Alzheimer’s disease is the most common form of dementia. It is a neurodegenerative disorder characterized by extracellular senile plaques and intracellular neurofibrillary tangles. The main constituent of the senile plaques is the neurotoxic β-amyloid peptide. Surrounding the senile plaques are activated astrocytes and microglia, believed to contribute to neurotoxicity through secretion of proinflammatory cytokines, like interleukin-1β and interleukin-6. For many inflammatory actions, including the cytokine induction in glial cells, the transcription factor NFκB plays a key role. This suggests that therapeutical strategies aimed to control the development of Alzheimer’s disease could include administration of drugs that hinder NFκB activation. The major aim of this thesis was to examine the effects of β-amyloid together with interleukin-1β on cytokine expression as well as NFκB activation in glial cells. The possibility to block NFκB activation, and downstream effects like interleukin-6 expression, by using an NFκB decoy was investigated. The possibility to improve the cellular uptake of the decoy by linking it to a cell-penetrating peptide was also investigated. The results obtained provide supportive evidence that inflammatory cytokines are induced by β-amyloid, and that they can indeed potentiate its effects. The results further demonstrate that by blocking NFκB activation, the induction of interleukin-6 expression can be inhibited. By using an improved cellular delivery system, the uptake of the NFκB decoy and hence the downstream cytokine inhibition could be increased. In conclusion, these results demonstrate the possibility to decrease the inflammatory reactions taken place in Alzheimer’s disease brains, which may ultimately lead to a possible way of controlling this disorder.

This thesis evaluated supplementation with two components of flaxseed during exercise training on inflammation in older adults.<P>Experiment 1: This experiment assessed secoisolariciresinol diglucoside (SDG) supplementation during aerobic exercise training on inflammation in older adults. Methods: One hundred subjects aged 50y or older were randomized to receive either SDG or placebo before completing a 6-month walking program. Fasting concentrations of interleukin-6 and tumor necrosis factor-á, glucose, triacylglycerol (TAG), high density lipoprotein (HDL), low density lipoprotein, and total cholesterol as well as leukocyte cell count were measured every two months while body composition, resting blood pressure, and a composite Z-score of six metabolic syndrome risk factors were assessed at baseline and 6 months. Results: Men on placebo increased metabolic syndrome composite Z-score (p<0.05). TAG increased (p=0.017) in men on placebo relative to men on SDG and men on SDG decreased (p=0.045) DBP relative to men on placebo. Conclusions: SDG had no effect on inflammation while it is effective in attenuating risk factors associated with metabolic syndrome in older males but not females.<p>Experiment 2: This experiment evaluated alpha-linolenic acid (ALA) supplementation during strength exercise training on inflammation in older adults. Methods: Fifty-one healthy older adults (65.4±0.8y) were randomized to receive ALA or a placebo before completing a 12 wk strength training program. Subjects were evaluated at baseline and 12 weeks for TNF-á and IL-6, muscle strength, body composition, and muscle thickness. Results: Males supplementing with ALA decreased IL-6 concentration (p=0.003). The female placebo and male ALA group had a significant increase in knee flexor thickness (p<0.05). Chest and leg press strength, lean tissue mass, and muscle thickness significantly increased, while percent fat and total body mass decreased with training (p<0.05), with no difference between ALA and placebo. Conclusions: ALA lowers IL-6 in older men, but has minimal effect on muscle mass and strength during resistance training.<p>General Conclusion: A composite score of metabolic syndrome is attenuated in males supplementing with SDG. ALA reduces IL-6 in older men. Older men, but not older women, derive specific health benefits from increased consumption of components of flaxseed consumed during an exercise program.

