects in both locations were repaired with histologically apparent hyaline cartilage observed from as early as 4 weeks until 48 weeks after transplantation. The repair cartilage in the medial femoral condyle was more irregular than in the patellar groove, but in all other respects was similar. The grafted tissue did not remodel and differentiate into the morphological zones seen in normal articular cartilage. No tidemark or subchondral bony plate formed even 48 weeks after transplantation. Biomechanically, the repaired cartilage demonstrated indentation values similar to normal articular cartilage 12 weeks after transplantation and remained the same 48 weeks after transplantation. By contrast, the control (i.e., empty) defects healed with tissue that exhibited very poor metachromatic staining and exhibited very high indentation values. Incomplete bonding of the repair tissue to the normal cartilage was seen, and the surface was significantly irregular with major discontinuities. These observations provide the basis for considering the use of allograft articular chondrocytes to repair articular cartilage defects in the weight-bearing regions of the knee.
Tadashi Kohyama - One of the best experts on this subject based on the ideXlab platform.
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Phosphodiesterase 4 Inhibitor Cilomilast Inhibits Fibroblast-Mediated Collagen Gel Degradation Induced by Tumor Necrosis Factor- � and
2013Co-Authors: Neutrophil Elastase, Tadashi Kohyama, Xiangde Liu, Fu Qiang Wen, Tetsu Kobayashi, Qiuhong Fang, Yun Kui Zhu, Hang Jun Wang, Stephen I RennardAbstract:Tissue destruction, resulting in emphysema, can be a consequence of several pathologic processes. The current study evaluated the effects of the phosphodiesterase (PDE)4 inhibitor, cilomilast, and other PDE inhibitors on the ability of fibroblasts to degrade extracellular matrix. Using the three-dimensional Collagen Gel culture system, fibroblasts (HFL-1) were cultured with tumor necrosis factor (TNF)-�, known to induce matrix metalloproteinase (MMP) release, and/or neutrophil elastase (NE), which can induce MMP activation. On Day 4, Gels containing TNF- � and NE were significantly degraded (20.8 � 2.9% of original Collagen content). Cilomilast (10 �M) inhibited this degradation (84.4 � 8.4%). Amrinone, a PDE3 inhibitor, and zaprinast, a PDE5 inhibitor, had no effect. Gelatin zymography and immunoblotting revealed that fibroblasts cultured with TNF- � released increased amounts of latent MMP-1 and-9. Th
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ultrafine carbon black particles inhibit human lung fibroblast mediated Collagen Gel contraction
2003Co-Authors: Tadashi Kohyama, Xiangde Liu, Fu Qiang Wen, Tetsu Kobayashi, Huijung Kim, Debra J RombergerAbstract:Both acute and chronic exposure to particulates have been associated with increased mortality and morbidity from a number of causes, including chronic obstructive pulmonary disease and other chronic lung diseases. The current study evaluated the hypothesis that ultrafine carbon particles, a component of ambient particulates, could affect tissue repair. To assess this, the three-dimensional Collagen Gel contraction model was used. Ultrafine carbon black particles, but not fine carbon black, inhibited fibroblast-mediated Collagen Gel contraction. Although previous research has indicated that inflammatory effects of ultrafine carbon black particles are mediated by oxidant mechanisms, the current study suggests that ultrafine carbon black's inhibition of fibroblast Gel contraction is mediated by the binding of both fibronectin and transforming growth factor (TGF)-β to the ultrafine particles. Binding of TGF-β was associated with a reduction in nuclear localization of Smads, indicative of inhibition of TGF-β s...
