High-fat Diet-induced Obese Model Research Articles

The anti-obesity properties of the proanthocyanidin extract from the leaves of Chinese bayberry (Myrica rubra Sieb.et Zucc.).

The anti-obesity effects of different proanthocyanidin extracts (PE) from Chinese bayberry (Myrica rubra Sieb.et Zucc.) leaves were evaluated in a high-fat (HF) diet-induced obese rat model. The leaves of Chinese bayberry (LCB), a non-desaccharified proanthocyanidin extract (NDPE), and a desaccharified proanthocyanidin extract (DPE) were compared with orlistat, a conventional anti-obesity drug used as a positive control. The rats from all of the PE-treated groups showed obvious weight loss, with the greatest weight loss in the DPE group (P < 0.05). Compared to the HF group, almost all of the PE-treated groups showed significantly reduced levels of serum TC, TG, AST, ALT, ALP, LDL-C, ADP and a LEP/ADP ratio, and increased levels of HDL-C and LEP. Furthermore, the expression levels of SIRT1, PPAR-γ, C/EBP-α, BMP4 and UCP1 were investigated in the liver, kidney, epididymis and abdominal adipose tissue. Compared to the HF group, PPAR-γ and C/EBP-α levels were significantly reduced and SIRT1, BMP4 and UCP1 levels were significantly upregulated in the DPE-treated group. Our results suggested that PE exerted its anti-obesity effects by upregulating the expression of SIRT1, thus inducing the deacetylation of PPAR-γ and downregulating the expression of C/EBP-α, and also upregulating the expression of BMP4 to boost the levels of brown fat.

Expression characteristics of long non-coding RNA-Co7Rik and its impacts on gluconeogenesis

Objective To explore the expression characteristics of long non-coding RNA-Co7Rik and to discuss its potential impacts on hepatic gluconeogenesis. Methods Building fasting-feeding model and high fat diet(HFD)feeding model to detect the expression level of LncRNA-Co7Rik. Separating different parts of C57BL/6J mice to observe its tissue specificity. Isolating primary hepatocytes and stimulating with dibutyryl cyclic-AMP(db-cAMP), Forskolin, dexamethasone, and hydrocortisone to measure the expression changes of LncRNA-Co7Rik. Using cytoplasm and nucleus separate technology to test the distribution characteristics in cell nucleus/cytoplasm of LncRNA-Co7Rik. Results Animal model studies have shown that the relative expression level of LncRNA-Co7Rik in different periods of starvation was 1.00±0.61, 2.98±0.87, 3.41±0.98, 6.73±1.21, and 1.53±0.78(P<0.05), this results indicated that the expression of LncRNA-Co7Rik was significantly increased along with the process of starvation, and returned to normal level after feeding. Meanwhile, LncRNA-Co7Rik was up-regulated in HFD induced obesity model compared with normal group (1.00±0.21 vs 2.92±0.63, P<0.01). According to qPCR, LncRNA-Co7Rik was specifically expressed in the liver, the expression level was 3-4 folds higher than other tissues (P<0.05). In vitro, LncRNA-Co7Rik was regulated by the signal of gluconeogenesis, which suggested it might be involved in the process of gluconeogenesis. Subcellular localization revealed LncRNA-Co7Rik mainly distributed in the nucleus, suggesting that it may play a role in the gene transcription level. Conclusion LncRNA-Co7Rik is a liver specific LncRNA regulated by glycogenic signal, and may participate in physiological and pathological process of gluconeogenesis. (Chin J Endocrinol Metab, 2016, 32: 934-939) Key words: LncRNA; Co7Rik; Glycogenic signal; Hepatic gluconeogenesis

Abstract 3752: A cell cycle-related kinase (CCRK) self-regulatory circuitry in NAFLD-associated hepatocarcinogenesis

