Peripherally Administered Y-2-Receptor Antagonist BIIE0246 Prevents Diet-Induced Obesity in Mice With Excess Neuropeptide Y, but Enhances Obesity in Control Mice

Neuropeptide Y (NPY) plays an important role in the regulation of energy homeostasis in the level of central and sympathetic nervous systems (SNSs). Genetic silencing of peripheral Y-2-receptors have anti-obesity effects, but it is not known whether pharmacological blocking of peripheral Y-2-receptors would similarly benefit energy homeostasis. The effects of a peripherally administered Y-2-receptor antagonist were studied in healthy and energy-rich conditions with or without excess NPY. Genetically obese mice overexpressing NPY in brain noradrenergic nerves and SNS (OE-NPYD beta H) represented the situation of elevated NPY levels, while wildtype (WT) mice represented the normal NPY levels. Specific Y-2-receptor antagonist, BIIE0246, was administered (1.3 mg/kg/day, i.p.) for 2 or 4.5 weeks to OE-NPYD beta H and WT mice feeding on chow or Western diet. Treatment with Y-2-receptor antagonist increased body weight gain in both genotypes on chow diet and caused metabolic disturbances (e.g., hyperinsulinemia and hypercholesterolemia), especially in WT mice. During energy surplus (i.e., on Western diet), blocking of Y-2-receptors induced obesity in WT mice, whereas OE-NPYD beta H mice showed reduced fat mass gain, hepatic glycogen and serum cholesterol levels relative to body adiposity. Thus, it can be concluded that with normal NPY levels, peripheral Y-2-receptor antagonist has no potential for treating obesity, but oppositely may even induce metabolic disorders. However, when energy-rich diet is combined with elevated NPY levels, e.g., stress combined with an unhealthy diet, Y-2-receptor antagonism has beneficial effects on metabolic status

Metformin decreases hyaluronan synthesis by vascular smooth muscle cells

Metformin is the first-line drug in the treatment of type 2 diabetes worldwide based on its effectiveness and cardiovascular safety. Currently metformin is increasingly used during pregnancy in women with gestational diabetes mellitus, even if the long-term effects of metformin on offspring are not exactly known. We have previously shown that high glucose concentration increases hyaluronan (HA) production of cultured human vascular smooth muscle cells (VSMC) via stimulating the expression of hyaluronan synthase 2 (HAS2). This offers a potential mechanism whereby hyperglycemia leads to vascular macroangiopathy. In this study, we examined whether gestational metformin use affects HA content in the aortic wall of mouse offspring in vivo. We also examined the effect of metformin on HA synthesis by cultured human VSMCs in vitro. We found that gestational metformin use significantly decreased HA content in the intima-media of mouse offspring aortas. In accordance with this, the synthesis of HA by VSMCs was also significantly decreased in response to treatment with metformin. This decrease in HA synthesis was shown to be due to the reduction of both the expression of HAS2 and the amount of HAS substrates, particularly UDP-N-acetylglucosamine. As shown here, gestational metformin use is capable to program reduced HA content in the vascular wall of the offspring strongly supporting the idea, that metformin possesses long-term vasculoprotective effects.</p

Peripherally Administered Y2-Receptor Antagonist BIIE0246 Prevents Diet-Induced Obesity in Mice With Excess Neuropeptide Y, but Enhances Obesity in Control Mice

Neuropeptide Y (NPY) plays an important role in the regulation of energy homeostasis in the level of central and sympathetic nervous systems (SNSs). Genetic silencing of peripheral Y2-receptors have anti-obesity effects, but it is not known whether pharmacological blocking of peripheral Y2-receptors would similarly benefit energy homeostasis. The effects of a peripherally administered Y2-receptor antagonist were studied in healthy and energy-rich conditions with or without excess NPY. Genetically obese mice overexpressing NPY in brain noradrenergic nerves and SNS (OE-NPYDβH) represented the situation of elevated NPY levels, while wildtype (WT) mice represented the normal NPY levels. Specific Y2-receptor antagonist, BIIE0246, was administered (1.3 mg/kg/day, i.p.) for 2 or 4.5 weeks to OE-NPYDβH and WT mice feeding on chow or Western diet. Treatment with Y2-receptor antagonist increased body weight gain in both genotypes on chow diet and caused metabolic disturbances (e.g., hyperinsulinemia and hypercholesterolemia), especially in WT mice. During energy surplus (i.e., on Western diet), blocking of Y2-receptors induced obesity in WT mice, whereas OE-NPYDβH mice showed reduced fat mass gain, hepatic glycogen and serum cholesterol levels relative to body adiposity. Thus, it can be concluded that with normal NPY levels, peripheral Y2-receptor antagonist has no potential for treating obesity, but oppositely may even induce metabolic disorders. However, when energy-rich diet is combined with elevated NPY levels, e.g., stress combined with an unhealthy diet, Y2-receptor antagonism has beneficial effects on metabolic status

