Throughout gestation, the blood vessel network of the placenta is formed sequentially by processes known as vasculogenesis and angiogenesis, which together meet the needs of the growing fetus. Normal placental angiogenesis is critical to support adequate fetal growth and assure the health of the offspring. Proper angiogenesis requires precise regulation of expression of agents that modulate this process; otherwise, pathologies of pregnancy such as preeclampsia may occur. The placenta is composed of different layers of tissue, including the lamellar (LZ), junctional, and glandular zones, each with a vascular morphology attuned to its function. We hypothesized that higher expression of pro-angiogenic factors is associated with increased morphological metrics in the LZ, the major vascularized zone. Thus, we aimed to characterize the major changes in morphology and vascular development in the placenta throughout pregnancy in cats, alongside a compressive analysis of the expression of major angiogenic factors and their receptors in the placenta, with an emphasis on the identification and interaction of different isoforms of the VEGF family. Microscopic analysis of tissue specimens from different stages of pregnancy revealed increased thickness of the LZ, especially during early to mid-gestation, at which time the tissue is composed of abundant materno-fetal interdigitations that appears rich in capillaries. VEGF proteins were detected in placental tissue in both fetal and maternal cells of the placenta, suggesting stimulatory interactions between different cell types to promote growth and angiogenesis. Gene expression analysis of placenta revealed upregulation of the pro-angiogenic factor VEGF-A in mid-pregnancy, followed by a steady decline toward term, consistent with morphologic changes in the LZ. In contrast, another pro-angiogenic factor, PlGF, showed a marked increase toward term; Flt-1, which acts as a receptor or reservoir for PLGF and VEGF A, was also upregulated at late pregnancy. Increased ratios of PLGF:VEGF-A may contribute to LZ proliferation in the last trimester. These findings are consistent with the creation of a proangiogenic placental state during gestation. Overall, we expect that this research will help elucidate mechanisms of placental vascularization, which can be applied to the design of improved strategies to treat vascular complications of pregnancy. Lastly, we applied the tools developed for placental studies to investigate pathologic angiogenesis in cutaneous squamous cell carcinoma (CSCC), a common skin cancer with major economic and medical impacts in humans and veterinary species. The creation of a new blood supply is essential for growth and metastasis of many tumor types. The goal of this study was to measure expression of variants of proteins that stimulate angiogenesis or transmit an angiogenic stimulus in feline CSCC. The results were mixed, with differences detected in expression of some regulatory agents and, for others, unexpectedly lower expression in CSSC compared to controls. Interestingly, the expression of VEGF-A relative to the protein that transmits its signal (KDR) was elevated in CSCC, suggestive of an altered signaling relationship. This finding supports our hypothesis and is consistent with human SCC studies. Our results encourage further studies on angiogenic factor variants in feline CSCC. / PHD

The primary aim of this text is to gain insight on how cellular activation by a insulin-like growth factor (IGF-I), in the presence of insulin-like growth factor binding protein-3 (IGFBP-3), is influenced by heparan sulfate proteoglycans (HSPG). Initial research will be presented, assumptions and hypotheses that were included in the development of mathematical models will be discussed, and the future enhancements of the models will be explored. There are many potential scenarios for how each component might influence the others. Mathematical modeling techniques will highlight the contributions made by numerous extracellular parameters on IGF-I cell surface binding. Tentative assumptions can be applied to modeling techniques and predictions may aid in the direction of future experiments. Experimentally, it was found that IGFBP-3 inhibited IGF-I Bovine Aortic Endothelial (BAE) cell surface binding while p9 HS slightly increased IGF-I BAE cell surface binding. IGFBP-3 has a higher binding affinity for IGF-I (3 x 10-9 M) than p9 HS has for IGF-I (1.5 x 10-8 M) as determined with cell-free binding assays. The presence of p9 HS countered the inhibiting effect of IGFBP-3 on IGF-I BAE cell surface binding. Although preliminary experiments with labeled p9 HS and IGFBP-3 indicated little to no cell surface binding, later experiments indicated that both IGFBP-3 and p9 HS do bind to the BAE cell surface. Pre-incubation of BAE cells with either IGFBP-3 or p9 HS resulted in an increase of IGF-I BAE cell surface binding . There was a more substantial increase of IGF-I surface binding when cells were pre-incubated with IGFBP- 3 than p9 HS. There was a larger increase of IGF-I BAE cell surface binding when cells were pre-incubated with p9 HS than when p9 HS and IGF-I were added simultaneously. This suggests that IGFBP-3 and p9 HS surface binding plays key role in IGF-I surface binding, however, p9 HS surface binding does not alter IGF-I surface binding as much as IGFBP-3 surface binding seems to. Experimental work helps further the understanding of IGF-I cellular activation as regulated by IGFBP-3 and p9 HS. Developing mathematical models allows the researcher to focus on individual elements in a complex systems and gain insight on how the real system will respond to individual changes. Discrepancies between the model results and the experimental data presented indicate that soluble receptor inhibition is not sufficient to account for experimental results. The alliance of engineering analysis and molecular biology helps to clarify significant principles relevant to the conveyance of growth factors into tissue. Awareness of the effects of individual parameters in the delivery system, made possible with mathematical models, will provide guidance and save time in the design of future therapeutics involving growth factors. / Master of Science

