Orientador: Jose Roberto Bosqueiro / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-11T17:39:01Z (GMT). No. of bitstreams: 1 Quallio_Silvana_M.pdf: 957537 bytes, checksum: 0c375a9b9290585b85244a414a6ea02d (MD5) Previous issue date: 2008 / Resumo: Introdução e objetivos: O aumento nos níveis de glicose circulante é o principal estímulo para a secreção de insulina. A insulina se liga a receptores de membrana desencadeando diversas respostas celulares. Qualquer alteração na sensibilidade à insulina pode levar a disfunções fisiológicas como a resistência à insulina observada em pacientes diabéticos tipo 2 (T2DM). Experimentalmente, essa condição patológica pode ser mimetizada pela administração de altas doses de glicocorticóides, provendo assim um bom modelo para seu estudo. O objetivo do presente trabalho foi avaliar a plasticidade das ilhotas pancreáticas submetidas à variação na necessidade secretória de insulina por indução de resistência periférica ao hormônio por tratamento com dexametasona e posterior interrupção do tratamento. Métodos: Ratos wistar com 90 dias de vida foram tratados com dexametasona (1mg/kg, ip) por 5 dias consecutivos (DEX). Em outro grupo (DEX10), os animais foram tratados da mesma maneira e avaliados 10 dias após o último dia da administração de dexametasona. Ratos controle (CTL) receberam administração de NaCl 0,9% apenas. As ilhotas foram isoladas pelo método da colagenase. A expressão de proteínas foi feita por immunoblotting. As análises morfométricas foram realizadas microscopicamente. Resultados: O grupo DEX exibiu marcante resistência periférica à insulina, que foi revertida após o período de 10 dias no grupo DEX10. As ilhotas do grupo DEX apresentaram alterações funcionais e morfológicas como aumento da secreção de insulina estimulada por secretagogos, da área, da densidade e tendência de aumento na massa de células ß ao contrário do grupo DEX10. O conteúdo de proteínas relacionadas ao ciclo celular como a CD2 e CDK4 e a fosforilação da AKT aumentou em ilhotas do grupo DEX, mas retornou aos níveis do CTL em ilhotas DEX10. Conclusão: Estes resultados mostram a plasticidade do pâncreas endócrino haja vista a habilidade de se adaptar a situações que exigem maior ou menor demanda de insulina / Abstract: Introduction and aims: Insulin binds to plasma membrane receptors leading to a variety of cellular responses. Malfunction in any of the insulin cell signalling pathways in target tissues may lead to several conditions and diseases, like hyperglycemia, insulin resistance and type 2 diabetes mellitus (T2DM). These effects may be experimentally reproduced using high doses of glucocorticoids, providing thus a good model for the study of T2DM. The aims of this study were to evaluate the plasticity of pancreatic islets subject to variation on the need for insulin secretory induction of peripheral resistance to the hormone by treatment with dexamethasone and subsequent treatment interruption. Methods: Male wistar rats (90 days old) were treated with dexamethasone (1mg/kg, ip) for 5 consecutive days (DEX). In another group (DEX10), the animals were treated in the same way and assessed 10 days after the last day of administration. Control rats (CTL) received equivalent volume of vehicle. Protein expression was assayed trough immunoblotting. Morphometric analyses were done using a optical microscope and specific digital analysis programs. Results: DEX group showed marked peripheral insulin resistance, reverted after the recovering period in the DEX10 group. DEX islets showed functional and morphological changes, like increased insulin secretion, superficial area, population density, and a tendency for increase in the total mass content of beta cell. Cell cycle proteins CD2 and CDK4 and AKT phosphorylation were increased in the DEX group when compared to CTL group. All these effects were reverted in the group DEX10. Conclusions: These results show that the endocrine pancreas possess a plasticity regarding the capacity of pancreatic islets to adapt themselves to situations where a higher or lower demand for insulin is needed. / Mestrado / Fisiologia / Mestre em Biologia Funcional e Molecular

No description available.

