Thesis (Ph. D.)--Ohio State University, 2006. / Available online via OhioLINK's ETD Center; full text release delayed at author's request until 2007 May 10

Thesis (Ph.D.)--Kent State University, 2006. / Title from PDF t.p. (viewed Jan. 11, 2007 ) Advisor: J Gary Meszaros. Keywords: cardiac fibroblast, angiotensin II, fibrosis, MAPK Includes bibliographical references (p. 150-168).

Thesis (M. Med. Sc.)--University of Hong Kong, 2005.

Thesis (Ph. D.)--Ohio State University, 2007. / Full text release at OhioLINK's ETD Center delayed at author's request

Abstract Cardiac hypertrophy and remodelling are mechanisms of adaptation to increased workload and acute injuries of the heart. In the long-term, these initially beneficial mechanisms become detrimental and ultimately lead to the development of heart failure. The molecular determinant of myocardial remodelling and heart failure is altered intracellular signal transduction and a modified gene expression pattern in the individual cardiomyocyte. This study was aimed at characterising the changes in mitogen-activated protein kinases (MAPKs) and their nuclear effector, GATA-4, and their functional significance and interaction in experimental models of increased cardiac workload and remodelling. To study the effects of increased cardiac workload on MAPKs and GATA-4, isolated perfused rat hearts were subjected to increased left ventricular wall stress and their activities were determined using western blot and gel mobility shift assays. Left ventricular wall stress rapidly activated the DNA binding of GATA-4, and this activation was abolished in the presence of endothelin-1 (ET-1) and angiotensin II receptor antagonists. Furthermore, the activation of GATA-4 DNA binding was significantly attenuated by p38 MAPK and extracellular signal regulated kinase (ERK) inhibition. To gain further insights into the role of p38 MAPK as a regulator of cardiac transcription factors, gene expression and remodelling, a gene transfer protocol of increased p38 MAPK activity was established. Direct adenovirus-mediated gene transfer of wild-type p38α and constitutively active upstream kinase mitogen-activated kinase kinase 3b (MKK3b) selectively increased p38 MAPK activity in the left ventricle, which was followed by up-regulation of cardiac gene expression, myocardial inflammation and fibrosis. Using a DNA microarray approach, the cardiac target genes of p38 MAPK were identified, including several cell division, inflammation and signal transduction-associated genes. Furthermore, p38 MAPK over-expression was found to increase the DNA binding activities of several transcription factors, including GATA-4. Finally, the functional role of p38 MAPK was determined using adenovirus-mediated gene transfer in an experimental model of myocardial infarction. Post-infarction remodelling was characterised by a sustained down-regulation of p38 MAPK, while rescue of p38 MAPK activity attenuated post-infarction remodelling through anti-apoptotic and angiogenic mechanisms. These results indicate that p38 MAPK is a key regulator of GATA-4 transcription factor and cardiac gene expression during left ventricular wall stress and remodelling. They demonstrate that p38 MAPK, being cardioprotective in the infarcted heart but promoting inflammation and fibrosis in the normal heart, has a unique dual role in the myocardium.

Thesis (Ph. D.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains ix, 86 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

Thesis (Ph. D.)--University of Virginia, 2008. / Title from title page. Includes bibliographical references. Also available online through Digital Dissertations.

