Adipose tissue (AT) expansion and remodeling that maintains healthy function relies on stromal preadipocytes capable of differentiating into new adipocytes (adipogenesis). During chronic positive energy balance, a relative deficit in adipogenesis, from either a decrease in preadipocyte number or their capacity to differentiate, leads to excessive adipocyte hypertrophy and AT dysfunction. AT contains macrophages whose number and activation state is dynamically regulated with changes in AT mass. This study aims to investigate the effect of macrophage-secreted factors on preadipocyte survival. To assess the effect of macrophage-secreted factors on preadipocytes, murine 3T3-L1 preadipocytes or human primary preadipocytes were incubated with macrophage-conditioned medium (MacCM), prepared from either murine (J774A.1, RAW264.7, bone marrow-derived) or human (THP-1, monocyte-derived) macrophage models, respectively. MacCM inhibited preadipocyte apoptosis and activated pro-survival signaling in both preadipocyte models. Inhibition of PDGFR, Akt, or ERK1/2 reduced the pro-survival effect of MacCM in 3T3-L1 preadipocytes. Inhibition of reactive oxygen species (ROS) generation, or enhancement of ROS clearance, reduced MacCM-dependent 3T3-L1 preadipocyte survival. Whereas anti-inflammatory activated macrophages retained the ability to prevent preadipocyte apoptosis, pro-inflammatory activated macrophages did not. TNF-α immunoneutralization restored the survival activity of pro-inflammatory MacCM on 3T3-L1 preadipocytes. These studies reveal a novel pro-survival effect of MacCM on preadipocytes, and identify signaling molecules (PDGF, Akt, ERK1/2, and ROS) that underlie this action. Macrophage activation was found to regulate the pro-survival activity of MacCM. These in vitro cell culture studies are consistent with a model in which the extent of preadipocyte apoptosis in vivo may determine preadipocyte number and the ability of AT to expand while maintaining healthy function during chronic positive energy balance.

Dans cette étude, l'aptitude de trois extraits de Gui fermentés (VAF) issus de trois arbres hôtes, à induire ou moduler la sécrétion de cytokines, telles que l'IL-1β, l'IL-6 et le TNF-α, a été explorée à l'aide de deux modèles de macrophages murins. Des traitements prolongés par des concentrations cytotoxiques, mais non sub-cytotoxiques, de VAFs induisent la sécrétion d'IL-1β. Dans ces conditions, les concentrations sub-cytotoxiques de VAFs amplifient les sécrétions d'IL-1β induite après stimulations par le LPS puis l'ATP, ou par l'imiquimod. Par ailleurs, appliqués brièvement et à concentrations sub-cytotoxiques, les VAFs accélèrent la sécrétion d'IL-1β induite après stimulations par le LPS puis l'ATP. / In this study, the ability of fermented extracts from mistletoe grown on three host trees to induce or modulate the secretion of pro-inflammatory cytokines, like IL-1β, IL-6 and TNF-α has been explored. Applied for long times, cytotoxic, but not sub-cytotoxic concentrations of fermented mistletoe extracts induce the secretion of IL-1β. In these conditions sub-cytotoxic concentrations increase the IL-1β secretions induced either by LPS and ATP, or by imiquimod. When applied briefy at sub-cytotoxic concentrations, fermented mistletoe extracts can accelerate the secretion of IL-1β induced by LPS and ATP.