Data_Sheet_1.docx

<p>Neuropeptide Y (NPY) plays an important role in the regulation of energy homeostasis in the level of central and sympathetic nervous systems (SNSs). Genetic silencing of peripheral Y₂-receptors have anti-obesity effects, but it is not known whether pharmacological blocking of peripheral Y₂-receptors would similarly benefit energy homeostasis. The effects of a peripherally administered Y₂-receptor antagonist were studied in healthy and energy-rich conditions with or without excess NPY. Genetically obese mice overexpressing NPY in brain noradrenergic nerves and SNS (OE-NPY^DβH) represented the situation of elevated NPY levels, while wildtype (WT) mice represented the normal NPY levels. Specific Y₂-receptor antagonist, BIIE0246, was administered (1.3 mg/kg/day, i.p.) for 2 or 4.5 weeks to OE-NPY^DβH and WT mice feeding on chow or Western diet. Treatment with Y₂-receptor antagonist increased body weight gain in both genotypes on chow diet and caused metabolic disturbances (e.g., hyperinsulinemia and hypercholesterolemia), especially in WT mice. During energy surplus (i.e., on Western diet), blocking of Y₂-receptors induced obesity in WT mice, whereas OE-NPY^DβH mice showed reduced fat mass gain, hepatic glycogen and serum cholesterol levels relative to body adiposity. Thus, it can be concluded that with normal NPY levels, peripheral Y₂-receptor antagonist has no potential for treating obesity, but oppositely may even induce metabolic disorders. However, when energy-rich diet is combined with elevated NPY levels, e.g., stress combined with an unhealthy diet, Y₂-receptor antagonism has beneficial effects on metabolic status.</p

Neuropeptide Y Overexpressing Female and Male Mice Show Divergent Metabolic but Not Gut Microbial Responses to Prenatal Metformin Exposure.

Prenatal metformin exposure has been shown to improve the metabolic outcome in the offspring of high fat diet fed dams. However, if this is evident also in a genetic model of obesity and whether gut microbiota has a role, is not known.The metabolic effects of prenatal metformin exposure were investigated in a genetic model of obesity, mice overexpressing neuropeptide Y in the sympathetic nervous system and in brain noradrenergic neurons (OE-NPYDβH). Metformin was given for 18 days to the mated female mice. Body weight, body composition, glucose tolerance and serum parameters of the offspring were investigated on regular diet from weaning and sequentially on western diet (at the age of 5-7 months). Gut microbiota composition was analysed by 16S rRNA sequencing at 10-11 weeks.In the male offspring, metformin exposure inhibited weight gain. Moreover, weight of white fat depots and serum insulin and lipids tended to be lower at 7 months. In contrast, in the female offspring, metformin exposure impaired glucose tolerance at 3 months, and subsequently increased body weight gain, fat mass and serum cholesterol. In the gut microbiota, a decline in Erysipelotrichaceae and Odoribacter was detected in the metformin exposed offspring. Furthermore, the abundance of Sutterella tended to be decreased and Parabacteroides increased. Gut microbiota composition of the metformin exposed male offspring correlated to their metabolic phenotype.Prenatal metformin exposure caused divergent metabolic phenotypes in the female and male offspring. Nevertheless, gut microbiota of metformin exposed offspring was similarly modified in both genders

Body weight development and body composition of the VEH and MET exposed OE-NPY^DβH offspring.

