Bakgrund: Kolesterol är en viktig byggsten i våra celler. Kolesterol stabiliserar cellmembranen och används bland annat till syntesen av östrogen, testosteron, kortisol och vitamin D samt för att bilda gallsyror. Kolesterol syntetiseras i levern men tas även upp via kosten. Kolesterol transporteras i blodet med hjälp av olika lipoproteiner som t. ex. low-density lipoprotein (LDL) och high-density lipoprotein (HDL).Höga värden av LDL och låga värden av HDL är kopplade till en ökad risk att drabbas av ateroskleros som i sin tur ökar risken att drabbas av hjärt-och kärlsjukdomar som t. ex. hjärtinfarkt. Syfte: Syftet med arbetet var att studera hur plasmakoncentrationen av LDL och HDL förändras vid olika dieter i kombination med statiner eller utan statiner samt se hur koncentrationerna förändras vid  läkemdelsbehandling med statiner som monoterapi eller i kombination med ezetimib. Metod: Detta arbete är en litteraturstudie baserad på sju olika randomiserade kontrollerade studier sökta från databasen PubMed. I tre av studierna utvärderas kostens roll att sänka kolesterolet. I två studier behandlades patienter med atorvastatin som monoterapi eller med kombination av ezetimib. Två studier utvärderade om simvastatin ska tas på morgon eller kväll samt om simvastatin skall tas i kombination med LCHF-kost jämfört med simvastatin plus ezetimib i kombination med LCHF-kost. Resultat: Resultaten visar att viktreducering och kostomläggning har stor betydelse vid förhöjdanivåer av LDL samt vid låga nivåer av HDL. Resultaten visar även att statiner i kombination med ezetimib har störst effekt att sänka nivåerna av LDL och öka HDL-nivåerna. Av resultaten framgår också att kontrollerad frisättning av simvastatin har likvärdig effekt oavsett om de adminstreras morgon eller kväll. Slutsats: Denna litteraturstudie har visat att viktreducering och kost är ett bra och säkert tillvägagångssätt att få positiva effekter på HDL- och LDL-koncentrationerna. Statiner är förstahandspreparat vid blodfettsrubbningar och vid förhöjda kolesterolvärden och har en god effekt på kolesterol-nivåerna. För bästa resultat bör kost med låg andel kolhydrater kombineras med statiner och ezetimib. / Background: Cholesterol is an important part in our cells. Cholesterol stabilize cell membranes and is needed for the synthesis of estrogen, testosterone, cortisol, vitamin D and in the formation of bile acid. Cholesterol is synthesized in the liver but the body also absorbs cholesterol from the diet. The transport of cholesterol in the blood is taken care of by LDL and HDL. When the levels of LDL are increased and HDL are decreased there is an increased risk of developing atherosclerosis and cardiovascular diseases which are the main cause of death in the western countries.  Purpose: One of three different purposes of this presented study was to evaluate if the levels of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) were changed when following different diets. The second purpose was to study the change in levels of LDL and HDL change after treatment with statins as monotherapy or in combination with ezetimibe. The third part of this study was to see how LDL and HDL were changed when different diets were combined with statins.  Method: This work was a literature study based on seven different randomized controlled trials that were found in the database PubMed. Three of the studies evaluated the role of the different diets when aiming at reducing the cholesterol levels. In two of the studies patients were either treated with atorvastatin as monotherapy or with atorvastatin plus ezetimib. The last two studies evaluated the use of simvastatin in combination with LCHF-diet as compared to the use of simvastatin plus ezetimib which were used in combination with a LCHF-diet. Results: The results showed that weight reduction and the choice of a specific diet are important factors when aiming at a decrease in levels of LDL and an increase in levels of HDL. Moreover, results obtained also suggested that statins, when used in combination with ezetimibe, gave the largest effect and was found to decrease levels of LDL and increase levels of  HDL. According to the results, it may be concluded that the controlled release of simvastatin has an equivalent effect on these levels regardless if administered in the morning or in the evening. Conclusion: The results obtained in this work suggest that weight reduction and eating according to a diet that consists of a low proportion of carbohydrates may be a good and safe approach to reduce the levels of  LDL and increase the levels of  HDL. Statins can be considered to be the first alternative to treat dyslipidemia and should be used at elevated levels of cholesterol. To achieve the best result, an analysis of the selected literature in this work, suggest that a low-carbohydrate diet should be combined with the use of statins and ezetimibe.

