Allergic contact dermatitis is an important occupational health disease. It represents a useful experimental paradigm in which the mechanisms and characteristics of cutaneous immune responses can be investigated. This thesis has focused on the sensitization phase of contact allergy, including Langerhans’ cell (LC) migration, cytokine expression and the ability of the protein lactoferrin (LF) to modulate aspects of these processes. Lactoferrin was originally identified as an antimicrobial protein. However, it is being recognized increasingly to have immunomodulatory effects on the cells of the immune system. Migration of LC in mice and in humans is mediated via two independent cytokine signals delivered by tumour necrosis factor (TNF)-α and interleukin (IL)-1β, which were thought to derive from keratinocytes and LC, respectively. Further, topical application of LF was shown to inhibit LC migration in both man and mouse potentially through the inhibition of de novo TNF-α production. The inhibitory effect of LF on LC mobilization induced by the contact allergen 4-ethoxymethylene-2-phenyl-2-oxazolin-5-one (oxazolone) has been confirmed in these investigations. Conversely, LF did not inhibit LC migration triggered by another contact allergen, 2,4-dinitrochlorobenzene (DNCB). That result prompted a comparison between oxazolone and DNCB with respect to their ability to induce LC migration and to provoke cutaneous cytokine production. It was discovered that DNCB induced LC mobilization in the absence of TNF-α signalling. Moreover, exposure to superoptimal doses of oxazolone resulted in TNF-α independent LC migration. Further experiments revealed that TNF-α independence might be mediated partially by the elevated concentration of IL-1β produced in the skin following exposure to DNCB and these superoptimal concentrations of oxazolone. Investigations of the immunomodulatory mechanism of LF in vitro demonstrated that it did not inhibit TNF-α production by THP-1 macrophages. On the contrary, LF was shown to stimulate TNF-α and IL-8 release by THP-1 macrophages in a dose dependent manner, via endotoxin-independent and nucleolin-dependent mechanism. Subsequently, the role of LF in modulation of keratinocyte activation was investigated. Keratinocytes expressed high levels of inducible TNF-α mRNA, however, this was not modulated specifically by LF. Additional examination of the effects of LF in vivo revealed that it inhibited cutaneous IL-17 and CXCL1 mRNA expression, induced by IL-1β and IL-1α, respectively. Lactoferrin treatment did not affect oxazolone-induced lymph node (LN) cell proliferation. However, it was demonstrated to decrease IL-17 production by LN cells 24h following exposure to oxazolone, which may be important in driving the vigour and/or quality of response to the contact allergen. Overall, these investigations have demonstrated a divergence within the family of contact allergens with regard to the requirement for TNF-α signalling for LC mobilization. It was established that when elevated concentrations of IL-1β are present LC migration can occur in the absence of TNF-α signalling. Moreover, a dual nature of LF, which can act in a stimulatory as well as inhibitory manner, was confirmed. These investigations have revealed a potential role for CXCL1 and IL-17 in the process of LC migration. Furthermore, it was shown that the inhibitory effect of LF on oxazolone induced LC migration might be mediated via its effect on IL-17.

