scholarly journals Modulation of the inflammatory response to LPS by the recruitment and activation of brown and brite adipocytes in mice

2020 ◽  
Vol 319 (5) ◽  
pp. E912-E922
Author(s):  
Patrick Munro ◽  
Océane Dufies ◽  
Samah Rekima ◽  
Agnès Loubat ◽  
Christophe Duranton ◽  
...  

Recruitment and activation of brown and brite adipocytes in the adipose tissue of mice lead to a local low-grade anti-inflammatory phenotype in response to acute endotoxemia without alteration of adipocyte phenotype and function.

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 1021
Author(s):  
Rosaria Varì ◽  
Beatrice Scazzocchio ◽  
Annalisa Silenzi ◽  
Claudio Giovannini ◽  
Roberta Masella

Curcumin is a lipophilic polyphenol, isolated from the plant turmeric of Curcuma longa. Curcuma longa has always been used in traditional medicine in Asian countries because it is believed to have numerous health benefits. Nowadays it is widely used as spice component and in emerging nutraceutical food worldwide. Numerous studies have shown that curcumin possesses, among others, potential anti-inflammatory properties. Obesity represents a main risk factor for several chronic diseases, including type 2 diabetes, cardiovascular disease, and some types of cancer. The establishment of a low-grade chronic inflammation, both systemically and locally in adipose tissue, occurring in obesity most likely represents a main factor in the pathogenesis of chronic diseases. The molecular mechanisms responsible for the onset of the obesity-associated inflammation are different from those involved in the classic inflammatory response caused by infections and involves different signaling pathways. The inflammatory process in obese people is triggered by an inadequate intake of nutrients that produces quantitative and qualitative alterations of adipose tissue lipid content, as well as of various molecules that act as endogenous ligands to activate immune cells. In particular, dysfunctional adipocytes secrete inflammatory cytokines and chemokines, the adipocytokines, able to recruit immune cells into adipose tissue, amplifying the inflammatory response also at systemic level. This review summarizes the most recent studies focused at elucidating the molecular targets of curcumin activity responsible for its anti-inflammatory properties in obesity-associated inflammation and related pathologies.


2018 ◽  
Vol 51 (3) ◽  
pp. 1051-1068 ◽  
Author(s):  
Jèssica Latorre ◽  
José M. Moreno-Navarrete ◽  
Mónica Sabater ◽  
Maria Buxo ◽  
José I. Rodriguez-Hermosa ◽  
...  

Background/Aims: Obesity is characterized by the immune activation that eventually dampens insulin sensitivity and changes metabolism. This study explores the impact of different inflammatory/ anti-inflammatory paradigms on the expression of toll-like receptors (TLR) found in adipocyte cultures, adipose tissue, and blood. Methods: We evaluated by real time PCR the impact of acute surgery stress in vivo (adipose tissue) and macrophages (MCM) in vitro (adipocytes). Weight loss was chosen as an anti-inflammatory model, so TLR were analyzed in fat samples collected before and after bariatric surgery-induced weight loss. Associations with inflammatory and metabolic parameters were analyzed in non-obese and obese subjects, in parallel with gene expression measures taken in blood and isolated adipocytes/ stromal-vascular cells (SVC). Treatments with an agonist of TLR3 were conducted in human adipocyte cultures under normal conditions and upon conditions that simulated the chronic low-grade inflammatory state of obesity. Results: Surgery stress raised TLR1 and TLR8 in subcutaneous (SAT), and TLR2 in SAT and visceral (VAT) adipose tissue, while decreasing VAT TLR3 and TLR4. MCM led to increased TLR2 and diminished TLR3, TLR4, and TLR5 expressions in human adipocytes. The anti-inflammatory impact of weight loss was concomitant with decreased TLR1, TLR3, and TLR8 in SAT. Cross-sectional associations confirmed increased V/ SAT TLR1 and TLR8, and decreased TLR3 in obese patients, as compared with non-obese subjects. As expected, TLR were predominant in SVC and adipocyte precursor cells, even though expression of all of them but TLR8 (very low levels) was also found in ex vivo isolated and in vitro differentiated adipocytes. Among SVC, CD14+ macrophages showed increased TLR1, TLR2, and TLR7, but decreased TLR3 mRNA. The opposite patterns shown for TLR2 and TLR3 in V/ SAT, SVC, and inflamed adipocytes were observed in blood as well, being TLR3 more likely linked to lymphocyte instead of neutrophil counts. On the other hand, decreased TLR3 in adipocytes challenged with MCM dampened lipogenesis and the inflammatory response to Poly(I:C). Conclusion: Functional variations in the expression of TLR found in blood and hypertrophied fat depots, namely decreased TLR3 in lymphocytes and inflamed adipocytes, are linked to metabolic inflammation.


2020 ◽  
Vol 79 (OCE2) ◽  
Author(s):  
Cécile Vors ◽  
Fabiana Piscitelli ◽  
Roberta Verde ◽  
Sofia Laforest ◽  
Janie Allaire ◽  
...  

