Atherosclerosis and symptoms of metabolic syndrome such as obesity, high cholesterol, and insulin resistance often coincide and exacerbate one another, but the cellular and molecular events in common with these conditions have not yet been fully elucidated. Low density lipoprotein receptor adaptor protein 1 (LDLRAP1) is an adaptor protein which interacts with the cytoplasmic tail of the LDL receptor, internalizing the receptor when it engages with LDL. Mutations in this gene lead to LDLR malfunction and cause Autosomal Recessive Hypercholesterolemia (ARH) in humans; however, direct causality on atherogenesis or metabolism in a defined pre-clinical model has not been reported. The aim of this study was to test the hypothesis that deletion of LDLRAP1 would lead to hypercholesterolemia and atherosclerosis. LDLRAP1-/- mice fed a high fat, western diet (HFD) for 16 weeks had significantly increased plasma cholesterol and triglyceride concentrations, accompanied with significantly increased plaque burden compared with wild-type controls. Unexpectedly, LDLRAP1-/- mice gained significantly more weight compared to the wild-type, LDLRAP1-/- mice were insulin resistant, and calorimetric studies suggested an altered metabolic profile. We determined that LDLRAP1 is highly expressed in white adipose tissue (WAT), and LDLRAP1-/- adipocytes are significantly larger and have reduced glucose uptake and AKT phosphorylation, but increased CD36 expression. WAT from LDLRAP1-/- mice is hypoxic, and has gene expression signatures of dysregulated lipid storage and energy homeostasis. These data indicate that lack of LDLRAP1 directly leads to atherosclerosis in mice, and also are the first to suggest that LDLRAP1 plays an unanticipated metabolic regulatory role in adipose tissue. LDLRAP1 deletion leads to systemic effects, and may act as a molecular link which regulates dyslipidemia, atherosclerosis, insulin resistance, and obesity. / Biomedical Sciences

Myeloid cells of the innate immune system have been strongly implicated in the pathogenesis of neurodegenerative diseases, including Alzheimer’s disease (AD) and Parkinson’s disease (PD). Similarly, several lines of evidence call on the adaptive immune system as a critical driver of disease, particularly in PD. The immune dynamics in both of these diseases are complex, and span across not only the innate and adaptive immune systems, but also across the periphery local action in the central nervous system (CNS). This thesis aims to address critical gaps in our knowledge regarding molecular and functional alterations of immune cells in AD and PD. We apply tools including single nucleus RNA – and ATAC – sequencing as well as protein – level and functional studies to advance our understanding of molecular pathways involved in the innate and adaptive immune dysfunction in these diseases, including both immune cells in the CNS as well as in the periphery. Chapter 1 provides an overview of the evidence implicating myeloid cell dysfunction in AD and PD, including microglia as well as peripheral myeloid cells such as monocytes. It also describes the features of immune dysregulation in both diseases, and evidence implicating the adaptive immune system in PD. Chapter 2 aims to address our currently limited understanding of microglial molecular phenotypes and diversity in PD, by characterizing microglial transcriptomic and chromatin signatures in disease. We demonstrate microglial subpopulation-specific effects, including the focal depletion of a microglial population in the substantia nigra in PD, which open novel avenues for targeted neuroimmune interventions in PD. Chapter 3 aims to identify interactions regulating the infiltration and retention of peripheral immune cells into the CNS in PD; a process which is implicated in the progression of this disease, but the mechanisms of which are not fully understood. We characterized transcriptomic signatures of infiltrating lymphocytes and blood brain barrier cells, and found increased T cell infiltration in PD as well as fibroblast and endothelial populations associated with disease. We further identified transcriptional shifts suggestive of a proinflammatory and profibrotic milieu in disease, in which chemokines and extracellular matrix elements produced by fibroblasts may influence T cell trafficking and retention in the substantia nigra in PD. Chapter 4 aims to address the gap in our knowledge of how myeloid dysfunction in the periphery contributes to AD. While genetics implicate all myeloid cells in AD and PD, contributions of peripheral myeloid cells, such as monocytes, have been largely overlooked in place of microglia, which are resident in the CNS. We evaluate the convergence of the AD genetic risk loci on functional outcomes in monocytes, in the context of Aβ as an immune stimulus. We identified functional convergence of the CD33 and SPI1 AD risk variants in the context of Aβ stress, including reduced phagocytosis and loss of surface TREM2 expression, demonstrating an interaction between genetics and environment to reduce myeloid cell fitness. Finally, Chapter 5 concludes with a summary of key findings from this work, and discusses future directions for modulating innate and adaptive immune populations, both in the CNS and in the periphery, as therapeutic approaches for these neurodegenerative diseases.