A pele é o maior órgão do corpo humano e constitui a principal defesa do organismo contra agentes físicos e químicos, sendo também fundamental para evitar a perda de água por dessecação. Formada por três camadas distintas, mas complementares, sendo as duas principais denominadas derme e epiderme, contendo diferentes tipos celulares, como fibroblastos, queratinócitos, melanócitos, células de Merkel e células de Langerhans, sendo que estas últimas desempenham um papel fundamental na hipersensibilidade de contato. Devido à importância da manutenção da pele saudável para a vida humana, existe uma crescente necessidade da elaboração de substitutos de tecidos para o tratamento de feridos e doentes, assim como, há grande demanda de pele para testes químicos das áreas farmacêutica e cosmética. Outro fator de fundamental importância para o desenvolvimento de métodos alternativos in vitro, é a pressão mundial para que estes testes substituam os modelos animais. Esta abordagem vai de encontro aos novos conceitos de substituição, redução e refinamento na utilização de animais em estudos científicos, ditando o futuro da cultura celular e bioengenharia de tecidos. Graças ao grande desenvolvimento do cultivo celular e descoberta de que as células cultivadas podem ser reagrupadas de acordo com o delineamento experimental, se torna possível à criação de equivalentes dermoepidérmicos para estudos in vitro, como por exemplo, testes de cito e fototoxicidade ou avaliação da fase inicial da reação alérgica e processos de sensibilização da pele. Neste caso, se faz necessária a obtenção de grande quantidade de células de Langerhans imaturas. As células de Langerhans (CLs) são células dendríticas imaturas localizadas na epiderme e epitélio superficial que desempenham um papel central na imunidade da pele, agindo como verdadeiras sentinelas capazes de captar antígenos de contato. Desta forma, foram testados quatro diferentes protocolos para extração e criopreservação destas células, sendo ainda analisadas as suas características morfológicas e fenotípicas. Obtivemos resultados não expressivos quanto ao isolamento, pureza e marcação positiva para CD1a no Protocolo 2 (Expansor de Pele). Os Protocolo 1A (Coleta de Sobrenadante) e 3 (Epiderme + Gradiente de Ficoll Paque) ofereceram altos níveis de células marcadas positivamente para CD1a, apresentando a mesma qualidade de marcação. No entanto, o Protocolo 3 forneceu um maior número de células viáveis, e uma maior pureza da amostra, uma vez que só utiliza a epiderme para a obtenção da suspensão de células, o que o coloca como modelo a ser seguido em posteriores experimentos. Os métodos aqui apontados como mais promissores, podem ser reproduzidos em laboratórios de cultura celular convencionais, contribuindo para aumentar a reprodutibilidade e confiabilidade de resultados experimentais relativos às CLs. Da mesma forma, avaliamos a utilização dos equivalentes de pele humana para a realização de testes in vitro de cito e fototoxicidade, os quais podem de fato reduzir a utilização de modelos animais para identificação do perfil tóxico de uma substância ou de formulações mais complexas. / The skin is the largest organ from the human body and constitutes the main protection of the organism against physical and chemical agents and it is also fundamental to avoid water loss by desiccation. Formed by three distinct stratus, yet complementary, being the two main called dermis and epidermis, containing different cell types, as fibroblasts, keratinocytes, melanocytes, Merkel cells and Langerhans cells (LCs), being these latter fundamental in the contact hypersensitivity. Due to the importance of the healthy skin maintenance to the human´s life, there is a growing need of elaboration of skin models to the treatment of injured and diseased, as well as there is a big demand of skin models to chemical tests from the pharmaceutics and cosmetology fields. Another factor of fundamental importance to the development of alternative in vitro methods is the worldwide pressure for these tests to replace animal models. This approach meets new concepts of replacement, reduction and refinement in the use of animals in scientific studies, dictating the future of cell culture and bioengineering of skin models. Thanks to the large development of cell culture and the discovery that the cultured cells can be regrouped according to the experimental delineation, the creation of skin models to in vitro studies is made possible, as for instance, tests of cytotoxicity and phototoxicity or evaluation of the initial phase from the allergic reaction and processes of skin sensitization. In this case, it is necessary the achievement of a large amount of immature Langerhans cells. The LCs are immature dendritic cells located in the epidermis and superficial epithelium that perform a central role in the skin immunity, acting as real sentinels able to collect contact antigens. Accordingly, were tested four different protocols for extraction and cryopreservation of these cells, and further analyzed its morphological and phenotypic features. We obtained no significant results in relation to the isolation, purity and CD1a positive expression in the Protocol 2. The Protocols 1A and 3 offered high levels of CD1a positively marked cells, showing the same expression levels. However, the Protocol 3 provided a bigger number of viable cells and a high purity yield, since it only uses the epidermis to obtain the single cell suspension, which places it as a model to be followed in subsequent experiments. The methods appointed here as the most promising, can be reproduced in conventional cell culture labs, contributing to increase the reproducibility and reliability of experimental results related to the LCs. In the same way, we evaluated the use of the human skin equivalents to the accomplishment of in vitro tests of cyto and phototoxicity, which can in fact reduce the use of animal models to the identification of single substances toxicity or even complex formulations.

