Curcumin induces brown fat-like phenotype in 3T3-L1 and primary white adipocytes

Lone, J.,Choi, J.H.,Kim, S.W.,Yun, J.W. Butterworths ; Elsevier Science Ltd 2016 The Journal of nutritional biochemistry Vol.27 No.-

<P>Recent advances have been made in the understanding of pharmacological and dietary agents that contribute to browning of white adipose tissue in order to combat obesity by promoting energy expenditure. Here, we show that curcumin induces browning of 3T3-L1 and primary white adipocytes via enhanced expression of brown fat-specific genes. Curcumin-induced browning in white adipocytes was investigated by determining expression levels of brown adipocyte-specific genes/proteins by realtime reverse transcriptase polymerase chain reaction, immunoblot analysis and immunocytochemical staining. Curcumin increased mitochondrial biogenesis, as evidenced by transmission electronic microscopic detection and enhanced expression of proteins involved in fat oxidation. Cucurmin also increased protein levels of hormone-sensitive lipase and p-acyl-CoA carboxylase, suggesting its possible role in augmentation of lipolysis and suppression of lipogenesis. Increased expression of UCP1 and other brown adipocyte-specific markers was possibly mediated by curcumin-induced activation of AMP-activated protein kinase (AMPK) based on the fact that inhibition of AMPK by dorsomorphin abolished expression of PRDM16, UCP1 and peroxisome proliferator-activated receptor gamma co-activator 1-alpha while the activator 5-Aminoimidazole-4-carboxamide ribonucleotide elevated expression of these brown marker proteins. Our findings suggest that curcumin plays a dual modulatory role in inhibition of adipogenesis as well as induction of the brown fat-like phenotype and thus may have potential therapeutic implications for treatment of obesity. (C) 2015 Elsevier Inc. All rights reserved.</P>

Sulforaphane attenuates obesity by inhibiting adipogenesis and activating the AMPK pathway in obese mice

Choi, K.M.,Lee, Y.S.,Kim, W.,Kim, S.J.,Shin, K.O.,Yu, J.Y.,Lee, M.K.,Lee, Y.M.,Hong, J.T.,Yun, Y.P.,Yoo, H.S. Butterworths ; Elsevier Science Ltd 2014 The Journal of nutritional biochemistry Vol.25 No.2

Obesity is associated with metabolic disorders. Sulforaphane, an isothiocyanate, inhibits adipogenesis and the occurrence of cardiovascular disease. In this study, we investigated whether sulforaphane could prevent high-fat diet (HFD)-induced obesity in C57BL/6N mice. Mice were fed a normal diet (ND), HFD or HFD plus 0.1% sulforaphane (SFN) for 6 weeks. Food efficiency ratios and body weight were lower in HFD-SFN-fed mice than in HFD-fed mice. SFN attenuated HFD-induced visceral adiposity, adipocyte hypertrophy and fat accumulation in the liver. Serum total cholesterol and leptin, and liver triglyceride levels were lower in HFD-SFN-fed mice than in HFD-fed mice. SFN decreased the expression of peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein α (C/EBPα) and leptin in the adipose tissue of HFD-SFN mice and increased adiponectin expression. Phosphorylation of AMP-activated protein kinase α (AMPKα) and acetyl-CoA carboxylase in the adipose tissue of HFD-SFN-fed mice was elevated, and HMG-CoA reductase expression was decreased compared with HFD-fed mice. Thus, these results suggest that SFN may induce antiobesity activity by inhibiting adipogenesis through down-regulation of PPARγ and C/EBPα and by suppressing lipogenesis through activation of the AMPK pathway.

Spatial color histogram based center voting method for subsequent object tracking and segmentation

Suryanto,Kim, D.H.,Kim, H.K.,Ko, S.J. Butterworths ; Elsevier Science Ltd 2011 Image and vision computing Vol.29 No.12

In this paper, we introduce an algorithm for object tracking in video sequences. In order to represent the object to be tracked, we propose a new spatial color histogram model which encodes both the color distribution and spatial information. Using this spatial color histogram model, a voting method based on the generalized Hough transform is employed to estimate the object location from frame to frame. The proposed voting based method, called the center voting method, requests every pixel near the previous object center to cast a vote for locating the new object center in the new frame. Once the location of the object is obtained, the back projection method is used to segment the object from the background. Experiment results show successful tracking of the object even when the object being tracked changes in size and shares similar color with the background.

