The human skeleton is a dynamic organ that serves multiple functions to maintain normal physiology and health. It protects vital organs, provides support for movement, houses marrow and maintains calcium homeostasis. The skeleton is maintained by the work of two cells with opposing functions: osteoblasts, cells that synthesize organic bone matrix and osteoclasts that degrade and resorb it. These cells interact with one another in a tightly regulated process known as the bone remodeling cycle. This cycle maintains the health of bone by removing and replacing weak or damaged bone and responding to stress loads by remodeling portions of the skeleton that require reinforcement. Osteoblasts differentiate from mesenchymal stem cells and respond to hormonal stimuli by synthesizing and secreting cytokines necessary for osteoclast differentiation. Osteoblasts may become embedded within mineralized matrix, becoming osteocytes, cells that can sense changes in mechanical loading and facilitate localization of the remodeling cycle. Osteoclasts differentiate from hematopoietic stem cells (HSC) when the cell surface receptors, c-FMS and RANK, are activated by ligands produced by osteoblasts, M-CSF and RANKL respectively. In addition to c-FMS and RANK stimulation, another calcium-mediated, co-stimulatory pathway must be activated to ensure proper osteoclast differentiation. This pathway is activated by two immunoreceptors, OSCAR and TREM-2 that interact with adaptor proteins termed FcRγ and DAP12 respectively. These adaptor proteins harbor immunoreceptor tyrosine-based activation motifs (ITAM), which exist on their cytoplasmic tail. Once the immunoreceptors are triggered, specific tyrosines within the ITAM motifs become phosphorylated and act as docking points for the tyrosine kinase, Syk. Once bound, Syk autophosphorylates and acts on its downstream targets. Syk dephosphorylation is, therefore, necessary to attenuate this signal to prevent over activation of osteoclasts. Recently, a novel tyrosine phosphatase, T-cell Ubiquitin ligand -2 (TULA-2) has been shown to dephosphorylate specific phosphotyrosine residues on Syk in various systems and has shown an increased specificity to dephosphorylate tyrosine 352. The goal of this project is to determine how TULA-2 mediated dephosphorylation of Syk regulates osteoclast differentiation and function. TULA-2 is a member of the TULA family of proteins, TULA and TULA-2. In spite of a significant homology and similar domain organization between TULA and TULA-2, only TULA-2 has significant phosphatase activity. Furthermore, whereas TULA is expressed only in lymphocytes, TULA-2 is expressed in most tissues albeit a higher level of expression is seen in cells of hematopoietic origin. In vivo analysis including Micro-computed tomography (Micro CT) and histomorphometry indicated that mice that lack both TULA and TULA-2 (DKO) have decreased bone mass compared to wild-type (WT) counterparts. An in vitro cell differentiation assay revealed that a larger population of osteoclast-like cells (OCL) could be cultivated from bone marrow isolated from DKO mice compared to OCL derived from WT bone marrow. An in vitro resorption pit assay revealed that DKO osteoclasts could resorb bone at a faster rate than WT counterparts. Additionally, over-expression of phosphatase-dead TULA-2 in WT osteoclasts increased the ability of the cells to resorb bone. At the molecular level, activation of the co-stimulatory pathway revealed increased tyrosine phosphorylation of Syk 352 in DKO pre-osteoclasts when compared to phosphorylation of Syk isolated from WT pre-osteoclasts. Cumulatively, the above data indicates that the absence of TULA-2 results in an increased signaling response leading to a larger population of hyperactive osteoclasts, which contributes to decreased bone mass in mice. These data suggest that the phosphatase activity of TULA-2 is required for negative regulation of bone resorption. / Cell Biology