<p>Body weight development of the female (a) and male (b) offspring. GTT and EchoMRI marked on the figures. The gray shaded area = western diet (WD). Fat mass (FM; g) of the VEH and MET exposed OE-NPY^DβH female (c) and male (d) offspring at 4 (during RD) and 7 months (during WD). The weight of inguinal^# (iWAT), gonadal/epididymal (gWAT/eWAT), retroperitoneal (rWAT), mesenteric (mWAT) white adipose tissue and brown adipose tissue (BAT) of the female (e) and male (f) offspring at 7 months. n(females) = 11 in VEH and 8 in MET exposed offspring and n(males) = 20 in VEH and 14 in MET exposed offspring. ^#n = 13 in iWAT of the MET exposed male offspring. Significances by 2-RM-ANOVA and Sidak’s multiple comparisons test (a, b) and Student’s t-test (c-f). The data expressed as mean ± SEM, *P < 0.05, **P < 0.01 and ***P < 0.001.</p

Comparison of the serum profile, HOMA-IR, HOMA-β and QUICKI of the VEH and MET exposed OE-NPY^DβH offspring at 7 months.

<p>Comparison of the serum profile, HOMA-IR, HOMA-β and QUICKI of the VEH and MET exposed OE-NPY^DβH offspring at 7 months.</p

Relative abundancies of gut bacteria at different taxonomical levels at 10–11 weeks.

<p>Relative abundance of <i>Bacteroidetes</i> (a), <i>Firmicutes</i> (b), <i>Proteobacteria</i> (c), <i>Erysipelotrichaceae</i> (d), <i>Odoribacter</i> (e), <i>Parabacteroides</i> (f) and <i>Sutterella</i> (g) in the VEH OE-NPY^DβH (gray boxes) and MET OE-NPY^DβH (white boxes) female and male offspring. Relative abundance expressed as decimal number where 1 corresponds to 100%. Box plots showing the 25^th, 75^th percentile and median and the whiskers extending from minimum to maximum together with all data points, <i>n</i> = 5–6. Significances by 2-way ANOVA, *P < 0.05.</p

Composition of the gut microbiota.

<p>Occupation of microbiota by 8 most prominent phyla in the VEH and MET exposed OE-NPY^DβH and VEH exposed WT female and male offspring at 10–11 weeks (a,b). Weighted PCoA of the VEH OE-NPY^DβH vs. MET OE-NPY^DβH vs. VEH WT female offspring microbiota where principal coordinates PC1 explains 40.61% and PC2 18.93% of the total variance (c). Unweighted PCoA of the VEH OE-NPY^DβH vs. MET OE-NPY^DβH vs. VEH WT female offspring microbiota where PC1 explains 18.76% and PC2 16.23% of the total variance (d). Weighted PCoA of the VEH OE-NPY^DβH vs. MET OE-NPY^DβH vs. VEH WT male offspring microbiota where PC1 explains 45.69% and PC2 13.27% of the total variance (e). Unweighted PCoA of the VEH OE-NPY^DβH vs. MET OE-NPY^DβH vs. VEH WT male offspring microbiota where PC1 explains 20.26% and PC2 14.51% of the total variance (f). Red squares and triangles = VEH OE-NPY^DβH female (<i>n</i> = 6) and male (<i>n</i> = 5) offspring, respectively; blue triangles and squares = MET OE-NPY^DβH female (<i>n</i> = 6) and male (<i>n</i> = 6), offspring, respectively; orange circles = VEH WT female (<i>n</i> = 6) and male (<i>n</i> = 6) offspring. Plots produced by Qiime.</p

Glucose homeostasis.

<p>Glucose tolerance test of the VEH and MET exposed OE-NPY^DβH female and male offspring at 3 months during RD (a, d) and at 6 months during WD (b, e), respectively. Corresponding AUC values of the GTTs (c, f). n(females) = 11 in VEH and 8 in MET exposed offspring and n(males) = 20 in VEH and 13 in MET exposed offspring. Significances by 2-RM-ANOVA (a, b, d, e) and Student’s t-test (c, f). The data expressed as mean ± SEM, *P < 0.05, **P < 0.0.1.</p