• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • 2
  • 1
  • Tagged with
  • 7
  • 7
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Bone Morphogenetic Protein-2 Plays an Antagonistic Role in Hepatic Fibrogenesis

Wu, Yi-Chen 24 August 2010 (has links)
Hepatic injuries due to viral infection and alcoholic abuse frequently lead to activation and proliferation of hepatic stellate cells (HSCs), concomitantly with tissue repairing and remodeling mechanism. Transforming growth factor-£]1 (TGF-£]1) is known to be one of the potent cytokines that directly upregulates synthesis of extracellular matrix, thereby aggravating liver fibrosis. Bone morphogenetic protein-2 (BMP-2), as a member of TGF-Hepatic injuries due to viral infection and alcoholic abuse frequently lead to activation and proliferation of hepatic stellate cells (HSCs), concomitantly with tissue repairing and remodeling mechanism. Transforming growth factor-£]1 (TGF-£]1) is known to be one of the potent cytokines that directly upregulates synthesis of extracellular matrix, thereby aggravating liver fibrosis. Bone morphogenetic protein-2 (BMP-2), as a member of TGF-£]1 superfamily, has been known to regulate cell proliferation, differentiation, and bone morphogenesis. Our previous study demonstrated that BMP-2 was downregulated in fibrotic liver of mice, supporting its antagonistic role in hepatic fibrogenesis. Downregulation of BMP-2 in fibrotic livers may lose its ability to antagonize the pro-fibrogenic action of TGF-£]1. The purpose of this study was to determine whether mutual regulatory mechanisms exist between BMP-2 and TGF-£]1. Treatment of recombinant protein, TGF-£]1, significantly suppressed BMP-2 expression in hepatocytes clone-9 and HSC-T6 cells. Moreover, treatment of BMP-2 in both cell also attenuated TGF-£]1protein levels in a dose-dependent manner. This finding supports that TGF-£]1 and BMP-2 mutually modulated their expression not only in vivo, but also in vitro. Western blotting analysis showed that TGF-£]1 and BMP-2 exerted different kinase phosphorylation profiles of signaling activities. However, the signal pathways and detail mechanisms of the interactions of BMP-2 and TGF-£]1 in the fibrogenic action will need to further evaluate.
2

Anti-fibrotic Effect of Chinese Medicine, Ezhu , on CCl4-induced Liver Fibrosis Mouse Model and Its Probable Molecular Mechanisms

Lu, Cheng-Nan 06 September 2005 (has links)
The incidence rate of chronic hepatopathy in Taiwan is high, which afflicts the patients by progressively developing irreversible cirrhosis. Hepatic fibrosis is the intermediate and crucial stage of this process, characterized by reversibility. If treated properly in this stage, cirrhosis can be successfully prevented. In the liver, activated stellate cells are the key mediators of fibrosis. Transforming growth factor-
3

TGF-β/Smad Signaling in Growth Control of Prostate Epithelial Cells

Yang, Jiayi January 2009 (has links)
No description available.
4

Estudo imuno-histoqu?mico da presen?a de miofibroblastos e da express?o do fator transformador de crescimento-beta1, interferon gama, metaloproteinase de matriz 13 e indutor de metaloproteinases de matriz em les?es odontog?nicas epiteliais