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phosphodiesterase 4 inhibitor cilomilast inhibits fibroblast mediated Collagen Gel degradation induced by tumor necrosis factor α and neutrophil elastase
2002Co-Authors: Tadashi Kohyama, Xiangde Liu, Fu Qiang Wen, Tetsu Kobayashi, Qiuhong Fang, Yun Kui Zhu, Hang Jun Wang, Stephen I RennardAbstract:Tissue destruction, resulting in emphysema, can be a consequence of several pathologic processes. The current study evaluated the effects of the phosphodiesterase (PDE)4 inhibitor, cilomilast, and other PDE inhibitors on the ability of fibroblasts to degrade extracellular matrix. Using the three-dimensional Collagen Gel culture system, fibroblasts (HFL-1) were cultured with tumor necrosis factor (TNF)-α, known to induce matrix metalloproteinase (MMP) release, and/or neutrophil elastase (NE), which can induce MMP activation. On Day 4, Gels containing TNF-α and NE were significantly degraded (20.8 ± 2.9% of original Collagen content). Cilomilast (10 μM) inhibited this degradation (84.4 ± 8.4%). Amrinone, a PDE3 inhibitor, and zaprinast, a PDE5 inhibitor, had no effect. Gelatin zymography and immunoblotting revealed that fibroblasts cultured with TNF-α released increased amounts of latent MMP-1 and -9. The addition of NE resulted in the conversion of MMP-1 and -9 to their active forms, indicative of Collagen...
Hajime Sugihara - One of the best experts on this subject based on the ideXlab platform.
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effects of fat cells on keratinocytes and fibroblasts in a reconstructed rat skin model using Collagen Gel matrix culture
2001Co-Authors: Hajime Sugihara, Shuji Toda, Nobuhisa Yonemitsu, Keiko WatanabeAbstract:Background Fat cells (stromal tissue cells), not only have the function of lipid metabolism, but produce various cytokines that exert an influence on other cell types through paracrine or endocrine mechanisms. Objectives To elucidate possible roles of fat cells in the skin, we examined their effects on the biological behaviour of keratinocytes and dermal fibroblasts in culture. Methods In the present study, focusing upon fat cell–keratinocyte or fat cell–dermal fibroblast interactions, we used a reconstructed skin system with rat skin cells in a three-dimensional Collagen Gel matrix culture. Results In this coculture system, fat cells promoted the proliferation and differentiation of keratinocytes. When keratinocytes were seeded directly on the fat cell layer without dermal fibroblasts, they proliferated extensively and formed a thick epidermal layer with a well-differentiated structure. Conversely, fat cells inhibited the proliferation of dermal fibroblasts. These effects of fat cells were presumed to be mediated by cytokines derived from the fat cells. Conclusions The effects of fat cells could not be mimicked by the addition of leptin, tumour necrosis factor-α or insulin-like growth factor-II, suggesting that fat cells are mediating these activities via some other cytokines.
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transforming growth factor β1 induces a mesenchyme like cell shape without epithelial polarization in thyrocytes and inhibits thyroid folliculogenesis in Collagen Gel culture
1997Co-Authors: Shuji Toda, Nobuhisa Yonemitsu, Sueo Matsumura, Noboru Fujitani, Tomohisa Nishimura, Hajime SugiharaAbstract:Transforming growth factor-beta1 (TGFbeta1) induces a mesenchyme-like cell shape in some epithelial cell types. To clarify the role of TGFbeta1 in the morphological regulation of thyrocytes, we performed Collagen Gel culture of porcine thyrocytes with serum-free medium. TGFbeta1-nontreated cells organized follicles. In contrast, the cells treated with 10 ng/ml TGFbeta1 became spindle shaped, i.e. they resembled mesenchymal fibroblasts, and did not form follicles. To characterize the spindle-shaped cells, we examined the fine structures and expression of thyroglobulin (Tg) and cytoskeletal proteins using electron microscopy, immunohistochemistry, and immunoblotting. TGFbeta1-nontreated cells had microvilli at the apical side facing follicle lumen and had basal lamina at the basal side in contact with Collagen Gel. TGFbeta1-treated cells showed both microvilli and basal lamina at the basal side. TGFbeta1-nontreated cells expressed Tg, whereas TGFbeta1-treated cells showed no expression. TGFbeta1-nontreated cells barely expressed vimentin, but they expressed enough cytokeratin. TGFbeta1-treated cells extensively displayed vimentin along with the change in shape to become spindle-like and retained a decreased expression of cytokeratin. TSH (10 mU/ml) did not essentially influence any TGFbeta1 effects on the cells. These results indicate that TGFbeta1 induces a mesenchyme-like cell shape accompanied by cytoskeletal molecular change and the loss of both epithelial polarization and a function in thyrocytes, and that it results in inhibiting thyroid folliculogenesis with or without TSH.