This thesis evaluated supplementation with two components of flaxseed during exercise training on inflammation in older adults.<P>Experiment 1: This experiment assessed secoisolariciresinol diglucoside (SDG) supplementation during aerobic exercise training on inflammation in older adults. Methods: One hundred subjects aged 50y or older were randomized to receive either SDG or placebo before completing a 6-month walking program. Fasting concentrations of interleukin-6 and tumor necrosis factor-á, glucose, triacylglycerol (TAG), high density lipoprotein (HDL), low density lipoprotein, and total cholesterol as well as leukocyte cell count were measured every two months while body composition, resting blood pressure, and a composite Z-score of six metabolic syndrome risk factors were assessed at baseline and 6 months. Results: Men on placebo increased metabolic syndrome composite Z-score (p<0.05). TAG increased (p=0.017) in men on placebo relative to men on SDG and men on SDG decreased (p=0.045) DBP relative to men on placebo. Conclusions: SDG had no effect on inflammation while it is effective in attenuating risk factors associated with metabolic syndrome in older males but not females.<p>Experiment 2: This experiment evaluated alpha-linolenic acid (ALA) supplementation during strength exercise training on inflammation in older adults. Methods: Fifty-one healthy older adults (65.4±0.8y) were randomized to receive ALA or a placebo before completing a 12 wk strength training program. Subjects were evaluated at baseline and 12 weeks for TNF-á and IL-6, muscle strength, body composition, and muscle thickness. Results: Males supplementing with ALA decreased IL-6 concentration (p=0.003). The female placebo and male ALA group had a significant increase in knee flexor thickness (p<0.05). Chest and leg press strength, lean tissue mass, and muscle thickness significantly increased, while percent fat and total body mass decreased with training (p<0.05), with no difference between ALA and placebo. Conclusions: ALA lowers IL-6 in older men, but has minimal effect on muscle mass and strength during resistance training.<p>General Conclusion: A composite score of metabolic syndrome is attenuated in males supplementing with SDG. ALA reduces IL-6 in older men. Older men, but not older women, derive specific health benefits from increased consumption of components of flaxseed consumed during an exercise program.

The etiology of nasopharyngeal carcinoma (NPC) is based on intricate interactions among environmental factors, genetic susceptibility and Epstein-Barr virus (EBV) infection. Information concerning the role of EBV infection, particularly during the early stage of NPC development is poorly understood. Our laboratory has shown that stable infection of EBV could be achieved in immortalized epithelial cell lines which harbor genetic alterations and altered cell signaling pathway. In this study, these cell models were used to elucidate early events involved in EBV infection in premalignant nasopharyngeal epithelial cell models and their implications on development and progression of nasopharyngeal carcinoma. The response of EBV-infected cells to a stromal inflammatory cytokine, interleukin-6 (IL-6), was examined. EBV infection and long-term propagation of EBV-infected nasopharyngeal epithelial cells confer enhanced sensitivity to STAT3 activation induced by IL-6. IL-6-induced STAT3 activation reinforced their malignant properties in nasopharyngeal epithelial cells and may play a role in the development of nasopharyngeal carcinoma. Furthermore, constitutive STAT3 activation was demonstrated to facilitate malignant transformation of EBV-infected premalignant nasopharyngeal epithelial cells to cancer cells, suggesting