scholarly journals Odontella aurita-enriched diet prevents high fat diet-induced liver insulin resistance

2015 ◽  
Vol 228 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Hamza Amine ◽  
Yacir Benomar ◽  
Adil Haimeur ◽  
Hafida Messaouri ◽  
Nadia Meskini ◽  
...  

The beneficial effect of polyunsaturated omega-3 fatty acid (w-3 FA) consumption regarding cardiovascular diseases, insulin resistance and inflammation has been widely reported. Fish oil is considered as the main source of commercialized w-3 FAs, and other alternative sources have been reported such as linseed or microalgae. However, despite numerous reports, the underlying mechanisms of action of w-3 FAs on insulin resistance are still not clearly established, especially those from microalgae. Here, we report that Odontella aurita, a microalga rich in w-3 FAs eicosapentaenoic acid, prevents high fat diet-induced insulin resistance and inflammation in the liver of Wistar rats. Indeed, a high fat diet (HFD) increased plasma insulin levels associated with the impairment of insulin receptor signaling and the up-regulation of toll-like receptor 4 (TLR4) expressions. Importantly, Odontella aurita-enriched HFD (HFOA) reduces body weight and plasma insulin levels and maintains normal insulin receptor expression and responsiveness. Furthermore, HFOA decreased TLR4 expression, JNK/p38 phosphorylation and pro-inflammatory factors. In conclusion, we demonstrate for the first time, to our knowledge, that diet supplementation with whole Ondontella aurita overcomes HFD-induced insulin resistance through the inhibition of TLR4/JNK/p38 MAP kinase signaling pathways.

2018 ◽  
Vol 315 (5) ◽  
pp. R934-R944 ◽  
Author(s):  
Ankit Gilani ◽  
Varunkumar Pandey ◽  
Victor Garcia ◽  
Kevin Agostinucci ◽  
Shailendra P. Singh ◽  
...  

20-Hydroxyeicosatetraenoic acid (20-HETE) has been shown to positively correlate with body mass index, hyperglycemia, and plasma insulin levels. This study seeks to identify a causal relationship between 20-HETE and obesity-driven insulin resistance. Cyp4a14−/− male mice, a model of 20-HETE overproduction, were fed a regular or high-fat diet (HFD) for 15 wk. 20-SOLA [2,5,8,11,14,17-hexaoxanonadecan-19-yl 20-hydroxyeicosa-6( Z),15( Z)-dienoate], a 20-HETE antagonist, was administered from week 0 or week 7 of HFD. HFD-fed mice gained significant weight (16.7 ± 3.2 vs. 3.8 ± 0.35 g, P < 0.05) and developed hyperglycemia (157 ± 3 vs. 121 ± 7 mg/dl, P < 0.05) and hyperinsulinemia (2.3 ± 0.4 vs. 0.5 ± 0.1 ng/ml, P < 0.05) compared with regular diet-fed mice. 20-SOLA attenuated HFD-induced weight gain (9.4 ± 1 vs. 16.7 ± 3 g, P < 0.05) and normalized the hyperglycemia (157 ± 7 vs. 102 ± 5 mg/dl, P < 0.05) and hyperinsulinemia (1.1 ± 0.1 vs. 2.3 ± 0.4 ng/ml, P < 0.05). The impaired glucose homeostasis and insulin resistance in HFD-fed mice evidenced by reduced insulin and glucose tolerance were also ameliorated by 20-SOLA. Circulatory and adipose tissue 20-HETE levels significantly increased in HFD-fed mice correlating with impaired insulin signaling, including reduction in insulin receptor tyrosine (Y972) phosphorylation and increased serine (S307) phosphorylation of the insulin receptor substrate-1 (IRS-1). 20-SOLA treatments prevented changes in insulin signaling. These findings indicate that 20-HETE contributes to HFD-induced obesity, insulin resistance, and impaired insulin signaling.


Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Varunkumar G Pandey ◽  
Lars Bellner ◽  
Victor Garcia ◽  
Joseph Schragenheim ◽  
Andrew Cohen ◽  
...  

