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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Effets du peroxyde d'hydrogène sur la fonction placentaire implication dans la physiopathologie de la prééclampsie

Leblanc, Samuel January 2009 (has links)
Des travaux antérieurs effectués dans notre laboratoire ont démontré une corrélation entre les niveaux circulants de peroxyde d'hydrogène (H[indice inférieur 2]O[indice inférieur 2]) et d'hormone gonadotrophine chorionique humaine (hCG) chez des femmes souffrant de prééclampsie (Kharfi et al, . 2005). Le peroxyde d'hydrogène étant surtout connu pour ses effets cytotoxiques, nous avons déterminé quels étaient ses effets sur des cellules placentaires in vitro, en rapport aux conditions retrouvées in vivo chez des femmes prééclamptiques. Pour ce faire, nous avons développé un modèle d'étude de cellules trophoblastiques in vitro, avec lequel nous avons pu évaluer les effets du peroxyde d'hydrogène sur la fonction placentaire via la production d'hCG, sur la production de TNF-[alpha] comme marqueur inflammatoire et sur l'oxyde nitrique (NO) comme facteur vasodilatateur. Nos résultats nous ont permis de constater divers effets du peroxyde d'hydrogène sur les cytotrophoblastes in vitro, effets qui peuvent être corrélés avec les niveaux constatés chez la femme prééclamptique. Premièrement, nous avons pu observer une augmentation de la production d'hCG sous l'effet de faibles concentrations de peroxyde d'hydrogène (<50 [micro]M), alors que des concentrations plus élevées diminuent l'activité placentaire en diminuant la sécrétion d'hCG, démontrant son action cytotoxique à plus forte dose. Ceci a également été constaté par une augmentation de l'apoptose. Le peroxyde d'hydrogène a aussi démontré ses effets sur la production par les cytotrophoblastes de facteurs pro-inflammatoires, tel le TNF-[alpha], ainsi que de son récepteur, le TNFR2, qui sont tous deux augmentés après traitement. Le peroxyde d'hydrogène semble aussi avoir une influence sur la production de médiateurs vasodilatateurs tel l'oxyde nitrique, dont la diminution est observée in vitro avec des concentrations croissantes d'H[indice inférieur 2]O[indice inférieur 2]. Le stress oxydatif dans la prééclampsie, représenté dans notre modèle in vitro par le peroxyde d'hydrogène, semble donc être central dans la physiopathologie de cette maladie, puisqu'on peut lui attribuer en partie la variation d'importants facteurs. Toutefois, les moyens de la prise en charge de cette condition pathologique doivent être soigneusement déterminés, puisque le peroxyde d'hydrogène paraît avoir tout de même un rôle physiologique important à jouer, d'où l'intérêt de parler d'équilibre oxydatif.
12

Effets d'anomalies biochimiques de l'obésité sur l'expression de cytokines pro-inflammatoires

Amyot, Julie January 2006 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
13

A2B adenosine receptor modulation of TNF-alpha expression in mouse rheumatoid arthritis