Eukaryotic organisms require the ability to respond to their environments. They do so by utilizing signal transduction pathways that allow for signals to effect final biological responses. Many times, these final responses require new gene expression events that have been stimulated or repressed within the nucleus. Thus, much of the understanding of signal transduction pathways converges on the understanding of how signaling affects gene expression alterations (Kumar et al., 2004). The regulation of gene expression involves the modification of chromatin between condensed (closed, silent) and expanded (open, active) states. Histone modifications, such as acetylation, can determine the open versus closed status of chromatin. The PHD (Plant HomeoDomain) finger is a structural domain primarily found in nuclear proteins across eukaryotes. This domain specifically recognizes the epigenetic marks H3K4me2 and H3K4me3, which are di- and tri-methylated lysine 4 residues of Histone H3 (Loewith et al., 2000; Kuzmichev et al., 2002; Vieyra et al. 2002; Shiseki et al., 2003; Pedeux et al., 2005, Doyon et al., 2006). It is estimated that there are ~150 proteins that contain the PHD finger in humans (Solimon and Riabowol, 2007). The PHD finger is conserved in yeast and plants, however an analysis of this domain has only been performed done in Arabidopsis thaliana (Lee et al., 2009). The work presented in this report aims to extend the analysis of this domain in plants by identifying the PHD fingers of the crop species Oryza sativa (rice). In addition, a phylogenetic analysis of all PHD fingers in Arabidopsis and rice was undertaken. From these analyses, it was determined that there are 78 PHD fingers in Arabidopsis and 70 in rice. In addition, these domains can be categorized into classes and groups by defining features within the conserved motif. In a separate study, I investigated the function of two of the PHD finger proteins from Arabidopsis, ING1 (INhibitor of Growth1) and ING2. In humans, these proteins can be found in complexes associated with both open and closed chromatin. They facilitate chromatin remodeling by recruiting histone acetyltransferases and histone deacetylases to chromatin (Doyon et al., 2006, Pena et al., 2006). In addition, these proteins recognize H3K4me2/3 marks and are believed to be "interpreters" of the histone code (Pena et al., 2006, Shi et al., 2006). To understand the function of ING proteins in plants, I took a reverse genetics approach and characterized ing1 and ing2 mutants. My analysis revealed that these mutants are altered in time of flowering, as well as their response to nutrient and stress conditions. Lastly, I was able to show that ING2 protein interacts in vitro with SnRK1.1, a nutrient/stress sensor (Baena-Gonzalez et al., 2007). These results indicate a novel function for PHD proteins in plant growth, development and stress response. / Master of Science

Ischemic heart disease is a leading cause of death worldwide. Ubiquitin (UB), an evolutionary conserved protein, is found in all eukaryotic cells. Previous work has shown that treatment of mice with exogenous UB (eUB) reduces inflammatory response and preserves heart function 3 days following ischemia/reperfusion injury (I/R). This study investigated the long-term (28 days post-I/R) cardioprotective potential of eUB using a mouse model of myocardial I/R; and tested the hypothesis that eUB modulates phenotype and function of macrophages (key cells involved in inflammation post-I/R) using thioglycolate-elicited mouse peritoneal macrophages. Heart function measured at 3, 7, 14 and 28 days post-I/R using echocardiography showed that eUB improves heart function throughout the observation period, and decreases I/R-mediated increase in left ventricular dilation at 3, 14 and 28 days timepoints. Myocardial fibrosis, hypertrophy and apoptosis were lower in eUB-treated hearts 28 days post-I/R. These changes in the heart associated with decreased expression of fibrosis-related proteins (collagen-1α1 and MMP-2) and hypertrophy-related protein (MYH-7B) in UB-treated hearts. Activation of GSK3β (pro-apoptotic kinase) was lower (vs. Sham), while activation of anti-apoptotic kinases, ERK1/2 (vs. I/R) and Akt (vs. Sham), was higher in eUB-treated hearts 28 days post-I/R. Serum levels of IL-6, IL-2 and G-CSF were lower in I/R+UB vs. I/R group 28 days post-I/R. In peritoneal macrophages, eUB induced cytoskeleton reorganization in M1-polarized (IFNγ treatment for 72 hours; 100U/mL) and M2-polarized (IL-4 treatment for 72 hours; 20ng/mL) cells. eUB decreased secretion of IL-1β and TNFα in M1-polarized macrophages, while it decreased secretion of TNFα, IL-10 and GM-CSF in M2-polarized macrophages. Efferocytosis was lower in eUB-treated M2-polarized macrophages, which was reversed by CXCR4 receptor antagonist (AMD3100). eUB enhanced migration of M1-polarized macrophages, while it decreased the migration of M2-polarized macrophages. AMD3100 negated the effects of eUB on M1-polarized macrophage migration. eUB decreased activation of STAT1 and FAK, while increasing activation of ERK1/2 in M1-polarized macrophages. In M2-polarized macrophages, eUB decreased Akt activation. Thus, UB treatment preserves heart function and decreases adverse cardiac remodeling 28 days post-I/R. In polarized macrophages, eUB reduces secretion of inflammatory cytokines, and alters phenotype and function of M1- and M2-polarized macrophages.

