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1.
Int J Obes (Lond) ; 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38351251

RESUMO

BACKGROUND/OBJECTIVES: Adipose tissue macrophages (ATM) are key actors in the pathophysiology of obesity-related diseases. They have a unique intermediate M2-M1 phenotype which has been linked to endoplasmic reticulum (ER) stress. We previously reported that human M2 macrophages treated with the ER stress inducer thapsigargin switched to a pro-inflammatory phenotype that depended on the stress protein GRP94. In these conditions, GRP94 promoted cathepsin L secretion and was co-secreted with complement C3. As cathepsin L and complement C3 have been reported to play a role in the pathophysiology of obesity, in this work we studied the involvement of GRP94 in the pro-inflammatory phenotype of ATM. METHODS: GRP94, cathepsin L and C3 expression were analyzed in CD206 + ATM from mice, WT or obesity-resistant transgenic fat-1, fed a high-fat diet (HFD) or a standard diet. GRP94 colocalization with cathepsin L and C3 and its effects were analyzed in human primary macrophages using thapsigargin as a control to induce ER stress and palmitic acid (PA) as a driver of metabolic activation. RESULTS: In WT, but not in fat-1 mice, fed a HFD, we observed an increase in crown-like structures consisting of CD206 + pSTAT1+ macrophages showing high expression of GRP94 that colocalized with cathepsin L and C3. In vitro experiments showed that PA favored a M2-M1 switch depending on GRP94. This switch was prevented by omega-3 fatty acids. PA-induced GRP94-cathepsin L colocalization and a decrease in cathepsin L enzymatic activity within the cells (while the enzymatic activity in the extracellular medium was increased). These effects were prevented by the GRP94 inhibitor PU-WS13. CONCLUSIONS: GRP94 is overexpressed in macrophages both in in vivo and in vitro conditions of obesity-associated inflammation and is involved in changing their profile towards a more pro-inflammatory profile. It colocalizes with complement C3 and cathepsin L and modulates cathepsin L activity.

2.
Artigo em Inglês | MEDLINE | ID: mdl-36589866

RESUMO

The gut microbiota constitutes a diverse community of organisms with pervasive effects on host homeostasis. The diversity and composition of the gut microbiota depend on both intrinsic (host genetics) and extrinsic (environmental) factors. Here, we investigated the reaction norms of fecal microbiota diversity and composition in three strains of mice infected with increasing doses of the gastrointestinal nematode Heligmosomoides polygyrus. We found that α-diversity (bacterial taxonomic unit richness) declined along the gradient of infective doses, and ß-diversity (dissimilarity between the composition of the microbiota of uninfected and infected mice) increased as the infective dose increased. We did not find evidence for genotype by environment (host strain by infective dose) interactions, except when focusing on the relative abundance of the commonest bacterial families. A simulation approach also showed that significant genotype by environment interactions would have been hardly found even with much larger sample size. These results show that increasing parasite burden progressively depauperates microbiota diversity and contributes to rapidly change its composition, independently from the host genetic background.

3.
Int J Parasitol ; 49(11): 873-883, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31525370

RESUMO

Resistance to infection is a multifactorial trait, and recent work has suggested that the gut microbiota can also contribute to resistance. Here, we performed a fecal microbiota transplant to disentangle the contribution of the gut microbiota and host genetics as drivers of resistance to the intestinal nematode Heligmosomoides polygyrus. We transplanted the microbiota of a strain of mice (SJL), resistant to H. polygyrus, into a susceptible strain (CBA) and vice-versa. We predicted that if the microbiota shapes resistance to H. polygyrus, the FMT should reverse the pattern of resistance between the two host strains. The two host strains had different microbiota diversities and compositions before the start of the experiment, and the FMT altered the microbiota of recipient mice. One mouse strain (SJL) was more resistant to colonization by the heterologous microbiota, and it maintained its resistance profile to H. polygyrus (lower parasite burden) independently of the FMT. On the contrary, CBA mice harbored parasites with lower fecundity during the early stage of the infection, and had an up-regulated expression of the cytokine IL-4 (a marker of H. polygyrus resistance) after receiving the heterologous microbiota. Therefore, while host genetics remains the main factor shaping the pattern of resistance to H. polygyrus, the composition of the gut microbiota also seems to play a strain-specific role.


