We recently demonstrated that palmitoleic acid (C16:1n7), a monounsaturated fatty acid, increases the metabolic and oxidative capacity of 3T3-L1 adipocytes. Herein, the effect of 16:1n7 ...supplementation on metabolic parameters on white adipose tissue (WAT) and liver of obese mice induced by a high-fat diet (HFD) was addressed by analyzing metabolic (dys)function and altered genes expression in adipose tissue, as well as liver and serum biochemistry analysis. For this purpose, mice were induced to obesity for 8 weeks, and from the 5th week, they received 16:1n7 (300 mg/kg per day) or water for 30 days, by gavage. Subcutaneous inguinal (ING) and epididymal (EPI) WAT were removed for analysis of metabolic, (anti)inflammatory, adipogenic, and thermogenic genes expression by real-time reverse transcriptase-polymerase chain reaction. Additionally, metabolic activities of isolated adipocytes, such as glucose uptake, lipogenesis (triacylglycerol esterification), β-oxidation, and lipolysis in ING adipocytes, were also assessed. Despite the higher fat intake, the HFD group showed lower food intake but higher body weight, increased glucose, significant dyslipidemia, and increased liver and adipose depot mass, accompanied by liver steatosis. The 16:1n7 supplementation slowed down the body mass gain and prevented the increase of lipids in the liver. HFD+n7 animals presented increased fatty acid oxidation and lipogenesis compared to control, but no effect was observed on lipolysis and glucose uptake in ING isolated adipocytes. Besides, 16:1n7 increased the content of the mRNA encoding FABP4, but partially prevented the expression of genes encoding ATGL, HSL, perilipin, lipin, C/EBP-α, PPAR-γ, C/EBP-β, CPT1, NRF1, TFAM, PRDM16, and nitric oxide synthase 2 in ING depot from HFD group of animals. Finally, HFD increased
and
α expression, and 16:1n7 promoted a more marked increase in it. In summary, the data show that palmitoleic acid promotes metabolic changes and partially prevents the increase in gene expression on adipocytes triggered by obesity, suggesting that HFD+n7 animals do not require the same magnitude of metabolic adaptation to cope with energy demand from the HFD. In the long term, the effects of 16:1n7 may be more evident and beneficial for the function/dysfunction of WAT from an obese organism, with relevant repercussions in the systemic metabolic homeostasis.
Exacerbated expansion of adipose tissue seen in diet-induced obesity leads to endocrine dysfunction and disturbance in adipokine secretion, with such abnormal profile positively associated with type ...2 diabetes and other mild chronic inflammatory conditions.
extract (GbE), a mixture of polyphenols with antioxidant properties, has been recently investigated in a variety of experimental models of endocrine dysfunction, with several potentially beneficial effects identified, including improvement in insulin sensitivity in obese rats, and reduction of weight gain in ovariectomy-induced obesity and diet-induced obesity. The aim of this study was to investigate in high fat diet-induced obese male rats the effects of GbE supplementation for 2 weeks on adipocyte volume and adipose tissue lipid accumulation. GbE supplementation was effective in reducing energy intake in obese rats compared to the saline-treated placebo group. Epididymal adipocyte volume was reduced in GbE-supplemented rats, as were epididymal 1-
C-acetate incorporation into fatty acids, perilipin (
) and fatty acid synthase (
) mRNA, and FAS protein levels. Adipocyte hypertrophy in obesity is associated with insulin resistance, and in the present study we observed a reduction in the adipocyte volume of GbE-supplemented obese rats to dimensions equivalent to adipocytes from non-obese rats. GbE supplementation significantly reduced acetate accumulation and tended to reduce
H-oleate incorporation, into epididymal adipose tissue, suggesting a potentially anti-obesogenic effect in longer term therapies. Further studies that investigate the effects of GbE supplementation in other experimental models are required to fully elucidate its suggested beneficial effects on mild chronic inflammatory conditions.