Abstract Background and aim: Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome including obesity and diabetes which elevate the risk of hepatocellular carcinoma (HCC). Accumulating evidence has unmasked the molecular linkage between androgen receptor (AR) signaling and gender disparity in NAFLD and HCC incidence. Our previous genome-wide location and functional analysis has pinpointed cell cycle-related kinase (CCRK) as a critical mediator of AR oncogenic activity in hepatitis B virus-associated HCC through glycogen synthase kinase-3β (GSK-3β)/β-catenin signaling (1-3). Here we investigated whether CCRK plays an oncogenic role in NAFLD-related HCC. Methods: We investigated the functional role of CCRK in a high-fat high carbohydrate diet-induced obesity model exposed to low-dose diethylnitrosamine using lentiviral-mediated gene knockdown, followed by measurement of glucose/lipid metabolism via intraperitoneal glucose tolerance test and triglyceride/non-esterified fatty acids levels, and HCC incidence. Gene regulation was assessed by chromatin immunoprecipitation, site-directed mutagenesis, luciferase reporter, co-immunoprecipitation and expression analyses. Results: Lentiviral-mediated Ccrk silencing in male mice significantly reduced obesity-promoted tumor multiplicity and size by &amp;gt;70%. The reduced tumorigenicity was also associated with significant restoration of circulating metabolic profiles and reduction in hepatocellular lipid level. Mechanistic studies demonstrated that the pro-inflammatory cytokine interleukin-6 (IL-6) triggered signal transducer and activator of transcription 3 (STAT3) signaling to up-regulate CCRK expression in an AR-dependent manner. Simultaneously, the phosphorylation of STAT3 by CCRK facilitated the co-occupancy of CCRK promoter by STAT3-AR complex and its subsequent transcriptional activation, thus forming a self-reinforcing circuitry. In addition, both in vitro and in vivo data suggested that CCRK phosphorylated GSK-3β to activate not only β-catenin but also mechanistic target of rapamycin complex 1 (mTORC1) signaling pathways that are crucial for cell survival, proliferation and lipogenesis. Furthermore, transgenic over-expression of CCRK in mouse liver led to concordant activation of STAT3, β-catenin and mTORC1 signaling pathways. Conclusion: Our findings highlight the critical role of CCRK in a self-reinforcing circuitry that regulates NAFLD-associated hepatocarcinogenesis and offer novel therapeutic strategies to combat this dreadful disease in an era of global obesity. Acknowledgement: This project was supported by the Collaborative Research Fund C4017-14G and General Research Fund 14102914.

Nanofibers based on chitin: a new functional food

Abstract Chitin (β-(1-4)-poly-N-acetyl-D-glucosamine) is widely distributed in nature. A method for the preparation of chitin nanofibers (CNFs) is reported. CNFs are considered to have several potential applications because they have useful properties such as high specific surface area and porosity. More recently, beneficial effects of CNF as functional foods were reported. First, the anti-inflammatory effect of oral administration of chitin CNFs was demonstrated in a mouse model of inflammatory bowel disease (IBD). It was found that CNFs improved clinical symptoms and suppressed IBD. CNFs decreased the areas with nuclear factor-κB (NF-κB) staining in colon tissue. Second, the anti-obesity effects of surface-deacetylated chitin nanofibers (SDACNF) in a mouse model of high-fat diet-induced obesity was evaluated. SDACNFs suppressed the increase in body weight produced by the high-fat diet; however, CNFs did not suppress such weight gain. SDACNFs decreased serum levels of leptin. These results suggest that CNF and SDACNF are promising functional foods for patients with IBD or obesity.

1,25-Dihydroxyvitamin D3 and type 2 diabetes: Ca2+-dependent molecular mechanisms and the role of vitamin D status.

The hormone 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] induces cellular Ca2+ signals which regulate insulin secretion, while low vitamin D status may be a risk factor for type 2 diabetes (T2D). In pancreatic β-cells in vitro, 1,25(OH)2D3 induces, via multiple Ca2+ signaling pathways, synchronous Ca2+ oscillations, which quantitatively, temporally, and spatially pattern pulsatile insulin secretion from these cells. In animal studies employing a high fat diet-induced obesity model of pre-T2D, an increased intake of vitamin D delayed development of T2D and adiposity and was associated with the improved blood markers of diabetes and the vitamin D nutritional and hormonal status [plasma concentrations of glucose, insulin, adiponectin, 25-hydroxyvitamin D, and 1,25(OH)2D3]. Observational studies demonstrated associations between vitamin D status, insulin secretion and resistance to T2D, however, randomized controlled trials did not provide conclusive insights into the potential role of vitamin D in prevention of T2D. The 1,25(OH)2D3-dependent cellular Ca2+ signaling can be important for maintaining the normal level of insulin secretion from pancreatic β-cells, and an increased intake of vitamin D may contribute to the prevention of T2D and metabolic disorders associated with this disease.