Assuntos
Resistência à Doença , Microbioma Gastrointestinal , Patrimônio Genético , Interações Hospedeiro-Parasita , Nematospiroides dubius/imunologia , Infecções por Strongylida/imunologia , Animais , Modelos Animais de Doenças , Transplante de Microbiota Fecal , Camundongos Endogâmicos
4.
Nutrients ; 11(9)2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31514316

RESUMO

Diets high in saturated fatty acids (FA) represent a risk factor for the development of obesity and associated metabolic disorders, partly through their impact on the epithelial cell barrier integrity. We hypothesized that unsaturated FA could alleviate saturated FA-induced endoplasmic reticulum (ER) stress occurring in intestinal secretory goblet cells, and consequently the reduced synthesis and secretion of mucins that form the protective mucus barrier. To investigate this hypothesis, we treated well-differentiated human colonic LS174T goblet cells with palmitic acid (PAL)-the most commonly used inducer of lipotoxicity in in vitro systems-or n-9, n-6, or n-3 unsaturated fatty acids alone or in co-treatment with PAL, and measured the impact of such treatments on ER stress and Muc2 production. Our results showed that only eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids protect goblet cells against ER stress-mediated altered Muc2 secretion induced by PAL, whereas neither linolenic acid nor n-9 and n-6 FA are able to provide such protection. We conclude that EPA and DHA could represent potential therapeutic nutrients against the detrimental lipotoxicity of saturated fatty acids, associated with type 2 diabetes and obesity or inflammatory bowel disease. These in vitro data remain to be explored in vivo in a context of dietary obesity.


Assuntos
Ácidos Docosa-Hexaenoicos/farmacologia , Ácido Eicosapentaenoico/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Células Caliciformes/efeitos dos fármacos , Mucina-2/metabolismo , Ácido Palmítico/toxicidade , Linhagem Celular , Citoproteção , Células Caliciformes/metabolismo , Células Caliciformes/patologia , Humanos , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/metabolismo , Via Secretória
5.
Biochimie ; 159: 66-71, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30690133

RESUMO

Obesity is now widely recognized to be associated with low-grade systemic inflammation. It has been shown that high-fat feeding modulates gut microbiota which strongly increased intestinal permeability leading to lipopolysaccharide absorption causing metabolic endotoxemia that triggers inflammation and metabolic disorders. N-3 polyunsaturated fatty acids (PUFAs) have been shown associated with anti-obesity properties, but results still remain heterogeneous and very few studies underlined the metabolic pathways involved. Thus, the use of Fat-1 transgenic mice allows to better understanding whether endogenous n-3 PUFAs enrichment contributes to obesity and associated metabolic disorders prevention. It specially evidence that such effects occur through modulations of gut microbiota and intestinal permeability. Then, by remodeling gut microbiota, endogenous n-3 PUFAs improve HF/HS-diet induced features of the metabolic syndrome which in turn affects host metabolism. Thus, increasing anti-obesogenic microbial species in the gut microbiota population (i.e Akkermansia) by appropriate n-3 PUFAs may represent a promising strategy to control or prevent metabolic diseases.


Assuntos
Disbiose , Ácidos Graxos Ômega-3/uso terapêutico , Microbioma Gastrointestinal/efeitos dos fármacos , Doenças Metabólicas , Obesidade , Animais , Disbiose/metabolismo , Disbiose/microbiologia , Disbiose/prevenção & controle , Humanos , Doenças Metabólicas/metabolismo , Doenças Metabólicas/microbiologia , Doenças Metabólicas/prevenção & controle , Camundongos , Obesidade/metabolismo , Obesidade/microbiologia , Obesidade/prevenção & controle
7.
Exp Gerontol ; 114: 19-26, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30366039