Cheung Chun Kai. / Thesis submitted in: December 2003. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 133-146). / Abstracts in English and Chinese. / Acknowledgements --- p.ii / Abstract --- p.iv / 摘要 --- p.vii / Table of Contents --- p.ix / List of Tables --- p.xv / List of Figures --- p.xvi / List of Abbreviations --- p.xxi / Chapter Chapter 1 --- Overview --- p.1 / Chapter Chapter 2 --- Literature Review --- p.3 / Chapter 2.1 --- Historical background --- p.3 / Chapter 2.2 --- Insulin-like growth factor --- p.5 / Chapter 2.2.1 --- Structure and synthesis --- p.5 / Chapter 2.2.2 --- Physiologic role and biological actions --- p.6 / Chapter 2.3 --- Insulin-like growth factor binding protein-3 --- p.8 / Chapter 2.3.1 --- Structure and synthesis --- p.8 / Chapter 2.3.2 --- Physiologic role and biological actions --- p.8 / Chapter 2.4 --- Clinical aspects --- p.10 / Chapter 2.4.1 --- Metabolic effects of IGF-1 --- p.10 / Chapter 2.4.1.1 --- Similarities between IGF-I and insulin --- p.11 / Chapter 2.4.1.2 --- Differences between IGF-I and insulin --- p.13 / Chapter 2.4.2 --- Glucose and protein metabolism --- p.14 / Chapter 2.4.3 --- Therapeutic use of IGF-I --- p.15 / Chapter 2.4.3.1 --- Type 1 diabetes mellitus --- p.16 / Chapter 2.4.3.2 --- Type 2 diabetes mellitus --- p.17 / Chapter 2.4.4 --- Side effects --- p.19 / Chapter 2.5 --- World demands --- p.21 / Chapter 2.5.1 --- Significance of large-scale production --- p.21 / Chapter 2.5.2 --- IGF-I production --- p.21 / Chapter 2.6 --- Plants as bioreactors --- p.24 / Chapter 2.6.1 --- Medical molecular farming --- p.24 / Chapter 2.6.2 --- Advantages of plant bioreactor --- p.24 / Chapter 2.6.3 --- Commercial biopharmaceutical protein --- p.25 / Chapter 2.7 --- Tobacco expression system --- p.26 / Chapter 2.7.1 --- Tobacco model plant --- p.26 / Chapter 2.7.2 --- Transformation methods --- p.26 / Chapter 2.8 --- Hypotheses and aims of study --- p.28 / Chapter Chapter 3 --- Expression of Human IGF-I and IGFBP-3 in Transgenic Tobacco --- p.30 / Chapter 3.1 --- Introduction --- p.30 / Chapter 3.2 --- Materials and methods --- p.31 / Chapter 3.2.1 --- Chemicals --- p.31 / Chapter 3.2.2 --- Plant materials --- p.31 / Chapter 3.2.3 --- Bacterial strains --- p.32 / Chapter 3.2.4 --- Codon modification of IGF-I and IGFBP-3 cDNAs --- p.32 / Chapter 3.2.5 --- Transient assay to study IGF-I or IGFBP-3 translatability --- p.39 / Chapter 3.2.5.1 --- Construction of chimeric genes for particle bombardment --- p.39 / Chapter 3.2.5.2 --- Particle bombardment of GUS fusion constructs --- p.42 / Chapter 3.2.6 --- Construction of chimeric genes for tobacco transformation --- p.44 / Chapter 3.2.6.1 --- Construction of chimeric genes with different promoters --- p.44 / Chapter 3.2.6.1.1 --- Construction of chimeric gene with CaMV 35S promoter --- p.44 / Chapter 3.2.6.1.2 --- Construction of chimeric genes with phaseolin promoter --- p.46 / Chapter 3.2.6.2 --- Construction of fusion constructs --- p.48 / Chapter 3.2.6.2.1 --- Construction of GUS fusion constructs --- p.48 / Chapter 3.2.6.2.2 --- Construction of LRP fusion constructs --- p.51 / Chapter 3.2.6.3 --- Construction of phaseolin targeting constructs --- p.56 / Chapter 3.2.6.3.1 --- Construction of phaseolin targeting constructs without AFVY --- p.56 / Chapter 3.2.6.3.2 --- Construction of phaseolin targeting constructs with AFVY --- p.60 / Chapter 3.2.6.4 --- Cloning of chimeric genes into Agrobacterium binary vector pBI 121 --- p.64 / Chapter 3.2.7 --- Confirmation of sequencing fidelity of chimeric genes --- p.66 / Chapter 3.2.8 --- Transformation of Agrobacterium by electroporation --- p.66 / Chapter 3.2.9 --- Transformation of tobacco --- p.67 / Chapter 3.2.10 --- Selection and regeneration of transgenic tobacco --- p.67 / Chapter 3.2.11 --- GUS assay --- p.68 / Chapter 3.2.12 --- Extraction of leaf genomic DNA --- p.68 / Chapter 3.2.13 --- PCR of genomic DNA --- p.69 / Chapter 3.2.14 --- Synthesis of DIG-labeled double-stranded DNA probe --- p.69 / Chapter 3.2.15 --- Southern blot analysis --- p.70 / Chapter 3.2.16 --- Extraction of total RNA from leaves or developing seeds --- p.70 / Chapter 3.2.17 --- Northern blot analysis --- p.71 / Chapter 3.2.18 --- Extraction of total protein --- p.71 / Chapter 3.2.19 --- Tricine SDS-PAGE --- p.72 / Chapter 3.2.20 --- Western blot analysis --- p.72 / Chapter 3.2.21 --- Enterokinase digestion of fusion protein --- p.73 / Chapter Chapter 4 --- Results --- p.74 / Chapter 4.1 --- Particle bombardment for transient assay --- p.74 / Chapter 4.1.1 --- Construction of GUS fusion genes for particle bombardment --- p.74 / Chapter 4.1.2 --- Transient expression of GUS fusion genes in soybean cotyledons and tobacco leaves --- p.76 / Chapter 4.2 --- Construction of chimeric genes for tobacco transformation --- p.78 / Chapter 4.3 --- "Tobacco transformation, selection and regeneration" --- p.81 / Chapter 4.4 --- Detection of GUS activity --- p.83 / Chapter 4.5 --- Detection of transgene integration --- p.84 / Chapter 4.5.1 --- Extraction of genomic DNA and PCR --- p.84 / Chapter 4.5.2 --- Southern blot analysis --- p.88 / Chapter 4.6 --- Detection of transgene transcription --- p.92 / Chapter 4.6.1 --- Extraction of total RNA --- p.92 / Chapter 4.6.2 --- Northern blot analysis --- p.92 / Chapter 4.7 --- Detection of transgene translation --- p.99 / Chapter 4.7.1 --- Extraction of total protein and Tricine SDS-PAGE --- p.99 / Chapter 4.7.2 --- Western blot analysis --- p.102 / Chapter 4.7.3 --- Enterokinase digestion of fusion protein --- p.109 / Chapter Chapter 5 --- Discussion --- p.111 / Chapter 5.1 --- Codon modification of IGF-I and IGFBP-3 cDNAs --- p.114 / Chapter 5.2 --- Transient expression of IGF-I and IGFBP-3 cDNAs --- p.116 / Chapter 5.3 --- Fusion of IGF-I and IGFBP-3 cDNA with LRP gene --- p.118 / Chapter 5.4 --- Enterokinase digestion --- p.120 / Chapter 5.5 --- Phaseolin targeting signal --- p.122 / Chapter 5.6 --- Gene silencing --- p.124 / Chapter 5.7 --- Future perspectives --- p.128 / Chapter Chapter 6 --- Conclusion --- p.131 / References --- p.133

