scholarly journals MGL1 promotes adipose tissue inflammation and insulin resistance by regulating 7/4hi monocytes in obesity

2009 ◽  
Vol 206 (13) ◽  
pp. 3143-3156 ◽  
Author(s):  
Daniel J. Westcott ◽  
Jennifer B. DelProposto ◽  
Lynn M. Geletka ◽  
Tianyi Wang ◽  
Kanakadurga Singer ◽  
...  

Adipose tissue macrophages (ATMs) play a critical role in obesity-induced inflammation and insulin resistance. Distinct subtypes of ATMs have been identified that differentially express macrophage galactose-type C-type lectin 1 (MGL1/CD301), a marker of alternatively activated macrophages. To evaluate if MGL1 is required for the anti-inflammatory function of resident (type 2) MGL1+ ATMs, we examined the effects of diet-induced obesity (DIO) on inflammation and metabolism in Mgl1−/− mice. We found that Mgl1 is not required for the trafficking of type 2 ATMs to adipose tissue. Surprisingly, obese Mgl1−/− mice were protected from glucose intolerance, insulin resistance, and steatosis despite having more visceral fat. This protection was caused by a significant decrease in inflammatory (type 1) CD11c+ ATMs in the visceral adipose tissue of Mgl1−/− mice. MGL1 was expressed specifically in 7/4hi inflammatory monocytes in the blood and obese Mgl1−/− mice had lower levels of 7/4hi monocytes. Mgl1−/− monocytes had decreased half-life after adoptive transfer and demonstrated decreased adhesion to adipocytes indicating a role for MGL1 in the regulation of monocyte function. This study identifies MGL1 as a novel regulator of inflammatory monocyte trafficking to adipose tissue in response to DIO.

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Anca D. Dobrian ◽  
Kaiwen Ma ◽  
Lindsey M. Glenn ◽  
Margaret A. Hatcher ◽  
Bronson A. Haynes ◽  
...  

Visceral adipose tissue (AT) inflammation is linked to the complications of obesity, including insulin resistance (IR) and type 2 diabetes. Recent data from our lab showed that germline deficiency in STAT4 reduces inflammation and improves IR in obese mice. The objective of this study was to determine the contribution of selective STAT4 deficiency in subsets of hematopoietic cells to IR and AT inflammation. To determine the contribution of hematopoietic lineage, we sublethally irradiated Stat4−/−C57Bl6 mice and reconstituted them with bone marrow cells (BMC) from Stat4+/+C57Bl6 congenic donors. We also established the contribution of selective STAT4 deficiency in CD4+ or CD8+ T cells using adoptive transfer in Rag1−/− mice. All mice received a HFD for 15 weeks (n=7–12 mice/group). BMC that expressed STAT4 induced increases in glucose intolerance and IR compared to STAT4-deficient cells. Also, AT inflammation was increased and the numbers of CD8+ cells infiltrating AT were higher in mice with STAT4 expressing BMC. Studies in Rag1−/− mice further confirmed the prominent role of CD8+ cells expressing STAT4 in insulin resistance and AT and islet inflammation. Collectively our results show specific and dominant contribution of STAT4 in the hematopoietic compartment to metabolic health and inflammation in diet-induced obesity.


2013 ◽  
Vol 210 (3) ◽  
pp. 535-549 ◽  
Author(s):  
Ari B. Molofsky ◽  
Jesse C. Nussbaum ◽  
Hong-Erh Liang ◽  
Steven J. Van Dyken ◽  
Laurence E. Cheng ◽  
...  

Eosinophils in visceral adipose tissue (VAT) have been implicated in metabolic homeostasis and the maintenance of alternatively activated macrophages (AAMs). The absence of eosinophils can lead to adiposity and systemic insulin resistance in experimental animals, but what maintains eosinophils in adipose tissue is unknown. We show that interleukin-5 (IL-5) deficiency profoundly impairs VAT eosinophil accumulation and results in increased adiposity and insulin resistance when animals are placed on a high-fat diet. Innate lymphoid type 2 cells (ILC2s) are resident in VAT and are the major source of IL-5 and IL-13, which promote the accumulation of eosinophils and AAM. Deletion of ILC2s causes significant reductions in VAT eosinophils and AAMs, and also impairs the expansion of VAT eosinophils after infection with Nippostrongylus brasiliensis, an intestinal parasite associated with increased adipose ILC2 cytokine production and enhanced insulin sensitivity. Further, IL-33, a cytokine previously shown to promote cytokine production by ILC2s, leads to rapid ILC2-dependent increases in VAT eosinophils and AAMs. Thus, ILC2s are resident in VAT and promote eosinophils and AAM implicated in metabolic homeostasis, and this axis is enhanced during Th2-associated immune stimulation.