Silencing CCR2 in Macrophages Alleviates Adipose Tissue Inflammation and the Associated Metabolic Syndrome in Dietary Obese Mice.

Adipose tissue macrophage (ATM)-mediated inflammation is a key feature contributing to the adverse metabolic outcomes of dietary obesity. Recruitment of macrophages to obese adipose tissues (AT) can occur through the engagement of CCR2, the receptor for MCP-1 (monocyte chemoattractant protein-1), which is expressed on peripheral monocytes/macrophages. Here, we show that i.p. administration of a rabies virus glycoprotein-derived acetylcholine receptor-binding peptide effectively delivers complexed siRNA into peritoneal macrophages and ATMs in a mouse model of high-fat diet-induced obesity. Treatment with siRNA against CCR2 inhibited macrophage infiltration and accumulation in AT and, therefore, proinflammatory cytokines produced by macrophages. Consequently, the treatment significantly improved glucose tolerance and insulin sensitivity profiles, and also alleviated the associated symptoms of hepatic steatosis and reduced hepatic triglyceride production. These results demonstrate that disruption of macrophage chemotaxis to the AT through cell-targeted gene knockdown strategies can provide a therapeutic intervention for obesity-related metabolic diseases. The study also highlights a siRNA delivery approach for targeting specific monocyte subsets that contribute to obesity-associated inflammation without affecting the function of other tissue-resident macrophages that are essential for host homeostasis and survival.

Citrus Peel Ethanol Extract Inhibits the Adipogenesis Caused from High Fat-Induced DIO Model

Background: Flavonoids are multi-functional bioactive compounds that have been used as natural compounds against various diseases. Citrus fruit is an important source for bioactive flavonoids with potential anti-obesity benefits. Methods: To determine the anti-obese effects of citrus peel, a 45% high fat diet-induced obesity (DIO) model using C57BL/6 mice was prepared for 10 weeks and then treated orally for 12 weeks with ethanol extracts of citrus peel (300 mg/kg, CP). CP was compared with normal chow diet (C), high fat diet (HF), and the anti-obesity drug orlistat (30 mg/kg, O) as a positive control. HF caused increases in lipid accumulation, body weight gain, and hepatic toxicity compared with the C group. Results: CP treatment reduced body weight gain and decreased epididymal fat, mesenteric fat, and plasma and hepatic TG levels in a similar manner as O treatment. Besides, CP was comparatively more effective than O at increasing high density lipoprotein cholesterol (HDL-c) while reducing hepatic toxicity, which is caused by HF. Fat accumulation in adipose tissue was decreased by CP treatment because of up-regulation of specific lipolysis enzymes such as HSL and AMPK and down-regulation of adipogenesis related genes such as C/EBPα and ACC. The proinflammatory cytokines, TNF-α and IL-6, which are the key factors for regulation of inflammation, were significantly decreased by CP. Conclusion: CP may be a potential natural source for new anti-obesity candidate because of its inhibitory effect on fat synthesis-related inflammation and its positive effect on lipolysis activation.

Phosphoprotein phosphatase 1CB (PPP1CB), a novel adipogenic activator, promotes 3T3-L1 adipogenesis

Understanding the molecular networks that regulate adipogenesis is crucial for gaining insight into obesity and identifying medicinal targets thereof is necessary for pharmacological interventions. However, the identity and molecular actions of activators that promote the early development of adipocytes are still largely unknown. Here, we demonstrate a novel role for phosphoprotein phosphatase 1CB (PPP1CB) as a potent adipogenic activator that promotes adipocyte differentiation. PPP1CB expression increased in vitro during the early phase of 3T3-L1 adipogenesis and in the murine model of high-fat diet-induced obesity. Depletion of PPP1CB dramatically suppressed the differentiation of 3T3-L1 cells into mature adipocytes, with a concomitant change in adipocyte marker genes and significantly inhibited clonal expansion. We also showed that knockdown of PPP1CB caused a significant decrease in C/EBPδ expression, which in turn resulted in attenuation of PPARγ, C/EBPα, adiponectin, and aP2. In addition, we elucidated the functional significance of PPP1CB by linking p38 activation to C/EBPδ expression in early adipogenesis. Overall, our findings demonstrate a novel function of PPP1CB in promoting adipogenesis and suggest that PPP1CB may be a promising therapeutic target for treatment of obesity and obesity-related diseases.