A doença enxerto contra hospedeiro é uma complicação comum nos pacientes submetidos ao transplante de medula óssea alogênico. Com o objetivo de contribuir para o esclarecimento da participação das células de Langerhans na doença enxerto contra hospedeiro crônica (GVHDc) quando de sua ocorrência na mucosa bucal, foram analisados 40 pacientes oncohematológicos e hematológicos submetidos ao transplante de medula óssea alogênico no Hospital Amaral Carvalho, Jaú - SP. Cortes microscópicos de 3µm de espessura da mucosa jugal com padrão de normalidade (controle - 20 pacientes) e de pacientes transplantados com e sem GVHDc, foram avaliados em hematoxilina e eosina e pela técnica imuno-histoquímica padrão da estreptavidina-biotina-peroxidase utilizando-se o anticorpo monoclonal anti- CD1a. As células de Langerhans imunomarcadas foram quantificadas no epitélio da mucosa jugal, sendo o número médio destas células estatisticamente comparado entre os pacientes controle e os pacientes transplantados com e sem GVHDc. Os resultados demonstraram um maior número de células de Langerhans na mucosa jugal dos pacientes com GVHDc quando comparado aqueles sem GVHDc e ao grupo controle (p=0,001). Foi observado também, a presença de intenso infiltrado inflamatório crônico, justaepitelial, com desorganização das células da camada basal do epitélio, com vacuolização celular, satelitose, corpúsculos acidofílicos e ocorrência de clivagem entre e o epitélio e o tecido conjuntivo nos pacientes que desenvolveram GVHDc. Estes resultados sugerem que a células de Langerhans participa da doença enxerto contra hospedeiro crônica na mucosa jugal dos pacientes submetidos ao transplante de medula óssea alogênico, sendo provavelmente recrutadas pelo processo inflamatório e imunopatológico que caracteriza esta doença. / The graft versus host disease (GVHD) is a common complication in patients submited to alogeneic bone marrow transplantation. To understand the role of Langerhans cells in chronic GVHD (cGVHD) in oral mucosa, we analyzed 40 oncohematological or hematological patients who received alogeneic bone marrow transplantation at Hospital Amaral Carvalho, Jaú - SP. Slices of 3µm from normal oral mucosa (control - 20 patients) and transplanted patients with and without cGVHD were analyzed by hematoxylin-eosin technique and conventional immunohistochemistry of streptavidin-biotin peroxidase technique for monoclonal antibody anti-CD1a. The immunomarked Langerhans cells were quantified in the epithelium of oral mucosa; the average number of these cells was statistically significant when compared to the control group and patients with and without cGVHD. The results showed higher number of Langerhans cells in oral mucosa of cGVHD when we compared the control group and the group of patients with and without cGVHD (p=0,001). We also observed the presence of chronic juxtaepithelial inflammatory infiltrate, with basal layer epithelium desorganization, vacuolization, satellitosis, acidophilic bodies and presence of gap between epithelium and connective tissue of patients with cGVHD. These results suggest that Langerhans cells may have a role in cGVHD of oral mucosa in patients submited to alogeneic bone marrow transplantation, and they may be recruited by inflammatory and immunopathologic process that are characteristic in this disease.

