Different Responses to a High-Fat Diet in IL-6 Conditional Knockout Mice Driven by Constitutive GFAP-Cre and Synapsin 1-Cre Expression

2019 ◽  
Vol 109 (2) ◽  
pp. 113-130 ◽  
Author(s):  
Olaya Fernández-Gayol ◽  
Paula Sanchis ◽  
Kevin Aguilar ◽  
Alicia Navarro-Sempere ◽  
Gemma Comes ◽  
...  

Background/Aims: Interleukin-6 (IL-6) is a major cytokine controlling body weight and metabolism, at least in part through actions in the central nervous system (CNS) from local sources. Methods: We herewith report results obtained in conditional IL-6 KO mice for brain cells (Il6ΔGfap and Il6ΔSyn). Results: The reporter RiboTag mouse line demonstrated specific astrocytic expression of GFAP-dependent Cre in the hypothalamus but not in other brain areas, whereas that of synapsin 1-dependent Cre was specific for neurons. Feeding a high-fat diet (HFD) or a control diet showed that Il6ΔGfap and Il6ΔSyn mice were more prone and resistant, respectively, to HFD-induced obesity. Energy intake was not altered in HFD experiments, but it was reduced in Il6ΔSyn male mice following a 24-h fast. HFD increased circulating insulin, leptin, and cholesterol levels, decreased triglycerides, and caused impaired responses to the insulin and glucose tolerance tests. In Il6ΔGfap mice, the only significant difference observed was an increase in insulin levels of females, whereas in Il6ΔSyn mice the effects of HFD were decreased. Hypothalamic Agrp expression was significantly decreased by HFD, further decreased in Il6ΔGfap, and increased in Il6ΔSyn female mice. Hypothalamic Il-6 mRNA levels were not decreased in Il6ΔSyn mice and even increased in Il6ΔGfapmale mice. Microarray analysis of hypothalamic RNA showed that female Il6ΔGfap mice had increased interferon-related pathways and affected processes in behavior, modulation of chemical synaptic transmission, learning, and memory. Conclusion: The present results demonstrate that brain production of IL-6 regulates body weight in the context of caloric excess and that the cellular source is critical.

Author(s):  
María J. Ríos-Lugo ◽  
Vanesa Jiménez-Ortega ◽  
Pilar Cano-Barquilla ◽  
Pilar Fernández Mateos ◽  
Eduardo J. Spinedi ◽  
...  

AbstractPrevious studies indicate that the administration of melatonin caused body weight and abdominal visceral fat reductions in rodent models of hyperadiposity. The objective of the present study performed in high-fat fed rats was to evaluate the activity of melatonin on gene expression of some medial basal hypothalamus (MBH) signals involved in feeding behavior regulation, including neuropeptide Y (NPY), proopiomelanocortin (POMC), prolactin-releasing peptide (PrRP), leptin- and insulin-receptors (R) and insulin-R substrate (IRS)-1 and -2. Blood levels of leptin and adiponectin were also measured.Adult Wistar male rats were divided into four groups (n=16 per group): (i) control diet (3% fat); (ii) high-fat (35%) diet; (iii) high-fat diet+melatonin; (iv) control diet+melatonin. Rats had free access to high-fat or control chow and one of the following drinking solutions: (a) tap water; (b) 25 μg/mL of melatonin.After 10 weeks, the high-fat fed rats showed augmented MBH mRNA levels of NPY, leptin-R, PrRP, insulin-R, IRS-1 and IRS-2. The concomitant administration of melatonin counteracted this increase. Feeding of rats with a high-fat diet augmented expression of the MBH POMC gene through an effect insensitive to melatonin treatment. The augmented levels of circulating leptin and adiponectin seen in high-fat fed rats were counteracted by melatonin as was the augmented body weight: melatonin significantly attenuated a body weight increase in high-fat fed rats without affecting chow or water consumption. Melatonin augmented plasma leptin and adiponectin in control rats.The results indicate that an effect on gene expression of feeding behavior signals at the central nervous system (CNS) may complement a peripheral rise of the energy expenditure produced by melatonin to decrease body weight in high-fat fed rats.