20-HETE (20-Hydroxyeicosatetraenoic acid) is a cytochrome P450 ω-hydroxylase metabolite of arachidonic acid that promotes endothelial dysfunction, microvascular remodeling and hypertension. Previous studies have shown that urinary 20-HETE levels correlate with BMI and plasma insulin levels. However, there is no direct evidence for the role of 20-HETE in the regulation of glucose metabolism, obesity and type 2 diabetes mellitus. In this study we examined the effect of 20-SOLA (2,5,8,11,14,17-hexaoxanonadecan-19-yl-20-hydroxyeicosa-6(Z),15(Z)-dienoate), a water-soluble 20-HETE antagonist, on blood pressure, weight gain and blood glucose in Cyp4a14 knockout (Cyp4a14-/-) mice fed high-fat diet (HFD). The Cyp4a14-/- male mice exhibit high vascular 20-HETE levels and display 20-HETE-dependent hypertension. There was no difference in weight gain and fasting blood glucose between Cyp4a14-/- and wild type (WT) on regular chow. When subjected to HFD for 15 weeks, a significant increase in weight was observed in Cyp4a14-/- as compared to WT mice (56.5±3.45 vs. 30.2±0.7g, p<0.05). Administration of 20-SOLA (10mg/kg/day in drinking water) significantly attenuated the weight gain (28.7±1.47g, p<0.05) and normalized blood pressure in Cyp4a14-/- mice on HFD (116±0.3 vs. 172.7±4.6mmHg, p<0.05). HFD fed Cyp4a14-/- mice exhibited hyperglycemia as opposed to normal glucose levels in WT on a HFD (154±1.9 vs. 96.3±3.0 mg/dL, p<0.05). 20-SOLA prevented the HFD-induced hyperglycemia in Cyp4a14-/- mice (91±8mg/dL, p<0.05). Plasma insulin levels were markedly high in Cyp4a14-/- mice vs. WT on HFD (2.66±0.7 vs. 0.58±0.18ng/mL, p<0.05); corrected by the treatment with 20-SOLA (0.69±0.09 ng/mL, p<0.05). Importantly, glucose and insulin tolerance tests showed impaired glucose homeostasis and insulin resistance in Cyp4a14-/- mice on HFD; ameliorated by treatment with 20-SOLA. This novel finding that blockade of 20-HETE actions by 20-SOLA prevents HFD-induced obesity and restores glucose homeostasis in Cyp4a14-/- mice suggests that 20-HETE contributes to obesity, hyperglycemia and insulin resistance in HFD induced metabolic disorder. The molecular mechanisms underlying 20-HETE mediated metabolic dysfunction are being currently explored.


2020 ◽  
Author(s):  
Geronimo Matteo ◽  
Myriam P Hoyeck ◽  
Hannah L Blair ◽  
Julia Zebarth ◽  
Kayleigh RC Rick ◽  
...  

AbstractObjectiveHuman studies consistently show an association between exposure to persistent organic pollutants, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, aka “dioxin”), and increased diabetes risk. We previously showed that acute high-dose TCDD exposure (20 μg/kg) decreased plasma insulin levels in both male and female mice in vivo; however, effects on glucose homeostasis were sex-dependent. The purpose of this study was to determine whether prolonged exposure to a physiologically relevant dose of TCDD impairs beta cell function and/or glucose homeostasis in a sex-dependent manner in either chow-fed or HFD-fed mice.MethodsMale and female mice were exposed to 20 ng/kg/d TCDD 2x/week for 12 weeks, and simultaneously fed a chow or 45% high-fat diet (HFD). Glucose metabolism was assessed by glucose and insulin tolerance tests throughout the study. Islets were isolated from females at 12 weeks for Tempo-Seq® analysis.ResultsLow-dose TCDD exposure did not lead to adverse metabolic consequences in chow-fed male or female mice, or in HFD-fed males. However, TCDD accelerated the onset of HFD-induced hyperglycemia and impaired glucose-induced plasma insulin levels in female mice. In addition, islet TempO-Seq® analysis showed that TCDD exposure promoted abnormal changes to endocrine and metabolic pathways in HFD-fed females.ConclusionsOur data suggest that TCDD exposure is more deleterious when combined with HFD-feeding in female mice, and that low-dose TCDD exposure increases diabetes susceptibility in females.


Endocrinology ◽  
2021 ◽  
Author(s):  
Geronimo Matteo ◽  
Myriam P Hoyeck ◽  
Hannah L Blair ◽  
Julia Zebarth ◽  
Kayleigh R C Rick ◽  
...  