A pele é o maior órgão do corpo humano e constitui a principal defesa do organismo contra agentes físicos e químicos, sendo também fundamental para evitar a perda de água por dessecação. Formada por três camadas distintas, mas complementares, sendo as duas principais denominadas derme e epiderme, contendo diferentes tipos celulares, como fibroblastos, queratinócitos, melanócitos, células de Merkel e células de Langerhans, sendo que estas últimas desempenham um papel fundamental na hipersensibilidade de contato. Devido à importância da manutenção da pele saudável para a vida humana, existe uma crescente necessidade da elaboração de substitutos de tecidos para o tratamento de feridos e doentes, assim como, há grande demanda de pele para testes químicos das áreas farmacêutica e cosmética. Outro fator de fundamental importância para o desenvolvimento de métodos alternativos in vitro, é a pressão mundial para que estes testes substituam os modelos animais. Esta abordagem vai de encontro aos novos conceitos de substituição, redução e refinamento na utilização de animais em estudos científicos, ditando o futuro da cultura celular e bioengenharia de tecidos. Graças ao grande desenvolvimento do cultivo celular e descoberta de que as células cultivadas podem ser reagrupadas de acordo com o delineamento experimental, se torna possível à criação de equivalentes dermoepidérmicos para estudos in vitro, como por exemplo, testes de cito e fototoxicidade ou avaliação da fase inicial da reação alérgica e processos de sensibilização da pele. Neste caso, se faz necessária a obtenção de grande quantidade de células de Langerhans imaturas. As células de Langerhans (CLs) são células dendríticas imaturas localizadas na epiderme e epitélio superficial que desempenham um papel central na imunidade da pele, agindo como verdadeiras sentinelas capazes de captar antígenos de contato. Desta forma, foram testados quatro diferentes protocolos para extração e criopreservação destas células, sendo ainda analisadas as suas características morfológicas e fenotípicas. Obtivemos resultados não expressivos quanto ao isolamento, pureza e marcação positiva para CD1a no Protocolo 2 (Expansor de Pele). Os Protocolo 1A (Coleta de Sobrenadante) e 3 (Epiderme + Gradiente de Ficoll Paque) ofereceram altos níveis de células marcadas positivamente para CD1a, apresentando a mesma qualidade de marcação. No entanto, o Protocolo 3 forneceu um maior número de células viáveis, e uma maior pureza da amostra, uma vez que só utiliza a epiderme para a obtenção da suspensão de células, o que o coloca como modelo a ser seguido em posteriores experimentos. Os métodos aqui apontados como mais promissores, podem ser reproduzidos em laboratórios de cultura celular convencionais, contribuindo para aumentar a reprodutibilidade e confiabilidade de resultados experimentais relativos às CLs. Da mesma forma, avaliamos a utilização dos equivalentes de pele humana para a realização de testes in vitro de cito e fototoxicidade, os quais podem de fato reduzir a utilização de modelos animais para identificação do perfil tóxico de uma substância ou de formulações mais complexas. / The skin is the largest organ from the human body and constitutes the main protection of the organism against physical and chemical agents and it is also fundamental to avoid water loss by desiccation. Formed by three distinct stratus, yet complementary, being the two main called dermis and epidermis, containing different cell types, as fibroblasts, keratinocytes, melanocytes, Merkel cells and Langerhans cells (LCs), being these latter fundamental in the contact hypersensitivity. Due to the importance of the healthy skin maintenance to the human´s life, there is a growing need of elaboration of skin models to the treatment of injured and diseased, as well as there is a big demand of skin models to chemical tests from the pharmaceutics and cosmetology fields. Another factor of fundamental importance to the development of alternative in vitro methods is the worldwide pressure for these tests to replace animal models. This approach meets new concepts of replacement, reduction and refinement in the use of animals in scientific studies, dictating the future of cell culture and bioengineering of skin models. Thanks to the large development of cell culture and the discovery that the cultured cells can be regrouped according to the experimental delineation, the creation of skin models to in vitro studies is made possible, as for instance, tests of cytotoxicity and phototoxicity or evaluation of the initial phase from the allergic reaction and processes of skin sensitization. In this case, it is necessary the achievement of a large amount of immature Langerhans cells. The LCs are immature dendritic cells located in the epidermis and superficial epithelium that perform a central role in the skin immunity, acting as real sentinels able to collect contact antigens. Accordingly, were tested four different protocols for extraction and cryopreservation of these cells, and further analyzed its morphological and phenotypic features. We obtained no significant results in relation to the isolation, purity and CD1a positive expression in the Protocol 2. The Protocols 1A and 3 offered high levels of CD1a positively marked cells, showing the same expression levels. However, the Protocol 3 provided a bigger number of viable cells and a high purity yield, since it only uses the epidermis to obtain the single cell suspension, which places it as a model to be followed in subsequent experiments. The methods appointed here as the most promising, can be reproduced in conventional cell culture labs, contributing to increase the reproducibility and reliability of experimental results related to the LCs. In the same way, we evaluated the use of the human skin equivalents to the accomplishment of in vitro tests of cyto and phototoxicity, which can in fact reduce the use of animal models to the identification of single substances toxicity or even complex formulations.