2014 ◽  
Vol 221 (3) ◽  
pp. 381-390 ◽  
Author(s):  
Gustavo W Fernandes ◽  
Cintia B Ueta ◽  
Tatiane L Fonseca ◽  
Cecilia H A Gouveia ◽  
Carmen L Lancellotti ◽  
...  

Three types of beta adrenergic receptors (ARβ1–3) mediate the sympathetic activation of brown adipose tissue (BAT), the key thermogenic site for mice which is also present in adult humans. In this study, we evaluated adaptive thermogenesis and metabolic profile of a mouse withArβ2knockout (ARβ2KO). At room temperature, ARβ2KO mice have normal core temperature and, upon acute cold exposure (4 °C for 4 h), ARβ2KO mice accelerate energy expenditure normally and attempt to maintain body temperature. ARβ2KO mice also exhibited normal interscapular BAT thermal profiles during a 30-min infusion of norepinephrine or dobutamine, possibly due to marked elevation of interscapular BAT (iBAT) and ofArβ1, andArβ3mRNA levels. In addition, ARβ2KO mice exhibit similar body weight, adiposity, fasting plasma glucose, cholesterol, and triglycerides when compared with WT controls, but exhibit marked fasting hyperinsulinemia and elevation in hepaticPepck(Pck1) mRNA levels. The animals were fed a high-fat diet (40% fat) for 6 weeks, ARβ2KO mice doubled their caloric intake, accelerated energy expenditure, and inducedUcp1expression in a manner similar to WT controls, exhibiting a similar body weight gain and increase in the size of white adipocytes to the WT controls. However, ARβ2KO mice maintain fasting hyperglycemia as compared with WT controls despite very elevated insulin levels, but similar degrees of liver steatosis and hyperlipidemia. In conclusion, inactivation of the ARβ2KO pathway preserves cold- and diet-induced adaptive thermogenesis but disrupts glucose homeostasis possibly by accelerating hepatic glucose production and insulin secretion. Feeding on a high-fat diet worsens the metabolic imbalance, with significant fasting hyperglycemia but similar liver structure and lipid profile to the WT controls.


2016 ◽  
Vol 48 (7) ◽  
pp. 491-501 ◽  
Author(s):  
Madeliene Stump ◽  
Deng-Fu Guo ◽  
Ko-Ting Lu ◽  
Masashi Mukohda ◽  
Xuebo Liu ◽  
...  

Peroxisome proliferator-activated receptor-γ (PPARγ), a master regulator of adipogenesis, was recently shown to affect energy homeostasis through its actions in the brain. Deletion of PPARγ in mouse brain, and specifically in the pro-opiomelanocortin (POMC) neurons, results in resistance to diet-induced obesity. To study the mechanisms by which PPARγ in POMC neurons controls energy balance, we constructed a Cre-recombinase-dependent conditionally activatable transgene expressing either wild-type (WT) or dominant-negative (P467L) PPARγ and the tdTomato reporter. Inducible expression of both forms of PPARγ was validated in cells in culture, in liver of mice infected with an adenovirus expressing Cre-recombinase (AdCre), and in the brain of mice expressing Cre-recombinase either in all neurons (NESCre/PPARγ-P467L) or selectively in POMC neurons (POMCCre/PPARγ-P467L). Whereas POMCCre/PPARγ-P467L mice exhibited a normal pattern of weight gain when fed 60% high-fat diet, they exhibited increased weight gain and fat mass accumulation in response to a 10% fat isocaloric-matched control diet. POMCCre/PPARγ-P467L mice were leptin sensitive on control diet but became leptin resistant when fed 60% high-fat diet. There was no difference in body weight between POMCCre/PPARγ-WT mice and controls in response to 60% high-fat diet. However, POMCCre/PPARγ-WT, but not POMCCre/PPARγ-P467L, mice increased body weight in response to rosiglitazone, a PPARγ agonist. These observations support the concept that alterations in PPARγ-driven mechanisms in POMC neurons can play a role in the regulation of metabolic homeostasis under certain dietary conditions.


