Obesity is associated with a chronic, low-grade, systemic inflammation that may contribute to the development of insulin resistance and type 2 diabetes. Resveratrol, a natural compound with ...anti-inflammatory properties, is shown to improve glucose tolerance and insulin sensitivity in obese mice and humans. Here, we tested the effect of a 2-year resveratrol administration on proinflammatory profile and insulin resistance caused by a high-fat, high-sugar (HFS) diet in white adipose tissue (WAT) from rhesus monkeys. Resveratrol supplementation (80 and 480 mg/day for the first and second year, respectively) decreased adipocyte size, increased sirtuin 1 expression, decreased NF-κB activation, and improved insulin sensitivity in visceral, but not subcutaneous, WAT from HFS-fed animals. These effects were reproduced in 3T3-L1 adipocytes cultured in media supplemented with serum from monkeys fed HFS ± resveratrol diets. In conclusion, chronic administration of resveratrol exerts beneficial metabolic and inflammatory adaptations in visceral WAT from diet-induced obese monkeys.
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•Resveratrol elicits transcriptional changes in visceral and subcutaneous WAT•Resveratrol exerts anti-inflammatory effects in visceral WAT of HFS-fed monkeys•Resveratrol’s anti-inflammatory effect coincides with improved insulin sensitivity•Adipocytes play a key role in the adaptations evoked by resveratrol
•The gut microbiota is related to the development of metabolic diseases, whose incidence is sexually dimorphic.•The incidence of metabolic diseases depends on gonadal status; for example, it ...increases after menopause.•We show differences in the composition of the gut microbiota between genders and people of different hormonal status.•Menopause alters the Firmicutes/Bacteroidetes ratio and may reduce the saccharolytic activity of the gut microbiota.
We explore the differences in the gut microbiota associated with gender and hormonal status.
We included 76 individuals in this study: 17 pre-menopausal women, 19 men matched by age, as a control group for the pre-menopausal women, 20 post-menopausal women and 20 men matched by age as a control group for the post-menopausal women; all 4 groups were also matched by body mass index (BMI) and nutritional background.
We analyzed the differences in the gut microbiota, endotoxemia, intestinal incretins, pro-inflammatory cytokines, and plasma levels of energy homeostasis regulatory hormones between pre- and post-menopausal women and compared them with their respective male control groups.
We found a higher Firmicutes/Bacteroidetes ratio, a higher relative abundance of Lachnospira and Roseburia, and higher GLP-1 plasma levels in pre-menopausal women than in post-menopausal women, who had similar levels to men. In contrast, we observed a lower relative abundance of the Prevotella, Parabacteroides and Bilophila genera, and IL-6 and MCP-1 plasma levels in pre-menopausal women than in post-menopausal women, who had similar levels to the men. We also found higher GiP and leptin plasma levels in women than in men, irrespective of the menopausal status of the women. In addition, adiponectin levels were higher in pre-menopausal women than in their corresponding age-matched male control group.
Our results suggest that the differences in the composition of gut microbiota between genders and between women of different hormonal status may be related to the sexual dimorphism observed in the incidence of metabolic diseases and their co-morbidities.
p53 is a well-known tumor suppressor that has emerged as an important player in energy balance. However, its metabolic role in the hypothalamus remains unknown. Herein, we show that mice lacking p53 ...in agouti-related peptide (AgRP), but not proopiomelanocortin (POMC) or steroidogenic factor-1 (SF1) neurons, are more prone to develop diet-induced obesity and show reduced brown adipose tissue (BAT) thermogenic activity. AgRP-specific ablation of p53 resulted in increased hypothalamic c-Jun N-terminal kinase (JNK) activity before the mice developed obesity, and central inhibition of JNK reversed the obese phenotype of these mice. The overexpression of p53 in the ARC or specifically in AgRP neurons of obese mice decreased body weight and stimulated BAT thermogenesis, resulting in body weight loss. Finally, p53 in AgRP neurons regulates the ghrelin-induced food intake and body weight. Overall, our findings provide evidence that p53 in AgRP neurons is required for normal adaptations against diet-induced obesity.
Adiponectin is a member of the family of adipose tissue-related hormones known as adipokines, which exerts antidiabetic, antiatherogenic, antiinflammatory, and antiangiogenic properties. Adiponectin ...actions are primarily mediated through binding to two receptors expressed in several tissues, AdipoR1 and AdipoR2. Likewise, adiponectin expression has been detected in adipocytes as well as in a variety of extra-adipose tissues, including the chicken pituitary. Interestingly, adiponectin secretion and adiponectin receptor expression in adipocytes have been shown to be regulated by pituitary hormones. These observations led us to investigate whether adiponectin, like the adipokine leptin, regulates pituitary hormone production. Specifically, we focused our analysis on somatotrophs and gonadotrophs because of the relationship between the control of energy metabolism, growth and reproduction. To this end, the effects of adiponectin on both GH and LH secretion as well as its interaction with major stimulatory regulators of somatotrophs (ghrelin and GHRH) and gonadotrophs (GnRH) and with their corresponding receptors (GHS-R, GHRH-R, and GnRH-R), were evaluated in rat pituitary cell cultures. Results show that adiponectin inhibits GH and LH release as well as both ghrelin-induced GH release and GnRH-stimulated LH secretion in short-term (4 h) treated cell cultures, wherein the adipokine also increases GHRH-R and GHS-R mRNA content while decreasing that of GnRH-R. Additionally, we demonstrate that the pituitary expresses both adiponectin and adiponectin receptors under the regulation of the adipokine. In sum, our data indicate that adiponectin, either locally produced or from other sources, may play a neuroendocrine role in the control of both somatotrophs and gonadotrophs.