RESUMO

Advanced age is often associated with a chronic inflammatory status and inflammatory diseases. It has been suggested that exposure to infectious agents that stimulate the inflammatory response at early ages might have carry over effects in terms of accelerated senescence and increased mortality at late ages. However, not all pathogens and parasites have pro-inflammatory effects. In particular, parasitic nematodes have been shown to dampen the inflammatory response and to prevent or alleviate the symptoms of inflammatory diseases. We, therefore, tentatively predicted that early infection with a parasite that has anti-inflammatory properties might postpone aging. We tested this idea using the association between the nematode Heligmosomoides polygyrus and its rodent host. In addition to the infection with H. polygyrus, we also activated the systemic inflammatory response with an Escherichia coli LPS injection, to explore the effect of H. polygyrus under control and inflammatory conditions. In addition to lifespan, we also assessed several biomarkers of aging, once the infection had been cleared. We found that both treatments (H. polygyrus infection and LPS challenge) reduced longevity. Most of the biomarkers of aging were affected by the previous infection status, suggesting that mice exposed to the nematode had an accentuated senescent phenotype. These results show that infection with immunomodulatory parasites per se does not prolong host lifespan and rather support the view that infection in early life accelerates the rate of aging.


Assuntos
Envelhecimento/imunologia , Interações Hospedeiro-Parasita/imunologia , Longevidade , Nematospiroides dubius , Infecções por Strongylida/imunologia , Animais , Biomarcadores , Modelos Animais de Doenças , Feminino , Inflamação/imunologia , Masculino , Camundongos , Camundongos Endogâmicos CBA
8.
Diabetes ; 67(8): 1512-1523, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29793999

RESUMO

Altering the gut microbiome may be beneficial to the host and recently arose as a promising strategy to manage obesity. Here, we investigated the relative contribution of ω3 polyunsaturated fatty acid (PUFA)-mediated alterations in the microbiota to metabolic parameter changes in mice. Four groups were compared: male fat-1 transgenic mice (with constitutive production of ω3 PUFAs) and male wild-type (WT) littermates fed an obesogenic (high fat/high sucrose [HFHS]) or a control diet. Unlike WT mice, HFHS-fed fat-1 mice were protected against obesity, glucose intolerance, and hepatic steatosis. Unlike WT mice, fat-1 mice maintained a normal barrier function, resulting in a significantly lower metabolic endotoxemia. The fat-1 mice displayed greater phylogenic diversity in the cecum, and fecal microbiota transplantation from fat-1 to WT mice was able to reverse weight gain and to normalize glucose tolerance and intestinal permeability. We concluded that the ω3 PUFA-mediated alteration of gut microbiota contributed to the prevention of metabolic syndrome in fat-1 mice. It occurred independently of changes in the PUFA content of host tissues and may represent a promising strategy to prevent metabolic disease and preserve a lean phenotype.


Assuntos
Ácidos Graxos Ômega-3/metabolismo , Transplante de Microbiota Fecal , Microbioma Gastrointestinal , Intolerância à Glucose/prevenção & controle , Resistência à Insulina , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Obesidade/prevenção & controle , Animais , Caderinas/genética , Caderinas/metabolismo , Dieta da Carga de Carboidratos/efeitos adversos , Dieta Hiperlipídica/efeitos adversos , Sacarose Alimentar/efeitos adversos , Disbiose/microbiologia , Disbiose/fisiopatologia , Disbiose/terapia , Endotoxemia/etiologia , Endotoxemia/prevenção & controle , Transplante de Microbiota Fecal/efeitos adversos , Intolerância à Glucose/microbiologia , Intolerância à Glucose/patologia , Intolerância à Glucose/fisiopatologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Mucosa Intestinal/fisiopatologia , Intestinos/microbiologia , Intestinos/patologia , Intestinos/fisiopatologia , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos Transgênicos , Músculo Esquelético/metabolismo , Hepatopatia Gordurosa não Alcoólica/microbiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Obesidade/microbiologia , Obesidade/patologia , Obesidade/fisiopatologia , Permeabilidade , Filogenia
9.
Am Nat ; 188(2): 253-63, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27420789

