Palmitoleic acid (n-7) increases white adipocytes GLUT4 content and glucose uptake in association with AMPK activation

Background: 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.Methods: for this, both differentiated 3 T3-L1 cells treated with either palmitoleic acid (16: 1n7, 200 mu M) or palmitic acid (16: 0, 200 mu M) 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.Results: 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) Thr172AMPKa, 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.Conclusions: in conclusion, palmitoleic acid increases glucose uptake and the GLUT4 content in association with AMPK activation

Palmitoleic acid (16:1n7) increases oxygen consumption, fatty acid oxidation and ATP content in white adipocytes

Abstract Background We have recently demonstrated that palmitoleic acid (16:1n7) increases lipolysis, glucose uptake and glucose utilization for energy production in white adipose cells. In the present study, we tested the hypothesis that palmitoleic acid modulates bioenergetic activity in white adipocytes. Methods For this, 3 T3-L1 pre-adipocytes were differentiated into mature adipocytes in the presence (or absence) of palmitic (16:0) or palmitoleic (16:1n7) acid at 100 or 200 μM. The following parameters were evaluated: lipolysis, lipogenesis, fatty acid (FA) oxidation, ATP content, oxygen consumption, mitochondrial mass, citrate synthase activity and protein content of mitochondrial oxidative phosphorylation (OXPHOS) complexes. Results Treatment with 16:1n7 during 9 days raised basal and isoproterenol-stimulated lipolysis, FA incorporation into triacylglycerol (TAG), FA oxidation, oxygen consumption, protein expression of subunits representing OXPHOS complex II, III, and V and intracellular ATP content. These effects were not observed in adipocytes treated with 16:0. Conclusions Palmitoleic acid, by concerted action on lipolysis, FA esterification, mitochondrial FA oxidation, oxygen consumption and ATP content, does enhance white adipocyte energy expenditure and may act as local hormone

Effect of Anti-IL17 Antibody Treatment Alone and in Combination With Rho-Kinase Inhibitor in a Murine Model of Asthma

Background: Interleukin-17 (IL-17) and Rho-kinase (ROCK) play an important role in regulating the expression of inflammatory mediators, immune cell recruitment, hyper-responsiveness, tissue remodeling, and oxidative stress. Modulation of IL-17 and ROCK proteins may represent a promising approach for the treatment of this disease.Objective: To study the effects of an anti-IL17 neutralizing antibody and ROCK inhibitor treatments, separately and in combination, in a murine model of chronic allergy-induced lung inflammation.Methods: Sixty-four BALBc mice, were divided into eight groups (n = 8): SAL (saline-instilled); OVA (exposed-ovalbumin); SAL-RHOi (saline and ROCK inhibitor), OVA-RHOi (exposed-ovalbumin and ROCK inhibitor); SAL-anti-IL17 (saline and anti-IL17); OVA-anti-IL17 (exposed-ovalbumin and anti-IL17); SAL-RHOi-anti-IL17 (saline, ROCK inhibitor and anti-IL17); and OVA-RHOi-anti-IL17 (exposed-ovalbumin, anti-IL17, and ROCK inhibitor). A 28-day protocol of albumin treatment was used for sensitization and induction of pulmonary inflammation. The anti-IL17A neutralizing antibody (7.5 μg per treatment) was administered by intraperitoneal injection and ROCK inhibitor (Y-27632) intranasally (10 mg/kg), 1 h prior to each ovalbumin challenge (days 22, 24, 26, and 28).Results: Treatment with the anti-IL17 neutralizing antibody and ROCK inhibitor attenuated the percentage of maximal increase of respiratory system resistance and respiratory system elastance after challenge with methacholine and the inflammatory response markers evaluated (CD4+, CD8+, ROCK1, ROCK2, IL-4, IL-5, IL-6, IL-10 IL-13, IL-17, TNF-α, TGF-β, NF-κB, dendritic cells, iNOS, MMP-9, MMP-12, TIMP-1, FOXP3, isoprostane, biglycan, decorin, fibronectin, collagen fibers content and gene expression of IL-17, VAChT, and arginase) compared to the OVA group (p < 0.05). Treatment with anti-IL17 and the ROCK inhibitor together resulted in potentiation in decreasing the percentage of resistance increase after challenge with methacholine, decreased the number of IL-5 positive cells in the airway, and reduced, IL-5, TGF-β, FOXP3, ROCK1 and ROCK2 positive cells in the alveolar septa compared to the OVA-RHOi and OVA-anti-IL17 groups (p < 0.05).Conclusion: Anti-IL17 treatment alone or in conjunction with the ROCK inhibitor, modulates airway responsiveness, inflammation, tissue remodeling, and oxidative stress in mice with chronic allergic lung inflammation

Impact of Doxorubicin Treatment on the Physiological Functions of White Adipose Tissue