Abstract Objective Human studies consistently show an association between exposure to persistent organic pollutants, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, aka “dioxin”), and increased diabetes risk. We previously showed that a single high-dose TCDD exposure (20 µg/kg) decreased plasma insulin levels in male and female mice in vivo, but effects on glucose homeostasis were sex-dependent. The current study assessed whether prolonged exposure to a physiologically relevant low-dose of TCDD impacts glucose homeostasis and/or the islet phenotype in a sex-dependent manner in chow-fed or high fat diet (HFD)-fed mice. Methods Male and female mice were exposed to 20 ng/kg/d TCDD 2x/week for 12 weeks and simultaneously fed standard chow or a 45% HFD. Glucose homeostasis was assessed by glucose and insulin tolerance tests, and glucose-induced plasma insulin levels were measured in vivo. Histological analysis was performed on pancreas from male and female mice, and islets were isolated from females for Tempo-Seq® analysis. Results Low-dose TCDD exposure did not lead to adverse metabolic consequences in chow-fed male or female mice, or in HFD-fed males. However, TCDD accelerated the onset of HFD-induced hyperglycemia and impaired glucose-induced plasma insulin levels in female mice. TCDD caused a modest increase in islet area in males but reduced % beta cell area within islets in females. RNAseq analysis revealed abnormal changes to endocrine and metabolic pathways in TCDDHFD females. Conclusions Our data suggest that prolonged low-dose TCDD exposure has minimal effects on glucose homeostasis and islet morphology in chow-fed male and female mice, but promotes maladaptive metabolic responses in HFD-fed females.


Author(s):  
Hamza Amine ◽  
Yacir Benomar ◽  
Nadia Meskini ◽  
Mohammed Taouis

2020 ◽  
Vol 44 (11) ◽  
pp. 2323-2334
Author(s):  
Belén Chanclón ◽  
Yanling Wu ◽  
Milica Vujičić ◽  
Marco Bauzá-Thorbrügge ◽  
Elin Banke ◽  
...  

Abstract Background/objectives Visceral adiposity is associated with increased diabetes risk, while expansion of subcutaneous adipose tissue may be protective. However, the visceral compartment contains different fat depots. Peripancreatic adipose tissue (PAT) is an understudied visceral fat depot. Here, we aimed to define PAT functionality in lean and high-fat-diet (HFD)-induced obese mice. Subjects/methods Four adipose tissue depots (inguinal, mesenteric, gonadal, and peripancreatic adipose tissue) from chow- and HFD-fed male mice were compared with respect to adipocyte size (n = 4–5/group), cellular composition (FACS analysis, n = 5–6/group), lipogenesis and lipolysis (n = 3/group), and gene expression (n = 6–10/group). Radioactive tracers were used to compare lipid and glucose metabolism between these four fat depots in vivo (n = 5–11/group). To determine the role of PAT in obesity-associated metabolic disturbances, PAT was surgically removed prior to challenging the mice with HFD. PAT-ectomized mice were compared to sham controls with respect to glucose tolerance, basal and glucose-stimulated insulin levels, hepatic and pancreatic steatosis, and gene expression (n = 8–10/group). Results We found that PAT is a tiny fat depot (~0.2% of the total fat mass) containing relatively small adipocytes and many “non-adipocytes” such as leukocytes and fibroblasts. PAT was distinguished from the other fat depots by increased glucose uptake and increased fatty acid oxidation in both lean and obese mice. Moreover, PAT was the only fat depot where the tissue weight correlated positively with liver weight in obese mice (R = 0.65; p = 0.009). Surgical removal of PAT followed by 16-week HFD feeding was associated with aggravated hepatic steatosis (p = 0.008) and higher basal (p < 0.05) and glucose-stimulated insulin levels (p < 0.01). PAT removal also led to enlarged pancreatic islets and increased pancreatic expression of markers of glucose-stimulated insulin secretion and islet development (p < 0.05). Conclusions PAT is a small metabolically highly active fat depot that plays a previously unrecognized role in the pathogenesis of hepatic steatosis and insulin resistance in advanced obesity.


2012 ◽  
Vol 11 (1) ◽  
pp. 80 ◽  
Author(s):  
Toshitaka Muneyuki ◽  
Kei Nakajima ◽  
Atsushi Aoki ◽  
Masashi Yoshida ◽  
Hiroshi Fuchigami ◽  
...  

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