RESUMO

Chronic infections imply that the parasite and the host immune system closely interact for a long time without a fatal outcome. Environmental changes encountered by hosts and parasites, such as coinfections, can deeply affect the stability of this apparent equilibrium. Our study aimed to determine the effect of the infectious environment on the costs and benefits of chronic infection with the gut nematode Heligmosomoides polygyrus in mice. Heligmosomoides polygyrus is known for its capacity to actively interfere with the host immune response by secreting molecules that can dampen immunity. We simulated bacterial coinfection of H. polygyrus-infected CBA-strain mice during the chronic phase of the infection by injecting them with Escherichia coli lipopolysaccharide. We found that infection by H. polygyrus induced only weak costs for the host (in terms of reproductive investment) and was characterized by the upregulation of both Th1 (interferon-γ) and anti-inflammatory (transforming growth factor-ß) cytokines, which is favorable to parasite persistence. However, when co-occurring with the simulated bacterial infection, H. polygyrus infection was associated with a pronounced shift toward a pro-inflammatory status, which was deleterious to both the parasite and the host. Our study highlights the dynamic equilibrium reached during chronic infection, where a rapid environmental change, such as a concomitant bacterial infection, can deeply affect the outcome of the host-parasite interaction.


Assuntos
Interações Hospedeiro-Patógeno/imunologia , Nematospiroides dubius/fisiologia , Infecções por Strongylida/imunologia , Animais , Coinfecção/imunologia , Coinfecção/microbiologia , Coinfecção/parasitologia , Citocinas/sangue , Escherichia coli , Feminino , Lipopolissacarídeos/farmacologia , Masculino , Camundongos Endogâmicos CBA , Reprodução/fisiologia , Infecções por Strongylida/microbiologia
10.
Diabetes ; 65(7): 1824-37, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27207550

RESUMO

Evidence suggests that alterations of glucose and lipid homeostasis induced by obesity are associated with the elevation of endocannabinoid tone. The biosynthesis of the two main endocannabinoids, N-arachidonoylethanolamine and 2-arachidonoyl-glycerol, which derive from arachidonic acid, is influenced by dietary fatty acids (FAs). We investigated whether exposure to n-3 FA at a young age may decrease tissue endocannabinoid levels and prevent metabolic disorders induced by a later high-fat diet (HFD) challenge. Three-week-old mice received a 5% lipid diet containing lard, lard plus safflower oil, or lard plus linseed oil for 10 weeks. Then, mice were challenged with a 30% lard diet for 10 additional weeks. A low n-6/n-3 FA ratio in the early diet induces a marked decrease in liver endocannabinoid levels. A similar reduction was observed in transgenic Fat-1 mice, which exhibit high tissue levels of n-3 FA compared with wild-type mice. Hepatic expression of key enzymes involved in carbohydrate and lipid metabolism was concomitantly changed. Interestingly, some gene modifications persisted after HFD challenge and were associated with improved glycemic control. These findings indicate that early dietary interventions based on n-3 FA may represent an alternative strategy to drugs for reducing endocannabinoid tone and improving metabolic parameters in the metabolic syndrome.


Assuntos
Glicemia/metabolismo , Endocanabinoides/metabolismo , Fígado/metabolismo , Ácido alfa-Linolênico/administração & dosagem , Animais , Peso Corporal/fisiologia , Metabolismo dos Carboidratos/genética , Dieta com Restrição de Gorduras , Dieta Hiperlipídica , Fígado Gorduroso/metabolismo , Homeostase/fisiologia , Metabolismo dos Lipídeos/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Obesidade/metabolismo
11.
J Exp Biol ; 217(Pt 15): 2734-9, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-24855677

RESUMO

Parasites (or diseases) are a major selective force for the evolution of life history traits and parasite-host evolution. Mothers can show a variety of responses to parasites during pregnancy, with different consequences for them or their offspring. However, whether information in the maternal environment before pregnancy can cause a change in the phenotype of the offspring is unknown. To avoid the confounding effect of pathogens and to reduce the risk of a direct effect of maternal immune system activation, we injected female laboratory mice with lipopolysaccharides (LPS) before they mated. In order to provide constant information on the potential infectious risk of the environment, females were mated with males that were also exposed to LPS before mating. Offspring from immune-challenged parents were larger and grew at a faster rate than offspring from control parents (injected with PBS). Additionally, offspring from immune-challenged parents that suffered the most from inflammation grew at a faster rate than offspring from low suffering parents. Producing heavier offspring that will reach sexual maturity earlier is likely to have fitness benefits for parents and offspring through improved reproductive success.


