Short-term high-fat diet affects macrophages inflammatory response, early signs of a long-term problem

Obesity is a chronic inflammatory disease that affects millions of people worldwide. Most studies observe the effects of a high-fat diet (HFD) in 10-12 weeks. This work investigated the effects induced by a HFD administered for 6 weeks on the nutritional status of mice and some aspects of the inflammatory response in mouse peritoneal macrophages. Male Swiss Webster mice, 2-3 months of age, were fed a control diet or HFD for 6 weeks. After this period, the mice were euthanized, and peritoneal macrophages were collected for immunoassays and assessment of biochemical parameters. A HFD was associated with increased cholesterol, insulin resistance, C-reactive protein (CRP), leptin, and serum resistin levels. Lipopolysaccharide (LPS)- stimulated adipocyte cultures of animals subjected to a HFD showed increased production of proinflammatory cytokines such as tumor necrosis factor alpha (TNF-α), interleukin-1 (IL-1), and interleukin-6 (IL-6). However, peritoneal macrophages of the HFD group showed no changes in the levels of these cytokines. LPS-stimulated peritoneal macrophages from HFD-treated animals showed a reduction in mRNA expression of TNF-α and IL-6, as well as a decrease in expression of the transcription factor nuclear factor-kappa B (NF-kB). In conclusion, HFD treatment for 6 weeks induces similar signs to metabolic syndrome and decreases the capacity of peritoneal macrophages to develop an appropriate inflammatory response to a bacterial component

Correction to: High-fat diet or low-protein diet changes peritoneal macrophages function in mice

The original version of this article [1], published on 28 June 2016, contains a mistake. The part labels in Fig. 1 are missing. The corrected version of Fig. 1 is given below.

Avaliação do controle da expressão gênica de citocinas pró inflamatórias mediado pela IL-10. Participação da IL-10 na modulação da resposta inflamatória exercida pela glutamina e na restrição alimentar / Proinflammatory cytokines gene expression control mediated by IL-10. Participation of IL-10 on inflammatory response exerted by glutamine and dietary restriction

O desenvolvimento de uma resposta imune adequada é um processo extremamente importante para a manutenção da homeostase do organismo. Uma série de processos são desencadeados a partir do primeiro contato com micro-organismos patógenos até a efetivação da resposta imune de memória. Todos esses processos envolvem a participação e a complexa atuação de mediadores como as citocinas inflamatórias e também citocinas regulatórias, que exercerão efeitos controlando o processo inflamatório. Diversos mecanismos moleculares, subjacentes à resposta inflamatória, ainda não estão totalmente compreendidos, como por exemplo o controle da expressão de genes inflamatórios exercido pela IL-10. Os processos envolvidos na resposta inflamatória são mantidos às custas do consumo de nutrientes, dentre eles podemos destacar o aminoácido glutamina, que atua em nível molecular, fornecendo nitrogênio para a formação do material genético e fonte energética para determinadas células do sistema imunológico como os macrófagos. Portanto, neste trabalho, investigamos os efeitos da IL-10 na modificação de nucleossomos, evidenciando o papel dessa citocina em regular a expressão de genes inflamatórios em macrófagos. Avaliamos também a função da glutamina, modulando a expressão de RNAm de citocinas inflamatórias e regulatórias dessas células. E por último, desenvolvemos um modelo de restrição alimentar em camundongos, nos quais avaliamos os efeitos desse modelo considerando-se alguns aspectos hematológicos e estudamos as alterações na resposta inflamatória em células esplênicas e do peritônio, bem como avaliamos a suplementação de glutamina in vitro na produção das citocinas (IL-12, TNF-alfa, IL-10) e a expressão do fator de transcrição NFkB. Os resultados compilados mostraram que a IL-10 leva a uma rápida redução da acetilação de nucleossomos, modulando a arquitetura da cromatina de genes inflamatórios como a IL-12. A glutamina modula a expressão de citocinas inflamatórias, regulando positivamente a expressão de IL-10 e Interferon beta. E a restrição alimentar induz a redução de citocinas proinflamatórias (IL-12 e TNF-α), influenciadas pelo aumento da produção de IL-10 e finalmente a suplementação com glutamina não interfere nesses parâmetros nas células peritoneiais e esplênicas do grupo submetido à restrição alimentar. Conclusão: a IL-10 modula a expressão gênica através da modificação de nucleossomos em macrófagos derivados da medula; a glutamina modula a expressão de IL-10 inibindo a resposta inflamatória, e a restrição alimentar modula alguns aspectos hematológicos e possui propriedades anti-inflamatórias.