Santos, Pedro Paulo de Andrade 28 February 2012 (has links)
Made available in DSpace on 2015-03-03T15:38:43Z (GMT). No. of bitstreams: 1 PedroPAS_TESE_1-70.pdf: 4719637 bytes, checksum: 8f16cb0e2326a80cfc947b1ea2b89641 (MD5) Previous issue date: 2012-02-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Myofibroblasts are cells that exhibit a hybrid phenotype, sharing the morphological characteristics of fibroblasts and smooth muscle cells, which is acquired during a process called differentiation. These cells then start to express -SMA, a marker that can be used for their identification. Studies suggest that myofibroblasts are related to the aggressiveness of different tumors and that TGF-1 and IFN- play a role in myofibroblast differentiation, stimulating or inhibiting this differentiation, respectively. The objective of this study was to investigate the role of myofibroblasts in epithelial odontogenic tumors, correlating the presence of these cells with the aggressiveness of the tumor. Immunohistochemistry was used to evaluate the expression of TGF-1 and IFN- in myofibroblast differentiation, as well as the expression of MMP-13, which is activated by myofibroblasts, and of EMMPRIN (extracellular matrix metalloproteinase inducer) as a precursor of this MMP. The sample consisted of 20 solid ameloblastomas, 10 unicystic ameloblastomas, 20 odontogenic keratocysts, and 20 adenomatoid odontogenic tumors. For evaluation of myofibroblasts, anti- -SMA-immunoreactive cells were quantified in connective tissue close to the epithelium. Immunoexpression of TGF-1, IFN-, MMP-13 and EMMPRIN was evaluated in the epithelial and connective tissue components, attributing scores of 0 to 4. The results showed a higher concentration of myofibroblasts in solid ameloblastomas (mean of 30.55), followed by odontogenic keratocysts (22.50), unicystic ameloblastomas (20.80), and adenomatoid odontogenic tumors (19.15) (p=0.001). No significant correlation between TGF-1 and IFN- was observed during the process of myofibroblast differentiation. There was also no correlation between the quantity of myofibroblasts and MMP-13 expression. Significant correlations were found between MMP-13 and TGF-1 (r=0.087; p=0.011), between MMP- 13 and IFN- (r=0.348; p=0.003), as well as between EMMPRIN and MMP-13 (r=0.474; p<0.001) and between EMMPRIN and IFN- (r=0.393; p=0.001). The higher quantity of myofibroblasts observed in solid ameloblastomas, odontogenic keratocysts and unicystic ameloblastomas suggests that these cells are one of the factors responsible for the more aggressive biological behavior of these tumors, although the myofibroblast population was not correlated with TGF-1, IFN-, MMP-13 or EMMPRIN. The correlation between MMP- 13 and TGF-1 suggests that the latter induces the expression of this metalloproteinase. The present results also support the well-established role of EMMPRIN as an inducer of MMP-13. Furthermore, the relationship between EMMPRIN and IFN- and between MMP-13 and IFN- suggests synergism in the antifibrotic effect of these markers / Os miofibroblastos s?o c?lulas que apresentam um fen?tipo h?brido exibindo caracter?sticas morfol?gicas de fibroblastos e de c?lulas musculares lisas, sendo a aquisi??o de tal fen?tipo denominada diferencia??o, passando ent?o a expressar a -SMA, a qual ? importante na identifica??o dessas c?lulas. Estudos t?m sugerido que os miofibroblastos apresentam rela??o com a agressividade de diversas les?es e que o seu processo de diferencia??o estaria relacionado ? express?o do TGF- 1 e do IFN- atuando, respectivamente, no est?mulo e na inibi??o dessa diferencia??o. O objetivo deste trabalho foi investigar o papel dos miofibroblastos em les?es odontog?nicas epiteliais, relacionando-os ? agressividade das les?es e analisar por meio da imuno-histoqu?mica, a express?o do TGF- 1 e IFN- no processo de diferencia??o, al?m da an?lise da MMP-13 que ? ativada por miofibroblastos e do indutor de metaloproteinases de matriz (EMMPRIN) como precursor desta MMP. A amostra foi constitu?da por 20 ameloblastomas s?lidos, 10 ameloblastomas unic?sticos, 20 ceratocistos odontog?nicos e 20 tumores odontog?nicos adenomat?ides. Para a avalia??o dos miofibroblastos, foram quantificadas as c?lulas imunorreativas ao anticorpo - SMA presentes no tecido conjuntivo, pr?ximo ao tecido epitelial. As express?es de TGF- 1, IFN- , MMP-13 e EMMPRIN, foram avaliadas no componente epitelial e no conjuntivo, estabelecendo-se o percentual de imunorreatividade e atribuindo-se escores de 0 a 4. A an?lise dos miofibroblastos evidenciou maior concentra??o nos ameloblastomas s?lidos (m?dia de 30,55), seguido pelos ceratocistos odontog?nicos (22,50), ameloblastomas unic?sticos (20,80) e tumores odontog?nicos adenomat?ides (19,15) com valor de p= 0,001. N?o foi encontrada correla??o significativa entre TGF- 1 e IFN- no processo de diferencia??o dos miofibroblastos, bem como na rela??o entre a quantidade de miofibroblastos e a express?o da MMP-13. Constatou-se, correla??o estat?stica entre MMP-13 e TGF- 1 (r= 0,087; p= 0,011) al?m de significante correla??o entre MMP-13 e IFN- (r=0,348; p=0,003). Entre EMMPRIN e MMP-13 verificou-se signific?ncia (r= 0,474; p<0,001) assim como entre EMMPRIN e IFN- (r=0,393; p=0,001). A maior quantidade de miofibroblastos evidenciada nos ameloblastomas s?lidos, ceratocistos odontog?nicos e ameloblastomas unic?sticos sugere que estas c?lulas podem ser um dos fatores respons?veis para um comportamento biol?gico mais agressivo destas les?es, embora a popula??o de miofibroblastos n?o tenha apresentado correla??o com TGF- - 1, IFN- ,MMP-13 e EMMPRIN. Quanto a correla??o evidenciada entre MMP-13 e TGF- 1, isto pode sugerir um papel indutor do TGF- 1 para a express?o da MMP-13, assim como os resultados deste estudo refor?am a rela??o bem estabelecida do EMMPRIN como indutor da MMP-13. Constatou-se tamb?m rela??o entre EMMPRIN e IFN- assim como entre MMP-13 e IFN- sugerindo, dessa forma, um sinergismo na a??o anti-fibr?tica desses marcadores
5