Islet transplantation has emerged as a promising cell-based therapy for the treatment of diabetes, but its clinical efficacy remains limited by deleterious host responses that underlie islet destruction. In this dissertation, we describe the assembly of cell surface-supported thin films that confer molecular-level control over the composition and biophysicochemical properties of the islet surface with implications for improving islet engraftment. Specifically, the process of layer-by-layer (LbL) polymer self assembly was employed to generate nanothin films of diverse architecture with tunable properties directly on the extracellular surface of individual islets. Importantly, these studies are the first to report in vivo survival and function of nanoencapsulated cells, and have helped establish a conceptual framework for translating the diverse applications of LbL films to cellular interfaces. Additionally, through proper design of film constituents, coatings displaying ligands and bioorthogonally reactive handles may be generated, providing a modular strategy for incorporating exogenously derived regulators of host responses alongside native constituents of the islet surface. Towards this end, a strategy was developed to tether thrombomodulin to the islet surface in a site-specific manner, thereby facilitating local generation of the powerful anti-inflammatory agent, activated protein C. Collectively, this work offers novel biomolecular strategies for cell surface engineering with broad biomedical and biotechnological applications in cell-based therapeutics and beyond.

Another growth factor candidate is a recently recognized bioactive peptide, islet-neogenesis associated protein (INGAP). A master pancreatic transcription factor, pancreatic duodenal homeobox-1 (Pdx-1), was overexpressed in PSCs by the adenovirus-mediated transfer method in the present study. With the infection of adenovirus expressing Pdx-1, several beta-cell developmental genes, including Isl-1, Beta2, Nkx2.2, Nkx6.1 and the endogenous Pdx-1 were found to be upregulated temporally in our PSCs-derived ICCs. Meanwhile, previous study has shown that Pdx-1/INGAP-positive cells represent a new stem cell subpopulation during early stage of pancreatic development. We thus explore whether any functional integration of Pdx-1 and INGAP in the growth and functional maturation of PSCs. In order to achieve this proposition, the effects of over-expressing PSCs with the Pdx-1 adenovirus in conjunction with the treatment of INGAP were then investigated. Interestingly, differentiation of the PSC-derived ICCs was not further enhanced by the synergistic treatment of Pdx-1 and INGAP when compared to those ICCs infected with adenovirus expressing Pdx-1 alone, as revealed by the endogenous Pdx-1 and insulin gene expression and their C-peptide content. These data might provide some clues to the intricate interaction between Pdx-1 and INGAP in regulating the ICC and/or the pancreatic endocrine differentiation. (Abstract shortened by UMI.) / Due to the scarcity of fetal pancreas for generating functional insulin-secreting cell clusters for sufficient islet transplantation, we targeted for searching pancreatic stem/progenitor cells. Putative PSCs can be aggregated and differentiated into islet-like cell clusters (ICCs) when exposed to serum-free medium containing various conventional growth factors, including HGF, GLP-1, betacellulin and nicotinamide. / Fetal pancreatic tissue consisting of immature progenitor cells serves as a potential source of stem cells as they possess a higher replicative capacity and longevity than their adult counterparts. / Two novel candidates and a key pancreatic transcription factor on the PSC/ICC proliferation and differentiation were investigated in the present study. One of them is a ubiquitously expressed multi-PDZ-domain protein, PDZ-domain-containing 2 (PDZD2), which was previously found to express in the mouse beta cells and exhibit mitogenic effects in beta cell line. Results showed that PDZD2 was detected in high levels in both human fetal pancreas and in PSCs. Results indicate the potential involvement of PDZD2 in regulating PSCs proliferation and differentiation and pancreatic development. / Suen Po Man, Ada. / "July 2007." / Adviser: P.S. Leung. / Source: Dissertation Abstracts International, Volume: 69-01, Section: B, page: 0051. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 194-214). / 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. / Abstracts in English and Chinese. / School code: 1307.