that EBV infection and STAT3 activation might synergistically promote the development of NPC. This study also provides support for the existence of a positive feedback loop of IL-6/STAT3/LMP in NP460hTert-EBV cells, which enhanced STAT3 activation in EBV-infected cells. Elevated levels of IL-6Rα expression were observed in EBV-infected NP460hTert cells compared with uninfected cells and were largely responsible for the enhanced sensitivity of IL-6-induced STAT3 activation in these cells. High expression level of IL-6Rα could amplify IL-6 signaling in nasopharyngeal epithelial cells to promote growth proliferation in NP460hTert cells and increase the growth rate of xenografted NPC cells in immune-suppressed animals, suggesting that IL-6Rα overexpression may play a role of contributing to the development of nasopharyngeal carcinoma. The serum concentrations of both IL-6 and sIL-6R were also higher in NPC patients than healthy individuals and may have prognostic values to predict clinical outcome and disease progression in NPC patients. In conclusion, these data support the hypothesis that EBV infection under inflammatory environment may activate aberrant gene expressions and cell signaling to facilitate malignant transformation. The inflammatory cytokine, IL-6, may mediate the role of EBV infection in the development of NPC. / published_or_final_version / Anatomy / Doctoral / Doctor of Philosophy

The purpose of this study was to determine the role of body composition and fat distribution on C-reactive protein (CRP) and interleukin-6 (IL-6); determine the differences in CRP and IL-6 among HT users and non-users; determine the effect of 12-months of resistance training and resulting body composition changes on IL-6 and CRP; determine the relationship between BMD and IL-6, CRP and creatine kinase (CK). Sedentary women (N=208, age 44-66, 3-10 years postmenopausal) taking HT (N=106) or not taking HT (N=102) were randomly assigned to resistance training: HTexercise (N=55), HT-no exercise (N=45), no HT-exercise (N=53), and no HT-no exercise (N=49). The program included three weekly 60-75 minute sessions of 8 exercises performed in 2 sets of 6-8 repetitions at 70-80% of 1RM. Total fat mass (TFM), lean soft tissue mass (LSTM) and BMD were assessed by dual-energy X-ray absorptiometry (DXA). Abdominal fat mass (AFM) was assessed using DXA region of interest. For each subject, baseline and 1- year IL-6, CRP and CK were measured. High TFM, high IL-6 and HT use were independently associated with high CRP levels. A stronger relationship between IL-6 and AFM compared to TFM was found in HT users. High TFM and LSTM were significantly related to higher IL-6 levels. A stronger relationship between CRP and AFM compared to TFM was found in HT non-users. CRP was higher in HT users (5.47±5.40 mg/L) compared to non-users (2.70±3.05 mg/L) and was higher in oral (5.76±5.29 mg/L opposed; 6.14±5.97 mg/L unopposed) compared to transdermal HT users (2.65±4.44 mg/L). CRP increased slightly (p=0.077) in exercisers (0.54 ± 0.34 mg/L) not taking HT compared to controls (-0.39 ± 0.35 mg/L). Reductions in TFM were associated with reductions in IL-6 and CRP in HT users. CK was positively associated to all BMD sites at baseline. IL-6 change was positively associated with change in femur neck BMD. CRP change was inversely correlated with change in lumbar spine BMD. CK change was directly related to change in total body and femur trochanter BMD. In conclusion, reductions in TFM were accompanied by reductions in IL-6 and CRP; AFM was more strongly correlated with inflammation than TFM; 12-months of resistance training did not decrease IL-6 or CRP; IL-6 and CK were positively related to BMD, and CRP was inversely associated with BMD.

