Abstract 537: Dock2 Deficiency Mitigates High-Fat Diet-Induced Obesity by Reducing Adipose Tissue Inflammation While Increasing Energy Expenditure

Obesity is a public health problem as its association with type 2 diabetes, cardiovascular disorders and many other diseases. Adipose tissue inflammation is frequently observed and plays a vital role in obesity and insulin resistance. Dedicator of cytokinesis 2 (DOCK2) has shown proinflammatory effect in several inflammatory diseases, but its role in obesity remain unknown. To explore the function of DOCK2 in obesity and insulin resistance, wild-type (WT) and DOCK2 knockout (DOCK2-/-) mice were fed with chow or high-fat diet (HFD) for 12 weeks. Metabolic, biochemical and histologic analyses were performed. DOCK2 expression was robustly up-regulated in adipose tissue in WT mice given HFD. DOCK2-/- mice were protected against HFD-enhanced body weight gain with an improved metabolic homeostasis and insulin resistance. In addition, DOCK2 deficiency attenuated adipose tissue and systemic inflammation accompanied by a reduced macrophage infiltration. Moreover, DOCK2 deficiency induced the adipose tissue browning and increased energy expenditure as shown by the up-regulation of metabolic genes in DOCK2-/- mice. Our data indicated that DOCK2 deficiency can protect mice from HFD-induced obesity, metabolic disorders, and insulin resistance. Therefore, targeting DOCK2 may be a potential therapeutic strategy for treating obesity-associated diseases.

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Luteolin Improves Insulin Resistance in Postmenopausal Obese Mice by Altering Macrophage Polarization (FS12-01-19)

Current Developments in Nutrition ◽

10.1093/cdn/nzz049.fs12-01-19 ◽

2019 ◽

Vol 3 (Supplement_1) ◽

Cited By ~ 1

Author(s):

Yunjung Baek ◽

Mi Nam Lee ◽

Dayong Wu ◽

Munkyong Pae

Keyword(s):

Insulin Resistance ◽

Body Weight ◽

Adipose Tissue ◽

High Fat Diet ◽

Ovarian Function ◽

Body Weight Gain ◽

Adipose Tissue Inflammation ◽

High Fat ◽

Tissue Inflammation ◽

Ovariectomized Mice

Abstract Objectives Previously, we showed that loss of ovarian function in mice fed high-fat diet exacerbated insulin resistance and adipose tissue inflammation. In the current study, we tested whether consumption of luteolin, an anti-inflammatory flavonoid, could mitigate adipose tissue inflammation and insulin resistance in obese ovariectomized mice. Methods Nine-week-old ovariectomized C57BL/6 mice were fed a low-fat diet (LFD), high-fat diet (HFD), or HFD supplemented with 0.005% luteolin (HFD + L) for 16 weeks. The anti-inflammatory drug salicylate was used as a positive control. Fasting blood glucose, insulin, and insulin resistance index HOMA-IR were measured every 4 weeks. Adipose tissue and spleen were characterized for tissue inflammation by real-time PCR and immune cell populations by flow cytometry after 16 weeks of feeding. Results HFD resulted in more body weight gain than LFD in ovariectomized mice and supplementing HFD with 0.005% luteolin did not affect the body weight gain. In addition, HFD elicited a significant elevation in fat mass, which were comparable between HFD and HFD + L groups. However, luteolin supplementation resulted in a significant decrease in CD11c+ macrophages in gonadal adipose tissue, as well as a trend of decrease in macrophage infiltration. Luteolin supplementation also significantly decreased mRNA expression of inflammatory and M1 markers MCP-1, CD11c, TNF-a, and IL-6, while maintaining expression of M2 marker MGL1. We further found that luteolin treatment protected mice from insulin resistance induced by HFD consumption; this improved insulin resistance was correlated with reductions in CD11c+ adipose tissue macrophages. Conclusions Our findings indicate that dietary luteolin supplementation attenuates adipose tissue inflammation and insulin resistance found in mice with loss of ovarian function coupled with a HFD intake, and this effect may be partly mediated through suppressing M1-like polarization of macrophages in adipose tissue. These results have clinical implication in implementing dietary intervention for prevention of metabolic syndrome associated with postmenopause and obesity. Funding Sources Supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (NRF-2018R1A1A1A05078886).

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