Insulin-like growth factor I (IGF-I) is a polypeptide protein hormone similar to insulin. It plays an important role in growth and anabolic effects in life. Most circulating IGF-I is bound to high-affinity insulin-like growth factor binding protein-3 (IGFBP-3), to form a complex (IGF-I/IGFBP-3) that can treat growth hormone insensitivity syndrome (GHIS) and can lower plasma glucose in diabetic patients. Its side effects can be reduced without affecting the therapeutic efficacy. Human insulin-like growth factor binding protein 3 (hIGFBP-3) alone is an anti-tumor agent. It has been shown to have anti-proliferation effect on numerous cancer cells, such as breast, prostate and liver cancers. / Our previous study has demonstrated that recombinant hIGF-I (rhIGF-I) and hIGFBP-3 (rhIGFBP-3) could be synthesized in transgenic tobacco plant. In the present study, we propose to establish an efficient bioreactor platform for mass production of hIGF-I and hIGFBP-3 in rice, as rice grain contains 8-15% of protein by dry weight. In order to enhance rhIGF-I and rhIGFBP-3 stability and yield, and to control their glycosylation, various constructs were designed and transformed into rice by Agrobacterium-mediated transformation. Protein targeting signal sequence (KDEL) was fused to direct the target proteins to specific compartments in rice grain for glycosylation in the Golgi apparatus or for stable accumulation without complex glycan processing in the endoplasmic reticulum. These expression constructs were driven by seed-specific glutelin promoter (Gt1pro). Western blot analysis showed that the rhIGF-I and rhIGFBP-3 were successfully expressed in transgenic rice grains. Biological activity of rhIGF-I was evidenced by the induction of membrane ruffling in L6 rat skeletal muscle cells, while rhIGFBP-3 was effective in inhibiting the effect of IGF-I on membrane ruffling of L6 cell. Moreover, rhIGFBP-3 was also found to inhibit the growth of human breast cancer MCF-7 cells. Biological activity results showed that the active expression levels of rhIGF-I and rhIGFBP-3 were found to be 10 ug and 7.36 ug per 1 g of rice seed respectively. These findings suggested that both rice-produced rhIGF-I and rhIGFBP-3 were biologically active. / Cheung, Chun Kai. / "September 2007." / Adviser: Peter Tong Chun Yip. / Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 4555. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 209-243). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.