Background: Obesity-related diseases are arising as a major problem among children. inflammation has recently been identified to play an important role in the relationship between obesity.- as well as stunting-related diseases. Objectives: The aim of this study was to assess the association between serum tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and C-reactive protein (CRP) concentrations and a variety of cardiometabolic and anthropometric indices of children in a township outside Potchefstroom, South Africa. Methods: Blood samples of 115 girls and 78 boys (mean age 15.6 ± 1.35) in the Physical Activity in the Young (PLAY) study were cross-sectionally analysed. Trained fieldworkers collected the demographic, Tanner growth stage and habitual physical activity information. Physiologists measured the children’s blood pressure. Anthropometric measurements were taken by. trained post-graduate students with level 1 or 2 qualifications in anthropometrics. A standard test battery was administered by trained postgraduate students in Human Movement Science to assess muscular strength. flexibility and endurance of the children. Blood samples were collected, centrifuged and stored frozen until further analyses. Results: Stunted girls had a significantly higher serum TNF-α concentration than the non-stunted girls (p=0.03). The factor analyses showed that the inflammatory. status clustered with the height for age-z-scores (HAZ) scores and the waist-hip-ratio (WHR). The HAZ-score of the over-fat boys (- 1.46) was significantly smaller than the lean boys (- 1.14, p=0.0 1). whereas the over-fat girls had a trend for a smaller HAZ-score (-1.07) than the lean girls (-0.89). No significant differences were found between the over-fat and the lean children-s inflammatory status. TNF-α and CRP levels tended to be higher in the over-fat children than in lean children. The girls' scrum IL-6 and CRP concentrations correlated significantly with their body mass index (BMI) and WHR (p<0.05 )and their TNF-α and IL-6 concentrations correlated significantly with their WHR (p<0.01 and p<0.05, respectively). Conclusion: In comparison to the non-stunted girls, stunted girls had a statistically significantly higher TNF-α concentration. Unusual fat distribution that is found in over-fat and stunted children may be associated with low-grade inflammation in children. More research is needed on these associations with markers of inflammation in a long-term longitudinal study. / Thesis (M.Sc. (Nutrition))--North-West University, Potchefstroom Campus, 2007.

Adipose tissue (AT) expansion and remodeling that maintains healthy function relies on stromal preadipocytes capable of differentiating into new adipocytes (adipogenesis). During chronic positive energy balance, a relative deficit in adipogenesis, from either a decrease in preadipocyte number or their capacity to differentiate, leads to excessive adipocyte hypertrophy and AT dysfunction. AT contains macrophages whose number and activation state is dynamically regulated with changes in AT mass. This study aims to investigate the effect of macrophage-secreted factors on preadipocyte survival. To assess the effect of macrophage-secreted factors on preadipocytes, murine 3T3-L1 preadipocytes or human primary preadipocytes were incubated with macrophage-conditioned medium (MacCM), prepared from either murine (J774A.1, RAW264.7, bone marrow-derived) or human (THP-1, monocyte-derived) macrophage models, respectively. MacCM inhibited preadipocyte apoptosis and activated pro-survival signaling in both preadipocyte models. Inhibition of PDGFR, Akt, or ERK1/2 reduced the pro-survival effect of MacCM in 3T3-L1 preadipocytes. Inhibition of reactive oxygen species (ROS) generation, or enhancement of ROS clearance, reduced MacCM-dependent 3T3-L1 preadipocyte survival. Whereas anti-inflammatory activated macrophages retained the ability to prevent preadipocyte apoptosis, pro-inflammatory activated macrophages did not. TNF-α immunoneutralization restored the survival activity of pro-inflammatory MacCM on 3T3-L1 preadipocytes. These studies reveal a novel pro-survival effect of MacCM on preadipocytes, and identify signaling molecules (PDGF, Akt, ERK1/2, and ROS) that underlie this action. Macrophage activation was found to regulate the pro-survival activity of MacCM. These in vitro cell culture studies are consistent with a model in which the extent of preadipocyte apoptosis in vivo may determine preadipocyte number and the ability of AT to expand while maintaining healthy function during chronic positive energy balance.