Ciocca, Caroline 12 July 2017 (has links)
Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that leads to destruction of articular cartilage and subchondral bone at the synovial joints. Clinically, RA is characterized by swelling, tenderness and destruction of synovial joints, which results in severe disability and premature mortality. In the RA disease state, inflammation in the synovial compartment is regulated by a complex cytokine and chemokine network, including tumor necrosis factor α (TNFα), which has been clinically demonstrated a key mediator of RA pathogenesis. TNFα can be found in elevated levels in the synovial fluid and serum of RA patients and the role of the cytokine in both the inflammation and bone destruction of RA suggests it is important in the understanding of disease progression as well as the development of therapeutic targets. Many of the biological processes that mediate RA, including bone turnover and cartilage resorption, involve signaling pathways that are mediated by adenosine and its receptors. The A2B adenosine receptor (A2BAR) is highly expressed in the synoviocytes of RA patients and the receptor has a similar expression profile in humans and mice. The goal of this thesis was to use a mouse model of RA to understand how the A2B adenosine receptor modulates TNFα and other destructive enzymes that contribute to the progression of the disease. A collagen antibody-induced arthritis (CAIA) mouse model was used to determine the effect of A2BAR ablation on systemic and joint-specific TNFα expression. Comparable arthritic conditions were observed in CAIA mice of both A2BAR knockout (KO) and wild-type (WT) genotypes and the absence of the A2BAR gene did not result in any observable differences in the gross arthritic state created in each genotype. Immunohistochemistry analysis of TNFα expression in mouse paws revealed that paw joints from CAIA A2BAR KO mice exhibited more robust TNFα staining compared to CAIA WT specimens of the same treatment duration. ELISA analysis of the serum showed that only CAIA A2BAR KO mice had greater serum production of TNFα at day 10 after induction of arthritis. TNFα and matrix metalloproteinase-9 mRNA expression were also elevated in KO CAIA knee joints in comparison to WT CAIA knee joints; however, WT CAIA mice were found to have higher levels of aggrecanase mRNA compared to KO mice. These results suggest that while the loss of A2BAR activity leads to a hyper-inflammatory state, the A2B adenosine receptor alone is not responsible for the progressive inflammation of the synovial joints associated with rheumatoid arthritis.
14

Mitochondrial DNA regulates TNF-alpha mRNA stability

Bond, Stephanie 08 April 2016 (has links)
Sepsis is defined as potentially fatal systemic inflammation, caused by an infection. It is the leading cause of ICU mortality and the 10th leading cause of death in the United States. Several models exist to mimic this disorder, and have demonstrated differential mortality rates between the models as well as the individual animals. Previous studies have shown that elevated levels of plasma mitochondrial DNA (mtDNA) correlated with mortality in septic patients, and cell-free mitochondrial DNA can elicit toll-like receptor mediated immune responses similar to LPS-mediated septicemia. However, the role of mtDNA in the pathophysiology sepsis is still unknown. The focus of this study was to create sepsis in a mouse model using the murine Cecal Ligation and Puncture (CLP) model, and measure plasma mtDNA levels. After CLP was performed on experimental mice, blood plasma was collected 24 hours later. Elevated amounts of circulating mtDNA were detectable in the plasma using real time PCR and cytochrome B2 as a marker of mitochondria. These data were correlated with plasma IL-6 levels, which were used to predict mortality within 5 days of CLP to stratify mice into two populations of those predicted to live or die following the procedure. We also aimed to investigate the effect of mtDNA and mitochondrial debris on naïve mouse macrophages in an in vitro study of the regulation of inflammatory cytokines interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and interleukin-1 beta (IL-1β). In order to observe the effects of mtDNA on murine macrophages, mitochondria was purified from mouse liver and used to stimulate these cells alongside positive control, LPS. Stimulation with mtDNA and mitochondrial debris resulted in increased levels of TNF-α mRNA in lysed cells as well as their surrounding media as compared to control cells, as well as increased transcript half life as measured over four hours post stimulation with transcription inhibitor actinomycin D. The increases in mRNA half-life elicited by mtDNA were comparable to those observed after LPS addition. Stimulation also caused increased binding of TNF-α mRNA to the RNA binding protein, AUF1, as measured by immunoprecipitation of RNA-protein complexes and assayed for TNF-α binding by PCR. These results demonstrate that mitochondrial damage-associated molecular patterns regulate TNF-α mRNA expression at the post-transcriptional level through AUF1, an mRNA destabilizing factor. This is a novel mechanism that likely contributes to sepsis pathophysiology, and demonstrates the involvement of the mitochondrial fission and fusion balance and its regulation in the sepsis innate immune response.
15

Tumor necrosis factor alpha and interleukin-6 drive a RANK-independent pathway of osteoclast activation