Huntington's Disease (HD) is a devastating neurodegenerative disorder caused by an expanded polyglutamine repeat within the Huntingtin gene IT15. In this study we demonstrated that Bcl-2 interacting mediator of cell death Extra Long (BimEL) protein expression was significantly increased in cells expressing mutant Huntingtin (mHtt). Moreover, striatal BimEL expression remained high in an R6/2 HD mouse model throughout the disease progression. Utilizing novel BimEL phospho-mutants we demonstrated the phosphorylation of Ser65 to be important for the stabilization of BimEL. We provided evidence that impaired proteasome function, increased JNK activity and reduced striatal BDNF lead to changes in the phosphorylation of BimEL, thereby promoting its stabilization specifically within the striatum of R6/2 mice. Furthermore, knocking down BimEL expression prevented mHtt-induced cell death in a HD cell culture. Taken together, these findings suggest that BimEL may contribute to the selective neurodegeneration and pathogenesis of HD. / by Rebecca Leon. / Thesis (Ph.D.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

The a of TNFa in title is the Greek alpha. / Thesis (MSc)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: Background: Cardiac hypertrophy is an adaptive process occurring in response to mechanical overload or tissue injury. The stimuli for cardiac hypertrophy are diverse and vary from increased afterload on the heart to cardiac remodeling in response to cytokines. Amongst others, obesity is characterized by excessive body weight resulting in metabolic disorders. This excess body weight necessitates an increased blood and oxygen delivery to the peripheral tissues, which is achieved by an elevated cardiac output. Total blood volume is also increased in the obese due to the increased tissue volume and vascularity. With time, the obesity induced increase in cardiac preload results in left ventricular hypertrophy and dilatation. Obesity is also associated with complications such as hypertension, insulin resistance and impaired glucose metabolism. In addition, adipose tissue has been implicated to contribute to elevated circulating TNFa levels in obesity and may contribute to the pathophysiology of the heart in obese individuals. The heart is a major cytokine-producing organ that generates amongst others tumor necrosis factor a (TNFa). TNFa is a proinflammatory cytokine, which acts to increase its own production, has cytotoxic and cytostatic effects on certain tumor cells and influences growth and differentiation in virtually all cell types including cardiomyocytes. Elevated levels of TNFa are detected peripherally in almost all forms of cardiac injury and in hypertrophic cardiomyopathy. These elevations are proposed to be deleterious to the heart, although an adaptive role for low levels of TNFa has been proposed. Aim: The aim of the study was to determine whether there is a correlation between obesity and serum, myocardial, and adipose tissue TNFa levels and cardiac hypertrophy. We also wished to determine whether the hearts from the obese animals functioned normally under normoxic conditions and whether they responded differently to ischaemia/reperfusion when compared with their concurrent controls. Materials and Methods: Male Sprague-Dawley rats (n=100) were fed a high caloric diet (HCD) containing 33% rat chow, 33% condensed milk, 7% sucrose and 27% water, or standard laboratory rat chow for 6-12 weeks. Food consumption, body weight gain, heart weight and tibia length were measured. Serum glucose, insulin