The development of an appropriate immune response is an important process to the organism's homeostatic maintenance. A series of processes are triggered upon the very first contact with pathogens, up to the immunological memory establishment. These processes implicate in the participation of complex mediators, such as inflammatory and regulatory cytokines that will control the inflammatory process. Some mechanisms underlying the inflammatory response are not totally understood, the control of inflammatory genes exerted by IL-10 is an example. The processes involved in the inflammatory response are kept with nutrients expense, among these nutrients we can highlight the amino acid glutamine. It acts in a molecular level, supplying nitrogen to genetic material formation and as an energy supply for immune cells such as macrophages. Thus, we investigated the IL-10 effects on nucleosome modifications evidencing this cytokine role regulating inflammatory genes expression in macrophages. We also evaluated glutamine functions modulating inflammatory and regulatory cytokines mRNA expression on these cells. Ultimately, we developed a dietary restriction animal model where we evaluated it's effects on selected haematological aspects, analyzing the alteration in the inflammatory response of splenic and peritoneal cells. We also evaluated in vitro glutamine supplementation assessing cytokines production (IL-12, TNF-α, and IL-10) and the expression of NFkB transcription factor. The compiled results a expressive reduction in nucleosome acetylation modifying the chromatin architecture of inflammatory genes such as IL-12 and IL-6. Glutamine modulates inflammatory cytokines gene expression upregulating the expression of IL-10 and interferon beta. The dietary restriction reduces proinflammatory cytokines production (IL-12 and TNF-α), these results are influenced by the upregulated IL-10 production, glutamine supplementation have no effect on these parameters in the dietary restriction group. In conclusion, we can infer that IL-10 modulates gene expression trough nucleosome modification in bone marrow derived macrophages, glutamine has a potential effect on IL-10 expression, inhibiting the inflammatory response and dietary restriction modifies hematological parameters, presenting anti-inflammatory properties.

Avaliação do controle da expressão gênica de citocinas pró inflamatórias mediado pela IL-10. Participação da IL-10 na modulação da resposta inflamatória exercida pela glutamina e na restrição alimentar / Proinflammatory cytokines gene expression control mediated by IL-10. Participation of IL-10 on inflammatory response exerted by glutamine and dietary restriction

O desenvolvimento de uma resposta imune adequada é um processo extremamente importante para a manutenção da homeostase do organismo. Uma série de processos são desencadeados a partir do primeiro contato com micro-organismos patógenos até a efetivação da resposta imune de memória. Todos esses processos envolvem a participação e a complexa atuação de mediadores como as citocinas inflamatórias e também citocinas regulatórias, que exercerão efeitos controlando o processo inflamatório. Diversos mecanismos moleculares, subjacentes à resposta inflamatória, ainda não estão totalmente compreendidos, como por exemplo o controle da expressão de genes inflamatórios exercido pela IL-10. Os processos envolvidos na resposta inflamatória são mantidos às custas do consumo de nutrientes, dentre eles podemos destacar o aminoácido glutamina, que atua em nível molecular, fornecendo nitrogênio para a formação do material genético e fonte energética para determinadas células do sistema imunológico como os macrófagos. Portanto, neste trabalho, investigamos os efeitos da IL-10 na modificação de nucleossomos, evidenciando o papel dessa citocina em regular a expressão de genes inflamatórios em macrófagos. Avaliamos também a função da glutamina, modulando a expressão de RNAm de citocinas inflamatórias e regulatórias dessas células. E por último, desenvolvemos um modelo de restrição alimentar em camundongos, nos quais avaliamos os efeitos desse modelo considerando-se alguns aspectos hematológicos e estudamos as alterações na resposta inflamatória em células esplênicas e do peritônio, bem como avaliamos a suplementação de glutamina in vitro na produção das citocinas (IL-12, TNF-alfa, IL-10) e a expressão do fator de transcrição NFkB. Os resultados compilados mostraram que a IL-10 leva a uma rápida redução da acetilação de nucleossomos, modulando a arquitetura da cromatina de genes inflamatórios como a IL-12. A glutamina modula a expressão de citocinas inflamatórias, regulando positivamente a expressão de IL-10 e Interferon beta. E a restrição alimentar induz a redução de citocinas proinflamatórias (IL-12 e TNF-α), influenciadas pelo aumento da produção de IL-10 e finalmente a suplementação com glutamina não interfere nesses parâmetros nas células peritoneiais e esplênicas do grupo submetido à restrição alimentar. Conclusão: a IL-10 modula a expressão gênica através da modificação de nucleossomos em macrófagos derivados da medula; a glutamina modula a expressão de IL-10 inibindo a resposta inflamatória, e a restrição alimentar modula alguns aspectos hematológicos e possui propriedades anti-inflamatórias