Fissel, Brian Michael 08 April 2016 (has links)
The skeleton is a dynamic organ that undergoes a continual process known as bone remodeling. Bone remodeling is necessary to maintain structural integrity, heal micro-fractures caused by from daily wear and tear, and to store and release essential ions and minerals. Remodeling is a highly regulated process, with bone resorption precisely balanced by bone formation under homeostatic conditions. In the setting of rheumatoid arthritis (RA), an inflammatory condition affecting joints, this balance is lost and bone around inflamed joints is eroded. These so-called "bone erosions" compromise joint function, causing disability. Osteoclasts, multinucleated cells of hematopoietic origin, are the only cells known to resorb bone. Osteoclasts are found at erosion sites in human joints, and data from mouse models of inflammatory arthritis suggest that osteoclasts are required for erosions to form in bone. The canonical pathway of osteoclast differentiation requires stimulation of myeloid precursors by the cytokine Receptor Activator of NF-Kappa B ligand (RANKL) through its receptor, RANK. In the inflamed joint, RANKL expression can be induced on mesenchymal lineage cells by inflammatory cytokines such as tumor necrosis factor alpha (TNF alpha). Surprisingly, our lab observed bone erosions and osteoclast formation in a mouse model of RA in the absence of RANK. Thus we hypothesized that in addition to RANKL expression, the cytokine milieu in RA may directly stimulate osteoclast formation. It was recently reported that the inflammatory cytokines TNF alpha and interleukin-6 (IL-6) in combination stimulate osteoclast differentiation, independent of exogenous RANKL. We have reproduced these results and shown that these osteoclast-like cells form entirely independently of RANK signaling. However, TNF alpha/IL-6 induced osteoclast formation still requires the transcription factor Nuclear Factor of Activated T cells (NFATc1), a master regulator of RANK-mediated osteoclast differentiation, as well as co-stimulatory signaling provided by the immunoreceptor tyrosine based activation motif (ITAM)-containing DNAX-activating protein (DAP12) molecules. We also showed that TNF alpha/IL-6 induced osteoclast formation requires activity of IL-6 receptor (IL-6R), as osteoclast formation can be inhibited through co-culture with an IL-6R blocking antibody (MR16-1). Finally, using an in vivo mouse model of RA in RANK-deficient mice, we tested whether blocking IL-6R with MR16-1 antibody protects against the formation of periarticular bone erosions. Our results suggest that a RANK-independent pathway of osteoclast formation contributes to inflammatory bone erosions. Targeting this pathway may improve outcomes for RA patients.
16

Soluble receptors for advanced glycation end products as predictors of restenosis following percutaneous coronary intervention