Ginger improves cognitive function via NGF-induced ERK/CREB activation in the hippocampus of the mouse

Lim, S.,Moon, M.,Oh, H.,Kim, H.G.,Kim, S.Y.,Oh, M.S. Butterworths ; Elsevier Science Ltd 2014 The Journal of nutritional biochemistry Vol.25 No.10

Ginger (the rhizome of Zingiber officinale Roscoe) has been used worldwide for many centuries in cooking and for treatment of several diseases. The main pharmacological properties of ginger include anti-inflammatory, antihyperglycemic, antiarthritic, antiemetic and neuroprotective actions. Recent studies demonstrated that ginger significantly enhances cognitive function in various cognitive disorders as well as in healthy brain. However, the biochemical mechanisms underlying the ginger-mediated enhancement of cognition have not yet been studied in normal or diseased brain. In the present study, we assessed the memory-enhancing effects of dried ginger extract (GE) in a model of scopolamine-induced memory deficits and in normal animals by performing a novel object recognition test. We found that GE administration significantly improved the ability of mice to recognize novel objects, indicating improvements in learning and memory. Furthermore, to elucidate the mechanisms of GE-mediated cognitive enhancement, we focused on nerve growth factor (NGF)-induced signaling pathways. NGF enzyme-linked immunosorbent assay analysis revealed that GE administration led to elevated NGF levels in both the mouse hippocampus and rat glioma C6 cells. GE administration also resulted in phosphorylation of extracellular-signal-regulated kinase (ERK) and cyclic AMP response element-binding protein (CREB), as revealed by Western blotting analysis. Neutralization of NGF with a specific NGF antibody inhibited GE-triggered activation of ERK and CREB in the hippocampus. Also, GE treatment significantly increased pre- and postsynaptic markers, synaptophysin and PSD-95, which are related to synapse formation in the brain. These data suggest that GE has a synaptogenic effect via NGF-induced ERK/CREB activation, resulting in memory enhancement.

The effects of egocentric and allocentric representations on presence and perceived realism: Tested in stereoscopic 3D games

Bae, S.,Lee, H.,Park, H.,Cho, H.,Park, J.,Kim, J. Butterworths ; Elsevier Science Ltd 2012 INTERACTING WITH COMPUTERS Vol.24 No.4

Recently, stereoscopic 3D technologies have come to be used widely in various applications including movies and computer games. Stereoscopic 3D is defined as that which provides visual depth and details by exploiting the stereoscopic vision of the eyes caused by binocular disparity. Prior studies proposed important system features of stereoscopic 3D that may increase the user's sense of presence. However, few studies, either theoretical or empirical, have investigated how these perceived system features affect the user's sense of presence. This study aims to construct a theoretical model that explains the perceived effects of stereoscopic 3D features on sense of presence, and to verify the validity of the model in the 3D computer game domain. The study focuses on spatial representation and perceived realism as important mediating factors between the perceived system features and sense of presence. According to the Dual Mode Model (DMM), two types of spatial representation are crucial for perceived realism and presence: egocentric representation and allocentric representation. Egocentric representation implies representing locations with respect to the particular perspective of the perceiver, while allocentric representation locates reference points outside of the perceiver, regardless of his or her position. Research questions in this study are: How strongly do perceived expression and manipulation features of stereoscopic 3D systems influence spatial representation? How does spatial representation influence perceived realism and presence in a stereoscopic 3D environment? In order to answer these research questions an empirical study was conducted in a controlled lab environment. A total number of 257 users participated in the study and collected data was analyzed by using structural equation modeling with SmartPLS2.0. The findings are as follows: First, both the perceived expression and manipulation features of the stereoscopic 3D system influenced spatial representation, but the perceived expression features had stronger effects than the perceived manipulation features. Second, both egocentric and allocentric representation were found to affect presence. In addition, egocentric representation was found to affect sense of presence both directly and indirectly through perceived realism, whereas allocentric representation contributed a sense of presence only indirectly through perceived realism. This paper concludes by discussing the study's limitations and implications.