Assuntos
Lipopolissacarídeos/farmacologia , Exposição Materna , Camundongos/crescimento & desenvolvimento , Camundongos/imunologia , Exposição Paterna , Animais , Tamanho Corporal/fisiologia , Feminino , Sistema Imunitário/fisiologia , Inflamação/fisiopatologia , Masculino , Gravidez
12.
PLoS One ; 9(1): e84606, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24400103

RESUMO

BACKGROUND: Immune protection against pathogenic organisms has been shown to incur costs. Previous studies investigating the cost of immunity have mostly focused on the metabolic requirements of immune maintenance and activation. In addition to these metabolic costs, the immune system can induce damage to the host if the immune response is mis-targeted or over-expressed. Given its non-specific nature, an over-expressed inflammatory response is often associated with substantial damage for the host. Here, we investigated the cost of an over-expressed inflammatory response in the reproductive function of male mice. METHODOLOGY/PRINCIPAL FINDINGS: We experimentally blocked the receptors of an anti-inflammatory cytokine (IL-10) in male mice exposed to a mild inflammatory challenge, with each treatment having an appropriate control group. The experiment was conducted on two age classes, young (3 month old) and old (15 month old) mice, to assess any age-related difference in the cost of a disrupted immune regulation. We found that the concomitant exposure to an inflammatory insult and the blockade of IL-10 induced a reduction in testis mass, compared to the three other groups. The frequency of abnormal sperm morphology was also higher in the group of mice exposed to the inflammatory challenge but did not depend on the blockade of the IL-10. CONCLUSIONS: Our results provide evidence that immune regulation confers protection against the risk of inflammation-induced infertility during infection. They also suggest that disruption of the effectors involved in the regulation of the inflammatory response can have serious fitness consequences even under mild inflammatory insult and benign environmental conditions.


Assuntos
Imunomodulação , Reprodução/imunologia , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/farmacologia , Peso Corporal , Imunomodulação/efeitos dos fármacos , Inflamação/tratamento farmacológico , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/mortalidade , Masculino , Camundongos , Tamanho do Órgão , Receptores de Interleucina-10/antagonistas & inibidores , Receptores de Interleucina-10/metabolismo , Reprodução/efeitos dos fármacos , Espermatozoides/citologia , Espermatozoides/patologia , Testículo/anatomia & histologia
13.
Biochimie ; 96: 22-7, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24012777

RESUMO

Overexpression of the tyrosine kinase receptor ErbB2/HER2/Neu, occurs in 25%-30% of invasive breast cancer (BC) with poor patient prognosis. Even if numerous studies have shown prevention of breast cancer by n-3 fatty acid intake, the experimental conditions under which n-3 fatty acids exert their protective effect have been variable from study to study, preventing unifying conclusions. Due to confounding factors, inconsistencies still remain regarding protective effects of n-3 polyunsaturated fatty acids (PUFA) on BC. When animals are fed with dietary supplementation in n-3 fatty acids (the traditional approach to modify tissue content and decrease the n-6/n-3 ratio) complex dietary interactions can occur among dietary lipids (antioxidants, vitamins…) that can modulate the activity of n-3 fatty acids. So, what are the specific roles of these n-3 PUFA in reducing breast cancer risk and particularly preventing HER2-positive breast cancer? In this review, we discuss crucial points that may account for discrepancies of results and provide a highly effective genetic approach that can eliminate confounding factors of diet for evaluating the molecular mechanisms of n-3 PUFA in HER2 signaling pathway regulation. The fat-1 transgenic mouse model is capable of converting n-6 to n-3 fatty acids leading to an increase in n-3 fatty acid content with a balanced n-6/n-3 fatty acid ratio in all tissues. The fat-1 mouse model allows well-controlled studies in HER2-positive breast cancer prevention to be performed, without the conflict of potential confounding factors of diet.