As elevadas taxas de colesterol plasmático representam um grande risco à saúde, uma vez que podem causar doenças cardiovasculares. Para o tratamento e prevenção da dislipidemia são utilizados medicamentos reguladores do colesterol, como as estatinas. Embora eficazes e extensamente utilizados, esses fármacos apresentam efeitos adversos se administrados na dosagem errada. Assim, faz-se necessário o desenvolvimento de um método de monitorização terapêutica a fim de se ajustar a concentração desses compostos no sangue. Este trabalho visa o desenvolvimento de um método para análise de pravastatina (PRA), atorvastatina (AT), fluvastatina (FLV) e sinvastatina (SV) em plasma humano usando cromatografia líquida acoplada à espectrometria de massas (LC-MS). Na etapa de preparo de amostras, de forma inédita, utilizou-se a técnica microextração por sorvente empacotado (MEPS) para a análise de plasma humano contendo quatro estatinas. Para a otimização das condições de extração avaliaram-se, por experimentos univariados, parâmetros como fase extratora, composição do solvente de eluição e de lavagem. Outros fatores como volume de amostra, ciclos de amostragem, ciclos de eluição e etapas de eluição foram avaliados empregando-se planejamento experimental multivariado. A extração foi realizada utilizando-se uma fase estacionária C18 Chromabond como sorvente. O método MEPS-LC-MS/MS desenvolvido foi validado baseando-se nas recomendações da agência nacional de vigilância sanitária (ANVISA) e apresentou linearidade, seletividade, precisão, exatidão e recuperação adequadas para as estatinas, excetuando-se para a sinvastatina. A faixa de linearidade obtida foi de 10-200 ng mL-1 (FLV e AT) e 20-200 ng mL-1 (PRA). Os limites de quantificação obtidos foram da ordem de 10 ng mL-1 (AT e FLV) e 20 ng mL-1 (PRA). Desta forma o método desenvolvido poderá ser utilizado para a determinação dos níveis de pravastatina, fluvastatina e atorvastatina em amostras de plasma humano. / Elevated plasma cholesterol level is a risk factor for coronary diseases, which are the most deadly sickness according to the World Health Organization (WHO). In order to fight the hypercholesterolemia in patients, statins are a well-established class of drugs to be prescribed. Even though they are efficient, some side effects can be associated with statin therapy, especially when interactions with other drugs occur. In these cases, monitoring the concentration can optimize the drug dosage to therapeutic effectiveness whilst minimizing the adverse effects. The aim of this work was to develop a method for analysis of pravastatin (PRA), atorvastatin (AT), fluvastatin (FLV) and simvastatin (SV) in human plasma. The experimental means chosen to attain the goal was liquid chromatography-tandem mass spectrometry (LC-MS/MS) and for the sample preparation, microextraction by packed sorbent (MEPS). To optimize the extraction conditions, parameters such as sorbent, elution and washing solution were evaluated. Other parameters such as sampling, elution cycles, sample volume and elution steps were evaluated using multivariate experimental design. The extraction was performed using C18 Chromabond as sorbent. The method was validated based on ANVISA recommendations and featured appropriated linearity, selectivity, accuracy, precision, and recovery, except for simvastatin. The calibration curve in plasma was obtained in the concentration range 10-200 ng mL-1 (FLV and AT) and 20-200 ng mL-1 (PRA) and the limit of quantification (LOQ) was 10 ng mL-1 (FLV and AT) and 20 ng mL-1 (PRA). The method developed proved to be suitable for the analysis of pravastatin, fluvastatin and atorvastatin in human plasma sample, but not simvastatin, and it can contribute to a more efficient usage of the statins in the treatment of hypercholesterolemia.

Cheung, Chi Yun. / "September 2011." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 57-59). / Abstracts in English and Chinese. / Acknowledgment --- p.i / Table of Contents --- p.ii / Abstract --- p.iii / Abstract (Chinese Version) --- p.iv / Abbreviation --- p.v / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- General Background --- p.1 / Chapter 1.2 --- Mechanism of action --- p.3 / Chapter 1.2.1 --- Biosynthetic pathway of cholesterol --- p.3 / Chapter 1.2.2 --- Inhibition of HMG-CoA reductase by statins --- p.4 / Chapter 1.2.3 --- Plasma cholesterol reduction effect --- p.5 / Chapter 1.3 --- Previous syntheses of statin analogs --- p.5 / Chapter 1.3.1 --- Synthesis from (S)-malic acid --- p.6 / Chapter 1.3.2 --- Synthesis via enantioselective deprotonation --- p.7 / Chapter 1.3.3 --- Synthesis via asymmetric Diels-Alder reaction --- p.9 / Chapter 2. --- Results and Discussion --- p.11 / Chapter 2.1 --- Approaches towards construction of statin analogs --- p.11 / Chapter 2.2 --- Attempt to synthesize alkene 49 from D-arabinose --- p.12 / Chapter 2.3 --- Construction of alkene 49 from D-mannitol --- p.14 / Chapter 2.4 --- Olefin metathesis and conversion to statin analogs --- p.28 / Chapter 3. --- Conclusion --- p.32 / Chapter 4. --- Experimental Section --- p.33 / Chapter 5. --- References --- p.57 / Chapter 6. --- Appendix ii --- p.60