McNair, Erick Donnell 11 September 2009
The principal cause of non-ST-segment myocardial infarction (NSTEMI), a subclass of acute coronary syndrome (ACS), is thrombosis and the underlying cause is atherosclerosis. Percutaneous coronary intervention (PCI) is one of the treatments to attenuate the ischemic effects of severe coronary artery stenosis. However, restenosis following PCI (post-PCI) is a major problem for the long-term success of the procedure. Recently, the interaction of advanced glycation end products (AGE) with the receptor for advanced glycation end products (RAGE) has been implicated in the development of atherosclerosis in animal models. Interaction of AGE with RAGE results in activation of nuclear factor kappa-B (NF-êB), release of cytokines including tumor necrosis factor-alpha (TNF-á), the expression of adhesion molecules including soluble vascular adhesion molecule-1 (sVCAM-1) and induction of oxidative stress all of which have been implicated in the development of atherosclerosis. The soluble receptor for advanced glycation end products (sRAGE) acts as a decoy for RAGE ligands (AGEs) and this occurs by competing with RAGE. In animal models, balloon inflation and de-endothelialization of the carotid artery increase the concentration of AGE and RAGE in the arterial wall and induces neointimal hyperplasia and stenosis. Treatment with sRAGE in animal models reduces neointimal growth and decreases smooth muscle cell migration and proliferation and expression of extracellular matrix.<p> It is hypothesized that NSTEMI and post-PCI restenosis may be due to low levels of serum sRAGE resulting in increased AGE and RAGE interactions. Low levels of sRAGE would also increase the levels of serum TNF-á and sVCAM-1.<p> The objectives of this study were to determine whether: (1) the levels of serum sRAGE are lower and the levels of AGE, TNF-á and sVCAM-1 are higher in NSTEMI patients compared to control; (2) the levels of serum sRAGE are lower and the levels of AGE, TNF-á and sVCAM-1 are higher in NSTEMI patients with restenosis compared to those without restenosis; and (3) sRAGE or AGE/sRAGE ratio may serve as a biomarker/ predictor of NSTEMI and post-PCI restenosis.<p> The study objectives include 46 consecutive NSTEMI patients undergoing elective PCI and 28 healthy age-matched male controls. Pre-PCI and 6 month post-PCI angiography were performed in all NSTEMI patients. Blood samples were collected at designated intervals for the measurement of sRAGE, AGE, TNF-á, and sVCAM-1 using commercially available enzyme-linked immunosorbent assay (ELISA) kits.<p> The levels of serum sRAGE were lower and those of TNF-á, sVCAM-1, AGE and AGE/sRAGE were higher in NSTEMI patients compared to control subjects. (sRAGE, 884.55 ± 50 vs. 1287 ± 41.5 pg/mL{p<0.001}; TNF-á, 23.1 ± 2.3 vs. 10.3 ± 0.8 pg/mL {p<0.002}; sVCAM-1, 1059.62 ± 70.8 vs. 651 ± 35.5 ng/mL {p<0.0003}, AGE, 1192.50 ± 82.6 vs. 669.40 ± 47.9 ng/mL {p<0.001}; and AGE/sRAGE, 1.75 ± 0.17 vs. 0.52 ± 0.06 {p<0.001}).<p> The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of the sRAGE biomarker test were 59%, 100%, 100%, 100% and 74% respectively, while those of the AGE/sRAGE test were 85%, 91%, 97%, 67% and 86%, respectively, in the diagnosis of patients with NSTEMI acute coronary syndrome. The pre-PCI levels of serum sRAGE in patients with restenosis were significantly lower (p<0.001) than in patients without restenosis (610.6 ± 24.1 vs. 1143.8 ± 52.5 pg/mL). The post-PCI levels of serum sRAGE were significantly lower (p<0.0001) in patients with restenosis compared to those without restenosis (477 ± 18.6 vs. 1106.7 ± 41.9 pg/mL). The pre-PCI levels of serum TNF-á and sVCAM-1 were significantly higher (p<0.001 and p<0.001) in patients with restenosis compared to those without restenosis (TNF-á, 37.9 ± 2.5 vs. 11.6 ± 0.41 pg/mL; sVCAM-1, 1381.8 ± 63.5 vs. 811.37 ± 26.5 ng/mL). The post PCI levels of serum TNF-á and sVCAM-1 were also significantly higher (p<0.0001 and p<0.0001) in patients with restenosis than in patients without restenosis (TNF-á, 48.4 ± 1.4 vs. 12.5 ± 0.44 pg/mL; sVCAM-1, 1381.8 ± 63.5 vs. 762.2 ± 26.4 ng/mL). The post-PCI levels sRAGE were lower while those of TNF-á and sVCAM-1 were higher compared to the pre-PCI levels in patients with restenosis. However, the pre- and post-PCI levels of serum sRAGE, TNF-á and sVCAM-1 were similar in patients without restenosis. The pre-PCI levels of serum AGE and AGE/sRAGE were significantly higher (p<0.001 and p<0.001) in patients with restenosis compared to those without restenosis (AGE, 1512.1 ± 84.53 vs. 891.7 ± 92.4 ng/mL; 2.39 ± 0.20 vs. 1.03 ± 0.17).<p> The sensitivity, specificity, PPV, NPV, and accuracy of the pre-PCI sRAGE tests were 73%, 100%, 100%, 80%, and 87%, respectively while those of the AGE/sRAGE tests were 81%, 94%, 93%, 84% and 88%, respectively in identifying patients with post-PCI restenosis.<p> In conclusion the results suggest that: (1) the levels of serum sRAGE are lower while those of TNF-á, sVCAM-1, AGE and AGE/sRAGE are higher in NSTEMI patients compared to control subjects; (2) serum levels of sRAGE are negatively correlated with the number of diseased vessels; (3) Both low sRAGE and high AGE/sRAGE may serve as a biomarker/predictor of NSTEMI, but AGE/sRAGE has a greater sensitivity compared to sRAGE; (4) the pre-PCI levels of serum sRAGE are lower while those of AGE/sRAGE are higher in patients with restenosis compared to those without restenosis; and (5) both low sRAGE and high AGE/sRAGE may serve as a predictor/ biomarker of post-PCI restenosis; however, AGE/sRAGE has a greater sensitivity than sRAGE.
17