The effect of fish oil (FO) treatment on high‐fat (HF) diet‐induced obesity and metabolic syndrome was addressed by analyzing dysfunctions in cells of different adipose depots. For this purpose, mice ...were initially induced to obesity for 8 weeks following a treatment with FO containing high concentration of EPA compared to DHA (5:1), for additional 8 weeks (by gavage, 3 times per week). Despite the higher fat intake, the HF group showed lower food intake but higher body weight, glucose intolerance and insulin resistance, significant dyslipidemia and increased liver, subcutaneous (inguinal‐ING) and visceral (retroperitoneal‐RP) adipose depots mass, accompanied by adipocyte hypertrophy and decreased cellularity in both adipose tissue depots. FO treatment reversed all these effects, as well as it improved the metabolic activities of isolated adipocytes, such as glucose uptake and lipolysis in both depots, and de novo synthesis of fatty acids in ING adipocytes. HF diet also significantly increased both the pro and anti‐inflammatory cytokines expression by adipocytes, while HF + FO did not differ from control group. Collectively, these data show that the concomitant administration of FO with the HF diet is able to revert metabolic changes triggered by the diet‐induced obesity, as well as to promote beneficial alterations in adipose cell activities. The main mechanism underlying all systemic effects involves direct and differential effects on ING and RP adipocytes.
The manuscript show relevant effects of fish oil (FO) treatment reversing both the metabolic syndrome induced by high‐fat diet (HF) and the changes in subcutaneous (inguinal ‐ING) and visceral (retroperitoneal ‐RP) adipocytes, such as glucose uptake, lipolysis, and lipogenesis. The major findings of our study is that the FO treatment reverses the deleterious effects caused by the excessive intake of a HF diet, and the mechanism involves, at least in part, direct and differential effects on ING and RP adipocytes. Altogether, these effects prevented adipocyte hypertrophy caused by HF diet and reflected in decreased adiposity. Additionally, FO treatment decreased the gene and protein expression of inflammation‐related factors. Thus, the work provided important evidence concerning the effectiveness of a low‐cost agent (as the FO) to treat the metabolic and inflammatory disorders triggered by obesity, which causes thousands of deaths annually and burdens the public coffers.
SCOPE: We tested herein the hypothesis that peroxisome proliferator activated receptor γ (PPARγ) is a major mediator of omega‐3 (n‐3) protective actions against high‐fat diet (HFD) induced obesity, ...glucose intolerance, and adipose tissue inflammation. METHODS AND RESULTS: C57BL6 wild‐type and fat‐1 transgenic (fat‐1) mice were fed a low‐fat diet (LFD) or HFD, treated or not with PPARγ antagonist, and evaluated for energy balance, adiposity, glucose tolerance, and adipose tissue inflammation. Fat‐1 mice were protected from obesity, fasting hyperglycemia, glucose intolerance, and adipose tissue inflammation. PPARγ inhibition completely abolished fat‐1 protection against HFD‐induced glucose intolerance, but not obesity or adipose tissue inflammation. To investigate the role of myeloid cell as mediator of n‐3 beneficial metabolic actions, mice with deletion (LyzM‐PPARγᴷᴼ) or nondeletion (LyzM‐PPARγᵂᵀ) of PPARγ in myeloid cells were fed either LFD or HFD (lard) or an HFD rich in n‐3 (fish oil). Our findings indicate that myeloid cell associated PPARγ is not involved in the attenuation of HFD‐induced glucose intolerance and adipose tissue inflammation induced by n‐3. CONCLUSION: High endogenous n‐3 fatty acid levels protect from HFD obesity, glucose intolerance, and adipose tissue inflammation. Among these, only protection against glucose intolerance is mediated by non‐myeloid cell PPARγ.
Diabetes mellitus is a product of low insulin sensibility and pancreatic β-cell insufficiency. Rats with streptozotocin-induced diabetes during the neonatal period by the fifth day of age develop the ...classic diabetic picture of hyperglycemia, hypoinsulinemia, polyuria, and polydipsia aggravated by insulin resistance in adulthood. In this study, we investigated whether the effect of long-term treatment with melatonin can improve insulin resistance and other metabolic disorders in these animals. At the fourth week of age, diabetic animals started an 8-wk treatment with melatonin (1 mg/kg body weight) in the drinking water at night. Animals were then killing, and the sc, epididymal (EP), and retroperitoneal (RP) fat pads were excised, weighed, and processed for adipocyte isolation for morphometric analysis as well as for measuring glucose uptake, oxidation, and incorporation of glucose into lipids. Blood samples were collected for biochemical assays. Melatonin treatment reduced hyperglycemia, polydipsia, and polyphagia as well as improved insulin resistance as demonstrated by constant glucose disappearance rate and homeostasis model of assessment-insulin resistance. However, melatonin treatment was unable to recover body weight deficiency, fat mass, and adipocyte size of diabetic animals. Adiponectin and fructosamine levels were completely recovered by melatonin, whereas neither plasma insulin level nor insulin secretion capacity was improved in diabetic animals. Furthermore, melatonin caused a marked delay in the sexual development, leaving genital structures smaller than those of nontreated diabetic animals. Melatonin treatment improved the responsiveness of adipocytes to insulin in diabetic animals measured by tests of glucose uptake (sc, EP, and RP), glucose oxidation, and incorporation of glucose into lipids (EP and RP), an effect that seems partially related to an increased expression of insulin receptor substrate 1, acetyl-coenzyme A carboxylase and fatty acid synthase. In conclusion, melatonin treatment was capable of ameliorating the metabolic abnormalities in this particular diabetes model, including insulin resistance and promoting a better long-term glycemic control.