Thesis (M.S.)--Ball State University, 2009. / Title from PDF t.p. (viewed on Nov. 30, 2009). Includes bibliographical references (p. 74-80).

The Mevalonate Pathway: A Potential Therapeutic Target for JAK2-driven Myeloproliferative Neoplasms Lori Nicole Griner Abstract Myeloproliferative neoplasms (MPNs) are diseases of hematopoietic stem cell origin and are characterized by uncontrolled growth of cells of the myeloid compartment. The Philadelphia chromosome negative classical MPNs, including polycythemia vera, essential thrombocythemia, and myelofibrosis, are diseases of dysregulated JAK2 signaling. In fact, the majority of MPN patients have activating mutations in JAK2 (e.g JAK2-V617F), a tyrosine kinase that contributes to the growth and survival of myeloid cells. While MPNs were first described over sixty years ago, a significant need remains to develop therapeutic strategies for them. Inhibitors of JAK2 are currently being developed, and one inhibitor, ruxolitinib, was recently approved for certain MPN patients. Ruxolitinib has made profound impacts on improving splenomegaly and constitutional symptoms in MPN patients, but it and other JAK2 inhibitors have not significantly reduced the JAK2 mutant allele burden, and thus such inhibitors have not induced remission in these patients. The current consensus in the MPN field supports JAK inhibition for the treatment of patients, but a further understanding of MPNs and JAK2 signaling, as well as improved JAK2 inhibitors, may be necessary for treating MPN patients. The work described in this dissertation has uncovered novel requirements for JAK2-V617F-driven signaling and transformation. We demonstrate that JAK2-V617F co-localizes with lipid rafts, cholesterol-rich microdomains within the plasma membrane that function to serve as platforms for signaling complex formation. Signaling complex formation is a necessary component for dysregulated signaling induced by JAK2-V617F. We provide evidence that cholesterol altering-lipid raft disrupting agents attenuate JAK2-V617F-driven signaling. We also show that cholesterol-lowering statins are effective at downregulating JAK2 signaling and inducing apoptosis in JAK2-V617F-driven cell lines. Importantly, we show that statins, inhibitors of the mevalonate pathway, inhibit the growth of primary MPN cells, while the same statin doses have no effect on healthy controls. Impressively, we demonstrate that statins cooperate with multiple JAK inhibitors, including ruxolitinib, to inhibit cell growth and induce apoptosis of JAK2-V617F-driven cells. This report establishes statin-mediated inhibition of the mevalonate pathway as a potential approach to improve MPN therapeutics. We propose future studies with statins and JAK2 inhibitors in the treatment of MPNs.

LPA1 lysophosphatidic acid receptors (LPA1Rs) are normally present on the surface of the cell. Our initial findings were that HMG-CoA reductase inhibitors (atorvastatin and mevastatin) induce the sequestration of the G protein-coupled LPA1R in recycling endosomes, most likely by inhibiting the recycling of tonically internalized receptors. Whereas, co-addition of geranylgeranylpyrophosphate (GGPP) or geranylgeraniol (GGOH) prevented atorvastatin-induced sequestration of LPA1Rs, the geranylgeranyltransferase-I inhibitor, GGTI-298, mimicked atorvastatin and induced LPA1R sequestration. This suggested that statin-induced endosomal sequestration was caused by defective protein prenylation. The likely targets of atorvastatin and GGTI-298 are the Rho family GTPases, RhoC and RhoA, since both inhibitors greatly reduced the abundance of these GTPases and since knockdown of endogenous RhoC or RhoA with small interfering RNAs (siRNAs) led to endosomal sequestration of LPA1R. Knockdown of RhoC was much more potent at inducing endosomal sequestration than knockdown of either RhoA or RhoB. In contrast, atorvastatin, GGTI-298, siRNA against RhoA, B, or C did not alter the internalization or recycling of transferrin receptors, indicating that recycling of transferrin receptors is distinct from LPA1Rs. Thus, these results, for the first time, implicate RhoA and RhoC in endocytic recycling of LPA1Rs and identify atorvastatin and GGTI-298 as novel inhibitors of this process. / Per the request of the author and advisor, and with the approval of the Graduate Education office, the following changes were made to this thesis: Replaced original page 1 with Errata Page 2. Replaced original pages 3-28 with Errata Pages 3 – 16. Replaced original pages 69-71 with Errata pages 17 – 19.

