Bovine fibroblasts and epithelial cells were isolated from surgically biopsied mammary tissue. Characterization of population doubling time, cytoskeletal intermediate filaments, cryopreservation survival, and viability were performed on all fibroblast and epithelial cells. Several clonal fibroblast cell lines were cotransfected with a plasmid bearing the SV-40 Large-T-antigen, and the pSV-2 neo plasmid. Transfected cells were subsequently selected with G418 sulfate and cloned. / MAC-T cells and non-clonal primary bovine mammary epithelial cells proliferated in response to IGF-I, insulin, serum and serum albumin. MAC-T cells did not proliferate when cultured in EGF, estrogen, progesterone, estrogen+progesterone, growth hormone, prolactin, and only modest proliferation was obtained after TGF-$ alpha$ treatment. Subsequent experiments used serum, insulin or IGF-I (and its analogues) to stimulate cellular proliferation. Serum albumin was not added to serum-free media preparations since it stimulated cellular proliferation. / TGF-$ beta$ receptors were characterized in MAC-T cells and normal fibroblasts. Affinity labelling studies revealed that MAC-T and MF-2 cells contained type I, II, and III autoregulatable receptors. Fibroblast proliferation, was inhibited 50% by TGF-$ beta$. TGF-$ beta$ inhibited MAC-T cellular proliferation at concentrations among the lowest ever reported, ED$ sb{ rm 50}$ = 4 pm. TGF-$ beta$ was not cytotoxic at concentrations 1000-fold higher. / Retinoic acid (RA) also inhibited proliferation of MAC-T cells. Inhibition of proliferation did not occur when cells were growth stimulated by IGF-I analogues that do not bind IGFBPs. Unlike TGF-$ beta$, RA treatment increased IGFBP-2 and decreased IGFBP-3 protein expression by cells into media and on the cell's membrane. RA was cytotoxic at concentrations 10-fold higher than ED$ sb{100}$. / Fibroblasts and epithelial cells expressed the gap junction (GJ) protein, connexin43, with transformed fibroblasts expressing significantly less connexin43. Perinuclear and cell surface connexin43 was immunodetected in epithelial and fibroblasts cells. TGF-$ beta$, RA or cAMP, increased connexin43 protein expression, especially phosphorylated species. Only cAMP noticeably altered immunolocalization patterns of connexin43, causing a shift from perinuclear pools to the cell surface. None of the growth inhibitors affected GJ communication as measured by dye transfer. Therefore, mammary epithelial cells are growth inhibited by TGF-$ beta$ and RA by distinct mechanisms and both growth inhibitors significantly enhance the gap junction protein, connexin43, without increasing GJ communication.

TGFbeta signaling peptides have been shown to play increasingly diverse roles in metazoan development and tissue homeostasis. Negative regulation of TGFbeta ligands such as Nodal can be achieved by physical interactions with inhibitory molecules. Dante is a recently identified putative member of DAN/Cerberus family of TGFbeta inhibitors. Previously shown to be unilaterally expressed on the right side of the mouse node, Dante has been suggested to play a role in Left-Right axis formation possibly by inhibition of Nodal molecules. The aim of this study was to further characterize Dante and to determine whether it can physically interact with Nodal. First, a longer Dante cDNA was isolated in an attempt to clone the full-length transcript. Furthermore, Dante expression pattern was analyzed during murine development and adult tissues. Lastly, co-immunoprecipitation experiments demonstrated that Dante is able to physically interact with Nodal, providing further support for its potential role as a Nodal inhibitor.