and lipid levels were also determined. Hearts were excised and perfused on the isolated Working Heart perfusion apparatus and cardiac function was monitored and documented. Hearts were then subjected to 15 minutes of total global ischaemia at 370C, and reperfused for 30 minutes. Cardiac function was again documented. A separate series of hearts were freeze-clamped at different time points during the experimental protocol and stored in liquid nitrogen for the determination of myocardial TNFa and cGMP levels. Serum TNFa levels were determined after 12 weeks on the high caloric or normal/control diet. After 12 weeks on the diet myocardial TNFa levels of the HCD fed animals and their concurrent controls were determined before and during ischaemia. Adipose tissue and myocardial tissue TNFa levels were also determined after 6, 9 and 12 weeks on the respective diets. Myocardial cGMP levels were measured in the HCD fed rats and the control rats after 6, 9, and 12 weeks. These data were used as an indirect index to determine whether the myocardial NOcGMP pathway was activated in the normoxic hearts on the respective diets. Results: The body weight of the HCO fed animals was significantly higher compared with their respective controls after 12 weeks on the diet (459.9 ± 173.8 g and 271.5 ± 102.6 g respectively (p<0.05». The HCO fed animals also had heart weight to body weight ratios that were significantly greater compared with the controls (4.2 ± 0.1 mglg and 3.7 ± 0.1 mglg respectively (p<0.05». The plasma glucose levels of the HCO fed animals were higher than their respective controls (9.2 ± 0.3 mmoiII and 7.8 ± 0.3 mmoiII respectively (p<0.05)), but their insulin levels were similar (12.87 ± 1.02 IlIUlml and 12.42 ± 5.06 IlIU/ml). Plasma lipid profiles (plasma cholesterol, high density lipoprotein (HOL) cholesterol and plasma triacylglyceride (TAG)) were abnormal in the HCO fed animals compared with the control rats. Plasma TAG levels in the HCO fed animals were significantly higher compared with the control rats (0.664 ± 0.062 mmoiII and 0.503 ± 0.043 (p<0.05», while plasma cholesterol levels (1.794 ± 0.058 mmoIII and 2.082 ± 0.062 mmoiII (p<0.05» and HOL cholesterol levels were significantly lower (1.207 ± 0.031 mmoiII and 1.451 ± 0.050 mmoiII (p<0.05». Cardiac mechanical function was similar for both groups before ischaemia, but the percentage aortic output recovery was lower for the hearts from the HCO fed animals when compared with their controls (47.86 ± 7.87% and 66.67 ± 3.76 % respectively (p<0.05». Serum TNFa levels of the HCO fed animals were higher compared with the control animals (51.04 ± 5.14 AU and 31.46 ± 3.72 AU respectively (p<0.05», but myocardial TNFa levels remained lower in these animals (312.0 ± 44.7 pglgram ww and 571.4 ± 132.9 pg/gram ww respectively (p<0.05)). During ischaemia these myocardial TNFa levels increased above those of the controls (442.9 ± 12.4 pg/gram ww and 410.0 ± 12.5 pg/gram ww respectively (p<0.05)). The adipose tissue TNFa levels were significantly increased after 12 weeks on the high caloric diet compared with the control animals (4.4 ± 0.4 pg/gram ww and 2.5 ± 0.3 pg/gram ww respectively (p<0.05)). There was no significant difference in the myocardial cGMP levels of the HCD rats compared with the conrol rats after 6, 9 and 12 weeks. Conclusion: 1) The high caloric diet induced obesity, which lead to cardiac hypertrophy in this study. 2) There was a strong correlation between elevated adipose tissue and serum TNFa levels, and cardiac hypertrophy. 