Soluble receptors for advanced glycation end products as predictors of restenosis following percutaneous coronary intervention

McNair, Erick Donnell 11 September 2009 (has links)
The principal cause of non-ST-segment myocardial infarction (NSTEMI), a subclass of acute coronary syndrome (ACS), is thrombosis and the underlying cause is atherosclerosis. Percutaneous coronary intervention (PCI) is one of the treatments to attenuate the ischemic effects of severe coronary artery stenosis. However, restenosis following PCI (post-PCI) is a major problem for the long-term success of the procedure. Recently, the interaction of advanced glycation end products (AGE) with the receptor for advanced glycation end products (RAGE) has been implicated in the development of atherosclerosis in animal models. Interaction of AGE with RAGE results in activation of nuclear factor kappa-B (NF-êB), release of cytokines including tumor necrosis factor-alpha (TNF-á), the expression of adhesion molecules including soluble vascular adhesion molecule-1 (sVCAM-1) and induction of oxidative stress all of which have been implicated in the development of atherosclerosis. The soluble receptor for advanced glycation end products (sRAGE) acts as a decoy for RAGE ligands (AGEs) and this occurs by competing with RAGE. In animal models, balloon inflation and de-endothelialization of the carotid artery increase the concentration of AGE and RAGE in the arterial wall and induces neointimal hyperplasia and stenosis. Treatment with sRAGE in animal models reduces neointimal growth and decreases smooth muscle cell migration and proliferation and expression of extracellular matrix.<p> It is hypothesized that NSTEMI and post-PCI restenosis may be due to low levels of serum sRAGE resulting in increased AGE and RAGE interactions. Low levels of sRAGE would also increase the levels of serum TNF-á and sVCAM-1.<p> The objectives of this study were to determine whether: (1) the levels of serum sRAGE are lower and the levels of AGE, TNF-á and sVCAM-1 are higher in NSTEMI patients compared to control; (2) the levels of serum sRAGE are lower and the levels of AGE, TNF-á and sVCAM-1 are higher in NSTEMI patients with restenosis compared to those without restenosis; and (3) sRAGE or AGE/sRAGE ratio may serve as a biomarker/ predictor of NSTEMI and post-PCI restenosis.<p> The study objectives include 46 consecutive NSTEMI patients undergoing elective PCI and 28 healthy age-matched male controls. Pre-PCI and 6 month post-PCI angiography were performed in all NSTEMI patients. Blood samples were collected at designated intervals for the measurement of sRAGE, AGE, TNF-á, and sVCAM-1 using commercially available enzyme-linked immunosorbent assay (ELISA) kits.