Recent observations have demonstrated that Insulin-like Growth Factors (IGFs) are able to form complexes with the extracellular matrix protein Vitronectin (VN). These complexes of VN:IGFBP:IGF-I significantly enhance the proliferation and migration of various cell lines including skin and corneal epithelial cells, as well as primary cells derived from human skin and corneal tissue. These enhanced effects arise from co- activation of the IGF-binding type-1 IGF receptor (IGF-1R) as well as activation of the VN-binding αv-integrins. Further studies suggest that these complexes can replace the requirement for serum in the ex vivo expansion of cells. In order to translate the VN:IGFBP:IGF-I technology into techniques for the improved culture of cells, we have designed, expressed and purified synthetic chimeric molecules, consisting of various domains of VN and mature IGF-I, using a baculovirus based expression system. The recombinant VN:IGF-I (rVN:IGF-I) chimeras were secreted into conditioned media of transfected Sf9 insect cells. Purification of the chimeras was achieved via methods including heparin-sepharose chromatography, Q-sepharose ion-exchange chromatography and Ni2+-NTA affinity chromatography. The rVN:IGF-I chimeras were detectable by Western blot analysis using a poly-clonal anti-VN antibody. Functional characterisation studies indicate that the chimeras promote cellular growth and migration to a similar extent as the VN:IGFBP:IGF-I complexes at 10x and 30x molar ratios. Additionally, function blocking antibodies directed to the IGF-1R and the VN binding αv-integrin were able to abolish this effect indicating that co-activation of these receptors is critical to the migratory effect of the chimeras. A functional chimera may lead to the development of cell culture techniques and methodologies that are devoid of xenogeneic or allogeneic support systems, thus paving the way to approved tissue engineering therapeutics that incorporate ex vivo expanded adult stem and progenitor cells.

Cartilage development relies on the coordinated presentation of biological signals to direct chondrocyte morphology and function. This is largely controlled by perlecan, a heparan sulfate proteoglycan (HSPG). Understanding the role of perlecan and its pendant glycosaminoglycan chains (GAG) in cartilage development is essential for advances in tissue engineered cartilage replacement strategies. Perlecan was immunolocalised to the pericellular matrix of prehypertrophic and hypertrophic chondrocytes in human fetal feet. Human fetal chondrocytes were isolated and cultured in 3-dimensional (3D) scaffolds for a period of 4 weeks. Their chondrogenic phenotype, based on extracellular matrix (ECM) components, was assessed and compared to 2D cultures. Chondrocyte perlecan was immunopurified from human fetal chondrocytes grown in vitro and fetal cartilage tissue and characterised using a combination of antibody-based techniques (ELISA, Western blotting) and gel electrophoresis. The biological function of chondrocyte perlecan was determined by its ability to form ternary complexes with fibroblast growth factors (FGF) and their receptors (FGFR) using an antibody-based technique as well as a cell proliferation assay using cells expressing FGFR isotypes. Perelcan was restricted to the prehypertrophic and hypertrophic zones of cartilage. This zonal organisation of chondrocytes and chondrogenic properties, determined by their morphology and PG deposition, was recapitulated in the 3D constructs while 2D cultures displayed dedifferentiated chondrocytes. Exogenous FGF2 promoted chondrocyte proliferation, while FGF18 stimulated the synthesis of perlecan, reflecting chondrocyte hypertrophy. Chondrocyte perlecan (630kDa) contained HS, chondroitin sulfate (CS) and keratan sulfate (KS) chains. Chondrocyte perlecan formed HS dependent ternary complexes with FGF2-FGFR1c and FGF18-FGFR3c, while FGF18-FGFR3c binding to perlecan protein core was also observed. Binding of FGF18-FGFR3c to chondrocyte perlecan HS was more promiscuous than FGF2-FGFR1c. Furthermore, chondrocyte perlecan HS mediated biological activity with FGF18 via FGFR3c, which was modulated by mammalian heparanase, while no biological activity was elicited by FGF2-FGFR1c. The findings underline how perlecan and its GAGs interact with FGF and FGFR in a spatio-temporal manner to promote signalling, effecting chondrocyte behaviour and morphology in cartilage development. This insight can be utilised in tissue engineering to improve the development of biologically functional cartilage replacements.