The development of an appropriate immune response is an important process to the organism's homeostatic maintenance. A series of processes are triggered upon the very first contact with pathogens, up to the immunological memory establishment. These processes implicate in the participation of complex mediators, such as inflammatory and regulatory cytokines that will control the inflammatory process. Some mechanisms underlying the inflammatory response are not totally understood, the control of inflammatory genes exerted by IL-10 is an example. The processes involved in the inflammatory response are kept with nutrients expense, among these nutrients we can highlight the amino acid glutamine. It acts in a molecular level, supplying nitrogen to genetic material formation and as an energy supply for immune cells such as macrophages. Thus, we investigated the IL-10 effects on nucleosome modifications evidencing this cytokine role regulating inflammatory genes expression in macrophages. We also evaluated glutamine functions modulating inflammatory and regulatory cytokines mRNA expression on these cells. Ultimately, we developed a dietary restriction animal model where we evaluated it's effects on selected haematological aspects, analyzing the alteration in the inflammatory response of splenic and peritoneal cells. We also evaluated in vitro glutamine supplementation assessing cytokines production (IL-12, TNF-α, and IL-10) and the expression of NFkB transcription factor. The compiled results a expressive reduction in nucleosome acetylation modifying the chromatin architecture of inflammatory genes such as IL-12 and IL-6. Glutamine modulates inflammatory cytokines gene expression upregulating the expression of IL-10 and interferon beta. The dietary restriction reduces proinflammatory cytokines production (IL-12 and TNF-α), these results are influenced by the upregulated IL-10 production, glutamine supplementation have no effect on these parameters in the dietary restriction group. In conclusion, we can infer that IL-10 modulates gene expression trough nucleosome modification in bone marrow derived macrophages, glutamine has a potential effect on IL-10 expression, inhibiting the inflammatory response and dietary restriction modifies hematological parameters, presenting anti-inflammatory properties

Glutamine metabolism and its effects on immune response: molecular mechanism and gene expression

This article aims to review glutamine metabolism and its effects on the immune response. Selected topics are addressed, particularly the effect of glutamine on cell survival and proliferation, as well as its importance in some biochemical pathways. The impact of glutamine on muscle, intestine, and liver metabolism are described, and a special section about glutamine regulation of the immune response is included. In this context, the modulation of glutamine on relevant signaling pathways as nuclear factor kappa B (NF-kB), mitogen-activated protein kinases (MAPKs), and heat shock protein and the influence of this amino acid on cell migration and adhesion molecules are highlighted. Some important immune response pathways modulated by glutamine were described as its action incritically ill patients. In summary, this review describes some important actions of glutamine, and a range of reactions and modulatory effects in different organs, which may inform new therapeutic strategies. However, further studies are necessary to provide information about glutamine use, especially about situations in which it can be better used as well as fine-tuning dose and administration.

High-fat diet or low-protein diet changes peritoneal macrophages function in mice

BACKGROUND: Obesity and protein malnutrition are major food problems nowadays, affecting billions of people around the world. The nutrition transition that has occurred in recent decades is changing the nutritional profile, reducing malnutrition and increasing the percentage of obese people. The innate immune response is greatly influenced by diet, with significant changes in both malnutrition and obesity. Therefore, we investigate the effects of protein malnutrition and obesity in nutritional and immunological parameters in mice. RESULTS: Peritoneal macrophages of malnourished animals showed reduced functions of adhesion, spreading, and fungicidal activity; production of hydrogen peroxide and nitric oxide were lower, reflecting changes in the innate immune response. However, the high-fat animals had macrophage functions slightly increased. CONCLUSIONS: Animals subjected to low-protein diet have immunosuppression, and animals subjected to high-fat diet increased visceral adipose tissue and the presence of an inflammatory process with increased peritoneal macrophage activity and similar systemic changes to metabolic syndrome.