2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Saki Shirako ◽  
Yumi Kojima ◽  
Naohiro Tomari ◽  
Yasushi Nakamura ◽  
Yasuki Matsumura ◽  
...  

Abstract PyroGlu-Leu is present in certain food protein hydrolysates and traditional Japanese fermented foods. Our previous study demonstrated that the oral administration of pyroGlu-Leu (0.1 mg/kg body weight) attenuates dysbiosis in mice with experimental colitis. The objective of this study was to elucidate why such a low dose of pyroGlu-Leu attenuates dysbiosis in different animal models. High fat diet extensively increased the ratio of Firmicutes/Bacteroidetes in feces of rats compared to control diet. Oral administration of pyroGlu-Leu (1 mg/kg body weight) significantly attenuated high fat diet-induced dysbiosis. By focusing on the production of intestinal antimicrobial peptides, we found that pyroGlu-Leu significantly increased the level of 4962 Da peptides, which identified as the propeptide of rattusin or defensin alpha 9, in ileum. We also observed increased tryptic fragment peptides from rattusin in the lumen. Here, we report that orally administered pyroGlu-Leu attenuates dysbiosis by increasing in the host antimicrobial peptide, rattusin.


2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Jun Muratsu ◽  
Yoshiaki Taniyama ◽  
Fumihiro Sanada ◽  
Atsuyuki Morishima ◽  
Katsuhiko Sakaguchi ◽  
...  

Abstract Background and Aims Obesity and its associated chronic inflammation in adipose tissue initiate insulin resistance, which is related to several pathologies including hypertension and atherosclerosis. Previous reports demonstrated that circulating hepatocyte growth factor (HGF) level was associated with obesity and type 2 diabetes. However, its precise role in obesity and related-pathology is unclear. Method In this experiment, cardiac-specific over-expression of human HGF in mice (HGF-Tg mice) which showed 4-5 times higher serum HGF levels than wild-type mice were used. We chose cardiac specific HGF overexpression, as other strain of HGF transgenic mice such as liver and kidney specific HGF overexpression mice develop cancer and cystic diseases, which are rare in the heart. In the present study, using HGF-Tg mice and anti-HGF neutralizing antibody (HGF-Ab), we explored the role of HGF in obese and insulin resistance induced by high fat diet (HFD) for 14 weeks (200 or 400ug/week). Results With normal chow diet (ND), there were no significant changes in body weight between WT and HGF-Tg mice. While body weight in wild-type mice fed with HFD for 14 weeks was significantly increased accompanied with insulin resistance, HGF-Tg mice prevented body weight gain and insulin resistance. Insulin resistance in obesity arises from the combination of altered functions of insulin target cells (e.g., liver, skeletal muscle, and adipose tissue) and the accumulation of macrophages that secrete pro-inflammatory mediators in adipose tissue. The accumulation of macrophages and elevated levels of inflammatory mediators in adipose tissue were significantly inhibited in HGF-Tg mice as compared to wild-type mice. In the gWAT, the mRNA levels of the mature macrophage marker F4/80, the chemoattractants, MCP-1 and CXCL2, and the inflammatory cytokines, such as TNF-α and iNOS, were significantly increased in WT mice fed with HFD. However, these levels were markedly reduced in HGF-Tg mice fed with HFD. Additionally, activation of Akt by insulin administration was significantly reduced in the gWAT SM, and liver by HFD; however, this activation was restored in HGF-Tg mice. Moreover, insulin-induced Akt signaling was decreased in HGF-Ab groups as compared to saline group under HFD condition. Importantly, HFD significantly increased the level of HGF mRNA by approximately 2 fold in gWAT, SM, and liver without changing cMet expression. All together, these data indicate that the HGF as one of the systemic gWAT, SM, and liver-derived growth factor plays a role in compensatory mechanism against insulin-resistance through the at least anti-inflammatory effect in adipose tissue. The HFD-induced obesity in wild-type mice treated with HGF-neutralizing antibody showed an exacerbated response to the glucose tolerance test. Conclusion HGF suppresses inflammation in adipose tissue induced by a high-fat diet, and as a result improves systemic insulin resistance. These gain-of-function and loss-of-function studies demonstrated that the elevated HGF level induced by HFD have protective role against obesity and insulin resistance.