Ma, Man Ting. / "July 2010." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 186-207). / Abstracts in English and Chinese. / Abstract --- p.I / List of Publications --- p.VI / Acknowledgements --- p.VIII / Table of Contents --- p.X / List of Figures --- p.XV / List of Tables --- p.XVIII / List of Abbreviations --- p.XIX / Chapter CHAPTER1 --- INTRODUCTION / Chapter 1.1 --- The Pancreas --- p.2 / Chapter 1.1.1 --- Structure of pancreas --- p.2 / Chapter 1.1.2 --- Structure and function of exocrine pancreas --- p.6 / Chapter 1.1.3 --- Structure and function of endocrine pancreas --- p.9 / Chapter 1.1.3.1 --- Pancreatic islet and islet cells --- p.9 / Chapter 1.1.3.2 --- Glucose-stimulated insulin secretion from islets --- p.12 / Chapter 1.2 --- Type 1 Diabetes Mellitus (T1DM) --- p.14 / Chapter 1.2.1 --- Pathophysiology of Diabetes Mellitus --- p.14 / Chapter 1.2.2 --- Autoimmunity in T1DM --- p.17 / Chapter 1.2.3 --- Management ofTlDM --- p.20 / Chapter 1.2.3.1 --- Insulin replacement --- p.20 / Chapter 1.2.3.2 --- Pancreas and islet transplantation --- p.21 / Chapter 1.2.3.3 --- Stem-cell-based transplantation --- p.22 / Chapter 1.3 --- The Adaptive Immune System --- p.26 / Chapter 1.3.1 --- T-lymphocytes --- p.26 / Chapter 1.3.2 --- B-lymphocytes --- p.29 / Chapter 1.3.3 --- Major histocompatibility complex (MHC) --- p.30 / Chapter 1.3.3.1 --- Classification of MHC molecules --- p.30 / Chapter 1.3.3.2 --- Structure of MHC class I and II molecules --- p.32 / Chapter 1.3.3.3 --- Function and regulation of MHC molecules --- p.34 / Chapter 1.3.4 --- HLA-G and its immuno-modulatory properties --- p.36 / Chapter 1.4 --- Transplantation Rejection --- p.40 / Chapter 1.4.1 --- Mechanisms involved in transplantation rejection --- p.40 / Chapter 1.4.2 --- Immunobiology of rejection --- p.41 / Chapter 1.4.2.1 --- Direct allorecognition pathway --- p.42 / Chapter 1.4.2.2 --- Indirect allorecognition pathway --- p.43 / Chapter 1.4.2.3 --- Semi-direct allorecognition pathway --- p.43 / Chapter 1.4.3 --- Xenotransplantation --- p.46 / Chapter 1.5 --- Cytokines and Immunity --- p.48 / Chapter 1.5.1 --- Interferons --- p.48 / Chapter 1.5.1.1 --- Interferon-γ and its immune regulation --- p.49 / Chapter 1.5.1.2 --- Effect and kinetics of interferon-γ on MHC molecules expression --- p.53 / Chapter 1.5.1.3 --- Regulation of interferon-γ production --- p.56 / Chapter 1.5.2 --- Interlukins --- p.58 / Chapter 1.5.2.1 --- IL-10 and its immune regulation --- p.58 / Chapter 1.5.2.2 --- IL-10 and HLA-G --- p.59 / Chapter 1.6 --- Stem Cells and their Immunogenicity --- p.62 / Chapter 1.6.1 --- Embroynic stem cells --- p.62 / Chapter 1.6.2 --- Mesenchymal stem cells --- p.64 / Chapter 1.6.3 --- Neural stem cells --- p.68 / Chapter 1.6.4 --- Fetal stem cells --- p.69 / Chapter 1.6.5 --- Potential immuno-study in human fetal pancreatic stem cells --- p.70 / Chapter 1.7 --- Aims and Objectives of study --- p.72 / Chapter CHAPTER2 --- MATERIALS AND METHODS / Chapter 2.1 --- Isolation of Pancreatic Progenitors (PPCs) from Human Fetal Pancreas and Induction of Islet-like Cell Cluster (ICCs) Differentiation --- p.75 / Chapter 2.1.1 --- Tissue procurement --- p.75 / Chapter 2.1.2 --- Tissue processing and PPCs culture --- p.75 / Chapter 2.1.3 --- In vitro differentiation of PPCs into ICCs --- p.78 / Chapter 2.1.4 --- Interferon-γ and IL-10 treatment --- p.80 / Chapter 2.2 --- Cell culture of human placental Choriocarcinoma JEG-3 Cell Line --- p.81 / Chapter 2.3 --- RNA Expression Detection --- p.82 / Chapter 2.3.1 --- RNA isolation --- p.82 / Chapter 2.3.2 --- Reverse transcriptase (RT) --- p.83 / Chapter 2.3.3 --- Design of primers for Polymerase Chain Reaction (PCR) and Real-time PCR --- p.84 / Chapter 2.3.4 --- PCR --- p.86 / Chapter 