AbstractOxylipins and endocannabinoids (eCBs) both belong to superclasses of lipid mediators with potent inflammation modulatory activities. The adipose tissue (AT) plays a key role in metabolic syndrome-related inflammation, via altered adipocyte physiology, infiltrated macrophages and altered profile of eCBs. We previously reported that DHA is more potent than EPA at modulating systemic inflammation, but the underlying mechanisms remain unclear. The objective of this study was to compare the individual effect of high-dose DHA and of EPA on circulating lipid mediators, i.e. plasma oxylipins and eCBs, and AT-related inflammation. In a randomized double-blind crossover trial, 154 volunteers with abdominal obesity and low-grade inflammation were subjected to three 10-wk supplementation phases: 1- EPA (2.7 g/d); 2- DHA (2.7 g/d); 3- corn oil (control), each separated by a 9-wk washout. Supplements were provided as re-esterified triacylglycerols. Profiling of plasma oxylipins and eCBs was performed on 58 subjects after each phase. Abdominal subcutaneous AT biopsies were also obtained from 13 individuals after each phase. Plasma DHA-, EPA-, arachidonic acid-derived oxylipins were analyzed by LC-MS. eCBs and some of their bioactive congeners were analyzed in plasma and AT by LC-APCI-MS. Adipocyte diameter was determined by histological analysis and AT macrophage infiltration was quantified by double immunofluorescence. Compared with EPA, DHA increased plasma levels of hydroxy-docosahexaenoic acids (7-, 11-, 14-, 4-, 17-HDOHE; P < 0.0001) and palmitoylethanolamide (PEA; P = 0.04). Compared with DHA, EPA led to higher plasma level of hydroxy-eicosapentaenoic acids (12-, 15-, 5-HEPE; P < 0.0001). In the AT, EPA increased the level of oleoylethanolamide (OEA; P = 0.01) compared with DHA, but no other difference was observed between treatments in adipose eCBs and eCB-related lipids. DHA and EPA did not differentially modify adipocyte size distributions (P > 0.50) and proportions of M1-type and M2-type macrophages (P > 0.30). In conclusion, increased plasma levels of anti-inflammatory DHA-derived oxylipins and plasma PEA may be responsible, at least to some extent, for the more potent anti-inflammatory effects of DHA compared with EPA observed in the ComparED study. Conversely, subcutaneous AT does not seem to be involved in explaining such differences between EPA and DHA.


Nutrients ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 438 ◽  
Author(s):  
Cecilia Colson ◽  
Rayane Ghandour ◽  
Océane Dufies ◽  
Samah Rekima ◽  
Agnès Loubat ◽  
...  

Oxylipins are metabolized from dietary ω3 and ω6 polyunsaturated fatty acids and are involved in an inflammatory response. Adipose tissue inflammatory background is a key factor of metabolic disorders and it is accepted that dietary fatty acids, in terms of quality and quantity, modulate oxylipin synthesis in this tissue. Moreover, it has been reported that diet supplementation in ω3 polyunsaturated fatty acids resolves some inflammatory situations. Thus, it is crucial to assess the influence of dietary polyunsaturated fatty acids on oxylipin synthesis and their impact on adipose tissue inflammation. To this end, mice fed an ω6- or ω3-enriched standard diet (ω6/ω3 ratio of 30 and 3.75, respectively) were analyzed for inflammatory phenotype and adipose tissue oxylipin content. Diet enrichment with an ω3 polyunsaturated fatty acid induced an increase in the oxylipins derived from ω6 linoleic acid, ω3 eicosapentaenoic, and ω3 docosahexaenoic acids in brown and white adipose tissues. Among these, the level of pro-resolving mediator intermediates, as well as anti-inflammatory metabolites, were augmented. Concomitantly, expressions of M2 macrophage markers were increased without affecting inflammatory cytokine contents. In vitro, these metabolites did not activate macrophages but participated in macrophage polarization by inflammatory stimuli. In conclusion, we demonstrated that an ω3-enriched diet, in non-obesogenic non-inflammatory conditions, induced synthesis of oxylipins which were involved in an anti-inflammatory response as well as enhancement of the M2 macrophage molecular signature, without affecting inflammatory cytokine secretion.


2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 1209-1209
Author(s):  
Hanna Davis ◽  
Mandana Pahlavani ◽  
Yujiao Zu ◽  
Latha Ramalingam ◽  
Shane Scoggin ◽  
...  