3) Elevated serum TNFa levels did not lead to activation of the myocardial NO-cGMP pathway in the normoxic hearts in this model. 4) The hypertrophied hearts from the HCD fed animals had poorer post-ischaemie myocardial functions than their concurrent controls. / AFRIKAANSE OPSOMMING: Agtergrond: Miokardiale hipertrofie is In aanpassing wat gebeur as In gevolg van meganiese oorbelading of weefsel beskadiging. Verskillende stimuli kan tot miokardiale hipertrofie aanleiding gee soos byvoorbeeld In verhoging in nalading, of miokardiale hermodellering in respons op sitokiene. Verhoging van voorbelading in vetsug mag ook tot hipertrofie aanleiding gee. Vetsug word gekenmerk deur In oormatige liggaamsmassa wat tot metaboliese versteurings lei. Die oormatige liggaamsmassa vereis In verhoging in bloed- en suurstofverskaffing aan die perifere weefsel wat deur In verhoging in die kardiale uitset vermag kan word. Die bloed volume van In vetsugtige individu word ook verhoog as gevolg van In verhoging in weefselvolume en vaskulariteit en met verloop van tyd induseer die verhoogde kardiale voorbelading linker ventrikulêre hipertrofie en dilatasie. Vetsug word ook met verskeie ander siekte toestande soos hipertensie, insulien weerstandigheid en versteurde glukose metabolisme, geassosieer. Vetweefsel dra ook by tot verhoging van tumor nekrose faktor alfa (TNFa) vlakke in die bloed, wat op sy beurt tot miokardiale hipertrofie mag bydra. TNFa is In proinflammatoriese sitokien wat sy eie produksie kan stimuleer. Dit het ook sitotoksiese en sitostatiese effekte op sekere tumor selle en kan groei en differensiasie in bykans alle seltipes, insluitende kardiomiosiete, stimuleer. Die hart kan ook TNFa produseer en verhoogde TNFa vlakke word feitlik in alle vorms van miokardiale besering en hipertrofiese kardiomiopatie waargeneem. Daar word voorgestel dat verhoogde TNFa vlakke vir die hart nadelig is, ten spyte van die vermoeding dat die sitokien In potensiële aanpassings rol by laer vlakke het. Doelstelling: Die doel van hierdie studie was om vas te stelof daar 'n verband tussen vetsug en serum, miokardiale en vetweefsel TNFa vlakke en miokardiale hipertrofie, bestaan. Ons het ook gepoog om te bepaal of harte van vetsugtige diere normaal funksioneer en of die response van sulke harte op isgemie-herperfusie van die van ooreenstemmende kontroles verskil. Materiaal en tegnieke: Manlike Sprague-Dawley rotte (n=100) is vir 6-12 weke op 'n hoë kalorie dieët (HKD) geplaas. Die HKD het uit 33% rotkos, 33% gekondenseerde melk, 7% sukrose en 27% water bestaan. Kontrole diere het standaard laboratorium rotkos ontvang. Voedselinname, liggaamsmassa toename, serum insulien, glukose en lipied vlakke is ook bepaal. Harte is geïsoleer en geperfuseer volgens die Werk Hart perfusie metode en hart funksie is gemonitor en gedokumenteer. Harte is vervolgens aan 15 minute globale isgemie by 3rC blootgestel en daarna weer vir 30 minute geherperfuseer waartydens hartfunksie weer gedokumenteer is. 'n Aparte groep harte is op spesifieke tydsintervalle gedurende die eksperimentele protokol gevriesklamp en in vloeibare stikstof gestoor vir die bepaling van miokardiale TNFa en sGMP vlakke. Serum TNFa vlakke is bepaal na 12 weke op die dieët. Na die diere 12 weke op die HKD was, is hierdie diere en hulooreenstemmende kontroles se miokardiale TNFa vlakke voor en na isgemie bepaal. Vetweefsel en miokardiale TNFa vlakke is ook onderskeidelik na 6, 9 en 12 weke bepaal. Miokardiale sGMP vlakke is in die HKD diere en in die kontrole diere na 6, 9 en 12 weke bepaal. sGMP vlakke is gebruik as 'n indirekte