MiRNAs are regulatory molecules that can be packaged into exosomes and secreted from cells. Here, we show that adipose tissue macrophages (ATMs) in obese mice secrete miRNA-containing exosomes (Exos), which cause glucose intolerance and insulin resistance when administered to lean mice. Conversely, ATM Exos obtained from lean mice improve glucose tolerance and insulin sensitivity when administered to obese recipients. miR-155 is one of the miRNAs overexpressed in obese ATM Exos, and earlier studies have shown that PPARγ is a miR-155 target. Our results show that miR-155KO animals are insulin sensitive and glucose tolerant compared to controls. Furthermore, transplantation of WT bone marrow into miR-155KO mice mitigated this phenotype. Taken together, these studies show that ATMs secrete exosomes containing miRNA cargo. These miRNAs can be transferred to insulin target cell types through mechanisms of paracrine or endocrine regulation with robust effects on cellular insulin action, in vivo insulin sensitivity, and overall glucose homeostasis.

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Emerging evidence suggests that inflammation provides a link between obesity and insulin resistance. The noncanonical IκB kinases IKKε and TANK-binding kinase 1 (TBK1) are induced in liver and fat after high fat diet by NF-κB activation, and in turn initiate a program of counter-inflammation that preserves energy storage. Here, we report the discovery of a small molecule inhibitor of these kinases called amlexanox. Treatment of obese mice with amlexanox elevates energy expenditure through increased thermogenesis, producing weight loss, improved insulin sensitivity and decreased steatosis in obese mice. Because of its record of safety in patients, amlexanox may be an interesting candidate for clinical evaluation in the treatment of obesity and related disorders.

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Chronic inflammation is a key component of obesity–induced insulin resistance and plays a central role in metabolic disease. In this study, we found that the major insulin target tissues, liver, muscle and adipose tissue exhibit increased levels of the chemotactic eicosanoid LTB4 in obese high fat diet (HFD) mice compared to lean chow fed mice. Inhibition of the LTB4 receptor, Ltb4r1, through either genetic or pharmacologic loss of function results in an anti–inflammatory phenotype with protection from systemic insulin resistance and hepatic steatosis in the setting of both HFD–induced and genetic obesity. Importantly, in vitro treatment with LTB4 directly enhanced macrophage chemotaxis, stimulated inflammatory pathways in macrophages, promoted de novo hepatic lipogenesis, decreased insulin stimulated glucose uptake in L6 myocytes, increased gluconeogenesis, and impaired insulin–mediated suppression of hepatic glucose output (HGO) in primary mouse hepatocytes. This was accompanied by decreased insulin stimulated Akt phosphorylation and increased Irs1 and Irs2 serine phosphorylation and all of these events were Gαi and Jnk dependent. Taken together, these observations elucidate a novel role of LTB4/Ltb4r1 in the etiology of insulin resistance in hepatocytes and myocytes, and shows that in vivo inhibition of Ltb4r1 leads to robust insulin sensitizing effects.

In this study, we examined eye movement guidance in Chinese reading. We embedded either a 2-character word or a 4-character word in the same sentence frame, and observed the eye movements of Chinese readers when they read these sentences. We found that when all saccades into the target words were considered that readers eyes tended to land near the beginning of the word. However, we also found that Chinese readers’ eyes landed at the center of words when they made only a single fixation on a word, and that they landed at the beginning of a word when they made more than one fixation on a word. However, simulations that we carried out suggest that these findings can’t be taken to unambiguously argue for word-based saccade targeting in Chinese reading. We discuss alternative accounts of eye guidance in Chinese reading and suggest that eye movement target planning for Chinese readers might involve a combination of character-based and word-based targeting contingent on word segmentation processes.

SUMMARY In obesity, macrophages and other immune cells accumulate in insulin target tissues, promoting a chronic inflammatory state and insulin resistance. Galectin-3 (Gal3), a lectin mainly secreted by macrophages, is elevated in both obese subjects and mice. Administration of Gal3 to mice causes insulin resistance and glucose intolerance, whereas inhibition of Gal3, through either genetic or pharmacologic loss of function, improved insulin sensitivity in obese mice. In vitro treatment with Gal3 directly enhanced macrophage chemotaxis, reduced insulin stimulated glucose uptake in myocytes and 3T3-L1 adipocytes and impaired insulin-mediated suppression of glucose output in primary mouse hepatocytes. Importantly, we found that Gal3 can bind directly to the insulin receptor (IR) and inhibit downstream IR signaling. These observations elucidate a novel role for Gal3 in hepatocytes, adipocytes and myocyte insulin resistance, suggesting that Gal3 can link inflammation to decreased insulin sensitivity. Inhibition of Gal3 could be a new approach to treat insulin resistance.

A polyionized hydrogel polymer (sodium polyacrylate-grafted poly(vinylidene fluoride) (PAAS-g-PVDF)) is fabricated via an alkaline-induced phase-inversion process. PAAS-g-PVDF coatings exhibit unprecedented anti-adhesion and self-cleaning properties to crude oils under an aqueous environment. A PAAS-g-PVDF-coated copper mesh can effectively separate a crude oil/water mixture with extremely high flux and high oil rejection driven by gravity, and is oil-fouling-free for long-term use.