Assuntos
Neoplasias da Mama/metabolismo , Ácidos Graxos Ômega-3/fisiologia , Receptor ErbB-2/metabolismo , Animais , Anticarcinógenos/administração & dosagem , Neoplasias da Mama/prevenção & controle , Proteínas de Caenorhabditis elegans/genética , Suplementos Nutricionais , Modelos Animais de Doenças , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Ômega-3/administração & dosagem , Feminino , Humanos , Camundongos , Camundongos Transgênicos
14.
J Lipid Res ; 54(12): 3453-63, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24052576

RESUMO

Overexpression of the tyrosine kinase receptor, ErbB2/HER2/Neu, occurs in 25-30% of invasive breast cancer (BC) with poor patient prognosis. Due to confounding factors, inconsistencies still remain regarding the protective effects of n-3 polyunsaturated fatty acids (PUFAs) on BC. We therefore evaluated whether fat-1 transgenic mice, endogenously synthesizing n-3 PUFAs from n-6 PUFAs, were protected against BC development, and we then aimed to study in vivo a mechanism potentially involved in such protection. E0771 BC cells were implanted into fat-1 and wild-type (WT) mice. After tumorigenesis examination, we analyzed the expression of proteins involved in the HER2 signaling pathway and lipidomic analyses were performed in tumor tissues and plasma. Our results showed that tumors totally disappeared by day 15 in fat-1 mice but continued to grow in WT mice. This prevention can be related in part to significant repression of the HER2/ß-catenin signaling pathway and formation of significant levels of n-3 PUFA-derived bioactive mediators (particularly 15-hydroxyeicosapentaenoic acid, 17-hydroxydocosahexaenoic acid, and prostaglandin E3) in the tumors of fat-1 mice compared with WT mice. All together these data demonstrate an anti-BC effect of n-3 PUFAs through, at least in part, HER2 signaling pathway downregulation, and highlight the importance of gene-diet interactions in BC.


Assuntos
Neoplasias da Mama/prevenção & controle , Proteínas de Caenorhabditis elegans/genética , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Ômega-3/farmacologia , Receptor ErbB-2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ácidos Docosa-Hexaenoicos/farmacologia , Ácidos Graxos Ômega-3/sangue , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Proto-Oncogênicas c-myc/metabolismo , Receptor ErbB-3/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Toxicol Lett ; 219(3): 288-97, 2013 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-23523905

RESUMO

The importance of dietary polyunsaturated fatty acids (PUFAs) in the reduction of cardiovascular disease has been recognized for many years. Docosahexaenoic acid (22:6n3, DHA) is an n-3 PUFA known to affect numerous biological functions and provide cardioprotection; however, the exact molecular and cellular protective mechanism(s) remain unknown. In contrast, DHA also possesses many anti-tumorgenic properties including suppressing cell growth and inducing apoptosis. In the present study, we investigated the effect of DHA toward H9c2 cells (an immortalized cardiac cell line) and neonatal primary cardiomyocytes (NCM). Cells were treated with 0µM, 10µM or 100µM DHA for upto 48h. Cell viability and mitochondrial activity were assayed at different time points. DHA caused a significant time- and dose-dependent decrease in cell viability and mitochondrial activity in H9c2 cells but not NCM. In addition, DHA decreased levels of TGF-ß1 but increased IL-6 release in H9c2 cells. Significant induction of apoptosis was observed only in H9c2 cells, which involved activation of caspase-8 and -3 activities with a marked release of cytochrome c from mitochondria. DHA-induced severe mitochondrial damage resulting in a fragmented and punctated morphology with corresponding loss of mitochondrial membrane potential within 3h, prior to activation of caspases and cytochrome c release at 6h in H9c2 cells. Our data indicate that DHA treatment targets mitochondria, triggering collapse of mitochondrial membrane potential, increasing cellular stress and mitochondrial fragmentation resulting in apoptosis in immortalized cardiac cells, H9c2, but not neonatal primary cardiomyocyte.