Macrophages play a pivotal role in the development of emphysema and depending on the microenvironment stimuli can be polarized into M1- or M2-like macrophage phenotypes. We compared macrophage ...polarizations in cigarette smoke (CS)- and porcine pancreatic elastase (PPE)-induced emphysema models. C57BL/6 mice were subdivided into four experimental groups. In the PPE group, animals received an intranasal instillation of PPE (0.677 IU); in the saline group, animals received an intranasal instillation of saline (0.9%). Animals from both groups were euthanized on day 28. In the CS group, animals were exposed to CS for 30 min, twice a day, 5 days per week for 12 weeks. In the control group, animals received filtered air. We observed an increase in total macrophages for both experimental models. For M1-like macrophage markers, we observed an increase in TNF-α
and IFN-γ
cells,
and
expressions in PPE and CS groups. Only in the CS group, we detected an increased expression of
For M2-like macrophages markers we observed a down regulation in IL-10, IL-4, IL-13,
and
and an increase of TGF-β
cells in the PPE group, while for the CS group there was an increase in TGF-β
cells and IL-10 expression. All exposure groups were compared to their respective controls. In summary, we demonstrated that CS- and PPE-induced models resulted in different microenvironmental stimuli. CS exposure induced an environmental stimulus related to M1- and M2-like macrophage phenotypes similar to previous results described in COPD patients, whereas the elastase-induced model provided an environmental stimulus related only to the M1 phenotype.
We investigated whether palmitoleic acid, a fatty acid that enhances whole body glucose disposal and suppresses hepatic steatosis, modulates triacylglycerol (TAG) metabolism in adipocytes. For this, ...both differentiated 3T3-L1 cells treated with either palmitoleic acid (16:1n7, 200 μM) or palmitic acid (16:0, 200 μM) for 24 h and primary adipocytes from wild-type or PPARα-deficient mice treated with 16:1n7 (300 mg·kg(-1)·day(-1)) or oleic acid (18:1n9, 300 mg·kg(-1)·day(-1)) by gavage for 10 days were evaluated for lipolysis, TAG, and glycerol 3-phosphate synthesis and gene and protein expression profile. Treatment of differentiated 3T3-L1 cells with 16:1n7, but not 16:0, increased basal and isoproterenol-stimulated lipolysis, mRNA levels of adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) and protein content of ATGL and pSer(660)-HSL. Such increase in lipolysis induced by 16:1n7, which can be prevented by pharmacological inhibition of PPARα, was associated with higher rates of PPARα binding to DNA. In contrast to lipolysis, both 16:1n7 and 16:0 increased fatty acid incorporation into TAG and glycerol 3-phosphate synthesis from glucose without affecting glyceroneogenesis and glycerokinase expression. Corroborating in vitro findings, treatment of wild-type but not PPARα-deficient mice with 16:1n7 increased primary adipocyte basal and stimulated lipolysis and ATGL and HSL mRNA levels. In contrast to lipolysis, however, 16:1n7 treatment increased fatty acid incorporation into TAG and glycerol 3-phosphate synthesis from glucose in both wild-type and PPARα-deficient mice. In conclusion, palmitoleic acid increases adipocyte lipolysis and lipases by a mechanism that requires a functional PPARα.
Palmitoleic acid was previously shown to improve glucose homeostasis by reducing hepatic glucose production and by enhancing insulin-stimulated glucose uptake in skeletal muscle. Herein we tested the ...hypothesis that palmitoleic acid positively modulates glucose uptake and metabolism in adipocytes.