2020 ◽  
Author(s):  
Ada Admin ◽  
Julia Braune ◽  
Andreas Lindhorst ◽  
Janine Fröba ◽  
Constance Hobusch ◽  
...  

Obesity is associated with a chronic low-grade inflammation in visceral adipose tissue (AT) characterized by an increasing number of adipose tissue macrophages (ATMs) and linked to type 2 diabetes. AT inflammation is histologically indicated by the formation of so-called crown-like structures (CLS), as accumulation of ATMs around dying adipocytes, and the occurrence of multi-nucleated giant cells (MGCs). However to date, the function of MGCs in obesity is unknown. Hence, the aim of this study was to characterize MGCs in AT and unravel the function of these cells. <p>We demonstrate that MGCs occur in obese patients and after 24 weeks of high fat diet (HFD) in mice, accompanying signs of AT inflammation and then represent ~3% of ATMs in mice. Mechanistically, we found evidence that adipocyte death triggers MGC formation. Most importantly, MGCs in obese AT have a higher capacity to phagocytose oversized particles, such as adipocytes, as shown by live-imaging of AT, 45 µm bead uptake <i>ex vivo</i> and a higher lipid content <i>in vivo</i>. Finally, we show that IL-4 treatment is sufficient to increase the number of MGCs in AT, whereas other factors maybe more important for endogenous MGC formation <i>in vivo</i>.</p>


2012 ◽  
Vol 108 (8) ◽  
pp. 1511-1518 ◽  
Author(s):  
Jéferson F. Goularte ◽  
Maria B. C. Ferreira ◽  
Gilberto L. Sanvitto

Obesity affects a large number of people around the world and appears to be the result of changes in food intake, eating habits and physical activity levels. Changes in dietary patterns and physical exercise are therefore strongly recommended to treat obesity and its complications. The present study tested the hypothesis that obesity and metabolic changes produced by a cafeteria diet can be prevented with dietary changes and/or physical exercise. A total of fifty-six female Wistar rats underwent one of five treatments: chow diet; cafeteria diet; cafeteria diet followed by a chow diet; cafeteria diet plus exercise; cafeteria diet followed by a chow diet plus exercise. The duration of the experiment was 34 weeks. The cafeteria diet resulted in higher energy intake, weight gain, increased visceral adipose tissue and liver weight, and insulin resistance. The cafeteria diet followed by the chow diet resulted in energy intake, body weight, visceral adipose tissue and liver weight and insulin sensitivity equal to that of the controls. Exercise increased total energy intake at week 34, but produced no changes in the animals' body weight or adipose tissue mass. However, insulin sensitivity in animals subjected to exercise and the diet was similar to that of the controls. The present study found that exposure to palatable food caused obesity and insulin resistance and a diet change was sufficient to prevent cafeteria diet-induced obesity and to maintain insulin sensitivity at normal levels. In addition, exercise resulted in normal insulin sensitivity in obese rats. These results may help to develop new approaches for the treatment of obesity and type 2 diabetes mellitus.


2020 ◽  
Vol 21 (16) ◽  
pp. 5738
Author(s):  
Xiong Weng ◽  
De Lin ◽  
Jeffrey T. J. Huang ◽  
Roland H. Stimson ◽  
David H. Wasserman ◽  
...  

Aberrant extracellular matrix (ECM) remodelling in muscle, liver and adipose tissue is a key characteristic of obesity and insulin resistance. Despite its emerging importance, the effective ECM targets remain largely undefined due to limitations of current approaches. Here, we developed a novel ECM-specific mass spectrometry-based proteomics technique to characterise the global view of the ECM changes in the skeletal muscle and liver of mice after high fat (HF) diet feeding. We identified distinct signatures of HF-induced protein changes between skeletal muscle and liver where the ECM remodelling was more prominent in the muscle than liver. In particular, most muscle collagen isoforms were increased by HF diet feeding whereas the liver collagens were differentially but moderately affected highlighting a different role of the ECM remodelling in different tissues of obesity. Moreover, we identified a novel association between collagen 24α1 and insulin resistance in the skeletal muscle. Using quantitative gene expression analysis, we extended this association to the white adipose tissue. Importantly, collagen 24α1 mRNA was increased in the visceral adipose tissue, but not the subcutaneous adipose tissue of obese diabetic subjects compared to lean controls, implying a potential pathogenic role of collagen 24α1 in obesity and type 2 diabetes.