Yung, Lai Hang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 93-115). / Abstract also in Chinese. / Declaration --- p.i / Acknowledgements --- p.ii / Abbreviations --- p.iii / Abstract in English --- p.v / Abstract in Chinese --- p.ix / Contents --- p.xi / Chapter Chapter I - --- Introduction / Chapter 1.1) --- Endothelial cells function --- p.1 / Chapter 1.2) --- Oxidative stress in the vascular wall --- p.2 / Chapter 1.2.1) --- Sources of ROS --- p.3 / Chapter 1.2.2) --- Actions of ROS --- p.3 / Chapter 1.2.2.1) --- Impaired endothelium-dependent vasodilatation --- p.3 / Chapter 1.2.2.2) --- VSMC migration --- p.4 / Chapter 1.2.2.3) --- Programmed cell death (cell apoptosis) --- p.4 / Chapter 1.3) --- Endothelial cell apoptosis --- p.7 / Chapter 1.3.1) --- Apoptosis and cardiovascular diseases --- p.7 / Chapter 1.3.2) --- Mechanisms of endothelial cells apoptosis --- p.7 / Chapter 1.3.2.1) --- What are caspases? --- p.8 / Chapter 1.3.2.2) --- Death receptor-mediated apoptosis --- p.9 / Chapter 1.3.2.3) --- Mitochondria-dependent pathway --- p.9 / Chapter 1.3.3) --- Regulations of endothelial cells apoptosis --- p.10 / Chapter 1.3.3.1) --- Oxidative stress --- p.10 / Chapter 1.3.3.2) --- Shear Stress --- p.11 / Chapter 1.3.3.3) --- Growth factors --- p.12 / Chapter 1.3.3.4) --- NO --- p.12 / Chapter 1.3.3.5) --- Inflammatory mediators --- p.13 / Chapter 1.4) --- Mitogen activated kinases signaling in apoptosis --- p.15 / Chapter 1.5) --- Bone morphogenic proteins (BMPs) --- p.17 / Chapter 1.5.1) --- BMPs functions and cardiovascular system --- p.17 / Chapter 1.5.2) --- BMPs signaling pathways --- p.18 / Chapter 1.5.2.1) --- Smad-dependent pathway --- p.18 / Chapter 1.5.2.2) --- MAPKs and SAPKs pathways --- p.19 / Chapter 1.5.2.3) --- Antagonists of BMPs signaling --- p.20 / Chapter 1.5.3) --- BMP4 and cardiovascular diseases --- p.20 / Chapter 1.6) --- "Justification, long-term significance and objectives of the present project" --- p.23 / Chapter Chapter II - --- Methods and Materials / Chapter 2.1) --- Animal handling --- p.24 / Chapter 2.2) --- Endothelial cell isolation and culture --- p.24 / Chapter 2.2.1) --- Primary culture of rat endothelial cells --- p.24 / Chapter 2.2.2) --- Culture of human umbilical cord vein endothelial cells… --- p.25 / Chapter 2.3) --- Apoptosis assessment --- p.25 / Chapter 2.3.1) --- Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay --- p.25 / Chapter 2.3.2) --- Cell death detection ELISA kit --- p.26 / Chapter 2.3.3) --- Flow cytometry --- p.27 / Chapter 2.4) --- Western blot analysis --- p.28 / Chapter 2.4.1) --- Sample preparation --- p.28 / Chapter 2.4.2) --- SDS-PAGE and transfer --- p.28 / Chapter 2.5) --- DHE fluorescence --- p.29 / Chapter 2.6) --- "Drugs, chemicals and other reagents" --- p.30 / Chapter 2.6.1) --- Drugs and chemicals used in the present experiments --- p.30 / Chapter 2.6.2) --- Reagents for Western blot analysis --- p.30 / Chapter 2.6.3) --- Primary antibodies --- p.33 / Chapter 2.7) --- Small interfering RNA experiment --- p.34 / Chapter 2.8) --- Statistical analysis --- p.34 / Chapter Chapter III - --- BMP4 induces endothelial cell apoptosis in ROS related p38 MAPK and JNK mediated caspase-3 dependent pathway / Chapter 3.1) --- Introduction --- p.35 / Chapter 3.2) --- Methods and materials --- p.39 / Chapter 3.2.1) --- Isolation and culture of endothelial cells --- p.39 / Chapter 3.2.2) --- Drugs treatment --- p.39 / Chapter 3.2.3) --- Assay for cell apoptosis --- p.40 / Chapter 3.2.3.1) --- Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay --- p.40 / Chapter 3.2.3.2) --- Cell death detection ELISA kit --- p.41 / Chapter 3.2.3.3) --- Flow cytometric analysis --- p.41 / Chapter 3.2.4) --- Western blot analysis --- p.41 / Chapter 3.2.5) --- Dihydroethidium (DHE) staining --- p.42 / Chapter 3.2.6) --- Statistical analysis --- p.42 / Chapter 3.3) --- Results --- p.43 / Chapter 3.3.1) --- Dose- and time-dependent effect of BMP4 --- p.43 / Chapter 3.3.2) --- Role of caspases in apoptosis of RAECs and HUVECs --- p.43 / Chapter 3.3.3) --- Roles of BMP4 and ROS in endothelial cell apoptosis --- p.44 / Chapter 3.3.3.1) --- Noggin antagonism of BMP4-induced effect --- p.44 / Chapter 3.3.3.2) --- NAD(P)H oxidase-mediated ROS production --- p.44 / Chapter 3.3.3.3) --- Inhibition of endothelial cell apoptosis by ROS scavengers --- p.45 / Chapter 3.3.4) --- Roles of MAPKs/SAPKs in BMP4-induced endothelial cell apoptosis --- p.45 / Chapter 3.3.5) --- Relationship between ROS and MAPKs/SAPKs --- p.46 / Chapter 3.3.6) --- Relationship between p38 MAPK and JNK --- p.46 / Chapter 3.4) --- Discussion --- p.82 / Chapter 3.4.1) --- Caspase-dependent pathways --- p.82 / Chapter 3.4.2) --- Oxidative stress --- p.85 / Chapter 3.4.3) --- Role of MAPKs activation in BMP4-induced endothelial cell apoptosis --- p.87 / Chapter 3.4.4) --- ROS mediates BMP4-induced activation of MAPKs --- p.88 / Chapter 3.4.5) --- Role of p38 MAPK in the activation of JNK 1 --- p.89 / Chapter 3.5) --- Concluding remarks --- p.91 / References --- p.93 / Publications and Awards --- p.116

published_or_final_version / abstract / Biochemistry / Master / Master of Philosophy

published_or_final_version / Paediatrics and Adolescent Medicine / Master / Master of Philosophy