The cellular microenvironment in vivo consists of both mechanical and chemical signals, which drive cell function and fate. These signals include the composition, architecture, and mechanical properties of the extracellular matrix (ECM), signaling molecules secreted by cells into their surroundings, as well as physical interactions between neighboring cells. Cells are able to interact with their surroundings through a number of different mechanisms such as remodeling of the ECM through adhesion, contraction, degradation, and deposition of proteins, as well as the secretion of pro- or anti-inflammatory molecules. In diseased states, where homeostasis has been perturbed, inflammatory signals are secreted which can modify the cellular microenvironment. Diseased states such as cancer and fibrosis are often associated with the excessive production of ECM proteins that subsequently lead to an increase in tissue stiffness and changes to ECM architecture. Such changes to the mechanical properties of the cellular microenvironment affect the cytoskeletal arrangement, migration and adhesion of both the parenchymal cells, as well as immune response cells, which migrate to the sites of injury. Further understanding of the inflammatory responses and their relationships to tissue stiffness and ECM architecture could aid in the development of novel strategies to predict diseases as well as to target and monitor therapies. Since inflammation and mechanical properties of the affected tissue are closely interlinked, obtaining a detailed understanding of the interplay between the properties of the microenvironment and the cells that reside within it will be very beneficial to obtain physiologically relevant information. We have investigated the combinatorial effects of matrix stiffness, and architecture in the presence of co-cultures of cells to determine the overall effect on cellular responses and phenotypes. We have conducted studies on co-cultures of cells in 2D and 3D environments to identify how cellular behavior is affected by dimensionality. / PHD / The cellular microenvironment in vivo consists of both mechanical and chemical signals, which drive cell function and fate. These signals include the composition and organization of the extracellular matrix (ECM), signaling molecules secreted by cells into their surroundings, as well as physical interactions between neighboring cells. Cells are able to interact with their surroundings through reorganization of the ECM and secretion of pro- or anti-inflammatory molecules. In diseased states, inflammatory signals are secreted which can modify the cellular microenvironment. Diseased states such as cancer and fibrosis are often associated with the excessive production of ECM proteins that subsequently lead to an increase in tissue stiffness and changes to ECM architecture. Such changes to the mechanical properties of the cellular microenvironment affect the function and behavior of cells within a given tissue. Further understanding of the inflammatory responses and their relationships to tissue stiffness and ECM architecture could aid in the development of novel strategies to predict diseases as well as to target and monitor therapies. Since inflammation and mechanical properties of the affected tissue are closely interlinked, obtaining a detailed understanding of the interplay between the properties of the microenvironment and the cells that reside within it will be very beneficial to obtain physiologically relevant information. We have investigated the combinatorial effects of matrix stiffness, and architecture in the presence of co-cultures of cells to determine the overall effect on cellular responses and phenotypes. We have conducted studies on co-cultures of cells in 2D and 3D environments to identify how cellular behavior is affected by dimensionality.

Yes / Cardiovascular disease is a leading cause of morbidity and mortality. Smooth muscle cells (SMC) comprising the vascular wall can switch phenotypes from contractile to synthetic, which can promote the development of aberrant remodelling and intimal hyperplasia (IH). MicroRNA‐21 (miR‐21) is a short, non‐coding RNA that has been implicated in cardiovascular diseases including proliferative vascular disease and ischaemic heart disease. However, its involvement in the complex development of atherosclerosis has yet to be ascertained. Smooth muscle cells (SMC) were isolated from human saphenous veins (SV). miR‐21 was over‐expressed and the impact of this on morphology, proliferation, gene and protein expression related to synthetic SMC phenotypes monitored. Over‐expression of miR‐21 increased the spread cell area and proliferative capacity of SV‐SMC and expression of MMP‐1, whilst reducing RECK protein, indicating a switch to the synthetic phenotype. Furthermore, platelet‐derived growth factor BB (PDGF‐BB; a growth factor implicated in vasculoproliferative conditions) was able to induce miR‐21 expression via the PI3K and ERK signalling pathways. This study has revealed a mechanism whereby PDGF‐BB induces expression of miR‐21 in SV‐SMC, subsequently driving conversion to a synthetic SMC phenotype, propagating the development of IH. Thus, these signaling pathways may be attractive therapeutic targets to minimise progression of the disease. / King Saud University; College of Medicine , Riyadh, Saudi Arabia