For this, both differentiated 3 T3-L1 cells treated with either palmitoleic acid (16:1n7, 200 μM) or palmitic acid (16:0, 200 μM) for 24 h and primary adipocytes from mice treated with 16:1n7 (300 mg/kg/day) or oleic acid (18:1n9, 300 mg/kg/day) by gavage for 10 days were evaluated for glucose uptake, oxidation, conversion to lactate and incorporation into fatty acids and glycerol components of TAG along with the activity and expression of lipogenic enzymes.
Treatment of adipocytes with palmitoleic, but not oleic (in vivo) or palmitic (in vitro) acids, increased basal and insulin-stimulated glucose uptake and GLUT4 mRNA levels and protein content. Along with uptake, palmitoleic acid enhanced glucose oxidation (aerobic glycolysis), conversion to lactate (anaerobic glycolysis) and incorporation into glycerol-TAG, but reduced de novo fatty acid synthesis from glucose and acetate and the activity of lipogenic enzymes glucose 6-phosphate dehydrogenase and ATP-citrate lyase. Importantly, palmitoleic acid induction of adipocyte glucose uptake and metabolism were associated with AMPK activation as evidenced by the increased protein content of phospho(p)Thr172AMPKα, but no changes in pSer473Akt and pThr308Akt. Importantly, such increase in GLUT4 content induced by 16:1n7, was prevented by pharmacological inhibition of AMPK with compound C.
In conclusion, palmitoleic acid increases glucose uptake and the GLUT4 content in association with AMPK activation.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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•Water/oil emulsions were prepared from Brazilian crude oil.•DSD was determined by an optical microscope at ambient and pressurized conditions.•PLS models were built to predict water ...content and DSD.•NIR predictions were adequate even in pressurized systems.
Droplet size distribution (DSD) and water content (WC) are two parameters that affect the type/intensity of treatment of water-in-crude oil (W/O) emulsions in the production fields. Besides, the crude oil viscosity and emulsion stability are strongly dependent of DSD and WC. Several papers have reported different techniques for evaluation of these properties; however, most of them were based on experiments performed at conditions of temperature and mainly pressure far from those found in the production fields. In this work, we demonstrate that optical microscopy and standard PLS models can be combined for calibration of a Near Infrared (NIR) spectrophotometer with regard to DSD of W/O emulsions with different water contents. Additionally, the NIR calibration models were validated considering the prediction of the DSD and WC of a distinct crude oil not used during the calibration step. Then, a new apparatus for online monitoring of W/O emulsions at pressures up to 30bar is presented. The proposed apparatus employed both techniques (optical microscopy and near infrared spectroscopy) installed in series in the pressurized pipeline. The results indicate that the proposed apparatus is efficient for online monitoring of pressurized emulsions with water contents up to 17wt% and average diameter (D(4,3)) from 6 to 40μm.
Maternal hyperglycemia during pregnancy can lead to fetal changes, like macrosomia or obesity in adult life. Experimental models of diabetes have been studied to evaluate the consequences of ...offspring lipid metabolism. This study aimed to investigate the metabolic changes in adipose tissue of offspring of streptozotocin-induced diabetic mothers during neonatal period.
Diabetes was induced in female rats by streptozotocin administration on 5th day of life. In adulthood, female rats were bred with control male rats. Male puppies were sacrificed on 12th week of life and epididymal (EP) and subcutaneous (SC) adipose fat pads were excised and weighted. Adipocytes were isolated and evaluated for basal and insulin-stimulated 2-deoxyglucose uptake, oxidation of glucose into CO2, and incorporation of glucose into lipids and lipolytic capacity.
Body weight, EP fat pad weight and diameter of adipocytes from offspring of diabetic mothers were increased in comparison to offspring of control mothers. EP adipocytes from offspring of diabetic mothers presented increased basal and insulin stimulated glucose uptake in comparison to control ones. Similar pattern was observed for glucose oxidation into CO2 and incorporation into lipids. However, significant difference in lipolytic capacity in vitro was not observed. Protein content of GLUT4, insulin receptor and acetyl-CoA carboxylase was significantly increased in EP fat pad of offspring of diabetic mothers in relation to control group.
Metabolic programming occurred in the adipose tissue of offspring of diabetic mothers, increasing its capacity to store lipids with no changes in lipolytic capacity.
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