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reconstruction of prostatic acinus like structure from ventral and dorsolateral prostatic epithelial cells of the rat in three dimensional Collagen Gel matrix culture
1997Co-Authors: Chisato Fujiyama, Zenjiro Masaki, Hajime SugiharaAbstract:ABSTRACTPurpose: The study was carried out to reconstruct a prostatic acinus-like structure from prostatic epithelial cells in a new culture system which can provide a more physiological condition than conventional cell culture methods.Materials and Methods: Prostatic epithelial cells were isolated from ventral and dorsolateral prostates of the rat and were separately cultured in three-dimensional Collagen Gel matrix. The cultured cells were observed by photo-microscopy and transmission electron microscopy. Differentiation and proliferation of the cultured cells were examined by immunohistochemistry using PAP and PSA kits and a bromodeoxy-uridine (BrdU) kit. The cell area of acinus-like structure in the transverse sections was measured by computer with the Interaktive Bild-Analyse System.Results: Dissociated prostatic epithelial cells were organized into three-dimensional spherical or branching cellular aggregates in Collagen Gel matrix. Through cell proliferation and differentiation, the cellular aggrega...
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reconstruction of the urinary bladder mucosa in three dimensional Collagen Gel culture fibroblast extracellular matrix interactions on the differentiation of transitional epithelial cells
1995Co-Authors: Chisato Fujiyama, Zenjiro Masaki, Hajime SugiharaAbstract:AbstractThe purpose of this study was to reconstruct a urinary bladder mucosa in three-dimensional Collagen Gel culture conditions that included fibroblasts. Transitional epithelial cells and fibroblasts, isolated respectively from the epithelial and lamina propria layers of porcine urinary bladder, were cultured in monolayer. These fibroblasts were embedded and cultured within a Collagen Gel matrix to reconstruct a lamina propria. The isolated transitional epithelial cells were then seeded in vitro on this reconstructed lamina propria on which the transitional epithelial cells formed a stratified urothelium composed of basal, intermediate and superficial layers. Urothelial differentiation was observed only on the fibroblast-containing Collagen matrix. Differentiation did not occur on a cell-free Collagen matrix through use of fibroblast conditioned medium. Thus, urothelial differentiation depended upon a fibroblast-extracellular matrix interaction. The differentiated transitional epithelial cell layer th...
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Reconstruction of alveolus-like structure from alveolar type II epithelial cells in three-dimensional Collagen Gel matrix culture.
1993Co-Authors: Hajime Sugihara, Chisato Fujiyama, Shuji Toda, Shinichi Miyabara, Nobuhisa YonemitsuAbstract:The purpose of this study is to reconstruct an alveolus-like structure from alveolar type II epithelial cells in a culture condition. Isolated alveolar type II epithelial cells of the rat were cultured in a three-dimensional Collagen Gel matrix. Single type II cells formed cellular aggregates that had a lumen after cell division in this culture condition. Through proliferation of the component cells, these aggregates grew to assume a globular or branching structure, part of which in turn developed into a large, cystic alveolus-like structure. This structure consisted of flattened epithelial cells intermingled with cuboidal epithelial cells. In these structures, the surfactant production was confirmed by immunohistochemistry and electron microscopy. To our knowledge, this is the first report of a reconstruction of an alveolus-like structure in a three-dimensional Collagen Gel matrix culture. This culture system seems to provide an appropriate physiological environment in which to study the differentiation and disorders of pulmonary alveoli.
Shigeyuki Wakitani - One of the best experts on this subject based on the ideXlab platform.