The chromatin structure, consisting of DNA and histones, changes dynamically during the cell cycle and cell differentiation. DNA can only be transcribed and replicated when it is packaged loosely, whereas tight packaging allows for more efficient storage. Chromatin remodelling is therefore one of the tools of gene expression control. The chromatin remodelling factors recognise chromatin with varying specificity and have an effect on the interaction between DNA and the histones. One of these factors is the Smarca5 protein. This study investigates the role of Smarca5; its goal is to create a mouse model with the ability to trigger Smarca5 overproduction in specific tissues. This model will be used to study the effect of a high, unregulated dose of Smarca5 on the physiological function of the protein. Previous studies have shown that non-physiological expression of a chromatin-remodelling factor can lead to malignant transformation. Our model can help to understand this process. Another goal of this study is to investigate some phenotype aspects of the mouse model with conditional deletion of Smarca5 in T and B cells, in particular the effects of this deletion on progenitor cell differentiation. Our results show that Smarca5 has an important role in lymphocyte development, and we have observed that...

Herzinsuffizienz mit konsekutivem Herzversagen ist ein zentrales kardiovaskuläres Problem der heutigen Bevölkerung.Ursächlich ist insbesondere eine progrediente Herzhypertrophie. Die Calcium-Calmodulin abhängige Phosphatase Calcineurin (CnR) spielt hierbei in der Pathogenese eine entscheidende Rolle. CnR wird über seine Calciumbindungsstellen an der regulatorischen Untereinheit Calcineurin B (CnB) aktiviert.Um zu untersuchen, inwieweit CnB bei der Hypertrophie verschiedener Ätiologien reguliert wird, wurde in linksventrikulären Myokardbiopsien von Patienten mit Aortenstenose (AS= 14) bzw. aus explantierten Herzen mit Dilatativer Kardiomyopathie (DCM=27) und Koronarer Herzerkrankung (KHK=7) der mRNA-und Proteingehalt von CnB bestimmt und mit der Expression von ANP und BNP korreliert. Als Kontrollgruppe dienten 15 abgelehnte Spenderherzen mit normaler systolischer Funktion und gesunder Morphologie. In den Herzen der Kontroll-, DCM-, und KHK-Gruppen wurde der linksventrikuläre Fibrosegehalt bestimmt. Hierzu wurden eine extern standardisierte Real-Time-PCR-Technik und ein etabliertes Western Blot Verfahren angewandt. Die Ergebnisse werden im Median ± 25%/75%-Perzentile angegeben und mit dem Mann-Whitney-Test bzw. Korrelationsanalysen nach Spearman berechnet. In den Herzen mit DCM zeigte sich eine signifikante Erhöhung der CnB mRNA auf ca. das Dreifache der Kontrollen (293% der Ko, p / Heart failure is a central cardiovascular problem for the current population. Cardiac hypertrophy is a central factor. The calcium-Calmodulin dependent phosphatase Calcineurin (CnR) plays a crucial role in the pathogenesis. CnR is activated via its calcium-binding site in the regulatory subunit Calcineurin B (CnB). In order to examine, to what extent CnB is regulated in different aetiologies of hypertrophy, we analysed CnB´s mRNA and protein in left ventricular samples from patients with aortic valve stenosis (AS = 14) and from explanted hearts with dilated (DCM=27) and ischemic (ICM=7) cardiomyopathy and correlated them with the expression of ANP and BNP. As a control, 15 rejected donor hearts with normal systolic function and non-pathologic changed morphology were used. Fibrosis of the left ventricle was determined in three groups: control , DCM and ICM. Therefore, we used an externally standardized real-time PCR and an established Western Blot. Data are given as median ± 25%/75%- percentiles; Mann Whitney test and Spearman´s correlation-analyses were used. CnB mRNA was significantly raised in DCM (293% of control, p