Abstract LB-267: Role of VEGFR-1 signaling in obesity-induced tumor progression

Abstract Background: Obesity associates with angiogenesis and increased macrophage infiltration in adipose tissues during weight gain. Whether these effects also occur in cancer to promote tumor progression in obese condition remains unclear. We have shown that the vascular endothelial growth factor receptor-1 (VEGFR-1) pathway can modulate tumor angiogenesis and recruitment of tumor-associated macrophages (TAMs). Here, we tested the emerging hypothesis that obesity enhances tumor progression and metastasis by augmenting angiogenesis and TAM recruitment via activation of the VEGFR-1 pathway. Methods: We used a high-fat diet-induced obesity model in either wild type (WT) or VEGFR-1 tyrosine kinase null (Flt1TK-/-) C57BL/6 mice. Then, we implanted orthotopically syngeneic pancreatic (PAN02) or breast (E0771) carcinomas. We evaluated the role of VEGFR-1 activity on systemic metabolism, tumor angiogenesis and immune environment, and tumor growth and metastasis. Results: Obesity increased p38-MAPK activation and TAM infiltration, tumor growth (p = 0.001) and metastasis (p = 0.035) in PAN02 tumors. VEGFR-1 inhibition reduced tumor growth (p = 0.007) and metastasis (p = 0.017) in obese but not lean mice. This was associated with a decreased p38-MAPK activity and a shift in TAM polarization towards the M1 phenotype with reduced secretion of pro-tumor cytokines, but no change in vascular density or number of TAMs. In the E0771 model, VEGFR-1 inhibition reduced MMP-9 expression and decreased lung metastatic burden (p = 0.026) in obese mice. In addition to these tumor effects, VEGFR-1 inhibition reduced weight gain, but caused metabolic disorder-hyperinsulinemia-during obesity. Combining metformin with VEGFR-1 inhibition not only prevented this metabolic alteration, but also by recruiting cytotoxic cells further decreased tumor growth in the PAN02 model (p = 0.047). Conclusion: Inactivation of VEGFR-1 signaling prevents weight gain and obesity-induced acceleration of tumor progression in pancreatic and breast cancer models. Targeting VEGFR-1 signaling axis in combination with an anti-diabetic drug such as metformin might be a considerable cancer therapeutic option in the obese setting. Note: This abstract was not presented at the meeting. Citation Format: Joao Incio, Joshua Tam, Nuh Rahbari, Priya Suboj, Daniel McManus, Shan Chin, Trupti Vardan-Kaur, Ana Batista, Suboj Babycutty, Keehoon Jung, Anna Khachatryan, Masabumi Shibuya, Raquel Soares, Dan Duda, Rakesh K. Jain, Dai Fukumura. Role of VEGFR-1 signaling in obesity-induced tumor progression. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-267. doi:10.1158/1538-7445.AM2015-LB-267

CD47 deficiency protects mice from diet-induced obesity and improves whole body glucose tolerance and insulin sensitivity.

CD47 is a transmembrane protein with several functions including self-recognition, immune cell communication, and cell signaling. Although it has been extensively studied in cancer and ischemia, CD47 function in obesity has never been explored. In this study, we utilized CD47 deficient mice in a high-fat diet induced obesity model to study for the first time whether CD47 plays a role in the development of obesity and metabolic complications. Male CD47 deficient and wild type (WT) control mice were fed with either low fat (LF) or high fat (HF) diets for 16 weeks. Interestingly, we found that CD47 deficient mice were protected from HF diet-induced obesity displaying decreased weight gain and reduced adiposity. This led to decreased MCP1/CCR2 dependent macrophage infiltration into adipose tissue and reduced inflammation, resulting in improved glucose tolerance and insulin sensitivity. In addition, CD47 deficiency stimulated the expression of UCP1 and carnitine palmitoyltransferase 1b (CPT1b) levels in brown adipose tissue, leading to increased lipid utilization and heat production. This contributes to the increased energy utilization and reduced adiposity observed in these mice. Taken together, these data revealed a novel role for CD47 in the development of obesity and its related metabolic complications.