Abstract Objectives Obesity is a global epidemic and complex disease associated with an expansion of white adipose tissue (WAT). Obesity is accompanied by chronic low-grade inflammation, characterized by elevated levels of secreted pro-inflammatory cytokines and M1 macrophage infiltration into WAT. Eicosapentaenoic acid (EPA), a long-chain omega-3 polyunsaturated fatty acid, has been reported to have anti-obesity and anti-inflammatory properties. Moreover, we previously showed that EPA dose-dependently improved glucose intolerance, and inflammation in diet-induced obese mice. The objective of this study is to further determine mechanisms underlying these metabolic protective effects of EPA in epididymal WAT (e-WAT). Methods Male B6 mice were fed a HF diet (45% kcal fat) or a HF diet supplemented with 9, 18, or 36 g/kg of EPA-enriched fish oil (EPA 9, 18 or 36) for 14 weeks. We performed histological assessments in eWAT to determine adipocyte size; and measure macrophage infiltration by immunohistochemistry using galectin-3. RNA was isolated from eWAT for RNA sequencing and gene expression analyses. Data were analyzed using GraphPad Prism software. Results EPA36-fed mice had significantly lower body weight and fat percentage, compared to HF (P &lt; 0.05). In addition, EPA18 and 36 significantly decreased weight of e-WAT (P &lt; 0.05) and increased glucose clearance compared to HF (P &lt; 0.05). Moreover, all EPA doses had smaller adipocytes (P &lt; 0.05). Compared to HF, EPA18 and 36 significantly reduced macrophage infiltration in e-7.43 fold, respectively. Consistent with these changes, EPA18 and 36 reduced the mRNA levels of HF-induced inflammatory markers, including arachidonate 5-lipoxygenase (Alox5) and leukotriene B4 receptor (Ltb4r) compared to HF (P &lt; 0.05). RNA Seq analyses revealed that EPA18 attenuated HF-induced inflammation in part by up-regulating cyclic AMP (cAMP)-dependent protein kinase A (PKA) signaling pathways and down-regulating triggering receptor expressed on myeloid cells 1 (TREM1) signaling. Conclusions EPA dose-dependently ameliorated HF-induced obesity and inflammation by reducing adipocyte size and macrophage infiltration and modulating pro- and anti-inflammatory pathways in e-WAT. These effects were achieved at human equivalent doses, that are currently prescribed for reducing triglycerides. Funding Sources USDA NIFA NIH.


2021 ◽  
Author(s):  
María Gutiérrez-Salmerón ◽  
Silvia Rocío Rocío Lucena ◽  
Ana Chocarro-Calvo ◽  
Jose Manuel Garcia-Martinez ◽  
Rosa M Martín Orozco ◽  
...  

Obesity is the strongest known risk factor to develop Type 2 diabetes (T2D) and both share a state of chronic, diffuse and low-grade inflammation, impaired immune responses and alterations in the composition and function of the microbiome. Notably, these hallmarks are shared with colorectal cancer (CRC), which is epidemiologically associated to obesity and T2D. Gut barrier damages in T2D, destabilize the microbiome that metabolizes the diet and modulates the host immune response triggering inflammatory and proliferative pathways. In this review, we discuss the pathways altered by defects in the immune response and microbiota that may link T2D to CRC development. Stressed adipocytes, metabolic incongruity in blood and gut barrier failure with dysbiosis cooperate to establish imbalances between immune innate and adaptive cells and cytokines such as interleukin 6 (IL-6) or tumour necrosis factor α (TNF-α) that define low-grade diffuse inflammation in T2D. Inflammation drives tissue repair through proliferation and migration (critical mechanisms for tumourigenesis) and under physiological conditions feeds anti-inflammatory cytokine production to resolve the process. The disproportion in pro- versus anti-inflammatory cells and cytokines imposed by T2D will impact the tumour micro- and macro-environment, favouring tumour proliferation, angiogenesis and decreased immune responses. Complex bidirectional relationships between the metabolic environment of T2D, gut microbiota, and immune dysfunctions may favour tumour cell demands and will define the outcome. Animal models developed to study the relationships between T2D and CRC in the context of microbiota and immune system are discussed.


Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 359
Author(s):  
Hyejeong Park ◽  
Seungmin Yu ◽  
Wooki Kim

Macrophages are involved in all inflammatory processes from killing pathogens to repairing damaged tissue. In the obese state, macrophages infiltrate into enlarged adipose tissue and polarize into pro-inflammatory M1 macrophages, resulting in chronic low-grade inflammation due to the secretion of inflammatory mediators. Rice bran oil (RBO) is an edible oil containing tocopherols, tocotrienols, and γ-oryzanol. Previous research in normal diet-fed mice suggested that RBO mitigates inflammatory responses by modulating mitochondrial respiration of macrophages. Therefore, we investigated if RBO had an anti-inflammatory effect in diet-induced obese mice by assessing the expression of inflammatory markers in epididymal white adipose tissue (eWAT) and polarization of bone marrow-derived macrophages (BMDMs). Rice bran oil exerted a local anti-inflammatory effect in white adipose tissue by suppressing the production of inflammatory mediators and upregulating transcription of anti-inflammatory genes. Rice bran oil also promoted anti-inflammatory M2 macrophage polarization in BMDMs thereby affecting systemic inflammation. Overall, our in vivo and ex vivo results highlight the potential of RBO as a dietary mediator that can ameliorate obesity-induced chronic low-grade inflammation by mediating the expression of inflammation-related factors and macrophage polarization.


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