Adiponectin binds to two widely expressed receptors (AdipoR1 and AdipoR2) that contain seven transmembrane domains but, unlike G-protein coupled receptors, present an extracellular C terminus and a ...cytosolic N terminus. Recently, AdipoR1 was found to associate in high order complexes. However, it is still unknown whether AdipoR2 may also form homomers or heteromers with AdipoR1 or if such interactions may be functionally relevant. Herein, we have analyzed the oligomerization pattern of AdipoRs by FRET and immunoprecipitation and evaluated both the internalization of AdipoRs in response to various adiponectin isoforms and the effect of adiponectin binding to different AdipoR combinations on AMP-activated protein kinase phosphorylation and peroxisome proliferator-activated receptor α activation. Transfection of HEK293AD cells with AdipoR1 and AdipoR2 showed that both receptors colocalize at both the plasma membrane and the endoplasmic reticulum. Co-transfection with the different AdipoR pairs yielded high FRET efficiencies in non-stimulated cells, which indicates that AdipoR1 and AdipoR2 form homo- and heteromeric complexes under resting conditions. Live FRET imaging suggested that both homo- and heteromeric AdipoR complexes dissociate in response to adiponectin, but heteromers separate faster than homomers. Finally, phosphorylation of AMP-activated protein kinase in response to adiponectin was delayed in cells wherein heteromer formation was favored. In sum, our findings indicate that AdipoR1 and AdipoR2 form homo- and heteromers that present unique interaction behaviors and signaling properties. This raises the possibility that the pleiotropic, tissue-dependent functions of adiponectin depend on the expression levels of AdipoR1 and AdipoR2 and, therefore, on the steady-state proportion of homo- and heteromeric complexes.
Background: Adiponectin receptors (AdipoR1 and 2) mediate the effects of adiponectin, which possesses insulin sensitizing and anti-inflammatory properties.
Results: AdipoRs organize into oligomers exhibiting distinct interaction and signaling properties.
Conclusion: The cellular response to adiponectin depends on the specific AdipoR repertoire.
Significance: To envisage novel therapeutic strategies, the capacity of AdipoRs to form oligomeric complexes must be taken into consideration.
p53 family members control several metabolic and cellular functions. The p53 ortholog p63 modulates cellular adaptations to stress and has a major role in cell maintenance and proliferation. Here we ...show that p63 regulates hepatic lipid metabolism. Mice with liver-specific p53 deletion develop steatosis and show increased levels of p63. Down-regulation of p63 attenuates liver steatosis in p53 knockout mice and in diet-induced obese mice, whereas the activation of p63 induces lipid accumulation. Hepatic overexpression of N-terminal transactivation domain TAp63 induces liver steatosis through IKKβ activation and the induction of ER stress, the inhibition of which rescues the liver functions. Expression of TAp63, IKKβ and XBP1s is also increased in livers of obese patients with NAFLD. In cultured human hepatocytes, TAp63 inhibition protects against oleic acid-induced lipid accumulation, whereas TAp63 overexpression promotes lipid storage, an effect reversible by IKKβ silencing. Our findings indicate an unexpected role of the p63/IKKβ/ER stress pathway in lipid metabolism and liver disease.