Com o propósito de colaborar na elucidação da fisiopatologia do pênfigo foliáceo endêmico (PFE), realizou-se titulação de anticorpos séricos e quantificação das células de Langerhans (CL) e células dendríticas dérmicas (CD) na pele de pacientes com PFE. Sangue e biopsia de pele de lesão ativa foram colhidos de 22 pacientes com PFE e, em 13 deles realizou-se também biopsia de pele normal não adjacente à lesão, em área não exposta ao sol. Dos 22 pacientes, 13 apresentavam a forma clínica localizada e 9, generalizada; 11 estavam em tratamento. O grupo controle constituiu-se de pele normal obtida da região torácica anterior de 8 cadáveres e de 12 mulheres submetidas à cirurgia plástica (mastoplastia). A imunofluorescência indireta (IFI) foi realizada com pele humana normal da região abdominal como substrato e anti-IgG humana. A identificação das CL e CD foi feita pela técnica imunohistoquímica da avidina-biotina-peroxidase com o anticorpo anti-CD1a e quantificação por análise morfométrica. Houve correlação entre a titulação de anticorpos séricos por IFI e a forma clínica do PFE, sendo esse maior na forma generalizada. O número de CL na lesão (60,18 CL/ mm2; 5,00 CL/ mm de membrana basal (MB); 3,55 CL/mm de camada córnea) e na pele normal do PFE (28,45 CL/ mm2; 2,50 CL/ mm de MB; 2,87 CL/mm de camada córnea) foi semelhante ao número de CL na pele dos grupos controles de cirurgia plástica (72,35 CL/ mm2; 4,53 CL/ mm de MB; 4,42 CL/mm de camada córnea) e de cadáveres (47,15 CL/ mm2; 2,53 CL/ mm de MB; 2,42 CL/mm de camada córnea). O número de CD dérmicas na pele lesada de PFE (0,98 CD/ mm de MB) foi semelhante ao do grupo controle de plástica de mama (0,48 CD/ mm de MB), porém maior do que o do grupo cadáver (0,13 CD/ mm de MB). A razão entre o número de CL e CD dérmicas foi menor na pele lesada do paciente com PFE comparada à dos grupos controles, confirmando maior número de CD na derme. Num mesmo paciente, as CL e CD da derme encontravam-se em maior número na lesão de PFE (61,50 CL/ mm2; 5,49 CL/ mm de MB; 6,64 CL/mm de camada córnea, 0,86 CD dérmicas/ mm de MB) quando comparadas à pele normal (28,45 CL/ mm2; 2,50 CL/ mm de MB; 2,87 CL/mm de camada córnea; 0,04 CD dérmicas/ mm de MB). Houve correlação direta entre o número de CD dérmicas na lesão de PFE e a titulação de anticorpos séricos por IFI (r=0,4779, p<0,05), indicativo de que as CD dérmicas poderiam estar participando da patogênese do PFE. Poder-se-ia supor que as CD estariam transitando pela derme em direção ao linfonodo regional, exercendo função estimuladora de linfócitos T na indução da resposta imune e produção de auto-anticorpos. / In order to contribute to the elucidation of pathophysiology of Endemic Pemphigus Foliaceus (EPF) titration of serum antibodies and quantification of Langerhans Cells (LC) and dermal dendritic cells (DC) in skin of patients with EPF were made. Blood and skin biopsies (lesional skin) of 22 EPF patients were collected and, in 13 of them, biopsies of normal sun-protected skin of non perilesional area were collected too. 13 patients had localized lesions and 9, generalized; 11 were in treatment. Control groups consisted of thoracic normal skin from 8 cadavers and 12 women submitted to breast plastic surgery. For indirect immunofluorescence (IFI), abdominal normal skin as substrate and anti-IgG were used. LC and dermal DC identification was done by immunohistochemistry with anti-CD1a antibody and quantification by morfometric analysis. It was found association between titration of serum antibodies by IFI and clinical form of EPF, with greater titration in the generalized