As doenças renais crônicas (DRC) evoluem com distúrbios na homeostase do cálcio e do fósforo, diminuição na produção de vitamina D e aumento na secreção de PTH. Osteodistrofia renal (OR) é o termo usado para definir as alterações ósseas dos pacientes com DRC e classifica-se em doença de alta remodelação representada pela osteíte fibrosa (OF) e doença mista (DM); e de baixa remodelação representada pela osteomalácia (OM) e pela doença adinâmica (DOA). Pacientes com DRC apresentam elevada incidência de fraturas e recentemente demonstrou-se que a hiperfosfatemia leva a diminuição do volume ósseo. Estudamos o efeito isolado do fósforo no tecido ósseo de animais com insuficiência renal mantidos com infusão fixa de PTH variando o conteúdo de fósforo na dieta. Cinqüenta e cinco ratos Wistar foram submetidos à paratireoidectomia (PTX) e nefrectomia (Nx) com reposição de PTH em diferentes concentrações ou foram sham operados e recebiam infusão de veículo. Todos os animais receberam a mesma dieta variando apenas a concentração de P (pobre em P (pP): 0,2% e rico em P (rP):1,2%). Dividimos os grupos em: Sham (N=8); Sham-pP (N=8); Sham-rP (N=7); NxPTHn-pP (N=8); NxPTHn-rP (N=8); NxPTHe-pP (N=9); NxPTHe-rP (N=7). Após 2 meses, realizamos análises bioquímicas e histomorfometria do fêmur proximal. Os animais que ingeriram dieta rica em fósforo apresentaram hiperfosfatemia assim como menor valor de cálcio sérico. A reposição de PTH foi efetiva e proporcional às concentrações infundidas. A histomorfometria óssea mostrou que os ratos que ingeriram dieta rica em fósforo independente da uremia tinham diminuição do volume ósseo (BV/TV), e que este efeito foi amenizado pela reposição do PTH em concentrações elevadas. Nossos resultados demonstram que o fósforo é deletério para o tecido ósseo e que na uremia são necessários níveis mais elevados de PTH para manter a integridade óssea. / Chronic kidney disease (CKD) involves disturbances in calcium and phosphorus metabolism, reduced vitamin D production and increased parathormone (PTH) secretion. Renal osteodistrophy (RO) is a term used to define bone disease complications of patients with CKD, and is classified in high turnover disease represented by osteitis fibrosa (OF) and mixed bone disease; and low turnover disease represented by osteomalacia (OM) and adynamic bone disease (ABD). It is already known that patients with CKD have high incidence of bone fractures, and it has been demonstrated that hyperphosphatemia results in to decreased trabecular bone volume (BV/TV). We evaluated the effect of phosphorus (P) in rats? bone tissue submitted to experimental uremia that received continuous infusion of 1-34 rat PTH in physiologic or five times the normal values. Fifty five Wistar rats were submitted to parathyroidectomy (PTX), nephrectomy (Nx) and received PTH in different concentrations or some were PTX and NX controls (Sham) that received only vehicle. Rats received identical diets, excepted for the P content which was different according to the group [Low P (LP): 0,2% and high P (HP): 1,2%]. Groups were divided as follow: Sham (N=8), Sham LP (N=8), Sham-HP (N=7), NxPTHn-LP (N=8), NxPTHn-HP (N=8), NxPTHh-LP (N=9), NxPTHh-HP (N=7). After two months, animals were sacrificed and biochemical and bone histomorphometry were performed. Rats who received high P diet developed hyperphosphatemia and hypocalcemia. PTH replacement was effective and in accordance with infusion concentration. Bone histomorphometric analysis showed that HP rats presented low trabecular bone volume (BV/TV) independently of the uremia. BV/TV decreased slightly in the group where PTH continuous infusion was five times the physiologic values. Our results demonstrated that P has a deleterious action on bone tissue and in uremia it is necessary high levels of PTH to maintain bone integrity.

Lam Hiu Yan, Janice. / "Architecture Department, Chinese University of Hong Kong, Master of Architecture Programme 2010-2011, design report." / Includes bibliographical references.

Tsang Chui Lan, Cara. / "Architecture Department, Chinese University of Hong Kong, Master of Architecture Programme 2006-2007, design report." / Includes bibliographical references (p. 68) / Chapter 1.0 --- Foreword / Chapter 1.0.1 --- Thesis Statement / Chapter 2.0 --- Background Study / Chapter 2.0.1 --- Old Dilapidated Industrial Buildings / Chapter 2.0.2 --- Other Uses in Industrial Buildings / Chapter 2.0.3 --- Exhibition Sites / Chapter 2.0.4 --- Concern of Artist / Chapter 2.0.5 --- Existing Galleries / Chapter 3.0 --- Site Study_ FoTan / Chapter 3.0.1 --- City Level _ FoTan Industrial District / Chapter 3.0.2 --- Building Level _ Wah Luen Industrial Center / Chapter 3.0.3 --- Unit Level _ Interview of Artsit / Chapter 4.0 --- Design / Chapter 4.0.1 --- Material / Chapter 4.0.2 --- City Level / Chapter 4.0.3 --- District Level / Chapter 4.0.4 --- Unit Level / Chapter 4.0.5 --- Details / Chapter 5.0 --- Precedent Study / Chapter 5.0.1 --- Steven Holl's Project / Chapter 5.0.2 --- Intervention / Chapter 5.0.2 --- Details / Chapter 6.0 --- Reading List / Chapter 7.0 --- Final Panels