<p> The levels of serum sRAGE were lower and those of TNF-á, sVCAM-1, AGE and AGE/sRAGE were higher in NSTEMI patients compared to control subjects. (sRAGE, 884.55 ± 50 vs. 1287 ± 41.5 pg/mL{p<0.001}; TNF-á, 23.1 ± 2.3 vs. 10.3 ± 0.8 pg/mL {p<0.002}; sVCAM-1, 1059.62 ± 70.8 vs. 651 ± 35.5 ng/mL {p<0.0003}, AGE, 1192.50 ± 82.6 vs. 669.40 ± 47.9 ng/mL {p<0.001}; and AGE/sRAGE, 1.75 ± 0.17 vs. 0.52 ± 0.06 {p<0.001}).<p> The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of the sRAGE biomarker test were 59%, 100%, 100%, 100% and 74% respectively, while those of the AGE/sRAGE test were 85%, 91%, 97%, 67% and 86%, respectively, in the diagnosis of patients with NSTEMI acute coronary syndrome. The pre-PCI levels of serum sRAGE in patients with restenosis were significantly lower (p<0.001) than in patients without restenosis (610.6 ± 24.1 vs. 1143.8 ± 52.5 pg/mL). The post-PCI levels of serum sRAGE were significantly lower (p<0.0001) in patients with restenosis compared to those without restenosis (477 ± 18.6 vs. 1106.7 ± 41.9 pg/mL). The pre-PCI levels of serum TNF-á and sVCAM-1 were significantly higher (p<0.001 and p<0.001) in patients with restenosis compared to those without restenosis (TNF-á, 37.9 ± 2.5 vs. 11.6 ± 0.41 pg/mL; sVCAM-1, 1381.8 ± 63.5 vs. 811.37 ± 26.5 ng/mL). The post PCI levels of serum TNF-á and sVCAM-1 were also significantly higher (p<0.0001 and p<0.0001) in patients with restenosis than in patients without restenosis (TNF-á, 48.4 ± 1.4 vs. 12.5 ± 0.44 pg/mL; sVCAM-1, 1381.8 ± 63.5 vs. 762.2 ± 26.4 ng/mL). The post-PCI levels sRAGE were lower while those of TNF-á and sVCAM-1 were higher compared to the pre-PCI levels in patients with restenosis. However, the pre- and post-PCI levels of serum sRAGE, TNF-á and sVCAM-1 were similar in patients without restenosis. The pre-PCI levels of serum AGE and AGE/sRAGE were significantly higher (p<0.001 and p<0.001) in patients with restenosis compared to those without restenosis (AGE, 1512.1 ± 84.53 vs. 891.7 ± 92.4 ng/mL; 2.39 ± 0.20 vs. 1.03 ± 0.17).<p> The sensitivity, specificity, PPV, NPV, and accuracy of the pre-PCI sRAGE tests were 73%, 100%, 100%, 80%, and 87%, respectively while those of the AGE/sRAGE tests were 81%, 94%, 93%, 84% and 88%, respectively in identifying patients with post-PCI restenosis.<p> In conclusion the results suggest that: (1) the levels of serum sRAGE are lower while those of TNF-á, sVCAM-1, AGE and AGE/sRAGE are higher in NSTEMI patients compared to control subjects; (2) serum levels of sRAGE are negatively correlated with the number of diseased vessels; (3) Both low sRAGE and high AGE/sRAGE may serve as a biomarker/predictor of NSTEMI, but AGE/sRAGE has a greater sensitivity compared to sRAGE; (4) the pre-PCI levels of serum sRAGE are lower while those of AGE/sRAGE are higher in patients with restenosis compared to those without restenosis; and (5) both low sRAGE and high AGE/sRAGE may serve as a predictor/ biomarker of post-PCI restenosis; however, AGE/sRAGE has a greater sensitivity than sRAGE.
18