2.3.5 --- Real-time PCR analysis --- p.88 / Chapter 2.3.6 --- Calculation using the comparative CT method --- p.90 / Chapter 2.4 --- Flow Cytometry --- p.91 / Chapter 2.5 --- Western Blotting Analysis --- p.93 / Chapter 2.5.1 --- Protein extraction and quantification --- p.93 / Chapter 2.5.2 --- Western blotting --- p.93 / Chapter 2.6 --- Mixed Lymphocyte Reaction (MLR) --- p.95 / Chapter 2.6.1 --- Isolation of peripheral blood mononuclear cells (PBMCs) --- p.95 / Chapter 2.6.2 --- PPC-PBMCs MLR --- p.98 / Chapter 2.6.3 --- ICC-PBMCs MLR --- p.98 / Chapter 2.6.4 --- Proliferation assay --- p.99 / Chapter 2.7 --- ICC Transplantation --- p.101 / Chapter 2.7.1 --- Streptozotocin-induced diabetic animals for transplantation --- p.101 / Chapter 2.7.2 --- Procedures of ICCs transplantation --- p.102 / Chapter 2.8 --- Histological Analysis of ICC Graft --- p.105 / Chapter 2.8.1 --- H&E staining --- p.105 / Chapter 2.8.2 --- DAB staining --- p.106 / Chapter 2.8.3 --- Immunofluorescence staining --- p.107 / Chapter 2.9 --- Enzyme-linked Immunosorbent Assay (ELISA) --- p.109 / Chapter 2.10 --- Statistical Data Analysis --- p.110 / Chapter CHAPTER3 --- RESULTS / Chapter 3.1 --- Immuno-characterization of PPCs and ICCs --- p.112 / Chapter 3.2 --- Effect of cytokines on immune-properties of PPCs and ICCs --- p.115 / Chapter 3.2.1 --- Effect of lFN-γ on MHC-I expression in PPCs --- p.115 / Chapter 3.2.2 --- Effect of lFN-γ and IL-10 on HLA-G expression in PPCs and ICCs --- p.119 / Chapter 3.2.3 --- Effect of IFN-γ on B7H4 expression in PPCs --- p.123 / Chapter 3.3 --- Comparison of immune-properties of PPCs and ICCs from 1st and 2nd trimester --- p.125 / Chapter 3.3.1 --- Differential expression of MHC molecules in PPCs --- p.125 / Chapter 3.3.2 --- Different immune-related gene expression in PPCs and ICCs --- p.128 / Chapter 3.3.3 --- Comparison of IFN-γ activated MHC molecules expression in PPCs/ICCs --- p.134 / Chapter 3.3.4 --- Comparison of other IFN-γ activated genes expression in PPCs --- p.139 / Chapter 3.4 --- Mixed lymphocyte reaction of PPCs from 1st and 2nd trimester --- p.143 / Chapter 3.4.1 --- Effect of PPCs on proliferation of PBMC --- p.143 / Chapter 3.4.2 --- Effect of ICCs on proliferation of PBMC --- p.145 / Chapter 3.4.3 --- Effect of PPCs on cytokine production in PBMC --- p.149 / Chapter 3.5 --- Xenotransplantation of ICCs into diabetic mouse model --- p.152 / Chapter 3.5.1 --- Blood glucose level of diabetic mice after transplantation --- p.152 / Chapter 3.5.2 --- Histological evaluation of transplanted ICCs grafts --- p.154 / Chapter 3.5.3 --- Infiltration of CD45 into transplanted grafts of 1st and 2nd trimester --- p.158 / Chapter CHAPTER4 --- DISCUSSION / Chapter 4.1 --- Expression of selected immuno-regulated genes in PPCs and ICCs --- p.163 / Chapter 4.2 --- Effect of IFN-g and IL-10 on expression of immuno-regulated genes in PPCs and ICCs --- p.166 / Chapter 4.3 --- In vitro studies on immunogenicity of PPCs and ICCs from first and second trimester --- p.171 / Chapter 4.3.1 --- Immune-related genes expression --- p.171 / Chapter 4.3.2 --- IFN-γ activated gene expression --- p.173 / Chapter 4.3.3 --- Mixed lymphocyte reaction --- p.175 / Chapter 4.3.4 --- Cytokine production of PBMC in MLR --- p.179 / Chapter 4.4 --- In vivo Xenotransplantation of ICCs into diabetic mouse model --- p.181 / Chapter 4.5 --- Conclusion --- p.187 / Chapter 4.6 --- Further studies --- p.188 / Chapter CHAPTER5 --- BIBLIOGRAPHY / Bibliography by Alphabetical Order --- p.189