2017 ◽  
Vol 28 (3) ◽  
pp. 748-759 ◽  
Author(s):  
Dominika Stygar ◽  
Tomasz Sawczyn ◽  
Bronisława Skrzep-Poloczek ◽  
Aleksander J. Owczarek ◽  
Natalia Matysiak ◽  
...  

2014 ◽  
Vol 306 (1) ◽  
pp. R34-R44 ◽  
Author(s):  
Beatriz de Carvalho Borges ◽  
Rodrigo Rorato ◽  
Ernane Torres Uchoa ◽  
Paula Marangon ◽  
Glauber S. F. da Silva ◽  
...  

Hypophagia induced by inflammation is associated with Janus kinase (JAK)-2/signal transducer and activator of transcription (STAT) 3 signaling pathway, and leptin-mediated hypophagia is also mediated by JAK2-STAT3 pathway. We have previously reported that lipopolysaccharide (LPS) did not reduce food intake in leptin-resistant high-fat diet (HFD) rats but maintained body weight loss. We investigated whether changes in p-STAT3 expression in the hypothalamus and brain stem could account for the desensitization of hypophagia in HFD animals after a low LPS dose (100 μg/kg). Wistar rats fed standard diet (3.95 kcal/g) or HFD (6.3 kcal/g) for 8 wk were assigned into control diet-saline, control diet-LPS, HFD-saline, and HFD-LPS groups. LPS reduced feeding in the control diet but not HFD. This group showed no p-STAT3 expression in the paraventricular nucleus (PVN) and ventromedial hypothalamic nucleus (VMH), but sustained, though lower than control, p-STAT3 in the nucleus of the solitary tract (NTS) and raphe pallidus (RPa). LPS decreased body weight in HFD rats and increased Fos expression in the NTS. LPS increased body temperature, oxygen consumption, and energy expenditure in both control diet and HFD rats, and this response was more pronounced in HFD-LPS group. Brown adipose tissue (BAT) thermogenesis and increased energy expenditure seem to contribute to body weight loss in HFD-LPS. This response might be related with increased brain stem activation. In conclusion, LPS activates STAT3-mediated pathway in the hypothalamus and brain stem, leading to hypophagia, however, LPS effects on food intake, but not body weight loss, are abolished by leptin resistance induced by HFD. The preserved STAT3 phosphorylation in the brain stem suggests that unresponsiveness to LPS on STAT3 activation under HFD might be selective to the hypothalamus.


Nutrients ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2475 ◽  
Author(s):  
Hyun Sook Lee ◽  
Su-Min Lim ◽  
Jae In Jung ◽  
So Mi Kim ◽  
Jae Kyoung Lee ◽  
...  

Gynostemma pentaphyllum is widely used in Asia as a herbal medicine to treat type 2 diabetes, dyslipidemia, and inflammation. Here, we investigated the anti-obesity effect and underlying mechanism of G. pentaphyllum extract (GPE) enriched in gypenoside L, gypenoside LI, and ginsenoside Rg3 and obtained using a novel extraction method. Five-week-old male C57BL/6N mice were fed a control diet (CD), high-fat diet (HFD), HFD + 100 mg/kg body weight (BW)/day GPE (GPE 100), HFD + 300 mg/kg BW/day GPE (GPE 300), or HFD + 30 mg/kg BW/day Orlistat (Orlistat 30) for 8 weeks. The HFD-fed mice showed significant increases in body weight, fat mass, white adipose tissue, and adipocyte hypertrophy compared to the CD group; but GPE inhibited those increases. GPE reduced serum levels of triglyceride, total cholesterol, and LDL-cholesterol, without affecting HDL-cholesterol. GPE significantly increased AMPK activation and suppressed adipogenesis by decreasing the mRNA expression of CCAAT/enhancer binding protein-α (C/EBPα), peroxisome proliferator-activated receptor-γ (PPARγ), sterol regulatory element-binding protein-1c (SREBP1c), PPARγ coactivator-1α, fatty acid synthase (FAS), adipocyte protein 2 (AP2), and sirtuin 1 (SIRT1) and by increasing that of carnitine palmitoyltransferase (CPT1) and hormone- sensitive lipase (HSL). This study demonstrated the ameliorative effect of GPE on obesity and elucidated the underlying molecular mechanism.