Cell engineering of human bone monolayers and the effect of growth factors and microcontact printed ECM proteins on wound healing. The role of ECM proteins, TGF¿-1, 2 and 3 and HCl/BSA in cellular adhesion, wound healing and imaging of the cell surface interface with the widefield surface plasmon microscope.

Sefat, Farshid January 2013 (has links)
Bone repair is modulated by different stimuli. There is evidence that the Transforming Growth Factor-beta (TGF-¿) super-family of cytokines have significant effects on bone structure by regulating the replication and differentiation of chondrocytes, osteoblasts and osteoclasts. There is also significant evidence that interactions with extracellular matrix molecules also influence cell behaviour. This study aimed at determining the role of the TGF-¿s, Collagen type I, Fibronectin and Laminin in bone cell behaviour. To do this MG63 bone cells were used to examine cell adhesion and alignment to different micro-contact printed ECM protein patterns of different widths. The study also aimed at examining how TGF-¿1, 2 and 3 and their solvent and carrier (HCl and BSA, respectively) effected cell surface interactions, cell morphology, cell proliferation and integrin expression. Finally, this study also aimed at examining how the TGF-¿s and their solvent and carrier influenced wound closure in an in vitro wound closure model and how TGF-¿s influence ECM secretion and integrin expression. 5, 10, 25, 50 and 100¿m wide repeat gratings of Collagen type I, Fibronectin and Laminin patterns were stamp patterned onto glass slides and plated with MG63 cells at 50,000 cells per coverslip. Cells on the fibronectin pattern attached and elongated soon after seeding, but did not adhere readily to collagen and laminin and appeared more rounded until 18hrs after seeding. Cells aligned significantly well on the 50¿m and 100¿m wide fibronectin patterned coverslips with mean angles of alignment ~7.87¿ ¿ 3.06SD and 6.45¿ ¿ 5.08SD, respectively, compared to those with smaller width (p<0.001). In comparison, cells aligned less readily to the other two ECM proteins, showing optimal alignments of 9.66¿ ¿ 4.18SD and 14.36¿ ¿ 1.57SD to the 50¿m wide collagen and laminin patterns, respectively. Differences in cell length mirrored those of alignment, with cells acquiring the greatest length when showing the greatest degree of alignment. The results indicate that MG63 cells responded significantly better to 50 and 100¿m wide fibronectin patterns compared to those with smaller width (p<0.001) indicating that the cells may attach mostly via fibronectin specific integrins. Cell surface attachment was examined via a trypsinisation assay in which the time taken to trypsinise cells from the surface provided a means of assessing the strength of attachment. The results indicated that treatment with the solvent (HCl), TGF-¿1, 2 and 3 all decreased cell attachment, but this effect was significantly greater in the case of HCl and TGF-¿3 (p<0.001). However, there were significant differences in trypsinisation rates between HCl and TGF-¿3 (p<0.001). The wound healing response to the TGF-¿s and their solvent/carrier was also investigated in 300¿m ± 10-30¿m SD wide model wounds induced in fully confluent monolayers of MG63 bone cells. The results indicated that TGF-¿3 and HCl significantly enhance wound closure when compared against negative controls, TGF-¿1 and TGF-¿2 treatment (p<0.001). It was also found that TGF-¿1 and TGF-¿2 treatment significantly improved wound closure rate in comparison to the controls (p<0.001). Experiments were performed to determine if the HCl effects on wound closure were dose dependent. Cells were incubated with 20¿M, 40¿M, 80¿M and 160¿M concentrations of HCl prior to wounding and wound closure rates were recorded. Wound closure was dependent on HCl dose with the 80¿M and 160¿M concentrations inducing increases in wound closure rates that were both significantly greater than those induced by 20¿M, 40¿M and control treatments (p<0.001). However, there were significant differences in wound closure between the 80¿M and 160¿M treatment groups after 30hrs of treatment (p<0.001). The effect of different TGF-¿ isomers and their combinations on proliferation rate and cell length of human bone cells were also assessed. The results suggest that cell morphology changes were observed significantly more in cells treated with TGF-¿(2+3) and TGF-¿(1+3) (p<0.001). Any cell treated with TGF-¿1, TGF-¿(1+2) and TGF-¿(1+2+3) showed significantly less elongation compared to the control and other TGF-¿ isomers. In terms of proliferation rate, TGF-¿3 and TGF-¿(2+3) increased cell numbers more than TGF-¿1, TGF-¿2 and other combinations. TGF-¿1 and its combinations did not show significant proliferation and attachment compared to the control due to perhaps its inhibitory effect in contact with human bone cells. Immunostaining indicated that treatment with TGF-¿3 significantly promoted the secretion of collagen type I and anti-human fibronectin in addition to integrin (¿3 and ¿1) expression. Statistically TGF-¿3 and their combinations showed significant differences in number of cells stained for collagen type I, anti-human fibronectin, ¿3 and ¿1integrin. Any cell treated with TGF-¿1 or any combination with TGF-¿1 showed significantly lower cell number stained with the same proteins and integrins (p<0.001). Imaging with WSPR allowed observation of the focal contacts without the need for immunostaining. WSPR images revealed guided cells with high contrast band like structures at the border of cells distal to the edge of guidance cue to which they aligned and with less concentrically formed band like features across the cell body. It is believed that the high contrast features are associated with the formation of focal contacts on the edge of the cells distal to the edge of fibronectin patterns, which suggests that cell guidance is aided by a decrease in cell attachment along a guidance feature. The WSPR experiments also indicated that TGF-¿s influenced the distribution of focal contacts. In the case of TGF-¿1 treated cells the bright high contrast regions were intense but only arranged around the periphery of the cell. In TGF-¿2 and TGF-¿3 cells the bright contrast regions were weaker but again mostly localised around the periphery. These findings supported the earlier trypsinisation results.
6