The production of viable germ cells during human embryonic development determines adult reproductive success. This is particularly true for females, as development of germ cells (GCs) into primordial follicles before birth is imperative for future fertility. During fetal development GCs migrate to the genital ridge to form the gonad, after which several tightly regulated events, including proliferation, differentiation, and association with somatic cells, must occur to form a functional gonad. In the ovary these processes also include the initiation and subsequent arrest of meiosis. These developmental processes are orchestrated by local autocrine and paracrine factors, many of which remain to be identified in the human. In order to decipher further the pathways by which the gonad and GCs develop, potential regulators including prostaglandin (PG) E2, the interleukin (IL)6-type cytokines, and the prokinetecins (PROKs), were examined in the human fetal ovary and PROKs in the human fetal testis. Patterns of gene expression, protein localisation, function, and interaction of the potential mediators throughout human development (8-20 weeks gestation) were determined. Primary fetal tissue was investigated, in addition to immortalized GCs (T-Cam2 cells) and a murine model of fetal ovarian development. PGE2 interacts with known regulators of GC development in non-reproductive organs. It was postulated PGE2 may regulate GC progression by modulating these factors. Examination of PGE2 receptors and precursor enzymes in the fetal ovary revealed that all were present and some were developmentally regulated, with mRNA expression increasing with gestation. These developmentally regulated components were localised to the GCs. The PGE2 receptors were among those differentially expressed, with one localised solely to mature GCs. Culture of human fetal ovary confirmed that PGE2 regulates known regulators of GC development, increasing expression of survival and anti-apoptotic factors. To test the hypothesis that PGE2 is necessary for female GC development, paracetamol, an inhibitor of PGE2 precursor enzymes, was utilised in a murine model of fetal exposure. Fetal ovaries from this experiment displayed disruption of normal development. The IL6-type cytokines are also postulated to be involved in early gonad development, and are known to regulate proliferation and differentiation of mouse embryonic stem and GCs in vitro. A significant increase in transcript levels of the shared receptor components was determined in second trimester human ovaries, as well as developmental increases of several of the IL6-type ligands. Both common receptor components were located specifically in the GCs identifying them as the target of IL6 action in the human fetal ovary. The PROKs regulate cell migration, proliferation and differentiation, and modulate secretion of PGE2 and expression of some IL6-type cytokines. To-date, PROKs have not been examined in the human fetal gonad. Transcript levels were higher in the fetal testis compared to the ovary, with receptor and ligand components increasing with gestation. Most components also increased with gestation in the ovary. However, location of PROK components was strikingly different between the two tissues, with GCs being the primary target of PROK action in the fetal ovary, and Leydig and interstitial cells being the target in the testis. PROKs interaction with other regulators of gonad development was examined utilising a GC line in the case of the ovary and primary interstitial cell cultures in the case of the testis. These studies have identified new factors involved in human fetal gonad development, and how they interact with known regulatory pathways of development.

<p>Glioblastoma (GBM) represents the most common and lethal brain tumor in adults, with glioma initiating cells (GICs) implicated to play a critical role in its progression and recurrence. However, the molecular mechanisms underlying the distinct function of GICs and non-GICs remain largely unknown. Elucidating distinct molecular features of GICs will pave the foundation for GIC directed therapies for GBM treatment. </p><p>We first demonstrated that GICs preferentially express two interleukin 6 (IL6) receptors: IL6 receptor alpha (IL6Ra) and glycoprotein 130 (gp130). Targeting IL6Ra; or IL6 ligand expression in GICs using short hairpin RNAs (shRNAs) significantly reduces growth and neurosphere formation capacity while increasing apoptosis. Block IL6 signaling in GICs attenuates Stat3 activation, and small molecule inhibitors of STAT3 potently induce GIC apoptosis. Targeting IL6Ra; or IL6 expression in GICs increases the survival of mice bearing intracranial human glioma xenografts. The promising application of anti-IL6 therapies is demonstrated by decreased subcutaneous tumor growth of human GIC-derived xenografts treated with IL6 antibody. Together, our data indicate that IL6 signaling contributes to glioma malignancy through the promotion of GIC growth and survival, and that targeting IL6 may offer benefit for glioma patients.