Assuntos
Ácidos Docosa-Hexaenoicos/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Animais , Western Blotting , Caspase 3/efeitos dos fármacos , Caspase 3/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Citocromos c/metabolismo , Interleucina-6/metabolismo , Mitocôndrias Cardíacas/efeitos dos fármacos , Ratos
16.
Biochim Biophys Acta ; 1831(4): 759-68, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23333652

RESUMO

Dietary conjugated linoleic acids (CLA) are fatty acid isomers with anticancer activities produced naturally in ruminants or from vegetable oil processing. The anticancer effects of CLA differ upon the cancer origin and the CLA isomers. In this study, we carried out to precise the effects of CLA isomers, c9,t11 and t10,c12 CLA, on mechanisms of cell death induction in colon cancer cells. We first showed that only t10,c12 CLA treatment (25 and 50µM) for 72h triggered apoptosis in colon cancer cells without affecting viability of normal-derived colon epithelial cells. Exposure of colon cancer cells to t10,c12 CLA activated ER stress characterized by induction of eIF2α phoshorylation, splicing of Xbp1 mRNA and CHOP expression. Furthermore, we evidenced that inhibition of CHOP expression and JNK signaling decreased t10,c12 CLA-mediated cancer cell death. Finally, we showed that CHOP induction by t10,c12 CLA was dependent on ROS production and that the anti-oxidant N-acetyl-cysteine reduced CHOP induction-dependent cell death. These results highlight that t10,c12 CLA exerts its cytotoxic effect through ROS generation and a subsequent ER stress-dependent apoptosis in colon cancer cells.


Assuntos
Morte Celular/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Ácidos Linoleicos Conjugados/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Imuno-Histoquímica , Reação em Cadeia da Polimerase Via Transcriptase Reversa
17.
Evolution ; 66(11): 3615-23, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23002997

RESUMO

Parasites impose a permanent threat for hosts. As a consequence, immune defenses are important for host fitness. However, the immune response can also produce self-damage and impair host fitness if not properly regulated. Effectors that up- and downregulate the immune response should, therefore, evolve in concert, and be under the action of correlational selection. To address this issue, we assessed the shape of the selection operating on pro- and anti-inflammatory effectors following an inflammatory challenge in laboratory mice.We found that selection acts on the combination of these two traits as individuals that produced large amount of pro-inflammatory cytokines could achieve relatively high fitness (survival) only if also producing a large amount of anti-inflammatory effectors. To our knowledge, this is the first study providing evidence for correlational selection on immunity.


Assuntos
Interleucina-10/sangue , Interleucina-6/sangue , Lipopolissacarídeos/administração & dosagem , Camundongos/fisiologia , Seleção Genética , Animais , Escherichia coli , Feminino , Citometria de Fluxo , Masculino , Camundongos/genética , Camundongos/imunologia , Análise de Regressão
18.
Curr Drug Metab ; 13(10): 1454-63, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22978399

RESUMO

Stearoyl-CoA desaturase 1 (SCD-1) is a delta-9 fatty acid desaturase that catalyzes the synthesis of monounsaturated fatty acids. Indeed, SCD-1 is the critical control point regulating hepatic lipogenesis and lipid oxidation. Due to its central role in lipid metabolism in the liver, recent studies have focused on the involvement of SCD-1 in the development of fatty liver during obesity, diabetes mellitus, hypertension, excessive alcohol consumption, and in subjects with high triglyceride blood concentrations. The accumulation of fat in liver cells can be a sign that harmful conditions are developing, possibly associated with or leading to inflammation of the liver. This review evaluates the recent advances in our understanding of the regulation of SCD-1 expression and its role in the development of nonalcoholic and alcoholic hepatosteatosis. Animal models presenting a liver-specific loss or inhibition of SCD-1, as well as dietary interventions, have highlighted the important role of the enzyme in the accumulation of fat (fatty infiltration) in hepatocytes during both alcoholic and nonalcoholic liver diseases. The data summarized in this article support the notion that SCD-1 plays a direct role in the development of fatty liver diseases, and is not simply a marker of an unfavorable diet or hepatic disorder. Accordingly, SCD-1 represents a promising therapeutic target for the treatment of hepatic steatosis.