one. LC number in lesion (60.18 LC/ mm2, 5.00 LC/ mm basement membrane (BM), 3.55 LC/mm stratum corneum) and normal skin of EPF patients (28.45 LC/ mm2, 2.50 LC/ mm BM, 2.87 LC/mm stratum corneum) was similar to LC number in skin of plastic surgery (72.35 LC/ mm2, 4.53 LC/ mm BM, 4.42 LC/mm stratum corneum) and cadaver controls (47.15 LC/ mm2, 2.53 LC/ mm BM, 2.42 LC/mm stratum corneum). Dermal DC number in lesional skin of EPF patients (0.98 DC/ mm BM) was similar to the DC number of plastic surgery controls (0.48 DC/ mm BM), but greater than DC number in cadaver controls (0.13 DC/ mm BM). The ratio LC number/ dermal DC number was smaller in lesional EPF skin than in controls, confirming the greatest DC number in dermis. In the same patient, LC and dermal DC were in greater amounts in EPF lesional skin (61.50 LC/ mm2, 5.49 LC/ mm BM, 6.64 LC/mm stratum corneum, 0.86 dermal DC/ mm BM) than in normal skin (28.45 LC/ mm2, 2.50 LC/ mm BM, 2.87 LC/mm stratum corneum, 0.04 dermal DC/ mm BM). It was found direct association between dermal DC number in lesional skin of EPF patients and titration of antibodies by IFI (r=0.4779, p<0.05), confirming that dermal DC could play an important role in EPF pathogenesis. It could be proposed that DC would be in transit through the dermis towards the regional lymph node, stimulating T lymphocytes to produce autoantibodies.

BMPs ocupam papel central na diferenciação e crescimento celulares. A sinalização intracelular das BMPs depende de substratos conhecidos como BR-SMADs (SMAD1/5/8). Em ilhotas pancreáticas de ratas grávidas, onde ocorre aumento da massa endócrina e da síntese e secreção de insulina, houve aumento da expressão do receptor BMPR1A. Em camundongos knockout para BMPR1A houve diminuição da expressão de genes-chave na exocitose de grânulos de insulina. Tais eventos estão associados à redução da atividade das BR-SMADs. O objetivo deste trabalho foi avaliar, em células <font face=\"Symbol\">b INS1E, o perfil de expressão gênica em larga escala após silenciamento das BR-SMADs. As expressões relativas de Munc18a, Munc18b e Snap23 foram reduzidas quando do silenciamento das BR-SMADs (n=3, p<0,05 vs CTL). O silenciamento de SMAD1 (n=3, p<0,05 vs CTL) ou SMAD5 (n=3, p<0,05 vs CTL) acarretaram redução do mRNA de Sintaxina 4. Conclui-se que as BR-SMADs estão envolvidas na regulação da secreção de insulina modulando proteínas envolvidas na fusão de vesículas contendo grânulos de insulina à membrana plasmática de células INS1E. / BMPs play a determinant role in cell differentiation and growth. BMP intracellular signaling involves the substrates know as BR-SMADs (SMAD1/5/8). BMPR1A receptor expression was upregulated in pancreatic islets from pregnant rats, in wich endocrine mass and insulin secretion are increased. Mice with attenuated BMPR1A signaling in <font face=\"Symbol\">b cells showed decreased expression of key genes involved in insulin exocytosis. These events are associated with reduction of BR-SMADs activity. The aim of this work was to perform a screening to evaluate changes in expression profiles after knockdown of BR-SMADs in INS1E <font face=\"Symbol\">b cells. Relative expressions of Munc18a, Munc18b and Snap23 were diminished after knockdown of the BRSMADs (n=3, p<0,05 vs CTL). Only SMAD1 (n=3, p<0,05 vs CTL) and SMAD5 (n=3, p<0,05 vs CTL) silencing caused reduction of sintaxin 4 expression. These data point to the involvement of BR-SMADs in the regulation of insulin secretion by modulating the expression of proteins responsible by fusion of insulin-containing granules to the membrane of INS1E cells.