Nedd4 Haploinsufficient Mice Display Moderate Insulin Resistance, Enhanced Lipolysis, and Protection Against High-Fat Diet-Induced Obesity

Neural precursor cell expressed developmentally down-regulated protein 4 (Nedd4) is the prototypical protein in the Nedd4 ubiquitin ligase (E3) family, which governs ubiquitin-dependent endocytosis and/or degradation of plasma membrane proteins. Loss of Nedd4 results in embryonic or neonatal lethality in mice and reduced insulin/IGF-1 signaling in embryonic fibroblasts. To delineate the roles of Nedd4 in vivo, we examined the phenotypes of heterozygous knockout mice using a high-fat diet-induced obesity (HFDIO) model. We observed that Nedd4+/- mice are moderately insulin resistant but paradoxically protected against HFDIO. After high-fat diet feeding, Nedd4+/- mice showed less body weight gain, less fat mass, and smaller adipocytes vs the wild type. Despite ameliorated HFDIO, Nedd4+/- mice did not manifest improvement in glucose tolerance vs the wild type in both genders. Nedd4+/- male, but not female, mice displayed significantly lower fasting blood glucose levels and serum insulin levels. Under obesogenic conditions, Nedd4+/- mice displayed elevated stimulated lipolytic activity, primarily through a β2-adrenergic receptor. Combined, these data support novel complex roles for Nedd4 in metabolic regulation involving altered insulin and β-adrenergic signaling pathways.

The mAb against adipocyte fatty acid-binding protein 2E4 attenuates the inflammation in the mouse model of high-fat diet-induced obesity via toll-like receptor 4 pathway

Adipocyte fatty acid-binding protein (A-FABP) plays an important role in fatty acid-mediated processes and related metabolic and inflammatory responses. In this study, we prepared a novel monoclonal antibody against A-FABP, designated 2E4. Our data showed that 2E4 specifically binded to the recombinant A-FABP and native A-FABP of mice adipose tissue. Furthermore, we investigated the effect of 2E4 on metabolic and inflammatory responses in C57BL/6J obese mice fed on a high fat diet. 2E4 administration improved glucose response in high-fat-diet induced obese mice. The 2E4 treated groups exhibited lower free fatty acids, cholesterol, and triglycerides in a concentration-dependent manner. These changes were accompanied by down-regulated expression of pro-inflammatory cytokines in adipose tissue, including tumor necrosis factor α, monocyte chemotactic protein-1, and interleukin-6. Meanwhile, our data demonstrated that 2E4 significantly decreased the mRNA and protein levels of A-FABP in adipose tissue of mice. Further experiments showed that 2E4 notably suppressed the phosphorylation of IκBα and jun-N-terminal kinase through toll-like receptor 4 signaling pathway. Taken together, 2E4 is an effective monoclonal antibody against A-FABP, which attenuated the inflammatory responses induced in the high-fat-diet mice. These findings may provide scientific insight into the treatment of chronic low-grade inflammation in obesity.

Effect of keishibukuryogan on genetic and dietary obesity models.

Obesity has been recognized as one of the most important risk factors for a variety of chronic diseases, such as diabetes, hypertension/cardiovascular diseases, steatosis/hepatitis, and cancer. Keishibukuryogan (KBG, Gui Zhi Fu Ling Wan in Chinese) is a traditional Chinese/Japanese (Kampo) medicine that has been known to improve blood circulation and is also known for its anti-inflammatory or scavenging effect. In this study, we evaluated the effect of KBG in two distinct rodent models of obesity driven by either a genetic (SHR/NDmcr-cp rat model) or dietary (high-fat diet-induced mouse obesity model) mechanism. Although there was no significant effect on the body composition in either the SHR rat or the DIO mouse models, KBG treatment significantly decreased the serum level of leptin and liver TG level in the DIO mouse, but not in the SHR rat model. Furthermore, a lower fat deposition in liver and a smaller size of adipocytes in white adipose tissue were observed in the DIO mice treated with KBG. Importantly, we further found downregulation of genes involved in lipid metabolism in the KBG-treated liver, along with decreased liver TG and cholesterol level. Our present data experimentally support in fact that KBG can be an attractive Kampo medicine to improve obese status through a regulation of systemic leptin level and/or lipid metabolism.