</p><p>MicroRNAs (miRNAs) are a class of non-coding small RNA molecules which negatively regulate gene expression and are deregulated in many types of cancer. Through a candidate-based screen, we identified microRNA-33a as a master determinant whose expression controls the functional differences between GIC and non-GICs. Antagonizing miR-33a function in GICs led to reduced self-renewal and tumor progression in immune-compromised mice, whereas overexpression of miR-33a in non-GICs rendered them to display features associated with GICs. Mechanistically, miR-33a acts to confer the biological property of GICs via enhancing the activities of cAMP/PKA pathway and Notch signaling by targeting negative regulators of these two pathways. Together these findings reveal a miR-33a-centered signaling network that dictates the identity/activity of GICs and consequently serves as a therapeutic target for the treatment of GBM.</p><p>In summary, this doctoral thesis reveals two novel molecular events that characterize the distinct feature of GICs and develops preclinical strategies for the therapeutic application of GBM.</p> / Dissertation

Für diese Arbeit wurden in-vitro-Studien an kaninen Mammatumorzellen und humanen follikulären B-NHL-Zellen durchgeführt. Es wurden erstmals die migratorischen Eigenschaften einer kaninen Mammatumorzelllinie (CMT-U-27, infiltrierendes duktuläres Karzinom mit Metastasen) und deren Beeinflussbarkeit untersucht. Die Experimente zeigten einen leichten promigratorischen Einfluss von Noradrenalin und EGF; mit dem Tumorpromotor PMA wurde eine sehr deutliche Stimulation der Migration erreicht. Es konnte gezeigt werden, dass Iscador® M in der Lage ist, die PMA-stimulierte Migration der CMT-U-27-Zellen zu hemmen, wobei die spontane, Matrix-induzierte Zellmigration unbeeinflusst blieb. Zwischen der migratorischen Aktivität von Tumorzellen und ihrer Fähigkeit Metastasen zu bilden, besteht ein Zusammenhang. Durch einen inhibierenden Effekt auf die Migration von Tumorzellen könnte eine Progression der Erkrankung durch Metastasenbildung verhindert oder zumindest verzögert werden. IL-6 dient als prognostischer Faktor bei lymphoproliferativen Erkrankungen der B-Zellen und kann sich negativ auf den Krankheitsverlauf bei B-Lymphompatienten auswirken. Unterstützend zu den guten in-vivo Erfahrungen in der Lukasklinik in Arlesheim, Schweiz, sollte in dieser Arbeit untersucht werden, ob Iscador® P bei follikulären B-NHL-Zelllinien (DoHH2, WSU-NHL, Sc-1) einen autokrinen IL-6-Loop auslösen kann. Dafür wurden die Zellen über definierte Zeiträume mit verschiedenen Iscador® P-Konzentrationen inkubiert. Es wurden Proben entnommen und durchflusszytometrische Messungen auf membrangebundenen IL-6R und gp130, Messungen der mRNA-Expression von IL-6, IL-6R und gp130 mittels Real-Time-RT-PCR und ELISA-Messungen zur Bestimmung von IL-6, löslichem IL-6R (sIL-6R) und löslichem gp130 (sgp130) durchgeführt. Es konnte kein Einfluss von Iscador® P auf die Oberflächen- oder Genexpression von IL-6 und den dazugehörigen Rezeptorkomponenten gp130 und IL-6R nachgewiesen werden. Zudem wird kein IL-6, sgp130 oder sIL-6R von den Zellen freigesetzt. Damit kann ein autokriner IL-6-Loop und ein durch Freisetzen von sIL-6R ermöglichtes Transsignalling bei den in dieser Arbeit untersuchten follikulären B-NHL-Zelllinien ausgeschlossen werden. In Wachstumskurven konnte gezeigt werden, dass Iscador® P den proliferativen Einfluss von IL-6, bei gleichzeitiger Inkubation, aufhebt. Genexpressionsmessungen der apoptoserelevanten Gene bcl-2, bax, bcl-xl und bad mittels Real-Time-RT-PCR zeigten bei den WSU-NHL-Zellen, dass die Apoptose über ein Verschieben des bcl-2/bax-Quotienten ausgelöst wird, welches mittels durchflusszytometrischer Analyse bestätigt werden konnte. Im Gegensatz dazu konnte bei Sc-1 Zellen keine Verschiebung des bcl﷓2/bax-Quotienten in Richtung Induktion der Apoptose beobachtet werden, sodass die bei dieser Zelllinie beobachtete Hemmung der IL-6 mediierten Proliferation durch Iscador® P, durch einen anderen, bislang noch nicht geklärten, Mechanismus ablaufen muss.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 4 uppsatser.

Ulm, Univ., Diss., 2008.