Modulation of the immune response following myocardial infarction utilizing biomaterial-based therapeutic delivery strategies

Somasuntharam, Inthirai 21 September 2015 (has links)
In 2015, American Heart Association (AHA) reported that 1 in 9 deaths are attributed to Heart failure (HF), the number one killer in the world. While advancements in interventional cardiology in conjunction with pharmacotherapies have significantly reduced the rate of mortality following MI, there has been a corresponding rise in chronic heart failure (CHF) in surviving patients, largely attributed to the limited regenerative capacity of the heart and the inadequate healing response. Myocardial ischemic injury triggers an exuberant local and systemic inflammation, and the extent and quality of the cardiac wound healing process is intricately tied to the delicate equilibrium of this inflammatory response. While cardiac regeneration is an important goal, it is imperative in the meantime to explore therapeutic strategies that target these inflammatory mediators of early cardiac repair. These interventions to influence and improve cardiac wound healing can represent a new therapeutic window to halt the progression of heart failure between the few hours that may be used to limit infarct size by reperfusion and an irreversible non-contractile cardiac scar. This dissertation examines three therapeutic delivery strategies aimed at modulating the immune response to enhance cardiac repair in rodent models MI: 1) Polyketal nanoparticles as siRNA delivery vehicles for antioxidant therapy; 2) Spherical nucleic acid particles for anti-inflammatory therapy and; 3) Bioactive PEG (polyethyleneglycol)-based hydrogel for immunomodulation. The work presented here applies novel nucleic acid delivery strategies for cardiac gene silencing and has contributed to new knowledge with regard to modulating the immune response following MI.
19

Modulation of innate immune cells by the NAD+ pathway

Al-Shabany, Abbas Jawad January 2017 (has links)
NAD+ has previously been shown to regulate TNF-α synthesis and TNF-α has been shown to regulate NAD+ homeostasis, thus providing a link between a pro-inflammatory response and redox status. Despite the well-established link between TNF-α and NAD+, the mechanism as to how NAD+ modulates TNF-α release is not fully understood. To achieve this, this link was investigated using THP-1 cell line-derived M1-like (pro-inflammatory) and M2-like (anti-inflammatory) macrophages using PMA and vitamin D3, respectively. NAD+ levels differed markedly between M1-like and M2-like macrophages, with M1-like having much higher basal levels. LPS increases NAD+ levels and TNF-α secretion in M1-like but not M2-like cells. In an effort to investigate the source of the NAD+ levels and the association with TNF-α release, three inhibitors (FK866, DPI and 1D-MT) were used. Following stimulation, NAD+ is produced partially via NADH oxidation and partially through NAD+ synthesis. Both DPI and FK866 reduced TNF-α secretion with DPI showing the largest effect. The two phenotypes showed differential profiles of NAD+ homeostasis gene expression compared with each other and with the progenitor THP-1 in both resting and activated states. While IDO expression was induced in both phenotypes, CD38 and NAMPT were upregulated in M1-like cells whereas CD157 was upregulated in M2-like cells. LPS induced M1-like cells to up-regulate CD38 and CD157 and down-regulate NAMPT unlike M2-like cells which up-regulated NAMPT and CD38 and down-regulated CD157. M1s increased glycolysis activity whereas conversely, decreased oxidative metabolism during LPS stimulation confirming previous findings showing that classical M1s are predominantly glycolytic. Collectively, these data suggest that the relationship between NAD+ levels and pro-/anti-inflammatory responses is complex and may be regulated via a combination of pathways. These findings open the possibility of pharmacological manipulation of NAD+ synthesis as a way of selectively modulating macrophage responses which may be beneficial for the development of therapeutics targeting inflammatory diseases.
20

Étude des gènes candidats reliés à l'hypertension artérielle et l'obésité dans une population hypertendue du Saguenay-Lac-Saint-Jean

Deslauriers, Benoit January 2003 (has links)
No description available.

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