Ng, Ka Yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 179-204). / Abstracts in English and Chinese. / Abstract --- p.I / 摘要 --- p.IV / Publications --- p.VII / Acknowledgements --- p.VIII / Table of contents --- p.IX / List of figures --- p.XV / List of tables --- p.XVII / List of abbreviations --- p.XVIII / Chapter Chapter 1 --- General Introduction / Chapter 1.1 --- The Pancreas --- p.2 / Chapter 1.1.1 --- Anatomy of Pancreas --- p.2 / Chapter 1.1.2 --- The Exocrine Pancreas --- p.4 / Chapter 1.1.3 --- The Endocrine Pancreas --- p.5 / Chapter 1.1.3.1 --- Structure of Islets --- p.5 / Chapter 1.1.3.2 --- "Functions of α-, β-, y-, ð-, Σ-and PP-cells in Islets" --- p.7 / Chapter 1.1.4 --- Overview of Pancreas Development --- p.9 / Chapter 1.1.4.1 --- Organ Morphology --- p.10 / Chapter 1.1.4.2 --- Cyto-differentiation --- p.12 / Chapter 1.1.4.3 --- Control by Transcriptional Factors --- p.14 / Chapter 1.1.5 --- Postnatal Pancreas Development and Regeneration --- p.18 / Chapter 1.1.5.1 --- Proliferation of Pre-existing β-cells --- p.19 / Chapter 1.1.5.2 --- Neogenesis from Precursor Cells --- p.20 / Chapter 1.1.5.3 --- Transdifferentiation of other Cells --- p.20 / Chapter 1.2 --- Diabetes Mellitus --- p.22 / Chapter 1.2.1 --- Pathophysiology of Diabetes Mellitus and Current Treatments --- p.24 / Chapter 1.2.1.1 --- Type I Diabetes Mellitus --- p.24 / Chapter 1.2.1.2 --- Type II Diabetes Mellitus --- p.25 / Chapter 1.2.1.3 --- Gestational Diabetes --- p.27 / Chapter 1.2.1.4 --- Secondary Diabetes --- p.28 / Chapter 1.3 --- Stem Cell therapy --- p.29 / Chapter 1.3.1 --- Stem Cell --- p.29 / Chapter 1.3.1.1 --- Mesenchymal Stem Sell --- p.31 / Chapter 1.3.1.2 --- Embryonic Stem Cell --- p.35 / Chapter 1.3.1.3 --- Induced Pluripotent Stem Cell --- p.36 / Chapter 1.3.2 --- Islets Engineering --- p.37 / Chapter 1.3.2.1 --- Genetic Modification --- p.37 / Chapter 1.3.2.2 --- Directed Differentiation --- p.38 / Chapter 1.3.2.3 --- Microenvironment --- p.38 / Chapter 1.3.2.4 --- In vivo Regeneration --- p.39 / Chapter 1.3.2.5 --- Cell Fusions --- p.40 / Chapter 1.3.2.6 --- Combinatory Treatments --- p.40 / Chapter 1.4 --- The Vitamin A & Vitamin D System --- p.42 / Chapter 1.4.1 --- The Vitamin A --- p.42 / Chapter 1.4.2 --- Vitamin A Metabolism --- p.44 / Chapter 1.4.3 --- Roles of vitamin A in Pancreatic Development --- p.46 / Chapter 1.4.4 --- The Vitamin D --- p.48 / Chapter 1.4.5 --- Vitamin D Metabolism --- p.49 / Chapter 1.4.6 --- Metabolic Functions of Vitamin D in Islets --- p.51 / Chapter 1.4.7 --- Cod Liver Oil --- p.53 / Chapter 1.4.8 --- Interactions between Vitamin A and Vitamin D --- p.53 / Chapter 1.5 --- The Relations of Liver and Pancreas Development --- p.55 / Chapter 1.5.1 --- Endoderm Induction for Hepatic and Pancreatic Differentiation of ESCs --- p.55 / Chapter 1.5.2 --- Bipotential Precursor Population within Embryonic Endoderm --- p.56 / Chapter 1.5.3 --- Pancreatic Islets Promote Mature Liver Hepatocytes Proliferation --- p.57 / Chapter 1.5.4 --- Transdifferentiation --- p.57 / Chapter 1.5.5 --- Transplantation in Liver Niche Promotes Maturation of Insulin-Producing Cells --- p.60 / Chapter 1.5.6 --- Neuronal Relay from the Liver to Pancreatic --- p.61 / Chapter 1.5.7 --- Development of Islets in the Nile Tilapia --- p.62 / Chapter 1.6 --- The Insulin-like Growth Factor-I (IGF1) --- p.64 / Chapter 1.6.1 --- IGF1 System --- p.64 / Chapter 1.6.2 --- IGF 1 Regulation --- p.65 / Chapter 1.6.3 --- Roles of IGF 1 in Pancreatic Development and Regeneration --- p.68 / Chapter 1.7 --- Aims and Objectives of Study --- p.70 / Chapter Chapter 2 --- General Materials and Methods / Chapter 2.1 --- Pancreatic progenitor cells (PPCs) and liver stromal cells (LSCs) isolation and cell culture --- p.72 / Chapter 2.1.1 --- Tissue procurement --- p.72 / Chapter 2.1.2 --- PPC and LSC culture --- p.72 / Chapter 2.1.3 --- "Treatments of vitamin A, vitamin D and IGF 1" --- p.76 / Chapter 2.1.4 --- "Cell culture of Caco-2, HepG2 and DU-145" --- p.76 / Chapter 2.2 --- Induction of Islet-like Cell Clusters (ICCs) Differentiation --- p.77 / Chapter 2.2.1 --- In vitro Directed Differentiation --- p.77 / Chapter 2.2.2 --- In vitro LSC Microenvironment --- p.77 / Chapter 2.3 --- RNA Expression Detection --- p.79 / Chapter 2.3.1 --- RNA isolation --- p.79 / Chapter 2.3.2 --- Reverse Transcription --- p.79 / Chapter 2.3.3 --- Polymerase Chain Reaction (PCR) --- p.80 / Chapter 2.3.4 --- Realtime PCR --- p.81 / Chapter 2.4 --- Immunocytochemistry --- p.83 / Chapter 2.5 --- Western Blotting --- p.85 / Chapter 2.5.1 --- Protein extraction and quantification --- p.85 / Chapter 2.5.2 --- Western Blotting --- p.85 / Chapter 2.6 --- Enzyme-linked Immunosorbent Assay (ELISA) --- p.87 / Chapter 2.6.1 --- Detection of cell viability --- p.87 / Chapter 2.6.2 --- Detection of cell proliferation --- p.87 / Chapter 2.6.3 --- Measurement of Cell death --- p.88 / Chapter 2.6.4 --- Measurement of IGF 1 level in condition medium --- p.89 / Chapter 2.6.5 --- Measurement of glucose induced insulin secretion --- p.90 / Chapter 2.7 --- Regeneration model --- p.92 / Chapter 2.7.1 --- Regeneration model in neonatal-STZ rat --- p.92 / Chapter 2.7.2 --- Change in IGF1 expression in pancreas and liver --- p.92 / Chapter 2.8 --- Statistical Data Analysis --- p.93 / Chapter Chapter 3 --- Vitamin D and vitamin A receptor expression and the proliferative effects of ligand activation of these receptors on the development of pancreatic progenitor cells derived from human fetal pancreas. (Stem Cell Rev. 2011;7:53-63) / Chapter 3.1 --- Abstract --- p.95 / Chapter 3.2 --- Introduction --- p.97 / Chapter 3.3 --- Materials and Methods --- p.101 / Chapter 3.3.1 --- Fetal Tissue Procurement --- p.101 / Chapter 3.3.2 --- Culture of Pancreatic Progenitor Cells --- p.101 / Chapter 3.3.3 --- RNA Expression Analysis by Reverse Transcription-Polymerase Chain Reaction (RT-PCR) --- p.102 / Chapter 3.3.4 --- Western Blot Analysis --- p.103 / Chapter 3.3.5 --- Immunocytochemstry --- p.105 / Chapter 3.3.6 --- PPC Proliferation Assays --- p.106 / Chapter 3.3.7 --- PPC Cell Death Assays --- p.107 / Chapter 3.3.8 --- Statistical Data Analysis --- p.108 / Chapter 3.4 --- Results --- p.110 / Chapter 3.4.1 --- "Expression and Localization of RAR, VDR and RXR, CYP26 and CYP24 in PPCs" --- p.110 / Chapter 3.4.2 --- Incubation of PPC with atRA Enhances PPC Viability due to Increased Proliferation and Anti-apoptosis --- p.111 / Chapter 3.4.3 --- Incubation of PPCs with Calcitriol Enhances Viability due to Increased Proliferation --- p.111 / Chapter 3.4.4 --- Both atRA and Calcitriol Induce Up-regulation of both the RAR and the VDR but not the RXR --- p.112 / Chapter 3.4.5 --- Combination Treatment with atRA and Calcitriol on Cell Viability and NGN3 Expression --- p.112 / Chapter 3.5 --- Discussion --- p.114 / Chapter Chapter 4 --- Human fetal liver stromal cell co-culture enhances the growth and differentiation of pancreatic progenitor cells into islet-like cell clusters (In submission to Gastroenterology) / Chapter 4.1 --- Abstract --- p.128 / Chapter 4.2 --- Introduction --- p.129 / Chapter 4.3 --- Materials and Methods --- p.133 / Chapter 4.3.1 --- Use of human and animal tissues --- p.133 / Chapter 4.3.2 --- "Cell preparation, characterizations and Differentiation" --- p.133 / Chapter 4.3.3 --- Examination of PPC growth and ICC differentiation and functions with LSC co-culture --- p.133 / Chapter 4.3.3 --- Identification of growth factors and investigation of their effects --- p.134 / Chapter 4.3.4 --- Statistical Analysis --- p.135 / Chapter 4.4 --- Results --- p.136 / Chapter 4.4.1 --- "Isolation, Culture and Characterizations of LSCs" --- p.136 / Chapter 4.4.2 --- Establishment of LSC co-culture system --- p.136 / Chapter 