Short and long-term impact of lipectomy on expression profile of hepatic anabolic genes in rats: a high fat and high cholesterol diet-induced obese model.

ObjectiveTo understand the molecular basis of the short and long-term effects of an immediate shortage of energy storage caused by lipectomy on expression profile of genes involved in lipid and carbohydrate metabolism in high fat and high cholesterol diet-induced obese rats.MethodsThe hepatic mRNA levels of enzymes, regulator and transcription factors involved in glucose and lipid metabolism were analyzed by quantitative real time polymerase chain reaction (RT-qPCR) ten days and eight weeks after lipectomy in obese rats. Body and liver weights and serum biochemical parameters, adiponectin, leptin and insulin were determined.ResultsNo significant difference was observed on the food intake between the lipectomized and sham-operated groups during the experimental period. Ten days after the operation, the lipectomized animals showed significant higher triacylglycerol, glucose and insulin levels, a lower adiponectin concentration than the sham-operated rats, along with significant higher hepatic mRNA levels of hepatocyte nuclear factor 4α (HNF4α) and the enzymes involved in lipogenesis, sterol biosynthesis and gluconeogenesis. The results of immunohistochemical (IHC) analysis also confirmed increased levels of lipogenic enzymes in the liver of lipectomized versus sham-operated animals. The lipectomized group had a significantly lower adiponectin/leptin ratio that was positively correlated to the level of LDL (r = 0.823, P<0.05) and negatively to glucose and insulin (r = −0.821 and −0.892 respectively, P<0.05). Eight weeks after the operation, the lipectomized animals revealed significant higher body and liver weights, weight gain, liver to body weight ratio, hepatic triacylglycerol and serum insulin level.ConclusionsIn response to lipectomy a short term enhancement of the expression of hepatic anabolic genes involved in lipid and carbohydrate metabolism was triggered that might eventually lead to the final extra weight gain. These metabolic changes could be the results of reduced circulating adiponectin that further influences the functions of insulin and hepatic HNF4α.

고지방식이 비만마우스 모델에서 파키스탄산 및 중국산 마황으로 조성된 강지환(降脂丸)의 비알콜성 지방간질환 개선효과 비교

Objectives : This study investigated the improvement effects of Pakistani (DF-a) and Chinese Ephedra herba-containing Gangjihwan (DF-b) on nonalcoholic fatty liver disease in a high fat diet-induced obese mouse model. Methods : Eight-week-old C57BL/6N mice were divided into five groups: a normal lean group given a standard diet, an obese control group given a high fat diet, and atorvastatin, DF-a, and DF-b groups given a high fat diet with atorvastatin (10 mg/kg), DF-a (80 mg/kg), and DF-b (80 mg/kg), respectively. After 8 weeks of treatment, body weight gain, blood lipid markers, ALT concentrations, liver weight and histology were examined. Results : 1. Body weight gain was significantly decreased in DF-a, DF-b, and atorvastatin groups compared with control. The extent of decreases was eminent in DF-a group. 2. Circulating concentrations of total cholesterol and LDL-cholesterol were significantly decreased in DF-a, DF-b, and atorvastatin groups compared with control. The decreases were most effective in atorvastatin group. 3. Liver weights were decreased in DF-a, DF-b, and atorvastatin groups compared with control. In particular, liver weight was significantly reduced in DF-b group. 4. Hepatic lipid accumulation was significantly decreased in DF-a, DF-b, and atorvastatin groups compared with control, and the magnitude of which was most effective in DF-b group. 5. Circulating ALT concentrations were decreased in DF-a, DF-b, and atorvastatin groups compared with control, but ALS levels were significantly reduced only in DF-b group. Conclusions : In conclusion, these results suggest that DF-a and DF-b decrease body weight gain, improve blood lipid metabolism, and reduce liver weight and hepatic lipid accumulation, contributing to the improvement of nonalcoholic fatty liver disease. In addition, these effects were similar between Pakistani and Chinese Ephedra herba-containing Gangjihwan.