indeks van aktivering van die miokardiale NO-sGMP boodskapper pad. Resultate: Na 12 weke op die dieët was die liggaamsmassa van die HKD diere beduidend hoër in vergeleke met hulooreenstemmende kontroles (459.9 ± 173.8 g en 271.5 ± 102.6 g (p<0.05)). Die HKD diere se hart massa tot liggaam massa verhouding was ook beduidend hoër in vergelyking met die van kontroles (4.2 ± 0.1 mglg en 3.7 ± 0.1 mglg (p<0.05)). Alhoewel insulien vlakke dieselfde was (12.42 ± 5.06 j.lIU/ml en 12.87 ± 1.02 j.lIU/ml), was serum glukose vlakke van die HKD diere hoër as die van die ooreenstemmende kontroles (9.2 ± 0.3 mmoiii en 7.8 ± 0.3 mmoiii (p<0.05)). Plasma lipied profiele (HOL cholesterol, plasma cholesterol en trigliseriede) was abnormaal in die HKD diere. Plasma TAG vlakke in die HKD diere was beduidend hoër as die van die kontroles (0.664 ± 0.062 mmoiii en 0.503 ± 0.043 (p<0.05)), terwyl plasma cholesterol vlakke (1.794 ± 0.058 mmoiii en 2.082 ± 0.062 mmoiii (p<0.05)) en HOL cholesterol vlakke beduidend laer was (1.207 ± 0.031 mmoiii en 1.451 ± 0.050 mmoiii (p<0.05)). Miokardiale meganiese funksie was dieselfde vir beide groepe voor isgemie, maar die persentasie aorta omset herstel tydens herperfusie was laer in die HKD diere in vergelyking met die van kontrole diere (47.86 ±. 7.87% en 66.67 ± 3.76% (p<0.05)). Serum TNFa vlakke van die HKD diere was beduidend hoër as die van kontrole diere (51.04 ± 5.14 AU en 31.46 ± 3.72 AU (p<0.05)), maar miokardiale TNFa vlakke was laer (312.0 ± 44.7 pglgram nat gewig en 571.4 ± 132.9 pglgram nat gewig (p<0.05)). Die vetweefsel TNFa vlakke was ook beduidend verhoog na 12 weke op "n hoë kalorie dieët wanneer dit vergelyk word met die van kontrole diere (4.4 ± 0.4 pglgram nat gewig en 2.5 ± 0.3 pglgram nat gewig respektiewelik (p<0.05)). Daar was geenbeduidende verskille in die miocardiale vlakke van sGMP in die HKD diere in vergelyking met die kontroles na 6, 9 en 12 weke. Gevolgtrekkings: 1) "n Hoë kalorie dieët het in dié studie vetsug geïnduseer en tot miokardiale hipertrofie gelei. 2) Daar was "n positiewe korrelasie tussen verhoogde vetweefsel en serum TNFa vlakke, en miokardiale hipertrofie. 3) Verhoogde serum TNFa vlakke het nie tot die aktivering van die miokardiale NO-sGMP pad in hierdie model gelei nie. 4) Die hipertrofiese harte het tydens herperfusie ná isgemie swakker as hulooreenstemmende kontroles gefunksioneer.

published_or_final_version / abstract / Pharmacology / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Medicine / Master / Master of Philosophy

published_or_final_version / abstract / Anatomy / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Pharmacology / Master / Master of Philosophy

published_or_final_version / Medicine / Master / Master of Philosophy

This study analyzed the relationship between the OF functioning of 100 incarcerated male offenders and their psychopathy symptoms. The study's rejected hypothesis had predicted a significant relationship between measures of OF functioning and the Defective Affective Experience (DAE) and Impulsive and Irresponsible Behavioral Style (IIB) factors of the Cooke and Michie (2001) three-factor model of psychopathy. Regression analysis failed to demonstrate a relationship between OF functioning and the DAE and IIB factors. Group differences on OF functioning were not demonstrated between participants in the upper and lower quartiles of a summed DAE and IIB factor score. A general role for OF functioning in criminal behavior was suggested as two OF measures accounted for 14.9% of the variance of criminal convictions.