The inhibitory effects of quercetin on obesity and obesity-induced inflammation by regulation of MAPK signaling

Seo, M.J.,Lee, Y.J.,Hwang, J.H.,Kim, K.J.,Lee, B.Y. Butterworths ; Elsevier Science Ltd 2015 The Journal of nutritional biochemistry Vol.26 No.11

Quercetin is a flavonoid found in fruits, vegetables, leaves and grains. It has inhibitory, antiviral, antiasthma, anticancer and antiinflammatory effects. Research has suggested that obesity is linked to metabolic disorders. In this study, we examined the inhibitory effect of quercetin on lipid accumulation and obesity-induced inflammation using 3T3-L1, RAW264.7, zebrafish and mouse models. Quercetin suppressed protein levels of the key adipogenic factors C/EBPβ, C/EBPα, PPARγ and FABP4 and the TG-synthesis enzymes lipin1, DGAT1 and LPAATθ. Activation of m-TOR and p70S6K, which are related to insulin and adipogenesis, was down-regulated during adipogenesis in 3T3-L1 cells. Recent research suggested that MAPK signaling factors were involved in adipogenesis and inflammation and that the adipokines MCP-1 and TNF-α attracted macrophages into adipose tissue. Our data showed that quercetin inhibited the MAPK signaling factors ERK½, JNK and p38MAPK and MCP-1 and TNF-α in adipocytes and macrophages. Quercetin also inhibited secretion of the inflammatory cytokines IL-1β and IL-6 and stimulated that of IL-10, an antiinflammatory cytokine. In this study, we confirmed the inhibitory effects of quercetin in adipogenesis and inflammation using a mouse model. In mice, quercetin reduced body weight (almost 40%) and suppressed expression of adipogenic, lipogenic and inflammation-related cytokines. Our data demonstrated that quercetin inhibits lipid accumulation and obesity-induced inflammation in the cell and animal models. Our study suggested that quercetin may represent a potential therapeutic agent for other metabolic disorders by regulating obesity and obesity-induced inflammation.

Nicotinamide improves glucose metabolism and affects the hepatic NAD-sirtuin pathway in a rodent model of obesity and type 2 diabetes

Yang, S.J.,Choi, J.M.,Kim, L.,Park, S.E.,Rhee, E.J.,Lee, W.Y.,Oh, K.W.,Park, S.W.,Park, C.Y. Butterworths ; Elsevier Science Ltd 2014 The Journal of nutritional biochemistry Vol.25 No.1

Nicotinic acid (NA) and nicotinamide (NAM) are major forms of niacin and exert their physiological functions as precursors of nicotinamide adenine dinucleotide (NAD). Sirtuins, which are NAD-dependent deacetylases, regulate glucose and lipid metabolism and are implicated in the pathophysiology of aging, diabetes, and hepatic steatosis. The aim of this study was to investigate the effects of two NAD donors, NA and NAM, on glucose metabolism and the hepatic NAD-sirtuin pathway. The effects were investigated in OLETF rats, a rodent model of obesity and type 2 diabetes. OLETF rats were divided into five groups: (1) high fat (HF) diet, (2) HF diet and 10 mg NA/kg body weight (BW)/day (NA 10), (3) HF diet and 100 mg NA/kg BW/day (NA 100), (4) HF diet and 10 mg NAM/kg BW/day (NAM 10), and (5) HF diet and 100 mg NAM/kg BW/day (NAM 100). NA and NAM were delivered via drinking water for four weeks. NAM 100 treatment affected glucose control significantly, as shown by lower levels of accumulative area under the curve during oral glucose tolerance test, serum fasting glucose, serum fasting insulin, and homeostasis model assessment of insulin resistance, and higher levels of serum adiponectin. With regard to NAD-sirtuin pathway, intracellular nicotinamide phosphoribosyltransferase, NAD, the NAD/NADH ratio, Sirt1, 2, 3, and 6 mRNA expressions, and Sirt1 activity all increased in livers of NAM 100-treated rats. These alterations were accompanied by the increased levels of proliferator-activated receptor gamma, coactivator 1 alpha and mitochondrial DNA. The effect of NA treatment was less evident than that of NAM 100. These results demonstrate that NAM is more effective than NA on the regulation of glucose metabolism and the NAD-sirtuin pathway, which may relate to the altered mitochondrial biogenesis.