Bibliography: leaves 112-140. / xi, 141, [39] leaves, [8] leaves of plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The aims of this thesis are to determine the initial cleavage sites of purified pepsin in long-R3-IGF-I and assess whether the resulting cleavages affect biological activity, to design and produce analogues of long-R3-IGF-I which contain amino acid substitutions, to characterise the resulting analogues for pepsin resistance and retention of biological activity and to assess the stability of the long-R3-IGF-I analogues under in vivo conditions using luminal stomach flushings. / Thesis (Ph.D.)--University of Adelaide, Dept. of Biochemistry, 1996

Includes errata on last 3 leaves. / Includes bibliographical references (leaves 232-246). / xix, 246 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Describes attempts to develop an immunoaffinity process for commercial-scale purification of TGF-[beta]2 from Whey Growth Factor Extract / Thesis (Ph.D.)--Adelaide University, Dept. of Chemical Engineering, 2001

Bibliography: leaves 175-206. / 206 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Evaluates the potential therapeutic application of peptide growth factors, in particular epidermal growth factor, in the treatment of colonic ulcerative conditions. / Thesis (Ph.D.)--University of Adelaide, Dept. of Obstetrics and Gynaecology, 1993?

Includes errata on last 3 leaves. / Includes bibliographical references (leaves 232-246). / xix, 246 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Describes attempts to develop an immunoaffinity process for commercial-scale purification of TGF-[beta]2 from Whey Growth Factor Extract / Thesis (Ph.D.)--Adelaide University, Dept. of Chemical Engineering, 2001

Cartilage development relies on the coordinated presentation of biological signals to direct chondrocyte morphology and function. This is largely controlled by perlecan, a heparan sulfate proteoglycan (HSPG). Understanding the role of perlecan and its pendant glycosaminoglycan chains (GAG) in cartilage development is essential for advances in tissue engineered cartilage replacement strategies. Perlecan was immunolocalised to the pericellular matrix of prehypertrophic and hypertrophic chondrocytes in human fetal feet. Human fetal chondrocytes were isolated and cultured in 3-dimensional (3D) scaffolds for a period of 4 weeks. Their chondrogenic phenotype, based on extracellular matrix (ECM) components, was assessed and compared to 2D cultures. Chondrocyte perlecan was immunopurified from human fetal chondrocytes grown in vitro and fetal cartilage tissue and characterised using a combination of antibody-based techniques (ELISA, Western blotting) and gel electrophoresis. The biological function of chondrocyte perlecan was determined by its ability to form ternary complexes with fibroblast growth factors (FGF) and their receptors (FGFR) using an antibody-based technique as well as a cell proliferation assay using cells expressing FGFR isotypes. Perelcan was restricted to the prehypertrophic and hypertrophic zones of cartilage. This zonal organisation of chondrocytes and chondrogenic properties, determined by their morphology and PG deposition, was recapitulated in the 3D constructs while 2D cultures displayed dedifferentiated chondrocytes. Exogenous FGF2 promoted chondrocyte proliferation, while FGF18 stimulated the synthesis of perlecan, reflecting chondrocyte hypertrophy. Chondrocyte perlecan (630kDa) contained HS, chondroitin sulfate (CS) and keratan sulfate (KS) chains. Chondrocyte perlecan formed HS dependent ternary complexes with FGF2-FGFR1c and FGF18-FGFR3c, while FGF18-FGFR3c binding to perlecan protein core was also observed. Binding of FGF18-FGFR3c to chondrocyte perlecan HS was more promiscuous than FGF2-FGFR1c. Furthermore, chondrocyte perlecan HS mediated biological activity with FGF18 via FGFR3c, which was modulated by mammalian heparanase, while no biological activity was elicited by FGF2-FGFR1c. The findings underline how perlecan and its GAGs interact with FGF and FGFR in a spatio-temporal manner to promote signalling, effecting chondrocyte behaviour and morphology in cartilage development. This insight can be utilised in tissue engineering to improve the development of biologically functional cartilage replacements.

Thesis (M.Sc.)--York University, 2006. Graduate Programme in Biology. / Typescript. Includes bibliographical references (leaves 124-138). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR19747