PLoS ONE ◽  
2012 ◽  
Vol 7 (10) ◽  
pp. e48155 ◽  
Author(s):  
Nuria Barbarroja ◽  
Chary Lopez-Pedrera ◽  
Lourdes Garrido-Sanchez ◽  
Maria Dolores Mayas ◽  
Wilfredo Oliva-Olivera ◽  
...  

World Science ◽  
2020 ◽  
Vol 2 (5(57)) ◽  
pp. 20-29
Author(s):  
Ковальчук А. В. ◽  
Зиныч О. В. ◽  
Корпачев В. В. ◽  
Кушнарева Н. Н. ◽  
Прибила О. В.

Osteocalcin (OK) is actively involved in the humoral regulation of energy homeostasis. However, the relationship between the level of OK as a modulator of metabolic processes and constitutional and metabolic features in patients with type 2 diabetes mellitus (DM) of a different gender remains not thoroughly studied.The study included 127 patients with type 2 diabetes ≥ 50 years of age. Of these, 70 were postmenopausal women and 57 men.It was found that in the general group of women, the concentration of OK in the blood serum was significantly higher than in men. The observed difference is due to significantly higher levels of OK in women of the older age group (≥ 60 years) in comparison with men. At the same time, a decrease in bone mineral density (BMD) in the femoral neck was observed in subgroups of men and women aged ≥ 60 years and older, while in the younger subgroups of patients, the BMD of lumbar and femoral zones were close to each other.The relationships between OK levels and adipose tissue parameters, evaluated by calculating the morphological and functional index of visceral obesity (IVO), were investigated. An increase in the OK level in the groups of men and women was accompanied by a decrease in the IVO values. The highest degree of insulin resistance was determined in groups of patients with minimal levels of OK and high IVO, and the lowest values were recorded in patients with high levels of OK and low IVO.The decrease of the blood OK level in patients with type 2 diabetes occurs in parallel with an increase in the degree of insulin resistance and dysfunction of visceral adipose tissue. In this case, IVO is a more accurate parameter reflecting the constitutional and metabolic phenotypic changes, compared with the index of the waist circumference. The decrease in BMD in patients with type 2 diabetes is the result of predominantly involutive processes that are noticeable at the age of ≥ 60 years and occur against the background of a decrease in the content of OK with age.


Endocrinology ◽  
2011 ◽  
Vol 152 (5) ◽  
pp. 1789-1799 ◽  
Author(s):  
Shiho Fujisaka ◽  
Isao Usui ◽  
Yukiko Kanatani ◽  
Masashi Ikutani ◽  
Ichiro Takasaki ◽  
...  

Diet-induced obesity is reported to induce a phenotypic switch in adipose tissue macrophages from an antiinflammatory M2 state to a proinflammatory M1 state. Telmisartan, an angiotensin II type 1 receptor blocker and a peroxisome proliferator-activated receptor-γ agonist, reportedly has more beneficial effects on insulin sensitivity than other angiotensin II type 1 receptor blockers. In this study, we studied the effects of telmisartan on the adipose tissue macrophage phenotype in high-fat-fed mice. Telmisartan was administered for 5 wk to high-fat-fed C57BL/6 mice. Insulin sensitivity, macrophage infiltration, and the gene expressions of M1 and M2 markers in visceral adipose tissues were then examined. An insulin- or a glucose-tolerance test showed that telmisartan treatment improved insulin resistance, decreasing the body weight gain, visceral fat weight, and adipocyte size without affecting the amount of energy intake. Telmisartan reduced the mRNA expression of CD11c and TNF-α, M1 macrophage markers, and significantly increased the expressions of M2 markers, such as CD163, CD209, and macrophage galactose N-acetyl-galactosamine specific lectin (Mgl2), in a quantitative RT-PCR analysis. A flow cytometry analysis showed that telmisartan decreased the number of M1 macrophages in visceral adipose tissues. In conclusion, telmisartan improves insulin sensitivity and modulates adipose tissue macrophage polarization to an antiinflammatory M2 state in high-fat-fed mice.


Sign in / Sign up

Export Citation Format

Share Document