4.4.3 --- LSC co-culture enhances PPC-derived ICC differentiation --- p.137 / Chapter 4.4.4 --- Differential expression of mRNA for cytokines and growth factors between 1st and 2nd trimester LSCs --- p.138 / Chapter 4.4.5 --- Characterization of IGF 1 receptors in PPCs and the effects of exogenous IGF1 on PPC growth and ICC differentiation --- p.139 / Chapter 4.4.6 --- Neutralizing antibodies against IGF1R inhibit ICC differentiation --- p.140 / Chapter 4.5 --- Discussion --- p.142 / Chapter 4.6 --- Supplementary Materials and Methods --- p.147 / Chapter 4.6.1 --- Cell Preparation and culture --- p.147 / Chapter 4.6.2 --- In Vitro ICC differentiation --- p.148 / Chapter 4.6.3 --- RNA expression analysis --- p.149 / Chapter 4.6.4 --- Immunocytochemistry --- p.149 / Chapter 4.6.5 --- PPC viability and cell count assays --- p.150 / Chapter 4.6.6 --- IGF1 and insulin ELISA --- p.151 / Chapter 4.6.7 --- Western blotting analysis --- p.152 / Chapter 4.6.8 --- Neonatal streptozotocin regeneration model --- p.153 / Chapter Chapter 5 --- General Discussion and Future Studies / Chapter 5.1 --- General Discussion --- p.165 / Chapter 5.1.1 --- Proliferative effects and enhance expression of NGN3 by vitamin A and vitamin D on PPC --- p.166 / Chapter 5.1.2 --- Induction of PPC derived ICCs by LSCs --- p.169 / Chapter 5.1.3 --- Potential effects of liver stroma derived IGF1 on PPC derived ICCs differentiation --- p.172 / Chapter 5.1.4 --- Significance of islet engineering in the management of diabetes --- p.174 / Chapter 5.1.5 --- Conclusions --- p.176 / Chapter 5.2 --- Future Studies --- p.177 / Chapter Chapter 6 --- Reference / Reference --- p.180

Type 1 diabetes affects one in every 400-600 children and adolescents in the US. Standard therapy with exogenous insulin is burdensome, associated with a significant risk of dangerous hypoglycemia, and only partially efficacious in preventing the long term complications of diabetes. Pancreatic islet transplantation has emerged as a promising therapy for type 1 diabetes. However, this cell-based therapy is significantly limited by inadequate islet supply (more than one donor pancreas is needed per recipient), instant blood-mediated inflammatory reaction, and loss of islet viability/function during isolation and following implantation. In particular, inadequate revascularization of transplanted islets results in reduced islet viability, function, and engraftment. Delivery of pro-vascularization factors has been shown to improve vascularization and islet function, but these strategies are hindered by insufficient and/or complex release pharmacokinetics and inadequate delivery matrices as well as technical and safety considerations. We hypothesized that controlled presentation of angiogenic cues within a bioartificial matrix could enhance the vascularization, viability, and function of transplanted islets. The primary objective of this dissertation was to enhance allogenic islet engraftment, survival and function by utilizing synthetic hydrogels as engineered delivery matrices. Polyethylene glycol (PEG)-maleimide hydrogels presenting cell adhesive motifs and vascular endothelial growth factor (VEGF) were designed to support islet activities and promote vascularization in vivo. We analyzed the material properties and cyto-compatibility of these engineered materials, islet engraftment in a transplantation model, and glycemic control in diabetic subjects. The rationale for this project is to establish novel biomaterial strategies for islet delivery that support islet viability and function via the induction of local vascularization.

Thesis (Ph. D.)--University of Lund, 1994. / "ISRN LUMEDW / MEMM-1037-SE."

Thesis (Ph. D.)--University of Lund, 1994. / "ISRN LUMEDW / MEMM-1037-SE."