Cell and tissue engineering of articular cartilage via regulation and alignment of primary chondrocyte using manipulated transforming growth factors and ECM proteins : effect of transforming growth factor-beta (TGF-β1, 2 and 3) on the biological regulation and wound repair of chondrocyte monolayers with and without presence of ECM proteins

Khaghani, Seyed Ali January 2010 (has links)
Articular cartilage is an avascular and flexible connective tissue found in joints. It produces a cushioning effect at the joints and provides low friction to protect the ends of the bones from wear and tear/damage. It has poor repair capacity and any injury can result pain and loss of mobility. One of the common forms of articular cartilage disease which has a huge impact on patient's life is arthritis. Research on cartilage cell/tissue engineering will help patients to improve their physical activity by replacing or treating the diseased/damaged cartilage tissue. Cartilage cell, called chondrocyte is embedded in the matrix (Lacunae) and has round shape in vivo. The in vitro monolayer culture of primary chondrocyte causes morphological change characterized as dedifferentiation. Transforming growth factor-beta (TGF-β), a cytokine superfamily, regulates cell function, including differentiation and proliferation. The effect of TGF-β1, 2, 3, and their manipulated forms in biological regulation of primary chondrocyte was investigated in this work. A novel method was developed to isolate and purify the primary chondrocytes from knee joint of neonate Sprague-Dawley rat, and the effect of some supplementations such as hyaluronic acid and antibiotics were also investigated to provide the most appropriate condition for in vitro culture of chondrocyte cells. Addition of 0.1mg/ml hyaluronic acid in chondrocyte culture media resulted an increase in primary chondrocyte proliferation and helped the cells to maintain chondrocytic morphology. TGF-β1, 2 and 3 caused chondrocytes to obtain fibroblastic phenotype, alongside an increase in apoptosis. The healing process of the wound closure assay of chondrocyte monolayers were slowed down by all three isoforms of TGF-β. All three types of TGF-β negatively affected the strength of chondrocyte adhesion. TGF-β1, 2 and 3 up regulated the expression of collagen type-II, but decreased synthesis of collagen type-I, Chondroitin sulfate glycoprotein, and laminin. They did not show any significant change in production of S-100 protein and fibronectin. TGF-β2, and 3 did not change expression of integrin-β1 (CD29), but TGF-β1 decreased the secretion of this adhesion protein. Manipulated TGF-β showed huge impact on formation of fibroblast like morphology of chondrocytes with chondrocytic phenotype. These isoforms also decreased the expression of laminin, chondroitin sulfate glycoprotein, and collagen type-I, but they increased production of collagen type-II and did not induce synthesis of fibronectin and S-100 protein. In addition, the strength of cell adhesion on solid surface was reduced by manipulated TGF-β. Only manipulated form of TGF-β1 and 2 could increase the proliferation rate. Manipulation of TGF-β did not up regulate the expression of integrin-β1 in planar culture system. The implications of this R&D work are that the manipulation of TGF-β by combination of TGF-β1, 2, and 3 can be utilized in production of superficial zone of cartilage and perichondrium. The collagen, fibronectin and hyaluronic acid could be recruited for the fabrication of a biodegradable scaffold that promotes chondrocyte growth for autologous chondrocyte implantation or for formation of cartilage.
7