Licentiatavhandling (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 3 uppsatser.

Diss. (sammanfattning) Linköping : Univ., 2005. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 4 uppsatser.

Diss. (sammanfattning) Umeå : Umeå universitet, 2008. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Virginia, 2008. / Includes bibliographical references. Also available in electronic form as viewed 2/16/2009.

Insulin-like growth factor-I is a small growth factor known to signal in a variety of mammalian cells through the IGF-I cell surface receptor (IGF-IR). A unique feature of the IGF-I system is the regulation of this binding by soluble IGF binding proteins. Recent studies from our laboratory show that there is a pH dependence in the association of IGF-I with the cell surface in the presence of IGFBP-3 which suggested increased association of IGF-I with IGFBP-3 at low pH. We studied cell free interaction of IGF-I and IGFBP-3 as a function of pH using surface plasmon resonance (SPR) in order to understand the mechanism that causes the increased association. In our studies three different SPR instruments with different surfaces for immobilization of one of the binding partners were used: a Leica Bio-SPR 9000 with a low molecular weight carboxymethylated dextran (CMD) surface, a BIAcore 2000 with a high molecular weight CMD surface and a Leica SPR 2001 Alpha with a planar mixed self-assembled monolayer (mSAM) surface. Since the experimental system we used was transport sensitive, only the mSAM surface, under optimized conditions, produced results that fit to a single site model. Results suggest that use of CMD layers for immobilization of one partner of a high-affinity binding complex can result in transport limited binding for which simple analysis is inappropriate. Future studies are planned to expand the work with the mSAM surface to elucidate whether a significant difference between the binding parameters as a function of pH exists. / Master of Science