고지방식이 비만마우스 모델에서 강지환(降脂丸)과 강지환(降脂丸)+가미소체환(加味消滯丸)의 비알콜성 지방간질환 개선효과 비교

Objectives : This study investigated the improvement effects of Gangjihwan (DF) and combination of Gangjihwan and Gamisochehwan (GSH) on nonalcoholic fatty liver disease in a high fat diet-induced obese mouse model. Methods : Eight-week-old C57BL/6N mice were divided into five groups: a normal lean group given a standard diet, an obese control group given a high fat diet, and atorvastatin, DF, and DF+GSH groups given a high fat diet with atorvastatin (10 mg/kg), DF (40 mg/kg), and DF+GSH (80 mg/kg), respectively. After 8 weeks of treatment, body weight gain, blood lipid markers, ALT concentrations, liver weight and histology were examined. Results : 1. Body weight gain was significantly decreased in DF, DF+GSH and atorvastatin groups compared with control. The extent of decreases was eminent in DF+GSH group. 2. Circulating concentrations of total cholesterol, HDL-cholesterol and LDL-cholesterol were decreased in DF, DF+GSH and atorvastatin groups compared with control. The decreases were significant in DF+GSH and atorvastatin groups. 3. Liver weights were decreased in DF, DF+GSH and atorvastatin groups compared with control. In particular, liver weight was significantly reduced only in DF+GSH group. 4. Hepatic lipid accumulation was significantly decreased in DF, DF+GSH and atorvastatin groups compared with control, and the magnitude of which was more effective in DF+GSH group than in DF-only group. 5. Circulating ALT concentrations were decreased in DF, DF+GSH and atorvastatin compared with control, but ALS levels were significantly reduced only in DF+GSH group. Conclusions : In conclusion, these results suggest that DF decreases body weight gain, improves blood lipid metabolism, and reduces liver weight and hepatic lipid accumulation, contributing to the improvement of nonalcoholic fatty liver disease. In addition, these effects were more effective in DF+GSH combination group than in DF-only group.

Altered ubiquitin-proteasome system leads to neuronal cell death in a spontaneous obese rat model

BackgroundObesity is associated with various progressive age-related diseases, including neurological disorders. However, underlying molecular basis for increased risk of neurodegeneration in obesity is unknown. A suitable animal model would immensely help in understanding the obesity-linked neurological problems. MethodsA spontaneously developed obese rat (WNIN/Ob) which is highly vulnerable for a variety of degenerative diseases was isolated from the existing WNIN stock rats. Ultrastructure of neurons in the cerebral cortex of 12-month old obese rats was evaluated by transmission electron microscopy. qRT-PCR and immunoblotting of ubiquitin C-terminal hydrolases (UCHs), ubiquitin, proteasomal sub-units, markers of ER stress and apoptosis were performed in the cerebral cortex. Proteasome activity was assayed by fluorometric method. Immunohistochemistry was performed for mediators of apoptosis, which was further confirmed by TUNEL assay. These investigations were also carried in high-fat diet-induced obese rat model. ResultsNeurons in the cerebral cortex of 12-month obese rats showed swollen mitochondria, disrupted ER and degenerating axons, nucleus and finally neurons. Results showed altered UPS, existence of ER stress, up-regulation of apoptotic markers and apoptosis in the cerebral cortex of obese rats. It appears that UCHL-1 mediated apoptosis through stabilizing p53 might play a role in neuronal cell death in obese rat. Similar changes were observed in the brain of diet-induced obese WNIN rats. ConclusionAltered UPS could be one of the underlying mechanisms for the neuronal cell death in obese conditions. General significanceThis is the first report to highlight the role of altered UPS in neurodegeneration due to obesity.

DJ-1 contributes to adipogenesis and obesity-induced inflammation.