Cell and tissue engineering of articular cartilage via regulation and alignment of primary chondrocyte using manipulated transforming growth factors and ECM proteins. Effect of transforming growth factor-beta (TGF-¿1, 2 and 3) on the biological regulation and wound repair of chondrocyte monolayers with and without presence of ECM proteins.

Khaghani, Seyed A. January 2010 (has links)
Articular cartilage is an avascular and flexible connective tissue found in joints. It produces a cushioning effect at the joints and provides low friction to protect the ends of the bones from wear and tear/damage. It has poor repair capacity and any injury can result pain and loss of mobility. One of the common forms of articular cartilage disease which has a huge impact on patient¿s life is arthritis. Research on cartilage cell/tissue engineering will help patients to improve their physical activity by replacing or treating the diseased/damaged cartilage tissue. Cartilage cell, called chondrocyte is embedded in the matrix (Lacunae) and has round shape in vivo. The in vitro monolayer culture of primary chondrocyte causes morphological change characterized as dedifferentiation. Transforming growth factor-beta (TGF-¿), a cytokine superfamily, regulates cell function, including differentiation and proliferation. The effect of TGF-¿1, 2, 3, and their manipulated forms in biological regulation of primary chondrocyte was investigated in this work. A novel method was developed to isolate and purify the primary chondrocytes from knee joint of neonate Sprague-Dawley rat, and the effect of some supplementations such as hyaluronic acid and antibiotics were also investigated to provide the most appropriate condition for in vitro culture of chondrocyte cells. Addition of 0.1mg/ml hyaluronic acid in chondrocyte culture media resulted an increase in primary chondrocyte proliferation and helped the cells to maintain chondrocytic morphology. TGF-¿1, 2 and 3 caused chondrocytes to obtain fibroblastic phenotype, alongside an increase in apoptosis. The healing process of the wound closure assay of chondrocyte monolayers were slowed down by all three isoforms of TGF-¿. All three types of TGF-¿ negatively affected the strength of chondrocyte adhesion. TGF-¿1, 2 and 3 up regulated the expression of collagen type-II, but decreased synthesis of collagen type-I, Chondroitin sulfate glycoprotein, and laminin. They did not show any significant change in production of S-100 protein and fibronectin. TGF-¿2, and 3 did not change expression of integrin-¿1 (CD29), but TGF-¿1 decreased the secretion of this adhesion protein. Manipulated TGF-¿ showed huge impact on formation of fibroblast like morphology of chondrocytes with chondrocytic phenotype. These isoforms also decreased the expression of laminin, chondroitin sulfate glycoprotein, and collagen type-I, but they increased production of collagen type-II and did not induce synthesis of fibronectin and S-100 protein. In addition, the strength of cell adhesion on solid surface was reduced by manipulated TGF-¿. Only manipulated form of TGF-¿1 and 2 could increase the proliferation rate. Manipulation of TGF-¿ did not up regulate the expression of integrin-¿1in planar culture system. The implications of this R&D work are that the manipulation of TGF-¿ by combination of TGF-¿1, 2, and 3 can be utilized in production of superficial zone of cartilage and perichondrium. The collagen, fibronectin and hyaluronic acid could be recruited for the fabrication of a biodegradable scaffold that promotes chondrocyte growth for autologous chondrocyte implantation or for formation of cartilage.

Page generated in 0.0161 seconds