Visual tracking of non-rigid objects with partial occlusion through elastic structure of local patches and hierarchical diffusion

Yi, K.M.,Jeong, H.,Kim, S.W.,Yin, S.,Oh, S.,Choi, J.Y. Butterworths ; Elsevier Science Ltd 2015 Image and vision computing Vol.39 No.-

In this paper, a tracking method based on sequential Bayesian inference is proposed. The proposed method focuses on solving both the problem of tracking under partial occlusions and the problem of non-rigid object tracking in real-time on a desktop personal computer (PC). The proposed method is mainly composed of two parts: (1) modeling the target object using elastic structure of local patches for robust performance; and (2) efficient hierarchical diffusion method to perform the tracking procedure in real-time. The elastic structure of local patches allows the proposed method to handle partial occlusions and non-rigid deformations through the relationship among neighboring patches. The proposed hierarchical diffusion method generates samples from the region where the posterior is concentrated to reduce computation time. The method is extensively tested on a number of challenging image sequences with occlusion and non-rigid deformation. The experimental results show the real-time capability and the robustness of the proposed method under various situations.

Robust stereo matching using adaptive random walk with restart algorithm

Lee, S.,Lee, J.H.,Lim, J.,Suh, I.H. Butterworths ; Elsevier Science Ltd 2015 Image and vision computing Vol.37 No.-

In this paper, we propose a robust dense stereo reconstruction algorithm using a random walk with restart. The pixel-wise matching costs are aggregated into superpixels and the modified random walk with restart algorithm updates the matching cost for all possible disparities between the superpixels. In comparison to the majority of existing stereo methods using the graph cut, belief propagation, or semi-global matching, our proposed method computes the final reconstruction through the determination of the best disparity at each pixel in the matching cost update. In addition, our method also considers occlusion and depth discontinuities through the visibility and fidelity terms. These terms assist in the cost update procedure in the calculation of the standard smoothness constraint. The method results in minimal computational costs while achieving high accuracy in the reconstruction. We test our method on standard benchmark datasets and challenging real-world sequences. We also show that the processing time increases linearly in relation to an increase in the disparity search range.

Involvement of resveratrol in crosstalk between adipokine adiponectin and hepatokine fetuin-A in vivo and in vitro

Lee, H.J.,Lim, Y.,Yang, S.J. Butterworths ; Elsevier Science Ltd 2015 The Journal of nutritional biochemistry Vol.26 No.11

Metabolic homeostasis is maintained by the coordinated regulation of several physiological processes and organ crosstalk. Especially, the interaction between adipose tissue and liver is critical for the regulation of glucose and lipid metabolism. This study investigated the involvement of resveratrol (RSV) in the crosstalk between adipokine adiponectin and hepatokine fetuin-A. Adipocytes-hepatocytes co-culture system and a high-fat (HF) diet-induced obesity (DIO) mouse model were utilized. Protein levels of adiponectin and fetuin-A were analyzed in adipocytes and hepatocytes with the knockdown of adiponectin and fetuin-A, respectively. After six weeks of the HF diet treatment, RSV was delivered via an osmotic pump for four weeks. The experimental groups were lean control fed with a standard diet, HF diet-induced obese control and HF_RSV (8 mg/kg/day). After 4 weeks of each treatment, blood and tissues were collected, and the levels of adiponectin and fetuin-A were analyzed. RNA interference during co-culture of adipocytes and hepatocytes demonstrated the existence of crosstalk between adiponectin and fetuin-A. The four-week RSV treatment resulted in increased serum adiponectin and decreased serum fetuin-A in diet-induced obesity mice. The serum levels of adiponectin and fetuin-A were inversely related. In epididymal fat depots, RSV increased adiponectin, peroxisome proliferator-activated receptor (PPAR) alpha, PPAR gamma, sirtuin1 and AMP-activated protein kinase (AMPK). RSV lowered fetuin-A and NF-κB, and increased liver AMPK. These results demonstrate the crosstalk between adiponectin and fetuin-A, and suggest that RSV may be involved in adipose tissue and liver crosstalk through the interaction between adiponectin and fetuin-A.