<div><p>White adipose tissue (WAT) plays a fundamental role in maintaining energy balance and important endocrine functions. The loss of WAT modifies adipokine secretion and disrupts homeostasis, potentially leading to severe metabolic effects and a reduced quality of life. Doxorubicin is a chemotherapeutic agent used clinically because of its good effectiveness against various types of cancer. However, doxorubicin has deleterious effects in many healthy tissues, including WAT, liver, and skeletal and cardiac muscles. Our objective was to investigate the effects of doxorubicin on white adipocytes through <i>in vivo</i> and <i>in vitro</i> experiments. Doxorubicin reduced the uptake of glucose by retroperitoneal adipocytes and 3T3-L1 cells via the inhibition of AMP-activated protein kinase Thr172 phosphorylation and glucose transporter 4 content. Doxorubicin also reduced the serum level of adiponectin and, to a greater extent, the expression of genes encoding lipogenic (<i>Fas</i> and <i>Acc</i>) and adipogenic factors (<i>Pparg</i>, <i>C/ebpa</i>, and <i>Srebp1</i>c) in retroperitoneal adipose tissue. In addition, doxorubicin inhibited both lipogenesis and lipolysis and reduced the hormone-sensitive lipase and adipose tissue triacylglycerol lipase protein levels. Therefore, our results demonstrate the impact of doxorubicin on WAT. These results are important to understand some side effects observed in patients receiving chemotherapy and should encourage new adjuvant treatments that aim to inhibit these side effects.</p></div

Doxorubicin reduces lipogenesis.

<p>Fatty acid incorporation into triacylglycerol (TAG) in isolated adipocytes of retroperitoneal adipose tissue from rats after 72 hours of doxorubicin (DX) (15 mg/kg weight) or saline (Control) injection i.p. Data are mean ± standard deviation of 4 to 6 experiments. The groups were compared using the Student t test, *p<0.05.</p

Doxorubicin reduces lipogenic enzymes.

<p>Gene expression of lipogenic enzymes <i>Fas</i> (A) and <i>Acc</i> (B) at 24 hours, 96 hours and 12 days after induction of cell differentiation in 3T3L1 cells treated with 1uM of doxorubicin. The gene expression was evaluated by real time PCR. Data are mean ± standard deviation of 4 to 6 experiments. The groups were compared using the Two way ANOVA followed by Bonferroni post test, *p <0.05, **p<0.01 and ***p<0.001.</p

Adipogenesis is compromised by doxorubicin in 3T3L1 cells.

<p>Gene expression of adipogenics factors <i>Ppparg</i> (A), <i>C/ebpa</i> (B) and <i>Srebp1c</i> (C) at 24 hours, 96 hours and 12 days after induction of cell differentiation in 3T3L1 cells treated with 1uM of doxorubicin. The gene expression was evaluated by real time PCR. Data are mean ± standard deviation of 4 to 6 experiments. The groups were compared using the Two way ANOVA followed by Bonferroni post test, *p<0.05, **p<0.01 and ***p<0.001.</p

Doxorubicin inhibits the lipolysis process.

<p>Glycerol released in assay of lipolysis the adipocytes isolated from retroperitoneal adipose tissue of rats after 72 hours of doxorubicin administration (15mg/kg of weighti.p), with or without isoproterenol stimulation (10uM) for 30 minutes (A). Concentration of glycerol (B) and lactate dehydrogenase LDH in incubation medium of 3T3L1 (C). Lipolysis was stimulated with isoproterenol (Iso) 10uM with doxorubicin (DX) at concentrations of 0.1 and 1uM for 24 hours, the parameters are normalized by the concentration of protein extracted from the cells. Values represent the mean ± standard deviation of 4 to 8 experiments. The groups were compared using the One-Way ANOVA followed by Bonferroni post test. *p<0.05, **p<0.01, ***p<0.001 (A, B and C). Protein expression of HSL phosphorylated at residue Ser-565, Ser-660, total HSL, ATGL and GAPDH (D). Proteins extracted from retroperitoneal adipose tissue of rats 72 hours after treatment with doxorubicin (15mg/kg). Figure represents 4 experiments per group (D).</p

Reduction of glucose uptake by doxorubicin in adipocytes.

<p>Glucose uptake from the retroperitoneal adipose tissues of rats (A) and glucose uptake from 3T3L1 cells (B and C). Protein expression of AMPK thr 172 phosphorylated, total content of GLUT4 and FABP4 from retroperitoneal adipose tissues of rats (D) and protein expression of AMPK threonine 172 phosphorylated, total content of GLUT4 and GAPDH from 3T3L1 cells (E). Adipocytes from the retroperitoneal adipose tissues of rats treated with a single dose of doxorubicin (15 mg/kg body weight ip), euthanized 72 hours after administration. The glucose uptake was measured by uptake of 2-DG with and without insulin stimulation (100nMol) in isolated adipocytes and 3T3L1 cells. 3T3L1 cells were incubated with doxorubicin (1uM) for 30 minutes (B) and 24 hours (C and E), after differentiation into mature adipocytes. Values represent the mean ± standard deviation of 5 to 6 experiments (A, B and C). Figures represents 4 experiments per group (D and E). The groups were compared using two-way ANOVA followed by Dunn’s (A, B, and C). *p<0.05 and **p<0.01.</p