Adipose tissue functions as an endocrine organ, and the development of systemic inflammation in adipose tissue is closely associated with metabolic diseases, such as obesity and insulin resistance. Accordingly, the fine regulation of the inflammatory response caused by obesity has therapeutic potential for the treatment of metabolic syndrome. In this study, we analyzed the role of DJ-1 (PARK7) in adipogenesis and inflammation related to obesity in vitro and in vivo. Many intracellular functions of DJ-1, including oxidative stress regulation, are known. However, the possibility of DJ-1 involvement in metabolic disease is largely unknown. Our results suggest that DJ-1 deficiency results in reduced adipogenesis and the down-regulation of pro-inflammatory cytokines in vitro. Furthermore, DJ-1-deficient mice show a low-level inflammatory response in the high-fat diet-induced obesity model. These results indicate previously unknown functions of DJ-1 in metabolism and therefore suggest that precise regulation of DJ-1 in adipose tissue might have a therapeutic advantage for metabolic disease treatment.

Obesity during pregnancy disrupts placental morphology, cell proliferation, and inflammation in a sex-specific manner across gestation in the mouse.

It is well-accepted that maternal obesity affects fetal development to elevate the risk of offspring disease, but how this happens is unclear. Understanding placental alterations during gestation as a consequence of maternal obesity is critical to understanding the impact of maternal obesity on fetal programming. Here, we used histological criteria, flow cytometry, quantitative PCR, and multiplex cytokine assays to examine changes in cell proliferation and inflammation in the placenta during gestation in a mouse model of maternal high-fat diet-induced obesity. We focused on mouse mid- to late gestation (approximately human late first and third trimester) because previous literature has indicated that this is when important regulators of metabolism, including that of the brain and endocrine pancreas, are forming. These studies were undertaken in order to understand how maternal obesity changes the placenta during this period, which might suggest a causal link to later-life metabolic dysfunction. We found that labyrinth thickness and cell proliferation were decreased at both pregnancy stages in obese compared to normal weight pregnancies. Inflammation was also altered in late pregnancy with increased macrophage activation and elevated cytokine gene expression in the placenta as well as increased abundance of some cytokines in the fetal circulation in obese compared to normal weight pregnancies. These changes in macrophage activation and cytokine gene expression were of greater magnitude and significance in placentas accompanying male fetuses. These data provide insight into placental changes in obesity and identify potential links between placental inflammation and programming of offspring disease by maternal obesity.

Abstract 609: Pharmacological Inhibition of NLRP3 Inflammasome by Parthenolide Improves Obesity-Induced Insulin Resistance in Diet-Induced Obese Mice

Many landmark studies have reported the Nod-like receptor proteins containing Pyrin domain (NLRP3) inflammasome activation in metabolic diseases that include obesity, atherosclerosis and type 2 diabetes. Therefore, the present study was aimed: (i) to determine the role of NLRP3 in inflammation and insulin resistance in high fat diet-induced obesity (DIO) model of mice, and (ii) to determine whether parthenolide, a NLRP3 inhibitor, is able to protect mice against inflammation and insulin resistance in high fat DIO model. METHODS: Lipopolysaccharide (1 ng/ml) primed mouse intraperitoneal macrophages were treated with Parthenolide (0.1 to 30 μM) to evaluate its effect on TNF-α and IL-1β. Parthenolide and Pioglitazone were administered to DIO mice (fed 60% high fat diet) at 5 and 30 mg/kg QD, PO, respectively for 60 days to evaluate their effect on insulin resistance. RESULTS: Parthenolide (5 mg/kg) markedly attenuated inflammatory cytokines as evidenced by significant and dose dependant inhibition of both TNF-α and IL-1β in LPS primed macrophages. Treatment also lowered the fed blood glucose from day 14 to the entire course of study supporting the hypothesis that attenuating inflammation would be a possible intervention to insulin resistance. Parthenolide also improved peripheral insulin resistance, as demonstrated by insulin tolerance test and a significant improvement in the glucose intolerance as demonstrated by the oral glucose tolerance test. Moreover, treatment lowered plasma insulin levels indicating a trend in the improvement in insulin sensitivity. CONCLUSIONS: Collectively, obtained results support our hypothesis that Parthenolide, an inflammasome inhibitor, could be a useful agent in antagonizing obesity-induced insulin resistance