The influence of protein malnutrition on the production of GM-CSF and M-CSF by macrophages

ABSTRACT It is well established that protein malnutrition (PM) impairs immune defenses and increases susceptibility to infection. Macrophages are cells that play a central role in innate immunity, constituting one of the first barriers against infections. Macrophages produce several soluble factors, including cytokines and growth factors, important to the immune response. Among those growth factors, granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF). GM-CSF and M-CSF are important to monocyte and macrophage development and stimulation of the immune response process. Knowing the importance of GM-CSF and M-CSF, we sought to investigate the influence of PM on macrophage production of these growth factors. Two-month-old male BALB/c mice were subjected to PM with a low-protein diet (2%) and compared to a control diet (12%) mouse group. Nutritional status, hemogram and the number of peritoneal cells were evaluated. Additionally, peritoneal macrophages were cultured and the production of GM-CSF and M-CSF and mRNA expression were evaluated. To determine if PM altered macrophage production of GM-CSF and M-CSF, they were stimulated with TNF-α. The PM animals had anemia, leukopenia and a reduced number of peritoneal cells. The production of M-CSF was not different between groups; however, cells from PM animals, stimulated with or without TNF-α, presented reduced capability to produce GM-CSF. These data imply that PM interferes with the production of GM-CSF, and consequently would affect the production and maturation of hematopoietic cells and the immune response.

Hematological and biochemical reference values for C57BL/6, Swiss Webster and BALB/c mice / Valores de referência hematológicos e bioquímicos para camundongos das linhagens C57BL/6, Swiss Webster e BALB/c

The use of animals in scientific research has contributed significantly to the development of science, promoting various advances in understanding the metabolic machinery and the discovery of treatments and preventive measures applied to human and veterinary medicine. The development and use of alternative methods is encouraged; however, in some situations, the use of animals in accordance with ethical policies is still required. Established hematological and clinical chemistry reference values in laboratory animals are essential to evaluate functional changes; however, there are few data in the literature on these values, being fundamentally a comparative basis. The aim of this investigation was the establishment of hematological and clinical chemistry reference values in common strains/stocks of mice used in animal experimentation. Blood profile (hemogram, reticulocytes and myelogram) and clinical chemistry serum determination of total protein, albumin, glucose, cholesterol, triglycerides, calcium and phosphorus were evaluated using C57BL/6, BALB/c and Swiss Webster mice, male, 2-3 months old. The results standardize reference intervals in animals reared in Laboratory Animal Facility, reflecting the expected condition in rodents subjected to scientific research...

O uso de animais na pesquisa científica tem contribuído significativamente para o desenvolvimento da ciência, promovendo vários avanços na compreensão da maquinaria metabólica, bem como a descoberta de tratamentos e medidas preventivas aplicadas à medicina humana e veterinária. O desenvolvimento e utilização de métodos alternativos é encorajado, no entanto, em algumas situações, ainda é necessária a utilização de animais em conformidade com termos éticos. Estabelecer valores de referência hematológicos e bioquímicos para animais de laboratório é essencial para avaliar alterações funcionais, no entanto, existem poucos dados na literatura sobre estes valores, sendo fundamentalmente uma base comparativa. O presente trabalho foi delineado para estabelecer valores de referência hematológicos e bioquímicos em linhagens camundongos utilizados em pesquisa científica. Foram avaliados o perfil sanguíneo (hemograma, reticulócitos e mielograma) e a determinação bioquímica sérica de proteínas totais, albumina, glicose, colesterol, triglicerídeos, cálcio e fósforo. Foram utilizados camundongos C57BL/6, BALB/c e Swiss Webster, do sexo masculino, 2-3 meses de idade. Os resultados padronizam intervalos de referência em camundongos criados em Biotério, refletindo a condição esperada nesses animais submetidos à investigação científica...