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repair of large full thickness articular cartilage defects with allograft articular chondrocytes embedded in a Collagen Gel
1998Co-Authors: Shigeyuki Wakitani, Tatsuhiko Goto, Randell G Young, Joseph M Mansour, Victor M Goldberg, Arnold I CaplanAbstract:Full-thickness articular cartilage defects are a major clinical problem; however, presently there is no treatment available to regeneratively repair these lesions. The current therapeutic approach is to drill the base of the defect to expose the subchondral bone with its cells and growth factors. This usually results in a repair tissue of fibrocartilage that functions poorly in the loaded joint environment. The use of phenotypically appropriate chondrocytes embedded in a Collagen Gel delivery vehicle may provide a method that could be used to repair full-thickness articular cartilage defects with functionally satisfactory hyaline cartilage. Allograft articular chondrocytes embedded in a type I Collagen Gel were transplanted into large ( 6 × 3 × 3 mm), full-thickness articular cartilage defects in condylar and patellar weightbearing surfaces to develop clinically applicable methods to repair articular cartilage defects. Chondrocytes were isolated from the articular cartilage of 4-week-old New Zealand rabbi...
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articular cartilage repair rabbit experiments with a Collagen Gel biomatrix and chondrocytes cultured in it
1998Co-Authors: Sadahito Kawamura, Shigeyuki Wakitani, Arnold I Caplan, Tomoatsu Kimura, Akira Maeda, Konsei Shino, Takahiro OchiAbstract:To repair a full-thickness articular cartilage defect in rabbit knees, we developed a technique of using a Collagen Gel hardened by cultured allogeneic chondrocytes in it. the Gel-chondrocyte composite accumulated an intense metachromatic matrix, and had elasticity and stiffness enough to be shaped easily after 2 weeks' culture in vitro. It was implanted into full-thickness articular cartilage defects. Histologic evaluation was performed up to 6 months after surgery, using a histologic grading scale composed of 5 categories.In the Gel-chondrocyte composite implanted group, good repair was observed from as early as 1 day up to 6 months. on the other hand, in the empty control group, no repair was observed 1 day to 2 weeks after the defects were made. At 4 weeks, some repair occurred, but even at 6 months the repair was not good.
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repair of large full thickness articular cartilage defects with allograft articular chondrocytes embedded in a Collagen Gel
1998Co-Authors: Shigeyuki Wakitani, Tatsuhiko Goto, Randell G Young, Joseph M Mansour, Victor M Goldberg, Arnold I CaplanAbstract:Full-thickness articular cartilage defects are a major clinical problem; however, presently there is no treatment available to regeneratively repair these lesions. The current therapeutic approach is to drill the base of the defect to expose the subchondral bone with its cells and growth factors. This usually results in a repair tissue of fibrocartilage that functions poorly in the loaded joint environment. The use of phenotypically appropriate chondrocytes embedded in a Collagen Gel delivery vehicle may provide a method that could be used to repair full-thickness articular cartilage defects with functionally satisfactory hyaline cartilage. Allograft articular chondrocytes embedded in a type I Collagen Gel were transplanted into large (6 x 3 x 3 mm), full-thickness articular cartilage defects in condylar and patellar weight-bearing surfaces to develop clinically applicable methods to repair articular cartilage defects. Chondrocytes were isolated from the articular cartilage of 4-week-old New Zealand rabbits and embedded in type I Collagen Gels. This composite was transplanted into a full-thickness defect on the medial femoral condyle and patellar groove of adolescent host rabbits. The repair cartilage was assessed histologically by a semiquantitative scoring system and biomechanically with a microindentation technique of specimens 4-48 weeks after chondrocyte transplantation. Defects in both locations were repaired with histologically apparent hyaline cartilage observed from as early as 4 weeks until 48 weeks after transplantation. The repair cartilage in the medial femoral condyle was more irregular than in the patellar groove, but in all other respects was similar. The grafted tissue did not remodel and differentiate into the morphological zones seen in normal articular cartilage. No tidemark or subchondral bony plate formed even 48 weeks after transplantation. Biomechanically, the repaired cartilage demonstrated indentation values similar to normal articular cartilage 12 weeks after transplantation and remained the same 48 weeks after transplantation. By contrast, the control (i.e., empty) defects healed with tissue that exhibited very poor metachromatic staining and exhibited very high indentation values. Incomplete bonding of the repair tissue to the normal cartilage was seen, and the surface was significantly irregular with major discontinuities. These observations provide the basis for considering the use of allograft articular chondrocytes to repair articular cartilage defects in the weight-bearing regions of the knee.