Thesis (Ph.D. in Immunology) -- University of Colorado, 2005. / Typescript. Includes bibliographical references (leaves 190-212). Free to UCDHSC affiliates. Online version available via ProQuest Digital Dissertations;

Dans cette étude, l'aptitude de trois extraits de Gui fermentés (VAF) issus de trois arbres hôtes, à induire ou moduler la sécrétion de cytokines, telles que l'IL-1β, l'IL-6 et le TNF-α, a été explorée à l'aide de deux modèles de macrophages murins. Des traitements prolongés par des concentrations cytotoxiques, mais non sub-cytotoxiques, de VAFs induisent la sécrétion d'IL-1β. Dans ces conditions, les concentrations sub-cytotoxiques de VAFs amplifient les sécrétions d'IL-1β induite après stimulations par le LPS puis l'ATP, ou par l'imiquimod. Par ailleurs, appliqués brièvement et à concentrations sub-cytotoxiques, les VAFs accélèrent la sécrétion d'IL-1β induite après stimulations par le LPS puis l'ATP. / In this study, the ability of fermented extracts from mistletoe grown on three host trees to induce or modulate the secretion of pro-inflammatory cytokines, like IL-1β, IL-6 and TNF-α has been explored. Applied for long times, cytotoxic, but not sub-cytotoxic concentrations of fermented mistletoe extracts induce the secretion of IL-1β. In these conditions sub-cytotoxic concentrations increase the IL-1β secretions induced either by LPS and ATP, or by imiquimod. When applied briefy at sub-cytotoxic concentrations, fermented mistletoe extracts can accelerate the secretion of IL-1β induced by LPS and ATP.

A lesão por isquemia-reperfusão (I/R) é o mecanismo fisiopatológico central no desenvolvimento da insuficiência hepática pós-operatória. Diversas estratégias para minimizar suas consequências estão sendo desenvolvidas, mas ainda sem resultados satisfatórios. Recentemente o pré-condicionamento isquêmico remoto (PCIR), método em que ciclos breves de I/R aplicados em um órgão ou membro é capaz de atenuar os resultados da I/R em um órgão distante, vem sendo utilizado, em modelos experimentais, com resultados promissores. No entanto seu mecanismo de ação ainda não foi esclarecido. Um dos mecanismos propostos é a modulação na expressão das citocinas sintetizadas durante a resposta inflamatória que acompanha o processo de I/R. Foram utilizados 36 ratos (Rattus norvegicus), machos, com peso entre 250 e 280 g, divididos em três grupos: Grupo Sham, cirurgia simulada; Grupo IR, isquemia de 70% do fígado por 45 minutos e reperfusão; e Grupo PCIR, pré-condicionamento isquêmico remoto do fígado através de seis ciclos de isquemia-reperfusão da pata do animal, com quatro minutos de isquemia e quatro minutos de reperfusão em cada ciclo, seguido de isquemia hepática semelhante ao do Grupo IR. Terminado os procedimentos cirúrgicos, metade dos animais foi morta decorridos 60 minutos de reperfusão, e a outra metade após 180 minutos. Foi coletado tecido hepático do lobo submetido à isquemia, para estudo histopatológico, utilizando o índice de injúria hepática modificado; e sangue, para dosagem plasmática de TNF-&#945;, IL-6, IL-10 e ALT. A análise histopatológica mostrou que a necrose celular foi significativamente reduzida no Grupo PCIR quando comparado com Grupo IR (p <0,0001). As transaminases mostraram o mesmo padrão com redução significativa dos seus valores no Grupo PCIR quando comparados com o Grupo I-R (p <0,0001). A dosagem das interleucinas mostrou redução significativa na expressão da IL-6 no Grupo PCIR quando comparado com o Grupo IR (p<0,001). Houve aumento da expressão de IL-10 nos grupo PCIR, porém não atingiu significância estatística. Não foi identificada diferença na dosagem de TNF-&#945; nos grupos estudados. O PCI-R foi eficaz na redução na necrose celular resultante da lesão por I-R nos grupos estudados. A redução na síntese de IL-6 segue o padrão observado em outros estudos. / Ischemia/Reperfusion (I/R) injury is an important pathophysiological mechanism in the postoperative liver failure. Different strategies to minimize the I/R liver injury have been developed during the last decades but the results had been disappointing. Recently, the remote ischemic preconditioning (RIPC), a method that involves a brief ischemic episode on an organ or tissue that subsequently affords protection to a remote organ or tissue, have been use in various experimental models with promising results. The precise pathway activated by the RIPC isnt clear, but cytokine release modulation has been proposed as a candidate mechanism. Thirty-six male rats (Rattus norvegicus) were divided in 3 groups: Sham; I/R injury, a 45 minutes lobar (70%) liver ischemia and reperfusion; and RIPC, 6 cycles of 4 minutes of ischemia and 4 minutes of reperfusion of the right hindlimb followed by a 45 minutes lobar (70%) liver ischemia and reperfusion. Liver tissue in the affected lobe and blood samples were collected after 60 minutes and 180 minutes of reperfusion for histopathological study of liver I/R, plasma cytokines (TNF-&#945;, IL-6 and IL-10) and liver aminotransferases measurement (ALT). The histopathological study demonstrated a significant lesser degree of liver necrosis in the RIPC group (p <0,001). The aminotransferases levels followed the same pattern, with significant lower levels in the RIPC group (p <0,001). The cytokines assessment showed a reduction in the expression of IL-6 in the RIPC when compared with the I/R group (p <0,01). Interleukin-10 levels were higher in the RIPC group, but the difference wasnt significant. The TNF-&#945; measurement didnt show any difference in the groups. The RIPC model presented consistently reduced the I/R injury to the liver and the IL-6 expression was similar to the reported in other studies.

Made available in DSpace on 2014-06-11T19:33:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-12-19Bitstream added on 2014-06-13T21:05:33Z : No. of bitstreams: 1 rivasgutierrez_jc_dr_arafo.pdf: 816322 bytes, checksum: ec255883d6c0c6ef8ebbe4d64cd79b98 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Os macrófagos constituem uma população celular do sistema imune. Estas células podem ser ativadas por uma variedade de estímulos e suas principais funções incluem a fagocitose de partículas estranhas, apresentação de antígenos, produção de citocinas e compostos intermediários do nitrogênio (NO) e do oxigênio (H202). Os cimentos endodônticos são capazes de promover uma estimulação do sistema imune. Neste estudo, foram analisados os níveis de quantificação das citocinas, além do mediador óxido nítrico, como uma medida de estimulação de macrófagos peritoneais de camundongos. Através de análise estatística dos dados, foram observados os níveis de citotoxicidade dos macrófagos de camundongos estimulados pelos diferentes cimentos endodônticos, meio RPMI-1640 (grupo controle -) e LPS (grupo controle +). Os diferentes cimentos testados apresentaram concentrações com diferentes citotoxicidades: Sealapex 35ug/ml, Polímero de Mamona 8,75 ug/ml, do Epiphany 17,5 ug/ml, do Epiphany + Primer 17,5 ug/ml, do Primer 35 ug/ml, do EndoRez 17,5 ug/ml e do AH Plus 70 ug/ml. Após a adequação das concentrações viáveis dos cimentos testados conclui-se que o material que mais estimulou a liberação de NO foi Primer, seguido do Endorez, AH Plus, Ephiphany, Sealapex, Epiphany + Primer. O Polímero de Mamona foi o que estimulou a uma menor produção de NO. Em relação à produção de TNF-alfa o material que estimulou maior produção foi o Primer, seguido de Epiphany, AH Plus, Epiphany + Primer, Sealapex e Polímero de Mamona. O EndoRez não foi capaz de estimular a produção de TNF-alfa. Nenhum dos cimentos testados induziu à liberação de IFN-y, sugerindo que outro mediadores tais como IL-1 e IL-12 possam estar envolvidos na liberação de NO observada no presente estudo. / It was evaluated the citotoxicity of the sealers, Sealapex, Polímero de Mamona, Epiphany, EndoRez and AH Plus in relation to the release of Nitric Oxide, Tumor Necrotic Factor-Alpha and Interferon Gamma in murine cells culture. After the ideal concentration was found, according to MTT test, it was conduded that the sealers with higher release were Polímero de Mamona, EndoRez, Epiphany + Primer, Epiphany, Primer do Epiphany = Sealapex and AH Plus. All sealers reached lower levels of citotoxicity than control.