Assuntos
Fígado Gorduroso/metabolismo , Estearoil-CoA Dessaturase/metabolismo , Animais , Ácidos Graxos Insaturados/metabolismo , Fígado Gorduroso Alcoólico/metabolismo , Humanos , Estearoil-CoA Dessaturase/antagonistas & inibidores , Fatores de Transcrição/metabolismo
19.
Mol Med Rep ; 5(2): 503-8, 2012 02.
Artigo em Inglês | MEDLINE | ID: mdl-22101421

RESUMO

Lung cancer is a malignant disease with poor outcome, which has led to a search for new therapeutics. The PI3K/Akt/mTOR and Ras/raf/Erk pathways are key regulators of tumor growth and survival. In the present study, their roles were evaluated by MTT assay, flow cytometry and Western blotting in lung cancer cells. We found that a high efficacy of antitumor activity was shown with GDC-0941 treatment in two gefitinib-resistant non-small cell lung cancer (NSCLC) cell lines, A549 and H460. In addition, H460 cells with activating mutations of PIK3CA were relatively more sensitive to GDC-0941 than A549 cells with wild-type PIK3CA. Furthermore, GDC-0941 was highly efficacious in combination with U0126 in inducing cell growth inhibition, G0-G1 arrest and cell apoptosis. These antitumor activities of combined treatment may be attributed to the alterations of G0-G1 phase regulators, apoptosis-related proteins and eukaryotic translation initiation factor 4B (eIF4B), induced by concomitant blockade of the PI3K/Akt/mTOR and Ras/raf/Erk pathways. In conclusion, this study suggests that multi­targeted intervention is the most effective treatment for tumors. Additionally, the blockade of PI3K, mTOR and Erk with GDC-0941 and MEK inhibitors shows promise for treating gefitinib-resistant NSCLC.


Assuntos
Butadienos/farmacologia , Indazóis/farmacologia , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Nitrilas/farmacologia , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais/efeitos dos fármacos , Sulfonamidas/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Apoptose , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Sinergismo Farmacológico , Ativação Enzimática , Pontos de Checagem da Fase G1 do Ciclo Celular , Humanos , Neoplasias Pulmonares/patologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Serina-Treonina Quinases TOR/metabolismo
20.
Clin Sci (Lond) ; 121(1): 19-28, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21288203

RESUMO

To investigate further the mechanisms of developmental programming, we analysed the effects of maternal overnutrition and of postnatal high-fat feeding on adipose tissue metabolism in the offspring. Postnatal changes in serum adiponectin, leptin and TAG [triacylglycerol (triglyceride)] levels, adipose tissue TAGs, fatty acids and enzyme activities were determined in offspring of cafeteria-diet-fed dams during gestation and lactation, weaned on to standard chow or on to cafeteria diet. Obese rats showed higher adiposity (+35% to 85%) as well as a significant increase in serum glucose, insulin, leptin, adiponectin and TAG levels (P<0.01) and adipose tissue LPL (lipoprotein lipase) and GPDH (glycerol-3-phosphate dehydrogenase) activities (P<0.01), compared with control pups at weaning (day 21) and at adulthood (day 90). Adipose HSL (hormone-sensitive lipase) activity was increased only at day 90 (P<0.05), and FAS (fatty acid synthase) activity remained unchanged. The proportions of SFAs (saturated fatty acids) and MUFAs (mono-unsaturated fatty acids) and the Δ(9)-desaturation index were significantly increased (P<0.05), whereas PUFAs (polyunsaturated fatty acids) were decreased (P<0.01) in serum and adipose TAGs of obese pups compared with controls. The cafeteria diet at weaning induced more severe abnormalities in obese rats. In conclusion, maternal overnutrition induced permanent changes in adipose tissue metabolism of the offspring. These pre-existing alterations in offspring were worsened under a high-fat diet from weaning to adulthood. Consequently, adipose adipokines and enzymes could provide a potential therapeutic target, and new investigations in this field could constitute strategies to improve the impact of early-life overnutrition.


Assuntos
Tecido Adiposo/metabolismo , Obesidade/metabolismo , Complicações na Gravidez/fisiopatologia , Efeitos Tardios da Exposição Pré-Natal , Fenômenos Fisiológicos da Nutrição Pré-Natal/fisiologia , Adipócitos/metabolismo , Tecido Adiposo/patologia , Animais , Glicemia/metabolismo , Peso Corporal/fisiologia , Ácidos Graxos/sangue , Comportamento Alimentar , Feminino , Hormônios/sangue , Obesidade/embriologia , Obesidade/fisiopatologia , Tamanho do Órgão/fisiologia , Gravidez , Ratos , Ratos Wistar , Triglicerídeos/sangue
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