Fu Qiang Wen - One of the best experts on this subject based on the ideXlab platform.
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Phosphodiesterase 4 Inhibitor Cilomilast Inhibits Fibroblast-Mediated Collagen Gel Degradation Induced by Tumor Necrosis Factor- � and
2013Co-Authors: Neutrophil Elastase, Tadashi Kohyama, Xiangde Liu, Fu Qiang Wen, Tetsu Kobayashi, Qiuhong Fang, Yun Kui Zhu, Hang Jun Wang, Stephen I RennardAbstract:Tissue destruction, resulting in emphysema, can be a consequence of several pathologic processes. The current study evaluated the effects of the phosphodiesterase (PDE)4 inhibitor, cilomilast, and other PDE inhibitors on the ability of fibroblasts to degrade extracellular matrix. Using the three-dimensional Collagen Gel culture system, fibroblasts (HFL-1) were cultured with tumor necrosis factor (TNF)-�, known to induce matrix metalloproteinase (MMP) release, and/or neutrophil elastase (NE), which can induce MMP activation. On Day 4, Gels containing TNF- � and NE were significantly degraded (20.8 � 2.9% of original Collagen content). Cilomilast (10 �M) inhibited this degradation (84.4 � 8.4%). Amrinone, a PDE3 inhibitor, and zaprinast, a PDE5 inhibitor, had no effect. Gelatin zymography and immunoblotting revealed that fibroblasts cultured with TNF- � released increased amounts of latent MMP-1 and-9. Th
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ultrafine carbon black particles inhibit human lung fibroblast mediated Collagen Gel contraction
2003Co-Authors: Tadashi Kohyama, Xiangde Liu, Fu Qiang Wen, Tetsu Kobayashi, Huijung Kim, Debra J RombergerAbstract:Both acute and chronic exposure to particulates have been associated with increased mortality and morbidity from a number of causes, including chronic obstructive pulmonary disease and other chronic lung diseases. The current study evaluated the hypothesis that ultrafine carbon particles, a component of ambient particulates, could affect tissue repair. To assess this, the three-dimensional Collagen Gel contraction model was used. Ultrafine carbon black particles, but not fine carbon black, inhibited fibroblast-mediated Collagen Gel contraction. Although previous research has indicated that inflammatory effects of ultrafine carbon black particles are mediated by oxidant mechanisms, the current study suggests that ultrafine carbon black's inhibition of fibroblast Gel contraction is mediated by the binding of both fibronectin and transforming growth factor (TGF)-β to the ultrafine particles. Binding of TGF-β was associated with a reduction in nuclear localization of Smads, indicative of inhibition of TGF-β s...
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phosphodiesterase 4 inhibitor cilomilast inhibits fibroblast mediated Collagen Gel degradation induced by tumor necrosis factor α and neutrophil elastase
2002Co-Authors: Tadashi Kohyama, Xiangde Liu, Fu Qiang Wen, Tetsu Kobayashi, Qiuhong Fang, Yun Kui Zhu, Hang Jun Wang, Stephen I RennardAbstract:Tissue destruction, resulting in emphysema, can be a consequence of several pathologic processes. The current study evaluated the effects of the phosphodiesterase (PDE)4 inhibitor, cilomilast, and other PDE inhibitors on the ability of fibroblasts to degrade extracellular matrix. Using the three-dimensional Collagen Gel culture system, fibroblasts (HFL-1) were cultured with tumor necrosis factor (TNF)-α, known to induce matrix metalloproteinase (MMP) release, and/or neutrophil elastase (NE), which can induce MMP activation. On Day 4, Gels containing TNF-α and NE were significantly degraded (20.8 ± 2.9% of original Collagen content). Cilomilast (10 μM) inhibited this degradation (84.4 ± 8.4%). Amrinone, a PDE3 inhibitor, and zaprinast, a PDE5 inhibitor, had no effect. Gelatin zymography and immunoblotting revealed that fibroblasts cultured with TNF-α released increased amounts of latent MMP-1 and -9. The addition of NE resulted in the conversion of MMP-1 and -9 to their active forms, indicative of Collagen...