Background Type 2 diabetes mellitus (T2DM) is one of the most widely spread diseases, affecting around 90% of the patients with diabetes. Metabolomics has proven useful in diabetes research ...discovering new biomarkers to assist in therapeutical studies and elucidating pathways of interest. However, this technique has not yet been applied to a cohort of patients that have remitted from T2DM. Methods All patients with a newly diagnosed T2DM at baseline (n = 190) were included. An untargeted metabolomics approach was employed to identify metabolic differences between individuals who remitted (RE), and those who did not (non-RE) from T2DM, during a 5-year study of dietary intervention. The biostatistical pipeline consisted of an orthogonal projection on the latent structure discriminant analysis (O-PLS DA), a generalized linear model (GLM), a receiver operating characteristic (ROC), a DeLong test, a Cox regression, and pathway analyses. Results The model identified a significant increase in 12 metabolites in the non-RE group compared to the RE group. Cox proportional hazard models, calculated using these 12 metabolites, showed that patients in the high-score tercile had significantly (p-value < 0.001) higher remission probabilities (Hazard Ratio, HR, .sub.high versus low = 2.70) than those in the lowest tercile. The predictive power of these metabolites was further studied using GLMs and ROCs. The area under the curve (AUC) of the clinical variables alone is 0.61, but this increases up to 0.72 if the 12 metabolites are considered. A DeLong test shows that this difference is statistically significant (p-value = 0.01). Conclusions Our study identified 12 endogenous metabolites with the potential to predict T2DM remission following a dietary intervention. These metabolites, combined with clinical variables, can be used to provide, in clinical practice, a more precise therapy. Trial registration ClinicalTrials.gov, NCT00924937. Keywords: Diabetes, Insulin resistance, Prospective human study, Metabolomics
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The incidence of type 2 diabetes mellitus (T2DM) is growing in Western countries. Nutritional interventions that promote high-quality dietary patterns could help reverse this trend. We aimed to ...evaluate whether changes in Nutrient-Rich Food Index 9.3 (NRF9.3) were related to the risk of developing T2DM in patients with coronary heart disease (CHD). The study was carried out in the context of two healthy dietary interventions (a Mediterranean and a low-fat diet). For this purpose, we evaluated all the patients in the CORDIOPREV study without T2DM at baseline. Data were obtained during the first 5 years of dietary intervention. The score was calculated using the Food Frequency Questionnaires at baseline and after 1 year of intervention. After 5 years of follow-up, 106 patients developed T2DM (incident-T2DM), while 316 subjects did not (non-T2DM). Total NRF9.3 score and changes during the first year of intervention were compared between incident-T2DM and non-T2DM. Incident-T2DM showed less improvement in NRF9.3 than non-T2DM (
= 0.010). In the multi-adjusted Cox proportional hazard study, patients with greater improvement in NRF9.3 had over 50% less risk of developing T2DM compared with the lowest tertile (HR 2.10, 95%, CI = 1.12-3.56). In conclusion, improved diet quality in terms of nutrient density after the dietary intervention was associated with a lower risk of T2DM in patients with CHD.
Purpose
Catecholamines (CA) play a major role in metabolism and immune response. Recent reports showing adipose tissue can synthetize CA enlighten new roles for these amines in obesity. This study ...aimed to evaluate the expression of both tyrosine hydroxylase (TH) and phenylethanolamine
N
-methyltransferase (PNMT) and CA content along preadipocytes differentiation, under normal and obesigenic conditions.
Methods
8–9 week-old male C57BL/6 mice were divided in two groups: one fed with a high-fat diet (HFD) and other with a standard diet (SD) for 20 weeks. Afterwards, both TH and PNMT expression, localization, and CA content in adipocytes, were evaluated.
Results
qPCR results showed no changes for TH and PNMT expression during the differentiation process for visceral and subcutaneous preadipocytes from mice fed with SD. Comparing to SD, HFD increased TH gene expression of subcutaneous preadipocytes and PNMT gene expression of both visceral preadipocytes and adipocytes. HPLC-ED analyses revealed HFD increased visceral adipocytes noradrenaline intracellular content comparing with preadipocytes (
p
= 0.037). When compared with SD, HFD raised and decreased noradrenaline content, respectively, in visceral adipocytes (
p
= 0.004) and subcutaneous preadipocytes (
p
= 0.001). Along the differentiation process, HFD increased visceral adrenaline intracellular content comparing with SD (
p
< 0.001). HFD increased visceral comparing to subcutaneous adrenaline content for both preadipocytes (
p
= 0.004) and adipocytes (
p
= 0.001).
Conclusions
TH and PNMT expression in adipose tissue is differently modulated in visceral and subcutaneous adipose depots, and seems to depend on diet. Differences observed in visceral adipose CA handling in HFD-fed mice might uncover novel pharmacological/nutritional strategies against obesity and cardiovascular risk.
Cell death determines the onset of obesity and associated insulin resistance. Here, we analyze the relationship among obesity, adipose tissue apoptosis, and insulin signaling.
The expression levels ...of initiator (CASP8/9) and effector (CASP3/7) caspases as well as antiapoptotic B-cell lymphoma (BCL)2 and inflammatory markers were assessed in visceral (VAT) and subcutaneous (SAT) adipose tissue from patients with different degrees of obesity and without insulin resistance or diabetes. Adipose tissue explants from lean subjects were cultured with TNF-α or IL-6, and the expression of apoptotic and insulin signaling components was analyzed and compared with basal expression levels in morbidly obese subjects.
SAT and VAT exhibited increased CASP3/7 and CASP8/9 expression levels and decreased BCL2 expression with BMI increase. These changes were accompanied by increased inflammatory cytokine mRNA levels and macrophage infiltration markers. In obese subjects, CASP3/7 activation and BCL2 downregulation correlated with the IRS-1/2-expression levels. Expression levels of caspases, BCL2, p21, p53, IRS-1/2, GLUT4, protein tyrosine phosphatase 1B, and leukocyte antigen-related phosphatase in TNF-α- or IL-6-treated explants from lean subjects were comparable with those found in adipose tissue samples from morbidly obese subjects. These insulin component expression levels were reverted with CASP3/7 inhibition in these TNF-α- or IL-6-treated explants.
Body fat mass increase is associated with CASP3/7 and BCL2 expression in adipose tissue. Moreover, this proapoptotic state correlated with insulin signaling, suggesting its potential contribution to the development of insulin resistance.
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