Made available in DSpace on 2014-06-11T19:23:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-07-17Bitstream added on 2014-06-13T20:29:53Z : No. of bitstreams: 1 dalmagro_p_me_araca.pdf: 405350 bytes, checksum: 6e68960f50834d47030b502e88fb55c8 (MD5) / Endotoxemia é distúrbio sistêmico que se origina da resposta do hospedeiro a um componente da membrana celular das bactérias Gram- negativas. Esta resposta se dá através da exposição dos receptores celulares TLR-4 e TLR-2 ao LPS. Os objetivos deste estudo foram investigar as alterações na expressão gênica da exposição ao LPS em leucócitos de equinos utilizando a técnica de microarray, avaliar a eficiência do modelo ex vivo para os estudos envolvendo a endotoxemia pela mesma técnica, avaliar a expressão global de genes em vias envolvidas, identificar componentes da cascata metabólica com potenciais para novas terapias, e fornecer subsídio para futuros estudos. Amostras de sangue total (15mL) de cavalos saudáveis (n=6) foram incubadas durante 4 horas a 37°C com 5% de CO2 na presença (1 ou 10 ng/mL) ou ausência de LPS (0 ng/mL). Alíquotas de 500µL de sangue foram coletadas nos momentos 0, 2 e 4 horas após o estímulo do LPS. O RNA, extraído das mostras, foi utilizado para a transcrição do cDNA. A hibridização do cDNA marcado com Cy-3 foi realizada em lâminas 4x44K v2 de humanos contendo sequências homólogas com a espécie equina para os genes de interesse. Após a leitura das lâminas, com filtro para genes 30x mais ou menos expressos, verificou-se um aumento da expressão do TLR-2 na concentração de 10 ng LPS/mL no momento 4 em relação ao momento 2. Este resultado sugere que, embora o receptor TLR-4 seja o principal receptor no reconhecimento do LPS, o receptor TLR-2 também tem um papel no reconhecimento destas moléculas / Endotoxemia is systemic disturbance that origins from the host response to a component of the cellular membrane of Gram-negative bacterias. This response occurs through exposure of cellular receptors TLR-4 and TLR-2 to LPS. The objectives of this study were to investigate changes in gene expression of exposure to LPS in horses leukocytes using the microarray technique, to evaluate the efficiency of the ex vivo model for studies of endotoxemia by the same technique, to evaluate the global expression of genes in the metabolic pathways involved, identify components of the metabolic cascade with potential for new therapies, and provide allowance for future studies. Whole blood samples (15mL) of healthy horses (n=6) were incubated for 4 hours at 37°C with 5% of CO2 in the presence (1 or 10 ng/ml) or absence of LPS (0 ng/ml). Aliquots of 500μL of blood were collected at 0,2 and 4 hours after LPS stimulation. The RNAs, extracted from the samples, were used for the transcription of the cDNAs. Hybridization of labeled cDNAs with Cy-3 were performed in 4x44K v2 slides containing human sequences homologous to the equine species for the genes of interest. After the reading of the slides with filter for genes 30x up regulation or down regulation expression, it was observed an increased expression of the TLR-2 concentration of 10 ng LPS/mL at time 4 compared to time 2. This result suggests that, although the TLR-4 receptor is the main LPS recognition receptor, the receptor TLR-2 also plays a role in recognition of these molecules