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.

A doença enxerto contra hospedeiro é uma complicação comum nos pacientes submetidos ao transplante de medula óssea alogênico. Com o objetivo de contribuir para o esclarecimento da participação das células de Langerhans na doença enxerto contra hospedeiro crônica (GVHDc) quando de sua ocorrência na mucosa bucal, foram analisados 40 pacientes oncohematológicos e hematológicos submetidos ao transplante de medula óssea alogênico no Hospital Amaral Carvalho, Jaú - SP. Cortes microscópicos de 3µm de espessura da mucosa jugal com padrão de normalidade (controle - 20 pacientes) e de pacientes transplantados com e sem GVHDc, foram avaliados em hematoxilina e eosina e pela técnica imuno-histoquímica padrão da estreptavidina-biotina-peroxidase utilizando-se o anticorpo monoclonal anti- CD1a. As células de Langerhans imunomarcadas foram quantificadas no epitélio da mucosa jugal, sendo o número médio destas células estatisticamente comparado entre os pacientes controle e os pacientes transplantados com e sem GVHDc. Os resultados demonstraram um maior número de células de Langerhans na mucosa jugal dos pacientes com GVHDc quando comparado aqueles sem GVHDc e ao grupo controle (p=0,001). Foi observado também, a presença de intenso infiltrado inflamatório crônico, justaepitelial, com desorganização das células da camada basal do epitélio, com vacuolização celular, satelitose, corpúsculos acidofílicos e ocorrência de clivagem entre e o epitélio e o tecido conjuntivo nos pacientes que desenvolveram GVHDc. Estes resultados sugerem que a células de Langerhans participa da doença enxerto contra hospedeiro crônica na mucosa jugal dos pacientes submetidos ao transplante de medula óssea alogênico, sendo provavelmente recrutadas pelo processo inflamatório e imunopatológico que caracteriza esta doença. / The graft versus host disease (GVHD) is a common complication in patients submited to alogeneic bone marrow transplantation. To understand the role of Langerhans cells in chronic GVHD (cGVHD) in oral mucosa, we analyzed 40 oncohematological or hematological patients who received alogeneic bone marrow transplantation at Hospital Amaral Carvalho, Jaú - SP. Slices of 3µm from normal oral mucosa (control - 20 patients) and transplanted patients with and without cGVHD were analyzed by hematoxylin-eosin technique and conventional immunohistochemistry of streptavidin-biotin peroxidase technique for monoclonal antibody anti-CD1a. The immunomarked Langerhans cells were quantified in the epithelium of oral mucosa; the average number of these cells was statistically significant when compared to the control group and patients with and without cGVHD. The results showed higher number of Langerhans cells in oral mucosa of cGVHD when we compared the control group and the group of patients with and without cGVHD (p=0,001). We also observed the presence of chronic juxtaepithelial inflammatory infiltrate, with basal layer epithelium desorganization, vacuolization, satellitosis, acidophilic bodies and presence of gap between epithelium and connective tissue of patients with cGVHD. These results suggest that Langerhans cells may have a role in cGVHD of oral mucosa in patients submited to alogeneic bone marrow transplantation, and they may be recruited by inflammatory and immunopathologic process that are characteristic in this disease.

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