Orientador: Everardo Magalhães Carneiro / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-06T11:23:18Z (GMT). No. of bitstreams: 1 Filiputti_Eliane_D.pdf: 3662221 bytes, checksum: e40ea0446558f8556a8352fd8c98a5fc (MD5) Previous issue date: 2006 / Resumo: Suspeita-se que a desnutrição intra-uterina e pós-natal produzam mudanças morfológicas e funcionais no pâncreas endócrino e em tecidos periféricos, que se traduzem em insulinopenia e resistência à insulina. Baseado nessas complicações avaliou-se neste trabalho a regulação da secreção de insulina em ilhotas de Langerhans de ratos e camundongos submetidos à restrição protéica e suplementados com leucina. A suplementação com leucina não modificou hábitos alimentares, ingestão hídrica e o peso corpóreo dos animais em estudo, mas alterou parâmetros bioquímicos importantes como glicose (G), ácidos graxos (AGL) em animais desnutridos. A fosforilação do receptor de insulina (IR) e de seu substrato (IRS-l) foi modificada em fígado e músculo levando a uma melhoria na homeostasia glicêmica em ratos desnutridos, a metabolismo de glicose em ilhotas de ratos controle e desnutridos teve redução após suplementação, a potencial de membrana das células B foi restaurado, o movimento de cálcio citoplasmático e a secreção de insulina estimulada por G e leucina apresentaram aumentados em ilhotas de ratos e camundongos desnutridos. Alterações ocorreram também no perfil eletroforético de proteínas citoplasmáticas após suplementação com leucina em ilhotas de ratos. Expressão gênica e protéica de proteínas chaves na cascata de sinalização de insulina como IR, IRS-l, PI3K, mTaR e S6K-l se alteraram em resposta à suplementação com leucina em ilhotas de ratos desnutridos, favorecendo vias de crescimento, em especial o aumento da PI3K a qual resultou em aumento de sua atividade em ilhotas de ratos controle e desnutridos. Por fim, podemos concluir que a suplementação com leucina promoveu modulação da sensibilidade periférica em fígado e músculo de maneira tecido específica. Isto confere uma regulação da homeostase glicêmica de maneira distinta entre animais controle e desnutridos suplementados. Além disso, direcionam para que os sinais metabólicos produzidos pela leucina devam promover seus efeitos, em ilhotas de Langerhans, via dois sensores: a GDH que controla a glutaminólise, e por outro lado está a PI3K que deve exercer seu papel, ativando vis envolvidas com a síntese protéica através da mTOR. Estes dois sensores devem atuar sinergicamente participando do rearranjo da concentração citosólica dos íons cálcio, principalmente em ilhotas de animais desnutridos que foram suplementados com leucina / Abstract: We think that intra-uterine mal nutrition and after birth produce morphological and changes in endocrine pancreas and in peripheric tissue that translate insulinopenia and insulin resistance. Based on these complications we have evaluated in this work the insulin secretion regulation in Langerhans islets from rats and mice fed a low protein diet and supplemented with leucine. The leucine supplementation hasn't changed the diet in the hybrid ingest and body weight but has changed important biochemistry standards as glucose (G) and FFA in malnutrition animals. The insulin receptor phosphorilation and its substract have been changed in liver and musc1e leading to an increase in glicemic homeostase in malnutrition rats. The glucose metabolism in control and malnutrition rats' islets had one reduction after supplementation. B cells potential membranes were restored; the citoplasmatic ca1cium movement and insulin secretion were stimulated by glucose and leucine. They have showed an increased in islets of control and malnourished rats and mice islets. Some alterations have also occurred in the citoplasmatic protein eletrophoretic profile after leucine supplementation in rats islets. The genetic and protein expression from key enzymes in the insulin cascade signalization as: IR; IRS-l; PI3K; mTOR and S6K-l have altered in leucine supplementation answer in malnutrition islets rats favoring growth pathways specially PI3K increase which resulted in an increasement of control and malnutrition rats islets activity. In the end we can conc1ude that the leucine supplementation has promoted peripheric sensibilization in liver and muscle in specific tissue manner. This confirms one glicemic homeostase regulation in distinct manner among control and malnutrition both supplemented animals. Furthermore they lead the metabolic signals produced by leucine should promote their effects in Langerhans islets throw sensor ways: GDH which controls glutaminolisis and on the otherhand is PI3K that should do its role activating growth pathways throw mTOR. These two sensors should work in synergism participating in citosolic concentration changes of ca1cium ions mainly in malnutrition animals' islets, which were supplemented. / Doutorado / Fisiologia / Doutor em Biologia Funcional e Molecular