Author(s):  
Jude Nwaogu ◽  
Ibrahim Babangida Abubakar ◽  
Chizoba Maria Udeze ◽  
Ukperoro Uyoyo Jeremiah

Background: Obesity, a metabolic disorder caused by an imbalance in energy intake and energy expenditure, is a major risk factor for chronic diseases such as type 2 diabetes, hypertension, cardiovascular heart diseases (CHD) and some types of cancer. This research was designed to investigate the effect of antioxidant rich- nutraceuticals in the management of high fat diet-induced obesity in rats. Method: Induction of obesity was achieved by feeding rats with a formulated high fat diet (HFD) for ten (10) weeks. Rats were subsequently group administered 250mg/kg body weight and 500mg/kg body weight of the nutraceutical respectively while apple cider vinegar of 5ml/kg body weight was administered to the standard group.        Result: Supplementation showed significant (P<0.05) decrease in the glucose, total cholesterol, triglyceride, low density lipoprotein- cholesterol, malondialdehyde and increased in high density lipoprotein-cholesterol and antioxidant status as compared with untreated high fat diet groups. However, there was no significant difference between supplementation of 500mg/kg and the standard group treated with 5ml/kg of Apple cider vinegar. Conclusion: Antioxidant rich nutraceuticals could provide a protective effect against oxidative stress in obesity and remedy complications associated with obesity by reversing the damage to near normal.


2010 ◽  
Vol 298 (5) ◽  
pp. R1320-R1332 ◽  
Author(s):  
ChuanFeng Wang ◽  
Rebecca J. Godar ◽  
Charles J. Billington ◽  
Catherine M. Kotz

An acute injection of brain-derived neurotrophic factor (BDNF) in the hypothalamic paraventricular nucleus (PVN) reduces body weight by decreasing feeding and increasing energy expenditure (EE), in animals on standard laboratory chow. Animals have divergent responses to a high-fat diet (HFD) exposure, with some developing obesity and others remaining lean. In the current study, we tested two hypotheses: 1) BDNF in the PVN reverses HFD-induced obesity, and 2) animals with higher body fat have a greater physiological response to BDNF than those with less body fat. Eighty-four 10-wk old rats were allowed HFD ad libitum for 9 wk and then prepared with bilateral PVN cannulas. Animals were then divided into tertiles based on their body fat rank: high, intermediate, and low (H, I, and L). Each group was further divided into 2 subgroups and then PVN injected with BDNF or control (artificial cerebrospinal fluid, aCSF) every other day for 3 wk. Energy intake (EI), body weight, and body composition were measured. At study's end, rats were killed to allow measurement of other metabolic indices. In parallel, another 12 rats were fed control diet (CD), PVN-cannulated and injected with aCSF. HFD exposure induced obesity, particularly in the H body fat group, with a significant increase in EI, body weight, fat mass, liver size, and serum glucose, triglycerides, insulin, and leptin. BDNF significantly reduced EI, body weight, body fat, lean mass, and serum metabolic indices. These BDNF effects were greatest in the H body fat group. These data indicate that BDNF reduced HFD-induced obesity and metabolic syndrome-like measures, and the animals with the most body fat had the most significant response to BDNF.


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