Statins induce beneficial vascular effects. How statins induce beneficial vascular effects is yet to be determined. Here we examine Simvastatin and vascular endothelial growth factor (VEGF) acting through the phosphoinositide 3-kinase (PI3K) pathway in human coronary artery endothelial cells (HCAEC). While Simvastatin and VEGF both activated mediators in the PI3K pathway, the proteins and the rates of activation were not always consistent. This suggests that although Simvastatin and VEGF share a common PI3K pathway in HCAEC and similar vascular effects, the agonists diverge in the induction of cellular signaling cascades. Simvastatin also was shown to induce phosphoinositide 3, 4, 5-triphosphate (PIPS) organization and PI3K p110 gamma (y) perinuclear localization. Beneficial, non-lipid lowering effects of statins may occur through the PI3K pathway through activation of distinct mediators from those of VEGF. Better understanding of the pathways associated with statins is necessary for the discovery of better treatments for cardiovascular disease (CVD). / Department of Biology

Statins are widely used to treat hypercholesterolemia. Statins inhibit cholesterol biosynthesis, thereby activating genes involved in cholesterol homeostasis, which are under the control of the Sterol Regulatory Element (SRE). Statins also have cholesterol-independent beneficial cardiovascular effects mediated through the phosphoinositide 3-kinase (PI3-K) / Akt signaling pathway and by inhibition of protein prenylation. Because statins inhibit the synthesis of isoprenoids, they can act by inhibiting the small signaling GTPases Ras and Rho, which require post-translational prenylation to become membrane-anchored and functional. We showed that simvastatin-mediated inhibition of protein prenylation does not appear to play a role in activation of SRE transcriptional activity in HepG2 cells. We also found that when isoprenoids were replenished, basal phospho-Akt decreased, suggesting that inhibition of prenylation by simvastatin mediates Akt phosphorylation. Future studies will be needed to investigate the role that inhibition of protein prenylation plays in the activation of the PI3-K/Akt pathway by simvastatin. / Department of Biology

Staphylococcus aureus is a common and versatile opportunistic pathogen in humans. Increases in the incidence of community acquired and nosocomial infections, coupled with the emergence of antibiotic resistant strains, are causing new treatment challenges for health care professionals. S. aureus readily binds to the endothelial cell surface and utilizes host cell endocytosis to evade host cell immune responses. Inhibition of endocytosis may cause S. aureus to remain unprotected at the host cell surface, allowing host immune systems and other therapeutics more time to clear an infection. Simvastatin inhibits host cell endocytosis. We hypothesize that using simvastatin to inhibit S. aureus invasion of host cells, a high throughput, small molecule screen can be developed. The high throughput screen will evaluate the National Institutes of Health small molecule library for compounds that better inhibit endocytosis. Additionally, 2-dimensional gel electrophoresis will be performed to elucidate the pathway simvastatin alters to inhibit endocytosis. / Department of Biology

Sepsis is a systemic inflammatory response that causes, increased heart rate, respirations, fever, and inadequate blood flow to organs. One of the most prevalent causes of sepsis is Staphylococcus aureus (S. aureus). With increasing numbers of strains of bacteria becoming antibiotic resistant, new methods for the treatment and clearance of sepsis are needed. Studies have shown that the lipid lowering drug simvastatin is protective for incidence of sepsis, having immunomodulatory effects and anti-inflammatory properties, specifically. Thus, it may be an alternative way to prevent sepsis due to S. aureus infections. Studies in our laboratory have shown that simvastatin pretreatment increases survival of mice infected with S. aureus and alters the adaptive immune response such that levels of IgG2c are reduced to the level of uninfected controls. Our studies have demonstrated that while simvastatin does not enhance bacterial clearance, or affect serum C5a levels, it does decrease serum levels of TNF. / Department of Biology