A lesão por isquemia-reperfusão (I/R) é o mecanismo fisiopatológico central no desenvolvimento da insuficiência hepática pós-operatória. Diversas estratégias para minimizar suas consequências estão sendo desenvolvidas, mas ainda sem resultados satisfatórios. Recentemente o pré-condicionamento isquêmico remoto (PCIR), método em que ciclos breves de I/R aplicados em um órgão ou membro é capaz de atenuar os resultados da I/R em um órgão distante, vem sendo utilizado, em modelos experimentais, com resultados promissores. No entanto seu mecanismo de ação ainda não foi esclarecido. Um dos mecanismos propostos é a modulação na expressão das citocinas sintetizadas durante a resposta inflamatória que acompanha o processo de I/R. Foram utilizados 36 ratos (Rattus norvegicus), machos, com peso entre 250 e 280 g, divididos em três grupos: Grupo Sham, cirurgia simulada; Grupo IR, isquemia de 70% do fígado por 45 minutos e reperfusão; e Grupo PCIR, pré-condicionamento isquêmico remoto do fígado através de seis ciclos de isquemia-reperfusão da pata do animal, com quatro minutos de isquemia e quatro minutos de reperfusão em cada ciclo, seguido de isquemia hepática semelhante ao do Grupo IR. Terminado os procedimentos cirúrgicos, metade dos animais foi morta decorridos 60 minutos de reperfusão, e a outra metade após 180 minutos. Foi coletado tecido hepático do lobo submetido à isquemia, para estudo histopatológico, utilizando o índice de injúria hepática modificado; e sangue, para dosagem plasmática de TNF-&#945;, IL-6, IL-10 e ALT. A análise histopatológica mostrou que a necrose celular foi significativamente reduzida no Grupo PCIR quando comparado com Grupo IR (p <0,0001). As transaminases mostraram o mesmo padrão com redução significativa dos seus valores no Grupo PCIR quando comparados com o Grupo I-R (p <0,0001). A dosagem das interleucinas mostrou redução significativa na expressão da IL-6 no Grupo PCIR quando comparado com o Grupo IR (p<0,001). Houve aumento da expressão de IL-10 nos grupo PCIR, porém não atingiu significância estatística. Não foi identificada diferença na dosagem de TNF-&#945; nos grupos estudados. O PCI-R foi eficaz na redução na necrose celular resultante da lesão por I-R nos grupos estudados. A redução na síntese de IL-6 segue o padrão observado em outros estudos. / Ischemia/Reperfusion (I/R) injury is an important pathophysiological mechanism in the postoperative liver failure. Different strategies to minimize the I/R liver injury have been developed during the last decades but the results had been disappointing. Recently, the remote ischemic preconditioning (RIPC), a method that involves a brief ischemic episode on an organ or tissue that subsequently affords protection to a remote organ or tissue, have been use in various experimental models with promising results. The precise pathway activated by the RIPC isnt clear, but cytokine release modulation has been proposed as a candidate mechanism. Thirty-six male rats (Rattus norvegicus) were divided in 3 groups: Sham; I/R injury, a 45 minutes lobar (70%) liver ischemia and reperfusion; and RIPC, 6 cycles of 4 minutes of ischemia and 4 minutes of reperfusion of the right hindlimb followed by a 45 minutes lobar (70%) liver ischemia and reperfusion. Liver tissue in the affected lobe and blood samples were collected after 60 minutes and 180 minutes of reperfusion for histopathological study of liver I/R, plasma cytokines (TNF-&#945;, IL-6 and IL-10) and liver aminotransferases measurement (ALT). The histopathological study demonstrated a significant lesser degree of liver necrosis in the RIPC group (p <0,001). The aminotransferases levels followed the same pattern, with significant lower levels in the RIPC group (p <0,001). The cytokines assessment showed a reduction in the expression of IL-6 in the RIPC when compared with the I/R group (p <0,01). Interleukin-10 levels were higher in the RIPC group, but the difference wasnt significant. The TNF-&#945; measurement didnt show any difference in the groups. The RIPC model presented consistently reduced the I/R injury to the liver and the IL-6 expression was similar to the reported in other studies.